Commit Graph

402 Commits

Author SHA1 Message Date
Nicholas Piggin
d83f4bc0a4 powerpc/perf: Fix disabling BHRB and instruction sampling
commit ea142e590aec55ba40c5affb4d49e68c713c63dc upstream.

When the PMU is disabled, MMCRA is not updated to disable BHRB and
instruction sampling. This can lead to those features remaining enabled,
which can slow down a real or emulated CPU.

Fixes: 1cade527f6 ("powerpc/perf: BHRB control to disable BHRB logic when not used")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231018153423.298373-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 16:54:55 +00:00
Sebastian Andrzej Siewior
d12372af89 powerpc/imc-pmu: Use the correct spinlock initializer.
[ Upstream commit 007240d59c11f87ac4f6cfc6a1d116630b6b634c ]

The macro __SPIN_LOCK_INITIALIZER() is implementation specific. Users
that desire to initialize a spinlock in a struct must use
__SPIN_LOCK_UNLOCKED().

Use __SPIN_LOCK_UNLOCKED() for the spinlock_t in imc_global_refc.

Fixes: 76d588dddc459 ("powerpc/imc-pmu: Fix use of mutex in IRQs disabled section")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230309134831.Nz12nqsU@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:06:53 +01:00
Kajol Jain
09a1c790e1 powerpc/perf/hv-24x7: Update domain value check
[ Upstream commit 4ff3ba4db5943cac1045e3e4a3c0463ea10f6930 ]

Valid domain value is in range 1 to HV_PERF_DOMAIN_MAX. Current code has
check for domain value greater than or equal to HV_PERF_DOMAIN_MAX. But
the check for domain value 0 is missing.

Fix this issue by adding check for domain value 0.

Before:
  # ./perf stat -v -e hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/ sleep 1
  Using CPUID 00800200
  Control descriptor is not initialized
  Error:
  The sys_perf_event_open() syscall returned with 5 (Input/output error) for
  event (hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/).
  /bin/dmesg | grep -i perf may provide additional information.

  Result from dmesg:
  [   37.819387] hv-24x7: hcall failed: [0 0x60040000 0x100 0] => ret
  0xfffffffffffffffc (-4) detail=0x2000000 failing ix=0

After:
  # ./perf stat -v -e hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/ sleep 1
  Using CPUID 00800200
  Control descriptor is not initialized
  Warning:
  hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/ event is not supported by the kernel.
  failed to read counter hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/

Fixes: ebd4a5a3eb ("powerpc/perf/hv-24x7: Minor improvements")
Reported-by: Krishan Gopal Sarawast <krishang@linux.vnet.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230825055601.360083-1-kjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-10 21:53:27 +02:00
Christophe Leroy
2f8269ca80 powerpc/perf: Convert fsl_emb notifier to state machine callbacks
[ Upstream commit 34daf445f82bd3a4df852bb5f1dffd792ac830a0 ]

  CC      arch/powerpc/perf/core-fsl-emb.o
arch/powerpc/perf/core-fsl-emb.c:675:6: error: no previous prototype for 'hw_perf_event_setup' [-Werror=missing-prototypes]
  675 | void hw_perf_event_setup(int cpu)
      |      ^~~~~~~~~~~~~~~~~~~

Looks like fsl_emb was completely missed by commit 3f6da39053 ("perf:
Rework and fix the arch CPU-hotplug hooks")

So, apply same changes as commit 3f6da39053 ("perf: Rework and fix
the arch CPU-hotplug hooks") then commit 57ecde42cc ("powerpc/perf:
Convert book3s notifier to state machine callbacks")

While at it, also fix following error:

arch/powerpc/perf/core-fsl-emb.c: In function 'perf_event_interrupt':
arch/powerpc/perf/core-fsl-emb.c:648:13: error: variable 'found' set but not used [-Werror=unused-but-set-variable]
  648 |         int found = 0;
      |             ^~~~~

Fixes: 3f6da39053 ("perf: Rework and fix the arch CPU-hotplug hooks")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/603e1facb32608f88f40b7d7b9094adc50e7b2dc.1692349125.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19 12:20:15 +02:00
Nathan Lynch
9626f83a6e powerpc/perf/hv-24x7: add missing RTAS retry status handling
[ Upstream commit cc4b26eab1859fa1a70711872caaf6414809973f ]

The ibm,get-system-parameter RTAS function may return -2 or 990x,
which indicate that the caller should try again. read_24x7_sys_info()
ignores this, allowing transient failures in reporting processor
module information.

Move the RTAS call into a coventional rtas_busy_delay()-based loop,
along with the parsing of results on success.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 8ba2142673 ("powerpc/hv-24x7: Add rtas call in hv-24x7 driver to get processor details")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-2-26929c8cce78@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:39:44 +01:00
Michael Ellerman
2d0f276d50 powerpc/imc-pmu: Revert nest_init_lock to being a mutex
commit ad53db4acb415976761d7302f5b02e97f2bd097e upstream.

The recent commit 76d588dddc45 ("powerpc/imc-pmu: Fix use of mutex in
IRQs disabled section") fixed warnings (and possible deadlocks) in the
IMC PMU driver by converting the locking to use spinlocks.

It also converted the init-time nest_init_lock to a spinlock, even
though it's not used at runtime in IRQ disabled sections or while
holding other spinlocks.

This leads to warnings such as:

  BUG: sleeping function called from invalid context at include/linux/percpu-rwsem.h:49
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0
  preempt_count: 1, expected: 0
  CPU: 7 PID: 1 Comm: swapper/0 Not tainted 6.2.0-rc2-14719-gf12cd06109f4-dirty #1
  Hardware name: Mambo,Simulated-System POWER9 0x4e1203 opal:v6.6.6 PowerNV
  Call Trace:
    dump_stack_lvl+0x74/0xa8 (unreliable)
    __might_resched+0x178/0x1a0
    __cpuhp_setup_state+0x64/0x1e0
    init_imc_pmu+0xe48/0x1250
    opal_imc_counters_probe+0x30c/0x6a0
    platform_probe+0x78/0x110
    really_probe+0x104/0x420
    __driver_probe_device+0xb0/0x170
    driver_probe_device+0x58/0x180
    __driver_attach+0xd8/0x250
    bus_for_each_dev+0xb4/0x140
    driver_attach+0x34/0x50
    bus_add_driver+0x1e8/0x2d0
    driver_register+0xb4/0x1c0
    __platform_driver_register+0x38/0x50
    opal_imc_driver_init+0x2c/0x40
    do_one_initcall+0x80/0x360
    kernel_init_freeable+0x310/0x3b8
    kernel_init+0x30/0x1a0
    ret_from_kernel_thread+0x5c/0x64

Fix it by converting nest_init_lock back to a mutex, so that we can call
sleeping functions while holding it. There is no interaction between
nest_init_lock and the runtime spinlocks used by the actual PMU routines.

Fixes: 76d588dddc45 ("powerpc/imc-pmu: Fix use of mutex in IRQs disabled section")
Tested-by: Kajol Jain<kjain@linux.ibm.com>
Reviewed-by: Kajol Jain<kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230130014401.540543-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-15 17:22:10 +01:00
Kajol Jain
8cbeb60320 powerpc/imc-pmu: Fix use of mutex in IRQs disabled section
commit 76d588dddc459fefa1da96e0a081a397c5c8e216 upstream.

Current imc-pmu code triggers a WARNING with CONFIG_DEBUG_ATOMIC_SLEEP
and CONFIG_PROVE_LOCKING enabled, while running a thread_imc event.

