xref: /openbmc/linux/drivers/gpu/drm/drm_bufs.c (revision cce8e04c)
1 /*
2  * Legacy: Generic DRM Buffer Management
3  *
4  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
6  * All Rights Reserved.
7  *
8  * Author: Rickard E. (Rik) Faith <faith@valinux.com>
9  * Author: Gareth Hughes <gareth@valinux.com>
10  *
11  * Permission is hereby granted, free of charge, to any person obtaining a
12  * copy of this software and associated documentation files (the "Software"),
13  * to deal in the Software without restriction, including without limitation
14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15  * and/or sell copies of the Software, and to permit persons to whom the
16  * Software is furnished to do so, subject to the following conditions:
17  *
18  * The above copyright notice and this permission notice (including the next
19  * paragraph) shall be included in all copies or substantial portions of the
20  * Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
25  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
26  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
27  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28  * OTHER DEALINGS IN THE SOFTWARE.
29  */
30 
31 #include <linux/vmalloc.h>
32 #include <linux/slab.h>
33 #include <linux/log2.h>
34 #include <linux/export.h>
35 #include <asm/shmparam.h>
36 #include <drm/drmP.h>
37 #include "drm_legacy.h"
38 
39 #include <linux/nospec.h>
40 
41 static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
42 						  struct drm_local_map *map)
43 {
44 	struct drm_map_list *entry;
45 	list_for_each_entry(entry, &dev->maplist, head) {
46 		/*
47 		 * Because the kernel-userspace ABI is fixed at a 32-bit offset
48 		 * while PCI resources may live above that, we only compare the
49 		 * lower 32 bits of the map offset for maps of type
50 		 * _DRM_FRAMEBUFFER or _DRM_REGISTERS.
51 		 * It is assumed that if a driver have more than one resource
52 		 * of each type, the lower 32 bits are different.
53 		 */
54 		if (!entry->map ||
55 		    map->type != entry->map->type ||
56 		    entry->master != dev->master)
57 			continue;
58 		switch (map->type) {
59 		case _DRM_SHM:
60 			if (map->flags != _DRM_CONTAINS_LOCK)
61 				break;
62 			return entry;
63 		case _DRM_REGISTERS:
64 		case _DRM_FRAME_BUFFER:
65 			if ((entry->map->offset & 0xffffffff) ==
66 			    (map->offset & 0xffffffff))
67 				return entry;
68 		default: /* Make gcc happy */
69 			;
70 		}
71 		if (entry->map->offset == map->offset)
72 			return entry;
73 	}
74 
75 	return NULL;
76 }
77 
78 static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
79 			  unsigned long user_token, int hashed_handle, int shm)
80 {
81 	int use_hashed_handle, shift;
82 	unsigned long add;
83 
84 #if (BITS_PER_LONG == 64)
85 	use_hashed_handle = ((user_token & 0xFFFFFFFF00000000UL) || hashed_handle);
86 #elif (BITS_PER_LONG == 32)
87 	use_hashed_handle = hashed_handle;
88 #else
89 #error Unsupported long size. Neither 64 nor 32 bits.
90 #endif
91 
92 	if (!use_hashed_handle) {
93 		int ret;
94 		hash->key = user_token >> PAGE_SHIFT;
95 		ret = drm_ht_insert_item(&dev->map_hash, hash);
96 		if (ret != -EINVAL)
97 			return ret;
98 	}
99 
100 	shift = 0;
101 	add = DRM_MAP_HASH_OFFSET >> PAGE_SHIFT;
102 	if (shm && (SHMLBA > PAGE_SIZE)) {
103 		int bits = ilog2(SHMLBA >> PAGE_SHIFT) + 1;
104 
105 		/* For shared memory, we have to preserve the SHMLBA
106 		 * bits of the eventual vma->vm_pgoff value during
107 		 * mmap().  Otherwise we run into cache aliasing problems
108 		 * on some platforms.  On these platforms, the pgoff of
109 		 * a mmap() request is used to pick a suitable virtual
110 		 * address for the mmap() region such that it will not
111 		 * cause cache aliasing problems.
112 		 *
113 		 * Therefore, make sure the SHMLBA relevant bits of the
114 		 * hash value we use are equal to those in the original
115 		 * kernel virtual address.
