A PCI endpoint function driver can define function specific attributes
under its function configfs directory using the add_cfs() endpoint driver
operation. This is done by tying up the mkdir operation for the function
configfs directory to a call to the add_cfs() operation. However, there
are no checks preventing the user from repeatedly creating function
specific attribute directories with different names, resulting in the same
endpoint specific attributes group being added multiple times, which also
result in an invalid reference counting for the attribute groups. E.g.,
using the pci-epf-ntb function driver as an example, the user creates the
function as follows:
$ modprobe pci-epf-ntb
$ cd /sys/kernel/config/pci_ep/functions/pci_epf_ntb
$ mkdir func0
$ tree func0
func0/
|-- baseclass_code
|-- cache_line_size
|-- ...
`-- vendorid
$ mkdir func0/attrs
$ tree func0
func0/
|-- attrs
| |-- db_count
| |-- mw1
| |-- mw2
| |-- mw3
| |-- mw4
| |-- num_mws
| `-- spad_count
|-- baseclass_code
|-- cache_line_size
|-- ...
`-- vendorid
At this point, the function can be started by linking the EP controller.
However, if the user mistakenly creates again a directory:
$ mkdir func0/attrs2
$ tree func0
func0/
|-- attrs
| |-- db_count
| |-- mw1
| |-- mw2
| |-- mw3
| |-- mw4
| |-- num_mws
| `-- spad_count
|-- attrs2
| |-- db_count
| |-- mw1
| |-- mw2
| |-- mw3
| |-- mw4
| |-- num_mws
| `-- spad_count
|-- baseclass_code
|-- cache_line_size
|-- ...
`-- vendorid
The endpoint function specific attributes are duplicated and cause a crash
when the endpoint function device is torn down:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 2 PID: 834 at lib/refcount.c:25 refcount_warn_saturate+0xc8/0x144
CPU: 2 PID: 834 Comm: rmdir Not tainted 6.3.0-rc1 #1
Hardware name: Pine64 RockPro64 v2.1 (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
...
Call trace:
refcount_warn_saturate+0xc8/0x144
config_item_get+0x7c/0x80
configfs_rmdir+0x17c/0x30c
vfs_rmdir+0x8c/0x204
do_rmdir+0x158/0x184
__arm64_sys_unlinkat+0x64/0x80
invoke_syscall+0x48/0x114
...
Fix this by modifying pci_epf_cfs_work() to execute the new function
pci_ep_cfs_add_type_group() which itself calls pci_epf_type_add_cfs() to
obtain the function specific attribute group and the group name (directory
name) from the endpoint function driver. If the function driver defines an
attribute group, pci_ep_cfs_add_type_group() then proceeds to register this
group using configfs_register_group(), thus automatically exposing the
function type specific configfs attributes to the user. E.g.:
$ modprobe pci-epf-ntb
$ cd /sys/kernel/config/pci_ep/functions/pci_epf_ntb
$ mkdir func0
$ tree func0
func0/
|-- baseclass_code
|-- cache_line_size
|-- ...
|-- pci_epf_ntb.0
| |-- db_count
| |-- mw1
| |-- mw2
| |-- mw3
| |-- mw4
| |-- num_mws
| `-- spad_count
|-- primary
|-- ...
`-- vendorid
With this change, there is no need for the user to create or delete
directories in the endpoint function attributes directory. The
pci_epf_type_group_ops group operations are thus removed.
Also update the documentation for the pci-epf-ntb and pci-epf-vntb function
drivers to reflect this change, removing the explanations showing the need
to manually create the sub-directory for the function specific attributes.
Link: https://lore.kernel.org/r/20230415023542.77601-2-dlemoal@kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
The underline syntax for "lspci output..." section is off-by-one less
than the section heading's length, hence triggers the warning:
Documentation/PCI/endpoint/pci-vntb-howto.rst:131: WARNING: Title underline too short.
Extend the underline by one to match the heading length.
Link: https://lore.kernel.org/linux-next/20220621200235.211b2e32@canb.auug.org.au/
Fixes: 0c4b285d9636cc ("Documentation: PCI: Add specification for the PCI vNTB function device")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: "Krzysztof Wilczyński" <kw@linux.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Frank Li <Frank.Li@nxp.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-next@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
The diagram in "Scratchpad Registers" isn't formatted inside code block,
hence triggers indentation warning:
Documentation/PCI/endpoint/pci-vntb-function.rst:82: WARNING: Unexpected indentation.
