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 "gem/i915_gem_internal.h"
10
11#include "i915_reg.h"
12#include "intel_engine_heartbeat.h"
13#include "intel_engine_pm.h"
14#include "intel_engine_regs.h"
15#include "intel_gpu_commands.h"
16#include "intel_gt_clock_utils.h"
17#include "intel_gt_pm.h"
18#include "intel_rc6.h"
19#include "selftest_engine_heartbeat.h"
20#include "selftest_rps.h"
21#include "selftests/igt_flush_test.h"
22#include "selftests/igt_spinner.h"
23#include "selftests/librapl.h"
24
25/* Try to isolate the impact of cstates from determing frequency response */
26#define CPU_LATENCY 0 /* -1 to disable pm_qos, 0 to disable cstates */
27
28static void dummy_rps_work(struct work_struct *wrk)
29{
30}
31
32static int cmp_u64(const void *A, const void *B)
33{
34	const u64 *a = A, *b = B;
35
36	if (*a < *b)
37		return -1;
38	else if (*a > *b)
39		return 1;
40	else
41		return 0;
42}
43
44static int cmp_u32(const void *A, const void *B)
45{
46	const u32 *a = A, *b = B;
47
48	if (*a < *b)
49		return -1;
50	else if (*a > *b)
51		return 1;
52	else
53		return 0;
54}
55
56static struct i915_vma *
57create_spin_counter(struct intel_engine_cs *engine,
58		    struct i915_address_space *vm,
59		    bool srm,
60		    u32 **cancel,
61		    u32 **counter)
62{
63	enum {
64		COUNT,
65		INC,
66		__NGPR__,
67	};
68#define CS_GPR(x) GEN8_RING_CS_GPR(engine->mmio_base, x)
69	struct drm_i915_gem_object *obj;
70	struct i915_vma *vma;
71	unsigned long end;
72	u32 *base, *cs;
73	int loop, i;
74	int err;
75
76	obj = i915_gem_object_create_internal(vm->i915, 64 << 10);
77	if (IS_ERR(obj))
78		return ERR_CAST(obj);
79
80	end = obj->base.size / sizeof(u32) - 1;
81
82	vma = i915_vma_instance(obj, vm, NULL);
83	if (IS_ERR(vma)) {
84		err = PTR_ERR(vma);
85		goto err_put;
86	}
87
88	err = i915_vma_pin(vma, 0, 0, PIN_USER);
89	if (err)
90		goto err_unlock;
91
92	i915_vma_lock(vma);
93
94	base = i915_gem_object_pin_map(obj, I915_MAP_WC);
95	if (IS_ERR(base)) {
96		err = PTR_ERR(base);
97		goto err_unpin;
98	}
99	cs = base;
100
101	*cs++ = MI_LOAD_REGISTER_IMM(__NGPR__ * 2);
102	for (i = 0; i < __NGPR__; i++) {
103		*cs++ = i915_mmio_reg_offset(CS_GPR(i));
104		*cs++ = 0;
105		*cs++ = i915_mmio_reg_offset(CS_GPR(i)) + 4;
106		*cs++ = 0;
107	}
108
109	*cs++ = MI_LOAD_REGISTER_IMM(1);
110	*cs++ = i915_mmio_reg_offset(CS_GPR(INC));
111	*cs++ = 1;
112
113	loop = cs - base;
114
115	/* Unroll the loop to avoid MI_BB_START stalls impacting measurements */
116	for (i = 0; i < 1024; i++) {
117		*cs++ = MI_MATH(4);
118		*cs++ = MI_MATH_LOAD(MI_MATH_REG_SRCA, MI_MATH_REG(COUNT));
119		*cs++ = MI_MATH_LOAD(MI_MATH_REG_SRCB, MI_MATH_REG(INC));
120		*cs++ = MI_MATH_ADD;
121		*cs++ = MI_MATH_STORE(MI_MATH_REG(COUNT), MI_MATH_REG_ACCU);
122
123		if (srm) {
124			*cs++ = MI_STORE_REGISTER_MEM_GEN8;
125			*cs++ = i915_mmio_reg_offset(CS_GPR(COUNT));
126			*cs++ = lower_32_bits(i915_vma_offset(vma) + end * sizeof(*cs));
127			*cs++ = upper_32_bits(i915_vma_offset(vma) + end * sizeof(*cs));
128		}
129	}
130
131	*cs++ = MI_BATCH_BUFFER_START_GEN8;
132	*cs++ = lower_32_bits(i915_vma_offset(vma) + loop * sizeof(*cs));
133	*cs++ = upper_32_bits(i915_vma_offset(vma) + loop * sizeof(*cs));
134	GEM_BUG_ON(cs - base > end);
135
136	i915_gem_object_flush_map(obj);
137
138	*cancel = base + loop;
139	*counter = srm ? memset32(base + end, 0, 1) : NULL;
140	return vma;
141
142err_unpin:
143	i915_vma_unpin(vma);
144err_unlock:
145	i915_vma_unlock(vma);
146err_put:
147	i915_gem_object_put(obj);
148	return ERR_PTR(err);
149}
150
151static u8 wait_for_freq(struct intel_rps *rps, u8 freq, int timeout_ms)
152{
153	u8 history[64], i;
154	unsigned long end;
155	int sleep;
156
157	i = 0;
158	memset(history, freq, sizeof(history));
159	sleep = 20;
160
161	/* The PCU does not change instantly, but drifts towards the goal? */
162	end = jiffies + msecs_to_jiffies(timeout_ms);
163	do {
164		u8 act;
165
166		act = read_cagf(rps);
167		if (time_after(jiffies, end))
168			return act;
169
170		/* Target acquired */
171		if (act == freq)
172			return act;
173
174		/* Any change within the last N samples? */
175		if (!memchr_inv(history, act, sizeof(history)))
176			return act;
177
178		history[i] = act;
179		i = (i + 1) % ARRAY_SIZE(history);
180
181		usleep_range(sleep, 2 * sleep);
182		sleep *= 2;
183		if (sleep > timeout_ms * 20)
184			sleep = timeout_ms * 20;
185	} while (1);
186}
187
188static u8 rps_set_check(struct intel_rps *rps, u8 freq)
189{
190	mutex_lock(&rps->lock);
191	GEM_BUG_ON(!intel_rps_is_active(rps));
192	if (wait_for(!intel_rps_set(rps, freq), 50)) {
193		mutex_unlock(&rps->lock);
194		return 0;
195	}
196	GEM_BUG_ON(rps->last_freq != freq);
197	mutex_unlock(&rps->lock);
198
199	return wait_for_freq(rps, freq, 50);
200}
201
202static void show_pstate_limits(struct intel_rps *rps)
203{
204	struct drm_i915_private *i915 = rps_to_i915(rps);
205
206	if (IS_BROXTON(i915)) {
207		pr_info("P_STATE_CAP[%x]: 0x%08x\n",
208			i915_mmio_reg_offset(BXT_RP_STATE_CAP),
