19383 Commits

Author SHA1 Message Date
Breno Leitao
63a0d6b03b powerpc/tm: Save MSR to PACA before RFID
As other exit points, move SRR1 (MSR) into paca->tm_scratch, so, if
there is a TM Bad Thing in RFID, it is easy to understand what was the
SRR1 value being used.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 14:46:50 +11:00
Breno Leitao
e1c3743e1a powerpc/tm: Set MSR[TS] just prior to recheckpoint
On a signal handler return, the user could set a context with MSR[TS] bits
set, and these bits would be copied to task regs->msr.

At restore_tm_sigcontexts(), after current task regs->msr[TS] bits are set,
several __get_user() are called and then a recheckpoint is executed.

This is a problem since a page fault (in kernel space) could happen when
calling __get_user(). If it happens, the process MSR[TS] bits were
already set, but recheckpoint was not executed, and SPRs are still invalid.

The page fault can cause the current process to be de-scheduled, with
MSR[TS] active and without tm_recheckpoint() being called.  More
importantly, without TEXASR[FS] bit set also.

Since TEXASR might not have the FS bit set, and when the process is
scheduled back, it will try to reclaim, which will be aborted because of
the CPU is not in the suspended state, and, then, recheckpoint. This
recheckpoint will restore thread->texasr into TEXASR SPR, which might be
zero, hitting a BUG_ON().

	kernel BUG at /build/linux-sf3Co9/linux-4.9.30/arch/powerpc/kernel/tm.S:434!
	cpu 0xb: Vector: 700 (Program Check) at [c00000041f1576d0]
	    pc: c000000000054550: restore_gprs+0xb0/0x180
	    lr: 0000000000000000
	    sp: c00000041f157950
	   msr: 8000000100021033
	  current = 0xc00000041f143000
	  paca    = 0xc00000000fb86300	 softe: 0	 irq_happened: 0x01
	    pid   = 1021, comm = kworker/11:1
	kernel BUG at /build/linux-sf3Co9/linux-4.9.30/arch/powerpc/kernel/tm.S:434!
	Linux version 4.9.0-3-powerpc64le (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian 4.9.30-2+deb9u2 (2017-06-26)
	enter ? for help
	[c00000041f157b30] c00000000001bc3c tm_recheckpoint.part.11+0x6c/0xa0
	[c00000041f157b70] c00000000001d184 __switch_to+0x1e4/0x4c0
	[c00000041f157bd0] c00000000082eeb8 __schedule+0x2f8/0x990
	[c00000041f157cb0] c00000000082f598 schedule+0x48/0xc0
	[c00000041f157ce0] c0000000000f0d28 worker_thread+0x148/0x610
	[c00000041f157d80] c0000000000f96b0 kthread+0x120/0x140
	[c00000041f157e30] c00000000000c0e0 ret_from_kernel_thread+0x5c/0x7c

This patch simply delays the MSR[TS] set, so, if there is any page fault in
the __get_user() section, it does not have regs->msr[TS] set, since the TM
structures are still invalid, thus avoiding doing TM operations for
in-kernel exceptions and possible process reschedule.

With this patch, the MSR[TS] will only be set just before recheckpointing
and setting TEXASR[FS] = 1, thus avoiding an interrupt with TM registers in
invalid state.

Other than that, if CONFIG_PREEMPT is set, there might be a preemption just
after setting MSR[TS] and before tm_recheckpoint(), thus, this block must
be atomic from a preemption perspective, thus, calling
preempt_disable/enable() on this code.

It is not possible to move tm_recheckpoint to happen earlier, because it is
required to get the checkpointed registers from userspace, with
__get_user(), thus, the only way to avoid this undesired behavior is
delaying the MSR[TS] set.

The 32-bits signal handler seems to be safe this current issue, but, it
might be exposed to the preemption issue, thus, disabling preemption in
this chunk of code.

Changes from v2:
 * Run the critical section with preempt_disable.

Fixes: 87b4e5393af7 ("powerpc/tm: Fix return of active 64bit signals")
Cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 14:46:50 +11:00
Suraj Jitindar Singh
ae59a7e194 KVM: PPC: Book3S HV: Keep rc bits in shadow pgtable in sync with host
The rc bits contained in ptes are used to track whether a page has been
accessed and whether it is dirty. The accessed bit is used to age a page
and the dirty bit to track whether a page is dirty or not.

