2 * Copyright © 2011-2012 Intel Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
24 * Ben Widawsky <ben@bwidawsk.net>
29 * This file implements HW context support. On gen5+ a HW context consists of an
30 * opaque GPU object which is referenced at times of context saves and restores.
31 * With RC6 enabled, the context is also referenced as the GPU enters and exists
32 * from RC6 (GPU has it's own internal power context, except on gen5). Though
33 * something like a context does exist for the media ring, the code only
34 * supports contexts for the render ring.
36 * In software, there is a distinction between contexts created by the user,
37 * and the default HW context. The default HW context is used by GPU clients
38 * that do not request setup of their own hardware context. The default
39 * context's state is never restored to help prevent programming errors. This
40 * would happen if a client ran and piggy-backed off another clients GPU state.
41 * The default context only exists to give the GPU some offset to load as the
42 * current to invoke a save of the context we actually care about. In fact, the
43 * code could likely be constructed, albeit in a more complicated fashion, to
44 * never use the default context, though that limits the driver's ability to
45 * swap out, and/or destroy other contexts.
47 * All other contexts are created as a request by the GPU client. These contexts
48 * store GPU state, and thus allow GPU clients to not re-emit state (and
49 * potentially query certain state) at any time. The kernel driver makes
50 * certain that the appropriate commands are inserted.
52 * The context life cycle is semi-complicated in that context BOs may live
53 * longer than the context itself because of the way the hardware, and object
54 * tracking works. Below is a very crude representation of the state machine
55 * describing the context life.
56 * refcount pincount active
57 * S0: initial state 0 0 0
58 * S1: context created 1 0 0
59 * S2: context is currently running 2 1 X
60 * S3: GPU referenced, but not current 2 0 1
61 * S4: context is current, but destroyed 1 1 0
62 * S5: like S3, but destroyed 1 0 1
64 * The most common (but not all) transitions:
65 * S0->S1: client creates a context
66 * S1->S2: client submits execbuf with context
67 * S2->S3: other clients submits execbuf with context
68 * S3->S1: context object was retired
69 * S3->S2: clients submits another execbuf
70 * S2->S4: context destroy called with current context
71 * S3->S5->S0: destroy path
72 * S4->S5->S0: destroy path on current context
74 * There are two confusing terms used above:
75 * The "current context" means the context which is currently running on the
76 * GPU. The GPU has loaded its state already and has stored away the gtt
77 * offset of the BO. The GPU is not actively referencing the data at this
78 * offset, but it will on the next context switch. The only way to avoid this
79 * is to do a GPU reset.
81 * An "active context' is one which was previously the "current context" and is
82 * on the active list waiting for the next context switch to occur. Until this
83 * happens, the object must remain at the same gtt offset. It is therefore
84 * possible to destroy a context, but it is still active.
89 #include <drm/i915_drm.h>
92 /* This is a HW constraint. The value below is the largest known requirement
93 * I've seen in a spec to date, and that was a workaround for a non-shipping
94 * part. It should be safe to decrease this, but it's more future proof as is.
