summaryrefslogtreecommitdiffstats
path: root/drivers/char/drm/drm_bufs.c
blob: 4c6191d231b8e06e20d876af0287d03df9335153 (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
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
/**
 * \file drm_bufs.h 
 * Generic buffer template
 * 
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Created: Thu Nov 23 03:10:50 2000 by gareth@valinux.com
 *
 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * 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, sublicense,
 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS 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 <linux/vmalloc.h>
#include "drmP.h"

/**
 * Compute size order.  Returns the exponent of the smaller power of two which
 * is greater or equal to given number.
 * 
 * \param size size.
 * \return order.
 *
 * \todo Can be made faster.
 */
int drm_order( unsigned long size )
{
	int order;
	unsigned long tmp;

	for (order = 0, tmp = size >> 1; tmp; tmp >>= 1, order++)
		;

	if (size & (size - 1))
		++order;

	return order;
}
EXPORT_SYMBOL(drm_order);

#ifdef CONFIG_COMPAT
/*
 * Used to allocate 32-bit handles for _DRM_SHM regions
 * The 0x10000000 value is chosen to be out of the way of
 * FB/register and GART physical addresses.
 */
static unsigned int map32_handle = 0x10000000;
#endif

/**
 * Ioctl to specify a range of memory that is available for mapping by a non-root process.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_map structure.
 * \return zero on success or a negative value on error.
 *
 * Adjusts the memory offset to its absolute value according to the mapping
 * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
 * applicable and if supported by the kernel.
 */
int drm_addmap( struct inode *inode, struct file *filp,
		 unsigned int cmd, unsigned long arg )
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_map_t *map;
	drm_map_t __user *argp = (void __user *)arg;
	drm_map_list_t *list;

	if ( !(filp->f_mode & 3) ) return -EACCES; /* Require read/write */

	map = drm_alloc( sizeof(*map), DRM_MEM_MAPS );
	if ( !map )
		return -ENOMEM;

	if ( copy_from_user( map, argp, sizeof(*map) ) ) {
		drm_free( map, sizeof(*map), DRM_MEM_MAPS );
		return -EFAULT;
	}

	/* Only allow shared memory to be removable since we only keep enough
	 * book keeping information about shared memory to allow for removal
	 * when processes fork.
	 */
	if ( (map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM ) {
		drm_free( map, sizeof(*map), DRM_MEM_MAPS );
		return -EINVAL;
	}
	DRM_DEBUG( "offset = 0x%08lx, size = 0x%08lx, type = %d\n",
		   map->offset, map->size, map->type );
	if ( (map->offset & (~PAGE_MASK)) || (map->size & (~PAGE_MASK)) ) {
		drm_free( map, sizeof(*map), DRM_MEM_MAPS );
		return -EINVAL;
	}
	map->mtrr   = -1;
	map->handle = NULL;

	switch ( map->type ) {
	case _DRM_REGISTERS:
	case _DRM_FRAME_BUFFER:
#if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__)
		if ( map->offset + map->size < map->offset ||
		     map->offset < virt_to_phys(high_memory) ) {
			drm_free( map, sizeof(*map), DRM_MEM_MAPS );
			return -EINVAL;
		}
#endif
#ifdef __alpha__
		map->offset += dev->hose->mem_space->start;
#endif
		if (drm_core_has_MTRR(dev)) {
			if ( map->type == _DRM_FRAME_BUFFER ||
			     (map->flags & _DRM_WRITE_COMBINING) ) {
				map->mtrr = mtrr_add( map->offset, map->size,
						      MTRR_TYPE_WRCOMB, 1 );
			}
		}
		if (map->type == _DRM_REGISTERS)
			map->handle = drm_ioremap( map->offset, map->size,
						    dev );
		break;

	case _DRM_SHM:
		map->handle = vmalloc_32(map->size);
		DRM_DEBUG( "%lu %d %p\n",
			   map->size, drm_order( map->size ), map->handle );
		if ( !map->handle ) {
			drm_free( map, sizeof(*map), DRM_MEM_MAPS );
			return -ENOMEM;
		}
		map->offset = (unsigned long)map->handle;
		if ( map->flags & _DRM_CONTAINS_LOCK ) {
			/* Prevent a 2nd X Server from creating a 2nd lock */
			if (dev->lock.hw_lock != NULL) {
				vfree( map->handle );
				drm_free( map, sizeof(*map), DRM_MEM_MAPS );
				return -EBUSY;
			}
			dev->sigdata.lock =
			dev->lock.hw_lock = map->handle; /* Pointer to lock */
		}
		break;
	case _DRM_AGP:
		if (drm_core_has_AGP(dev)) {
#ifdef __alpha__
			map->offset += dev->hose->mem_space->start;
#endif
			map->offset += dev->agp->base;
			map->mtrr   = dev->agp->agp_mtrr; /* for getmap */
		}
		break;
	case _DRM_SCATTER_GATHER:
		if (!dev->sg) {
			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
			return -EINVAL;
		}
		map->offset += dev->sg->handle;
		break;

