xref: /freebsd/sys/dev/drm2/drm_bufs.c (revision 86c9d9918f1db7cdd968b60f8902466887bcd9e9)
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 <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include <sys/param.h>
40 #include <sys/shm.h>
41 
42 #include <dev/pci/pcireg.h>
43 
44 #include <dev/drm2/drmP.h>
45 
46 /* Allocation of PCI memory resources (framebuffer, registers, etc.) for
47  * drm_get_resource_*.  Note that they are not RF_ACTIVE, so there's no virtual
48  * address for accessing them.  Cleaned up at unload.
49  */
50 static int drm_alloc_resource(struct drm_device *dev, int resource)
51 {
52 	struct resource *res;
53 	int rid;
54 
55 	if (resource >= DRM_MAX_PCI_RESOURCE) {
56 		DRM_ERROR("Resource %d too large\n", resource);
57 		return 1;
58 	}
59 
60 	if (dev->pcir[resource] != NULL) {
61 		return 0;
62 	}
63 
64 	rid = PCIR_BAR(resource);
65 	res = bus_alloc_resource_any(dev->dev, SYS_RES_MEMORY, &rid,
66 	    RF_SHAREABLE);
67 	if (res == NULL) {
68 		DRM_ERROR("Couldn't find resource 0x%x\n", resource);
69 		return 1;
70 	}
71 
72 	if (dev->pcir[resource] == NULL) {
73 		dev->pcirid[resource] = rid;
74 		dev->pcir[resource] = res;
75 	}
76 
77 	return 0;
78 }
79 
80 unsigned long drm_get_resource_start(struct drm_device *dev,
81 				     unsigned int resource)
82 {
83 	unsigned long start;
84 
85 	mtx_lock(&dev->pcir_lock);
86 
87 	if (drm_alloc_resource(dev, resource) != 0)
88 		return 0;
89 
90 	start = rman_get_start(dev->pcir[resource]);
91 
92 	mtx_unlock(&dev->pcir_lock);
93 
94 	return (start);
95 }
96 
97 unsigned long drm_get_resource_len(struct drm_device *dev,
98 				   unsigned int resource)
99 {
100 	unsigned long len;
101 
102 	mtx_lock(&dev->pcir_lock);
103 
104 	if (drm_alloc_resource(dev, resource) != 0)
105 		return 0;
106 
107 	len = rman_get_size(dev->pcir[resource]);
108 
109 	mtx_unlock(&dev->pcir_lock);
110 
111 	return (len);
112 }
113 
114 static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
115 						  struct drm_local_map *map)
116 {
117 	struct drm_map_list *entry;
118 	list_for_each_entry(entry, &dev->maplist, head) {
119 		/*
120 		 * Because the kernel-userspace ABI is fixed at a 32-bit offset
121 		 * while PCI resources may live above that, we only compare the
122 		 * lower 32 bits of the map offset for maps of type
123 		 * _DRM_FRAMEBUFFER or _DRM_REGISTERS.
124 		 * It is assumed that if a driver have more than one resource
125 		 * of each type, the lower 32 bits are different.
126 		 */
127 		if (!entry->map ||
128 		    map->type != entry->map->type ||
129 		    entry->master != dev->primary->master)
130 			continue;
131 		switch (map->type) {
132 		case _DRM_SHM:
133 			if (map->flags != _DRM_CONTAINS_LOCK)
134 				break;
135 			return entry;
136 		case _DRM_REGISTERS:
137 		case _DRM_FRAME_BUFFER:
138 			if ((entry->map->offset & 0xffffffff) ==
139 			    (map->offset & 0xffffffff))
140 				return entry;
141 		default: /* Make gcc happy */
142 			;
143 		}
144 		if (entry->map->offset == map->offset)
145 			return entry;
146 	}
147 
148 	return NULL;
149 }
150 
151 static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
152 			  unsigned long user_token, int hashed_handle, int shm)
153 {
154 	int use_hashed_handle, shift;
155 	unsigned long add;
156 
157 #if (BITS_PER_LONG == 64)
158 	use_hashed_handle = ((user_token & 0xFFFFFFFF00000000UL) || hashed_handle);
159 #elif (BITS_PER_LONG == 32)
160 	use_hashed_handle = hashed_handle;
161 #else
162 #error Unsupported long size. Neither 64 nor 32 bits.
163 #endif
164 
165 	if (!use_hashed_handle) {
166 		int ret;
167 		hash->key = user_token >> PAGE_SHIFT;
168 		ret = drm_ht_insert_item(&dev->map_hash, hash);
169 		if (ret != -EINVAL)
170 			return ret;
171 	}
172 
173 	shift = 0;
174 	add = DRM_MAP_HASH_OFFSET >> PAGE_SHIFT;
175 	if (shm && (SHMLBA > PAGE_SIZE)) {
176 		int bits = ilog2(SHMLBA >> PAGE_SHIFT) + 1;
177 
178 		/* For shared memory, we have to preserve the SHMLBA
179 		 * bits of the eventual vma->vm_pgoff value during
180 		 * mmap().  Otherwise we run into cache aliasing problems
181 		 * on some platforms.  On these platforms, the pgoff of
182 		 * a mmap() request is used to pick a suitable virtual
183 		 * address for the mmap() region such that it will not
184 		 * cause cache aliasing problems.
185 		 *
186 		 * Therefore, make sure the SHMLBA relevant bits of the
187 		 * hash value we use are equal to those in the original
188 		 * kernel virtual address.
189 		 */
190 		shift = bits;
191 		add |= ((user_token >> PAGE_SHIFT) & ((1UL << bits) - 1UL));
192 	}
193 
194 	return drm_ht_just_insert_please(&dev->map_hash, hash,
195 					 user_token, 32 - PAGE_SHIFT - 3,
196 					 shift, add);
197 }
198 
199 /**
200  * Core function to create a range of memory available for mapping by a
201  * non-root process.
202  *
203  * Adjusts the memory offset to its absolute value according to the mapping
204  * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
205  * applicable and if supported by the kernel.
206  */
207 static int drm_addmap_core(struct drm_device * dev, resource_size_t offset,
208 			   unsigned int size, enum drm_map_type type,
209 			   enum drm_map_flags flags,
210 			   struct drm_map_list ** maplist)
211 {
212 	struct drm_local_map *map;
213 	struct drm_map_list *list;
214 	drm_dma_handle_t *dmah;
215 	unsigned long user_token;
216 	int ret;
217 	int align;
218 
219 	map = malloc(sizeof(*map), DRM_MEM_MAPS, M_NOWAIT);
220 	if (!map)
221 		return -ENOMEM;
222 
223 	map->offset = offset;
224 	map->size = size;
225 	map->flags = flags;
226 	map->type = type;
227 
228 	/* Only allow shared memory to be removable since we only keep enough
229 	 * book keeping information about shared memory to allow for removal
230 	 * when processes fork.
231 	 */
232 	if ((map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM) {
233 		free(map, DRM_MEM_MAPS);
234 		return -EINVAL;
235 	}
236 	DRM_DEBUG("offset = 0x%08llx, size = 0x%08lx, type = %d\n",
237 		  (unsigned long long)map->offset, map->size, map->type);
238 
239 	/* page-align _DRM_SHM maps. They are allocated here so there is no security
240 	 * hole created by that and it works around various broken drivers that use
241 	 * a non-aligned quantity to map the SAREA. --BenH
242 	 */
243 	if (map->type == _DRM_SHM)
244 		map->size = PAGE_ALIGN(map->size);
245 
246 	/*
247 	 * FreeBSD port note: FreeBSD's PAGE_MASK is the inverse of
248 	 * Linux's one. That's why the test below doesn't inverse the
249 	 * constant.