Fix the warning by using code-block directive to format the diagram
inside code block, as in other diagrams in Documentation/. While at it,
unindent the preceeding text.
Link: https://lore.kernel.org/linux-next/20220621200235.211b2e32@canb.auug.org.au/
Fixes: 0c4b285d9636cc ("Documentation: PCI: Add specification for the PCI vNTB function device")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: "Krzysztof Wilczyński" <kw@linux.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Frank Li <Frank.Li@nxp.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-next@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Add specification for the PCI vNTB function device. The endpoint function
driver and the host PCI driver should be created based on this
specification.
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Add Documentation to help users use PCI endpoint to create virtual
functions using configfs. An endpoint function is designated as a
virtual endpoint function device when it is linked to a physical
endpoint function device (instead of a endpoint controller).
Link: https://lore.kernel.org/r/20210819123343.1951-9-kishon@ti.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Add documentation to help users use pci-epf-ntb function driver and
existing host side NTB infrastructure for NTB functionality.
[bhelgaas: fix a few typos]
Link: https://lore.kernel.org/r/20210201195809.7342-18-kishon@ti.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Add binding documentation for pci-ntb endpoint function that helps in
adding and configuring pci-ntb endpoint function.
Link: https://lore.kernel.org/r/20210201195809.7342-17-kishon@ti.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Now that PCI endpoint core supports to add secondary endpoint controller
(EPC) with endpoint function (EPF), Add support in configfs to associate
two EPCs with EPF. This creates "primary" and "secondary" directory inside
the directory created by users for EPF device. Users have to add a symlink
of endpoint controller (pci_ep/controllers/) to "primary" or "secondary"
directory to bind EPF to primary and secondary EPF interfaces respectively.
Existing method of linking directory representing EPF device to directory
representing EPC device to associate a single EPC device with a EPF device
will continue to work.
Link: https://lore.kernel.org/r/20210201195809.7342-8-kishon@ti.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add specification for the PCI NTB function device. The endpoint function
driver and the host PCI driver should be created based on this
specification.
[bhelgaas: fix a few typos]
Link: https://lore.kernel.org/r/20210201195809.7342-2-kishon@ti.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Drop the doubled word "the".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: linux-pci@vger.kernel.org
Link: https://lore.kernel.org/r/20200703212156.30453-3-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Drop the doubled word "and".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: linux-pci@vger.kernel.org
Link: https://lore.kernel.org/r/20200703212156.30453-2-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Convert plain text documentation to reStructuredText format and add it to
Sphinx TOC tree. No essential content change.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Convert plain text documentation to reStructuredText format and add it to
Sphinx TOC tree. No essential content change.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Convert plain text documentation to reStructuredText format and add it to
Sphinx TOC tree. No essential content change.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Convert plain text documentation to reStructuredText format and add it to
Sphinx TOC tree. No essential content change.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Change tool compiling process in order to be build using the same
mechanism used in other linux tools (e.g. iio, perf, etc). This will
allow in future the buildroot tool to build and integrate this tool in
a more expeditious way.
Update documentation accordingly.
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com>
Add MSI-X support and update driver documentation accordingly.
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Cleanup PCI_ENDPOINT_TEST memspace (by moving the interrupt number away
from command section).
Add IRQ_TYPE register to identify the triggered ID interrupt required
for the READ/WRITE/COPY tests and raise IRQ test commands.
Update documentation accordingly.
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Add documentation to help users use pci-epf-test function driver and
pci_endpoint_test host driver for testing PCI.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add binding documentation for pci-test endpoint function that helps in
adding and configuring pci-test endpoint function.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add specification for the *PCI test* virtual function device. The endpoint
function driver and the host PCI driver should be created based on this
specification.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add Documentation to help users use PCI endpoint to configure PCI endpoint
function and to bind the endpoint function with endpoint controller.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-By: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add Documentation to help users use endpoint library to enable endpoint
mode in the PCI controller and add new PCI endpoint functions.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-By: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
