1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020 Intel Corporation
4  */
5 
6 #include <linux/pm_qos.h>
7 #include <linux/sort.h>
8 
9 #include "intel_engine_heartbeat.h"
10 #include "intel_engine_pm.h"
11 #include "intel_engine_regs.h"
12 #include "intel_gpu_commands.h"
13 #include "intel_gt_clock_utils.h"
14 #include "intel_gt_pm.h"
15 #include "intel_rc6.h"
16 #include "selftest_engine_heartbeat.h"
17 #include "selftest_rps.h"
18 #include "selftests/igt_flush_test.h"
19 #include "selftests/igt_spinner.h"
20 #include "selftests/librapl.h"
21 
22 /* Try to isolate the impact of cstates from determing frequency response */
23 #define CPU_LATENCY 0 /* -1 to disable pm_qos, 0 to disable cstates */
24 
25 static void dummy_rps_work(struct work_struct *wrk)
26 {
27 }
28 
29 static int cmp_u64(const void *A, const void *B)
30 {
31 	const u64 *a = A, *b = B;
32 
33 	if (*a < *b)
34 		return -1;
35 	else if (*a > *b)
36 		return 1;
37 	else
38 		return 0;
39 }
40 
41 static int cmp_u32(const void *A, const void *B)
42 {
43 	const u32 *a = A, *b = B;
44 
45 	if (*a < *b)
46 		return -1;
47 	else if (*a > *b)
48 		return 1;
49 	else
50 		return 0;
51 }
52 
53 static struct i915_vma *
54 create_spin_counter(struct intel_engine_cs *engine,
55 		    struct i915_address_space *vm,
56 		    bool srm,
57 		    u32 **cancel,
58 		    u32 **counter)
59 {
60 	enum {
61 		COUNT,
62 		INC,
63 		__NGPR__,
64 	};
65 #define CS_GPR(x) GEN8_RING_CS_GPR(engine->mmio_base, x)
66 	struct drm_i915_gem_object *obj;
67 	struct i915_vma *vma;
68 	unsigned long end;
69 	u32 *base, *cs;
70 	int loop, i;
71 	int err;
72 
73 	obj = i915_gem_object_create_internal(vm->i915, 64 << 10);
74 	if (IS_ERR(obj))
75 		return ERR_CAST(obj);
76 
77 	end = obj->base.size / sizeof(u32) - 1;
78 
79 	vma = i915_vma_instance(obj, vm, NULL);
80 	if (IS_ERR(vma)) {
81 		err = PTR_ERR(vma);
82 		goto err_put;
83 	}
84 
85 	err = i915_vma_pin(vma, 0, 0, PIN_USER);
86 	if (err)
87 		goto err_unlock;
88 
89 	i915_vma_lock(vma);
90 
91 	base = i915_gem_object_pin_map(obj, I915_MAP_WC);
92 	if (IS_ERR(base)) {
93 		err = PTR_ERR(base);
94 		goto err_unpin;
95 	}
96 	cs = base;
97 
98 	*cs++ = MI_LOAD_REGISTER_IMM(__NGPR__ * 2);
99 	for (i = 0; i < __NGPR__; i++) {
100 		*cs++ = i915_mmio_reg_offset(CS_GPR(i));
101 		*cs++ = 0;
102 		*cs++ = i915_mmio_reg_offset(CS_GPR(i)) + 4;
103 		*cs++ = 0;
104 	}
105 
106 	*cs++ = MI_LOAD_REGISTER_IMM(1);
107 	*cs++ = i915_mmio_reg_offset(CS_GPR(INC));
108 	*cs++ = 1;
109 
110 	loop = cs - base;
111 
112 	/* Unroll the loop to avoid MI_BB_START stalls impacting measurements */
113 	for (i = 0; i < 1024; i++) {
114 		*cs++ = MI_MATH(4);
115 		*cs++ = MI_MATH_LOAD(MI_MATH_REG_SRCA, MI_MATH_REG(COUNT));
116 		*cs++ = MI_MATH_LOAD(MI_MATH_REG_SRCB, MI_MATH_REG(INC));
117 		*cs++ = MI_MATH_ADD;
118 		*cs++ = MI_MATH_STORE(MI_MATH_REG(COUNT), MI_MATH_REG_ACCU);
119 
120 		if (srm) {
121 			*cs++ = MI_STORE_REGISTER_MEM_GEN8;
122 			*cs++ = i915_mmio_reg_offset(CS_GPR(COUNT));
123 			*cs++ = lower_32_bits(vma->node.start + end * sizeof(*cs));
124 			*cs++ = upper_32_bits(vma->node.start + end * sizeof(*cs));
125 		}
126 	}
127 
128 	*cs++ = MI_BATCH_BUFFER_START_GEN8;
129 	*cs++ = lower_32_bits(vma->node.start + loop * sizeof(*cs));
130 	*cs++ = upper_32_bits(vma->node.start + loop * sizeof(*cs));
131 	GEM_BUG_ON(cs - base > end);
132 
133 	i915_gem_object_flush_map(obj);
134 
135 	*cancel = base + loop;
136 	*counter = srm ? memset32(base + end, 0, 1) : NULL;
137 	return vma;
138 
139 err_unpin:
140 	i915_vma_unpin(vma);
141 err_unlock:
142 	i915_vma_unlock(vma);
143 err_put:
144 	i915_gem_object_put(obj);
145 	return ERR_PTR(err);
146 }
147 
148 static u8 wait_for_freq(struct intel_rps *rps, u8 freq, int timeout_ms)
149 {
150 	u8 history[64], i;
151 	unsigned long end;
152 	int sleep;
153 
154 	i = 0;
155 	memset(history, freq, sizeof(history));
156 	sleep = 20;
157 
158 	/* The PCU does not change instantly, but drifts towards the goal? */
159 	end = jiffies + msecs_to_jiffies(timeout_ms);
160 	do {
161 		u8 act;
162 
163 		act = read_cagf(rps);
164 		if (time_after(jiffies, end))
165 			return act;
166 
167 		/* Target acquired */
168 		if (act == freq)
169 			return act;
170 
171 		/* Any change within the last N samples? */
172 		if (!memchr_inv(history, act, sizeof(history)))
173 			return act;
174 
175 		history[i] = act;
176 		i = (i + 1) % ARRAY_SIZE(history);
177 
178 		usleep_range(sleep, 2 * sleep);
179 		sleep *= 2;
180 		if (sleep > timeout_ms * 20)
181 			sleep = timeout_ms * 20;
182 	} while (1);
183 }
184 
185 static u8 rps_set_check(struct intel_rps *rps, u8 freq)
186 {
187 	mutex_lock(&rps->lock);
188 	GEM_BUG_ON(!intel_rps_is_active(rps));
189 	if (wait_for(!intel_rps_set(rps, freq), 50)) {
190 		mutex_unlock(&rps->lock);
191 		return 0;
192 	}
193 	GEM_BUG_ON(rps->last_freq != freq);
194 	mutex_unlock(&rps->lock);
195 
196 	return wait_for_freq(rps, freq, 50);
197 }
198 
199 static void show_pstate_limits(struct intel_rps *rps)
200 {
201 	struct drm_i915_private *i915 = rps_to_i915(rps);
202 
203 	if (IS_BROXTON(i915)) {
204 		pr_info("P_STATE_CAP[%x]: 0x%08x\n",
