xref: /linux/drivers/gpu/drm/i915/gt/selftest_engine_pm.c (revision 34dc1baba215b826e454b8d19e4f24adbeb7d00d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright © 2018 Intel Corporation
4  */
5 
6 #include <linux/sort.h>
7 
8 #include "gt/intel_gt_print.h"
9 #include "i915_selftest.h"
10 #include "intel_engine_regs.h"
11 #include "intel_gpu_commands.h"
12 #include "intel_gt_clock_utils.h"
13 #include "selftest_engine.h"
14 #include "selftest_engine_heartbeat.h"
15 #include "selftests/igt_atomic.h"
16 #include "selftests/igt_flush_test.h"
17 #include "selftests/igt_spinner.h"
18 
19 #define COUNT 5
20 
21 static int cmp_u64(const void *A, const void *B)
22 {
23 	const u64 *a = A, *b = B;
24 
25 	return *a - *b;
26 }
27 
28 static u64 trifilter(u64 *a)
29 {
30 	sort(a, COUNT, sizeof(*a), cmp_u64, NULL);
31 	return (a[1] + 2 * a[2] + a[3]) >> 2;
32 }
33 
34 static u32 *emit_wait(u32 *cs, u32 offset, int op, u32 value)
35 {
36 	*cs++ = MI_SEMAPHORE_WAIT |
37 		MI_SEMAPHORE_GLOBAL_GTT |
38 		MI_SEMAPHORE_POLL |
39 		op;
40 	*cs++ = value;
41 	*cs++ = offset;
42 	*cs++ = 0;
43 
44 	return cs;
45 }
46 
47 static u32 *emit_store(u32 *cs, u32 offset, u32 value)
48 {
49 	*cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
50 	*cs++ = offset;
51 	*cs++ = 0;
52 	*cs++ = value;
53 
54 	return cs;
55 }
56 
57 static u32 *emit_srm(u32 *cs, i915_reg_t reg, u32 offset)
58 {
59 	*cs++ = MI_STORE_REGISTER_MEM_GEN8 | MI_USE_GGTT;
60 	*cs++ = i915_mmio_reg_offset(reg);
61 	*cs++ = offset;
62 	*cs++ = 0;
63 
64 	return cs;
65 }
66 
67 static void write_semaphore(u32 *x, u32 value)
68 {
69 	WRITE_ONCE(*x, value);
70 	wmb();
71 }
72 
73 static int __measure_timestamps(struct intel_context *ce,
74 				u64 *dt, u64 *d_ring, u64 *d_ctx)
75 {
76 	struct intel_engine_cs *engine = ce->engine;
77 	u32 *sema = memset32(engine->status_page.addr + 1000, 0, 5);
78 	u32 offset = i915_ggtt_offset(engine->status_page.vma);
79 	struct i915_request *rq;
80 	u32 *cs;
81 
82 	rq = intel_context_create_request(ce);
83 	if (IS_ERR(rq))
84 		return PTR_ERR(rq);
85 
86 	cs = intel_ring_begin(rq, 28);
87 	if (IS_ERR(cs)) {
88 		i915_request_add(rq);
89 		return PTR_ERR(cs);
90 	}
91 
92 	/* Signal & wait for start */
93 	cs = emit_store(cs, offset + 4008, 1);
94 	cs = emit_wait(cs, offset + 4008, MI_SEMAPHORE_SAD_NEQ_SDD, 1);
95 
96 	cs = emit_srm(cs, RING_TIMESTAMP(engine->mmio_base), offset + 4000);
97 	cs = emit_srm(cs, RING_CTX_TIMESTAMP(engine->mmio_base), offset + 4004);
98 
99 	/* Busy wait */
100 	cs = emit_wait(cs, offset + 4008, MI_SEMAPHORE_SAD_EQ_SDD, 1);
101 
102 	cs = emit_srm(cs, RING_TIMESTAMP(engine->mmio_base), offset + 4016);
103 	cs = emit_srm(cs, RING_CTX_TIMESTAMP(engine->mmio_base), offset + 4012);
104 
105 	intel_ring_advance(rq, cs);
106 	i915_request_get(rq);
