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| author | Shaokun Zhang <zhangshaokun@hisilicon.com> | 2021-06-03 15:15:02 +0800 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-06-03 09:53:17 +0100 |
| commit | 281e44f5fd4f82d86a2b86f0592c698f7311a674 (patch) | |
| tree | 88d2fc59d771c6f906d73b8814845bb3d34f8054 /arch/arm64/kernel | |
| parent | 0d0f144a8f5f9815a180d16ef7d08b6269016897 (diff) | |
| download | linux-281e44f5fd4f82d86a2b86f0592c698f7311a674.tar.bz2 | |
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 <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>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/perf_event.c | 33 |
1 files changed, 33 insertions, 0 deletions
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, }; |