Command to trigger the warning:
  # perf stat -e thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/ sleep 5

   Performance counter stats for 'sleep 5':

                   0      thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/

         5.002117947 seconds time elapsed

         0.000131000 seconds user
         0.001063000 seconds sys

Below is snippet of the warning in dmesg:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 2869, name: perf-exec
  preempt_count: 2, expected: 0
  4 locks held by perf-exec/2869:
   #0: c00000004325c540 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: bprm_execve+0x64/0xa90
   #1: c00000004325c5d8 (&sig->exec_update_lock){++++}-{3:3}, at: begin_new_exec+0x460/0xef0
   #2: c0000003fa99d4e0 (&cpuctx_lock){-...}-{2:2}, at: perf_event_exec+0x290/0x510
   #3: c000000017ab8418 (&ctx->lock){....}-{2:2}, at: perf_event_exec+0x29c/0x510
  irq event stamp: 4806
  hardirqs last  enabled at (4805): [<c000000000f65b94>] _raw_spin_unlock_irqrestore+0x94/0xd0
  hardirqs last disabled at (4806): [<c0000000003fae44>] perf_event_exec+0x394/0x510
  softirqs last  enabled at (0): [<c00000000013c404>] copy_process+0xc34/0x1ff0
  softirqs last disabled at (0): [<0000000000000000>] 0x0
  CPU: 36 PID: 2869 Comm: perf-exec Not tainted 6.2.0-rc2-00011-g1247637727f2 #61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  Call Trace:
    dump_stack_lvl+0x98/0xe0 (unreliable)
    __might_resched+0x2f8/0x310
    __mutex_lock+0x6c/0x13f0
    thread_imc_event_add+0xf4/0x1b0
    event_sched_in+0xe0/0x210
    merge_sched_in+0x1f0/0x600
    visit_groups_merge.isra.92.constprop.166+0x2bc/0x6c0
    ctx_flexible_sched_in+0xcc/0x140
    ctx_sched_in+0x20c/0x2a0
    ctx_resched+0x104/0x1c0
    perf_event_exec+0x340/0x510
    begin_new_exec+0x730/0xef0
    load_elf_binary+0x3f8/0x1e10
  ...
  do not call blocking ops when !TASK_RUNNING; state=2001 set at [<00000000fd63e7cf>] do_nanosleep+0x60/0x1a0
  WARNING: CPU: 36 PID: 2869 at kernel/sched/core.c:9912 __might_sleep+0x9c/0xb0
  CPU: 36 PID: 2869 Comm: sleep Tainted: G        W          6.2.0-rc2-00011-g1247637727f2 #61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  NIP:  c000000000194a1c LR: c000000000194a18 CTR: c000000000a78670
  REGS: c00000004d2134e0 TRAP: 0700   Tainted: G        W           (6.2.0-rc2-00011-g1247637727f2)
  MSR:  9000000000021033 <SF,HV,ME,IR,DR,RI,LE>  CR: 48002824  XER: 00000000
  CFAR: c00000000013fb64 IRQMASK: 1

The above warning triggered because the current imc-pmu code uses mutex
lock in interrupt disabled sections. The function mutex_lock()
internally calls __might_resched(), which will check if IRQs are
disabled and in case IRQs are disabled, it will trigger the warning.

Fix the issue by changing the mutex lock to spinlock.

Fixes: 8f95faaac5 ("powerpc/powernv: Detect and create IMC device")
Reported-by: Michael Petlan <mpetlan@redhat.com>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
[mpe: Fix comments, trim oops in change log, add reported-by tags]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230106065157.182648-1-kjain@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18 11:44:58 +01:00
Kajol Jain
464506de9b powerpc/hv-gpci: Fix hv_gpci event list
[ Upstream commit 03f7c1d2a49acd30e38789cd809d3300721e9b0e ]

Based on getPerfCountInfo v1.018 documentation, some of the
hv_gpci events were deprecated for platform firmware that
supports counter_info_version 0x8 or above.

Fix the hv_gpci event list by adding a new attribute group
called "hv_gpci_event_attrs_v6" and a "ENABLE_EVENTS_COUNTERINFO_V6"
macro to enable these events for platform firmware
that supports counter_info_version 0x6 or below. And assigning
the hv_gpci event list based on output counter info version
of underlying plaform.

Fixes: 97bf264018 ("powerpc/perf/hv-gpci: add the remaining gpci requests")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Reviewed-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221130174513.87501-1-kjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:07 +01:00
Nicholas Piggin
da1a33795d powerpc/perf: callchain validate kernel stack pointer bounds
[ Upstream commit 32c5209214bd8d4f8c4e9d9b630ef4c671f58e79 ]

The interrupt frame detection and loads from the hypothetical pt_regs
are not bounds-checked. The next-frame validation only bounds-checks
STACK_FRAME_OVERHEAD, which does not include the pt_regs. Add another
test for this.

The user could set r1 to be equal to the address matching the first
interrupt frame - STACK_INT_FRAME_SIZE, which is in the previous page
due to the kernel redzone, and induce the kernel to load the marker from
there. Possibly this could cause a crash at least. If the user could
induce the previous page to contain a valid marker, then it might be
able to direct perf to read specific memory addresses in a way that
could be transmitted back to the user in the perf data.

Fixes: 20002ded4d ("perf_counter: powerpc: Add callchain support")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-4-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:07 +01:00
Athira Rajeev
875b2bf469 powerpc/perf: Optimize clearing the pending PMI and remove WARN_ON for PMI check in power_pmu_disable
[ Upstream commit 890005a7d98f7452cfe86dcfb2aeeb7df01132ce ]

commit 2c9ac51b850d ("powerpc/perf: Fix PMU callbacks to clear
pending PMI before resetting an overflown PMC") added a new
function "pmi_irq_pending" in hw_irq.h. This function is to check
if there is a PMI marked as pending in Paca (PACA_IRQ_PMI).This is
used in power_pmu_disable in a WARN_ON. The intention here is to
provide a warning if there is PMI pending, but no counter is found
overflown.

During some of the perf runs, below warning is hit:

WARNING: CPU: 36 PID: 0 at arch/powerpc/perf/core-book3s.c:1332 power_pmu_disable+0x25c/0x2c0
 Modules linked in:
 -----

 NIP [c000000000141c3c] power_pmu_disable+0x25c/0x2c0
 LR [c000000000141c8c] power_pmu_disable+0x2ac/0x2c0
 Call Trace:
 [c000000baffcfb90] [c000000000141c8c] power_pmu_disable+0x2ac/0x2c0 (unreliable)
 [c000000baffcfc10] [c0000000003e2f8c] perf_pmu_disable+0x4c/0x60
 [c000000baffcfc30] [c0000000003e3344] group_sched_out.part.124+0x44/0x100
 [c000000baffcfc80] [c0000000003e353c] __perf_event_disable+0x13c/0x240
 [c000000baffcfcd0] [c0000000003dd334] event_function+0xc4/0x140
 [c000000baffcfd20] [c0000000003d855c] remote_function+0x7c/0xa0
 [c000000baffcfd50] [c00000000026c394] flush_smp_call_function_queue+0xd4/0x300
 [c000000baffcfde0] [c000000000065b24] smp_ipi_demux_relaxed+0xa4/0x100
 [c000000baffcfe20] [c0000000000cb2b0] xive_muxed_ipi_action+0x20/0x40
 [c000000baffcfe40] [c000000000207c3c] __handle_irq_event_percpu+0x8c/0x250
 [c000000baffcfee0] [c000000000207e2c] handle_irq_event_percpu+0x2c/0xa0
 [c000000baffcff10] [c000000000210a04] handle_percpu_irq+0x84/0xc0
 [c000000baffcff40] [c000000000205f14] generic_handle_irq+0x54/0x80
 [c000000baffcff60] [c000000000015740] __do_irq+0x90/0x1d0
 [c000000baffcff90] [c000000000016990] __do_IRQ+0xc0/0x140
 [c0000009732f3940] [c000000bafceaca8] 0xc000000bafceaca8
 [c0000009732f39d0] [c000000000016b78] do_IRQ+0x168/0x1c0
 [c0000009732f3a00] [c0000000000090c8] hardware_interrupt_common_virt+0x218/0x220

