aboutsummaryrefslogtreecommitdiffstats
path: root/src/mesa/drivers/dri/i965/intel_buffer_objects.c
blob: bec2c8fe177fc7cdd4646b8553cc05ba8370d5ec (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
/**************************************************************************
 * 
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * 
 **************************************************************************/


#include "main/imports.h"
#include "main/mtypes.h"
#include "main/macros.h"
#include "main/bufferobj.h"

#include "brw_context.h"
#include "intel_blit.h"
#include "intel_buffer_objects.h"
#include "intel_batchbuffer.h"
#include "intel_fbo.h"
#include "intel_mipmap_tree.h"
#include "intel_regions.h"

#include "brw_context.h"

static GLboolean
intel_bufferobj_unmap(struct gl_context * ctx, struct gl_buffer_object *obj);

/** Allocates a new drm_intel_bo to store the data for the buffer object. */
static void
intel_bufferobj_alloc_buffer(struct brw_context *brw,
			     struct intel_buffer_object *intel_obj)
{
   intel_obj->buffer = drm_intel_bo_alloc(brw->bufmgr, "bufferobj",
					  intel_obj->Base.Size, 64);

   /* the buffer might be bound as a uniform buffer, need to update it
    */
   brw->state.dirty.brw |= BRW_NEW_UNIFORM_BUFFER;
}

static void
release_buffer(struct intel_buffer_object *intel_obj)
{
   drm_intel_bo_unreference(intel_obj->buffer);
   intel_obj->buffer = NULL;
   intel_obj->offset = 0;
}

/**
 * There is some duplication between mesa's bufferobjects and our
 * bufmgr buffers.  Both have an integer handle and a hashtable to
 * lookup an opaque structure.  It would be nice if the handles and
 * internal structure where somehow shared.
 */
static struct gl_buffer_object *
intel_bufferobj_alloc(struct gl_context * ctx, GLuint name, GLenum target)
{
   struct intel_buffer_object *obj = CALLOC_STRUCT(intel_buffer_object);

   _mesa_initialize_buffer_object(ctx, &obj->Base, name, target);

   obj->buffer = NULL;

   return &obj->Base;
}

/**
 * Deallocate/free a vertex/pixel buffer object.
 * Called via glDeleteBuffersARB().
 */
static void
intel_bufferobj_free(struct gl_context * ctx, struct gl_buffer_object *obj)
{
   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);

   assert(intel_obj);

   /* Buffer objects are automatically unmapped when deleting according
    * to the spec, but Mesa doesn't do UnmapBuffer for us at context destroy
    * (though it does if you call glDeleteBuffers)
    */
   if (obj->Pointer)
      intel_bufferobj_unmap(ctx, obj);

   drm_intel_bo_unreference(intel_obj->buffer);
   free(intel_obj);
}



/**
 * Allocate space for and store data in a buffer object.  Any data that was
 * previously stored in the buffer object is lost.  If data is NULL,
 * memory will be allocated, but no copy will occur.
 * Called via ctx->Driver.BufferData().
 * \return true for success, false if out of memory
 */
static GLboolean
intel_bufferobj_data(struct gl_context * ctx,
                     GLenum target,
                     GLsizeiptrARB size,
                     const GLvoid * data,
                     GLenum usage, struct gl_buffer_object *obj)
{
   struct brw_context *brw = brw_context(ctx);
   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);

   /* Part of the ABI, but this function doesn't use it.
    */
   (void) target;

   intel_obj->Base.Size = size;
   intel_obj->Base.Usage = usage;

   assert(!obj->Pointer); /* Mesa should have unmapped it */

   if (intel_obj->buffer != NULL)
      release_buffer(intel_obj);

   if (size != 0) {
      intel_bufferobj_alloc_buffer(brw, intel_obj);
      if (!intel_obj->buffer)
         return false;

