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Backmerge remote-tracking branch 'drm/drm-next' into drm-misc-next

Browse Source 
Required bump from v5.13-rc3 to v5.14-rc3, and to pick up sysfb compilation fixes.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
This commit is contained in:
Maarten Lankhorst 2021-07-27 12:48:17 +02:00
commit ca31fef11d
11807 changed files with 541951 additions and 285611 deletions
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13
.clang-format
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@ -109,8 +109,8 @@ ForEachMacros:
- 'css_for_each_child'
- 'css_for_each_descendant_post'
- 'css_for_each_descendant_pre'
- 'cxl_for_each_cmd'
- 'device_for_each_child_node'
- 'displayid_iter_for_each'
- 'dma_fence_chain_for_each'
- 'do_for_each_ftrace_op'
- 'drm_atomic_crtc_for_each_plane'
@ -136,6 +136,7 @@ ForEachMacros:
- 'drm_mm_for_each_node_in_range'
- 'drm_mm_for_each_node_safe'
- 'flow_action_for_each'
- 'for_each_acpi_dev_match'
- 'for_each_active_dev_scope'
- 'for_each_active_drhd_unit'
- 'for_each_active_iommu'
@ -171,7 +172,6 @@ ForEachMacros:
- 'for_each_dapm_widgets'
- 'for_each_dev_addr'
- 'for_each_dev_scope'
- 'for_each_displayid_db'
- 'for_each_dma_cap_mask'
- 'for_each_dpcm_be'
- 'for_each_dpcm_be_rollback'
@ -179,6 +179,7 @@ ForEachMacros:
- 'for_each_dpcm_fe'
- 'for_each_drhd_unit'
- 'for_each_dss_dev'
- 'for_each_dtpm_table'
- 'for_each_efi_memory_desc'
- 'for_each_efi_memory_desc_in_map'
- 'for_each_element'
@ -215,6 +216,7 @@ ForEachMacros:
- 'for_each_migratetype_order'
- 'for_each_msi_entry'
- 'for_each_msi_entry_safe'
- 'for_each_msi_vector'
- 'for_each_net'
- 'for_each_net_continue_reverse'
- 'for_each_netdev'
@ -270,6 +272,12 @@ ForEachMacros:
- 'for_each_prime_number_from'
- 'for_each_process'
- 'for_each_process_thread'
- 'for_each_prop_codec_conf'
- 'for_each_prop_dai_codec'
- 'for_each_prop_dai_cpu'
- 'for_each_prop_dlc_codecs'
- 'for_each_prop_dlc_cpus'
- 'for_each_prop_dlc_platforms'
- 'for_each_property_of_node'
- 'for_each_registered_fb'
- 'for_each_requested_gpio'
@ -430,6 +438,7 @@ ForEachMacros:
- 'queue_for_each_hw_ctx'
- 'radix_tree_for_each_slot'
- 'radix_tree_for_each_tagged'
- 'rb_for_each'
- 'rbtree_postorder_for_each_entry_safe'
- 'rdma_for_each_block'
- 'rdma_for_each_port'

6
.mailmap
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@ -102,6 +102,7 @@ Felipe W Damasio <felipewd@terra.com.br>
Felix Kuhling <fxkuehl@gmx.de>
Felix Moeller <felix@derklecks.de>
Filipe Lautert <filipe@icewall.org>
Finn Thain <fthain@linux-m68k.org> <fthain@telegraphics.com.au>
Franck Bui-Huu <vagabon.xyz@gmail.com>
Frank Rowand <frowand.list@gmail.com> <frank.rowand@am.sony.com>
Frank Rowand <frowand.list@gmail.com> <frank.rowand@sonymobile.com>
@ -212,6 +213,8 @@ Manivannan Sadhasivam <mani@kernel.org> <manivannanece23@gmail.com>
Manivannan Sadhasivam <mani@kernel.org> <manivannan.sadhasivam@linaro.org>
Marcin Nowakowski <marcin.nowakowski@mips.com> <marcin.nowakowski@imgtec.com>
Marc Zyngier <maz@kernel.org> <marc.zyngier@arm.com>
Marek Behún <kabel@kernel.org> <marek.behun@nic.cz>
Marek Behún <kabel@kernel.org> Marek Behun <marek.behun@nic.cz>
Mark Brown <broonie@sirena.org.uk>
Mark Starovoytov <mstarovo@pm.me> <mstarovoitov@marvell.com>
Mark Yao <markyao0591@gmail.com> <mark.yao@rock-chips.com>
@ -243,6 +246,9 @@ Maxime Ripard <mripard@kernel.org> <maxime.ripard@free-electrons.com>
Mayuresh Janorkar <mayur@ti.com>
Michael Buesch <m@bues.ch>
Michel Dänzer <michel@tungstengraphics.com>
Michel Lespinasse <michel@lespinasse.org>
Michel Lespinasse <michel@lespinasse.org> <walken@google.com>
Michel Lespinasse <michel@lespinasse.org> <walken@zoy.org>
Miguel Ojeda <ojeda@kernel.org> <miguel.ojeda.sandonis@gmail.com>
Mike Rapoport <rppt@kernel.org> <mike@compulab.co.il>
Mike Rapoport <rppt@kernel.org> <mike.rapoport@gmail.com>

182
Documentation/ABI/obsolete/sysfs-bus-iio Normal file
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@ -0,0 +1,182 @@
What: /sys/bus/iio/devices/iio:deviceX/buffer/length
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Number of scans contained by the buffer.
Since Kernel 5.11, multiple buffers are supported.
so, it is better to use, instead:
/sys/bus/iio/devices/iio:deviceX/bufferY/length
What: /sys/bus/iio/devices/iio:deviceX/buffer/enable
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Actually start the buffer capture up. Will start trigger
if first device and appropriate.
Since Kernel 5.11, multiple buffers are supported.
so, it is better to use, instead:
/sys/bus/iio/devices/iio:deviceX/bufferY/enable
What: /sys/bus/iio/devices/iio:deviceX/scan_elements
KernelVersion: 2.6.37
Contact: linux-iio@vger.kernel.org
Description:
Directory containing interfaces for elements that will be
captured for a single triggered sample set in the buffer.
Since kernel 5.11 the scan_elements attributes are merged into
the bufferY directory, to be configurable per buffer.
What: /sys/.../iio:deviceX/scan_elements/in_accel_x_en
What: /sys/.../iio:deviceX/scan_elements/in_accel_y_en
What: /sys/.../iio:deviceX/scan_elements/in_accel_z_en
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_x_en
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_y_en
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_z_en
What: /sys/.../iio:deviceX/scan_elements/in_magn_x_en
What: /sys/.../iio:deviceX/scan_elements/in_magn_y_en
What: /sys/.../iio:deviceX/scan_elements/in_magn_z_en
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_magnetic_en
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_true_en
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_magnetic_tilt_comp_en
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_true_tilt_comp_en
What: /sys/.../iio:deviceX/scan_elements/in_timestamp_en
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_supply_en
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_en
What: /sys/.../iio:deviceX/scan_elements/in_voltageY-voltageZ_en
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_i_en
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_q_en
What: /sys/.../iio:deviceX/scan_elements/in_voltage_i_en
What: /sys/.../iio:deviceX/scan_elements/in_voltage_q_en
What: /sys/.../iio:deviceX/scan_elements/in_incli_x_en
What: /sys/.../iio:deviceX/scan_elements/in_incli_y_en
What: /sys/.../iio:deviceX/scan_elements/in_pressureY_en
What: /sys/.../iio:deviceX/scan_elements/in_pressure_en
What: /sys/.../iio:deviceX/scan_elements/in_rot_quaternion_en
What: /sys/.../iio:deviceX/scan_elements/in_proximity_en
KernelVersion: 2.6.37
Contact: linux-iio@vger.kernel.org
Description:
Scan element control for triggered data capture.
Since kernel 5.11 the scan_elements attributes are merged into
the bufferY directory, to be configurable per buffer.
What: /sys/.../iio:deviceX/scan_elements/in_accel_type
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_type
What: /sys/.../iio:deviceX/scan_elements/in_magn_type
What: /sys/.../iio:deviceX/scan_elements/in_incli_type
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_type
What: /sys/.../iio:deviceX/scan_elements/in_voltage_type
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_supply_type
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_i_type
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_q_type
What: /sys/.../iio:deviceX/scan_elements/in_voltage_i_type
What: /sys/.../iio:deviceX/scan_elements/in_voltage_q_type
What: /sys/.../iio:deviceX/scan_elements/in_timestamp_type
What: /sys/.../iio:deviceX/scan_elements/in_pressureY_type
What: /sys/.../iio:deviceX/scan_elements/in_pressure_type
What: /sys/.../iio:deviceX/scan_elements/in_rot_quaternion_type
What: /sys/.../iio:deviceX/scan_elements/in_proximity_type
KernelVersion: 2.6.37
Contact: linux-iio@vger.kernel.org
Description:
Description of the scan element data storage within the buffer
and hence the form in which it is read from user-space.
Form is [be|le]:[s|u]bits/storagebits[>>shift].
be or le specifies big or little endian. s or u specifies if
signed (2's complement) or unsigned. bits is the number of bits
of data and storagebits is the space (after padding) that it
occupies in the buffer. shift if specified, is the shift that
needs to be applied prior to masking out unused bits. Some
devices put their data in the middle of the transferred elements
with additional information on both sides. Note that some
devices will have additional information in the unused bits
so to get a clean value, the bits value must be used to mask
the buffer output value appropriately. The storagebits value
also specifies the data alignment. So s48/64>>2 will be a
signed 48 bit integer stored in a 64 bit location aligned to
a 64 bit boundary. To obtain the clean value, shift right 2
and apply a mask to zero the top 16 bits of the result.
For other storage combinations this attribute will be extended
appropriately.
Since kernel 5.11 the scan_elements attributes are merged into
the bufferY directory, to be configurable per buffer.
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_index
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_supply_index
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_i_index
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_q_index
What: /sys/.../iio:deviceX/scan_elements/in_voltage_i_index
What: /sys/.../iio:deviceX/scan_elements/in_voltage_q_index
What: /sys/.../iio:deviceX/scan_elements/in_accel_x_index
What: /sys/.../iio:deviceX/scan_elements/in_accel_y_index
What: /sys/.../iio:deviceX/scan_elements/in_accel_z_index
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_x_index
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_y_index
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_z_index
What: /sys/.../iio:deviceX/scan_elements/in_magn_x_index
What: /sys/.../iio:deviceX/scan_elements/in_magn_y_index
What: /sys/.../iio:deviceX/scan_elements/in_magn_z_index
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_magnetic_index
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_true_index
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_magnetic_tilt_comp_index
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_true_tilt_comp_index
What: /sys/.../iio:deviceX/scan_elements/in_incli_x_index
What: /sys/.../iio:deviceX/scan_elements/in_incli_y_index
What: /sys/.../iio:deviceX/scan_elements/in_timestamp_index
What: /sys/.../iio:deviceX/scan_elements/in_pressureY_index
What: /sys/.../iio:deviceX/scan_elements/in_pressure_index
What: /sys/.../iio:deviceX/scan_elements/in_rot_quaternion_index
What: /sys/.../iio:deviceX/scan_elements/in_proximity_index
KernelVersion: 2.6.37
Description:
A single positive integer specifying the position of this
scan element in the buffer. Note these are not dependent on
what is enabled and may not be contiguous. Thus for user-space
to establish the full layout these must be used in conjunction
with all _en attributes to establish which channels are present,
and the relevant _type attributes to establish the data storage
format.
Since kernel 5.11 the scan_elements attributes are merged into
the bufferY directory, to be configurable per buffer.
What: /sys/bus/iio/devices/iio:deviceX/buffer/watermark
KernelVersion: 4.2
Contact: linux-iio@vger.kernel.org
Description:
A single positive integer specifying the maximum number of scan
elements to wait for.
Poll will block until the watermark is reached.
Blocking read will wait until the minimum between the requested
read amount or the low water mark is available.
Non-blocking read will retrieve the available samples from the
buffer even if there are less samples then watermark level. This
allows the application to block on poll with a timeout and read
the available samples after the timeout expires and thus have a
maximum delay guarantee.
Since Kernel 5.11, multiple buffers are supported.
so, it is better to use, instead:
/sys/bus/iio/devices/iio:deviceX/bufferY/watermark
What: /sys/bus/iio/devices/iio:deviceX/buffer/data_available
KernelVersion: 4.16
Contact: linux-iio@vger.kernel.org
Description:
A read-only value indicating the bytes of data available in the
buffer. In the case of an output buffer, this indicates the
amount of empty space available to write data to. In the case of
an input buffer, this indicates the amount of data available for
reading.
Since Kernel 5.11, multiple buffers are supported.
so, it is better to use, instead:
/sys/bus/iio/devices/iio:deviceX/bufferY/data_available

2
Documentation/ABI/obsolete/sysfs-cpuidle
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@ -6,4 +6,4 @@ Description:
with the update that cpuidle governor can be changed at runtime in default,
both current_governor and current_governor_ro co-exist under
/sys/devices/system/cpu/cpuidle/ file, it's duplicate so make
current_governor_ro obselete.
current_governor_ro obsolete.

2
Documentation/ABI/removed/sysfs-kernel-uids
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@ -5,7 +5,7 @@ Contact: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Description:
The /sys/kernel/uids/<uid>/cpu_shares tunable is used
to set the cpu bandwidth a user is allowed. This is a
propotional value. What that means is that if there
proportional value. What that means is that if there
are two users logged in, each with an equal number of
shares, then they will get equal CPU bandwidth. Another
example would be, if User A has shares = 1024 and user

2
Documentation/ABI/stable/sysfs-bus-vmbus
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@ -61,7 +61,7 @@ Date: September. 2017
KernelVersion: 4.14
Contact: Stephen Hemminger <sthemmin@microsoft.com>
Description: Directory for per-channel information
NN is the VMBUS relid associtated with the channel.
NN is the VMBUS relid associated with the channel.
What: /sys/bus/vmbus/devices/<UUID>/channels/<N>/cpu
Date: September. 2017

2
Documentation/ABI/stable/sysfs-bus-xen-backend
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@ -19,7 +19,7 @@ Date: April 2011
KernelVersion: 3.0
Contact: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Description:
The major:minor number (in hexidecimal) of the
The major:minor number (in hexadecimal) of the
physical device providing the storage for this backend
block device.

20
Documentation/ABI/stable/sysfs-class-infiniband
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@ -731,26 +731,6 @@ Description:
is the irq number of "sdma3", and M is irq number of "sdma4" in
the /proc/interrupts file.
sysfs interface for Intel(R) X722 iWARP i40iw driver
----------------------------------------------------
What: /sys/class/infiniband/i40iwX/hw_rev
What: /sys/class/infiniband/i40iwX/hca_type
What: /sys/class/infiniband/i40iwX/board_id
Date: Jan, 2016
KernelVersion: v4.10
Contact: linux-rdma@vger.kernel.org
Description:
=============== ==== ========================
hw_rev: (RO) Hardware revision number
hca_type: (RO) Show HCA type (I40IW)
board_id: (RO) I40IW board ID
=============== ==== ========================
sysfs interface for QLogic qedr NIC Driver
------------------------------------------

83
Documentation/ABI/stable/sysfs-devices-system-cpu
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@ -23,3 +23,86 @@ Description: Default value for the Data Stream Control Register (DSCR) on
here).
If set by a process it will be inherited by child processes.
Values: 64 bit unsigned integer (bit field)
What: /sys/devices/system/cpu/cpuX/topology/physical_package_id
Description: physical package id of cpuX. Typically corresponds to a physical
socket number, but the actual value is architecture and platform
dependent.
Values: integer
What: /sys/devices/system/cpu/cpuX/topology/die_id
Description: the CPU die ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent.
Values: integer
What: /sys/devices/system/cpu/cpuX/topology/core_id
Description: the CPU core ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent.
Values: integer
What: /sys/devices/system/cpu/cpuX/topology/book_id
Description: the book ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent. it's only used on s390.
Values: integer
What: /sys/devices/system/cpu/cpuX/topology/drawer_id
Description: the drawer ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent. it's only used on s390.
Values: integer
What: /sys/devices/system/cpu/cpuX/topology/core_cpus
Description: internal kernel map of CPUs within the same core.
(deprecated name: "thread_siblings")
Values: hexadecimal bitmask.
What: /sys/devices/system/cpu/cpuX/topology/core_cpus_list
Description: human-readable list of CPUs within the same core.
The format is like 0-3, 8-11, 14,17.
(deprecated name: "thread_siblings_list").
Values: decimal list.
What: /sys/devices/system/cpu/cpuX/topology/package_cpus
Description: internal kernel map of the CPUs sharing the same physical_package_id.
(deprecated name: "core_siblings").
Values: hexadecimal bitmask.
What: /sys/devices/system/cpu/cpuX/topology/package_cpus_list
Description: human-readable list of CPUs sharing the same physical_package_id.
The format is like 0-3, 8-11, 14,17.
(deprecated name: "core_siblings_list")
Values: decimal list.
What: /sys/devices/system/cpu/cpuX/topology/die_cpus
Description: internal kernel map of CPUs within the same die.
Values: hexadecimal bitmask.
What: /sys/devices/system/cpu/cpuX/topology/die_cpus_list
Description: human-readable list of CPUs within the same die.
The format is like 0-3, 8-11, 14,17.
Values: decimal list.
What: /sys/devices/system/cpu/cpuX/topology/book_siblings
Description: internal kernel map of cpuX's hardware threads within the same
book_id. it's only used on s390.
Values: hexadecimal bitmask.
What: /sys/devices/system/cpu/cpuX/topology/book_siblings_list
Description: human-readable list of cpuX's hardware threads within the same
book_id.
The format is like 0-3, 8-11, 14,17. it's only used on s390.
Values: decimal list.
What: /sys/devices/system/cpu/cpuX/topology/drawer_siblings
Description: internal kernel map of cpuX's hardware threads within the same
drawer_id. it's only used on s390.
Values: hexadecimal bitmask.
What: /sys/devices/system/cpu/cpuX/topology/drawer_siblings_list
Description: human-readable list of cpuX's hardware threads within the same
drawer_id.
The format is like 0-3, 8-11, 14,17. it's only used on s390.
Values: decimal list.

2
Documentation/ABI/stable/sysfs-driver-dma-idxd
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@ -173,7 +173,7 @@ What: /sys/bus/dsa/devices/wq<m>.<n>/priority
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The priority value of this work queue, it is a vlue relative to
Description: The priority value of this work queue, it is a value relative to
other work queue in the same group to control quality of service
for dispatching work from multiple workqueues in the same group.

4
Documentation/ABI/stable/sysfs-driver-mlxreg-io
View File

@ -137,7 +137,7 @@ Contact: Vadim Pasternak <vadimpmellanox.com>
Description: These files show the system reset cause, as following:
COMEX thermal shutdown; wathchdog power off or reset was derived
by one of the next components: COMEX, switch board or by Small Form
Factor mezzanine, reset requested from ASIC, reset cuased by BIOS
Factor mezzanine, reset requested from ASIC, reset caused by BIOS
reload. Value 1 in file means this is reset cause, 0 - otherwise.
Only one of the above causes could be 1 at the same time, representing
only last reset cause.
@ -183,7 +183,7 @@ What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/vpd_wp
Date: January 2020
KernelVersion: 5.6
Contact: Vadim Pasternak <vadimpmellanox.com>
Description: This file allows to overwrite system VPD hardware wrtie
Description: This file allows to overwrite system VPD hardware write
protection when attribute is set 1.
The file is read/write.

13
Documentation/ABI/stable/sysfs-driver-w1_ds2438 Normal file
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@ -0,0 +1,13 @@
What: /sys/bus/w1/devices/.../page1
Date: April 2021
Contact: Luiz Sampaio <sampaio.ime@gmail.com>
Description: read the contents of the page1 of the DS2438
see Documentation/w1/slaves/w1_ds2438.rst for detailed information
Users: any user space application which wants to communicate with DS2438
What: /sys/bus/w1/devices/.../offset
Date: April 2021
Contact: Luiz Sampaio <sampaio.ime@gmail.com>
Description: write the contents to the offset register of the DS2438
see Documentation/w1/slaves/w1_ds2438.rst for detailed information
Users: any user space application which wants to communicate with DS2438

2
Documentation/ABI/testing/configfs-iio
View File

@ -31,4 +31,4 @@ Date: April 2016
KernelVersion: 4.7
Description:
Dummy IIO devices directory. Creating a directory here will result
in creating a dummy IIO device in the IIO subystem.
in creating a dummy IIO device in the IIO subsystem.