This means that there is no PMC overflown among the active events
in the PMU, but there is a PMU pending in Paca. The function
"any_pmc_overflown" checks the PMCs on active events in
cpuhw->n_events. Code snippet:

<<>>
if (any_pmc_overflown(cpuhw))
 	clear_pmi_irq_pending();
 else
 	WARN_ON(pmi_irq_pending());
<<>>

Here the PMC overflown is not from active event. Example: When we do
perf record, default cycles and instructions will be running on PMC6
and PMC5 respectively. It could happen that overflowed event is currently
not active and pending PMI is for the inactive event. Debug logs from
trace_printk:

<<>>
any_pmc_overflown: idx is 5: pmc value is 0xd9a
power_pmu_disable: PMC1: 0x0, PMC2: 0x0, PMC3: 0x0, PMC4: 0x0, PMC5: 0xd9a, PMC6: 0x80002011
<<>>

Here active PMC (from idx) is PMC5 , but overflown PMC is PMC6(0x80002011).
When we handle PMI interrupt for such cases, if the PMC overflown is
from inactive event, it will be ignored. Reference commit:
commit bc09c219b2 ("powerpc/perf: Fix finding overflowed PMC in interrupt")

Patch addresses two changes:
1) Fix 1 : Removal of warning ( WARN_ON(pmi_irq_pending()); )
   We were printing warning if no PMC is found overflown among active PMU
   events, but PMI pending in PACA. But this could happen in cases where
   PMC overflown is not in active PMC. An inactive event could have caused
   the overflow. Hence the warning is not needed. To know pending PMI is
   from an inactive event, we need to loop through all PMC's which will
   cause more SPR reads via mfspr and increase in context switch. Also in
   existing function: perf_event_interrupt, already we ignore PMI's
   overflown when it is from an inactive PMC.

2) Fix 2: optimization in clearing pending PMI.
   Currently we check for any active PMC overflown before clearing PMI
   pending in Paca. This is causing additional SPR read also. From point 1,
   we know that if PMI pending in Paca from inactive cases, that is going
   to be ignored during replay. Hence if there is pending PMI in Paca, just
   clear it irrespective of PMC overflown or not.

In summary, remove the any_pmc_overflown check entirely in
power_pmu_disable. ie If there is a pending PMI in Paca, clear it, since
we are in pmu_disable. There could be cases where PMI is pending because
of inactive PMC ( which later when replayed also will get ignored ), so
WARN_ON could give false warning. Hence removing it.

Fixes: 2c9ac51b850d ("powerpc/perf: Fix PMU callbacks to clear pending PMI before resetting an overflown PMC")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220522142256.24699-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:16:06 +02:00
Kajol Jain
cca915d691 powerpc/perf: Fix the threshold compare group constraint for power9
[ Upstream commit ab0cc6bbf0c812731c703ec757fcc3fc3a457a34 ]

Thresh compare bits for a event is used to program thresh compare
field in Monitor Mode Control Register A (MMCRA: 9-18 bits for power9).
When scheduling events as a group, all events in that group should
match value in threshold bits (like thresh compare, thresh control,
thresh select). Otherwise event open for the sibling events should fail.
But in the current code, incase thresh compare bits are not valid,
we are not failing in group_constraint function which can result
in invalid group schduling.

Fix the issue by returning -1 incase event is threshold and threshold
compare value is not valid.

Thresh control bits in the event code is used to program thresh_ctl
field in Monitor Mode Control Register A (MMCRA: 48-55). In below example,
the scheduling of group events PM_MRK_INST_CMPL (873534401e0) and
PM_THRESH_MET (8734340101ec) is expected to fail as both event
request different thresh control bits and invalid thresh compare value.

Result before the patch changes:

[command]# perf stat -e "{r8735340401e0,r8734340101ec}" sleep 1

 Performance counter stats for 'sleep 1':

            11,048      r8735340401e0
             1,967      r8734340101ec

       1.001354036 seconds time elapsed

       0.001421000 seconds user
       0.000000000 seconds sys

Result after the patch changes:

[command]# perf stat -e "{r8735340401e0,r8734340101ec}" sleep 1
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument)
for event (r8735340401e0).
/bin/dmesg | grep -i perf may provide additional information.

Fixes: 78a16d9fc1 ("powerpc/perf: Avoid FAB_*_MATCH checks for power9")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220506061015.43916-2-kjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:21:18 +02:00
Alexey Kardashevskiy
42e8ec3b4b powerpc/perf: Fix 32bit compile
[ Upstream commit bb82c574691daf8f7fa9a160264d15c5804cb769 ]

The "read_bhrb" global symbol is only called under CONFIG_PPC64 of
arch/powerpc/perf/core-book3s.c but it is compiled for both 32 and 64 bit
anyway (and LLVM fails to link this on 32bit).

This fixes it by moving bhrb.o to obj64 targets.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220421025756.571995-1-aik@ozlabs.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-09 09:05:06 +02:00
Athira Rajeev
e012f9d1af powerpc/perf: Fix power9 event alternatives
[ Upstream commit 0dcad700bb2776e3886fe0a645a4bf13b1e747cd ]

When scheduling a group of events, there are constraint checks done to
make sure all events can go in a group. Example, one of the criteria is
that events in a group cannot use the same PMC. But platform specific
PMU supports alternative event for some of the event codes. During
perf_event_open(), if any event group doesn't match constraint check
criteria, further lookup is done to find alternative event.

By current design, the array of alternatives events in PMU code is
expected to be sorted by column 0. This is because in
find_alternative() the return criteria is based on event code
comparison. ie. "event < ev_alt[i][0])". This optimisation is there
since find_alternative() can be called multiple times. In power9 PMU
code, the alternative event array is not sorted properly and hence there
is breakage in finding alternative events.

To work with existing logic, fix the alternative event array to be
sorted by column 0 for power9-pmu.c

Results:

With alternative events, multiplexing can be avoided. That is, for
example, in power9 PM_LD_MISS_L1 (0x3e054) has alternative event,
PM_LD_MISS_L1_ALT (0x400f0). This is an identical event which can be
programmed in a different PMC.

Before:

 # perf stat -e r3e054,r300fc

 Performance counter stats for 'system wide':

           1057860      r3e054              (50.21%)
               379      r300fc              (49.79%)

       0.944329741 seconds time elapsed

Since both the events are using PMC3 in this case, they are
multiplexed here.

After:

 # perf stat -e r3e054,r300fc

 Performance counter stats for 'system wide':

           1006948      r3e054
               182      r300fc

Fixes: 91e0bd1e62 ("powerpc/perf: Add PM_LD_MISS_L1 and PM_BR_2PATH to power9 event list")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220419114828.89843-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-27 13:53:56 +02:00
Athira Rajeev
b5d363ff17 powerpc/perf: Don't use perf_hw_context for trace IMC PMU
[ Upstream commit 0198322379c25215b2778482bf1221743a76e2b5 ]

Trace IMC (In-Memory collection counters) in powerpc is useful for
application level profiling.