250 	 */
251 	if ((map->offset & ((resource_size_t)PAGE_MASK)) || (map->size & (PAGE_MASK))) {
252 		free(map, DRM_MEM_MAPS);
253 		return -EINVAL;
254 	}
255 	map->mtrr = -1;
256 	map->handle = NULL;
257 
258 	switch (map->type) {
259 	case _DRM_REGISTERS:
260 	case _DRM_FRAME_BUFFER:
261 #ifdef __linux__
262 #if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__) && !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__arm__)
263 		if (map->offset + (map->size-1) < map->offset ||
264 		    map->offset < virt_to_phys(high_memory)) {
265 			kfree(map);
266 			return -EINVAL;
267 		}
268 #endif
269 #endif
270 		/* Some drivers preinitialize some maps, without the X Server
271 		 * needing to be aware of it.  Therefore, we just return success
272 		 * when the server tries to create a duplicate map.
273 		 */
274 		list = drm_find_matching_map(dev, map);
275 		if (list != NULL) {
276 			if (list->map->size != map->size) {
277 				DRM_DEBUG("Matching maps of type %d with "
278 					  "mismatched sizes, (%ld vs %ld)\n",
279 					  map->type, map->size,
280 					  list->map->size);
281 				list->map->size = map->size;
282 			}
283 
284 			free(map, DRM_MEM_MAPS);
285 			*maplist = list;
286 			return 0;
287 		}
288 
289 		if (drm_core_has_MTRR(dev)) {
290 			if (map->type == _DRM_FRAME_BUFFER ||
291 			    (map->flags & _DRM_WRITE_COMBINING)) {
292 				if (drm_mtrr_add(
293 				    map->offset, map->size,
294 				    DRM_MTRR_WC) == 0)
295 					map->mtrr = 1;
296 			}
297 		}
298 		if (map->type == _DRM_REGISTERS) {
299 			drm_core_ioremap(map, dev);
300 			if (!map->handle) {
301 				free(map, DRM_MEM_MAPS);
302 				return -ENOMEM;
303 			}
304 		}
305 
306 		break;
307 	case _DRM_SHM:
308 		list = drm_find_matching_map(dev, map);
309 		if (list != NULL) {
310 			if(list->map->size != map->size) {
311 				DRM_DEBUG("Matching maps of type %d with "
312 					  "mismatched sizes, (%ld vs %ld)\n",
313 					  map->type, map->size, list->map->size);
314 				list->map->size = map->size;
315 			}
316 
317 			free(map, DRM_MEM_MAPS);
318 			*maplist = list;
319 			return 0;
320 		}
321 		map->handle = malloc(map->size, DRM_MEM_MAPS, M_NOWAIT);
322 		DRM_DEBUG("%lu %d %p\n",
323 			  map->size, drm_order(map->size), map->handle);
324 		if (!map->handle) {
325 			free(map, DRM_MEM_MAPS);
326 			return -ENOMEM;
327 		}
328 		map->offset = (unsigned long)map->handle;
329 		if (map->flags & _DRM_CONTAINS_LOCK) {
330 			/* Prevent a 2nd X Server from creating a 2nd lock */
331 			if (dev->primary->master->lock.hw_lock != NULL) {
332 				free(map->handle, DRM_MEM_MAPS);
333 				free(map, DRM_MEM_MAPS);
334 				return -EBUSY;
335 			}
336 			dev->sigdata.lock = dev->primary->master->lock.hw_lock = map->handle;	/* Pointer to lock */
337 		}
338 		break;
339 	case _DRM_AGP: {
340 		struct drm_agp_mem *entry;
341 		int valid = 0;
342 
343 		if (!drm_core_has_AGP(dev)) {
344 			free(map, DRM_MEM_MAPS);
345 			return -EINVAL;
346 		}
347 #ifdef __linux__
348 #ifdef __alpha__
349 		map->offset += dev->hose->mem_space->start;
350 #endif
351 #endif
352 		/* In some cases (i810 driver), user space may have already
353 		 * added the AGP base itself, because dev->agp->base previously
354 		 * only got set during AGP enable.  So, only add the base
355 		 * address if the map's offset isn't already within the
356 		 * aperture.
357 		 */
358 		if (map->offset < dev->agp->base ||
359 		    map->offset > dev->agp->base +
360 		    dev->agp->agp_info.ai_aperture_size * 1024 * 1024 - 1) {
361 			map->offset += dev->agp->base;
362 		}
363 		map->mtrr = dev->agp->agp_mtrr;	/* for getmap */
364 
365 		/* This assumes the DRM is in total control of AGP space.
366 		 * It's not always the case as AGP can be in the control
367 		 * of user space (i.e. i810 driver). So this loop will get
368 		 * skipped and we double check that dev->agp->memory is
369 		 * actually set as well as being invalid before EPERM'ing
370 		 */
371 		list_for_each_entry(entry, &dev->agp->memory, head) {
372 			if ((map->offset >= entry->bound) &&
373 			    (map->offset + map->size <= entry->bound + entry->pages * PAGE_SIZE)) {
374 				valid = 1;
375 				break;
376 			}
377 		}
378 		if (!list_empty(&dev->agp->memory) && !valid) {
379 			free(map, DRM_MEM_MAPS);
380 			return -EPERM;
381 		}
382 		DRM_DEBUG("AGP offset = 0x%08llx, size = 0x%08lx\n",
383 			  (unsigned long long)map->offset, map->size);
384 
385 		break;
386 	}
387 	case _DRM_GEM:
388 		DRM_ERROR("tried to addmap GEM object\n");
389 		break;
390 	case _DRM_SCATTER_GATHER:
391 		if (!dev->sg) {
392 			free(map, DRM_MEM_MAPS);
393 			return -EINVAL;
394 		}
395 		map->handle = (void *)(dev->sg->vaddr + offset);
396 		map->offset += dev->sg->vaddr;
397 		break;
398 	case _DRM_CONSISTENT:
399 		/* dma_addr_t is 64bit on i386 with CONFIG_HIGHMEM64G,
400 		 * As we're limiting the address to 2^32-1 (or less),
401 		 * casting it down to 32 bits is no problem, but we
402 		 * need to point to a 64bit variable first. */
403 		align = map->size;
404 		if ((align & (align - 1)) != 0)
405 			align = PAGE_SIZE;
406 		dmah = drm_pci_alloc(dev, map->size, align, BUS_SPACE_MAXADDR);
407 		if (!dmah) {
408 			free(map, DRM_MEM_MAPS);
409 			return -ENOMEM;
410 		}
411 		map->handle = dmah->vaddr;
412 		map->offset = dmah->busaddr;
413 		map->dmah = dmah;
414 		break;
415 	default:
416 		free(map, DRM_MEM_MAPS);
417 		return -EINVAL;
418 	}
419 
420 	list = malloc(sizeof(*list), DRM_MEM_MAPS, M_ZERO | M_NOWAIT);
421 	if (!list) {
422 		if (map->type == _DRM_REGISTERS)
423 			drm_core_ioremapfree(map, dev);
424 		free(map, DRM_MEM_MAPS);
425 		return -EINVAL;
426 	}
427 	list->map = map;
428 
429 	DRM_LOCK(dev);
430 	list_add(&list->head, &dev->maplist);
431 
432 	/* Assign a 32-bit handle */
433 	/* We do it here so that dev->struct_mutex protects the increment */
434 	user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle :
435 		map->offset;
436 	ret = drm_map_handle(dev, &list->hash, user_token, 0,
437 			     (map->type == _DRM_SHM));
438 	if (ret) {
439 		if (map->type == _DRM_REGISTERS)
440 			drm_core_ioremapfree(map, dev);
441 		free(map, DRM_MEM_MAPS);
442 		free(list, DRM_MEM_MAPS);
443 		DRM_UNLOCK(dev);
444 		return ret;
445 	}
446 
447 	list->user_token = list->hash.key << PAGE_SHIFT;
448 	DRM_UNLOCK(dev);
449 
450 	if (!(map->flags & _DRM_DRIVER))
451 		list->master = dev->primary->master;
452 	*maplist = list;
453 	return 0;
454 	}
455 
456 int drm_addmap(struct drm_device * dev, resource_size_t offset,
457 	       unsigned int size, enum drm_map_type type,
458 	       enum drm_map_flags flags, struct drm_local_map ** map_ptr)
459 {
460 	struct drm_map_list *list;
461 	int rc;
462 
463 	rc = drm_addmap_core(dev, offset, size, type, flags, &list);
464 	if (!rc)
465 		*map_ptr = list->map;
466 	return rc;
467 }
468 
469 EXPORT_SYMBOL(drm_addmap);
470 
471 /**
472  * Ioctl to specify a range of memory that is available for mapping by a
473  * non-root process.
