xref: /openbmc/linux/drivers/gpu/drm/drm_bufs.c (revision d2999e1b)
1 /**
2  * \file drm_bufs.c
3  * Generic buffer template
4  *
5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
6  * \author Gareth Hughes <gareth@valinux.com>
7  */
8 
9 /*
10  * Created: Thu Nov 23 03:10:50 2000 by gareth@valinux.com
11  *
12  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
13  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14  * All Rights Reserved.
15  *
16  * Permission is hereby granted, free of charge, to any person obtaining a
17  * copy of this software and associated documentation files (the "Software"),
18  * to deal in the Software without restriction, including without limitation
19  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
20  * and/or sell copies of the Software, and to permit persons to whom the
21  * Software is furnished to do so, subject to the following conditions:
22  *
23  * The above copyright notice and this permission notice (including the next
24  * paragraph) shall be included in all copies or substantial portions of the
25  * Software.
26  *
27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
28  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
29  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
30  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
31  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
32  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
33  * OTHER DEALINGS IN THE SOFTWARE.
34  */
35 
36 #include <linux/vmalloc.h>
37 #include <linux/slab.h>
38 #include <linux/log2.h>
39 #include <linux/export.h>
40 #include <asm/shmparam.h>
41 #include <drm/drmP.h>
42 
43 static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
44 						  struct drm_local_map *map)
45 {
46 	struct drm_map_list *entry;
47 	list_for_each_entry(entry, &dev->maplist, head) {
48 		/*
49 		 * Because the kernel-userspace ABI is fixed at a 32-bit offset
50 		 * while PCI resources may live above that, we only compare the
51 		 * lower 32 bits of the map offset for maps of type
52 		 * _DRM_FRAMEBUFFER or _DRM_REGISTERS.
53 		 * It is assumed that if a driver have more than one resource
54 		 * of each type, the lower 32 bits are different.
55 		 */
56 		if (!entry->map ||
57 		    map->type != entry->map->type ||
58 		    entry->master != dev->primary->master)
59 			continue;
60 		switch (map->type) {
61 		case _DRM_SHM:
62 			if (map->flags != _DRM_CONTAINS_LOCK)
63 				break;
64 			return entry;
65 		case _DRM_REGISTERS:
66 		case _DRM_FRAME_BUFFER:
67 			if ((entry->map->offset & 0xffffffff) ==
68 			    (map->offset & 0xffffffff))
69 				return entry;
70 		default: /* Make gcc happy */
71 			;
72 		}
73 		if (entry->map->offset == map->offset)
74 			return entry;
75 	}
76 
77 	return NULL;
78 }
79 
80 static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
81 			  unsigned long user_token, int hashed_handle, int shm)
82 {
83 	int use_hashed_handle, shift;
84 	unsigned long add;
85 
86 #if (BITS_PER_LONG == 64)
87 	use_hashed_handle = ((user_token & 0xFFFFFFFF00000000UL) || hashed_handle);
88 #elif (BITS_PER_LONG == 32)
89 	use_hashed_handle = hashed_handle;
90 #else
91 #error Unsupported long size. Neither 64 nor 32 bits.
92 #endif
93 
94 	if (!use_hashed_handle) {
95 		int ret;
96 		hash->key = user_token >> PAGE_SHIFT;
97 		ret = drm_ht_insert_item(&dev->map_hash, hash);
98 		if (ret != -EINVAL)
99 			return ret;
100 	}
101 
102 	shift = 0;
103 	add = DRM_MAP_HASH_OFFSET >> PAGE_SHIFT;
104 	if (shm && (SHMLBA > PAGE_SIZE)) {
105 		int bits = ilog2(SHMLBA >> PAGE_SHIFT) + 1;
106 
107 		/* For shared memory, we have to preserve the SHMLBA
108 		 * bits of the eventual vma->vm_pgoff value during
109 		 * mmap().  Otherwise we run into cache aliasing problems
110 		 * on some platforms.  On these platforms, the pgoff of
111 		 * a mmap() request is used to pick a suitable virtual
112 		 * address for the mmap() region such that it will not
113 		 * cause cache aliasing problems.
114 		 *
115 		 * Therefore, make sure the SHMLBA relevant bits of the
116 		 * hash value we use are equal to those in the original
117 		 * kernel virtual address.
118 		 */
119 		shift = bits;
120 		add |= ((user_token >> PAGE_SHIFT) & ((1UL << bits) - 1UL));
121 	}
122 
123 	return drm_ht_just_insert_please(&dev->map_hash, hash,
124 					 user_token, 32 - PAGE_SHIFT - 3,
125 					 shift, add);
126 }
127 
128 /**
129  * Core function to create a range of memory available for mapping by a
130  * non-root process.
131  *
132  * Adjusts the memory offset to its absolute value according to the mapping
133  * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
134  * applicable and if supported by the kernel.
135  */
136 static int drm_addmap_core(struct drm_device * dev, resource_size_t offset,
137 			   unsigned int size, enum drm_map_type type,
138 			   enum drm_map_flags flags,
139 			   struct drm_map_list ** maplist)
140 {
141 	struct drm_local_map *map;
142 	struct drm_map_list *list;
143 	drm_dma_handle_t *dmah;
144 	unsigned long user_token;
145 	int ret;
146 
147 	map = kmalloc(sizeof(*map), GFP_KERNEL);
148 	if (!map)
149 		return -ENOMEM;
150 
151 	map->offset = offset;
152 	map->size = size;
153 	map->flags = flags;
154 	map->type = type;
155 
156 	/* Only allow shared memory to be removable since we only keep enough
157 	 * book keeping information about shared memory to allow for removal
158 	 * when processes fork.
159 	 */
160 	if ((map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM) {
161 		kfree(map);
162 		return -EINVAL;
163 	}
164 	DRM_DEBUG("offset = 0x%08llx, size = 0x%08lx, type = %d\n",
165 		  (unsigned long long)map->offset, map->size, map->type);
166 
167 	/* page-align _DRM_SHM maps. They are allocated here so there is no security
168 	 * hole created by that and it works around various broken drivers that use
169 	 * a non-aligned quantity to map the SAREA. --BenH
170 	 */
171 	if (map->type == _DRM_SHM)
172 		map->size = PAGE_ALIGN(map->size);
173 
174 	if ((map->offset & (~(resource_size_t)PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
175 		kfree(map);
176 		return -EINVAL;
177 	}
178 	map->mtrr = -1;
179 	map->handle = NULL;
180 
181 	switch (map->type) {
182 	case _DRM_REGISTERS:
183 	case _DRM_FRAME_BUFFER:
184 #if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__) && !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__arm__)
185 		if (map->offset + (map->size-1) < map->offset ||
186 		    map->offset < virt_to_phys(high_memory)) {
187 			kfree(map);
188 			return -EINVAL;
189 		}
190 #endif
191 		/* Some drivers preinitialize some maps, without the X Server
192 		 * needing to be aware of it.  Therefore, we just return success
193 		 * when the server tries to create a duplicate map.
