From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 25 Jun 2021 10:24:12 +0000 (+0200)
Subject: 4.9-stable patches
X-Git-Tag: v5.12.14~47
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6c8960fff8ddb23265cc9e141eb9e2c49499d0f6;p=thirdparty%2Fkernel%2Fstable-queue.git

4.9-stable patches

added patches:
	arm64-perf-disable-pmu-while-processing-counter-overflows.patch
---

diff --git a/queue-4.9/arm64-perf-disable-pmu-while-processing-counter-overflows.patch b/queue-4.9/arm64-perf-disable-pmu-while-processing-counter-overflows.patch
new file mode 100644
index 00000000000..cb04be7f233
--- /dev/null
+++ b/queue-4.9/arm64-perf-disable-pmu-while-processing-counter-overflows.patch
@@ -0,0 +1,112 @@
+From 3cce50dfec4a5b0414c974190940f47dd32c6dee Mon Sep 17 00:00:00 2001
+From: Suzuki K Poulose <suzuki.poulose@arm.com>
+Date: Tue, 10 Jul 2018 09:58:03 +0100
+Subject: arm64: perf: Disable PMU while processing counter overflows
+
+From: Suzuki K Poulose <suzuki.poulose@arm.com>
+
+commit 3cce50dfec4a5b0414c974190940f47dd32c6dee upstream.
+
+The arm64 PMU updates the event counters and reprograms the
+counters in the overflow IRQ handler without disabling the
+PMU. This could potentially cause skews in for group counters,
+where the overflowed counters may potentially loose some event
+counts, while they are reprogrammed. To prevent this, disable
+the PMU while we process the counter overflows and enable it
+right back when we are done.
+
+This patch also moves the PMU stop/start routines to avoid a
+forward declaration.
+
+Suggested-by: Mark Rutland <mark.rutland@arm.com>
+Cc: Will Deacon <will.deacon@arm.com>
+Acked-by: Mark Rutland <mark.rutland@arm.com>
+Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
+Signed-off-by: Will Deacon <will.deacon@arm.com>
+Signed-off-by: Aman Priyadarshi <apeureka@amazon.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/arm64/kernel/perf_event.c |   50 ++++++++++++++++++++++-------------------
+ 1 file changed, 28 insertions(+), 22 deletions(-)
+
+--- a/arch/arm64/kernel/perf_event.c
++++ b/arch/arm64/kernel/perf_event.c
+@@ -748,6 +748,28 @@ static void armv8pmu_disable_event(struc
+ 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
+ }
+ 
++static void armv8pmu_start(struct arm_pmu *cpu_pmu)
++{
++	unsigned long flags;
++	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
++
++	raw_spin_lock_irqsave(&events->pmu_lock, flags);
++	/* Enable all counters */
++	armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMU_PMCR_E);
++	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
++}
++
++static void armv8pmu_stop(struct arm_pmu *cpu_pmu)
++{
++	unsigned long flags;
++	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
++
++	raw_spin_lock_irqsave(&events->pmu_lock, flags);
++	/* Disable all counters */
++	armv8pmu_pmcr_write(armv8pmu_pmcr_read() & ~ARMV8_PMU_PMCR_E);
++	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
++}
++
+ static irqreturn_t armv8pmu_handle_irq(int irq_num, void *dev)
+ {
+ 	u32 pmovsr;
+@@ -773,6 +795,11 @@ static irqreturn_t armv8pmu_handle_irq(i
+ 	 */
+ 	regs = get_irq_regs();
+ 
++	/*
++	 * Stop the PMU while processing the counter overflows
++	 * to prevent skews in group events.
++	 */
++	armv8pmu_stop(cpu_pmu);
+ 	for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
+ 		struct perf_event *event = cpuc->events[idx];
+ 		struct hw_perf_event *hwc;
+@@ -797,6 +824,7 @@ static irqreturn_t armv8pmu_handle_irq(i
+ 		if (perf_event_overflow(event, &data, regs))
+ 			cpu_pmu->disable(event);
+ 	}
++	armv8pmu_start(cpu_pmu);
+ 
+ 	/*
+ 	 * Handle the pending perf events.
+@@ -810,28 +838,6 @@ static irqreturn_t armv8pmu_handle_irq(i
+ 	return IRQ_HANDLED;
+ }
+ 
+-static void armv8pmu_start(struct arm_pmu *cpu_pmu)
+-{
+-	unsigned long flags;
+-	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
+-
+-	raw_spin_lock_irqsave(&events->pmu_lock, flags);
+-	/* Enable all counters */
+-	armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMU_PMCR_E);
+-	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
+-}
+-
+-static void armv8pmu_stop(struct arm_pmu *cpu_pmu)
+-{
+-	unsigned long flags;
+-	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
+-
+-	raw_spin_lock_irqsave(&events->pmu_lock, flags);
+-	/* Disable all counters */
+-	armv8pmu_pmcr_write(armv8pmu_pmcr_read() & ~ARMV8_PMU_PMCR_E);
+-	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
+-}
+-
+ static int armv8pmu_get_event_idx(struct pmu_hw_events *cpuc,
+ 				  struct perf_event *event)
+ {
diff --git a/queue-4.9/series b/queue-4.9/series
index cb13f8fe63e..b5dd84f305c 100644
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -51,3 +51,4 @@ inet-use-bigger-hash-table-for-ip-id-generation.patch
 i40e-be-much-more-verbose-about-what-we-can-and-cannot-offload.patch
 arm-9081-1-fix-gcc-10-thumb2-kernel-regression.patch
 makefile-move-wno-unused-but-set-variable-out-of-gcc-only-block.patch
+arm64-perf-disable-pmu-while-processing-counter-overflows.patch