8
Documentation/ABI/testing/configfs-most
View File

@ -20,7 +20,7 @@ Description:
subbuffer_size
configure the sub-buffer size for this channel
(needed for synchronous and isochrnous data)
(needed for synchronous and isochronous data)
num_buffers
@ -75,7 +75,7 @@ Description:
subbuffer_size
configure the sub-buffer size for this channel
(needed for synchronous and isochrnous data)
(needed for synchronous and isochronous data)
num_buffers
@ -130,7 +130,7 @@ Description:
subbuffer_size
configure the sub-buffer size for this channel
(needed for synchronous and isochrnous data)
(needed for synchronous and isochronous data)
num_buffers
@ -196,7 +196,7 @@ Description:
subbuffer_size
configure the sub-buffer size for this channel
(needed for synchronous and isochrnous data)
(needed for synchronous and isochronous data)
num_buffers

2
Documentation/ABI/testing/configfs-usb-gadget
View File

@ -137,7 +137,7 @@ Description:
This group contains "OS String" extension handling attributes.
============= ===============================================
use flag turning "OS Desctiptors" support on/off
use flag turning "OS Descriptors" support on/off
b_vendor_code one-byte value used for custom per-device and
per-interface requests
qw_sign an identifier to be reported as "OS String"

2
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@ -8,6 +8,8 @@ Description:
c_chmask capture channel mask
c_srate capture sampling rate
c_ssize capture sample size (bytes)
c_sync capture synchronization type (async/adaptive)
fb_max maximum extra bandwidth in async mode
p_chmask playback channel mask
p_srate playback sampling rate
p_ssize playback sample size (bytes)

4
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@ -170,7 +170,7 @@ Description: Default color matching descriptors
bMatrixCoefficients matrix used to compute luma and
chroma values from the color primaries
bTransferCharacteristics optoelectronic transfer
characteristic of the source picutre,
characteristic of the source picture,
also called the gamma function
bColorPrimaries color primaries and the reference
white
@ -311,7 +311,7 @@ Description: Specific streaming header descriptors
a hardware trigger interrupt event
bTriggerSupport flag specifying if hardware
triggering is supported
bStillCaptureMethod method of still image caputre
bStillCaptureMethod method of still image capture
supported
bTerminalLink id of the output terminal to which
the video endpoint of this interface

2
Documentation/ABI/testing/debugfs-driver-genwqe
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@ -31,7 +31,7 @@ What: /sys/kernel/debug/genwqe/genwqe<n>_card/prev_regs
Date: Oct 2013
Contact: haver@linux.vnet.ibm.com
Description: Dump of the error registers before the last reset of
the card occured.
the card occurred.
Only available for PF.
What: /sys/kernel/debug/genwqe/genwqe<n>_card/prev_dbg_uid0

10
Documentation/ABI/testing/debugfs-driver-habanalabs
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@ -153,7 +153,7 @@ KernelVersion: 5.1
Contact: ogabbay@kernel.org
Description: Triggers an I2C transaction that is generated by the device's
CPU. Writing to this file generates a write transaction while
reading from the file generates a read transcation
reading from the file generates a read transaction
What: /sys/kernel/debug/habanalabs/hl<n>/i2c_reg
Date: Jan 2019
@ -207,6 +207,14 @@ Contact: ogabbay@kernel.org
Description: Sets the PCI power state. Valid values are "1" for D0 and "2"
for D3Hot
What: /sys/kernel/debug/habanalabs/hl<n>/skip_reset_on_timeout
Date: Jun 2021
KernelVersion: 5.13
Contact: ynudelman@habana.ai
Description: Sets the skip reset on timeout option for the device. Value of
"0" means device will be reset in case some CS has timed out,
otherwise it will not be reset.
What: /sys/kernel/debug/habanalabs/hl<n>/stop_on_err
Date: Mar 2020
KernelVersion: 5.6

36
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@ -24,7 +24,7 @@ Description:
1 Enable digital signature validation
2 Permit modification of EVM-protected metadata at
runtime. Not supported if HMAC validation and
creation is enabled.
creation is enabled (deprecated).
31 Disable further runtime modification of EVM policy
=== ==================================================
@ -47,10 +47,38 @@ Description:
will enable digital signature validation, permit
modification of EVM-protected metadata and
disable all further modification of policy
disable all further modification of policy. This option is now
deprecated in favor of::
Note that once a key has been loaded, it will no longer be
possible to enable metadata modification.
echo 0x80000002 ><securityfs>/evm
as the outstanding issues that prevent the usage of EVM portable
signatures have been solved.
Echoing a value is additive, the new value is added to the
existing initialization flags.
For example, after::
echo 2 ><securityfs>/evm
another echo can be performed::
echo 1 ><securityfs>/evm
and the resulting value will be 3.
Note that once an HMAC key has been loaded, it will no longer
be possible to enable metadata modification. Signaling that an
HMAC key has been loaded will clear the corresponding flag.
For example, if the current value is 6 (2 and 4 set)::
echo 1 ><securityfs>/evm
will set the new value to 3 (4 cleared).
Loading an HMAC key is the only way to disable metadata
modification.
Until key loading has been signaled EVM can not create
or validate the 'security.evm' xattr, but returns

85
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@ -57,6 +57,7 @@ Description:
What: /sys/bus/counter/devices/counterX/countY/count_mode_available
What: /sys/bus/counter/devices/counterX/countY/error_noise_available
What: /sys/bus/counter/devices/counterX/countY/function_available
What: /sys/bus/counter/devices/counterX/countY/prescaler_available
What: /sys/bus/counter/devices/counterX/countY/signalZ_action_available
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
@ -154,6 +155,15 @@ Description:
Count Y. If possible, this should match the name of the
respective channel as it appears in the device datasheet.
What: /sys/bus/counter/devices/counterX/countY/prescaler
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
Description:
Configure the prescaler value associated with Count Y.
On the FlexTimer, the counter clock source passes through a
prescaler (i.e. a counter). This acts like a clock
divider.
What: /sys/bus/counter/devices/counterX/countY/preset
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
@ -193,6 +203,15 @@ Description:
both edges:
Any state transition.
What: /sys/bus/counter/devices/counterX/countY/spike_filter_ns
KernelVersion: 5.14
Contact: linux-iio@vger.kernel.org
Description:
If the counter device supports programmable spike filter this
attribute indicates the value in nanoseconds where noise pulses
shorter or equal to configured value are ignored. Value 0 means
filter is disabled.
What: /sys/bus/counter/devices/counterX/name
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
@ -215,11 +234,45 @@ Description:
Read-only attribute that indicates the total number of Signals
belonging to the Counter.
What: /sys/bus/counter/devices/counterX/signalY/signal
What: /sys/bus/counter/devices/counterX/signalY/cable_fault
KernelVersion: 5.7
Contact: linux-iio@vger.kernel.org
Description:
Read-only attribute that indicates whether a differential
encoder cable fault (not connected or loose wires) is detected
for the respective channel of Signal Y. Valid attribute values
are boolean. Detection must first be enabled via the
corresponding cable_fault_enable attribute.
What: /sys/bus/counter/devices/counterX/signalY/cable_fault_enable
KernelVersion: 5.7
Contact: linux-iio@vger.kernel.org
Description:
Whether detection of differential encoder cable faults for the
respective channel of Signal Y is enabled. Valid attribute
values are boolean.
What: /sys/bus/counter/devices/counterX/signalY/filter_clock_prescaler
KernelVersion: 5.7
Contact: linux-iio@vger.kernel.org
Description:
Filter clock factor for input Signal Y. This prescaler value
affects the inputs of both quadrature pair signals.
What: /sys/bus/counter/devices/counterX/signalY/index_polarity
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
Description:
Signal data of Signal Y represented as a string.
Active level of index input Signal Y; irrelevant in
non-synchronous load mode.
What: /sys/bus/counter/devices/counterX/signalY/index_polarity_available
What: /sys/bus/counter/devices/counterX/signalY/synchronous_mode_available
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
Description:
Discrete set of available values for the respective Signal Y
configuration are listed in this file.
What: /sys/bus/counter/devices/counterX/signalY/name
KernelVersion: 5.2
@ -228,3 +281,31 @@ Description:
Read-only attribute that indicates the device-specific name of
Signal Y. If possible, this should match the name of the
respective signal as it appears in the device datasheet.
What: /sys/bus/counter/devices/counterX/signalY/signal
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
Description:
Signal data of Signal Y represented as a string.
What: /sys/bus/counter/devices/counterX/signalY/synchronous_mode
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
Description:
Configure the counter associated with Signal Y for
non-synchronous or synchronous load mode. Synchronous load mode
cannot be selected in non-quadrature (Pulse-Direction) clock
mode.
non-synchronous:
A logic low level is the active level at this index
input. The index function (as enabled via preset_enable)
is performed directly on the active level of the index
input.
synchronous:
Intended for interfacing with encoder Index output in
quadrature clock mode. The active level is configured
via index_polarity. The index function (as enabled via
preset_enable) is performed synchronously with the
quadrature clock on the active level of the index input.

61
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@ -1,61 +0,0 @@
What: /sys/bus/counter/devices/counterX/signalY/cable_fault
KernelVersion: 5.7
Contact: linux-iio@vger.kernel.org
Description:
Read-only attribute that indicates whether a differential
encoder cable fault (not connected or loose wires) is detected
for the respective channel of Signal Y. Valid attribute values
are boolean. Detection must first be enabled via the
corresponding cable_fault_enable attribute.
What: /sys/bus/counter/devices/counterX/signalY/cable_fault_enable
KernelVersion: 5.7
Contact: linux-iio@vger.kernel.org
Description:
Whether detection of differential encoder cable faults for the
respective channel of Signal Y is enabled. Valid attribute
values are boolean.
What: /sys/bus/counter/devices/counterX/signalY/filter_clock_prescaler
KernelVersion: 5.7
Contact: linux-iio@vger.kernel.org
Description:
Filter clock factor for input Signal Y. This prescaler value
affects the inputs of both quadrature pair signals.
What: /sys/bus/counter/devices/counterX/signalY/index_polarity
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
Description:
Active level of index input Signal Y; irrelevant in
non-synchronous load mode.
What: /sys/bus/counter/devices/counterX/signalY/index_polarity_available
What: /sys/bus/counter/devices/counterX/signalY/synchronous_mode_available
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
Description:
Discrete set of available values for the respective Signal Y
configuration are listed in this file.
What: /sys/bus/counter/devices/counterX/signalY/synchronous_mode
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
Description:
Configure the counter associated with Signal Y for
non-synchronous or synchronous load mode. Synchronous load mode
cannot be selected in non-quadrature (Pulse-Direction) clock
mode.
non-synchronous:
A logic low level is the active level at this index
input. The index function (as enabled via preset_enable)
is performed directly on the active level of the index
input.
synchronous:
Intended for interfacing with encoder Index output in
quadrature clock mode. The active level is configured
via index_polarity. The index function (as enabled via
preset_enable) is performed synchronously with the
quadrature clock on the active level of the index input.

16
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@ -1,16 +0,0 @@
What: /sys/bus/counter/devices/counterX/countY/prescaler_available
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
Description:
Discrete set of available values for the respective Count Y
configuration are listed in this file. Values are delimited by
newline characters.
What: /sys/bus/counter/devices/counterX/countY/prescaler
KernelVersion: 5.2
Contact: linux-iio@vger.kernel.org
Description:
Configure the prescaler value associated with Count Y.
On the FlexTimer, the counter clock source passes through a
prescaler (i.e. a counter). This acts like a clock
divider.

103
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@ -24,3 +24,106 @@ Description:
(RO) "Persistent Only Capacity" as bytes. Represents the
identically named field in the Identify Memory Device Output
Payload in the CXL-2.0 specification.
What: /sys/bus/cxl/devices/*/devtype
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
CXL device objects export the devtype attribute which mirrors
the same value communicated in the DEVTYPE environment variable
for uevents for devices on the "cxl" bus.
What: /sys/bus/cxl/devices/portX/uport
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
CXL port objects are enumerated from either a platform firmware
device (ACPI0017 and ACPI0016) or PCIe switch upstream port with
CXL component registers. The 'uport' symlink connects the CXL
portX object to the device that published the CXL port
capability.
What: /sys/bus/cxl/devices/portX/dportY
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
CXL port objects are enumerated from either a platform firmware
device (ACPI0017 and ACPI0016) or PCIe switch upstream port with
CXL component registers. The 'dportY' symlink identifies one or
more downstream ports that the upstream port may target in its
decode of CXL memory resources. The 'Y' integer reflects the
hardware port unique-id used in the hardware decoder target
list.
What: /sys/bus/cxl/devices/decoderX.Y
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
CXL decoder objects are enumerated from either a platform
firmware description, or a CXL HDM decoder register set in a
PCIe device (see CXL 2.0 section 8.2.5.12 CXL HDM Decoder
Capability Structure). The 'X' in decoderX.Y represents the
cxl_port container of this decoder, and 'Y' represents the
instance id of a given decoder resource.
What: /sys/bus/cxl/devices/decoderX.Y/{start,size}
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
The 'start' and 'size' attributes together convey the physical
address base and number of bytes mapped in the decoder's decode
window. For decoders of devtype "cxl_decoder_root" the address
range is fixed. For decoders of devtype "cxl_decoder_switch" the
address is bounded by the decode range of the cxl_port ancestor
of the decoder's cxl_port, and dynamically updates based on the
active memory regions in that address space.
What: /sys/bus/cxl/devices/decoderX.Y/locked
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
CXL HDM decoders have the capability to lock the configuration
until the next device reset. For decoders of devtype
"cxl_decoder_root" there is no standard facility to unlock them.
For decoders of devtype "cxl_decoder_switch" a secondary bus
reset, of the PCIe bridge that provides the bus for this
decoders uport, unlocks / resets the decoder.
What: /sys/bus/cxl/devices/decoderX.Y/target_list
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
Display a comma separated list of the current decoder target
configuration. The list is ordered by the current configured
interleave order of the decoder's dport instances. Each entry in
the list is a dport id.
What: /sys/bus/cxl/devices/decoderX.Y/cap_{pmem,ram,type2,type3}
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
When a CXL decoder is of devtype "cxl_decoder_root", it
represents a fixed memory window identified by platform
firmware. A fixed window may only support a subset of memory
types. The 'cap_*' attributes indicate whether persistent
memory, volatile memory, accelerator memory, and / or expander
memory may be mapped behind this decoder's memory window.
What: /sys/bus/cxl/devices/decoderX.Y/target_type
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
When a CXL decoder is of devtype "cxl_decoder_switch", it can
optionally decode either accelerator memory (type-2) or expander
memory (type-3). The 'target_type' attribute indicates the
current setting which may dynamically change based on what
memory regions are activated in this decode hierarchy.

2
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@ -12,7 +12,7 @@ KernelVersion: 4.12
Contact: linux-fsi@lists.ozlabs.org
Description:
Sends an FSI BREAK command on a master's communication
link to any connnected slaves. A BREAK resets connected
link to any connected slaves. A BREAK resets connected
device's logic and preps it to receive further commands
from the master.

131
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@ -455,6 +455,19 @@ Contact: linux-iio@vger.kernel.org
Description:
Hardware applied calibration offset (assumed to fix production
inaccuracies).
icm42600: For this device values are real physical offsets
expressed in SI units (m/s^2 for accelerometers and rad/s
for gyroscope)/
What: /sys/bus/iio/devices/iio:deviceX/in_accel_calibbias_available
What: /sys/bus/iio/devices/iio:deviceX/in_anglvel_calibbias_available
KernelVersion: 5.8
Contact: linux-iio@vger.kernel.org
Description:
Available values of calibbias. Maybe expressed as either of:
- a small discrete set of values like "0 2 4 6 8"
- a range specified as "[min step max]"
What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_calibscale
What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_supply_calibscale
@ -652,6 +665,25 @@ Description:
Output frequency for channel Y in Hz. The number must always be
specified and unique if the output corresponds to a single
channel.
Some drivers have additional constraints:
ADF4371 has an integrated VCO with fundamendal output
frequency ranging from 4000000000 Hz 8000000000 Hz.
out_altvoltage0_frequency:
A divide by 1, 2, 4, 8, 16, 32 or circuit generates
frequencies from 62500000 Hz to 8000000000 Hz.
out_altvoltage1_frequency:
This channel duplicates the channel 0 frequency
out_altvoltage2_frequency:
A frequency doubler generates frequencies from
8000000000 Hz to 16000000000 Hz.
out_altvoltage3_frequency:
A frequency quadrupler generates frequencies from
16000000000 Hz to 32000000000 Hz.
Note: writes to one of the channels will affect the frequency of
all the other channels, since it involves changing the VCO
fundamental output frequency.
What: /sys/bus/iio/devices/iio:deviceX/out_altvoltageY_phase
KernelVersion: 3.4.0
@ -663,6 +695,17 @@ Description:
specified and unique if the output corresponds to a single
channel.
What: /sys/bus/iio/devices/iio:deviceX/out_currentY_raw
Date: May 2012
KernelVersion: 3.5
Contact: Johan Hovold <jhovold@gmail.com>
Description:
Set/get output current for channel Y. Units after application
of scale and offset are milliamps.
For some devices current channels are used to specify
current supplied to elements used in taking a measurement
of a different type. E.g. LED currents.
What: /sys/bus/iio/devices/iio:deviceX/events
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
@ -786,7 +829,7 @@ What: /sys/.../events/in_capacitanceY_adaptive_thresh_rising_en
What: /sys/.../events/in_capacitanceY_adaptive_thresh_falling_en
KernelVersion: 5.13
Contact: linux-iio@vger.kernel.org
Descrption:
Description:
Adaptive thresholds are similar to normal fixed thresholds
but the value is expressed as an offset from a value which
provides a low frequency approximation of the channel itself.
@ -798,10 +841,10 @@ What: /sys/.../in_capacitanceY_adaptive_thresh_rising_timeout
What: /sys/.../in_capacitanceY_adaptive_thresh_falling_timeout
KernelVersion: 5.11
Contact: linux-iio@vger.kernel.org
Descrption:
Description:
When adaptive thresholds are used, the tracking signal
may adjust too slowly to step changes in the raw signal.
*_timeout (in seconds) specifies a time for which the
Thus these specify the time in seconds for which the
difference between the slow tracking signal and the raw
signal is allowed to remain out-of-range before a reset
event occurs in which the tracking signal is made equal
@ -1195,16 +1238,12 @@ Description:
The name of the trigger source being used, as per string given
in /sys/class/iio/triggerY/name.
What: /sys/bus/iio/devices/iio:deviceX/buffer/length
KernelVersion: 2.6.35
What: /sys/bus/iio/devices/iio:deviceX/bufferY/length
KernelVersion: 5.11
Contact: linux-iio@vger.kernel.org
Description:
Number of scans contained by the buffer.
What: /sys/bus/iio/devices/iio:deviceX/buffer/enable
KernelVersion: 2.6.35
What: /sys/bus/iio/devices/iio:deviceX/bufferY/enable
KernelVersion: 5.11
Contact: linux-iio@vger.kernel.org
@ -1212,8 +1251,6 @@ Description:
Actually start the buffer capture up. Will start trigger
if first device and appropriate.
What: /sys/bus/iio/devices/iio:deviceX/scan_elements
KernelVersion: 2.6.37
What: /sys/bus/iio/devices/iio:deviceX/bufferY
KernelVersion: 5.11
Contact: linux-iio@vger.kernel.org
@ -1224,34 +1261,6 @@ Description:
Since kernel 5.11 the scan_elements attributes are merged into
the bufferY directory, to be configurable per buffer.
What: /sys/.../iio:deviceX/scan_elements/in_accel_x_en
What: /sys/.../iio:deviceX/scan_elements/in_accel_y_en
What: /sys/.../iio:deviceX/scan_elements/in_accel_z_en
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_x_en
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_y_en
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_z_en
What: /sys/.../iio:deviceX/scan_elements/in_magn_x_en
What: /sys/.../iio:deviceX/scan_elements/in_magn_y_en
What: /sys/.../iio:deviceX/scan_elements/in_magn_z_en
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_magnetic_en
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_true_en
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_magnetic_tilt_comp_en
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_true_tilt_comp_en
What: /sys/.../iio:deviceX/scan_elements/in_timestamp_en
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_supply_en
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_en
What: /sys/.../iio:deviceX/scan_elements/in_voltageY-voltageZ_en
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_i_en
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_q_en
What: /sys/.../iio:deviceX/scan_elements/in_voltage_i_en
What: /sys/.../iio:deviceX/scan_elements/in_voltage_q_en
What: /sys/.../iio:deviceX/scan_elements/in_incli_x_en
What: /sys/.../iio:deviceX/scan_elements/in_incli_y_en
What: /sys/.../iio:deviceX/scan_elements/in_pressureY_en
What: /sys/.../iio:deviceX/scan_elements/in_pressure_en
What: /sys/.../iio:deviceX/scan_elements/in_rot_quaternion_en
What: /sys/.../iio:deviceX/scan_elements/in_proximity_en
KernelVersion: 2.6.37
What: /sys/.../iio:deviceX/bufferY/in_accel_x_en
What: /sys/.../iio:deviceX/bufferY/in_accel_y_en
What: /sys/.../iio:deviceX/bufferY/in_accel_z_en
@ -1284,23 +1293,6 @@ Contact: linux-iio@vger.kernel.org
Description:
Scan element control for triggered data capture.
What: /sys/.../iio:deviceX/scan_elements/in_accel_type
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_type
What: /sys/.../iio:deviceX/scan_elements/in_magn_type
What: /sys/.../iio:deviceX/scan_elements/in_incli_type
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_type
What: /sys/.../iio:deviceX/scan_elements/in_voltage_type
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_supply_type
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_i_type
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_q_type
What: /sys/.../iio:deviceX/scan_elements/in_voltage_i_type
What: /sys/.../iio:deviceX/scan_elements/in_voltage_q_type
What: /sys/.../iio:deviceX/scan_elements/in_timestamp_type
What: /sys/.../iio:deviceX/scan_elements/in_pressureY_type
What: /sys/.../iio:deviceX/scan_elements/in_pressure_type
What: /sys/.../iio:deviceX/scan_elements/in_rot_quaternion_type
What: /sys/.../iio:deviceX/scan_elements/in_proximity_type
KernelVersion: 2.6.37
What: /sys/.../iio:deviceX/bufferY/in_accel_type
What: /sys/.../iio:deviceX/bufferY/in_anglvel_type
What: /sys/.../iio:deviceX/bufferY/in_magn_type
@ -1347,33 +1339,6 @@ Description:
If the type parameter can take one of a small set of values,
this attribute lists them.
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_index
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_supply_index
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_i_index
What: /sys/.../iio:deviceX/scan_elements/in_voltageY_q_index
What: /sys/.../iio:deviceX/scan_elements/in_voltage_i_index
What: /sys/.../iio:deviceX/scan_elements/in_voltage_q_index
What: /sys/.../iio:deviceX/scan_elements/in_accel_x_index
What: /sys/.../iio:deviceX/scan_elements/in_accel_y_index
What: /sys/.../iio:deviceX/scan_elements/in_accel_z_index
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_x_index
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_y_index
What: /sys/.../iio:deviceX/scan_elements/in_anglvel_z_index
What: /sys/.../iio:deviceX/scan_elements/in_magn_x_index
What: /sys/.../iio:deviceX/scan_elements/in_magn_y_index
What: /sys/.../iio:deviceX/scan_elements/in_magn_z_index
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_magnetic_index
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_true_index
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_magnetic_tilt_comp_index
What: /sys/.../iio:deviceX/scan_elements/in_rot_from_north_true_tilt_comp_index
What: /sys/.../iio:deviceX/scan_elements/in_incli_x_index
What: /sys/.../iio:deviceX/scan_elements/in_incli_y_index
What: /sys/.../iio:deviceX/scan_elements/in_timestamp_index
What: /sys/.../iio:deviceX/scan_elements/in_pressureY_index
What: /sys/.../iio:deviceX/scan_elements/in_pressure_index
What: /sys/.../iio:deviceX/scan_elements/in_rot_quaternion_index
What: /sys/.../iio:deviceX/scan_elements/in_proximity_index
KernelVersion: 2.6.37
What: /sys/.../iio:deviceX/bufferY/in_voltageY_index
What: /sys/.../iio:deviceX/bufferY/in_voltageY_supply_index
What: /sys/.../iio:deviceX/bufferY/in_voltageY_i_index
@ -1613,8 +1578,6 @@ Description:
Specifies number of seconds in which we compute the steps
that occur in order to decide if the consumer is making steps.
What: /sys/bus/iio/devices/iio:deviceX/buffer/watermark
KernelVersion: 4.2
What: /sys/bus/iio/devices/iio:deviceX/bufferY/watermark
KernelVersion: 5.11
Contact: linux-iio@vger.kernel.org
@ -1633,8 +1596,6 @@ Description:
the available samples after the timeout expires and thus have a
maximum delay guarantee.
What: /sys/bus/iio/devices/iio:deviceX/buffer/data_available
KernelVersion: 4.16
What: /sys/bus/iio/devices/iio:deviceX/bufferY/data_available
KernelVersion: 5.11
Contact: linux-iio@vger.kernel.org

33
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@ -1,28 +1,3 @@
What: /sys/bus/iio/devices/iio:deviceX/out_altvoltageY_frequency
KernelVersion:
Contact: linux-iio@vger.kernel.org
Description:
Stores the PLL frequency in Hz for channel Y.
Reading returns the actual frequency in Hz.
The ADF4371 has an integrated VCO with fundamendal output
frequency ranging from 4000000000 Hz 8000000000 Hz.
out_altvoltage0_frequency:
A divide by 1, 2, 4, 8, 16, 32 or circuit generates
frequencies from 62500000 Hz to 8000000000 Hz.
out_altvoltage1_frequency:
This channel duplicates the channel 0 frequency
out_altvoltage2_frequency:
A frequency doubler generates frequencies from
8000000000 Hz to 16000000000 Hz.
out_altvoltage3_frequency:
A frequency quadrupler generates frequencies from
16000000000 Hz to 32000000000 Hz.
Note: writes to one of the channels will affect the frequency of
all the other channels, since it involves changing the VCO
fundamental output frequency.
What: /sys/bus/iio/devices/iio:deviceX/out_altvoltageY_name
KernelVersion:
Contact: linux-iio@vger.kernel.org
@ -34,11 +9,3 @@ Description:
out_altvoltage2_name: RF16x
out_altvoltage3_name: RF32x
What: /sys/bus/iio/devices/iio:deviceX/out_altvoltageY_powerdown
KernelVersion:
Contact: linux-iio@vger.kernel.org
Description:
This attribute allows the user to power down the PLL and it's
RFOut buffers.
Writing 1 causes the specified channel to power down.
Clearing returns to normal operation.

