summaryrefslogtreecommitdiff
path: root/linux-core/drm_agpsupport.c
blob: 79d9a835434ee75cdbb6f2f901795fcf35f69f2c (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
/**
 * \file drm_agpsupport.c
 * DRM support for AGP/GART backend
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Copyright 1999 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 "drmP.h"
#include <linux/module.h>

#if __OS_HAS_AGP

/**
 * Get AGP information.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a (output) drm_agp_info structure.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the AGP device has been initialized and acquired and fills in the
 * drm_agp_info structure with the information in drm_agp_head::agp_info.
 */
int drm_agp_info(drm_device_t * dev, drm_agp_info_t *info)
{
	DRM_AGP_KERN *kern;

	if (!dev->agp || !dev->agp->acquired)
		return -EINVAL;

	kern = &dev->agp->agp_info;
	info->agp_version_major = kern->version.major;
	info->agp_version_minor = kern->version.minor;
	info->mode = kern->mode;
	info->aperture_base = kern->aper_base;
	info->aperture_size = kern->aper_size * 1024 * 1024;
	info->memory_allowed = kern->max_memory << PAGE_SHIFT;
	info->memory_used = kern->current_memory << PAGE_SHIFT;
	info->id_vendor = kern->device->vendor;
	info->id_device = kern->device->device;

	return 0;
}
EXPORT_SYMBOL(drm_agp_info);

int drm_agp_info_ioctl(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_agp_info_t info;
	int err;

	err = drm_agp_info(dev, &info);
	if (err)
		return err;
	
	if (copy_to_user((drm_agp_info_t __user *) arg, &info, sizeof(info)))
		return -EFAULT;
	return 0;
}

/**
 * Acquire the AGP device.
 *
 * \param dev DRM device that is to acquire AGP.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the AGP device hasn't been acquired before and calls
 * \c agp_backend_acquire.
 */
int drm_agp_acquire(drm_device_t * dev)
{
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,11)
	int retcode;
#endif

	if (!dev->agp)
		return -ENODEV;
	if (dev->agp->acquired)
		return -EBUSY;
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,11)
	if ((retcode = agp_backend_acquire()))
		return retcode;
#else
	if (!(dev->agp->bridge = agp_backend_acquire(dev->pdev)))
		return -ENODEV;
#endif

	dev->agp->acquired = 1;
	return 0;
}
EXPORT_SYMBOL(drm_agp_acquire);

/**
 * Acquire the AGP device (ioctl).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the AGP device hasn't been acquired before and calls
 * \c agp_backend_acquire.
 */
int drm_agp_acquire_ioctl(struct inode *inode, struct file *filp,
			  unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	
	return drm_agp_acquire( (drm_device_t *) priv->head->dev );
}

/**
 * Release the AGP device.
 *
 * \param dev DRM device that is to release AGP.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the AGP device has been acquired and calls \c agp_backend_release.
 */
int drm_agp_release(drm_device_t *dev)
{
	if (!dev->agp || !dev->agp->acquired)
		return -EINVAL;
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,11)
	agp_backend_release();
#else
	agp_backend_release(dev->agp->bridge);
#endif
	dev->agp->acquired = 0;
	return 0;

}
EXPORT_SYMBOL(drm_agp_release);

int drm_agp_release_ioctl(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;
	
	return drm_agp_release(dev);
}

/**
 * Enable the AGP bus.
 *
 * \param dev DRM device that has previously acquired AGP.
 * \param mode Requested AGP mode.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the AGP device has been acquired but not enabled, and calls
 * \c agp_enable.
 */
int drm_agp_enable(drm_device_t *dev, drm_agp_mode_t mode)
{
	if (!dev->agp || !dev->agp->acquired)
		return -EINVAL;

