Commit Graph

407 Commits

Author SHA1 Message Date
Athira Rajeev 5ae5fbd210 powerpc/perf: Fix handling of privilege level checks in perf interrupt context
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
2021-03-02 22:41:51 +11:00
Linus Torvalds b12b472496 powerpc updates for 5.12
A large series adding wrappers for our interrupt handlers, so that irq/nmi/user
 tracking can be isolated in the wrappers rather than spread in each handler.
 
 Conversion of the 32-bit syscall handling into C.
 
 A series from Nick to streamline our TLB flushing when using the Radix MMU.
 
 Switch to using queued spinlocks by default for 64-bit server CPUs.
 
 A rework of our PCI probing so that it happens later in boot, when more generic
 infrastructure is available.
 
 Two small fixes to allow 32-bit little-endian processes to run on 64-bit
 kernels.
 
 Other smaller features, fixes & cleanups.
 
 Thanks to:
   Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh Kumar K.V, Athira
   Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang Fan, Christophe Leroy,
   Christopher M. Riedl, Fabiano Rosas, Florian Fainelli, Frederic Barrat, Ganesh
   Goudar, Hari Bathini, Jiapeng Chong, Joseph J Allen, Kajol Jain, Markus
   Elfring, Michal Suchanek, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver
   O'Halloran, Pingfan Liu, Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan
   Das, Stephen Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, Zheng
   Yongjun.
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Merge tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - A large series adding wrappers for our interrupt handlers, so that
   irq/nmi/user tracking can be isolated in the wrappers rather than
   spread in each handler.

 - Conversion of the 32-bit syscall handling into C.

 - A series from Nick to streamline our TLB flushing when using the
   Radix MMU.

 - Switch to using queued spinlocks by default for 64-bit server CPUs.

 - A rework of our PCI probing so that it happens later in boot, when
   more generic infrastructure is available.

 - Two small fixes to allow 32-bit little-endian processes to run on
   64-bit kernels.

 - Other smaller features, fixes & cleanups.

Thanks to: Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh
Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang
Fan, Christophe Leroy, Christopher M. Riedl, Fabiano Rosas, Florian
Fainelli, Frederic Barrat, Ganesh Goudar, Hari Bathini, Jiapeng Chong,
Joseph J Allen, Kajol Jain, Markus Elfring, Michal Suchanek, Nathan
Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pingfan Liu,
Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan Das, Stephen
Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, and Zheng Yongjun.

* tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (188 commits)
  powerpc/perf: Adds support for programming of Thresholding in P10
  powerpc/pci: Remove unimplemented prototypes
  powerpc/uaccess: Merge raw_copy_to_user_allowed() into raw_copy_to_user()
  powerpc/uaccess: Merge __put_user_size_allowed() into __put_user_size()
  powerpc/uaccess: get rid of small constant size cases in raw_copy_{to,from}_user()
  powerpc/64: Fix stack trace not displaying final frame
  powerpc/time: Remove get_tbl()
  powerpc/time: Avoid using get_tbl()
  spi: mpc52xx: Avoid using get_tbl()
  powerpc/syscall: Avoid storing 'current' in another pointer
  powerpc/32: Handle bookE debugging in C in syscall entry/exit
  powerpc/syscall: Do not check unsupported scv vector on PPC32
  powerpc/32: Remove the counter in global_dbcr0
  powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry
  powerpc/syscall: implement system call entry/exit logic in C for PPC32
  powerpc/32: Always save non volatile GPRs at syscall entry
  powerpc/syscall: Change condition to check MSR_RI
  powerpc/syscall: Save r3 in regs->orig_r3
  powerpc/syscall: Use is_compat_task()
  powerpc/syscall: Make interrupt.c buildable on PPC32
  ...
2021-02-22 14:34:00 -08:00
Kajol Jain 82d2c16b35 powerpc/perf: Adds support for programming of Thresholding in P10
Thresholding, a performance monitoring unit feature, can be
used to identify marked instructions which take more than
expected cycles between start event and end event.
Threshold compare (thresh_cmp) bits are programmed in MMCRA
register. In Power9, thresh_cmp bits were part of the
event code. But in case of P10, thresh_cmp are not part of
event code due to inclusion of MMCR3 bits.

