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[PATCH v3 0/6] powerpc/perf: Export memory hierarchy level

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  [PATCH v3 0/6] powerpc/perf: Export memory hierarchy level Madhavan Srinivasan <maddy@linux.vnet.ibm.com> - 2017-04-11 04:00 +0200
    [PATCH v3 4/6] powerpc/perf: Support to export SIERs bit in Power8 Madhavan Srinivasan <maddy@linux.vnet.ibm.com> - 2017-04-11 04:00 +0200
    [PATCH v3 5/6] powerpc/perf: Support to export SIERs bit in Power9 Madhavan Srinivasan <maddy@linux.vnet.ibm.com> - 2017-04-11 04:00 +0200
    [PATCH v3 6/6] powerpc/perf: Add Power8 mem_access event to sysfs Madhavan Srinivasan <maddy@linux.vnet.ibm.com> - 2017-04-11 04:00 +0200
    [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src Madhavan Srinivasan <maddy@linux.vnet.ibm.com> - 2017-04-11 04:00 +0200
      Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of  perf_mem_data_src Peter Zijlstra <peterz@infradead.org> - 2017-04-13 14:40 +0200
        Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src Michael Ellerman <mpe@ellerman.id.au> - 2017-04-13 15:30 +0200
          Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of  perf_mem_data_src Madhavan Srinivasan <maddy@linux.vnet.ibm.com> - 2017-04-17 05:50 +0200
        Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of  perf_mem_data_src Madhavan Srinivasan <maddy@linux.vnet.ibm.com> - 2017-04-17 05:50 +0200
        Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src Michael Ellerman <mpe@ellerman.id.au> - 2017-04-19 07:00 +0200
          Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of  perf_mem_data_src Madhavan Srinivasan <maddy@linux.vnet.ibm.com> - 2017-04-19 16:50 +0200
            Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src Michael Ellerman <mpe@ellerman.id.au> - 2017-04-20 00:20 +0200
      Re: [v3, 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src Michael Ellerman <patch-notifications@ellerman.id.au> - 2017-04-20 00:10 +0200
    [PATCH v3 3/6] powerpc/perf: Support to export MMCRA[TEC*] field to userspace Madhavan Srinivasan <maddy@linux.vnet.ibm.com> - 2017-04-11 04:00 +0200

#1620831 — [PATCH v3 0/6] powerpc/perf: Export memory hierarchy level

Power8/Power9 Perforence Monitoring Unit (PMU) supports
different sampling modes (SM) such as Random Instruction
Sampling (RIS), Random Load/Store Facility Sampling (RLS)
and Random Branch Sampling (RBS). Sample mode RLS updates
Sampled Instruction Event Register [SIER] bits with memory
hierarchy information for a cache reload. Patchset exports
the hierarchy information to the user via the perf_mem_data_src
object from SIER.

Patchset is a rebase of the work posted previously with minor
updates to it.

https://lkml.org/lkml/2015/6/11/92

Changelog v3:
-Removed is_load_store() and merged the same to get_memdata_src callback
-Added a check to update OP_LOAD or OP_STORE in data_src->val

Changelog v2:
-Updated the commit messages
-Fixed isa207_find_source() to consider all the possible sier[ldst] values.

Changelog v1:
- Fixed author-ship for the first patch and added suka's "Signed-off-by:".

Madhavan Srinivasan (5):
  powerpc/perf: Export memory hierarchy info to user space
  powerpc/perf: Support to export MMCRA[TEC*] field to userspace
  powerpc/perf: Support to export SIERs bit in Power8
  powerpc/perf: Support to export SIERs bit in Power9
  powerpc/perf: Add Power8 mem_access event to sysfs

Sukadev Bhattiprolu (1):
  powerpc/perf: Define big-endian version of perf_mem_data_src

 arch/powerpc/include/asm/perf_event_server.h |  3 +
 arch/powerpc/perf/core-book3s.c              |  8 +++
 arch/powerpc/perf/isa207-common.c            | 82 ++++++++++++++++++++++++++++
 arch/powerpc/perf/isa207-common.h            | 26 ++++++++-
 arch/powerpc/perf/power8-events-list.h       |  6 ++
 arch/powerpc/perf/power8-pmu.c               |  4 ++
 arch/powerpc/perf/power9-pmu.c               |  2 +
 include/uapi/linux/perf_event.h              | 16 ++++++
 tools/include/uapi/linux/perf_event.h        | 16 ++++++
 9 files changed, 162 insertions(+), 1 deletion(-)

-- 
2.7.4

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#1620832 — [PATCH v3 4/6] powerpc/perf: Support to export SIERs bit in Power8

Patch to export SIER bits to userspace via
perf_mem_data_src and perf_sample_data struct.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 arch/powerpc/perf/power8-pmu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/perf/power8-pmu.c b/arch/powerpc/perf/power8-pmu.c
index ce15b19a7962..932d7536f0eb 100644
--- a/arch/powerpc/perf/power8-pmu.c
+++ b/arch/powerpc/perf/power8-pmu.c
@@ -325,6 +325,8 @@ static struct power_pmu power8_pmu = {
 	.bhrb_filter_map	= power8_bhrb_filter_map,
 	.get_constraint		= isa207_get_constraint,
 	.get_alternatives	= power8_get_alternatives,
+	.get_mem_data_src	= isa207_get_mem_data_src,
+	.get_mem_weight		= isa207_get_mem_weight,
 	.disable_pmc		= isa207_disable_pmc,
 	.flags			= PPMU_HAS_SIER | PPMU_ARCH_207S,
 	.n_generic		= ARRAY_SIZE(power8_generic_events),
-- 
2.7.4

