1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2017 Intel Corporation
5  */
6 
7 #include <linux/prime_numbers.h>
8 
9 #include "gem/i915_gem_pm.h"
10 #include "gt/intel_engine_pm.h"
11 #include "gt/intel_gt.h"
12 #include "gt/intel_gt_requests.h"
13 #include "gt/intel_reset.h"
14 #include "i915_selftest.h"
15 
16 #include "gem/selftests/igt_gem_utils.h"
17 #include "selftests/i915_random.h"
18 #include "selftests/igt_flush_test.h"
19 #include "selftests/igt_live_test.h"
20 #include "selftests/igt_reset.h"
21 #include "selftests/igt_spinner.h"
22 #include "selftests/mock_drm.h"
23 #include "selftests/mock_gem_device.h"
24 
25 #include "huge_gem_object.h"
26 #include "igt_gem_utils.h"
27 
28 #define DW_PER_PAGE (PAGE_SIZE / sizeof(u32))
29 
30 static inline struct i915_address_space *ctx_vm(struct i915_gem_context *ctx)
31 {
32 	/* single threaded, private ctx */
33 	return rcu_dereference_protected(ctx->vm, true);
34 }
35 
36 static int live_nop_switch(void *arg)
37 {
38 	const unsigned int nctx = 1024;
39 	struct drm_i915_private *i915 = arg;
40 	struct intel_engine_cs *engine;
41 	struct i915_gem_context **ctx;
42 	struct igt_live_test t;
43 	struct file *file;
44 	unsigned long n;
45 	int err = -ENODEV;
46 
47 	/*
48 	 * Create as many contexts as we can feasibly get away with
49 	 * and check we can switch between them rapidly.
50 	 *
51 	 * Serves as very simple stress test for submission and HW switching
52 	 * between contexts.
53 	 */
54 
55 	if (!DRIVER_CAPS(i915)->has_logical_contexts)
56 		return 0;
57 
58 	file = mock_file(i915);
59 	if (IS_ERR(file))
60 		return PTR_ERR(file);
61 
62 	ctx = kcalloc(nctx, sizeof(*ctx), GFP_KERNEL);
63 	if (!ctx) {
64 		err = -ENOMEM;
65 		goto out_file;
66 	}
67 
68 	for (n = 0; n < nctx; n++) {
69 		ctx[n] = live_context(i915, file);
70 		if (IS_ERR(ctx[n])) {
71 			err = PTR_ERR(ctx[n]);
72 			goto out_file;
73 		}
74 	}
75 
76 	for_each_uabi_engine(engine, i915) {
77 		struct i915_request *rq = NULL;
78 		unsigned long end_time, prime;
79 		ktime_t times[2] = {};
80 
81 		times[0] = ktime_get_raw();
82 		for (n = 0; n < nctx; n++) {
83 			struct i915_request *this;
84 
85 			this = igt_request_alloc(ctx[n], engine);
86 			if (IS_ERR(this)) {
87 				err = PTR_ERR(this);
88 				goto out_file;
89 			}
90 			if (rq) {
91 				i915_request_await_dma_fence(this, &rq->fence);
92 				i915_request_put(rq);
93 			}
94 			rq = i915_request_get(this);
95 			i915_request_add(this);
96 		}
97 		if (i915_request_wait(rq, 0, HZ / 5) < 0) {
98 			pr_err("Failed to populated %d contexts\n", nctx);
99 			intel_gt_set_wedged(&i915->gt);
100 			i915_request_put(rq);
101 			err = -EIO;
102 			goto out_file;
103 		}
104 		i915_request_put(rq);
105 
106 		times[1] = ktime_get_raw();
107 
108 		pr_info("Populated %d contexts on %s in %lluns\n",
109 			nctx, engine->name, ktime_to_ns(times[1] - times[0]));
110 
111 		err = igt_live_test_begin(&t, i915, __func__, engine->name);
112 		if (err)
113 			goto out_file;
114 
115 		end_time = jiffies + i915_selftest.timeout_jiffies;
116 		for_each_prime_number_from(prime, 2, 8192) {
117 			times[1] = ktime_get_raw();
118 
119 			rq = NULL;
120 			for (n = 0; n < prime; n++) {
121 				struct i915_request *this;
122 
123 				this = igt_request_alloc(ctx[n % nctx], engine);
124 				if (IS_ERR(this)) {
125 					err = PTR_ERR(this);
126 					goto out_file;
127 				}
128 
129 				if (rq) { /* Force submission order */
130 					i915_request_await_dma_fence(this, &rq->fence);
131 					i915_request_put(rq);
132 				}
133 
134 				/*
135 				 * This space is left intentionally blank.
136 				 *
137 				 * We do not actually want to perform any
138 				 * action with this request, we just want
139 				 * to measure the latency in allocation
140 				 * and submission of our breadcrumbs -
141 				 * ensuring that the bare request is sufficient
142 				 * for the system to work (i.e. proper HEAD
143 				 * tracking of the rings, interrupt handling,
144 				 * etc). It also gives us the lowest bounds
145 				 * for latency.
146 				 */
147 
148 				rq = i915_request_get(this);
149 				i915_request_add(this);
150 			}
151 			GEM_BUG_ON(!rq);
152 			if (i915_request_wait(rq, 0, HZ / 5) < 0) {
153 				pr_err("Switching between %ld contexts timed out\n",
154 				       prime);
155 				intel_gt_set_wedged(&i915->gt);
156 				i915_request_put(rq);
157 				break;
158 			}
159 			i915_request_put(rq);
160 
161 			times[1] = ktime_sub(ktime_get_raw(), times[1]);
162 			if (prime == 2)
163 				times[0] = times[1];
164 
165 			if (__igt_timeout(end_time, NULL))
166 				break;
167 		}
168 
169 		err = igt_live_test_end(&t);
170 		if (err)
171 			goto out_file;
172 
173 		pr_info("Switch latencies on %s: 1 = %lluns, %lu = %lluns\n",
174 			engine->name,
175 			ktime_to_ns(times[0]),
176 			prime - 1, div64_u64(ktime_to_ns(times[1]), prime - 1));
177 	}
178 
179 out_file:
180 	fput(file);
181 	return err;
182 }
183 
184 struct parallel_switch {
185 	struct task_struct *tsk;
186 	struct intel_context *ce[2];
187 };
188 
189 static int __live_parallel_switch1(void *data)
190 {
191 	struct parallel_switch *arg = data;
192 	IGT_TIMEOUT(end_time);
193 	unsigned long count;
194 
195 	count = 0;
196 	do {
197 		struct i915_request *rq = NULL;
198 		int err, n;
199 
200 		err = 0;
201 		for (n = 0; !err && n < ARRAY_SIZE(arg->ce); n++) {
202 			struct i915_request *prev = rq;
203 
204 			rq = i915_request_create(arg->ce[n]);
205 			if (IS_ERR(rq)) {
206 				i915_request_put(prev);
207 				return PTR_ERR(rq);
208 			}
209 
210 			i915_request_get(rq);
211 			if (prev) {
212 				err = i915_request_await_dma_fence(rq, &prev->fence);
213 				i915_request_put(prev);
214 			}
215 
216 			i915_request_add(rq);
217 		}
218 		if (i915_request_wait(rq, 0, HZ / 5) < 0)
219 			err = -ETIME;
220 		i915_request_put(rq);
221 		if (err)
222 			return err;
223 
224 		count++;
225 	} while (!__igt_timeout(end_time, NULL));
226 
227 	pr_info("%s: %lu switches (sync)\n", arg->ce[0]->engine->name, count);
228 	return 0;
229 }
230 
231 static int __live_parallel_switchN(void *data)
232 {
233 	struct parallel_switch *arg = data;
234 	struct i915_request *rq = NULL;
235 	IGT_TIMEOUT(end_time);
236 	unsigned long count;
237 	int n;
238 
239 	count = 0;
240 	do {
241 		for (n = 0; n < ARRAY_SIZE(arg->ce); n++) {
242 			struct i915_request *prev = rq;
243 			int err = 0;
244 
245 			rq = i915_request_create(arg->ce[n]);
246 			if (IS_ERR(rq)) {
247 				i915_request_put(prev);
248 				return PTR_ERR(rq);
249 			}
250 
251 			i915_request_get(rq);
252 			if (prev) {
253 				err = i915_request_await_dma_fence(rq, &prev->fence);
254 				i915_request_put(prev);
255 			}
256 
257 			i915_request_add(rq);
258 			if (err) {
259 				i915_request_put(rq);
260 				return err;
261 			}
262 		}
263 
264 		count++;
265 	} while (!__igt_timeout(end_time, NULL));
266 	i915_request_put(rq);
267 
268 	pr_info("%s: %lu switches (many)\n", arg->ce[0]->engine->name, count);
269 	return 0;
270 }
271 
272 static int live_parallel_switch(void *arg)
273 {
274 	struct drm_i915_private *i915 = arg;
275 	static int (* const func[])(void *arg) = {
276 		__live_parallel_switch1,
277 		__live_parallel_switchN,
278 		NULL,
279 	};
280 	struct parallel_switch *data = NULL;
281 	struct i915_gem_engines *engines;
282 	struct i915_gem_engines_iter it;
283 	int (* const *fn)(void *arg);
284 	struct i915_gem_context *ctx;
285 	struct intel_context *ce;
286 	struct file *file;
287 	int n, m, count;
288 	int err = 0;
289 
290 	/*
291 	 * Check we can process switches on all engines simultaneously.
