1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2011-2012 Intel Corporation
5  */
6 
7 /*
8  * This file implements HW context support. On gen5+ a HW context consists of an
9  * opaque GPU object which is referenced at times of context saves and restores.
10  * With RC6 enabled, the context is also referenced as the GPU enters and exists
11  * from RC6 (GPU has it's own internal power context, except on gen5). Though
12  * something like a context does exist for the media ring, the code only
13  * supports contexts for the render ring.
14  *
15  * In software, there is a distinction between contexts created by the user,
16  * and the default HW context. The default HW context is used by GPU clients
17  * that do not request setup of their own hardware context. The default
18  * context's state is never restored to help prevent programming errors. This
19  * would happen if a client ran and piggy-backed off another clients GPU state.
20  * The default context only exists to give the GPU some offset to load as the
21  * current to invoke a save of the context we actually care about. In fact, the
22  * code could likely be constructed, albeit in a more complicated fashion, to
23  * never use the default context, though that limits the driver's ability to
24  * swap out, and/or destroy other contexts.
25  *
26  * All other contexts are created as a request by the GPU client. These contexts
27  * store GPU state, and thus allow GPU clients to not re-emit state (and
28  * potentially query certain state) at any time. The kernel driver makes
29  * certain that the appropriate commands are inserted.
30  *
31  * The context life cycle is semi-complicated in that context BOs may live
32  * longer than the context itself because of the way the hardware, and object
33  * tracking works. Below is a very crude representation of the state machine
34  * describing the context life.
35  *                                         refcount     pincount     active
36  * S0: initial state                          0            0           0
37  * S1: context created                        1            0           0
38  * S2: context is currently running           2            1           X
39  * S3: GPU referenced, but not current        2            0           1
40  * S4: context is current, but destroyed      1            1           0
41  * S5: like S3, but destroyed                 1            0           1
42  *
43  * The most common (but not all) transitions:
44  * S0->S1: client creates a context
45  * S1->S2: client submits execbuf with context
46  * S2->S3: other clients submits execbuf with context
47  * S3->S1: context object was retired
48  * S3->S2: clients submits another execbuf
49  * S2->S4: context destroy called with current context
50  * S3->S5->S0: destroy path
51  * S4->S5->S0: destroy path on current context
52  *
53  * There are two confusing terms used above:
54  *  The "current context" means the context which is currently running on the
55  *  GPU. The GPU has loaded its state already and has stored away the gtt
56  *  offset of the BO. The GPU is not actively referencing the data at this
57  *  offset, but it will on the next context switch. The only way to avoid this
58  *  is to do a GPU reset.
59  *
60  *  An "active context' is one which was previously the "current context" and is
61  *  on the active list waiting for the next context switch to occur. Until this
62  *  happens, the object must remain at the same gtt offset. It is therefore
63  *  possible to destroy a context, but it is still active.
64  *
65  */
66 
67 #include <linux/log2.h>
68 #include <linux/nospec.h>
69 
70 #include <drm/i915_drm.h>
71 
72 #include "gt/intel_lrc_reg.h"
73 #include "gt/intel_engine_user.h"
74 
75 #include "i915_gem_context.h"
76 #include "i915_globals.h"
77 #include "i915_trace.h"
78 #include "i915_user_extensions.h"
79 
80 #define ALL_L3_SLICES(dev) (1 << NUM_L3_SLICES(dev)) - 1
81 
82 static struct i915_global_gem_context {
83 	struct i915_global base;
84 	struct kmem_cache *slab_luts;
85 } global;
86 
87 struct i915_lut_handle *i915_lut_handle_alloc(void)
88 {
89 	return kmem_cache_alloc(global.slab_luts, GFP_KERNEL);
90 }
91 
92 void i915_lut_handle_free(struct i915_lut_handle *lut)
93 {
94 	return kmem_cache_free(global.slab_luts, lut);
95 }
96 
97 static void lut_close(struct i915_gem_context *ctx)
98 {
99 	struct radix_tree_iter iter;
100 	void __rcu **slot;
101 
102 	lockdep_assert_held(&ctx->mutex);
103 
104 	rcu_read_lock();
105 	radix_tree_for_each_slot(slot, &ctx->handles_vma, &iter, 0) {
106 		struct i915_vma *vma = rcu_dereference_raw(*slot);
107 		struct drm_i915_gem_object *obj = vma->obj;
108 		struct i915_lut_handle *lut;
109 
110 		if (!kref_get_unless_zero(&obj->base.refcount))
111 			continue;
112 
113 		rcu_read_unlock();
114 		i915_gem_object_lock(obj);
115 		list_for_each_entry(lut, &obj->lut_list, obj_link) {
116 			if (lut->ctx != ctx)
117 				continue;
118 
119 			if (lut->handle != iter.index)
120 				continue;
121 
122 			list_del(&lut->obj_link);
123 			break;
124 		}
125 		i915_gem_object_unlock(obj);
126 		rcu_read_lock();
127 
128 		if (&lut->obj_link != &obj->lut_list) {
129 			i915_lut_handle_free(lut);
130 			radix_tree_iter_delete(&ctx->handles_vma, &iter, slot);
131 			if (atomic_dec_and_test(&vma->open_count) &&
132 			    !i915_vma_is_ggtt(vma))
133 				i915_vma_close(vma);
134 			i915_gem_object_put(obj);
135 		}
136 
137 		i915_gem_object_put(obj);
138 	}
139 	rcu_read_unlock();
140 }
141 
142 static struct intel_context *
143 lookup_user_engine(struct i915_gem_context *ctx,
144 		   unsigned long flags,
145 		   const struct i915_engine_class_instance *ci)
146 #define LOOKUP_USER_INDEX BIT(0)
147 {
148 	int idx;
149 
150 	if (!!(flags & LOOKUP_USER_INDEX) != i915_gem_context_user_engines(ctx))
151 		return ERR_PTR(-EINVAL);
152 
153 	if (!i915_gem_context_user_engines(ctx)) {
154 		struct intel_engine_cs *engine;
155 
156 		engine = intel_engine_lookup_user(ctx->i915,
157 						  ci->engine_class,
158 						  ci->engine_instance);
159 		if (!engine)
160 			return ERR_PTR(-EINVAL);
161 
162 		idx = engine->legacy_idx;
163 	} else {
164 		idx = ci->engine_instance;
165 	}
166 
167 	return i915_gem_context_get_engine(ctx, idx);
168 }
169 
170 static void __free_engines(struct i915_gem_engines *e, unsigned int count)
171 {
172 	while (count--) {
173 		if (!e->engines[count])
174 			continue;
175 
176 		intel_context_put(e->engines[count]);
177 	}
178 	kfree(e);
179 }
180 
181 static void free_engines(struct i915_gem_engines *e)
182 {
183 	__free_engines(e, e->num_engines);
184 }
185 
186 static void free_engines_rcu(struct rcu_head *rcu)
187 {
188 	free_engines(container_of(rcu, struct i915_gem_engines, rcu));
189 }
190 
191 static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx)
192 {
193 	const struct intel_gt *gt = &ctx->i915->gt;
194 	struct intel_engine_cs *engine;
195 	struct i915_gem_engines *e;
196 	enum intel_engine_id id;
197 
198 	e = kzalloc(struct_size(e, engines, I915_NUM_ENGINES), GFP_KERNEL);
199 	if (!e)
200 		return ERR_PTR(-ENOMEM);
201 
202 	init_rcu_head(&e->rcu);
203 	for_each_engine(engine, gt, id) {
204 		struct intel_context *ce;
205 
206 		ce = intel_context_create(ctx, engine);
207 		if (IS_ERR(ce)) {
208 			__free_engines(e, id);
209 			return ERR_CAST(ce);
210 		}
211 
212 		e->engines[id] = ce;
213 		e->num_engines = id + 1;
214 	}
215 
216 	return e;
217 }
218 
219 static void i915_gem_context_free(struct i915_gem_context *ctx)
220 {
221 	GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
222 
223 	spin_lock(&ctx->i915->gem.contexts.lock);
224 	list_del(&ctx->link);
225 	spin_unlock(&ctx->i915->gem.contexts.lock);
226 
227 	free_engines(rcu_access_pointer(ctx->engines));
228 	mutex_destroy(&ctx->engines_mutex);
229 
230 	if (ctx->timeline)
231 		intel_timeline_put(ctx->timeline);
232 
233 	kfree(ctx->name);
234 	put_pid(ctx->pid);
235 
236 	mutex_destroy(&ctx->mutex);
237 
238 	kfree_rcu(ctx, rcu);
239 }
240 
241 static void contexts_free_all(struct llist_node *list)
242 {
243 	struct i915_gem_context *ctx, *cn;
244 
245 	llist_for_each_entry_safe(ctx, cn, list, free_link)
246 		i915_gem_context_free(ctx);
247 }
248 
249 static void contexts_flush_free(struct i915_gem_contexts *gc)
250 {
251 	contexts_free_all(llist_del_all(&gc->free_list));
252 }
253 
254 static void contexts_free_worker(struct work_struct *work)
255 {
256 	struct i915_gem_contexts *gc =
257 		container_of(work, typeof(*gc), free_work);
258 
259 	contexts_flush_free(gc);
260 }
261 
262 void i915_gem_context_release(struct kref *ref)
263 {
264 	struct i915_gem_context *ctx = container_of(ref, typeof(*ctx), ref);
265 	struct i915_gem_contexts *gc = &ctx->i915->gem.contexts;
266 
267 	trace_i915_context_free(ctx);
268 	if (llist_add(&ctx->free_link, &gc->free_list))
269 		schedule_work(&gc->free_work);
270 }
271 
272 static void context_close(struct i915_gem_context *ctx)
273 {
274 	struct i915_address_space *vm;
275 
276 	i915_gem_context_set_closed(ctx);
277 
278 	mutex_lock(&ctx->mutex);
279 
280 	vm = i915_gem_context_vm(ctx);
281 	if (vm)
282 		i915_vm_close(vm);
283 
284 	ctx->file_priv = ERR_PTR(-EBADF);
285 
286 	/*
287 	 * The LUT uses the VMA as a backpointer to unref the object,
288 	 * so we need to clear the LUT before we close all the VMA (inside
289 	 * the ppgtt).