474  *
475  * \param inode device inode.
476  * \param file_priv DRM file private.
477  * \param cmd command.
478  * \param arg pointer to a drm_map structure.
479  * \return zero on success or a negative value on error.
480  *
481  */
482 int drm_addmap_ioctl(struct drm_device *dev, void *data,
483 		     struct drm_file *file_priv)
484 {
485 	struct drm_map *map = data;
486 	struct drm_map_list *maplist;
487 	int err;
488 
489 	if (!(DRM_SUSER(DRM_CURPROC) || map->type == _DRM_AGP || map->type == _DRM_SHM))
490 		return -EPERM;
491 
492 	err = drm_addmap_core(dev, map->offset, map->size, map->type,
493 			      map->flags, &maplist);
494 
495 	if (err)
496 		return err;
497 
498 	/* avoid a warning on 64-bit, this casting isn't very nice, but the API is set so too late */
499 	map->handle = (void *)(unsigned long)maplist->user_token;
500 	return 0;
501 }
502 
503 /**
504  * Remove a map private from list and deallocate resources if the mapping
505  * isn't in use.
506  *
507  * Searches the map on drm_device::maplist, removes it from the list, see if
508  * its being used, and free any associate resource (such as MTRR's) if it's not
509  * being on use.
510  *
511  * \sa drm_addmap
512  */
513 int drm_rmmap_locked(struct drm_device *dev, struct drm_local_map *map)
514 {
515 	struct drm_map_list *r_list = NULL, *list_t;
516 	int found = 0;
517 	struct drm_master *master;
518 
519 	/* Find the list entry for the map and remove it */
520 	list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
521 		if (r_list->map == map) {
522 			master = r_list->master;
523 			list_del(&r_list->head);
524 			drm_ht_remove_key(&dev->map_hash,
525 					  r_list->user_token >> PAGE_SHIFT);
526 			free(r_list, DRM_MEM_MAPS);
527 			found = 1;
528 			break;
529 		}
530 	}
531 
532 	if (!found)
533 		return -EINVAL;
534 
535 	switch (map->type) {
536 	case _DRM_REGISTERS:
537 		drm_core_ioremapfree(map, dev);
538 		/* FALLTHROUGH */
539 	case _DRM_FRAME_BUFFER:
540 		if (drm_core_has_MTRR(dev) && map->mtrr >= 0) {
541 			int retcode;
542 			retcode = drm_mtrr_del(map->mtrr, map->offset,
543 			    map->size, DRM_MTRR_WC);
544 			DRM_DEBUG("mtrr_del=%d\n", retcode);
545 		}
546 		break;
547 	case _DRM_SHM:
548 		free(map->handle, DRM_MEM_MAPS);
549 		if (master) {
550 			if (dev->sigdata.lock == master->lock.hw_lock)
551 				dev->sigdata.lock = NULL;
552 			master->lock.hw_lock = NULL;   /* SHM removed */
553 			master->lock.file_priv = NULL;
554 			DRM_WAKEUP_INT((void *)&master->lock.lock_queue);
555 		}
556 		break;
557 	case _DRM_AGP:
558 	case _DRM_SCATTER_GATHER:
559 		break;
560 	case _DRM_CONSISTENT:
561 		drm_pci_free(dev, map->dmah);
562 		break;
563 	case _DRM_GEM:
564 		DRM_ERROR("tried to rmmap GEM object\n");
565 		break;
566 	}
567 	free(map, DRM_MEM_MAPS);
568 
569 	return 0;
570 }
571 EXPORT_SYMBOL(drm_rmmap_locked);
572 
573 int drm_rmmap(struct drm_device *dev, struct drm_local_map *map)
574 {
575 	int ret;
576 
577 	DRM_LOCK(dev);
578 	ret = drm_rmmap_locked(dev, map);
579 	DRM_UNLOCK(dev);
580 
581 	return ret;
582 }
583 EXPORT_SYMBOL(drm_rmmap);
584 
585 /* The rmmap ioctl appears to be unnecessary.  All mappings are torn down on
586  * the last close of the device, and this is necessary for cleanup when things
587  * exit uncleanly.  Therefore, having userland manually remove mappings seems
588  * like a pointless exercise since they're going away anyway.
589  *
590  * One use case might be after addmap is allowed for normal users for SHM and
591  * gets used by drivers that the server doesn't need to care about.  This seems
592  * unlikely.
593  *
594  * \param inode device inode.
595  * \param file_priv DRM file private.
596  * \param cmd command.
597  * \param arg pointer to a struct drm_map structure.
598  * \return zero on success or a negative value on error.
599  */
600 int drm_rmmap_ioctl(struct drm_device *dev, void *data,
601 		    struct drm_file *file_priv)
602 {
603 	struct drm_map *request = data;
604 	struct drm_local_map *map = NULL;
605 	struct drm_map_list *r_list;
606 	int ret;
607 
608 	DRM_LOCK(dev);
609 	list_for_each_entry(r_list, &dev->maplist, head) {
610 		if (r_list->map &&
611 		    r_list->user_token == (unsigned long)request->handle &&
612 		    r_list->map->flags & _DRM_REMOVABLE) {
613 			map = r_list->map;
614 			break;
615 		}
616 	}
617 
618 	/* List has wrapped around to the head pointer, or its empty we didn't
619 	 * find anything.
620 	 */
621 	if (list_empty(&dev->maplist) || !map) {
622 		DRM_UNLOCK(dev);
623 		return -EINVAL;
624 	}
625 
626 	/* Register and framebuffer maps are permanent */
627 	if ((map->type == _DRM_REGISTERS) || (map->type == _DRM_FRAME_BUFFER)) {
628 		DRM_UNLOCK(dev);
629 		return 0;
630 	}
631 
632 	ret = drm_rmmap_locked(dev, map);
633 
634 	DRM_UNLOCK(dev);
635 
636 	return ret;
637 }
638 
639 /**
640  * Cleanup after an error on one of the addbufs() functions.
641  *
642  * \param dev DRM device.
643  * \param entry buffer entry where the error occurred.
644  *
645  * Frees any pages and buffers associated with the given entry.
646  */
647 static void drm_cleanup_buf_error(struct drm_device * dev,
648 				  struct drm_buf_entry * entry)
649 {
650 	int i;
651 
652 	if (entry->seg_count) {
653 		for (i = 0; i < entry->seg_count; i++) {
654 			if (entry->seglist[i]) {
655 				drm_pci_free(dev, entry->seglist[i]);
656 			}
657 		}
658 		free(entry->seglist, DRM_MEM_SEGS);
659 
660 		entry->seg_count = 0;
661 	}
662 
663 	if (entry->buf_count) {
664 		for (i = 0; i < entry->buf_count; i++) {
665 			free(entry->buflist[i].dev_private, DRM_MEM_BUFS);
666 		}
667 		free(entry->buflist, DRM_MEM_BUFS);
668 
669 		entry->buf_count = 0;
670 	}
671 }
672 
673 #if __OS_HAS_AGP
674 /**
675  * Add AGP buffers for DMA transfers.
