[PATCH v3 1/3] selftests: Add infrastructure for powerpc selftests

[PATCH v3 1/3] selftests: Add infrastructure for powerpc selftests

[Michael Ellerman]

This commit adds a powerpc subdirectory to tools/testing/selftests,
for tests that are powerpc specific.

On other architectures nothing is built. The makefile supports cross
compilation if the user sets ARCH and CROSS_COMPILE.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
v3: Add tags
v2: No change

 tools/testing/selftests/Makefile         |  1 +
 tools/testing/selftests/powerpc/Makefile | 39 ++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100644 tools/testing/selftests/powerpc/Makefile

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 4cb14ca..9f3eae2 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -8,6 +8,7 @@ TARGETS += net
 TARGETS += ptrace
 TARGETS += timers
 TARGETS += vm
+TARGETS += powerpc
 
 all:
 	for TARGET in $(TARGETS); do \
diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile
new file mode 100644
index 0000000..b315740
--- /dev/null
+++ b/tools/testing/selftests/powerpc/Makefile
@@ -0,0 +1,39 @@
+# Makefile for powerpc selftests
+
+# ARCH can be overridden by the user for cross compiling
+ARCH ?= $(shell uname -m)
+ARCH := $(shell echo $(ARCH) | sed -e s/ppc.*/powerpc/)
+
+ifeq ($(ARCH),powerpc)
+
+GIT_VERSION = $(shell git describe --always --long --dirty || echo "unknown")
+
+CC := $(CROSS_COMPILE)$(CC)
+CFLAGS := -Wall -O2 -flto -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CURDIR) $(CFLAGS)
+
+export CC CFLAGS
+
+TARGETS =
+
+endif
+
+all:
+	@for TARGET in $(TARGETS); do \
+		$(MAKE) -C $$TARGET all; \
+	done;
+
+run_tests: all
+	@for TARGET in $(TARGETS); do \
+		$(MAKE) -C $$TARGET run_tests; \
+	done;
+
+clean:
+	@for TARGET in $(TARGETS); do \
+		$(MAKE) -C $$TARGET clean; \
+	done;
+	rm -f tags
+
+tags:
+	find . -name '*.c' -o -name '*.h' | xargs ctags
+
+.PHONY: all run_tests clean tags
-- 
1.8.1.2

[PATCH v3 2/3] selftests: Add support files for powerpc tests

[Michael Ellerman]

This commit adds support code used by upcoming powerpc tests.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
v3: Print when the child dies due to a signal
v2: Put back the SIGALARM handler to make the hang logic work.

 tools/testing/selftests/powerpc/harness.c | 105 ++++++++++++++++++++++++++++++
 tools/testing/selftests/powerpc/subunit.h |  47 +++++++++++++
 tools/testing/selftests/powerpc/utils.h   |  34 ++++++++++
 3 files changed, 186 insertions(+)
 create mode 100644 tools/testing/selftests/powerpc/harness.c
 create mode 100644 tools/testing/selftests/powerpc/subunit.h
 create mode 100644 tools/testing/selftests/powerpc/utils.h