290 	 */
291 	lut_close(ctx);
292 
293 	mutex_unlock(&ctx->mutex);
294 	i915_gem_context_put(ctx);
295 }
296 
297 static struct i915_gem_context *
298 __create_context(struct drm_i915_private *i915)
299 {
300 	struct i915_gem_context *ctx;
301 	struct i915_gem_engines *e;
302 	int err;
303 	int i;
304 
305 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
306 	if (!ctx)
307 		return ERR_PTR(-ENOMEM);
308 
309 	kref_init(&ctx->ref);
310 	ctx->i915 = i915;
311 	ctx->sched.priority = I915_USER_PRIORITY(I915_PRIORITY_NORMAL);
312 	mutex_init(&ctx->mutex);
313 
314 	mutex_init(&ctx->engines_mutex);
315 	e = default_engines(ctx);
316 	if (IS_ERR(e)) {
317 		err = PTR_ERR(e);
318 		goto err_free;
319 	}
320 	RCU_INIT_POINTER(ctx->engines, e);
321 
322 	INIT_RADIX_TREE(&ctx->handles_vma, GFP_KERNEL);
323 
324 	/* NB: Mark all slices as needing a remap so that when the context first
325 	 * loads it will restore whatever remap state already exists. If there
326 	 * is no remap info, it will be a NOP. */
327 	ctx->remap_slice = ALL_L3_SLICES(i915);
328 
329 	i915_gem_context_set_bannable(ctx);
330 	i915_gem_context_set_recoverable(ctx);
331 
332 	for (i = 0; i < ARRAY_SIZE(ctx->hang_timestamp); i++)
333 		ctx->hang_timestamp[i] = jiffies - CONTEXT_FAST_HANG_JIFFIES;
334 
335 	spin_lock(&i915->gem.contexts.lock);
336 	list_add_tail(&ctx->link, &i915->gem.contexts.list);
337 	spin_unlock(&i915->gem.contexts.lock);
338 
339 	return ctx;
340 
341 err_free:
342 	kfree(ctx);
343 	return ERR_PTR(err);
344 }
345 
346 static void
347 context_apply_all(struct i915_gem_context *ctx,
348 		  void (*fn)(struct intel_context *ce, void *data),
349 		  void *data)
350 {
351 	struct i915_gem_engines_iter it;
352 	struct intel_context *ce;
353 
354 	for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it)
355 		fn(ce, data);
356 	i915_gem_context_unlock_engines(ctx);
357 }
358 
359 static void __apply_ppgtt(struct intel_context *ce, void *vm)
360 {
361 	i915_vm_put(ce->vm);
362 	ce->vm = i915_vm_get(vm);
363 }
364 
365 static struct i915_address_space *
366 __set_ppgtt(struct i915_gem_context *ctx, struct i915_address_space *vm)
367 {
368 	struct i915_address_space *old = i915_gem_context_vm(ctx);
369 
370 	GEM_BUG_ON(old && i915_vm_is_4lvl(vm) != i915_vm_is_4lvl(old));
371 
372 	rcu_assign_pointer(ctx->vm, i915_vm_open(vm));
373 	context_apply_all(ctx, __apply_ppgtt, vm);
374 
375 	return old;
376 }
377 
378 static void __assign_ppgtt(struct i915_gem_context *ctx,
379 			   struct i915_address_space *vm)
380 {
381 	if (vm == rcu_access_pointer(ctx->vm))
382 		return;
383 
384 	vm = __set_ppgtt(ctx, vm);
385 	if (vm)
386 		i915_vm_close(vm);
387 }
388 
389 static void __set_timeline(struct intel_timeline **dst,
390 			   struct intel_timeline *src)
391 {
392 	struct intel_timeline *old = *dst;
393 
394 	*dst = src ? intel_timeline_get(src) : NULL;
395 
396 	if (old)
397 		intel_timeline_put(old);
398 }
399 
400 static void __apply_timeline(struct intel_context *ce, void *timeline)
401 {
402 	__set_timeline(&ce->timeline, timeline);
403 }
404 
405 static void __assign_timeline(struct i915_gem_context *ctx,
406 			      struct intel_timeline *timeline)
407 {
408 	__set_timeline(&ctx->timeline, timeline);
409 	context_apply_all(ctx, __apply_timeline, timeline);
410 }
411 
412 static struct i915_gem_context *
413 i915_gem_create_context(struct drm_i915_private *i915, unsigned int flags)
414 {
415 	struct i915_gem_context *ctx;
416 
417 	if (flags & I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE &&
418 	    !HAS_EXECLISTS(i915))
419 		return ERR_PTR(-EINVAL);
420 
421 	/* Reap the stale contexts */
422 	contexts_flush_free(&i915->gem.contexts);
423 
424 	ctx = __create_context(i915);
425 	if (IS_ERR(ctx))
426 		return ctx;
427 
428 	if (HAS_FULL_PPGTT(i915)) {
429 		struct i915_ppgtt *ppgtt;
430 
431 		ppgtt = i915_ppgtt_create(i915);
432 		if (IS_ERR(ppgtt)) {
433 			DRM_DEBUG_DRIVER("PPGTT setup failed (%ld)\n",
434 					 PTR_ERR(ppgtt));
435 			context_close(ctx);
436 			return ERR_CAST(ppgtt);
437 		}
438 
439 		mutex_lock(&ctx->mutex);
440 		__assign_ppgtt(ctx, &ppgtt->vm);
441 		mutex_unlock(&ctx->mutex);
442 
443 		i915_vm_put(&ppgtt->vm);
444 	}
445 
446 	if (flags & I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE) {
447 		struct intel_timeline *timeline;
448 
449 		timeline = intel_timeline_create(&i915->gt, NULL);
450 		if (IS_ERR(timeline)) {
451 			context_close(ctx);
452 			return ERR_CAST(timeline);
453 		}
454 
455 		__assign_timeline(ctx, timeline);
456 		intel_timeline_put(timeline);
457 	}
458 
459 	trace_i915_context_create(ctx);
460 
461 	return ctx;
462 }
463 
464 static void
465 destroy_kernel_context(struct i915_gem_context **ctxp)
466 {
467 	struct i915_gem_context *ctx;
468 
469 	/* Keep the context ref so that we can free it immediately ourselves */
470 	ctx = i915_gem_context_get(fetch_and_zero(ctxp));
471 	GEM_BUG_ON(!i915_gem_context_is_kernel(ctx));
472 
473 	context_close(ctx);
474 	i915_gem_context_free(ctx);
475 }
476 
477 struct i915_gem_context *
478 i915_gem_context_create_kernel(struct drm_i915_private *i915, int prio)
479 {
480 	struct i915_gem_context *ctx;
481 
482 	ctx = i915_gem_create_context(i915, 0);
483 	if (IS_ERR(ctx))
484 		return ctx;
485 
486 	i915_gem_context_clear_bannable(ctx);
487 	ctx->sched.priority = I915_USER_PRIORITY(prio);
488 
489 	GEM_BUG_ON(!i915_gem_context_is_kernel(ctx));
490 
491 	return ctx;
492 }
493 
494 static void init_contexts(struct i915_gem_contexts *gc)
495 {
496 	spin_lock_init(&gc->lock);
497 	INIT_LIST_HEAD(&gc->list);
498 
499 	INIT_WORK(&gc->free_work, contexts_free_worker);
500 	init_llist_head(&gc->free_list);
501 }
502 
503 int i915_gem_init_contexts(struct drm_i915_private *i915)
504 {
505 	struct i915_gem_context *ctx;
506 
507 	/* Reassure ourselves we are only called once */
508 	GEM_BUG_ON(i915->kernel_context);
509 
510 	init_contexts(&i915->gem.contexts);
511 
512 	/* lowest priority; idle task */
513 	ctx = i915_gem_context_create_kernel(i915, I915_PRIORITY_MIN);
514 	if (IS_ERR(ctx)) {
515 		DRM_ERROR("Failed to create default global context\n");
516 		return PTR_ERR(ctx);
517 	}
518 	i915->kernel_context = ctx;