Now that we support nested guests there are three ptes which track the
state of the same page:
- The partition-scoped page table in the L1 guest, mapping L2->L1 address
- The partition-scoped page table in the host for the L1 guest, mapping
  L1->L0 address
- The shadow partition-scoped page table for the nested guest in the host,
  mapping L2->L0 address

The idea is to attempt to keep the rc state of these three ptes in sync,
both when setting and when clearing rc bits.

When setting the bits we achieve consistency by:
- Initially setting the bits in the shadow page table as the 'and' of the
  other two.
- When updating in software the rc bits in the shadow page table we
  ensure the state is consistent with the other two locations first, and
  update these before reflecting the change into the shadow page table.
  i.e. only set the bits in the L2->L0 pte if also set in both the
       L2->L1 and the L1->L0 pte.

When clearing the bits we achieve consistency by:
- The rc bits in the shadow page table are only cleared when discarding
  a pte, and we don't need to record this as if either bit is set then
  it must also be set in the pte mapping L1->L0.
- When L1 clears an rc bit in the L2->L1 mapping it __should__ issue a
  tlbie instruction
  - This means we will discard the pte from the shadow page table
    meaning the mapping will have to be setup again.
  - When setup the pte again in the shadow page table we will ensure
    consistency with the L2->L1 pte.
- When the host clears an rc bit in the L1->L0 mapping we need to also
  clear the bit in any ptes in the shadow page table which map the same
  gfn so we will be notified if a nested guest accesses the page.
  This case is what this patch specifically concerns.
  - We can search the nest_rmap list for that given gfn and clear the
    same bit from all corresponding ptes in shadow page tables.
  - If a nested guest causes either of the rc bits to be set by software
    in future then we will update the L1->L0 pte and maintain consistency.

With the process outlined above we aim to maintain consistency of the 3
pte locations where we track rc for a given guest page.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-21 14:42:07 +11:00
Suraj Jitindar Singh
90165d3da0 KVM: PPC: Book3S HV: Introduce kvmhv_update_nest_rmap_rc_list()
Introduce a function kvmhv_update_nest_rmap_rc_list() which for a given
nest_rmap list will traverse it, find the corresponding pte in the shadow
page tables, and if it still maps the same host page update the rc bits
accordingly.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-21 14:39:35 +11:00
Suraj Jitindar Singh
8b23eee4e5 KVM: PPC: Book3S HV: Apply combination of host and l1 pte rc for nested guest
The shadow page table contains ptes for translations from nested guest
address to host address. Currently when creating these ptes we take the
rc bits from the pte for the L1 guest address to host address
translation. This is incorrect as we must also factor in the rc bits
from the pte for the nested guest address to L1 guest address
translation (as contained in the L1 guest partition table for the nested
guest).

By not calculating these bits correctly L1 may not have been correctly
notified when it needed to update its rc bits in the partition table it
maintains for its nested guest.

Modify the code so that the rc bits in the resultant pte for the L2->L0
translation are the 'and' of the rc bits in the L2->L1 pte and the L1->L0
pte, also accounting for whether this was a write access when setting
the dirty bit.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-21 14:37:43 +11:00
Suraj Jitindar Singh
8400f87406 KVM: PPC: Book3S HV: Align gfn to L1 page size when inserting nest-rmap entry
Nested rmap entries are used to store the translation from L1 gpa to L2
gpa when entries are inserted into the shadow (nested) page tables. This
rmap list is located by indexing the rmap array in the memslot by L1
gfn. When we come to search for these entries we only know the L1 page size
(which could be PAGE_SIZE, 2M or a 1G page) and so can only select a gfn
aligned to that size. This means that when we insert the entry, so we can
find it later, we need to align the gfn we use to select the rmap list
in which to insert the entry to L1 page size as well.