116 		 */
117 		shift = bits;
118 		add |= ((user_token >> PAGE_SHIFT) & ((1UL << bits) - 1UL));
119 	}
120 
121 	return drm_ht_just_insert_please(&dev->map_hash, hash,
122 					 user_token, 32 - PAGE_SHIFT - 3,
123 					 shift, add);
124 }
125 
126 /**
127  * Core function to create a range of memory available for mapping by a
128  * non-root process.
129  *
130  * Adjusts the memory offset to its absolute value according to the mapping
131  * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
132  * applicable and if supported by the kernel.
133  */
134 static int drm_addmap_core(struct drm_device *dev, resource_size_t offset,
135 			   unsigned int size, enum drm_map_type type,
136 			   enum drm_map_flags flags,
137 			   struct drm_map_list **maplist)
138 {
139 	struct drm_local_map *map;
140 	struct drm_map_list *list;
141 	drm_dma_handle_t *dmah;
142 	unsigned long user_token;
143 	int ret;
144 
145 	map = kmalloc(sizeof(*map), GFP_KERNEL);
146 	if (!map)
147 		return -ENOMEM;
148 
149 	map->offset = offset;
150 	map->size = size;
151 	map->flags = flags;
152 	map->type = type;
153 
154 	/* Only allow shared memory to be removable since we only keep enough
155 	 * book keeping information about shared memory to allow for removal
156 	 * when processes fork.
157 	 */
158 	if ((map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM) {
159 		kfree(map);
160 		return -EINVAL;
161 	}
162 	DRM_DEBUG("offset = 0x%08llx, size = 0x%08lx, type = %d\n",
163 		  (unsigned long long)map->offset, map->size, map->type);
164 
165 	/* page-align _DRM_SHM maps. They are allocated here so there is no security
166 	 * hole created by that and it works around various broken drivers that use
167 	 * a non-aligned quantity to map the SAREA. --BenH
168 	 */
169 	if (map->type == _DRM_SHM)
170 		map->size = PAGE_ALIGN(map->size);
171 
172 	if ((map->offset & (~(resource_size_t)PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
173 		kfree(map);
174 		return -EINVAL;
175 	}
176 	map->mtrr = -1;
177 	map->handle = NULL;
178 
179 	switch (map->type) {
180 	case _DRM_REGISTERS:
181 	case _DRM_FRAME_BUFFER:
182 #if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__) && !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__arm__)
183 		if (map->offset + (map->size-1) < map->offset ||
184 		    map->offset < virt_to_phys(high_memory)) {
185 			kfree(map);
186 			return -EINVAL;
187 		}
188 #endif
189 		/* Some drivers preinitialize some maps, without the X Server
190 		 * needing to be aware of it.  Therefore, we just return success
191 		 * when the server tries to create a duplicate map.
192 		 */
193 		list = drm_find_matching_map(dev, map);
194 		if (list != NULL) {
195 			if (list->map->size != map->size) {
196 				DRM_DEBUG("Matching maps of type %d with "
197 					  "mismatched sizes, (%ld vs %ld)\n",
198 					  map->type, map->size,
199 					  list->map->size);
200 				list->map->size = map->size;
201 			}
202 
203 			kfree(map);
204 			*maplist = list;
205 			return 0;
206 		}
207 
208 		if (map->type == _DRM_FRAME_BUFFER ||
209 		    (map->flags & _DRM_WRITE_COMBINING)) {
210 			map->mtrr =
211 				arch_phys_wc_add(map->offset, map->size);
212 		}
213 		if (map->type == _DRM_REGISTERS) {
214 			if (map->flags & _DRM_WRITE_COMBINING)
215 				map->handle = ioremap_wc(map->offset,
216 							 map->size);
217 			else
218 				map->handle = ioremap(map->offset, map->size);
219 			if (!map->handle) {
220 				kfree(map);
221 				return -ENOMEM;
222 			}
223 		}
224 
225 		break;
226 	case _DRM_SHM:
227 		list = drm_find_matching_map(dev, map);
228 		if (list != NULL) {
229 			if (list->map->size != map->size) {
230 				DRM_DEBUG("Matching maps of type %d with "
231 					  "mismatched sizes, (%ld vs %ld)\n",
232 					  map->type, map->size, list->map->size);
233 				list->map->size = map->size;
234 			}
235 
236 			kfree(map);
237 			*maplist = list;
238 			return 0;
239 		}
240 		map->handle = vmalloc_user(map->size);
241 		DRM_DEBUG("%lu %d %p\n",
242 			  map->size, order_base_2(map->size), map->handle);
243 		if (!map->handle) {
244 			kfree(map);
245 			return -ENOMEM;
246 		}
247 		map->offset = (unsigned long)map->handle;