519 
520 	DRM_DEBUG_DRIVER("%s context support initialized\n",
521 			 DRIVER_CAPS(i915)->has_logical_contexts ?
522 			 "logical" : "fake");
523 	return 0;
524 }
525 
526 void i915_gem_driver_release__contexts(struct drm_i915_private *i915)
527 {
528 	destroy_kernel_context(&i915->kernel_context);
529 }
530 
531 static int context_idr_cleanup(int id, void *p, void *data)
532 {
533 	context_close(p);
534 	return 0;
535 }
536 
537 static int vm_idr_cleanup(int id, void *p, void *data)
538 {
539 	i915_vm_put(p);
540 	return 0;
541 }
542 
543 static int gem_context_register(struct i915_gem_context *ctx,
544 				struct drm_i915_file_private *fpriv)
545 {
546 	struct i915_address_space *vm;
547 	int ret;
548 
549 	ctx->file_priv = fpriv;
550 
551 	mutex_lock(&ctx->mutex);
552 	vm = i915_gem_context_vm(ctx);
553 	if (vm)
554 		WRITE_ONCE(vm->file, fpriv); /* XXX */
555 	mutex_unlock(&ctx->mutex);
556 
557 	ctx->pid = get_task_pid(current, PIDTYPE_PID);
558 	ctx->name = kasprintf(GFP_KERNEL, "%s[%d]",
559 			      current->comm, pid_nr(ctx->pid));
560 	if (!ctx->name) {
561 		ret = -ENOMEM;
562 		goto err_pid;
563 	}
564 
565 	/* And finally expose ourselves to userspace via the idr */
566 	mutex_lock(&fpriv->context_idr_lock);
567 	ret = idr_alloc(&fpriv->context_idr, ctx, 0, 0, GFP_KERNEL);
568 	mutex_unlock(&fpriv->context_idr_lock);
569 	if (ret >= 0)
570 		goto out;
571 
572 	kfree(fetch_and_zero(&ctx->name));
573 err_pid:
574 	put_pid(fetch_and_zero(&ctx->pid));
575 out:
576 	return ret;
577 }
578 
579 int i915_gem_context_open(struct drm_i915_private *i915,
580 			  struct drm_file *file)
581 {
582 	struct drm_i915_file_private *file_priv = file->driver_priv;
583 	struct i915_gem_context *ctx;
584 	int err;
585 
586 	mutex_init(&file_priv->context_idr_lock);
587 	mutex_init(&file_priv->vm_idr_lock);
588 
589 	idr_init(&file_priv->context_idr);
590 	idr_init_base(&file_priv->vm_idr, 1);
591 
592 	ctx = i915_gem_create_context(i915, 0);
593 	if (IS_ERR(ctx)) {
594 		err = PTR_ERR(ctx);
595 		goto err;
596 	}
597 
598 	err = gem_context_register(ctx, file_priv);
599 	if (err < 0)
600 		goto err_ctx;
601 
602 	GEM_BUG_ON(i915_gem_context_is_kernel(ctx));
603 	GEM_BUG_ON(err > 0);
604 
605 	return 0;
606 
607 err_ctx:
608 	context_close(ctx);
609 err:
610 	idr_destroy(&file_priv->vm_idr);
611 	idr_destroy(&file_priv->context_idr);
612 	mutex_destroy(&file_priv->vm_idr_lock);
613 	mutex_destroy(&file_priv->context_idr_lock);
614 	return err;
615 }
616 
617 void i915_gem_context_close(struct drm_file *file)
618 {
619 	struct drm_i915_file_private *file_priv = file->driver_priv;
620 	struct drm_i915_private *i915 = file_priv->dev_priv;
621 
622 	idr_for_each(&file_priv->context_idr, context_idr_cleanup, NULL);
623 	idr_destroy(&file_priv->context_idr);
624 	mutex_destroy(&file_priv->context_idr_lock);
625 
626 	idr_for_each(&file_priv->vm_idr, vm_idr_cleanup, NULL);
627 	idr_destroy(&file_priv->vm_idr);
628 	mutex_destroy(&file_priv->vm_idr_lock);
629 
630 	contexts_flush_free(&i915->gem.contexts);
631 }
632 
633 int i915_gem_vm_create_ioctl(struct drm_device *dev, void *data,
634 			     struct drm_file *file)
635 {
636 	struct drm_i915_private *i915 = to_i915(dev);
637 	struct drm_i915_gem_vm_control *args = data;
638 	struct drm_i915_file_private *file_priv = file->driver_priv;
639 	struct i915_ppgtt *ppgtt;
640 	int err;
641 
642 	if (!HAS_FULL_PPGTT(i915))
643 		return -ENODEV;
644 
645 	if (args->flags)
646 		return -EINVAL;
647 
648 	ppgtt = i915_ppgtt_create(i915);
649 	if (IS_ERR(ppgtt))
650 		return PTR_ERR(ppgtt);
651 
652 	ppgtt->vm.file = file_priv;
653 
654 	if (args->extensions) {
655 		err = i915_user_extensions(u64_to_user_ptr(args->extensions),
656 					   NULL, 0,
657 					   ppgtt);
658 		if (err)
659 			goto err_put;
660 	}
661 
662 	err = mutex_lock_interruptible(&file_priv->vm_idr_lock);
663 	if (err)
664 		goto err_put;
665 
666 	err = idr_alloc(&file_priv->vm_idr, &ppgtt->vm, 0, 0, GFP_KERNEL);
667 	if (err < 0)
668 		goto err_unlock;
669 
670 	GEM_BUG_ON(err == 0); /* reserved for invalid/unassigned ppgtt */
671 
672 	mutex_unlock(&file_priv->vm_idr_lock);
673 
674 	args->vm_id = err;
675 	return 0;
676 
677 err_unlock:
678 	mutex_unlock(&file_priv->vm_idr_lock);
679 err_put:
680 	i915_vm_put(&ppgtt->vm);
681 	return err;
682 }
683 
684 int i915_gem_vm_destroy_ioctl(struct drm_device *dev, void *data,
685 			      struct drm_file *file)
686 {
687 	struct drm_i915_file_private *file_priv = file->driver_priv;
688 	struct drm_i915_gem_vm_control *args = data;
689 	struct i915_address_space *vm;
690 	int err;
691 	u32 id;
692 
693 	if (args->flags)
694 		return -EINVAL;
695 
696 	if (args->extensions)
697 		return -EINVAL;
698 
699 	id = args->vm_id;
700 	if (!id)
701 		return -ENOENT;
702 
703 	err = mutex_lock_interruptible(&file_priv->vm_idr_lock);
704 	if (err)
705 		return err;
706 
707 	vm = idr_remove(&file_priv->vm_idr, id);
708 
709 	mutex_unlock(&file_priv->vm_idr_lock);
710 	if (!vm)
711 		return -ENOENT;
712 
713 	i915_vm_put(vm);
714 	return 0;
715 }
716 
717 struct context_barrier_task {
718 	struct i915_active base;
719 	void (*task)(void *data);
720 	void *data;
721 };
722 
723 __i915_active_call
724 static void cb_retire(struct i915_active *base)
725 {
726 	struct context_barrier_task *cb = container_of(base, typeof(*cb), base);
727 
728 	if (cb->task)
729 		cb->task(cb->data);
730 
731 	i915_active_fini(&cb->base);
732 	kfree(cb);
733 }
734 
735 I915_SELFTEST_DECLARE(static intel_engine_mask_t context_barrier_inject_fault);
736 static int context_barrier_task(struct i915_gem_context *ctx,
737 				intel_engine_mask_t engines,
738 				bool (*skip)(struct intel_context *ce, void *data),
739 				int (*emit)(struct i915_request *rq, void *data),
740 				void (*task)(void *data),
741 				void *data)
742 {
743 	struct context_barrier_task *cb;
744 	struct i915_gem_engines_iter it;
745 	struct intel_context *ce;
746 	int err = 0;
747 
748 	GEM_BUG_ON(!task);
749 
750 	cb = kmalloc(sizeof(*cb), GFP_KERNEL);
751 	if (!cb)
752 		return -ENOMEM;
753 
754 	i915_active_init(&cb->base, NULL, cb_retire);
755 	err = i915_active_acquire(&cb->base);
756 	if (err) {
757 		kfree(cb);
758 		return err;
759 	}
760 
761 	for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
762 		struct i915_request *rq;
763 
764 		if (I915_SELFTEST_ONLY(context_barrier_inject_fault &
765 				       ce->engine->mask)) {
766 			err = -ENXIO;
767 			break;
768 		}
769 
770 		if (!(ce->engine->mask & engines))
771 			continue;
772 
773 		if (skip && skip(ce, data))
774 			continue;
775 
776 		rq = intel_context_create_request(ce);
777 		if (IS_ERR(rq)) {
778 			err = PTR_ERR(rq);
779 			break;
780 		}
781 
782 		err = 0;
783 		if (emit)
784 			err = emit(rq, data);
785 		if (err == 0)
786 			err = i915_active_add_request(&cb->base, rq);
787 
788 		i915_request_add(rq);
789 		if (err)
790 			break;
791 	}
792 	i915_gem_context_unlock_engines(ctx);
793 
794 	cb->task = err ? NULL : task; /* caller needs to unwind instead */
795 	cb->data = data;
796 
797 	i915_active_release(&cb->base);
798 
799 	return err;
800 }
801 
802 static int get_ppgtt(struct drm_i915_file_private *file_priv,
803 		     struct i915_gem_context *ctx,
804 		     struct drm_i915_gem_context_param *args)
805 {
806 	struct i915_address_space *vm;
807 	int ret;
808 
809 	if (!rcu_access_pointer(ctx->vm))
810 		return -ENODEV;
811 
812 	rcu_read_lock();
813 	vm = i915_vm_get(ctx->vm);
814 	rcu_read_unlock();
815 
816 	ret = mutex_lock_interruptible(&file_priv->vm_idr_lock);
817 	if (ret)
818 		goto err_put;
819 
820 	ret = idr_alloc(&file_priv->vm_idr, vm, 0, 0, GFP_KERNEL);
821 	GEM_BUG_ON(!ret);
822 	if (ret < 0)
823 		goto err_unlock;
824 
825 	i915_vm_open(vm);
826 
827 	args->size = 0;
828 	args->value = ret;
829 
830 	ret = 0;
831 err_unlock:
832 	mutex_unlock(&file_priv->vm_idr_lock);
833 err_put:
834 	i915_vm_put(vm);
835 	return ret;
836 }
837 
838 static void set_ppgtt_barrier(void *data)
839 {
840 	struct i915_address_space *old = data;
841 
842 	if (INTEL_GEN(old->i915) < 8)
843 		gen6_ppgtt_unpin_all(i915_vm_to_ppgtt(old));
844 
845 	i915_vm_close(old);
846 }
847 
848 static int emit_ppgtt_update(struct i915_request *rq, void *data)
849 {
850 	struct i915_address_space *vm = rq->hw_context->vm;
851 	struct intel_engine_cs *engine = rq->engine;
852 	u32 base = engine->mmio_base;
853 	u32 *cs;
854 	int i;
855 
856 	if (i915_vm_is_4lvl(vm)) {
857 		struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
858 		const dma_addr_t pd_daddr = px_dma(ppgtt->pd);
859 
860 		cs = intel_ring_begin(rq, 6);
861 		if (IS_ERR(cs))
862 			return PTR_ERR(cs);
863 
864 		*cs++ = MI_LOAD_REGISTER_IMM(2);
865 
866 		*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, 0));
867 		*cs++ = upper_32_bits(pd_daddr);
868 		*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, 0));
869 		*cs++ = lower_32_bits(pd_daddr);
870 
871 		*cs++ = MI_NOOP;
872 		intel_ring_advance(rq, cs);
873 	} else if (HAS_LOGICAL_RING_CONTEXTS(engine->i915)) {
874 		struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
875 		int err;
876 
877 		/* Magic required to prevent forcewake errors! */
878 		err = engine->emit_flush(rq, EMIT_INVALIDATE);
879 		if (err)
880 			return err;
881 
882 		cs = intel_ring_begin(rq, 4 * GEN8_3LVL_PDPES + 2);
883 		if (IS_ERR(cs))
884 			return PTR_ERR(cs);
885 
886 		*cs++ = MI_LOAD_REGISTER_IMM(2 * GEN8_3LVL_PDPES) | MI_LRI_FORCE_POSTED;
887 		for (i = GEN8_3LVL_PDPES; i--; ) {
888 			const dma_addr_t pd_daddr = i915_page_dir_dma_addr(ppgtt, i);
889 
890 			*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, i));
891 			*cs++ = upper_32_bits(pd_daddr);
892 			*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, i));
893 			*cs++ = lower_32_bits(pd_daddr);
894 		}
895 		*cs++ = MI_NOOP;
896 		intel_ring_advance(rq, cs);
897 	} else {
898 		/* ppGTT is not part of the legacy context image */
899 		gen6_ppgtt_pin(i915_vm_to_ppgtt(vm));
900 	}
901 
902 	return 0;
903 }
904 
905 static bool skip_ppgtt_update(struct intel_context *ce, void *data)
906 {
907 	if (HAS_LOGICAL_RING_CONTEXTS(ce->engine->i915))
908 		return !ce->state;
909 	else
910 		return !atomic_read(&ce->pin_count);
911 }
912 
913 static int set_ppgtt(struct drm_i915_file_private *file_priv,
914 		     struct i915_gem_context *ctx,
915 		     struct drm_i915_gem_context_param *args)
916 {
917 	struct i915_address_space *vm, *old;
918 	int err;
919 
920 	if (args->size)
921 		return -EINVAL;
922 
923 	if (!rcu_access_pointer(ctx->vm))
924 		return -ENODEV;
925 
926 	if (upper_32_bits(args->value))
927 		return -ENOENT;
928 
929 	rcu_read_lock();
930 	vm = idr_find(&file_priv->vm_idr, args->value);
931 	if (vm && !kref_get_unless_zero(&vm->ref))
932 		vm = NULL;
933 	rcu_read_unlock();
934 	if (!vm)
935 		return -ENOENT;
936 
937 	err = mutex_lock_interruptible(&ctx->mutex);
938 	if (err)
939 		goto out;
940 
941 	if (i915_gem_context_is_closed(ctx)) {
942 		err = -ENOENT;
943 		goto out;
944 	}
945 
946 	if (vm == rcu_access_pointer(ctx->vm))
947 		goto unlock;
948 
949 	/* Teardown the existing obj:vma cache, it will have to be rebuilt. */
950 	lut_close(ctx);
951 
952 	old = __set_ppgtt(ctx, vm);
953 
954 	/*
955 	 * We need to flush any requests using the current ppgtt before
956 	 * we release it as the requests do not hold a reference themselves,
957 	 * only indirectly through the context.