By not doing this we were missing nested rmap entries when modifying L1
ptes which were for a page also passed through to an L2 guest.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-21 14:37:43 +11:00
Suraj Jitindar Singh
bec6e03b5e KVM: PPC: Book3S HV: Hold kvm->mmu_lock across updating nested pte rc bits
We already hold the kvm->mmu_lock spin lock across updating the rc bits
in the pte for the L1 guest. Continue to hold the lock across updating
the rc bits in the pte for the nested guest as well to prevent
invalidations from occurring.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-21 14:37:43 +11:00
Mahesh Salgaonkar
0db6896ff6 powerpc/fadump: Do not allow hot-remove memory from fadump reserved area.
For fadump to work successfully there should not be any holes in reserved
memory ranges where kernel has asked firmware to move the content of old
kernel memory in event of crash. Now that fadump uses CMA for reserved
area, this memory area is now not protected from hot-remove operations
unless it is cma allocated. Hence, fadump service can fail to re-register
after the hot-remove operation, if hot-removed memory belongs to fadump
reserved region. To avoid this make sure that memory from fadump reserved
area is not hot-removable if fadump is registered.

However, if user still wants to remove that memory, he can do so by
manually stopping fadump service before hot-remove operation.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Mahesh Salgaonkar
f86593be1e powerpc/fadump: Throw proper error message on fadump registration failure
fadump fails to register when there are holes in reserved memory area.
This can happen if user has hot-removed a memory that falls in the
fadump reserved memory area. Throw a meaningful error message to the
user in such case.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
[mpe: is_reserved_memory_area_contiguous() returns bool, unsplit string]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Mahesh Salgaonkar
a4e92ce8e4 powerpc/fadump: Reservationless firmware assisted dump
One of the primary issues with Firmware Assisted Dump (fadump) on Power
is that it needs a large amount of memory to be reserved. On large
systems with TeraBytes of memory, this reservation can be quite
significant.

In some cases, fadump fails if the memory reserved is insufficient, or
if the reserved memory was DLPAR hot-removed.

In the normal case, post reboot, the preserved memory is filtered to
extract only relevant areas of interest using the makedumpfile tool.
While the tool provides flexibility to determine what needs to be part
of the dump and what memory to filter out, all supported distributions
default this to "Capture only kernel data and nothing else".

We take advantage of this default and the Linux kernel's Contiguous
Memory Allocator (CMA) to fundamentally change the memory reservation
model for fadump.

Instead of setting aside a significant chunk of memory nobody can use,
this patch uses CMA instead, to reserve a significant chunk of memory
that the kernel is prevented from using (due to MIGRATE_CMA), but
applications are free to use it. With this fadump will still be able
to capture all of the kernel memory and most of the user space memory
except the user pages that were present in CMA region.

Essentially, on a P9 LPAR with 2 cores, 8GB RAM and current upstream:
[root@zzxx-yy10 ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:           7557         193        6822          12         541        6725
Swap:          4095           0        4095

With this patch:
[root@zzxx-yy10 ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:           8133         194        7464          12         475        7338
Swap:          4095           0        4095

Changes made here are completely transparent to how fadump has
traditionally worked.

Thanks to Aneesh Kumar and Anshuman Khandual for helping us understand
CMA and its usage.

TODO:
- Handle case where CMA reservation spans nodes.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Mahesh Salgaonkar
08fb726df1 powerpc/powernv: Move opal_power_control_init() call in opal_init().
opal_power_control_init() depends on opal message notifier to be
initialized, which is done in opal_init()->opal_message_init(). But both
these initialization are called through machine initcalls and it all
depends on in which order they being called. So far these are called in
correct order (may be we got lucky) and never saw any issue. But it is
clearer to control initialization order explicitly by moving
opal_power_control_init() into opal_init().

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Markus Elfring
ae6263cc33 powerpc/4xx: Delete an unnecessary return statement in two functions
The script "checkpatch.pl" pointed information out like the following.

WARNING: void function return statements are not generally useful

Thus remove such a statement in the affected functions.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Markus Elfring
a8d5dadae5 powerpc/4xx: Delete error message for a ENOMEM in two functions
Omit an extra message for a memory allocation failure in these
functions.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Markus Elfring
52930bc6e8 powerpc/4xx: Use seq_putc() in ocm_debugfs_show()
A single character (line break) should be put into a sequence.
Thus use the corresponding function "seq_putc".