209			intel_uncore_read(rps_to_uncore(rps),
210					  BXT_RP_STATE_CAP));
211	} else if (GRAPHICS_VER(i915) == 9) {
212		pr_info("P_STATE_LIMITS[%x]: 0x%08x\n",
213			i915_mmio_reg_offset(GEN9_RP_STATE_LIMITS),
214			intel_uncore_read(rps_to_uncore(rps),
215					  GEN9_RP_STATE_LIMITS));
216	}
217}
218
219int live_rps_clock_interval(void *arg)
220{
221	struct intel_gt *gt = arg;
222	struct intel_rps *rps = &gt->rps;
223	void (*saved_work)(struct work_struct *wrk);
224	struct intel_engine_cs *engine;
225	enum intel_engine_id id;
226	struct igt_spinner spin;
227	int err = 0;
228
229	if (!intel_rps_is_enabled(rps) || GRAPHICS_VER(gt->i915) < 6)
230		return 0;
231
232	if (igt_spinner_init(&spin, gt))
233		return -ENOMEM;
234
235	intel_gt_pm_wait_for_idle(gt);
236	saved_work = rps->work.func;
237	rps->work.func = dummy_rps_work;
238
239	intel_gt_pm_get(gt);
240	intel_rps_disable(&gt->rps);
241
242	intel_gt_check_clock_frequency(gt);
243
244	for_each_engine(engine, gt, id) {
245		struct i915_request *rq;
246		u32 cycles;
247		u64 dt;
248
249		if (!intel_engine_can_store_dword(engine))
250			continue;
251
252		st_engine_heartbeat_disable(engine);
253
254		rq = igt_spinner_create_request(&spin,
255						engine->kernel_context,
256						MI_NOOP);
257		if (IS_ERR(rq)) {
258			st_engine_heartbeat_enable(engine);
259			err = PTR_ERR(rq);
260			break;
261		}
262
263		i915_request_add(rq);
264
265		if (!igt_wait_for_spinner(&spin, rq)) {
266			pr_err("%s: RPS spinner did not start\n",
267			       engine->name);
268			igt_spinner_end(&spin);
269			st_engine_heartbeat_enable(engine);
270			intel_gt_set_wedged(engine->gt);
271			err = -EIO;
272			break;
273		}
274
275		intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
276
277		intel_uncore_write_fw(gt->uncore, GEN6_RP_CUR_UP_EI, 0);
278
279		/* Set the evaluation interval to infinity! */
280		intel_uncore_write_fw(gt->uncore,
281				      GEN6_RP_UP_EI, 0xffffffff);
282		intel_uncore_write_fw(gt->uncore,
283				      GEN6_RP_UP_THRESHOLD, 0xffffffff);
284
285		intel_uncore_write_fw(gt->uncore, GEN6_RP_CONTROL,
286				      GEN6_RP_ENABLE | GEN6_RP_UP_BUSY_AVG);
287
288		if (wait_for(intel_uncore_read_fw(gt->uncore,
289						  GEN6_RP_CUR_UP_EI),
290			     10)) {
291			/* Just skip the test; assume lack of HW support */
292			pr_notice("%s: rps evaluation interval not ticking\n",
293				  engine->name);
294			err = -ENODEV;
295		} else {
296			ktime_t dt_[5];
297			u32 cycles_[5];
298			int i;
299
300			for (i = 0; i < 5; i++) {
301				preempt_disable();
302
303				cycles_[i] = -intel_uncore_read_fw(gt->uncore, GEN6_RP_CUR_UP_EI);
304				dt_[i] = ktime_get();
305
306				udelay(1000);
307
308				cycles_[i] += intel_uncore_read_fw(gt->uncore, GEN6_RP_CUR_UP_EI);
309				dt_[i] = ktime_sub(ktime_get(), dt_[i]);
310
311				preempt_enable();
312			}
313
314			/* Use the median of both cycle/dt; close enough */
315			sort(cycles_, 5, sizeof(*cycles_), cmp_u32, NULL);
316			cycles = (cycles_[1] + 2 * cycles_[2] + cycles_[3]) / 4;
317			sort(dt_, 5, sizeof(*dt_), cmp_u64, NULL);
318			dt = div_u64(dt_[1] + 2 * dt_[2] + dt_[3], 4);
319		}
320
321		intel_uncore_write_fw(gt->uncore, GEN6_RP_CONTROL, 0);
322		intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
323
324		igt_spinner_end(&spin);
325		st_engine_heartbeat_enable(engine);
326
327		if (err == 0) {
328			u64 time = intel_gt_pm_interval_to_ns(gt, cycles);
329			u32 expected =
330				intel_gt_ns_to_pm_interval(gt, dt);
331
332			pr_info("%s: rps counted %d C0 cycles [%lldns] in %lldns [%d cycles], using GT clock frequency of %uKHz\n",
333				engine->name, cycles, time, dt, expected,
334				gt->clock_frequency / 1000);
335
336			if (10 * time < 8 * dt ||
337			    8 * time > 10 * dt) {
338				pr_err("%s: rps clock time does not match walltime!\n",
339				       engine->name);
340				err = -EINVAL;
341			}
342
343			if (10 * expected < 8 * cycles ||
344			    8 * expected > 10 * cycles) {
345				pr_err("%s: walltime does not match rps clock ticks!\n",
346				       engine->name);
347				err = -EINVAL;
348			}
349		}
350
351		if (igt_flush_test(gt->i915))
352			err = -EIO;
353
354		break; /* once is enough */
355	}
356
357	intel_rps_enable(&gt->rps);
358	intel_gt_pm_put(gt);
359
360	igt_spinner_fini(&spin);
361
362	intel_gt_pm_wait_for_idle(gt);
363	rps->work.func = saved_work;
364
365	if (err == -ENODEV) /* skipped, don't report a fail */
366		err = 0;
367
368	return err;
369}
370
371int live_rps_control(void *arg)
372{
373	struct intel_gt *gt = arg;
374	struct intel_rps *rps = &gt->rps;
375	void (*saved_work)(struct work_struct *wrk);
376	struct intel_engine_cs *engine;
377	enum intel_engine_id id;
378	struct igt_spinner spin;
379	int err = 0;
380
381	/*
382	 * Check that the actual frequency matches our requested frequency,
383	 * to verify our control mechanism. We have to be careful that the
384	 * PCU may throttle the GPU in which case the actual frequency used
385	 * will be lowered than requested.