	default:
		drm_free( map, sizeof(*map), DRM_MEM_MAPS );
		return -EINVAL;
	}

	list = drm_alloc(sizeof(*list), DRM_MEM_MAPS);
	if(!list) {
		drm_free(map, sizeof(*map), DRM_MEM_MAPS);
		return -EINVAL;
	}
	memset(list, 0, sizeof(*list));
	list->map = map;

	down(&dev->struct_sem);
	list_add(&list->head, &dev->maplist->head);
#ifdef CONFIG_COMPAT
	/* Assign a 32-bit handle for _DRM_SHM mappings */
	/* We do it here so that dev->struct_sem protects the increment */
	if (map->type == _DRM_SHM)
		map->offset = map32_handle += PAGE_SIZE;
#endif
 	up(&dev->struct_sem);

	if ( copy_to_user( argp, map, sizeof(*map) ) )
		return -EFAULT;
	if (copy_to_user(&argp->handle, &map->offset, sizeof(map->offset)))
		return -EFAULT;
	return 0;
}


/**
 * Remove a map private from list and deallocate resources if the mapping
 * isn't in use.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_map_t structure.
 * \return zero on success or a negative value on error.
 *
 * Searches the map on drm_device::maplist, removes it from the list, see if
 * its being used, and free any associate resource (such as MTRR's) if it's not
 * being on use.
 *
 * \sa addmap().
 */
int drm_rmmap(struct inode *inode, struct file *filp,
	       unsigned int cmd, unsigned long arg)
{
	drm_file_t	*priv	= filp->private_data;
	drm_device_t	*dev	= priv->head->dev;
	struct list_head *list;
	drm_map_list_t *r_list = NULL;
	drm_vma_entry_t *pt, *prev;
	drm_map_t *map;
	drm_map_t request;
	int found_maps = 0;

	if (copy_from_user(&request, (drm_map_t __user *)arg,
			   sizeof(request))) {
		return -EFAULT;
	}

	down(&dev->struct_sem);
	list = &dev->maplist->head;
	list_for_each(list, &dev->maplist->head) {
		r_list = list_entry(list, drm_map_list_t, head);

		if(r_list->map &&
		   r_list->map->offset == (unsigned long) request.handle &&
		   r_list->map->flags & _DRM_REMOVABLE) break;
	}

	/* List has wrapped around to the head pointer, or its empty we didn't
	 * find anything.
	 */
	if(list == (&dev->maplist->head)) {
		up(&dev->struct_sem);
		return -EINVAL;
	}
	map = r_list->map;
	list_del(list);
	drm_free(list, sizeof(*list), DRM_MEM_MAPS);

	for (pt = dev->vmalist, prev = NULL; pt; prev = pt, pt = pt->next) {
		if (pt->vma->vm_private_data == map) found_maps++;
	}

	if(!found_maps) {
		switch (map->type) {
		case _DRM_REGISTERS:
		case _DRM_FRAME_BUFFER:
		  if (drm_core_has_MTRR(dev)) {
				if (map->mtrr >= 0) {
					int retcode;
					retcode = mtrr_del(map->mtrr,
							   map->offset,
							   map->size);
					DRM_DEBUG("mtrr_del = %d\n", retcode);
				}
			}
			drm_ioremapfree(map->handle, map->size, dev);
			break;
		case _DRM_SHM:
			vfree(map->handle);
			break;
		case _DRM_AGP:
		case _DRM_SCATTER_GATHER:
			break;
		}
		drm_free(map, sizeof(*map), DRM_MEM_MAPS);
	}
	up(&dev->struct_sem);
	return 0;
}

/**
 * Cleanup after an error on one of the addbufs() functions.
 *
 * \param entry buffer entry where the error occurred.
 *
 * Frees any pages and buffers associated with the given entry.
 */
static void drm_cleanup_buf_error(drm_device_t *dev, drm_buf_entry_t *entry)
{
	int i;

	if (entry->seg_count) {
		for (i = 0; i < entry->seg_count; i++) {
			if (entry->seglist[i]) {
				drm_free_pages(entry->seglist[i],
					        entry->page_order,
					        DRM_MEM_DMA);
			}
		}
		drm_free(entry->seglist,
			  entry->seg_count *
			  sizeof(*entry->seglist),
			  DRM_MEM_SEGS);