Patch here adds an option to use attr.config1 variable
to be used to pass thresh_cmp value to be programmed in
MMCRA register. A new ppmu flag called PPMU_HAS_ATTR_CONFIG1
has been added and this flag is used to notify the use of
attr.config1 variable.

Patch has extended the parameter list of 'compute_mmcr',
to include power_pmu's 'flags' element and parameter list of
get_constraint to include attr.config1 value. It also extend
parameter list of power_check_constraints inorder to pass
perf_event list.

As stated by commit ef0e3b650f ("powerpc/perf: Fix Threshold
Event Counter Multiplier width for P10"), constraint bits for
thresh_cmp is also needed to be increased to 11 bits, which is
handled as part of this patch. We added bit number 53 as part
of constraint bits of thresh_cmp for power10 to make it an
11 bit field.

Updated layout for p10:

/*
 * Layout of constraint bits:
 *
 *        60        56        52        48        44        40        36        32
 * | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - |
 *   [   fab_match   ]         [       thresh_cmp      ] [   thresh_ctl    ] [   ]
 *                                          |                                  |
 *                           [  thresh_cmp bits for p10]           thresh_sel -*
 *
 *        28        24        20        16        12         8         4         0
 * | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - |
 *               [ ] |   [ ] |  [  sample ]   [     ]   [6] [5]   [4] [3]   [2] [1]
 *                |  |    |  |                  |
 *      BHRB IFM -*  |    |  |*radix_scope      |      Count of events for each PMC.
 *              EBB -*    |                     |        p1, p2, p3, p4, p5, p6.
 *      L1 I/D qualifier -*                     |
 *                     nc - number of counters -*
 *
 * The PMC fields P1..P6, and NC, are adder fields. As we accumulate constraints
 * we want the low bit of each field to be added to any existing value.
 *
 * Everything else is a value field.
 */

Result:
command#: cat /sys/devices/cpu/format/thresh_cmp
config1:0-17

ex. usage:

command#: perf record -I --weight -d  -e
	 cpu/event=0x67340101EC,thresh_cmp=500/ ./ebizzy -S 2 -t 1 -s 4096
1826636 records/s
real  2.00 s
user  2.00 s
sys   0.00 s
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.038 MB perf.data (61 samples) ]

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210209095234.837356-1-kjain@linux.ibm.com
2021-02-11 23:35:36 +11:00
Athira Rajeev d137845c97 powerpc/perf: Record counter overflow always if SAMPLE_IP is unset
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
2021-02-09 01:09:46 +11:00
Athira Rajeev e79b76e03b powerpc/perf: Expose Performance Monitor Counter SPR's as part of extended regs
Currently Monitor Mode Control Registers and Sampling registers are
part of extended regs. Patch adds support to include Performance Monitor
Counter Registers (PMC1 to PMC6 ) as part of extended registers.

PMCs are saved in the perf interrupt handler as part of
per-cpu array 'pmcs' in struct cpu_hw_events. While capturing
the register values for extended regs, fetch these saved PMC values.

Simplified the PERF_REG_PMU_MASK_300/31 definition to include PMU
SPRs MMCR0 to PMC6. Exclude the unsupported SPRs (MMCR3, SIER2, SIER3)
from extended mask value for CPU_FTR_ARCH_300 in the new definition.

PERF_REG_EXTENDED_MAX is used to check if any index beyond the extended
registers is requested in the sample. Have one PERF_REG_EXTENDED_MAX
for CPU_FTR_ARCH_300/CPU_FTR_ARCH_31 since perf_reg_validate function
already checks the extended mask for the presence of any unsupported
register.

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/1612335337-1888-3-git-send-email-atrajeev@linux.vnet.ibm.com
2021-02-09 01:09:44 +11:00
Athira Rajeev 91f3469a43 powerpc/perf: Include PMCs as part of per-cpu cpuhw_events struct
To support capturing of PMC's as part of extended registers, the
value of SPR's PMC1 to PMC6 has to be saved in the starting of PMI
interrupt handler. This is needed since we are resetting the
overflown PMC before creating sample and hence directly reading
SPRN_PMCx in 'perf_reg_value' will be capturing the modified value.

