<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/powerpc/perf, branch v5.9</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>powerpc/perf: Fix reading of MSR[HV/PR] bits in trace-imc</title>
<updated>2020-08-27T07:41:45+00:00</updated>
<author>
<name>Athira Rajeev</name>
<email>atrajeev@linux.vnet.ibm.com</email>
</author>
<published>2020-08-26T06:40:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=82715a0f332843d3a1830d7ebc9ac7c99a00c880'/>
<id>82715a0f332843d3a1830d7ebc9ac7c99a00c880</id>
<content type='text'>
IMC trace-mode uses MSR[HV/PR] bits to set the cpumode for the
instruction pointer captured in each sample. The bits are fetched from
the third double word of the trace record. Reading third double word
from IMC trace record should use be64_to_cpu() along with READ_ONCE
inorder to fetch correct MSR[HV/PR] bits. Patch addresses this change.

Currently we are using PERF_RECORD_MISC_HYPERVISOR as cpumode if MSR
HV is 1 and PR is 0 which means the address is from host counter. But
using PERF_RECORD_MISC_HYPERVISOR for host counter data will fail to
resolve the address -&gt; symbol during "perf report" because perf tools
side uses PERF_RECORD_MISC_KERNEL to represent the host counter data.
Therefore, fix the trace imc sample data to use
PERF_RECORD_MISC_KERNEL as cpumode for host kernel information.

Fixes: 77ca3951cc37 ("powerpc/perf: Add kernel support for new MSR[HV PR] bits in trace-imc")
Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1598424029-1662-1-git-send-email-atrajeev@linux.vnet.ibm.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
IMC trace-mode uses MSR[HV/PR] bits to set the cpumode for the
instruction pointer captured in each sample. The bits are fetched from
the third double word of the trace record. Reading third double word
from IMC trace record should use be64_to_cpu() along with READ_ONCE
inorder to fetch correct MSR[HV/PR] bits. Patch addresses this change.

Currently we are using PERF_RECORD_MISC_HYPERVISOR as cpumode if MSR
HV is 1 and PR is 0 which means the address is from host counter. But
using PERF_RECORD_MISC_HYPERVISOR for host counter data will fail to
resolve the address -&gt; symbol during "perf report" because perf tools
side uses PERF_RECORD_MISC_KERNEL to represent the host counter data.
Therefore, fix the trace imc sample data to use
PERF_RECORD_MISC_KERNEL as cpumode for host kernel information.

Fixes: 77ca3951cc37 ("powerpc/perf: Add kernel support for new MSR[HV PR] bits in trace-imc")
Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1598424029-1662-1-git-send-email-atrajeev@linux.vnet.ibm.com
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/perf: Fix crashes with generic_compat_pmu &amp; BHRB</title>
<updated>2020-08-27T07:41:44+00:00</updated>
<author>
<name>Alexey Kardashevskiy</name>
<email>aik@ozlabs.ru</email>
</author>
<published>2020-06-02T02:56:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b460b512417ae9c8b51a3bdcc09020cd6c60ff69'/>
<id>b460b512417ae9c8b51a3bdcc09020cd6c60ff69</id>
<content type='text'>
The bhrb_filter_map ("The Branch History Rolling Buffer") callback is
only defined in raw CPUs' power_pmu structs. The "architected" CPUs
use generic_compat_pmu, which does not have this callback, and crashes
occur if a user tries to enable branch stack for an event.

This add a NULL pointer check for bhrb_filter_map() which behaves as
if the callback returned an error.

This does not add the same check for config_bhrb() as the only caller
checks for cpuhw-&gt;bhrb_users which remains zero if bhrb_filter_map==0.

Fixes: be80e758d0c2 ("powerpc/perf: Add generic compat mode pmu driver")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Reviewed-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200602025612.62707-1-aik@ozlabs.ru
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The bhrb_filter_map ("The Branch History Rolling Buffer") callback is
only defined in raw CPUs' power_pmu structs. The "architected" CPUs
use generic_compat_pmu, which does not have this callback, and crashes
occur if a user tries to enable branch stack for an event.

This add a NULL pointer check for bhrb_filter_map() which behaves as
if the callback returned an error.

This does not add the same check for config_bhrb() as the only caller
checks for cpuhw-&gt;bhrb_users which remains zero if bhrb_filter_map==0.