      if (data != NULL)
	 drm_intel_bo_subdata(intel_obj->buffer, 0, size, data);
   }

   return true;
}


/**
 * Replace data in a subrange of buffer object.  If the data range
 * specified by size + offset extends beyond the end of the buffer or
 * if data is NULL, no copy is performed.
 * Called via glBufferSubDataARB().
 */
static void
intel_bufferobj_subdata(struct gl_context * ctx,
                        GLintptrARB offset,
                        GLsizeiptrARB size,
                        const GLvoid * data, struct gl_buffer_object *obj)
{
   struct brw_context *brw = brw_context(ctx);
   struct intel_context *intel = intel_context(ctx);
   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
   bool busy;

   if (size == 0)
      return;

   assert(intel_obj);

   busy =
      drm_intel_bo_busy(intel_obj->buffer) ||
      drm_intel_bo_references(intel->batch.bo, intel_obj->buffer);

   if (busy) {
      if (size == intel_obj->Base.Size) {
	 /* Replace the current busy bo with fresh data. */
	 drm_intel_bo_unreference(intel_obj->buffer);
	 intel_bufferobj_alloc_buffer(brw, intel_obj);
	 drm_intel_bo_subdata(intel_obj->buffer, 0, size, data);
      } else {
         perf_debug("Using a blit copy to avoid stalling on %ldb "
                    "glBufferSubData() to a busy buffer object.\n",
                    (long)size);
	 drm_intel_bo *temp_bo =
	    drm_intel_bo_alloc(brw->bufmgr, "subdata temp", size, 64);

	 drm_intel_bo_subdata(temp_bo, 0, size, data);

	 intel_emit_linear_blit(brw,
				intel_obj->buffer, offset,
				temp_bo, 0,
				size);

	 drm_intel_bo_unreference(temp_bo);
      }
   } else {
      drm_intel_bo_subdata(intel_obj->buffer, offset, size, data);
   }
}


/**
 * Called via glGetBufferSubDataARB().
 */
static void
intel_bufferobj_get_subdata(struct gl_context * ctx,
                            GLintptrARB offset,
                            GLsizeiptrARB size,
                            GLvoid * data, struct gl_buffer_object *obj)
{
   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
   struct brw_context *brw = brw_context(ctx);
   struct intel_context *intel = intel_context(ctx);

   assert(intel_obj);
   if (drm_intel_bo_references(intel->batch.bo, intel_obj->buffer)) {
      intel_batchbuffer_flush(brw);
   }
   drm_intel_bo_get_subdata(intel_obj->buffer, offset, size, data);
}



/**
 * Called via glMapBufferRange and glMapBuffer
 *
 * The goal of this extension is to allow apps to accumulate their rendering
 * at the same time as they accumulate their buffer object.  Without it,
 * you'd end up blocking on execution of rendering every time you mapped
 * the buffer to put new data in.
 *
 * We support it in 3 ways: If unsynchronized, then don't bother
 * flushing the batchbuffer before mapping the buffer, which can save blocking
 * in many cases.  If we would still block, and they allow the whole buffer
 * to be invalidated, then just allocate a new buffer to replace the old one.
 * If not, and we'd block, and they allow the subrange of the buffer to be
 * invalidated, then we can make a new little BO, let them write into that,
 * and blit it into the real BO at unmap time.
 */
static void *
intel_bufferobj_map_range(struct gl_context * ctx,
			  GLintptr offset, GLsizeiptr length,
			  GLbitfield access, struct gl_buffer_object *obj)
{
   struct brw_context *brw = brw_context(ctx);
   struct intel_context *intel = intel_context(ctx);
   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);

   assert(intel_obj);

   /* _mesa_MapBufferRange (GL entrypoint) sets these, but the vbo module also
    * internally uses our functions directly.
    */
   obj->Offset = offset;
   obj->Length = length;
   obj->AccessFlags = access;

   if (intel_obj->buffer == NULL) {
      obj->Pointer = NULL;
      return NULL;
   }