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#1620833 — [PATCH v3 5/6] powerpc/perf: Support to export SIERs bit in Power9

Patch to export SIER bits to userspace via
perf_mem_data_src and perf_sample_data struct.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 arch/powerpc/perf/power9-pmu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/perf/power9-pmu.c b/arch/powerpc/perf/power9-pmu.c
index 7f6582708e06..018f8e90ac35 100644
--- a/arch/powerpc/perf/power9-pmu.c
+++ b/arch/powerpc/perf/power9-pmu.c
@@ -427,6 +427,8 @@ static struct power_pmu power9_pmu = {
 	.bhrb_filter_map	= power9_bhrb_filter_map,
 	.get_constraint		= isa207_get_constraint,
 	.get_alternatives	= power9_get_alternatives,
+	.get_mem_data_src	= isa207_get_mem_data_src,
+	.get_mem_weight		= isa207_get_mem_weight,
 	.disable_pmc		= isa207_disable_pmc,
 	.flags			= PPMU_HAS_SIER | PPMU_ARCH_207S,
 	.n_generic		= ARRAY_SIZE(power9_generic_events),
-- 
2.7.4

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#1620834 — [PATCH v3 6/6] powerpc/perf: Add Power8 mem_access event to sysfs

Patch add "mem_access" event to sysfs. This as-is not a raw event
supported by Power8 pmu. Instead, it is formed based on
raw event encoding specificed in isa207-common.h.

Primary PMU event used here is PM_MRK_INST_CMPL.
This event tracks only the completed marked instructions.

Random sampling mode (MMCRA[SM]) with Random Instruction
Sampling (RIS) is enabled to mark type of instructions.

With Random sampling in RLS mode with PM_MRK_INST_CMPL event,
the LDST /DATA_SRC fields in SIER identifies the memory
hierarchy level (eg: L1, L2 etc) statisfied a data-cache
miss for a marked instruction.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 arch/powerpc/perf/power8-events-list.h | 6 ++++++
 arch/powerpc/perf/power8-pmu.c         | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/arch/powerpc/perf/power8-events-list.h b/arch/powerpc/perf/power8-events-list.h
index 3a2e6e8ebb92..0f1d184627cc 100644
--- a/arch/powerpc/perf/power8-events-list.h
+++ b/arch/powerpc/perf/power8-events-list.h
@@ -89,3 +89,9 @@ EVENT(PM_MRK_FILT_MATCH,			0x2013c)
 EVENT(PM_MRK_FILT_MATCH_ALT,			0x3012e)
 /* Alternate event code for PM_LD_MISS_L1 */
 EVENT(PM_LD_MISS_L1_ALT,			0x400f0)
+/*
+ * Memory Access Event -- mem_access
+ * Primary PMU event used here is PM_MRK_INST_CMPL, along with
+ * Random Load/Store Facility Sampling (RIS) in Random sampling mode (MMCRA[SM]).
+ */
+EVENT(MEM_ACCESS,				0x10401e0)
diff --git a/arch/powerpc/perf/power8-pmu.c b/arch/powerpc/perf/power8-pmu.c
index 932d7536f0eb..5463516e369b 100644
--- a/arch/powerpc/perf/power8-pmu.c
+++ b/arch/powerpc/perf/power8-pmu.c
@@ -90,6 +90,7 @@ GENERIC_EVENT_ATTR(branch-instructions,		PM_BRU_FIN);
 GENERIC_EVENT_ATTR(branch-misses,		PM_BR_MPRED_CMPL);
 GENERIC_EVENT_ATTR(cache-references,		PM_LD_REF_L1);
 GENERIC_EVENT_ATTR(cache-misses,		PM_LD_MISS_L1);
+GENERIC_EVENT_ATTR(mem_access,			MEM_ACCESS);
 
 CACHE_EVENT_ATTR(L1-dcache-load-misses,		PM_LD_MISS_L1);
 CACHE_EVENT_ATTR(L1-dcache-loads,		PM_LD_REF_L1);
@@ -120,6 +121,7 @@ static struct attribute *power8_events_attr[] = {
 	GENERIC_EVENT_PTR(PM_BR_MPRED_CMPL),
 	GENERIC_EVENT_PTR(PM_LD_REF_L1),
 	GENERIC_EVENT_PTR(PM_LD_MISS_L1),
+	GENERIC_EVENT_PTR(MEM_ACCESS),
 
 	CACHE_EVENT_PTR(PM_LD_MISS_L1),
 	CACHE_EVENT_PTR(PM_LD_REF_L1),
-- 
2.7.4

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#1620835 — [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src