194 		 */
195 		list = drm_find_matching_map(dev, map);
196 		if (list != NULL) {
197 			if (list->map->size != map->size) {
198 				DRM_DEBUG("Matching maps of type %d with "
199 					  "mismatched sizes, (%ld vs %ld)\n",
200 					  map->type, map->size,
201 					  list->map->size);
202 				list->map->size = map->size;
203 			}
204 
205 			kfree(map);
206 			*maplist = list;
207 			return 0;
208 		}
209 
210 		if (map->type == _DRM_FRAME_BUFFER ||
211 		    (map->flags & _DRM_WRITE_COMBINING)) {
212 			map->mtrr =
213 				arch_phys_wc_add(map->offset, map->size);
214 		}
215 		if (map->type == _DRM_REGISTERS) {
216 			if (map->flags & _DRM_WRITE_COMBINING)
217 				map->handle = ioremap_wc(map->offset,
218 							 map->size);
219 			else
220 				map->handle = ioremap(map->offset, map->size);
221 			if (!map->handle) {
222 				kfree(map);
223 				return -ENOMEM;
224 			}
225 		}
226 
227 		break;
228 	case _DRM_SHM:
229 		list = drm_find_matching_map(dev, map);
230 		if (list != NULL) {
231 			if(list->map->size != map->size) {
232 				DRM_DEBUG("Matching maps of type %d with "
233 					  "mismatched sizes, (%ld vs %ld)\n",
234 					  map->type, map->size, list->map->size);
235 				list->map->size = map->size;
236 			}
237 
238 			kfree(map);
239 			*maplist = list;
240 			return 0;
241 		}
242 		map->handle = vmalloc_user(map->size);
243 		DRM_DEBUG("%lu %d %p\n",
244 			  map->size, order_base_2(map->size), map->handle);
245 		if (!map->handle) {
246 			kfree(map);
247 			return -ENOMEM;
248 		}
249 		map->offset = (unsigned long)map->handle;
250 		if (map->flags & _DRM_CONTAINS_LOCK) {
251 			/* Prevent a 2nd X Server from creating a 2nd lock */
252 			if (dev->primary->master->lock.hw_lock != NULL) {
253 				vfree(map->handle);
254 				kfree(map);
255 				return -EBUSY;
256 			}
257 			dev->sigdata.lock = dev->primary->master->lock.hw_lock = map->handle;	/* Pointer to lock */
258 		}
259 		break;
260 	case _DRM_AGP: {
261 		struct drm_agp_mem *entry;
262 		int valid = 0;
263 
264 		if (!dev->agp) {
265 			kfree(map);
266 			return -EINVAL;
267 		}
268 #ifdef __alpha__
269 		map->offset += dev->hose->mem_space->start;
270 #endif
271 		/* In some cases (i810 driver), user space may have already
272 		 * added the AGP base itself, because dev->agp->base previously
273 		 * only got set during AGP enable.  So, only add the base
274 		 * address if the map's offset isn't already within the
275 		 * aperture.
276 		 */
277 		if (map->offset < dev->agp->base ||
278 		    map->offset > dev->agp->base +
279 		    dev->agp->agp_info.aper_size * 1024 * 1024 - 1) {
280 			map->offset += dev->agp->base;
281 		}
282 		map->mtrr = dev->agp->agp_mtrr;	/* for getmap */
283 
284 		/* This assumes the DRM is in total control of AGP space.
285 		 * It's not always the case as AGP can be in the control
286 		 * of user space (i.e. i810 driver). So this loop will get
287 		 * skipped and we double check that dev->agp->memory is
288 		 * actually set as well as being invalid before EPERM'ing
289 		 */
290 		list_for_each_entry(entry, &dev->agp->memory, head) {
291 			if ((map->offset >= entry->bound) &&
292 			    (map->offset + map->size <= entry->bound + entry->pages * PAGE_SIZE)) {
293 				valid = 1;
294 				break;
295 			}
296 		}
297 		if (!list_empty(&dev->agp->memory) && !valid) {
298 			kfree(map);
299 			return -EPERM;
300 		}
301 		DRM_DEBUG("AGP offset = 0x%08llx, size = 0x%08lx\n",
302 			  (unsigned long long)map->offset, map->size);
303 
304 		break;
305 	}
306 	case _DRM_SCATTER_GATHER:
307 		if (!dev->sg) {
308 			kfree(map);
309 			return -EINVAL;
310 		}
311 		map->offset += (unsigned long)dev->sg->virtual;
312 		break;
313 	case _DRM_CONSISTENT:
314 		/* dma_addr_t is 64bit on i386 with CONFIG_HIGHMEM64G,
315 		 * As we're limiting the address to 2^32-1 (or less),
316 		 * casting it down to 32 bits is no problem, but we
317 		 * need to point to a 64bit variable first. */
318 		dmah = drm_pci_alloc(dev, map->size, map->size);
319 		if (!dmah) {
320 			kfree(map);
321 			return -ENOMEM;
322 		}
323 		map->handle = dmah->vaddr;
324 		map->offset = (unsigned long)dmah->busaddr;
325 		kfree(dmah);
326 		break;
327 	default:
328 		kfree(map);
329 		return -EINVAL;
330 	}
331 
332 	list = kzalloc(sizeof(*list), GFP_KERNEL);
333 	if (!list) {
334 		if (map->type == _DRM_REGISTERS)
335 			iounmap(map->handle);
336 		kfree(map);
337 		return -EINVAL;
338 	}
339 	list->map = map;
340 
341 	mutex_lock(&dev->struct_mutex);
342 	list_add(&list->head, &dev->maplist);
343 
344 	/* Assign a 32-bit handle */
345 	/* We do it here so that dev->struct_mutex protects the increment */
346 	user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle :
347 		map->offset;
348 	ret = drm_map_handle(dev, &list->hash, user_token, 0,
349 			     (map->type == _DRM_SHM));
350 	if (ret) {
351 		if (map->type == _DRM_REGISTERS)
352 			iounmap(map->handle);
353 		kfree(map);
354 		kfree(list);
355 		mutex_unlock(&dev->struct_mutex);
356 		return ret;
357 	}
358 
359 	list->user_token = list->hash.key << PAGE_SHIFT;
360 	mutex_unlock(&dev->struct_mutex);
361 
362 	if (!(map->flags & _DRM_DRIVER))
363 		list->master = dev->primary->master;
364 	*maplist = list;
365 	return 0;
366 }
367 
368 int drm_addmap(struct drm_device * dev, resource_size_t offset,
369 	       unsigned int size, enum drm_map_type type,
370 	       enum drm_map_flags flags, struct drm_local_map ** map_ptr)
371 {
372 	struct drm_map_list *list;
373 	int rc;
374 
375 	rc = drm_addmap_core(dev, offset, size, type, flags, &list);
376 	if (!rc)
377 		*map_ptr = list->map;
378 	return rc;
379 }
380 
381 EXPORT_SYMBOL(drm_addmap);
382 
383 /**
384  * Ioctl to specify a range of memory that is available for mapping by a
385  * non-root process.
