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Diffstat (limited to 'arch/x86/kernel/cpu/perf_event.c')
-rw-r--r--arch/x86/kernel/cpu/perf_event.c167
1 files changed, 160 insertions, 7 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 5adce1040b11..0a18d16cb58d 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -24,6 +24,7 @@
#include <linux/slab.h>
#include <linux/cpu.h>
#include <linux/bitops.h>
+#include <linux/device.h>
#include <asm/apic.h>
#include <asm/stacktrace.h>
@@ -31,6 +32,7 @@
#include <asm/compat.h>
#include <asm/smp.h>
#include <asm/alternative.h>
+#include <asm/timer.h>
#include "perf_event.h"
@@ -351,6 +353,36 @@ int x86_setup_perfctr(struct perf_event *event)
return 0;
}
+/*
+ * check that branch_sample_type is compatible with
+ * settings needed for precise_ip > 1 which implies
+ * using the LBR to capture ALL taken branches at the
+ * priv levels of the measurement
+ */
+static inline int precise_br_compat(struct perf_event *event)
+{
+ u64 m = event->attr.branch_sample_type;
+ u64 b = 0;
+
+ /* must capture all branches */
+ if (!(m & PERF_SAMPLE_BRANCH_ANY))
+ return 0;
+
+ m &= PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_USER;
+
+ if (!event->attr.exclude_user)
+ b |= PERF_SAMPLE_BRANCH_USER;
+
+ if (!event->attr.exclude_kernel)
+ b |= PERF_SAMPLE_BRANCH_KERNEL;
+
+ /*
+ * ignore PERF_SAMPLE_BRANCH_HV, not supported on x86
+ */
+
+ return m == b;
+}
+
int x86_pmu_hw_config(struct perf_event *event)
{
if (event->attr.precise_ip) {
@@ -367,6 +399,36 @@ int x86_pmu_hw_config(struct perf_event *event)
if (event->attr.precise_ip > precise)
return -EOPNOTSUPP;
+ /*
+ * check that PEBS LBR correction does not conflict with
+ * whatever the user is asking with attr->branch_sample_type
+ */
+ if (event->attr.precise_ip > 1) {
+ u64 *br_type = &event->attr.branch_sample_type;
+
+ if (has_branch_stack(event)) {
+ if (!precise_br_compat(event))
+ return -EOPNOTSUPP;
+
+ /* branch_sample_type is compatible */
+
+ } else {
+ /*
+ * user did not specify branch_sample_type
+ *
+ * For PEBS fixups, we capture all
+ * the branches at the priv level of the
+ * event.
+ */
+ *br_type = PERF_SAMPLE_BRANCH_ANY;
+
+ if (!event->attr.exclude_user)
+ *br_type |= PERF_SAMPLE_BRANCH_USER;
+
+ if (!event->attr.exclude_kernel)
+ *br_type |= PERF_SAMPLE_BRANCH_KERNEL;
+ }
+ }
}
/*
@@ -424,6 +486,10 @@ static int __x86_pmu_event_init(struct perf_event *event)
/* mark unused */
event->hw.extra_reg.idx = EXTRA_REG_NONE;
+ /* mark not used */
+ event->hw.extra_reg.idx = EXTRA_REG_NONE;
+ event->hw.branch_reg.idx = EXTRA_REG_NONE;
+
return x86_pmu.hw_config(event);
}
@@ -1210,6 +1276,8 @@ x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
break;
case CPU_STARTING:
+ if (x86_pmu.attr_rdpmc)
+ set_in_cr4(X86_CR4_PCE);
if (x86_pmu.cpu_starting)
x86_pmu.cpu_starting(cpu);
break;
@@ -1319,6 +1387,8 @@ static int __init init_hw_perf_events(void)
}
}
+ x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */
+
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);
@@ -1542,23 +1612,106 @@ static int x86_pmu_event_init(struct perf_event *event)
return err;
}
+static int x86_pmu_event_idx(struct perf_event *event)
+{
+ int idx = event->hw.idx;
+
+ if (x86_pmu.num_counters_fixed && idx >= X86_PMC_IDX_FIXED) {
+ idx -= X86_PMC_IDX_FIXED;
+ idx |= 1 << 30;
+ }
+
+ return idx + 1;
+}
+
+static ssize_t get_attr_rdpmc(struct device *cdev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return snprintf(buf, 40, "%d\n", x86_pmu.attr_rdpmc);
+}
+
+static void change_rdpmc(void *info)
+{
+ bool enable = !!(unsigned long)info;
+
+ if (enable)
+ set_in_cr4(X86_CR4_PCE);
+ else
+ clear_in_cr4(X86_CR4_PCE);
+}
+
+static ssize_t set_attr_rdpmc(struct device *cdev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned long val = simple_strtoul(buf, NULL, 0);
+
+ if (!!val != !!x86_pmu.attr_rdpmc) {
+ x86_pmu.attr_rdpmc = !!val;
+ smp_call_function(change_rdpmc, (void *)val, 1);
+ }
+
+ return count;
+}
+
+static DEVICE_ATTR(rdpmc, S_IRUSR | S_IWUSR, get_attr_rdpmc, set_attr_rdpmc);
+
+static struct attribute *x86_pmu_attrs[] = {
+ &dev_attr_rdpmc.attr,
+ NULL,
+};
+
+static struct attribute_group x86_pmu_attr_group = {
+ .attrs = x86_pmu_attrs,
+};
+
+static const struct attribute_group *x86_pmu_attr_groups[] = {
+ &x86_pmu_attr_group,
+ NULL,
+};
+
+static void x86_pmu_flush_branch_stack(void)
+{
+ if (x86_pmu.flush_branch_stack)
+ x86_pmu.flush_branch_stack();
+}
+
static struct pmu pmu = {
- .pmu_enable = x86_pmu_enable,
- .pmu_disable = x86_pmu_disable,
+ .pmu_enable = x86_pmu_enable,
+ .pmu_disable = x86_pmu_disable,
+
+ .attr_groups = x86_pmu_attr_groups,
.event_init = x86_pmu_event_init,
- .add = x86_pmu_add,
- .del = x86_pmu_del,
- .start = x86_pmu_start,
- .stop = x86_pmu_stop,
- .read = x86_pmu_read,
+ .add = x86_pmu_add,
+ .del = x86_pmu_del,
+ .start = x86_pmu_start,
+ .stop = x86_pmu_stop,
+ .read = x86_pmu_read,
.start_txn = x86_pmu_start_txn,
.cancel_txn = x86_pmu_cancel_txn,
.commit_txn = x86_pmu_commit_txn,
+
+ .event_idx = x86_pmu_event_idx,
+ .flush_branch_stack = x86_pmu_flush_branch_stack,
};
+void perf_update_user_clock(struct perf_event_mmap_page *userpg, u64 now)
+{
+ if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
+ return;
+
+ if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
+ return;
+
+ userpg->time_mult = this_cpu_read(cyc2ns);
+ userpg->time_shift = CYC2NS_SCALE_FACTOR;
+ userpg->time_offset = this_cpu_read(cyc2ns_offset) - now;
+}
+
/*
* callchain support
*/