205 			i915_mmio_reg_offset(BXT_RP_STATE_CAP),
206 			intel_uncore_read(rps_to_uncore(rps),
207 					  BXT_RP_STATE_CAP));
208 	} else if (GRAPHICS_VER(i915) == 9) {
209 		pr_info("P_STATE_LIMITS[%x]: 0x%08x\n",
210 			i915_mmio_reg_offset(GEN9_RP_STATE_LIMITS),
211 			intel_uncore_read(rps_to_uncore(rps),
212 					  GEN9_RP_STATE_LIMITS));
213 	}
214 }
215 
216 int live_rps_clock_interval(void *arg)
217 {
218 	struct intel_gt *gt = arg;
219 	struct intel_rps *rps = &gt->rps;
220 	void (*saved_work)(struct work_struct *wrk);
221 	struct intel_engine_cs *engine;
222 	enum intel_engine_id id;
223 	struct igt_spinner spin;
224 	int err = 0;
225 
226 	if (!intel_rps_is_enabled(rps) || GRAPHICS_VER(gt->i915) < 6)
227 		return 0;
228 
229 	if (igt_spinner_init(&spin, gt))
230 		return -ENOMEM;
231 
232 	intel_gt_pm_wait_for_idle(gt);
233 	saved_work = rps->work.func;
234 	rps->work.func = dummy_rps_work;
235 
236 	intel_gt_pm_get(gt);
237 	intel_rps_disable(&gt->rps);
238 
239 	intel_gt_check_clock_frequency(gt);
240 
241 	for_each_engine(engine, gt, id) {
242 		struct i915_request *rq;
243 		u32 cycles;
244 		u64 dt;
245 
246 		if (!intel_engine_can_store_dword(engine))
247 			continue;
248 
249 		st_engine_heartbeat_disable(engine);
250 
251 		rq = igt_spinner_create_request(&spin,
252 						engine->kernel_context,
253 						MI_NOOP);
254 		if (IS_ERR(rq)) {
255 			st_engine_heartbeat_enable(engine);
256 			err = PTR_ERR(rq);
257 			break;
258 		}
259 
260 		i915_request_add(rq);
261 
262 		if (!igt_wait_for_spinner(&spin, rq)) {
263 			pr_err("%s: RPS spinner did not start\n",
264 			       engine->name);
265 			igt_spinner_end(&spin);
266 			st_engine_heartbeat_enable(engine);
267 			intel_gt_set_wedged(engine->gt);
268 			err = -EIO;
269 			break;
270 		}
271 
272 		intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
273 
274 		intel_uncore_write_fw(gt->uncore, GEN6_RP_CUR_UP_EI, 0);
275 
276 		/* Set the evaluation interval to infinity! */
277 		intel_uncore_write_fw(gt->uncore,
278 				      GEN6_RP_UP_EI, 0xffffffff);
279 		intel_uncore_write_fw(gt->uncore,
280 				      GEN6_RP_UP_THRESHOLD, 0xffffffff);
281 
282 		intel_uncore_write_fw(gt->uncore, GEN6_RP_CONTROL,
283 				      GEN6_RP_ENABLE | GEN6_RP_UP_BUSY_AVG);
284 
285 		if (wait_for(intel_uncore_read_fw(gt->uncore,
286 						  GEN6_RP_CUR_UP_EI),
287 			     10)) {
288 			/* Just skip the test; assume lack of HW support */
289 			pr_notice("%s: rps evaluation interval not ticking\n",
290 				  engine->name);
291 			err = -ENODEV;
292 		} else {
293 			ktime_t dt_[5];
294 			u32 cycles_[5];
295 			int i;
296 
297 			for (i = 0; i < 5; i++) {
298 				preempt_disable();
299 
300 				dt_[i] = ktime_get();
301 				cycles_[i] = -intel_uncore_read_fw(gt->uncore, GEN6_RP_CUR_UP_EI);
302 
303 				udelay(1000);
304 
305 				dt_[i] = ktime_sub(ktime_get(), dt_[i]);
306 				cycles_[i] += intel_uncore_read_fw(gt->uncore, GEN6_RP_CUR_UP_EI);
307 
308 				preempt_enable();
309 			}
310 
311 			/* Use the median of both cycle/dt; close enough */
312 			sort(cycles_, 5, sizeof(*cycles_), cmp_u32, NULL);
313 			cycles = (cycles_[1] + 2 * cycles_[2] + cycles_[3]) / 4;
314 			sort(dt_, 5, sizeof(*dt_), cmp_u64, NULL);
315 			dt = div_u64(dt_[1] + 2 * dt_[2] + dt_[3], 4);
316 		}
317 
318 		intel_uncore_write_fw(gt->uncore, GEN6_RP_CONTROL, 0);
319 		intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
320 
321 		igt_spinner_end(&spin);
322 		st_engine_heartbeat_enable(engine);
323 
324 		if (err == 0) {
325 			u64 time = intel_gt_pm_interval_to_ns(gt, cycles);
326 			u32 expected =
327 				intel_gt_ns_to_pm_interval(gt, dt);
328 
329 			pr_info("%s: rps counted %d C0 cycles [%lldns] in %lldns [%d cycles], using GT clock frequency of %uKHz\n",
330 				engine->name, cycles, time, dt, expected,
331 				gt->clock_frequency / 1000);
332 
333 			if (10 * time < 8 * dt ||
334 			    8 * time > 10 * dt) {
335 				pr_err("%s: rps clock time does not match walltime!\n",
336 				       engine->name);
337 				err = -EINVAL;
338 			}
339 
340 			if (10 * expected < 8 * cycles ||
341 			    8 * expected > 10 * cycles) {
342 				pr_err("%s: walltime does not match rps clock ticks!\n",
343 				       engine->name);
344 				err = -EINVAL;
345 			}
346 		}
347 
348 		if (igt_flush_test(gt->i915))
349 			err = -EIO;
350 
351 		break; /* once is enough */
352 	}
353 
354 	intel_rps_enable(&gt->rps);
355 	intel_gt_pm_put(gt);
356 
357 	igt_spinner_fini(&spin);
358 
359 	intel_gt_pm_wait_for_idle(gt);
360 	rps->work.func = saved_work;
361 
362 	if (err == -ENODEV) /* skipped, don't report a fail */
363 		err = 0;
364 
365 	return err;
366 }
367 
368 int live_rps_control(void *arg)
369 {
370 	struct intel_gt *gt = arg;
371 	struct intel_rps *rps = &gt->rps;
372 	void (*saved_work)(struct work_struct *wrk);
373 	struct intel_engine_cs *engine;
374 	enum intel_engine_id id;
375 	struct igt_spinner spin;
376 	int err = 0;
377 
378 	/*
379 	 * Check that the actual frequency matches our requested frequency,
380 	 * to verify our control mechanism. We have to be careful that the
381 	 * PCU may throttle the GPU in which case the actual frequency used
382 	 * will be lowered than requested.
