1/*
2 * Copyright 2003 VMware, Inc.
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sublicense, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the
14 * next paragraph) shall be included in all copies or substantial portions
15 * of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
21 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
22 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
23 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 */
25
26/**
27 * @file intel_buffer_objects.c
28 *
29 * This provides core GL buffer object functionality.
30 */
31
32#include "main/imports.h"
33#include "main/mtypes.h"
34#include "main/macros.h"
35#include "main/streaming-load-memcpy.h"
36#include "main/bufferobj.h"
37#include "x86/common_x86_asm.h"
38
39#include "brw_context.h"
40#include "brw_blorp.h"
41#include "intel_buffer_objects.h"
42#include "intel_batchbuffer.h"
43
44static void
45mark_buffer_gpu_usage(struct intel_buffer_object *intel_obj,
46                               uint32_t offset, uint32_t size)
47{
48   intel_obj->gpu_active_start = MIN2(intel_obj->gpu_active_start, offset);
49   intel_obj->gpu_active_end = MAX2(intel_obj->gpu_active_end, offset + size);
50}
51
52static void
53mark_buffer_inactive(struct intel_buffer_object *intel_obj)
54{
55   intel_obj->gpu_active_start = ~0;
56   intel_obj->gpu_active_end = 0;
57}
58
59static void
60mark_buffer_valid_data(struct intel_buffer_object *intel_obj,
61                       uint32_t offset, uint32_t size)
62{
63   intel_obj->valid_data_start = MIN2(intel_obj->valid_data_start, offset);
64   intel_obj->valid_data_end = MAX2(intel_obj->valid_data_end, offset + size);
65}
66
67static void
68mark_buffer_invalid(struct intel_buffer_object *intel_obj)
69{
70   intel_obj->valid_data_start = ~0;
71   intel_obj->valid_data_end = 0;
72}
73
74/** Allocates a new brw_bo to store the data for the buffer object. */
75static void
76alloc_buffer_object(struct brw_context *brw,
77                    struct intel_buffer_object *intel_obj)
78{
79   const struct gl_context *ctx = &brw->ctx;
80
81   uint64_t size = intel_obj->Base.Size;
82   if (ctx->Const.RobustAccess) {
83      /* Pad out buffer objects with an extra 2kB (half a page).
84       *
85       * When pushing UBOs, we need to safeguard against 3DSTATE_CONSTANT_*
86       * reading out of bounds memory.  The application might bind a UBO that's
87       * smaller than what the program expects.  Ideally, we'd bind an extra
88       * push buffer containing zeros, but we have a limited number of those,
89       * so it's not always viable.  Our only safe option is to pad all buffer
90       * objects by the maximum push data length, so that it will never read
91       * past the end of a BO.
92       *
93       * This is unfortunate, but it should result in at most 1 extra page,
94       * which probably isn't too terrible.
95       */
96      size += 64 * 32; /* max read length of 64 256-bit units */
97   }
98   intel_obj->buffer =
99      brw_bo_alloc(brw->bufmgr, "bufferobj", size, BRW_MEMZONE_OTHER);
100
101   /* the buffer might be bound as a uniform buffer, need to update it
102    */
103   if (intel_obj->Base.UsageHistory & USAGE_UNIFORM_BUFFER)
104      brw->ctx.NewDriverState |= BRW_NEW_UNIFORM_BUFFER;
105   if (intel_obj->Base.UsageHistory & USAGE_SHADER_STORAGE_BUFFER)
106      brw->ctx.NewDriverState |= BRW_NEW_UNIFORM_BUFFER;
107   if (intel_obj->Base.UsageHistory & USAGE_TEXTURE_BUFFER)
108      brw->ctx.NewDriverState |= BRW_NEW_TEXTURE_BUFFER;
109   if (intel_obj->Base.UsageHistory & USAGE_ATOMIC_COUNTER_BUFFER)
110      brw->ctx.NewDriverState |= BRW_NEW_UNIFORM_BUFFER;
111
112   mark_buffer_inactive(intel_obj);
113   mark_buffer_invalid(intel_obj);
114}
115
116static void
117release_buffer(struct intel_buffer_object *intel_obj)
118{
119   brw_bo_unreference(intel_obj->buffer);
120   intel_obj->buffer = NULL;
121}
122
123/**
124 * The NewBufferObject() driver hook.
125 *
126 * Allocates a new intel_buffer_object structure and initializes it.