292 	 */
293 
294 	if (!DRIVER_CAPS(i915)->has_logical_contexts)
295 		return 0;
296 
297 	file = mock_file(i915);
298 	if (IS_ERR(file))
299 		return PTR_ERR(file);
300 
301 	ctx = live_context(i915, file);
302 	if (IS_ERR(ctx)) {
303 		err = PTR_ERR(ctx);
304 		goto out_file;
305 	}
306 
307 	engines = i915_gem_context_lock_engines(ctx);
308 	count = engines->num_engines;
309 
310 	data = kcalloc(count, sizeof(*data), GFP_KERNEL);
311 	if (!data) {
312 		i915_gem_context_unlock_engines(ctx);
313 		err = -ENOMEM;
314 		goto out_file;
315 	}
316 
317 	m = 0; /* Use the first context as our template for the engines */
318 	for_each_gem_engine(ce, engines, it) {
319 		err = intel_context_pin(ce);
320 		if (err) {
321 			i915_gem_context_unlock_engines(ctx);
322 			goto out;
323 		}
324 		data[m++].ce[0] = intel_context_get(ce);
325 	}
326 	i915_gem_context_unlock_engines(ctx);
327 
328 	/* Clone the same set of engines into the other contexts */
329 	for (n = 1; n < ARRAY_SIZE(data->ce); n++) {
330 		ctx = live_context(i915, file);
331 		if (IS_ERR(ctx)) {
332 			err = PTR_ERR(ctx);
333 			goto out;
334 		}
335 
336 		for (m = 0; m < count; m++) {
337 			if (!data[m].ce[0])
338 				continue;
339 
340 			ce = intel_context_create(data[m].ce[0]->engine);
341 			if (IS_ERR(ce))
342 				goto out;
343 
344 			err = intel_context_pin(ce);
345 			if (err) {
346 				intel_context_put(ce);
347 				goto out;
348 			}
349 
350 			data[m].ce[n] = ce;
351 		}
352 	}
353 
354 	for (fn = func; !err && *fn; fn++) {
355 		struct igt_live_test t;
356 		int n;
357 
358 		err = igt_live_test_begin(&t, i915, __func__, "");
359 		if (err)
360 			break;
361 
362 		for (n = 0; n < count; n++) {
363 			if (!data[n].ce[0])
364 				continue;
365 
366 			data[n].tsk = kthread_run(*fn, &data[n],
367 						  "igt/parallel:%s",
368 						  data[n].ce[0]->engine->name);
369 			if (IS_ERR(data[n].tsk)) {
370 				err = PTR_ERR(data[n].tsk);
371 				break;
372 			}
373 			get_task_struct(data[n].tsk);
374 		}
375 
376 		yield(); /* start all threads before we kthread_stop() */
377 
378 		for (n = 0; n < count; n++) {
379 			int status;
380 
381 			if (IS_ERR_OR_NULL(data[n].tsk))
382 				continue;
383 
384 			status = kthread_stop(data[n].tsk);
385 			if (status && !err)
386 				err = status;
387 
388 			put_task_struct(data[n].tsk);
389 			data[n].tsk = NULL;
390 		}
391 
392 		if (igt_live_test_end(&t))
393 			err = -EIO;
394 	}
395 
396 out:
397 	for (n = 0; n < count; n++) {
398 		for (m = 0; m < ARRAY_SIZE(data->ce); m++) {
399 			if (!data[n].ce[m])
400 				continue;
401 
402 			intel_context_unpin(data[n].ce[m]);
403 			intel_context_put(data[n].ce[m]);
404 		}
405 	}
406 	kfree(data);
407 out_file:
408 	fput(file);
409 	return err;
410 }
411 
412 static unsigned long real_page_count(struct drm_i915_gem_object *obj)
413 {
414 	return huge_gem_object_phys_size(obj) >> PAGE_SHIFT;
415 }
416 
417 static unsigned long fake_page_count(struct drm_i915_gem_object *obj)
418 {
419 	return huge_gem_object_dma_size(obj) >> PAGE_SHIFT;
420 }
421 
422 static int gpu_fill(struct intel_context *ce,
423 		    struct drm_i915_gem_object *obj,
424 		    unsigned int dw)
425 {
426 	struct i915_vma *vma;
427 	int err;
428 
429 	GEM_BUG_ON(obj->base.size > ce->vm->total);
430 	GEM_BUG_ON(!intel_engine_can_store_dword(ce->engine));
431 
432 	vma = i915_vma_instance(obj, ce->vm, NULL);
433 	if (IS_ERR(vma))
434 		return PTR_ERR(vma);
435 
436 	err = i915_vma_pin(vma, 0, 0, PIN_HIGH | PIN_USER);
437 	if (err)
438 		return err;
439 
440 	/*
441 	 * Within the GTT the huge objects maps every page onto
442 	 * its 1024 real pages (using phys_pfn = dma_pfn % 1024).
443 	 * We set the nth dword within the page using the nth
444 	 * mapping via the GTT - this should exercise the GTT mapping
445 	 * whilst checking that each context provides a unique view
446 	 * into the object.