383 	 */
384 
385 	if (!intel_rps_is_enabled(rps))
386 		return 0;
387 
388 	if (IS_CHERRYVIEW(gt->i915)) /* XXX fragile PCU */
389 		return 0;
390 
391 	if (igt_spinner_init(&spin, gt))
392 		return -ENOMEM;
393 
394 	intel_gt_pm_wait_for_idle(gt);
395 	saved_work = rps->work.func;
396 	rps->work.func = dummy_rps_work;
397 
398 	intel_gt_pm_get(gt);
399 	for_each_engine(engine, gt, id) {
400 		struct i915_request *rq;
401 		ktime_t min_dt, max_dt;
402 		int f, limit;
403 		int min, max;
404 
405 		if (!intel_engine_can_store_dword(engine))
406 			continue;
407 
408 		st_engine_heartbeat_disable(engine);
409 
410 		rq = igt_spinner_create_request(&spin,
411 						engine->kernel_context,
412 						MI_NOOP);
413 		if (IS_ERR(rq)) {
414 			err = PTR_ERR(rq);
415 			break;
416 		}
417 
418 		i915_request_add(rq);
419 
420 		if (!igt_wait_for_spinner(&spin, rq)) {
421 			pr_err("%s: RPS spinner did not start\n",
422 			       engine->name);
423 			igt_spinner_end(&spin);
424 			st_engine_heartbeat_enable(engine);
425 			intel_gt_set_wedged(engine->gt);
426 			err = -EIO;
427 			break;
428 		}
429 
430 		if (rps_set_check(rps, rps->min_freq) != rps->min_freq) {
431 			pr_err("%s: could not set minimum frequency [%x], only %x!\n",
432 			       engine->name, rps->min_freq, read_cagf(rps));
433 			igt_spinner_end(&spin);
434 			st_engine_heartbeat_enable(engine);
435 			show_pstate_limits(rps);
436 			err = -EINVAL;
437 			break;
438 		}
439 
440 		for (f = rps->min_freq + 1; f < rps->max_freq; f++) {
441 			if (rps_set_check(rps, f) < f)
442 				break;
443 		}
444 
445 		limit = rps_set_check(rps, f);
446 
447 		if (rps_set_check(rps, rps->min_freq) != rps->min_freq) {
448 			pr_err("%s: could not restore minimum frequency [%x], only %x!\n",
449 			       engine->name, rps->min_freq, read_cagf(rps));
450 			igt_spinner_end(&spin);
451 			st_engine_heartbeat_enable(engine);
452 			show_pstate_limits(rps);
453 			err = -EINVAL;
454 			break;
455 		}
456 
457 		max_dt = ktime_get();
458 		max = rps_set_check(rps, limit);
459 		max_dt = ktime_sub(ktime_get(), max_dt);
460 
461 		min_dt = ktime_get();
462 		min = rps_set_check(rps, rps->min_freq);
463 		min_dt = ktime_sub(ktime_get(), min_dt);
464 
465 		igt_spinner_end(&spin);
466 		st_engine_heartbeat_enable(engine);
467 
468 		pr_info("%s: range:[%x:%uMHz, %x:%uMHz] limit:[%x:%uMHz], %x:%x response %lluns:%lluns\n",
469 			engine->name,
470 			rps->min_freq, intel_gpu_freq(rps, rps->min_freq),
471 			rps->max_freq, intel_gpu_freq(rps, rps->max_freq),
472 			limit, intel_gpu_freq(rps, limit),
473 			min, max, ktime_to_ns(min_dt), ktime_to_ns(max_dt));
474 
475 		if (limit == rps->min_freq) {
476 			pr_err("%s: GPU throttled to minimum!\n",
477 			       engine->name);
478 			show_pstate_limits(rps);
479 			err = -ENODEV;
480 			break;
481 		}
482 
483 		if (igt_flush_test(gt->i915)) {
484 			err = -EIO;
485 			break;
486 		}
487 	}
488 	intel_gt_pm_put(gt);
489 
490 	igt_spinner_fini(&spin);
491 
492 	intel_gt_pm_wait_for_idle(gt);
493 	rps->work.func = saved_work;
494 
495 	return err;
496 }
497 
498 static void show_pcu_config(struct intel_rps *rps)
499 {
500 	struct drm_i915_private *i915 = rps_to_i915(rps);
501 	unsigned int max_gpu_freq, min_gpu_freq;
502 	intel_wakeref_t wakeref;
503 	int gpu_freq;
504 
505 	if (!HAS_LLC(i915))
506 		return;
507 
508 	min_gpu_freq = rps->min_freq;
509 	max_gpu_freq = rps->max_freq;
510 	if (GRAPHICS_VER(i915) >= 9) {
511 		/* Convert GT frequency to 50 HZ units */
512 		min_gpu_freq /= GEN9_FREQ_SCALER;
513 		max_gpu_freq /= GEN9_FREQ_SCALER;
514 	}
515 
516 	wakeref = intel_runtime_pm_get(rps_to_uncore(rps)->rpm);
517 
518 	pr_info("%5s  %5s  %5s\n", "GPU", "eCPU", "eRing");
519 	for (gpu_freq = min_gpu_freq; gpu_freq <= max_gpu_freq; gpu_freq++) {
520 		int ia_freq = gpu_freq;
521 
522 		snb_pcode_read(i915, GEN6_PCODE_READ_MIN_FREQ_TABLE,
523 			       &ia_freq, NULL);
524 
525 		pr_info("%5d  %5d  %5d\n",
526 			gpu_freq * 50,
527 			((ia_freq >> 0) & 0xff) * 100,
528 			((ia_freq >> 8) & 0xff) * 100);
529 	}
530 
531 	intel_runtime_pm_put(rps_to_uncore(rps)->rpm, wakeref);
532 }
533 
534 static u64 __measure_frequency(u32 *cntr, int duration_ms)
535 {
536 	u64 dc, dt;
537 
538 	dt = ktime_get();
539 	dc = READ_ONCE(*cntr);
540 	usleep_range(1000 * duration_ms, 2000 * duration_ms);
541 	dc = READ_ONCE(*cntr) - dc;
542 	dt = ktime_get() - dt;
543 
544 	return div64_u64(1000 * 1000 * dc, dt);
545 }
546 
547 static u64 measure_frequency_at(struct intel_rps *rps, u32 *cntr, int *freq)
548 {
549 	u64 x[5];
550 	int i;
551 
552 	*freq = rps_set_check(rps, *freq);
553 	for (i = 0; i < 5; i++)
554 		x[i] = __measure_frequency(cntr, 2);
555 	*freq = (*freq + read_cagf(rps)) / 2;
556 
557 	/* A simple triangle filter for better result stability */
558 	sort(x, 5, sizeof(*x), cmp_u64, NULL);
559 	return div_u64(x[1] + 2 * x[2] + x[3], 4);
560 }
561 
562 static u64 __measure_cs_frequency(struct intel_engine_cs *engine,
563 				  int duration_ms)
564 {
565 	u64 dc, dt;
566 
567 	dt = ktime_get();
568 	dc = intel_uncore_read_fw(engine->uncore, CS_GPR(0));
569 	usleep_range(1000 * duration_ms, 2000 * duration_ms);
570 	dc = intel_uncore_read_fw(engine->uncore, CS_GPR(0)) - dc;
571 	dt = ktime_get() - dt;
572 
573 	return div64_u64(1000 * 1000 * dc, dt);
574 }
575 
576 static u64 measure_cs_frequency_at(struct intel_rps *rps,
577 				   struct intel_engine_cs *engine,
578 				   int *freq)
579 {
580 	u64 x[5];
581 	int i;
582 
583 	*freq = rps_set_check(rps, *freq);
584 	for (i = 0; i < 5; i++)
585 		x[i] = __measure_cs_frequency(engine, 2);
586 	*freq = (*freq + read_cagf(rps)) / 2;
587 
588 	/* A simple triangle filter for better result stability */
589 	sort(x, 5, sizeof(*x), cmp_u64, NULL);
590 	return div_u64(x[1] + 2 * x[2] + x[3], 4);
591 }
592 
593 static bool scaled_within(u64 x, u64 y, u32 f_n, u32 f_d)
594 {
595 	return f_d * x > f_n * y && f_n * x < f_d * y;
596 }
597 
598 int live_rps_frequency_cs(void *arg)
599 {
600 	void (*saved_work)(struct work_struct *wrk);
601 	struct intel_gt *gt = arg;
602 	struct intel_rps *rps = &gt->rps;
603 	struct intel_engine_cs *engine;
604 	struct pm_qos_request qos;
605 	enum intel_engine_id id;
606 	int err = 0;
607 
608 	/*
609 	 * The premise is that the GPU does change frequency at our behest.
610 	 * Let's check there is a correspondence between the requested
611 	 * frequency, the actual frequency, and the observed clock rate.
