linux/drivers/gpu/drm/i915/gt/selftest_slpc.c

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2021 Intel Corporation
 */

#define NUM_STEPS 5
#define H2G_DELAY 50000
#define delay_for_h2g() usleep_range(H2G_DELAY, H2G_DELAY + 10000)
#define FREQUENCY_REQ_UNIT	DIV_ROUND_CLOSEST(GT_FREQUENCY_MULTIPLIER, \
						  GEN9_FREQ_SCALER)

static int slpc_set_min_freq(struct intel_guc_slpc *slpc, u32 freq)
{
	int ret;

	ret = intel_guc_slpc_set_min_freq(slpc, freq);
	if (ret)
		pr_err("Could not set min frequency to [%u]\n", freq);
	else /* Delay to ensure h2g completes */
		delay_for_h2g();

	return ret;
}

static int slpc_set_max_freq(struct intel_guc_slpc *slpc, u32 freq)
{
	int ret;

	ret = intel_guc_slpc_set_max_freq(slpc, freq);
	if (ret)
		pr_err("Could not set maximum frequency [%u]\n",
		       freq);
	else /* Delay to ensure h2g completes */
		delay_for_h2g();

	return ret;
}

static int live_slpc_clamp_min(void *arg)
{
	struct drm_i915_private *i915 = arg;
	struct intel_gt *gt = to_gt(i915);
	struct intel_guc_slpc *slpc = &gt->uc.guc.slpc;
	struct intel_rps *rps = &gt->rps;
	struct intel_engine_cs *engine;
	enum intel_engine_id id;
	struct igt_spinner spin;
	u32 slpc_min_freq, slpc_max_freq;
	int err = 0;

	if (!intel_uc_uses_guc_slpc(&gt->uc))
		return 0;

	if (igt_spinner_init(&spin, gt))
		return -ENOMEM;

	if (intel_guc_slpc_get_max_freq(slpc, &slpc_max_freq)) {
		pr_err("Could not get SLPC max freq\n");
		return -EIO;
	}

	if (intel_guc_slpc_get_min_freq(slpc, &slpc_min_freq)) {
		pr_err("Could not get SLPC min freq\n");
		return -EIO;
	}

	if (slpc_min_freq == slpc_max_freq) {
		pr_err("Min/Max are fused to the same value\n");
		return -EINVAL;
	}

	intel_gt_pm_wait_for_idle(gt);
	intel_gt_pm_get(gt);
	for_each_engine(engine, gt, id) {
		struct i915_request *rq;
		u32 step, min_freq, req_freq;
		u32 act_freq, max_act_freq;

		if (!intel_engine_can_store_dword(engine))
			continue;

		/* Go from min to max in 5 steps */
		step = (slpc_max_freq - slpc_min_freq) / NUM_STEPS;
		max_act_freq = slpc_min_freq;
		for (min_freq = slpc_min_freq; min_freq < slpc_max_freq;
					min_freq += step) {
			err = slpc_set_min_freq(slpc, min_freq);
			if (err)
				break;

			st_engine_heartbeat_disable(engine);

			rq = igt_spinner_create_request(&spin,
							engine->kernel_context,
							MI_NOOP);
			if (IS_ERR(rq)) {
				err = PTR_ERR(rq);
				st_engine_heartbeat_enable(engine);
				break;
			}

			i915_request_add(rq);

			if (!igt_wait_for_spinner(&spin, rq)) {
				pr_err("%s: Spinner did not start\n",
				       engine->name);
				igt_spinner_end(&spin);
				st_engine_heartbeat_enable(engine);
				intel_gt_set_wedged(engine->gt);
				err = -EIO;
				break;
			}

			/* Wait for GuC to detect business and raise
			 * requested frequency if necessary.
			 */
			delay_for_h2g();

			req_freq = intel_rps_read_punit_req_frequency(rps);

			/* GuC requests freq in multiples of 50/3 MHz */
			if (req_freq < (min_freq - FREQUENCY_REQ_UNIT)) {
				pr_err("SWReq is %d, should be at least %d\n", req_freq,
				       min_freq - FREQUENCY_REQ_UNIT);
				igt_spinner_end(&spin);
				st_engine_heartbeat_enable(engine);
				err = -EINVAL;
				break;
			}

			act_freq =  intel_rps_read_actual_frequency(rps);
			if (act_freq > max_act_freq)
				max_act_freq = act_freq;

			igt_spinner_end(&spin);
			st_engine_heartbeat_enable(engine);
		}

		pr_info("Max actual frequency for %s was %d\n",
			engine->name, max_act_freq);

