[PATCH 02/13] perf: Adding sysfs group format attribute for pmu device

From: Arnaldo Carvalho de Melo
Date: Fri Mar 16 2012 - 16:03:24 EST


From: Jiri Olsa <jolsa@xxxxxxxxxx>

Adding sysfs group 'format' attribute for pmu device that
contains a syntax description on how to construct raw events.

The event configuration is described in following
struct pefr_event_attr attributes:

config
config1
config2

Each sysfs attribute within the format attribute group,
describes mapping of name and bitfield definition within
one of above attributes.

eg:
"/sys/...<dev>/format/event" contains "config:0-7"
"/sys/...<dev>/format/umask" contains "config:8-15"
"/sys/...<dev>/format/usr" contains "config:16"

the attribute value syntax is:

line: config ':' bits
config: 'config' | 'config1' | 'config2"
bits: bits ',' bit_term | bit_term
bit_term: VALUE '-' VALUE | VALUE

Adding format attribute definitions for x86 cpu pmus.

Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-vhdk5y2hyype9j63prymty36@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
.../testing/sysfs-bus-event_source-devices-format | 14 ++++++++
arch/x86/kernel/cpu/perf_event.c | 7 ++++
arch/x86/kernel/cpu/perf_event.h | 1 +
arch/x86/kernel/cpu/perf_event_amd.c | 18 ++++++++++
arch/x86/kernel/cpu/perf_event_intel.c | 36 ++++++++++++++++++++
arch/x86/kernel/cpu/perf_event_p6.c | 19 +++++++++++
include/linux/perf_event.h | 14 ++++++++
7 files changed, 109 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-event_source-devices-format

diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-format b/Documentation/ABI/testing/sysfs-bus-event_source-devices-format
new file mode 100644
index 0000000..079afc7
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-format
@@ -0,0 +1,14 @@
+Where: /sys/bus/event_source/devices/<dev>/format
+Date: January 2012
+Kernel Version: 3.3
+Contact: Jiri Olsa <jolsa@xxxxxxxxxx>
+Description:
+ Attribute group to describe the magic bits that go into
+ perf_event_attr::config[012] for a particular pmu.
+ Each attribute of this group defines the 'hardware' bitmask
+ we want to export, so that userspace can deal with sane
+ name/value pairs.
+
+ Example: 'config1:1,6-10,44'
+ Defines contents of attribute that occupies bits 1,6-10,44 of
+ perf_event_attr::config1.
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 0a18d16..453ac94 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1314,6 +1314,11 @@ static void __init pmu_check_apic(void)
pr_info("no hardware sampling interrupt available.\n");
}

+static struct attribute_group x86_pmu_format_group = {
+ .name = "format",
+ .attrs = NULL,
+};
+
static int __init init_hw_perf_events(void)
{
struct x86_pmu_quirk *quirk;
@@ -1388,6 +1393,7 @@ static int __init init_hw_perf_events(void)
}

x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */
+ x86_pmu_format_group.attrs = x86_pmu.format_attrs;

pr_info("... version: %d\n", x86_pmu.version);
pr_info("... bit width: %d\n", x86_pmu.cntval_bits);
@@ -1668,6 +1674,7 @@ static struct attribute_group x86_pmu_attr_group = {

static const struct attribute_group *x86_pmu_attr_groups[] = {
&x86_pmu_attr_group,
+ &x86_pmu_format_group,
NULL,
};

diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 8484e77..6638aaf 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -339,6 +339,7 @@ struct x86_pmu {
* sysfs attrs
*/
int attr_rdpmc;
+ struct attribute **format_attrs;

/*
* CPU Hotplug hooks
diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index dd002fa..95e7fe1 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -404,6 +404,21 @@ static void amd_pmu_cpu_dead(int cpu)
}
}

+PMU_FORMAT_ATTR(event, "config:0-7,32-35");
+PMU_FORMAT_ATTR(umask, "config:8-15" );
+PMU_FORMAT_ATTR(edge, "config:18" );
+PMU_FORMAT_ATTR(inv, "config:23" );
+PMU_FORMAT_ATTR(cmask, "config:24-31" );
+
+static struct attribute *amd_format_attr[] = {
+ &format_attr_event.attr,
+ &format_attr_umask.attr,
+ &format_attr_edge.attr,
+ &format_attr_inv.attr,
+ &format_attr_cmask.attr,
+ NULL,
+};
+
static __initconst const struct x86_pmu amd_pmu = {
.name = "AMD",
.handle_irq = x86_pmu_handle_irq,
@@ -426,6 +441,8 @@ static __initconst const struct x86_pmu amd_pmu = {
.get_event_constraints = amd_get_event_constraints,
.put_event_constraints = amd_put_event_constraints,

+ .format_attrs = amd_format_attr,
+
.cpu_prepare = amd_pmu_cpu_prepare,
.cpu_starting = amd_pmu_cpu_starting,
.cpu_dead = amd_pmu_cpu_dead,
@@ -596,6 +613,7 @@ static __initconst const struct x86_pmu amd_pmu_f15h = {
.cpu_dead = amd_pmu_cpu_dead,
#endif
.cpu_starting = amd_pmu_cpu_starting,
+ .format_attrs = amd_format_attr,
};

__init int amd_pmu_init(void)
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 6a84e7f..26b3e2f 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1431,6 +1431,24 @@ static void core_pmu_enable_all(int added)
}
}