		entry->seg_count = 0;
	}

   	if (entry->buf_count) {
	   	for (i = 0; i < entry->buf_count; i++) {
			if (entry->buflist[i].dev_private) {
				drm_free(entry->buflist[i].dev_private,
					  entry->buflist[i].dev_priv_size,
					  DRM_MEM_BUFS);
			}
		}
		drm_free(entry->buflist,
			  entry->buf_count *
			  sizeof(*entry->buflist),
			  DRM_MEM_BUFS);

		entry->buf_count = 0;
	}
}

#if __OS_HAS_AGP
/**
 * Add AGP buffers for DMA transfers (ioctl).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_buf_desc_t request.
 * \return zero on success or a negative number on failure.
 * 
 * After some sanity checks creates a drm_buf structure for each buffer and
 * reallocates the buffer list of the same size order to accommodate the new
 * buffers.
 */
static int drm_addbufs_agp( struct inode *inode, struct file *filp,
			    unsigned int cmd, unsigned long arg )
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_desc_t request;
	drm_buf_entry_t *entry;
	drm_buf_t *buf;
	unsigned long offset;
	unsigned long agp_offset;
	int count;
	int order;
	int size;
	int alignment;
	int page_order;
	int total;
	int byte_count;
	int i;
	drm_buf_t **temp_buflist;
	drm_buf_desc_t __user *argp = (void __user *)arg;

	if ( !dma ) return -EINVAL;

	if ( copy_from_user( &request, argp,
			     sizeof(request) ) )
		return -EFAULT;

	count = request.count;
	order = drm_order( request.size );
	size = 1 << order;

	alignment  = (request.flags & _DRM_PAGE_ALIGN)
		? PAGE_ALIGN(size) : size;
	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
	total = PAGE_SIZE << page_order;

	byte_count = 0;
	agp_offset = dev->agp->base + request.agp_start;

	DRM_DEBUG( "count:      %d\n",  count );
	DRM_DEBUG( "order:      %d\n",  order );
	DRM_DEBUG( "size:       %d\n",  size );
	DRM_DEBUG( "agp_offset: %lu\n", agp_offset );
	DRM_DEBUG( "alignment:  %d\n",  alignment );
	DRM_DEBUG( "page_order: %d\n",  page_order );
	DRM_DEBUG( "total:      %d\n",  total );

	if ( order < DRM_MIN_ORDER || order > DRM_MAX_ORDER ) return -EINVAL;
	if ( dev->queue_count ) return -EBUSY; /* Not while in use */

	spin_lock( &dev->count_lock );
	if ( dev->buf_use ) {
		spin_unlock( &dev->count_lock );
		return -EBUSY;
	}
	atomic_inc( &dev->buf_alloc );
	spin_unlock( &dev->count_lock );

	down( &dev->struct_sem );
	entry = &dma->bufs[order];
	if ( entry->buf_count ) {
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM; /* May only call once for each order */
	}

	if (count < 0 || count > 4096) {
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -EINVAL;
	}

	entry->buflist = drm_alloc( count * sizeof(*entry->buflist),
				    DRM_MEM_BUFS );
	if ( !entry->buflist ) {
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM;
	}
	memset( entry->buflist, 0, count * sizeof(*entry->buflist) );

	entry->buf_size = size;
	entry->page_order = page_order;

	offset = 0;

	while ( entry->buf_count < count ) {
		buf          = &entry->buflist[entry->buf_count];
		buf->idx     = dma->buf_count + entry->buf_count;
		buf->total   = alignment;
		buf->order   = order;
		buf->used    = 0;

		buf->offset  = (dma->byte_count + offset);
		buf->bus_address = agp_offset + offset;
		buf->address = (void *)(agp_offset + offset);
		buf->next    = NULL;
		buf->waiting = 0;
		buf->pending = 0;
		init_waitqueue_head( &buf->dma_wait );
		buf->filp    = NULL;

		buf->dev_priv_size = dev->driver->dev_priv_size;
		buf->dev_private = drm_alloc( buf->dev_priv_size,
					       DRM_MEM_BUFS );
		if(!buf->dev_private) {
			/* Set count correctly so we free the proper amount. */
			entry->buf_count = count;
			drm_cleanup_buf_error(dev,entry);
			up( &dev->struct_sem );
			atomic_dec( &dev->buf_alloc );
			return -ENOMEM;
		}
		memset( buf->dev_private, 0, buf->dev_priv_size );

		DRM_DEBUG( "buffer %d @ %p\n",
			   entry->buf_count, buf->address );

		offset += alignment;
		entry->buf_count++;
		byte_count += PAGE_SIZE << page_order;
	}