96 #define GEN6_CONTEXT_ALIGN (64<<10)
97 #define GEN7_CONTEXT_ALIGN 4096
99 static int do_switch(struct intel_ring_buffer
*ring
,
100 struct i915_hw_context
*to
);
102 static void do_ppgtt_cleanup(struct i915_hw_ppgtt
*ppgtt
)
104 struct drm_device
*dev
= ppgtt
->base
.dev
;
105 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
106 struct i915_address_space
*vm
= &ppgtt
->base
;
108 if (ppgtt
== dev_priv
->mm
.aliasing_ppgtt
||
109 (list_empty(&vm
->active_list
) && list_empty(&vm
->inactive_list
))) {
110 ppgtt
->base
.cleanup(&ppgtt
->base
);
115 * Make sure vmas are unbound before we take down the drm_mm
117 * FIXME: Proper refcounting should take care of this, this shouldn't be
120 if (!list_empty(&vm
->active_list
)) {
121 struct i915_vma
*vma
;
123 list_for_each_entry(vma
, &vm
->active_list
, mm_list
)
124 if (WARN_ON(list_empty(&vma
->vma_link
) ||
125 list_is_singular(&vma
->vma_link
)))
128 i915_gem_evict_vm(&ppgtt
->base
, true);
130 i915_gem_retire_requests(dev
);
131 i915_gem_evict_vm(&ppgtt
->base
, false);
134 ppgtt
->base
.cleanup(&ppgtt
->base
);
137 static void ppgtt_release(struct kref
*kref
)
139 struct i915_hw_ppgtt
*ppgtt
=
140 container_of(kref
, struct i915_hw_ppgtt
, ref
);
142 do_ppgtt_cleanup(ppgtt
);
146 static size_t get_context_alignment(struct drm_device
*dev
)
149 return GEN6_CONTEXT_ALIGN
;
151 return GEN7_CONTEXT_ALIGN
;
154 static int get_context_size(struct drm_device
*dev
)
156 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
160 switch (INTEL_INFO(dev
)->gen
) {
162 reg
= I915_READ(CXT_SIZE
);
163 ret
= GEN6_CXT_TOTAL_SIZE(reg
) * 64;
166 reg
= I915_READ(GEN7_CXT_SIZE
);
168 ret
= HSW_CXT_TOTAL_SIZE
;
170 ret
= GEN7_CXT_TOTAL_SIZE(reg
) * 64;
173 ret
= GEN8_CXT_TOTAL_SIZE
;
182 void i915_gem_context_free(struct kref
*ctx_ref
)
184 struct i915_hw_context
*ctx
= container_of(ctx_ref
,
186 struct i915_hw_ppgtt
*ppgtt
= NULL
;
188 /* We refcount even the aliasing PPGTT to keep the code symmetric */
189 if (USES_PPGTT(ctx
->obj
->base
.dev
))
190 ppgtt
= ctx_to_ppgtt(ctx
);
192 /* XXX: Free up the object before tearing down the address space, in
193 * case we're bound in the PPGTT */
194 drm_gem_object_unreference(&ctx
->obj
->base
);
197 kref_put(&ppgtt
->ref
, ppgtt_release
);
198 list_del(&ctx
->link
);
202 static struct i915_hw_ppgtt
*
203 create_vm_for_ctx(struct drm_device
*dev
, struct i915_hw_context
*ctx
)
205 struct i915_hw_ppgtt
*ppgtt
;
208 ppgtt
= kzalloc(sizeof(*ppgtt
), GFP_KERNEL
);
210 return ERR_PTR(-ENOMEM
);
212 ret
= i915_gem_init_ppgtt(dev
, ppgtt
);
221 static struct i915_hw_context
*
222 __create_hw_context(struct drm_device
*dev
,
223 struct drm_i915_file_private
*file_priv
)
225 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
226 struct i915_hw_context
*ctx
;
229 ctx
= kzalloc(sizeof(*ctx
), GFP_KERNEL
);
231 return ERR_PTR(-ENOMEM
);
233 kref_init(&ctx
->ref
);
234 ctx
->obj
= i915_gem_alloc_object(dev
, dev_priv
->hw_context_size
);
235 INIT_LIST_HEAD(&ctx
->link
);
236 if (ctx
->obj
== NULL
) {
238 DRM_DEBUG_DRIVER("Context object allocated failed\n");
239 return ERR_PTR(-ENOMEM
);
242 if (INTEL_INFO(dev
)->gen
>= 7) {
243 ret
= i915_gem_object_set_cache_level(ctx
->obj
,
245 /* Failure shouldn't ever happen this early */
250 list_add_tail(&ctx
->link
, &dev_priv
->context_list
);
252 /* Default context will never have a file_priv */
253 if (file_priv
== NULL
)
256 ret
= idr_alloc(&file_priv
->context_idr
, ctx
, DEFAULT_CONTEXT_ID
, 0,
261 ctx
->file_priv
= file_priv
;
263 /* NB: Mark all slices as needing a remap so that when the context first
264 * loads it will restore whatever remap state already exists. If there
265 * is no remap info, it will be a NOP. */
266 ctx
->remap_slice
= (1 << NUM_L3_SLICES(dev
)) - 1;
271 i915_gem_context_unreference(ctx
);
276 * The default context needs to exist per ring that uses contexts. It stores the
277 * context state of the GPU for applications that don't utilize HW contexts, as
278 * well as an idle case.