	dev->agp->mode = mode.mode;
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,11)
	agp_enable(mode.mode);
#else
	agp_enable(dev->agp->bridge, mode.mode);
#endif
	dev->agp->base = dev->agp->agp_info.aper_base;
	dev->agp->enabled = 1;
	return 0;
}
EXPORT_SYMBOL(drm_agp_enable);

int drm_agp_enable_ioctl(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_agp_mode_t mode;


	if (copy_from_user(&mode, (drm_agp_mode_t __user *) arg, sizeof(mode)))
		return -EFAULT;

	return drm_agp_enable(dev, mode);
}

/**
 * Allocate AGP memory.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_agp_buffer structure.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the AGP device is present and has been acquired, allocates the
 * memory via alloc_agp() and creates a drm_agp_mem entry for it.
 */
int drm_agp_alloc(drm_device_t *dev, drm_agp_buffer_t *request)
{
	drm_agp_mem_t *entry;
	DRM_AGP_MEM *memory;
	unsigned long pages;
	u32 type;

	if (!dev->agp || !dev->agp->acquired)
		return -EINVAL;
	if (!(entry = drm_alloc(sizeof(*entry), DRM_MEM_AGPLISTS)))
		return -ENOMEM;

	memset(entry, 0, sizeof(*entry));

	pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
	type = (u32) request->type;
	if (!(memory = drm_alloc_agp(dev, pages, type))) {
		drm_free(entry, sizeof(*entry), DRM_MEM_AGPLISTS);
		return -ENOMEM;
	}

	entry->handle = (unsigned long)memory->key + 1;
	entry->memory = memory;
	entry->bound = 0;
	entry->pages = pages;
	entry->prev = NULL;
	entry->next = dev->agp->memory;
	if (dev->agp->memory)
		dev->agp->memory->prev = entry;
	dev->agp->memory = entry;

	request->handle = entry->handle;
	request->physical = memory->physical;

	return 0;
}
EXPORT_SYMBOL(drm_agp_alloc);


int drm_agp_alloc_ioctl(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_agp_buffer_t request;
	drm_agp_buffer_t __user *argp = (void __user *)arg;
	int err;

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

	err = drm_agp_alloc(dev, &request);
	if (err)
		return err;

	if (copy_to_user(argp, &request, sizeof(request))) {
		drm_agp_mem_t *entry = dev->agp->memory;

		dev->agp->memory = entry->next;
		dev->agp->memory->prev = NULL;
		drm_free_agp(entry->memory, entry->pages);
		drm_free(entry, sizeof(*entry), DRM_MEM_AGPLISTS);
		return -EFAULT;
	}

	return 0;
}

/**
 * Search for the AGP memory entry associated with a handle.
 *
 * \param dev DRM device structure.
 * \param handle AGP memory handle.
 * \return pointer to the drm_agp_mem structure associated with \p handle.
 *
 * Walks through drm_agp_head::memory until finding a matching handle.
 */
static drm_agp_mem_t *drm_agp_lookup_entry(drm_device_t * dev,
					   unsigned long handle)
{
	drm_agp_mem_t *entry;

	for (entry = dev->agp->memory; entry; entry = entry->next) {
		if (entry->handle == handle)
			return entry;
	}
	return NULL;
}

/**
 * Unbind AGP memory from the GATT (ioctl).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_agp_binding structure.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the AGP device is present and acquired, looks-up the AGP memory
 * entry and passes it to the unbind_agp() function.
 */
int drm_agp_unbind(drm_device_t *dev, drm_agp_binding_t *request)
{
	drm_agp_mem_t *entry;
	int ret;

	if (!dev->agp || !dev->agp->acquired)
		return -EINVAL;
	if (!(entry = drm_agp_lookup_entry(dev, request->handle)))
		return -EINVAL;
	if (!entry->bound)
		return -EINVAL;
	ret = drm_unbind_agp(entry->memory);
	if (ret == 0)
		entry->bound = 0;
	return ret;
}
EXPORT_SYMBOL(drm_agp_unbind);


int drm_agp_unbind_ioctl(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_agp_binding_t request;

