perf: add struct hw_perf_event

Change-Id: I0938e2b18064ad805a9edb6e15d26cf438bf0a59

lib/include/ihk/cpu.h

@@ -17,6 +17,7 @@
 #include <list.h>
 #include <ihk/context.h>
 #include <arch/cpu.h>
+#include <mc_perf_event.h>
 
 extern int num_processors;
 
@@ -89,6 +90,12 @@ unsigned long ihk_mc_hw_cache_event_map(unsigned long hw_cache_event);
 unsigned long ihk_mc_hw_cache_extra_reg_map(unsigned long hw_cache_event);
 unsigned long ihk_mc_raw_event_map(unsigned long raw_event);
 int ihk_mc_validate_event(unsigned long hw_config);
+int hw_perf_event_init(struct mc_perf_event *event);
+
+static inline int is_sampling_event(struct mc_perf_event *event)
+{
+	return event->attr.sample_period != 0;
+}
 
 /* returns the 'prev' argument of the call that caused the switch to the context returned. */
 void *ihk_mc_switch_context(ihk_mc_kernel_context_t *old_ctx,

lib/include/mc_perf_event.h

@@ -257,6 +257,31 @@ struct hw_perf_event_extra {
 	int idx;
 };
 
+struct hw_perf_event {
+	/*
+	 * The last observed hardware counter value, updated with a
+	 * local64_cmpxchg() such that pmu::read() can be called nested.
+	 */
+	ihk_atomic64_t			prev_count;
+
+	/*
+	 * The period to start the next sample with.
+	 */
+	uint64_t			sample_period;
+
+	/*
+	 * The period we started this sample with.
+	 */
+	uint64_t			last_period;
+
+	/*
+	 * However much is left of the current period; note that this is
+	 * a full 64bit value and allows for generation of periods longer
+	 * than hardware might allow.
+	 */
+	ihk_atomic64_t			period_left;
+};
+
 /**
  * enum perf_event_state - the states of an event:
  */
@@ -291,6 +316,7 @@ struct mc_perf_event {
 	long long			base_system_tsc;
 	long long			stopped_system_tsc;
 	long long			system_accum_count;
+	struct hw_perf_event		hw;
 };
 
 struct perf_event_mmap_page {