127 *
128 * There is some duplication between mesa's bufferobjects and our
129 * bufmgr buffers.  Both have an integer handle and a hashtable to
130 * lookup an opaque structure.  It would be nice if the handles and
131 * internal structure where somehow shared.
132 */
133static struct gl_buffer_object *
134brw_new_buffer_object(struct gl_context * ctx, GLuint name)
135{
136   struct intel_buffer_object *obj = CALLOC_STRUCT(intel_buffer_object);
137   if (!obj) {
138      _mesa_error_no_memory(__func__);
139      return NULL;
140   }
141
142   _mesa_initialize_buffer_object(ctx, &obj->Base, name);
143
144   obj->buffer = NULL;
145
146   return &obj->Base;
147}
148
149/**
150 * The DeleteBuffer() driver hook.
151 *
152 * Deletes a single OpenGL buffer object.  Used by glDeleteBuffers().
153 */
154static void
155brw_delete_buffer(struct gl_context * ctx, struct gl_buffer_object *obj)
156{
157   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
158
159   assert(intel_obj);
160
161   /* Buffer objects are automatically unmapped when deleting according
162    * to the spec, but Mesa doesn't do UnmapBuffer for us at context destroy
163    * (though it does if you call glDeleteBuffers)
164    */
165   _mesa_buffer_unmap_all_mappings(ctx, obj);
166
167   brw_bo_unreference(intel_obj->buffer);
168   _mesa_delete_buffer_object(ctx, obj);
169}
170
171
172/**
173 * The BufferData() driver hook.
174 *
175 * Implements glBufferData(), which recreates a buffer object's data store
176 * and populates it with the given data, if present.
177 *
178 * Any data that was previously stored in the buffer object is lost.
179 *
180 * \return true for success, false if out of memory
181 */
182static GLboolean
183brw_buffer_data(struct gl_context *ctx,
184                GLenum target,
185                GLsizeiptrARB size,
186                const GLvoid *data,
187                GLenum usage,
188                GLbitfield storageFlags,
189                struct gl_buffer_object *obj)
190{
191   struct brw_context *brw = brw_context(ctx);
192   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
193
194   /* Part of the ABI, but this function doesn't use it.
195    */
196   (void) target;
197
198   intel_obj->Base.Size = size;
199   intel_obj->Base.Usage = usage;
200   intel_obj->Base.StorageFlags = storageFlags;
201
202   assert(!obj->Mappings[MAP_USER].Pointer); /* Mesa should have unmapped it */
203   assert(!obj->Mappings[MAP_INTERNAL].Pointer);
204
205   if (intel_obj->buffer != NULL)
206      release_buffer(intel_obj);
207
208   if (size != 0) {
209      alloc_buffer_object(brw, intel_obj);
210      if (!intel_obj->buffer)
211         return false;
212
213      if (data != NULL) {
214         brw_bo_subdata(intel_obj->buffer, 0, size, data);
215         mark_buffer_valid_data(intel_obj, 0, size);
216      }
217   }
218
219   return true;
220}
221
222
223/**
224 * The BufferSubData() driver hook.
225 *
226 * Implements glBufferSubData(), which replaces a portion of the data in a
227 * buffer object.
228 *
229 * If the data range specified by (size + offset) extends beyond the end of
230 * the buffer or if data is NULL, no copy is performed.
231 */
232static void
233brw_buffer_subdata(struct gl_context *ctx,
234                   GLintptrARB offset,
235                   GLsizeiptrARB size,
236                   const GLvoid *data,
237                   struct gl_buffer_object *obj)
238{
239   struct brw_context *brw = brw_context(ctx);
240   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
241   bool busy;
242
243   if (size == 0)
244      return;
245
246   assert(intel_obj);
247
248   /* See if we can unsynchronized write the data into the user's BO. This
249    * avoids GPU stalls in unfortunately common user patterns (uploading
250    * sequentially into a BO, with draw calls in between each upload).