10
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@ -18,6 +18,8 @@ Description:
respectively which simply helper channels containing the
calculated difference in the value of stage 1 - 2 and 3 - 4.
The values are expressed in 24-bit twos complement.
The LED current for the stage is controlled via
out_currentY_raw.
What: /sys/bus/iio/devices/iio:deviceX/in_intensityY_offset
Date: May 2016
@ -35,11 +37,3 @@ Contact: Andrew F. Davis <afd@ti.com>
Description:
Get and set the resistance and the capacitance settings for the
Transimpedance Amplifier during the associated stage.
What: /sys/bus/iio/devices/iio:deviceX/out_currentY_raw
Date: May 2016
KernelVersion:
Contact: Andrew F. Davis <afd@ti.com>
Description:
Get and set the LED current for the specified LED active during
this stage. Y is the specific stage number.

20
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@ -1,20 +0,0 @@
What: /sys/bus/iio/devices/iio:deviceX/in_accel_x_calibbias
What: /sys/bus/iio/devices/iio:deviceX/in_accel_y_calibbias
What: /sys/bus/iio/devices/iio:deviceX/in_accel_z_calibbias
What: /sys/bus/iio/devices/iio:deviceX/in_anglvel_x_calibbias
What: /sys/bus/iio/devices/iio:deviceX/in_anglvel_y_calibbias
What: /sys/bus/iio/devices/iio:deviceX/in_anglvel_z_calibbias
KernelVersion: 5.8
Contact: linux-iio@vger.kernel.org
Description:
Hardware applied calibration offset (assumed to fix production
inaccuracies). Values represent a real physical offset expressed
in SI units (m/s^2 for accelerometer and rad/s for gyroscope).
What: /sys/bus/iio/devices/iio:deviceX/in_accel_calibbias_available
What: /sys/bus/iio/devices/iio:deviceX/in_anglvel_calibbias_available
KernelVersion: 5.8
Contact: linux-iio@vger.kernel.org
Description:
Range of available values for hardware offset. Values in SI
units (m/s^2 for accelerometer and rad/s for gyroscope).

11
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@ -41,14 +41,6 @@ Description:
Get the current light zone (0..4) as defined by the
in_illuminance0_threshY_{falling,rising} thresholds.
What: /sys/bus/iio/devices/iio:deviceX/out_currentY_raw
Date: May 2012
KernelVersion: 3.5
Contact: Johan Hovold <jhovold@gmail.com>
Description:
Get output current for channel Y (0..255), that is,
out_currentY_currentZ_raw, where Z is the current zone.
What: /sys/bus/iio/devices/iio:deviceX/out_currentY_currentZ_raw
Date: May 2012
KernelVersion: 3.5
@ -59,3 +51,6 @@ Description:
These values correspond to the ALS-mapper target registers for
ALS-mapper Y + 1.
Note that out_currentY_raw provides the current for the
current zone.

8
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View File

@ -39,9 +39,11 @@ KernelVersion: v5.9
Contact: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, nvdimm@lists.linux.dev,
Description:
(RO) Report various performance stats related to papr-scm NVDIMM
device. Each stat is reported on a new line with each line
composed of a stat-identifier followed by it value. Below are
currently known dimm performance stats which are reported:
device. This attribute is only available for NVDIMM devices
that support reporting NVDIMM performance stats. Each stat is
reported on a new line with each line composed of a
stat-identifier followed by it value. Below are currently known
dimm performance stats which are reported:
* "CtlResCt" : Controller Reset Count
* "CtlResTm" : Controller Reset Elapsed Time

4
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@ -139,8 +139,8 @@ Description:
binary file containing the Vital Product Data for the
device. It should follow the VPD format defined in
PCI Specification 2.1 or 2.2, but users should consider
that some devices may have malformatted data. If the
underlying VPD has a writable section then the
that some devices may have incorrectly formatted data.
If the underlying VPD has a writable section then the
corresponding section of this file will be writable.
What: /sys/bus/pci/devices/.../virtfnN

31
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@ -0,0 +1,31 @@
What: /sys/bus/spi/devices/.../spi-nor/jedec_id
Date: April 2021
KernelVersion: 5.14
Contact: linux-mtd@lists.infradead.org
Description: (RO) The JEDEC ID of the SPI NOR flash as reported by the
flash device.
What: /sys/bus/spi/devices/.../spi-nor/manufacturer
Date: April 2021
KernelVersion: 5.14
Contact: linux-mtd@lists.infradead.org
Description: (RO) Manufacturer of the SPI NOR flash.
What: /sys/bus/spi/devices/.../spi-nor/partname
Date: April 2021
KernelVersion: 5.14
Contact: linux-mtd@lists.infradead.org
Description: (RO) Part name of the SPI NOR flash.
What: /sys/bus/spi/devices/.../spi-nor/sfdp
Date: April 2021
KernelVersion: 5.14
Contact: linux-mtd@lists.infradead.org
Description: (RO) This attribute is only present if the SPI NOR flash
device supports the "Read SFDP" command (5Ah).
If present, it contains the complete SFDP (serial flash
discoverable parameters) binary data of the flash.

82
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@ -1,4 +1,4 @@
What: /sys/bus/thunderbolt/devices/.../domainX/boot_acl
What: /sys/bus/thunderbolt/devices/.../domainX/boot_acl
Date: Jun 2018
KernelVersion: 4.17
Contact: thunderbolt-software@lists.01.org
@ -21,7 +21,7 @@ Description: Holds a comma separated list of device unique_ids that
If a device is authorized automatically during boot its
boot attribute is set to 1.
What: /sys/bus/thunderbolt/devices/.../domainX/deauthorization
What: /sys/bus/thunderbolt/devices/.../domainX/deauthorization
Date: May 2021
KernelVersion: 5.12
Contact: Mika Westerberg <mika.westerberg@linux.intel.com>
@ -30,7 +30,7 @@ Description: This attribute tells whether the system supports
de-authorize PCIe tunnel by writing 0 to authorized
attribute under each device.
What: /sys/bus/thunderbolt/devices/.../domainX/iommu_dma_protection
What: /sys/bus/thunderbolt/devices/.../domainX/iommu_dma_protection
Date: Mar 2019
KernelVersion: 4.21
Contact: thunderbolt-software@lists.01.org
@ -39,7 +39,7 @@ Description: This attribute tells whether the system uses IOMMU
it is not (DMA protection is solely based on Thunderbolt
security levels).
What: /sys/bus/thunderbolt/devices/.../domainX/security
What: /sys/bus/thunderbolt/devices/.../domainX/security
Date: Sep 2017
KernelVersion: 4.13
Contact: thunderbolt-software@lists.01.org
@ -61,7 +61,7 @@ Description: This attribute holds current Thunderbolt security level
the BIOS.
======= ==================================================
What: /sys/bus/thunderbolt/devices/.../authorized
What: /sys/bus/thunderbolt/devices/.../authorized
Date: Sep 2017
KernelVersion: 4.13
Contact: thunderbolt-software@lists.01.org
@ -95,14 +95,14 @@ Description: This attribute is used to authorize Thunderbolt devices
EKEYREJECTED if the challenge response did not match.
== ========================================================
What: /sys/bus/thunderbolt/devices/.../boot
What: /sys/bus/thunderbolt/devices/.../boot
Date: Jun 2018
KernelVersion: 4.17
Contact: thunderbolt-software@lists.01.org
Description: This attribute contains 1 if Thunderbolt device was already
authorized on boot and 0 otherwise.
What: /sys/bus/thunderbolt/devices/.../generation
What: /sys/bus/thunderbolt/devices/.../generation
Date: Jan 2020
KernelVersion: 5.5
Contact: Christian Kellner <christian@kellner.me>
@ -110,7 +110,7 @@ Description: This attribute contains the generation of the Thunderbolt
controller associated with the device. It will contain 4
for USB4.
What: /sys/bus/thunderbolt/devices/.../key
What: /sys/bus/thunderbolt/devices/.../key
Date: Sep 2017
KernelVersion: 4.13
Contact: thunderbolt-software@lists.01.org
@ -213,12 +213,15 @@ Description: When new NVM image is written to the non-active NVM
restarted with the new NVM firmware. If the image
verification fails an error code is returned instead.
This file will accept writing values "1" or "2"
This file will accept writing values "1", "2" or "3".
- Writing "1" will flush the image to the storage
area and authenticate the image in one action.
- Writing "2" will run some basic validation on the image
and flush it to the storage area.
- Writing "3" will authenticate the image that is
currently written in the storage area. This is only
supported with USB4 devices and retimers.
When read holds status of the last authentication
operation if an error occurred during the process. This
@ -226,6 +229,20 @@ Description: When new NVM image is written to the non-active NVM
based mailbox before the device is power cycled. Writing
0 here clears the status.
What: /sys/bus/thunderbolt/devices/.../nvm_authenticate_on_disconnect
Date: Oct 2020
KernelVersion: v5.9
Contact: Mario Limonciello <mario.limonciello@dell.com>
Description: For supported devices, automatically authenticate the new Thunderbolt
image when the device is disconnected from the host system.
This file will accept writing values "1" or "2"
- Writing "1" will flush the image to the storage
area and prepare the device for authentication on disconnect.
- Writing "2" will run some basic validation on the image
and flush it to the storage area.
What: /sys/bus/thunderbolt/devices/<xdomain>.<service>/key
Date: Jan 2018
KernelVersion: 4.15
@ -276,6 +293,39 @@ Contact: thunderbolt-software@lists.01.org
Description: This contains XDomain service specific settings as
bitmask. Format: %x
What: /sys/bus/thunderbolt/devices/usb4_portX/link
Date: Sep 2021
KernelVersion: v5.14
Contact: Mika Westerberg <mika.westerberg@linux.intel.com>
Description: Returns the current link mode. Possible values are
"usb4", "tbt" and "none".
What: /sys/bus/thunderbolt/devices/usb4_portX/offline
Date: Sep 2021
KernelVersion: v5.14
Contact: Rajmohan Mani <rajmohan.mani@intel.com>
Description: Writing 1 to this attribute puts the USB4 port into
offline mode. Only allowed when there is nothing
connected to the port (link attribute returns "none").
Once the port is in offline mode it does not receive any
hotplug events. This is used to update NVM firmware of
on-board retimers. Writing 0 puts the port back to
online mode.
This attribute is only visible if the platform supports
powering on retimers when there is no cable connected.
What: /sys/bus/thunderbolt/devices/usb4_portX/rescan
Date: Sep 2021
KernelVersion: v5.14
Contact: Rajmohan Mani <rajmohan.mani@intel.com>
Description: When the USB4 port is in offline mode writing 1 to this
attribute forces rescan of the sideband for on-board
retimers. Each retimer appear under the USB4 port as if
the USB4 link was up. These retimers act in the same way
as if the cable was connected so upgrading their NVM
firmware can be done the usual way.
What: /sys/bus/thunderbolt/devices/<device>:<port>.<index>/device
Date: Oct 2020
KernelVersion: v5.9
@ -308,17 +358,3 @@ Date: Oct 2020
KernelVersion: v5.9
Contact: Mika Westerberg <mika.westerberg@linux.intel.com>
Description: Retimer vendor identifier read from the hardware.
What: /sys/bus/thunderbolt/devices/.../nvm_authenticate_on_disconnect
Date: Oct 2020
KernelVersion: v5.9
Contact: Mario Limonciello <mario.limonciello@dell.com>
Description: For supported devices, automatically authenticate the new Thunderbolt
image when the device is disconnected from the host system.
This file will accept writing values "1" or "2"
- Writing "1" will flush the image to the storage
area and prepare the device for authentication on disconnect.
- Writing "2" will run some basic validation on the image
and flush it to the storage area.

11
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@ -154,17 +154,6 @@ Description:
files hold a string value (enable or disable) indicating whether
or not USB3 hardware LPM U1 or U2 is enabled for the device.
What: /sys/bus/usb/devices/.../removable
Date: February 2012
Contact: Matthew Garrett <mjg@redhat.com>
Description:
Some information about whether a given USB device is
physically fixed to the platform can be inferred from a
combination of hub descriptor bits and platform-specific data
such as ACPI. This file will read either "removable" or
"fixed" if the information is available, and "unknown"
otherwise.
What: /sys/bus/usb/devices/.../ltm_capable
Date: July 2012
Contact: Sarah Sharp <sarah.a.sharp@linux.intel.com>

100
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@ -84,3 +84,103 @@ Description:
It can be enabled by writing the value stored in
/sys/class/backlight/<backlight>/max_brightness to
/sys/class/backlight/<backlight>/brightness.
What: /sys/class/backlight/<backlight>/<ambient light zone>_max
Date: Sep, 2009
KernelVersion: v2.6.32
Contact: device-drivers-devel@blackfin.uclinux.org
Description:
Control the maximum brightness for <ambient light zone>
on this <backlight>. Values are between 0 and 127. This file
will also show the brightness level stored for this
<ambient light zone>.
The <ambient light zone> is device-driver specific:
For ADP5520 and ADP5501, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
daylight /sys/class/backlight/<backlight>/daylight_max
office /sys/class/backlight/<backlight>/office_max
dark /sys/class/backlight/<backlight>/dark_max
=========== ================================================
For ADP8860, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
l1_daylight /sys/class/backlight/<backlight>/l1_daylight_max
l2_office /sys/class/backlight/<backlight>/l2_office_max
l3_dark /sys/class/backlight/<backlight>/l3_dark_max
=========== ================================================
For ADP8870, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
l1_daylight /sys/class/backlight/<backlight>/l1_daylight_max
l2_bright /sys/class/backlight/<backlight>/l2_bright_max
l3_office /sys/class/backlight/<backlight>/l3_office_max
l4_indoor /sys/class/backlight/<backlight>/l4_indoor_max
l5_dark /sys/class/backlight/<backlight>/l5_dark_max
=========== ================================================
See also: /sys/class/backlight/<backlight>/ambient_light_zone.
What: /sys/class/backlight/<backlight>/<ambient light zone>_dim
Date: Sep, 2009
KernelVersion: v2.6.32
Contact: device-drivers-devel@blackfin.uclinux.org
Description:
Control the dim brightness for <ambient light zone>
on this <backlight>. Values are between 0 and 127, typically
set to 0. Full off when the backlight is disabled.
This file will also show the dim brightness level stored for
this <ambient light zone>.
The <ambient light zone> is device-driver specific:
For ADP5520 and ADP5501, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
daylight /sys/class/backlight/<backlight>/daylight_dim
office /sys/class/backlight/<backlight>/office_dim
dark /sys/class/backlight/<backlight>/dark_dim
=========== ================================================
For ADP8860, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
l1_daylight /sys/class/backlight/<backlight>/l1_daylight_dim
l2_office /sys/class/backlight/<backlight>/l2_office_dim
l3_dark /sys/class/backlight/<backlight>/l3_dark_dim
=========== ================================================
For ADP8870, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
l1_daylight /sys/class/backlight/<backlight>/l1_daylight_dim
l2_bright /sys/class/backlight/<backlight>/l2_bright_dim
l3_office /sys/class/backlight/<backlight>/l3_office_dim
l4_indoor /sys/class/backlight/<backlight>/l4_indoor_dim
l5_dark /sys/class/backlight/<backlight>/l5_dark_dim
=========== ================================================
See also: /sys/class/backlight/<backlight>/ambient_light_zone.

31
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@ -1,31 +0,0 @@
sysfs interface for analog devices adp5520(01) backlight driver
---------------------------------------------------------------
The backlight brightness control operates at three different levels for the
adp5520 and adp5501 devices: daylight (level 1), office (level 2) and dark
(level 3). By default the brightness operates at the daylight brightness level.
What: /sys/class/backlight/<backlight>/daylight_max
What: /sys/class/backlight/<backlight>/office_max
What: /sys/class/backlight/<backlight>/dark_max
Date: Sep, 2009
KernelVersion: v2.6.32
Contact: Michael Hennerich <michael.hennerich@analog.com>
Description:
(RW) Maximum current setting for the backlight when brightness
is at one of the three levels (daylight, office or dark). This
is an input code between 0 and 127, which is transformed to a
value between 0 mA and 30 mA using linear or non-linear
algorithms.
What: /sys/class/backlight/<backlight>/daylight_dim
What: /sys/class/backlight/<backlight>/office_dim
What: /sys/class/backlight/<backlight>/dark_dim
Date: Sep, 2009
KernelVersion: v2.6.32
Contact: Michael Hennerich <michael.hennerich@analog.com>
Description:
(RW) Dim current setting for the backlight when brightness is at
one of the three levels (daylight, office or dark). This is an
input code between 0 and 127, which is transformed to a value
between 0 mA and 30 mA using linear or non-linear algorithms.

37
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@ -1,37 +0,0 @@
sysfs interface for analog devices adp8860 backlight driver
-----------------------------------------------------------
The backlight brightness control operates at three different levels for the
adp8860, adp8861 and adp8863 devices: daylight (level 1), office (level 2) and
dark (level 3). By default the brightness operates at the daylight brightness
level.
See also /sys/class/backlight/<backlight>/ambient_light_level and
/sys/class/backlight/<backlight>/ambient_light_zone.
What: /sys/class/backlight/<backlight>/l1_daylight_max
What: /sys/class/backlight/<backlight>/l2_office_max
What: /sys/class/backlight/<backlight>/l3_dark_max
Date: Apr, 2010
KernelVersion: v2.6.35
Contact: Michael Hennerich <michael.hennerich@analog.com>
Description:
(RW) Maximum current setting for the backlight when brightness
is at one of the three levels (daylight, office or dark). This
is an input code between 0 and 127, which is transformed to a
value between 0 mA and 30 mA using linear or non-linear
algorithms.
What: /sys/class/backlight/<backlight>/l1_daylight_dim
What: /sys/class/backlight/<backlight>/l2_office_dim
What: /sys/class/backlight/<backlight>/l3_dark_dim
Date: Apr, 2010
KernelVersion: v2.6.35
Contact: Michael Hennerich <michael.hennerich@analog.com>
Description:
(RW) Dim current setting for the backlight when brightness is at
one of the three levels (daylight, office or dark). This is an
input code between 0 and 127, which is transformed to a value
between 0 mA and 30 mA using linear or non-linear algorithms.

32
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@ -1,32 +0,0 @@
See also /sys/class/backlight/<backlight>/ambient_light_level and
/sys/class/backlight/<backlight>/ambient_light_zone.
What: /sys/class/backlight/<backlight>/<ambient light zone>_max
What: /sys/class/backlight/<backlight>/l1_daylight_max
What: /sys/class/backlight/<backlight>/l2_bright_max
What: /sys/class/backlight/<backlight>/l3_office_max
What: /sys/class/backlight/<backlight>/l4_indoor_max
What: /sys/class/backlight/<backlight>/l5_dark_max
Date: May 2011
KernelVersion: 3.0
Contact: device-drivers-devel@blackfin.uclinux.org
Description:
Control the maximum brightness for <ambient light zone>
on this <backlight>. Values are between 0 and 127. This file
will also show the brightness level stored for this
<ambient light zone>.
What: /sys/class/backlight/<backlight>/<ambient light zone>_dim
What: /sys/class/backlight/<backlight>/l2_bright_dim
What: /sys/class/backlight/<backlight>/l3_office_dim
What: /sys/class/backlight/<backlight>/l4_indoor_dim
What: /sys/class/backlight/<backlight>/l5_dark_dim
Date: May 2011
KernelVersion: 3.0
Contact: device-drivers-devel@blackfin.uclinux.org
Description:
Control the dim brightness for <ambient light zone>
on this <backlight>. Values are between 0 and 127, typically
set to 0. Full off when the backlight is disabled.
This file will also show the dim brightness level stored for
this <ambient light zone>.

18
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@ -197,8 +197,24 @@ Description:
Drivers may emit a CHANGE uevent when a password is set or unset
userspace may check it again.
On Dell systems, if Admin password is set, then all BIOS attributes
On Dell and Lenovo systems, if Admin password is set, then all BIOS attributes
require password validation.
On Lenovo systems if you change the Admin password the new password is not active until
the next boot.
Lenovo specific class extensions
------------------------------
On Lenovo systems the following additional settings are available:
lenovo_encoding:
The encoding method that is used. This can be either "ascii"
or "scancode". Default is set to "ascii"
lenovo_kbdlang:
The keyboard language method that is used. This is generally a
two char code (e.g. "us", "fr", "gr") and may vary per platform.
Default is set to "us"
What: /sys/class/firmware-attributes/*/attributes/pending_reboot
Date: February 2021

9
Documentation/ABI/testing/sysfs-class-led-driver-el15203000
View File

@ -1,9 +0,0 @@
What: /sys/class/leds/<led>/repeat
Date: September 2019
KernelVersion: 5.5
Description:
EL15203000 supports only indefinitely patterns,
so this file should always store -1.
For more info, please see:
Documentation/ABI/testing/sysfs-class-led-trigger-pattern

3
Documentation/ABI/testing/sysfs-class-led-trigger-pattern
View File

@ -35,3 +35,6 @@ Description:
This file will always return the originally written repeat
number.
It should be noticed that some leds, like EL15203000 may
only support indefinitely patterns, so they always store -1.

19
Documentation/ABI/testing/sysfs-class-spi-eeprom Normal file
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@ -0,0 +1,19 @@
What: /sys/class/spi_master/spi<bus>/spi<bus>.<dev>/fram
Date: June 2021
KernelVersion: 5.14
Contact: Jiri Prchal <jiri.prchal@aksignal.cz>
Description:
Contains the FRAM binary data. Same as EEPROM, just another file
name to indicate that it employs ferroelectric process.
It performs write operations at bus speed - no write delays.
What: /sys/class/spi_master/spi<bus>/spi<bus>.<dev>/sernum
Date: May 2021
KernelVersion: 5.14
Contact: Jiri Prchal <jiri.prchal@aksignal.cz>
Description:
Contains the serial number of the Cypress FRAM (FM25VN) if it is
present. It will be displayed as a 8 byte hex string, as read
from the device.
This is a read-only attribute.