248 		if (map->flags & _DRM_CONTAINS_LOCK) {
249 			/* Prevent a 2nd X Server from creating a 2nd lock */
250 			if (dev->master->lock.hw_lock != NULL) {
251 				vfree(map->handle);
252 				kfree(map);
253 				return -EBUSY;
254 			}
255 			dev->sigdata.lock = dev->master->lock.hw_lock = map->handle;	/* Pointer to lock */
256 		}
257 		break;
258 	case _DRM_AGP: {
259 		struct drm_agp_mem *entry;
260 		int valid = 0;
261 
262 		if (!dev->agp) {
263 			kfree(map);
264 			return -EINVAL;
265 		}
266 #ifdef __alpha__
267 		map->offset += dev->hose->mem_space->start;
268 #endif
269 		/* In some cases (i810 driver), user space may have already
270 		 * added the AGP base itself, because dev->agp->base previously
271 		 * only got set during AGP enable.  So, only add the base
272 		 * address if the map's offset isn't already within the
273 		 * aperture.
274 		 */
275 		if (map->offset < dev->agp->base ||
276 		    map->offset > dev->agp->base +
277 		    dev->agp->agp_info.aper_size * 1024 * 1024 - 1) {
278 			map->offset += dev->agp->base;
279 		}
280 		map->mtrr = dev->agp->agp_mtrr;	/* for getmap */
281 
282 		/* This assumes the DRM is in total control of AGP space.
283 		 * It's not always the case as AGP can be in the control
284 		 * of user space (i.e. i810 driver). So this loop will get
285 		 * skipped and we double check that dev->agp->memory is
286 		 * actually set as well as being invalid before EPERM'ing
287 		 */
288 		list_for_each_entry(entry, &dev->agp->memory, head) {
289 			if ((map->offset >= entry->bound) &&
290 			    (map->offset + map->size <= entry->bound + entry->pages * PAGE_SIZE)) {
291 				valid = 1;
292 				break;
293 			}
294 		}
295 		if (!list_empty(&dev->agp->memory) && !valid) {
296 			kfree(map);
297 			return -EPERM;
298 		}
299 		DRM_DEBUG("AGP offset = 0x%08llx, size = 0x%08lx\n",
300 			  (unsigned long long)map->offset, map->size);
301 
302 		break;
303 	}
304 	case _DRM_SCATTER_GATHER:
305 		if (!dev->sg) {
306 			kfree(map);
307 			return -EINVAL;
308 		}
309 		map->offset += (unsigned long)dev->sg->virtual;
310 		break;
311 	case _DRM_CONSISTENT:
312 		/* dma_addr_t is 64bit on i386 with CONFIG_HIGHMEM64G,
313 		 * As we're limiting the address to 2^32-1 (or less),
314 		 * casting it down to 32 bits is no problem, but we
315 		 * need to point to a 64bit variable first. */
316 		dmah = drm_pci_alloc(dev, map->size, map->size);
317 		if (!dmah) {
318 			kfree(map);
319 			return -ENOMEM;
320 		}
321 		map->handle = dmah->vaddr;
322 		map->offset = (unsigned long)dmah->busaddr;
323 		kfree(dmah);
324 		break;
325 	default:
326 		kfree(map);
327 		return -EINVAL;
328 	}
329 
330 	list = kzalloc(sizeof(*list), GFP_KERNEL);
331 	if (!list) {
332 		if (map->type == _DRM_REGISTERS)
333 			iounmap(map->handle);
334 		kfree(map);
335 		return -EINVAL;
336 	}
337 	list->map = map;
338 
339 	mutex_lock(&dev->struct_mutex);
340 	list_add(&list->head, &dev->maplist);
341 
342 	/* Assign a 32-bit handle */
343 	/* We do it here so that dev->struct_mutex protects the increment */
344 	user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle :
345 		map->offset;
346 	ret = drm_map_handle(dev, &list->hash, user_token, 0,
347 			     (map->type == _DRM_SHM));
348 	if (ret) {
349 		if (map->type == _DRM_REGISTERS)
350 			iounmap(map->handle);
351 		kfree(map);
352 		kfree(list);
353 		mutex_unlock(&dev->struct_mutex);
354 		return ret;
355 	}
356 
357 	list->user_token = list->hash.key << PAGE_SHIFT;
358 	mutex_unlock(&dev->struct_mutex);
359 
360 	if (!(map->flags & _DRM_DRIVER))
361 		list->master = dev->master;
362 	*maplist = list;
363 	return 0;
364 }
365 
366 int drm_legacy_addmap(struct drm_device *dev, resource_size_t offset,
367 		      unsigned int size, enum drm_map_type type,
368 		      enum drm_map_flags flags, struct drm_local_map **map_ptr)
369 {
370 	struct drm_map_list *list;
371 	int rc;
372 
373 	rc = drm_addmap_core(dev, offset, size, type, flags, &list);
374 	if (!rc)
375 		*map_ptr = list->map;
376 	return rc;
377 }
378 EXPORT_SYMBOL(drm_legacy_addmap);
379 
380 /**
381  * Ioctl to specify a range of memory that is available for mapping by a
382  * non-root process.