For trace_imc, presently task context (task_ctx_nr) is set to
perf_hw_context. But perf_hw_context should only be used for CPU PMU.
See commit 2665784850 ("perf/core: Verify we have a single
perf_hw_context PMU").

So for trace_imc, even though it is per thread PMU, it is preferred to
use sw_context in order to be able to do application level monitoring.
Hence change the task_ctx_nr to use perf_sw_context.

Fixes: 012ae24484 ("powerpc/perf: Trace imc PMU functions")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
[mpe: Update subject & incorporate notes into change log, reflow comment]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220202041837.65968-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:40:14 +02:00
Athira Rajeev
55402a4618 powerpc/perf: Fix power_pmu_disable to call clear_pmi_irq_pending only if PMI is pending
[ Upstream commit fb6433b48a178d4672cb26632454ee0b21056eaa ]

Running selftest with CONFIG_PPC_IRQ_SOFT_MASK_DEBUG enabled in kernel
triggered below warning:

[  172.851380] ------------[ cut here ]------------
[  172.851391] WARNING: CPU: 8 PID: 2901 at arch/powerpc/include/asm/hw_irq.h:246 power_pmu_disable+0x270/0x280
[  172.851402] Modules linked in: dm_mod bonding nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables rfkill nfnetlink sunrpc xfs libcrc32c pseries_rng xts vmx_crypto uio_pdrv_genirq uio sch_fq_codel ip_tables ext4 mbcache jbd2 sd_mod t10_pi sg ibmvscsi ibmveth scsi_transport_srp fuse
[  172.851442] CPU: 8 PID: 2901 Comm: lost_exception_ Not tainted 5.16.0-rc5-03218-g798527287598 #2
[  172.851451] NIP:  c00000000013d600 LR: c00000000013d5a4 CTR: c00000000013b180
[  172.851458] REGS: c000000017687860 TRAP: 0700   Not tainted  (5.16.0-rc5-03218-g798527287598)
[  172.851465] MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 48004884  XER: 20040000
[  172.851482] CFAR: c00000000013d5b4 IRQMASK: 1
[  172.851482] GPR00: c00000000013d5a4 c000000017687b00 c000000002a10600 0000000000000004
[  172.851482] GPR04: 0000000082004000 c0000008ba08f0a8 0000000000000000 00000008b7ed0000
[  172.851482] GPR08: 00000000446194f6 0000000000008000 c00000000013b118 c000000000d58e68
[  172.851482] GPR12: c00000000013d390 c00000001ec54a80 0000000000000000 0000000000000000
[  172.851482] GPR16: 0000000000000000 0000000000000000 c000000015d5c708 c0000000025396d0
[  172.851482] GPR20: 0000000000000000 0000000000000000 c00000000a3bbf40 0000000000000003
[  172.851482] GPR24: 0000000000000000 c0000008ba097400 c0000000161e0d00 c00000000a3bb600
[  172.851482] GPR28: c000000015d5c700 0000000000000001 0000000082384090 c0000008ba0020d8
[  172.851549] NIP [c00000000013d600] power_pmu_disable+0x270/0x280
[  172.851557] LR [c00000000013d5a4] power_pmu_disable+0x214/0x280
[  172.851565] Call Trace:
[  172.851568] [c000000017687b00] [c00000000013d5a4] power_pmu_disable+0x214/0x280 (unreliable)
[  172.851579] [c000000017687b40] [c0000000003403ac] perf_pmu_disable+0x4c/0x60
[  172.851588] [c000000017687b60] [c0000000003445e4] __perf_event_task_sched_out+0x1d4/0x660
[  172.851596] [c000000017687c50] [c000000000d1175c] __schedule+0xbcc/0x12a0
[  172.851602] [c000000017687d60] [c000000000d11ea8] schedule+0x78/0x140
[  172.851608] [c000000017687d90] [c0000000001a8080] sys_sched_yield+0x20/0x40
[  172.851615] [c000000017687db0] [c0000000000334dc] system_call_exception+0x18c/0x380
[  172.851622] [c000000017687e10] [c00000000000c74c] system_call_common+0xec/0x268

The warning indicates that MSR_EE being set(interrupt enabled) when
there was an overflown PMC detected. This could happen in
power_pmu_disable since it runs under interrupt soft disable
condition ( local_irq_save ) and not with interrupts hard disabled.
commit 2c9ac51b850d ("powerpc/perf: Fix PMU callbacks to clear
pending PMI before resetting an overflown PMC") intended to clear
PMI pending bit in Paca when disabling the PMU. It could happen
that PMC gets overflown while code is in power_pmu_disable
callback function. Hence add a check to see if PMI pending bit
is set in Paca before clearing it via clear_pmi_pending.

Fixes: 2c9ac51b850d ("powerpc/perf: Fix PMU callbacks to clear pending PMI before resetting an overflown PMC")
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220122033429.25395-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-01 17:25:46 +01:00
Athira Rajeev
ef798cd035 powerpc/perf: Fix PMU callbacks to clear pending PMI before resetting an overflown PMC
[ Upstream commit 2c9ac51b850d84ee496b0a5d832ce66d411ae552 ]

Running perf fuzzer showed below in dmesg logs:
  "Can't find PMC that caused IRQ"

This means a PMU exception happened, but none of the PMC's (Performance
Monitor Counter) were found to be overflown. There are some corner cases
that clears the PMCs after PMI gets masked. In such cases, the perf
interrupt handler will not find the active PMC values that had caused
the overflow and thus leads to this message while replaying.

Case 1: PMU Interrupt happens during replay of other interrupts and
counter values gets cleared by PMU callbacks before replay:

During replay of interrupts like timer, __do_irq() and doorbell
exception, we conditionally enable interrupts via may_hard_irq_enable().
This could potentially create a window to generate a PMI. Since irq soft
mask is set to ALL_DISABLED, the PMI will get masked here. We could get
IPIs run before perf interrupt is replayed and the PMU events could
be deleted or stopped. This will change the PMU SPR values and resets
the counters. Snippet of ftrace log showing PMU callbacks invoked in
__do_irq():

  <idle>-0 [051] dns. 132025441306354: __do_irq <-call_do_irq
  <idle>-0 [051] dns. 132025441306430: irq_enter <-__do_irq
  <idle>-0 [051] dns. 132025441306503: irq_enter_rcu <-__do_irq
  <idle>-0 [051] dnH. 132025441306599: xive_get_irq <-__do_irq
  <<>>
  <idle>-0 [051] dnH. 132025441307770: generic_smp_call_function_single_interrupt <-smp_ipi_demux_relaxed
  <idle>-0 [051] dnH. 132025441307839: flush_smp_call_function_queue <-smp_ipi_demux_relaxed
  <idle>-0 [051] dnH. 132025441308057: _raw_spin_lock <-event_function
  <idle>-0 [051] dnH. 132025441308206: power_pmu_disable <-perf_pmu_disable
  <idle>-0 [051] dnH. 132025441308337: power_pmu_del <-event_sched_out
  <idle>-0 [051] dnH. 132025441308407: power_pmu_read <-power_pmu_del
  <idle>-0 [051] dnH. 132025441308477: read_pmc <-power_pmu_read
  <idle>-0 [051] dnH. 132025441308590: isa207_disable_pmc <-power_pmu_del
  <idle>-0 [051] dnH. 132025441308663: write_pmc <-power_pmu_del
  <idle>-0 [051] dnH. 132025441308787: power_pmu_event_idx <-perf_event_update_userpage
  <idle>-0 [051] dnH. 132025441308859: rcu_read_unlock_strict <-perf_event_update_userpage
  <idle>-0 [051] dnH. 132025441308975: power_pmu_enable <-perf_pmu_enable
  <<>>
  <idle>-0 [051] dnH. 132025441311108: irq_exit <-__do_irq
  <idle>-0 [051] dns. 132025441311319: performance_monitor_exception <-replay_soft_interrupts

Case 2: PMI's masked during local_* operations, example local_add(). If
the local_add() operation happens within a local_irq_save(), replay of
PMI will be during local_irq_restore(). Similar to case 1, this could
also create a window before replay where PMU events gets deleted or
stopped.