78
Documentation/ABI/testing/sysfs-devices-platform-soc-ipa Normal file
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@ -0,0 +1,78 @@
What: /sys/devices/platform/soc@X/XXXXXXX.ipa/
Date: June 2021
KernelVersion: v5.14
Contact: Alex Elder <elder@kernel.org>
Description:
The /sys/devices/platform/soc@X/XXXXXXX.ipa/ directory
contains read-only attributes exposing information about
an IPA device. The X values could vary, but are typically
"soc@0/1e40000.ipa".
What: .../XXXXXXX.ipa/version
Date: June 2021
KernelVersion: v5.14
Contact: Alex Elder <elder@kernel.org>
Description:
The .../XXXXXXX.ipa/version file contains the IPA hardware
version, as a period-separated set of two or three integers
(e.g., "3.5.1" or "4.2").
What: .../XXXXXXX.ipa/feature/
Date: June 2021
KernelVersion: v5.14
Contact: Alex Elder <elder@kernel.org>
Description:
The .../XXXXXXX.ipa/feature/ directory contains a set of
attributes describing features implemented by the IPA
hardware.
What: .../XXXXXXX.ipa/feature/rx_offload
Date: June 2021
KernelVersion: v5.14
Contact: Alex Elder <elder@kernel.org>
Description:
The .../XXXXXXX.ipa/feature/rx_offload file contains a
string indicating the type of receive checksum offload
that is supported by the hardware. The possible values
are "MAPv4" or "MAPv5".
What: .../XXXXXXX.ipa/feature/tx_offload
Date: June 2021
KernelVersion: v5.14
Contact: Alex Elder <elder@kernel.org>
Description:
The .../XXXXXXX.ipa/feature/tx_offload file contains a
string indicating the type of transmit checksum offload
that is supported by the hardware. The possible values
are "MAPv4" or "MAPv5".
What: .../XXXXXXX.ipa/modem/
Date: June 2021
KernelVersion: v5.14
Contact: Alex Elder <elder@kernel.org>
Description:
The .../XXXXXXX.ipa/modem/ directory contains a set of
attributes describing properties of the modem execution
environment reachable by the IPA hardware.
What: .../XXXXXXX.ipa/modem/rx_endpoint_id
Date: June 2021
KernelVersion: v5.14
Contact: Alex Elder <elder@kernel.org>
Description:
The .../XXXXXXX.ipa/feature/rx_endpoint_id file contains
the AP endpoint ID that receives packets originating from
the modem execution environment. The "rx" is from the
perspective of the AP; this endpoint is considered an "IPA
producer". An endpoint ID is a small unsigned integer.
What: .../XXXXXXX.ipa/modem/tx_endpoint_id
Date: June 2021
KernelVersion: v5.14
Contact: Alex Elder <elder@kernel.org>
Description:
The .../XXXXXXX.ipa/feature/tx_endpoint_id file contains
the AP endpoint ID used to transmit packets destined for
the modem execution environment. The "tx" is from the
perspective of the AP; this endpoint is considered an "IPA
consumer". An endpoint ID is a small unsigned integer.

18
Documentation/ABI/testing/sysfs-devices-removable Normal file
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@ -0,0 +1,18 @@
What: /sys/devices/.../removable
Date: May 2021
Contact: Rajat Jain <rajatxjain@gmail.com>
Description:
Information about whether a given device can be removed from the
platform by the user. This is determined by its subsystem in a
bus / platform-specific way. This attribute is only present for
devices that can support determining such information:
"removable": device can be removed from the platform by the user
"fixed": device is fixed to the platform / cannot be removed
by the user.
"unknown": The information is unavailable / cannot be deduced.
Currently this is only supported by USB (which infers the
information from a combination of hub descriptor bits and
platform-specific data such as ACPI) and PCI (which gets this
from ACPI / device tree).

10
Documentation/ABI/testing/sysfs-devices-system-cpu
View File

@ -50,7 +50,7 @@ Description: Dynamic addition and removal of CPU's. This is not hotplug
architecture specific.
release: writes to this file dynamically remove a CPU from
the system. Information writtento the file to remove CPU's
the system. Information written to the file to remove CPU's
is architecture specific.
What: /sys/devices/system/cpu/cpu#/node
@ -97,7 +97,7 @@ Description: CPU topology files that describe a logical CPU's relationship
corresponds to a physical socket number, but the actual value
is architecture and platform dependent.
thread_siblings: internel kernel map of cpu#'s hardware
thread_siblings: internal kernel map of cpu#'s hardware
threads within the same core as cpu#
thread_siblings_list: human-readable list of cpu#'s hardware
@ -280,7 +280,7 @@ Description: Disable L3 cache indices
on a processor with this functionality will return the currently
disabled index for that node. There is one L3 structure per
node, or per internal node on MCM machines. Writing a valid
index to one of these files will cause the specificed cache
index to one of these files will cause the specified cache
index to be disabled.
All AMD processors with L3 caches provide this functionality.
@ -295,7 +295,7 @@ Description: Processor frequency boosting control
This switch controls the boost setting for the whole system.
Boosting allows the CPU and the firmware to run at a frequency
beyound it's nominal limit.
beyond it's nominal limit.
More details can be found in
Documentation/admin-guide/pm/cpufreq.rst
@ -532,7 +532,7 @@ What: /sys/devices/system/cpu/smt
/sys/devices/system/cpu/smt/control
Date: June 2018
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description: Control Symetric Multi Threading (SMT)
Description: Control Symmetric Multi Threading (SMT)
active: Tells whether SMT is active (enabled and siblings online)

130
Documentation/ABI/testing/sysfs-driver-ufs
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@ -168,7 +168,7 @@ Description: This file shows the manufacturing date in BCD format.
What: /sys/bus/platform/drivers/ufshcd/*/device_descriptor/manufacturer_id
Date: February 2018
Contact: Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
Description: This file shows the manufacturee ID. This is one of the
Description: This file shows the manufacturer ID. This is one of the
UFS device descriptor parameters. The full information about
the descriptor could be found at UFS specifications 2.1.
@ -521,7 +521,7 @@ Description: This file shows maximum VCC, VCCQ and VCCQ2 value for
What: /sys/bus/platform/drivers/ufshcd/*/string_descriptors/manufacturer_name
Date: February 2018
Contact: Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
Description: This file contains a device manufactureer name string.
Description: This file contains a device manufacturer name string.
The full information about the descriptor could be found at
UFS specifications 2.1.
@ -995,6 +995,132 @@ Description: This entry shows the target state of an UFS UIC link
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/monitor_enable
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows the status of performance monitor enablement
and it can be used to start/stop the monitor. When the monitor
is stopped, the performance data collected is also cleared.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/monitor_chunk_size
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file tells the monitor to focus on requests transferring
data of specific chunk size (in Bytes). 0 means any chunk size.
It can only be changed when monitor is disabled.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/read_total_sectors
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows how many sectors (in 512 Bytes) have been
sent from device to host after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/read_total_busy
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows how long (in micro seconds) has been spent
sending data from device to host after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/read_nr_requests
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows how many read requests have been sent after
monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/read_req_latency_max
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows the maximum latency (in micro seconds) of
read requests after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/read_req_latency_min
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows the minimum latency (in micro seconds) of
read requests after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/read_req_latency_avg
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows the average latency (in micro seconds) of
read requests after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/read_req_latency_sum
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows the total latency (in micro seconds) of
read requests sent after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/write_total_sectors
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows how many sectors (in 512 Bytes) have been sent
from host to device after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/write_total_busy
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows how long (in micro seconds) has been spent
sending data from host to device after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/write_nr_requests
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows how many write requests have been sent after
monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/write_req_latency_max
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows the maximum latency (in micro seconds) of write
requests after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/write_req_latency_min
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows the minimum latency (in micro seconds) of write
requests after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/write_req_latency_avg
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows the average latency (in micro seconds) of write
requests after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/monitor/write_req_latency_sum
Date: January 2021
Contact: Can Guo <cang@codeaurora.org>
Description: This file shows the total latency (in micro seconds) of write
requests after monitor gets started.
The file is read only.
What: /sys/bus/platform/drivers/ufshcd/*/device_descriptor/wb_presv_us_en
Date: June 2020
Contact: Asutosh Das <asutoshd@codeaurora.org>

4
Documentation/ABI/testing/sysfs-firmware-memmap
View File

@ -56,6 +56,10 @@ Description:
- System RAM
- ACPI Tables
- ACPI Non-volatile Storage
- Unusable memory
- Persistent Memory (legacy)
- Persistent Memory
- Soft Reserved
- reserved
Following shell snippet can be used to display that memory

59
Documentation/ABI/testing/sysfs-fs-f2fs
View File

@ -203,7 +203,34 @@ Description: Shows total written kbytes issued to disk.
What: /sys/fs/f2fs/<disk>/features
Date: July 2017
Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
Description: Shows all enabled features in current device.
Description: <deprecated: should use /sys/fs/f2fs/<disk>/feature_list/
Shows all enabled features in current device.
Supported features:
encryption, blkzoned, extra_attr, projquota, inode_checksum,
flexible_inline_xattr, quota_ino, inode_crtime, lost_found,
verity, sb_checksum, casefold, readonly, compression, pin_file.
What: /sys/fs/f2fs/<disk>/feature_list/
Date: June 2021
Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
Description: Expand /sys/fs/f2fs/<disk>/features to meet sysfs rule.
Supported on-disk features:
encryption, block_zoned (aka blkzoned), extra_attr,
project_quota (aka projquota), inode_checksum,
flexible_inline_xattr, quota_ino, inode_crtime, lost_found,
verity, sb_checksum, casefold, readonly, compression.
Note that, pin_file is moved into /sys/fs/f2fs/features/.
What: /sys/fs/f2fs/features/
Date: July 2017
Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
Description: Shows all enabled kernel features.
Supported features:
encryption, block_zoned, extra_attr, project_quota,
inode_checksum, flexible_inline_xattr, quota_ino,
inode_crtime, lost_found, verity, sb_checksum,
casefold, readonly, compression, test_dummy_encryption_v2,
atomic_write, pin_file, encrypted_casefold.
What: /sys/fs/f2fs/<disk>/inject_rate
Date: May 2016
@ -238,7 +265,7 @@ Description: Shows current reserved blocks in system, it may be temporarily
What: /sys/fs/f2fs/<disk>/gc_urgent
Date: August 2017
Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
Description: Do background GC agressively when set. When gc_urgent = 1,
Description: Do background GC aggressively when set. When gc_urgent = 1,
background thread starts to do GC by given gc_urgent_sleep_time
interval. When gc_urgent = 2, F2FS will lower the bar of
checking idle in order to process outstanding discard commands
@ -438,3 +465,31 @@ Description: Show the count of inode newly enabled for compression since mount.
Note that when the compression is disabled for the files, this count
doesn't decrease. If you write "0" here, you can initialize
compr_new_inode to "0".
What: /sys/fs/f2fs/<disk>/atgc_candidate_ratio
Date: May 2021
Contact: "Chao Yu" <yuchao0@huawei.com>
Description: When ATGC is on, it controls candidate ratio in order to limit total
number of potential victim in all candidates, the value should be in
range of [0, 100], by default it was initialized as 20(%).
What: /sys/fs/f2fs/<disk>/atgc_candidate_count
Date: May 2021
Contact: "Chao Yu" <yuchao0@huawei.com>
Description: When ATGC is on, it controls candidate count in order to limit total
number of potential victim in all candidates, by default it was
initialized as 10 (sections).
What: /sys/fs/f2fs/<disk>/atgc_age_weight
Date: May 2021
Contact: "Chao Yu" <yuchao0@huawei.com>
Description: When ATGC is on, it controls age weight to balance weight proportion
in between aging and valid blocks, the value should be in range of
[0, 100], by default it was initialized as 60(%).
What: /sys/fs/f2fs/<disk>/atgc_age_threshold
Date: May 2021
Contact: "Chao Yu" <yuchao0@huawei.com>
Description: When ATGC is on, it controls age threshold to bypass GCing young
candidates whose age is not beyond the threshold, by default it was
initialized as 604800 seconds (equals to 7 days).

12
Documentation/ABI/testing/sysfs-kernel-iommu_groups
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@ -25,14 +25,10 @@ Description: /sys/kernel/iommu_groups/reserved_regions list IOVA
the base IOVA, the second is the end IOVA and the third
field describes the type of the region.
What: /sys/kernel/iommu_groups/reserved_regions
Date: June 2019
KernelVersion: v5.3
Contact: Eric Auger <eric.auger@redhat.com>
Description: In case an RMRR is used only by graphics or USB devices
it is now exposed as "direct-relaxable" instead of "direct".
In device assignment use case, for instance, those RMRR
are considered to be relaxable and safe.
Since kernel 5.3, in case an RMRR is used only by graphics or
USB devices it is now exposed as "direct-relaxable" instead
of "direct". In device assignment use case, for instance,
those RMRR are considered to be relaxable and safe.
What: /sys/kernel/iommu_groups/<grp_id>/type
Date: November 2020

55
Documentation/ABI/testing/sysfs-platform-dell-privacy-wmi Normal file
View File

@ -0,0 +1,55 @@
What: /sys/bus/wmi/devices/6932965F-1671-4CEB-B988-D3AB0A901919/dell_privacy_supported_type
Date: Apr 2021
KernelVersion: 5.13
Contact: "perry.yuan@dell.com>"
Description:
Display which dell hardware level privacy devices are supported
“Dell Privacy” is a set of HW, FW, and SW features to enhance
Dell’s commitment to platform privacy for MIC, Camera, and
ePrivacy screens.
The supported hardware privacy devices are:
Attributes:
Microphone Mute:
Identifies the local microphone can be muted by hardware, no applications
is available to capture system mic sound
Camera Shutter:
Identifies camera shutter controlled by hardware, which is a micromechanical
shutter assembly that is built onto the camera module to block capturing images
from outside the laptop
supported:
The privacy device is supported by this system
unsupported:
The privacy device is not supported on this system
For example to check which privacy devices are supported:
# cat /sys/bus/wmi/drivers/dell-privacy/6932965F-1671-4CEB-B988-D3AB0A901919/dell_privacy_supported_type
[Microphone Mute] [supported]
[Camera Shutter] [supported]
[ePrivacy Screen] [unsupported]
What: /sys/bus/wmi/devices/6932965F-1671-4CEB-B988-D3AB0A901919/dell_privacy_current_state
Date: Apr 2021
KernelVersion: 5.13
Contact: "perry.yuan@dell.com>"
Description:
Allow user space to check current dell privacy device state.
Describes the Device State class exposed by BIOS which can be
consumed by various applications interested in knowing the Privacy
feature capabilities
Attributes:
muted:
Identifies the privacy device is turned off and cannot send stream to OS applications
unmuted:
Identifies the privacy device is turned on ,audio or camera driver can get
stream from mic and camera module to OS applications
For example to check all supported current privacy device states:
# cat /sys/bus/wmi/drivers/dell-privacy/6932965F-1671-4CEB-B988-D3AB0A901919/dell_privacy_current_state
[Microphone] [unmuted]
[Camera Shutter] [unmuted]

20
Documentation/ABI/testing/sysfs-ptp
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@ -33,6 +33,13 @@ Description:
frequency adjustment value (a positive integer) in
parts per billion.
What: /sys/class/ptp/ptpN/max_vclocks
Date: May 2021
Contact: Yangbo Lu <yangbo.lu@nxp.com>
Description:
This file contains the maximum number of ptp vclocks.
Write integer to re-configure it.
What: /sys/class/ptp/ptpN/n_alarms
Date: September 2010
Contact: Richard Cochran <richardcochran@gmail.com>
@ -61,6 +68,19 @@ Description:
This file contains the number of programmable pins
offered by the PTP hardware clock.
What: /sys/class/ptp/ptpN/n_vclocks
Date: May 2021
Contact: Yangbo Lu <yangbo.lu@nxp.com>
Description:
This file contains the number of virtual PTP clocks in
use. By default, the value is 0 meaning that only the
physical clock is in use. Setting the value creates
the corresponding number of virtual clocks and causes
the physical clock to become free running. Setting the
value back to 0 deletes the virtual clocks and
switches the physical clock back to normal, adjustable
operation.
What: /sys/class/ptp/ptpN/pins
Date: March 2014
Contact: Richard Cochran <richardcochran@gmail.com>

2
Documentation/Makefile
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@ -76,7 +76,7 @@ quiet_cmd_sphinx = SPHINX $@ --> file://$(abspath $(BUILDDIR)/$3/$4)
PYTHONDONTWRITEBYTECODE=1 \
BUILDDIR=$(abspath $(BUILDDIR)) SPHINX_CONF=$(abspath $(srctree)/$(src)/$5/$(SPHINX_CONF)) \
$(PYTHON3) $(srctree)/scripts/jobserver-exec \
$(SHELL) $(srctree)/Documentation/sphinx/parallel-wrapper.sh \
$(CONFIG_SHELL) $(srctree)/Documentation/sphinx/parallel-wrapper.sh \
$(SPHINXBUILD) \
-b $2 \
-c $(abspath $(srctree)/$(src)) \

18
Documentation/PCI/acpi-info.rst
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@ -22,9 +22,9 @@ or if the device has INTx interrupts connected by platform interrupt
controllers and a _PRT is needed to describe those connections.
ACPI resource description is done via _CRS objects of devices in the ACPI
namespace [2].   The _CRS is like a generalized PCI BAR: the OS can read
namespace [2]. The _CRS is like a generalized PCI BAR: the OS can read
_CRS and figure out what resource is being consumed even if it doesn't have
a driver for the device [3].  That's important because it means an old OS
a driver for the device [3]. That's important because it means an old OS
can work correctly even on a system with new devices unknown to the OS.
The new devices might not do anything, but the OS can at least make sure no
resources conflict with them.
@ -41,15 +41,15 @@ ACPI, that device will have a specific _HID/_CID that tells the OS what
driver to bind to it, and the _CRS tells the OS and the driver where the
device's registers are.
PCI host bridges are PNP0A03 or PNP0A08 devices.  Their _CRS should
describe all the address space they consume.  This includes all the windows
PCI host bridges are PNP0A03 or PNP0A08 devices. Their _CRS should
describe all the address space they consume. This includes all the windows
they forward down to the PCI bus, as well as registers of the host bridge
itself that are not forwarded to PCI.  The host bridge registers include
itself that are not forwarded to PCI. The host bridge registers include
things like secondary/subordinate bus registers that determine the bus
range below the bridge, window registers that describe the apertures, etc.
These are all device-specific, non-architected things, so the only way a
PNP0A03/PNP0A08 driver can manage them is via _PRS/_CRS/_SRS, which contain
the device-specific details.  The host bridge registers also include ECAM
the device-specific details. The host bridge registers also include ECAM
space, since it is consumed by the host bridge.
ACPI defines a Consumer/Producer bit to distinguish the bridge registers
@ -66,7 +66,7 @@ the PNP0A03/PNP0A08 device itself. The workaround was to describe the
bridge registers (including ECAM space) in PNP0C02 catch-all devices [6].
With the exception of ECAM, the bridge register space is device-specific
anyway, so the generic PNP0A03/PNP0A08 driver (pci_root.c) has no need to
know about it.  
know about it.
New architectures should be able to use "Consumer" Extended Address Space
descriptors in the PNP0A03 device for bridge registers, including ECAM,
@ -75,9 +75,9 @@ ia64 kernels assume all address space descriptors, including "Consumer"
Extended Address Space ones, are windows, so it would not be safe to
describe bridge registers this way on those architectures.
PNP0C02 "motherboard" devices are basically a catch-all.  There's no
PNP0C02 "motherboard" devices are basically a catch-all. There's no
programming model for them other than "don't use these resources for
anything else."  So a PNP0C02 _CRS should claim any address space that is
anything else." So a PNP0C02 _CRS should claim any address space that is
(1) not claimed by _CRS under any other device object in the ACPI namespace
and (2) should not be assigned by the OS to something else.

2
Documentation/PCI/endpoint/pci-endpoint-cfs.rst
View File

@ -125,4 +125,4 @@ all the EPF devices are created and linked with the EPC device.
| interrupt_pin
| function
[1] :doc:`pci-endpoint`
[1] Documentation/PCI/endpoint/pci-endpoint.rst

2
Documentation/PCI/pci-error-recovery.rst
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@ -295,7 +295,7 @@ and let the driver restart normal I/O processing.
A driver can still return a critical failure for this function if
it can't get the device operational after reset. If the platform
previously tried a soft reset, it might now try a hard reset (power
cycle) and then call slot_reset() again. It the device still can't
cycle) and then call slot_reset() again. If the device still can't
be recovered, there is nothing more that can be done; the platform
will typically report a "permanent failure" in such a case. The
device will be considered "dead" in this case.

6
Documentation/PCI/pci.rst
View File

@ -265,7 +265,7 @@ Set the DMA mask size
---------------------
.. note::
If anything below doesn't make sense, please refer to
:doc:`/core-api/dma-api`. This section is just a reminder that
Documentation/core-api/dma-api.rst. This section is just a reminder that
drivers need to indicate DMA capabilities of the device and is not
an authoritative source for DMA interfaces.
@ -291,7 +291,7 @@ Many 64-bit "PCI" devices (before PCI-X) and some PCI-X devices are
Setup shared control data
-------------------------
Once the DMA masks are set, the driver can allocate "consistent" (a.k.a. shared)
memory. See :doc:`/core-api/dma-api` for a full description of
memory. See Documentation/core-api/dma-api.rst for a full description of
the DMA APIs. This section is just a reminder that it needs to be done
before enabling DMA on the device.
@ -421,7 +421,7 @@ owners if there is one.
Then clean up "consistent" buffers which contain the control data.
See :doc:`/core-api/dma-api` for details on unmapping interfaces.
See Documentation/core-api/dma-api.rst for details on unmapping interfaces.
Unregister from other subsystems

6
Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst
View File

@ -21,7 +21,7 @@ Any code that happens after the end of a given RCU grace period is guaranteed
to see the effects of all accesses prior to the beginning of that grace
period that are within RCU read-side critical sections.
Similarly, any code that happens before the beginning of a given RCU grace
period is guaranteed to see the effects of all accesses following the end
period is guaranteed to not see the effects of all accesses following the end
of that grace period that are within RCU read-side critical sections.
Note well that RCU-sched read-side critical sections include any region
@ -339,14 +339,14 @@ The diagram below shows the path of ordering if the leftmost
leftmost ``rcu_node`` structure offlines its last CPU and if the next
``rcu_node`` structure has no online CPUs).
.. kernel-figure:: TreeRCU-gp-init-1.svg
.. kernel-figure:: TreeRCU-gp-init-2.svg
The final ``rcu_gp_init()`` pass through the ``rcu_node`` tree traverses
breadth-first, setting each ``rcu_node`` structure's ``->gp_seq`` field
to the newly advanced value from the ``rcu_state`` structure, as shown
in the following diagram.
.. kernel-figure:: TreeRCU-gp-init-1.svg
.. kernel-figure:: TreeRCU-gp-init-3.svg
This change will also cause each CPU's next call to
``__note_gp_changes()`` to notice that a new grace period has started,

