From 281e44f5fd4f82d86a2b86f0592c698f7311a674 Mon Sep 17 00:00:00 2001 From: Shaokun Zhang Date: Thu, 3 Jun 2021 15:15:02 +0800 Subject: arm64: perf: Add more support on caps under sysfs Armv8.7 has introduced BUS_SLOTS and BUS_WIDTH in PMMIR_EL1 register, add two entries in caps for bus_slots and bus_width under sysfs. It will return the true slots and width if the information is available, otherwise it will return 0. Cc: Will Deacon Cc: Mark Rutland Cc: Robin Murphy Signed-off-by: Shaokun Zhang Link: https://lore.kernel.org/r/1622704502-63951-1-git-send-email-zhangshaokun@hisilicon.com Signed-off-by: Will Deacon --- arch/arm64/include/asm/perf_event.h | 5 +++++ arch/arm64/kernel/perf_event.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/arch/arm64/include/asm/perf_event.h b/arch/arm64/include/asm/perf_event.h index 60731f602d3e..4ef6f19331f9 100644 --- a/arch/arm64/include/asm/perf_event.h +++ b/arch/arm64/include/asm/perf_event.h @@ -239,6 +239,11 @@ /* PMMIR_EL1.SLOTS mask */ #define ARMV8_PMU_SLOTS_MASK 0xff +#define ARMV8_PMU_BUS_SLOTS_SHIFT 8 +#define ARMV8_PMU_BUS_SLOTS_MASK 0xff +#define ARMV8_PMU_BUS_WIDTH_SHIFT 16 +#define ARMV8_PMU_BUS_WIDTH_MASK 0xf + #ifdef CONFIG_PERF_EVENTS struct pt_regs; extern unsigned long perf_instruction_pointer(struct pt_regs *regs); diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index 44b6eda69a81..a661010308c0 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -317,8 +317,41 @@ static ssize_t slots_show(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RO(slots); +static ssize_t bus_slots_show(struct device *dev, struct device_attribute *attr, + char *page) +{ + struct pmu *pmu = dev_get_drvdata(dev); + struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu); + u32 bus_slots = (cpu_pmu->reg_pmmir >> ARMV8_PMU_BUS_SLOTS_SHIFT) + & ARMV8_PMU_BUS_SLOTS_MASK; + + return sysfs_emit(page, "0x%08x\n", bus_slots); +} + +static DEVICE_ATTR_RO(bus_slots); + +static ssize_t bus_width_show(struct device *dev, struct device_attribute *attr, + char *page) +{ + struct pmu *pmu = dev_get_drvdata(dev); + struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu); + u32 bus_width = (cpu_pmu->reg_pmmir >> ARMV8_PMU_BUS_WIDTH_SHIFT) + & ARMV8_PMU_BUS_WIDTH_MASK; + u32 val = 0; + + /* Encoded as Log2(number of bytes), plus one */ + if (bus_width > 2 && bus_width < 13) + val = 1 << (bus_width - 1); + + return sysfs_emit(page, "0x%08x\n", val); +} + +static DEVICE_ATTR_RO(bus_width); + static struct attribute *armv8_pmuv3_caps_attrs[] = { &dev_attr_slots.attr, + &dev_attr_bus_slots.attr, + &dev_attr_bus_width.attr, NULL, }; -- cgit