251    *
252    * Once we've hit this path, we mark this GL BO as preferring stalling to
253    * blits, so that we can hopefully hit this path again in the future
254    * (otherwise, an app that might occasionally stall but mostly not will end
255    * up with blitting all the time, at the cost of bandwidth)
256    */
257   if (offset + size <= intel_obj->gpu_active_start ||
258       intel_obj->gpu_active_end <= offset ||
259       offset + size <= intel_obj->valid_data_start ||
260       intel_obj->valid_data_end <= offset) {
261      void *map = brw_bo_map(brw, intel_obj->buffer, MAP_WRITE | MAP_ASYNC);
262      memcpy(map + offset, data, size);
263      brw_bo_unmap(intel_obj->buffer);
264
265      if (intel_obj->gpu_active_end > intel_obj->gpu_active_start)
266         intel_obj->prefer_stall_to_blit = true;
267
268      mark_buffer_valid_data(intel_obj, offset, size);
269      return;
270   }
271
272   busy =
273      brw_bo_busy(intel_obj->buffer) ||
274      brw_batch_references(&brw->batch, intel_obj->buffer);
275
276   if (busy) {
277      if (size == intel_obj->Base.Size ||
278          (intel_obj->valid_data_start >= offset &&
279           intel_obj->valid_data_end <= offset + size)) {
280         /* Replace the current busy bo so the subdata doesn't stall. */
281         brw_bo_unreference(intel_obj->buffer);
282         alloc_buffer_object(brw, intel_obj);
283      } else if (!intel_obj->prefer_stall_to_blit) {
284         perf_debug("Using a blit copy to avoid stalling on "
285                    "glBufferSubData(%ld, %ld) (%ldkb) to a busy "
286                    "(%d-%d) / valid (%d-%d) buffer object.\n",
287                    (long)offset, (long)offset + size, (long)(size/1024),
288                    intel_obj->gpu_active_start,
289                    intel_obj->gpu_active_end,
290                    intel_obj->valid_data_start,
291                    intel_obj->valid_data_end);
292         struct brw_bo *temp_bo =
293            brw_bo_alloc(brw->bufmgr, "subdata temp", size, BRW_MEMZONE_OTHER);
294
295         brw_bo_subdata(temp_bo, 0, size, data);
296
297         brw_blorp_copy_buffers(brw,
298                                temp_bo, 0,
299                                intel_obj->buffer, offset,
300                                size);
301         brw_emit_mi_flush(brw);
302
303         brw_bo_unreference(temp_bo);
304         mark_buffer_valid_data(intel_obj, offset, size);
305         return;
306      } else {
307         perf_debug("Stalling on glBufferSubData(%ld, %ld) (%ldkb) to a busy "
308                    "(%d-%d) buffer object.  Use glMapBufferRange() to "
309                    "avoid this.\n",
310                    (long)offset, (long)offset + size, (long)(size/1024),
311                    intel_obj->gpu_active_start,
312                    intel_obj->gpu_active_end);
313         intel_batchbuffer_flush(brw);
314      }
315   }
316
317   brw_bo_subdata(intel_obj->buffer, offset, size, data);
318   mark_buffer_inactive(intel_obj);
319   mark_buffer_valid_data(intel_obj, offset, size);
320}
321
322/* Typedef for memcpy function (used in brw_get_buffer_subdata below). */
323typedef void *(*mem_copy_fn)(void *dest, const void *src, size_t n);
324
325/**
326 * The GetBufferSubData() driver hook.
327 *
328 * Implements glGetBufferSubData(), which copies a subrange of a buffer
329 * object into user memory.
330 */
331static void
332brw_get_buffer_subdata(struct gl_context *ctx,
333                       GLintptrARB offset,
334                       GLsizeiptrARB size,
335                       GLvoid *data,
336                       struct gl_buffer_object *obj)
337{
338   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
339   struct brw_context *brw = brw_context(ctx);
340
341   assert(intel_obj);
342   if (brw_batch_references(&brw->batch, intel_obj->buffer)) {
343      intel_batchbuffer_flush(brw);
344   }
345
346   unsigned int map_flags = MAP_READ;
347   mem_copy_fn memcpy_fn = memcpy;
348#ifdef USE_SSE41
349   if (!intel_obj->buffer->cache_coherent && cpu_has_sse4_1) {
350      /* Rather than acquire a new WB mmaping of the buffer object and pull
351       * it into the CPU cache, keep using the WC mmap that we have for writes,
352       * and use the magic movntd instructions instead.
353       */
354      map_flags |= MAP_COHERENT;
355      memcpy_fn = (mem_copy_fn) _mesa_streaming_load_memcpy;
356   }
357#endif
358
359   void *map = brw_bo_map(brw, intel_obj->buffer, map_flags);
360   if (unlikely(!map)) {
361      _mesa_error_no_memory(__func__);
362      return;
363   }
364   memcpy_fn(data, map + offset, size);
365   brw_bo_unmap(intel_obj->buffer);
366
367   mark_buffer_inactive(intel_obj);
368}
369
370
371/**
372 * The MapBufferRange() driver hook.