447 	 */
448 	err = igt_gpu_fill_dw(ce, vma,
449 			      (dw * real_page_count(obj)) << PAGE_SHIFT |
450 			      (dw * sizeof(u32)),
451 			      real_page_count(obj),
452 			      dw);
453 	i915_vma_unpin(vma);
454 
455 	return err;
456 }
457 
458 static int cpu_fill(struct drm_i915_gem_object *obj, u32 value)
459 {
460 	const bool has_llc = HAS_LLC(to_i915(obj->base.dev));
461 	unsigned int n, m, need_flush;
462 	int err;
463 
464 	err = i915_gem_object_prepare_write(obj, &need_flush);
465 	if (err)
466 		return err;
467 
468 	for (n = 0; n < real_page_count(obj); n++) {
469 		u32 *map;
470 
471 		map = kmap_atomic(i915_gem_object_get_page(obj, n));
472 		for (m = 0; m < DW_PER_PAGE; m++)
473 			map[m] = value;
474 		if (!has_llc)
475 			drm_clflush_virt_range(map, PAGE_SIZE);
476 		kunmap_atomic(map);
477 	}
478 
479 	i915_gem_object_finish_access(obj);
480 	obj->read_domains = I915_GEM_DOMAIN_GTT | I915_GEM_DOMAIN_CPU;
481 	obj->write_domain = 0;
482 	return 0;
483 }
484 
485 static noinline int cpu_check(struct drm_i915_gem_object *obj,
486 			      unsigned int idx, unsigned int max)
487 {
488 	unsigned int n, m, needs_flush;
489 	int err;
490 
491 	err = i915_gem_object_prepare_read(obj, &needs_flush);
492 	if (err)
493 		return err;
494 
495 	for (n = 0; n < real_page_count(obj); n++) {
496 		u32 *map;
497 
498 		map = kmap_atomic(i915_gem_object_get_page(obj, n));
499 		if (needs_flush & CLFLUSH_BEFORE)
500 			drm_clflush_virt_range(map, PAGE_SIZE);
501 
502 		for (m = 0; m < max; m++) {
503 			if (map[m] != m) {
504 				pr_err("%pS: Invalid value at object %d page %d/%ld, offset %d/%d: found %x expected %x\n",
505 				       __builtin_return_address(0), idx,
506 				       n, real_page_count(obj), m, max,
507 				       map[m], m);
508 				err = -EINVAL;
509 				goto out_unmap;
510 			}
511 		}
512 
513 		for (; m < DW_PER_PAGE; m++) {
514 			if (map[m] != STACK_MAGIC) {
515 				pr_err("%pS: Invalid value at object %d page %d, offset %d: found %x expected %x (uninitialised)\n",
516 				       __builtin_return_address(0), idx, n, m,
517 				       map[m], STACK_MAGIC);
518 				err = -EINVAL;
519 				goto out_unmap;
520 			}
521 		}
522 
523 out_unmap:
524 		kunmap_atomic(map);
525 		if (err)
526 			break;
527 	}
528 
529 	i915_gem_object_finish_access(obj);
530 	return err;
531 }
532 
533 static int file_add_object(struct file *file, struct drm_i915_gem_object *obj)
534 {
535 	int err;
536 
537 	GEM_BUG_ON(obj->base.handle_count);
538 
539 	/* tie the object to the drm_file for easy reaping */
540 	err = idr_alloc(&to_drm_file(file)->object_idr,
541 			&obj->base, 1, 0, GFP_KERNEL);
542 	if (err < 0)
543 		return err;
544 
545 	i915_gem_object_get(obj);
546 	obj->base.handle_count++;
547 	return 0;
548 }
549 
550 static struct drm_i915_gem_object *
551 create_test_object(struct i915_address_space *vm,
552 		   struct file *file,
553 		   struct list_head *objects)
554 {
555 	struct drm_i915_gem_object *obj;
556 	u64 size;
557 	int err;
558 
559 	/* Keep in GEM's good graces */
560 	intel_gt_retire_requests(vm->gt);
561 
562 	size = min(vm->total / 2, 1024ull * DW_PER_PAGE * PAGE_SIZE);
563 	size = round_down(size, DW_PER_PAGE * PAGE_SIZE);
564 
565 	obj = huge_gem_object(vm->i915, DW_PER_PAGE * PAGE_SIZE, size);
566 	if (IS_ERR(obj))
567 		return obj;
568 
569 	err = file_add_object(file, obj);
570 	i915_gem_object_put(obj);
571 	if (err)
572 		return ERR_PTR(err);
573 
574 	err = cpu_fill(obj, STACK_MAGIC);
575 	if (err) {
576 		pr_err("Failed to fill object with cpu, err=%d\n",
577 		       err);
578 		return ERR_PTR(err);
579 	}
580 
581 	list_add_tail(&obj->st_link, objects);
582 	return obj;
583 }
584 
585 static unsigned long max_dwords(struct drm_i915_gem_object *obj)
586 {
587 	unsigned long npages = fake_page_count(obj);
588 
589 	GEM_BUG_ON(!IS_ALIGNED(npages, DW_PER_PAGE));
590 	return npages / DW_PER_PAGE;
591 }
592 
593 static void throttle_release(struct i915_request **q, int count)
594 {
595 	int i;
596 
597 	for (i = 0; i < count; i++) {
598 		if (IS_ERR_OR_NULL(q[i]))
599 			continue;
600 
601 		i915_request_put(fetch_and_zero(&q[i]));
602 	}
603 }
604 
605 static int throttle(struct intel_context *ce,
606 		    struct i915_request **q, int count)
607 {
608 	int i;
609 
610 	if (!IS_ERR_OR_NULL(q[0])) {
611 		if (i915_request_wait(q[0],
612 				      I915_WAIT_INTERRUPTIBLE,
613 				      MAX_SCHEDULE_TIMEOUT) < 0)
614 			return -EINTR;
615 
616 		i915_request_put(q[0]);
617 	}
618 
619 	for (i = 0; i < count - 1; i++)
620 		q[i] = q[i + 1];
621 
622 	q[i] = intel_context_create_request(ce);
623 	if (IS_ERR(q[i]))
624 		return PTR_ERR(q[i]);
625 
626 	i915_request_get(q[i]);
627 	i915_request_add(q[i]);
628 
629 	return 0;
630 }
631 
632 static int igt_ctx_exec(void *arg)
633 {
634 	struct drm_i915_private *i915 = arg;
635 	struct intel_engine_cs *engine;
636 	int err = -ENODEV;
637 
638 	/*
639 	 * Create a few different contexts (with different mm) and write
640 	 * through each ctx/mm using the GPU making sure those writes end
641 	 * up in the expected pages of our obj.
642 	 */
643 
644 	if (!DRIVER_CAPS(i915)->has_logical_contexts)
645 		return 0;
646 
647 	for_each_uabi_engine(engine, i915) {
648 		struct drm_i915_gem_object *obj = NULL;
649 		unsigned long ncontexts, ndwords, dw;
650 		struct i915_request *tq[5] = {};
651 		struct igt_live_test t;
652 		IGT_TIMEOUT(end_time);
653 		LIST_HEAD(objects);
654 		struct file *file;
655 
656 		if (!intel_engine_can_store_dword(engine))
657 			continue;
658 
659 		if (!engine->context_size)
660 			continue; /* No logical context support in HW */
661 
662 		file = mock_file(i915);
663 		if (IS_ERR(file))
664 			return PTR_ERR(file);
665 
666 		err = igt_live_test_begin(&t, i915, __func__, engine->name);
667 		if (err)
668 			goto out_file;
669 
670 		ncontexts = 0;
671 		ndwords = 0;
672 		dw = 0;
673 		while (!time_after(jiffies, end_time)) {
674 			struct i915_gem_context *ctx;
675 			struct intel_context *ce;
676 
677 			ctx = kernel_context(i915);
678 			if (IS_ERR(ctx)) {
679 				err = PTR_ERR(ctx);
680 				goto out_file;
681 			}
682 
683 			ce = i915_gem_context_get_engine(ctx, engine->legacy_idx);
684 			GEM_BUG_ON(IS_ERR(ce));
685 
686 			if (!obj) {
687 				obj = create_test_object(ce->vm, file, &objects);
688 				if (IS_ERR(obj)) {
689 					err = PTR_ERR(obj);
690 					intel_context_put(ce);
691 					kernel_context_close(ctx);
692 					goto out_file;
693 				}
694 			}
695 
696 			err = gpu_fill(ce, obj, dw);
697 			if (err) {
698 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
699 				       ndwords, dw, max_dwords(obj),
700 				       engine->name,
701 				       yesno(!!rcu_access_pointer(ctx->vm)),
702 				       err);
703 				intel_context_put(ce);
704 				kernel_context_close(ctx);
705 				goto out_file;
706 			}
707 
708 			err = throttle(ce, tq, ARRAY_SIZE(tq));
709 			if (err) {
710 				intel_context_put(ce);
711 				kernel_context_close(ctx);
712 				goto out_file;
713 			}
714 
715 			if (++dw == max_dwords(obj)) {
716 				obj = NULL;
717 				dw = 0;
718 			}
719 
720 			ndwords++;
721 			ncontexts++;
722 
723 			intel_context_put(ce);
724 			kernel_context_close(ctx);
725 		}
726 
727 		pr_info("Submitted %lu contexts to %s, filling %lu dwords\n",
728 			ncontexts, engine->name, ndwords);
729 
730 		ncontexts = dw = 0;
731 		list_for_each_entry(obj, &objects, st_link) {
732 			unsigned int rem =
733 				min_t(unsigned int, ndwords - dw, max_dwords(obj));
734 
735 			err = cpu_check(obj, ncontexts++, rem);
736 			if (err)
737 				break;
738 
739 			dw += rem;
740 		}
741 
742 out_file:
743 		throttle_release(tq, ARRAY_SIZE(tq));
744 		if (igt_live_test_end(&t))
745 			err = -EIO;
746 
747 		fput(file);
748 		if (err)
749 			return err;
750 
751 		i915_gem_drain_freed_objects(i915);
752 	}
753 
754 	return 0;
755 }
756 
757 static int igt_shared_ctx_exec(void *arg)
758 {
759 	struct drm_i915_private *i915 = arg;
760 	struct i915_request *tq[5] = {};
761 	struct i915_gem_context *parent;
762 	struct intel_engine_cs *engine;
763 	struct igt_live_test t;
764 	struct file *file;
765 	int err = 0;
766 
767 	/*
768 	 * Create a few different contexts with the same mm and write
769 	 * through each ctx using the GPU making sure those writes end
770 	 * up in the expected pages of our obj.