958 	 */
959 	err = context_barrier_task(ctx, ALL_ENGINES,
960 				   skip_ppgtt_update,
961 				   emit_ppgtt_update,
962 				   set_ppgtt_barrier,
963 				   old);
964 	if (err) {
965 		i915_vm_close(__set_ppgtt(ctx, old));
966 		i915_vm_close(old);
967 	}
968 
969 unlock:
970 	mutex_unlock(&ctx->mutex);
971 out:
972 	i915_vm_put(vm);
973 	return err;
974 }
975 
976 static int gen8_emit_rpcs_config(struct i915_request *rq,
977 				 struct intel_context *ce,
978 				 struct intel_sseu sseu)
979 {
980 	u64 offset;
981 	u32 *cs;
982 
983 	cs = intel_ring_begin(rq, 4);
984 	if (IS_ERR(cs))
985 		return PTR_ERR(cs);
986 
987 	offset = i915_ggtt_offset(ce->state) +
988 		 LRC_STATE_PN * PAGE_SIZE +
989 		 CTX_R_PWR_CLK_STATE * 4;
990 
991 	*cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
992 	*cs++ = lower_32_bits(offset);
993 	*cs++ = upper_32_bits(offset);
994 	*cs++ = intel_sseu_make_rpcs(rq->i915, &sseu);
995 
996 	intel_ring_advance(rq, cs);
997 
998 	return 0;
999 }
1000 
1001 static int
1002 gen8_modify_rpcs(struct intel_context *ce, struct intel_sseu sseu)
1003 {
1004 	struct i915_request *rq;
1005 	int ret;
1006 
1007 	lockdep_assert_held(&ce->pin_mutex);
1008 
1009 	/*
1010 	 * If the context is not idle, we have to submit an ordered request to
1011 	 * modify its context image via the kernel context (writing to our own
1012 	 * image, or into the registers directory, does not stick). Pristine
1013 	 * and idle contexts will be configured on pinning.
1014 	 */
1015 	if (!intel_context_is_pinned(ce))
1016 		return 0;
1017 
1018 	rq = i915_request_create(ce->engine->kernel_context);
1019 	if (IS_ERR(rq))
1020 		return PTR_ERR(rq);
1021 
1022 	/* Serialise with the remote context */
1023 	ret = intel_context_prepare_remote_request(ce, rq);
1024 	if (ret == 0)
1025 		ret = gen8_emit_rpcs_config(rq, ce, sseu);
1026 
1027 	i915_request_add(rq);
1028 	return ret;
1029 }
1030 
1031 static int
1032 intel_context_reconfigure_sseu(struct intel_context *ce, struct intel_sseu sseu)
1033 {
1034 	int ret;
1035 
1036 	GEM_BUG_ON(INTEL_GEN(ce->engine->i915) < 8);
1037 
1038 	ret = intel_context_lock_pinned(ce);
1039 	if (ret)
1040 		return ret;
1041 
1042 	/* Nothing to do if unmodified. */
1043 	if (!memcmp(&ce->sseu, &sseu, sizeof(sseu)))
1044 		goto unlock;
1045 
1046 	ret = gen8_modify_rpcs(ce, sseu);
1047 	if (!ret)
1048 		ce->sseu = sseu;
1049 
1050 unlock:
1051 	intel_context_unlock_pinned(ce);
1052 	return ret;
1053 }
1054 
1055 static int
1056 user_to_context_sseu(struct drm_i915_private *i915,
1057 		     const struct drm_i915_gem_context_param_sseu *user,
1058 		     struct intel_sseu *context)
1059 {
1060 	const struct sseu_dev_info *device = &RUNTIME_INFO(i915)->sseu;
1061 
1062 	/* No zeros in any field. */
1063 	if (!user->slice_mask || !user->subslice_mask ||
1064 	    !user->min_eus_per_subslice || !user->max_eus_per_subslice)
1065 		return -EINVAL;
1066 
1067 	/* Max > min. */
1068 	if (user->max_eus_per_subslice < user->min_eus_per_subslice)
1069 		return -EINVAL;
1070 
1071 	/*
1072 	 * Some future proofing on the types since the uAPI is wider than the
1073 	 * current internal implementation.
1074 	 */
1075 	if (overflows_type(user->slice_mask, context->slice_mask) ||
1076 	    overflows_type(user->subslice_mask, context->subslice_mask) ||
1077 	    overflows_type(user->min_eus_per_subslice,
1078 			   context->min_eus_per_subslice) ||
1079 	    overflows_type(user->max_eus_per_subslice,
1080 			   context->max_eus_per_subslice))
1081 		return -EINVAL;
1082 
1083 	/* Check validity against hardware. */
1084 	if (user->slice_mask & ~device->slice_mask)
1085 		return -EINVAL;
1086 
1087 	if (user->subslice_mask & ~device->subslice_mask[0])
1088 		return -EINVAL;
1089 
1090 	if (user->max_eus_per_subslice > device->max_eus_per_subslice)
1091 		return -EINVAL;
1092 
1093 	context->slice_mask = user->slice_mask;
1094 	context->subslice_mask = user->subslice_mask;
1095 	context->min_eus_per_subslice = user->min_eus_per_subslice;
1096 	context->max_eus_per_subslice = user->max_eus_per_subslice;
1097 
1098 	/* Part specific restrictions. */
1099 	if (IS_GEN(i915, 11)) {
1100 		unsigned int hw_s = hweight8(device->slice_mask);
1101 		unsigned int hw_ss_per_s = hweight8(device->subslice_mask[0]);
1102 		unsigned int req_s = hweight8(context->slice_mask);
1103 		unsigned int req_ss = hweight8(context->subslice_mask);
1104 
1105 		/*
1106 		 * Only full subslice enablement is possible if more than one
1107 		 * slice is turned on.
1108 		 */
1109 		if (req_s > 1 && req_ss != hw_ss_per_s)
1110 			return -EINVAL;
1111 
1112 		/*
1113 		 * If more than four (SScount bitfield limit) subslices are
1114 		 * requested then the number has to be even.
1115 		 */
1116 		if (req_ss > 4 && (req_ss & 1))
1117 			return -EINVAL;
1118 
1119 		/*
1120 		 * If only one slice is enabled and subslice count is below the
1121 		 * device full enablement, it must be at most half of the all
1122 		 * available subslices.
1123 		 */
1124 		if (req_s == 1 && req_ss < hw_ss_per_s &&
1125 		    req_ss > (hw_ss_per_s / 2))
1126 			return -EINVAL;
1127 
1128 		/* ABI restriction - VME use case only. */
1129 
1130 		/* All slices or one slice only. */
1131 		if (req_s != 1 && req_s != hw_s)
1132 			return -EINVAL;
1133 
1134 		/*
1135 		 * Half subslices or full enablement only when one slice is
1136 		 * enabled.