From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>

perf_mem_data_src is an union that is initialized via the ->val field
and accessed via the bitmap fields. For this to work on big endian
platforms (Which is broken now), we also need a big-endian represenation
of perf_mem_data_src. i.e, in a big endian system, if user request
PERF_SAMPLE_DATA_SRC (perf report -d), will get the default value from
perf_sample_data_init(), which is PERF_MEM_NA. Value for PERF_MEM_NA
is constructed using shifts:

  /* TLB access */
  #define PERF_MEM_TLB_NA		0x01 /* not available */
  ...
  #define PERF_MEM_TLB_SHIFT	26

  #define PERF_MEM_S(a, s) \
	(((__u64)PERF_MEM_##a##_##s) << PERF_MEM_##a##_SHIFT)

  #define PERF_MEM_NA (PERF_MEM_S(OP, NA)   |\
		    PERF_MEM_S(LVL, NA)   |\
		    PERF_MEM_S(SNOOP, NA) |\
		    PERF_MEM_S(LOCK, NA)  |\
		    PERF_MEM_S(TLB, NA))

Which works out as:

  ((0x01 << 0) | (0x01 << 5) | (0x01 << 19) | (0x01 << 24) | (0x01 << 26))

Which means the PERF_MEM_NA value comes out of the kernel as 0x5080021
in CPU endian.

But then in the perf tool, the code uses the bitfields to inspect the
value, and currently the bitfields are defined using little endian
ordering.

So eg. in perf_mem__tlb_scnprintf() we see:
  data_src->val = 0x5080021
             op = 0x0
            lvl = 0x0
          snoop = 0x0
           lock = 0x0
           dtlb = 0x0
           rsvd = 0x5080021

Patch does a minimal fix of adding big endian definition of the bitfields
to match the values that are already exported by the kernel on big endian.
And it makes no change on little endian.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 include/uapi/linux/perf_event.h       | 16 ++++++++++++++++
 tools/include/uapi/linux/perf_event.h | 16 ++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index c66a485a24ac..c4af1159a200 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -891,6 +891,7 @@ enum perf_callchain_context {
 #define PERF_FLAG_PID_CGROUP		(1UL << 2) /* pid=cgroup id, per-cpu mode only */
 #define PERF_FLAG_FD_CLOEXEC		(1UL << 3) /* O_CLOEXEC */
 
+#if defined(__LITTLE_ENDIAN_BITFIELD)
 union perf_mem_data_src {
 	__u64 val;
 	struct {
@@ -902,6 +903,21 @@ union perf_mem_data_src {
 			mem_rsvd:31;
 	};
 };
+#elif defined(__BIG_ENDIAN_BITFIELD)
+union perf_mem_data_src {
+	__u64 val;
+	struct {
+		__u64	mem_rsvd:31,
+			mem_dtlb:7,	/* tlb access */
+			mem_lock:2,	/* lock instr */
+			mem_snoop:5,	/* snoop mode */
+			mem_lvl:14,	/* memory hierarchy level */
+			mem_op:5;	/* type of opcode */
+	};
+};
+#else
+#error "Unknown endianness"
+#endif
 
 /* type of opcode (load/store/prefetch,code) */
 #define PERF_MEM_OP_NA		0x01 /* not available */
diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
index c66a485a24ac..c4af1159a200 100644
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -891,6 +891,7 @@ enum perf_callchain_context {
 #define PERF_FLAG_PID_CGROUP		(1UL << 2) /* pid=cgroup id, per-cpu mode only */
 #define PERF_FLAG_FD_CLOEXEC		(1UL << 3) /* O_CLOEXEC */
 
+#if defined(__LITTLE_ENDIAN_BITFIELD)
 union perf_mem_data_src {
 	__u64 val;
 	struct {
@@ -902,6 +903,21 @@ union perf_mem_data_src {
 			mem_rsvd:31;
 	};
 };
+#elif defined(__BIG_ENDIAN_BITFIELD)
+union perf_mem_data_src {
+	__u64 val;
+	struct {
+		__u64	mem_rsvd:31,
+			mem_dtlb:7,	/* tlb access */
+			mem_lock:2,	/* lock instr */
+			mem_snoop:5,	/* snoop mode */
+			mem_lvl:14,	/* memory hierarchy level */
+			mem_op:5;	/* type of opcode */
+	};
+};
+#else
+#error "Unknown endianness"
+#endif
 
 /* type of opcode (load/store/prefetch,code) */
 #define PERF_MEM_OP_NA		0x01 /* not available */
-- 
2.7.4

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#1622988 — Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src