Fixes: be80e758d0c2 ("powerpc/perf: Add generic compat mode pmu driver")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Reviewed-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200602025612.62707-1-aik@ozlabs.ru
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/perf/hv-24x7: Move cpumask file to top folder of hv-24x7 driver</title>
<updated>2020-08-21T13:35:27+00:00</updated>
<author>
<name>Kajol Jain</name>
<email>kjain@linux.ibm.com</email>
</author>
<published>2020-08-21T08:06:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=64ef8f2c4791940d7f3945507b6a45c20d959260'/>
<id>64ef8f2c4791940d7f3945507b6a45c20d959260</id>
<content type='text'>
Commit 792f73f747b8 ("powerpc/hv-24x7: Add sysfs files inside hv-24x7
device to show cpumask") added cpumask file as part of hv-24x7 driver
inside the interface folder. The cpumask file is supposed to be in the
top folder of the PMU driver in order to make hotplug work.

This patch fixes that issue and creates new group 'cpumask_attr_group'
to add cpumask file and make sure it added in top folder.

  command:# cat /sys/devices/hv_24x7/cpumask
  0

Fixes: 792f73f747b8 ("powerpc/hv-24x7: Add sysfs files inside hv-24x7 device to show cpumask")
Signed-off-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200821080610.123997-1-kjain@linux.ibm.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 792f73f747b8 ("powerpc/hv-24x7: Add sysfs files inside hv-24x7
device to show cpumask") added cpumask file as part of hv-24x7 driver
inside the interface folder. The cpumask file is supposed to be in the
top folder of the PMU driver in order to make hotplug work.

This patch fixes that issue and creates new group 'cpumask_attr_group'
to add cpumask file and make sure it added in top folder.

  command:# cat /sys/devices/hv_24x7/cpumask
  0

Fixes: 792f73f747b8 ("powerpc/hv-24x7: Add sysfs files inside hv-24x7 device to show cpumask")
Signed-off-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200821080610.123997-1-kjain@linux.ibm.com
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/perf: Fix soft lockups due to missed interrupt accounting</title>
<updated>2020-08-20T10:29:09+00:00</updated>
<author>
<name>Athira Rajeev</name>
<email>atrajeev@linux.vnet.ibm.com</email>
</author>
<published>2020-08-06T12:46:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=17899eaf88d689529b866371344c8f269ba79b5f'/>
<id>17899eaf88d689529b866371344c8f269ba79b5f</id>
<content type='text'>
Performance monitor interrupt handler checks if any counter has
overflown and calls record_and_restart() in core-book3s which invokes
perf_event_overflow() to record the sample information. Apart from
creating sample, perf_event_overflow() also does the interrupt and
period checks via perf_event_account_interrupt().

Currently we record information only if the SIAR (Sampled Instruction
Address Register) valid bit is set (using siar_valid() check) and
hence the interrupt check.

But it is possible that we do sampling for some events that are not
generating valid SIAR, and hence there is no chance to disable the
event if interrupts are more than max_samples_per_tick. This leads to
soft lockup.

Fix this by adding perf_event_account_interrupt() in the invalid SIAR
code path for a sampling event. ie if SIAR is invalid, just do
interrupt check and don't record the sample information.

Reported-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Tested-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1596717992-7321-1-git-send-email-atrajeev@linux.vnet.ibm.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Performance monitor interrupt handler checks if any counter has
overflown and calls record_and_restart() in core-book3s which invokes
perf_event_overflow() to record the sample information. Apart from
creating sample, perf_event_overflow() also does the interrupt and
period checks via perf_event_account_interrupt().

Currently we record information only if the SIAR (Sampled Instruction
Address Register) valid bit is set (using siar_valid() check) and
hence the interrupt check.

But it is possible that we do sampling for some events that are not
generating valid SIAR, and hence there is no chance to disable the
event if interrupts are more than max_samples_per_tick. This leads to
soft lockup.

Fix this by adding perf_event_account_interrupt() in the invalid SIAR
code path for a sampling event. ie if SIAR is invalid, just do
interrupt check and don't record the sample information.

Reported-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Tested-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1596717992-7321-1-git-send-email-atrajeev@linux.vnet.ibm.com
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/perf: Add extended regs support for power10 platform</title>
<updated>2020-08-17T03:11:22+00:00</updated>
<author>
<name>Athira Rajeev</name>
<email>atrajeev@linux.vnet.ibm.com</email>
</author>
<published>2020-08-07T10:05:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d735599a069f6936c1392e07075c34a19bda949a'/>
<id>d735599a069f6936c1392e07075c34a19bda949a</id>
<content type='text'>
Include capability flag PERF_PMU_CAP_EXTENDED_REGS for power10 and
expose MMCR3, SIER2, SIER3 registers as part of extended regs. Also
introduce PERF_REG_PMU_MASK_31 to define extended mask value at
runtime for power10.