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Markus Elfring
b52106a040 powerpc/4xx: Combine four seq_printf() calls into two in ocm_debugfs_show()
Some data were printed into a sequence by four separate function calls.
Print the same data by two single function calls instead.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Christophe Leroy
96d19d70e1 powerpc/8xx: Allow pinning IMMR TLB when using early debug console
CONFIG_EARLY_DEBUG_CPM requires IMMR area TLB to be pinned
otherwise it doesn't survive MMU_init, and the boot fails.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Oliver O'Halloran
5f639e5fad powerpc/powernv: Remove PCI_MSI ifdef checks
CONFIG_PCI_MSI was made mandatory by commit a311e738b6d8
("powerpc/powernv: Make PCI non-optional") so the #ifdef
checks around CONFIG_PCI_MSI here can be removed entirely.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Alexandre Belloni
a083787680 powerpc/fsl-rio: fix spelling mistake "reserverd" -> "reserved"
Fix a spelling mistake in a register description.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Ravi Bangoria
0c9108b083 Powerpc/perf: Wire up PMI throttling
Commit 14c63f17b1fde ("perf: Drop sample rate when sampling is too
slow") introduced a way to throttle PMU interrupts if we're spending
too much time just processing those. Wire up powerpc PMI handler to
use this infrastructure.

We have throttling of the *rate* of interrupts, but this adds
throttling based on the *time taken* to process the interrupts.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
David S. Miller
2be09de7d6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Lots of conflicts, by happily all cases of overlapping
changes, parallel adds, things of that nature.

Thanks to Stephen Rothwell, Saeed Mahameed, and others
for their guidance in these resolutions.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-20 11:53:36 -08:00
Radim Krčmář
cfdfaf4a86 PPC KVM update for 4.21
The main new feature this time is support in HV nested KVM for passing
 a device that is emulated by a level 0 hypervisor and presented to
 level 1 as a PCI device through to a level 2 guest using VFIO.
 
 Apart from that there are improvements for migration of radix guests
 under HV KVM and some other fixes and cleanups.
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Merge tag 'kvm-ppc-next-4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

PPC KVM update for 4.21 from Paul Mackerras

The main new feature this time is support in HV nested KVM for passing
a device that is emulated by a level 0 hypervisor and presented to
level 1 as a PCI device through to a level 2 guest using VFIO.

Apart from that there are improvements for migration of radix guests
under HV KVM and some other fixes and cleanups.
2018-12-20 14:54:09 +01:00
YueHaibing
8c6c942d33 powerpc/eeh: Fix debugfs_simple_attr.cocci warnings
Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
for debugfs files.

Semantic patch information:
Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file()
imposes some significant overhead as compared to
DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe().

Generated by: scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Alexey Kardashevskiy
c20577014f powerpc/powernv/eeh/npu: Fix uninitialized variables in opal_pci_eeh_freeze_status
The current implementation of the OPAL_PCI_EEH_FREEZE_STATUS call in
skiboot's NPU driver does not touch the pci_error_type parameter so
it might have garbage but the powernv code analyzes it nevertheless.

This initializes pcierr and fstate to zero in all call sites.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Alexey Kardashevskiy
a25de7af34 powerpc/powernv/ioda: Reduce a number of hooks in pnv_phb
fixup_phb() is never used, this removes it.

pick_m64_pe() and reserve_m64_pe() are always defined for all powernv
PHBs: they are initialized by pnv_ioda_parse_m64_window() which is
called unconditionally from pnv_pci_init_ioda_phb() which initializes
all known PHB types on powernv so we can open code them.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
dfa88658fb powerpc/fsl: Update Spectre v2 reporting
Report branch predictor state flush as a mitigation for
Spectre variant 2.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Alexey Kardashevskiy
f21b0a45e4 powerpc/powernv/ioda1: Remove dead code for a single device PE
At the moment PNV_IODA_PE_DEV is only used for NPU PEs which are not
present on IODA1 machines (i.e. POWER7) so let's remove a piece of
dead code.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
3bc8ea8603 powerpc/fsl: Enable runtime patching if nospectre_v2 boot arg is used
If the user choses not to use the mitigations, replace
the code sequence with nops.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
e7aa61f47b powerpc/fsl: Flush branch predictor when entering KVM
Switching from the guest to host is another place
where the speculative accesses can be exploited.
Flush the branch predictor when entering KVM.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Alexey Kardashevskiy
fa1ada7889 powerpc/powernv/npu: Remove unused headers and a macro.
The macro and few headers are not used so remove them.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
7fef436295 powerpc/fsl: Flush the branch predictor at each kernel entry (32 bit)
In order to protect against speculation attacks on
indirect branches, the branch predictor is flushed at
kernel entry to protect for the following situations:
- userspace process attacking another userspace process
- userspace process attacking the kernel
Basically when the privillege level change (i.e.the kernel
is entered), the branch predictor state is flushed.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Alexey Kardashevskiy
bdbf649efe powerpc/powernv/ioda: Allocate indirect TCE levels of cached userspace addresses on demand
The powernv platform maintains 2 TCE tables for VFIO - a hardware TCE
table and a table with userspace addresses; the latter is used for
marking pages dirty when corresponging TCEs are unmapped from
the hardware table.

