[Intel-gfx] [PATCH i-g-t 3/4] i915_pm_freq_api: Add some basic SLPC igt tests

[Vinay Belgaumkar]

Validate basic api for GT freq control. Also test
interaction with GT reset. We skip rps tests with
SLPC enabled, this will re-introduce some coverage.
SLPC selftests are already covering some other workload
related scenarios.

v2: Rename test (Rodrigo)
v3: Review comments (Ashutosh)
v4: Skip when SLPC is disabled. Check for enable_guc is
not sufficient as kernel config may have it but the
platform doesn't actually support it.
v5: Use the updated SLPC helper

Reviewed-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar at intel.com>
---
 tests/i915/i915_pm_freq_api.c | 152 ++++++++++++++++++++++++++++++++++
 tests/meson.build             |   1 +
 2 files changed, 153 insertions(+)
 create mode 100644 tests/i915/i915_pm_freq_api.c

diff --git a/tests/i915/i915_pm_freq_api.c b/tests/i915/i915_pm_freq_api.c
new file mode 100644
index 00000000..d42b3a2b
--- /dev/null
+++ b/tests/i915/i915_pm_freq_api.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "drmtest.h"
+#include "i915/gem.h"
+#include "igt_sysfs.h"
+#include "igt.h"
+
+IGT_TEST_DESCRIPTION("Test SLPC freq API");
+/*
+ * Too many intermediate components and steps before freq is adjusted
+ * Specially if workload is under execution, so let's wait 100 ms.
+ */
+#define ACT_FREQ_LATENCY_US 100000
+
+static uint32_t get_freq(int dirfd, uint8_t id)
+{
+	uint32_t val;
+
+	igt_assert(igt_sysfs_rps_scanf(dirfd, id, "%u", &val) == 1);
+
+	return val;
+}
+
+static int set_freq(int dirfd, uint8_t id, uint32_t val)
+{
+	return igt_sysfs_rps_printf(dirfd, id, "%u", val);
+}
+
+static void test_freq_basic_api(int dirfd, int gt)
+{
+	uint32_t rpn, rp0, rpe;
+
+	/* Save frequencies */
+	rpn = get_freq(dirfd, RPS_RPn_FREQ_MHZ);
+	rp0 = get_freq(dirfd, RPS_RP0_FREQ_MHZ);
+	rpe = get_freq(dirfd, RPS_RP1_FREQ_MHZ);
+	igt_info("System min freq: %dMHz; max freq: %dMHz\n", rpn, rp0);
+
+	/*
+	 * Negative bound tests
+	 * RPn is the floor
+	 * RP0 is the ceiling
+	 */
+	igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rpn - 1) < 0);
+	igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rp0 + 1) < 0);
+	igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rpn - 1) < 0);
+	igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rp0 + 1) < 0);
+
+	/* Assert min requests are respected from rp0 to rpn */
+	igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rp0) > 0);
+	igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rp0);
+	igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rpe) > 0);
+	igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rpe);
+	igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rpn) > 0);
+	igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rpn);
+
+	/* Assert max requests are respected from rpn to rp0 */
+	igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rpn) > 0);
+	igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rpn);
+	igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rpe) > 0);
+	igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rpe);
+	igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rp0) > 0);
+	igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rp0);
+
+}
+
+static void test_reset(int i915, int dirfd, int gt)
+{
+	uint32_t rpn = get_freq(dirfd, RPS_RPn_FREQ_MHZ);
+	int fd;
+
+	igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rpn) > 0);
+	igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rpn) > 0);
+	usleep(ACT_FREQ_LATENCY_US);
+	igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rpn);
+
+	/* Manually trigger a GT reset */
+	fd = igt_debugfs_gt_open(i915, gt, "reset", O_WRONLY);
+	igt_require(fd >= 0);
+	igt_ignore_warn(write(fd, "1\n", 2));
+	close(fd);
+
+	igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rpn);
+	igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rpn);
+}
+
+igt_main
+{
+	int i915 = -1;
+	uint32_t *stash_min, *stash_max;
+
+	igt_fixture {
+		int num_gts, dirfd, gt;
+
+		i915 = drm_open_driver(DRIVER_INTEL);
+		igt_require_gem(i915);
+		/* i915_pm_rps already covers execlist path */
+		igt_skip_on_f(!i915_is_slpc_enabled(i915, 0),
+			      "This test is supported only with SLPC enabled\n");
+
+		num_gts = igt_sysfs_get_num_gt(i915);
+		stash_min = (uint32_t*)malloc(sizeof(uint32_t) * num_gts);
+		stash_max = (uint32_t*)malloc(sizeof(uint32_t) * num_gts);
+
+		/* Save curr min and max across GTs */
+		for_each_sysfs_gt_dirfd(i915, dirfd, gt) {
+			stash_min[gt] = get_freq(dirfd, RPS_MIN_FREQ_MHZ);
+			stash_max[gt] = get_freq(dirfd, RPS_MAX_FREQ_MHZ);
+		}
+	}
+
+	igt_describe("Test basic API for controlling min/max GT frequency");
+	igt_subtest_with_dynamic_f("freq-basic-api") {
+		int dirfd, gt;
+
+		for_each_sysfs_gt_dirfd(i915, dirfd, gt)
+			igt_dynamic_f("gt%u", gt)
+				test_freq_basic_api(dirfd, gt);
+	}
+
+	igt_describe("Test basic freq API works after a reset");
+	igt_subtest_with_dynamic_f("freq-reset") {
+		int dirfd, gt;
+
+		for_each_sysfs_gt_dirfd(i915, dirfd, gt)
+			igt_dynamic_f("gt%u", gt)
+				test_reset(i915, dirfd, gt);
+	}
+
+	igt_fixture {
+		int dirfd, gt;
+		/* Restore frequencies */
+		for_each_sysfs_gt_dirfd(i915, dirfd, gt) {
+			igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, stash_max[gt]) > 0);
+			igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, stash_min[gt]) > 0);
+		}
+		close(i915);
+	}
+}
diff --git a/tests/meson.build b/tests/meson.build
index da31e782..46109f10 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -202,6 +202,7 @@ i915_progs = [
 	'gem_workarounds',
 	'i915_fb_tiling',
 	'i915_getparams_basic',
+	'i915_pm_freq_api',
 	'i915_hangman',
 	'i915_hwmon',
 	'i915_module_load',
-- 
2.38.1