selftests/powerpc/pmu: Add event_init_sampling function

Extended event_init_opts() to include initialization of sampling
testcases. Patch adds an event_init_sampling() wrapper to initialize
event attribute fields for sampling events. This includes initializing
sample period, sample type and event type.
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-6-kjain@linux.ibm.com

tools/testing/selftests/powerpc/pmu/event.c

@@ -8,6 +8,7 @@
 #include <sys/syscall.h>
 #include <string.h>
 #include <stdio.h>
+#include <stdbool.h>
 #include <sys/ioctl.h>
 
 #include "event.h"
@@ -20,7 +21,8 @@ int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
 			   group_fd, flags);
 }
 
-void event_init_opts(struct event *e, u64 config, int type, char *name)
+static void  __event_init_opts(struct event *e, u64 config,
+			       int type, char *name, bool sampling)
 {
 	memset(e, 0, sizeof(*e));
 
@@ -32,6 +34,16 @@ void event_init_opts(struct event *e, u64 config, int type, char *name)
 	/* This has to match the structure layout in the header */
 	e->attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | \
 				  PERF_FORMAT_TOTAL_TIME_RUNNING;
+	if (sampling) {
+		e->attr.sample_period = 1000;
+		e->attr.sample_type = PERF_SAMPLE_REGS_INTR;
+		e->attr.disabled = 1;
+	}
+}
+
+void event_init_opts(struct event *e, u64 config, int type, char *name)
+{
+	__event_init_opts(e, config, type, name, false);
 }
 
 void event_init_named(struct event *e, u64 config, char *name)
@@ -44,6 +56,11 @@ void event_init(struct event *e, u64 config)
 	event_init_opts(e, config, PERF_TYPE_RAW, "event");
 }
 
+void event_init_sampling(struct event *e, u64 config)
+{
+	__event_init_opts(e, config, PERF_TYPE_RAW, "event", true);
+}
+
 #define PERF_CURRENT_PID	0
 #define PERF_NO_PID		-1
 #define PERF_NO_CPU		-1

tools/testing/selftests/powerpc/pmu/event.h

@@ -32,6 +32,7 @@ struct event {
 void event_init(struct event *e, u64 config);
 void event_init_named(struct event *e, u64 config, char *name);
 void event_init_opts(struct event *e, u64 config, int type, char *name);
+void event_init_sampling(struct event *e, u64 config);
 int event_open_with_options(struct event *e, pid_t pid, int cpu, int group_fd);
 int event_open_with_group(struct event *e, int group_fd);
 int event_open_with_pid(struct event *e, pid_t pid);