From 0f78d2d5ccf72ec834da6901886a40fd8e3b7615 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 28 Apr 2011 10:17:04 +0100 Subject: [PATCH] ARM: perf: lock PMU registers per-CPU Currently, a single lock serialises access to CPU PMU registers. This global locking is unnecessary as PMU registers are local to the CPU they monitor. This patch replaces the global lock with a per-CPU lock. As the lock is in struct cpu_hw_events, PMUs providing a single cpu_hw_events instance can be locked globally. Signed-off-by: Mark Rutland Reviewed-by: Will Deacon Reviewed-by: Jamie Iles Reviewed-by: Ashwin Chaugule Signed-off-by: Will Deacon --- arch/arm/kernel/perf_event.c | 17 +++++++----- arch/arm/kernel/perf_event_v6.c | 25 ++++++++++-------- arch/arm/kernel/perf_event_v7.c | 20 +++++++++------ arch/arm/kernel/perf_event_xscale.c | 40 +++++++++++++++++------------ 4 files changed, 62 insertions(+), 40 deletions(-) diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 5ce6c3332915..9331d5731445 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -26,12 +26,6 @@ #include #include -/* - * Hardware lock to serialize accesses to PMU registers. Needed for the - * read/modify/write sequences. - */ -static DEFINE_RAW_SPINLOCK(pmu_lock); - /* * ARMv6 supports a maximum of 3 events, starting from index 0. If we add * another platform that supports more, we need to increase this to be the @@ -55,6 +49,12 @@ struct cpu_hw_events { * an event. A 0 means that the counter can be used. */ unsigned long used_mask[BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)]; + + /* + * Hardware lock to serialize accesses to PMU registers. Needed for the + * read/modify/write sequences. + */ + raw_spinlock_t pmu_lock; }; static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events); @@ -685,6 +685,11 @@ static struct cpu_hw_events *armpmu_get_cpu_events(void) static void __init cpu_pmu_init(struct arm_pmu *armpmu) { + int cpu; + for_each_possible_cpu(cpu) { + struct cpu_hw_events *events = &per_cpu(cpu_hw_events, cpu); + raw_spin_lock_init(&events->pmu_lock); + } armpmu->get_hw_events = armpmu_get_cpu_events; } diff --git a/arch/arm/kernel/perf_event_v6.c b/arch/arm/kernel/perf_event_v6.c index 839012862264..68cf70425f2f 100644 --- a/arch/arm/kernel/perf_event_v6.c +++ b/arch/arm/kernel/perf_event_v6.c @@ -433,6 +433,7 @@ armv6pmu_enable_event(struct hw_perf_event *hwc, int idx) { unsigned long val, mask, evt, flags; + struct cpu_hw_events *events = armpmu->get_hw_events(); if (ARMV6_CYCLE_COUNTER == idx) { mask = 0; @@ -454,12 +455,12 @@ armv6pmu_enable_event(struct hw_perf_event *hwc, * Mask out the current event and set the counter to count the event * that we're interested in. */ - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = armv6_pmcr_read(); val &= ~mask; val |= evt; armv6_pmcr_write(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static int counter_is_active(unsigned long pmcr, int idx) @@ -544,24 +545,26 @@ static void armv6pmu_start(void) { unsigned long flags, val; + struct cpu_hw_events *events = armpmu->get_hw_events(); - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = armv6_pmcr_read(); val |= ARMV6_PMCR_ENABLE; armv6_pmcr_write(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static void armv6pmu_stop(void) { unsigned long flags, val; + struct cpu_hw_events *events = armpmu->get_hw_events(); - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = armv6_pmcr_read(); val &= ~ARMV6_PMCR_ENABLE; armv6_pmcr_write(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static int @@ -595,6 +598,7 @@ armv6pmu_disable_event(struct hw_perf_event *hwc, int idx) { unsigned long val, mask, evt, flags; + struct cpu_hw_events *events = armpmu->get_hw_events(); if (ARMV6_CYCLE_COUNTER == idx) { mask = ARMV6_PMCR_CCOUNT_IEN; @@ -615,12 +619,12 @@ armv6pmu_disable_event(struct hw_perf_event *hwc, * of ETM bus signal assertion cycles. The external reporting should * be disabled and so this should never increment. */ - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = armv6_pmcr_read(); val &= ~mask; val |= evt; armv6_pmcr_write(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static void @@ -628,6 +632,7 @@ armv6mpcore_pmu_disable_event(struct hw_perf_event *hwc, int idx) { unsigned long val, mask, flags, evt = 0; + struct cpu_hw_events *events = armpmu->get_hw_events(); if (ARMV6_CYCLE_COUNTER == idx) { mask = ARMV6_PMCR_CCOUNT_IEN; @@ -644,12 +649,12 @@ armv6mpcore_pmu_disable_event(struct hw_perf_event *hwc, * Unlike UP ARMv6, we don't have a way of stopping the counters. We * simply disable the interrupt reporting. */ - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = armv6_pmcr_read(); val &= ~mask; val |= evt; armv6_pmcr_write(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static struct arm_pmu armv6pmu = { diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c index f4170fc228b6..68ac522fd940 100644 --- a/arch/arm/kernel/perf_event_v7.c +++ b/arch/arm/kernel/perf_event_v7.c @@ -936,12 +936,13 @@ static void armv7_pmnc_dump_regs(void) static void armv7pmu_enable_event(struct hw_perf_event *hwc, int idx) { unsigned long flags; + struct cpu_hw_events *events = armpmu->get_hw_events(); /* * Enable counter and interrupt, and set the counter to count * the event that we're interested in. */ - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); /* * Disable counter @@ -966,17 +967,18 @@ static void armv7pmu_enable_event(struct hw_perf_event *hwc, int idx) */ armv7_pmnc_enable_counter(idx); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static void armv7pmu_disable_event(struct hw_perf_event *hwc, int idx) { unsigned long flags; + struct cpu_hw_events *events = armpmu->get_hw_events(); /* * Disable counter and interrupt */ - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); /* * Disable counter @@ -988,7 +990,7 @@ static void armv7pmu_disable_event(struct hw_perf_event *hwc, int idx) */ armv7_pmnc_disable_intens(idx); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static irqreturn_t armv7pmu_handle_irq(int irq_num, void *dev) @@ -1054,21 +1056,23 @@ static irqreturn_t armv7pmu_handle_irq(int irq_num, void *dev) static void armv7pmu_start(void) { unsigned long flags; + struct cpu_hw_events *events = armpmu->get_hw_events(); - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); /* Enable all counters */ armv7_pmnc_write(armv7_pmnc_read() | ARMV7_PMNC_E); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static void armv7pmu_stop(void) { unsigned long flags; + struct cpu_hw_events *events = armpmu->get_hw_events(); - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); /* Disable all counters */ armv7_pmnc_write(armv7_pmnc_read() & ~ARMV7_PMNC_E); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static int armv7pmu_get_event_idx(struct cpu_hw_events *cpuc, diff --git a/arch/arm/kernel/perf_event_xscale.c b/arch/arm/kernel/perf_event_xscale.c index ca89a06c8e92..18e4823a0a62 100644 --- a/arch/arm/kernel/perf_event_xscale.c +++ b/arch/arm/kernel/perf_event_xscale.c @@ -281,6 +281,7 @@ static void xscale1pmu_enable_event(struct hw_perf_event *hwc, int idx) { unsigned long val, mask, evt, flags; + struct cpu_hw_events *events = armpmu->get_hw_events(); switch (idx) { case XSCALE_CYCLE_COUNTER: @@ -302,18 +303,19 @@ xscale1pmu_enable_event(struct hw_perf_event *hwc, int idx) return; } - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = xscale1pmu_read_pmnc(); val &= ~mask; val |= evt; xscale1pmu_write_pmnc(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static void xscale1pmu_disable_event(struct hw_perf_event *hwc, int idx) { unsigned long val, mask, evt, flags; + struct cpu_hw_events *events = armpmu->get_hw_events(); switch (idx) { case XSCALE_CYCLE_COUNTER: @@ -333,12 +335,12 @@ xscale1pmu_disable_event(struct hw_perf_event *hwc, int idx) return; } - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = xscale1pmu_read_pmnc(); val &= ~mask; val |= evt; xscale1pmu_write_pmnc(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static int @@ -365,24 +367,26 @@ static void xscale1pmu_start(void) { unsigned long flags, val; + struct cpu_hw_events *events = armpmu->get_hw_events(); - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = xscale1pmu_read_pmnc(); val |= XSCALE_PMU_ENABLE; xscale1pmu_write_pmnc(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static void xscale1pmu_stop(void) { unsigned long flags, val; + struct cpu_hw_events *events = armpmu->get_hw_events(); - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = xscale1pmu_read_pmnc(); val &= ~XSCALE_PMU_ENABLE; xscale1pmu_write_pmnc(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static inline u32 @@ -610,6 +614,7 @@ static void xscale2pmu_enable_event(struct hw_perf_event *hwc, int idx) { unsigned long flags, ien, evtsel; + struct cpu_hw_events *events = armpmu->get_hw_events(); ien = xscale2pmu_read_int_enable(); evtsel = xscale2pmu_read_event_select(); @@ -643,16 +648,17 @@ xscale2pmu_enable_event(struct hw_perf_event *hwc, int idx) return; } - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); xscale2pmu_write_event_select(evtsel); xscale2pmu_write_int_enable(ien); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static void xscale2pmu_disable_event(struct hw_perf_event *hwc, int idx) { unsigned long flags, ien, evtsel; + struct cpu_hw_events *events = armpmu->get_hw_events(); ien = xscale2pmu_read_int_enable(); evtsel = xscale2pmu_read_event_select(); @@ -686,10 +692,10 @@ xscale2pmu_disable_event(struct hw_perf_event *hwc, int idx) return; } - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); xscale2pmu_write_event_select(evtsel); xscale2pmu_write_int_enable(ien); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static int @@ -712,24 +718,26 @@ static void xscale2pmu_start(void) { unsigned long flags, val; + struct cpu_hw_events *events = armpmu->get_hw_events(); - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = xscale2pmu_read_pmnc() & ~XSCALE_PMU_CNT64; val |= XSCALE_PMU_ENABLE; xscale2pmu_write_pmnc(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static void xscale2pmu_stop(void) { unsigned long flags, val; + struct cpu_hw_events *events = armpmu->get_hw_events(); - raw_spin_lock_irqsave(&pmu_lock, flags); + raw_spin_lock_irqsave(&events->pmu_lock, flags); val = xscale2pmu_read_pmnc(); val &= ~XSCALE_PMU_ENABLE; xscale2pmu_write_pmnc(val); - raw_spin_unlock_irqrestore(&pmu_lock, flags); + raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } static inline u32 -- 2.20.1