a68bd1267b72 ("powerpc/powernv/ioda: Allocate indirect TCE levels
on demand") enabled on-demand allocation of the hardware table,
however it missed the other table so it has still been fully allocated
at the boot time. This fixes the issue by allocating a single level,
just like we do for the hardware table.

Fixes: a68bd1267b72 ("powerpc/powernv/ioda: Allocate indirect TCE levels on demand")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
10c5e83afd powerpc/fsl: Flush the branch predictor at each kernel entry (64bit)
In order to protect against speculation attacks on
indirect branches, the branch predictor is flushed at
kernel entry to protect for the following situations:
- userspace process attacking another userspace process
- userspace process attacking the kernel
Basically when the privillege level change (i.e. the
kernel is entered), the branch predictor state is flushed.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
f633a8ad63 powerpc/fsl: Add nospectre_v2 command line argument
When the command line argument is present, the Spectre variant 2
mitigations are disabled.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
98518c4d87 powerpc/fsl: Emulate SPRN_BUCSR register
In order to flush the branch predictor the guest kernel performs
writes to the BUCSR register which is hypervisor privilleged. However,
the branch predictor is flushed at each KVM entry, so the branch
predictor has been already flushed, so just return as soon as possible
to guest.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
[mpe: Tweak comment formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
7d8bad99ba powerpc/fsl: Fix spectre_v2 mitigations reporting
Currently for CONFIG_PPC_FSL_BOOK3E the spectre_v2 file is incorrect:

  $ cat /sys/devices/system/cpu/vulnerabilities/spectre_v2
  "Mitigation: Software count cache flush"

Which is wrong. Fix it to report vulnerable for now.

Fixes: ee13cb249fab ("powerpc/64s: Add support for software count cache flush")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
1cbf8990d7 powerpc/fsl: Add macro to flush the branch predictor
The BUCSR register can be used to invalidate the entries in the
branch prediction mechanisms.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:58:57 +11:00
Diana Craciun
76a5eaa38b powerpc/fsl: Add infrastructure to fixup branch predictor flush
In order to protect against speculation attacks (Spectre
variant 2) on NXP PowerPC platforms, the branch predictor
should be flushed when the privillege level is changed.
This patch is adding the infrastructure to fixup at runtime
the code sections that are performing the branch predictor flush
depending on a boot arg parameter which is added later in a
separate patch.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:53:39 +11:00
Christophe Leroy
f242e0ac95 powerpc/prom: move the device tree if not in declared memory.
If the device tree doesn't reside in the memory which is declared
inside it, it has to be moved as well as this memory will not be
mapped by the kernel.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Michael Ellerman
2b874a5c7b powerpc/configs: Don't enable PPC_EARLY_DEBUG in defconfigs
This reverts the remains of commit b9ef7d6b11c1 ("powerpc: Update
default configurations").

That commit was proceeded by a commit which added a config option to
control use of BOOTX for early debug, ie. PPC_EARLY_DEBUG_BOOTX, and
then the update of the defconfigs was intended to not change behaviour
by then enabling the new config option.

However enabling PPC_EARLY_DEBUG had other consequences, notably
causing us to register the udbg console at the end of udbg_early_init().

This means on a system which doesn't have anything that BOOTX can
use (most systems), we register the udbg console very early but the
bootx code just throws everything away, meaning early boot messages
are never printed to the console.

What we want to happen is for the udbg console to only be registered
later (from setup_arch()) once we've setup udbg_putc, and then all
early boot messages will be replayed.