383  *
384  * \param inode device inode.
385  * \param file_priv DRM file private.
386  * \param cmd command.
387  * \param arg pointer to a drm_map structure.
388  * \return zero on success or a negative value on error.
389  *
390  */
391 int drm_legacy_addmap_ioctl(struct drm_device *dev, void *data,
392 			    struct drm_file *file_priv)
393 {
394 	struct drm_map *map = data;
395 	struct drm_map_list *maplist;
396 	int err;
397 
398 	if (!(capable(CAP_SYS_ADMIN) || map->type == _DRM_AGP || map->type == _DRM_SHM))
399 		return -EPERM;
400 
401 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
402 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
403 		return -EOPNOTSUPP;
404 
405 	err = drm_addmap_core(dev, map->offset, map->size, map->type,
406 			      map->flags, &maplist);
407 
408 	if (err)
409 		return err;
410 
411 	/* avoid a warning on 64-bit, this casting isn't very nice, but the API is set so too late */
412 	map->handle = (void *)(unsigned long)maplist->user_token;
413 
414 	/*
415 	 * It appears that there are no users of this value whatsoever --
416 	 * drmAddMap just discards it.  Let's not encourage its use.
417 	 * (Keeping drm_addmap_core's returned mtrr value would be wrong --
418 	 *  it's not a real mtrr index anymore.)
419 	 */
420 	map->mtrr = -1;
421 
422 	return 0;
423 }
424 
425 /*
426  * Get a mapping information.
427  *
428  * \param inode device inode.
429  * \param file_priv DRM file private.
430  * \param cmd command.
431  * \param arg user argument, pointing to a drm_map structure.
432  *
433  * \return zero on success or a negative number on failure.
434  *
435  * Searches for the mapping with the specified offset and copies its information
436  * into userspace
437  */
438 int drm_legacy_getmap_ioctl(struct drm_device *dev, void *data,
439 			    struct drm_file *file_priv)
440 {
441 	struct drm_map *map = data;
442 	struct drm_map_list *r_list = NULL;
443 	struct list_head *list;
444 	int idx;
445 	int i;
446 
447 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
448 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
449 		return -EOPNOTSUPP;
450 
451 	idx = map->offset;
452 	if (idx < 0)
453 		return -EINVAL;
454 
455 	i = 0;
456 	mutex_lock(&dev->struct_mutex);
457 	list_for_each(list, &dev->maplist) {
458 		if (i == idx) {
459 			r_list = list_entry(list, struct drm_map_list, head);
460 			break;
461 		}
462 		i++;
463 	}
464 	if (!r_list || !r_list->map) {
465 		mutex_unlock(&dev->struct_mutex);
466 		return -EINVAL;
467 	}
468 
469 	map->offset = r_list->map->offset;
470 	map->size = r_list->map->size;
471 	map->type = r_list->map->type;
472 	map->flags = r_list->map->flags;
473 	map->handle = (void *)(unsigned long) r_list->user_token;
474 	map->mtrr = arch_phys_wc_index(r_list->map->mtrr);
475 
476 	mutex_unlock(&dev->struct_mutex);
477 
478 	return 0;
479 }
480 
481 /**
482  * Remove a map private from list and deallocate resources if the mapping
483  * isn't in use.