   /* If the access is synchronized (like a normal buffer mapping), then get
    * things flushed out so the later mapping syncs appropriately through GEM.
    * If the user doesn't care about existing buffer contents and mapping would
    * cause us to block, then throw out the old buffer.
    *
    * If they set INVALIDATE_BUFFER, we can pitch the current contents to
    * achieve the required synchronization.
    */
   if (!(access & GL_MAP_UNSYNCHRONIZED_BIT)) {
      if (drm_intel_bo_references(intel->batch.bo, intel_obj->buffer)) {
	 if (access & GL_MAP_INVALIDATE_BUFFER_BIT) {
	    drm_intel_bo_unreference(intel_obj->buffer);
	    intel_bufferobj_alloc_buffer(brw, intel_obj);
	 } else {
            perf_debug("Stalling on the GPU for mapping a busy buffer "
                       "object\n");
	    intel_flush(ctx);
	 }
      } else if (drm_intel_bo_busy(intel_obj->buffer) &&
		 (access & GL_MAP_INVALIDATE_BUFFER_BIT)) {
	 drm_intel_bo_unreference(intel_obj->buffer);
	 intel_bufferobj_alloc_buffer(brw, intel_obj);
      }
   }

   /* If the user is mapping a range of an active buffer object but
    * doesn't require the current contents of that range, make a new
    * BO, and we'll copy what they put in there out at unmap or
    * FlushRange time.
    */
   if ((access & GL_MAP_INVALIDATE_RANGE_BIT) &&
       drm_intel_bo_busy(intel_obj->buffer)) {
      if (access & GL_MAP_FLUSH_EXPLICIT_BIT) {
	 intel_obj->range_map_buffer = malloc(length);
	 obj->Pointer = intel_obj->range_map_buffer;
      } else {
	 intel_obj->range_map_bo = drm_intel_bo_alloc(brw->bufmgr,
						      "range map",
						      length, 64);
	 if (!(access & GL_MAP_READ_BIT)) {
	    drm_intel_gem_bo_map_gtt(intel_obj->range_map_bo);
	 } else {
	    drm_intel_bo_map(intel_obj->range_map_bo,
			     (access & GL_MAP_WRITE_BIT) != 0);
	 }
	 obj->Pointer = intel_obj->range_map_bo->virtual;
      }
      return obj->Pointer;
   }

   if (access & GL_MAP_UNSYNCHRONIZED_BIT)
      drm_intel_gem_bo_map_unsynchronized(intel_obj->buffer);
   else if (!(access & GL_MAP_READ_BIT)) {
      drm_intel_gem_bo_map_gtt(intel_obj->buffer);
   } else {
      drm_intel_bo_map(intel_obj->buffer, (access & GL_MAP_WRITE_BIT) != 0);
   }

   obj->Pointer = intel_obj->buffer->virtual + offset;
   return obj->Pointer;
}

/* Ideally we'd use a BO to avoid taking up cache space for the temporary
 * data, but FlushMappedBufferRange may be followed by further writes to
 * the pointer, so we would have to re-map after emitting our blit, which
 * would defeat the point.
 */
static void
intel_bufferobj_flush_mapped_range(struct gl_context *ctx,
				   GLintptr offset, GLsizeiptr length,
				   struct gl_buffer_object *obj)
{
   struct brw_context *brw = brw_context(ctx);
   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
   drm_intel_bo *temp_bo;

   /* Unless we're in the range map using a temporary system buffer,
    * there's no work to do.
    */
   if (intel_obj->range_map_buffer == NULL)
      return;

   if (length == 0)
      return;

   temp_bo = drm_intel_bo_alloc(brw->bufmgr, "range map flush", length, 64);

   drm_intel_bo_subdata(temp_bo, 0, length, intel_obj->range_map_buffer);

   intel_emit_linear_blit(brw,
			  intel_obj->buffer, obj->Offset + offset,
			  temp_bo, 0,
			  length);

   drm_intel_bo_unreference(temp_bo);
}


/**
 * Called via glUnmapBuffer().
 */
static GLboolean
intel_bufferobj_unmap(struct gl_context * ctx, struct gl_buffer_object *obj)
{
   struct brw_context *brw = brw_context(ctx);
   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);