771 	 */
772 	if (!DRIVER_CAPS(i915)->has_logical_contexts)
773 		return 0;
774 
775 	file = mock_file(i915);
776 	if (IS_ERR(file))
777 		return PTR_ERR(file);
778 
779 	parent = live_context(i915, file);
780 	if (IS_ERR(parent)) {
781 		err = PTR_ERR(parent);
782 		goto out_file;
783 	}
784 
785 	if (!parent->vm) { /* not full-ppgtt; nothing to share */
786 		err = 0;
787 		goto out_file;
788 	}
789 
790 	err = igt_live_test_begin(&t, i915, __func__, "");
791 	if (err)
792 		goto out_file;
793 
794 	for_each_uabi_engine(engine, i915) {
795 		unsigned long ncontexts, ndwords, dw;
796 		struct drm_i915_gem_object *obj = NULL;
797 		IGT_TIMEOUT(end_time);
798 		LIST_HEAD(objects);
799 
800 		if (!intel_engine_can_store_dword(engine))
801 			continue;
802 
803 		dw = 0;
804 		ndwords = 0;
805 		ncontexts = 0;
806 		while (!time_after(jiffies, end_time)) {
807 			struct i915_gem_context *ctx;
808 			struct intel_context *ce;
809 
810 			ctx = kernel_context(i915);
811 			if (IS_ERR(ctx)) {
812 				err = PTR_ERR(ctx);
813 				goto out_test;
814 			}
815 
816 			mutex_lock(&ctx->mutex);
817 			__assign_ppgtt(ctx, ctx_vm(parent));
818 			mutex_unlock(&ctx->mutex);
819 
820 			ce = i915_gem_context_get_engine(ctx, engine->legacy_idx);
821 			GEM_BUG_ON(IS_ERR(ce));
822 
823 			if (!obj) {
824 				obj = create_test_object(ctx_vm(parent),
825 							 file, &objects);
826 				if (IS_ERR(obj)) {
827 					err = PTR_ERR(obj);
828 					intel_context_put(ce);
829 					kernel_context_close(ctx);
830 					goto out_test;
831 				}
832 			}
833 
834 			err = gpu_fill(ce, obj, dw);
835 			if (err) {
836 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
837 				       ndwords, dw, max_dwords(obj),
838 				       engine->name,
839 				       yesno(!!rcu_access_pointer(ctx->vm)),
840 				       err);
841 				intel_context_put(ce);
842 				kernel_context_close(ctx);
843 				goto out_test;
844 			}
845 
846 			err = throttle(ce, tq, ARRAY_SIZE(tq));
847 			if (err) {
848 				intel_context_put(ce);
849 				kernel_context_close(ctx);
850 				goto out_test;
851 			}
852 
853 			if (++dw == max_dwords(obj)) {
854 				obj = NULL;
855 				dw = 0;
856 			}
857 
858 			ndwords++;
859 			ncontexts++;
860 
861 			intel_context_put(ce);
862 			kernel_context_close(ctx);
863 		}
864 		pr_info("Submitted %lu contexts to %s, filling %lu dwords\n",
865 			ncontexts, engine->name, ndwords);
866 
867 		ncontexts = dw = 0;
868 		list_for_each_entry(obj, &objects, st_link) {
869 			unsigned int rem =
870 				min_t(unsigned int, ndwords - dw, max_dwords(obj));
871 
872 			err = cpu_check(obj, ncontexts++, rem);
873 			if (err)
874 				goto out_test;
875 
876 			dw += rem;
877 		}
878 
879 		i915_gem_drain_freed_objects(i915);
880 	}
881 out_test:
882 	throttle_release(tq, ARRAY_SIZE(tq));
883 	if (igt_live_test_end(&t))
884 		err = -EIO;
885 out_file:
886 	fput(file);
887 	return err;
888 }
889 
890 static struct i915_vma *rpcs_query_batch(struct i915_vma *vma)
891 {
892 	struct drm_i915_gem_object *obj;
893 	u32 *cmd;
894 	int err;
895 
896 	if (INTEL_GEN(vma->vm->i915) < 8)
897 		return ERR_PTR(-EINVAL);
898 
899 	obj = i915_gem_object_create_internal(vma->vm->i915, PAGE_SIZE);
900 	if (IS_ERR(obj))
901 		return ERR_CAST(obj);
902 
903 	cmd = i915_gem_object_pin_map(obj, I915_MAP_WB);
904 	if (IS_ERR(cmd)) {
905 		err = PTR_ERR(cmd);
906 		goto err;
907 	}
908 
909 	*cmd++ = MI_STORE_REGISTER_MEM_GEN8;
910 	*cmd++ = i915_mmio_reg_offset(GEN8_R_PWR_CLK_STATE);
911 	*cmd++ = lower_32_bits(vma->node.start);
912 	*cmd++ = upper_32_bits(vma->node.start);
913 	*cmd = MI_BATCH_BUFFER_END;
914 
915 	__i915_gem_object_flush_map(obj, 0, 64);
916 	i915_gem_object_unpin_map(obj);
917 
918 	intel_gt_chipset_flush(vma->vm->gt);
919 
920 	vma = i915_vma_instance(obj, vma->vm, NULL);
921 	if (IS_ERR(vma)) {
922 		err = PTR_ERR(vma);
923 		goto err;
924 	}
925 
926 	err = i915_vma_pin(vma, 0, 0, PIN_USER);
927 	if (err)
928 		goto err;
929 
930 	return vma;
931 
932 err:
933 	i915_gem_object_put(obj);
934 	return ERR_PTR(err);
935 }
936 
937 static int
938 emit_rpcs_query(struct drm_i915_gem_object *obj,
939 		struct intel_context *ce,
940 		struct i915_request **rq_out)
941 {
942 	struct i915_request *rq;
943 	struct i915_vma *batch;
944 	struct i915_vma *vma;
945 	int err;
946 
947 	GEM_BUG_ON(!intel_engine_can_store_dword(ce->engine));
948 
949 	vma = i915_vma_instance(obj, ce->vm, NULL);
950 	if (IS_ERR(vma))
951 		return PTR_ERR(vma);
952 
953 	i915_gem_object_lock(obj);
954 	err = i915_gem_object_set_to_gtt_domain(obj, false);
955 	i915_gem_object_unlock(obj);
956 	if (err)
957 		return err;
958 
959 	err = i915_vma_pin(vma, 0, 0, PIN_USER);
960 	if (err)
961 		return err;
962 
963 	batch = rpcs_query_batch(vma);
964 	if (IS_ERR(batch)) {
965 		err = PTR_ERR(batch);
966 		goto err_vma;
967 	}
968 
969 	rq = i915_request_create(ce);
970 	if (IS_ERR(rq)) {
971 		err = PTR_ERR(rq);
972 		goto err_batch;
973 	}
974 
975 	err = rq->engine->emit_bb_start(rq,
976 					batch->node.start, batch->node.size,
977 					0);
978 	if (err)
979 		goto err_request;
980 
981 	i915_vma_lock(batch);
982 	err = i915_request_await_object(rq, batch->obj, false);
983 	if (err == 0)
984 		err = i915_vma_move_to_active(batch, rq, 0);
985 	i915_vma_unlock(batch);
986 	if (err)
987 		goto skip_request;
988 
989 	i915_vma_lock(vma);
990 	err = i915_request_await_object(rq, vma->obj, true);
991 	if (err == 0)
992 		err = i915_vma_move_to_active(vma, rq, EXEC_OBJECT_WRITE);
993 	i915_vma_unlock(vma);
994 	if (err)
995 		goto skip_request;
996 
997 	i915_vma_unpin_and_release(&batch, 0);
998 	i915_vma_unpin(vma);
999 
1000 	*rq_out = i915_request_get(rq);
1001 
1002 	i915_request_add(rq);
1003 
1004 	return 0;
1005 
1006 skip_request:
1007 	i915_request_skip(rq, err);
1008 err_request:
1009 	i915_request_add(rq);
1010 err_batch:
1011 	i915_vma_unpin_and_release(&batch, 0);
1012 err_vma:
1013 	i915_vma_unpin(vma);
1014 
1015 	return err;
1016 }
1017 
1018 #define TEST_IDLE	BIT(0)