386	 */
387
388	if (!intel_rps_is_enabled(rps))
389		return 0;
390
391	if (IS_CHERRYVIEW(gt->i915)) /* XXX fragile PCU */
392		return 0;
393
394	if (igt_spinner_init(&spin, gt))
395		return -ENOMEM;
396
397	intel_gt_pm_wait_for_idle(gt);
398	saved_work = rps->work.func;
399	rps->work.func = dummy_rps_work;
400
401	intel_gt_pm_get(gt);
402	for_each_engine(engine, gt, id) {
403		struct i915_request *rq;
404		ktime_t min_dt, max_dt;
405		int f, limit;
406		int min, max;
407
408		if (!intel_engine_can_store_dword(engine))
409			continue;
410
411		st_engine_heartbeat_disable(engine);
412
413		rq = igt_spinner_create_request(&spin,
414						engine->kernel_context,
415						MI_NOOP);
416		if (IS_ERR(rq)) {
417			err = PTR_ERR(rq);
418			break;
419		}
420
421		i915_request_add(rq);
422
423		if (!igt_wait_for_spinner(&spin, rq)) {
424			pr_err("%s: RPS spinner did not start\n",
425			       engine->name);
426			igt_spinner_end(&spin);
427			st_engine_heartbeat_enable(engine);
428			intel_gt_set_wedged(engine->gt);
429			err = -EIO;
430			break;
431		}
432
433		if (rps_set_check(rps, rps->min_freq) != rps->min_freq) {
434			pr_err("%s: could not set minimum frequency [%x], only %x!\n",
435			       engine->name, rps->min_freq, read_cagf(rps));
436			igt_spinner_end(&spin);
437			st_engine_heartbeat_enable(engine);
438			show_pstate_limits(rps);
439			err = -EINVAL;
440			break;
441		}
442
443		for (f = rps->min_freq + 1; f < rps->max_freq; f++) {
444			if (rps_set_check(rps, f) < f)
445				break;
446		}
447
448		limit = rps_set_check(rps, f);
449
450		if (rps_set_check(rps, rps->min_freq) != rps->min_freq) {
451			pr_err("%s: could not restore minimum frequency [%x], only %x!\n",
452			       engine->name, rps->min_freq, read_cagf(rps));
453			igt_spinner_end(&spin);
454			st_engine_heartbeat_enable(engine);
455			show_pstate_limits(rps);
456			err = -EINVAL;
457			break;
458		}
459
460		max_dt = ktime_get();
461		max = rps_set_check(rps, limit);
462		max_dt = ktime_sub(ktime_get(), max_dt);
463
464		min_dt = ktime_get();
465		min = rps_set_check(rps, rps->min_freq);
466		min_dt = ktime_sub(ktime_get(), min_dt);
467
468		igt_spinner_end(&spin);
469		st_engine_heartbeat_enable(engine);
470
471		pr_info("%s: range:[%x:%uMHz, %x:%uMHz] limit:[%x:%uMHz], %x:%x response %lluns:%lluns\n",
472			engine->name,
473			rps->min_freq, intel_gpu_freq(rps, rps->min_freq),
474			rps->max_freq, intel_gpu_freq(rps, rps->max_freq),
475			limit, intel_gpu_freq(rps, limit),
476			min, max, ktime_to_ns(min_dt), ktime_to_ns(max_dt));
477
478		if (limit == rps->min_freq) {
479			pr_err("%s: GPU throttled to minimum!\n",
480			       engine->name);
481			show_pstate_limits(rps);
482			err = -ENODEV;
483			break;
484		}
485
486		if (igt_flush_test(gt->i915)) {
487			err = -EIO;
488			break;
489		}
490	}
491	intel_gt_pm_put(gt);
492
493	igt_spinner_fini(&spin);
494
495	intel_gt_pm_wait_for_idle(gt);
496	rps->work.func = saved_work;
497
498	return err;
499}
500
501static void show_pcu_config(struct intel_rps *rps)
502{
503	struct drm_i915_private *i915 = rps_to_i915(rps);
504	unsigned int max_gpu_freq, min_gpu_freq;
505	intel_wakeref_t wakeref;
506	int gpu_freq;
507
508	if (!HAS_LLC(i915))
509		return;
510
511	min_gpu_freq = rps->min_freq;
512	max_gpu_freq = rps->max_freq;
513	if (GRAPHICS_VER(i915) >= 9) {
514		/* Convert GT frequency to 50 HZ units */
515		min_gpu_freq /= GEN9_FREQ_SCALER;
516		max_gpu_freq /= GEN9_FREQ_SCALER;
517	}
518
519	wakeref = intel_runtime_pm_get(rps_to_uncore(rps)->rpm);
520
521	pr_info("%5s  %5s  %5s\n", "GPU", "eCPU", "eRing");
522	for (gpu_freq = min_gpu_freq; gpu_freq <= max_gpu_freq; gpu_freq++) {
523		int ia_freq = gpu_freq;
524
525		snb_pcode_read(rps_to_gt(rps)->uncore, GEN6_PCODE_READ_MIN_FREQ_TABLE,
526			       &ia_freq, NULL);
527
528		pr_info("%5d  %5d  %5d\n",
529			gpu_freq * 50,
530			((ia_freq >> 0) & 0xff) * 100,
531			((ia_freq >> 8) & 0xff) * 100);
532	}
533
534	intel_runtime_pm_put(rps_to_uncore(rps)->rpm, wakeref);
535}
536
537static u64 __measure_frequency(u32 *cntr, int duration_ms)
538{
539	u64 dc, dt;
540
541	dc = READ_ONCE(*cntr);
542	dt = ktime_get();
543	usleep_range(1000 * duration_ms, 2000 * duration_ms);
544	dc = READ_ONCE(*cntr) - dc;
545	dt = ktime_get() - dt;
546
547	return div64_u64(1000 * 1000 * dc, dt);
548}
549
550static u64 measure_frequency_at(struct intel_rps *rps, u32 *cntr, int *freq)
551{
552	u64 x[5];
553	int i;
554
555	*freq = rps_set_check(rps, *freq);
556	for (i = 0; i < 5; i++)
557		x[i] = __measure_frequency(cntr, 2);
558	*freq = (*freq + read_cagf(rps)) / 2;
559
560	/* A simple triangle filter for better result stability */
561	sort(x, 5, sizeof(*x), cmp_u64, NULL);
562	return div_u64(x[1] + 2 * x[2] + x[3], 4);
563}
564
565static u64 __measure_cs_frequency(struct intel_engine_cs *engine,
566				  int duration_ms)
567{
568	u64 dc, dt;
569
570	dc = intel_uncore_read_fw(engine->uncore, CS_GPR(0));
571	dt = ktime_get();
572	usleep_range(1000 * duration_ms, 2000 * duration_ms);
573	dc = intel_uncore_read_fw(engine->uncore, CS_GPR(0)) - dc;
574	dt = ktime_get() - dt;
575
576	return div64_u64(1000 * 1000 * dc, dt);
577}
578
579static u64 measure_cs_frequency_at(struct intel_rps *rps,
580				   struct intel_engine_cs *engine,
581				   int *freq)
582{
583	u64 x[5];
584	int i;
585
586	*freq = rps_set_check(rps, *freq);
587	for (i = 0; i < 5; i++)
588		x[i] = __measure_cs_frequency(engine, 2);
589	*freq = (*freq + read_cagf(rps)) / 2;
590
591	/* A simple triangle filter for better result stability */
592	sort(x, 5, sizeof(*x), cmp_u64, NULL);
593	return div_u64(x[1] + 2 * x[2] + x[3], 4);
594}
595
596static bool scaled_within(u64 x, u64 y, u32 f_n, u32 f_d)
597{
598	return f_d * x > f_n * y && f_n * x < f_d * y;
599}
600
601int live_rps_frequency_cs(void *arg)
602{
603	void (*saved_work)(struct work_struct *wrk);
604	struct intel_gt *gt = arg;
605	struct intel_rps *rps = &gt->rps;
606	struct intel_engine_cs *engine;
607	struct pm_qos_request qos;
608	enum intel_engine_id id;
609	int err = 0;
610
611	/*
612	 * The premise is that the GPU does change frequency at our behest.
613	 * Let's check there is a correspondence between the requested
614	 * frequency, the actual frequency, and the observed clock rate.