Fix it by updating the PMU callback function power_pmu_disable() to
check for pending perf interrupt. If there is an overflown PMC and
pending perf interrupt indicated in paca, clear the PMI bit in paca to
drop that sample. Clearing of PMI bit is done in power_pmu_disable()
since disable is invoked before any event gets deleted/stopped. With
this fix, if there are more than one event running in the PMU, there is
a chance that we clear the PMI bit for the event which is not getting
deleted/stopped. The other events may still remain active. Hence to make
sure we don't drop valid sample in such cases, another check is added in
power_pmu_enable. This checks if there is an overflown PMC found among
the active events and if so enable back the PMI bit. Two new helper
functions are introduced to clear/set the PMI, ie
clear_pmi_irq_pending() and set_pmi_irq_pending(). Helper function
pmi_irq_pending() is introduced to give a warning if there is pending
PMI bit in paca, but no PMC is overflown.

Also there are corner cases which result in performance monitor
interrupts being triggered during power_pmu_disable(). This happens
since PMXE bit is not cleared along with disabling of other MMCR0 bits
in the pmu_disable. Such PMI's could leave the PMU running and could
trigger PMI again which will set MMCR0 PMAO bit. This could lead to
spurious interrupts in some corner cases. Example, a timer after
power_pmu_del() which will re-enable interrupts and triggers a PMI again
since PMAO bit is still set. But fails to find valid overflow since PMC
was cleared in power_pmu_del(). Fix that by disabling PMXE along with
disabling of other MMCR0 bits in power_pmu_disable().

We can't just replay PMI any time. Hence this approach is preferred
rather than replaying PMI before resetting overflown PMC. Patch also
documents core-book3s on a race condition which can trigger these PMC
messages during idle path in PowerNV.

Fixes: f442d00480 ("powerpc/64s: Add support to mask perf interrupts and replay them")
Reported-by: Nageswara R Sastry <nasastry@in.ibm.com>
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Suggested-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make pmi_irq_pending() return bool, reflow/reword some comments]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1626846509-1350-2-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 10:54:05 +01:00
Nicholas Piggin
c9ffa84a3b powerpc/perf: move perf irq/nmi handling details into traps.c
[ Upstream commit 156b5371a9c2482a9ad23ec82d1a4f89a3ab430d ]

This is required in order to allow more significant differences between
NMI type interrupt handlers and regular asynchronous handlers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-20-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 10:54:05 +01:00
Athira Rajeev
a0758b3be4 powerpc/perf: MMCR0 control for PMU registers under PMCC=00
[ Upstream commit 91668ab7db4bcfae332e561df1de2401f3f18553 ]

PowerISA v3.1 introduces new control bit (PMCCEXT) for restricting
access to group B PMU registers in problem state when
MMCR0 PMCC=0b00. In problem state and when MMCR0 PMCC=0b00,
setting the Monitor Mode Control Register bit 54 (MMCR0 PMCCEXT),
will restrict read permission on Group B Performance Monitor
Registers (SIER, SIAR, SDAR and MMCR1). When this bit is set to zero,
group B registers will be readable. In other platforms (like power9),
the older behaviour is retained where group B PMU SPRs are readable.

Patch adds support for MMCR0 PMCCEXT bit in power10 by enabling
this bit during boot and during the PMU event enable/disable callback
functions.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1606409684-1589-8-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 10:54:05 +01:00
Kajol Jain
37566a343f powerpc/perf/hv-gpci: Fix counter value parsing
commit f9addd85fbfacf0d155e83dbee8696d6df5ed0c7 upstream.

H_GetPerformanceCounterInfo (0xF080) hcall returns the counter data in
the result buffer. Result buffer has specific format defined in the PAPR
specification. One of the fields is counter offset and width of the
counter data returned.

Counter data are returned in a unsigned char array in big endian byte
order. To get the final counter data, the values must be left shifted
byte at a time. But commit 220a0c609a ("powerpc/perf: Add support for
the hv gpci (get performance counter info) interface") made the shifting
bitwise and also assumed little endian order. Because of that, hcall
counters values are reported incorrectly.

In particular this can lead to counters go backwards which messes up the
counter prev vs now calculation and leads to huge counter value
reporting:

  #: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
           -C 0 -I 1000
        time             counts unit events
     1.000078854 18,446,744,073,709,535,232      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     2.000213293                  0      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     3.000320107                  0      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     4.000428392                  0      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     5.000537864                  0      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     6.000649087                  0      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     7.000760312                  0      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     8.000865218             16,448      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     9.000978985 18,446,744,073,709,535,232      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
    10.001088891             16,384      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
    11.001201435                  0      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
    12.001307937 18,446,744,073,709,535,232      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/

Fix the shifting logic to correct match the format, ie. read bytes in
big endian order.

Fixes: e4f226b158 ("powerpc/perf/hv-gpci: Increase request buffer size")
Cc: stable@vger.kernel.org # v4.6+
Reported-by: Nageswara R Sastry<rnsastry@linux.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Tested-by: Nageswara R Sastry<rnsastry@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210813082158.429023-1-kjain@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-18 13:40:06 +02:00
Athira Rajeev
d3c38d8549 powerpc/perf: Invoke per-CPU variable access with disabled interrupts
commit f66de7ac4849eb42a7b18e26b8ee49e08130fd27 upstream.

The power_pmu_event_init() callback access per-cpu variable
(cpu_hw_events) to check for event constraints and Branch Stack
(BHRB). Current usage is to disable preemption when accessing the
per-cpu variable, but this does not prevent timer callback from
interrupting event_init. Fix this by using 'local_irq_save/restore'
to make sure the code path is invoked with disabled interrupts.

This change is tested in mambo simulator to ensure that, if a timer
interrupt comes in during the per-cpu access in event_init, it will be
soft masked and replayed later. For testing purpose, introduced a
udelay() in power_pmu_event_init() to make sure a timer interrupt arrives
while in per-cpu variable access code between local_irq_save/resore.
As expected the timer interrupt was replayed later during local_irq_restore
called from power_pmu_event_init. This was confirmed by adding
breakpoint in mambo and checking the backtrace when timer_interrupt
was hit.

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1606814880-1720-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-03 10:09:29 +02:00
Athira Rajeev
e06a532f31 powerpc/perf: Fix the threshold event selection for memory events in power10
[ Upstream commit 66d9b7492887d34c711bc05b36c22438acba51b4 ]

Memory events (mem-loads and mem-stores) currently use the threshold
event selection as issue to finish. Power10 supports issue to complete
as part of thresholding which is more appropriate for mem-loads and
mem-stores. Hence fix the event code for memory events to use issue
to complete.

Fixes: a64e697cef ("powerpc/perf: power10 Performance Monitoring support")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1614840015-1535-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14 09:50:42 +02:00
Athira Rajeev
8ce329c689 powerpc/perf: Fix PMU constraint check for EBB events
[ Upstream commit 10f8f96179ecc7f69c927f6d231f6d02736cea83 ]

The power PMU group constraints includes check for EBB events to make
sure all events in a group must agree on EBB. This will prevent
scheduling EBB and non-EBB events together. But in the existing check,
settings for constraint mask and value is interchanged. Patch fixes the
same.