1019 #define TEST_BUSY	BIT(1)
1020 #define TEST_RESET	BIT(2)
1021 
1022 static int
1023 __sseu_prepare(const char *name,
1024 	       unsigned int flags,
1025 	       struct intel_context *ce,
1026 	       struct igt_spinner **spin)
1027 {
1028 	struct i915_request *rq;
1029 	int ret;
1030 
1031 	*spin = NULL;
1032 	if (!(flags & (TEST_BUSY | TEST_RESET)))
1033 		return 0;
1034 
1035 	*spin = kzalloc(sizeof(**spin), GFP_KERNEL);
1036 	if (!*spin)
1037 		return -ENOMEM;
1038 
1039 	ret = igt_spinner_init(*spin, ce->engine->gt);
1040 	if (ret)
1041 		goto err_free;
1042 
1043 	rq = igt_spinner_create_request(*spin, ce, MI_NOOP);
1044 	if (IS_ERR(rq)) {
1045 		ret = PTR_ERR(rq);
1046 		goto err_fini;
1047 	}
1048 
1049 	i915_request_add(rq);
1050 
1051 	if (!igt_wait_for_spinner(*spin, rq)) {
1052 		pr_err("%s: Spinner failed to start!\n", name);
1053 		ret = -ETIMEDOUT;
1054 		goto err_end;
1055 	}
1056 
1057 	return 0;
1058 
1059 err_end:
1060 	igt_spinner_end(*spin);
1061 err_fini:
1062 	igt_spinner_fini(*spin);
1063 err_free:
1064 	kfree(fetch_and_zero(spin));
1065 	return ret;
1066 }
1067 
1068 static int
1069 __read_slice_count(struct intel_context *ce,
1070 		   struct drm_i915_gem_object *obj,
1071 		   struct igt_spinner *spin,
1072 		   u32 *rpcs)
1073 {
1074 	struct i915_request *rq = NULL;
1075 	u32 s_mask, s_shift;
1076 	unsigned int cnt;
1077 	u32 *buf, val;
1078 	long ret;
1079 
1080 	ret = emit_rpcs_query(obj, ce, &rq);
1081 	if (ret)
1082 		return ret;
1083 
1084 	if (spin)
1085 		igt_spinner_end(spin);
1086 
1087 	ret = i915_request_wait(rq, 0, MAX_SCHEDULE_TIMEOUT);
1088 	i915_request_put(rq);
1089 	if (ret < 0)
1090 		return ret;
1091 
1092 	buf = i915_gem_object_pin_map(obj, I915_MAP_WB);
1093 	if (IS_ERR(buf)) {
1094 		ret = PTR_ERR(buf);
1095 		return ret;
1096 	}
1097 
1098 	if (INTEL_GEN(ce->engine->i915) >= 11) {
1099 		s_mask = GEN11_RPCS_S_CNT_MASK;
1100 		s_shift = GEN11_RPCS_S_CNT_SHIFT;
1101 	} else {
1102 		s_mask = GEN8_RPCS_S_CNT_MASK;
1103 		s_shift = GEN8_RPCS_S_CNT_SHIFT;
1104 	}
1105 
1106 	val = *buf;
1107 	cnt = (val & s_mask) >> s_shift;
1108 	*rpcs = val;
1109 
1110 	i915_gem_object_unpin_map(obj);
1111 
1112 	return cnt;
1113 }
1114 
1115 static int
1116 __check_rpcs(const char *name, u32 rpcs, int slices, unsigned int expected,
1117 	     const char *prefix, const char *suffix)
1118 {
1119 	if (slices == expected)
1120 		return 0;
1121 
1122 	if (slices < 0) {
1123 		pr_err("%s: %s read slice count failed with %d%s\n",
1124 		       name, prefix, slices, suffix);
1125 		return slices;
1126 	}
1127 
1128 	pr_err("%s: %s slice count %d is not %u%s\n",
1129 	       name, prefix, slices, expected, suffix);
1130 
1131 	pr_info("RPCS=0x%x; %u%sx%u%s\n",
1132 		rpcs, slices,
1133 		(rpcs & GEN8_RPCS_S_CNT_ENABLE) ? "*" : "",
1134 		(rpcs & GEN8_RPCS_SS_CNT_MASK) >> GEN8_RPCS_SS_CNT_SHIFT,
1135 		(rpcs & GEN8_RPCS_SS_CNT_ENABLE) ? "*" : "");
1136 
1137 	return -EINVAL;
1138 }
1139 
1140 static int
1141 __sseu_finish(const char *name,
1142 	      unsigned int flags,
1143 	      struct intel_context *ce,
1144 	      struct drm_i915_gem_object *obj,
1145 	      unsigned int expected,
1146 	      struct igt_spinner *spin)
1147 {
1148 	unsigned int slices = hweight32(ce->engine->sseu.slice_mask);
1149 	u32 rpcs = 0;
1150 	int ret = 0;
1151 
1152 	if (flags & TEST_RESET) {
1153 		ret = intel_engine_reset(ce->engine, "sseu");
1154 		if (ret)
1155 			goto out;
1156 	}
1157 
1158 	ret = __read_slice_count(ce, obj,
1159 				 flags & TEST_RESET ? NULL : spin, &rpcs);
1160 	ret = __check_rpcs(name, rpcs, ret, expected, "Context", "!");
1161 	if (ret)
1162 		goto out;
1163 
1164 	ret = __read_slice_count(ce->engine->kernel_context, obj, NULL, &rpcs);
1165 	ret = __check_rpcs(name, rpcs, ret, slices, "Kernel context", "!");
1166 
1167 out:
1168 	if (spin)
1169 		igt_spinner_end(spin);
1170 
1171 	if ((flags & TEST_IDLE) && ret == 0) {
1172 		ret = igt_flush_test(ce->engine->i915);
1173 		if (ret)
1174 			return ret;
1175 
1176 		ret = __read_slice_count(ce, obj, NULL, &rpcs);
1177 		ret = __check_rpcs(name, rpcs, ret, expected,
1178 				   "Context", " after idle!");
1179 	}
1180 
1181 	return ret;
1182 }
1183 
1184 static int
1185 __sseu_test(const char *name,
1186 	    unsigned int flags,
1187 	    struct intel_context *ce,
1188 	    struct drm_i915_gem_object *obj,
1189 	    struct intel_sseu sseu)
1190 {
1191 	struct igt_spinner *spin = NULL;
1192 	int ret;
1193 
1194 	intel_engine_pm_get(ce->engine);
1195 
1196 	ret = __sseu_prepare(name, flags, ce, &spin);
1197 	if (ret)
1198 		goto out_pm;
1199 
1200 	ret = intel_context_reconfigure_sseu(ce, sseu);
1201 	if (ret)
1202 		goto out_spin;
1203 
1204 	ret = __sseu_finish(name, flags, ce, obj,
1205 			    hweight32(sseu.slice_mask), spin);
1206 
1207 out_spin:
1208 	if (spin) {
1209 		igt_spinner_end(spin);
1210 		igt_spinner_fini(spin);
1211 		kfree(spin);
1212 	}
1213 out_pm:
1214 	intel_engine_pm_put(ce->engine);
1215 	return ret;
1216 }
1217 
1218 static int
1219 __igt_ctx_sseu(struct drm_i915_private *i915,
1220 	       const char *name,
1221 	       unsigned int flags)
1222 {
1223 	struct drm_i915_gem_object *obj;
1224 	int inst = 0;
1225 	int ret = 0;
1226 
1227 	if (INTEL_GEN(i915) < 9 || !RUNTIME_INFO(i915)->sseu.has_slice_pg)
1228 		return 0;
1229 
1230 	if (flags & TEST_RESET)
1231 		igt_global_reset_lock(&i915->gt);
1232 
1233 	obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
1234 	if (IS_ERR(obj)) {
1235 		ret = PTR_ERR(obj);
1236 		goto out_unlock;
1237 	}
1238 
1239 	do {
1240 		struct intel_engine_cs *engine;
1241 		struct intel_context *ce;
1242 		struct intel_sseu pg_sseu;
1243 
1244 		engine = intel_engine_lookup_user(i915,
1245 						  I915_ENGINE_CLASS_RENDER,
1246 						  inst++);
1247 		if (!engine)
1248 			break;
1249 
1250 		if (hweight32(engine->sseu.slice_mask) < 2)
1251 			continue;
1252 
1253 		/*
1254 		 * Gen11 VME friendly power-gated configuration with
1255 		 * half enabled sub-slices.