280 static struct i915_hw_context
*
281 i915_gem_create_context(struct drm_device
*dev
,
282 struct drm_i915_file_private
*file_priv
,
285 const bool is_global_default_ctx
= file_priv
== NULL
;
286 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
287 struct i915_hw_context
*ctx
;
290 BUG_ON(!mutex_is_locked(&dev
->struct_mutex
));
292 ctx
= __create_hw_context(dev
, file_priv
);
296 if (is_global_default_ctx
) {
297 /* We may need to do things with the shrinker which
298 * require us to immediately switch back to the default
299 * context. This can cause a problem as pinning the
300 * default context also requires GTT space which may not
301 * be available. To avoid this we always pin the default
304 ret
= i915_gem_obj_ggtt_pin(ctx
->obj
,
305 get_context_alignment(dev
), 0);
307 DRM_DEBUG_DRIVER("Couldn't pin %d\n", ret
);
313 struct i915_hw_ppgtt
*ppgtt
= create_vm_for_ctx(dev
, ctx
);
315 if (IS_ERR_OR_NULL(ppgtt
)) {
316 DRM_DEBUG_DRIVER("PPGTT setup failed (%ld)\n",
318 ret
= PTR_ERR(ppgtt
);
321 ctx
->vm
= &ppgtt
->base
;
323 /* This case is reserved for the global default context and
324 * should only happen once. */
325 if (is_global_default_ctx
) {
326 if (WARN_ON(dev_priv
->mm
.aliasing_ppgtt
)) {
331 dev_priv
->mm
.aliasing_ppgtt
= ppgtt
;
333 } else if (USES_PPGTT(dev
)) {
334 /* For platforms which only have aliasing PPGTT, we fake the
335 * address space and refcounting. */
336 ctx
->vm
= &dev_priv
->mm
.aliasing_ppgtt
->base
;
337 kref_get(&dev_priv
->mm
.aliasing_ppgtt
->ref
);
339 ctx
->vm
= &dev_priv
->gtt
.base
;
344 if (is_global_default_ctx
)
345 i915_gem_object_ggtt_unpin(ctx
->obj
);
347 i915_gem_context_unreference(ctx
);
351 void i915_gem_context_reset(struct drm_device
*dev
)
353 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
354 struct intel_ring_buffer
*ring
;
357 if (!HAS_HW_CONTEXTS(dev
))
360 /* Prevent the hardware from restoring the last context (which hung) on
362 for (i
= 0; i
< I915_NUM_RINGS
; i
++) {
363 struct i915_hw_context
*dctx
;
364 if (!(INTEL_INFO(dev
)->ring_mask
& (1<<i
)))
367 /* Do a fake switch to the default context */
368 ring
= &dev_priv
->ring
[i
];
369 dctx
= ring
->default_context
;
373 if (!ring
->last_context
)
376 if (ring
->last_context
== dctx
)
380 WARN_ON(i915_gem_obj_ggtt_pin(dctx
->obj
,
381 get_context_alignment(dev
), 0));
382 /* Fake a finish/inactive */
383 dctx
->obj
->base
.write_domain
= 0;
384 dctx
->obj
->active
= 0;
387 i915_gem_context_unreference(ring
->last_context
);
388 i915_gem_context_reference(dctx
);
389 ring
->last_context
= dctx
;
393 int i915_gem_context_init(struct drm_device
*dev
)
395 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
396 struct intel_ring_buffer
*ring
;
399 if (!HAS_HW_CONTEXTS(dev
))