   assert(intel_obj);
   assert(obj->Pointer);
   if (intel_obj->range_map_buffer != NULL) {
      /* Since we've emitted some blits to buffers that will (likely) be used
       * in rendering operations in other cache domains in this batch, emit a
       * flush.  Once again, we wish for a domain tracker in libdrm to cover
       * usage inside of a batchbuffer.
       */
      intel_batchbuffer_emit_mi_flush(brw);
      free(intel_obj->range_map_buffer);
      intel_obj->range_map_buffer = NULL;
   } else if (intel_obj->range_map_bo != NULL) {
      drm_intel_bo_unmap(intel_obj->range_map_bo);

      intel_emit_linear_blit(brw,
			     intel_obj->buffer, obj->Offset,
			     intel_obj->range_map_bo, 0,
			     obj->Length);

      /* Since we've emitted some blits to buffers that will (likely) be used
       * in rendering operations in other cache domains in this batch, emit a
       * flush.  Once again, we wish for a domain tracker in libdrm to cover
       * usage inside of a batchbuffer.
       */
      intel_batchbuffer_emit_mi_flush(brw);

      drm_intel_bo_unreference(intel_obj->range_map_bo);
      intel_obj->range_map_bo = NULL;
   } else if (intel_obj->buffer != NULL) {
      drm_intel_bo_unmap(intel_obj->buffer);
   }
   obj->Pointer = NULL;
   obj->Offset = 0;
   obj->Length = 0;

   return true;
}

drm_intel_bo *
intel_bufferobj_buffer(struct brw_context *brw,
                       struct intel_buffer_object *intel_obj,
		       GLuint flag)
{
   if (intel_obj->buffer == NULL)
      intel_bufferobj_alloc_buffer(brw, intel_obj);

   return intel_obj->buffer;
}

#define INTEL_UPLOAD_SIZE (64*1024)

void
intel_upload_finish(struct brw_context *brw)
{
   struct intel_context *intel = &brw->intel;
   if (!intel->upload.bo)
	   return;

   if (intel->upload.buffer_len) {
	   drm_intel_bo_subdata(intel->upload.bo,
				intel->upload.buffer_offset,
				intel->upload.buffer_len,
				intel->upload.buffer);
	   intel->upload.buffer_len = 0;
   }

   drm_intel_bo_unreference(intel->upload.bo);
   intel->upload.bo = NULL;
}

static void wrap_buffers(struct brw_context *brw, GLuint size)
{
   struct intel_context *intel = &brw->intel;
   intel_upload_finish(brw);

   if (size < INTEL_UPLOAD_SIZE)
      size = INTEL_UPLOAD_SIZE;

   intel->upload.bo = drm_intel_bo_alloc(brw->bufmgr, "upload", size, 0);
   intel->upload.offset = 0;
}

void intel_upload_data(struct brw_context *brw,
		       const void *ptr, GLuint size, GLuint align,
		       drm_intel_bo **return_bo,
		       GLuint *return_offset)
{
   struct intel_context *intel = &brw->intel;
   GLuint base, delta;

   base = (intel->upload.offset + align - 1) / align * align;
   if (intel->upload.bo == NULL || base + size > intel->upload.bo->size) {
      wrap_buffers(brw, size);
      base = 0;
   }

   drm_intel_bo_reference(intel->upload.bo);
   *return_bo = intel->upload.bo;
   *return_offset = base;

   delta = base - intel->upload.offset;
   if (intel->upload.buffer_len &&
       intel->upload.buffer_len + delta + size > sizeof(intel->upload.buffer))
   {
      drm_intel_bo_subdata(intel->upload.bo,
			   intel->upload.buffer_offset,
			   intel->upload.buffer_len,
			   intel->upload.buffer);
      intel->upload.buffer_len = 0;
   }

   if (size < sizeof(intel->upload.buffer))
   {
      if (intel->upload.buffer_len == 0)
	 intel->upload.buffer_offset = base;
      else
	 intel->upload.buffer_len += delta;

      memcpy(intel->upload.buffer + intel->upload.buffer_len, ptr, size);
      intel->upload.buffer_len += size;
   }
   else
   {
      drm_intel_bo_subdata(intel->upload.bo, base, size, ptr);
   }

