linux/drivers/gpu/drm/i915/selftests/i915_perf.c

/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright © 2019 Intel Corporation
 */

#include <linux/kref.h>

#include "gem/i915_gem_pm.h"
#include "gt/intel_gt.h"

#include "i915_selftest.h"

#include "igt_flush_test.h"
#include "lib_sw_fence.h"

#define TEST_OA_CONFIG_UUID "12345678-1234-1234-1234-1234567890ab"

static int
alloc_empty_config(struct i915_perf *perf)
{
	struct i915_oa_config *oa_config;

	oa_config = kzalloc_obj(*oa_config);
	if (!oa_config)
		return -ENOMEM;

	oa_config->perf = perf;
	kref_init(&oa_config->ref);

	strscpy(oa_config->uuid, TEST_OA_CONFIG_UUID, sizeof(oa_config->uuid));

	mutex_lock(&perf->metrics_lock);

	oa_config->id = idr_alloc(&perf->metrics_idr, oa_config, 2, 0, GFP_KERNEL);
	if (oa_config->id < 0)  {
		mutex_unlock(&perf->metrics_lock);
		i915_oa_config_put(oa_config);
		return -ENOMEM;
	}

	mutex_unlock(&perf->metrics_lock);

	return 0;
}

static void
destroy_empty_config(struct i915_perf *perf)
{
	struct i915_oa_config *oa_config = NULL, *tmp;
	int id;

	mutex_lock(&perf->metrics_lock);

	idr_for_each_entry(&perf->metrics_idr, tmp, id) {
		if (!strcmp(tmp->uuid, TEST_OA_CONFIG_UUID)) {
			oa_config = tmp;
			break;
		}
	}

	if (oa_config)
		idr_remove(&perf->metrics_idr, oa_config->id);

	mutex_unlock(&perf->metrics_lock);

	if (oa_config)
		i915_oa_config_put(oa_config);
}

static struct i915_oa_config *
get_empty_config(struct i915_perf *perf)
{
	struct i915_oa_config *oa_config = NULL, *tmp;
	int id;

	mutex_lock(&perf->metrics_lock);

	idr_for_each_entry(&perf->metrics_idr, tmp, id) {
		if (!strcmp(tmp->uuid, TEST_OA_CONFIG_UUID)) {
			oa_config = i915_oa_config_get(tmp);
			break;
		}
	}

	mutex_unlock(&perf->metrics_lock);

	return oa_config;
}

static struct i915_perf_stream *
test_stream(struct i915_perf *perf)
{
	struct drm_i915_perf_open_param param = {};
	struct i915_oa_config *oa_config = get_empty_config(perf);
	struct perf_open_properties props = {
		.engine = intel_engine_lookup_user(perf->i915,
						   I915_ENGINE_CLASS_RENDER,
						   0),
		.sample_flags = SAMPLE_OA_REPORT,
		.oa_format = GRAPHICS_VER(perf->i915) == 12 ?
		I915_OA_FORMAT_A32u40_A4u32_B8_C8 : I915_OA_FORMAT_C4_B8,
	};
	struct i915_perf_stream *stream;
	struct intel_gt *gt;

	if (!props.engine)
		return NULL;

	gt = props.engine->gt;

	if (!oa_config)
		return NULL;

	props.metrics_set = oa_config->id;

	stream = kzalloc_obj(*stream);
	if (!stream) {
		i915_oa_config_put(oa_config);
		return NULL;
	}

	stream->perf = perf;

	mutex_lock(&gt->perf.lock);
	if (i915_oa_stream_init(stream, &param, &props)) {
		kfree(stream);
		stream =  NULL;
	}
	mutex_unlock(&gt->perf.lock);

	i915_oa_config_put(oa_config);

	return stream;
}

static void stream_destroy(struct i915_perf_stream *stream)
{
	struct intel_gt *gt = stream->engine->gt;

	mutex_lock(&gt->perf.lock);
	i915_perf_destroy_locked(stream);
	mutex_unlock(&gt->perf.lock);
}

static int live_sanitycheck(void *arg)
{
	struct drm_i915_private *i915 = arg;
	struct i915_perf_stream *stream;