373 *
374 * This implements both glMapBufferRange() and glMapBuffer().
375 *
376 * The goal of this extension is to allow apps to accumulate their rendering
377 * at the same time as they accumulate their buffer object.  Without it,
378 * you'd end up blocking on execution of rendering every time you mapped
379 * the buffer to put new data in.
380 *
381 * We support it in 3 ways: If unsynchronized, then don't bother
382 * flushing the batchbuffer before mapping the buffer, which can save blocking
383 * in many cases.  If we would still block, and they allow the whole buffer
384 * to be invalidated, then just allocate a new buffer to replace the old one.
385 * If not, and we'd block, and they allow the subrange of the buffer to be
386 * invalidated, then we can make a new little BO, let them write into that,
387 * and blit it into the real BO at unmap time.
388 */
389static void *
390brw_map_buffer_range(struct gl_context *ctx,
391                     GLintptr offset, GLsizeiptr length,
392                     GLbitfield access, struct gl_buffer_object *obj,
393                     gl_map_buffer_index index)
394{
395   struct brw_context *brw = brw_context(ctx);
396   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
397
398   assert(intel_obj);
399
400   STATIC_ASSERT(GL_MAP_UNSYNCHRONIZED_BIT == MAP_ASYNC);
401   STATIC_ASSERT(GL_MAP_WRITE_BIT == MAP_WRITE);
402   STATIC_ASSERT(GL_MAP_READ_BIT == MAP_READ);
403   STATIC_ASSERT(GL_MAP_PERSISTENT_BIT == MAP_PERSISTENT);
404   STATIC_ASSERT(GL_MAP_COHERENT_BIT == MAP_COHERENT);
405   assert((access & MAP_INTERNAL_MASK) == 0);
406
407   /* _mesa_MapBufferRange (GL entrypoint) sets these, but the vbo module also
408    * internally uses our functions directly.
409    */
410   obj->Mappings[index].Offset = offset;
411   obj->Mappings[index].Length = length;
412   obj->Mappings[index].AccessFlags = access;
413
414   if (intel_obj->buffer == NULL) {
415      obj->Mappings[index].Pointer = NULL;
416      return NULL;
417   }
418
419   /* If the access is synchronized (like a normal buffer mapping), then get
420    * things flushed out so the later mapping syncs appropriately through GEM.
421    * If the user doesn't care about existing buffer contents and mapping would
422    * cause us to block, then throw out the old buffer.
423    *
424    * If they set INVALIDATE_BUFFER, we can pitch the current contents to
425    * achieve the required synchronization.
426    */
427   if (!(access & GL_MAP_UNSYNCHRONIZED_BIT)) {
428      if (brw_batch_references(&brw->batch, intel_obj->buffer)) {
429         if (access & GL_MAP_INVALIDATE_BUFFER_BIT) {
430            brw_bo_unreference(intel_obj->buffer);
431            alloc_buffer_object(brw, intel_obj);
432         } else {
433            perf_debug("Stalling on the GPU for mapping a busy buffer "
434                       "object\n");
435            intel_batchbuffer_flush(brw);
436         }
437      } else if (brw_bo_busy(intel_obj->buffer) &&
438                 (access & GL_MAP_INVALIDATE_BUFFER_BIT)) {
439         brw_bo_unreference(intel_obj->buffer);
440         alloc_buffer_object(brw, intel_obj);
441      }
442   }
443
444   if (access & MAP_WRITE)
445      mark_buffer_valid_data(intel_obj, offset, length);
446
447   /* If the user is mapping a range of an active buffer object but
448    * doesn't require the current contents of that range, make a new
449    * BO, and we'll copy what they put in there out at unmap or
450    * FlushRange time.
451    *
452    * That is, unless they're looking for a persistent mapping -- we would
453    * need to do blits in the MemoryBarrier call, and it's easier to just do a
454    * GPU stall and do a mapping.
455    */
456   if (!(access & (GL_MAP_UNSYNCHRONIZED_BIT | GL_MAP_PERSISTENT_BIT)) &&
457       (access & GL_MAP_INVALIDATE_RANGE_BIT) &&
458       brw_bo_busy(intel_obj->buffer)) {
459      /* Ensure that the base alignment of the allocation meets the alignment
460       * guarantees the driver has advertised to the application.