To solve this, add a per-cpu array as part of structure cpu_hw_events
and use this array to capture PMC values in the perf interrupt handler.
Patch also re-factor's the interrupt handler code to use this per-cpu
array instead of current local array.

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/1612335337-1888-2-git-send-email-atrajeev@linux.vnet.ibm.com
2021-02-09 01:09:44 +11:00
Nicholas Piggin 156b5371a9 powerpc/perf: move perf irq/nmi handling details into traps.c
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
2021-02-09 00:02:10 +11:00
Kan Liang 2a6c6b7d7a perf/core: Add PERF_SAMPLE_WEIGHT_STRUCT
Current PERF_SAMPLE_WEIGHT sample type is very useful to expresses the
cost of an action represented by the sample. This allows the profiler
to scale the samples to be more informative to the programmer. It could
also help to locate a hotspot, e.g., when profiling by memory latencies,
the expensive load appear higher up in the histograms. But current
PERF_SAMPLE_WEIGHT sample type is solely determined by one factor. This
could be a problem, if users want two or more factors to contribute to
the weight. For example, Golden Cove core PMU can provide both the
instruction latency and the cache Latency information as factors for the
memory profiling.

For current X86 platforms, although meminfo::latency is defined as a
u64, only the lower 32 bits include the valid data in practice (No
memory access could last than 4G cycles). The higher 32 bits can be used
to store new factors.

Add a new sample type, PERF_SAMPLE_WEIGHT_STRUCT, to indicate the new
sample weight structure. It shares the same space as the
PERF_SAMPLE_WEIGHT sample type.

Users can apply either the PERF_SAMPLE_WEIGHT sample type or the
PERF_SAMPLE_WEIGHT_STRUCT sample type to retrieve the sample weight, but
they cannot apply both sample types simultaneously.

Currently, only X86 and PowerPC use the PERF_SAMPLE_WEIGHT sample type.
- For PowerPC, there is nothing changed for the PERF_SAMPLE_WEIGHT
  sample type. There is no effect for the new PERF_SAMPLE_WEIGHT_STRUCT
  sample type. PowerPC can re-struct the weight field similarly later.
- For X86, the same value will be dumped for the PERF_SAMPLE_WEIGHT
  sample type or the PERF_SAMPLE_WEIGHT_STRUCT sample type for now.
  The following patches will apply the new factors for the
  PERF_SAMPLE_WEIGHT_STRUCT sample type.

The field in the union perf_sample_weight should be shared among
different architectures. A generic name is required, but it's hard to
abstract a name that applies to all architectures. For example, on X86,
the fields are to store all kinds of latency. While on PowerPC, it
stores MMCRA[TECX/TECM], which should not be latency. So a general name
prefix 'var$NUM' is used here.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1611873611-156687-2-git-send-email-kan.liang@linux.intel.com
2021-02-01 15:31:36 +01:00
Kajol Jain e5f9d88586 powerpc/perf/hv-24x7: Dont create sysfs event files for dummy events
The hv_24x7 performance monitoring unit creates a list of supported
events from the event catalog obtained via HCALL. The hv_24x7 catalog
could also contain invalid or dummy events with names like RESERVED*.
These events do not have any hardware counters backing them. Add a
check to string compare the event names to filter such events out.

Result on power9 machine:

Before this patch:
  .....
  hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/              [Kernel PMU event]
  hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/       [Kernel PMU event]
  hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/       [Kernel PMU event]
  hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/         [Kernel PMU event]
  hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/    [Kernel PMU event]
  hv_24x7/PM_XTS_ATSD_SENT,chip=?/                   [Kernel PMU event]
  hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/               [Kernel PMU event]
  hv_24x7/RESERVED_NEST1,chip=?/                     [Kernel PMU event]
  hv_24x7/RESERVED_NEST10,chip=?/                    [Kernel PMU event]
  hv_24x7/RESERVED_NEST11,chip=?/                    [Kernel PMU event]
  hv_24x7/RESERVED_NEST12,chip=?/                    [Kernel PMU event]
  hv_24x7/RESERVED_NEST13,chip=?/                    [Kernel PMU event]
  ......

dmesg:
  [    0.000362] printk: console [hvc0] enabled
  [    0.815452] hv-24x7: read 1530 catalog entries, created 537 event attrs (0 failures), 275 descs

