From fdbef8c4e68ad423416aa6cc93d1616d6f8ac5b3 Mon Sep 17 00:00:00 2001 From: Yang Jihong Date: Fri, 30 Apr 2021 09:26:59 +0800 Subject: arm_pmu: Fix write counter incorrect in ARMv7 big-endian mode Commit 3a95200d3f89 ("arm_pmu: Change API to support 64bit counter values") changes the input "value" type from 32-bit to 64-bit, which introduces the following problem: ARMv7 PMU counters is 32-bit width, in big-endian mode, write counter uses high 32-bit, which writes an incorrect value. Before: Performance counter stats for 'ls': 2.22 msec task-clock # 0.675 CPUs utilized 0 context-switches # 0.000 K/sec 0 cpu-migrations # 0.000 K/sec 49 page-faults # 0.022 M/sec 2150476593 cycles # 966.663 GHz 2148588788 instructions # 1.00 insn per cycle 2147745484 branches # 965435.074 M/sec 2147508540 branch-misses # 99.99% of all branches None of the above hw event counters are correct. Solution: "value" forcibly converted to 32-bit type before being written to PMU register. After: Performance counter stats for 'ls': 2.09 msec task-clock # 0.681 CPUs utilized 0 context-switches # 0.000 K/sec 0 cpu-migrations # 0.000 K/sec 46 page-faults # 0.022 M/sec 2807301 cycles # 1.344 GHz 1060159 instructions # 0.38 insn per cycle 250496 branches # 119.914 M/sec 23192 branch-misses # 9.26% of all branches Fixes: 3a95200d3f89 ("arm_pmu: Change API to support 64bit counter values") Cc: Signed-off-by: Yang Jihong Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20210430012659.232110-1-yangjihong1@huawei.com Signed-off-by: Will Deacon --- arch/arm/kernel/perf_event_v7.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c index 2924d7910b10..eb2190477da1 100644 --- a/arch/arm/kernel/perf_event_v7.c +++ b/arch/arm/kernel/perf_event_v7.c @@ -773,10 +773,10 @@ static inline void armv7pmu_write_counter(struct perf_event *event, u64 value) pr_err("CPU%u writing wrong counter %d\n", smp_processor_id(), idx); } else if (idx == ARMV7_IDX_CYCLE_COUNTER) { - asm volatile("mcr p15, 0, %0, c9, c13, 0" : : "r" (value)); + asm volatile("mcr p15, 0, %0, c9, c13, 0" : : "r" ((u32)value)); } else { armv7_pmnc_select_counter(idx); - asm volatile("mcr p15, 0, %0, c9, c13, 2" : : "r" (value)); + asm volatile("mcr p15, 0, %0, c9, c13, 2" : : "r" ((u32)value)); } } -- cgit v1.2.3 From 8848f0665b3cd4fbb3107b384f5205380c90634d Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 15 Jun 2021 12:12:24 +0100 Subject: arm64: Add cpuidle context save/restore helpers As we need to start doing some additional work on all idle paths, let's introduce a set of macros that will perform the work related to the GICv3 pseudo-NMI idle entry exit. Stubs are introduced to 32bit ARM for compatibility. As these helpers are currently unused, there is no functional change. Tested-by: Valentin Schneider Reviewed-by: Lorenzo Pieralisi Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210615111227.2454465-2-maz@kernel.org Signed-off-by: Will Deacon --- arch/arm/include/asm/cpuidle.h | 5 +++++ arch/arm64/include/asm/cpuidle.h | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) (limited to 'arch/arm') diff --git a/arch/arm/include/asm/cpuidle.h b/arch/arm/include/asm/cpuidle.h index 0d67ed682e07..dc8f53f1a219 100644 --- a/arch/arm/include/asm/cpuidle.h +++ b/arch/arm/include/asm/cpuidle.h @@ -49,4 +49,9 @@ extern int arm_cpuidle_suspend(int index); extern int arm_cpuidle_init(int cpu); +struct arm_cpuidle_irq_context { }; + +#define arm_cpuidle_save_irq_context(c) (void)c +#define arm_cpuidle_restore_irq_context(c) (void)c + #endif diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h index 3c5ddb429ea2..14a19d1141bd 100644 --- a/arch/arm64/include/asm/cpuidle.h +++ b/arch/arm64/include/asm/cpuidle.h @@ -18,4 +18,39 @@ static inline int arm_cpuidle_suspend(int index) return -EOPNOTSUPP; } #endif + +#ifdef CONFIG_ARM64_PSEUDO_NMI +#include + +struct arm_cpuidle_irq_context { + unsigned long pmr; + unsigned long daif_bits; +}; + +#define arm_cpuidle_save_irq_context(__c) \ + do { \ + struct arm_cpuidle_irq_context *c = __c; \ + if (system_uses_irq_prio_masking()) { \ + c->daif_bits = read_sysreg(daif); \ + write_sysreg(c->daif_bits | PSR_I_BIT | PSR_F_BIT, \ + daif); \ + c->pmr = gic_read_pmr(); \ + gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); \ + } \ + } while (0) + +#define arm_cpuidle_restore_irq_context(__c) \ + do { \ + struct arm_cpuidle_irq_context *c = __c; \ + if (system_uses_irq_prio_masking()) { \ + gic_write_pmr(c->pmr); \ + write_sysreg(c->daif_bits, daif); \ + } \ + } while (0) +#else +struct arm_cpuidle_irq_context { }; + +#define arm_cpuidle_save_irq_context(c) (void)c +#define arm_cpuidle_restore_irq_context(c) (void)c +#endif #endif -- cgit v1.2.3