diff --git a/tools/testing/selftests/powerpc/harness.c b/tools/testing/selftests/powerpc/harness.c
new file mode 100644
index 0000000..e80c42a
--- /dev/null
+++ b/tools/testing/selftests/powerpc/harness.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "subunit.h"
+#include "utils.h"
+
+#define TIMEOUT		120
+#define KILL_TIMEOUT	5
+
+
+int run_test(int (test_function)(void), char *name)
+{
+	bool terminated;
+	int rc, status;
+	pid_t pid;
+
+	/* Make sure output is flushed before forking */
+	fflush(stdout);
+
+	pid = fork();
+	if (pid == 0) {
+		exit(test_function());
+	} else if (pid == -1) {
+		perror("fork");
+		return 1;
+	}
+
+	/* Wake us up in timeout seconds */
+	alarm(TIMEOUT);
+	terminated = false;
+
+wait:
+	rc = waitpid(pid, &status, 0);
+	if (rc == -1) {
+		if (errno != EINTR) {
+			printf("unknown error from waitpid\n");
+			return 1;
+		}
+
+		if (terminated) {
+			printf("!! force killing %s\n", name);
+			kill(pid, SIGKILL);
+			return 1;
+		} else {
+			printf("!! killing %s\n", name);
+			kill(pid, SIGTERM);
+			terminated = true;
+			alarm(KILL_TIMEOUT);
+			goto wait;
+		}
+	}
+
+	if (WIFEXITED(status))
+		status = WEXITSTATUS(status);
+	else {
+		if (WIFSIGNALED(status))
+			printf("!! child died by signal %d\n", WTERMSIG(status));
+		else
+			printf("!! child died by unknown cause\n");
+
+		status = 1; /* Signal or other */
+	}
+
+	return status;
+}
+
+static void alarm_handler(int signum)
+{
+	/* Jut wake us up from waitpid */
+}
+
+static struct sigaction alarm_action = {
+	.sa_handler = alarm_handler,
+};
+
+int test_harness(int (test_function)(void), char *name)
+{
+	int rc;
+
+	test_start(name);
+	test_set_git_version(GIT_VERSION);
+
+	if (sigaction(SIGALRM, &alarm_action, NULL)) {
+		perror("sigaction");
+		test_error(name);
+		return 1;
+	}
+
+	rc = run_test(test_function, name);
+
+	test_finish(name, rc);
+
+	return rc;
+}
diff --git a/tools/testing/selftests/powerpc/subunit.h b/tools/testing/selftests/powerpc/subunit.h
new file mode 100644
index 0000000..98a2292
--- /dev/null
+++ b/tools/testing/selftests/powerpc/subunit.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#ifndef _SELFTESTS_POWERPC_SUBUNIT_H
+#define _SELFTESTS_POWERPC_SUBUNIT_H
+
+static inline void test_start(char *name)
+{
+	printf("test: %s\n", name);
+}
+
+static inline void test_failure_detail(char *name, char *detail)
+{
+	printf("failure: %s [%s]\n", name, detail);
+}
+
+static inline void test_failure(char *name)
+{
+	printf("failure: %s\n", name);
+}
+
+static inline void test_error(char *name)
+{
+	printf("error: %s\n", name);
+}
+
+static inline void test_success(char *name)
+{
+	printf("success: %s\n", name);
+}
+
+static inline void test_finish(char *name, int status)
+{
+	if (status)
+		test_failure(name);
+	else
+		test_success(name);
+}
+
+static inline void test_set_git_version(char *value)
+{
+	printf("tags: git_version:%s\n", value);
+}
+
+#endif /* _SELFTESTS_POWERPC_SUBUNIT_H */
diff --git a/tools/testing/selftests/powerpc/utils.h b/tools/testing/selftests/powerpc/utils.h
new file mode 100644
index 0000000..5851c4b
--- /dev/null
+++ b/tools/testing/selftests/powerpc/utils.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#ifndef _SELFTESTS_POWERPC_UTILS_H
+#define _SELFTESTS_POWERPC_UTILS_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/* Avoid headaches with PRI?64 - just use %ll? always */
+typedef unsigned long long u64;
+typedef   signed long long s64;
+
+/* Just for familiarity */
+typedef uint32_t u32;
+typedef uint8_t u8;
+
+
+int test_harness(int (test_function)(void), char *name);
+
+
+/* Yes, this is evil */
+#define FAIL_IF(x)						\
+do {								\
+	if ((x)) {						\
+		fprintf(stderr,					\
+		"[FAIL] Test FAILED on line %d\n", __LINE__);	\
+		return 1;					\
+	}							\
+} while (0)
+
+#endif /* _SELFTESTS_POWERPC_UTILS_H */
-- 
1.8.1.2

[PATCH v3 3/3] selftests: Add test of PMU instruction counting on powerpc

[Michael Ellerman]

