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Merge tag 'perf_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/…
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…linux/kernel/git/tip/tip

Pull x86 perf fixes from Borislav Petkov:

 - Define the correct set of default hw events on AMD Zen4

 - Use the correct stalled cycles PMCs on AMD Zen2 and newer

 - Fix detection of the LBR freeze feature on AMD

* tag 'perf_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/amd/core: Define a proper ref-cycles event for Zen 4 and later
  perf/x86/amd/core: Update and fix stalled-cycles-* events for Zen 2 and later
  perf/x86/amd/lbr: Use freeze based on availability
  x86/cpufeatures: Add new word for scattered features
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torvalds committed Mar 31, 2024
2 parents 8d338df + 68cdf1e commit 448f828
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Showing 7 changed files with 62 additions and 16 deletions.
39 changes: 34 additions & 5 deletions arch/x86/events/amd/core.c
Original file line number Diff line number Diff line change
Expand Up @@ -250,7 +250,7 @@ static const u64 amd_perfmon_event_map[PERF_COUNT_HW_MAX] =
/*
* AMD Performance Monitor Family 17h and later:
*/
static const u64 amd_f17h_perfmon_event_map[PERF_COUNT_HW_MAX] =
static const u64 amd_zen1_perfmon_event_map[PERF_COUNT_HW_MAX] =
{
[PERF_COUNT_HW_CPU_CYCLES] = 0x0076,
[PERF_COUNT_HW_INSTRUCTIONS] = 0x00c0,
Expand All @@ -262,10 +262,39 @@ static const u64 amd_f17h_perfmon_event_map[PERF_COUNT_HW_MAX] =
[PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = 0x0187,
};

static const u64 amd_zen2_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] = 0x00a9,
};

static const u64 amd_zen4_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] = 0x00a9,
[PERF_COUNT_HW_REF_CPU_CYCLES] = 0x100000120,
};

static u64 amd_pmu_event_map(int hw_event)
{
if (boot_cpu_data.x86 >= 0x17)
return amd_f17h_perfmon_event_map[hw_event];
if (cpu_feature_enabled(X86_FEATURE_ZEN4) || boot_cpu_data.x86 >= 0x1a)
return amd_zen4_perfmon_event_map[hw_event];

if (cpu_feature_enabled(X86_FEATURE_ZEN2) || boot_cpu_data.x86 >= 0x19)
return amd_zen2_perfmon_event_map[hw_event];

if (cpu_feature_enabled(X86_FEATURE_ZEN1))
return amd_zen1_perfmon_event_map[hw_event];

return amd_perfmon_event_map[hw_event];
}
Expand Down Expand Up @@ -904,8 +933,8 @@ static int amd_pmu_v2_handle_irq(struct pt_regs *regs)
if (!status)
goto done;

/* Read branch records before unfreezing */
if (status & GLOBAL_STATUS_LBRS_FROZEN) {
/* Read branch records */
if (x86_pmu.lbr_nr) {
amd_pmu_lbr_read();
status &= ~GLOBAL_STATUS_LBRS_FROZEN;
}
Expand Down
16 changes: 10 additions & 6 deletions arch/x86/events/amd/lbr.c
Original file line number Diff line number Diff line change
Expand Up @@ -402,10 +402,12 @@ void amd_pmu_lbr_enable_all(void)
wrmsrl(MSR_AMD64_LBR_SELECT, lbr_select);
}

rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl);
rdmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg);
if (cpu_feature_enabled(X86_FEATURE_AMD_LBR_PMC_FREEZE)) {
rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl);
wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI);
}

wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI);
rdmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg);
wrmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg | DBG_EXTN_CFG_LBRV2EN);
}

