@@ -76,6 +76,8 @@ struct arm_pmu {
void (*disable)(struct hw_perf_event *evt, int idx);
int (*get_event_idx)(struct cpu_hw_events *cpuc,
struct hw_perf_event *hwc);
+ int (*set_event_filter)(struct hw_perf_event *evt,
+ struct perf_event_attr *attr);
u32 (*read_counter)(int idx);
void (*write_counter)(int idx, u32 val);
void (*start)(void);
@@ -479,6 +481,13 @@ hw_perf_event_destroy(struct perf_event *event)
}
static int
+event_requires_mode_exclusion(struct perf_event_attr *attr)
+{
+ return attr->exclude_idle || attr->exclude_user ||
+ attr->exclude_kernel || attr->exclude_hv;
+}
+
+static int
__hw_perf_event_init(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
@@ -503,34 +512,31 @@ __hw_perf_event_init(struct perf_event *event)
}
/*
+ * We don't assign an index until we actually place the event onto
+ * hardware. Use -1 to signify that we haven't decided where to put it
+ * yet. For SMP systems, each core has it's own PMU so we can't do any
+ * clever allocation or constraints checking at this point.
+ */
+ hwc->idx = -1;
+ hwc->config_base = 0;
+ hwc->config = 0;
+ hwc->event_base = 0;
+
+ /*
* Check whether we need to exclude the counter from certain modes.
- * The ARM performance counters are on all of the time so if someone
- * has asked us for some excludes then we have to fail.
*/
- if (event->attr.exclude_kernel || event->attr.exclude_user ||
- event->attr.exclude_hv || event->attr.exclude_idle) {
+ if ((!armpmu->set_event_filter ||
+ armpmu->set_event_filter(hwc, &event->attr)) &&
+ event_requires_mode_exclusion(&event->attr)) {
pr_debug("ARM performance counters do not support "
"mode exclusion\n");
return -EPERM;
}
/*
- * We don't assign an index until we actually place the event onto
- * hardware. Use -1 to signify that we haven't decided where to put it
- * yet. For SMP systems, each core has it's own PMU so we can't do any
- * clever allocation or constraints checking at this point.
- */
- hwc->idx = -1;
-
- /*
- * Store the event encoding into the config_base field. config and
- * event_base are unused as the only 2 things we need to know are
- * the event mapping and the counter to use. The counter to use is
- * also the indx and the config_base is the event type.
+ * Store the event encoding into the config_base field.
*/
- hwc->config_base = (unsigned long)mapping;
- hwc->config = 0;
- hwc->event_base = 0;
+ hwc->config_base |= (unsigned long)mapping;
if (!hwc->sample_period) {
hwc->sample_period = armpmu->max_period;
Modern PMUs allow for mode exclusion, so we no longer wish to return -EPERM if it is requested. This patch provides a hook in the armpmu structure for implementing mode exclusion. The hw_perf_event initialisation is slightly delayed so that the backend code can update the structure if required. Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm/kernel/perf_event.c | 44 +++++++++++++++++++++++------------------ 1 files changed, 25 insertions(+), 19 deletions(-)