484  *
485  * Searches the map on drm_device::maplist, removes it from the list, see if
486  * its being used, and free any associate resource (such as MTRR's) if it's not
487  * being on use.
488  *
489  * \sa drm_legacy_addmap
490  */
491 int drm_legacy_rmmap_locked(struct drm_device *dev, struct drm_local_map *map)
492 {
493 	struct drm_map_list *r_list = NULL, *list_t;
494 	drm_dma_handle_t dmah;
495 	int found = 0;
496 	struct drm_master *master;
497 
498 	/* Find the list entry for the map and remove it */
499 	list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
500 		if (r_list->map == map) {
501 			master = r_list->master;
502 			list_del(&r_list->head);
503 			drm_ht_remove_key(&dev->map_hash,
504 					  r_list->user_token >> PAGE_SHIFT);
505 			kfree(r_list);
506 			found = 1;
507 			break;
508 		}
509 	}
510 
511 	if (!found)
512 		return -EINVAL;
513 
514 	switch (map->type) {
515 	case _DRM_REGISTERS:
516 		iounmap(map->handle);
517 		/* FALLTHROUGH */
518 	case _DRM_FRAME_BUFFER:
519 		arch_phys_wc_del(map->mtrr);
520 		break;
521 	case _DRM_SHM:
522 		vfree(map->handle);
523 		if (master) {
524 			if (dev->sigdata.lock == master->lock.hw_lock)
525 				dev->sigdata.lock = NULL;
526 			master->lock.hw_lock = NULL;   /* SHM removed */
527 			master->lock.file_priv = NULL;
528 			wake_up_interruptible_all(&master->lock.lock_queue);
529 		}
530 		break;
531 	case _DRM_AGP:
532 	case _DRM_SCATTER_GATHER:
533 		break;
534 	case _DRM_CONSISTENT:
535 		dmah.vaddr = map->handle;
536 		dmah.busaddr = map->offset;
537 		dmah.size = map->size;
538 		__drm_legacy_pci_free(dev, &dmah);
539 		break;
540 	}
541 	kfree(map);
542 
543 	return 0;
544 }
545 EXPORT_SYMBOL(drm_legacy_rmmap_locked);
546 
547 void drm_legacy_rmmap(struct drm_device *dev, struct drm_local_map *map)
548 {
549 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
550 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
551 		return;
552 
553 	mutex_lock(&dev->struct_mutex);
554 	drm_legacy_rmmap_locked(dev, map);
555 	mutex_unlock(&dev->struct_mutex);
556 }
557 EXPORT_SYMBOL(drm_legacy_rmmap);
558 
559 void drm_legacy_master_rmmaps(struct drm_device *dev, struct drm_master *master)
560 {
561 	struct drm_map_list *r_list, *list_temp;
562 
563 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
564 		return;
565 
566 	mutex_lock(&dev->struct_mutex);
567 	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
568 		if (r_list->master == master) {
569 			drm_legacy_rmmap_locked(dev, r_list->map);
570 			r_list = NULL;
571 		}
572 	}
573 	mutex_unlock(&dev->struct_mutex);
574 }
575 
576 /* The rmmap ioctl appears to be unnecessary.  All mappings are torn down on
577  * the last close of the device, and this is necessary for cleanup when things
578  * exit uncleanly.  Therefore, having userland manually remove mappings seems
579  * like a pointless exercise since they're going away anyway.
580  *
581  * One use case might be after addmap is allowed for normal users for SHM and
582  * gets used by drivers that the server doesn't need to care about.  This seems
583  * unlikely.
584  *
585  * \param inode device inode.
586  * \param file_priv DRM file private.
587  * \param cmd command.
588  * \param arg pointer to a struct drm_map structure.
589  * \return zero on success or a negative value on error.