461       */
462      const unsigned alignment = ctx->Const.MinMapBufferAlignment;
463
464      intel_obj->map_extra[index] = (uintptr_t) offset % alignment;
465      intel_obj->range_map_bo[index] =
466         brw_bo_alloc(brw->bufmgr, "BO blit temp",
467                      length + intel_obj->map_extra[index],
468                      BRW_MEMZONE_OTHER);
469      void *map = brw_bo_map(brw, intel_obj->range_map_bo[index], access);
470      obj->Mappings[index].Pointer = map + intel_obj->map_extra[index];
471      return obj->Mappings[index].Pointer;
472   }
473
474   void *map = brw_bo_map(brw, intel_obj->buffer, access);
475   if (!(access & GL_MAP_UNSYNCHRONIZED_BIT)) {
476      mark_buffer_inactive(intel_obj);
477   }
478
479   obj->Mappings[index].Pointer = map + offset;
480   return obj->Mappings[index].Pointer;
481}
482
483/**
484 * The FlushMappedBufferRange() driver hook.
485 *
486 * Implements glFlushMappedBufferRange(), which signifies that modifications
487 * have been made to a range of a mapped buffer, and it should be flushed.
488 *
489 * This is only used for buffers mapped with GL_MAP_FLUSH_EXPLICIT_BIT.
490 *
491 * Ideally we'd use a BO to avoid taking up cache space for the temporary
492 * data, but FlushMappedBufferRange may be followed by further writes to
493 * the pointer, so we would have to re-map after emitting our blit, which
494 * would defeat the point.
495 */
496static void
497brw_flush_mapped_buffer_range(struct gl_context *ctx,
498                              GLintptr offset, GLsizeiptr length,
499                              struct gl_buffer_object *obj,
500                              gl_map_buffer_index index)
501{
502   struct brw_context *brw = brw_context(ctx);
503   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
504
505   assert(obj->Mappings[index].AccessFlags & GL_MAP_FLUSH_EXPLICIT_BIT);
506
507   /* If we gave a direct mapping of the buffer instead of using a temporary,
508    * then there's nothing to do.
509    */
510   if (intel_obj->range_map_bo[index] == NULL)
511      return;
512
513   if (length == 0)
514      return;
515
516   /* Note that we're not unmapping our buffer while executing the blit.  We
517    * need to have a mapping still at the end of this call, since the user
518    * gets to make further modifications and glFlushMappedBufferRange() calls.
519    * This is safe, because:
520    *
521    * - On LLC platforms, we're using a CPU mapping that's coherent with the
522    *   GPU (except for the render caches), so the kernel doesn't need to do
523    *   any flushing work for us except for what happens at batch exec time
524    *   anyway.
525    *
526    * - On non-LLC platforms, we're using a GTT mapping that writes directly
527    *   to system memory (except for the chipset cache that gets flushed at
528    *   batch exec time).
529    *
530    * In both cases we don't need to stall for the previous blit to complete
531    * so we can re-map (and we definitely don't want to, since that would be
532    * slow): If the user edits a part of their buffer that's previously been
533    * blitted, then our lack of synchoronization is fine, because either
534    * they'll get some too-new data in the first blit and not do another blit
535    * of that area (but in that case the results are undefined), or they'll do
536    * another blit of that area and the complete newer data will land the
537    * second time.
538    */
539   brw_blorp_copy_buffers(brw,
540                          intel_obj->range_map_bo[index],
541                          intel_obj->map_extra[index] + offset,
542                          intel_obj->buffer,
543                          obj->Mappings[index].Offset + offset,
544                          length);
545   mark_buffer_gpu_usage(intel_obj,
546                         obj->Mappings[index].Offset + offset,
547                         length);
548   brw_emit_mi_flush(brw);
549}
550
551
552/**
553 * The UnmapBuffer() driver hook.
554 *
555 * Implements glUnmapBuffer().