402 /* Init should only be called once per module load. Eventually the
403 * restriction on the context_disabled check can be loosened. */
404 if (WARN_ON(dev_priv
->ring
[RCS
].default_context
))
407 dev_priv
->hw_context_size
= round_up(get_context_size(dev
), 4096);
409 if (dev_priv
->hw_context_size
> (1<<20)) {
410 DRM_DEBUG_DRIVER("Disabling HW Contexts; invalid size\n");
414 dev_priv
->ring
[RCS
].default_context
=
415 i915_gem_create_context(dev
, NULL
, USES_PPGTT(dev
));
417 if (IS_ERR_OR_NULL(dev_priv
->ring
[RCS
].default_context
)) {
418 DRM_DEBUG_DRIVER("Disabling HW Contexts; create failed %ld\n",
419 PTR_ERR(dev_priv
->ring
[RCS
].default_context
));
420 return PTR_ERR(dev_priv
->ring
[RCS
].default_context
);
423 for (i
= RCS
+ 1; i
< I915_NUM_RINGS
; i
++) {
424 if (!(INTEL_INFO(dev
)->ring_mask
& (1<<i
)))
427 ring
= &dev_priv
->ring
[i
];
429 /* NB: RCS will hold a ref for all rings */
430 ring
->default_context
= dev_priv
->ring
[RCS
].default_context
;
433 DRM_DEBUG_DRIVER("HW context support initialized\n");
437 void i915_gem_context_fini(struct drm_device
*dev
)
439 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
440 struct i915_hw_context
*dctx
= dev_priv
->ring
[RCS
].default_context
;
443 if (!HAS_HW_CONTEXTS(dev
))
446 /* The only known way to stop the gpu from accessing the hw context is
447 * to reset it. Do this as the very last operation to avoid confusing
448 * other code, leading to spurious errors. */
449 intel_gpu_reset(dev
);
451 /* When default context is created and switched to, base object refcount
452 * will be 2 (+1 from object creation and +1 from do_switch()).
453 * i915_gem_context_fini() will be called after gpu_idle() has switched
454 * to default context. So we need to unreference the base object once
455 * to offset the do_switch part, so that i915_gem_context_unreference()
456 * can then free the base object correctly. */
457 WARN_ON(!dev_priv
->ring
[RCS
].last_context
);
458 if (dev_priv
->ring
[RCS
].last_context
== dctx
) {
459 /* Fake switch to NULL context */
460 WARN_ON(dctx
->obj
->active
);
461 i915_gem_object_ggtt_unpin(dctx
->obj
);
462 i915_gem_context_unreference(dctx
);
463 dev_priv
->ring
[RCS
].last_context
= NULL
;
466 for (i
= 0; i
< I915_NUM_RINGS
; i
++) {
467 struct intel_ring_buffer
*ring
= &dev_priv
->ring
[i
];
468 if (!(INTEL_INFO(dev
)->ring_mask
& (1<<i
)))
471 if (ring
->last_context
)
472 i915_gem_context_unreference(ring
->last_context
);
474 ring
->default_context
= NULL
;
475 ring
->last_context
= NULL
;
478 i915_gem_object_ggtt_unpin(dctx
->obj
);
479 i915_gem_context_unreference(dctx
);
480 dev_priv
->mm
.aliasing_ppgtt
= NULL
;
483 int i915_gem_context_enable(struct drm_i915_private
*dev_priv
)
485 struct intel_ring_buffer
*ring
;