+PMU_FORMAT_ATTR(event, "config:0-7" );
+PMU_FORMAT_ATTR(umask, "config:8-15" );
+PMU_FORMAT_ATTR(edge, "config:18" );
+PMU_FORMAT_ATTR(pc, "config:19" );
+PMU_FORMAT_ATTR(any, "config:21" ); /* v3 + */
+PMU_FORMAT_ATTR(inv, "config:23" );
+PMU_FORMAT_ATTR(cmask, "config:24-31" );
+
+static struct attribute *intel_arch_formats_attr[] = {
+ &format_attr_event.attr,
+ &format_attr_umask.attr,
+ &format_attr_edge.attr,
+ &format_attr_pc.attr,
+ &format_attr_inv.attr,
+ &format_attr_cmask.attr,
+ NULL,
+};
+
static __initconst const struct x86_pmu core_pmu = {
.name = "core",
.handle_irq = x86_pmu_handle_irq,
@@ -1455,6 +1473,7 @@ static __initconst const struct x86_pmu core_pmu = {
.put_event_constraints = intel_put_event_constraints,
.event_constraints = intel_core_event_constraints,
.guest_get_msrs = core_guest_get_msrs,
+ .format_attrs = intel_arch_formats_attr,
};

struct intel_shared_regs *allocate_shared_regs(int cpu)
@@ -1553,6 +1572,21 @@ static void intel_pmu_flush_branch_stack(void)
intel_pmu_lbr_reset();
}

+PMU_FORMAT_ATTR(offcore_rsp, "config1:0-63");
+
+static struct attribute *intel_arch3_formats_attr[] = {
+ &format_attr_event.attr,
+ &format_attr_umask.attr,
+ &format_attr_edge.attr,
+ &format_attr_pc.attr,
+ &format_attr_any.attr,
+ &format_attr_inv.attr,
+ &format_attr_cmask.attr,
+
+ &format_attr_offcore_rsp.attr, /* XXX do NHM/WSM + SNB breakout */
+ NULL,
+};
+
static __initconst const struct x86_pmu intel_pmu = {
.name = "Intel",
.handle_irq = intel_pmu_handle_irq,
@@ -1576,6 +1610,8 @@ static __initconst const struct x86_pmu intel_pmu = {
.get_event_constraints = intel_get_event_constraints,
.put_event_constraints = intel_put_event_constraints,

+ .format_attrs = intel_arch3_formats_attr,
+
.cpu_prepare = intel_pmu_cpu_prepare,
.cpu_starting = intel_pmu_cpu_starting,
.cpu_dying = intel_pmu_cpu_dying,
diff --git a/arch/x86/kernel/cpu/perf_event_p6.c b/arch/x86/kernel/cpu/perf_event_p6.c
index c7181be..32bcfc7 100644
--- a/arch/x86/kernel/cpu/perf_event_p6.c
+++ b/arch/x86/kernel/cpu/perf_event_p6.c
@@ -87,6 +87,23 @@ static void p6_pmu_enable_event(struct perf_event *event)
(void)checking_wrmsrl(hwc->config_base, val);
}

+PMU_FORMAT_ATTR(event, "config:0-7" );
+PMU_FORMAT_ATTR(umask, "config:8-15" );
+PMU_FORMAT_ATTR(edge, "config:18" );
+PMU_FORMAT_ATTR(pc, "config:19" );
+PMU_FORMAT_ATTR(inv, "config:23" );
+PMU_FORMAT_ATTR(cmask, "config:24-31" );
+
+static struct attribute *intel_p6_formats_attr[] = {
+ &format_attr_event.attr,
+ &format_attr_umask.attr,
+ &format_attr_edge.attr,
+ &format_attr_pc.attr,
+ &format_attr_inv.attr,
+ &format_attr_cmask.attr,
+ NULL,
+};
+
static __initconst const struct x86_pmu p6_pmu = {
.name = "p6",
.handle_irq = x86_pmu_handle_irq,
@@ -115,6 +132,8 @@ static __initconst const struct x86_pmu p6_pmu = {
.cntval_mask = (1ULL << 32) - 1,
.get_event_constraints = x86_get_event_constraints,
.event_constraints = p6_event_constraints,
+
+ .format_attrs = intel_p6_formats_attr,
};

__init int p6_pmu_init(void)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index bd9f55a..57ae485 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -550,6 +550,7 @@ struct perf_guest_info_callbacks {
#include <linux/irq_work.h>
#include <linux/static_key.h>
#include <linux/atomic.h>
+#include <linux/sysfs.h>
#include <asm/local.h>

#define PERF_MAX_STACK_DEPTH 255
@@ -1291,5 +1292,18 @@ do { \
register_cpu_notifier(&fn##_nb); \
} while (0)

+
+#define PMU_FORMAT_ATTR(_name, _format) \
+static ssize_t \
+_name##_show(struct device *dev, \
+ struct device_attribute *attr, \
+ char *page) \
+{ \
+ BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE); \
+ return sprintf(page, _format "\n"); \
+} \
+ \
+static struct device_attribute format_attr_##_name = __ATTR_RO(_name)
+
#endif /* __KERNEL__ */
#endif /* _LINUX_PERF_EVENT_H */
--
1.7.9.2.358.g22243

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