1137 		 */
1138 		if (req_s == 1 &&
1139 		    (req_ss != hw_ss_per_s && req_ss != (hw_ss_per_s / 2)))
1140 			return -EINVAL;
1141 
1142 		/* No EU configuration changes. */
1143 		if ((user->min_eus_per_subslice !=
1144 		     device->max_eus_per_subslice) ||
1145 		    (user->max_eus_per_subslice !=
1146 		     device->max_eus_per_subslice))
1147 			return -EINVAL;
1148 	}
1149 
1150 	return 0;
1151 }
1152 
1153 static int set_sseu(struct i915_gem_context *ctx,
1154 		    struct drm_i915_gem_context_param *args)
1155 {
1156 	struct drm_i915_private *i915 = ctx->i915;
1157 	struct drm_i915_gem_context_param_sseu user_sseu;
1158 	struct intel_context *ce;
1159 	struct intel_sseu sseu;
1160 	unsigned long lookup;
1161 	int ret;
1162 
1163 	if (args->size < sizeof(user_sseu))
1164 		return -EINVAL;
1165 
1166 	if (!IS_GEN(i915, 11))
1167 		return -ENODEV;
1168 
1169 	if (copy_from_user(&user_sseu, u64_to_user_ptr(args->value),
1170 			   sizeof(user_sseu)))
1171 		return -EFAULT;
1172 
1173 	if (user_sseu.rsvd)
1174 		return -EINVAL;
1175 
1176 	if (user_sseu.flags & ~(I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX))
1177 		return -EINVAL;
1178 
1179 	lookup = 0;
1180 	if (user_sseu.flags & I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX)
1181 		lookup |= LOOKUP_USER_INDEX;
1182 
1183 	ce = lookup_user_engine(ctx, lookup, &user_sseu.engine);
1184 	if (IS_ERR(ce))
1185 		return PTR_ERR(ce);
1186 
1187 	/* Only render engine supports RPCS configuration. */
1188 	if (ce->engine->class != RENDER_CLASS) {
1189 		ret = -ENODEV;
1190 		goto out_ce;
1191 	}
1192 
1193 	ret = user_to_context_sseu(i915, &user_sseu, &sseu);
1194 	if (ret)
1195 		goto out_ce;
1196 
1197 	ret = intel_context_reconfigure_sseu(ce, sseu);
1198 	if (ret)
1199 		goto out_ce;
1200 
1201 	args->size = sizeof(user_sseu);
1202 
1203 out_ce:
1204 	intel_context_put(ce);
1205 	return ret;
1206 }
1207 
1208 struct set_engines {
1209 	struct i915_gem_context *ctx;
1210 	struct i915_gem_engines *engines;
1211 };
1212 
1213 static int
1214 set_engines__load_balance(struct i915_user_extension __user *base, void *data)
1215 {
1216 	struct i915_context_engines_load_balance __user *ext =
1217 		container_of_user(base, typeof(*ext), base);
1218 	const struct set_engines *set = data;
1219 	struct intel_engine_cs *stack[16];
1220 	struct intel_engine_cs **siblings;
1221 	struct intel_context *ce;
1222 	u16 num_siblings, idx;
1223 	unsigned int n;
1224 	int err;
1225 
1226 	if (!HAS_EXECLISTS(set->ctx->i915))
1227 		return -ENODEV;
1228 
1229 	if (USES_GUC_SUBMISSION(set->ctx->i915))
1230 		return -ENODEV; /* not implement yet */
1231 
1232 	if (get_user(idx, &ext->engine_index))
1233 		return -EFAULT;
1234 
1235 	if (idx >= set->engines->num_engines) {
1236 		DRM_DEBUG("Invalid placement value, %d >= %d\n",
1237 			  idx, set->engines->num_engines);
1238 		return -EINVAL;
1239 	}
1240 
1241 	idx = array_index_nospec(idx, set->engines->num_engines);
1242 	if (set->engines->engines[idx]) {
1243 		DRM_DEBUG("Invalid placement[%d], already occupied\n", idx);
1244 		return -EEXIST;
1245 	}
1246 
1247 	if (get_user(num_siblings, &ext->num_siblings))
1248 		return -EFAULT;
1249 
1250 	err = check_user_mbz(&ext->flags);
1251 	if (err)
1252 		return err;
1253 
1254 	err = check_user_mbz(&ext->mbz64);
1255 	if (err)
1256 		return err;
1257 
1258 	siblings = stack;
1259 	if (num_siblings > ARRAY_SIZE(stack)) {
1260 		siblings = kmalloc_array(num_siblings,
1261 					 sizeof(*siblings),
1262 					 GFP_KERNEL);
1263 		if (!siblings)
1264 			return -ENOMEM;
1265 	}
1266 
1267 	for (n = 0; n < num_siblings; n++) {
1268 		struct i915_engine_class_instance ci;
1269 
1270 		if (copy_from_user(&ci, &ext->engines[n], sizeof(ci))) {
1271 			err = -EFAULT;
1272 			goto out_siblings;
1273 		}
1274 
1275 		siblings[n] = intel_engine_lookup_user(set->ctx->i915,
1276 						       ci.engine_class,
1277 						       ci.engine_instance);
1278 		if (!siblings[n]) {
1279 			DRM_DEBUG("Invalid sibling[%d]: { class:%d, inst:%d }\n",
1280 				  n, ci.engine_class, ci.engine_instance);
1281 			err = -EINVAL;
1282 			goto out_siblings;
1283 		}
1284 	}
1285 
1286 	ce = intel_execlists_create_virtual(set->ctx, siblings, n);
1287 	if (IS_ERR(ce)) {
1288 		err = PTR_ERR(ce);
1289 		goto out_siblings;
1290 	}
1291 
1292 	if (cmpxchg(&set->engines->engines[idx], NULL, ce)) {
1293 		intel_context_put(ce);
1294 		err = -EEXIST;
1295 		goto out_siblings;
1296 	}
1297 
1298 out_siblings:
1299 	if (siblings != stack)
1300 		kfree(siblings);
1301 
1302 	return err;
1303 }
1304 
1305 static int
1306 set_engines__bond(struct i915_user_extension __user *base, void *data)
1307 {
1308 	struct i915_context_engines_bond __user *ext =
1309 		container_of_user(base, typeof(*ext), base);
1310 	const struct set_engines *set = data;
1311 	struct i915_engine_class_instance ci;
1312 	struct intel_engine_cs *virtual;
1313 	struct intel_engine_cs *master;
1314 	u16 idx, num_bonds;
1315 	int err, n;
1316 
1317 	if (get_user(idx, &ext->virtual_index))
1318 		return -EFAULT;
1319 
1320 	if (idx >= set->engines->num_engines) {
1321 		DRM_DEBUG("Invalid index for virtual engine: %d >= %d\n",
1322 			  idx, set->engines->num_engines);
1323 		return -EINVAL;
1324 	}
1325 
1326 	idx = array_index_nospec(idx, set->engines->num_engines);
1327 	if (!set->engines->engines[idx]) {
1328 		DRM_DEBUG("Invalid engine at %d\n", idx);
1329 		return -EINVAL;
1330 	}
1331 	virtual = set->engines->engines[idx]->engine;
1332 
1333 	err = check_user_mbz(&ext->flags);
1334 	if (err)
1335 		return err;
1336 
1337 	for (n = 0; n < ARRAY_SIZE(ext->mbz64); n++) {
1338 		err = check_user_mbz(&ext->mbz64[n]);
1339 		if (err)
1340 			return err;
1341 	}
1342 
1343 	if (copy_from_user(&ci, &ext->master, sizeof(ci)))
1344 		return -EFAULT;
1345 
1346 	master = intel_engine_lookup_user(set->ctx->i915,
1347 					  ci.engine_class, ci.engine_instance);
1348 	if (!master) {
1349 		DRM_DEBUG("Unrecognised master engine: { class:%u, instance:%u }\n",
1350 			  ci.engine_class, ci.engine_instance);
1351 		return -EINVAL;
1352 	}
1353 
1354 	if (get_user(num_bonds, &ext->num_bonds))
1355 		return -EFAULT;
1356 
1357 	for (n = 0; n < num_bonds; n++) {
1358 		struct intel_engine_cs *bond;
1359 
1360 		if (copy_from_user(&ci, &ext->engines[n], sizeof(ci)))
1361 			return -EFAULT;
1362 
1363 		bond = intel_engine_lookup_user(set->ctx->i915,
1364 						ci.engine_class,
1365 						ci.engine_instance);
1366 		if (!bond) {
1367 			DRM_DEBUG("Unrecognised engine[%d] for bonding: { class:%d, instance: %d }\n",
1368 				  n, ci.engine_class, ci.engine_instance);
1369 			return -EINVAL;
1370 		}
1371 
1372 		/*
1373 		 * A non-virtual engine has no siblings to choose between; and
1374 		 * a submit fence will always be directed to the one engine.
1375 		 */
1376 		if (intel_engine_is_virtual(virtual)) {
1377 			err = intel_virtual_engine_attach_bond(virtual,
1378 							       master,
1379 							       bond);
1380 			if (err)
1381 				return err;
1382 		}
1383 	}
1384 
1385 	return 0;
1386 }
1387 
1388 static const i915_user_extension_fn set_engines__extensions[] = {
1389 	[I915_CONTEXT_ENGINES_EXT_LOAD_BALANCE] = set_engines__load_balance,
1390 	[I915_CONTEXT_ENGINES_EXT_BOND] = set_engines__bond,
1391 };
1392 
1393 static int
1394 set_engines(struct i915_gem_context *ctx,
1395 	    const struct drm_i915_gem_context_param *args)
1396 {
1397 	struct i915_context_param_engines __user *user =
1398 		u64_to_user_ptr(args->value);
1399 	struct set_engines set = { .ctx = ctx };
1400 	unsigned int num_engines, n;
1401 	u64 extensions;
1402 	int err;
1403 
1404 	if (!args->size) { /* switch back to legacy user_ring_map */
1405 		if (!i915_gem_context_user_engines(ctx))
1406 			return 0;
1407 
1408 		set.engines = default_engines(ctx);
1409 		if (IS_ERR(set.engines))
1410 			return PTR_ERR(set.engines);
1411 
1412 		goto replace;
1413 	}
1414 
1415 	BUILD_BUG_ON(!IS_ALIGNED(sizeof(*user), sizeof(*user->engines)));
1416 	if (args->size < sizeof(*user) ||
1417 	    !IS_ALIGNED(args->size, sizeof(*user->engines))) {
1418 		DRM_DEBUG("Invalid size for engine array: %d\n",
1419 			  args->size);
1420 		return -EINVAL;
1421 	}
1422 
1423 	/*
1424 	 * Note that I915_EXEC_RING_MASK limits execbuf to only using the
1425 	 * first 64 engines defined here.