612 	 */
613 
614 	if (!intel_rps_is_enabled(rps))
615 		return 0;
616 
617 	if (GRAPHICS_VER(gt->i915) < 8) /* for CS simplicity */
618 		return 0;
619 
620 	if (CPU_LATENCY >= 0)
621 		cpu_latency_qos_add_request(&qos, CPU_LATENCY);
622 
623 	intel_gt_pm_wait_for_idle(gt);
624 	saved_work = rps->work.func;
625 	rps->work.func = dummy_rps_work;
626 
627 	for_each_engine(engine, gt, id) {
628 		struct i915_request *rq;
629 		struct i915_vma *vma;
630 		u32 *cancel, *cntr;
631 		struct {
632 			u64 count;
633 			int freq;
634 		} min, max;
635 
636 		st_engine_heartbeat_disable(engine);
637 
638 		vma = create_spin_counter(engine,
639 					  engine->kernel_context->vm, false,
640 					  &cancel, &cntr);
641 		if (IS_ERR(vma)) {
642 			err = PTR_ERR(vma);
643 			st_engine_heartbeat_enable(engine);
644 			break;
645 		}
646 
647 		rq = intel_engine_create_kernel_request(engine);
648 		if (IS_ERR(rq)) {
649 			err = PTR_ERR(rq);
650 			goto err_vma;
651 		}
652 
653 		err = i915_request_await_object(rq, vma->obj, false);
654 		if (!err)
655 			err = i915_vma_move_to_active(vma, rq, 0);
656 		if (!err)
657 			err = rq->engine->emit_bb_start(rq,
658 							vma->node.start,
659 							PAGE_SIZE, 0);
660 		i915_request_add(rq);
661 		if (err)
662 			goto err_vma;
663 
664 		if (wait_for(intel_uncore_read(engine->uncore, CS_GPR(0)),
665 			     10)) {
666 			pr_err("%s: timed loop did not start\n",
667 			       engine->name);
668 			goto err_vma;
669 		}
670 
671 		min.freq = rps->min_freq;
672 		min.count = measure_cs_frequency_at(rps, engine, &min.freq);
673 
674 		max.freq = rps->max_freq;
675 		max.count = measure_cs_frequency_at(rps, engine, &max.freq);
676 
677 		pr_info("%s: min:%lluKHz @ %uMHz, max:%lluKHz @ %uMHz [%d%%]\n",
678 			engine->name,
679 			min.count, intel_gpu_freq(rps, min.freq),
680 			max.count, intel_gpu_freq(rps, max.freq),
681 			(int)DIV64_U64_ROUND_CLOSEST(100 * min.freq * max.count,
682 						     max.freq * min.count));
683 
684 		if (!scaled_within(max.freq * min.count,
685 				   min.freq * max.count,
686 				   2, 3)) {
687 			int f;
688 
689 			pr_err("%s: CS did not scale with frequency! scaled min:%llu, max:%llu\n",
690 			       engine->name,
691 			       max.freq * min.count,
692 			       min.freq * max.count);
693 			show_pcu_config(rps);
694 
695 			for (f = min.freq + 1; f <= rps->max_freq; f++) {
696 				int act = f;
697 				u64 count;
698 
699 				count = measure_cs_frequency_at(rps, engine, &act);
700 				if (act < f)
701 					break;
702 
703 				pr_info("%s: %x:%uMHz: %lluKHz [%d%%]\n",
704 					engine->name,
705 					act, intel_gpu_freq(rps, act), count,
706 					(int)DIV64_U64_ROUND_CLOSEST(100 * min.freq * count,
707 								     act * min.count));
708 
709 				f = act; /* may skip ahead [pcu granularity] */
710 			}
711 
712 			err = -EINTR; /* ignore error, continue on with test */
713 		}
714 
715 err_vma:
716 		*cancel = MI_BATCH_BUFFER_END;
717 		i915_gem_object_flush_map(vma->obj);
718 		i915_gem_object_unpin_map(vma->obj);
719 		i915_vma_unpin(vma);
720 		i915_vma_unlock(vma);
721 		i915_vma_put(vma);
722 
723 		st_engine_heartbeat_enable(engine);
724 		if (igt_flush_test(gt->i915))
725 			err = -EIO;
726 		if (err)
727 			break;
728 	}
729 
730 	intel_gt_pm_wait_for_idle(gt);
731 	rps->work.func = saved_work;
732 
733 	if (CPU_LATENCY >= 0)
734 		cpu_latency_qos_remove_request(&qos);
735 
736 	return err;
737 }
738 
739 int live_rps_frequency_srm(void *arg)
740 {
741 	void (*saved_work)(struct work_struct *wrk);
742 	struct intel_gt *gt = arg;
743 	struct intel_rps *rps = &gt->rps;
744 	struct intel_engine_cs *engine;
745 	struct pm_qos_request qos;
746 	enum intel_engine_id id;
747 	int err = 0;
748 
749 	/*
750 	 * The premise is that the GPU does change frequency at our behest.
751 	 * Let's check there is a correspondence between the requested
752 	 * frequency, the actual frequency, and the observed clock rate.
753 	 */
754 
755 	if (!intel_rps_is_enabled(rps))
756 		return 0;
757 
758 	if (GRAPHICS_VER(gt->i915) < 8) /* for CS simplicity */