	DRM_DEBUG( "byte_count: %d\n", byte_count );

	temp_buflist = drm_realloc( dma->buflist,
				     dma->buf_count * sizeof(*dma->buflist),
				     (dma->buf_count + entry->buf_count)
				     * sizeof(*dma->buflist),
				     DRM_MEM_BUFS );
	if(!temp_buflist) {
		/* Free the entry because it isn't valid */
		drm_cleanup_buf_error(dev,entry);
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM;
	}
	dma->buflist = temp_buflist;

	for ( i = 0 ; i < entry->buf_count ; i++ ) {
		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
	}

	dma->buf_count += entry->buf_count;
	dma->byte_count += byte_count;

	DRM_DEBUG( "dma->buf_count : %d\n", dma->buf_count );
	DRM_DEBUG( "entry->buf_count : %d\n", entry->buf_count );

	up( &dev->struct_sem );

	request.count = entry->buf_count;
	request.size = size;

	if ( copy_to_user( argp, &request, sizeof(request) ) )
		return -EFAULT;

	dma->flags = _DRM_DMA_USE_AGP;

	atomic_dec( &dev->buf_alloc );
	return 0;
}
#endif /* __OS_HAS_AGP */

static int drm_addbufs_pci( struct inode *inode, struct file *filp,
			    unsigned int cmd, unsigned long arg )
{
   	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_desc_t request;
	int count;
	int order;
	int size;
	int total;
	int page_order;
	drm_buf_entry_t *entry;
	unsigned long page;
	drm_buf_t *buf;
	int alignment;
	unsigned long offset;
	int i;
	int byte_count;
	int page_count;
	unsigned long *temp_pagelist;
	drm_buf_t **temp_buflist;
	drm_buf_desc_t __user *argp = (void __user *)arg;

	if (!drm_core_check_feature(dev, DRIVER_PCI_DMA)) return -EINVAL;
	if ( !dma ) return -EINVAL;

	if ( copy_from_user( &request, argp, sizeof(request) ) )
		return -EFAULT;

	count = request.count;
	order = drm_order( request.size );
	size = 1 << order;

	DRM_DEBUG( "count=%d, size=%d (%d), order=%d, queue_count=%d\n",
		   request.count, request.size, size,
		   order, dev->queue_count );

	if ( order < DRM_MIN_ORDER || order > DRM_MAX_ORDER ) return -EINVAL;
	if ( dev->queue_count ) return -EBUSY; /* Not while in use */

	alignment = (request.flags & _DRM_PAGE_ALIGN)
		? PAGE_ALIGN(size) : size;
	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
	total = PAGE_SIZE << page_order;

	spin_lock( &dev->count_lock );
	if ( dev->buf_use ) {
		spin_unlock( &dev->count_lock );
		return -EBUSY;
	}
	atomic_inc( &dev->buf_alloc );
	spin_unlock( &dev->count_lock );

	down( &dev->struct_sem );
	entry = &dma->bufs[order];
	if ( entry->buf_count ) {
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM;	/* May only call once for each order */
	}

	if (count < 0 || count > 4096) {
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -EINVAL;
	}

	entry->buflist = drm_alloc( count * sizeof(*entry->buflist),
				    DRM_MEM_BUFS );
	if ( !entry->buflist ) {
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM;
	}
	memset( entry->buflist, 0, count * sizeof(*entry->buflist) );

	entry->seglist = drm_alloc( count * sizeof(*entry->seglist),
				    DRM_MEM_SEGS );
	if ( !entry->seglist ) {
		drm_free( entry->buflist,
			  count * sizeof(*entry->buflist),
			  DRM_MEM_BUFS );
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM;
	}
	memset( entry->seglist, 0, count * sizeof(*entry->seglist) );

	/* Keep the original pagelist until we know all the allocations
	 * have succeeded
	 */
	temp_pagelist = drm_alloc( (dma->page_count + (count << page_order))
				    * sizeof(*dma->pagelist),
				    DRM_MEM_PAGES );
	if (!temp_pagelist) {
		drm_free( entry->buflist,
			   count * sizeof(*entry->buflist),
			   DRM_MEM_BUFS );
		drm_free( entry->seglist,
			   count * sizeof(*entry->seglist),
			   DRM_MEM_SEGS );
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM;
	}
	memcpy(temp_pagelist,
	       dma->pagelist,
	       dma->page_count * sizeof(*dma->pagelist));
	DRM_DEBUG( "pagelist: %d entries\n",
		   dma->page_count + (count << page_order) );

	entry->buf_size	= size;
	entry->page_order = page_order;
	byte_count = 0;
	page_count = 0;