   intel->upload.offset = base + size;
}

void *intel_upload_map(struct brw_context *brw, GLuint size, GLuint align)
{
   struct intel_context *intel = &brw->intel;
   GLuint base, delta;
   char *ptr;

   base = (intel->upload.offset + align - 1) / align * align;
   if (intel->upload.bo == NULL || base + size > intel->upload.bo->size) {
      wrap_buffers(brw, size);
      base = 0;
   }

   delta = base - intel->upload.offset;
   if (intel->upload.buffer_len &&
       intel->upload.buffer_len + delta + size > sizeof(intel->upload.buffer))
   {
      drm_intel_bo_subdata(intel->upload.bo,
			   intel->upload.buffer_offset,
			   intel->upload.buffer_len,
			   intel->upload.buffer);
      intel->upload.buffer_len = 0;
   }

   if (size <= sizeof(intel->upload.buffer)) {
      if (intel->upload.buffer_len == 0)
	 intel->upload.buffer_offset = base;
      else
	 intel->upload.buffer_len += delta;

      ptr = intel->upload.buffer + intel->upload.buffer_len;
      intel->upload.buffer_len += size;
   } else
      ptr = malloc(size);

   return ptr;
}

void intel_upload_unmap(struct brw_context *brw,
			const void *ptr, GLuint size, GLuint align,
			drm_intel_bo **return_bo,
			GLuint *return_offset)
{
   struct intel_context *intel = &brw->intel;
   GLuint base;

   base = (intel->upload.offset + align - 1) / align * align;
   if (size > sizeof(intel->upload.buffer)) {
      drm_intel_bo_subdata(intel->upload.bo, base, size, ptr);
      free((void*)ptr);
   }

   drm_intel_bo_reference(intel->upload.bo);
   *return_bo = intel->upload.bo;
   *return_offset = base;

   intel->upload.offset = base + size;
}

drm_intel_bo *
intel_bufferobj_source(struct brw_context *brw,
                       struct intel_buffer_object *intel_obj,
		       GLuint align, GLuint *offset)
{
   *offset = intel_obj->offset;
   return intel_obj->buffer;
}

static void
intel_bufferobj_copy_subdata(struct gl_context *ctx,
			     struct gl_buffer_object *src,
			     struct gl_buffer_object *dst,
			     GLintptr read_offset, GLintptr write_offset,
			     GLsizeiptr size)
{
   struct brw_context *brw = brw_context(ctx);
   struct intel_buffer_object *intel_src = intel_buffer_object(src);
   struct intel_buffer_object *intel_dst = intel_buffer_object(dst);
   drm_intel_bo *src_bo, *dst_bo;
   GLuint src_offset;

   if (size == 0)
      return;

   dst_bo = intel_bufferobj_buffer(brw, intel_dst, INTEL_WRITE_PART);
   src_bo = intel_bufferobj_source(brw, intel_src, 64, &src_offset);

   intel_emit_linear_blit(brw,
			  dst_bo, write_offset,
			  src_bo, read_offset + src_offset, size);

   /* Since we've emitted some blits to buffers that will (likely) be used
    * in rendering operations in other cache domains in this batch, emit a
    * flush.  Once again, we wish for a domain tracker in libdrm to cover
    * usage inside of a batchbuffer.
    */
   intel_batchbuffer_emit_mi_flush(brw);
}

static GLenum
intel_buffer_purgeable(drm_intel_bo *buffer)
{
   int retained = 0;

   if (buffer != NULL)
      retained = drm_intel_bo_madvise (buffer, I915_MADV_DONTNEED);

   return retained ? GL_VOLATILE_APPLE : GL_RELEASED_APPLE;
}

static GLenum
intel_buffer_object_purgeable(struct gl_context * ctx,
                              struct gl_buffer_object *obj,
                              GLenum option)
{
   struct intel_buffer_object *intel_obj = intel_buffer_object (obj);

   if (intel_obj->buffer != NULL)
      return intel_buffer_purgeable(intel_obj->buffer);