107 	i915_request_add(rq);
108 	intel_engine_flush_submission(engine);
109 
110 	/* Wait for the request to start executing, that then waits for us */
111 	while (READ_ONCE(sema[2]) == 0)
112 		cpu_relax();
113 
114 	/* Run the request for a 100us, sampling timestamps before/after */
115 	local_irq_disable();
116 	write_semaphore(&sema[2], 0);
117 	while (READ_ONCE(sema[1]) == 0) /* wait for the gpu to catch up */
118 		cpu_relax();
119 	*dt = local_clock();
120 	udelay(100);
121 	*dt = local_clock() - *dt;
122 	write_semaphore(&sema[2], 1);
123 	local_irq_enable();
124 
125 	if (i915_request_wait(rq, 0, HZ / 2) < 0) {
126 		i915_request_put(rq);
127 		return -ETIME;
128 	}
129 	i915_request_put(rq);
130 
131 	pr_debug("%s CTX_TIMESTAMP: [%x, %x], RING_TIMESTAMP: [%x, %x]\n",
132 		 engine->name, sema[1], sema[3], sema[0], sema[4]);
133 
134 	*d_ctx = sema[3] - sema[1];
135 	*d_ring = sema[4] - sema[0];
136 	return 0;
137 }
138 
139 static int __live_engine_timestamps(struct intel_engine_cs *engine)
140 {
141 	u64 s_ring[COUNT], s_ctx[COUNT], st[COUNT], d_ring, d_ctx, dt;
142 	struct intel_context *ce;
143 	int i, err = 0;
144 
145 	ce = intel_context_create(engine);
146 	if (IS_ERR(ce))
147 		return PTR_ERR(ce);
148 
149 	for (i = 0; i < COUNT; i++) {
150 		err = __measure_timestamps(ce, &st[i], &s_ring[i], &s_ctx[i]);
151 		if (err)
152 			break;
153 	}
154 	intel_context_put(ce);
155 	if (err)
156 		return err;
157 
158 	dt = trifilter(st);
159 	d_ring = trifilter(s_ring);
160 	d_ctx = trifilter(s_ctx);
161 
162 	pr_info("%s elapsed:%lldns, CTX_TIMESTAMP:%lldns, RING_TIMESTAMP:%lldns\n",
163 		engine->name, dt,
164 		intel_gt_clock_interval_to_ns(engine->gt, d_ctx),
165 		intel_gt_clock_interval_to_ns(engine->gt, d_ring));
166 
167 	d_ring = intel_gt_clock_interval_to_ns(engine->gt, d_ring);
168 	if (3 * dt > 4 * d_ring || 4 * dt < 3 * d_ring) {
169 		pr_err("%s Mismatch between ring timestamp and walltime!\n",
170 		       engine->name);
171 		return -EINVAL;
172 	}
173 
174 	d_ring = trifilter(s_ring);
175 	d_ctx = trifilter(s_ctx);
176 
177 	d_ctx *= engine->gt->clock_frequency;
178 	if (GRAPHICS_VER(engine->i915) == 11)
179 		d_ring *= 12500000; /* Fixed 80ns for GEN11 ctx timestamp? */
180 	else
181 		d_ring *= engine->gt->clock_frequency;
182 
183 	if (3 * d_ctx > 4 * d_ring || 4 * d_ctx < 3 * d_ring) {
184 		pr_err("%s Mismatch between ring and context timestamps!\n",
185 		       engine->name);
186 		return -EINVAL;
187 	}
188 
189 	return 0;
190 }
191 
192 static int live_engine_timestamps(void *arg)
193 {
194 	struct intel_gt *gt = arg;
195 	struct intel_engine_cs *engine;
196 	enum intel_engine_id id;
197 
198 	/*
199 	 * Check that CS_TIMESTAMP / CTX_TIMESTAMP are in sync, i.e. share
200 	 * the same CS clock.