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

	return drm_agp_unbind(dev, &request);
}


/**
 * Bind AGP memory into the GATT (ioctl)
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_agp_binding structure.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the AGP device is present and has been acquired and that no memory
 * is currently bound into the GATT. Looks-up the AGP memory entry and passes
 * it to bind_agp() function.
 */
int drm_agp_bind(drm_device_t *dev, drm_agp_binding_t *request)
{
	drm_agp_mem_t *entry;
	int retcode;
	int page;

	if (!dev->agp || !dev->agp->acquired)
		return -EINVAL;
	if (!(entry = drm_agp_lookup_entry(dev, request->handle)))
		return -EINVAL;
	if (entry->bound)
		return -EINVAL;
	page = (request->offset + PAGE_SIZE - 1) / PAGE_SIZE;
	if ((retcode = drm_bind_agp(entry->memory, page)))
		return retcode;
	entry->bound = dev->agp->base + (page << PAGE_SHIFT);
	DRM_DEBUG("base = 0x%lx entry->bound = 0x%lx\n",
		  dev->agp->base, entry->bound);
	return 0;
}
EXPORT_SYMBOL(drm_agp_bind);


int drm_agp_bind_ioctl(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_agp_binding_t request;

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

	return drm_agp_bind(dev, &request);
}


/**
 * Free AGP memory (ioctl).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_agp_buffer structure.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the AGP device is present and has been acquired and looks up the
 * AGP memory entry. If the memory it's currently bound, unbind it via
 * unbind_agp(). Frees it via free_agp() as well as the entry itself
 * and unlinks from the doubly linked list it's inserted in.
 */
int drm_agp_free(drm_device_t *dev, drm_agp_buffer_t *request)
{
	drm_agp_mem_t *entry;

	if (!dev->agp || !dev->agp->acquired)
		return -EINVAL;
	if (!(entry = drm_agp_lookup_entry(dev, request->handle)))
		return -EINVAL;
	if (entry->bound)
		drm_unbind_agp(entry->memory);

	if (entry->prev)
		entry->prev->next = entry->next;
	else
		dev->agp->memory = entry->next;

	if (entry->next)
		entry->next->prev = entry->prev;

	drm_free_agp(entry->memory, entry->pages);
	drm_free(entry, sizeof(*entry), DRM_MEM_AGPLISTS);
	return 0;
}
EXPORT_SYMBOL(drm_agp_free);



int drm_agp_free_ioctl(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_agp_buffer_t request;

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

	return drm_agp_free(dev, &request);
}


/**
 * Initialize the AGP resources.
 *
 * \return pointer to a drm_agp_head structure.
 *
 * Gets the drm_agp_t structure which is made available by the agpgart module
 * via the inter_module_* functions. Creates and initializes a drm_agp_head
 * structure.
 */
drm_agp_head_t *drm_agp_init(drm_device_t *dev)
{
	drm_agp_head_t *head = NULL;

	if (!(head = drm_alloc(sizeof(*head), DRM_MEM_AGPLISTS)))
		return NULL;
	memset((void *)head, 0, sizeof(*head));

#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,11)
	agp_copy_info(&head->agp_info);
#else
	head->bridge = agp_find_bridge(dev->pdev);
	if (!head->bridge) {
		if (!(head->bridge = agp_backend_acquire(dev->pdev))) {
			drm_free(head, sizeof(*head), DRM_MEM_AGPLISTS);
			return NULL;
	}
		agp_copy_info(head->bridge, &head->agp_info);
		agp_backend_release(head->bridge);
	} else {
		agp_copy_info(head->bridge, &head->agp_info);
	}
#endif
	if (head->agp_info.chipset == NOT_SUPPORTED) {
		drm_free(head, sizeof(*head), DRM_MEM_AGPLISTS);
		return NULL;
	}
	head->memory = NULL;
	head->cant_use_aperture = head->agp_info.cant_use_aperture;
	head->page_mask = head->agp_info.page_mask;
	return head;
}