	while ( entry->buf_count < count ) {
		page = drm_alloc_pages( page_order, DRM_MEM_DMA );
		if ( !page ) {
			/* Set count correctly so we free the proper amount. */
			entry->buf_count = count;
			entry->seg_count = count;
			drm_cleanup_buf_error(dev, entry);
			drm_free( temp_pagelist,
				   (dma->page_count + (count << page_order))
				   * sizeof(*dma->pagelist),
				   DRM_MEM_PAGES );
			up( &dev->struct_sem );
			atomic_dec( &dev->buf_alloc );
			return -ENOMEM;
		}
		entry->seglist[entry->seg_count++] = page;
		for ( i = 0 ; i < (1 << page_order) ; i++ ) {
			DRM_DEBUG( "page %d @ 0x%08lx\n",
				   dma->page_count + page_count,
				   page + PAGE_SIZE * i );
			temp_pagelist[dma->page_count + page_count++]
				= page + PAGE_SIZE * i;
		}
		for ( offset = 0 ;
		      offset + size <= total && entry->buf_count < count ;
		      offset += alignment, ++entry->buf_count ) {
			buf	     = &entry->buflist[entry->buf_count];
			buf->idx     = dma->buf_count + entry->buf_count;
			buf->total   = alignment;
			buf->order   = order;
			buf->used    = 0;
			buf->offset  = (dma->byte_count + byte_count + offset);
			buf->address = (void *)(page + offset);
			buf->next    = NULL;
			buf->waiting = 0;
			buf->pending = 0;
			init_waitqueue_head( &buf->dma_wait );
			buf->filp    = NULL;

			buf->dev_priv_size = dev->driver->dev_priv_size;
			buf->dev_private = drm_alloc( buf->dev_priv_size,
						       DRM_MEM_BUFS );
			if(!buf->dev_private) {
				/* Set count correctly so we free the proper amount. */
				entry->buf_count = count;
				entry->seg_count = count;
				drm_cleanup_buf_error(dev,entry);
				drm_free( temp_pagelist,
					   (dma->page_count + (count << page_order))
					   * sizeof(*dma->pagelist),
					   DRM_MEM_PAGES );
				up( &dev->struct_sem );
				atomic_dec( &dev->buf_alloc );
				return -ENOMEM;
			}
			memset( buf->dev_private, 0, buf->dev_priv_size );

			DRM_DEBUG( "buffer %d @ %p\n",
				   entry->buf_count, buf->address );
		}
		byte_count += PAGE_SIZE << page_order;
	}

	temp_buflist = drm_realloc( dma->buflist,
				     dma->buf_count * sizeof(*dma->buflist),
				     (dma->buf_count + entry->buf_count)
				     * sizeof(*dma->buflist),
				     DRM_MEM_BUFS );
	if (!temp_buflist) {
		/* Free the entry because it isn't valid */
		drm_cleanup_buf_error(dev,entry);
		drm_free( temp_pagelist,
			   (dma->page_count + (count << page_order))
			   * sizeof(*dma->pagelist),
			   DRM_MEM_PAGES );
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM;
	}
	dma->buflist = temp_buflist;

	for ( i = 0 ; i < entry->buf_count ; i++ ) {
		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
	}

	/* No allocations failed, so now we can replace the orginal pagelist
	 * with the new one.
	 */
	if (dma->page_count) {
		drm_free(dma->pagelist,
			  dma->page_count * sizeof(*dma->pagelist),
			  DRM_MEM_PAGES);
	}
	dma->pagelist = temp_pagelist;

	dma->buf_count += entry->buf_count;
	dma->seg_count += entry->seg_count;
	dma->page_count += entry->seg_count << page_order;
	dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);

	up( &dev->struct_sem );

	request.count = entry->buf_count;
	request.size = size;

	if ( copy_to_user( argp, &request, sizeof(request) ) )
		return -EFAULT;

	atomic_dec( &dev->buf_alloc );
	return 0;

}

static int drm_addbufs_sg( struct inode *inode, struct file *filp,
			   unsigned int cmd, unsigned long arg )
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_desc_t __user *argp = (void __user *)arg;
	drm_buf_desc_t request;
	drm_buf_entry_t *entry;
	drm_buf_t *buf;
	unsigned long offset;
	unsigned long agp_offset;
	int count;
	int order;
	int size;
	int alignment;
	int page_order;
	int total;
	int byte_count;
	int i;
	drm_buf_t **temp_buflist;

	if (!drm_core_check_feature(dev, DRIVER_SG)) return -EINVAL;
	
	if ( !dma ) return -EINVAL;

	if ( copy_from_user( &request, argp, sizeof(request) ) )
		return -EFAULT;

	count = request.count;
	order = drm_order( request.size );
	size = 1 << order;

	alignment  = (request.flags & _DRM_PAGE_ALIGN)
			? PAGE_ALIGN(size) : size;
	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
	total = PAGE_SIZE << page_order;

	byte_count = 0;
	agp_offset = request.agp_start;