615	 */
616
617	if (!intel_rps_is_enabled(rps))
618		return 0;
619
620	if (GRAPHICS_VER(gt->i915) < 8) /* for CS simplicity */
621		return 0;
622
623	if (CPU_LATENCY >= 0)
624		cpu_latency_qos_add_request(&qos, CPU_LATENCY);
625
626	intel_gt_pm_wait_for_idle(gt);
627	saved_work = rps->work.func;
628	rps->work.func = dummy_rps_work;
629
630	for_each_engine(engine, gt, id) {
631		struct i915_request *rq;
632		struct i915_vma *vma;
633		u32 *cancel, *cntr;
634		struct {
635			u64 count;
636			int freq;
637		} min, max;
638
639		st_engine_heartbeat_disable(engine);
640
641		vma = create_spin_counter(engine,
642					  engine->kernel_context->vm, false,
643					  &cancel, &cntr);
644		if (IS_ERR(vma)) {
645			err = PTR_ERR(vma);
646			st_engine_heartbeat_enable(engine);
647			break;
648		}
649
650		rq = intel_engine_create_kernel_request(engine);
651		if (IS_ERR(rq)) {
652			err = PTR_ERR(rq);
653			goto err_vma;
654		}
655
656		err = i915_vma_move_to_active(vma, rq, 0);
657		if (!err)
658			err = rq->engine->emit_bb_start(rq,
659							i915_vma_offset(vma),
660							PAGE_SIZE, 0);
661		i915_request_add(rq);
662		if (err)
663			goto err_vma;
664
665		if (wait_for(intel_uncore_read(engine->uncore, CS_GPR(0)),
666			     10)) {
667			pr_err("%s: timed loop did not start\n",
668			       engine->name);
669			goto err_vma;
670		}
671
672		min.freq = rps->min_freq;
673		min.count = measure_cs_frequency_at(rps, engine, &min.freq);
674
675		max.freq = rps->max_freq;
676		max.count = measure_cs_frequency_at(rps, engine, &max.freq);
677
678		pr_info("%s: min:%lluKHz @ %uMHz, max:%lluKHz @ %uMHz [%d%%]\n",
679			engine->name,
680			min.count, intel_gpu_freq(rps, min.freq),
681			max.count, intel_gpu_freq(rps, max.freq),
682			(int)DIV64_U64_ROUND_CLOSEST(100 * min.freq * max.count,
683						     max.freq * min.count));
684
685		if (!scaled_within(max.freq * min.count,
686				   min.freq * max.count,
687				   2, 3)) {
688			int f;
689
690			pr_err("%s: CS did not scale with frequency! scaled min:%llu, max:%llu\n",
691			       engine->name,
692			       max.freq * min.count,
693			       min.freq * max.count);
694			show_pcu_config(rps);
695
696			for (f = min.freq + 1; f <= rps->max_freq; f++) {
697				int act = f;
698				u64 count;
699
700				count = measure_cs_frequency_at(rps, engine, &act);
701				if (act < f)
702					break;
703
704				pr_info("%s: %x:%uMHz: %lluKHz [%d%%]\n",
705					engine->name,
706					act, intel_gpu_freq(rps, act), count,
707					(int)DIV64_U64_ROUND_CLOSEST(100 * min.freq * count,
708								     act * min.count));
709
710				f = act; /* may skip ahead [pcu granularity] */
711			}
712
713			err = -EINTR; /* ignore error, continue on with test */
714		}
715
716err_vma:
717		*cancel = MI_BATCH_BUFFER_END;
718		i915_gem_object_flush_map(vma->obj);
719		i915_gem_object_unpin_map(vma->obj);
720		i915_vma_unpin(vma);
721		i915_vma_unlock(vma);
722		i915_vma_put(vma);
723
724		st_engine_heartbeat_enable(engine);
725		if (igt_flush_test(gt->i915))
726			err = -EIO;
727		if (err)
728			break;
729	}
730
731	intel_gt_pm_wait_for_idle(gt);
732	rps->work.func = saved_work;
733
734	if (CPU_LATENCY >= 0)
735		cpu_latency_qos_remove_request(&qos);
736
737	return err;
738}
739
740int live_rps_frequency_srm(void *arg)
741{
742	void (*saved_work)(struct work_struct *wrk);
743	struct intel_gt *gt = arg;
744	struct intel_rps *rps = &gt->rps;
745	struct intel_engine_cs *engine;
746	struct pm_qos_request qos;
747	enum intel_engine_id id;
748	int err = 0;
749
750	/*
751	 * The premise is that the GPU does change frequency at our behest.
752	 * Let's check there is a correspondence between the requested
753	 * frequency, the actual frequency, and the observed clock rate.
754	 */
755
756	if (!intel_rps_is_enabled(rps))
757		return 0;
758
759	if (GRAPHICS_VER(gt->i915) < 8) /* for CS simplicity */