On Tue, Apr 11, 2017 at 07:21:05AM +0530, Madhavan Srinivasan wrote:
> From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
> 
> perf_mem_data_src is an union that is initialized via the ->val field
> and accessed via the bitmap fields. For this to work on big endian
> platforms (Which is broken now), we also need a big-endian represenation
> of perf_mem_data_src. i.e, in a big endian system, if user request
> PERF_SAMPLE_DATA_SRC (perf report -d), will get the default value from
> perf_sample_data_init(), which is PERF_MEM_NA. Value for PERF_MEM_NA
> is constructed using shifts:
> 
>   /* TLB access */
>   #define PERF_MEM_TLB_NA		0x01 /* not available */
>   ...
>   #define PERF_MEM_TLB_SHIFT	26
> 
>   #define PERF_MEM_S(a, s) \
> 	(((__u64)PERF_MEM_##a##_##s) << PERF_MEM_##a##_SHIFT)
> 
>   #define PERF_MEM_NA (PERF_MEM_S(OP, NA)   |\
> 		    PERF_MEM_S(LVL, NA)   |\
> 		    PERF_MEM_S(SNOOP, NA) |\
> 		    PERF_MEM_S(LOCK, NA)  |\
> 		    PERF_MEM_S(TLB, NA))
> 
> Which works out as:
> 
>   ((0x01 << 0) | (0x01 << 5) | (0x01 << 19) | (0x01 << 24) | (0x01 << 26))
> 
> Which means the PERF_MEM_NA value comes out of the kernel as 0x5080021
> in CPU endian.
> 
> But then in the perf tool, the code uses the bitfields to inspect the
> value, and currently the bitfields are defined using little endian
> ordering.
> 
> So eg. in perf_mem__tlb_scnprintf() we see:
>   data_src->val = 0x5080021
>              op = 0x0
>             lvl = 0x0
>           snoop = 0x0
>            lock = 0x0
>            dtlb = 0x0
>            rsvd = 0x5080021
> 
> Patch does a minimal fix of adding big endian definition of the bitfields
> to match the values that are already exported by the kernel on big endian.
> And it makes no change on little endian.

I think it is important to note that there are no current big-endian
users. So 'fixing' this will not break anybody and will ensure future
users (next patch) will work correctly.

Aside from that amendment,

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

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#1623012 — Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src

Peter Zijlstra <peterz@infradead.org> writes:

> On Tue, Apr 11, 2017 at 07:21:05AM +0530, Madhavan Srinivasan wrote:
>> From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
>> 
>> perf_mem_data_src is an union that is initialized via the ->val field
>> and accessed via the bitmap fields. For this to work on big endian
>> platforms (Which is broken now), we also need a big-endian represenation
>> of perf_mem_data_src. i.e, in a big endian system, if user request
>> PERF_SAMPLE_DATA_SRC (perf report -d), will get the default value from
>> perf_sample_data_init(), which is PERF_MEM_NA. Value for PERF_MEM_NA
>> is constructed using shifts:
>> 
>>   /* TLB access */
>>   #define PERF_MEM_TLB_NA		0x01 /* not available */
>>   ...
>>   #define PERF_MEM_TLB_SHIFT	26
>> 
>>   #define PERF_MEM_S(a, s) \
>> 	(((__u64)PERF_MEM_##a##_##s) << PERF_MEM_##a##_SHIFT)
>> 
>>   #define PERF_MEM_NA (PERF_MEM_S(OP, NA)   |\
>> 		    PERF_MEM_S(LVL, NA)   |\
>> 		    PERF_MEM_S(SNOOP, NA) |\
>> 		    PERF_MEM_S(LOCK, NA)  |\
>> 		    PERF_MEM_S(TLB, NA))
>> 
>> Which works out as:
>> 
>>   ((0x01 << 0) | (0x01 << 5) | (0x01 << 19) | (0x01 << 24) | (0x01 << 26))
>> 
>> Which means the PERF_MEM_NA value comes out of the kernel as 0x5080021
>> in CPU endian.
>> 
>> But then in the perf tool, the code uses the bitfields to inspect the
>> value, and currently the bitfields are defined using little endian
>> ordering.
>> 
>> So eg. in perf_mem__tlb_scnprintf() we see:
>>   data_src->val = 0x5080021
>>              op = 0x0
>>             lvl = 0x0
>>           snoop = 0x0
>>            lock = 0x0
>>            dtlb = 0x0
>>            rsvd = 0x5080021
>> 
>> Patch does a minimal fix of adding big endian definition of the bitfields
>> to match the values that are already exported by the kernel on big endian.
>> And it makes no change on little endian.
>
> I think it is important to note that there are no current big-endian
> users. So 'fixing' this will not break anybody and will ensure future
> users (next patch) will work correctly.

Sure I'll fold in something along those lines.

> Aside from that amendment,
>
> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Thanks.

cheers

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#1624527 — Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src

