[PATCH 1/2 RESEND] perf/x86/amd: Add missing L2 misses event spec to AMD Family 17h's event map

[PATCH 1/2 RESEND] perf/x86/amd: Add missing L2 misses event spec to AMD Family 17h's event map

[Kim Phillips]

Commit 3fe3331bb285 ("perf/x86/amd: Add event map for AMD Family 17h"),
claimed L2 misses were unsupported, due to them not being found in its
referenced documentation, whose link has now moved [1].

That old documentation listed PMCx064 unit mask bit 3 as:

    "LsRdBlkC: LS Read Block C S L X Change to X Miss."

and bit 0 as:

    "IcFillMiss: IC Fill Miss"

We now have new public documentation [2] with improved descriptions, that
clearly indicate what events those unit mask bits represent:

Bit 3 now clearly states:

    "LsRdBlkC: Data Cache Req Miss in L2 (all types)"

and bit 0 is:

    "IcFillMiss: Instruction Cache Req Miss in L2."

So we can now add support for L2 misses in perf's genericised events as
PMCx064 with both the above unit masks.

[1] The commit's original documentation reference, "Processor Programming
    Reference (PPR) for AMD Family 17h Model 01h, Revision B1 Processors",
    originally available here:

        https://www.amd.com/system/files/TechDocs/54945_PPR_Family_17h_Models_00h-0Fh.pdf

    is now available here:

        https://developer.amd.com/wordpress/media/2017/11/54945_PPR_Family_17h_Models_00h-0Fh.pdf

[2] "Processor Programming Reference (PPR) for Family 17h Model 31h,
    Revision B0 Processors", available here:

	https://developer.amd.com/wp-content/resources/55803_0.54-PUB.pdf

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Babu Moger <babu.moger@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Frank van der Linden <fllinden@amazon.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luwei Kang <luwei.kang@intel.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Reported-by: Babu Moger <babu.moger@amd.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Fixes: 3fe3331bb285 ("perf/x86/amd: Add event map for AMD Family 17h")
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
---
RESENDing because I wasn't sure if the original version of this patch would get
ignored because it was sent with "[PATCH internal v2]" in the subject line:

	https://lkml.org/lkml/2020/1/8/894

FWIW, I updated the Cc list to merge with those in patch 2/2 of this series.

 arch/x86/events/amd/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 1f22b6bbda68..39eb276d0277 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -250,6 +250,7 @@ static const u64 amd_f17h_perfmon_event_map[PERF_COUNT_HW_MAX] =
 	[PERF_COUNT_HW_CPU_CYCLES]		= 0x0076,
 	[PERF_COUNT_HW_INSTRUCTIONS]		= 0x00c0,
 	[PERF_COUNT_HW_CACHE_REFERENCES]	= 0xff60,
+	[PERF_COUNT_HW_CACHE_MISSES]		= 0x0964,
 	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= 0x00c2,
 	[PERF_COUNT_HW_BRANCH_MISSES]		= 0x00c3,
 	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= 0x0287,
-- 
2.24.1

[PATCH 2/2] x86/cpu/amd: Enable the fixed intructions retired free counter IRPERF

[Kim Phillips]

commit aaf248848db50 ("perf/x86/msr: Add AMD IRPERF (Instructions
Retired) performance counter") added support for 'perf -e msr/irperf/',
but when exercised, we always get a 0 count:

BEFORE:

$ sudo perf stat -e instructions,msr/irperf/ true

 Performance counter stats for 'true':

           624,833      instructions
                                                  #    0.00  stalled cycles per insn
                 0      msr/irperf/

It turns out it simply needs its enable bit - HWCR bit 30 - set.  This patch
does just that.

Enablement is restricted to all machines advertising IRPERF capability,
except those susceptible to an erratum that makes the IRPERF return
bad values.

That erratum occurs in Family 17h models 00-1fh [1], but not in F17h
models 20h and above [2].

AFTER (on a family 17h model 31h machine):

$ sudo perf stat -e instructions,msr/irperf/ true

 Performance counter stats for 'true':

           621,690      instructions
                                                  #    0.00  stalled cycles per insn
           622,490      msr/irperf/

[1] "Revision Guide for AMD Family 17h Models 00h-0Fh Processors",
    currently available here:

    https://www.amd.com/system/files/TechDocs/55449_Fam_17h_M_00h-0Fh_Rev_Guide.pdf

[2] "Revision Guide for AMD Family 17h Models 30h-3Fh Processors",
    currently available here:

    https://developer.amd.com/wp-content/resources/56323-PUB_0.74.pdf

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Babu Moger <babu.moger@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Frank van der Linden <fllinden@amazon.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luwei Kang <luwei.kang@intel.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: aaf248848db50 ("perf/x86/msr: Add AMD IRPERF (Instructions Retired) performance counter")
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
---
 arch/x86/include/asm/msr-index.h | 2 ++
 arch/x86/kernel/cpu/amd.c        | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 084e98da04a7..717660f82f8f 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -512,6 +512,8 @@
 #define MSR_K7_HWCR			0xc0010015
 #define MSR_K7_HWCR_SMMLOCK_BIT		0
 #define MSR_K7_HWCR_SMMLOCK		BIT_ULL(MSR_K7_HWCR_SMMLOCK_BIT)
+#define MSR_K7_HWCR_IRPERF_EN_BIT	30
+#define MSR_K7_HWCR_IRPERF_EN		BIT_ULL(MSR_K7_HWCR_IRPERF_EN_BIT)
 #define MSR_K7_FID_VID_CTL		0xc0010041
 #define MSR_K7_FID_VID_STATUS		0xc0010042
 
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 90f75e515876..765b2b6672eb 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -978,6 +978,15 @@ static void init_amd(struct cpuinfo_x86 *c)
 	/* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
 	if (!cpu_has(c, X86_FEATURE_XENPV))
 		set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
+
+	/*
+	 * Turn on the Instructions Retired free counter on machines not
+	 * susceptible to erratum #1054 "Instructions Retired Performance
+	 * Counter May Be Inaccurate"
+	 */
+	if (cpu_has(c, X86_FEATURE_IRPERF) &&
+	    !(c->x86 == 0x17 && c->x86_model <= 0x1f))
+		msr_set_bit(MSR_K7_HWCR, MSR_K7_HWCR_IRPERF_EN_BIT);
 }
 
 #ifdef CONFIG_X86_32
-- 
2.24.1

Re: [PATCH 2/2] x86/cpu/amd: Enable the fixed intructions retired free counter IRPERF

[Andi Kleen]

> +	if (cpu_has(c, X86_FEATURE_IRPERF) &&
> +	    !(c->x86 == 0x17 && c->x86_model <= 0x1f))

Such checks are normally through a x86_pmu lag or possibly a X86_BUG_* flag

> +		msr_set_bit(MSR_K7_HWCR, MSR_K7_HWCR_IRPERF_EN_BIT);
>  }
>  
>  #ifdef CONFIG_X86_32
> -- 
> 2.24.1
>