760		return 0;
761
762	if (CPU_LATENCY >= 0)
763		cpu_latency_qos_add_request(&qos, CPU_LATENCY);
764
765	intel_gt_pm_wait_for_idle(gt);
766	saved_work = rps->work.func;
767	rps->work.func = dummy_rps_work;
768
769	for_each_engine(engine, gt, id) {
770		struct i915_request *rq;
771		struct i915_vma *vma;
772		u32 *cancel, *cntr;
773		struct {
774			u64 count;
775			int freq;
776		} min, max;
777
778		st_engine_heartbeat_disable(engine);
779
780		vma = create_spin_counter(engine,
781					  engine->kernel_context->vm, true,
782					  &cancel, &cntr);
783		if (IS_ERR(vma)) {
784			err = PTR_ERR(vma);
785			st_engine_heartbeat_enable(engine);
786			break;
787		}
788
789		rq = intel_engine_create_kernel_request(engine);
790		if (IS_ERR(rq)) {
791			err = PTR_ERR(rq);
792			goto err_vma;
793		}
794
795		err = i915_vma_move_to_active(vma, rq, 0);
796		if (!err)
797			err = rq->engine->emit_bb_start(rq,
798							i915_vma_offset(vma),
799							PAGE_SIZE, 0);
800		i915_request_add(rq);
801		if (err)
802			goto err_vma;
803
804		if (wait_for(READ_ONCE(*cntr), 10)) {
805			pr_err("%s: timed loop did not start\n",
806			       engine->name);
807			goto err_vma;
808		}
809
810		min.freq = rps->min_freq;
811		min.count = measure_frequency_at(rps, cntr, &min.freq);
812
813		max.freq = rps->max_freq;
814		max.count = measure_frequency_at(rps, cntr, &max.freq);
815
816		pr_info("%s: min:%lluKHz @ %uMHz, max:%lluKHz @ %uMHz [%d%%]\n",
817			engine->name,
818			min.count, intel_gpu_freq(rps, min.freq),
819			max.count, intel_gpu_freq(rps, max.freq),
820			(int)DIV64_U64_ROUND_CLOSEST(100 * min.freq * max.count,
821						     max.freq * min.count));
822
823		if (!scaled_within(max.freq * min.count,
824				   min.freq * max.count,
825				   1, 2)) {
826			int f;
827
828			pr_err("%s: CS did not scale with frequency! scaled min:%llu, max:%llu\n",
829			       engine->name,
830			       max.freq * min.count,
831			       min.freq * max.count);
832			show_pcu_config(rps);
833
834			for (f = min.freq + 1; f <= rps->max_freq; f++) {
835				int act = f;
836				u64 count;
837
838				count = measure_frequency_at(rps, cntr, &act);
839				if (act < f)
840					break;
841
842				pr_info("%s: %x:%uMHz: %lluKHz [%d%%]\n",
843					engine->name,
844					act, intel_gpu_freq(rps, act), count,
845					(int)DIV64_U64_ROUND_CLOSEST(100 * min.freq * count,
846								     act * min.count));
847
848				f = act; /* may skip ahead [pcu granularity] */
849			}
850
851			err = -EINTR; /* ignore error, continue on with test */
852		}
853
854err_vma:
855		*cancel = MI_BATCH_BUFFER_END;
856		i915_gem_object_flush_map(vma->obj);
857		i915_gem_object_unpin_map(vma->obj);
858		i915_vma_unpin(vma);
859		i915_vma_unlock(vma);
860		i915_vma_put(vma);
861
862		st_engine_heartbeat_enable(engine);
863		if (igt_flush_test(gt->i915))
864			err = -EIO;
865		if (err)
866			break;
867	}
868
869	intel_gt_pm_wait_for_idle(gt);
870	rps->work.func = saved_work;
871
872	if (CPU_LATENCY >= 0)
873		cpu_latency_qos_remove_request(&qos);
874
875	return err;
876}
877
878static void sleep_for_ei(struct intel_rps *rps, int timeout_us)
879{
880	/* Flush any previous EI */
881	usleep_range(timeout_us, 2 * timeout_us);
882
883	/* Reset the interrupt status */
884	rps_disable_interrupts(rps);
885	GEM_BUG_ON(rps->pm_iir);
886	rps_enable_interrupts(rps);
887
888	/* And then wait for the timeout, for real this time */
889	usleep_range(2 * timeout_us, 3 * timeout_us);
890}
891
892static int __rps_up_interrupt(struct intel_rps *rps,
893			      struct intel_engine_cs *engine,
894			      struct igt_spinner *spin)
895{
896	struct intel_uncore *uncore = engine->uncore;
897	struct i915_request *rq;
898	u32 timeout;
899
900	if (!intel_engine_can_store_dword(engine))
901		return 0;
902
903	rps_set_check(rps, rps->min_freq);
904
