perf: Adding sysfs group format attribute for pmu device

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@infradead.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-vhdk5y2hyype9j63prymty36@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

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 (file)
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@redhat.com>
+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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 */