/** Calls agp_allocate_memory() */
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,11)
DRM_AGP_MEM *drm_agp_allocate_memory(size_t pages, u32 type)
{
	return agp_allocate_memory(pages, type);
}
#else
DRM_AGP_MEM *drm_agp_allocate_memory(struct agp_bridge_data *bridge,
				     size_t pages, u32 type)
{
	return agp_allocate_memory(bridge, pages, type);
}
#endif

/** Calls agp_free_memory() */
int drm_agp_free_memory(DRM_AGP_MEM * handle)
{
	if (!handle)
		return 0;
	agp_free_memory(handle);
	return 1;
}

/** Calls agp_bind_memory() */
int drm_agp_bind_memory(DRM_AGP_MEM * handle, off_t start)
{
	if (!handle)
		return -EINVAL;
	return agp_bind_memory(handle, start);
}
EXPORT_SYMBOL(drm_agp_bind_memory);

/** Calls agp_unbind_memory() */
int drm_agp_unbind_memory(DRM_AGP_MEM * handle)
{
	if (!handle)
		return -EINVAL;
	return agp_unbind_memory(handle);
}



/*
 * AGP ttm backend interface.
 */

#ifndef AGP_USER_TYPES
#define AGP_USER_TYPES (1 << 16)
#define AGP_USER_MEMORY (AGP_USER_TYPES)
#define AGP_USER_CACHED_MEMORY (AGP_USER_TYPES + 1)
#endif

static int drm_agp_needs_unbind_cache_adjust(drm_ttm_backend_t *backend) {
	return ((backend->flags & DRM_BE_FLAG_BOUND_CACHED) ? 0 : 1);
}


static int drm_agp_populate(drm_ttm_backend_t *backend, unsigned long num_pages, 
			    struct page **pages) {

	drm_agp_ttm_priv *agp_priv = (drm_agp_ttm_priv *) backend->private;
	struct page **cur_page, **last_page = pages + num_pages;
	DRM_AGP_MEM *mem;

	if (drm_alloc_memctl(num_pages * sizeof(void *)))
		return -1;

	DRM_DEBUG("drm_agp_populate_ttm\n");
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,11)
	mem = drm_agp_allocate_memory(num_pages, agp_priv->alloc_type);
#else
	mem = drm_agp_allocate_memory(agp_priv->bridge, num_pages, agp_priv->alloc_type);
#endif
	if (!mem) {
		drm_free_memctl(num_pages *sizeof(void *));
		return -1;
	}

	DRM_DEBUG("Current page count is %ld\n", (long) mem->page_count);
	mem->page_count = 0;
	for (cur_page = pages; cur_page < last_page; ++cur_page) {
		mem->memory[mem->page_count++] = phys_to_gart(page_to_phys(*cur_page));
	}
	agp_priv->mem = mem;
	return 0;
}

static int drm_agp_bind_ttm(drm_ttm_backend_t *backend, 
			    unsigned long offset,
			    int cached) 
{
	drm_agp_ttm_priv *agp_priv = (drm_agp_ttm_priv *) backend->private;
	DRM_AGP_MEM *mem = agp_priv->mem;
	int ret;

	DRM_DEBUG("drm_agp_bind_ttm\n");
	DRM_MASK_VAL(backend->flags, DRM_BE_FLAG_BOUND_CACHED,
		     (cached) ? DRM_BE_FLAG_BOUND_CACHED : 0);
	mem->is_flushed = TRUE;
	mem->type = (cached) ? agp_priv->cached_type : agp_priv->uncached_type;
	ret = drm_agp_bind_memory(mem, offset);
	if (ret) {
		DRM_ERROR("AGP Bind memory failed\n");
	}
	return ret;
}

static int drm_agp_unbind_ttm(drm_ttm_backend_t *backend) {

	drm_agp_ttm_priv *agp_priv = (drm_agp_ttm_priv *) backend->private;