Expand All @@ -418,10 +420,12 @@ void amd_pmu_lbr_disable_all(void)
return;

rdmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg);
rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl);

wrmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg & ~DBG_EXTN_CFG_LBRV2EN);
wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl & ~DEBUGCTLMSR_FREEZE_LBRS_ON_PMI);

if (cpu_feature_enabled(X86_FEATURE_AMD_LBR_PMC_FREEZE)) {
rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl);
wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl & ~DEBUGCTLMSR_FREEZE_LBRS_ON_PMI);
}
}

__init int amd_pmu_lbr_init(void)
Expand Down
6 changes: 4 additions & 2 deletions arch/x86/include/asm/cpufeature.h
Original file line number Diff line number Diff line change
Expand Up @@ -91,8 +91,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \
CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \
CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 20, feature_bit) || \
CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 21, feature_bit) || \
REQUIRED_MASK_CHECK || \
BUILD_BUG_ON_ZERO(NCAPINTS != 21))
BUILD_BUG_ON_ZERO(NCAPINTS != 22))

#define DISABLED_MASK_BIT_SET(feature_bit) \
( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \
Expand All @@ -116,8 +117,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \
CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \
CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 20, feature_bit) || \
CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 21, feature_bit) || \
DISABLED_MASK_CHECK || \
BUILD_BUG_ON_ZERO(NCAPINTS != 21))
BUILD_BUG_ON_ZERO(NCAPINTS != 22))

#define cpu_has(c, bit) \
(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
Expand Down
10 changes: 9 additions & 1 deletion arch/x86/include/asm/cpufeatures.h
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,7 @@
/*
* Defines x86 CPU feature bits
*/
#define NCAPINTS 21 /* N 32-bit words worth of info */
#define NCAPINTS 22 /* N 32-bit words worth of info */
#define NBUGINTS 2 /* N 32-bit bug flags */

/*
Expand Down Expand Up @@ -459,6 +459,14 @@
#define X86_FEATURE_IBPB_BRTYPE (20*32+28) /* "" MSR_PRED_CMD[IBPB] flushes all branch type predictions */
#define X86_FEATURE_SRSO_NO (20*32+29) /* "" CPU is not affected by SRSO */

/*
* Extended auxiliary flags: Linux defined - for features scattered in various
* CPUID levels like 0x80000022, etc.
*
* Reuse free bits when adding new feature flags!
*/
#define X86_FEATURE_AMD_LBR_PMC_FREEZE (21*32+ 0) /* AMD LBR and PMC Freeze */

/*
* BUG word(s)
*/
Expand Down
3 changes: 2 additions & 1 deletion arch/x86/include/asm/disabled-features.h
Original file line number Diff line number Diff line change
Expand Up @@ -155,6 +155,7 @@
#define DISABLED_MASK18 (DISABLE_IBT)
#define DISABLED_MASK19 (DISABLE_SEV_SNP)
#define DISABLED_MASK20 0
#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 21)
#define DISABLED_MASK21 0
#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 22)

#endif /* _ASM_X86_DISABLED_FEATURES_H */
3 changes: 2 additions & 1 deletion arch/x86/include/asm/required-features.h
Original file line number Diff line number Diff line change
Expand Up @@ -99,6 +99,7 @@
#define REQUIRED_MASK18 0
#define REQUIRED_MASK19 0
#define REQUIRED_MASK20 0
#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 21)
#define REQUIRED_MASK21 0
#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 22)

#endif /* _ASM_X86_REQUIRED_FEATURES_H */
1 change: 1 addition & 0 deletions arch/x86/kernel/cpu/scattered.c
Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,7 @@ static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_BMEC, CPUID_EBX, 3, 0x80000020, 0 },
{ X86_FEATURE_PERFMON_V2, CPUID_EAX, 0, 0x80000022, 0 },
{ X86_FEATURE_AMD_LBR_V2, CPUID_EAX, 1, 0x80000022, 0 },
{ X86_FEATURE_AMD_LBR_PMC_FREEZE, CPUID_EAX, 2, 0x80000022, 0 },
{ 0, 0, 0, 0, 0 }
};

Expand Down

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