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