759 		return 0;
760 
761 	if (CPU_LATENCY >= 0)
762 		cpu_latency_qos_add_request(&qos, CPU_LATENCY);
763 
764 	intel_gt_pm_wait_for_idle(gt);
765 	saved_work = rps->work.func;
766 	rps->work.func = dummy_rps_work;
767 
768 	for_each_engine(engine, gt, id) {
769 		struct i915_request *rq;
770 		struct i915_vma *vma;
771 		u32 *cancel, *cntr;
772 		struct {
773 			u64 count;
774 			int freq;
775 		} min, max;
776 
777 		st_engine_heartbeat_disable(engine);
778 
779 		vma = create_spin_counter(engine,
780 					  engine->kernel_context->vm, true,
781 					  &cancel, &cntr);
782 		if (IS_ERR(vma)) {
783 			err = PTR_ERR(vma);
784 			st_engine_heartbeat_enable(engine);
785 			break;
786 		}
787 
788 		rq = intel_engine_create_kernel_request(engine);
789 		if (IS_ERR(rq)) {
790 			err = PTR_ERR(rq);
791 			goto err_vma;
792 		}
793 
794 		err = i915_request_await_object(rq, vma->obj, false);
795 		if (!err)
796 			err = i915_vma_move_to_active(vma, rq, 0);
797 		if (!err)
798 			err = rq->engine->emit_bb_start(rq,
799 							vma->node.start,
800 							PAGE_SIZE, 0);
801 		i915_request_add(rq);
802 		if (err)
803 			goto err_vma;
804 
805 		if (wait_for(READ_ONCE(*cntr), 10)) {
806 			pr_err("%s: timed loop did not start\n",
807 			       engine->name);
808 			goto err_vma;
809 		}
810 
811 		min.freq = rps->min_freq;
812 		min.count = measure_frequency_at(rps, cntr, &min.freq);
813 
814 		max.freq = rps->max_freq;
815 		max.count = measure_frequency_at(rps, cntr, &max.freq);
816 
817 		pr_info("%s: min:%lluKHz @ %uMHz, max:%lluKHz @ %uMHz [%d%%]\n",
818 			engine->name,
819 			min.count, intel_gpu_freq(rps, min.freq),
820 			max.count, intel_gpu_freq(rps, max.freq),
821 			(int)DIV64_U64_ROUND_CLOSEST(100 * min.freq * max.count,
822 						     max.freq * min.count));
823 
824 		if (!scaled_within(max.freq * min.count,
825 				   min.freq * max.count,
826 				   1, 2)) {
827 			int f;
828 
829 			pr_err("%s: CS did not scale with frequency! scaled min:%llu, max:%llu\n",
830 			       engine->name,
831 			       max.freq * min.count,
832 			       min.freq * max.count);
833 			show_pcu_config(rps);
834 
835 			for (f = min.freq + 1; f <= rps->max_freq; f++) {
836 				int act = f;
837 				u64 count;
838 
839 				count = measure_frequency_at(rps, cntr, &act);
840 				if (act < f)
841 					break;
842 
843 				pr_info("%s: %x:%uMHz: %lluKHz [%d%%]\n",
844 					engine->name,
845 					act, intel_gpu_freq(rps, act), count,
846 					(int)DIV64_U64_ROUND_CLOSEST(100 * min.freq * count,
847 								     act * min.count));
848 
849 				f = act; /* may skip ahead [pcu granularity] */
850 			}
851 
852 			err = -EINTR; /* ignore error, continue on with test */
853 		}
854 
855 err_vma:
856 		*cancel = MI_BATCH_BUFFER_END;
857 		i915_gem_object_flush_map(vma->obj);
858 		i915_gem_object_unpin_map(vma->obj);
859 		i915_vma_unpin(vma);
860 		i915_vma_unlock(vma);
861 		i915_vma_put(vma);
862 
863 		st_engine_heartbeat_enable(engine);
864 		if (igt_flush_test(gt->i915))
865 			err = -EIO;
866 		if (err)
867 			break;
868 	}
869 
870 	intel_gt_pm_wait_for_idle(gt);
871 	rps->work.func = saved_work;
872 
873 	if (CPU_LATENCY >= 0)
874 		cpu_latency_qos_remove_request(&qos);
875 
876 	return err;
877 }
878 
879 static void sleep_for_ei(struct intel_rps *rps, int timeout_us)
880 {
881 	/* Flush any previous EI */
882 	usleep_range(timeout_us, 2 * timeout_us);
883 
884 	/* Reset the interrupt status */
885 	rps_disable_interrupts(rps);
886 	GEM_BUG_ON(rps->pm_iir);
887 	rps_enable_interrupts(rps);
888 
889 	/* And then wait for the timeout, for real this time */
890 	usleep_range(2 * timeout_us, 3 * timeout_us);
891 }
892 
893 static int __rps_up_interrupt(struct intel_rps *rps,
894 			      struct intel_engine_cs *engine,
895 			      struct igt_spinner *spin)
896 {
897 	struct intel_uncore *uncore = engine->uncore;
898 	struct i915_request *rq;
899 	u32 timeout;
900 
901 	if (!intel_engine_can_store_dword(engine))
902 		return 0;
903 
904 	rps_set_check(rps, rps->min_freq);
905 