On Thursday 13 April 2017 06:53 PM, Michael Ellerman wrote:
> Peter Zijlstra <peterz@infradead.org> writes:
>
>> On Tue, Apr 11, 2017 at 07:21:05AM +0530, Madhavan Srinivasan wrote:
>>> From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
>>>
>>> perf_mem_data_src is an union that is initialized via the ->val field
>>> and accessed via the bitmap fields. For this to work on big endian
>>> platforms (Which is broken now), we also need a big-endian represenation
>>> of perf_mem_data_src. i.e, in a big endian system, if user request
>>> PERF_SAMPLE_DATA_SRC (perf report -d), will get the default value from
>>> perf_sample_data_init(), which is PERF_MEM_NA. Value for PERF_MEM_NA
>>> is constructed using shifts:
>>>
>>>    /* TLB access */
>>>    #define PERF_MEM_TLB_NA		0x01 /* not available */
>>>    ...
>>>    #define PERF_MEM_TLB_SHIFT	26
>>>
>>>    #define PERF_MEM_S(a, s) \
>>> 	(((__u64)PERF_MEM_##a##_##s) << PERF_MEM_##a##_SHIFT)
>>>
>>>    #define PERF_MEM_NA (PERF_MEM_S(OP, NA)   |\
>>> 		    PERF_MEM_S(LVL, NA)   |\
>>> 		    PERF_MEM_S(SNOOP, NA) |\
>>> 		    PERF_MEM_S(LOCK, NA)  |\
>>> 		    PERF_MEM_S(TLB, NA))
>>>
>>> Which works out as:
>>>
>>>    ((0x01 << 0) | (0x01 << 5) | (0x01 << 19) | (0x01 << 24) | (0x01 << 26))
>>>
>>> Which means the PERF_MEM_NA value comes out of the kernel as 0x5080021
>>> in CPU endian.
>>>
>>> But then in the perf tool, the code uses the bitfields to inspect the
>>> value, and currently the bitfields are defined using little endian
>>> ordering.
>>>
>>> So eg. in perf_mem__tlb_scnprintf() we see:
>>>    data_src->val = 0x5080021
>>>               op = 0x0
>>>              lvl = 0x0
>>>            snoop = 0x0
>>>             lock = 0x0
>>>             dtlb = 0x0
>>>             rsvd = 0x5080021
>>>
>>> Patch does a minimal fix of adding big endian definition of the bitfields
>>> to match the values that are already exported by the kernel on big endian.
>>> And it makes no change on little endian.
>> I think it is important to note that there are no current big-endian
>> users. So 'fixing' this will not break anybody and will ensure future
>> users (next patch) will work correctly.
> Sure I'll fold in something along those lines.

Thanks mpe.

Maddy

>
>> Aside from that amendment,
>>
>> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Thanks.
>
> cheers
>

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#1624526 — Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src

On Thursday 13 April 2017 06:08 PM, Peter Zijlstra wrote:
> On Tue, Apr 11, 2017 at 07:21:05AM +0530, Madhavan Srinivasan wrote:
>> From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
>>
>> perf_mem_data_src is an union that is initialized via the ->val field
>> and accessed via the bitmap fields. For this to work on big endian
>> platforms (Which is broken now), we also need a big-endian represenation
>> of perf_mem_data_src. i.e, in a big endian system, if user request
>> PERF_SAMPLE_DATA_SRC (perf report -d), will get the default value from
>> perf_sample_data_init(), which is PERF_MEM_NA. Value for PERF_MEM_NA
>> is constructed using shifts:
>>
>>    /* TLB access */
>>    #define PERF_MEM_TLB_NA		0x01 /* not available */
>>    ...
>>    #define PERF_MEM_TLB_SHIFT	26
>>
>>    #define PERF_MEM_S(a, s) \
>> 	(((__u64)PERF_MEM_##a##_##s) << PERF_MEM_##a##_SHIFT)
>>
>>    #define PERF_MEM_NA (PERF_MEM_S(OP, NA)   |\
>> 		    PERF_MEM_S(LVL, NA)   |\
>> 		    PERF_MEM_S(SNOOP, NA) |\
>> 		    PERF_MEM_S(LOCK, NA)  |\
>> 		    PERF_MEM_S(TLB, NA))
>>
>> Which works out as:
>>
>>    ((0x01 << 0) | (0x01 << 5) | (0x01 << 19) | (0x01 << 24) | (0x01 << 26))
>>
>> Which means the PERF_MEM_NA value comes out of the kernel as 0x5080021
>> in CPU endian.
>>
>> But then in the perf tool, the code uses the bitfields to inspect the
>> value, and currently the bitfields are defined using little endian
>> ordering.
>>
>> So eg. in perf_mem__tlb_scnprintf() we see:
>>    data_src->val = 0x5080021
>>               op = 0x0
>>              lvl = 0x0
>>            snoop = 0x0
>>             lock = 0x0
>>             dtlb = 0x0
>>             rsvd = 0x5080021
>>
>> Patch does a minimal fix of adding big endian definition of the bitfields
>> to match the values that are already exported by the kernel on big endian.
>> And it makes no change on little endian.
> I think it is important to note that there are no current big-endian
> users. So 'fixing' this will not break anybody and will ensure future
> users (next patch) will work correctly.
>
> Aside from that amendment,
>
> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Thanks
Maddy

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#1625811 — Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src

Peter Zijlstra <peterz@infradead.org> writes:

> On Tue, Apr 11, 2017 at 07:21:05AM +0530, Madhavan Srinivasan wrote:
>> From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
>> 
>> perf_mem_data_src is an union that is initialized via the ->val field
>> and accessed via the bitmap fields. For this to work on big endian
>> platforms (Which is broken now), we also need a big-endian represenation
>> of perf_mem_data_src. i.e, in a big endian system, if user request
>> PERF_SAMPLE_DATA_SRC (perf report -d), will get the default value from
>> perf_sample_data_init(), which is PERF_MEM_NA. Value for PERF_MEM_NA
>> is constructed using shifts:
>> 
>>   /* TLB access */
>>   #define PERF_MEM_TLB_NA		0x01 /* not available */
>>   ...
>>   #define PERF_MEM_TLB_SHIFT	26
>> 
>>   #define PERF_MEM_S(a, s) \
>> 	(((__u64)PERF_MEM_##a##_##s) << PERF_MEM_##a##_SHIFT)
>> 
>>   #define PERF_MEM_NA (PERF_MEM_S(OP, NA)   |\
>> 		    PERF_MEM_S(LVL, NA)   |\
>> 		    PERF_MEM_S(SNOOP, NA) |\
>> 		    PERF_MEM_S(LOCK, NA)  |\
>> 		    PERF_MEM_S(TLB, NA))
>> 
>> Which works out as:
>> 
>>   ((0x01 << 0) | (0x01 << 5) | (0x01 << 19) | (0x01 << 24) | (0x01 << 26))
>> 
>> Which means the PERF_MEM_NA value comes out of the kernel as 0x5080021
>> in CPU endian.
>> 
>> But then in the perf tool, the code uses the bitfields to inspect the
>> value, and currently the bitfields are defined using little endian
>> ordering.
>> 
>> So eg. in perf_mem__tlb_scnprintf() we see:
>>   data_src->val = 0x5080021
>>              op = 0x0
>>             lvl = 0x0
>>           snoop = 0x0
>>            lock = 0x0
>>            dtlb = 0x0
>>            rsvd = 0x5080021
>> 
>> Patch does a minimal fix of adding big endian definition of the bitfields
>> to match the values that are already exported by the kernel on big endian.
>> And it makes no change on little endian.
>
> I think it is important to note that there are no current big-endian
> users. So 'fixing' this will not break anybody and will ensure future
> users (next patch) will work correctly.

Actually that's only partly true. As I describe above the PERF_MEM_NA
value is currently exported on BE platforms when a user requests it.

So I added this text after the output from perf_mem__tlb_scnprintf():

  Because of the way the perf tool code is written this is still displayed to the
  user as "N/A", so there is no bug visible at the UI level.
  
  Currently there are no big endian architectures which export a meaningful
  value (ie. other than PERF_MEM_NA), so the extent of the bug on big endian
  platforms is that the PERF_MEM_NA value is exported incorrectly as described
  above. Subsequent patches will add support on big endian powerpc for populating
  the data source value.


Hope that is clear.

It also occurred to me that we don't actually have to redefine the whole
union, it's only the bitfields that matter, so we could reduce the diff
to:

diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index c66a485a24ac..97152c79df6b 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -894,12 +894,23 @@ enum perf_callchain_context {
 union perf_mem_data_src {
 	__u64 val;
 	struct {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
 		__u64   mem_op:5,	/* type of opcode */
 			mem_lvl:14,	/* memory hierarchy level */
 			mem_snoop:5,	/* snoop mode */
 			mem_lock:2,	/* lock instr */
 			mem_dtlb:7,	/* tlb access */
 			mem_rsvd:31;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+		__u64	mem_rsvd:31,
+			mem_dtlb:7,	/* tlb access */
+			mem_lock:2,	/* lock instr */
+			mem_snoop:5,	/* snoop mode */
+			mem_lvl:14,	/* memory hierarchy level */
+			mem_op:5;	/* type of opcode */
+#else
+#error "Unknown endianness"
+#endif
 	};
 };
 

That looks better to me, thoughts?

cheers

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#1626210 — Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src