386  *
387  * \param inode device inode.
388  * \param file_priv DRM file private.
389  * \param cmd command.
390  * \param arg pointer to a drm_map structure.
391  * \return zero on success or a negative value on error.
392  *
393  */
394 int drm_addmap_ioctl(struct drm_device *dev, void *data,
395 		     struct drm_file *file_priv)
396 {
397 	struct drm_map *map = data;
398 	struct drm_map_list *maplist;
399 	int err;
400 
401 	if (!(capable(CAP_SYS_ADMIN) || map->type == _DRM_AGP || map->type == _DRM_SHM))
402 		return -EPERM;
403 
404 	err = drm_addmap_core(dev, map->offset, map->size, map->type,
405 			      map->flags, &maplist);
406 
407 	if (err)
408 		return err;
409 
410 	/* avoid a warning on 64-bit, this casting isn't very nice, but the API is set so too late */
411 	map->handle = (void *)(unsigned long)maplist->user_token;
412 
413 	/*
414 	 * It appears that there are no users of this value whatsoever --
415 	 * drmAddMap just discards it.  Let's not encourage its use.
416 	 * (Keeping drm_addmap_core's returned mtrr value would be wrong --
417 	 *  it's not a real mtrr index anymore.)
418 	 */
419 	map->mtrr = -1;
420 
421 	return 0;
422 }
423 
424 /**
425  * Remove a map private from list and deallocate resources if the mapping
426  * isn't in use.
427  *
428  * Searches the map on drm_device::maplist, removes it from the list, see if
429  * its being used, and free any associate resource (such as MTRR's) if it's not
430  * being on use.
431  *
432  * \sa drm_addmap
433  */
434 int drm_rmmap_locked(struct drm_device *dev, struct drm_local_map *map)
435 {
436 	struct drm_map_list *r_list = NULL, *list_t;
437 	drm_dma_handle_t dmah;
438 	int found = 0;
439 	struct drm_master *master;
440 
441 	/* Find the list entry for the map and remove it */
442 	list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
443 		if (r_list->map == map) {
444 			master = r_list->master;
445 			list_del(&r_list->head);
446 			drm_ht_remove_key(&dev->map_hash,
447 					  r_list->user_token >> PAGE_SHIFT);
448 			kfree(r_list);
449 			found = 1;
450 			break;
451 		}
452 	}
453 
454 	if (!found)
455 		return -EINVAL;
456 
457 	switch (map->type) {
458 	case _DRM_REGISTERS:
459 		iounmap(map->handle);
460 		/* FALLTHROUGH */
461 	case _DRM_FRAME_BUFFER:
462 		arch_phys_wc_del(map->mtrr);
463 		break;
464 	case _DRM_SHM:
465 		vfree(map->handle);
466 		if (master) {
467 			if (dev->sigdata.lock == master->lock.hw_lock)
468 				dev->sigdata.lock = NULL;
469 			master->lock.hw_lock = NULL;   /* SHM removed */
470 			master->lock.file_priv = NULL;
471 			wake_up_interruptible_all(&master->lock.lock_queue);
472 		}
473 		break;
474 	case _DRM_AGP:
475 	case _DRM_SCATTER_GATHER:
476 		break;
477 	case _DRM_CONSISTENT:
478 		dmah.vaddr = map->handle;
479 		dmah.busaddr = map->offset;
480 		dmah.size = map->size;
481 		__drm_pci_free(dev, &dmah);
482 		break;
483 	}
484 	kfree(map);
485 
486 	return 0;
487 }
488 EXPORT_SYMBOL(drm_rmmap_locked);
489 
490 int drm_rmmap(struct drm_device *dev, struct drm_local_map *map)
491 {
492 	int ret;
493 
494 	mutex_lock(&dev->struct_mutex);
495 	ret = drm_rmmap_locked(dev, map);
496 	mutex_unlock(&dev->struct_mutex);
497 
498 	return ret;
499 }
500 EXPORT_SYMBOL(drm_rmmap);
501 
502 /* The rmmap ioctl appears to be unnecessary.  All mappings are torn down on
503  * the last close of the device, and this is necessary for cleanup when things
504  * exit uncleanly.  Therefore, having userland manually remove mappings seems
505  * like a pointless exercise since they're going away anyway.
506  *
507  * One use case might be after addmap is allowed for normal users for SHM and
508  * gets used by drivers that the server doesn't need to care about.  This seems
509  * unlikely.
510  *
511  * \param inode device inode.
512  * \param file_priv DRM file private.
513  * \param cmd command.
514  * \param arg pointer to a struct drm_map structure.
515  * \return zero on success or a negative value on error.
516  */
517 int drm_rmmap_ioctl(struct drm_device *dev, void *data,
518 		    struct drm_file *file_priv)
519 {
520 	struct drm_map *request = data;
521 	struct drm_local_map *map = NULL;
522 	struct drm_map_list *r_list;
523 	int ret;
524 
525 	mutex_lock(&dev->struct_mutex);
526 	list_for_each_entry(r_list, &dev->maplist, head) {
527 		if (r_list->map &&
528 		    r_list->user_token == (unsigned long)request->handle &&
529 		    r_list->map->flags & _DRM_REMOVABLE) {
530 			map = r_list->map;
531 			break;
532 		}
533 	}
534 
535 	/* List has wrapped around to the head pointer, or its empty we didn't
536 	 * find anything.
537 	 */
538 	if (list_empty(&dev->maplist) || !map) {
539 		mutex_unlock(&dev->struct_mutex);
540 		return -EINVAL;
541 	}
542 
543 	/* Register and framebuffer maps are permanent */
544 	if ((map->type == _DRM_REGISTERS) || (map->type == _DRM_FRAME_BUFFER)) {
545 		mutex_unlock(&dev->struct_mutex);
546 		return 0;
547 	}
548 
549 	ret = drm_rmmap_locked(dev, map);
550 
551 	mutex_unlock(&dev->struct_mutex);
552 
553 	return ret;
554 }
555 
556 /**
557  * Cleanup after an error on one of the addbufs() functions.