	DRM_DEBUG("drm_agp_unbind_ttm\n");
	if (agp_priv->mem->is_bound)
		return drm_agp_unbind_memory(agp_priv->mem);
	else
		return 0;
}

static void drm_agp_clear_ttm(drm_ttm_backend_t *backend) {

	drm_agp_ttm_priv *agp_priv = (drm_agp_ttm_priv *) backend->private;
	DRM_AGP_MEM *mem = agp_priv->mem;

	DRM_DEBUG("drm_agp_clear_ttm\n");
	if (mem) {
		unsigned long num_pages = mem->page_count;
		backend->unbind(backend);
		agp_free_memory(mem);
		drm_free_memctl(num_pages *sizeof(void *));
	}

	agp_priv->mem = NULL;
}

static void drm_agp_destroy_ttm(drm_ttm_backend_t *backend) {

	drm_agp_ttm_priv *agp_priv; 
	
	if (backend) {
		DRM_DEBUG("drm_agp_destroy_ttm\n");
		agp_priv = (drm_agp_ttm_priv *) backend->private;
		if (agp_priv) {
			if (agp_priv->mem) {
				backend->clear(backend);
			}
			drm_ctl_free(agp_priv, sizeof(*agp_priv), DRM_MEM_MAPPINGS);
			backend->private = NULL;
		}
		if (backend->flags & DRM_BE_FLAG_NEEDS_FREE) {
			drm_ctl_free(backend, sizeof(*backend), DRM_MEM_MAPPINGS);                     
		}
	}
}
	

drm_ttm_backend_t *drm_agp_init_ttm(struct drm_device *dev,
				    drm_ttm_backend_t *backend)
{

        drm_ttm_backend_t *agp_be;
	drm_agp_ttm_priv *agp_priv;

	agp_be = (backend != NULL) ? backend:
		drm_ctl_calloc(1, sizeof(*agp_be), DRM_MEM_MAPPINGS);

	if (!agp_be)
		return NULL;
	
	agp_priv = drm_ctl_calloc(1, sizeof(*agp_priv), DRM_MEM_MAPPINGS);
	
	if (!agp_priv) {
		drm_ctl_free(agp_be, sizeof(*agp_be), DRM_MEM_MAPPINGS);
		return NULL;
	}
	
	agp_priv->mem = NULL;
	agp_priv->alloc_type = AGP_USER_MEMORY;
	agp_priv->cached_type = AGP_USER_CACHED_MEMORY;
	agp_priv->uncached_type = AGP_USER_MEMORY;
	agp_priv->bridge = dev->agp->bridge;
	agp_priv->populated = FALSE;
	agp_be->aperture_base = dev->agp->agp_info.aper_base;
	agp_be->private = (void *) agp_priv;
	agp_be->needs_ub_cache_adjust = drm_agp_needs_unbind_cache_adjust;
	agp_be->populate = drm_agp_populate;
	agp_be->clear = drm_agp_clear_ttm;
	agp_be->bind = drm_agp_bind_ttm;
	agp_be->unbind = drm_agp_unbind_ttm;
	agp_be->destroy = drm_agp_destroy_ttm;
	DRM_MASK_VAL(agp_be->flags, DRM_BE_FLAG_NEEDS_FREE,
		     (backend == NULL) ? DRM_BE_FLAG_NEEDS_FREE : 0);
	DRM_MASK_VAL(agp_be->flags, DRM_BE_FLAG_CBA,
		     (dev->agp->cant_use_aperture) ? DRM_BE_FLAG_CBA : 0);
	agp_be->drm_map_type = _DRM_AGP;
	return agp_be;
}
EXPORT_SYMBOL(drm_agp_init_ttm);

#endif				/* __OS_HAS_AGP */