[GIT PULL] perf events fixes

[GIT PULL] perf events fixes

[Ingo Molnar]

Linus,

Please pull the latest perf/urgent git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-2023-10-01

   # HEAD: 599522d9d2e19d6240e4312577f1c5f3ffca22f6 perf/x86/amd: Do not WARN() on every IRQ

Misc fixes: work around an AMD microcode bug on certain models,
and fix kexec kernel PMI handlers on AMD systems that get loaded
on older kernels that have an unexpected register state.

 Thanks,

	Ingo

------------------>
Breno Leitao (1):
      perf/x86/amd: Do not WARN() on every IRQ

Sandipan Das (1):
      perf/x86/amd/core: Fix overflow reset on hotplug


 arch/x86/events/amd/core.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index abadd5f23425..e24976593a29 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -534,8 +534,12 @@ static void amd_pmu_cpu_reset(int cpu)
 	/* Clear enable bits i.e. PerfCntrGlobalCtl.PerfCntrEn */
 	wrmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_CTL, 0);
 
-	/* Clear overflow bits i.e. PerfCntrGLobalStatus.PerfCntrOvfl */
-	wrmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR, amd_pmu_global_cntr_mask);
+	/*
+	 * Clear freeze and overflow bits i.e. PerfCntrGLobalStatus.LbrFreeze
+	 * and PerfCntrGLobalStatus.PerfCntrOvfl
+	 */
+	wrmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR,
+	       GLOBAL_STATUS_LBRS_FROZEN | amd_pmu_global_cntr_mask);
 }
 
 static int amd_pmu_cpu_prepare(int cpu)
@@ -570,6 +574,7 @@ static void amd_pmu_cpu_starting(int cpu)
 	int i, nb_id;
 
 	cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY;
+	amd_pmu_cpu_reset(cpu);
 
 	if (!x86_pmu.amd_nb_constraints)
 		return;
@@ -591,8 +596,6 @@ static void amd_pmu_cpu_starting(int cpu)
 
 	cpuc->amd_nb->nb_id = nb_id;
 	cpuc->amd_nb->refcnt++;
-
-	amd_pmu_cpu_reset(cpu);
 }
 
 static void amd_pmu_cpu_dead(int cpu)
@@ -601,6 +604,7 @@ static void amd_pmu_cpu_dead(int cpu)
 
 	kfree(cpuhw->lbr_sel);
 	cpuhw->lbr_sel = NULL;
+	amd_pmu_cpu_reset(cpu);
 
 	if (!x86_pmu.amd_nb_constraints)
 		return;
@@ -613,8 +617,6 @@ static void amd_pmu_cpu_dead(int cpu)
 
 		cpuhw->amd_nb = NULL;
 	}
-
-	amd_pmu_cpu_reset(cpu);
 }
 
 static inline void amd_pmu_set_global_ctl(u64 ctl)
@@ -884,7 +886,7 @@ static int amd_pmu_v2_handle_irq(struct pt_regs *regs)
 	struct hw_perf_event *hwc;
 	struct perf_event *event;
 	int handled = 0, idx;
-	u64 status, mask;
+	u64 reserved, status, mask;
 	bool pmu_enabled;
 
 	/*
@@ -909,6 +911,14 @@ static int amd_pmu_v2_handle_irq(struct pt_regs *regs)
 		status &= ~GLOBAL_STATUS_LBRS_FROZEN;
 	}
 
+	reserved = status & ~amd_pmu_global_cntr_mask;
+	if (reserved)
+		pr_warn_once("Reserved PerfCntrGlobalStatus bits are set (0x%llx), please consider updating microcode\n",
+			     reserved);
+
+	/* Clear any reserved bits set by buggy microcode */
+	status &= amd_pmu_global_cntr_mask;
+
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
 		if (!test_bit(idx, cpuc->active_mask))
 			continue;

Re: [GIT PULL] perf events fixes

[pr-tracker-bot]

The pull request you sent on Sun, 1 Oct 2023 10:35:42 +0200:

> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-2023-10-01

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/3a38c57a87aeb5c6d71a1b6dd572569112dbce38

Thank you!

-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/prtracker.html

[GIT PULL] perf events fixes

[Ingo Molnar]

Linus,

Please pull the latest perf/urgent Git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-2024-03-17

   # HEAD: ad8c91282c95f801c37812d59d2d9eba6899b384 perf/x86/amd/core: Avoid register reset when CPU is dead

Two x86 PMU fixes:

 - Work around AMD erratum to filter out bogus LBR stack entries

 - Fix incorrect PMU reset that can result in warnings (or worse)
   during suspend/hibernation.

 Thanks,

	Ingo

------------------>
Sandipan Das (2):
      perf/x86/amd/lbr: Discard erroneous branch entries
      perf/x86/amd/core: Avoid register reset when CPU is dead


 arch/x86/events/amd/core.c | 1 -
 arch/x86/events/amd/lbr.c  | 6 ++++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 69a3b02e50bb..aec16e581f5b 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -604,7 +604,6 @@ static void amd_pmu_cpu_dead(int cpu)
 
 	kfree(cpuhw->lbr_sel);
 	cpuhw->lbr_sel = NULL;
-	amd_pmu_cpu_reset(cpu);
 
 	if (!x86_pmu.amd_nb_constraints)
 		return;
diff --git a/arch/x86/events/amd/lbr.c b/arch/x86/events/amd/lbr.c
index eb31f850841a..4a1e600314d5 100644
--- a/arch/x86/events/amd/lbr.c
+++ b/arch/x86/events/amd/lbr.c
@@ -173,9 +173,11 @@ void amd_pmu_lbr_read(void)
 
 		/*
 		 * Check if a branch has been logged; if valid = 0, spec = 0
-		 * then no branch was recorded
+		 * then no branch was recorded; if reserved = 1 then an
+		 * erroneous branch was recorded (see Erratum 1452)
 		 */
-		if (!entry.to.split.valid && !entry.to.split.spec)
+		if ((!entry.to.split.valid && !entry.to.split.spec) ||
+		    entry.to.split.reserved)
 			continue;
 
 		perf_clear_branch_entry_bitfields(br + out);

Re: [GIT PULL] perf events fixes

[pr-tracker-bot]

The pull request you sent on Sun, 17 Mar 2024 09:57:38 +0100:

> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-2024-03-17

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/b463a3c347df6f4d2d24f47c65716ae3166006e6

Thank you!

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Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/prtracker.html