1256 		 */
1257 		pg_sseu = engine->sseu;
1258 		pg_sseu.slice_mask = 1;
1259 		pg_sseu.subslice_mask =
1260 			~(~0 << (hweight32(engine->sseu.subslice_mask) / 2));
1261 
1262 		pr_info("%s: SSEU subtest '%s', flags=%x, def_slices=%u, pg_slices=%u\n",
1263 			engine->name, name, flags,
1264 			hweight32(engine->sseu.slice_mask),
1265 			hweight32(pg_sseu.slice_mask));
1266 
1267 		ce = intel_context_create(engine);
1268 		if (IS_ERR(ce)) {
1269 			ret = PTR_ERR(ce);
1270 			goto out_put;
1271 		}
1272 
1273 		ret = intel_context_pin(ce);
1274 		if (ret)
1275 			goto out_ce;
1276 
1277 		/* First set the default mask. */
1278 		ret = __sseu_test(name, flags, ce, obj, engine->sseu);
1279 		if (ret)
1280 			goto out_unpin;
1281 
1282 		/* Then set a power-gated configuration. */
1283 		ret = __sseu_test(name, flags, ce, obj, pg_sseu);
1284 		if (ret)
1285 			goto out_unpin;
1286 
1287 		/* Back to defaults. */
1288 		ret = __sseu_test(name, flags, ce, obj, engine->sseu);
1289 		if (ret)
1290 			goto out_unpin;
1291 
1292 		/* One last power-gated configuration for the road. */
1293 		ret = __sseu_test(name, flags, ce, obj, pg_sseu);
1294 		if (ret)
1295 			goto out_unpin;
1296 
1297 out_unpin:
1298 		intel_context_unpin(ce);
1299 out_ce:
1300 		intel_context_put(ce);
1301 	} while (!ret);
1302 
1303 	if (igt_flush_test(i915))
1304 		ret = -EIO;
1305 
1306 out_put:
1307 	i915_gem_object_put(obj);
1308 
1309 out_unlock:
1310 	if (flags & TEST_RESET)
1311 		igt_global_reset_unlock(&i915->gt);
1312 
1313 	if (ret)
1314 		pr_err("%s: Failed with %d!\n", name, ret);
1315 
1316 	return ret;
1317 }
1318 
1319 static int igt_ctx_sseu(void *arg)
1320 {
1321 	struct {
1322 		const char *name;
1323 		unsigned int flags;
1324 	} *phase, phases[] = {
1325 		{ .name = "basic", .flags = 0 },
1326 		{ .name = "idle", .flags = TEST_IDLE },
1327 		{ .name = "busy", .flags = TEST_BUSY },
1328 		{ .name = "busy-reset", .flags = TEST_BUSY | TEST_RESET },
1329 		{ .name = "busy-idle", .flags = TEST_BUSY | TEST_IDLE },
1330 		{ .name = "reset-idle", .flags = TEST_RESET | TEST_IDLE },
1331 	};
1332 	unsigned int i;
1333 	int ret = 0;
1334 
1335 	for (i = 0, phase = phases; ret == 0 && i < ARRAY_SIZE(phases);
1336 	     i++, phase++)
1337 		ret = __igt_ctx_sseu(arg, phase->name, phase->flags);
1338 
1339 	return ret;
1340 }
1341 
1342 static int igt_ctx_readonly(void *arg)
1343 {
1344 	struct drm_i915_private *i915 = arg;
1345 	unsigned long idx, ndwords, dw, num_engines;
1346 	struct drm_i915_gem_object *obj = NULL;
1347 	struct i915_request *tq[5] = {};
1348 	struct i915_gem_engines_iter it;
1349 	struct i915_address_space *vm;
1350 	struct i915_gem_context *ctx;
1351 	struct intel_context *ce;
1352 	struct igt_live_test t;
1353 	I915_RND_STATE(prng);
1354 	IGT_TIMEOUT(end_time);
1355 	LIST_HEAD(objects);
1356 	struct file *file;
1357 	int err = -ENODEV;
1358 
1359 	/*
1360 	 * Create a few read-only objects (with the occasional writable object)
1361 	 * and try to write into these object checking that the GPU discards
1362 	 * any write to a read-only object.
1363 	 */
1364 
1365 	file = mock_file(i915);
1366 	if (IS_ERR(file))
1367 		return PTR_ERR(file);
1368 
1369 	err = igt_live_test_begin(&t, i915, __func__, "");
1370 	if (err)
1371 		goto out_file;
1372 
1373 	ctx = live_context(i915, file);
1374 	if (IS_ERR(ctx)) {
1375 		err = PTR_ERR(ctx);
1376 		goto out_file;
1377 	}
1378 
1379 	vm = ctx_vm(ctx) ?: &i915->ggtt.alias->vm;
1380 	if (!vm || !vm->has_read_only) {
1381 		err = 0;
1382 		goto out_file;
1383 	}
1384 
1385 	num_engines = 0;
1386 	for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it)
1387 		if (intel_engine_can_store_dword(ce->engine))
1388 			num_engines++;
1389 	i915_gem_context_unlock_engines(ctx);
1390 
1391 	ndwords = 0;
1392 	dw = 0;
1393 	while (!time_after(jiffies, end_time)) {
1394 		for_each_gem_engine(ce,
1395 				    i915_gem_context_lock_engines(ctx), it) {
1396 			if (!intel_engine_can_store_dword(ce->engine))
1397 				continue;
1398 
1399 			if (!obj) {
1400 				obj = create_test_object(ce->vm, file, &objects);
1401 				if (IS_ERR(obj)) {
1402 					err = PTR_ERR(obj);
1403 					i915_gem_context_unlock_engines(ctx);
1404 					goto out_file;
1405 				}
1406 
1407 				if (prandom_u32_state(&prng) & 1)
1408 					i915_gem_object_set_readonly(obj);
1409 			}
1410 
1411 			err = gpu_fill(ce, obj, dw);
1412 			if (err) {
1413 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
1414 				       ndwords, dw, max_dwords(obj),
1415 				       ce->engine->name,
1416 				       yesno(!!ctx_vm(ctx)),
1417 				       err);
1418 				i915_gem_context_unlock_engines(ctx);
1419 				goto out_file;
1420 			}
1421 
1422 			err = throttle(ce, tq, ARRAY_SIZE(tq));
1423 			if (err) {
1424 				i915_gem_context_unlock_engines(ctx);
1425 				goto out_file;
1426 			}
1427 
1428 			if (++dw == max_dwords(obj)) {
1429 				obj = NULL;
1430 				dw = 0;
1431 			}
1432 			ndwords++;
1433 		}
1434 		i915_gem_context_unlock_engines(ctx);
1435 	}
1436 	pr_info("Submitted %lu dwords (across %lu engines)\n",
1437 		ndwords, num_engines);
1438 
1439 	dw = 0;
1440 	idx = 0;
1441 	list_for_each_entry(obj, &objects, st_link) {
1442 		unsigned int rem =
1443 			min_t(unsigned int, ndwords - dw, max_dwords(obj));
1444 		unsigned int num_writes;
1445 
1446 		num_writes = rem;
1447 		if (i915_gem_object_is_readonly(obj))
1448 			num_writes = 0;
1449 
1450 		err = cpu_check(obj, idx++, num_writes);
1451 		if (err)
1452 			break;
1453 
1454 		dw += rem;
1455 	}
1456 
1457 out_file:
1458 	throttle_release(tq, ARRAY_SIZE(tq));
1459 	if (igt_live_test_end(&t))
1460 		err = -EIO;
1461 
1462 	fput(file);
1463 	return err;
1464 }
1465 
1466 static int check_scratch(struct i915_address_space *vm, u64 offset)
1467 {
1468 	struct drm_mm_node *node =
1469 		__drm_mm_interval_first(&vm->mm,
1470 					offset, offset + sizeof(u32) - 1);
1471 	if (!node || node->start > offset)
1472 		return 0;
1473 
1474 	GEM_BUG_ON(offset >= node->start + node->size);
1475 
1476 	pr_err("Target offset 0x%08x_%08x overlaps with a node in the mm!\n",