53
Documentation/RCU/checklist.rst
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@ -211,27 +211,40 @@ over a rather long period of time, but improvements are always welcome!
of the system, especially to real-time workloads running on
the rest of the system.
7. As of v4.20, a given kernel implements only one RCU flavor,
which is RCU-sched for PREEMPTION=n and RCU-preempt for PREEMPTION=y.
If the updater uses call_rcu() or synchronize_rcu(),
then the corresponding readers may use rcu_read_lock() and
rcu_read_unlock(), rcu_read_lock_bh() and rcu_read_unlock_bh(),
or any pair of primitives that disables and re-enables preemption,
for example, rcu_read_lock_sched() and rcu_read_unlock_sched().
If the updater uses synchronize_srcu() or call_srcu(),
then the corresponding readers must use srcu_read_lock() and
srcu_read_unlock(), and with the same srcu_struct. The rules for
the expedited primitives are the same as for their non-expedited
counterparts. Mixing things up will result in confusion and
broken kernels, and has even resulted in an exploitable security
issue.
7. As of v4.20, a given kernel implements only one RCU flavor, which
is RCU-sched for PREEMPTION=n and RCU-preempt for PREEMPTION=y.
If the updater uses call_rcu() or synchronize_rcu(), then
the corresponding readers may use: (1) rcu_read_lock() and
rcu_read_unlock(), (2) any pair of primitives that disables
and re-enables softirq, for example, rcu_read_lock_bh() and
rcu_read_unlock_bh(), or (3) any pair of primitives that disables
and re-enables preemption, for example, rcu_read_lock_sched() and
rcu_read_unlock_sched(). If the updater uses synchronize_srcu()
or call_srcu(), then the corresponding readers must use
srcu_read_lock() and srcu_read_unlock(), and with the same
srcu_struct. The rules for the expedited RCU grace-period-wait
primitives are the same as for their non-expedited counterparts.
One exception to this rule: rcu_read_lock() and rcu_read_unlock()
may be substituted for rcu_read_lock_bh() and rcu_read_unlock_bh()
in cases where local bottom halves are already known to be
disabled, for example, in irq or softirq context. Commenting
such cases is a must, of course! And the jury is still out on
whether the increased speed is worth it.
If the updater uses call_rcu_tasks() or synchronize_rcu_tasks(),
then the readers must refrain from executing voluntary
context switches, that is, from blocking. If the updater uses
call_rcu_tasks_trace() or synchronize_rcu_tasks_trace(), then
the corresponding readers must use rcu_read_lock_trace() and
rcu_read_unlock_trace(). If an updater uses call_rcu_tasks_rude()
or synchronize_rcu_tasks_rude(), then the corresponding readers
must use anything that disables interrupts.
Mixing things up will result in confusion and broken kernels, and
has even resulted in an exploitable security issue. Therefore,
when using non-obvious pairs of primitives, commenting is
of course a must. One example of non-obvious pairing is
the XDP feature in networking, which calls BPF programs from
network-driver NAPI (softirq) context. BPF relies heavily on RCU
protection for its data structures, but because the BPF program
invocation happens entirely within a single local_bh_disable()
section in a NAPI poll cycle, this usage is safe. The reason
that this usage is safe is that readers can use anything that
disables BH when updaters use call_rcu() or synchronize_rcu().
8. Although synchronize_rcu() is slower than is call_rcu(), it
usually results in simpler code. So, unless update performance is

12
Documentation/accounting/delay-accounting.rst
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@ -69,13 +69,15 @@ Compile the kernel with::
CONFIG_TASK_DELAY_ACCT=y
CONFIG_TASKSTATS=y
Delay accounting is enabled by default at boot up.
To disable, add::
Delay accounting is disabled by default at boot up.
To enable, add::
nodelayacct
delayacct
to the kernel boot options. The rest of the instructions
below assume this has not been done.
to the kernel boot options. The rest of the instructions below assume this has
been done. Alternatively, use sysctl kernel.task_delayacct to switch the state
at runtime. Note however that only tasks started after enabling it will have
delayacct information.
After the system has booted up, use a utility
similar to getdelays.c to access the delays

30
Documentation/admin-guide/bootconfig.rst
View File

@ -89,13 +89,35 @@ you can use ``+=`` operator. For example::
In this case, the key ``foo`` has ``bar``, ``baz`` and ``qux``.
However, a sub-key and a value can not co-exist under a parent key.
For example, following config is NOT allowed.::
Moreover, sub-keys and a value can coexist under a parent key.
For example, following config is allowed.::
foo = value1
foo.bar = value2 # !ERROR! subkey "bar" and value "value1" can NOT co-exist
foo.bar := value2 # !ERROR! even with the override operator, this is NOT allowed.
foo.bar = value2
foo := value3 # This will update foo's value.
Note, since there is no syntax to put a raw value directly under a
structured key, you have to define it outside of the brace. For example::
foo {
bar = value1
bar {
baz = value2
qux = value3
}
}
Also, the order of the value node under a key is fixed. If there
are a value and subkeys, the value is always the first child node
of the key. Thus if user specifies subkeys first, e.g.::
foo.bar = value1
foo = value2
In the program (and /proc/bootconfig), it will be shown as below::
foo = value2
foo.bar = value1
Comments
--------

155
Documentation/admin-guide/cgroup-v1/blkio-controller.rst
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@ -17,36 +17,37 @@ level logical devices like device mapper.
HOWTO
=====
Throttling/Upper Limit policy
-----------------------------
- Enable Block IO controller::
Enable Block IO controller::
CONFIG_BLK_CGROUP=y
- Enable throttling in block layer::
Enable throttling in block layer::
CONFIG_BLK_DEV_THROTTLING=y
- Mount blkio controller (see cgroups.txt, Why are cgroups needed?)::
Mount blkio controller (see cgroups.txt, Why are cgroups needed?)::
mount -t cgroup -o blkio none /sys/fs/cgroup/blkio
- Specify a bandwidth rate on particular device for root group. The format
for policy is "<major>:<minor> <bytes_per_second>"::
Specify a bandwidth rate on particular device for root group. The format
for policy is "<major>:<minor> <bytes_per_second>"::
echo "8:16 1048576" > /sys/fs/cgroup/blkio/blkio.throttle.read_bps_device
Above will put a limit of 1MB/second on reads happening for root group
on device having major/minor number 8:16.
This will put a limit of 1MB/second on reads happening for root group
on device having major/minor number 8:16.
- Run dd to read a file and see if rate is throttled to 1MB/s or not::
Run dd to read a file and see if rate is throttled to 1MB/s or not::
# dd iflag=direct if=/mnt/common/zerofile of=/dev/null bs=4K count=1024
1024+0 records in
1024+0 records out
4194304 bytes (4.2 MB) copied, 4.0001 s, 1.0 MB/s
Limits for writes can be put using blkio.throttle.write_bps_device file.
Limits for writes can be put using blkio.throttle.write_bps_device file.
Hierarchical Cgroups
====================
@ -79,85 +80,89 @@ following::
Various user visible config options
===================================
CONFIG_BLK_CGROUP
- Block IO controller.
CONFIG_BFQ_CGROUP_DEBUG
- Debug help. Right now some additional stats file show up in cgroup
CONFIG_BLK_CGROUP
Block IO controller.
CONFIG_BFQ_CGROUP_DEBUG
Debug help. Right now some additional stats file show up in cgroup
if this option is enabled.
CONFIG_BLK_DEV_THROTTLING
- Enable block device throttling support in block layer.
CONFIG_BLK_DEV_THROTTLING
Enable block device throttling support in block layer.
Details of cgroup files
=======================
Proportional weight policy files
--------------------------------
- blkio.weight
- Specifies per cgroup weight. This is default weight of the group
on all the devices until and unless overridden by per device rule.
(See blkio.weight_device).
Currently allowed range of weights is from 10 to 1000.
- blkio.weight_device
- One can specify per cgroup per device rules using this interface.
These rules override the default value of group weight as specified
by blkio.weight.
blkio.bfq.weight
Specifies per cgroup weight. This is default weight of the group
on all the devices until and unless overridden by per device rule
(see `blkio.bfq.weight_device` below).
Currently allowed range of weights is from 1 to 1000. For more details,
see Documentation/block/bfq-iosched.rst.
blkio.bfq.weight_device
Specifes per cgroup per device weights, overriding the default group
weight. For more details, see Documentation/block/bfq-iosched.rst.
Following is the format::
# echo dev_maj:dev_minor weight > blkio.weight_device
# echo dev_maj:dev_minor weight > blkio.bfq.weight_device
Configure weight=300 on /dev/sdb (8:16) in this cgroup::
# echo 8:16 300 > blkio.weight_device
# cat blkio.weight_device
# echo 8:16 300 > blkio.bfq.weight_device
# cat blkio.bfq.weight_device
dev weight
8:16 300
Configure weight=500 on /dev/sda (8:0) in this cgroup::
# echo 8:0 500 > blkio.weight_device
# cat blkio.weight_device
# echo 8:0 500 > blkio.bfq.weight_device
# cat blkio.bfq.weight_device
dev weight
8:0 500
8:16 300
Remove specific weight for /dev/sda in this cgroup::
# echo 8:0 0 > blkio.weight_device
# cat blkio.weight_device
# echo 8:0 0 > blkio.bfq.weight_device
# cat blkio.bfq.weight_device
dev weight
8:16 300
- blkio.time
- disk time allocated to cgroup per device in milliseconds. First
blkio.time
Disk time allocated to cgroup per device in milliseconds. First
two fields specify the major and minor number of the device and
third field specifies the disk time allocated to group in
milliseconds.
- blkio.sectors
- number of sectors transferred to/from disk by the group. First
blkio.sectors
Number of sectors transferred to/from disk by the group. First
two fields specify the major and minor number of the device and
third field specifies the number of sectors transferred by the
group to/from the device.
- blkio.io_service_bytes
- Number of bytes transferred to/from the disk by the group. These
blkio.io_service_bytes
Number of bytes transferred to/from the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of bytes.
- blkio.io_serviced
- Number of IOs (bio) issued to the disk by the group. These
blkio.io_serviced
Number of IOs (bio) issued to the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of IOs.
- blkio.io_service_time
- Total amount of time between request dispatch and request completion
blkio.io_service_time
Total amount of time between request dispatch and request completion
for the IOs done by this cgroup. This is in nanoseconds to make it
meaningful for flash devices too. For devices with queue depth of 1,
this time represents the actual service time. When queue_depth > 1,
@ -170,8 +175,8 @@ Proportional weight policy files
specifies the operation type and the fourth field specifies the
io_service_time in ns.
- blkio.io_wait_time
- Total amount of time the IOs for this cgroup spent waiting in the
blkio.io_wait_time
Total amount of time the IOs for this cgroup spent waiting in the
scheduler queues for service. This can be greater than the total time
elapsed since it is cumulative io_wait_time for all IOs. It is not a
measure of total time the cgroup spent waiting but rather a measure of
@ -185,24 +190,24 @@ Proportional weight policy files
minor number of the device, third field specifies the operation type
and the fourth field specifies the io_wait_time in ns.
- blkio.io_merged
- Total number of bios/requests merged into requests belonging to this
blkio.io_merged
Total number of bios/requests merged into requests belonging to this
cgroup. This is further divided by the type of operation - read or
write, sync or async.
- blkio.io_queued
- Total number of requests queued up at any given instant for this
blkio.io_queued
Total number of requests queued up at any given instant for this
cgroup. This is further divided by the type of operation - read or
write, sync or async.
- blkio.avg_queue_size
- Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
blkio.avg_queue_size
Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
The average queue size for this cgroup over the entire time of this
cgroup's existence. Queue size samples are taken each time one of the
queues of this cgroup gets a timeslice.
- blkio.group_wait_time
- Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
blkio.group_wait_time
Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
This is the amount of time the cgroup had to wait since it became busy
(i.e., went from 0 to 1 request queued) to get a timeslice for one of
its queues. This is different from the io_wait_time which is the
@ -212,8 +217,8 @@ Proportional weight policy files
will only report the group_wait_time accumulated till the last time it
got a timeslice and will not include the current delta.
- blkio.empty_time
- Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
blkio.empty_time
Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
This is the amount of time a cgroup spends without any pending
requests when not being served, i.e., it does not include any time
spent idling for one of the queues of the cgroup. This is in
@ -221,8 +226,8 @@ Proportional weight policy files
the stat will only report the empty_time accumulated till the last
time it had a pending request and will not include the current delta.
- blkio.idle_time
- Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
blkio.idle_time
Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
This is the amount of time spent by the IO scheduler idling for a
given cgroup in anticipation of a better request than the existing ones
from other queues/cgroups. This is in nanoseconds. If this is read
@ -230,60 +235,60 @@ Proportional weight policy files
idle_time accumulated till the last idle period and will not include
the current delta.
- blkio.dequeue
- Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y. This
blkio.dequeue
Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y. This
gives the statistics about how many a times a group was dequeued
from service tree of the device. First two fields specify the major
and minor number of the device and third field specifies the number
of times a group was dequeued from a particular device.
- blkio.*_recursive
- Recursive version of various stats. These files show the
blkio.*_recursive
Recursive version of various stats. These files show the
same information as their non-recursive counterparts but
include stats from all the descendant cgroups.
Throttling/Upper limit policy files
-----------------------------------
- blkio.throttle.read_bps_device
- Specifies upper limit on READ rate from the device. IO rate is
blkio.throttle.read_bps_device
Specifies upper limit on READ rate from the device. IO rate is
specified in bytes per second. Rules are per device. Following is
the format::
echo "<major>:<minor> <rate_bytes_per_second>" > /cgrp/blkio.throttle.read_bps_device
- blkio.throttle.write_bps_device
- Specifies upper limit on WRITE rate to the device. IO rate is
blkio.throttle.write_bps_device
Specifies upper limit on WRITE rate to the device. IO rate is
specified in bytes per second. Rules are per device. Following is
the format::
echo "<major>:<minor> <rate_bytes_per_second>" > /cgrp/blkio.throttle.write_bps_device
- blkio.throttle.read_iops_device
- Specifies upper limit on READ rate from the device. IO rate is
blkio.throttle.read_iops_device
Specifies upper limit on READ rate from the device. IO rate is
specified in IO per second. Rules are per device. Following is
the format::
echo "<major>:<minor> <rate_io_per_second>" > /cgrp/blkio.throttle.read_iops_device
- blkio.throttle.write_iops_device
- Specifies upper limit on WRITE rate to the device. IO rate is
blkio.throttle.write_iops_device
Specifies upper limit on WRITE rate to the device. IO rate is
specified in io per second. Rules are per device. Following is
the format::
echo "<major>:<minor> <rate_io_per_second>" > /cgrp/blkio.throttle.write_iops_device
Note: If both BW and IOPS rules are specified for a device, then IO is
subjected to both the constraints.
Note: If both BW and IOPS rules are specified for a device, then IO is
subjected to both the constraints.
- blkio.throttle.io_serviced
- Number of IOs (bio) issued to the disk by the group. These
blkio.throttle.io_serviced
Number of IOs (bio) issued to the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of IOs.
- blkio.throttle.io_service_bytes
- Number of bytes transferred to/from the disk by the group. These
blkio.throttle.io_service_bytes
Number of bytes transferred to/from the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
@ -291,6 +296,6 @@ Note: If both BW and IOPS rules are specified for a device, then IO is
Common files among various policies
-----------------------------------
- blkio.reset_stats
- Writing an int to this file will result in resetting all the stats
blkio.reset_stats
Writing an int to this file will result in resetting all the stats
for that cgroup.

70
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@ -56,6 +56,7 @@ v1 is available under :ref:`Documentation/admin-guide/cgroup-v1/index.rst <cgrou
5-3-3. IO Latency
5-3-3-1. How IO Latency Throttling Works
5-3-3-2. IO Latency Interface Files
5-3-4. IO Priority
5-4. PID
5-4-1. PID Interface Files
5-5. Cpuset
@ -952,6 +953,21 @@ All cgroup core files are prefixed with "cgroup."
it's possible to delete a frozen (and empty) cgroup, as well as
create new sub-cgroups.
cgroup.kill
A write-only single value file which exists in non-root cgroups.
The only allowed value is "1".
Writing "1" to the file causes the cgroup and all descendant cgroups to
be killed. This means that all processes located in the affected cgroup
tree will be killed via SIGKILL.
Killing a cgroup tree will deal with concurrent forks appropriately and
is protected against migrations.
In a threaded cgroup, writing this file fails with EOPNOTSUPP as
killing cgroups is a process directed operation, i.e. it affects
the whole thread-group.
Controllers
===========
@ -1866,6 +1882,60 @@ IO Latency Interface Files
duration of time between evaluation events. Windows only elapse
with IO activity. Idle periods extend the most recent window.
IO Priority
~~~~~~~~~~~
A single attribute controls the behavior of the I/O priority cgroup policy,
namely the blkio.prio.class attribute. The following values are accepted for
that attribute:
no-change
Do not modify the I/O priority class.
none-to-rt
For requests that do not have an I/O priority class (NONE),
change the I/O priority class into RT. Do not modify
the I/O priority class of other requests.
restrict-to-be
For requests that do not have an I/O priority class or that have I/O
priority class RT, change it into BE. Do not modify the I/O priority
class of requests that have priority class IDLE.
idle
Change the I/O priority class of all requests into IDLE, the lowest
I/O priority class.
The following numerical values are associated with the I/O priority policies:
+-------------+---+
| no-change | 0 |
+-------------+---+
| none-to-rt | 1 |
+-------------+---+
| rt-to-be | 2 |
+-------------+---+
| all-to-idle | 3 |
+-------------+---+
The numerical value that corresponds to each I/O priority class is as follows:
+-------------------------------+---+
| IOPRIO_CLASS_NONE | 0 |
+-------------------------------+---+
| IOPRIO_CLASS_RT (real-time) | 1 |
+-------------------------------+---+
| IOPRIO_CLASS_BE (best effort) | 2 |
+-------------------------------+---+
| IOPRIO_CLASS_IDLE | 3 |
+-------------------------------+---+
The algorithm to set the I/O priority class for a request is as follows:
- Translate the I/O priority class policy into a number.
- Change the request I/O priority class into the maximum of the I/O priority
class policy number and the numerical I/O priority class.
PID
---

85
Documentation/admin-guide/cputopology.rst
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@ -2,87 +2,10 @@
How CPU topology info is exported via sysfs
===========================================
Export CPU topology info via sysfs. Items (attributes) are similar
to /proc/cpuinfo output of some architectures. They reside in
/sys/devices/system/cpu/cpuX/topology/:
physical_package_id:
physical package id of cpuX. Typically corresponds to a physical
socket number, but the actual value is architecture and platform
dependent.
die_id:
the CPU die ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent.
core_id:
the CPU core ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent.
book_id:
the book ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent.
drawer_id:
the drawer ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent.
core_cpus:
internal kernel map of CPUs within the same core.
(deprecated name: "thread_siblings")
core_cpus_list:
human-readable list of CPUs within the same core.
(deprecated name: "thread_siblings_list");
package_cpus:
internal kernel map of the CPUs sharing the same physical_package_id.
(deprecated name: "core_siblings")
package_cpus_list:
human-readable list of CPUs sharing the same physical_package_id.
(deprecated name: "core_siblings_list")
die_cpus:
internal kernel map of CPUs within the same die.
die_cpus_list:
human-readable list of CPUs within the same die.
book_siblings:
internal kernel map of cpuX's hardware threads within the same
book_id.
book_siblings_list:
human-readable list of cpuX's hardware threads within the same
book_id.
drawer_siblings:
internal kernel map of cpuX's hardware threads within the same
drawer_id.
drawer_siblings_list:
human-readable list of cpuX's hardware threads within the same
drawer_id.
CPU topology info is exported via sysfs. Items (attributes) are similar
to /proc/cpuinfo output of some architectures. They reside in
/sys/devices/system/cpu/cpuX/topology/. Please refer to the ABI file:
Documentation/ABI/stable/sysfs-devices-system-cpu.
Architecture-neutral, drivers/base/topology.c, exports these attributes.
However, the book and drawer related sysfs files will only be created if

25
Documentation/admin-guide/device-mapper/writecache.rst
View File

@ -12,7 +12,6 @@ first sector should contain valid superblock from previous invocation.
Constructor parameters:
1. type of the cache device - "p" or "s"
- p - persistent memory
- s - SSD
2. the underlying device that will be cached
@ -21,7 +20,6 @@ Constructor parameters:
size)
5. the number of optional parameters (the parameters with an argument
count as two)
start_sector n (default: 0)
offset from the start of cache device in 512-byte sectors
high_watermark n (default: 50)
@ -53,6 +51,27 @@ Constructor parameters:
- some underlying devices perform better with fua, some
with nofua. The user should test it
cleaner
when this option is activated (either in the constructor
arguments or by a message), the cache will not promote
new writes (however, writes to already cached blocks are
promoted, to avoid data corruption due to misordered
writes) and it will gradually writeback any cached
data. The userspace can then monitor the cleaning
process with "dmsetup status". When the number of cached
blocks drops to zero, userspace can unload the
dm-writecache target and replace it with dm-linear or
other targets.
max_age n
specifies the maximum age of a block in milliseconds. If
a block is stored in the cache for too long, it will be
written to the underlying device and cleaned up.
metadata_only
only metadata is promoted to the cache. This option
improves performance for heavier REQ_META workloads.
pause_writeback n (default: 3000)
pause writeback if there was some write I/O redirected to
the origin volume in the last n milliseconds
Status:
1. error indicator - 0 if there was no error, otherwise error number
@ -77,3 +96,5 @@ Messages:
5. resume the device, so that it will use the linear
target
6. the cache device is now inactive and it can be deleted
cleaner
See above "cleaner" constructor documentation.

2
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@ -392,7 +392,7 @@ When mounting an ext4 filesystem, the following option are accepted:
dax
Use direct access (no page cache). See
Documentation/filesystems/dax.txt. Note that this option is
Documentation/filesystems/dax.rst. Note that this option is
incompatible with data=journal.
inlinecrypt

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@ -0,0 +1,223 @@
.. SPDX-License-Identifier: GPL-2.0
===============
Core Scheduling
===============
Core scheduling support allows userspace to define groups of tasks that can
share a core. These groups can be specified either for security usecases (one
group of tasks don't trust another), or for performance usecases (some
workloads may benefit from running on the same core as they don't need the same
hardware resources of the shared core, or may prefer different cores if they
do share hardware resource needs). This document only describes the security
usecase.
Security usecase
----------------
A cross-HT attack involves the attacker and victim running on different Hyper
Threads of the same core. MDS and L1TF are examples of such attacks. The only
full mitigation of cross-HT attacks is to disable Hyper Threading (HT). Core
scheduling is a scheduler feature that can mitigate some (not all) cross-HT
attacks. It allows HT to be turned on safely by ensuring that only tasks in a
user-designated trusted group can share a core. This increase in core sharing
can also improve performance, however it is not guaranteed that performance
will always improve, though that is seen to be the case with a number of real
world workloads. In theory, core scheduling aims to perform at least as good as
when Hyper Threading is disabled. In practice, this is mostly the case though
not always: as synchronizing scheduling decisions across 2 or more CPUs in a
core involves additional overhead - especially when the system is lightly
loaded. When ``total_threads <= N_CPUS/2``, the extra overhead may cause core
scheduling to perform more poorly compared to SMT-disabled, where N_CPUS is the
total number of CPUs. Please measure the performance of your workloads always.
Usage
-----
Core scheduling support is enabled via the ``CONFIG_SCHED_CORE`` config option.
Using this feature, userspace defines groups of tasks that can be co-scheduled
on the same core. The core scheduler uses this information to make sure that
tasks that are not in the same group never run simultaneously on a core, while
doing its best to satisfy the system's scheduling requirements.
Core scheduling can be enabled via the ``PR_SCHED_CORE`` prctl interface.
This interface provides support for the creation of core scheduling groups, as
well as admission and removal of tasks from created groups::
#include <sys/prctl.h>
int prctl(int option, unsigned long arg2, unsigned long arg3,
unsigned long arg4, unsigned long arg5);
option:
``PR_SCHED_CORE``
arg2:
Command for operation, must be one off:
- ``PR_SCHED_CORE_GET`` -- get core_sched cookie of ``pid``.
- ``PR_SCHED_CORE_CREATE`` -- create a new unique cookie for ``pid``.
- ``PR_SCHED_CORE_SHARE_TO`` -- push core_sched cookie to ``pid``.
- ``PR_SCHED_CORE_SHARE_FROM`` -- pull core_sched cookie from ``pid``.
arg3:
``pid`` of the task for which the operation applies.
arg4:
``pid_type`` for which the operation applies. It is of type ``enum pid_type``.
For example, if arg4 is ``PIDTYPE_TGID``, then the operation of this command
will be performed for all tasks in the task group of ``pid``.
arg5:
userspace pointer to an unsigned long for storing the cookie returned by
``PR_SCHED_CORE_GET`` command. Should be 0 for all other commands.
In order for a process to push a cookie to, or pull a cookie from a process, it
is required to have the ptrace access mode: `PTRACE_MODE_READ_REALCREDS` to the
process.
Building hierarchies of tasks
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The simplest way to build hierarchies of threads/processes which share a
cookie and thus a core is to rely on the fact that the core-sched cookie is
inherited across forks/clones and execs, thus setting a cookie for the
'initial' script/executable/daemon will place every spawned child in the
same core-sched group.
Cookie Transferral
~~~~~~~~~~~~~~~~~~
Transferring a cookie between the current and other tasks is possible using
PR_SCHED_CORE_SHARE_FROM and PR_SCHED_CORE_SHARE_TO to inherit a cookie from a
specified task or a share a cookie with a task. In combination this allows a
simple helper program to pull a cookie from a task in an existing core
scheduling group and share it with already running tasks.
Design/Implementation
---------------------
Each task that is tagged is assigned a cookie internally in the kernel. As
mentioned in `Usage`_, tasks with the same cookie value are assumed to trust
each other and share a core.
The basic idea is that, every schedule event tries to select tasks for all the
siblings of a core such that all the selected tasks running on a core are
trusted (same cookie) at any point in time. Kernel threads are assumed trusted.
The idle task is considered special, as it trusts everything and everything
trusts it.
During a schedule() event on any sibling of a core, the highest priority task on
the sibling's core is picked and assigned to the sibling calling schedule(), if
the sibling has the task enqueued. For rest of the siblings in the core,
highest priority task with the same cookie is selected if there is one runnable
in their individual run queues. If a task with same cookie is not available,
the idle task is selected. Idle task is globally trusted.
Once a task has been selected for all the siblings in the core, an IPI is sent to
siblings for whom a new task was selected. Siblings on receiving the IPI will
switch to the new task immediately. If an idle task is selected for a sibling,
then the sibling is considered to be in a `forced idle` state. I.e., it may
have tasks on its on runqueue to run, however it will still have to run idle.
More on this in the next section.
Forced-idling of hyperthreads
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The scheduler tries its best to find tasks that trust each other such that all
tasks selected to be scheduled are of the highest priority in a core. However,
it is possible that some runqueues had tasks that were incompatible with the
highest priority ones in the core. Favoring security over fairness, one or more
siblings could be forced to select a lower priority task if the highest
priority task is not trusted with respect to the core wide highest priority
task. If a sibling does not have a trusted task to run, it will be forced idle
by the scheduler (idle thread is scheduled to run).
When the highest priority task is selected to run, a reschedule-IPI is sent to
the sibling to force it into idle. This results in 4 cases which need to be
considered depending on whether a VM or a regular usermode process was running
on either HT::
HT1 (attack) HT2 (victim)
A idle -> user space user space -> idle
B idle -> user space guest -> idle
C idle -> guest user space -> idle
D idle -> guest guest -> idle
Note that for better performance, we do not wait for the destination CPU
(victim) to enter idle mode. This is because the sending of the IPI would bring
the destination CPU immediately into kernel mode from user space, or VMEXIT
in the case of guests. At best, this would only leak some scheduler metadata
which may not be worth protecting. It is also possible that the IPI is received
too late on some architectures, but this has not been observed in the case of
x86.
Trust model
~~~~~~~~~~~
Core scheduling maintains trust relationships amongst groups of tasks by
assigning them a tag that is the same cookie value.
When a system with core scheduling boots, all tasks are considered to trust
each other. This is because the core scheduler does not have information about
trust relationships until userspace uses the above mentioned interfaces, to
communicate them. In other words, all tasks have a default cookie value of 0.
and are considered system-wide trusted. The forced-idling of siblings running
cookie-0 tasks is also avoided.
Once userspace uses the above mentioned interfaces to group sets of tasks, tasks
within such groups are considered to trust each other, but do not trust those
outside. Tasks outside the group also don't trust tasks within.
Limitations of core-scheduling
------------------------------
Core scheduling tries to guarantee that only trusted tasks run concurrently on a
core. But there could be small window of time during which untrusted tasks run
concurrently or kernel could be running concurrently with a task not trusted by
kernel.
IPI processing delays
~~~~~~~~~~~~~~~~~~~~~
Core scheduling selects only trusted tasks to run together. IPI is used to notify
the siblings to switch to the new task. But there could be hardware delays in
receiving of the IPI on some arch (on x86, this has not been observed). This may
cause an attacker task to start running on a CPU before its siblings receive the
IPI. Even though cache is flushed on entry to user mode, victim tasks on siblings
may populate data in the cache and micro architectural buffers after the attacker
starts to run and this is a possibility for data leak.
Open cross-HT issues that core scheduling does not solve
--------------------------------------------------------
1. For MDS
~~~~~~~~~~
Core scheduling cannot protect against MDS attacks between an HT running in
user mode and another running in kernel mode. Even though both HTs run tasks
which trust each other, kernel memory is still considered untrusted. Such
attacks are possible for any combination of sibling CPU modes (host or guest mode).
2. For L1TF
~~~~~~~~~~~
Core scheduling cannot protect against an L1TF guest attacker exploiting a
guest or host victim. This is because the guest attacker can craft invalid
PTEs which are not inverted due to a vulnerable guest kernel. The only
solution is to disable EPT (Extended Page Tables).
For both MDS and L1TF, if the guest vCPU is configured to not trust each
other (by tagging separately), then the guest to guest attacks would go away.
Or it could be a system admin policy which considers guest to guest attacks as
a guest problem.
Another approach to resolve these would be to make every untrusted task on the
system to not trust every other untrusted task. While this could reduce
parallelism of the untrusted tasks, it would still solve the above issues while
allowing system processes (trusted tasks) to share a core.
3. Protecting the kernel (IRQ, syscall, VMEXIT)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Unfortunately, core scheduling does not protect kernel contexts running on
sibling hyperthreads from one another. Prototypes of mitigations have been posted
to LKML to solve this, but it is debatable whether such windows are practically
exploitable, and whether the performance overhead of the prototypes are worth
it (not to mention, the added code complexity).
Other Use cases
---------------
The main use case for Core scheduling is mitigating the cross-HT vulnerabilities
with SMT enabled. There are other use cases where this feature could be used:
- Isolating tasks that needs a whole core: Examples include realtime tasks, tasks
that uses SIMD instructions etc.
- Gang scheduling: Requirements for a group of tasks that needs to be scheduled
together could also be realized using core scheduling. One example is vCPUs of
a VM.