After this patch:
  ......
  hv_24x7/PM_XLINK2_OUT_ODD_AVLBL_CYC,chip=?/        [Kernel PMU event]
  hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/              [Kernel PMU event]
  hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/       [Kernel PMU event]
  hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/       [Kernel PMU event]
  hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/         [Kernel PMU event]
  hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/    [Kernel PMU event]
  hv_24x7/PM_XTS_ATSD_SENT,chip=?/                   [Kernel PMU event]
  hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/               [Kernel PMU event]
  hv_24x7/TOD,chip=?/                                [Kernel PMU event]
  ......

dmesg:
  [    0.000357] printk: console [hvc0] enabled
  [    0.808592] hv-24x7: read 1530 catalog entries, created 509 event attrs (0 failures), 275 descs

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
[mpe: Simplify ignore_event(), minor change log formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201228085204.18026-1-kjain@linux.ibm.com
2021-01-30 11:39:25 +11:00
Linus Torvalds 8a5be36b93 powerpc updates for 5.11
- Switch to the generic C VDSO, as well as some cleanups of our VDSO
    setup/handling code.
 
  - Support for KUAP (Kernel User Access Prevention) on systems using the hashed
    page table MMU, using memory protection keys.
 
  - Better handling of PowerVM SMT8 systems where all threads of a core do not
    share an L2, allowing the scheduler to make better scheduling decisions.
 
  - Further improvements to our machine check handling.
 
  - Show registers when unwinding interrupt frames during stack traces.
 
  - Improvements to our pseries (PowerVM) partition migration code.
 
  - Several series from Christophe refactoring and cleaning up various parts of
    the 32-bit code.
 
  - Other smaller features, fixes & cleanups.
 
 Thanks to:
   Alan Modra, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Ard
   Biesheuvel, Athira Rajeev, Balamuruhan S, Bill Wendling, Cédric Le Goater,
   Christophe Leroy, Christophe Lombard, Colin Ian King, Daniel Axtens, David
   Hildenbrand, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geert
   Uytterhoeven, Giuseppe Sacco, Greg Kurz, Harish, Jan Kratochvil, Jordan
   Niethe, Kaixu Xia, Laurent Dufour, Leonardo Bras, Madhavan Srinivasan, Mahesh
   Salgaonkar, Mathieu Desnoyers, Nathan Lynch, Nicholas Piggin, Oleg Nesterov,
   Oliver O'Halloran, Oscar Salvador, Po-Hsu Lin, Qian Cai, Qinglang Miao, Randy
   Dunlap, Ravi Bangoria, Sachin Sant, Sandipan Das, Sebastian Andrzej Siewior ,
   Segher Boessenkool, Srikar Dronamraju, Tyrel Datwyler, Uwe Kleine-König,
   Vincent Stehlé, Youling Tang, Zhang Xiaoxu.
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Merge tag 'powerpc-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Switch to the generic C VDSO, as well as some cleanups of our VDSO
   setup/handling code.

 - Support for KUAP (Kernel User Access Prevention) on systems using the
   hashed page table MMU, using memory protection keys.

 - Better handling of PowerVM SMT8 systems where all threads of a core
   do not share an L2, allowing the scheduler to make better scheduling
   decisions.

 - Further improvements to our machine check handling.

 - Show registers when unwinding interrupt frames during stack traces.

 - Improvements to our pseries (PowerVM) partition migration code.

 - Several series from Christophe refactoring and cleaning up various
   parts of the 32-bit code.

 - Other smaller features, fixes & cleanups.

Thanks to: Alan Modra, Alexey Kardashevskiy, Andrew Donnellan, Aneesh
Kumar K.V, Ard Biesheuvel, Athira Rajeev, Balamuruhan S, Bill Wendling,
Cédric Le Goater, Christophe Leroy, Christophe Lombard, Colin Ian King,
Daniel Axtens, David Hildenbrand, Frederic Barrat, Ganesh Goudar,
Gautham R. Shenoy, Geert Uytterhoeven, Giuseppe Sacco, Greg Kurz,
Harish, Jan Kratochvil, Jordan Niethe, Kaixu Xia, Laurent Dufour,
Leonardo Bras, Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu
Desnoyers, Nathan Lynch, Nicholas Piggin, Oleg Nesterov, Oliver
O'Halloran, Oscar Salvador, Po-Hsu Lin, Qian Cai, Qinglang Miao, Randy
Dunlap, Ravi Bangoria, Sachin Sant, Sandipan Das, Sebastian Andrzej
Siewior , Segher Boessenkool, Srikar Dronamraju, Tyrel Datwyler, Uwe
Kleine-König, Vincent Stehlé, Youling Tang, and Zhang Xiaoxu.