1477 	       upper_32_bits(offset), lower_32_bits(offset));
1478 	return -EINVAL;
1479 }
1480 
1481 static int write_to_scratch(struct i915_gem_context *ctx,
1482 			    struct intel_engine_cs *engine,
1483 			    u64 offset, u32 value)
1484 {
1485 	struct drm_i915_private *i915 = ctx->i915;
1486 	struct drm_i915_gem_object *obj;
1487 	struct i915_address_space *vm;
1488 	struct i915_request *rq;
1489 	struct i915_vma *vma;
1490 	u32 *cmd;
1491 	int err;
1492 
1493 	GEM_BUG_ON(offset < I915_GTT_PAGE_SIZE);
1494 
1495 	obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
1496 	if (IS_ERR(obj))
1497 		return PTR_ERR(obj);
1498 
1499 	cmd = i915_gem_object_pin_map(obj, I915_MAP_WB);
1500 	if (IS_ERR(cmd)) {
1501 		err = PTR_ERR(cmd);
1502 		goto out;
1503 	}
1504 
1505 	*cmd++ = MI_STORE_DWORD_IMM_GEN4;
1506 	if (INTEL_GEN(i915) >= 8) {
1507 		*cmd++ = lower_32_bits(offset);
1508 		*cmd++ = upper_32_bits(offset);
1509 	} else {
1510 		*cmd++ = 0;
1511 		*cmd++ = offset;
1512 	}
1513 	*cmd++ = value;
1514 	*cmd = MI_BATCH_BUFFER_END;
1515 	__i915_gem_object_flush_map(obj, 0, 64);
1516 	i915_gem_object_unpin_map(obj);
1517 
1518 	intel_gt_chipset_flush(engine->gt);
1519 
1520 	vm = i915_gem_context_get_vm_rcu(ctx);
1521 	vma = i915_vma_instance(obj, vm, NULL);
1522 	if (IS_ERR(vma)) {
1523 		err = PTR_ERR(vma);
1524 		goto out_vm;
1525 	}
1526 
1527 	err = i915_vma_pin(vma, 0, 0, PIN_USER | PIN_OFFSET_FIXED);
1528 	if (err)
1529 		goto out_vm;
1530 
1531 	err = check_scratch(vm, offset);
1532 	if (err)
1533 		goto err_unpin;
1534 
1535 	rq = igt_request_alloc(ctx, engine);
1536 	if (IS_ERR(rq)) {
1537 		err = PTR_ERR(rq);
1538 		goto err_unpin;
1539 	}
1540 
1541 	err = engine->emit_bb_start(rq, vma->node.start, vma->node.size, 0);
1542 	if (err)
1543 		goto err_request;
1544 
1545 	i915_vma_lock(vma);
1546 	err = i915_request_await_object(rq, vma->obj, false);
1547 	if (err == 0)
1548 		err = i915_vma_move_to_active(vma, rq, 0);
1549 	i915_vma_unlock(vma);
1550 	if (err)
1551 		goto skip_request;
1552 
1553 	i915_vma_unpin(vma);
1554 
1555 	i915_request_add(rq);
1556 
1557 	goto out_vm;
1558 skip_request:
1559 	i915_request_skip(rq, err);
1560 err_request:
1561 	i915_request_add(rq);
1562 err_unpin:
1563 	i915_vma_unpin(vma);
1564 out_vm:
1565 	i915_vm_put(vm);
1566 out:
1567 	i915_gem_object_put(obj);
1568 	return err;
1569 }
1570 
1571 static int read_from_scratch(struct i915_gem_context *ctx,
1572 			     struct intel_engine_cs *engine,
1573 			     u64 offset, u32 *value)
1574 {
1575 	struct drm_i915_private *i915 = ctx->i915;
1576 	struct drm_i915_gem_object *obj;
1577 	struct i915_address_space *vm;
1578 	const u32 RCS_GPR0 = 0x2600; /* not all engines have their own GPR! */
1579 	const u32 result = 0x100;
1580 	struct i915_request *rq;
1581 	struct i915_vma *vma;
1582 	u32 *cmd;
1583 	int err;
1584 
1585 	GEM_BUG_ON(offset < I915_GTT_PAGE_SIZE);
1586 
1587 	obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
1588 	if (IS_ERR(obj))
1589 		return PTR_ERR(obj);
1590 
1591 	cmd = i915_gem_object_pin_map(obj, I915_MAP_WB);
1592 	if (IS_ERR(cmd)) {
1593 		err = PTR_ERR(cmd);
1594 		goto out;
1595 	}
1596 
1597 	memset(cmd, POISON_INUSE, PAGE_SIZE);
1598 	if (INTEL_GEN(i915) >= 8) {
1599 		*cmd++ = MI_LOAD_REGISTER_MEM_GEN8;
1600 		*cmd++ = RCS_GPR0;
1601 		*cmd++ = lower_32_bits(offset);
1602 		*cmd++ = upper_32_bits(offset);
1603 		*cmd++ = MI_STORE_REGISTER_MEM_GEN8;
1604 		*cmd++ = RCS_GPR0;
1605 		*cmd++ = result;
1606 		*cmd++ = 0;
1607 	} else {
1608 		*cmd++ = MI_LOAD_REGISTER_MEM;
1609 		*cmd++ = RCS_GPR0;
1610 		*cmd++ = offset;
1611 		*cmd++ = MI_STORE_REGISTER_MEM;
1612 		*cmd++ = RCS_GPR0;
1613 		*cmd++ = result;
1614 	}
1615 	*cmd = MI_BATCH_BUFFER_END;
1616 
1617 	i915_gem_object_flush_map(obj);
1618 	i915_gem_object_unpin_map(obj);
1619 
1620 	intel_gt_chipset_flush(engine->gt);
1621 
1622 	vm = i915_gem_context_get_vm_rcu(ctx);
1623 	vma = i915_vma_instance(obj, vm, NULL);
1624 	if (IS_ERR(vma)) {
1625 		err = PTR_ERR(vma);
1626 		goto out_vm;
1627 	}
1628 
1629 	err = i915_vma_pin(vma, 0, 0, PIN_USER | PIN_OFFSET_FIXED);
1630 	if (err)
1631 		goto out_vm;
1632 
1633 	err = check_scratch(vm, offset);
1634 	if (err)
1635 		goto err_unpin;
1636 
1637 	rq = igt_request_alloc(ctx, engine);
1638 	if (IS_ERR(rq)) {
1639 		err = PTR_ERR(rq);
1640 		goto err_unpin;
1641 	}
1642 
1643 	err = engine->emit_bb_start(rq, vma->node.start, vma->node.size, 0);
1644 	if (err)
1645 		goto err_request;
1646 
1647 	i915_vma_lock(vma);
1648 	err = i915_request_await_object(rq, vma->obj, true);
1649 	if (err == 0)
1650 		err = i915_vma_move_to_active(vma, rq, EXEC_OBJECT_WRITE);
1651 	i915_vma_unlock(vma);
1652 	if (err)
1653 		goto skip_request;
1654 
1655 	i915_vma_unpin(vma);
1656 	i915_vma_close(vma);
1657 
1658 	i915_request_add(rq);
1659 
1660 	i915_gem_object_lock(obj);
1661 	err = i915_gem_object_set_to_cpu_domain(obj, false);
1662 	i915_gem_object_unlock(obj);
1663 	if (err)
1664 		goto out_vm;
1665 
1666 	cmd = i915_gem_object_pin_map(obj, I915_MAP_WB);
1667 	if (IS_ERR(cmd)) {
1668 		err = PTR_ERR(cmd);
1669 		goto out_vm;
1670 	}
1671 
1672 	*value = cmd[result / sizeof(*cmd)];
1673 	i915_gem_object_unpin_map(obj);
1674 
1675 	goto out_vm;
1676 skip_request:
1677 	i915_request_skip(rq, err);
1678 err_request:
1679 	i915_request_add(rq);
1680 err_unpin:
1681 	i915_vma_unpin(vma);
1682 out_vm:
1683 	i915_vm_put(vm);
1684 out:
1685 	i915_gem_object_put(obj);
1686 	return err;
1687 }
1688 
1689 static int igt_vm_isolation(void *arg)
1690 {
1691 	struct drm_i915_private *i915 = arg;
1692 	struct i915_gem_context *ctx_a, *ctx_b;
1693 	unsigned long num_engines, count;
1694 	struct intel_engine_cs *engine;
1695 	struct igt_live_test t;
1696 	I915_RND_STATE(prng);
1697 	struct file *file;
1698 	u64 vm_total;
1699 	int err;
1700 
1701 	if (INTEL_GEN(i915) < 7)
1702 		return 0;
1703 
1704 	/*
1705 	 * The simple goal here is that a write into one context is not
1706 	 * observed in a second (separate page tables and scratch).