	DRM_DEBUG( "count:      %d\n",  count );
	DRM_DEBUG( "order:      %d\n",  order );
	DRM_DEBUG( "size:       %d\n",  size );
	DRM_DEBUG( "agp_offset: %lu\n", agp_offset );
	DRM_DEBUG( "alignment:  %d\n",  alignment );
	DRM_DEBUG( "page_order: %d\n",  page_order );
	DRM_DEBUG( "total:      %d\n",  total );

	if ( order < DRM_MIN_ORDER || order > DRM_MAX_ORDER ) return -EINVAL;
	if ( dev->queue_count ) return -EBUSY; /* Not while in use */

	spin_lock( &dev->count_lock );
	if ( dev->buf_use ) {
		spin_unlock( &dev->count_lock );
		return -EBUSY;
	}
	atomic_inc( &dev->buf_alloc );
	spin_unlock( &dev->count_lock );

	down( &dev->struct_sem );
	entry = &dma->bufs[order];
	if ( entry->buf_count ) {
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM; /* May only call once for each order */
	}

	if (count < 0 || count > 4096) {
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -EINVAL;
	}

	entry->buflist = drm_alloc( count * sizeof(*entry->buflist),
				     DRM_MEM_BUFS );
	if ( !entry->buflist ) {
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM;
	}
	memset( entry->buflist, 0, count * sizeof(*entry->buflist) );

	entry->buf_size = size;
	entry->page_order = page_order;

	offset = 0;

	while ( entry->buf_count < count ) {
		buf          = &entry->buflist[entry->buf_count];
		buf->idx     = dma->buf_count + entry->buf_count;
		buf->total   = alignment;
		buf->order   = order;
		buf->used    = 0;

		buf->offset  = (dma->byte_count + offset);
		buf->bus_address = agp_offset + offset;
		buf->address = (void *)(agp_offset + offset + dev->sg->handle);
		buf->next    = NULL;
		buf->waiting = 0;
		buf->pending = 0;
		init_waitqueue_head( &buf->dma_wait );
		buf->filp    = NULL;

		buf->dev_priv_size = dev->driver->dev_priv_size;
		buf->dev_private = drm_alloc( buf->dev_priv_size,
					       DRM_MEM_BUFS );
		if(!buf->dev_private) {
			/* Set count correctly so we free the proper amount. */
			entry->buf_count = count;
			drm_cleanup_buf_error(dev,entry);
			up( &dev->struct_sem );
			atomic_dec( &dev->buf_alloc );
			return -ENOMEM;
		}

		memset( buf->dev_private, 0, buf->dev_priv_size );

		DRM_DEBUG( "buffer %d @ %p\n",
			   entry->buf_count, buf->address );

		offset += alignment;
		entry->buf_count++;
		byte_count += PAGE_SIZE << page_order;
	}

	DRM_DEBUG( "byte_count: %d\n", byte_count );

	temp_buflist = drm_realloc( dma->buflist,
				     dma->buf_count * sizeof(*dma->buflist),
				     (dma->buf_count + entry->buf_count)
				     * sizeof(*dma->buflist),
				     DRM_MEM_BUFS );
	if(!temp_buflist) {
		/* Free the entry because it isn't valid */
		drm_cleanup_buf_error(dev,entry);
		up( &dev->struct_sem );
		atomic_dec( &dev->buf_alloc );
		return -ENOMEM;
	}
	dma->buflist = temp_buflist;

	for ( i = 0 ; i < entry->buf_count ; i++ ) {
		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
	}

	dma->buf_count += entry->buf_count;
	dma->byte_count += byte_count;

	DRM_DEBUG( "dma->buf_count : %d\n", dma->buf_count );
	DRM_DEBUG( "entry->buf_count : %d\n", entry->buf_count );

	up( &dev->struct_sem );

	request.count = entry->buf_count;
	request.size = size;

	if ( copy_to_user( argp, &request, sizeof(request) ) )
		return -EFAULT;

	dma->flags = _DRM_DMA_USE_SG;

	atomic_dec( &dev->buf_alloc );
	return 0;
}

/**
 * Add buffers for DMA transfers (ioctl).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_buf_desc_t request.
 * \return zero on success or a negative number on failure.
 *
 * According with the memory type specified in drm_buf_desc::flags and the
 * build options, it dispatches the call either to addbufs_agp(),
 * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
 * PCI memory respectively.
 */
int drm_addbufs( struct inode *inode, struct file *filp,
		  unsigned int cmd, unsigned long arg )
{
	drm_buf_desc_t request;
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	
	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		return -EINVAL;

	if ( copy_from_user( &request, (drm_buf_desc_t __user *)arg,
			     sizeof(request) ) )
		return -EFAULT;

#if __OS_HAS_AGP
	if ( request.flags & _DRM_AGP_BUFFER )
		return drm_addbufs_agp( inode, filp, cmd, arg );
	else
#endif
	if ( request.flags & _DRM_SG_BUFFER )
		return drm_addbufs_sg( inode, filp, cmd, arg );
	else
		return drm_addbufs_pci( inode, filp, cmd, arg );
}