676  *
677  * \param dev struct drm_device to which the buffers are to be added.
678  * \param request pointer to a struct drm_buf_desc describing the request.
679  * \return zero on success or a negative number on failure.
680  *
681  * After some sanity checks creates a drm_buf structure for each buffer and
682  * reallocates the buffer list of the same size order to accommodate the new
683  * buffers.
684  */
685 int drm_addbufs_agp(struct drm_device * dev, struct drm_buf_desc * request)
686 {
687 	struct drm_device_dma *dma = dev->dma;
688 	struct drm_buf_entry *entry;
689 	struct drm_agp_mem *agp_entry;
690 	struct drm_buf *buf;
691 	unsigned long offset;
692 	unsigned long agp_offset;
693 	int count;
694 	int order;
695 	int size;
696 	int alignment;
697 	int page_order;
698 	int total;
699 	int byte_count;
700 	int i, valid;
701 	struct drm_buf **temp_buflist;
702 
703 	if (!dma)
704 		return -EINVAL;
705 
706 	count = request->count;
707 	order = drm_order(request->size);
708 	size = 1 << order;
709 
710 	alignment = (request->flags & _DRM_PAGE_ALIGN)
711 	    ? PAGE_ALIGN(size) : size;
712 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
713 	total = PAGE_SIZE << page_order;
714 
715 	byte_count = 0;
716 	agp_offset = dev->agp->base + request->agp_start;
717 
718 	DRM_DEBUG("count:      %d\n", count);
719 	DRM_DEBUG("order:      %d\n", order);
720 	DRM_DEBUG("size:       %d\n", size);
721 	DRM_DEBUG("agp_offset: %lx\n", agp_offset);
722 	DRM_DEBUG("alignment:  %d\n", alignment);
723 	DRM_DEBUG("page_order: %d\n", page_order);
724 	DRM_DEBUG("total:      %d\n", total);
725 
726 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
727 		return -EINVAL;
728 
729 	/* Make sure buffers are located in AGP memory that we own */
730 	valid = 0;
731 	list_for_each_entry(agp_entry, &dev->agp->memory, head) {
732 		if ((agp_offset >= agp_entry->bound) &&
733 		    (agp_offset + total * count <= agp_entry->bound + agp_entry->pages * PAGE_SIZE)) {
734 			valid = 1;
735 			break;
736 		}
737 	}
738 	if (!list_empty(&dev->agp->memory) && !valid) {
739 		DRM_DEBUG("zone invalid\n");
740 		return -EINVAL;
741 	}
742 	mtx_lock(&dev->count_lock);
743 	if (dev->buf_use) {
744 		mtx_unlock(&dev->count_lock);
745 		return -EBUSY;
746 	}
747 	atomic_inc(&dev->buf_alloc);
748 	mtx_unlock(&dev->count_lock);
749 
750 	DRM_LOCK(dev);
751 	entry = &dma->bufs[order];
752 	if (entry->buf_count) {
753 		DRM_UNLOCK(dev);
754 		atomic_dec(&dev->buf_alloc);
755 		return -ENOMEM;	/* May only call once for each order */
756 	}
757 
758 	if (count < 0 || count > 4096) {
759 		DRM_UNLOCK(dev);
760 		atomic_dec(&dev->buf_alloc);
761 		return -EINVAL;
762 	}
763 
764 	entry->buflist = malloc(count * sizeof(*entry->buflist), DRM_MEM_BUFS,
765 	    M_NOWAIT | M_ZERO);
766 	if (!entry->buflist) {
767 		DRM_UNLOCK(dev);
768 		atomic_dec(&dev->buf_alloc);
769 		return -ENOMEM;
770 	}
771 
772 	entry->buf_size = size;
773 	entry->page_order = page_order;
774 
775 	offset = 0;
776 
777 	while (entry->buf_count < count) {
778 		buf = &entry->buflist[entry->buf_count];
779 		buf->idx = dma->buf_count + entry->buf_count;
780 		buf->total = alignment;
781 		buf->order = order;
782 		buf->used = 0;
783 
784 		buf->offset = (dma->byte_count + offset);
785 		buf->bus_address = agp_offset + offset;
786 		buf->address = (void *)(agp_offset + offset);
787 		buf->next = NULL;
788 		buf->waiting = 0;
789 		buf->pending = 0;
790 		buf->file_priv = NULL;
791 
792 		buf->dev_priv_size = dev->driver->dev_priv_size;
793 		buf->dev_private = malloc(buf->dev_priv_size, DRM_MEM_BUFS,
794 		    M_NOWAIT | M_ZERO);
795 		if (!buf->dev_private) {
796 			/* Set count correctly so we free the proper amount. */
797 			entry->buf_count = count;
798 			drm_cleanup_buf_error(dev, entry);
799 			DRM_UNLOCK(dev);
800 			atomic_dec(&dev->buf_alloc);
801 			return -ENOMEM;
802 		}
803 
804 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
805 
806 		offset += alignment;
807 		entry->buf_count++;
808 		byte_count += PAGE_SIZE << page_order;
809 	}
810 
811 	DRM_DEBUG("byte_count: %d\n", byte_count);
812 
813 	temp_buflist = realloc(dma->buflist,
814 	    (dma->buf_count + entry->buf_count) * sizeof(*dma->buflist),
815 	    DRM_MEM_BUFS, M_NOWAIT);
816 	if (!temp_buflist) {
817 		/* Free the entry because it isn't valid */
818 		drm_cleanup_buf_error(dev, entry);
819 		DRM_UNLOCK(dev);
820 		atomic_dec(&dev->buf_alloc);
821 		return -ENOMEM;
822 	}
823 	dma->buflist = temp_buflist;
824 
825 	for (i = 0; i < entry->buf_count; i++) {
826 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
827 	}
828 
829 	dma->buf_count += entry->buf_count;
830 	dma->seg_count += entry->seg_count;
831 	dma->page_count += byte_count >> PAGE_SHIFT;
832 	dma->byte_count += byte_count;
833 
834 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
835 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
836 
837 	DRM_UNLOCK(dev);
838 
839 	request->count = entry->buf_count;
840 	request->size = size;
841 
842 	dma->flags = _DRM_DMA_USE_AGP;
843 
844 	atomic_dec(&dev->buf_alloc);
845 	return 0;
846 }
847 EXPORT_SYMBOL(drm_addbufs_agp);
848 #endif				/* __OS_HAS_AGP */
849 
850 int drm_addbufs_pci(struct drm_device * dev, struct drm_buf_desc * request)
851 {
852 	struct drm_device_dma *dma = dev->dma;
853 	int count;
854 	int order;
855 	int size;
856 	int total;
857 	int page_order;
858 	struct drm_buf_entry *entry;
