Re: [Intel-gfx] [PATCH 14/15] drm/i915/guc/slpc: Add SLPC selftest

["Belgaumkar, Vinay" <vinay.belgaumkar@intel.com>]

On 7/27/2021 12:16 PM, Matthew Brost wrote:
> On Mon, Jul 26, 2021 at 12:07:59PM -0700, Vinay Belgaumkar wrote:
>> Tests that exercise the SLPC get/set frequency interfaces.
>>
>> Clamp_max will set max frequency to multiple levels and check
>> that SLPC requests frequency lower than or equal to it.
>>
>> Clamp_min will set min frequency to different levels and check
>> if SLPC requests are higher or equal to those levels.
>>
>> v2: Address review comments (Michal W)
>> v3: Checkpatch() corrections
>>
>> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
>> ---
>>   drivers/gpu/drm/i915/gt/intel_rps.c           |   1 +
>>   drivers/gpu/drm/i915/gt/selftest_slpc.c       | 311 ++++++++++++++++++
>>   drivers/gpu/drm/i915/gt/selftest_slpc.h       |  12 +
>>   .../drm/i915/selftests/i915_live_selftests.h  |   1 +
>>   4 files changed, 325 insertions(+)
>>   create mode 100644 drivers/gpu/drm/i915/gt/selftest_slpc.c
>>   create mode 100644 drivers/gpu/drm/i915/gt/selftest_slpc.h
>>
>> diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
>> index 48d4147165a9..6237332835fe 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_rps.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_rps.c
>> @@ -2318,4 +2318,5 @@ EXPORT_SYMBOL_GPL(i915_gpu_turbo_disable);
>>   
>>   #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
>>   #include "selftest_rps.c"
>> +#include "selftest_slpc.c"
>>   #endif
>> diff --git a/drivers/gpu/drm/i915/gt/selftest_slpc.c b/drivers/gpu/drm/i915/gt/selftest_slpc.c
>> new file mode 100644
>> index 000000000000..5018f686686f
>> --- /dev/null
>> +++ b/drivers/gpu/drm/i915/gt/selftest_slpc.c
>> @@ -0,0 +1,311 @@
>> +// SPDX-License-Identifier: MIT
>> +/*
>> + * Copyright © 2021 Intel Corporation
>> + */
>> +
>> +#include "selftest_slpc.h"
>> +
>> +#define NUM_STEPS 5
>> +#define H2G_DELAY 50000
>> +#define delay_for_h2g() usleep_range(H2G_DELAY, H2G_DELAY + 10000)
>> +
>> +static int 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 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;
>> +}
>> +
>> +int live_slpc_clamp_min(void *arg)
>> +{
>> +	struct drm_i915_private *i915 = arg;
>> +	struct intel_gt *gt = &i915->gt;
>> +	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 = 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 - 50/3)) {
>> +				pr_err("SWReq is %d, should be at least %d\n", req_freq,
>> +					min_freq - 50/3);
>> +				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 */
>> +	set_max_freq(slpc, slpc_max_freq);
>> +	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;
>> +}
>> +
>> +int live_slpc_clamp_max(void *arg)
>> +{
> 
> This test is really similar to live_slpc_clamp_min, have you tried to
> combine these into a single function with arguments?

We could, but the for loop in clamp min goes from min to max whereas 
clamp_max goes from max to min. It's more intutive and easy to 
understand if we keep it this way.

> 
>> +	struct drm_i915_private *i915 = arg;
>> +	struct intel_gt *gt = &i915->gt;
>> +	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 = 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 + 50/3)) {
>> +				pr_err("SWReq is %d, should be at most %d\n", req_freq,
>> +					max_freq + 50/3);
>> +				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 */
>> +	set_max_freq(slpc, slpc_max_freq);
>> +	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(&i915->gt))
>> +		return 0;
>> +
>> +	return i915_live_subtests(tests, i915);
>> +}
>> diff --git a/drivers/gpu/drm/i915/gt/selftest_slpc.h b/drivers/gpu/drm/i915/gt/selftest_slpc.h
>> new file mode 100644
> 
> I don't think you need this header as selftest_slpc.c is the only user
> and you need to forward decl these functions. Even if you did, you could
> just forward decl these in the C file.

Sure, will remove.
Thanks,
Vinay.
> 
> Matt
> 
>> index 000000000000..0480e62ed3d7
>> --- /dev/null
>> +++ b/drivers/gpu/drm/i915/gt/selftest_slpc.h
>> @@ -0,0 +1,12 @@
>> +/* SPDX-License-Identifier: MIT */
>> +/*
>> + * Copyright © 2021 Intel Corporation
>> + */
>> +
>> +#ifndef SELFTEST_SLPC_H
>> +#define SELFTEST_SLPC_H
>> +
>> +int live_slpc_clamp_max(void *arg);
>> +int live_slpc_clamp_min(void *arg);
>> +
>> +#endif /* SELFTEST_SLPC_H */
>> diff --git a/drivers/gpu/drm/i915/selftests/i915_live_selftests.h b/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
>> index e2fd1b61af71..1746a56dda06 100644
>> --- a/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
>> +++ b/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
>> @@ -47,5 +47,6 @@ selftest(hangcheck, intel_hangcheck_live_selftests)
>>   selftest(execlists, intel_execlists_live_selftests)
>>   selftest(ring_submission, intel_ring_submission_live_selftests)
>>   selftest(perf, i915_perf_live_selftests)
>> +selftest(slpc, intel_slpc_live_selftests)
>>   /* Here be dragons: keep last to run last! */
>>   selftest(late_gt_pm, intel_gt_pm_late_selftests)
>> -- 
>> 2.25.0
>>
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