906 	rq = igt_spinner_create_request(spin, engine->kernel_context, MI_NOOP);
907 	if (IS_ERR(rq))
908 		return PTR_ERR(rq);
909 
910 	i915_request_get(rq);
911 	i915_request_add(rq);
912 
913 	if (!igt_wait_for_spinner(spin, rq)) {
914 		pr_err("%s: RPS spinner did not start\n",
915 		       engine->name);
916 		i915_request_put(rq);
917 		intel_gt_set_wedged(engine->gt);
918 		return -EIO;
919 	}
920 
921 	if (!intel_rps_is_active(rps)) {
922 		pr_err("%s: RPS not enabled on starting spinner\n",
923 		       engine->name);
924 		igt_spinner_end(spin);
925 		i915_request_put(rq);
926 		return -EINVAL;
927 	}
928 
929 	if (!(rps->pm_events & GEN6_PM_RP_UP_THRESHOLD)) {
930 		pr_err("%s: RPS did not register UP interrupt\n",
931 		       engine->name);
932 		i915_request_put(rq);
933 		return -EINVAL;
934 	}
935 
936 	if (rps->last_freq != rps->min_freq) {
937 		pr_err("%s: RPS did not program min frequency\n",
938 		       engine->name);
939 		i915_request_put(rq);
940 		return -EINVAL;
941 	}
942 
943 	timeout = intel_uncore_read(uncore, GEN6_RP_UP_EI);
944 	timeout = intel_gt_pm_interval_to_ns(engine->gt, timeout);
945 	timeout = DIV_ROUND_UP(timeout, 1000);
946 
947 	sleep_for_ei(rps, timeout);
948 	GEM_BUG_ON(i915_request_completed(rq));
949 
950 	igt_spinner_end(spin);
951 	i915_request_put(rq);
952 
953 	if (rps->cur_freq != rps->min_freq) {
954 		pr_err("%s: Frequency unexpectedly changed [up], now %d!\n",
955 		       engine->name, intel_rps_read_actual_frequency(rps));
956 		return -EINVAL;
957 	}
958 
959 	if (!(rps->pm_iir & GEN6_PM_RP_UP_THRESHOLD)) {
960 		pr_err("%s: UP interrupt not recorded for spinner, pm_iir:%x, prev_up:%x, up_threshold:%x, up_ei:%x\n",
961 		       engine->name, rps->pm_iir,
962 		       intel_uncore_read(uncore, GEN6_RP_PREV_UP),
963 		       intel_uncore_read(uncore, GEN6_RP_UP_THRESHOLD),
964 		       intel_uncore_read(uncore, GEN6_RP_UP_EI));
965 		return -EINVAL;
966 	}
967 
968 	return 0;
969 }
970 
971 static int __rps_down_interrupt(struct intel_rps *rps,
972 				struct intel_engine_cs *engine)
973 {
974 	struct intel_uncore *uncore = engine->uncore;
975 	u32 timeout;
976 
977 	rps_set_check(rps, rps->max_freq);
978 
979 	if (!(rps->pm_events & GEN6_PM_RP_DOWN_THRESHOLD)) {
980 		pr_err("%s: RPS did not register DOWN interrupt\n",
981 		       engine->name);
982 		return -EINVAL;
983 	}
984 
985 	if (rps->last_freq != rps->max_freq) {
986 		pr_err("%s: RPS did not program max frequency\n",
987 		       engine->name);
988 		return -EINVAL;
989 	}
990 
991 	timeout = intel_uncore_read(uncore, GEN6_RP_DOWN_EI);
992 	timeout = intel_gt_pm_interval_to_ns(engine->gt, timeout);
993 	timeout = DIV_ROUND_UP(timeout, 1000);
994 
995 	sleep_for_ei(rps, timeout);
996 
997 	if (rps->cur_freq != rps->max_freq) {
998 		pr_err("%s: Frequency unexpectedly changed [down], now %d!\n",
999 		       engine->name,
1000 		       intel_rps_read_actual_frequency(rps));
1001 		return -EINVAL;
1002 	}
1003 
1004 	if (!(rps->pm_iir & (GEN6_PM_RP_DOWN_THRESHOLD | GEN6_PM_RP_DOWN_TIMEOUT))) {
1005 		pr_err("%s: DOWN interrupt not recorded for idle, pm_iir:%x, prev_down:%x, down_threshold:%x, down_ei:%x [prev_up:%x, up_threshold:%x, up_ei:%x]\n",
1006 		       engine->name, rps->pm_iir,
1007 		       intel_uncore_read(uncore, GEN6_RP_PREV_DOWN),
1008 		       intel_uncore_read(uncore, GEN6_RP_DOWN_THRESHOLD),
1009 		       intel_uncore_read(uncore, GEN6_RP_DOWN_EI),
1010 		       intel_uncore_read(uncore, GEN6_RP_PREV_UP),
1011 		       intel_uncore_read(uncore, GEN6_RP_UP_THRESHOLD),
1012 		       intel_uncore_read(uncore, GEN6_RP_UP_EI));
1013 		return -EINVAL;
1014 	}
1015 
1016 	return 0;
1017 }
1018 
1019 int live_rps_interrupt(void *arg)
1020 {
1021 	struct intel_gt *gt = arg;
1022 	struct intel_rps *rps = &gt->rps;
1023 	void (*saved_work)(struct work_struct *wrk);
1024 	struct intel_engine_cs *engine;
1025 	enum intel_engine_id id;
1026 	struct igt_spinner spin;
1027 	u32 pm_events;
1028 	int err = 0;
1029 
1030 	/*
1031 	 * First, let's check whether or not we are receiving interrupts.