488 if (!HAS_HW_CONTEXTS(dev_priv
->dev
))
491 /* This is the only place the aliasing PPGTT gets enabled, which means
492 * it has to happen before we bail on reset */
493 if (dev_priv
->mm
.aliasing_ppgtt
) {
494 struct i915_hw_ppgtt
*ppgtt
= dev_priv
->mm
.aliasing_ppgtt
;
495 ppgtt
->enable(ppgtt
);
498 /* FIXME: We should make this work, even in reset */
499 if (i915_reset_in_progress(&dev_priv
->gpu_error
))
502 BUG_ON(!dev_priv
->ring
[RCS
].default_context
);
504 for_each_ring(ring
, dev_priv
, i
) {
505 ret
= do_switch(ring
, ring
->default_context
);
513 static int context_idr_cleanup(int id
, void *p
, void *data
)
515 struct i915_hw_context
*ctx
= p
;
517 /* Ignore the default context because close will handle it */
518 if (i915_gem_context_is_default(ctx
))
521 i915_gem_context_unreference(ctx
);
525 int i915_gem_context_open(struct drm_device
*dev
, struct drm_file
*file
)
527 struct drm_i915_file_private
*file_priv
= file
->driver_priv
;
528 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
530 if (!HAS_HW_CONTEXTS(dev
)) {
531 /* Cheat for hang stats */
532 file_priv
->private_default_ctx
=
533 kzalloc(sizeof(struct i915_hw_context
), GFP_KERNEL
);
535 if (file_priv
->private_default_ctx
== NULL
)
538 file_priv
->private_default_ctx
->vm
= &dev_priv
->gtt
.base
;
542 idr_init(&file_priv
->context_idr
);
544 mutex_lock(&dev
->struct_mutex
);
545 file_priv
->private_default_ctx
=
546 i915_gem_create_context(dev
, file_priv
, USES_FULL_PPGTT(dev
));
547 mutex_unlock(&dev
->struct_mutex
);
549 if (IS_ERR(file_priv
->private_default_ctx
)) {
550 idr_destroy(&file_priv
->context_idr
);
551 return PTR_ERR(file_priv
->private_default_ctx
);
557 void i915_gem_context_close(struct drm_device
*dev
, struct drm_file
*file
)
559 struct drm_i915_file_private
*file_priv
= file
->driver_priv
;
561 if (!HAS_HW_CONTEXTS(dev
)) {
562 kfree(file_priv
->private_default_ctx
);
566 idr_for_each(&file_priv
->context_idr
, context_idr_cleanup
, NULL
);
567 i915_gem_context_unreference(file_priv
->private_default_ctx
);
568 idr_destroy(&file_priv
->context_idr
);
571 struct i915_hw_context
*
572 i915_gem_context_get(struct drm_i915_file_private
*file_priv
, u32 id
)
574 struct i915_hw_context
*ctx
;
576 if (!HAS_HW_CONTEXTS(file_priv
->dev_priv
->dev
))
577 return file_priv
->private_default_ctx
;
579 ctx
= (struct i915_hw_context
*)idr_find(&file_priv
->context_idr
, id
);
581 return ERR_PTR(-ENOENT
);
587 mi_set_context(struct intel_ring_buffer
*ring
,
588 struct i915_hw_context
*new_context
,
593 /* w/a: If Flush TLB Invalidation Mode is enabled, driver must do a TLB
594 * invalidation prior to MI_SET_CONTEXT. On GEN6 we don't set the value
595 * explicitly, so we rely on the value at ring init, stored in
596 * itlb_before_ctx_switch.