859 	drm_dma_handle_t *dmah;
860 	struct drm_buf *buf;
861 	int alignment;
862 	unsigned long offset;
863 	int i;
864 	int byte_count;
865 	int page_count;
866 	unsigned long *temp_pagelist;
867 	struct drm_buf **temp_buflist;
868 
869 	if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
870 		return -EINVAL;
871 
872 	if (!dma)
873 		return -EINVAL;
874 
875 	if (!DRM_SUSER(DRM_CURPROC))
876 		return -EPERM;
877 
878 	count = request->count;
879 	order = drm_order(request->size);
880 	size = 1 << order;
881 
882 	DRM_DEBUG("count=%d, size=%d (%d), order=%d\n",
883 		  request->count, request->size, size, order);
884 
885 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
886 		return -EINVAL;
887 
888 	alignment = (request->flags & _DRM_PAGE_ALIGN)
889 	    ? PAGE_ALIGN(size) : size;
890 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
891 	total = PAGE_SIZE << page_order;
892 
893 	mtx_lock(&dev->count_lock);
894 	if (dev->buf_use) {
895 		mtx_unlock(&dev->count_lock);
896 		return -EBUSY;
897 	}
898 	atomic_inc(&dev->buf_alloc);
899 	mtx_unlock(&dev->count_lock);
900 
901 	DRM_LOCK(dev);
902 	entry = &dma->bufs[order];
903 	if (entry->buf_count) {
904 		DRM_UNLOCK(dev);
905 		atomic_dec(&dev->buf_alloc);
906 		return -ENOMEM;	/* May only call once for each order */
907 	}
908 
909 	if (count < 0 || count > 4096) {
910 		DRM_UNLOCK(dev);
911 		atomic_dec(&dev->buf_alloc);
912 		return -EINVAL;
913 	}
914 
915 	entry->buflist = malloc(count * sizeof(*entry->buflist), DRM_MEM_BUFS,
916 	    M_NOWAIT | M_ZERO);
917 	if (!entry->buflist) {
918 		DRM_UNLOCK(dev);
919 		atomic_dec(&dev->buf_alloc);
920 		return -ENOMEM;
921 	}
922 
923 	entry->seglist = malloc(count * sizeof(*entry->seglist), DRM_MEM_SEGS,
924 	    M_NOWAIT | M_ZERO);
925 	if (!entry->seglist) {
926 		free(entry->buflist, DRM_MEM_BUFS);
927 		DRM_UNLOCK(dev);
928 		atomic_dec(&dev->buf_alloc);
929 		return -ENOMEM;
930 	}
931 
932 	/* Keep the original pagelist until we know all the allocations
933 	 * have succeeded
934 	 */
935 	temp_pagelist = malloc((dma->page_count + (count << page_order)) *
936 	    sizeof(*dma->pagelist), DRM_MEM_PAGES, M_NOWAIT);
937 	if (!temp_pagelist) {
938 		free(entry->buflist, DRM_MEM_BUFS);
939 		free(entry->seglist, DRM_MEM_SEGS);
940 		DRM_UNLOCK(dev);
941 		atomic_dec(&dev->buf_alloc);
942 		return -ENOMEM;
943 	}
944 	memcpy(temp_pagelist,
945 	       dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
946 	DRM_DEBUG("pagelist: %d entries\n",
947 		  dma->page_count + (count << page_order));
948 
949 	entry->buf_size = size;
950 	entry->page_order = page_order;
951 	byte_count = 0;
952 	page_count = 0;
953 
954 	while (entry->buf_count < count) {
955 
956 		dmah = drm_pci_alloc(dev, PAGE_SIZE << page_order, 0x1000, BUS_SPACE_MAXADDR);
957 
958 		if (!dmah) {
959 			/* Set count correctly so we free the proper amount. */
960 			entry->buf_count = count;
961 			entry->seg_count = count;
962 			drm_cleanup_buf_error(dev, entry);
963 			free(temp_pagelist, DRM_MEM_PAGES);
964 			DRM_UNLOCK(dev);
965 			atomic_dec(&dev->buf_alloc);
966 			return -ENOMEM;
967 		}
968 		entry->seglist[entry->seg_count++] = dmah;
969 		for (i = 0; i < (1 << page_order); i++) {
970 			DRM_DEBUG("page %d @ 0x%08lx\n",
971 				  dma->page_count + page_count,
972 				  (unsigned long)dmah->vaddr + PAGE_SIZE * i);
973 			temp_pagelist[dma->page_count + page_count++]
974 				= (unsigned long)dmah->vaddr + PAGE_SIZE * i;
975 		}
976 		for (offset = 0;
977 		     offset + size <= total && entry->buf_count < count;
978 		     offset += alignment, ++entry->buf_count) {
979 			buf = &entry->buflist[entry->buf_count];
980 			buf->idx = dma->buf_count + entry->buf_count;
981 			buf->total = alignment;
982 			buf->order = order;
983 			buf->used = 0;
984 			buf->offset = (dma->byte_count + byte_count + offset);
985 			buf->address = (void *)((char *)dmah->vaddr + offset);
986 			buf->bus_address = dmah->busaddr + offset;
987 			buf->next = NULL;
988 			buf->waiting = 0;
989 			buf->pending = 0;
990 			buf->file_priv = NULL;
991 
992 			buf->dev_priv_size = dev->driver->dev_priv_size;
993 			buf->dev_private = malloc(buf->dev_priv_size,
994 			    DRM_MEM_BUFS, M_NOWAIT | M_ZERO);
995 			if (!buf->dev_private) {
996 				/* Set count correctly so we free the proper amount. */
997 				entry->buf_count = count;
998 				entry->seg_count = count;
999 				drm_cleanup_buf_error(dev, entry);
1000 				free(temp_pagelist, DRM_MEM_PAGES);
1001 				DRM_UNLOCK(dev);
1002 				atomic_dec(&dev->buf_alloc);
1003 				return -ENOMEM;
1004 			}
1005 
1006 			DRM_DEBUG("buffer %d @ %p\n",
1007 				  entry->buf_count, buf->address);
1008 		}
1009 		byte_count += PAGE_SIZE << page_order;
1010 	}
1011 
1012 	temp_buflist = realloc(dma->buflist,
1013 	    (dma->buf_count + entry->buf_count) * sizeof(*dma->buflist),
1014 	    DRM_MEM_BUFS, M_NOWAIT);
1015 	if (!temp_buflist) {
1016 		/* Free the entry because it isn't valid */
1017 		drm_cleanup_buf_error(dev, entry);
1018 		free(temp_pagelist, DRM_MEM_PAGES);
1019 		DRM_UNLOCK(dev);
1020 		atomic_dec(&dev->buf_alloc);
1021 		return -ENOMEM;
1022 	}
1023 	dma->buflist = temp_buflist;
1024 
1025 	for (i = 0; i < entry->buf_count; i++) {
1026 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1027 	}
1028 
1029 	/* No allocations failed, so now we can replace the original pagelist
1030 	 * with the new one.
