1 files changed, 121 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 4a3374e61a93..4428fd178bce 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1316,6 +1316,121 @@ static struct attribute_group x86_pmu_format_group = {
         .attrs = NULL,
 };
 
+struct perf_pmu_events_attr {
+        struct device_attribute attr;
+        u64 id;
+};
+
+/*
+ * Remove all undefined events (x86_pmu.event_map(id) == 0)
+ * out of events_attr attributes.
+ */
+static void __init filter_events(struct attribute **attrs)
+{
+        int i, j;
+
+        for (i = 0; attrs[i]; i++) {
+                if (x86_pmu.event_map(i))
+                        continue;
+
+                for (j = i; attrs[j]; j++)
+                        attrs[j] = attrs[j + 1];
+
+                /* Check the shifted attr. */
+                i--;
+        }
+}
+
+static ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr,
+                          char *page)
+{
+        struct perf_pmu_events_attr *pmu_attr = \
+                container_of(attr, struct perf_pmu_events_attr, attr);
+
+        u64 config = x86_pmu.event_map(pmu_attr->id);
+        return x86_pmu.events_sysfs_show(page, config);
+}
+
+#define EVENT_VAR(_id)  event_attr_##_id
+#define EVENT_PTR(_id) &event_attr_##_id.attr.attr
+
+#define EVENT_ATTR(_name, _id)                                  \
+static struct perf_pmu_events_attr EVENT_VAR(_id) = {           \
+        .attr = __ATTR(_name, 0444, events_sysfs_show, NULL),   \
+        .id   =  PERF_COUNT_HW_##_id,                           \
+};
+
+EVENT_ATTR(cpu-cycles,                  CPU_CYCLES              );
+EVENT_ATTR(instructions,                INSTRUCTIONS            );
+EVENT_ATTR(cache-references,            CACHE_REFERENCES        );
+EVENT_ATTR(cache-misses,                CACHE_MISSES            );
+EVENT_ATTR(branch-instructions,         BRANCH_INSTRUCTIONS     );
+EVENT_ATTR(branch-misses,               BRANCH_MISSES           );
+EVENT_ATTR(bus-cycles,                  BUS_CYCLES              );
+EVENT_ATTR(stalled-cycles-frontend,     STALLED_CYCLES_FRONTEND );
+EVENT_ATTR(stalled-cycles-backend,      STALLED_CYCLES_BACKEND  );
+EVENT_ATTR(ref-cycles,                  REF_CPU_CYCLES          );
+
+static struct attribute *empty_attrs;
+
+static struct attribute *events_attr[] = {
+        EVENT_PTR(CPU_CYCLES),
+        EVENT_PTR(INSTRUCTIONS),
+        EVENT_PTR(CACHE_REFERENCES),
+        EVENT_PTR(CACHE_MISSES),
+        EVENT_PTR(BRANCH_INSTRUCTIONS),
+        EVENT_PTR(BRANCH_MISSES),
+        EVENT_PTR(BUS_CYCLES),
+        EVENT_PTR(STALLED_CYCLES_FRONTEND),
+        EVENT_PTR(STALLED_CYCLES_BACKEND),
+        EVENT_PTR(REF_CPU_CYCLES),
+        NULL,
+};
+
+static struct attribute_group x86_pmu_events_group = {
+        .name = "events",
+        .attrs = events_attr,
+};
+
+ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event)
+{
+        u64 umask  = (config & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
+        u64 cmask  = (config & ARCH_PERFMON_EVENTSEL_CMASK) >> 24;
+        bool edge  = (config & ARCH_PERFMON_EVENTSEL_EDGE);
+        bool pc    = (config & ARCH_PERFMON_EVENTSEL_PIN_CONTROL);
+        bool any   = (config & ARCH_PERFMON_EVENTSEL_ANY);
+        bool inv   = (config & ARCH_PERFMON_EVENTSEL_INV);
+        ssize_t ret;
+
+        /*
+        * We have whole page size to spend and just little data
+        * to write, so we can safely use sprintf.
+        */
+        ret = sprintf(page, "event=0x%02llx", event);
+
+        if (umask)
+                ret += sprintf(page + ret, ",umask=0x%02llx", umask);
+
+        if (edge)
+                ret += sprintf(page + ret, ",edge");
+
+        if (pc)
+                ret += sprintf(page + ret, ",pc");
+
+        if (any)
+                ret += sprintf(page + ret, ",any");
+
+        if (inv)
+                ret += sprintf(page + ret, ",inv");
+
+        if (cmask)
+                ret += sprintf(page + ret, ",cmask=0x%02llx", cmask);
+
+        ret += sprintf(page + ret, "\n");
+
+        return ret;
+}
+
 static int __init init_hw_perf_events(void)
 {
         struct x86_pmu_quirk *quirk;
@@ -1362,6 +1477,11 @@ 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;
 
+        if (!x86_pmu.events_sysfs_show)
+                x86_pmu_events_group.attrs = &empty_attrs;
+        else
+                filter_events(x86_pmu_events_group.attrs);
+
         pr_info("... version:                %d\n",     x86_pmu.version);
         pr_info("... bit width:              %d\n",     x86_pmu.cntval_bits);
         pr_info("... generic registers:      %d\n",     x86_pmu.num_counters);
@@ -1651,6 +1771,7 @@ 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,
+        &x86_pmu_events_group,
         NULL,
 };