* tag 'powerpc-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (304 commits)
  powerpc/32s: Fix cleanup_cpu_mmu_context() compile bug
  powerpc: Add config fragment for disabling -Werror
  powerpc/configs: Add ppc64le_allnoconfig target
  powerpc/powernv: Rate limit opal-elog read failure message
  powerpc/pseries/memhotplug: Quieten some DLPAR operations
  powerpc/ps3: use dma_mapping_error()
  powerpc: force inlining of csum_partial() to avoid multiple csum_partial() with GCC10
  powerpc/perf: Fix Threshold Event Counter Multiplier width for P10
  powerpc/mm: Fix hugetlb_free_pmd_range() and hugetlb_free_pud_range()
  KVM: PPC: Book3S HV: Fix mask size for emulated msgsndp
  KVM: PPC: fix comparison to bool warning
  KVM: PPC: Book3S: Assign boolean values to a bool variable
  powerpc: Inline setup_kup()
  powerpc/64s: Mark the kuap/kuep functions non __init
  KVM: PPC: Book3S HV: XIVE: Add a comment regarding VP numbering
  powerpc/xive: Improve error reporting of OPAL calls
  powerpc/xive: Simplify xive_do_source_eoi()
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_EOI_FW
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_MASK_FW
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_SHIFT_BUG
  ...
2020-12-17 13:34:25 -08:00
Linus Torvalds 5e60366d56 fallthrough fixes for Clang for 5.11-rc1
Hi Linus,
 
 Please, pull the following patches that fix many fall-through warnings
 when building with Clang 12.0.0 and this[1] change reverted. Notice
 that in order to enable -Wimplicit-fallthrough for Clang, such change[1]
 is meant to be reverted at some point. So, these patches help to move
 in that direction.
 
 - powerpc: boot: include compiler_attributes.h (Nick Desaulniers)
 - Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" (Nick Desaulniers)
 - powerpc: fix -Wimplicit-fallthrough (Nick Desaulniers)
 - lib: Fix fall-through warnings for Clang (Gustavo A. R. Silva)
 
 Thanks!
 
 [1] commit e2079e93f5 ("kbuild: Do not enable -Wimplicit-fallthrough for clang for now")
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Merge tag 'fallthrough-fixes-clang-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull fallthrough fixes from Gustavo A. R. Silva:
 "Fix many fall-through warnings when building with Clang 12.0.0
  using -Wimplicit-fallthrough.

   - powerpc: boot: include compiler_attributes.h (Nick Desaulniers)

   - Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"
     (Nick Desaulniers)

   - powerpc: fix -Wimplicit-fallthrough (Nick Desaulniers)

   - lib: Fix fall-through warnings for Clang (Gustavo A. R. Silva)"

* tag 'fallthrough-fixes-clang-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  lib: Fix fall-through warnings for Clang
  powerpc: fix -Wimplicit-fallthrough
  Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"
  powerpc: boot: include compiler_attributes.h
2020-12-16 00:24:16 -08:00
Madhavan Srinivasan ef0e3b650f powerpc/perf: Fix Threshold Event Counter Multiplier width for P10
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
2020-12-15 22:50:04 +11:00
Athira Rajeev aa8e21c053 powerpc/perf: Exclude kernel samples while counting events in user space.
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
2020-12-10 23:04:35 +11:00
Christophe Leroy 70b588a068 powerpc/ppc-opcode: Add PPC_RAW_MFSPR()
Add PPC_RAW_MFSPR() to replace open coding done in 8xx-pmu.c

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e281e3a611eead8817c49cf06a60072a021af823.1606231483.git.christophe.leroy@csgroup.eu
2020-12-09 23:48:13 +11:00
Christophe Leroy 89eecd938c powerpc/8xx: Use SPRN_SPRG_SCRATCH2 in DTLB miss exception
Use SPRN_SPRG_SCRATCH2 in DTLB miss exception instead of DAR
in order to be similar to ITLB miss exception.