905	rq = igt_spinner_create_request(spin, engine->kernel_context, MI_NOOP);
906	if (IS_ERR(rq))
907		return PTR_ERR(rq);
908
909	i915_request_get(rq);
910	i915_request_add(rq);
911
912	if (!igt_wait_for_spinner(spin, rq)) {
913		pr_err("%s: RPS spinner did not start\n",
914		       engine->name);
915		i915_request_put(rq);
916		intel_gt_set_wedged(engine->gt);
917		return -EIO;
918	}
919
920	if (!intel_rps_is_active(rps)) {
921		pr_err("%s: RPS not enabled on starting spinner\n",
922		       engine->name);
923		igt_spinner_end(spin);
924		i915_request_put(rq);
925		return -EINVAL;
926	}
927
928	if (!(rps->pm_events & GEN6_PM_RP_UP_THRESHOLD)) {
929		pr_err("%s: RPS did not register UP interrupt\n",
930		       engine->name);
931		i915_request_put(rq);
932		return -EINVAL;
933	}
934
935	if (rps->last_freq != rps->min_freq) {
936		pr_err("%s: RPS did not program min frequency\n",
937		       engine->name);
938		i915_request_put(rq);
939		return -EINVAL;
940	}
941
942	timeout = intel_uncore_read(uncore, GEN6_RP_UP_EI);
943	timeout = intel_gt_pm_interval_to_ns(engine->gt, timeout);
944	timeout = DIV_ROUND_UP(timeout, 1000);
945
946	sleep_for_ei(rps, timeout);
947	GEM_BUG_ON(i915_request_completed(rq));
948
949	igt_spinner_end(spin);
950	i915_request_put(rq);
951
952	if (rps->cur_freq != rps->min_freq) {
953		pr_err("%s: Frequency unexpectedly changed [up], now %d!\n",
954		       engine->name, intel_rps_read_actual_frequency(rps));
955		return -EINVAL;
956	}
957
958	if (!(rps->pm_iir & GEN6_PM_RP_UP_THRESHOLD)) {
959		pr_err("%s: UP interrupt not recorded for spinner, pm_iir:%x, prev_up:%x, up_threshold:%x, up_ei:%x\n",
960		       engine->name, rps->pm_iir,
961		       intel_uncore_read(uncore, GEN6_RP_PREV_UP),
962		       intel_uncore_read(uncore, GEN6_RP_UP_THRESHOLD),
963		       intel_uncore_read(uncore, GEN6_RP_UP_EI));
964		return -EINVAL;
965	}
966
967	return 0;
968}
969
970static int __rps_down_interrupt(struct intel_rps *rps,
971				struct intel_engine_cs *engine)
972{
973	struct intel_uncore *uncore = engine->uncore;
974	u32 timeout;
975
976	rps_set_check(rps, rps->max_freq);
977
978	if (!(rps->pm_events & GEN6_PM_RP_DOWN_THRESHOLD)) {
979		pr_err("%s: RPS did not register DOWN interrupt\n",
980		       engine->name);
981		return -EINVAL;
982	}
983
984	if (rps->last_freq != rps->max_freq) {
985		pr_err("%s: RPS did not program max frequency\n",
986		       engine->name);
987		return -EINVAL;
988	}
989
990	timeout = intel_uncore_read(uncore, GEN6_RP_DOWN_EI);
991	timeout = intel_gt_pm_interval_to_ns(engine->gt, timeout);
992	timeout = DIV_ROUND_UP(timeout, 1000);
993
994	sleep_for_ei(rps, timeout);
995
996	if (rps->cur_freq != rps->max_freq) {
997		pr_err("%s: Frequency unexpectedly changed [down], now %d!\n",
998		       engine->name,
999		       intel_rps_read_actual_frequency(rps));
1000		return -EINVAL;
1001	}
1002
1003	if (!(rps->pm_iir & (GEN6_PM_RP_DOWN_THRESHOLD | GEN6_PM_RP_DOWN_TIMEOUT))) {
1004		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",
1005		       engine->name, rps->pm_iir,
1006		       intel_uncore_read(uncore, GEN6_RP_PREV_DOWN),
1007		       intel_uncore_read(uncore, GEN6_RP_DOWN_THRESHOLD),
1008		       intel_uncore_read(uncore, GEN6_RP_DOWN_EI),
1009		       intel_uncore_read(uncore, GEN6_RP_PREV_UP),
1010		       intel_uncore_read(uncore, GEN6_RP_UP_THRESHOLD),
1011		       intel_uncore_read(uncore, GEN6_RP_UP_EI));
1012		return -EINVAL;
1013	}
1014
1015	return 0;
1016}
1017
1018int live_rps_interrupt(void *arg)
1019{
1020	struct intel_gt *gt = arg;
1021	struct intel_rps *rps = &gt->rps;
1022	void (*saved_work)(struct work_struct *wrk);
1023	struct intel_engine_cs *engine;
1024	enum intel_engine_id id;
1025	struct igt_spinner spin;
1026	u32 pm_events;
1027	int err = 0;
1028
1029	/*
1030	 * First, let's check whether or not we are receiving interrupts.