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@ -15,3 +15,4 @@ are configurable at compile, boot or run time.
tsx_async_abort
multihit.rst
special-register-buffer-data-sampling.rst
core-scheduling.rst

3
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@ -3,7 +3,8 @@
SRBDS - Special Register Buffer Data Sampling
=============================================
SRBDS is a hardware vulnerability that allows MDS :doc:`mds` techniques to
SRBDS is a hardware vulnerability that allows MDS
Documentation/admin-guide/hw-vuln/mds.rst techniques to
infer values returned from special register accesses. Special register
accesses are accesses to off core registers. According to Intel's evaluation,
the special register reads that have a security expectation of privacy are

192
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@ -2,7 +2,7 @@
Documentation for Kdump - The kexec-based Crash Dumping Solution
================================================================
This document includes overview, setup and installation, and analysis
This document includes overview, setup, installation, and analysis
information.
Overview
@ -13,9 +13,9 @@ dump of the system kernel's memory needs to be taken (for example, when
the system panics). The system kernel's memory image is preserved across
the reboot and is accessible to the dump-capture kernel.
You can use common commands, such as cp and scp, to copy the
memory image to a dump file on the local disk, or across the network to
a remote system.
You can use common commands, such as cp, scp or makedumpfile to copy
the memory image to a dump file on the local disk, or across the network
to a remote system.
Kdump and kexec are currently supported on the x86, x86_64, ppc64, ia64,
s390x, arm and arm64 architectures.
@ -26,13 +26,15 @@ the dump-capture kernel. This ensures that ongoing Direct Memory Access
The kexec -p command loads the dump-capture kernel into this reserved
memory.
On x86 machines, the first 640 KB of physical memory is needed to boot,
regardless of where the kernel loads. Therefore, kexec backs up this
region just before rebooting into the dump-capture kernel.
On x86 machines, the first 640 KB of physical memory is needed for boot,
regardless of where the kernel loads. For simpler handling, the whole
low 1M is reserved to avoid any later kernel or device driver writing
data into this area. Like this, the low 1M can be reused as system RAM
by kdump kernel without extra handling.
Similarly on PPC64 machines first 32KB of physical memory is needed for
booting regardless of where the kernel is loaded and to support 64K page
size kexec backs up the first 64KB memory.
On PPC64 machines first 32KB of physical memory is needed for booting
regardless of where the kernel is loaded and to support 64K page size
kexec backs up the first 64KB memory.
For s390x, when kdump is triggered, the crashkernel region is exchanged
with the region [0, crashkernel region size] and then the kdump kernel
@ -46,14 +48,14 @@ passed to the dump-capture kernel through the elfcorehdr= boot
parameter. Optionally the size of the ELF header can also be passed
when using the elfcorehdr=[size[KMG]@]offset[KMG] syntax.
With the dump-capture kernel, you can access the memory image through
/proc/vmcore. This exports the dump as an ELF-format file that you can
write out using file copy commands such as cp or scp. Further, you can
use analysis tools such as the GNU Debugger (GDB) and the Crash tool to
debug the dump file. This method ensures that the dump pages are correctly
ordered.
write out using file copy commands such as cp or scp. You can also use
makedumpfile utility to analyze and write out filtered contents with
options, e.g with '-d 31' it will only write out kernel data. Further,
you can use analysis tools such as the GNU Debugger (GDB) and the Crash
tool to debug the dump file. This method ensures that the dump pages are
correctly ordered.
Setup and Installation
======================
@ -125,9 +127,18 @@ dump-capture kernels for enabling kdump support.
System kernel config options
----------------------------
1) Enable "kexec system call" in "Processor type and features."::
1) Enable "kexec system call" or "kexec file based system call" in
"Processor type and features."::
CONFIG_KEXEC=y
CONFIG_KEXEC=y or CONFIG_KEXEC_FILE=y
And both of them will select KEXEC_CORE::
CONFIG_KEXEC_CORE=y
Subsequently, CRASH_CORE is selected by KEXEC_CORE::
CONFIG_CRASH_CORE=y
2) Enable "sysfs file system support" in "Filesystem" -> "Pseudo
filesystems." This is usually enabled by default::
@ -175,17 +186,19 @@ Dump-capture kernel config options (Arch Dependent, i386 and x86_64)
CONFIG_HIGHMEM4G
2) On i386 and x86_64, disable symmetric multi-processing support
under "Processor type and features"::
2) With CONFIG_SMP=y, usually nr_cpus=1 need specified on the kernel
command line when loading the dump-capture kernel because one
CPU is enough for kdump kernel to dump vmcore on most of systems.
CONFIG_SMP=n
However, you can also specify nr_cpus=X to enable multiple processors
in kdump kernel. In this case, "disable_cpu_apicid=" is needed to
tell kdump kernel which cpu is 1st kernel's BSP. Please refer to
admin-guide/kernel-parameters.txt for more details.
(If CONFIG_SMP=y, then specify maxcpus=1 on the kernel command line
when loading the dump-capture kernel, see section "Load the Dump-capture
Kernel".)
With CONFIG_SMP=n, the above things are not related.
3) If one wants to build and use a relocatable kernel,
Enable "Build a relocatable kernel" support under "Processor type and
3) A relocatable kernel is suggested to be built by default. If not yet,
enable "Build a relocatable kernel" support under "Processor type and
features"::
CONFIG_RELOCATABLE=y
@ -232,7 +245,7 @@ Dump-capture kernel config options (Arch Dependent, ia64)
as a dump-capture kernel if desired.
The crashkernel region can be automatically placed by the system
kernel at run time. This is done by specifying the base address as 0,
kernel at runtime. This is done by specifying the base address as 0,
or omitting it all together::
crashkernel=256M@0
@ -241,10 +254,6 @@ Dump-capture kernel config options (Arch Dependent, ia64)
crashkernel=256M
If the start address is specified, note that the start address of the
kernel will be aligned to 64Mb, so if the start address is not then
any space below the alignment point will be wasted.
Dump-capture kernel config options (Arch Dependent, arm)
----------------------------------------------------------
@ -260,46 +269,82 @@ Dump-capture kernel config options (Arch Dependent, arm64)
on non-VHE systems even if it is configured. This is because the CPU
will not be reset to EL2 on panic.
Extended crashkernel syntax
crashkernel syntax
===========================
1) crashkernel=size@offset
While the "crashkernel=size[@offset]" syntax is sufficient for most
configurations, sometimes it's handy to have the reserved memory dependent
on the value of System RAM -- that's mostly for distributors that pre-setup
the kernel command line to avoid a unbootable system after some memory has
been removed from the machine.
The syntax is::
crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
range=start-[end]
For example::
crashkernel=512M-2G:64M,2G-:128M
This would mean:
1) if the RAM is smaller than 512M, then don't reserve anything
(this is the "rescue" case)
2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
3) if the RAM size is larger than 2G, then reserve 128M
Boot into System Kernel
=======================
1) Update the boot loader (such as grub, yaboot, or lilo) configuration
files as necessary.
2) Boot the system kernel with the boot parameter "crashkernel=Y@X",
where Y specifies how much memory to reserve for the dump-capture kernel
and X specifies the beginning of this reserved memory. For example,
Here 'size' specifies how much memory to reserve for the dump-capture kernel
and 'offset' specifies the beginning of this reserved memory. For example,
"crashkernel=64M@16M" tells the system kernel to reserve 64 MB of memory
starting at physical address 0x01000000 (16MB) for the dump-capture kernel.
On x86 and x86_64, use "crashkernel=64M@16M".
The crashkernel region can be automatically placed by the system
kernel at run time. This is done by specifying the base address as 0,
or omitting it all together::
crashkernel=256M@0
or::
crashkernel=256M
If the start address is specified, note that the start address of the
kernel will be aligned to a value (which is Arch dependent), so if the
start address is not then any space below the alignment point will be
wasted.
2) range1:size1[,range2:size2,...][@offset]
While the "crashkernel=size[@offset]" syntax is sufficient for most
configurations, sometimes it's handy to have the reserved memory dependent
on the value of System RAM -- that's mostly for distributors that pre-setup
the kernel command line to avoid a unbootable system after some memory has
been removed from the machine.
The syntax is::
crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
range=start-[end]
For example::
crashkernel=512M-2G:64M,2G-:128M
This would mean:
1) if the RAM is smaller than 512M, then don't reserve anything
(this is the "rescue" case)
2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
3) if the RAM size is larger than 2G, then reserve 128M
3) crashkernel=size,high and crashkernel=size,low
If memory above 4G is preferred, crashkernel=size,high can be used to
fulfill that. With it, physical memory is allowed to be allocated from top,
so could be above 4G if system has more than 4G RAM installed. Otherwise,
memory region will be allocated below 4G if available.
When crashkernel=X,high is passed, kernel could allocate physical memory
region above 4G, low memory under 4G is needed in this case. There are
three ways to get low memory:
1) Kernel will allocate at least 256M memory below 4G automatically
if crashkernel=Y,low is not specified.
2) Let user specify low memory size instead.
3) Specified value 0 will disable low memory allocation::
crashkernel=0,low
Boot into System Kernel
-----------------------
1) Update the boot loader (such as grub, yaboot, or lilo) configuration
files as necessary.
2) Boot the system kernel with the boot parameter "crashkernel=Y@X".
On x86 and x86_64, use "crashkernel=Y[@X]". Most of the time, the
start address 'X' is not necessary, kernel will search a suitable
area. Unless an explicit start address is expected.
On ppc64, use "crashkernel=128M@32M".
@ -331,8 +376,8 @@ of dump-capture kernel. Following is the summary.
For i386 and x86_64:
- Use vmlinux if kernel is not relocatable.
- Use bzImage/vmlinuz if kernel is relocatable.
- Use vmlinux if kernel is not relocatable.
For ppc64:
@ -392,7 +437,7 @@ loading dump-capture kernel.
For i386, x86_64 and ia64:
"1 irqpoll maxcpus=1 reset_devices"
"1 irqpoll nr_cpus=1 reset_devices"
For ppc64:
@ -400,7 +445,7 @@ For ppc64:
For s390x:
"1 maxcpus=1 cgroup_disable=memory"
"1 nr_cpus=1 cgroup_disable=memory"
For arm:
@ -408,7 +453,7 @@ For arm:
For arm64:
"1 maxcpus=1 reset_devices"
"1 nr_cpus=1 reset_devices"
Notes on loading the dump-capture kernel:
@ -488,6 +533,10 @@ the following command::
cp /proc/vmcore <dump-file>
You can also use makedumpfile utility to write out the dump file
with specified options to filter out unwanted contents, e.g::
makedumpfile -l --message-level 1 -d 31 /proc/vmcore <dump-file>
Analysis
========
@ -535,8 +584,7 @@ This will cause a kdump to occur at the add_taint()->panic() call.
Contact
=======
- Vivek Goyal (vgoyal@redhat.com)
- Maneesh Soni (maneesh@in.ibm.com)
- kexec@lists.infradead.org
GDB macros
==========

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@ -76,6 +76,11 @@ to change, such as less cores in the CPU list, then N and any ranges using N
will also change. Use the same on a small 4 core system, and "16-N" becomes
"16-3" and now the same boot input will be flagged as invalid (start > end).
The special case-tolerant group name "all" has a meaning of selecting all CPUs,
so that "nohz_full=all" is the equivalent of "nohz_full=0-N".
The semantics of "N" and "all" is supported on a level of bitmaps and holds for
all users of bitmap_parse().
This document may not be entirely up to date and comprehensive. The command
"modinfo -p ${modulename}" shows a current list of all parameters of a loadable

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@ -113,7 +113,7 @@
the GPE dispatcher.
This facility can be used to prevent such uncontrolled
GPE floodings.
Format: <byte>
Format: <byte> or <bitmap-list>
acpi_no_auto_serialize [HW,ACPI]
Disable auto-serialization of AML methods
@ -301,6 +301,9 @@
allowed anymore to lift isolation
requirements as needed. This option
does not override iommu=pt
force_enable - Force enable the IOMMU on platforms known
to be buggy with IOMMU enabled. Use this
option with care.
amd_iommu_dump= [HW,X86-64]
Enable AMD IOMMU driver option to dump the ACPI table
@ -497,16 +500,21 @@
ccw_timeout_log [S390]
See Documentation/s390/common_io.rst for details.
cgroup_disable= [KNL] Disable a particular controller
Format: {name of the controller(s) to disable}
cgroup_disable= [KNL] Disable a particular controller or optional feature
Format: {name of the controller(s) or feature(s) to disable}
The effects of cgroup_disable=foo are:
- foo isn't auto-mounted if you mount all cgroups in
a single hierarchy
- foo isn't visible as an individually mountable
subsystem
- if foo is an optional feature then the feature is
disabled and corresponding cgroup files are not
created
{Currently only "memory" controller deal with this and
cut the overhead, others just disable the usage. So
only cgroup_disable=memory is actually worthy}
Specifying "pressure" disables per-cgroup pressure
stall information accounting feature
cgroup_no_v1= [KNL] Disable cgroup controllers and named hierarchies in v1
Format: { { controller | "all" | "named" }
@ -581,6 +589,28 @@
loops can be debugged more effectively on production
systems.
clocksource.max_cswd_read_retries= [KNL]
Number of clocksource_watchdog() retries due to
external delays before the clock will be marked
unstable. Defaults to three retries, that is,
four attempts to read the clock under test.
clocksource.verify_n_cpus= [KNL]
Limit the number of CPUs checked for clocksources
marked with CLOCK_SOURCE_VERIFY_PERCPU that
are marked unstable due to excessive skew.
A negative value says to check all CPUs, while
zero says not to check any. Values larger than
nr_cpu_ids are silently truncated to nr_cpu_ids.
The actual CPUs are chosen randomly, with
no replacement if the same CPU is chosen twice.
clocksource-wdtest.holdoff= [KNL]
Set the time in seconds that the clocksource
watchdog test waits before commencing its tests.
Defaults to zero when built as a module and to
10 seconds when built into the kernel.
clearcpuid=BITNUM[,BITNUM...] [X86]
Disable CPUID feature X for the kernel. See
arch/x86/include/asm/cpufeatures.h for the valid bit
@ -1092,6 +1122,11 @@
the driver will use only 32-bit accessors to read/write
the device registers.
liteuart,<addr>
Start an early console on a litex serial port at the
specified address. The serial port must already be
setup and configured. Options are not yet supported.
meson,<addr>
Start an early, polled-mode console on a meson serial
port at the specified address. The serial port must
@ -1567,6 +1602,23 @@
Documentation/admin-guide/mm/hugetlbpage.rst.
Format: size[KMG]
hugetlb_free_vmemmap=
[KNL] Reguires CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
enabled.
Allows heavy hugetlb users to free up some more
memory (6 * PAGE_SIZE for each 2MB hugetlb page).
Format: { on | off (default) }
on: enable the feature
off: disable the feature
Built with CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON=y,
the default is on.
This is not compatible with memory_hotplug.memmap_on_memory.
If both parameters are enabled, hugetlb_free_vmemmap takes
precedence over memory_hotplug.memmap_on_memory.
hung_task_panic=
[KNL] Should the hung task detector generate panics.
Format: 0 | 1
@ -1987,7 +2039,7 @@
forcing Dual Address Cycle for PCI cards supporting
greater than 32-bit addressing.
iommu.strict= [ARM64] Configure TLB invalidation behaviour
iommu.strict= [ARM64, X86] Configure TLB invalidation behaviour
Format: { "0" | "1" }
0 - Lazy mode.
Request that DMA unmap operations use deferred
@ -1998,6 +2050,10 @@
1 - Strict mode (default).
DMA unmap operations invalidate IOMMU hardware TLBs
synchronously.
Note: on x86, the default behaviour depends on the
equivalent driver-specific parameters, but a strict
mode explicitly specified by either method takes
precedence.
iommu.passthrough=
[ARM64, X86] Configure DMA to bypass the IOMMU by default.
@ -2833,6 +2889,10 @@
Note that even when enabled, there are a few cases where
the feature is not effective.
This is not compatible with hugetlb_free_vmemmap. If
both parameters are enabled, hugetlb_free_vmemmap takes
precedence over memory_hotplug.memmap_on_memory.
memtest= [KNL,X86,ARM,PPC,RISCV] Enable memtest
Format: <integer>
default : 0 <disable>
@ -3244,7 +3304,7 @@
noclflush [BUGS=X86] Don't use the CLFLUSH instruction
nodelayacct [KNL] Disable per-task delay accounting
delayacct [KNL] Enable per-task delay accounting
nodsp [SH] Disable hardware DSP at boot time.
@ -3513,6 +3573,9 @@
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
numa=off [KNL, ARM64, PPC, RISCV, SPARC, X86] Disable NUMA, Only
set up a single NUMA node spanning all memory.
numa_balancing= [KNL,ARM64,PPC,RISCV,S390,X86] Enable or disable automatic
NUMA balancing.
Allowed values are enable and disable
@ -3566,6 +3629,12 @@
off: turn off poisoning (default)
on: turn on poisoning
page_reporting.page_reporting_order=
[KNL] Minimal page reporting order
Format: <integer>
Adjust the minimal page reporting order. The page
reporting is disabled when it exceeds (MAX_ORDER-1).
panic= [KNL] Kernel behaviour on panic: delay <timeout>
timeout > 0: seconds before rebooting
timeout = 0: wait forever
@ -4290,6 +4359,11 @@
whole algorithm to behave better in low memory
condition.
rcutree.rcu_delay_page_cache_fill_msec= [KNL]
Set the page-cache refill delay (in milliseconds)
in response to low-memory conditions. The range
of permitted values is in the range 0:100000.
rcutree.jiffies_till_first_fqs= [KNL]
Set delay from grace-period initialization to
first attempt to force quiescent states.
@ -4775,11 +4849,6 @@
Reserves a hole at the top of the kernel virtual
address space.
reservelow= [X86]
Format: nn[K]
Set the amount of memory to reserve for BIOS at
the bottom of the address space.
reset_devices [KNL] Force drivers to reset the underlying device
during initialization.
@ -5283,6 +5352,14 @@
exception. Default behavior is by #AC if
both features are enabled in hardware.
ratelimit:N -
Set system wide rate limit to N bus locks
per second for bus lock detection.
0 < N <= 1000.
N/A for split lock detection.
If an #AC exception is hit in the kernel or in
firmware (i.e. not while executing in user mode)
the kernel will oops in either "warn" or "fatal"
@ -5605,12 +5682,25 @@
Note, echoing 1 into this file without the
tracepoint_printk kernel cmdline option has no effect.
The tp_printk_stop_on_boot (see below) can also be used
to stop the printing of events to console at
late_initcall_sync.
** CAUTION **
Having tracepoints sent to printk() and activating high
frequency tracepoints such as irq or sched, can cause
the system to live lock.
tp_printk_stop_on_boot[FTRACE]
When tp_printk (above) is set, it can cause a lot of noise
on the console. It may be useful to only include the
printing of events during boot up, as user space may
make the system inoperable.
This command line option will stop the printing of events
to console at the late_initcall_sync() time frame.
traceoff_on_warning
[FTRACE] enable this option to disable tracing when a
warning is hit. This turns off "tracing_on". Tracing can