558  *
559  * \param dev DRM device.
560  * \param entry buffer entry where the error occurred.
561  *
562  * Frees any pages and buffers associated with the given entry.
563  */
564 static void drm_cleanup_buf_error(struct drm_device * dev,
565 				  struct drm_buf_entry * entry)
566 {
567 	int i;
568 
569 	if (entry->seg_count) {
570 		for (i = 0; i < entry->seg_count; i++) {
571 			if (entry->seglist[i]) {
572 				drm_pci_free(dev, entry->seglist[i]);
573 			}
574 		}
575 		kfree(entry->seglist);
576 
577 		entry->seg_count = 0;
578 	}
579 
580 	if (entry->buf_count) {
581 		for (i = 0; i < entry->buf_count; i++) {
582 			kfree(entry->buflist[i].dev_private);
583 		}
584 		kfree(entry->buflist);
585 
586 		entry->buf_count = 0;
587 	}
588 }
589 
590 #if __OS_HAS_AGP
591 /**
592  * Add AGP buffers for DMA transfers.
593  *
594  * \param dev struct drm_device to which the buffers are to be added.
595  * \param request pointer to a struct drm_buf_desc describing the request.
596  * \return zero on success or a negative number on failure.
597  *
598  * After some sanity checks creates a drm_buf structure for each buffer and
599  * reallocates the buffer list of the same size order to accommodate the new
600  * buffers.
601  */
602 int drm_addbufs_agp(struct drm_device * dev, struct drm_buf_desc * request)
603 {
604 	struct drm_device_dma *dma = dev->dma;
605 	struct drm_buf_entry *entry;
606 	struct drm_agp_mem *agp_entry;
607 	struct drm_buf *buf;
608 	unsigned long offset;
609 	unsigned long agp_offset;
610 	int count;
611 	int order;
612 	int size;
613 	int alignment;
614 	int page_order;
615 	int total;
616 	int byte_count;
617 	int i, valid;
618 	struct drm_buf **temp_buflist;
619 
620 	if (!dma)
621 		return -EINVAL;
622 
623 	count = request->count;
624 	order = order_base_2(request->size);
625 	size = 1 << order;
626 
627 	alignment = (request->flags & _DRM_PAGE_ALIGN)
628 	    ? PAGE_ALIGN(size) : size;
629 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
630 	total = PAGE_SIZE << page_order;
631 
632 	byte_count = 0;
633 	agp_offset = dev->agp->base + request->agp_start;
634 
635 	DRM_DEBUG("count:      %d\n", count);
636 	DRM_DEBUG("order:      %d\n", order);
637 	DRM_DEBUG("size:       %d\n", size);
638 	DRM_DEBUG("agp_offset: %lx\n", agp_offset);
639 	DRM_DEBUG("alignment:  %d\n", alignment);
640 	DRM_DEBUG("page_order: %d\n", page_order);
641 	DRM_DEBUG("total:      %d\n", total);
642 
643 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
644 		return -EINVAL;
645 
646 	/* Make sure buffers are located in AGP memory that we own */
647 	valid = 0;
648 	list_for_each_entry(agp_entry, &dev->agp->memory, head) {
649 		if ((agp_offset >= agp_entry->bound) &&
650 		    (agp_offset + total * count <= agp_entry->bound + agp_entry->pages * PAGE_SIZE)) {
651 			valid = 1;
652 			break;
653 		}
654 	}
655 	if (!list_empty(&dev->agp->memory) && !valid) {
656 		DRM_DEBUG("zone invalid\n");
657 		return -EINVAL;
658 	}
659 	spin_lock(&dev->buf_lock);
660 	if (dev->buf_use) {
661 		spin_unlock(&dev->buf_lock);
662 		return -EBUSY;
663 	}
664 	atomic_inc(&dev->buf_alloc);
665 	spin_unlock(&dev->buf_lock);
666 
667 	mutex_lock(&dev->struct_mutex);
668 	entry = &dma->bufs[order];
669 	if (entry->buf_count) {
670 		mutex_unlock(&dev->struct_mutex);
671 		atomic_dec(&dev->buf_alloc);
672 		return -ENOMEM;	/* May only call once for each order */
673 	}
674 
675 	if (count < 0 || count > 4096) {
676 		mutex_unlock(&dev->struct_mutex);
677 		atomic_dec(&dev->buf_alloc);
678 		return -EINVAL;
679 	}
680 
681 	entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
682 	if (!entry->buflist) {
683 		mutex_unlock(&dev->struct_mutex);
684 		atomic_dec(&dev->buf_alloc);
685 		return -ENOMEM;
686 	}
687 
688 	entry->buf_size = size;
689 	entry->page_order = page_order;
690 
691 	offset = 0;
692 
693 	while (entry->buf_count < count) {
694 		buf = &entry->buflist[entry->buf_count];
695 		buf->idx = dma->buf_count + entry->buf_count;
696 		buf->total = alignment;
697 		buf->order = order;
698 		buf->used = 0;
699 
700 		buf->offset = (dma->byte_count + offset);
701 		buf->bus_address = agp_offset + offset;
702 		buf->address = (void *)(agp_offset + offset);
703 		buf->next = NULL;
704 		buf->waiting = 0;
705 		buf->pending = 0;
706 		buf->file_priv = NULL;
707 
708 		buf->dev_priv_size = dev->driver->dev_priv_size;
709 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
710 		if (!buf->dev_private) {
711 			/* Set count correctly so we free the proper amount. */
712 			entry->buf_count = count;
713 			drm_cleanup_buf_error(dev, entry);
714 			mutex_unlock(&dev->struct_mutex);
715 			atomic_dec(&dev->buf_alloc);
716 			return -ENOMEM;
717 		}
718 
719 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
720 
721 		offset += alignment;
722 		entry->buf_count++;
723 		byte_count += PAGE_SIZE << page_order;
724 	}
725 
726 	DRM_DEBUG("byte_count: %d\n", byte_count);
727 
728 	temp_buflist = krealloc(dma->buflist,
729 				(dma->buf_count + entry->buf_count) *
730 				sizeof(*dma->buflist), GFP_KERNEL);
731 	if (!temp_buflist) {
732 		/* Free the entry because it isn't valid */
733 		drm_cleanup_buf_error(dev, entry);
734 		mutex_unlock(&dev->struct_mutex);
735 		atomic_dec(&dev->buf_alloc);
736 		return -ENOMEM;
737 	}
738 	dma->buflist = temp_buflist;
739 
740 	for (i = 0; i < entry->buf_count; i++) {
741 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
742 	}
743 
744 	dma->buf_count += entry->buf_count;
745 	dma->seg_count += entry->seg_count;
746 	dma->page_count += byte_count >> PAGE_SHIFT;
747 	dma->byte_count += byte_count;
748 
749 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
750 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
751 
752 	mutex_unlock(&dev->struct_mutex);
753 