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>
---
v2,3: No change

 tools/testing/selftests/powerpc/Makefile           |   2 +-
 tools/testing/selftests/powerpc/pmu/Makefile       |  23 ++++
 .../selftests/powerpc/pmu/count_instructions.c     | 135 +++++++++++++++++++++
 tools/testing/selftests/powerpc/pmu/event.c        | 105 ++++++++++++++++
 tools/testing/selftests/powerpc/pmu/event.h        |  39 ++++++
 tools/testing/selftests/powerpc/pmu/loop.S         |  46 +++++++
 6 files changed, 349 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/powerpc/pmu/Makefile
 create mode 100644 tools/testing/selftests/powerpc/pmu/count_instructions.c
 create mode 100644 tools/testing/selftests/powerpc/pmu/event.c
 create mode 100644 tools/testing/selftests/powerpc/pmu/event.h
 create mode 100644 tools/testing/selftests/powerpc/pmu/loop.S

diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile
index b315740..bd24ae5 100644
--- a/tools/testing/selftests/powerpc/Makefile
+++ b/tools/testing/selftests/powerpc/Makefile
@@ -13,7 +13,7 @@ CFLAGS := -Wall -O2 -flto -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CUR
 
 export CC CFLAGS
 
-TARGETS =
+TARGETS = pmu
 
 endif
 
diff --git a/tools/testing/selftests/powerpc/pmu/Makefile b/tools/testing/selftests/powerpc/pmu/Makefile
new file mode 100644
index 0000000..7216f00
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/Makefile
@@ -0,0 +1,23 @@
+noarg:
+	$(MAKE) -C ../
+
+PROGS := count_instructions
+EXTRA_SOURCES := ../harness.c event.c
+
+all: $(PROGS)
+
+$(PROGS): $(EXTRA_SOURCES)
+
+# loop.S can only be built 64-bit
+count_instructions: loop.S count_instructions.c $(EXTRA_SOURCES)
+	$(CC) $(CFLAGS) -m64 -o $@ $^
+
+run_tests: all
+	@-for PROG in $(PROGS); do \
+		./$$PROG; \
+	done;
+
+clean:
+	rm -f $(PROGS) loop.o
+
+.PHONY: all run_tests clean
diff --git a/tools/testing/selftests/powerpc/pmu/count_instructions.c b/tools/testing/selftests/powerpc/pmu/count_instructions.c
new file mode 100644
index 0000000..312b4f0
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/count_instructions.c
@@ -0,0 +1,135 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/prctl.h>
+
+#include "event.h"
+#include "utils.h"
+
+extern void thirty_two_instruction_loop(u64 loops);
+
+static void setup_event(struct event *e, u64 config, char *name)
+{
+	event_init_opts(e, config, PERF_TYPE_HARDWARE, name);
+
+	e->attr.disabled = 1;
+	e->attr.exclude_kernel = 1;
+	e->attr.exclude_hv = 1;
+	e->attr.exclude_idle = 1;
+}
+
+static int do_count_loop(struct event *events, u64 instructions,
+			 u64 overhead, bool report)
+{
+	s64 difference, expected;
+	double percentage;
+
+	prctl(PR_TASK_PERF_EVENTS_ENABLE);
+
+	/* Run for 1M instructions */
+	thirty_two_instruction_loop(instructions >> 5);
+
+	prctl(PR_TASK_PERF_EVENTS_DISABLE);
+
+	event_read(&events[0]);
+	event_read(&events[1]);
+
+	expected = instructions + overhead;
+	difference = events[0].result.value - expected;
+	percentage = (double)difference / events[0].result.value * 100;
+
+	if (report) {
+		event_report(&events[0]);
+		event_report(&events[1]);
+
+		printf("Looped for %llu instructions, overhead %llu\n", instructions, overhead);
+		printf("Expected %llu\n", expected);
+		printf("Actual   %llu\n", events[0].result.value);
+		printf("Delta    %lld, %f%%\n", difference, percentage);
+	}
+
+	event_reset(&events[0]);
+	event_reset(&events[1]);
+
+	if (difference < 0)
+		difference = -difference;
+
+	/* Tolerate a difference below 0.0001 % */
+	difference *= 10000 * 100;
