pmu: add ihk_mc_perfctr_value function

Change-Id: I88d25586dd470737a3eac4c3a4f1955ae6e41d64

arch/arm64/kernel/perfctr.c

@@ -198,6 +198,14 @@ unsigned long ihk_mc_perfctr_read(int counter)
 	return count;
 }
 
+unsigned long ihk_mc_perfctr_value(int counter, unsigned long correction)
+{
+	unsigned long count = ihk_mc_perfctr_read(counter) + correction;
+
+	count &= ((1UL << 32) - 1);
+	return count;
+}
+
 int ihk_mc_perfctr_alloc_counter(unsigned int *type, unsigned long *config,
 				 unsigned long pmc_status)
 {

arch/x86_64/kernel/perfctr.c

@@ -421,6 +421,14 @@ unsigned long ihk_mc_perfctr_read(int counter)
 	return retval;
 }
 
+unsigned long ihk_mc_perfctr_value(int counter, unsigned long correction)
+{
+	unsigned long count = ihk_mc_perfctr_read(counter) + correction;
+
+	count &= 0x000000ffffffffffL;
+	return count;
+}
+
 // read by rdmsr
 unsigned long ihk_mc_perfctr_read_msr(int counter)
 {

kernel/syscall.c

@@ -3723,8 +3723,8 @@ unsigned long perf_event_read_value(struct mc_perf_event *event)
 	int counter_id = event->counter_id;
 
 	if(event->pid == 0) {
-		pmc_count = ihk_mc_perfctr_read(counter_id) + event->attr.sample_freq;
-		pmc_count &= 0x000000ffffffffffL; // 40bit MASK
+		pmc_count = ihk_mc_perfctr_value(counter_id,
+						 event->attr.sample_freq);
 	}
 
 	rtn_count += event->count + pmc_count;

lib/include/ihk/perfctr.h

@@ -70,6 +70,7 @@ int ihk_mc_perfctr_reset(int counter);
 int ihk_mc_perfctr_set(int counter, long value);
 int ihk_mc_perfctr_read_mask(unsigned long counter_mask, unsigned long *value);
 unsigned long ihk_mc_perfctr_read(int counter);
+unsigned long ihk_mc_perfctr_value(int counter, unsigned long correction);
 unsigned long ihk_mc_perfctr_read_msr(int counter);
 int ihk_mc_perfctr_alloc_counter(unsigned int *type, unsigned long *config, unsigned long pmc_status);
 int ihk_mc_perfctr_alloc(struct thread *thread, struct mc_perf_event *event);