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arm64: perf: Add more support on caps under sysfs

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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 <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Link: https://lore.kernel.org/r/1622704502-63951-1-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Shaokun Zhang 2021-06-03 15:15:02 +08:00 committed by Will Deacon
parent 0d0f144a8f
commit 281e44f5fd
2 changed files with 38 additions and 0 deletions
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5
arch/arm64/include/asm/perf_event.h
View File

@ -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);

33
arch/arm64/kernel/perf_event.c
View File

@ -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,
};