1031 	 */
1032 	if (dma->page_count) {
1033 		free(dma->pagelist, DRM_MEM_PAGES);
1034 	}
1035 	dma->pagelist = temp_pagelist;
1036 
1037 	dma->buf_count += entry->buf_count;
1038 	dma->seg_count += entry->seg_count;
1039 	dma->page_count += entry->seg_count << page_order;
1040 	dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);
1041 
1042 	DRM_UNLOCK(dev);
1043 
1044 	request->count = entry->buf_count;
1045 	request->size = size;
1046 
1047 	if (request->flags & _DRM_PCI_BUFFER_RO)
1048 		dma->flags = _DRM_DMA_USE_PCI_RO;
1049 
1050 	atomic_dec(&dev->buf_alloc);
1051 	return 0;
1052 
1053 }
1054 EXPORT_SYMBOL(drm_addbufs_pci);
1055 
1056 static int drm_addbufs_sg(struct drm_device * dev, struct drm_buf_desc * request)
1057 {
1058 	struct drm_device_dma *dma = dev->dma;
1059 	struct drm_buf_entry *entry;
1060 	struct drm_buf *buf;
1061 	unsigned long offset;
1062 	unsigned long agp_offset;
1063 	int count;
1064 	int order;
1065 	int size;
1066 	int alignment;
1067 	int page_order;
1068 	int total;
1069 	int byte_count;
1070 	int i;
1071 	struct drm_buf **temp_buflist;
1072 
1073 	if (!drm_core_check_feature(dev, DRIVER_SG))
1074 		return -EINVAL;
1075 
1076 	if (!dma)
1077 		return -EINVAL;
1078 
1079 	if (!DRM_SUSER(DRM_CURPROC))
1080 		return -EPERM;
1081 
1082 	count = request->count;
1083 	order = drm_order(request->size);
1084 	size = 1 << order;
1085 
1086 	alignment = (request->flags & _DRM_PAGE_ALIGN)
1087 	    ? PAGE_ALIGN(size) : size;
1088 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
1089 	total = PAGE_SIZE << page_order;
1090 
1091 	byte_count = 0;
1092 	agp_offset = request->agp_start;
1093 
1094 	DRM_DEBUG("count:      %d\n", count);
1095 	DRM_DEBUG("order:      %d\n", order);
1096 	DRM_DEBUG("size:       %d\n", size);
1097 	DRM_DEBUG("agp_offset: %lu\n", agp_offset);
1098 	DRM_DEBUG("alignment:  %d\n", alignment);
1099 	DRM_DEBUG("page_order: %d\n", page_order);
1100 	DRM_DEBUG("total:      %d\n", total);
1101 
1102 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1103 		return -EINVAL;
1104 
1105 	mtx_lock(&dev->count_lock);
1106 	if (dev->buf_use) {
1107 		mtx_unlock(&dev->count_lock);
1108 		return -EBUSY;
1109 	}
1110 	atomic_inc(&dev->buf_alloc);
1111 	mtx_unlock(&dev->count_lock);
1112 
1113 	DRM_LOCK(dev);
1114 	entry = &dma->bufs[order];
1115 	if (entry->buf_count) {
1116 		DRM_UNLOCK(dev);
1117 		atomic_dec(&dev->buf_alloc);
1118 		return -ENOMEM;	/* May only call once for each order */
1119 	}
1120 
1121 	if (count < 0 || count > 4096) {
1122 		DRM_UNLOCK(dev);
1123 		atomic_dec(&dev->buf_alloc);
1124 		return -EINVAL;
1125 	}
1126 
1127 	entry->buflist = malloc(count * sizeof(*entry->buflist), DRM_MEM_BUFS,
1128 	    M_NOWAIT | M_ZERO);
1129 	if (!entry->buflist) {
1130 		DRM_UNLOCK(dev);
1131 		atomic_dec(&dev->buf_alloc);
1132 		return -ENOMEM;
1133 	}
1134 
1135 	entry->buf_size = size;
1136 	entry->page_order = page_order;
1137 
1138 	offset = 0;
1139 
1140 	while (entry->buf_count < count) {
1141 		buf = &entry->buflist[entry->buf_count];
1142 		buf->idx = dma->buf_count + entry->buf_count;
1143 		buf->total = alignment;
1144 		buf->order = order;
1145 		buf->used = 0;
1146 
1147 		buf->offset = (dma->byte_count + offset);
1148 		buf->bus_address = agp_offset + offset;
1149 		buf->address = (void *)(agp_offset + offset
1150 					+ (unsigned long)dev->sg->vaddr);
1151 		buf->next = NULL;
1152 		buf->waiting = 0;
1153 		buf->pending = 0;
1154 		buf->file_priv = NULL;
1155 
1156 		buf->dev_priv_size = dev->driver->dev_priv_size;
1157 		buf->dev_private = malloc(buf->dev_priv_size, DRM_MEM_BUFS,
1158 		    M_NOWAIT | M_ZERO);
1159 		if (!buf->dev_private) {
1160 			/* Set count correctly so we free the proper amount. */
1161 			entry->buf_count = count;
1162 			drm_cleanup_buf_error(dev, entry);
1163 			DRM_UNLOCK(dev);
1164 			atomic_dec(&dev->buf_alloc);
1165 			return -ENOMEM;
1166 		}
1167 
1168 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
1169 
1170 		offset += alignment;
1171 		entry->buf_count++;
1172 		byte_count += PAGE_SIZE << page_order;
1173 	}
1174 
1175 	DRM_DEBUG("byte_count: %d\n", byte_count);
1176 
1177 	temp_buflist = realloc(dma->buflist,
1178 	    (dma->buf_count + entry->buf_count) * sizeof(*dma->buflist),
1179 	    DRM_MEM_BUFS, M_NOWAIT);
1180 	if (!temp_buflist) {
1181 		/* Free the entry because it isn't valid */
1182 		drm_cleanup_buf_error(dev, entry);
1183 		DRM_UNLOCK(dev);
1184 		atomic_dec(&dev->buf_alloc);
1185 		return -ENOMEM;
1186 	}
1187 	dma->buflist = temp_buflist;
1188 
1189 	for (i = 0; i < entry->buf_count; i++) {
1190 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1191 	}
1192 
1193 	dma->buf_count += entry->buf_count;
1194 	dma->seg_count += entry->seg_count;
1195 	dma->page_count += byte_count >> PAGE_SHIFT;
1196 	dma->byte_count += byte_count;
1197 
1198 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
1199 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
1200 
1201 	DRM_UNLOCK(dev);
1202 
1203 	request->count = entry->buf_count;
1204 	request->size = size;
1205 
1206 	dma->flags = _DRM_DMA_USE_SG;
1207 
1208 	atomic_dec(&dev->buf_alloc);
1209 	return 0;
1210 }
1211 
1212 static int drm_addbufs_fb(struct drm_device * dev, struct drm_buf_desc * request)
1213 {
1214 	struct drm_device_dma *dma = dev->dma;
1215 	struct drm_buf_entry *entry;
1216 	struct drm_buf *buf;
1217 	unsigned long offset;
1218 	unsigned long agp_offset;
1219 	int count;
1220 	int order;
1221 	int size;
1222 	int alignment;
1223 	int page_order;
1224 	int total;
1225 	int byte_count;
1226 	int i;
1227 	struct drm_buf **temp_buflist;
1228 
1229 	if (!drm_core_check_feature(dev, DRIVER_FB_DMA))
1230 		return -EINVAL;
1231 
1232 	if (!dma)
1233 		return -EINVAL;
1234 
1235 	if (!DRM_SUSER(DRM_CURPROC))
1236 		return -EPERM;
1237 
1238 	count = request->count;
1239 	order = drm_order(request->size);
1240 	size = 1 << order;
1241 
1242 	alignment = (request->flags & _DRM_PAGE_ALIGN)
1243 	    ? PAGE_ALIGN(size) : size;
1244 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
1245 	total = PAGE_SIZE << page_order;
1246 
1247 	byte_count = 0;
1248 	agp_offset = request->agp_start;
1249 
1250 	DRM_DEBUG("count:      %d\n", count);
1251 	DRM_DEBUG("order:      %d\n", order);
1252 	DRM_DEBUG("size:       %d\n", size);
1253 	DRM_DEBUG("agp_offset: %lu\n", agp_offset);
1254 	DRM_DEBUG("alignment:  %d\n", alignment);
1255 	DRM_DEBUG("page_order: %d\n", page_order);
1256 	DRM_DEBUG("total:      %d\n", total);
1257 
1258 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1259 		return -EINVAL;
1260 
1261 	mtx_lock(&dev->count_lock);
1262 	if (dev->buf_use) {
1263 		mtx_unlock(&dev->count_lock);
1264 		return -EBUSY;
1265 	}
1266 	atomic_inc(&dev->buf_alloc);
1267 	mtx_unlock(&dev->count_lock);
1268 
1269 	DRM_LOCK(dev);
1270 	entry = &dma->bufs[order];
1271 	if (entry->buf_count) {
1272 		DRM_UNLOCK(dev);
1273 		atomic_dec(&dev->buf_alloc);
1274 		return -ENOMEM;	/* May only call once for each order */
1275 	}
1276 
1277 	if (count < 0 || count > 4096) {