1707 	 */
1708 
1709 	file = mock_file(i915);
1710 	if (IS_ERR(file))
1711 		return PTR_ERR(file);
1712 
1713 	err = igt_live_test_begin(&t, i915, __func__, "");
1714 	if (err)
1715 		goto out_file;
1716 
1717 	ctx_a = live_context(i915, file);
1718 	if (IS_ERR(ctx_a)) {
1719 		err = PTR_ERR(ctx_a);
1720 		goto out_file;
1721 	}
1722 
1723 	ctx_b = live_context(i915, file);
1724 	if (IS_ERR(ctx_b)) {
1725 		err = PTR_ERR(ctx_b);
1726 		goto out_file;
1727 	}
1728 
1729 	/* We can only test vm isolation, if the vm are distinct */
1730 	if (ctx_vm(ctx_a) == ctx_vm(ctx_b))
1731 		goto out_file;
1732 
1733 	vm_total = ctx_vm(ctx_a)->total;
1734 	GEM_BUG_ON(ctx_vm(ctx_b)->total != vm_total);
1735 	vm_total -= I915_GTT_PAGE_SIZE;
1736 
1737 	count = 0;
1738 	num_engines = 0;
1739 	for_each_uabi_engine(engine, i915) {
1740 		IGT_TIMEOUT(end_time);
1741 		unsigned long this = 0;
1742 
1743 		if (!intel_engine_can_store_dword(engine))
1744 			continue;
1745 
1746 		while (!__igt_timeout(end_time, NULL)) {
1747 			u32 value = 0xc5c5c5c5;
1748 			u64 offset;
1749 
1750 			div64_u64_rem(i915_prandom_u64_state(&prng),
1751 				      vm_total, &offset);
1752 			offset = round_down(offset, alignof_dword);
1753 			offset += I915_GTT_PAGE_SIZE;
1754 
1755 			err = write_to_scratch(ctx_a, engine,
1756 					       offset, 0xdeadbeef);
1757 			if (err == 0)
1758 				err = read_from_scratch(ctx_b, engine,
1759 							offset, &value);
1760 			if (err)
1761 				goto out_file;
1762 
1763 			if (value) {
1764 				pr_err("%s: Read %08x from scratch (offset 0x%08x_%08x), after %lu reads!\n",
1765 				       engine->name, value,
1766 				       upper_32_bits(offset),
1767 				       lower_32_bits(offset),
1768 				       this);
1769 				err = -EINVAL;
1770 				goto out_file;
1771 			}
1772 
1773 			this++;
1774 		}
1775 		count += this;
1776 		num_engines++;
1777 	}
1778 	pr_info("Checked %lu scratch offsets across %lu engines\n",
1779 		count, num_engines);
1780 
1781 out_file:
1782 	if (igt_live_test_end(&t))
1783 		err = -EIO;
1784 	fput(file);
1785 	return err;
1786 }
1787 
1788 static bool skip_unused_engines(struct intel_context *ce, void *data)
1789 {
1790 	return !ce->state;
1791 }
1792 
1793 static void mock_barrier_task(void *data)
1794 {
1795 	unsigned int *counter = data;
1796 
1797 	++*counter;
1798 }
1799 
1800 static int mock_context_barrier(void *arg)
1801 {
1802 #undef pr_fmt
1803 #define pr_fmt(x) "context_barrier_task():" # x
1804 	struct drm_i915_private *i915 = arg;
1805 	struct i915_gem_context *ctx;
1806 	struct i915_request *rq;
1807 	unsigned int counter;
1808 	int err;
1809 
1810 	/*
1811 	 * The context barrier provides us with a callback after it emits
1812 	 * a request; useful for retiring old state after loading new.
1813 	 */
1814 
1815 	ctx = mock_context(i915, "mock");
1816 	if (!ctx)
1817 		return -ENOMEM;
1818 
1819 	counter = 0;
1820 	err = context_barrier_task(ctx, 0,
1821 				   NULL, NULL, mock_barrier_task, &counter);
1822 	if (err) {
1823 		pr_err("Failed at line %d, err=%d\n", __LINE__, err);
1824 		goto out;
1825 	}
1826 	if (counter == 0) {
1827 		pr_err("Did not retire immediately with 0 engines\n");
1828 		err = -EINVAL;
1829 		goto out;
1830 	}
1831 
1832 	counter = 0;
1833 	err = context_barrier_task(ctx, ALL_ENGINES,
1834 				   skip_unused_engines,
1835 				   NULL,
1836 				   mock_barrier_task,
1837 				   &counter);
1838 	if (err) {
1839 		pr_err("Failed at line %d, err=%d\n", __LINE__, err);
1840 		goto out;
1841 	}
1842 	if (counter == 0) {
1843 		pr_err("Did not retire immediately for all unused engines\n");
1844 		err = -EINVAL;
1845 		goto out;
1846 	}
1847 
1848 	rq = igt_request_alloc(ctx, i915->engine[RCS0]);
1849 	if (IS_ERR(rq)) {
1850 		pr_err("Request allocation failed!\n");
1851 		goto out;
1852 	}
1853 	i915_request_add(rq);
1854 
1855 	counter = 0;
1856 	context_barrier_inject_fault = BIT(RCS0);
1857 	err = context_barrier_task(ctx, ALL_ENGINES,
1858 				   NULL, NULL, mock_barrier_task, &counter);
1859 	context_barrier_inject_fault = 0;
1860 	if (err == -ENXIO)
1861 		err = 0;
1862 	else
1863 		pr_err("Did not hit fault injection!\n");
1864 	if (counter != 0) {
1865 		pr_err("Invoked callback on error!\n");
1866 		err = -EIO;
1867 	}
1868 	if (err)
1869 		goto out;
1870 
1871 	counter = 0;
1872 	err = context_barrier_task(ctx, ALL_ENGINES,
1873 				   skip_unused_engines,
1874 				   NULL,
1875 				   mock_barrier_task,
1876 				   &counter);
1877 	if (err) {
1878 		pr_err("Failed at line %d, err=%d\n", __LINE__, err);
1879 		goto out;
1880 	}
1881 	mock_device_flush(i915);
1882 	if (counter == 0) {
1883 		pr_err("Did not retire on each active engines\n");
1884 		err = -EINVAL;
1885 		goto out;
1886 	}
1887 
1888 out:
1889 	mock_context_close(ctx);
1890 	return err;
1891 #undef pr_fmt
1892 #define pr_fmt(x) x
1893 }
1894 
1895 int i915_gem_context_mock_selftests(void)
1896 {
1897 	static const struct i915_subtest tests[] = {
1898 		SUBTEST(mock_context_barrier),
1899 	};
1900 	struct drm_i915_private *i915;
1901 	int err;
1902 
1903 	i915 = mock_gem_device();
1904 	if (!i915)
1905 		return -ENOMEM;
1906 
1907 	err = i915_subtests(tests, i915);
1908 
1909 	drm_dev_put(&i915->drm);
1910 	return err;
1911 }
1912 
1913 int i915_gem_context_live_selftests(struct drm_i915_private *i915)
1914 {
1915 	static const struct i915_subtest tests[] = {
1916 		SUBTEST(live_nop_switch),
1917 		SUBTEST(live_parallel_switch),
1918 		SUBTEST(igt_ctx_exec),
1919 		SUBTEST(igt_ctx_readonly),
1920 		SUBTEST(igt_ctx_sseu),
1921 		SUBTEST(igt_shared_ctx_exec),
1922 		SUBTEST(igt_vm_isolation),
1923 	};
1924 
1925 	if (intel_gt_is_wedged(&i915->gt))
1926 		return 0;
1927 
1928 	return i915_live_subtests(tests, i915);
1929 }
1930