598 if (IS_GEN6(ring
->dev
) && ring
->itlb_before_ctx_switch
) {
599 ret
= ring
->flush(ring
, I915_GEM_GPU_DOMAINS
, 0);
604 ret
= intel_ring_begin(ring
, 6);
608 /* WaProgramMiArbOnOffAroundMiSetContext:ivb,vlv,hsw */
609 if (IS_GEN7(ring
->dev
))
610 intel_ring_emit(ring
, MI_ARB_ON_OFF
| MI_ARB_DISABLE
);
612 intel_ring_emit(ring
, MI_NOOP
);
614 intel_ring_emit(ring
, MI_NOOP
);
615 intel_ring_emit(ring
, MI_SET_CONTEXT
);
616 intel_ring_emit(ring
, i915_gem_obj_ggtt_offset(new_context
->obj
) |
618 MI_SAVE_EXT_STATE_EN
|
619 MI_RESTORE_EXT_STATE_EN
|
622 * w/a: MI_SET_CONTEXT must always be followed by MI_NOOP
623 * WaMiSetContext_Hang:snb,ivb,vlv
625 intel_ring_emit(ring
, MI_NOOP
);
627 if (IS_GEN7(ring
->dev
))
628 intel_ring_emit(ring
, MI_ARB_ON_OFF
| MI_ARB_ENABLE
);
630 intel_ring_emit(ring
, MI_NOOP
);
632 intel_ring_advance(ring
);
637 static int do_switch(struct intel_ring_buffer
*ring
,
638 struct i915_hw_context
*to
)
640 struct drm_i915_private
*dev_priv
= ring
->dev
->dev_private
;
641 struct i915_hw_context
*from
= ring
->last_context
;
642 struct i915_hw_ppgtt
*ppgtt
= ctx_to_ppgtt(to
);
646 if (from
!= NULL
&& ring
== &dev_priv
->ring
[RCS
]) {
647 BUG_ON(from
->obj
== NULL
);
648 BUG_ON(!i915_gem_obj_is_pinned(from
->obj
));
651 if (from
== to
&& from
->last_ring
== ring
&& !to
->remap_slice
)
654 /* Trying to pin first makes error handling easier. */
655 if (ring
== &dev_priv
->ring
[RCS
]) {
656 ret
= i915_gem_obj_ggtt_pin(to
->obj
,
657 get_context_alignment(ring
->dev
), 0);
663 * Pin can switch back to the default context if we end up calling into
664 * evict_everything - as a last ditch gtt defrag effort that also
665 * switches to the default context. Hence we need to reload from here.
667 from
= ring
->last_context
;
669 if (USES_FULL_PPGTT(ring
->dev
)) {
670 ret
= ppgtt
->switch_mm(ppgtt
, ring
, false);
675 if (ring
!= &dev_priv
->ring
[RCS
]) {
677 i915_gem_context_unreference(from
);
682 * Clear this page out of any CPU caches for coherent swap-in/out. Note
683 * that thanks to write = false in this call and us not setting any gpu
684 * write domains when putting a context object onto the active list
685 * (when switching away from it), this won't block.
687 * XXX: We need a real interface to do this instead of trickery.
689 ret
= i915_gem_object_set_to_gtt_domain(to
->obj
, false);
693 if (!to
->obj
->has_global_gtt_mapping
) {
694 struct i915_vma
*vma
= i915_gem_obj_to_vma(to
->obj
,
695 &dev_priv
->gtt
.base
);
696 vma
->bind_vma(vma
, to
->obj
->cache_level
, GLOBAL_BIND
);
699 if (!to
->is_initialized
|| i915_gem_context_is_default(to
))
700 hw_flags
|= MI_RESTORE_INHIBIT
;
702 ret
= mi_set_context(ring
, to
, hw_flags
);
706 for (i
= 0; i
< MAX_L3_SLICES
; i
++) {
707 if (!(to
->remap_slice
& (1<<i
)))
710 ret
= i915_gem_l3_remap(ring
, i
);
711 /* If it failed, try again next round */
713 DRM_DEBUG_DRIVER("L3 remapping failed\n");
715 to
->remap_slice
&= ~(1<<i
);
718 /* The backing object for the context is done after switching to the
719 * *next* context. Therefore we cannot retire the previous context until
720 * the next context has already started running. In fact, the below code
721 * is a bit suboptimal because the retiring can occur simply after the
722 * MI_SET_CONTEXT instead of when the next seqno has completed.