201 	 */
202 
203 	if (GRAPHICS_VER(gt->i915) < 8)
204 		return 0;
205 
206 	for_each_engine(engine, gt, id) {
207 		int err;
208 
209 		st_engine_heartbeat_disable(engine);
210 		err = __live_engine_timestamps(engine);
211 		st_engine_heartbeat_enable(engine);
212 		if (err)
213 			return err;
214 	}
215 
216 	return 0;
217 }
218 
219 static int __spin_until_busier(struct intel_engine_cs *engine, ktime_t busyness)
220 {
221 	ktime_t start, unused, dt;
222 
223 	if (!intel_engine_uses_guc(engine))
224 		return 0;
225 
226 	/*
227 	 * In GuC mode of submission, the busyness stats may get updated after
228 	 * the batch starts running. Poll for a change in busyness and timeout
229 	 * after 500 us.
230 	 */
231 	start = ktime_get();
232 	while (intel_engine_get_busy_time(engine, &unused) == busyness) {
233 		dt = ktime_get() - start;
234 		if (dt > 10000000) {
235 			pr_err("active wait timed out %lld\n", dt);
236 			ENGINE_TRACE(engine, "active wait time out %lld\n", dt);
237 			return -ETIME;
238 		}
239 	}
240 
241 	return 0;
242 }
243 
244 static int live_engine_busy_stats(void *arg)
245 {
246 	struct intel_gt *gt = arg;
247 	struct intel_engine_cs *engine;
248 	enum intel_engine_id id;
249 	struct igt_spinner spin;
250 	int err = 0;
251 
252 	/*
253 	 * Check that if an engine supports busy-stats, they tell the truth.
254 	 */
255 
256 	if (igt_spinner_init(&spin, gt))
257 		return -ENOMEM;
258 
259 	GEM_BUG_ON(intel_gt_pm_is_awake(gt));
260 	for_each_engine(engine, gt, id) {
261 		struct i915_request *rq;
262 		ktime_t busyness, dummy;
263 		ktime_t de, dt;
264 		ktime_t t[2];
265 
266 		if (!intel_engine_supports_stats(engine))
267 			continue;
268 
269 		if (!intel_engine_can_store_dword(engine))
270 			continue;
271 
272 		if (intel_gt_pm_wait_for_idle(gt)) {
273 			err = -EBUSY;
274 			break;
275 		}
276 
277 		st_engine_heartbeat_disable(engine);
278 
279 		ENGINE_TRACE(engine, "measuring idle time\n");
280 		preempt_disable();
281 		de = intel_engine_get_busy_time(engine, &t[0]);
282 		udelay(100);
283 		de = ktime_sub(intel_engine_get_busy_time(engine, &t[1]), de);
284 		preempt_enable();
285 		dt = ktime_sub(t[1], t[0]);
286 		if (de < 0 || de > 10) {
287 			pr_err("%s: reported %lldns [%d%%] busyness while sleeping [for %lldns]\n",
288 			       engine->name,
289 			       de, (int)div64_u64(100 * de, dt), dt);
290 			GEM_TRACE_DUMP();
291 			err = -EINVAL;
292 			goto end;
293 		}
294 
295 		/* 100% busy */
296 		rq = igt_spinner_create_request(&spin,
297 						engine->kernel_context,
298 						MI_NOOP);
299 		if (IS_ERR(rq)) {
300 			err = PTR_ERR(rq);
301 			goto end;
302 		}
303 		i915_request_add(rq);
304 
305 		busyness = intel_engine_get_busy_time(engine, &dummy);
306 		if (!igt_wait_for_spinner(&spin, rq)) {
307 			intel_gt_set_wedged(engine->gt);
308 			err = -ETIME;
309 			goto end;
310 		}
311 
312 		err = __spin_until_busier(engine, busyness);
313 		if (err) {
314 			GEM_TRACE_DUMP();
315 			goto end;
316 		}
317 
318 		ENGINE_TRACE(engine, "measuring busy time\n");
319 		preempt_disable();