11
Documentation/admin-guide/laptops/laptop-mode.rst
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@ -101,17 +101,6 @@ this results in concentration of disk activity in a small time interval which
occurs only once every 10 minutes, or whenever the disk is forced to spin up by
a cache miss. The disk can then be spun down in the periods of inactivity.
If you want to find out which process caused the disk to spin up, you can
gather information by setting the flag /proc/sys/vm/block_dump. When this flag
is set, Linux reports all disk read and write operations that take place, and
all block dirtyings done to files. This makes it possible to debug why a disk
needs to spin up, and to increase battery life even more. The output of
block_dump is written to the kernel output, and it can be retrieved using
"dmesg". When you use block_dump and your kernel logging level also includes
kernel debugging messages, you probably want to turn off klogd, otherwise
the output of block_dump will be logged, causing disk activity that is not
normally there.
Configuration
-------------

4
Documentation/admin-guide/lockup-watchdogs.rst
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@ -39,7 +39,7 @@ in principle, they should work in any architecture where these
subsystems are present.
A periodic hrtimer runs to generate interrupts and kick the watchdog
task. An NMI perf event is generated every "watchdog_thresh"
job. An NMI perf event is generated every "watchdog_thresh"
(compile-time initialized to 10 and configurable through sysctl of the
same name) seconds to check for hardlockups. If any CPU in the system
does not receive any hrtimer interrupt during that time the
@ -47,7 +47,7 @@ does not receive any hrtimer interrupt during that time the
generate a kernel warning or call panic, depending on the
configuration.
The watchdog task is a high priority kernel thread that updates a
The watchdog job runs in a stop scheduling thread that updates a
timestamp every time it is scheduled. If that timestamp is not updated
for 2*watchdog_thresh seconds (the softlockup threshold) the
'softlockup detector' (coded inside the hrtimer callback function)

15
Documentation/admin-guide/media/bt8xx.rst
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@ -15,11 +15,12 @@ Authors:
General information
-------------------
This class of cards has a bt878a as the PCI interface, and require the bttv driver
for accessing the i2c bus and the gpio pins of the bt8xx chipset.
This class of cards has a bt878a as the PCI interface, and require the bttv
driver for accessing the i2c bus and the gpio pins of the bt8xx chipset.
Please see :doc:`bttv-cardlist` for a complete list of Cards based on the
Conexant Bt8xx PCI bridge supported by the Linux Kernel.
Please see Documentation/admin-guide/media/bttv-cardlist.rst for a complete
list of Cards based on the Conexant Bt8xx PCI bridge supported by the
Linux Kernel.
In order to be able to compile the kernel, some config options should be
enabled::
@ -80,7 +81,7 @@ for dvb-bt8xx drivers by passing modprobe parameters may be necessary.
Running TwinHan and Clones
~~~~~~~~~~~~~~~~~~~~~~~~~~
As shown at :doc:`bttv-cardlist`, TwinHan and
As shown at Documentation/admin-guide/media/bttv-cardlist.rst, TwinHan and
clones use ``card=113`` modprobe parameter. So, in order to properly
detect it for devices without EEPROM, you should use::
@ -105,12 +106,12 @@ The autodetected values are determined by the cards' "response string".
In your logs see f. ex.: dst_get_device_id: Recognize [DSTMCI].
For bug reports please send in a complete log with verbose=4 activated.
Please also see :doc:`ci`.
Please also see Documentation/admin-guide/media/ci.rst.
Running multiple cards
~~~~~~~~~~~~~~~~~~~~~~
See :doc:`bttv-cardlist` for a complete list of
See Documentation/admin-guide/media/bttv-cardlist.rst for a complete list of
Card ID. Some examples:
=========================== ===

21
Documentation/admin-guide/media/bttv.rst
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@ -24,7 +24,8 @@ If your board has digital TV, you'll also need::
./scripts/config -m DVB_BT8XX
In this case, please see :doc:`bt8xx` for additional notes.
In this case, please see Documentation/admin-guide/media/bt8xx.rst
for additional notes.
Make bttv work with your card
-----------------------------
@ -39,7 +40,7 @@ If it doesn't bttv likely could not autodetect your card and needs some
insmod options. The most important insmod option for bttv is "card=n"
to select the correct card type. If you get video but no sound you've
very likely specified the wrong (or no) card type. A list of supported
cards is in :doc:`bttv-cardlist`.
cards is in Documentation/admin-guide/media/bttv-cardlist.rst.
If bttv takes very long to load (happens sometimes with the cheap
cards which have no tuner), try adding this to your modules configuration
@ -57,8 +58,8 @@ directory should be enough for it to be autoload during the driver's
probing mode (e. g. when the Kernel boots or when the driver is
manually loaded via ``modprobe`` command).
If your card isn't listed in :doc:`bttv-cardlist` or if you have
trouble making audio work, please read :ref:`still_doesnt_work`.
If your card isn't listed in Documentation/admin-guide/media/bttv-cardlist.rst
or if you have trouble making audio work, please read :ref:`still_doesnt_work`.
Autodetecting cards
@ -77,8 +78,8 @@ the Subsystem ID in the second line, looks like this:
only bt878-based cards can have a subsystem ID (which does not mean
that every card really has one). bt848 cards can't have a Subsystem
ID and therefore can't be autodetected. There is a list with the ID's
at :doc:`bttv-cardlist` (in case you are interested or want to mail
patches with updates).
at Documentation/admin-guide/media/bttv-cardlist.rst
(in case you are interested or want to mail patches with updates).
.. _still_doesnt_work:
@ -259,15 +260,15 @@ bug. It is very helpful if you can tell where exactly it broke
With a hard freeze you probably doesn't find anything in the logfiles.
The only way to capture any kernel messages is to hook up a serial
console and let some terminal application log the messages. /me uses
screen. See :doc:`/admin-guide/serial-console` for details on setting
up a serial console.
screen. See Documentation/admin-guide/serial-console.rst for details on
setting up a serial console.
Read :doc:`/admin-guide/bug-hunting` to learn how to get any useful
Read Documentation/admin-guide/bug-hunting.rst to learn how to get any useful
information out of a register+stack dump printed by the kernel on
protection faults (so-called "kernel oops").
If you run into some kind of deadlock, you can try to dump a call trace
for each process using sysrq-t (see :doc:`/admin-guide/sysrq`).
for each process using sysrq-t (see Documentation/admin-guide/sysrq.rst).
This way it is possible to figure where *exactly* some process in "D"
state is stuck.

12
Documentation/admin-guide/media/index.rst
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@ -11,12 +11,14 @@ its supported drivers.
Please see:
- :doc:`/userspace-api/media/index`
for the userspace APIs used on media devices.
Documentation/userspace-api/media/index.rst
- :doc:`/driver-api/media/index`
for driver development information and Kernel APIs used by
media devices;
- for the userspace APIs used on media devices.
Documentation/driver-api/media/index.rst
- for driver development information and Kernel APIs used by
media devices;
The media subsystem
===================

35
Documentation/admin-guide/media/ipu3.rst
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@ -234,22 +234,23 @@ The IPU3 ImgU pipelines can be configured using the Media Controller, defined at
Running mode and firmware binary selection
------------------------------------------
ImgU works based on firmware, currently the ImgU firmware support run 2 pipes in
time-sharing with single input frame data. Each pipe can run at certain mode -
"VIDEO" or "STILL", "VIDEO" mode is commonly used for video frames capture, and
"STILL" is used for still frame capture. However, you can also select "VIDEO" to
capture still frames if you want to capture images with less system load and
power. For "STILL" mode, ImgU will try to use smaller BDS factor and output
larger bayer frame for further YUV processing than "VIDEO" mode to get high
quality images. Besides, "STILL" mode need XNR3 to do noise reduction, hence
"STILL" mode will need more power and memory bandwidth than "VIDEO" mode. TNR
will be enabled in "VIDEO" mode and bypassed by "STILL" mode. ImgU is running at
“VIDEO” mode by default, the user can use v4l2 control V4L2_CID_INTEL_IPU3_MODE
(currently defined in drivers/staging/media/ipu3/include/intel-ipu3.h) to query
and set the running mode. For user, there is no difference for buffer queueing
between the "VIDEO" and "STILL" mode, mandatory input and main output node
should be enabled and buffers need be queued, the statistics and the view-finder
queues are optional.
ImgU works based on firmware, currently the ImgU firmware support run 2 pipes
in time-sharing with single input frame data. Each pipe can run at certain mode
- "VIDEO" or "STILL", "VIDEO" mode is commonly used for video frames capture,
and "STILL" is used for still frame capture. However, you can also select
"VIDEO" to capture still frames if you want to capture images with less system
load and power. For "STILL" mode, ImgU will try to use smaller BDS factor and
output larger bayer frame for further YUV processing than "VIDEO" mode to get
high quality images. Besides, "STILL" mode need XNR3 to do noise reduction,
hence "STILL" mode will need more power and memory bandwidth than "VIDEO" mode.
TNR will be enabled in "VIDEO" mode and bypassed by "STILL" mode. ImgU is
running at "VIDEO" mode by default, the user can use v4l2 control
V4L2_CID_INTEL_IPU3_MODE (currently defined in
drivers/staging/media/ipu3/include/uapi/intel-ipu3.h) to query and set the
running mode. For user, there is no difference for buffer queueing between the
"VIDEO" and "STILL" mode, mandatory input and main output node should be
enabled and buffers need be queued, the statistics and the view-finder queues
are optional.
The firmware binary will be selected according to current running mode, such log
"using binary if_to_osys_striped " or "using binary if_to_osys_primary_striped"
@ -586,7 +587,7 @@ preserved.
References
==========
.. [#f5] drivers/staging/media/ipu3/include/intel-ipu3.h
.. [#f5] drivers/staging/media/ipu3/include/uapi/intel-ipu3.h
.. [#f1] https://github.com/intel/nvt

3
Documentation/admin-guide/media/saa7134.rst
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@ -50,7 +50,8 @@ To build and install, you should run::
Once the new Kernel is booted, saa7134 driver should be loaded automatically.
Depending on the card you might have to pass ``card=<nr>`` as insmod option.
If so, please check :doc:`saa7134-cardlist` for valid choices.
If so, please check Documentation/admin-guide/media/saa7134-cardlist.rst
for valid choices.
Once you have your card type number, you can pass a modules configuration
via a file (usually, it is either ``/etc/modules.conf`` or some file at

11
Documentation/admin-guide/mm/hugetlbpage.rst
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@ -60,6 +60,10 @@ HugePages_Surp
the pool above the value in ``/proc/sys/vm/nr_hugepages``. The
maximum number of surplus huge pages is controlled by
``/proc/sys/vm/nr_overcommit_hugepages``.
Note: When the feature of freeing unused vmemmap pages associated
with each hugetlb page is enabled, the number of surplus huge pages
may be temporarily larger than the maximum number of surplus huge
pages when the system is under memory pressure.
Hugepagesize
is the default hugepage size (in Kb).
Hugetlb
@ -80,6 +84,10 @@ returned to the huge page pool when freed by a task. A user with root
privileges can dynamically allocate more or free some persistent huge pages
by increasing or decreasing the value of ``nr_hugepages``.
Note: When the feature of freeing unused vmemmap pages associated with each
hugetlb page is enabled, we can fail to free the huge pages triggered by
the user when ths system is under memory pressure. Please try again later.
Pages that are used as huge pages are reserved inside the kernel and cannot
be used for other purposes. Huge pages cannot be swapped out under
memory pressure.
@ -145,6 +153,9 @@ default_hugepagesz
will all result in 256 2M huge pages being allocated. Valid default
huge page size is architecture dependent.
hugetlb_free_vmemmap
When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables freeing
unused vmemmap pages associated with each HugeTLB page.
When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages``
indicates the current number of pre-allocated huge pages of the default size.

13
Documentation/admin-guide/mm/memory-hotplug.rst
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@ -357,6 +357,19 @@ creates ZONE_MOVABLE as following.
Unfortunately, there is no information to show which memory block belongs
to ZONE_MOVABLE. This is TBD.
Memory offlining can fail when dissolving a free huge page on ZONE_MOVABLE
and the feature of freeing unused vmemmap pages associated with each hugetlb
page is enabled.
This can happen when we have plenty of ZONE_MOVABLE memory, but not enough
kernel memory to allocate vmemmmap pages. We may even be able to migrate
huge page contents, but will not be able to dissolve the source huge page.
This will prevent an offline operation and is unfortunate as memory offlining
is expected to succeed on movable zones. Users that depend on memory hotplug
to succeed for movable zones should carefully consider whether the memory
savings gained from this feature are worth the risk of possibly not being
able to offline memory in certain situations.
.. note::
Techniques that rely on long-term pinnings of memory (especially, RDMA and
vfio) are fundamentally problematic with ZONE_MOVABLE and, therefore, memory

2
Documentation/admin-guide/mm/pagemap.rst
View File

@ -21,6 +21,8 @@ There are four components to pagemap:
* Bit 55 pte is soft-dirty (see
:ref:`Documentation/admin-guide/mm/soft-dirty.rst <soft_dirty>`)
* Bit 56 page exclusively mapped (since 4.2)
* Bit 57 pte is uffd-wp write-protected (since 5.13) (see
:ref:`Documentation/admin-guide/mm/userfaultfd.rst <userfaultfd>`)
* Bits 57-60 zero
* Bit 61 page is file-page or shared-anon (since 3.5)
* Bit 62 page swapped

3
Documentation/admin-guide/mm/userfaultfd.rst
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@ -77,7 +77,8 @@ events, except page fault notifications, may be generated:
- ``UFFD_FEATURE_MINOR_HUGETLBFS`` indicates that the kernel supports
``UFFDIO_REGISTER_MODE_MINOR`` registration for hugetlbfs virtual memory
areas.
areas. ``UFFD_FEATURE_MINOR_SHMEM`` is the analogous feature indicating
support for shmem virtual memory areas.
The userland application should set the feature flags it intends to use
when invoking the ``UFFDIO_API`` ioctl, to request that those features be

77
Documentation/admin-guide/pm/cpuidle.rst
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@ -347,81 +347,8 @@ for tickless systems. It follows the same basic strategy as the ``menu`` `one
<menu-gov_>`_: it always tries to find the deepest idle state suitable for the
given conditions. However, it applies a different approach to that problem.
First, it does not use sleep length correction factors, but instead it attempts
to correlate the observed idle duration values with the available idle states
and use that information to pick up the idle state that is most likely to
"match" the upcoming CPU idle interval. Second, it does not take the tasks
that were running on the given CPU in the past and are waiting on some I/O
operations to complete now at all (there is no guarantee that they will run on
the same CPU when they become runnable again) and the pattern detection code in
it avoids taking timer wakeups into account. It also only uses idle duration
values less than the current time till the closest timer (with the scheduler
tick excluded) for that purpose.
Like in the ``menu`` governor `case <menu-gov_>`_, the first step is to obtain
the *sleep length*, which is the time until the closest timer event with the
assumption that the scheduler tick will be stopped (that also is the upper bound
on the time until the next CPU wakeup). That value is then used to preselect an
idle state on the basis of three metrics maintained for each idle state provided
by the ``CPUIdle`` driver: ``hits``, ``misses`` and ``early_hits``.
The ``hits`` and ``misses`` metrics measure the likelihood that a given idle
state will "match" the observed (post-wakeup) idle duration if it "matches" the
sleep length. They both are subject to decay (after a CPU wakeup) every time
the target residency of the idle state corresponding to them is less than or
equal to the sleep length and the target residency of the next idle state is
greater than the sleep length (that is, when the idle state corresponding to
them "matches" the sleep length). The ``hits`` metric is increased if the
former condition is satisfied and the target residency of the given idle state
is less than or equal to the observed idle duration and the target residency of
the next idle state is greater than the observed idle duration at the same time
(that is, it is increased when the given idle state "matches" both the sleep
length and the observed idle duration). In turn, the ``misses`` metric is
increased when the given idle state "matches" the sleep length only and the
observed idle duration is too short for its target residency.
The ``early_hits`` metric measures the likelihood that a given idle state will
"match" the observed (post-wakeup) idle duration if it does not "match" the
sleep length. It is subject to decay on every CPU wakeup and it is increased
when the idle state corresponding to it "matches" the observed (post-wakeup)
idle duration and the target residency of the next idle state is less than or
equal to the sleep length (i.e. the idle state "matching" the sleep length is
deeper than the given one).
The governor walks the list of idle states provided by the ``CPUIdle`` driver
and finds the last (deepest) one with the target residency less than or equal
to the sleep length. Then, the ``hits`` and ``misses`` metrics of that idle
state are compared with each other and it is preselected if the ``hits`` one is
greater (which means that that idle state is likely to "match" the observed idle
duration after CPU wakeup). If the ``misses`` one is greater, the governor
preselects the shallower idle state with the maximum ``early_hits`` metric
(or if there are multiple shallower idle states with equal ``early_hits``
metric which also is the maximum, the shallowest of them will be preselected).
[If there is a wakeup latency constraint coming from the `PM QoS framework
<cpu-pm-qos_>`_ which is hit before reaching the deepest idle state with the
target residency within the sleep length, the deepest idle state with the exit
latency within the constraint is preselected without consulting the ``hits``,
``misses`` and ``early_hits`` metrics.]
Next, the governor takes several idle duration values observed most recently
into consideration and if at least a half of them are greater than or equal to
the target residency of the preselected idle state, that idle state becomes the
final candidate to ask for. Otherwise, the average of the most recent idle
duration values below the target residency of the preselected idle state is
computed and the governor walks the idle states shallower than the preselected
one and finds the deepest of them with the target residency within that average.
That idle state is then taken as the final candidate to ask for.
Still, at this point the governor may need to refine the idle state selection if
it has not decided to `stop the scheduler tick <idle-cpus-and-tick_>`_. That
generally happens if the target residency of the idle state selected so far is
less than the tick period and the tick has not been stopped already (in a
previous iteration of the idle loop). Then, like in the ``menu`` governor
`case <menu-gov_>`_, the sleep length used in the previous computations may not
reflect the real time until the closest timer event and if it really is greater
than that time, a shallower state with a suitable target residency may need to
be selected.
.. kernel-doc:: drivers/cpuidle/governors/teo.c
:doc: teo-description
.. _idle-states-representation:

16
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@ -20,8 +20,8 @@ Nehalem and later generations of Intel processors, but the level of support for
a particular processor model in it depends on whether or not it recognizes that
processor model and may also depend on information coming from the platform
firmware. [To understand ``intel_idle`` it is necessary to know how ``CPUIdle``
works in general, so this is the time to get familiar with :doc:`cpuidle` if you
have not done that yet.]
works in general, so this is the time to get familiar with
Documentation/admin-guide/pm/cpuidle.rst if you have not done that yet.]
``intel_idle`` uses the ``MWAIT`` instruction to inform the processor that the
logical CPU executing it is idle and so it may be possible to put some of the
@ -53,7 +53,8 @@ processor) corresponding to them depends on the processor model and it may also
depend on the configuration of the platform.
In order to create a list of available idle states required by the ``CPUIdle``
subsystem (see :ref:`idle-states-representation` in :doc:`cpuidle`),
subsystem (see :ref:`idle-states-representation` in
Documentation/admin-guide/pm/cpuidle.rst),
``intel_idle`` can use two sources of information: static tables of idle states
for different processor models included in the driver itself and the ACPI tables
of the system. The former are always used if the processor model at hand is
@ -98,7 +99,8 @@ states may not be enabled by default if there are no matching entries in the
preliminary list of idle states coming from the ACPI tables. In that case user
space still can enable them later (on a per-CPU basis) with the help of
the ``disable`` idle state attribute in ``sysfs`` (see
:ref:`idle-states-representation` in :doc:`cpuidle`). This basically means that
:ref:`idle-states-representation` in
Documentation/admin-guide/pm/cpuidle.rst). This basically means that
the idle states "known" to the driver may not be enabled by default if they have
not been exposed by the platform firmware (through the ACPI tables).
@ -186,7 +188,8 @@ be desirable. In practice, it is only really necessary to do that if the idle
states in question cannot be enabled during system startup, because in the
working state of the system the CPU power management quality of service (PM
QoS) feature can be used to prevent ``CPUIdle`` from touching those idle states
even if they have been enumerated (see :ref:`cpu-pm-qos` in :doc:`cpuidle`).
even if they have been enumerated (see :ref:`cpu-pm-qos` in
Documentation/admin-guide/pm/cpuidle.rst).
Setting ``max_cstate`` to 0 causes the ``intel_idle`` initialization to fail.
The ``no_acpi`` and ``use_acpi`` module parameters (recognized by ``intel_idle``
@ -202,7 +205,8 @@ Namely, the positions of the bits that are set in the ``states_off`` value are
the indices of idle states to be disabled by default (as reflected by the names
of the corresponding idle state directories in ``sysfs``, :file:`state0`,
:file:`state1` ... :file:`state<i>` ..., where ``<i>`` is the index of the given
idle state; see :ref:`idle-states-representation` in :doc:`cpuidle`).
idle state; see :ref:`idle-states-representation` in
Documentation/admin-guide/pm/cpuidle.rst).
For example, if ``states_off`` is equal to 3, the driver will disable idle
states 0 and 1 by default, and if it is equal to 8, idle state 3 will be