	/* Quick check we can create a perf stream */

	stream = test_stream(&i915->perf);
	if (!stream)
		return -EINVAL;

	stream_destroy(stream);
	return 0;
}

static int write_timestamp(struct i915_request *rq, int slot)
{
	u32 *cs;
	int len;

	cs = intel_ring_begin(rq, 6);
	if (IS_ERR(cs))
		return PTR_ERR(cs);

	len = 5;
	if (GRAPHICS_VER(rq->i915) >= 8)
		len++;

	*cs++ = GFX_OP_PIPE_CONTROL(len);
	*cs++ = PIPE_CONTROL_GLOBAL_GTT_IVB |
		PIPE_CONTROL_STORE_DATA_INDEX |
		PIPE_CONTROL_WRITE_TIMESTAMP;
	*cs++ = slot * sizeof(u32);
	*cs++ = 0;
	*cs++ = 0;
	*cs++ = 0;

	intel_ring_advance(rq, cs);

	return 0;
}

static ktime_t poll_status(struct i915_request *rq, int slot)
{
	while (!intel_read_status_page(rq->engine, slot) &&
	       !i915_request_completed(rq))
		cpu_relax();

	return ktime_get();
}

static int live_noa_delay(void *arg)
{
	struct drm_i915_private *i915 = arg;
	struct i915_perf_stream *stream;
	struct i915_request *rq;
	ktime_t t0, t1;
	u64 expected;
	u32 delay;
	int err;
	int i;

	/* Check that the GPU delays matches expectations */

	stream = test_stream(&i915->perf);
	if (!stream)
		return -ENOMEM;

	expected = atomic64_read(&stream->perf->noa_programming_delay);

	if (stream->engine->class != RENDER_CLASS) {
		err = -ENODEV;
		goto out;
	}

	for (i = 0; i < 4; i++)
		intel_write_status_page(stream->engine, 0x100 + i, 0);

	rq = intel_engine_create_kernel_request(stream->engine);
	if (IS_ERR(rq)) {
		err = PTR_ERR(rq);
		goto out;
	}

	if (rq->engine->emit_init_breadcrumb) {
		err = rq->engine->emit_init_breadcrumb(rq);
		if (err) {
			i915_request_add(rq);
			goto out;
		}
	}

	err = write_timestamp(rq, 0x100);
	if (err) {
		i915_request_add(rq);
		goto out;
	}

	err = rq->engine->emit_bb_start(rq,
					i915_ggtt_offset(stream->noa_wait), 0,
					I915_DISPATCH_SECURE);
	if (err) {
		i915_request_add(rq);
		goto out;
	}

	err = write_timestamp(rq, 0x102);
	if (err) {
		i915_request_add(rq);
		goto out;
	}

	i915_request_get(rq);
	i915_request_add(rq);

	preempt_disable();
	t0 = poll_status(rq, 0x100);
	t1 = poll_status(rq, 0x102);
	preempt_enable();

	pr_info("CPU delay: %lluns, expected %lluns\n",
		ktime_sub(t1, t0), expected);

	delay = intel_read_status_page(stream->engine, 0x102);
	delay -= intel_read_status_page(stream->engine, 0x100);
	delay = intel_gt_clock_interval_to_ns(stream->engine->gt, delay);
	pr_info("GPU delay: %uns, expected %lluns\n",
		delay, expected);

	if (4 * delay < 3 * expected || 2 * delay > 3 * expected) {
		pr_err("GPU delay [%uus] outside of expected threshold! [%lluus, %lluus]\n",
		       delay / 1000,
		       div_u64(3 * expected, 4000),
		       div_u64(3 * expected, 2000));
		err = -EINVAL;
	}

	i915_request_put(rq);
out:
	stream_destroy(stream);
	return err;
}

static int live_noa_gpr(void *arg)
{
	struct drm_i915_private *i915 = arg;
	struct i915_perf_stream *stream;
	struct intel_context *ce;
	struct i915_request *rq;
	u32 *cs, *store;
	void *scratch;
	u32 gpr0;
	int err;
	int i;

	/* Check that the delay does not clobber user context state (GPR) */

	stream = test_stream(&i915->perf);
	if (!stream)
		return -ENOMEM;

	gpr0 = i915_mmio_reg_offset(GEN8_RING_CS_GPR(stream->engine->mmio_base, 0));

	ce = intel_context_create(stream->engine);
	if (IS_ERR(ce)) {
		err = PTR_ERR(ce);
		goto out;
	}