1032 	 */
1033 
1034 	if (!intel_rps_has_interrupts(rps) || GRAPHICS_VER(gt->i915) < 6)
1035 		return 0;
1036 
1037 	intel_gt_pm_get(gt);
1038 	pm_events = rps->pm_events;
1039 	intel_gt_pm_put(gt);
1040 	if (!pm_events) {
1041 		pr_err("No RPS PM events registered, but RPS is enabled?\n");
1042 		return -ENODEV;
1043 	}
1044 
1045 	if (igt_spinner_init(&spin, gt))
1046 		return -ENOMEM;
1047 
1048 	intel_gt_pm_wait_for_idle(gt);
1049 	saved_work = rps->work.func;
1050 	rps->work.func = dummy_rps_work;
1051 
1052 	for_each_engine(engine, gt, id) {
1053 		/* Keep the engine busy with a spinner; expect an UP! */
1054 		if (pm_events & GEN6_PM_RP_UP_THRESHOLD) {
1055 			intel_gt_pm_wait_for_idle(engine->gt);
1056 			GEM_BUG_ON(intel_rps_is_active(rps));
1057 
1058 			st_engine_heartbeat_disable(engine);
1059 
1060 			err = __rps_up_interrupt(rps, engine, &spin);
1061 
1062 			st_engine_heartbeat_enable(engine);
1063 			if (err)
1064 				goto out;
1065 
1066 			intel_gt_pm_wait_for_idle(engine->gt);
1067 		}
1068 
1069 		/* Keep the engine awake but idle and check for DOWN */
1070 		if (pm_events & GEN6_PM_RP_DOWN_THRESHOLD) {
1071 			st_engine_heartbeat_disable(engine);
1072 			intel_rc6_disable(&gt->rc6);
1073 
1074 			err = __rps_down_interrupt(rps, engine);
1075 
1076 			intel_rc6_enable(&gt->rc6);
1077 			st_engine_heartbeat_enable(engine);
1078 			if (err)
1079 				goto out;
1080 		}
1081 	}
1082 
1083 out:
1084 	if (igt_flush_test(gt->i915))
1085 		err = -EIO;
1086 
1087 	igt_spinner_fini(&spin);
1088 
1089 	intel_gt_pm_wait_for_idle(gt);
1090 	rps->work.func = saved_work;
1091 
1092 	return err;
1093 }
1094 
1095 static u64 __measure_power(int duration_ms)
1096 {
1097 	u64 dE, dt;
1098 
1099 	dt = ktime_get();
1100 	dE = librapl_energy_uJ();
1101 	usleep_range(1000 * duration_ms, 2000 * duration_ms);
1102 	dE = librapl_energy_uJ() - dE;
1103 	dt = ktime_get() - dt;
1104 
1105 	return div64_u64(1000 * 1000 * dE, dt);
1106 }
1107 
1108 static u64 measure_power_at(struct intel_rps *rps, int *freq)
1109 {
1110 	u64 x[5];
1111 	int i;
1112 
1113 	*freq = rps_set_check(rps, *freq);
1114 	for (i = 0; i < 5; i++)
1115 		x[i] = __measure_power(5);
1116 	*freq = (*freq + read_cagf(rps)) / 2;
1117 
1118 	/* A simple triangle filter for better result stability */
1119 	sort(x, 5, sizeof(*x), cmp_u64, NULL);
1120 	return div_u64(x[1] + 2 * x[2] + x[3], 4);
1121 }
1122 
1123 int live_rps_power(void *arg)
1124 {
1125 	struct intel_gt *gt = arg;
1126 	struct intel_rps *rps = &gt->rps;
1127 	void (*saved_work)(struct work_struct *wrk);
1128 	struct intel_engine_cs *engine;
1129 	enum intel_engine_id id;
1130 	struct igt_spinner spin;
1131 	int err = 0;
1132 
1133 	/*
1134 	 * Our fundamental assumption is that running at lower frequency
1135 	 * actually saves power. Let's see if our RAPL measurement support
1136 	 * that theory.