   if (option == GL_RELEASED_APPLE) {
      return GL_RELEASED_APPLE;
   } else {
      /* XXX Create the buffer and madvise(MADV_DONTNEED)? */
      struct brw_context *brw = brw_context(ctx);
      drm_intel_bo *bo = intel_bufferobj_buffer(brw, intel_obj, INTEL_READ);

      return intel_buffer_purgeable(bo);
   }
}

static GLenum
intel_texture_object_purgeable(struct gl_context * ctx,
                               struct gl_texture_object *obj,
                               GLenum option)
{
   struct intel_texture_object *intel;

   (void) ctx;
   (void) option;

   intel = intel_texture_object(obj);
   if (intel->mt == NULL || intel->mt->region == NULL)
      return GL_RELEASED_APPLE;

   return intel_buffer_purgeable(intel->mt->region->bo);
}

static GLenum
intel_render_object_purgeable(struct gl_context * ctx,
                              struct gl_renderbuffer *obj,
                              GLenum option)
{
   struct intel_renderbuffer *intel;

   (void) ctx;
   (void) option;

   intel = intel_renderbuffer(obj);
   if (intel->mt == NULL)
      return GL_RELEASED_APPLE;

   return intel_buffer_purgeable(intel->mt->region->bo);
}

static GLenum
intel_buffer_unpurgeable(drm_intel_bo *buffer)
{
   int retained;

   retained = 0;
   if (buffer != NULL)
      retained = drm_intel_bo_madvise (buffer, I915_MADV_WILLNEED);

   return retained ? GL_RETAINED_APPLE : GL_UNDEFINED_APPLE;
}

static GLenum
intel_buffer_object_unpurgeable(struct gl_context * ctx,
                                struct gl_buffer_object *obj,
                                GLenum option)
{
   (void) ctx;
   (void) option;

   return intel_buffer_unpurgeable(intel_buffer_object (obj)->buffer);
}

static GLenum
intel_texture_object_unpurgeable(struct gl_context * ctx,
                                 struct gl_texture_object *obj,
                                 GLenum option)
{
   struct intel_texture_object *intel;

   (void) ctx;
   (void) option;

   intel = intel_texture_object(obj);
   if (intel->mt == NULL || intel->mt->region == NULL)
      return GL_UNDEFINED_APPLE;

   return intel_buffer_unpurgeable(intel->mt->region->bo);
}

static GLenum
intel_render_object_unpurgeable(struct gl_context * ctx,
                                struct gl_renderbuffer *obj,
                                GLenum option)
{
   struct intel_renderbuffer *intel;

   (void) ctx;
   (void) option;

   intel = intel_renderbuffer(obj);
   if (intel->mt == NULL)
      return GL_UNDEFINED_APPLE;

   return intel_buffer_unpurgeable(intel->mt->region->bo);
}

void
intelInitBufferObjectFuncs(struct dd_function_table *functions)
{
   functions->NewBufferObject = intel_bufferobj_alloc;
   functions->DeleteBuffer = intel_bufferobj_free;
   functions->BufferData = intel_bufferobj_data;
   functions->BufferSubData = intel_bufferobj_subdata;
   functions->GetBufferSubData = intel_bufferobj_get_subdata;
   functions->MapBufferRange = intel_bufferobj_map_range;
   functions->FlushMappedBufferRange = intel_bufferobj_flush_mapped_range;
   functions->UnmapBuffer = intel_bufferobj_unmap;
   functions->CopyBufferSubData = intel_bufferobj_copy_subdata;

   functions->BufferObjectPurgeable = intel_buffer_object_purgeable;
   functions->TextureObjectPurgeable = intel_texture_object_purgeable;
   functions->RenderObjectPurgeable = intel_render_object_purgeable;

   functions->BufferObjectUnpurgeable = intel_buffer_object_unpurgeable;
   functions->TextureObjectUnpurgeable = intel_texture_object_unpurgeable;
   functions->RenderObjectUnpurgeable = intel_render_object_unpurgeable;
}