15
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@ -18,8 +18,8 @@ General Information
(``CPUFreq``). It is a scaling driver for the Sandy Bridge and later
generations of Intel processors. Note, however, that some of those processors
may not be supported. [To understand ``intel_pstate`` it is necessary to know
how ``CPUFreq`` works in general, so this is the time to read :doc:`cpufreq` if
you have not done that yet.]
how ``CPUFreq`` works in general, so this is the time to read
Documentation/admin-guide/pm/cpufreq.rst if you have not done that yet.]
For the processors supported by ``intel_pstate``, the P-state concept is broader
than just an operating frequency or an operating performance point (see the
@ -365,6 +365,9 @@ argument is passed to the kernel in the command line.
inclusive) including both turbo and non-turbo P-states (see
`Turbo P-states Support`_).
This attribute is present only if the value exposed by it is the same
for all of the CPUs in the system.
The value of this attribute is not affected by the ``no_turbo``
setting described `below <no_turbo_attr_>`_.
@ -374,6 +377,9 @@ argument is passed to the kernel in the command line.
Ratio of the `turbo range <turbo_>`_ size to the size of the entire
range of supported P-states, in percent.
This attribute is present only if the value exposed by it is the same
for all of the CPUs in the system.
This attribute is read-only.
.. _no_turbo_attr:
@ -445,8 +451,9 @@ Interpretation of Policy Attributes
-----------------------------------
The interpretation of some ``CPUFreq`` policy attributes described in
:doc:`cpufreq` is special with ``intel_pstate`` as the current scaling driver
and it generally depends on the driver's `operation mode <Operation Modes_>`_.
Documentation/admin-guide/pm/cpufreq.rst is special with ``intel_pstate``
as the current scaling driver and it generally depends on the driver's
`operation mode <Operation Modes_>`_.
First of all, the values of the ``cpuinfo_max_freq``, ``cpuinfo_min_freq`` and
``scaling_cur_freq`` attributes are produced by applying a processor-specific

14
Documentation/admin-guide/pstore-blk.rst
View File

@ -45,15 +45,18 @@ blkdev
The block device to use. Most of the time, it is a partition of block device.
It's required for pstore/blk. It is also used for MTD device.
It accepts the following variants for block device:
When pstore/blk is built as a module, "blkdev" accepts the following variants:
1. <hex_major><hex_minor> device number in hexadecimal represents itself; no
leading 0x, for example b302.
#. /dev/<disk_name> represents the device number of disk
1. /dev/<disk_name> represents the device number of disk
#. /dev/<disk_name><decimal> represents the device number of partition - device
number of disk plus the partition number
#. /dev/<disk_name>p<decimal> - same as the above; this form is used when disk
name of partitioned disk ends with a digit.
When pstore/blk is built into the kernel, "blkdev" accepts the following variants:
#. <hex_major><hex_minor> device number in hexadecimal representation,
with no leading 0x, for example b302.
#. PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF represents the unique id of
a partition if the partition table provides it. The UUID may be either an
EFI/GPT UUID, or refer to an MSDOS partition using the format SSSSSSSS-PP,
@ -227,8 +230,5 @@ For developer reference, here are all the important structures and APIs:
.. kernel-doc:: include/linux/pstore_zone.h
:internal:
.. kernel-doc:: fs/pstore/blk.c
:internal:
.. kernel-doc:: include/linux/pstore_blk.h
:internal:

2
Documentation/admin-guide/reporting-issues.rst
View File

@ -1248,7 +1248,7 @@ paragraph makes the severeness obvious.
In case you performed a successful bisection, use the title of the change that
introduced the regression as the second part of your subject. Make the report
also mention the commit id of the culprit. In case of an unsuccessful bisection,
also mention the commit id of the culprit. In case of an unsuccessful bisection,
make your report mention the latest tested version that's working fine (say 5.7)
and the oldest where the issue occurs (say 5.8-rc1).

2
Documentation/admin-guide/sysctl/abi.rst
View File

@ -11,7 +11,7 @@ Documentation for /proc/sys/abi/
Copyright (c) 2020, Stephen Kitt
For general info, see :doc:`index`.
For general info, see Documentation/admin-guide/sysctl/index.rst.
------------------------------------------------------------------------------

78
Documentation/admin-guide/sysctl/kernel.rst
View File

@ -9,7 +9,8 @@ Copyright (c) 1998, 1999, Rik van Riel <riel@nl.linux.org>
Copyright (c) 2009, Shen Feng<shen@cn.fujitsu.com>
For general info and legal blurb, please look in :doc:`index`.
For general info and legal blurb, please look in
Documentation/admin-guide/sysctl/index.rst.
------------------------------------------------------------------------------
@ -54,7 +55,7 @@ free space valid for 30 seconds.
acpi_video_flags
================
See :doc:`/power/video`. This allows the video resume mode to be set,
See Documentation/power/video.rst. This allows the video resume mode to be set,
in a similar fashion to the ``acpi_sleep`` kernel parameter, by
combining the following values:
@ -89,7 +90,7 @@ is 0x15 and the full version number is 0x234, this file will contain
the value 340 = 0x154.
See the ``type_of_loader`` and ``ext_loader_type`` fields in
:doc:`/x86/boot` for additional information.
Documentation/x86/boot.rst for additional information.
bootloader_version (x86 only)
@ -99,7 +100,7 @@ The complete bootloader version number. In the example above, this
file will contain the value 564 = 0x234.
See the ``type_of_loader`` and ``ext_loader_ver`` fields in
:doc:`/x86/boot` for additional information.
Documentation/x86/boot.rst for additional information.
bpf_stats_enabled
@ -269,7 +270,7 @@ see the ``hostname(1)`` man page.
firmware_config
===============
See :doc:`/driver-api/firmware/fallback-mechanisms`.
See Documentation/driver-api/firmware/fallback-mechanisms.rst.
The entries in this directory allow the firmware loader helper
fallback to be controlled:
@ -297,7 +298,7 @@ crashes and outputting them to a serial console.
ftrace_enabled, stack_tracer_enabled
====================================
See :doc:`/trace/ftrace`.
See Documentation/trace/ftrace.rst.
hardlockup_all_cpu_backtrace
@ -325,7 +326,7 @@ when a hard lockup is detected.
1 Panic on hard lockup.
= ===========================
See :doc:`/admin-guide/lockup-watchdogs` for more information.
See Documentation/admin-guide/lockup-watchdogs.rst for more information.
This can also be set using the nmi_watchdog kernel parameter.
@ -333,7 +334,12 @@ hotplug
=======
Path for the hotplug policy agent.
Default value is "``/sbin/hotplug``".
Default value is ``CONFIG_UEVENT_HELPER_PATH``, which in turn defaults
to the empty string.
This file only exists when ``CONFIG_UEVENT_HELPER`` is enabled. Most
modern systems rely exclusively on the netlink-based uevent source and
don't need this.
hung_task_all_cpu_backtrace
@ -582,7 +588,8 @@ in a KVM virtual machine. This default can be overridden by adding::
nmi_watchdog=1
to the guest kernel command line (see :doc:`/admin-guide/kernel-parameters`).
to the guest kernel command line (see
Documentation/admin-guide/kernel-parameters.rst).
numa_balancing
@ -1067,7 +1074,7 @@ that support this feature.
real-root-dev
=============
See :doc:`/admin-guide/initrd`.
See Documentation/admin-guide/initrd.rst.
reboot-cmd (SPARC only)
@ -1088,6 +1095,13 @@ Model available). If your platform happens to meet the
requirements for EAS but you do not want to use it, change
this value to 0.
task_delayacct
===============
Enables/disables task delay accounting (see
:doc:`accounting/delay-accounting.rst`). Enabling this feature incurs
a small amount of overhead in the scheduler but is useful for debugging
and performance tuning. It is required by some tools such as iotop.
sched_schedstats
================
@ -1154,7 +1168,7 @@ will take effect.
seccomp
=======
See :doc:`/userspace-api/seccomp_filter`.
See Documentation/userspace-api/seccomp_filter.rst.
sg-big-buff
@ -1283,11 +1297,11 @@ This parameter can be used to control the soft lockup detector.
= =================================
The soft lockup detector monitors CPUs for threads that are hogging the CPUs
without rescheduling voluntarily, and thus prevent the 'watchdog/N' threads
from running. The mechanism depends on the CPUs ability to respond to timer
interrupts which are needed for the 'watchdog/N' threads to be woken up by
the watchdog timer function, otherwise the NMI watchdog — if enabled — can
detect a hard lockup condition.
without rescheduling voluntarily, and thus prevent the 'migration/N' threads
from running, causing the watchdog work fail to execute. The mechanism depends
on the CPUs ability to respond to timer interrupts which are needed for the
watchdog work to be queued by the watchdog timer function, otherwise the NMI
watchdog — if enabled — can detect a hard lockup condition.
stack_erasing
@ -1325,7 +1339,7 @@ the boot PROM.
sysrq
=====
See :doc:`/admin-guide/sysrq`.
See Documentation/admin-guide/sysrq.rst.
tainted
@ -1355,15 +1369,16 @@ ORed together. The letters are seen in "Tainted" line of Oops reports.
131072 `(T)` The kernel was built with the struct randomization plugin
====== ===== ==============================================================
See :doc:`/admin-guide/tainted-kernels` for more information.
See Documentation/admin-guide/tainted-kernels.rst for more information.
Note:
writes to this sysctl interface will fail with ``EINVAL`` if the kernel is
booted with the command line option ``panic_on_taint=<bitmask>,nousertaint``
and any of the ORed together values being written to ``tainted`` match with
the bitmask declared on panic_on_taint.
See :doc:`/admin-guide/kernel-parameters` for more details on that particular
kernel command line option and its optional ``nousertaint`` switch.
See Documentation/admin-guide/kernel-parameters.rst for more details on
that particular kernel command line option and its optional
``nousertaint`` switch.
threads-max
===========
@ -1387,7 +1402,7 @@ If a value outside of this range is written to ``threads-max`` an
traceoff_on_warning
===================
When set, disables tracing (see :doc:`/trace/ftrace`) when a
When set, disables tracing (see Documentation/trace/ftrace.rst) when a
``WARN()`` is hit.
@ -1407,8 +1422,8 @@ will send them to printk() again.
This only works if the kernel was booted with ``tp_printk`` enabled.
See :doc:`/admin-guide/kernel-parameters` and
:doc:`/trace/boottime-trace`.
See Documentation/admin-guide/kernel-parameters.rst and
Documentation/trace/boottime-trace.rst.
.. _unaligned-dump-stack:
@ -1458,11 +1473,22 @@ unprivileged_bpf_disabled
=========================
Writing 1 to this entry will disable unprivileged calls to ``bpf()``;
once disabled, calling ``bpf()`` without ``CAP_SYS_ADMIN`` will return
``-EPERM``.
once disabled, calling ``bpf()`` without ``CAP_SYS_ADMIN`` or ``CAP_BPF``
will return ``-EPERM``. Once set to 1, this can't be cleared from the
running kernel anymore.
Once set, this can't be cleared.
Writing 2 to this entry will also disable unprivileged calls to ``bpf()``,
however, an admin can still change this setting later on, if needed, by
writing 0 or 1 to this entry.
If ``BPF_UNPRIV_DEFAULT_OFF`` is enabled in the kernel config, then this
entry will default to 2 instead of 0.
= =============================================================
0 Unprivileged calls to ``bpf()`` are enabled
1 Unprivileged calls to ``bpf()`` are disabled without recovery
2 Unprivileged calls to ``bpf()`` are disabled
= =============================================================
watchdog
========

50
Documentation/admin-guide/sysctl/vm.rst
View File

@ -25,7 +25,6 @@ files can be found in mm/swap.c.
Currently, these files are in /proc/sys/vm:
- admin_reserve_kbytes
- block_dump
- compact_memory
- compaction_proactiveness
- compact_unevictable_allowed
@ -64,7 +63,7 @@ Currently, these files are in /proc/sys/vm:
- overcommit_ratio
- page-cluster
- panic_on_oom
- percpu_pagelist_fraction
- percpu_pagelist_high_fraction
- stat_interval
- stat_refresh
- numa_stat
@ -106,13 +105,6 @@ On x86_64 this is about 128MB.
Changing this takes effect whenever an application requests memory.
block_dump
==========
block_dump enables block I/O debugging when set to a nonzero value. More
information on block I/O debugging is in Documentation/admin-guide/laptops/laptop-mode.rst.
compact_memory
==============
@ -790,22 +782,24 @@ panic_on_oom=2+kdump gives you very strong tool to investigate
why oom happens. You can get snapshot.
percpu_pagelist_fraction
========================
percpu_pagelist_high_fraction
=============================
This is the fraction of pages at most (high mark pcp->high) in each zone that
are allocated for each per cpu page list. The min value for this is 8. It
means that we don't allow more than 1/8th of pages in each zone to be
allocated in any single per_cpu_pagelist. This entry only changes the value
of hot per cpu pagelists. User can specify a number like 100 to allocate
1/100th of each zone to each per cpu page list.
This is the fraction of pages in each zone that are can be stored to
per-cpu page lists. It is an upper boundary that is divided depending
on the number of online CPUs. The min value for this is 8 which means
that we do not allow more than 1/8th of pages in each zone to be stored
on per-cpu page lists. This entry only changes the value of hot per-cpu
page lists. A user can specify a number like 100 to allocate 1/100th of
each zone between per-cpu lists.
The batch value of each per cpu pagelist is also updated as a result. It is
set to pcp->high/4. The upper limit of batch is (PAGE_SHIFT * 8)
The batch value of each per-cpu page list remains the same regardless of
the value of the high fraction so allocation latencies are unaffected.
The initial value is zero. Kernel does not use this value at boot time to set
the high water marks for each per cpu page list. If the user writes '0' to this
sysctl, it will revert to this default behavior.
The initial value is zero. Kernel uses this value to set the high pcp->high
mark based on the low watermark for the zone and the number of local
online CPUs. If the user writes '0' to this sysctl, it will revert to
this default behavior.
stat_interval
@ -936,12 +930,12 @@ allocations, THP and hugetlbfs pages.
To make it sensible with respect to the watermark_scale_factor
parameter, the unit is in fractions of 10,000. The default value of
15,000 on !DISCONTIGMEM configurations means that up to 150% of the high
watermark will be reclaimed in the event of a pageblock being mixed due
to fragmentation. The level of reclaim is determined by the number of
fragmentation events that occurred in the recent past. If this value is
smaller than a pageblock then a pageblocks worth of pages will be reclaimed
(e.g. 2MB on 64-bit x86). A boost factor of 0 will disable the feature.
15,000 means that up to 150% of the high watermark will be reclaimed in the
event of a pageblock being mixed due to fragmentation. The level of reclaim
is determined by the number of fragmentation events that occurred in the
recent past. If this value is smaller than a pageblock then a pageblocks
worth of pages will be reclaimed (e.g. 2MB on 64-bit x86). A boost factor
of 0 will disable the feature.
watermark_scale_factor

29
Documentation/admin-guide/thunderbolt.rst
View File

@ -256,6 +256,35 @@ Note names of the NVMem devices ``nvm_activeN`` and ``nvm_non_activeN``
depend on the order they are registered in the NVMem subsystem. N in
the name is the identifier added by the NVMem subsystem.
Upgrading on-board retimer NVM when there is no cable connected
---------------------------------------------------------------
If the platform supports, it may be possible to upgrade the retimer NVM
firmware even when there is nothing connected to the USB4
ports. When this is the case the ``usb4_portX`` devices have two special
attributes: ``offline`` and ``rescan``. The way to upgrade the firmware
is to first put the USB4 port into offline mode::
# echo 1 > /sys/bus/thunderbolt/devices/0-0/usb4_port1/offline
This step makes sure the port does not respond to any hotplug events,
and also ensures the retimers are powered on. The next step is to scan
for the retimers::
# echo 1 > /sys/bus/thunderbolt/devices/0-0/usb4_port1/rescan
This enumerates and adds the on-board retimers. Now retimer NVM can be
upgraded in the same way than with cable connected (see previous
section). However, the retimer is not disconnected as we are offline
mode) so after writing ``1`` to ``nvm_authenticate`` one should wait for
5 or more seconds before running rescan again::
# echo 1 > /sys/bus/thunderbolt/devices/0-0/usb4_port1/rescan
This point if everything went fine, the port can be put back to
functional state again::
# echo 0 > /sys/bus/thunderbolt/devices/0-0/usb4_port1/offline
Upgrading NVM when host controller is in safe mode
--------------------------------------------------
If the existing NVM is not properly authenticated (or is missing) the

2
Documentation/arm/marvell.rst
View File

@ -259,7 +259,7 @@ Storage family
https://web.archive.org/web/20191129073953/http://www.marvell.com/storage/armada-sp/
Core:
Sheeva ARMv7 comatible Quad-core PJ4C
Sheeva ARMv7 compatible Quad-core PJ4C
(not supported in upstream Linux kernel)

6
Documentation/arm64/booting.rst
View File

@ -277,6 +277,12 @@ Before jumping into the kernel, the following conditions must be met:
- SCR_EL3.FGTEn (bit 27) must be initialised to 0b1.
For CPUs with support for HCRX_EL2 (FEAT_HCX) present:
- If EL3 is present and the kernel is entered at EL2:
- SCR_EL3.HXEn (bit 38) must be initialised to 0b1.
For CPUs with Advanced SIMD and floating point support:
- If EL3 is present:

24
Documentation/arm64/tagged-address-abi.rst
View File

@ -45,14 +45,24 @@ how the user addresses are used by the kernel:
1. User addresses not accessed by the kernel but used for address space
management (e.g. ``mprotect()``, ``madvise()``). The use of valid
tagged pointers in this context is allowed with the exception of
``brk()``, ``mmap()`` and the ``new_address`` argument to
``mremap()`` as these have the potential to alias with existing
user addresses.
tagged pointers in this context is allowed with these exceptions:
NOTE: This behaviour changed in v5.6 and so some earlier kernels may
incorrectly accept valid tagged pointers for the ``brk()``,
``mmap()`` and ``mremap()`` system calls.
- ``brk()``, ``mmap()`` and the ``new_address`` argument to
``mremap()`` as these have the potential to alias with existing
user addresses.
NOTE: This behaviour changed in v5.6 and so some earlier kernels may
incorrectly accept valid tagged pointers for the ``brk()``,
``mmap()`` and ``mremap()`` system calls.
- The ``range.start``, ``start`` and ``dst`` arguments to the
``UFFDIO_*`` ``ioctl()``s used on a file descriptor obtained from
``userfaultfd()``, as fault addresses subsequently obtained by reading
the file descriptor will be untagged, which may otherwise confuse
tag-unaware programs.
NOTE: This behaviour changed in v5.14 and so some earlier kernels may
incorrectly accept valid tagged pointers for this system call.
2. User addresses accessed by the kernel (e.g. ``write()``). This ABI
relaxation is disabled by default and the application thread needs to

38
Documentation/block/bfq-iosched.rst
View File

@ -553,20 +553,36 @@ throughput sustainable with bfq, because updating the blkio.bfq.*
stats is rather costly, especially for some of the stats enabled by
CONFIG_BFQ_CGROUP_DEBUG.
Parameters to set
-----------------
Parameters
----------
For each group, there is only the following parameter to set.
For each group, the following parameters can be set:
weight (namely blkio.bfq.weight or io.bfq-weight): the weight of the
group inside its parent. Available values: 1..1000 (default 100). The
linear mapping between ioprio and weights, described at the beginning
of the tunable section, is still valid, but all weights higher than
IOPRIO_BE_NR*10 are mapped to ioprio 0.
weight
This specifies the default weight for the cgroup inside its parent.
Available values: 1..1000 (default: 100).
Recall that, if low-latency is set, then BFQ automatically raises the
weight of the queues associated with interactive and soft real-time
applications. Unset this tunable if you need/want to control weights.
For cgroup v1, it is set by writing the value to `blkio.bfq.weight`.
For cgroup v2, it is set by writing the value to `io.bfq.weight`.
(with an optional prefix of `default` and a space).
The linear mapping between ioprio and weights, described at the beginning
of the tunable section, is still valid, but all weights higher than
IOPRIO_BE_NR*10 are mapped to ioprio 0.
Recall that, if low-latency is set, then BFQ automatically raises the
weight of the queues associated with interactive and soft real-time
applications. Unset this tunable if you need/want to control weights.
weight_device
This specifies a per-device weight for the cgroup. The syntax is
`minor:major weight`. A weight of `0` may be used to reset to the default
weight.
For cgroup v1, it is set by writing the value to `blkio.bfq.weight_device`.
For cgroup v2, the file name is `io.bfq.weight`.
[1]

2
Documentation/block/biodoc.rst
View File

@ -196,7 +196,7 @@ a virtual address mapping (unlike the earlier scheme of virtual address
do not have a corresponding kernel virtual address space mapping) and
low-memory pages.
Note: Please refer to :doc:`/core-api/dma-api-howto` for a discussion
Note: Please refer to Documentation/core-api/dma-api-howto.rst for a discussion
on PCI high mem DMA aspects and mapping of scatter gather lists, and support
for 64 bit PCI.

4
Documentation/block/blk-mq.rst
View File

@ -62,7 +62,7 @@ queue, to be sent in the future, when the hardware is able.
Software staging queues
~~~~~~~~~~~~~~~~~~~~~~~
The block IO subsystem adds requests in the software staging queues
The block IO subsystem adds requests in the software staging queues
(represented by struct blk_mq_ctx) in case that they weren't sent
directly to the driver. A request is one or more BIOs. They arrived at the
block layer through the data structure struct bio. The block layer
@ -132,7 +132,7 @@ In order to indicate which request has been completed, every request is
identified by an integer, ranging from 0 to the dispatch queue size. This tag
is generated by the block layer and later reused by the device driver, removing
the need to create a redundant identifier. When a request is completed in the
drive, the tag is sent back to the block layer to notify it of the finalization.
driver, the tag is sent back to the block layer to notify it of the finalization.
This removes the need to do a linear search to find out which IO has been
completed.

2
Documentation/block/stat.rst
View File

@ -18,7 +18,7 @@ A.
each, it would be impossible to guarantee that a set of readings
represent a single point in time.
The stat file consists of a single line of text containing 11 decimal
The stat file consists of a single line of text containing 17 decimal
values separated by whitespace. The fields are summarized in the
following table, and described in more detail below.

13
Documentation/bpf/bpf_lsm.rst
View File

@ -20,10 +20,10 @@ LSM hook:
Other LSM hooks which can be instrumented can be found in
``include/linux/lsm_hooks.h``.
eBPF programs that use :doc:`/bpf/btf` do not need to include kernel headers
for accessing information from the attached eBPF program's context. They can
simply declare the structures in the eBPF program and only specify the fields
that need to be accessed.
eBPF programs that use Documentation/bpf/btf.rst do not need to include kernel
headers for accessing information from the attached eBPF program's context.
They can simply declare the structures in the eBPF program and only specify
the fields that need to be accessed.
.. code-block:: c
@ -88,8 +88,9 @@ example:
The ``__attribute__((preserve_access_index))`` is a clang feature that allows
the BPF verifier to update the offsets for the access at runtime using the
:doc:`/bpf/btf` information. Since the BPF verifier is aware of the types, it
also validates all the accesses made to the various types in the eBPF program.
Documentation/bpf/btf.rst information. Since the BPF verifier is aware of the
types, it also validates all the accesses made to the various types in the
eBPF program.
Loading
-------

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