On Wednesday 19 April 2017 10:20 AM, Michael Ellerman wrote:
> Peter Zijlstra <peterz@infradead.org> writes:
>
>> On Tue, Apr 11, 2017 at 07:21:05AM +0530, Madhavan Srinivasan wrote:
>>> From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
>>>
>>> perf_mem_data_src is an union that is initialized via the ->val field
>>> and accessed via the bitmap fields. For this to work on big endian
>>> platforms (Which is broken now), we also need a big-endian represenation
>>> of perf_mem_data_src. i.e, in a big endian system, if user request
>>> PERF_SAMPLE_DATA_SRC (perf report -d), will get the default value from
>>> perf_sample_data_init(), which is PERF_MEM_NA. Value for PERF_MEM_NA
>>> is constructed using shifts:
>>>
>>>    /* TLB access */
>>>    #define PERF_MEM_TLB_NA		0x01 /* not available */
>>>    ...
>>>    #define PERF_MEM_TLB_SHIFT	26
>>>
>>>    #define PERF_MEM_S(a, s) \
>>> 	(((__u64)PERF_MEM_##a##_##s) << PERF_MEM_##a##_SHIFT)
>>>
>>>    #define PERF_MEM_NA (PERF_MEM_S(OP, NA)   |\
>>> 		    PERF_MEM_S(LVL, NA)   |\
>>> 		    PERF_MEM_S(SNOOP, NA) |\
>>> 		    PERF_MEM_S(LOCK, NA)  |\
>>> 		    PERF_MEM_S(TLB, NA))
>>>
>>> Which works out as:
>>>
>>>    ((0x01 << 0) | (0x01 << 5) | (0x01 << 19) | (0x01 << 24) | (0x01 << 26))
>>>
>>> Which means the PERF_MEM_NA value comes out of the kernel as 0x5080021
>>> in CPU endian.
>>>
>>> But then in the perf tool, the code uses the bitfields to inspect the
>>> value, and currently the bitfields are defined using little endian
>>> ordering.
>>>
>>> So eg. in perf_mem__tlb_scnprintf() we see:
>>>    data_src->val = 0x5080021
>>>               op = 0x0
>>>              lvl = 0x0
>>>            snoop = 0x0
>>>             lock = 0x0
>>>             dtlb = 0x0
>>>             rsvd = 0x5080021
>>>
>>> Patch does a minimal fix of adding big endian definition of the bitfields
>>> to match the values that are already exported by the kernel on big endian.
>>> And it makes no change on little endian.
>> I think it is important to note that there are no current big-endian
>> users. So 'fixing' this will not break anybody and will ensure future
>> users (next patch) will work correctly.
> Actually that's only partly true. As I describe above the PERF_MEM_NA
> value is currently exported on BE platforms when a user requests it.
>
> So I added this text after the output from perf_mem__tlb_scnprintf():
>
>    Because of the way the perf tool code is written this is still displayed to the
>    user as "N/A", so there is no bug visible at the UI level.
>    
>    Currently there are no big endian architectures which export a meaningful
>    value (ie. other than PERF_MEM_NA), so the extent of the bug on big endian
>    platforms is that the PERF_MEM_NA value is exported incorrectly as described
>    above. Subsequent patches will add support on big endian powerpc for populating
>    the data source value.
>
>
> Hope that is clear.
>
> It also occurred to me that we don't actually have to redefine the whole
> union, it's only the bitfields that matter, so we could reduce the diff
> to:
>
> diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
> index c66a485a24ac..97152c79df6b 100644
> --- a/include/uapi/linux/perf_event.h
> +++ b/include/uapi/linux/perf_event.h
> @@ -894,12 +894,23 @@ enum perf_callchain_context {
>   union perf_mem_data_src {
>   	__u64 val;
>   	struct {
> +#if defined(__LITTLE_ENDIAN_BITFIELD)
>   		__u64   mem_op:5,	/* type of opcode */
>   			mem_lvl:14,	/* memory hierarchy level */
>   			mem_snoop:5,	/* snoop mode */
>   			mem_lock:2,	/* lock instr */
>   			mem_dtlb:7,	/* tlb access */
>   			mem_rsvd:31;
> +#elif defined(__BIG_ENDIAN_BITFIELD)
> +		__u64	mem_rsvd:31,
> +			mem_dtlb:7,	/* tlb access */
> +			mem_lock:2,	/* lock instr */
> +			mem_snoop:5,	/* snoop mode */
> +			mem_lvl:14,	/* memory hierarchy level */
> +			mem_op:5;	/* type of opcode */
> +#else
> +#error "Unknown endianness"
> +#endif
>   	};
>   };
>
>
> That looks better to me, thoughts?

Yep.  Looks fine to me and also tested the same.

Maddy

>
> cheers
>

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#1626835 — Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src

Madhavan Srinivasan <maddy@linux.vnet.ibm.com> writes:
> On Wednesday 19 April 2017 10:20 AM, Michael Ellerman wrote:
>> It also occurred to me that we don't actually have to redefine the whole
>> union, it's only the bitfields that matter, so we could reduce the diff
>> to:
>>
>> diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
>> index c66a485a24ac..97152c79df6b 100644
>> --- a/include/uapi/linux/perf_event.h
>> +++ b/include/uapi/linux/perf_event.h
>> @@ -894,12 +894,23 @@ enum perf_callchain_context {
>>   union perf_mem_data_src {
>>   	__u64 val;
>>   	struct {
>> +#if defined(__LITTLE_ENDIAN_BITFIELD)
>>   		__u64   mem_op:5,	/* type of opcode */
>>   			mem_lvl:14,	/* memory hierarchy level */
>>   			mem_snoop:5,	/* snoop mode */
>>   			mem_lock:2,	/* lock instr */
>>   			mem_dtlb:7,	/* tlb access */
>>   			mem_rsvd:31;
>> +#elif defined(__BIG_ENDIAN_BITFIELD)
>> +		__u64	mem_rsvd:31,
>> +			mem_dtlb:7,	/* tlb access */
>> +			mem_lock:2,	/* lock instr */
>> +			mem_snoop:5,	/* snoop mode */
>> +			mem_lvl:14,	/* memory hierarchy level */
>> +			mem_op:5;	/* type of opcode */
>> +#else
>> +#error "Unknown endianness"
>> +#endif
>>   	};
>>   };
>>
>>
>> That looks better to me, thoughts?
>
> Yep.  Looks fine to me and also tested the same.

I merged the original version, as that's what Peterz acked and I didn't
want to block the series any longer.