320 		de = intel_engine_get_busy_time(engine, &t[0]);
321 		mdelay(100);
322 		de = ktime_sub(intel_engine_get_busy_time(engine, &t[1]), de);
323 		preempt_enable();
324 		dt = ktime_sub(t[1], t[0]);
325 		if (100 * de < 95 * dt || 95 * de > 100 * dt) {
326 			pr_err("%s: reported %lldns [%d%%] busyness while spinning [for %lldns]\n",
327 			       engine->name,
328 			       de, (int)div64_u64(100 * de, dt), dt);
329 			GEM_TRACE_DUMP();
330 			err = -EINVAL;
331 			goto end;
332 		}
333 
334 end:
335 		st_engine_heartbeat_enable(engine);
336 		igt_spinner_end(&spin);
337 		if (igt_flush_test(gt->i915))
338 			err = -EIO;
339 		if (err)
340 			break;
341 	}
342 
343 	igt_spinner_fini(&spin);
344 	if (igt_flush_test(gt->i915))
345 		err = -EIO;
346 	return err;
347 }
348 
349 static int live_engine_pm(void *arg)
350 {
351 	struct intel_gt *gt = arg;
352 	struct intel_engine_cs *engine;
353 	enum intel_engine_id id;
354 
355 	/*
356 	 * Check we can call intel_engine_pm_put from any context. No
357 	 * failures are reported directly, but if we mess up lockdep should
358 	 * tell us.
359 	 */
360 	if (intel_gt_pm_wait_for_idle(gt)) {
361 		pr_err("Unable to flush GT pm before test\n");
362 		return -EBUSY;
363 	}
364 
365 	GEM_BUG_ON(intel_gt_pm_is_awake(gt));
366 	for_each_engine(engine, gt, id) {
367 		const typeof(*igt_atomic_phases) *p;
368 
369 		for (p = igt_atomic_phases; p->name; p++) {
370 			/*
371 			 * Acquisition is always synchronous, except if we
372 			 * know that the engine is already awake, in which
373 			 * case we should use intel_engine_pm_get_if_awake()
374 			 * to atomically grab the wakeref.
375 			 *
376 			 * In practice,
377 			 *    intel_engine_pm_get();
378 			 *    intel_engine_pm_put();
379 			 * occurs in one thread, while simultaneously
380 			 *    intel_engine_pm_get_if_awake();
381 			 *    intel_engine_pm_put();
382 			 * occurs from atomic context in another.
383 			 */
384 			GEM_BUG_ON(intel_engine_pm_is_awake(engine));
385 			intel_engine_pm_get(engine);
386 
387 			p->critical_section_begin();
388 			if (!intel_engine_pm_get_if_awake(engine))
389 				pr_err("intel_engine_pm_get_if_awake(%s) failed under %s\n",
390 				       engine->name, p->name);
391 			else
392 				intel_engine_pm_put_async(engine);
393 			intel_engine_pm_put_async(engine);
394 			p->critical_section_end();
395 
396 			intel_engine_pm_flush(engine);
397 
398 			if (intel_engine_pm_is_awake(engine)) {
399 				pr_err("%s is still awake after flushing pm\n",
400 				       engine->name);
401 				return -EINVAL;
402 			}
403 
404 			/* gt wakeref is async (deferred to workqueue) */
405 			if (intel_gt_pm_wait_for_idle(gt)) {
406 				gt_err(gt, "GT failed to idle\n");
407 				return -EINVAL;
408 			}
409 		}
410 	}
411 
412 	return 0;
413 }
414 
415 int live_engine_pm_selftests(struct intel_gt *gt)
416 {
417 	static const struct i915_subtest tests[] = {
418 		SUBTEST(live_engine_timestamps),
419 		SUBTEST(live_engine_busy_stats),
420 		SUBTEST(live_engine_pm),
421 	};
422 
423 	return intel_gt_live_subtests(tests, gt);
424 }
425