754 	request->count = entry->buf_count;
755 	request->size = size;
756 
757 	dma->flags = _DRM_DMA_USE_AGP;
758 
759 	atomic_dec(&dev->buf_alloc);
760 	return 0;
761 }
762 EXPORT_SYMBOL(drm_addbufs_agp);
763 #endif				/* __OS_HAS_AGP */
764 
765 int drm_addbufs_pci(struct drm_device * dev, struct drm_buf_desc * request)
766 {
767 	struct drm_device_dma *dma = dev->dma;
768 	int count;
769 	int order;
770 	int size;
771 	int total;
772 	int page_order;
773 	struct drm_buf_entry *entry;
774 	drm_dma_handle_t *dmah;
775 	struct drm_buf *buf;
776 	int alignment;
777 	unsigned long offset;
778 	int i;
779 	int byte_count;
780 	int page_count;
781 	unsigned long *temp_pagelist;
782 	struct drm_buf **temp_buflist;
783 
784 	if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
785 		return -EINVAL;
786 
787 	if (!dma)
788 		return -EINVAL;
789 
790 	if (!capable(CAP_SYS_ADMIN))
791 		return -EPERM;
792 
793 	count = request->count;
794 	order = order_base_2(request->size);
795 	size = 1 << order;
796 
797 	DRM_DEBUG("count=%d, size=%d (%d), order=%d\n",
798 		  request->count, request->size, size, order);
799 
800 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
801 		return -EINVAL;
802 
803 	alignment = (request->flags & _DRM_PAGE_ALIGN)
804 	    ? PAGE_ALIGN(size) : size;
805 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
806 	total = PAGE_SIZE << page_order;
807 
808 	spin_lock(&dev->buf_lock);
809 	if (dev->buf_use) {
810 		spin_unlock(&dev->buf_lock);
811 		return -EBUSY;
812 	}
813 	atomic_inc(&dev->buf_alloc);
814 	spin_unlock(&dev->buf_lock);
815 
816 	mutex_lock(&dev->struct_mutex);
817 	entry = &dma->bufs[order];
818 	if (entry->buf_count) {
819 		mutex_unlock(&dev->struct_mutex);
820 		atomic_dec(&dev->buf_alloc);
821 		return -ENOMEM;	/* May only call once for each order */
822 	}
823 
824 	if (count < 0 || count > 4096) {
825 		mutex_unlock(&dev->struct_mutex);
826 		atomic_dec(&dev->buf_alloc);
827 		return -EINVAL;
828 	}
829 
830 	entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
831 	if (!entry->buflist) {
832 		mutex_unlock(&dev->struct_mutex);
833 		atomic_dec(&dev->buf_alloc);
834 		return -ENOMEM;
835 	}
836 
837 	entry->seglist = kzalloc(count * sizeof(*entry->seglist), GFP_KERNEL);
838 	if (!entry->seglist) {
839 		kfree(entry->buflist);
840 		mutex_unlock(&dev->struct_mutex);
841 		atomic_dec(&dev->buf_alloc);
842 		return -ENOMEM;
843 	}
844 
845 	/* Keep the original pagelist until we know all the allocations
846 	 * have succeeded
847 	 */
848 	temp_pagelist = kmalloc((dma->page_count + (count << page_order)) *
849 			       sizeof(*dma->pagelist), GFP_KERNEL);
850 	if (!temp_pagelist) {
851 		kfree(entry->buflist);
852 		kfree(entry->seglist);
853 		mutex_unlock(&dev->struct_mutex);
854 		atomic_dec(&dev->buf_alloc);
855 		return -ENOMEM;
856 	}
857 	memcpy(temp_pagelist,
858 	       dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
859 	DRM_DEBUG("pagelist: %d entries\n",
860 		  dma->page_count + (count << page_order));
861 
862 	entry->buf_size = size;
863 	entry->page_order = page_order;
864 	byte_count = 0;
865 	page_count = 0;
866 
867 	while (entry->buf_count < count) {
868 
869 		dmah = drm_pci_alloc(dev, PAGE_SIZE << page_order, 0x1000);
870 
871 		if (!dmah) {
872 			/* Set count correctly so we free the proper amount. */
873 			entry->buf_count = count;
874 			entry->seg_count = count;
875 			drm_cleanup_buf_error(dev, entry);
876 			kfree(temp_pagelist);
877 			mutex_unlock(&dev->struct_mutex);
878 			atomic_dec(&dev->buf_alloc);
879 			return -ENOMEM;
880 		}
881 		entry->seglist[entry->seg_count++] = dmah;
882 		for (i = 0; i < (1 << page_order); i++) {
883 			DRM_DEBUG("page %d @ 0x%08lx\n",
884 				  dma->page_count + page_count,
885 				  (unsigned long)dmah->vaddr + PAGE_SIZE * i);
886 			temp_pagelist[dma->page_count + page_count++]
887 				= (unsigned long)dmah->vaddr + PAGE_SIZE * i;
888 		}
889 		for (offset = 0;
890 		     offset + size <= total && entry->buf_count < count;
891 		     offset += alignment, ++entry->buf_count) {
892 			buf = &entry->buflist[entry->buf_count];
893 			buf->idx = dma->buf_count + entry->buf_count;
894 			buf->total = alignment;
895 			buf->order = order;
896 			buf->used = 0;
897 			buf->offset = (dma->byte_count + byte_count + offset);
898 			buf->address = (void *)(dmah->vaddr + offset);
899 			buf->bus_address = dmah->busaddr + offset;
900 			buf->next = NULL;
901 			buf->waiting = 0;
902 			buf->pending = 0;
903 			buf->file_priv = NULL;
904 
905 			buf->dev_priv_size = dev->driver->dev_priv_size;
906 			buf->dev_private = kzalloc(buf->dev_priv_size,
907 						GFP_KERNEL);
908 			if (!buf->dev_private) {
909 				/* Set count correctly so we free the proper amount. */
910 				entry->buf_count = count;
911 				entry->seg_count = count;
912 				drm_cleanup_buf_error(dev, entry);
913 				kfree(temp_pagelist);
914 				mutex_unlock(&dev->struct_mutex);
915 				atomic_dec(&dev->buf_alloc);
916 				return -ENOMEM;
917 			}
918 
919 			DRM_DEBUG("buffer %d @ %p\n",
920 				  entry->buf_count, buf->address);
921 		}
922 		byte_count += PAGE_SIZE << page_order;
923 	}
924 
925 	temp_buflist = krealloc(dma->buflist,
926 				(dma->buf_count + entry->buf_count) *
927 				sizeof(*dma->buflist), GFP_KERNEL);
928 	if (!temp_buflist) {
929 		/* Free the entry because it isn't valid */
930 		drm_cleanup_buf_error(dev, entry);
931 		kfree(temp_pagelist);
932 		mutex_unlock(&dev->struct_mutex);
933 		atomic_dec(&dev->buf_alloc);
934 		return -ENOMEM;
935 	}
936 	dma->buflist = temp_buflist;
937 
938 	for (i = 0; i < entry->buf_count; i++) {
939 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
940 	}
941 
942 	/* No allocations failed, so now we can replace the original pagelist
943 	 * with the new one.