I'll send an incremental patch to do the cleanup.

cheers

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#1626834 — Re: [v3, 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src

On Tue, 2017-04-11 at 01:51:05 UTC, Madhavan Srinivasan wrote:
> From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
> 
> perf_mem_data_src is an union that is initialized via the ->val field
> and accessed via the bitmap fields. For this to work on big endian
> platforms (Which is broken now), we also need a big-endian represenation
> of perf_mem_data_src. i.e, in a big endian system, if user request
> PERF_SAMPLE_DATA_SRC (perf report -d), will get the default value from
> perf_sample_data_init(), which is PERF_MEM_NA. Value for PERF_MEM_NA
> is constructed using shifts:
...
> 
> Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
> Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/8c5073db0ee680c7e70e123918c9b2

cheers

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#1620837 — [PATCH v3 3/6] powerpc/perf: Support to export MMCRA[TEC*] field to userspace

Threshold feature when used with MMCRA [Threshold Event Counter Event],
MMCRA[Threshold Start event] and MMCRA[Threshold End event] will update
MMCRA[Threashold Event Counter Exponent] and MMCRA[Threshold Event
Counter Multiplier] with the corresponding threshold event count values.
Patch to export MMCRA[TECX/TECM] to userspace in 'weight' field of
struct perf_sample_data.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/perf_event_server.h |  1 +
 arch/powerpc/perf/core-book3s.c              |  4 ++++
 arch/powerpc/perf/isa207-common.c            |  8 ++++++++
 arch/powerpc/perf/isa207-common.h            | 10 ++++++++++
 4 files changed, 23 insertions(+)

diff --git a/arch/powerpc/include/asm/perf_event_server.h b/arch/powerpc/include/asm/perf_event_server.h
index 446cdcd9b7f5..723bf48e7494 100644
--- a/arch/powerpc/include/asm/perf_event_server.h
+++ b/arch/powerpc/include/asm/perf_event_server.h
@@ -40,6 +40,7 @@ struct power_pmu {
 				u64 alt[]);
 	void		(*get_mem_data_src)(union perf_mem_data_src *dsrc,
 				u32 flags, struct pt_regs *regs);
+	void		(*get_mem_weight)(u64 *weight);
 	u64             (*bhrb_filter_map)(u64 branch_sample_type);
 	void            (*config_bhrb)(u64 pmu_bhrb_filter);
 	void		(*disable_pmc)(unsigned int pmc, unsigned long mmcr[]);
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index e241ebebab6f..6c2d4168daec 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -2053,6 +2053,10 @@ static void record_and_restart(struct perf_event *event, unsigned long val,
 						ppmu->get_mem_data_src)
 			ppmu->get_mem_data_src(&data.data_src, ppmu->flags, regs);
 
+		if (event->attr.sample_type & PERF_SAMPLE_WEIGHT &&
+						ppmu->get_mem_weight)
+			ppmu->get_mem_weight(&data.weight);
+
 		if (perf_event_overflow(event, &data, regs))
 			power_pmu_stop(event, 0);
 	}
diff --git a/arch/powerpc/perf/isa207-common.c b/arch/powerpc/perf/isa207-common.c
index a8b100ef8e6c..8125160be7bc 100644
--- a/arch/powerpc/perf/isa207-common.c
+++ b/arch/powerpc/perf/isa207-common.c
@@ -221,6 +221,14 @@ void isa207_get_mem_data_src(union perf_mem_data_src *dsrc, u32 flags,
 	}
 }
 
+void isa207_get_mem_weight(u64 *weight)
+{
+	u64 mmcra = mfspr(SPRN_MMCRA);
+	u64 exp = MMCRA_THR_CTR_EXP(mmcra);
+	u64 mantissa = MMCRA_THR_CTR_MANT(mmcra);
+
+	*weight = mantissa << (2 * exp);
+}
 
 int isa207_get_constraint(u64 event, unsigned long *maskp, unsigned long *valp)
 {
diff --git a/arch/powerpc/perf/isa207-common.h b/arch/powerpc/perf/isa207-common.h
index f711f337e358..8acbe6e802c7 100644
--- a/arch/powerpc/perf/isa207-common.h
+++ b/arch/powerpc/perf/isa207-common.h
@@ -248,6 +248,15 @@
 #define MMCRA_SDAR_MODE_TLB		(1ull << MMCRA_SDAR_MODE_SHIFT)
 #define MMCRA_SDAR_MODE_NO_UPDATES	~(0x3ull << MMCRA_SDAR_MODE_SHIFT)
 #define MMCRA_IFM_SHIFT			30
+#define MMCRA_THR_CTR_MANT_SHIFT	19
+#define MMCRA_THR_CTR_MANT_MASK		0x7Ful
+#define MMCRA_THR_CTR_MANT(v)		(((v) >> MMCRA_THR_CTR_MANT_SHIFT) &\
+						MMCRA_THR_CTR_MANT_MASK)
+
+#define MMCRA_THR_CTR_EXP_SHIFT		27
+#define MMCRA_THR_CTR_EXP_MASK		0x7ul
+#define MMCRA_THR_CTR_EXP(v)		(((v) >> MMCRA_THR_CTR_EXP_SHIFT) &\
+						MMCRA_THR_CTR_EXP_MASK)
 
 /* MMCR1 Threshold Compare bit constant for power9 */
 #define p9_MMCRA_THR_CMP_SHIFT	45
@@ -282,5 +291,6 @@ int isa207_get_alternatives(u64 event, u64 alt[],
 				const unsigned int ev_alt[][MAX_ALT], int size);
 void isa207_get_mem_data_src(union perf_mem_data_src *dsrc, u32 flags,
 							struct pt_regs *regs);
+void isa207_get_mem_weight(u64 *weight);
 
 #endif
-- 
2.7.4

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