590  */
591 int drm_legacy_rmmap_ioctl(struct drm_device *dev, void *data,
592 			   struct drm_file *file_priv)
593 {
594 	struct drm_map *request = data;
595 	struct drm_local_map *map = NULL;
596 	struct drm_map_list *r_list;
597 	int ret;
598 
599 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
600 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
601 		return -EOPNOTSUPP;
602 
603 	mutex_lock(&dev->struct_mutex);
604 	list_for_each_entry(r_list, &dev->maplist, head) {
605 		if (r_list->map &&
606 		    r_list->user_token == (unsigned long)request->handle &&
607 		    r_list->map->flags & _DRM_REMOVABLE) {
608 			map = r_list->map;
609 			break;
610 		}
611 	}
612 
613 	/* List has wrapped around to the head pointer, or its empty we didn't
614 	 * find anything.
615 	 */
616 	if (list_empty(&dev->maplist) || !map) {
617 		mutex_unlock(&dev->struct_mutex);
618 		return -EINVAL;
619 	}
620 
621 	/* Register and framebuffer maps are permanent */
622 	if ((map->type == _DRM_REGISTERS) || (map->type == _DRM_FRAME_BUFFER)) {
623 		mutex_unlock(&dev->struct_mutex);
624 		return 0;
625 	}
626 
627 	ret = drm_legacy_rmmap_locked(dev, map);
628 
629 	mutex_unlock(&dev->struct_mutex);
630 
631 	return ret;
632 }
633 
634 /**
635  * Cleanup after an error on one of the addbufs() functions.
636  *
637  * \param dev DRM device.
638  * \param entry buffer entry where the error occurred.
639  *
640  * Frees any pages and buffers associated with the given entry.
641  */
642 static void drm_cleanup_buf_error(struct drm_device *dev,
643 				  struct drm_buf_entry *entry)
644 {
645 	int i;
646 
647 	if (entry->seg_count) {
648 		for (i = 0; i < entry->seg_count; i++) {
649 			if (entry->seglist[i]) {
650 				drm_pci_free(dev, entry->seglist[i]);
651 			}
652 		}
653 		kfree(entry->seglist);
654 
655 		entry->seg_count = 0;
656 	}
657 
658 	if (entry->buf_count) {
659 		for (i = 0; i < entry->buf_count; i++) {
660 			kfree(entry->buflist[i].dev_private);
661 		}
662 		kfree(entry->buflist);
663 
664 		entry->buf_count = 0;
665 	}
666 }
667 
668 #if IS_ENABLED(CONFIG_AGP)
669 /**
670  * Add AGP buffers for DMA transfers.
671  *
672  * \param dev struct drm_device to which the buffers are to be added.
673  * \param request pointer to a struct drm_buf_desc describing the request.
674  * \return zero on success or a negative number on failure.
675  *
676  * After some sanity checks creates a drm_buf structure for each buffer and
677  * reallocates the buffer list of the same size order to accommodate the new
678  * buffers.
679  */
680 int drm_legacy_addbufs_agp(struct drm_device *dev,
681 			   struct drm_buf_desc *request)
682 {
683 	struct drm_device_dma *dma = dev->dma;
684 	struct drm_buf_entry *entry;
685 	struct drm_agp_mem *agp_entry;
686 	struct drm_buf *buf;
687 	unsigned long offset;
688 	unsigned long agp_offset;
689 	int count;
690 	int order;
691 	int size;
692 	int alignment;
693 	int page_order;
694 	int total;
695 	int byte_count;
696 	int i, valid;
697 	struct drm_buf **temp_buflist;
698 
699 	if (!dma)
700 		return -EINVAL;
701 
702 	count = request->count;
703 	order = order_base_2(request->size);
704 	size = 1 << order;
705 
706 	alignment = (request->flags & _DRM_PAGE_ALIGN)
707 	    ? PAGE_ALIGN(size) : size;
708 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
709 	total = PAGE_SIZE << page_order;
710 
711 	byte_count = 0;
712 	agp_offset = dev->agp->base + request->agp_start;
713 
714 	DRM_DEBUG("count:      %d\n", count);
715 	DRM_DEBUG("order:      %d\n", order);
716 	DRM_DEBUG("size:       %d\n", size);
717 	DRM_DEBUG("agp_offset: %lx\n", agp_offset);
718 	DRM_DEBUG("alignment:  %d\n", alignment);
719 	DRM_DEBUG("page_order: %d\n", page_order);