1278 		DRM_UNLOCK(dev);
1279 		atomic_dec(&dev->buf_alloc);
1280 		return -EINVAL;
1281 	}
1282 
1283 	entry->buflist = malloc(count * sizeof(*entry->buflist), DRM_MEM_BUFS,
1284 	    M_NOWAIT | M_ZERO);
1285 	if (!entry->buflist) {
1286 		DRM_UNLOCK(dev);
1287 		atomic_dec(&dev->buf_alloc);
1288 		return -ENOMEM;
1289 	}
1290 
1291 	entry->buf_size = size;
1292 	entry->page_order = page_order;
1293 
1294 	offset = 0;
1295 
1296 	while (entry->buf_count < count) {
1297 		buf = &entry->buflist[entry->buf_count];
1298 		buf->idx = dma->buf_count + entry->buf_count;
1299 		buf->total = alignment;
1300 		buf->order = order;
1301 		buf->used = 0;
1302 
1303 		buf->offset = (dma->byte_count + offset);
1304 		buf->bus_address = agp_offset + offset;
1305 		buf->address = (void *)(agp_offset + offset);
1306 		buf->next = NULL;
1307 		buf->waiting = 0;
1308 		buf->pending = 0;
1309 		buf->file_priv = NULL;
1310 
1311 		buf->dev_priv_size = dev->driver->dev_priv_size;
1312 		buf->dev_private = malloc(buf->dev_priv_size, DRM_MEM_BUFS,
1313 		    M_NOWAIT | M_ZERO);
1314 		if (!buf->dev_private) {
1315 			/* Set count correctly so we free the proper amount. */
1316 			entry->buf_count = count;
1317 			drm_cleanup_buf_error(dev, entry);
1318 			DRM_UNLOCK(dev);
1319 			atomic_dec(&dev->buf_alloc);
1320 			return -ENOMEM;
1321 		}
1322 
1323 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
1324 
1325 		offset += alignment;
1326 		entry->buf_count++;
1327 		byte_count += PAGE_SIZE << page_order;
1328 	}
1329 
1330 	DRM_DEBUG("byte_count: %d\n", byte_count);
1331 
1332 	temp_buflist = realloc(dma->buflist,
1333 	    (dma->buf_count + entry->buf_count) * sizeof(*dma->buflist),
1334 	    DRM_MEM_BUFS, M_NOWAIT);
1335 	if (!temp_buflist) {
1336 		/* Free the entry because it isn't valid */
1337 		drm_cleanup_buf_error(dev, entry);
1338 		DRM_UNLOCK(dev);
1339 		atomic_dec(&dev->buf_alloc);
1340 		return -ENOMEM;
1341 	}
1342 	dma->buflist = temp_buflist;
1343 
1344 	for (i = 0; i < entry->buf_count; i++) {
1345 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1346 	}
1347 
1348 	dma->buf_count += entry->buf_count;
1349 	dma->seg_count += entry->seg_count;
1350 	dma->page_count += byte_count >> PAGE_SHIFT;
1351 	dma->byte_count += byte_count;
1352 
1353 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
1354 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
1355 
1356 	DRM_UNLOCK(dev);
1357 
1358 	request->count = entry->buf_count;
1359 	request->size = size;
1360 
1361 	dma->flags = _DRM_DMA_USE_FB;
1362 
1363 	atomic_dec(&dev->buf_alloc);
1364 	return 0;
1365 }
1366 
1367 
1368 /**
1369  * Add buffers for DMA transfers (ioctl).
1370  *
1371  * \param inode device inode.
1372  * \param file_priv DRM file private.
1373  * \param cmd command.
1374  * \param arg pointer to a struct drm_buf_desc request.
1375  * \return zero on success or a negative number on failure.
1376  *
1377  * According with the memory type specified in drm_buf_desc::flags and the
1378  * build options, it dispatches the call either to addbufs_agp(),
1379  * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
1380  * PCI memory respectively.
1381  */
1382 int drm_addbufs(struct drm_device *dev, void *data,
1383 		struct drm_file *file_priv)
1384 {
1385 	struct drm_buf_desc *request = data;
1386 	int ret;
1387 
1388 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1389 		return -EINVAL;
1390 
1391 #if __OS_HAS_AGP
1392 	if (request->flags & _DRM_AGP_BUFFER)
1393 		ret = drm_addbufs_agp(dev, request);
1394 	else
1395 #endif
1396 	if (request->flags & _DRM_SG_BUFFER)
1397 		ret = drm_addbufs_sg(dev, request);
1398 	else if (request->flags & _DRM_FB_BUFFER)
1399 		ret = drm_addbufs_fb(dev, request);
1400 	else
1401 		ret = drm_addbufs_pci(dev, request);
1402 
1403 	return ret;
1404 }
1405 
1406 /**
1407  * Get information about the buffer mappings.
1408  *
1409  * This was originally mean for debugging purposes, or by a sophisticated
1410  * client library to determine how best to use the available buffers (e.g.,
1411  * large buffers can be used for image transfer).
1412  *
1413  * \param inode device inode.
1414  * \param file_priv DRM file private.
1415  * \param cmd command.
1416  * \param arg pointer to a drm_buf_info structure.
1417  * \return zero on success or a negative number on failure.
1418  *
1419  * Increments drm_device::buf_use while holding the drm_device::count_lock
1420  * lock, preventing of allocating more buffers after this call. Information
1421  * about each requested buffer is then copied into user space.
1422  */
1423 int drm_infobufs(struct drm_device *dev, void *data,
1424 		 struct drm_file *file_priv)
1425 {
1426 	struct drm_device_dma *dma = dev->dma;
1427 	struct drm_buf_info *request = data;
1428 	int i;
1429 	int count;
1430 
1431 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1432 		return -EINVAL;
1433 
1434 	if (!dma)
1435 		return -EINVAL;
1436 
1437 	mtx_lock(&dev->count_lock);
1438 	if (atomic_read(&dev->buf_alloc)) {
1439 		mtx_unlock(&dev->count_lock);
1440 		return -EBUSY;
1441 	}
1442 	++dev->buf_use;		/* Can't allocate more after this call */
1443 	mtx_unlock(&dev->count_lock);
1444 
1445 	for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1446 		if (dma->bufs[i].buf_count)
1447 			++count;
1448 	}
1449 
1450 	DRM_DEBUG("count = %d\n", count);
1451 
1452 	if (request->count >= count) {
1453 		for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1454 			if (dma->bufs[i].buf_count) {
1455 				struct drm_buf_desc __user *to =
1456 				    &request->list[count];
1457 				struct drm_buf_entry *from = &dma->bufs[i];
1458 				struct drm_freelist *list = &dma->bufs[i].freelist;
1459 				if (copy_to_user(&to->count,
1460 						 &from->buf_count,
1461 						 sizeof(from->buf_count)) ||
1462 				    copy_to_user(&to->size,
1463 						 &from->buf_size,
1464 						 sizeof(from->buf_size)) ||
1465 				    copy_to_user(&to->low_mark,
1466 						 &list->low_mark,
1467 						 sizeof(list->low_mark)) ||
1468 				    copy_to_user(&to->high_mark,
1469 						 &list->high_mark,
1470 						 sizeof(list->high_mark)))
1471 					return -EFAULT;
1472 
1473 				DRM_DEBUG("%d %d %d %d %d\n",
1474 					  i,
1475 					  dma->bufs[i].buf_count,
1476 					  dma->bufs[i].buf_size,
1477 					  dma->bufs[i].freelist.low_mark,
1478 					  dma->bufs[i].freelist.high_mark);
1479 				++count;
1480 			}
1481 		}
1482 	}
1483 	request->count = count;
1484 
1485 	return 0;
1486 }
1487 
1488 /**
1489  * Specifies a low and high water mark for buffer allocation
1490  *
1491  * \param inode device inode.
1492  * \param file_priv DRM file private.
1493  * \param cmd command.
1494  * \param arg a pointer to a drm_buf_desc structure.
1495  * \return zero on success or a negative number on failure.
1496  *
1497  * Verifies that the size order is bounded between the admissible orders and
1498  * updates the respective drm_device_dma::bufs entry low and high water mark.
1499  *
1500  * \note This ioctl is deprecated and mostly never used.