		/* Actual frequency should rise above min */
		if (max_act_freq == slpc_min_freq) {
			pr_err("Actual freq did not rise above min\n");
			err = -EINVAL;
		}

		if (err)
			break;
	}

	/* Restore min/max frequencies */
	slpc_set_max_freq(slpc, slpc_max_freq);
	slpc_set_min_freq(slpc, slpc_min_freq);

	if (igt_flush_test(gt->i915))
		err = -EIO;

	intel_gt_pm_put(gt);
	igt_spinner_fini(&spin);
	intel_gt_pm_wait_for_idle(gt);

	return err;
}

static int live_slpc_clamp_max(void *arg)
{
	struct drm_i915_private *i915 = arg;
	struct intel_gt *gt = to_gt(i915);
	struct intel_guc_slpc *slpc;
	struct intel_rps *rps;
	struct intel_engine_cs *engine;
	enum intel_engine_id id;
	struct igt_spinner spin;
	int err = 0;
	u32 slpc_min_freq, slpc_max_freq;

	slpc = &gt->uc.guc.slpc;
	rps = &gt->rps;

	if (!intel_uc_uses_guc_slpc(&gt->uc))
		return 0;

	if (igt_spinner_init(&spin, gt))
		return -ENOMEM;

	if (intel_guc_slpc_get_max_freq(slpc, &slpc_max_freq)) {
		pr_err("Could not get SLPC max freq\n");
		return -EIO;
	}

	if (intel_guc_slpc_get_min_freq(slpc, &slpc_min_freq)) {
		pr_err("Could not get SLPC min freq\n");
		return -EIO;
	}

	if (slpc_min_freq == slpc_max_freq) {
		pr_err("Min/Max are fused to the same value\n");
		return -EINVAL;
	}

	intel_gt_pm_wait_for_idle(gt);
	intel_gt_pm_get(gt);
	for_each_engine(engine, gt, id) {
		struct i915_request *rq;
		u32 max_freq, req_freq;
		u32 act_freq, max_act_freq;
		u32 step;

		if (!intel_engine_can_store_dword(engine))
			continue;

		/* Go from max to min in 5 steps */
		step = (slpc_max_freq - slpc_min_freq) / NUM_STEPS;
		max_act_freq = slpc_min_freq;
		for (max_freq = slpc_max_freq; max_freq > slpc_min_freq;
					max_freq -= step) {
			err = slpc_set_max_freq(slpc, max_freq);
			if (err)
				break;

			st_engine_heartbeat_disable(engine);

			rq = igt_spinner_create_request(&spin,
							engine->kernel_context,
							MI_NOOP);
			if (IS_ERR(rq)) {
				st_engine_heartbeat_enable(engine);
				err = PTR_ERR(rq);
				break;
			}

			i915_request_add(rq);

			if (!igt_wait_for_spinner(&spin, rq)) {
				pr_err("%s: SLPC spinner did not start\n",
				       engine->name);
				igt_spinner_end(&spin);
				st_engine_heartbeat_enable(engine);
				intel_gt_set_wedged(engine->gt);
				err = -EIO;
				break;
			}

			delay_for_h2g();

			/* Verify that SWREQ indeed was set to specific value */
			req_freq = intel_rps_read_punit_req_frequency(rps);

			/* GuC requests freq in multiples of 50/3 MHz */
			if (req_freq > (max_freq + FREQUENCY_REQ_UNIT)) {
				pr_err("SWReq is %d, should be at most %d\n", req_freq,
				       max_freq + FREQUENCY_REQ_UNIT);
				igt_spinner_end(&spin);
				st_engine_heartbeat_enable(engine);
				err = -EINVAL;
				break;
			}

			act_freq =  intel_rps_read_actual_frequency(rps);
			if (act_freq > max_act_freq)
				max_act_freq = act_freq;

			st_engine_heartbeat_enable(engine);
			igt_spinner_end(&spin);

			if (err)
				break;
		}

		pr_info("Max actual frequency for %s was %d\n",
			engine->name, max_act_freq);

		/* Actual frequency should rise above min */
		if (max_act_freq == slpc_min_freq) {
			pr_err("Actual freq did not rise above min\n");
			err = -EINVAL;
		}

		if (igt_flush_test(gt->i915)) {
			err = -EIO;
			break;
		}

		if (err)
			break;
	}

	/* Restore min/max freq */
	slpc_set_max_freq(slpc, slpc_max_freq);
	slpc_set_min_freq(slpc, slpc_min_freq);

	intel_gt_pm_put(gt);
	igt_spinner_fini(&spin);
	intel_gt_pm_wait_for_idle(gt);

	return err;
}

int intel_slpc_live_selftests(struct drm_i915_private *i915)
{
	static const struct i915_subtest tests[] = {
		SUBTEST(live_slpc_clamp_max),
		SUBTEST(live_slpc_clamp_min),
	};

	if (intel_gt_is_wedged(to_gt(i915)))
		return 0;

	return i915_live_subtests(tests, i915);
}