Fixes: b9ef7d6b11c1 ("powerpc: Update default configurations")
Reported-by: Torsten Duwe <duwe@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Arnd Bergmann
2fea82db11 powerpc: eeh_event: convert semaphore to completion
For this use case, completions and semaphores are equivalent,
but semaphores are an awkward interface that should generally
be avoided, so use the completion instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Benjamin Herrenschmidt
3cfb9ebe90 powerpc/44x/bamboo: Fix PCI range
The bamboo dts has a bug: it uses a non-naturally aligned range
for PCI memory space. This isnt' supported by the code, thus
causing PCI to break on this system.

This is due to the fact that while the chip memory map has 1G
reserved for PCI memory, it's only 512M aligned. The code doesn't
know how to split that into 2 different PMMs and fails, so limit
the region to 512M.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Darren Stevens
51f4cc2047 powerpc/pasemi: Add Nemo board IRQ initroutine
Add a IRQ init routine for the Nemo board which inits and attatches
the i8259 found in the SB600, and a cascade routine to dispatch the
interrupts.

Signed-off-by: Darren Stevens <darren@stevens-zone.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Darren Stevens
656fdf3ad8 powerpc/pasemi: Add Nemo board device init code.
Add routines for Nemo specific devices to init at boot time, these
being board level power-off and SB600's rtc.

Also add a run time variable to prevent these being activated
if we boot on a reference board.

Signed-off-by: Darren Stevens <darren@stevens-zone.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Darren Stevens
0428a5f494 powerpc/pasemi: Add Nemo board IRQ initroutine
Add a IRQ init routine for the Nemo board which inits and attatches
the i8259 found in the SB600, and a cascade routine to dispatch the
interrupts.

Signed-off-by: Darren Stevens <darren@stevens-zone.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Darren Stevens
68f211a4d1 powerpc/pasemi: Add PCI initialisation for Nemo board.
The A-Eon Amigaone X1000's Nemo motherboard has an AMD SB600
connected to one of the PCI-e root ports on its PaSemi
Pwrficient 1628M SoC. Normally the SB600 southbridge would be
connected to a hidden PCI-e port on the system's northbridge,
and as a result doesn't fully comply with the PCI-e spec.

Add code to relax the PCI-e detection in both the root port
and the Linux kernel allowing on board devices to be detected.

Signed-off-by: Darren Stevens <darren@stevens-zone.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christophe Leroy
49a502ea23 powerpc/mm: Make NULL pointer deferences explicit on bad page faults.
As several other arches including x86, this patch makes it explicit
that a bad page fault is a NULL pointer dereference when the fault
address is lower than PAGE_SIZE

In the mean time, this page makes all bad_page_fault() messages
shorter so that they remain on one single line. And it prefixes them
by "BUG: " so that they get easily grepped.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Avoid pr_cont()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Dmitry V. Levin
8dbdec0bcb powerpc/ptrace: Combine SYSCALL_EMU & SYSCALL_TRACE handling
Combine the SYSCALL_EMU and SYSCALL_TRACE handling so that we only
call tracehook_report_syscall_entry() in one place.

Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
[mpe: Flesh out change log, s/cached_flags/flags/, reflow comments]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christoph Hellwig
25078dc1f7 powerpc: use mm zones more sensibly
Powerpc has somewhat odd usage where ZONE_DMA is used for all memory on
common 64-bit configfs, and ZONE_DMA32 is used for 31-bit schemes.

Move to a scheme closer to what other architectures use (and I dare to
say the intent of the system):

 - ZONE_DMA: optionally for memory < 31-bit (64-bit embedded only)
 - ZONE_NORMAL: everything addressable by the kernel
 - ZONE_HIGHMEM: memory > 32-bit for 32-bit kernels

Also provide information on how ZONE_DMA is used by defining
ARCH_ZONE_DMA_BITS.

Contains various fixes from Benjamin Herrenschmidt.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christoph Hellwig
44a0337b32 powerpc/dma: split the two __dma_alloc_coherent implementations
The implemementation for the CONFIG_NOT_COHERENT_CACHE case doesn't share
any code with the one for systems with coherent caches.  Split it off
and merge it with the helpers in dma-noncoherent.c that have no other
callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christoph Hellwig
9c15a87cfc powerpc/dma: remove the unused dma_iommu_ops export
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00