/**
 * Get information about the buffer mappings.
 *
 * This was originally mean for debugging purposes, or by a sophisticated
 * client library to determine how best to use the available buffers (e.g.,
 * large buffers can be used for image transfer).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_buf_info structure.
 * \return zero on success or a negative number on failure.
 *
 * Increments drm_device::buf_use while holding the drm_device::count_lock
 * lock, preventing of allocating more buffers after this call. Information
 * about each requested buffer is then copied into user space.
 */
int drm_infobufs( struct inode *inode, struct file *filp,
		   unsigned int cmd, unsigned long arg )
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_info_t request;
	drm_buf_info_t __user *argp = (void __user *)arg;
	int i;
	int count;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		return -EINVAL;

	if ( !dma ) return -EINVAL;

	spin_lock( &dev->count_lock );
	if ( atomic_read( &dev->buf_alloc ) ) {
		spin_unlock( &dev->count_lock );
		return -EBUSY;
	}
	++dev->buf_use;		/* Can't allocate more after this call */
	spin_unlock( &dev->count_lock );

	if ( copy_from_user( &request, argp, sizeof(request) ) )
		return -EFAULT;

	for ( i = 0, count = 0 ; i < DRM_MAX_ORDER + 1 ; i++ ) {
		if ( dma->bufs[i].buf_count ) ++count;
	}

	DRM_DEBUG( "count = %d\n", count );

	if ( request.count >= count ) {
		for ( i = 0, count = 0 ; i < DRM_MAX_ORDER + 1 ; i++ ) {
			if ( dma->bufs[i].buf_count ) {
				drm_buf_desc_t __user *to = &request.list[count];
				drm_buf_entry_t *from = &dma->bufs[i];
				drm_freelist_t *list = &dma->bufs[i].freelist;
				if ( copy_to_user( &to->count,
						   &from->buf_count,
						   sizeof(from->buf_count) ) ||
				     copy_to_user( &to->size,
						   &from->buf_size,
						   sizeof(from->buf_size) ) ||
				     copy_to_user( &to->low_mark,
						   &list->low_mark,
						   sizeof(list->low_mark) ) ||
				     copy_to_user( &to->high_mark,
						   &list->high_mark,
						   sizeof(list->high_mark) ) )
					return -EFAULT;

				DRM_DEBUG( "%d %d %d %d %d\n",
					   i,
					   dma->bufs[i].buf_count,
					   dma->bufs[i].buf_size,
					   dma->bufs[i].freelist.low_mark,
					   dma->bufs[i].freelist.high_mark );
				++count;
			}
		}
	}
	request.count = count;

	if ( copy_to_user( argp, &request, sizeof(request) ) )
		return -EFAULT;

	return 0;
}

/**
 * Specifies a low and high water mark for buffer allocation
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg a pointer to a drm_buf_desc structure.
 * \return zero on success or a negative number on failure.
 *
 * Verifies that the size order is bounded between the admissible orders and
 * updates the respective drm_device_dma::bufs entry low and high water mark.
 *
 * \note This ioctl is deprecated and mostly never used.
 */
int drm_markbufs( struct inode *inode, struct file *filp,
		   unsigned int cmd, unsigned long arg )
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_desc_t request;
	int order;
	drm_buf_entry_t *entry;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		return -EINVAL;

	if ( !dma ) return -EINVAL;

	if ( copy_from_user( &request,
			     (drm_buf_desc_t __user *)arg,
			     sizeof(request) ) )
		return -EFAULT;

	DRM_DEBUG( "%d, %d, %d\n",
		   request.size, request.low_mark, request.high_mark );
	order = drm_order( request.size );
	if ( order < DRM_MIN_ORDER || order > DRM_MAX_ORDER ) return -EINVAL;
	entry = &dma->bufs[order];

	if ( request.low_mark < 0 || request.low_mark > entry->buf_count )
		return -EINVAL;
	if ( request.high_mark < 0 || request.high_mark > entry->buf_count )
		return -EINVAL;

	entry->freelist.low_mark  = request.low_mark;
	entry->freelist.high_mark = request.high_mark;

	return 0;
}

/**
 * Unreserve the buffers in list, previously reserved using drmDMA. 
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_buf_free structure.
 * \return zero on success or a negative number on failure.
 * 
 * Calls free_buffer() for each used buffer.
 * This function is primarily used for debugging.
 */
int drm_freebufs( struct inode *inode, struct file *filp,
		   unsigned int cmd, unsigned long arg )
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_free_t request;
	int i;
	int idx;
	drm_buf_t *buf;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		return -EINVAL;

	if ( !dma ) return -EINVAL;

	if ( copy_from_user( &request,
			     (drm_buf_free_t __user *)arg,
			     sizeof(request) ) )
		return -EFAULT;