Before the patch, PMU selftest "cpu_event_pinned_vs_ebb_test" fails with
below in dmesg logs. This happens because EBB event gets enabled along
with a non-EBB cpu event.

  [35600.453346] cpu_event_pinne[41326]: illegal instruction (4)
  at 10004a18 nip 10004a18 lr 100049f8 code 1 in
  cpu_event_pinned_vs_ebb_test[10000000+10000]

Test results after the patch:

  $ ./pmu/ebb/cpu_event_pinned_vs_ebb_test
  test: cpu_event_pinned_vs_ebb
  tags: git_version:v5.12-rc5-93-gf28c3125acd3-dirty
  Binding to cpu 8
  EBB Handler is at 0x100050c8
  read error on event 0x7fffe6bd4040!
  PM_RUN_INST_CMPL: result 9872 running/enabled 37930432
  success: cpu_event_pinned_vs_ebb

This bug was hidden by other logic until commit 1908dc9117 (perf:
Tweak perf_event_attr::exclusive semantics).

Fixes: 4df4899911 ("powerpc/perf: Add power8 EBB support")
Reported-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Mention commit 1908dc9117]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1617725761-1464-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14 09:50:34 +02:00
Athira Rajeev
eb5a9ee32c powerpc/perf: Record counter overflow always if SAMPLE_IP is unset
[ Upstream commit d137845c973147a22622cc76c7b0bc16f6206323 ]

While sampling for marked events, currently we record the sample only
if the SIAR valid bit of Sampled Instruction Event Register (SIER) is
set. SIAR_VALID bit is used for fetching the instruction address from
Sampled Instruction Address Register(SIAR). But there are some
usecases, where the user is interested only in the PMU stats at each
counter overflow and the exact IP of the overflow event is not
required. Dropping SIAR invalid samples will fail to record some of
the counter overflows in such cases.

Example of such usecase is dumping the PMU stats (event counts) after
some regular amount of instructions/events from the userspace (ex: via
ptrace). Here counter overflow is indicated to userspace via signal
handler, and captured by monitoring and enabling I/O signaling on the
event file descriptor. In these cases, we expect to get
sample/overflow indication after each specified sample_period.

Perf event attribute will not have PERF_SAMPLE_IP set in the
sample_type if exact IP of the overflow event is not requested. So
while profiling if SAMPLE_IP is not set, just record the counter
overflow irrespective of SIAR_VALID check.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Reflow comment and if formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1612516492-1428-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:23 +01:00
Athira Rajeev
ac022fbee6 powerpc/perf: Fix handling of privilege level checks in perf interrupt context
commit 5ae5fbd2107959b68ac69a8b75412208663aea88 upstream.

Running "perf mem record" in powerpc platforms with selinux enabled
resulted in soft lockup's. Below call-trace was seen in the logs:

  CPU: 58 PID: 3751 Comm: sssd_nss Not tainted 5.11.0-rc7+ #2
  NIP:  c000000000dff3d4 LR: c000000000dff3d0 CTR: 0000000000000000
  REGS: c000007fffab7d60 TRAP: 0100   Not tainted  (5.11.0-rc7+)
  ...
  NIP _raw_spin_lock_irqsave+0x94/0x120
  LR  _raw_spin_lock_irqsave+0x90/0x120
  Call Trace:
    0xc00000000fd47260 (unreliable)
    skb_queue_tail+0x3c/0x90
    audit_log_end+0x6c/0x180
    common_lsm_audit+0xb0/0xe0
    slow_avc_audit+0xa4/0x110
    avc_has_perm+0x1c4/0x260
    selinux_perf_event_open+0x74/0xd0
    security_perf_event_open+0x68/0xc0
    record_and_restart+0x6e8/0x7f0
    perf_event_interrupt+0x22c/0x560
    performance_monitor_exception0x4c/0x60
    performance_monitor_common_virt+0x1c8/0x1d0
  interrupt: f00 at _raw_spin_lock_irqsave+0x38/0x120
  NIP:  c000000000dff378 LR: c000000000b5fbbc CTR: c0000000007d47f0
  REGS: c00000000fd47860 TRAP: 0f00   Not tainted  (5.11.0-rc7+)
  ...
  NIP _raw_spin_lock_irqsave+0x38/0x120
  LR  skb_queue_tail+0x3c/0x90
  interrupt: f00
    0x38 (unreliable)
    0xc00000000aae6200
    audit_log_end+0x6c/0x180
    audit_log_exit+0x344/0xf80
    __audit_syscall_exit+0x2c0/0x320
    do_syscall_trace_leave+0x148/0x200
    syscall_exit_prepare+0x324/0x390
    system_call_common+0xfc/0x27c

The above trace shows that while the CPU was handling a performance
monitor exception, there was a call to security_perf_event_open()
function. In powerpc core-book3s, this function is called from
perf_allow_kernel() check during recording of data address in the
sample via perf_get_data_addr().

Commit da97e18458 ("perf_event: Add support for LSM and SELinux
checks") introduced security enhancements to perf. As part of this
commit, the new security hook for perf_event_open() was added in all
places where perf paranoid check was previously used. In powerpc
core-book3s code, originally had paranoid checks in
perf_get_data_addr() and power_pmu_bhrb_read(). So
perf_paranoid_kernel() checks were replaced with perf_allow_kernel()
in these PMU helper functions as well.

The intention of paranoid checks in core-book3s was to verify
privilege access before capturing some of the sample data. Along with
paranoid checks, perf_allow_kernel() also does a
security_perf_event_open(). Since these functions are accessed while
recording a sample, we end up calling selinux_perf_event_open() in PMI
context. Some of the security functions use spinlock like
sidtab_sid2str_put(). If a perf interrupt hits under a spin lock and
if we end up in calling selinux hook functions in PMI handler, this
could cause a dead lock.

Since the purpose of this security hook is to control access to
perf_event_open(), it is not right to call this in interrupt context.

The paranoid checks in powerpc core-book3s were done at interrupt time
which is also not correct.

Reference commits:
  Commit cd1231d703 ("powerpc/perf: Prevent kernel address leak via perf_get_data_addr()")
  Commit bb19af8160 ("powerpc/perf: Prevent kernel address leak to userspace via BHRB buffer")

We only allow creation of events that have already passed the
privilege checks in perf_event_open(). So these paranoid checks are
not needed at event time. As a fix, patch uses
'event->attr.exclude_kernel' check to prevent exposing kernel address
for userspace only sampling.

Fixes: cd1231d703 ("powerpc/perf: Prevent kernel address leak via perf_get_data_addr()")
Cc: stable@vger.kernel.org # v4.17+
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1614247839-1428-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:10 +01:00
Athira Rajeev
58b97af176 powerpc/perf: Exclude kernel samples while counting events in user space.
commit aa8e21c053d72b6639ea5a7f1d3a1d0209534c94 upstream.

Perf event attritube supports exclude_kernel flag to avoid
sampling/profiling in supervisor state (kernel). Based on this event
attr flag, Monitor Mode Control Register bit is set to freeze on
supervisor state. But sometimes (due to hardware limitation), Sampled
Instruction Address Register (SIAR) locks on to kernel address even
when freeze on supervisor is set. Patch here adds a check to drop
those samples.