1426 	 */
1427 	num_engines = (args->size - sizeof(*user)) / sizeof(*user->engines);
1428 
1429 	set.engines = kmalloc(struct_size(set.engines, engines, num_engines),
1430 			      GFP_KERNEL);
1431 	if (!set.engines)
1432 		return -ENOMEM;
1433 
1434 	init_rcu_head(&set.engines->rcu);
1435 	for (n = 0; n < num_engines; n++) {
1436 		struct i915_engine_class_instance ci;
1437 		struct intel_engine_cs *engine;
1438 		struct intel_context *ce;
1439 
1440 		if (copy_from_user(&ci, &user->engines[n], sizeof(ci))) {
1441 			__free_engines(set.engines, n);
1442 			return -EFAULT;
1443 		}
1444 
1445 		if (ci.engine_class == (u16)I915_ENGINE_CLASS_INVALID &&
1446 		    ci.engine_instance == (u16)I915_ENGINE_CLASS_INVALID_NONE) {
1447 			set.engines->engines[n] = NULL;
1448 			continue;
1449 		}
1450 
1451 		engine = intel_engine_lookup_user(ctx->i915,
1452 						  ci.engine_class,
1453 						  ci.engine_instance);
1454 		if (!engine) {
1455 			DRM_DEBUG("Invalid engine[%d]: { class:%d, instance:%d }\n",
1456 				  n, ci.engine_class, ci.engine_instance);
1457 			__free_engines(set.engines, n);
1458 			return -ENOENT;
1459 		}
1460 
1461 		ce = intel_context_create(ctx, engine);
1462 		if (IS_ERR(ce)) {
1463 			__free_engines(set.engines, n);
1464 			return PTR_ERR(ce);
1465 		}
1466 
1467 		set.engines->engines[n] = ce;
1468 	}
1469 	set.engines->num_engines = num_engines;
1470 
1471 	err = -EFAULT;
1472 	if (!get_user(extensions, &user->extensions))
1473 		err = i915_user_extensions(u64_to_user_ptr(extensions),
1474 					   set_engines__extensions,
1475 					   ARRAY_SIZE(set_engines__extensions),
1476 					   &set);
1477 	if (err) {
1478 		free_engines(set.engines);
1479 		return err;
1480 	}
1481 
1482 replace:
1483 	mutex_lock(&ctx->engines_mutex);
1484 	if (args->size)
1485 		i915_gem_context_set_user_engines(ctx);
1486 	else
1487 		i915_gem_context_clear_user_engines(ctx);
1488 	rcu_swap_protected(ctx->engines, set.engines, 1);
1489 	mutex_unlock(&ctx->engines_mutex);
1490 
1491 	call_rcu(&set.engines->rcu, free_engines_rcu);
1492 
1493 	return 0;
1494 }
1495 
1496 static struct i915_gem_engines *
1497 __copy_engines(struct i915_gem_engines *e)
1498 {
1499 	struct i915_gem_engines *copy;
1500 	unsigned int n;
1501 
1502 	copy = kmalloc(struct_size(e, engines, e->num_engines), GFP_KERNEL);
1503 	if (!copy)
1504 		return ERR_PTR(-ENOMEM);
1505 
1506 	init_rcu_head(&copy->rcu);
1507 	for (n = 0; n < e->num_engines; n++) {
1508 		if (e->engines[n])
1509 			copy->engines[n] = intel_context_get(e->engines[n]);
1510 		else
1511 			copy->engines[n] = NULL;
1512 	}
1513 	copy->num_engines = n;
1514 
1515 	return copy;
1516 }
1517 
1518 static int
1519 get_engines(struct i915_gem_context *ctx,
1520 	    struct drm_i915_gem_context_param *args)
1521 {
1522 	struct i915_context_param_engines __user *user;
1523 	struct i915_gem_engines *e;
1524 	size_t n, count, size;
1525 	int err = 0;
1526 
1527 	err = mutex_lock_interruptible(&ctx->engines_mutex);
1528 	if (err)
1529 		return err;
1530 
1531 	e = NULL;
1532 	if (i915_gem_context_user_engines(ctx))
1533 		e = __copy_engines(i915_gem_context_engines(ctx));
1534 	mutex_unlock(&ctx->engines_mutex);
1535 	if (IS_ERR_OR_NULL(e)) {
1536 		args->size = 0;
1537 		return PTR_ERR_OR_ZERO(e);
1538 	}
1539 
1540 	count = e->num_engines;
1541 
1542 	/* Be paranoid in case we have an impedance mismatch */
1543 	if (!check_struct_size(user, engines, count, &size)) {
1544 		err = -EINVAL;
1545 		goto err_free;
1546 	}
1547 	if (overflows_type(size, args->size)) {
1548 		err = -EINVAL;
1549 		goto err_free;
1550 	}
1551 
1552 	if (!args->size) {
1553 		args->size = size;
1554 		goto err_free;
1555 	}
1556 
1557 	if (args->size < size) {
1558 		err = -EINVAL;
1559 		goto err_free;
1560 	}
1561 
1562 	user = u64_to_user_ptr(args->value);
1563 	if (!access_ok(user, size)) {
1564 		err = -EFAULT;
1565 		goto err_free;
1566 	}
1567 
1568 	if (put_user(0, &user->extensions)) {
1569 		err = -EFAULT;
1570 		goto err_free;
1571 	}
1572 
1573 	for (n = 0; n < count; n++) {
1574 		struct i915_engine_class_instance ci = {
1575 			.engine_class = I915_ENGINE_CLASS_INVALID,
1576 			.engine_instance = I915_ENGINE_CLASS_INVALID_NONE,
1577 		};
1578 
1579 		if (e->engines[n]) {
1580 			ci.engine_class = e->engines[n]->engine->uabi_class;
1581 			ci.engine_instance = e->engines[n]->engine->uabi_instance;
1582 		}
1583 
1584 		if (copy_to_user(&user->engines[n], &ci, sizeof(ci))) {
1585 			err = -EFAULT;
1586 			goto err_free;
1587 		}
1588 	}
1589 
1590 	args->size = size;
1591 
1592 err_free:
1593 	free_engines(e);
1594 	return err;
1595 }
1596 
1597 static int ctx_setparam(struct drm_i915_file_private *fpriv,
1598 			struct i915_gem_context *ctx,
1599 			struct drm_i915_gem_context_param *args)
1600 {
1601 	int ret = 0;
1602 
1603 	switch (args->param) {
1604 	case I915_CONTEXT_PARAM_NO_ZEROMAP:
1605 		if (args->size)
1606 			ret = -EINVAL;
1607 		else if (args->value)
1608 			set_bit(UCONTEXT_NO_ZEROMAP, &ctx->user_flags);
1609 		else
1610 			clear_bit(UCONTEXT_NO_ZEROMAP, &ctx->user_flags);
1611 		break;
1612 
1613 	case I915_CONTEXT_PARAM_NO_ERROR_CAPTURE:
1614 		if (args->size)
1615 			ret = -EINVAL;
1616 		else if (args->value)
1617 			i915_gem_context_set_no_error_capture(ctx);
1618 		else
1619 			i915_gem_context_clear_no_error_capture(ctx);
1620 		break;
1621 
1622 	case I915_CONTEXT_PARAM_BANNABLE:
1623 		if (args->size)
1624 			ret = -EINVAL;
1625 		else if (!capable(CAP_SYS_ADMIN) && !args->value)
1626 			ret = -EPERM;
1627 		else if (args->value)
1628 			i915_gem_context_set_bannable(ctx);
1629 		else
1630 			i915_gem_context_clear_bannable(ctx);
1631 		break;
1632 
1633 	case I915_CONTEXT_PARAM_RECOVERABLE:
1634 		if (args->size)
1635 			ret = -EINVAL;
1636 		else if (args->value)
1637 			i915_gem_context_set_recoverable(ctx);
1638 		else
1639 			i915_gem_context_clear_recoverable(ctx);
1640 		break;
1641 
1642 	case I915_CONTEXT_PARAM_PRIORITY:
1643 		{
1644 			s64 priority = args->value;
1645 
1646 			if (args->size)
1647 				ret = -EINVAL;
1648 			else if (!(ctx->i915->caps.scheduler & I915_SCHEDULER_CAP_PRIORITY))
1649 				ret = -ENODEV;
1650 			else if (priority > I915_CONTEXT_MAX_USER_PRIORITY ||
1651 				 priority < I915_CONTEXT_MIN_USER_PRIORITY)
1652 				ret = -EINVAL;
1653 			else if (priority > I915_CONTEXT_DEFAULT_PRIORITY &&
1654 				 !capable(CAP_SYS_NICE))
1655 				ret = -EPERM;
1656 			else
1657 				ctx->sched.priority =
1658 					I915_USER_PRIORITY(priority);
1659 		}
1660 		break;
1661 
1662 	case I915_CONTEXT_PARAM_SSEU:
1663 		ret = set_sseu(ctx, args);
1664 		break;
1665 
1666 	case I915_CONTEXT_PARAM_VM:
1667 		ret = set_ppgtt(fpriv, ctx, args);
1668 		break;
1669 
1670 	case I915_CONTEXT_PARAM_ENGINES:
1671 		ret = set_engines(ctx, args);
1672 		break;
1673 
1674 	case I915_CONTEXT_PARAM_BAN_PERIOD:
1675 	default:
1676 		ret = -EINVAL;
1677 		break;
1678 	}
1679 
1680 	return ret;
1681 }
1682 
1683 struct create_ext {
1684 	struct i915_gem_context *ctx;
1685 	struct drm_i915_file_private *fpriv;
1686 };
1687 
1688 static int create_setparam(struct i915_user_extension __user *ext, void *data)
1689 {
1690 	struct drm_i915_gem_context_create_ext_setparam local;
1691 	const struct create_ext *arg = data;
1692 
1693 	if (copy_from_user(&local, ext, sizeof(local)))
1694 		return -EFAULT;
1695 
1696 	if (local.param.ctx_id)
1697 		return -EINVAL;
1698 
1699 	return ctx_setparam(arg->fpriv, arg->ctx, &local.param);
1700 }
1701 
1702 static int clone_engines(struct i915_gem_context *dst,
1703 			 struct i915_gem_context *src)
1704 {
1705 	struct i915_gem_engines *e = i915_gem_context_lock_engines(src);
1706 	struct i915_gem_engines *clone;
1707 	bool user_engines;
1708 	unsigned long n;
1709 
1710 	clone = kmalloc(struct_size(e, engines, e->num_engines), GFP_KERNEL);
1711 	if (!clone)
1712 		goto err_unlock;
1713 
1714 	init_rcu_head(&clone->rcu);
1715 	for (n = 0; n < e->num_engines; n++) {
1716 		struct intel_engine_cs *engine;
1717 
1718 		if (!e->engines[n]) {
1719 			clone->engines[n] = NULL;
1720 			continue;
1721 		}
1722 		engine = e->engines[n]->engine;
1723 
1724 		/*
1725 		 * Virtual engines are singletons; they can only exist
1726 		 * inside a single context, because they embed their
1727 		 * HW context... As each virtual context implies a single
1728 		 * timeline (each engine can only dequeue a single request
1729 		 * at any time), it would be surprising for two contexts
1730 		 * to use the same engine. So let's create a copy of
1731 		 * the virtual engine instead.