	DRM_DEBUG( "%d\n", request.count );
	for ( i = 0 ; i < request.count ; i++ ) {
		if ( copy_from_user( &idx,
				     &request.list[i],
				     sizeof(idx) ) )
			return -EFAULT;
		if ( idx < 0 || idx >= dma->buf_count ) {
			DRM_ERROR( "Index %d (of %d max)\n",
				   idx, dma->buf_count - 1 );
			return -EINVAL;
		}
		buf = dma->buflist[idx];
		if ( buf->filp != filp ) {
			DRM_ERROR( "Process %d freeing buffer not owned\n",
				   current->pid );
			return -EINVAL;
		}
		drm_free_buffer( dev, buf );
	}

	return 0;
}

/**
 * Maps all of the DMA buffers into client-virtual space (ioctl).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_buf_map structure.
 * \return zero on success or a negative number on failure.
 *
 * Maps the AGP or SG buffer region with do_mmap(), and copies information
 * about each buffer into user space. The PCI buffers are already mapped on the
 * addbufs_pci() call.
 */
int drm_mapbufs( struct inode *inode, struct file *filp,
		  unsigned int cmd, unsigned long arg )
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_map_t __user *argp = (void __user *)arg;
	int retcode = 0;
	const int zero = 0;
	unsigned long virtual;
	unsigned long address;
	drm_buf_map_t request;
	int i;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		return -EINVAL;

	if ( !dma ) return -EINVAL;

	spin_lock( &dev->count_lock );
	if ( atomic_read( &dev->buf_alloc ) ) {
		spin_unlock( &dev->count_lock );
		return -EBUSY;
	}
	dev->buf_use++;		/* Can't allocate more after this call */
	spin_unlock( &dev->count_lock );

	if ( copy_from_user( &request, argp, sizeof(request) ) )
		return -EFAULT;

	if ( request.count >= dma->buf_count ) {
		if ((drm_core_has_AGP(dev) && (dma->flags & _DRM_DMA_USE_AGP)) ||
		    (drm_core_check_feature(dev, DRIVER_SG) && (dma->flags & _DRM_DMA_USE_SG)) ) {
			drm_map_t *map = dev->agp_buffer_map;

			if ( !map ) {
				retcode = -EINVAL;
				goto done;
			}

#if LINUX_VERSION_CODE <= 0x020402
			down( &current->mm->mmap_sem );
#else
			down_write( &current->mm->mmap_sem );
#endif
			virtual = do_mmap( filp, 0, map->size,
					   PROT_READ | PROT_WRITE,
					   MAP_SHARED,
					   (unsigned long)map->offset );
#if LINUX_VERSION_CODE <= 0x020402
			up( &current->mm->mmap_sem );
#else
			up_write( &current->mm->mmap_sem );
#endif
		} else {
#if LINUX_VERSION_CODE <= 0x020402
			down( &current->mm->mmap_sem );
#else
			down_write( &current->mm->mmap_sem );
#endif
			virtual = do_mmap( filp, 0, dma->byte_count,
					   PROT_READ | PROT_WRITE,
					   MAP_SHARED, 0 );
#if LINUX_VERSION_CODE <= 0x020402
			up( &current->mm->mmap_sem );
#else
			up_write( &current->mm->mmap_sem );
#endif
		}
		if ( virtual > -1024UL ) {
			/* Real error */
			retcode = (signed long)virtual;
			goto done;
		}
		request.virtual = (void __user *)virtual;

		for ( i = 0 ; i < dma->buf_count ; i++ ) {
			if ( copy_to_user( &request.list[i].idx,
					   &dma->buflist[i]->idx,
					   sizeof(request.list[0].idx) ) ) {
				retcode = -EFAULT;
				goto done;
			}
			if ( copy_to_user( &request.list[i].total,
					   &dma->buflist[i]->total,
					   sizeof(request.list[0].total) ) ) {
				retcode = -EFAULT;
				goto done;
			}
			if ( copy_to_user( &request.list[i].used,
					   &zero,
					   sizeof(zero) ) ) {
				retcode = -EFAULT;
				goto done;
			}
			address = virtual + dma->buflist[i]->offset; /* *** */
			if ( copy_to_user( &request.list[i].address,
					   &address,
					   sizeof(address) ) ) {
				retcode = -EFAULT;
				goto done;
			}
		}
	}
 done:
	request.count = dma->buf_count;
	DRM_DEBUG( "%d buffers, retcode = %d\n", request.count, retcode );

	if ( copy_to_user( argp, &request, sizeof(request) ) )
		return -EFAULT;

	return retcode;
}

OpenPOWER on IntegriCloud