Cc: stable@vger.kernel.org
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1606289215-1433-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:10 +01:00
Madhavan Srinivasan
34169b582a powerpc/perf: Fix Threshold Event Counter Multiplier width for P10
[ Upstream commit ef0e3b650f8ddc54bb70868852f50642ee3ae765 ]

Threshold Event Counter Multiplier (TECM) is part of Monitor Mode
Control Register A (MMCRA). This field along with Threshold Event
Counter Exponent (TECE) is used to get threshould counter value.
In Power10, this is a 8bit field, so patch fixes the
current code to modify the MMCRA[TECM] extraction macro to
handle this change. ISA v3.1 says this is a 7 bit field but
POWER10 it's actually 8 bits which will hopefully be fixed
in ISA v3.1 update.

Fixes: 170a315f41 ("powerpc/perf: Support to export MMCRA[TEC*] field to userspace")
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1608022578-1532-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:53 +01:00
Athira Rajeev
ba6a7e6ca5 powerpc/perf: Fix the PMU group constraints for threshold events in power10
[ Upstream commit 0263bbb377af0c2d38bc8b2ad2ff147e240094de ]

The PMU group constraints mask for threshold events covers
all thresholding bits which includes threshold control value
(start/stop), select value as well as thresh_cmp value (MMCRA[9:18].
In power9, thresh_cmp bits were part of the event code. But in case
of power10, thresh_cmp bits are not part of event code due to
inclusion of MMCR3 bits. Hence thresh_cmp is not valid for
group constraints for power10.

Fix the PMU group constraints checking for threshold events in
power10 by using constraint mask and value for only threshold control
and select bits.

Fixes: a64e697cef ("powerpc/perf: power10 Performance Monitoring support")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1606409684-1589-4-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:32 +01:00
Athira Rajeev
e559aaba71 powerpc/perf: Update the PMU group constraints for l2l3 events in power10
[ Upstream commit e924be7b0b0d1f37d0509c854a92c7a71e3cdfe7 ]

In Power9, L2/L3 bus events are always available as a
"bank" of 4 events. To obtain the counts for any of the
l2/l3 bus events in a given bank, the user will have to
program PMC4 with corresponding l2/l3 bus event for that
bank.

Commit 59029136d7 ("powerpc/perf: Add constraints for power9 l2/l3 bus events")
enforced this rule in Power9. But this is not valid for
Power10, since in Power10 Monitor Mode Control Register2
(MMCR2) has bits to configure l2/l3 event bits. Hence remove
this PMC4 constraint check from power10.

Since the l2/l3 bits in MMCR2 are not per-pmc, patch handles
group constrints checks for l2/l3 bits in MMCR2.

Fixes: a64e697cef ("powerpc/perf: power10 Performance Monitoring support")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1606409684-1589-3-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:32 +01:00
Athira Rajeev
0760233fd4 powerpc/perf: Fix to update radix_scope_qual in power10
[ Upstream commit d3afd28cd2f35b2a1046b76e0cf010b684da2e84 ]

power10 uses bit 9 of the raw event code as RADIX_SCOPE_QUAL.
This bit is used for enabling the radix process events.
Patch fixes the PMU counter support functions to program bit
18 of MMCR1 ( Monitor Mode Control Register1 ) with the
RADIX_SCOPE_QUAL bit value. Since this field is not per-pmc,
add this to PMU group constraints to make sure events in a
group will have same bit value for this field. Use bit 21 as
constraint bit field for radix_scope_qual. Patch also updates
the power10 raw event encoding layout information, format field
and constraints bit layout to include the radix_scope_qual bit.

Fixes: a64e697cef ("powerpc/perf: power10 Performance Monitoring support")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1606409684-1589-2-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:32 +01:00
Athira Rajeev
668f649850 powerpc/perf: Fix crash with is_sier_available when pmu is not set
[ Upstream commit f75e7d73bdf73f07b0701a6d21c111ef5d9021dd ]

On systems without any specific PMU driver support registered, running
'perf record' with —intr-regs  will crash ( perf record -I <workload> ).

The relevant portion from crash logs and Call Trace:

Unable to handle kernel paging request for data at address 0x00000068
Faulting instruction address: 0xc00000000013eb18
Oops: Kernel access of bad area, sig: 11 [#1]
CPU: 2 PID: 13435 Comm: kill Kdump: loaded Not tainted 4.18.0-193.el8.ppc64le #1
NIP:  c00000000013eb18 LR: c000000000139f2c CTR: c000000000393d80
REGS: c0000004a07ab4f0 TRAP: 0300   Not tainted  (4.18.0-193.el8.ppc64le)
NIP [c00000000013eb18] is_sier_available+0x18/0x30
LR [c000000000139f2c] perf_reg_value+0x6c/0xb0
Call Trace:
[c0000004a07ab770] [c0000004a07ab7c8] 0xc0000004a07ab7c8 (unreliable)
[c0000004a07ab7a0] [c0000000003aa77c] perf_output_sample+0x60c/0xac0
[c0000004a07ab840] [c0000000003ab3f0] perf_event_output_forward+0x70/0xb0
[c0000004a07ab8c0] [c00000000039e208] __perf_event_overflow+0x88/0x1a0
[c0000004a07ab910] [c00000000039e42c] perf_swevent_hrtimer+0x10c/0x1d0
[c0000004a07abc50] [c000000000228b9c] __hrtimer_run_queues+0x17c/0x480
[c0000004a07abcf0] [c00000000022aaf4] hrtimer_interrupt+0x144/0x520
[c0000004a07abdd0] [c00000000002a864] timer_interrupt+0x104/0x2f0
[c0000004a07abe30] [c0000000000091c4] decrementer_common+0x114/0x120

When perf record session is started with "-I" option, capturing registers
on each sample calls is_sier_available() to check for the
SIER (Sample Instruction Event Register) availability in the platform.
This function in core-book3s accesses 'ppmu->flags'. If a platform specific
PMU driver is not registered, ppmu is set to NULL and accessing its
members results in a crash. Fix the crash by returning false in
is_sier_available() if ppmu is not set.

Fixes: 333804dc3b ("powerpc/perf: Update perf_regs structure to include SIER")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1606185640-1720-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:31 +01:00
Peter Zijlstra
76a4efa809 perf/arch: Remove perf_sample_data::regs_user_copy
struct perf_sample_data lives on-stack, we should be careful about it's
size. Furthermore, the pt_regs copy in there is only because x86_64 is a
trainwreck, solve it differently.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20201030151955.258178461@infradead.org
2020-11-09 18:12:34 +01:00
Peter Zijlstra
267fb27352 perf: Reduce stack usage of perf_output_begin()
__perf_output_begin() has an on-stack struct perf_sample_data in the
unlikely case it needs to generate a LOST record. However, every call
to perf_output_begin() must already have a perf_sample_data on-stack.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151954.985416146@infradead.org
2020-11-09 18:12:33 +01:00
Kajol Jain
09b791d955 powerpc/hv-gpci: Add sysfs files inside hv-gpci device to show cpumask
Patch here adds a cpumask attr to hv_gpci pmu along with ABI documentation.

Primary use to expose the cpumask is for the perf tool which has the
capability to parse the driver sysfs folder and understand the
cpumask file. Having cpumask file will reduce the number of perf command
line parameters (will avoid "-C" option in the perf tool
command line). It can also notify the user which is
the current cpu used to retrieve the counter data.

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

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201003074943.338618-5-kjain@linux.ibm.com
2020-10-07 22:34:49 +11:00
Kajol Jain
dcb5cdf60a powerpc/perf/hv-gpci: Add cpu hotplug support
Patch here adds cpu hotplug functions to hv_gpci pmu.
A new cpuhp_state "CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE" enum
is added.

