selftests: Add test of PMU instruction counting on powerpc

This commit adds a test of instruction counting using the PMU on powerpc.

Although the bulk of the code is architecture agnostic, the code needs to
run a precisely sized loop which is implemented in assembler.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 105 insertions, 0 deletions

diff --git a/tools/testing/selftests/powerpc/pmu/event.c b/tools/testing/selftests/powerpc/pmu/event.c
new file mode 100644
index 000000000000..2b2d11df2450
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/event.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#define _GNU_SOURCE
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <string.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+
+#include "event.h"
+
+
+int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
+		int group_fd, unsigned long flags)
+{
+	return syscall(__NR_perf_event_open, attr, pid, cpu,
+			   group_fd, flags);
+}
+
+void event_init_opts(struct event *e, u64 config, int type, char *name)
+{
+	memset(e, 0, sizeof(*e));
+
+	e->name = name;
+
+	e->attr.type = type;
+	e->attr.config = config;
+	e->attr.size = sizeof(e->attr);
+	/* This has to match the structure layout in the header */
+	e->attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | \
+				  PERF_FORMAT_TOTAL_TIME_RUNNING;
+}
+
+void event_init_named(struct event *e, u64 config, char *name)
+{
+	event_init_opts(e, config, PERF_TYPE_RAW, name);
+}
+
+#define PERF_CURRENT_PID	0
+#define PERF_NO_CPU		-1
+#define PERF_NO_GROUP		-1
+
+int event_open_with_options(struct event *e, pid_t pid, int cpu, int group_fd)
+{
+	e->fd = perf_event_open(&e->attr, pid, cpu, group_fd, 0);
+	if (e->fd == -1) {
+		perror("perf_event_open");
+		return -1;
+	}
+
+	return 0;
+}
+
+int event_open_with_group(struct event *e, int group_fd)
+{
+	return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, group_fd);
+}
+
+int event_open(struct event *e)
+{
+	return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, PERF_NO_GROUP);
+}
+
+void event_close(struct event *e)
+{
+	close(e->fd);
+}
+
+int event_reset(struct event *e)
+{
+	return ioctl(e->fd, PERF_EVENT_IOC_RESET);
+}
+
+int event_read(struct event *e)
+{
+	int rc;
+
+	rc = read(e->fd, &e->result, sizeof(e->result));
+	if (rc != sizeof(e->result)) {
+		fprintf(stderr, "read error on event %p!\n", e);
+		return -1;
+	}
+
+	return 0;
+}
+
+void event_report_justified(struct event *e, int name_width, int result_width)
+{
+	printf("%*s: result %*llu ", name_width, e->name, result_width,
+	       e->result.value);
+
+	if (e->result.running == e->result.enabled)
+		printf("running/enabled %llu\n", e->result.running);
+	else
+		printf("running %llu enabled %llu\n", e->result.running,
+			e->result.enabled);
+}
+
+void event_report(struct event *e)
+{
+	event_report_justified(e, 0, 0);
+}