1031	 */
1032
1033	if (!intel_rps_has_interrupts(rps) || GRAPHICS_VER(gt->i915) < 6)
1034		return 0;
1035
1036	intel_gt_pm_get(gt);
1037	pm_events = rps->pm_events;
1038	intel_gt_pm_put(gt);
1039	if (!pm_events) {
1040		pr_err("No RPS PM events registered, but RPS is enabled?\n");
1041		return -ENODEV;
1042	}
1043
1044	if (igt_spinner_init(&spin, gt))
1045		return -ENOMEM;
1046
1047	intel_gt_pm_wait_for_idle(gt);
1048	saved_work = rps->work.func;
1049	rps->work.func = dummy_rps_work;
1050
1051	for_each_engine(engine, gt, id) {
1052		/* Keep the engine busy with a spinner; expect an UP! */
1053		if (pm_events & GEN6_PM_RP_UP_THRESHOLD) {
1054			intel_gt_pm_wait_for_idle(engine->gt);
1055			GEM_BUG_ON(intel_rps_is_active(rps));
1056
1057			st_engine_heartbeat_disable(engine);
1058
1059			err = __rps_up_interrupt(rps, engine, &spin);
1060
1061			st_engine_heartbeat_enable(engine);
1062			if (err)
1063				goto out;
1064
1065			intel_gt_pm_wait_for_idle(engine->gt);
1066		}
1067
1068		/* Keep the engine awake but idle and check for DOWN */
1069		if (pm_events & GEN6_PM_RP_DOWN_THRESHOLD) {
1070			st_engine_heartbeat_disable(engine);
1071			intel_rc6_disable(&gt->rc6);
1072
1073			err = __rps_down_interrupt(rps, engine);
1074
1075			intel_rc6_enable(&gt->rc6);
1076			st_engine_heartbeat_enable(engine);
1077			if (err)
1078				goto out;
1079		}
1080	}
1081
1082out:
1083	if (igt_flush_test(gt->i915))
1084		err = -EIO;
1085
1086	igt_spinner_fini(&spin);
1087
1088	intel_gt_pm_wait_for_idle(gt);
1089	rps->work.func = saved_work;
1090
1091	return err;
1092}
1093
1094static u64 __measure_power(int duration_ms)
1095{
1096	u64 dE, dt;
1097
1098	dE = librapl_energy_uJ();
1099	dt = ktime_get();
1100	usleep_range(1000 * duration_ms, 2000 * duration_ms);
1101	dE = librapl_energy_uJ() - dE;
1102	dt = ktime_get() - dt;
1103
1104	return div64_u64(1000 * 1000 * dE, dt);
1105}
1106
1107static u64 measure_power(struct intel_rps *rps, int *freq)
1108{
1109	u64 x[5];
1110	int i;
1111
1112	for (i = 0; i < 5; i++)
1113		x[i] = __measure_power(5);
1114
1115	*freq = (*freq + intel_rps_read_actual_frequency(rps)) / 2;
1116
1117	/* A simple triangle filter for better result stability */
1118	sort(x, 5, sizeof(*x), cmp_u64, NULL);
1119	return div_u64(x[1] + 2 * x[2] + x[3], 4);
1120}
1121
1122static u64 measure_power_at(struct intel_rps *rps, int *freq)
1123{
1124	*freq = rps_set_check(rps, *freq);
1125	return measure_power(rps, freq);
1126}
1127
1128int live_rps_power(void *arg)
1129{
1130	struct intel_gt *gt = arg;
1131	struct intel_rps *rps = &gt->rps;
1132	void (*saved_work)(struct work_struct *wrk);
1133	struct intel_engine_cs *engine;
1134	enum intel_engine_id id;
1135	struct igt_spinner spin;
1136	int err = 0;
1137
1138	/*
1139	 * Our fundamental assumption is that running at lower frequency
1140	 * actually saves power. Let's see if our RAPL measurement support
1141	 * that theory.