1137 	 */
1138 
1139 	if (!intel_rps_is_enabled(rps) || GRAPHICS_VER(gt->i915) < 6)
1140 		return 0;
1141 
1142 	if (!librapl_supported(gt->i915))
1143 		return 0;
1144 
1145 	if (igt_spinner_init(&spin, gt))
1146 		return -ENOMEM;
1147 
1148 	intel_gt_pm_wait_for_idle(gt);
1149 	saved_work = rps->work.func;
1150 	rps->work.func = dummy_rps_work;
1151 
1152 	for_each_engine(engine, gt, id) {
1153 		struct i915_request *rq;
1154 		struct {
1155 			u64 power;
1156 			int freq;
1157 		} min, max;
1158 
1159 		if (!intel_engine_can_store_dword(engine))
1160 			continue;
1161 
1162 		st_engine_heartbeat_disable(engine);
1163 
1164 		rq = igt_spinner_create_request(&spin,
1165 						engine->kernel_context,
1166 						MI_NOOP);
1167 		if (IS_ERR(rq)) {
1168 			st_engine_heartbeat_enable(engine);
1169 			err = PTR_ERR(rq);
1170 			break;
1171 		}
1172 
1173 		i915_request_add(rq);
1174 
1175 		if (!igt_wait_for_spinner(&spin, rq)) {
1176 			pr_err("%s: RPS spinner did not start\n",
1177 			       engine->name);
1178 			igt_spinner_end(&spin);
1179 			st_engine_heartbeat_enable(engine);
1180 			intel_gt_set_wedged(engine->gt);
1181 			err = -EIO;
1182 			break;
1183 		}
1184 
1185 		max.freq = rps->max_freq;
1186 		max.power = measure_power_at(rps, &max.freq);
1187 
1188 		min.freq = rps->min_freq;
1189 		min.power = measure_power_at(rps, &min.freq);
1190 
1191 		igt_spinner_end(&spin);
1192 		st_engine_heartbeat_enable(engine);
1193 
1194 		pr_info("%s: min:%llumW @ %uMHz, max:%llumW @ %uMHz\n",
1195 			engine->name,
1196 			min.power, intel_gpu_freq(rps, min.freq),
1197 			max.power, intel_gpu_freq(rps, max.freq));
1198 
1199 		if (10 * min.freq >= 9 * max.freq) {
1200 			pr_notice("Could not control frequency, ran at [%d:%uMHz, %d:%uMhz]\n",
1201 				  min.freq, intel_gpu_freq(rps, min.freq),
1202 				  max.freq, intel_gpu_freq(rps, max.freq));
1203 			continue;
1204 		}
1205 
1206 		if (11 * min.power > 10 * max.power) {
1207 			pr_err("%s: did not conserve power when setting lower frequency!\n",
1208 			       engine->name);
1209 			err = -EINVAL;
1210 			break;
1211 		}
1212 
1213 		if (igt_flush_test(gt->i915)) {
1214 			err = -EIO;
1215 			break;
1216 		}
1217 	}
1218 
1219 	igt_spinner_fini(&spin);
1220 
1221 	intel_gt_pm_wait_for_idle(gt);
1222 	rps->work.func = saved_work;
1223 
1224 	return err;
1225 }
1226 
1227 int live_rps_dynamic(void *arg)
1228 {
1229 	struct intel_gt *gt = arg;
1230 	struct intel_rps *rps = &gt->rps;
1231 	struct intel_engine_cs *engine;
1232 	enum intel_engine_id id;
1233 	struct igt_spinner spin;
1234 	int err = 0;
1235 
1236 	/*
1237 	 * We've looked at the bascs, and have established that we
1238 	 * can change the clock frequency and that the HW will generate
1239 	 * interrupts based on load. Now we check how we integrate those
1240 	 * moving parts into dynamic reclocking based on load.
1241 	 */
1242 
1243 	if (!intel_rps_is_enabled(rps) || GRAPHICS_VER(gt->i915) < 6)
1244 		return 0;
1245 
1246 	if (igt_spinner_init(&spin, gt))
1247 		return -ENOMEM;
1248 
1249 	if (intel_rps_has_interrupts(rps))
1250 		pr_info("RPS has interrupt support\n");
1251 	if (intel_rps_uses_timer(rps))
1252 		pr_info("RPS has timer support\n");
1253 
1254 	for_each_engine(engine, gt, id) {
1255 		struct i915_request *rq;
1256 		struct {
1257 			ktime_t dt;
1258 			u8 freq;
1259 		} min, max;
1260 
1261 		if (!intel_engine_can_store_dword(engine))
1262 			continue;
1263 
1264 		intel_gt_pm_wait_for_idle(gt);
1265 		GEM_BUG_ON(intel_rps_is_active(rps));
1266 		rps->cur_freq = rps->min_freq;
1267 
1268 		intel_engine_pm_get(engine);
1269 		intel_rc6_disable(&gt->rc6);
1270 		GEM_BUG_ON(rps->last_freq != rps->min_freq);
1271 
1272 		rq = igt_spinner_create_request(&spin,
1273 						engine->kernel_context,
1274 						MI_NOOP);
1275 		if (IS_ERR(rq)) {
1276 			err = PTR_ERR(rq);
1277 			goto err;
1278 		}
1279 
1280 		i915_request_add(rq);
1281 
1282 		max.dt = ktime_get();
1283 		max.freq = wait_for_freq(rps, rps->max_freq, 500);
1284 		max.dt = ktime_sub(ktime_get(), max.dt);
1285 
1286 		igt_spinner_end(&spin);
1287 
1288 		min.dt = ktime_get();
1289 		min.freq = wait_for_freq(rps, rps->min_freq, 2000);
1290 		min.dt = ktime_sub(ktime_get(), min.dt);
1291 
1292 		pr_info("%s: dynamically reclocked to %u:%uMHz while busy in %lluns, and %u:%uMHz while idle in %lluns\n",
1293 			engine->name,
1294 			max.freq, intel_gpu_freq(rps, max.freq),
1295 			ktime_to_ns(max.dt),
1296 			min.freq, intel_gpu_freq(rps, min.freq),
1297 			ktime_to_ns(min.dt));
1298 		if (min.freq >= max.freq) {
1299 			pr_err("%s: dynamic reclocking of spinner failed\n!",
1300 			       engine->name);
1301 			err = -EINVAL;
1302 		}
1303 
1304 err:
1305 		intel_rc6_enable(&gt->rc6);
1306 		intel_engine_pm_put(engine);
1307 
1308 		if (igt_flush_test(gt->i915))
1309 			err = -EIO;
1310 		if (err)
1311 			break;
1312 	}
1313 
1314 	igt_spinner_fini(&spin);
1315 
1316 	return err;
1317 }
1318