Suggested-by: Ryan Grimm &lt;grimm@linux.ibm.com&gt;
Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Tested-by: Nageswara R Sastry &lt;nasastry@in.ibm.com&gt;
Reviewed-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Reviewed-and-tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1596794701-23530-3-git-send-email-atrajeev@linux.vnet.ibm.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Include capability flag PERF_PMU_CAP_EXTENDED_REGS for power10 and
expose MMCR3, SIER2, SIER3 registers as part of extended regs. Also
introduce PERF_REG_PMU_MASK_31 to define extended mask value at
runtime for power10.

Suggested-by: Ryan Grimm &lt;grimm@linux.ibm.com&gt;
Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Tested-by: Nageswara R Sastry &lt;nasastry@in.ibm.com&gt;
Reviewed-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Reviewed-and-tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1596794701-23530-3-git-send-email-atrajeev@linux.vnet.ibm.com
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/perf: Add support for outputting extended regs in perf intr_regs</title>
<updated>2020-08-17T03:11:22+00:00</updated>
<author>
<name>Anju T Sudhakar</name>
<email>anju@linux.vnet.ibm.com</email>
</author>
<published>2020-08-07T10:05:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=781fa4811d95314c1965c0c3337c9ac36ef26093'/>
<id>781fa4811d95314c1965c0c3337c9ac36ef26093</id>
<content type='text'>
Add support for perf extended register capability in powerpc. The
capability flag PERF_PMU_CAP_EXTENDED_REGS, is used to indicate the
PMU which support extended registers. The generic code define the mask
of extended registers as 0 for non supported architectures.

Patch adds extended regs support for power9 platform by exposing
MMCR0, MMCR1 and MMCR2 registers.

REG_RESERVED mask needs update to include extended regs.
PERF_REG_EXTENDED_MASK, contains mask value of the supported
registers, is defined at runtime in the kernel based on platform since
the supported registers may differ from one processor version to
another and hence the MASK value.

With the patch:

  available registers: r0 r1 r2 r3 r4 r5 r6 r7 r8 r9 r10 r11
  r12 r13 r14 r15 r16 r17 r18 r19 r20 r21 r22 r23 r24 r25 r26
  r27 r28 r29 r30 r31 nip msr orig_r3 ctr link xer ccr softe
  trap dar dsisr sier mmcra mmcr0 mmcr1 mmcr2

  PERF_RECORD_SAMPLE(IP, 0x1): 4784/4784: 0 period: 1 addr: 0
  ... intr regs: mask 0xffffffffffff ABI 64-bit
  .... r0    0xc00000000012b77c
  .... r1    0xc000003fe5e03930
  .... r2    0xc000000001b0e000
  .... r3    0xc000003fdcddf800
  .... r4    0xc000003fc7880000
  .... r5    0x9c422724be
  .... r6    0xc000003fe5e03908
  .... r7    0xffffff63bddc8706
  .... r8    0x9e4
  .... r9    0x0
  .... r10   0x1
  .... r11   0x0
  .... r12   0xc0000000001299c0
  .... r13   0xc000003ffffc4800
  .... r14   0x0
  .... r15   0x7fffdd8b8b00
  .... r16   0x0
  .... r17   0x7fffdd8be6b8
  .... r18   0x7e7076607730
  .... r19   0x2f
  .... r20   0xc00000001fc26c68
  .... r21   0xc0002041e4227e00
  .... r22   0xc00000002018fb60
  .... r23   0x1
  .... r24   0xc000003ffec4d900
  .... r25   0x80000000
  .... r26   0x0
  .... r27   0x1
  .... r28   0x1
  .... r29   0xc000000001be1260
  .... r30   0x6008010
  .... r31   0xc000003ffebb7218
  .... nip   0xc00000000012b910
  .... msr   0x9000000000009033
  .... orig_r3 0xc00000000012b86c
  .... ctr   0xc0000000001299c0
  .... link  0xc00000000012b77c
  .... xer   0x0
  .... ccr   0x28002222
  .... softe 0x1
  .... trap  0xf00
  .... dar   0x0
  .... dsisr 0x80000000000
  .... sier  0x0
  .... mmcra 0x80000000000
  .... mmcr0 0x82008090
  .... mmcr1 0x1e000000
  .... mmcr2 0x0
   ... thread: perf:4784

Signed-off-by: Anju T Sudhakar &lt;anju@linux.vnet.ibm.com&gt;
Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Tested-by: Nageswara R Sastry &lt;nasastry@in.ibm.com&gt;
Reviewed-by: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Reviewed-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Reviewed-and-tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1596794701-23530-2-git-send-email-atrajeev@linux.vnet.ibm.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support for perf extended register capability in powerpc. The
capability flag PERF_PMU_CAP_EXTENDED_REGS, is used to indicate the
PMU which support extended registers. The generic code define the mask
of extended registers as 0 for non supported architectures.