The online callback function updates the cpumask only if its
empty. As the primary intention of adding hotplug support
is to designate a CPU to make HCALL to collect the
counter data.

The offline function test and clear corresponding cpu in a cpumask
and update cpumask to any other active cpu.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201003074943.338618-4-kjain@linux.ibm.com
2020-10-07 22:34:48 +11:00
Kajol Jain
0f9866f7e8 powerpc/perf/hv-gpci: Fix starting index value
Commit 9e9f601084 ("powerpc/perf/{hv-gpci, hv-common}: generate
requests with counters annotated") adds a framework for defining
gpci counters.
In this patch, they adds starting_index value as '0xffffffffffffffff'.
which is wrong as starting_index is of size 32 bits.

Because of this, incase we try to run hv-gpci event we get error.

In power9 machine:

command#: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
          -C 0 -I 1000
event syntax error: '..bie_count_and_time_tlbie_instructions_issued/'
                                  \___ value too big for format, maximum is 4294967295

This patch fix this issue and changes starting_index value to '0xffffffff'

After this patch:

command#: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ -C 0 -I 1000
     1.000085786              1,024      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     2.000287818              1,024      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     2.439113909             17,408      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/

Fixes: 9e9f601084 ("powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201003074943.338618-1-kjain@linux.ibm.com
2020-10-07 22:34:48 +11:00
Athira Rajeev
3b6c3adbb2 powerpc/perf: Exclude pmc5/6 from the irrelevant PMU group constraints
PMU counter support functions enforces event constraints for group of
events to check if all events in a group can be monitored. Incase of
event codes using PMC5 and PMC6 ( 500fa and 600f4 respectively ), not
all constraints are applicable, say the threshold or sample bits. But
current code includes pmc5 and pmc6 in some group constraints (like
IC_DC Qualifier bits) which is actually not applicable and hence
results in those events not getting counted when scheduled along with
group of other events. Patch fixes this by excluding PMC5/6 from
constraints which are not relevant for it.

Fixes: 7ffd948 ("powerpc/perf: factor out power8 pmu functions")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1600672204-1610-1-git-send-email-atrajeev@linux.vnet.ibm.com
2020-10-06 23:22:27 +11:00
Michael Ellerman
d10ebe79df powerpc/perf: Add declarations to fix sparse warnings
Sparse warns about all the init functions:
  symbol init_ppc970_pmu was not declared. Should it be static?
  symbol init_power5p_pmu was not declared. Should it be static?
  symbol init_power5_pmu was not declared. Should it be static?
  symbol init_power6_pmu was not declared. Should it be static?
  symbol init_power7_pmu was not declared. Should it be static?
  symbol init_power9_pmu was not declared. Should it be static?
  symbol init_power8_pmu was not declared. Should it be static?
  symbol init_generic_compat_pmu was not declared. Should it be static?

They're already declared in internal.h, so just make sure all the C
files include that directly or indirectly.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://lore.kernel.org/r/20200916115637.3100484-2-mpe@ellerman.id.au
2020-09-18 19:59:43 +10:00
Michael Ellerman
960e370813 Merge branch 'fixes' into next
Bring in our fixes branch for this cycle which avoids some small
conflicts with upcoming commits.
2020-09-14 22:57:18 +10:00
Scott Cheloha
59562b5c33 powerpc/perf: consolidate GPCI hcall structs into asm/hvcall.h
The H_GetPerformanceCounterInfo (GPCI) hypercall input/output structs are
useful to modules outside of perf/, so move them into asm/hvcall.h to live
alongside the other powerpc hypercall structs.

Leave the perf-specific GPCI stuff in perf/hv-gpci.h.

Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com>
Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200727184605.2945095-1-cheloha@linux.ibm.com
2020-09-02 11:00:20 +10:00
Athira Rajeev
82715a0f33 powerpc/perf: Fix reading of MSR[HV/PR] bits in trace-imc
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 -> 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: 77ca3951cc ("powerpc/perf: Add kernel support for new MSR[HV PR] bits in trace-imc")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1598424029-1662-1-git-send-email-atrajeev@linux.vnet.ibm.com
2020-08-27 17:41:45 +10:00
Alexey Kardashevskiy
b460b51241 powerpc/perf: Fix crashes with generic_compat_pmu & BHRB
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->bhrb_users which remains zero if bhrb_filter_map==0.

Fixes: be80e758d0 ("powerpc/perf: Add generic compat mode pmu driver")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200602025612.62707-1-aik@ozlabs.ru
2020-08-27 17:41:44 +10:00
zhengbin
ef23cf9a89 powerpc/perf: Remove set but not used variable 'target'
Fix gcc '-Wunused-but-set-variable' warning:

arch/powerpc/perf/imc-pmu.c: In function trace_imc_event_init:
arch/powerpc/perf/imc-pmu.c:1292:22: warning: variable target set but not used [-Wunused-but-set-variable]

It is introduced by commit 012ae24484 ("powerpc/perf:
Trace imc PMU functions"), but never used, so remove it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1574144074-142032-3-git-send-email-zhengbin13@huawei.com
2020-08-25 01:31:32 +10:00
Kajol Jain
64ef8f2c47 powerpc/perf/hv-24x7: Move cpumask file to top folder of hv-24x7 driver
Commit 792f73f747 ("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: 792f73f747 ("powerpc/hv-24x7: Add sysfs files inside hv-24x7 device to show cpumask")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200821080610.123997-1-kjain@linux.ibm.com
2020-08-21 23:35:27 +10:00
Athira Rajeev
17899eaf88 powerpc/perf: Fix soft lockups due to missed interrupt accounting
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 <aik@ozlabs.ru>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1596717992-7321-1-git-send-email-atrajeev@linux.vnet.ibm.com
2020-08-20 20:29:09 +10:00
Athira Rajeev
d735599a06 powerpc/perf: Add extended regs support for power10 platform
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 <grimm@linux.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Nageswara R Sastry <nasastry@in.ibm.com>
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-and-tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1596794701-23530-3-git-send-email-atrajeev@linux.vnet.ibm.com
2020-08-17 13:11:22 +10:00
Anju T Sudhakar
781fa4811d powerpc/perf: Add support for outputting extended regs in perf intr_regs
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 <anju@linux.vnet.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Nageswara R Sastry <nasastry@in.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-and-tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1596794701-23530-2-git-send-email-atrajeev@linux.vnet.ibm.com
2020-08-17 13:11:22 +10:00
Linus Torvalds
25d8d4eeca Merge tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:

 - Add support for (optionally) using queued spinlocks & 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
  ...
2020-08-07 10:33:50 -07:00
Michal Suchanek
d3a133aa0e powerpc/perf: Consolidate perf_callchain_user_[64|32]()
perf_callchain_user_64() and perf_callchain_user_32() are nearly
identical. Consolidate into one function with thin wrappers.

Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
[mpe: Adapt to copy_from_user_nofault(), minor formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200406210022.32265-1-msuchanek@suse.de
2020-07-30 22:53:49 +10:00
Nicholas Piggin
909adfc66b powerpc/64s/hash: Fix hash_preload running with interrupts enabled
Commit 2f92447f9f ("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> 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: 2f92447f9f ("powerpc/book3s64/hash: Use the pte_t address from the caller")
Reported-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reported-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200727060947.10060-1-npiggin@gmail.com
2020-07-27 17:02:09 +10:00
Athira Rajeev
1cade527f6 powerpc/perf: BHRB control to disable BHRB logic when not used
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 <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1594996707-3727-12-git-send-email-atrajeev@linux.vnet.ibm.com
2020-07-22 21:56:42 +10:00