1732 		 */
1733 		if (intel_engine_is_virtual(engine))
1734 			clone->engines[n] =
1735 				intel_execlists_clone_virtual(dst, engine);
1736 		else
1737 			clone->engines[n] = intel_context_create(dst, engine);
1738 		if (IS_ERR_OR_NULL(clone->engines[n])) {
1739 			__free_engines(clone, n);
1740 			goto err_unlock;
1741 		}
1742 	}
1743 	clone->num_engines = n;
1744 
1745 	user_engines = i915_gem_context_user_engines(src);
1746 	i915_gem_context_unlock_engines(src);
1747 
1748 	free_engines(dst->engines);
1749 	RCU_INIT_POINTER(dst->engines, clone);
1750 	if (user_engines)
1751 		i915_gem_context_set_user_engines(dst);
1752 	else
1753 		i915_gem_context_clear_user_engines(dst);
1754 	return 0;
1755 
1756 err_unlock:
1757 	i915_gem_context_unlock_engines(src);
1758 	return -ENOMEM;
1759 }
1760 
1761 static int clone_flags(struct i915_gem_context *dst,
1762 		       struct i915_gem_context *src)
1763 {
1764 	dst->user_flags = src->user_flags;
1765 	return 0;
1766 }
1767 
1768 static int clone_schedattr(struct i915_gem_context *dst,
1769 			   struct i915_gem_context *src)
1770 {
1771 	dst->sched = src->sched;
1772 	return 0;
1773 }
1774 
1775 static int clone_sseu(struct i915_gem_context *dst,
1776 		      struct i915_gem_context *src)
1777 {
1778 	struct i915_gem_engines *e = i915_gem_context_lock_engines(src);
1779 	struct i915_gem_engines *clone;
1780 	unsigned long n;
1781 	int err;
1782 
1783 	clone = dst->engines; /* no locking required; sole access */
1784 	if (e->num_engines != clone->num_engines) {
1785 		err = -EINVAL;
1786 		goto unlock;
1787 	}
1788 
1789 	for (n = 0; n < e->num_engines; n++) {
1790 		struct intel_context *ce = e->engines[n];
1791 
1792 		if (clone->engines[n]->engine->class != ce->engine->class) {
1793 			/* Must have compatible engine maps! */
1794 			err = -EINVAL;
1795 			goto unlock;
1796 		}
1797 
1798 		/* serialises with set_sseu */
1799 		err = intel_context_lock_pinned(ce);
1800 		if (err)
1801 			goto unlock;
1802 
1803 		clone->engines[n]->sseu = ce->sseu;
1804 		intel_context_unlock_pinned(ce);
1805 	}
1806 
1807 	err = 0;
1808 unlock:
1809 	i915_gem_context_unlock_engines(src);
1810 	return err;
1811 }
1812 
1813 static int clone_timeline(struct i915_gem_context *dst,
1814 			  struct i915_gem_context *src)
1815 {
1816 	if (src->timeline)
1817 		__assign_timeline(dst, src->timeline);
1818 
1819 	return 0;
1820 }
1821 
1822 static int clone_vm(struct i915_gem_context *dst,
1823 		    struct i915_gem_context *src)
1824 {
1825 	struct i915_address_space *vm;
1826 	int err = 0;
1827 
1828 	rcu_read_lock();
1829 	do {
1830 		vm = rcu_dereference(src->vm);
1831 		if (!vm)
1832 			break;
1833 
1834 		if (!kref_get_unless_zero(&vm->ref))
1835 			continue;
1836 
1837 		/*
1838 		 * This ppgtt may have be reallocated between
1839 		 * the read and the kref, and reassigned to a third
1840 		 * context. In order to avoid inadvertent sharing
1841 		 * of this ppgtt with that third context (and not
1842 		 * src), we have to confirm that we have the same
1843 		 * ppgtt after passing through the strong memory
1844 		 * barrier implied by a successful
1845 		 * kref_get_unless_zero().
1846 		 *
1847 		 * Once we have acquired the current ppgtt of src,
1848 		 * we no longer care if it is released from src, as
1849 		 * it cannot be reallocated elsewhere.
1850 		 */
1851 
1852 		if (vm == rcu_access_pointer(src->vm))
1853 			break;
1854 
1855 		i915_vm_put(vm);
1856 	} while (1);
1857 	rcu_read_unlock();
1858 
1859 	if (vm) {
1860 		if (!mutex_lock_interruptible(&dst->mutex)) {
1861 			__assign_ppgtt(dst, vm);
1862 			mutex_unlock(&dst->mutex);
1863 		} else {
1864 			err = -EINTR;
1865 		}
1866 		i915_vm_put(vm);
1867 	}
1868 
1869 	return err;
1870 }
1871 
1872 static int create_clone(struct i915_user_extension __user *ext, void *data)
1873 {
1874 	static int (* const fn[])(struct i915_gem_context *dst,
1875 				  struct i915_gem_context *src) = {
1876 #define MAP(x, y) [ilog2(I915_CONTEXT_CLONE_##x)] = y
1877 		MAP(ENGINES, clone_engines),
1878 		MAP(FLAGS, clone_flags),
1879 		MAP(SCHEDATTR, clone_schedattr),
1880 		MAP(SSEU, clone_sseu),
1881 		MAP(TIMELINE, clone_timeline),
1882 		MAP(VM, clone_vm),
1883 #undef MAP
1884 	};
1885 	struct drm_i915_gem_context_create_ext_clone local;
1886 	const struct create_ext *arg = data;
1887 	struct i915_gem_context *dst = arg->ctx;
1888 	struct i915_gem_context *src;
1889 	int err, bit;
1890 
1891 	if (copy_from_user(&local, ext, sizeof(local)))
1892 		return -EFAULT;
1893 
1894 	BUILD_BUG_ON(GENMASK(BITS_PER_TYPE(local.flags) - 1, ARRAY_SIZE(fn)) !=
1895 		     I915_CONTEXT_CLONE_UNKNOWN);
1896 
1897 	if (local.flags & I915_CONTEXT_CLONE_UNKNOWN)
1898 		return -EINVAL;
1899 
1900 	if (local.rsvd)
1901 		return -EINVAL;
1902 
1903 	rcu_read_lock();
1904 	src = __i915_gem_context_lookup_rcu(arg->fpriv, local.clone_id);
1905 	rcu_read_unlock();
1906 	if (!src)
1907 		return -ENOENT;
1908 
1909 	GEM_BUG_ON(src == dst);
1910 
1911 	for (bit = 0; bit < ARRAY_SIZE(fn); bit++) {
1912 		if (!(local.flags & BIT(bit)))
1913 			continue;
1914 
1915 		err = fn[bit](dst, src);
1916 		if (err)
1917 			return err;
1918 	}
1919 
1920 	return 0;
1921 }
1922 
1923 static const i915_user_extension_fn create_extensions[] = {
1924 	[I915_CONTEXT_CREATE_EXT_SETPARAM] = create_setparam,
1925 	[I915_CONTEXT_CREATE_EXT_CLONE] = create_clone,
1926 };
1927 
1928 static bool client_is_banned(struct drm_i915_file_private *file_priv)
1929 {
1930 	return atomic_read(&file_priv->ban_score) >= I915_CLIENT_SCORE_BANNED;
1931 }
1932 
1933 int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
1934 				  struct drm_file *file)
1935 {
1936 	struct drm_i915_private *i915 = to_i915(dev);
1937 	struct drm_i915_gem_context_create_ext *args = data;
1938 	struct create_ext ext_data;
1939 	int ret;
1940 
1941 	if (!DRIVER_CAPS(i915)->has_logical_contexts)
1942 		return -ENODEV;
1943 
1944 	if (args->flags & I915_CONTEXT_CREATE_FLAGS_UNKNOWN)
1945 		return -EINVAL;
1946 
1947 	ret = intel_gt_terminally_wedged(&i915->gt);
1948 	if (ret)
1949 		return ret;
1950 
1951 	ext_data.fpriv = file->driver_priv;
1952 	if (client_is_banned(ext_data.fpriv)) {
1953 		DRM_DEBUG("client %s[%d] banned from creating ctx\n",
1954 			  current->comm,
1955 			  pid_nr(get_task_pid(current, PIDTYPE_PID)));
1956 		return -EIO;
1957 	}
1958 
1959 	ext_data.ctx = i915_gem_create_context(i915, args->flags);
1960 	if (IS_ERR(ext_data.ctx))
1961 		return PTR_ERR(ext_data.ctx);
1962 
1963 	if (args->flags & I915_CONTEXT_CREATE_FLAGS_USE_EXTENSIONS) {
1964 		ret = i915_user_extensions(u64_to_user_ptr(args->extensions),
1965 					   create_extensions,
1966 					   ARRAY_SIZE(create_extensions),
1967 					   &ext_data);
1968 		if (ret)
1969 			goto err_ctx;
1970 	}
1971 
1972 	ret = gem_context_register(ext_data.ctx, ext_data.fpriv);
1973 	if (ret < 0)
1974 		goto err_ctx;
1975 
1976 	args->ctx_id = ret;
1977 	DRM_DEBUG("HW context %d created\n", args->ctx_id);
1978 
1979 	return 0;
1980 
1981 err_ctx:
1982 	context_close(ext_data.ctx);
1983 	return ret;
1984 }
1985 