Patch adds extended regs support for power9 platform by exposing
MMCR0, MMCR1 and MMCR2 registers.

REG_RESERVED mask needs update to include extended regs.
PERF_REG_EXTENDED_MASK, contains mask value of the supported
registers, is defined at runtime in the kernel based on platform since
the supported registers may differ from one processor version to
another and hence the MASK value.

With the patch:

  available registers: r0 r1 r2 r3 r4 r5 r6 r7 r8 r9 r10 r11
  r12 r13 r14 r15 r16 r17 r18 r19 r20 r21 r22 r23 r24 r25 r26
  r27 r28 r29 r30 r31 nip msr orig_r3 ctr link xer ccr softe
  trap dar dsisr sier mmcra mmcr0 mmcr1 mmcr2

  PERF_RECORD_SAMPLE(IP, 0x1): 4784/4784: 0 period: 1 addr: 0
  ... intr regs: mask 0xffffffffffff ABI 64-bit
  .... r0    0xc00000000012b77c
  .... r1    0xc000003fe5e03930
  .... r2    0xc000000001b0e000
  .... r3    0xc000003fdcddf800
  .... r4    0xc000003fc7880000
  .... r5    0x9c422724be
  .... r6    0xc000003fe5e03908
  .... r7    0xffffff63bddc8706
  .... r8    0x9e4
  .... r9    0x0
  .... r10   0x1
  .... r11   0x0
  .... r12   0xc0000000001299c0
  .... r13   0xc000003ffffc4800
  .... r14   0x0
  .... r15   0x7fffdd8b8b00
  .... r16   0x0
  .... r17   0x7fffdd8be6b8
  .... r18   0x7e7076607730
  .... r19   0x2f
  .... r20   0xc00000001fc26c68
  .... r21   0xc0002041e4227e00
  .... r22   0xc00000002018fb60
  .... r23   0x1
  .... r24   0xc000003ffec4d900
  .... r25   0x80000000
  .... r26   0x0
  .... r27   0x1
  .... r28   0x1
  .... r29   0xc000000001be1260
  .... r30   0x6008010
  .... r31   0xc000003ffebb7218
  .... nip   0xc00000000012b910
  .... msr   0x9000000000009033
  .... orig_r3 0xc00000000012b86c
  .... ctr   0xc0000000001299c0
  .... link  0xc00000000012b77c
  .... xer   0x0
  .... ccr   0x28002222
  .... softe 0x1
  .... trap  0xf00
  .... dar   0x0
  .... dsisr 0x80000000000
  .... sier  0x0
  .... mmcra 0x80000000000
  .... mmcr0 0x82008090
  .... mmcr1 0x1e000000
  .... mmcr2 0x0
   ... thread: perf:4784

Signed-off-by: Anju T Sudhakar &lt;anju@linux.vnet.ibm.com&gt;
Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Tested-by: Nageswara R Sastry &lt;nasastry@in.ibm.com&gt;
Reviewed-by: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Reviewed-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Reviewed-and-tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1596794701-23530-2-git-send-email-atrajeev@linux.vnet.ibm.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2020-08-07T17:33:50+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-08-07T17:33:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=25d8d4eecace9de5a6a2193e4df1917afbdd3052'/>
<id>25d8d4eecace9de5a6a2193e4df1917afbdd3052</id>
<content type='text'>
Pull powerpc updates from Michael Ellerman:

 - Add support for (optionally) using queued spinlocks &amp; rwlocks.

 - Support for a new faster system call ABI using the scv instruction on
   Power9 or later.

 - Drop support for the PROT_SAO mmap/mprotect flag as it will be
   unsupported on Power10 and future processors, leaving us with no way
   to implement the functionality it requests. This risks breaking
   userspace, though we believe it is unused in practice.

 - A bug fix for, and then the removal of, our custom stack expansion
   checking. We now allow stack expansion up to the rlimit, like other
   architectures.

 - Remove the remnants of our (previously disabled) topology update
   code, which tried to react to NUMA layout changes on virtualised
   systems, but was prone to crashes and other problems.

 - Add PMU support for Power10 CPUs.

 - A change to our signal trampoline so that we don't unbalance the link
   stack (branch return predictor) in the signal delivery path.

 - Lots of other cleanups, refactorings, smaller features and so on as
   usual.