556 */
557static GLboolean
558brw_unmap_buffer(struct gl_context *ctx,
559                 struct gl_buffer_object *obj,
560                 gl_map_buffer_index index)
561{
562   struct brw_context *brw = brw_context(ctx);
563   struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
564
565   assert(intel_obj);
566   assert(obj->Mappings[index].Pointer);
567   if (intel_obj->range_map_bo[index] != NULL) {
568      brw_bo_unmap(intel_obj->range_map_bo[index]);
569
570      if (!(obj->Mappings[index].AccessFlags & GL_MAP_FLUSH_EXPLICIT_BIT)) {
571         brw_blorp_copy_buffers(brw,
572                                intel_obj->range_map_bo[index],
573                                intel_obj->map_extra[index],
574                                intel_obj->buffer, obj->Mappings[index].Offset,
575                                obj->Mappings[index].Length);
576         mark_buffer_gpu_usage(intel_obj, obj->Mappings[index].Offset,
577                               obj->Mappings[index].Length);
578         brw_emit_mi_flush(brw);
579      }
580
581      /* Since we've emitted some blits to buffers that will (likely) be used
582       * in rendering operations in other cache domains in this batch, emit a
583       * flush.  Once again, we wish for a domain tracker in libdrm to cover
584       * usage inside of a batchbuffer.
585       */
586
587      brw_bo_unreference(intel_obj->range_map_bo[index]);
588      intel_obj->range_map_bo[index] = NULL;
589   } else if (intel_obj->buffer != NULL) {
590      brw_bo_unmap(intel_obj->buffer);
591   }
592   obj->Mappings[index].Pointer = NULL;
593   obj->Mappings[index].Offset = 0;
594   obj->Mappings[index].Length = 0;
595
596   return true;
597}
598
599/**
600 * Gets a pointer to the object's BO, and marks the given range as being used
601 * on the GPU.
602 *
603 * Anywhere that uses buffer objects in the pipeline should be using this to
604 * mark the range of the buffer that is being accessed by the pipeline.
605 */
606struct brw_bo *
607intel_bufferobj_buffer(struct brw_context *brw,
608                       struct intel_buffer_object *intel_obj,
609                       uint32_t offset, uint32_t size, bool write)
610{
611   /* This is needed so that things like transform feedback and texture buffer
612    * objects that need a BO but don't want to check that they exist for
613    * draw-time validation can just always get a BO from a GL buffer object.
614    */
615   if (intel_obj->buffer == NULL)
616      alloc_buffer_object(brw, intel_obj);
617
618   mark_buffer_gpu_usage(intel_obj, offset, size);
619
620   /* If writing, (conservatively) mark this section as having valid data. */
621   if (write)
622      mark_buffer_valid_data(intel_obj, offset, size);
623
624   return intel_obj->buffer;
625}
626
627/**
628 * The CopyBufferSubData() driver hook.
629 *
630 * Implements glCopyBufferSubData(), which copies a portion of one buffer
631 * object's data to another.  Independent source and destination offsets
632 * are allowed.
633 */
634static void
635brw_copy_buffer_subdata(struct gl_context *ctx,
636                        struct gl_buffer_object *src,
637                        struct gl_buffer_object *dst,
638                        GLintptr read_offset, GLintptr write_offset,
639                        GLsizeiptr size)
640{
641   struct brw_context *brw = brw_context(ctx);
642   struct intel_buffer_object *intel_src = intel_buffer_object(src);
643   struct intel_buffer_object *intel_dst = intel_buffer_object(dst);
644   struct brw_bo *src_bo, *dst_bo;
645
646   if (size == 0)
647      return;
648
649   dst_bo = intel_bufferobj_buffer(brw, intel_dst, write_offset, size, true);
650   src_bo = intel_bufferobj_buffer(brw, intel_src, read_offset, size, false);
651
652   brw_blorp_copy_buffers(brw,
653                          src_bo, read_offset,
654                          dst_bo, write_offset, size);
655
656   /* Since we've emitted some blits to buffers that will (likely) be used
657    * in rendering operations in other cache domains in this batch, emit a
658    * flush.  Once again, we wish for a domain tracker in libdrm to cover
659    * usage inside of a batchbuffer.
660    */
661   brw_emit_mi_flush(brw);
662}
663
664void
665intelInitBufferObjectFuncs(struct dd_function_table *functions)
666{
667   functions->NewBufferObject = brw_new_buffer_object;
668   functions->DeleteBuffer = brw_delete_buffer;
669   functions->BufferData = brw_buffer_data;
670   functions->BufferSubData = brw_buffer_subdata;
671   functions->GetBufferSubData = brw_get_buffer_subdata;
672   functions->MapBufferRange = brw_map_buffer_range;
673   functions->FlushMappedBufferRange = brw_flush_mapped_buffer_range;
674   functions->UnmapBuffer = brw_unmap_buffer;
675   functions->CopyBufferSubData = brw_copy_buffer_subdata;
676}
677