* [PATCH v2] arm64: perf: Add more support on caps under sysfs
@ 2021-05-29 6:19 Shaokun Zhang
2021-06-02 16:42 ` Will Deacon
0 siblings, 1 reply; 3+ messages in thread
From: Shaokun Zhang @ 2021-05-29 6:19 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Shaokun Zhang, Will Deacon, Mark Rutland, Robin Murphy
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>
---
ChangeLog:
v1-->v2:
1. Address Robin's comment on bus_width calculation.
2. Add the comment on calculation formula.
Will & Robin,
I don't change any about visible, if have more comments,
please let me know.
arch/arm64/include/asm/perf_event.h | 5 +++++
arch/arm64/kernel/perf_event.c | 35 +++++++++++++++++++++++++++++++++++
2 files changed, 40 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 f594957e29bd..453e0d8a442e 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -317,8 +317,43 @@ 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 snprintf(page, PAGE_SIZE, "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;
+
+ /* Encoded as Log2(number of bytes), plus one */
+ if (bus_width > 2 && bus_width < 13)
+ val = 1 << (bus_width - 1);
+ else
+ val = 0;
+
+ return snprintf(page, PAGE_SIZE, "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,
};
--
2.7.4
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^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] arm64: perf: Add more support on caps under sysfs
2021-05-29 6:19 [PATCH v2] arm64: perf: Add more support on caps under sysfs Shaokun Zhang
@ 2021-06-02 16:42 ` Will Deacon
2021-06-03 0:37 ` Shaokun Zhang
0 siblings, 1 reply; 3+ messages in thread
From: Will Deacon @ 2021-06-02 16:42 UTC (permalink / raw)
To: Shaokun Zhang; +Cc: linux-arm-kernel, Mark Rutland, Robin Murphy
On Sat, May 29, 2021 at 02:19:46PM +0800, Shaokun Zhang wrote:
> 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>
> ---
> ChangeLog:
> v1-->v2:
> 1. Address Robin's comment on bus_width calculation.
> 2. Add the comment on calculation formula.
>
> Will & Robin,
>
> I don't change any about visible, if have more comments,
> please let me know.
>
> arch/arm64/include/asm/perf_event.h | 5 +++++
> arch/arm64/kernel/perf_event.c | 35 +++++++++++++++++++++++++++++++++++
> 2 files changed, 40 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 f594957e29bd..453e0d8a442e 100644
> --- a/arch/arm64/kernel/perf_event.c
> +++ b/arch/arm64/kernel/perf_event.c
> @@ -317,8 +317,43 @@ 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 snprintf(page, PAGE_SIZE, "0x%08x\n", bus_slots);
Can you use sysfs_emit() instead?
> +}
> +
> +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;
Just initialise val to 0 here and drop the 'else' below.
> + /* Encoded as Log2(number of bytes), plus one */
> + if (bus_width > 2 && bus_width < 13)
> + val = 1 << (bus_width - 1);
> + else
> + val = 0;
> +
> + return snprintf(page, PAGE_SIZE, "0x%08x\n", val);
Again, sysfs_emit?
Will
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] arm64: perf: Add more support on caps under sysfs
2021-06-02 16:42 ` Will Deacon
@ 2021-06-03 0:37 ` Shaokun Zhang
0 siblings, 0 replies; 3+ messages in thread
From: Shaokun Zhang @ 2021-06-03 0:37 UTC (permalink / raw)
To: Will Deacon; +Cc: linux-arm-kernel, Mark Rutland, Robin Murphy
Hi Will,
On 2021/6/3 0:42, Will Deacon wrote:
> On Sat, May 29, 2021 at 02:19:46PM +0800, Shaokun Zhang wrote:
>> 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>
>> ---
>> ChangeLog:
>> v1-->v2:
>> 1. Address Robin's comment on bus_width calculation.
>> 2. Add the comment on calculation formula.
>>
>> Will & Robin,
>>
>> I don't change any about visible, if have more comments,
>> please let me know.
>>
>> arch/arm64/include/asm/perf_event.h | 5 +++++
>> arch/arm64/kernel/perf_event.c | 35 +++++++++++++++++++++++++++++++++++
>> 2 files changed, 40 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 f594957e29bd..453e0d8a442e 100644
>> --- a/arch/arm64/kernel/perf_event.c
>> +++ b/arch/arm64/kernel/perf_event.c
>> @@ -317,8 +317,43 @@ 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 snprintf(page, PAGE_SIZE, "0x%08x\n", bus_slots);
>
> Can you use sysfs_emit() instead?
>
Ok,
>> +}
>> +
>> +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;
>
> Just initialise val to 0 here and drop the 'else' below.
>
Sure,
>> + /* Encoded as Log2(number of bytes), plus one */
>> + if (bus_width > 2 && bus_width < 13)
>> + val = 1 << (bus_width - 1);
>> + else
>> + val = 0;
>> +
>> + return snprintf(page, PAGE_SIZE, "0x%08x\n", val);
>
> Again, sysfs_emit?
Got it and will fix these in next version.
Thanks,
Shaokun
>
> Will
> .
>
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