1501  */
1502 int drm_markbufs(struct drm_device *dev, void *data,
1503 		 struct drm_file *file_priv)
1504 {
1505 	struct drm_device_dma *dma = dev->dma;
1506 	struct drm_buf_desc *request = data;
1507 	int order;
1508 	struct drm_buf_entry *entry;
1509 
1510 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1511 		return -EINVAL;
1512 
1513 	if (!dma)
1514 		return -EINVAL;
1515 
1516 	DRM_DEBUG("%d, %d, %d\n",
1517 		  request->size, request->low_mark, request->high_mark);
1518 	order = drm_order(request->size);
1519 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1520 		return -EINVAL;
1521 	entry = &dma->bufs[order];
1522 
1523 	if (request->low_mark < 0 || request->low_mark > entry->buf_count)
1524 		return -EINVAL;
1525 	if (request->high_mark < 0 || request->high_mark > entry->buf_count)
1526 		return -EINVAL;
1527 
1528 	entry->freelist.low_mark = request->low_mark;
1529 	entry->freelist.high_mark = request->high_mark;
1530 
1531 	return 0;
1532 }
1533 
1534 /**
1535  * Unreserve the buffers in list, previously reserved using drmDMA.
1536  *
1537  * \param inode device inode.
1538  * \param file_priv DRM file private.
1539  * \param cmd command.
1540  * \param arg pointer to a drm_buf_free structure.
1541  * \return zero on success or a negative number on failure.
1542  *
1543  * Calls free_buffer() for each used buffer.
1544  * This function is primarily used for debugging.
1545  */
1546 int drm_freebufs(struct drm_device *dev, void *data,
1547 		 struct drm_file *file_priv)
1548 {
1549 	struct drm_device_dma *dma = dev->dma;
1550 	struct drm_buf_free *request = data;
1551 	int i;
1552 	int idx;
1553 	struct drm_buf *buf;
1554 
1555 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1556 		return -EINVAL;
1557 
1558 	if (!dma)
1559 		return -EINVAL;
1560 
1561 	DRM_DEBUG("%d\n", request->count);
1562 	for (i = 0; i < request->count; i++) {
1563 		if (copy_from_user(&idx, &request->list[i], sizeof(idx)))
1564 			return -EFAULT;
1565 		if (idx < 0 || idx >= dma->buf_count) {
1566 			DRM_ERROR("Index %d (of %d max)\n",
1567 				  idx, dma->buf_count - 1);
1568 			return -EINVAL;
1569 		}
1570 		buf = dma->buflist[idx];
1571 		if (buf->file_priv != file_priv) {
1572 			DRM_ERROR("Process %d freeing buffer not owned\n",
1573 				  DRM_CURRENTPID);
1574 			return -EINVAL;
1575 		}
1576 		drm_free_buffer(dev, buf);
1577 	}
1578 
1579 	return 0;
1580 }
1581 
1582 /**
1583  * Maps all of the DMA buffers into client-virtual space (ioctl).
1584  *
1585  * \param inode device inode.
1586  * \param file_priv DRM file private.
1587  * \param cmd command.
1588  * \param arg pointer to a drm_buf_map structure.
1589  * \return zero on success or a negative number on failure.
1590  *
1591  * Maps the AGP, SG or PCI buffer region with vm_mmap(), and copies information
1592  * about each buffer into user space. For PCI buffers, it calls vm_mmap() with
1593  * offset equal to 0, which drm_mmap() interpretes as PCI buffers and calls
1594  * drm_mmap_dma().
1595  */
1596 int drm_mapbufs(struct drm_device *dev, void *data,
1597 	        struct drm_file *file_priv)
1598 {
1599 	struct drm_device_dma *dma = dev->dma;
1600 	int retcode = 0;
1601 	const int zero = 0;
1602 	vm_offset_t virtual;
1603 	vm_offset_t address;
1604 	struct vmspace *vms;
1605 	struct drm_buf_map *request = data;
1606 	int i;
1607 
1608 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1609 		return -EINVAL;
1610 
1611 	if (!dma)
1612 		return -EINVAL;
1613 
1614 	mtx_lock(&dev->count_lock);
1615 	if (atomic_read(&dev->buf_alloc)) {
1616 		mtx_unlock(&dev->count_lock);
1617 		return -EBUSY;
1618 	}
1619 	dev->buf_use++;		/* Can't allocate more after this call */
1620 	mtx_unlock(&dev->count_lock);
1621 
1622 	vms = DRM_CURPROC->td_proc->p_vmspace;
1623 
1624 	if (request->count >= dma->buf_count) {
1625 		if ((drm_core_has_AGP(dev) && (dma->flags & _DRM_DMA_USE_AGP))
1626 		    || (drm_core_check_feature(dev, DRIVER_SG)
1627 			&& (dma->flags & _DRM_DMA_USE_SG))
1628 		    || (drm_core_check_feature(dev, DRIVER_FB_DMA)
1629 			&& (dma->flags & _DRM_DMA_USE_FB))) {
1630 			struct drm_local_map *map = dev->agp_buffer_map;
1631 			vm_ooffset_t token = dev->agp_buffer_token;
1632 
1633 			if (!map) {
1634 				retcode = -EINVAL;
1635 				goto done;
1636 			}
1637 			retcode = vm_mmap(&vms->vm_map, &virtual, map->size,
1638 			    VM_PROT_READ | VM_PROT_WRITE, VM_PROT_ALL,
1639 			    MAP_SHARED | MAP_NOSYNC, OBJT_DEVICE,
1640 			    file_priv->minor->device, token);
1641 		} else {
1642 			retcode = vm_mmap(&vms->vm_map, &virtual, dma->byte_count,
1643 			    VM_PROT_READ | VM_PROT_WRITE, VM_PROT_ALL,
1644 			    MAP_SHARED | MAP_NOSYNC, OBJT_DEVICE,
1645 			    file_priv->minor->device, 0);
1646 		}
1647 		if (retcode) {
1648 			/* Real error */
1649 			retcode = -retcode;
1650 			goto done;
1651 		}
1652 		request->virtual = (void __user *)virtual;
1653 
1654 		for (i = 0; i < dma->buf_count; i++) {
1655 			if (copy_to_user(&request->list[i].idx,
1656 					 &dma->buflist[i]->idx,
1657 					 sizeof(request->list[0].idx))) {
1658 				retcode = -EFAULT;
1659 				goto done;
1660 			}
1661 			if (copy_to_user(&request->list[i].total,
1662 					 &dma->buflist[i]->total,
1663 					 sizeof(request->list[0].total))) {
1664 				retcode = -EFAULT;
1665 				goto done;
1666 			}
1667 			if (copy_to_user(&request->list[i].used,
1668 					 &zero, sizeof(zero))) {
1669 				retcode = -EFAULT;
1670 				goto done;
1671 			}
1672 			address = virtual + dma->buflist[i]->offset;	/* *** */
1673 			if (copy_to_user(&request->list[i].address,
1674 					 &address, sizeof(address))) {
1675 				retcode = -EFAULT;
1676 				goto done;
1677 			}
1678 		}
1679 	}
1680       done:
1681 	request->count = dma->buf_count;
1682 	DRM_DEBUG("%d buffers, retcode = %d\n", request->count, retcode);
1683 
1684 	return retcode;
1685 }
1686 
1687 /**
1688  * Compute size order.  Returns the exponent of the smaller power of two which
1689  * is greater or equal to given number.
1690  *
1691  * \param size size.
1692  * \return order.
1693  *
1694  * \todo Can be made faster.
1695  */
1696 int drm_order(unsigned long size)
1697 {
1698 	int order;
1699 	unsigned long tmp;
1700 
1701 	for (order = 0, tmp = size >> 1; tmp; tmp >>= 1, order++) ;
1702 
1703 	if (size & (size - 1))
1704 		++order;
1705 
1706 	return order;
1707 }
1708 EXPORT_SYMBOL(drm_order);
1709