944 	 */
945 	if (dma->page_count) {
946 		kfree(dma->pagelist);
947 	}
948 	dma->pagelist = temp_pagelist;
949 
950 	dma->buf_count += entry->buf_count;
951 	dma->seg_count += entry->seg_count;
952 	dma->page_count += entry->seg_count << page_order;
953 	dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);
954 
955 	mutex_unlock(&dev->struct_mutex);
956 
957 	request->count = entry->buf_count;
958 	request->size = size;
959 
960 	if (request->flags & _DRM_PCI_BUFFER_RO)
961 		dma->flags = _DRM_DMA_USE_PCI_RO;
962 
963 	atomic_dec(&dev->buf_alloc);
964 	return 0;
965 
966 }
967 EXPORT_SYMBOL(drm_addbufs_pci);
968 
969 static int drm_addbufs_sg(struct drm_device * dev, struct drm_buf_desc * request)
970 {
971 	struct drm_device_dma *dma = dev->dma;
972 	struct drm_buf_entry *entry;
973 	struct drm_buf *buf;
974 	unsigned long offset;
975 	unsigned long agp_offset;
976 	int count;
977 	int order;
978 	int size;
979 	int alignment;
980 	int page_order;
981 	int total;
982 	int byte_count;
983 	int i;
984 	struct drm_buf **temp_buflist;
985 
986 	if (!drm_core_check_feature(dev, DRIVER_SG))
987 		return -EINVAL;
988 
989 	if (!dma)
990 		return -EINVAL;
991 
992 	if (!capable(CAP_SYS_ADMIN))
993 		return -EPERM;
994 
995 	count = request->count;
996 	order = order_base_2(request->size);
997 	size = 1 << order;
998 
999 	alignment = (request->flags & _DRM_PAGE_ALIGN)
1000 	    ? PAGE_ALIGN(size) : size;
1001 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
1002 	total = PAGE_SIZE << page_order;
1003 
1004 	byte_count = 0;
1005 	agp_offset = request->agp_start;
1006 
1007 	DRM_DEBUG("count:      %d\n", count);
1008 	DRM_DEBUG("order:      %d\n", order);
1009 	DRM_DEBUG("size:       %d\n", size);
1010 	DRM_DEBUG("agp_offset: %lu\n", agp_offset);
1011 	DRM_DEBUG("alignment:  %d\n", alignment);
1012 	DRM_DEBUG("page_order: %d\n", page_order);
1013 	DRM_DEBUG("total:      %d\n", total);
1014 
1015 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1016 		return -EINVAL;
1017 
1018 	spin_lock(&dev->buf_lock);
1019 	if (dev->buf_use) {
1020 		spin_unlock(&dev->buf_lock);
1021 		return -EBUSY;
1022 	}
1023 	atomic_inc(&dev->buf_alloc);
1024 	spin_unlock(&dev->buf_lock);
1025 
1026 	mutex_lock(&dev->struct_mutex);
1027 	entry = &dma->bufs[order];
1028 	if (entry->buf_count) {
1029 		mutex_unlock(&dev->struct_mutex);
1030 		atomic_dec(&dev->buf_alloc);
1031 		return -ENOMEM;	/* May only call once for each order */
1032 	}
1033 
1034 	if (count < 0 || count > 4096) {
1035 		mutex_unlock(&dev->struct_mutex);
1036 		atomic_dec(&dev->buf_alloc);
1037 		return -EINVAL;
1038 	}
1039 
1040 	entry->buflist = kzalloc(count * sizeof(*entry->buflist),
1041 				GFP_KERNEL);
1042 	if (!entry->buflist) {
1043 		mutex_unlock(&dev->struct_mutex);
1044 		atomic_dec(&dev->buf_alloc);
1045 		return -ENOMEM;
1046 	}
1047 
1048 	entry->buf_size = size;
1049 	entry->page_order = page_order;
1050 
1051 	offset = 0;
1052 
1053 	while (entry->buf_count < count) {
1054 		buf = &entry->buflist[entry->buf_count];
1055 		buf->idx = dma->buf_count + entry->buf_count;
1056 		buf->total = alignment;
1057 		buf->order = order;
1058 		buf->used = 0;
1059 
1060 		buf->offset = (dma->byte_count + offset);
1061 		buf->bus_address = agp_offset + offset;
1062 		buf->address = (void *)(agp_offset + offset
1063 					+ (unsigned long)dev->sg->virtual);
1064 		buf->next = NULL;
1065 		buf->waiting = 0;
1066 		buf->pending = 0;
1067 		buf->file_priv = NULL;
1068 
1069 		buf->dev_priv_size = dev->driver->dev_priv_size;
1070 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
1071 		if (!buf->dev_private) {
1072 			/* Set count correctly so we free the proper amount. */
1073 			entry->buf_count = count;
1074 			drm_cleanup_buf_error(dev, entry);
1075 			mutex_unlock(&dev->struct_mutex);
1076 			atomic_dec(&dev->buf_alloc);
1077 			return -ENOMEM;
1078 		}
1079 
1080 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
1081 
1082 		offset += alignment;
1083 		entry->buf_count++;
1084 		byte_count += PAGE_SIZE << page_order;
1085 	}
1086 
1087 	DRM_DEBUG("byte_count: %d\n", byte_count);
1088 
1089 	temp_buflist = krealloc(dma->buflist,
1090 				(dma->buf_count + entry->buf_count) *
1091 				sizeof(*dma->buflist), GFP_KERNEL);
1092 	if (!temp_buflist) {
1093 		/* Free the entry because it isn't valid */
1094 		drm_cleanup_buf_error(dev, entry);
1095 		mutex_unlock(&dev->struct_mutex);
1096 		atomic_dec(&dev->buf_alloc);
1097 		return -ENOMEM;
1098 	}
1099 	dma->buflist = temp_buflist;
1100 
1101 	for (i = 0; i < entry->buf_count; i++) {
1102 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1103 	}
1104 
1105 	dma->buf_count += entry->buf_count;
1106 	dma->seg_count += entry->seg_count;
1107 	dma->page_count += byte_count >> PAGE_SHIFT;
1108 	dma->byte_count += byte_count;
1109 
1110 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
1111 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
1112 
1113 	mutex_unlock(&dev->struct_mutex);
1114 
1115 	request->count = entry->buf_count;
1116 	request->size = size;
1117 
1118 	dma->flags = _DRM_DMA_USE_SG;
1119 
1120 	atomic_dec(&dev->buf_alloc);
1121 	return 0;
1122 }
1123 
1124 /**
1125  * Add buffers for DMA transfers (ioctl).
