From: Shaokun Zhang <zhangshaokun@hisilicon.com>
To: <linux-arm-kernel@lists.infradead.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>
Subject: [PATCH] arm64: perf: Add more support on caps under sysfs
Date: Fri, 21 May 2021 15:25:44 +0800 [thread overview]
Message-ID: <1621581944-17381-1-git-send-email-zhangshaokun@hisilicon.com> (raw)
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>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
---
arch/arm64/include/asm/perf_event.h | 5 +++
arch/arm64/kernel/perf_event.c | 64 +++++++++++++++++++++++++++++++++++++
2 files changed, 69 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..f0847e4f48a9 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -317,8 +317,72 @@ 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;
+
+ switch (bus_width) {
+ case 3:
+ val = 4;
+ break;
+ case 4:
+ val = 8;
+ break;
+ case 5:
+ val = 16;
+ break;
+ case 6:
+ val = 32;
+ break;
+ case 7:
+ val = 64;
+ break;
+ case 8:
+ val = 128;
+ break;
+ case 9:
+ val = 256;
+ break;
+ case 10:
+ val = 512;
+ break;
+ case 11:
+ val = 1024;
+ break;
+ case 12:
+ val = 2048;
+ break;
+ default:
+ 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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next reply other threads:[~2021-05-21 7:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-21 7:25 Shaokun Zhang [this message]
2021-05-24 17:18 ` [PATCH] arm64: perf: Add more support on caps under sysfs Robin Murphy
2021-05-25 2:13 ` Shaokun Zhang
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