	/* Poison the ce->vm so we detect writes not to the GGTT gt->scratch */
	scratch = __px_vaddr(ce->vm->scratch[0]);
	memset(scratch, POISON_FREE, PAGE_SIZE);

	rq = intel_context_create_request(ce);
	if (IS_ERR(rq)) {
		err = PTR_ERR(rq);
		goto out_ce;
	}
	i915_request_get(rq);

	if (rq->engine->emit_init_breadcrumb) {
		err = rq->engine->emit_init_breadcrumb(rq);
		if (err) {
			i915_request_add(rq);
			goto out_rq;
		}
	}

	/* Fill the 16 qword [32 dword] GPR with a known unlikely value */
	cs = intel_ring_begin(rq, 2 * 32 + 2);
	if (IS_ERR(cs)) {
		err = PTR_ERR(cs);
		i915_request_add(rq);
		goto out_rq;
	}

	*cs++ = MI_LOAD_REGISTER_IMM(32);
	for (i = 0; i < 32; i++) {
		*cs++ = gpr0 + i * sizeof(u32);
		*cs++ = STACK_MAGIC;
	}
	*cs++ = MI_NOOP;
	intel_ring_advance(rq, cs);

	/* Execute the GPU delay */
	err = rq->engine->emit_bb_start(rq,
					i915_ggtt_offset(stream->noa_wait), 0,
					I915_DISPATCH_SECURE);
	if (err) {
		i915_request_add(rq);
		goto out_rq;
	}

	/* Read the GPR back, using the pinned global HWSP for convenience */
	store = memset32(rq->engine->status_page.addr + 512, 0, 32);
	for (i = 0; i < 32; i++) {
		u32 cmd;

		cs = intel_ring_begin(rq, 4);
		if (IS_ERR(cs)) {
			err = PTR_ERR(cs);
			i915_request_add(rq);
			goto out_rq;
		}

		cmd = MI_STORE_REGISTER_MEM;
		if (GRAPHICS_VER(i915) >= 8)
			cmd++;
		cmd |= MI_USE_GGTT;

		*cs++ = cmd;
		*cs++ = gpr0 + i * sizeof(u32);
		*cs++ = i915_ggtt_offset(rq->engine->status_page.vma) +
			offset_in_page(store) +
			i * sizeof(u32);
		*cs++ = 0;
		intel_ring_advance(rq, cs);
	}

	i915_request_add(rq);

	if (i915_request_wait(rq, I915_WAIT_INTERRUPTIBLE, HZ / 2) < 0) {
		pr_err("noa_wait timed out\n");
		intel_gt_set_wedged(stream->engine->gt);
		err = -EIO;
		goto out_rq;
	}

	/* Verify that the GPR contain our expected values */
	for (i = 0; i < 32; i++) {
		if (store[i] == STACK_MAGIC)
			continue;

		pr_err("GPR[%d] lost, found:%08x, expected:%08x!\n",
		       i, store[i], STACK_MAGIC);
		err = -EINVAL;
	}

	/* Verify that the user's scratch page was not used for GPR storage */
	if (memchr_inv(scratch, POISON_FREE, PAGE_SIZE)) {
		pr_err("Scratch page overwritten!\n");
		igt_hexdump(scratch, 4096);
		err = -EINVAL;
	}

out_rq:
	i915_request_put(rq);
out_ce:
	intel_context_put(ce);
out:
	stream_destroy(stream);
	return err;
}

int i915_perf_live_selftests(struct drm_i915_private *i915)
{
	static const struct i915_subtest tests[] = {
		SUBTEST(live_sanitycheck),
		SUBTEST(live_noa_delay),
		SUBTEST(live_noa_gpr),
	};
	struct i915_perf *perf = &i915->perf;
	int err;

	if (!perf->metrics_kobj || !perf->ops.enable_metric_set)
		return 0;

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

	err = alloc_empty_config(&i915->perf);
	if (err)
		return err;

	err = i915_live_subtests(tests, i915);

	destroy_empty_config(&i915->perf);

	return err;
}