1126  *
1127  * \param inode device inode.
1128  * \param file_priv DRM file private.
1129  * \param cmd command.
1130  * \param arg pointer to a struct drm_buf_desc request.
1131  * \return zero on success or a negative number on failure.
1132  *
1133  * According with the memory type specified in drm_buf_desc::flags and the
1134  * build options, it dispatches the call either to addbufs_agp(),
1135  * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
1136  * PCI memory respectively.
1137  */
1138 int drm_addbufs(struct drm_device *dev, void *data,
1139 		struct drm_file *file_priv)
1140 {
1141 	struct drm_buf_desc *request = data;
1142 	int ret;
1143 
1144 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1145 		return -EINVAL;
1146 
1147 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1148 		return -EINVAL;
1149 
1150 #if __OS_HAS_AGP
1151 	if (request->flags & _DRM_AGP_BUFFER)
1152 		ret = drm_addbufs_agp(dev, request);
1153 	else
1154 #endif
1155 	if (request->flags & _DRM_SG_BUFFER)
1156 		ret = drm_addbufs_sg(dev, request);
1157 	else if (request->flags & _DRM_FB_BUFFER)
1158 		ret = -EINVAL;
1159 	else
1160 		ret = drm_addbufs_pci(dev, request);
1161 
1162 	return ret;
1163 }
1164 
1165 /**
1166  * Get information about the buffer mappings.
1167  *
1168  * This was originally mean for debugging purposes, or by a sophisticated
1169  * client library to determine how best to use the available buffers (e.g.,
1170  * large buffers can be used for image transfer).
1171  *
1172  * \param inode device inode.
1173  * \param file_priv DRM file private.
1174  * \param cmd command.
1175  * \param arg pointer to a drm_buf_info structure.
1176  * \return zero on success or a negative number on failure.
1177  *
1178  * Increments drm_device::buf_use while holding the drm_device::buf_lock
1179  * lock, preventing of allocating more buffers after this call. Information
1180  * about each requested buffer is then copied into user space.
1181  */
1182 int drm_infobufs(struct drm_device *dev, void *data,
1183 		 struct drm_file *file_priv)
1184 {
1185 	struct drm_device_dma *dma = dev->dma;
1186 	struct drm_buf_info *request = data;
1187 	int i;
1188 	int count;
1189 
1190 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1191 		return -EINVAL;
1192 
1193 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1194 		return -EINVAL;
1195 
1196 	if (!dma)
1197 		return -EINVAL;
1198 
1199 	spin_lock(&dev->buf_lock);
1200 	if (atomic_read(&dev->buf_alloc)) {
1201 		spin_unlock(&dev->buf_lock);
1202 		return -EBUSY;
1203 	}
1204 	++dev->buf_use;		/* Can't allocate more after this call */
1205 	spin_unlock(&dev->buf_lock);
1206 
1207 	for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1208 		if (dma->bufs[i].buf_count)
1209 			++count;
1210 	}
1211 
1212 	DRM_DEBUG("count = %d\n", count);
1213 
1214 	if (request->count >= count) {
1215 		for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1216 			if (dma->bufs[i].buf_count) {
1217 				struct drm_buf_desc __user *to =
1218 				    &request->list[count];
1219 				struct drm_buf_entry *from = &dma->bufs[i];
1220 				struct drm_freelist *list = &dma->bufs[i].freelist;
1221 				if (copy_to_user(&to->count,
1222 						 &from->buf_count,
1223 						 sizeof(from->buf_count)) ||
1224 				    copy_to_user(&to->size,
1225 						 &from->buf_size,
1226 						 sizeof(from->buf_size)) ||
1227 				    copy_to_user(&to->low_mark,
1228 						 &list->low_mark,
1229 						 sizeof(list->low_mark)) ||
1230 				    copy_to_user(&to->high_mark,
1231 						 &list->high_mark,
1232 						 sizeof(list->high_mark)))
1233 					return -EFAULT;
1234 
1235 				DRM_DEBUG("%d %d %d %d %d\n",
1236 					  i,
1237 					  dma->bufs[i].buf_count,
1238 					  dma->bufs[i].buf_size,
1239 					  dma->bufs[i].freelist.low_mark,
1240 					  dma->bufs[i].freelist.high_mark);
1241 				++count;
1242 			}
1243 		}
1244 	}
1245 	request->count = count;
1246 
1247 	return 0;
1248 }
1249 
1250 /**
1251  * Specifies a low and high water mark for buffer allocation
1252  *
1253  * \param inode device inode.
1254  * \param file_priv DRM file private.
1255  * \param cmd command.
1256  * \param arg a pointer to a drm_buf_desc structure.
1257  * \return zero on success or a negative number on failure.
1258  *
1259  * Verifies that the size order is bounded between the admissible orders and
1260  * updates the respective drm_device_dma::bufs entry low and high water mark.
1261  *
1262  * \note This ioctl is deprecated and mostly never used.
1263  */
1264 int drm_markbufs(struct drm_device *dev, void *data,
1265 		 struct drm_file *file_priv)
1266 {
1267 	struct drm_device_dma *dma = dev->dma;
1268 	struct drm_buf_desc *request = data;
1269 	int order;
1270 	struct drm_buf_entry *entry;
1271 
1272 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1273 		return -EINVAL;
1274 
1275 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1276 		return -EINVAL;
1277 
1278 	if (!dma)
1279 		return -EINVAL;
1280 
1281 	DRM_DEBUG("%d, %d, %d\n",
1282 		  request->size, request->low_mark, request->high_mark);
1283 	order = order_base_2(request->size);
1284 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1285 		return -EINVAL;
1286 	entry = &dma->bufs[order];
1287 
1288 	if (request->low_mark < 0 || request->low_mark > entry->buf_count)
1289 		return -EINVAL;
1290 	if (request->high_mark < 0 || request->high_mark > entry->buf_count)
1291 		return -EINVAL;
1292 
1293 	entry->freelist.low_mark = request->low_mark;
1294 	entry->freelist.high_mark = request->high_mark;
1295 
1296 	return 0;
1297 }
1298 
1299 /**
1300  * Unreserve the buffers in list, previously reserved using drmDMA.