+	if (difference / events[0].result.value)
+		return -1;
+
+	return 0;
+}
+
+/* Count how many instructions it takes to do a null loop */
+static u64 determine_overhead(struct event *events)
+{
+	u64 current, overhead;
+	int i;
+
+	do_count_loop(events, 0, 0, false);
+	overhead = events[0].result.value;
+
+	for (i = 0; i < 100; i++) {
+		do_count_loop(events, 0, 0, false);
+		current = events[0].result.value;
+		if (current < overhead) {
+			printf("Replacing overhead %llu with %llu\n", overhead, current);
+			overhead = current;
+		}
+	}
+
+	return overhead;
+}
+
+static int count_instructions(void)
+{
+	struct event events[2];
+	u64 overhead;
+
+	setup_event(&events[0], PERF_COUNT_HW_INSTRUCTIONS, "instructions");
+	setup_event(&events[1], PERF_COUNT_HW_CPU_CYCLES, "cycles");
+
+	if (event_open(&events[0])) {
+		perror("perf_event_open");
+		return -1;
+	}
+
+	if (event_open_with_group(&events[1], events[0].fd)) {
+		perror("perf_event_open");
+		return -1;
+	}
+
+	overhead = determine_overhead(events);
+	printf("Overhead of null loop: %llu instructions\n", overhead);
+
+	/* Run for 1M instructions */
+	FAIL_IF(do_count_loop(events, 0x100000, overhead, true));
+
+	/* Run for 10M instructions */
+	FAIL_IF(do_count_loop(events, 0xa00000, overhead, true));
+
+	/* Run for 100M instructions */
+	FAIL_IF(do_count_loop(events, 0x6400000, overhead, true));
+
+	/* Run for 1G instructions */
+	FAIL_IF(do_count_loop(events, 0x40000000, overhead, true));
+
+	event_close(&events[0]);
+	event_close(&events[1]);
+
+	return 0;
+}
+
+int main(void)
+{
+	return test_harness(count_instructions, "count_instructions");
+}
diff --git a/tools/testing/selftests/powerpc/pmu/event.c b/tools/testing/selftests/powerpc/pmu/event.c
new file mode 100644
index 0000000..2b2d11d
--- /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);
+}
diff --git a/tools/testing/selftests/powerpc/pmu/event.h b/tools/testing/selftests/powerpc/pmu/event.h
new file mode 100644
index 0000000..e699319
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/event.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#ifndef _SELFTESTS_POWERPC_PMU_EVENT_H
+#define _SELFTESTS_POWERPC_PMU_EVENT_H
+
+#include <unistd.h>
+#include <linux/perf_event.h>
+
+#include "utils.h"
+
+
+struct event {
+	struct perf_event_attr attr;
+	char *name;
+	int fd;
+	/* This must match the read_format we use */
+	struct {
+		u64 value;
+		u64 running;
+		u64 enabled;
+	} result;
+};
+
+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);
+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(struct event *e);
+void event_close(struct event *e);
+int event_reset(struct event *e);
+int event_read(struct event *e);
+void event_report_justified(struct event *e, int name_width, int result_width);
+void event_report(struct event *e);
+
+#endif /* _SELFTESTS_POWERPC_PMU_EVENT_H */
diff --git a/tools/testing/selftests/powerpc/pmu/loop.S b/tools/testing/selftests/powerpc/pmu/loop.S
new file mode 100644
index 0000000..8820e3d
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/loop.S
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+	.text
+
+	.global thirty_two_instruction_loop
+	.type .thirty_two_instruction_loop,@function
+	.section ".opd","aw",@progbits
+thirty_two_instruction_loop:
+	.quad .thirty_two_instruction_loop, .TOC.@tocbase, 0
+	.previous
+.thirty_two_instruction_loop:
+	cmpwi	%r3,0
+	beqlr
+	addi	%r4,%r3,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1
+	addi	%r4,%r4,1	# 28 addi's
+	subi	%r3,%r3,1
+	b	.thirty_two_instruction_loop
-- 
1.8.1.2