Thanks to: Abhishek Goel, Alastair D'Silva, Alexander A. Klimov, Alexey
Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju
T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Balamuruhan
S, Bharata B Rao, Bill Wendling, Bin Meng, Cédric Le Goater, Chris
Packham, Christophe Leroy, Christoph Hellwig, Daniel Axtens, Dan
Williams, David Lamparter, Desnes A. Nunes do Rosario, Erhard F., Finn
Thain, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geoff Levand,
Greg Kurz, Gustavo A. R. Silva, Hari Bathini, Harish, Imre Kaloz, Joel
Stanley, Joe Perches, John Crispin, Jordan Niethe, Kajol Jain, Kamalesh
Babulal, Kees Cook, Laurent Dufour, Leonardo Bras, Li RongQing, Madhavan
Srinivasan, Mahesh Salgaonkar, Mark Cave-Ayland, Michal Suchanek, Milton
Miller, Mimi Zohar, Murilo Opsfelder Araujo, Nathan Chancellor, Nathan
Lynch, Naveen N. Rao, Nayna Jain, Nicholas Piggin, Oliver O'Halloran,
Palmer Dabbelt, Pedro Miraglia Franco de Carvalho, Philippe Bergheaud,
Pingfan Liu, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Randy
Dunlap, Ravi Bangoria, Sachin Sant, Sam Bobroff, Sandipan Das, Santosh
Sivaraj, Satheesh Rajendran, Shirisha Ganta, Sourabh Jain, Srikar
Dronamraju, Stan Johnson, Stephen Rothwell, Thadeu Lima de Souza
Cascardo, Thiago Jung Bauermann, Tom Lane, Vaibhav Jain, Vladis Dronov,
Wei Yongjun, Wen Xiong, YueHaibing.

* tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (337 commits)
  selftests/powerpc: Fix pkey syscall redefinitions
  powerpc: Fix circular dependency between percpu.h and mmu.h
  powerpc/powernv/sriov: Fix use of uninitialised variable
  selftests/powerpc: Skip vmx/vsx/tar/etc tests on older CPUs
  powerpc/40x: Fix assembler warning about r0
  powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric
  powerpc/papr_scm: Fetch nvdimm performance stats from PHYP
  cpuidle: pseries: Fixup exit latency for CEDE(0)
  cpuidle: pseries: Add function to parse extended CEDE records
  cpuidle: pseries: Set the latency-hint before entering CEDE
  selftests/powerpc: Fix online CPU selection
  powerpc/perf: Consolidate perf_callchain_user_[64|32]()
  powerpc/pseries/hotplug-cpu: Remove double free in error path
  powerpc/pseries/mobility: Add pr_debug() for device tree changes
  powerpc/pseries/mobility: Set pr_fmt()
  powerpc/cacheinfo: Warn if cache object chain becomes unordered
  powerpc/cacheinfo: Improve diagnostics about malformed cache lists
  powerpc/cacheinfo: Use name@unit instead of full DT path in debug messages
  powerpc/cacheinfo: Set pr_fmt()
  powerpc: fix function annotations to avoid section mismatch warnings with gcc-10
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull powerpc updates from Michael Ellerman:

 - Add support for (optionally) using queued spinlocks &amp; rwlocks.

 - Support for a new faster system call ABI using the scv instruction on
   Power9 or later.

 - Drop support for the PROT_SAO mmap/mprotect flag as it will be
   unsupported on Power10 and future processors, leaving us with no way
   to implement the functionality it requests. This risks breaking
   userspace, though we believe it is unused in practice.

 - A bug fix for, and then the removal of, our custom stack expansion
   checking. We now allow stack expansion up to the rlimit, like other
   architectures.

 - Remove the remnants of our (previously disabled) topology update
   code, which tried to react to NUMA layout changes on virtualised
   systems, but was prone to crashes and other problems.

 - Add PMU support for Power10 CPUs.

 - A change to our signal trampoline so that we don't unbalance the link
   stack (branch return predictor) in the signal delivery path.

 - Lots of other cleanups, refactorings, smaller features and so on as
   usual.

Thanks to: Abhishek Goel, Alastair D'Silva, Alexander A. Klimov, Alexey
Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju
T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Balamuruhan
S, Bharata B Rao, Bill Wendling, Bin Meng, Cédric Le Goater, Chris
Packham, Christophe Leroy, Christoph Hellwig, Daniel Axtens, Dan
Williams, David Lamparter, Desnes A. Nunes do Rosario, Erhard F., Finn
Thain, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geoff Levand,
Greg Kurz, Gustavo A. R. Silva, Hari Bathini, Harish, Imre Kaloz, Joel
Stanley, Joe Perches, John Crispin, Jordan Niethe, Kajol Jain, Kamalesh
Babulal, Kees Cook, Laurent Dufour, Leonardo Bras, Li RongQing, Madhavan
Srinivasan, Mahesh Salgaonkar, Mark Cave-Ayland, Michal Suchanek, Milton
Miller, Mimi Zohar, Murilo Opsfelder Araujo, Nathan Chancellor, Nathan
Lynch, Naveen N. Rao, Nayna Jain, Nicholas Piggin, Oliver O'Halloran,
Palmer Dabbelt, Pedro Miraglia Franco de Carvalho, Philippe Bergheaud,
Pingfan Liu, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Randy
Dunlap, Ravi Bangoria, Sachin Sant, Sam Bobroff, Sandipan Das, Santosh
Sivaraj, Satheesh Rajendran, Shirisha Ganta, Sourabh Jain, Srikar
Dronamraju, Stan Johnson, Stephen Rothwell, Thadeu Lima de Souza
Cascardo, Thiago Jung Bauermann, Tom Lane, Vaibhav Jain, Vladis Dronov,
Wei Yongjun, Wen Xiong, YueHaibing.

* tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (337 commits)
  selftests/powerpc: Fix pkey syscall redefinitions
  powerpc: Fix circular dependency between percpu.h and mmu.h
  powerpc/powernv/sriov: Fix use of uninitialised variable
  selftests/powerpc: Skip vmx/vsx/tar/etc tests on older CPUs
  powerpc/40x: Fix assembler warning about r0
  powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric
  powerpc/papr_scm: Fetch nvdimm performance stats from PHYP
  cpuidle: pseries: Fixup exit latency for CEDE(0)
  cpuidle: pseries: Add function to parse extended CEDE records
  cpuidle: pseries: Set the latency-hint before entering CEDE
  selftests/powerpc: Fix online CPU selection
  powerpc/perf: Consolidate perf_callchain_user_[64|32]()
  powerpc/pseries/hotplug-cpu: Remove double free in error path
  powerpc/pseries/mobility: Add pr_debug() for device tree changes
  powerpc/pseries/mobility: Set pr_fmt()
  powerpc/cacheinfo: Warn if cache object chain becomes unordered
  powerpc/cacheinfo: Improve diagnostics about malformed cache lists
  powerpc/cacheinfo: Use name@unit instead of full DT path in debug messages
  powerpc/cacheinfo: Set pr_fmt()
  powerpc: fix function annotations to avoid section mismatch warnings with gcc-10
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/perf: Consolidate perf_callchain_user_[64|32]()</title>
<updated>2020-07-30T12:53:49+00:00</updated>
<author>
<name>Michal Suchanek</name>
<email>msuchanek@suse.de</email>
</author>
<published>2020-04-06T21:00:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d3a133aa0e029e0bbb67170f5f18c8fcd4701370'/>
<id>d3a133aa0e029e0bbb67170f5f18c8fcd4701370</id>
<content type='text'>
perf_callchain_user_64() and perf_callchain_user_32() are nearly
identical. Consolidate into one function with thin wrappers.

Suggested-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
[mpe: Adapt to copy_from_user_nofault(), minor formatting]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200406210022.32265-1-msuchanek@suse.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
perf_callchain_user_64() and perf_callchain_user_32() are nearly
identical. Consolidate into one function with thin wrappers.

Suggested-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
[mpe: Adapt to copy_from_user_nofault(), minor formatting]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200406210022.32265-1-msuchanek@suse.de
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64s/hash: Fix hash_preload running with interrupts enabled</title>
<updated>2020-07-27T07:02:09+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2020-07-27T06:09:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=909adfc66b9a1db21b5e8733e9ebfa6cd5135d74'/>
<id>909adfc66b9a1db21b5e8733e9ebfa6cd5135d74</id>
<content type='text'>
Commit 2f92447f9f96 ("powerpc/book3s64/hash: Use the pte_t address from the
caller") removed the local_irq_disable from hash_preload, but it was
required for more than just the page table walk: the hash pte busy bit is
effectively a lock which may be taken in interrupt context, and the local
update flag test must not be preempted before it's used.

This solves apparent lockups with perf interrupting __hash_page_64K. If
get_perf_callchain then also takes a hash fault on the same page while it
is already locked, it will loop forever taking hash faults, which looks like
this:

  cpu 0x49e: Vector: 100 (System Reset) at [c00000001a4f7d70]
      pc: c000000000072dc8: hash_page_mm+0x8/0x800
      lr: c00000000000c5a4: do_hash_page+0x24/0x38
      sp: c0002ac1cc69ac70
     msr: 8000000000081033
    current = 0xc0002ac1cc602e00
    paca    = 0xc00000001de1f280   irqmask: 0x03   irq_happened: 0x01
      pid   = 20118, comm = pread2_processe
  Linux version 5.8.0-rc6-00345-g1fad14f18bc6
  49e:mon&gt; t
  [c0002ac1cc69ac70] c00000000000c5a4 do_hash_page+0x24/0x38 (unreliable)
  --- Exception: 300 (Data Access) at c00000000008fa60 __copy_tofrom_user_power7+0x20c/0x7ac
  [link register   ] c000000000335d10 copy_from_user_nofault+0xf0/0x150
  [c0002ac1cc69af70] c00032bf9fa3c880 (unreliable)
  [c0002ac1cc69afa0] c000000000109df0 read_user_stack_64+0x70/0xf0
  [c0002ac1cc69afd0] c000000000109fcc perf_callchain_user_64+0x15c/0x410
  [c0002ac1cc69b060] c000000000109c00 perf_callchain_user+0x20/0x40
  [c0002ac1cc69b080] c00000000031c6cc get_perf_callchain+0x25c/0x360
  [c0002ac1cc69b120] c000000000316b50 perf_callchain+0x70/0xa0
  [c0002ac1cc69b140] c000000000316ddc perf_prepare_sample+0x25c/0x790
  [c0002ac1cc69b1a0] c000000000317350 perf_event_output_forward+0x40/0xb0
  [c0002ac1cc69b220] c000000000306138 __perf_event_overflow+0x88/0x1a0
  [c0002ac1cc69b270] c00000000010cf70 record_and_restart+0x230/0x750
  [c0002ac1cc69b620] c00000000010d69c perf_event_interrupt+0x20c/0x510
  [c0002ac1cc69b730] c000000000027d9c performance_monitor_exception+0x4c/0x60
  [c0002ac1cc69b750] c00000000000b2f8 performance_monitor_common_virt+0x1b8/0x1c0
  --- Exception: f00 (Performance Monitor) at c0000000000cb5b0 pSeries_lpar_hpte_insert+0x0/0x160
  [link register   ] c0000000000846f0 __hash_page_64K+0x210/0x540
  [c0002ac1cc69ba50] 0000000000000000 (unreliable)
  [c0002ac1cc69bb00] c000000000073ae0 update_mmu_cache+0x390/0x3a0
  [c0002ac1cc69bb70] c00000000037f024 wp_page_copy+0x364/0xce0
  [c0002ac1cc69bc20] c00000000038272c do_wp_page+0xdc/0xa60
  [c0002ac1cc69bc70] c0000000003857bc handle_mm_fault+0xb9c/0x1b60
  [c0002ac1cc69bd50] c00000000006c434 __do_page_fault+0x314/0xc90
  [c0002ac1cc69be20] c00000000000c5c8 handle_page_fault+0x10/0x2c
  --- Exception: 300 (Data Access) at 00007fff8c861fe8
  SP (7ffff6b19660) is in userspace

Fixes: 2f92447f9f96 ("powerpc/book3s64/hash: Use the pte_t address from the caller")
Reported-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Reported-by: Anton Blanchard &lt;anton@ozlabs.org&gt;
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Reviewed-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200727060947.10060-1-npiggin@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 2f92447f9f96 ("powerpc/book3s64/hash: Use the pte_t address from the
caller") removed the local_irq_disable from hash_preload, but it was
required for more than just the page table walk: the hash pte busy bit is
effectively a lock which may be taken in interrupt context, and the local
update flag test must not be preempted before it's used.

This solves apparent lockups with perf interrupting __hash_page_64K. If
get_perf_callchain then also takes a hash fault on the same page while it
is already locked, it will loop forever taking hash faults, which looks like
this:

  cpu 0x49e: Vector: 100 (System Reset) at [c00000001a4f7d70]
      pc: c000000000072dc8: hash_page_mm+0x8/0x800
      lr: c00000000000c5a4: do_hash_page+0x24/0x38
      sp: c0002ac1cc69ac70
     msr: 8000000000081033
    current = 0xc0002ac1cc602e00
    paca    = 0xc00000001de1f280   irqmask: 0x03   irq_happened: 0x01
      pid   = 20118, comm = pread2_processe
  Linux version 5.8.0-rc6-00345-g1fad14f18bc6
  49e:mon&gt; t
  [c0002ac1cc69ac70] c00000000000c5a4 do_hash_page+0x24/0x38 (unreliable)
  --- Exception: 300 (Data Access) at c00000000008fa60 __copy_tofrom_user_power7+0x20c/0x7ac
  [link register   ] c000000000335d10 copy_from_user_nofault+0xf0/0x150
  [c0002ac1cc69af70] c00032bf9fa3c880 (unreliable)
  [c0002ac1cc69afa0] c000000000109df0 read_user_stack_64+0x70/0xf0
  [c0002ac1cc69afd0] c000000000109fcc perf_callchain_user_64+0x15c/0x410
  [c0002ac1cc69b060] c000000000109c00 perf_callchain_user+0x20/0x40
  [c0002ac1cc69b080] c00000000031c6cc get_perf_callchain+0x25c/0x360
  [c0002ac1cc69b120] c000000000316b50 perf_callchain+0x70/0xa0
  [c0002ac1cc69b140] c000000000316ddc perf_prepare_sample+0x25c/0x790
  [c0002ac1cc69b1a0] c000000000317350 perf_event_output_forward+0x40/0xb0
  [c0002ac1cc69b220] c000000000306138 __perf_event_overflow+0x88/0x1a0
  [c0002ac1cc69b270] c00000000010cf70 record_and_restart+0x230/0x750
  [c0002ac1cc69b620] c00000000010d69c perf_event_interrupt+0x20c/0x510
  [c0002ac1cc69b730] c000000000027d9c performance_monitor_exception+0x4c/0x60
  [c0002ac1cc69b750] c00000000000b2f8 performance_monitor_common_virt+0x1b8/0x1c0
  --- Exception: f00 (Performance Monitor) at c0000000000cb5b0 pSeries_lpar_hpte_insert+0x0/0x160
  [link register   ] c0000000000846f0 __hash_page_64K+0x210/0x540
  [c0002ac1cc69ba50] 0000000000000000 (unreliable)
  [c0002ac1cc69bb00] c000000000073ae0 update_mmu_cache+0x390/0x3a0
  [c0002ac1cc69bb70] c00000000037f024 wp_page_copy+0x364/0xce0
  [c0002ac1cc69bc20] c00000000038272c do_wp_page+0xdc/0xa60
  [c0002ac1cc69bc70] c0000000003857bc handle_mm_fault+0xb9c/0x1b60
  [c0002ac1cc69bd50] c00000000006c434 __do_page_fault+0x314/0xc90
  [c0002ac1cc69be20] c00000000000c5c8 handle_page_fault+0x10/0x2c
  --- Exception: 300 (Data Access) at 00007fff8c861fe8
  SP (7ffff6b19660) is in userspace

Fixes: 2f92447f9f96 ("powerpc/book3s64/hash: Use the pte_t address from the caller")
Reported-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Reported-by: Anton Blanchard &lt;anton@ozlabs.org&gt;
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Reviewed-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200727060947.10060-1-npiggin@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/perf: BHRB control to disable BHRB logic when not used</title>
<updated>2020-07-22T11:56:42+00:00</updated>
<author>
<name>Athira Rajeev</name>
<email>atrajeev@linux.vnet.ibm.com</email>
</author>
<published>2020-07-17T14:38:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1cade527f6e9bec6a6412d0641643c359ada8096'/>
<id>1cade527f6e9bec6a6412d0641643c359ada8096</id>
<content type='text'>
PowerISA v3.1 has few updates for the Branch History Rolling
Buffer(BHRB).

BHRB disable is controlled via Monitor Mode Control Register A (MMCRA)
bit, namely "BHRB Recording Disable (BHRBRD)". This field controls
whether BHRB entries are written when BHRB recording is enabled by
other bits. This patch implements support for this BHRB disable bit.
By setting 0b1 to this bit will disable the BHRB and by setting 0b0 to
this bit will have BHRB enabled. This addresses backward
compatibility (for older OS), since this bit will be cleared and
hardware will be writing to BHRB by default.

This patch addresses changes to set MMCRA (BHRBRD) at boot for
power10 (there by the core will run faster) and enable this feature
only on runtime ie, on explicit need from user. Also save/restore
MMCRA in the restore path of state-loss idle state to make sure we
keep BHRB disabled if it was not enabled on request at runtime.

Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1594996707-3727-12-git-send-email-atrajeev@linux.vnet.ibm.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
PowerISA v3.1 has few updates for the Branch History Rolling
Buffer(BHRB).

BHRB disable is controlled via Monitor Mode Control Register A (MMCRA)
bit, namely "BHRB Recording Disable (BHRBRD)". This field controls
whether BHRB entries are written when BHRB recording is enabled by
other bits. This patch implements support for this BHRB disable bit.
By setting 0b1 to this bit will disable the BHRB and by setting 0b0 to
this bit will have BHRB enabled. This addresses backward
compatibility (for older OS), since this bit will be cleared and
hardware will be writing to BHRB by default.

This patch addresses changes to set MMCRA (BHRBRD) at boot for
power10 (there by the core will run faster) and enable this feature
only on runtime ie, on explicit need from user. Also save/restore
MMCRA in the restore path of state-loss idle state to make sure we
keep BHRB disabled if it was not enabled on request at runtime.

Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1594996707-3727-12-git-send-email-atrajeev@linux.vnet.ibm.com
</pre>
</div>
</content>
</entry>
</feed>