1301  *
1302  * \param inode device inode.
1303  * \param file_priv DRM file private.
1304  * \param cmd command.
1305  * \param arg pointer to a drm_buf_free structure.
1306  * \return zero on success or a negative number on failure.
1307  *
1308  * Calls free_buffer() for each used buffer.
1309  * This function is primarily used for debugging.
1310  */
1311 int drm_freebufs(struct drm_device *dev, void *data,
1312 		 struct drm_file *file_priv)
1313 {
1314 	struct drm_device_dma *dma = dev->dma;
1315 	struct drm_buf_free *request = data;
1316 	int i;
1317 	int idx;
1318 	struct drm_buf *buf;
1319 
1320 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1321 		return -EINVAL;
1322 
1323 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1324 		return -EINVAL;
1325 
1326 	if (!dma)
1327 		return -EINVAL;
1328 
1329 	DRM_DEBUG("%d\n", request->count);
1330 	for (i = 0; i < request->count; i++) {
1331 		if (copy_from_user(&idx, &request->list[i], sizeof(idx)))
1332 			return -EFAULT;
1333 		if (idx < 0 || idx >= dma->buf_count) {
1334 			DRM_ERROR("Index %d (of %d max)\n",
1335 				  idx, dma->buf_count - 1);
1336 			return -EINVAL;
1337 		}
1338 		buf = dma->buflist[idx];
1339 		if (buf->file_priv != file_priv) {
1340 			DRM_ERROR("Process %d freeing buffer not owned\n",
1341 				  task_pid_nr(current));
1342 			return -EINVAL;
1343 		}
1344 		drm_free_buffer(dev, buf);
1345 	}
1346 
1347 	return 0;
1348 }
1349 
1350 /**
1351  * Maps all of the DMA buffers into client-virtual space (ioctl).
1352  *
1353  * \param inode device inode.
1354  * \param file_priv DRM file private.
1355  * \param cmd command.
1356  * \param arg pointer to a drm_buf_map structure.
1357  * \return zero on success or a negative number on failure.
1358  *
1359  * Maps the AGP, SG or PCI buffer region with vm_mmap(), and copies information
1360  * about each buffer into user space. For PCI buffers, it calls vm_mmap() with
1361  * offset equal to 0, which drm_mmap() interpretes as PCI buffers and calls
1362  * drm_mmap_dma().
1363  */
1364 int drm_mapbufs(struct drm_device *dev, void *data,
1365 	        struct drm_file *file_priv)
1366 {
1367 	struct drm_device_dma *dma = dev->dma;
1368 	int retcode = 0;
1369 	const int zero = 0;
1370 	unsigned long virtual;
1371 	unsigned long address;
1372 	struct drm_buf_map *request = data;
1373 	int i;
1374 
1375 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1376 		return -EINVAL;
1377 
1378 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1379 		return -EINVAL;
1380 
1381 	if (!dma)
1382 		return -EINVAL;
1383 
1384 	spin_lock(&dev->buf_lock);
1385 	if (atomic_read(&dev->buf_alloc)) {
1386 		spin_unlock(&dev->buf_lock);
1387 		return -EBUSY;
1388 	}
1389 	dev->buf_use++;		/* Can't allocate more after this call */
1390 	spin_unlock(&dev->buf_lock);
1391 
1392 	if (request->count >= dma->buf_count) {
1393 		if ((dev->agp && (dma->flags & _DRM_DMA_USE_AGP))
1394 		    || (drm_core_check_feature(dev, DRIVER_SG)
1395 			&& (dma->flags & _DRM_DMA_USE_SG))) {
1396 			struct drm_local_map *map = dev->agp_buffer_map;
1397 			unsigned long token = dev->agp_buffer_token;
1398 
1399 			if (!map) {
1400 				retcode = -EINVAL;
1401 				goto done;
1402 			}
1403 			virtual = vm_mmap(file_priv->filp, 0, map->size,
1404 					  PROT_READ | PROT_WRITE,
1405 					  MAP_SHARED,
1406 					  token);
1407 		} else {
1408 			virtual = vm_mmap(file_priv->filp, 0, dma->byte_count,
1409 					  PROT_READ | PROT_WRITE,
1410 					  MAP_SHARED, 0);
1411 		}
1412 		if (virtual > -1024UL) {
1413 			/* Real error */
1414 			retcode = (signed long)virtual;
1415 			goto done;
1416 		}
1417 		request->virtual = (void __user *)virtual;
1418 
1419 		for (i = 0; i < dma->buf_count; i++) {
1420 			if (copy_to_user(&request->list[i].idx,
1421 					 &dma->buflist[i]->idx,
1422 					 sizeof(request->list[0].idx))) {
1423 				retcode = -EFAULT;
1424 				goto done;
1425 			}
1426 			if (copy_to_user(&request->list[i].total,
1427 					 &dma->buflist[i]->total,
1428 					 sizeof(request->list[0].total))) {
1429 				retcode = -EFAULT;
1430 				goto done;
1431 			}
1432 			if (copy_to_user(&request->list[i].used,
1433 					 &zero, sizeof(zero))) {
1434 				retcode = -EFAULT;
1435 				goto done;
1436 			}
1437 			address = virtual + dma->buflist[i]->offset;	/* *** */
1438 			if (copy_to_user(&request->list[i].address,
1439 					 &address, sizeof(address))) {
1440 				retcode = -EFAULT;
1441 				goto done;
1442 			}
1443 		}
1444 	}
1445       done:
1446 	request->count = dma->buf_count;
1447 	DRM_DEBUG("%d buffers, retcode = %d\n", request->count, retcode);
1448 
1449 	return retcode;
1450 }
1451 
1452 int drm_dma_ioctl(struct drm_device *dev, void *data,
1453 		  struct drm_file *file_priv)
1454 {
1455 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1456 		return -EINVAL;
1457 
1458 	if (dev->driver->dma_ioctl)
1459 		return dev->driver->dma_ioctl(dev, data, file_priv);
1460 	else
1461 		return -EINVAL;
1462 }
1463 
1464 struct drm_local_map *drm_getsarea(struct drm_device *dev)
1465 {
1466 	struct drm_map_list *entry;
1467 
1468 	list_for_each_entry(entry, &dev->maplist, head) {
1469 		if (entry->map && entry->map->type == _DRM_SHM &&
1470 		    (entry->map->flags & _DRM_CONTAINS_LOCK)) {
1471 			return entry->map;
1472 		}
1473 	}
1474 	return NULL;
1475 }
1476 EXPORT_SYMBOL(drm_getsarea);
1477