This also simplifies mpc8xx_pmu_del()

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e3cc8f023ef40e1e8ae144e4dd1330a5ff022528.1606231483.git.christophe.leroy@csgroup.eu
2020-12-09 23:48:13 +11:00
Christophe Leroy a314ea5abf powerpc/8xx: Use SPRN_SPRG_SCRATCH2 in ITLB miss exception
In order to re-enable MMU earlier, ensure ITLB miss exception
cannot clobber SPRN_SPRG_SCRATCH0 and SPRN_SPRG_SCRATCH1.
Do so by using SPRN_SPRG_SCRATCH2 and SPRN_M_TW instead, like
the DTLB miss exception.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/abc78e8e9577d473691ebb9996c6413b37bfd9ca.1606231483.git.christophe.leroy@csgroup.eu
2020-12-09 23:48:12 +11:00
Athira Rajeev 91668ab7db powerpc/perf: MMCR0 control for PMU registers under PMCC=00
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
2020-12-04 01:01:29 +11:00
Athira Rajeev 9a8ee52634 powerpc/perf: Fix to update cache events with l2l3 events in power10
Export l2l3 events (PM_L2_ST_MISS and PM_L2_ST) and LLC-prefetches
(PM_L3_PF_MISS_L3) via sysfs, and also add these to list of
cache_events.

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/1606409684-1589-7-git-send-email-atrajeev@linux.vnet.ibm.com
2020-12-04 01:01:29 +11:00
Athira Rajeev 1f12316394 powerpc/perf: Fix to update generic event codes for power10
Fix the event code for events: branch-instructions (to PM_BR_FIN),
branch-misses (to PM_MPRED_BR_FIN) and cache-misses (to
PM_LD_DEMAND_MISS_L1_FIN) for power10 PMU. Update the
list of generic events with this modified event code.

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/1606409684-1589-6-git-send-email-atrajeev@linux.vnet.ibm.com
2020-12-04 01:01:29 +11:00
Athira Rajeev c0e3985790 powerpc/perf: Add generic and cache event list for power10 DD1
There are event code updates for some of the generic events
and cache events for power10. Inorder to maintain the current
event codes work with DD1 also, create a new array of generic_events,
cache_events and pmu_attr_groups with suffix _dd1, example,
power10_events_attr_dd1. So that further updates to event codes
can be made in the original list, ie, power10_events_attr. Update the
power10 pmu init code to pick the dd1 list while registering
the power PMU, based on the pvr (Processor Version Register) value.

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/1606409684-1589-5-git-send-email-atrajeev@linux.vnet.ibm.com
2020-12-04 01:01:29 +11:00
Athira Rajeev 0263bbb377 powerpc/perf: Fix the PMU group constraints for threshold events in power10
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
2020-12-04 01:01:28 +11:00
Athira Rajeev e924be7b0b powerpc/perf: Update the PMU group constraints for l2l3 events in power10
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
2020-12-04 01:01:28 +11:00
Athira Rajeev d3afd28cd2 powerpc/perf: Fix to update radix_scope_qual in power10
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
2020-12-04 01:01:28 +11:00
Athira Rajeev f66de7ac48 powerpc/perf: Invoke per-CPU variable access with disabled interrupts
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
2020-12-04 01:01:21 +11:00
Christophe Leroy 91bf695596 powerpc/vdso: Retrieve sigtramp offsets at buildtime
This is copied from arm64.

Instead of using runtime generated signal trampoline offsets,
get offsets at buildtime.

If the said trampoline doesn't exist, build will fail. So no
need to check whether the trampoline exists or not in the VDSO.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f8bfd6812c3e3678b1cdb4d55a52f9eb022b40d3.1601197618.git.christophe.leroy@csgroup.eu
2020-12-04 01:01:17 +11:00
Christophe Leroy c102f07667 powerpc/vdso: Replace vdso_base by vdso
All other architectures but s390 use a void pointer named 'vdso'
to reference the VDSO mapping.