1986 int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
1987 				   struct drm_file *file)
1988 {
1989 	struct drm_i915_gem_context_destroy *args = data;
1990 	struct drm_i915_file_private *file_priv = file->driver_priv;
1991 	struct i915_gem_context *ctx;
1992 
1993 	if (args->pad != 0)
1994 		return -EINVAL;
1995 
1996 	if (!args->ctx_id)
1997 		return -ENOENT;
1998 
1999 	if (mutex_lock_interruptible(&file_priv->context_idr_lock))
2000 		return -EINTR;
2001 
2002 	ctx = idr_remove(&file_priv->context_idr, args->ctx_id);
2003 	mutex_unlock(&file_priv->context_idr_lock);
2004 	if (!ctx)
2005 		return -ENOENT;
2006 
2007 	context_close(ctx);
2008 	return 0;
2009 }
2010 
2011 static int get_sseu(struct i915_gem_context *ctx,
2012 		    struct drm_i915_gem_context_param *args)
2013 {
2014 	struct drm_i915_gem_context_param_sseu user_sseu;
2015 	struct intel_context *ce;
2016 	unsigned long lookup;
2017 	int err;
2018 
2019 	if (args->size == 0)
2020 		goto out;
2021 	else if (args->size < sizeof(user_sseu))
2022 		return -EINVAL;
2023 
2024 	if (copy_from_user(&user_sseu, u64_to_user_ptr(args->value),
2025 			   sizeof(user_sseu)))
2026 		return -EFAULT;
2027 
2028 	if (user_sseu.rsvd)
2029 		return -EINVAL;
2030 
2031 	if (user_sseu.flags & ~(I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX))
2032 		return -EINVAL;
2033 
2034 	lookup = 0;
2035 	if (user_sseu.flags & I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX)
2036 		lookup |= LOOKUP_USER_INDEX;
2037 
2038 	ce = lookup_user_engine(ctx, lookup, &user_sseu.engine);
2039 	if (IS_ERR(ce))
2040 		return PTR_ERR(ce);
2041 
2042 	err = intel_context_lock_pinned(ce); /* serialises with set_sseu */
2043 	if (err) {
2044 		intel_context_put(ce);
2045 		return err;
2046 	}
2047 
2048 	user_sseu.slice_mask = ce->sseu.slice_mask;
2049 	user_sseu.subslice_mask = ce->sseu.subslice_mask;
2050 	user_sseu.min_eus_per_subslice = ce->sseu.min_eus_per_subslice;
2051 	user_sseu.max_eus_per_subslice = ce->sseu.max_eus_per_subslice;
2052 
2053 	intel_context_unlock_pinned(ce);
2054 	intel_context_put(ce);
2055 
2056 	if (copy_to_user(u64_to_user_ptr(args->value), &user_sseu,
2057 			 sizeof(user_sseu)))
2058 		return -EFAULT;
2059 
2060 out:
2061 	args->size = sizeof(user_sseu);
2062 
2063 	return 0;
2064 }
2065 
2066 int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
2067 				    struct drm_file *file)
2068 {
2069 	struct drm_i915_file_private *file_priv = file->driver_priv;
2070 	struct drm_i915_gem_context_param *args = data;
2071 	struct i915_gem_context *ctx;
2072 	int ret = 0;
2073 
2074 	ctx = i915_gem_context_lookup(file_priv, args->ctx_id);
2075 	if (!ctx)
2076 		return -ENOENT;
2077 
2078 	switch (args->param) {
2079 	case I915_CONTEXT_PARAM_NO_ZEROMAP:
2080 		args->size = 0;
2081 		args->value = test_bit(UCONTEXT_NO_ZEROMAP, &ctx->user_flags);
2082 		break;
2083 
2084 	case I915_CONTEXT_PARAM_GTT_SIZE:
2085 		args->size = 0;
2086 		rcu_read_lock();
2087 		if (rcu_access_pointer(ctx->vm))
2088 			args->value = rcu_dereference(ctx->vm)->total;
2089 		else
2090 			args->value = to_i915(dev)->ggtt.vm.total;
2091 		rcu_read_unlock();
2092 		break;
2093 
2094 	case I915_CONTEXT_PARAM_NO_ERROR_CAPTURE:
2095 		args->size = 0;
2096 		args->value = i915_gem_context_no_error_capture(ctx);
2097 		break;
2098 
2099 	case I915_CONTEXT_PARAM_BANNABLE:
2100 		args->size = 0;
2101 		args->value = i915_gem_context_is_bannable(ctx);
2102 		break;
2103 
2104 	case I915_CONTEXT_PARAM_RECOVERABLE:
2105 		args->size = 0;
2106 		args->value = i915_gem_context_is_recoverable(ctx);
2107 		break;
2108 
2109 	case I915_CONTEXT_PARAM_PRIORITY:
2110 		args->size = 0;
2111 		args->value = ctx->sched.priority >> I915_USER_PRIORITY_SHIFT;
2112 		break;
2113 
2114 	case I915_CONTEXT_PARAM_SSEU:
2115 		ret = get_sseu(ctx, args);
2116 		break;
2117 
2118 	case I915_CONTEXT_PARAM_VM:
2119 		ret = get_ppgtt(file_priv, ctx, args);
2120 		break;
2121 
2122 	case I915_CONTEXT_PARAM_ENGINES:
2123 		ret = get_engines(ctx, args);
2124 		break;
2125 
2126 	case I915_CONTEXT_PARAM_BAN_PERIOD:
2127 	default:
2128 		ret = -EINVAL;
2129 		break;
2130 	}
2131 
2132 	i915_gem_context_put(ctx);
2133 	return ret;
2134 }
2135 
2136 int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
2137 				    struct drm_file *file)
2138 {
2139 	struct drm_i915_file_private *file_priv = file->driver_priv;
2140 	struct drm_i915_gem_context_param *args = data;
2141 	struct i915_gem_context *ctx;
2142 	int ret;
2143 
2144 	ctx = i915_gem_context_lookup(file_priv, args->ctx_id);
2145 	if (!ctx)
2146 		return -ENOENT;
2147 
2148 	ret = ctx_setparam(file_priv, ctx, args);
2149 
2150 	i915_gem_context_put(ctx);
2151 	return ret;
2152 }
2153 
2154 int i915_gem_context_reset_stats_ioctl(struct drm_device *dev,
2155 				       void *data, struct drm_file *file)
2156 {
2157 	struct drm_i915_private *i915 = to_i915(dev);
2158 	struct drm_i915_reset_stats *args = data;
2159 	struct i915_gem_context *ctx;
2160 	int ret;
2161 
2162 	if (args->flags || args->pad)
2163 		return -EINVAL;
2164 
2165 	ret = -ENOENT;
2166 	rcu_read_lock();
2167 	ctx = __i915_gem_context_lookup_rcu(file->driver_priv, args->ctx_id);
2168 	if (!ctx)
2169 		goto out;
2170 
2171 	/*
2172 	 * We opt for unserialised reads here. This may result in tearing
2173 	 * in the extremely unlikely event of a GPU hang on this context
2174 	 * as we are querying them. If we need that extra layer of protection,
2175 	 * we should wrap the hangstats with a seqlock.
2176 	 */
2177 
2178 	if (capable(CAP_SYS_ADMIN))
2179 		args->reset_count = i915_reset_count(&i915->gpu_error);
2180 	else
2181 		args->reset_count = 0;
2182 
2183 	args->batch_active = atomic_read(&ctx->guilty_count);
2184 	args->batch_pending = atomic_read(&ctx->active_count);
2185 
2186 	ret = 0;
2187 out:
2188 	rcu_read_unlock();
2189 	return ret;
2190 }
2191 
2192 /* GEM context-engines iterator: for_each_gem_engine() */
2193 struct intel_context *
2194 i915_gem_engines_iter_next(struct i915_gem_engines_iter *it)
2195 {
2196 	const struct i915_gem_engines *e = it->engines;
2197 	struct intel_context *ctx;
2198 
2199 	do {
2200 		if (it->idx >= e->num_engines)
2201 			return NULL;
2202 
2203 		ctx = e->engines[it->idx++];
2204 	} while (!ctx);
2205 
2206 	return ctx;
2207 }
2208 
2209 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
2210 #include "selftests/mock_context.c"
2211 #include "selftests/i915_gem_context.c"
2212 #endif
2213 
2214 static void i915_global_gem_context_shrink(void)
2215 {
2216 	kmem_cache_shrink(global.slab_luts);
2217 }
2218 
2219 static void i915_global_gem_context_exit(void)
2220 {
2221 	kmem_cache_destroy(global.slab_luts);
2222 }
2223 
2224 static struct i915_global_gem_context global = { {
2225 	.shrink = i915_global_gem_context_shrink,
2226 	.exit = i915_global_gem_context_exit,
2227 } };
2228 
2229 int __init i915_global_gem_context_init(void)
2230 {
2231 	global.slab_luts = KMEM_CACHE(i915_lut_handle, 0);
2232 	if (!global.slab_luts)
2233 		return -ENOMEM;
2234 
2235 	i915_global_register(&global.base);
2236 	return 0;
2237 }
2238