725 from
->obj
->base
.read_domains
= I915_GEM_DOMAIN_INSTRUCTION
;
726 i915_vma_move_to_active(i915_gem_obj_to_ggtt(from
->obj
), ring
);
727 /* As long as MI_SET_CONTEXT is serializing, ie. it flushes the
728 * whole damn pipeline, we don't need to explicitly mark the
729 * object dirty. The only exception is that the context must be
730 * correct in case the object gets swapped out. Ideally we'd be
731 * able to defer doing this until we know the object would be
732 * swapped, but there is no way to do that yet.
734 from
->obj
->dirty
= 1;
735 BUG_ON(from
->obj
->ring
!= ring
);
737 /* obj is kept alive until the next request by its active ref */
738 i915_gem_object_ggtt_unpin(from
->obj
);
739 i915_gem_context_unreference(from
);
742 to
->is_initialized
= true;
745 i915_gem_context_reference(to
);
746 ring
->last_context
= to
;
747 to
->last_ring
= ring
;
753 i915_gem_object_ggtt_unpin(to
->obj
);
758 * i915_switch_context() - perform a GPU context switch.
759 * @ring: ring for which we'll execute the context switch
760 * @file_priv: file_priv associated with the context, may be NULL
761 * @to: the context to switch to
763 * The context life cycle is simple. The context refcount is incremented and
764 * decremented by 1 and create and destroy. If the context is in use by the GPU,
765 * it will have a refoucnt > 1. This allows us to destroy the context abstract
766 * object while letting the normal object tracking destroy the backing BO.
768 int i915_switch_context(struct intel_ring_buffer
*ring
,
769 struct drm_file
*file
,
770 struct i915_hw_context
*to
)
772 struct drm_i915_private
*dev_priv
= ring
->dev
->dev_private
;
774 WARN_ON(!mutex_is_locked(&dev_priv
->dev
->struct_mutex
));
776 BUG_ON(file
&& to
== NULL
);
778 /* We have the fake context, but don't supports switching. */
779 if (!HAS_HW_CONTEXTS(ring
->dev
))
782 return do_switch(ring
, to
);
785 int i915_gem_context_create_ioctl(struct drm_device
*dev
, void *data
,
786 struct drm_file
*file
)
788 struct drm_i915_gem_context_create
*args
= data
;
789 struct drm_i915_file_private
*file_priv
= file
->driver_priv
;
790 struct i915_hw_context
*ctx
;
793 if (!HAS_HW_CONTEXTS(dev
))
796 ret
= i915_mutex_lock_interruptible(dev
);
800 ctx
= i915_gem_create_context(dev
, file_priv
, USES_FULL_PPGTT(dev
));
801 mutex_unlock(&dev
->struct_mutex
);
805 args
->ctx_id
= ctx
->id
;
806 DRM_DEBUG_DRIVER("HW context %d created\n", args
->ctx_id
);
811 int i915_gem_context_destroy_ioctl(struct drm_device
*dev
, void *data
,
812 struct drm_file
*file
)
814 struct drm_i915_gem_context_destroy
*args
= data
;
815 struct drm_i915_file_private
*file_priv
= file
->driver_priv
;
816 struct i915_hw_context
*ctx
;
819 if (args
->ctx_id
== DEFAULT_CONTEXT_ID
)
822 ret
= i915_mutex_lock_interruptible(dev
);
826 ctx
= i915_gem_context_get(file_priv
, args
->ctx_id
);
828 mutex_unlock(&dev
->struct_mutex
);
832 idr_remove(&ctx
->file_priv
->context_idr
, ctx
->id
);
833 i915_gem_context_unreference(ctx
);
834 mutex_unlock(&dev
->struct_mutex
);
836 DRM_DEBUG_DRIVER("HW context %d destroyed\n", args
->ctx_id
);