1142	 */
1143
1144	if (!intel_rps_is_enabled(rps) || GRAPHICS_VER(gt->i915) < 6)
1145		return 0;
1146
1147	if (!librapl_supported(gt->i915))
1148		return 0;
1149
1150	if (igt_spinner_init(&spin, gt))
1151		return -ENOMEM;
1152
1153	intel_gt_pm_wait_for_idle(gt);
1154	saved_work = rps->work.func;
1155	rps->work.func = dummy_rps_work;
1156
1157	for_each_engine(engine, gt, id) {
1158		struct i915_request *rq;
1159		struct {
1160			u64 power;
1161			int freq;
1162		} min, max;
1163
1164		if (!intel_engine_can_store_dword(engine))
1165			continue;
1166
1167		st_engine_heartbeat_disable(engine);
1168
1169		rq = igt_spinner_create_request(&spin,
1170						engine->kernel_context,
1171						MI_NOOP);
1172		if (IS_ERR(rq)) {
1173			st_engine_heartbeat_enable(engine);
1174			err = PTR_ERR(rq);
1175			break;
1176		}
1177
1178		i915_request_add(rq);
1179
1180		if (!igt_wait_for_spinner(&spin, rq)) {
1181			pr_err("%s: RPS spinner did not start\n",
1182			       engine->name);
1183			igt_spinner_end(&spin);
1184			st_engine_heartbeat_enable(engine);
1185			intel_gt_set_wedged(engine->gt);
1186			err = -EIO;
1187			break;
1188		}
1189
1190		max.freq = rps->max_freq;
1191		max.power = measure_power_at(rps, &max.freq);
1192
1193		min.freq = rps->min_freq;
1194		min.power = measure_power_at(rps, &min.freq);
1195
1196		igt_spinner_end(&spin);
1197		st_engine_heartbeat_enable(engine);
1198
1199		pr_info("%s: min:%llumW @ %uMHz, max:%llumW @ %uMHz\n",
1200			engine->name,
1201			min.power, intel_gpu_freq(rps, min.freq),
1202			max.power, intel_gpu_freq(rps, max.freq));
1203
1204		if (10 * min.freq >= 9 * max.freq) {
1205			pr_notice("Could not control frequency, ran at [%d:%uMHz, %d:%uMhz]\n",
1206				  min.freq, intel_gpu_freq(rps, min.freq),
1207				  max.freq, intel_gpu_freq(rps, max.freq));
1208			continue;
1209		}
1210
1211		if (11 * min.power > 10 * max.power) {
1212			pr_err("%s: did not conserve power when setting lower frequency!\n",
1213			       engine->name);
1214			err = -EINVAL;
1215			break;
1216		}
1217
1218		if (igt_flush_test(gt->i915)) {
1219			err = -EIO;
1220			break;
1221		}
1222	}
1223
1224	igt_spinner_fini(&spin);
1225
1226	intel_gt_pm_wait_for_idle(gt);
1227	rps->work.func = saved_work;
1228
1229	return err;
1230}
1231
1232int live_rps_dynamic(void *arg)
1233{
1234	struct intel_gt *gt = arg;
1235	struct intel_rps *rps = &gt->rps;
1236	struct intel_engine_cs *engine;
1237	enum intel_engine_id id;
1238	struct igt_spinner spin;
1239	int err = 0;
1240
1241	/*
1242	 * We've looked at the bascs, and have established that we
1243	 * can change the clock frequency and that the HW will generate
1244	 * interrupts based on load. Now we check how we integrate those
1245	 * moving parts into dynamic reclocking based on load.
1246	 */
1247
1248	if (!intel_rps_is_enabled(rps) || GRAPHICS_VER(gt->i915) < 6)
1249		return 0;
1250
1251	if (igt_spinner_init(&spin, gt))
1252		return -ENOMEM;
1253
1254	if (intel_rps_has_interrupts(rps))
1255		pr_info("RPS has interrupt support\n");
1256	if (intel_rps_uses_timer(rps))
1257		pr_info("RPS has timer support\n");
1258
1259	for_each_engine(engine, gt, id) {
1260		struct i915_request *rq;
1261		struct {
1262			ktime_t dt;
1263			u8 freq;
1264		} min, max;
1265
1266		if (!intel_engine_can_store_dword(engine))
1267			continue;
1268
1269		intel_gt_pm_wait_for_idle(gt);
1270		GEM_BUG_ON(intel_rps_is_active(rps));
1271		rps->cur_freq = rps->min_freq;
1272
1273		intel_engine_pm_get(engine);
1274		intel_rc6_disable(&gt->rc6);
1275		GEM_BUG_ON(rps->last_freq != rps->min_freq);
1276
1277		rq = igt_spinner_create_request(&spin,
1278						engine->kernel_context,
1279						MI_NOOP);
1280		if (IS_ERR(rq)) {
1281			err = PTR_ERR(rq);
1282			goto err;
1283		}
1284
1285		i915_request_add(rq);
1286
1287		max.dt = ktime_get();
1288		max.freq = wait_for_freq(rps, rps->max_freq, 500);
1289		max.dt = ktime_sub(ktime_get(), max.dt);
1290
1291		igt_spinner_end(&spin);
1292
1293		min.dt = ktime_get();
1294		min.freq = wait_for_freq(rps, rps->min_freq, 2000);
1295		min.dt = ktime_sub(ktime_get(), min.dt);
1296
1297		pr_info("%s: dynamically reclocked to %u:%uMHz while busy in %lluns, and %u:%uMHz while idle in %lluns\n",
1298			engine->name,
1299			max.freq, intel_gpu_freq(rps, max.freq),
1300			ktime_to_ns(max.dt),
1301			min.freq, intel_gpu_freq(rps, min.freq),
1302			ktime_to_ns(min.dt));
1303		if (min.freq >= max.freq) {
1304			pr_err("%s: dynamic reclocking of spinner failed\n!",
1305			       engine->name);
1306			err = -EINVAL;
1307		}
1308
1309err:
1310		intel_rc6_enable(&gt->rc6);
1311		intel_engine_pm_put(engine);
1312
1313		if (igt_flush_test(gt->i915))
1314			err = -EIO;
1315		if (err)
1316			break;
1317	}
1318
1319	igt_spinner_fini(&spin);
1320
1321	return err;
1322}
1323