In a following patch, the VDSO data page will be put in front of
text, vdso_base will then not anymore point to VDSO text.

To avoid confusion between vdso_base and VDSO text, rename vdso_base
into vdso and make it a void __user *.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8e6cefe474aa4ceba028abb729485cd46c140990.1601197618.git.christophe.leroy@csgroup.eu
2020-12-04 01:01:16 +11:00
Athira Rajeev f75e7d73bd powerpc/perf: Fix crash with is_sier_available when pmu is not set
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
2020-12-04 01:01:09 +11:00
Peter Zijlstra 20c7775aec Merge remote-tracking branch 'origin/master' into perf/core
Further perf/core patches will depend on:

  d3f7b1bb20 ("mm/gup: fix gup_fast with dynamic page table folding")

which is already in Linus' tree.
2020-11-26 13:16:55 +01:00
Madhavan Srinivasan 2ca13a4cc5 powerpc/perf: Use regs->nip when SIAR is zero
In power10 DD1, there is an issue where the SIAR (Sampled Instruction
Address Register) is not latching to the sampled address during random
sampling. This results in value of 0s in the SIAR. Add a check to use
regs->nip when SIAR is zero.

Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201021085329.384535-5-maddy@linux.ibm.com
2020-11-19 16:56:56 +11:00
Athira Rajeev d9f7088dd6 powerpc/perf: Use the address from SIAR register to set cpumode flags
While setting the processor mode for any sample, perf_get_misc_flags()
expects the privilege level to differentiate the userspace and kernel
address. On power10 DD1, there is an issue that causes MSR_HV MSR_PR
bits of Sampled Instruction Event Register (SIER) not to be set for
marked events. Hence add a check to use the address in SIAR (Sampled
Instruction Address Register) to identify the privilege level.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201021085329.384535-3-maddy@linux.ibm.com
2020-11-19 16:56:56 +11:00
Athira Rajeev fdf13a6575 powerpc/perf: Drop the check for SIAR_VALID
In power10 DD1, there is an issue that causes the SIAR_VALID bit of
the SIER (Sampled Instruction Event Register) to not be set. But the
SIAR_VALID bit is used for fetching the instruction address from the
SIAR (Sampled Instruction Address Register), and marked events are
sampled only if the SIAR_VALID bit is set. So drop the check for
SIAR_VALID and return true always incase of power10 DD1.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201021085329.384535-2-maddy@linux.ibm.com
2020-11-19 16:56:56 +11:00
Athira Rajeev 9e8d13697c powerpc/perf: Add new power PMU flag "PPMU_P10_DD1" for power10 DD1
Add a new power PMU flag "PPMU_P10_DD1" which can be used to
conditionally add any code path for power10 DD1 processor version.
Also modify power10 PMU driver code to set this flag only for DD1,
based on the Processor Version Register (PVR) value.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201021085329.384535-1-maddy@linux.ibm.com
2020-11-19 16:56:55 +11:00
Nicholas Piggin 987c426320 powerpc/64s/perf: perf interrupt does not have to get_user_pages to access user memory
read_user_stack_slow that walks user address translation by hand is
only required on hash, because a hash fault can not be serviced from
"NMI" context (to avoid re-entering the hash code) so the user stack
can be mapped into Linux page tables but not accessible by the CPU.

Radix MMU mode does not have this restriction. A page fault failure
would indicate the page is not accessible via get_user_pages either,
so avoid this on radix.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201111120151.3150658-1-npiggin@gmail.com
2020-11-19 16:56:52 +11:00
Nick Desaulniers 49a4136505 powerpc: fix -Wimplicit-fallthrough
The "fallthrough" pseudo-keyword was added as a portable way to denote
intentional fallthrough. Clang will still warn on cases where there is a
fallthrough to an immediate break. Add explicit breaks for those cases.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/236
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-11-18 14:18:09 -06:00
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
Kan Liang 4cb6a42e4c powerpc/perf: Support PERF_SAMPLE_DATA_PAGE_SIZE
The new sample type, PERF_SAMPLE_DATA_PAGE_SIZE, requires the virtual
address. Update the data->addr if the sample type is set.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201001135749.2804-4-kan.liang@linux.intel.com
2020-10-29 11:00:39 +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