720 	DRM_DEBUG("total:      %d\n", total);
721 
722 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
723 		return -EINVAL;
724 
725 	/* Make sure buffers are located in AGP memory that we own */
726 	valid = 0;
727 	list_for_each_entry(agp_entry, &dev->agp->memory, head) {
728 		if ((agp_offset >= agp_entry->bound) &&
729 		    (agp_offset + total * count <= agp_entry->bound + agp_entry->pages * PAGE_SIZE)) {
730 			valid = 1;
731 			break;
732 		}
733 	}
734 	if (!list_empty(&dev->agp->memory) && !valid) {
735 		DRM_DEBUG("zone invalid\n");
736 		return -EINVAL;
737 	}
738 	spin_lock(&dev->buf_lock);
739 	if (dev->buf_use) {
740 		spin_unlock(&dev->buf_lock);
741 		return -EBUSY;
742 	}
743 	atomic_inc(&dev->buf_alloc);
744 	spin_unlock(&dev->buf_lock);
745 
746 	mutex_lock(&dev->struct_mutex);
747 	entry = &dma->bufs[order];
748 	if (entry->buf_count) {
749 		mutex_unlock(&dev->struct_mutex);
750 		atomic_dec(&dev->buf_alloc);
751 		return -ENOMEM;	/* May only call once for each order */
752 	}
753 
754 	if (count < 0 || count > 4096) {
755 		mutex_unlock(&dev->struct_mutex);
756 		atomic_dec(&dev->buf_alloc);
757 		return -EINVAL;
758 	}
759 
760 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
761 	if (!entry->buflist) {
762 		mutex_unlock(&dev->struct_mutex);
763 		atomic_dec(&dev->buf_alloc);
764 		return -ENOMEM;
765 	}
766 
767 	entry->buf_size = size;
768 	entry->page_order = page_order;
769 
770 	offset = 0;
771 
772 	while (entry->buf_count < count) {
773 		buf = &entry->buflist[entry->buf_count];
774 		buf->idx = dma->buf_count + entry->buf_count;
775 		buf->total = alignment;
776 		buf->order = order;
777 		buf->used = 0;
778 
779 		buf->offset = (dma->byte_count + offset);
780 		buf->bus_address = agp_offset + offset;
781 		buf->address = (void *)(agp_offset + offset);
782 		buf->next = NULL;
783 		buf->waiting = 0;
784 		buf->pending = 0;
785 		buf->file_priv = NULL;
786 
787 		buf->dev_priv_size = dev->driver->dev_priv_size;
788 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
789 		if (!buf->dev_private) {
790 			/* Set count correctly so we free the proper amount. */
791 			entry->buf_count = count;
792 			drm_cleanup_buf_error(dev, entry);
793 			mutex_unlock(&dev->struct_mutex);
794 			atomic_dec(&dev->buf_alloc);
795 			return -ENOMEM;
796 		}
797 
798 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
799 
800 		offset += alignment;
801 		entry->buf_count++;
802 		byte_count += PAGE_SIZE << page_order;
803 	}
804 
805 	DRM_DEBUG("byte_count: %d\n", byte_count);
806 
807 	temp_buflist = krealloc(dma->buflist,
808 				(dma->buf_count + entry->buf_count) *
809 				sizeof(*dma->buflist), GFP_KERNEL);
810 	if (!temp_buflist) {
811 		/* Free the entry because it isn't valid */
812 		drm_cleanup_buf_error(dev, entry);
813 		mutex_unlock(&dev->struct_mutex);
814 		atomic_dec(&dev->buf_alloc);
815 		return -ENOMEM;
816 	}
817 	dma->buflist = temp_buflist;
818 
819 	for (i = 0; i < entry->buf_count; i++) {
820 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
821 	}
822 
823 	dma->buf_count += entry->buf_count;
824 	dma->seg_count += entry->seg_count;
825 	dma->page_count += byte_count >> PAGE_SHIFT;
826 	dma->byte_count += byte_count;
827 
828 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
829 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
830 
831 	mutex_unlock(&dev->struct_mutex);
832 
833 	request->count = entry->buf_count;
834 	request->size = size;
835 
836 	dma->flags = _DRM_DMA_USE_AGP;
837 
838 	atomic_dec(&dev->buf_alloc);
839 	return 0;
840 }
841 EXPORT_SYMBOL(drm_legacy_addbufs_agp);
842 #endif /* CONFIG_AGP */
843 
844 int drm_legacy_addbufs_pci(struct drm_device *dev,
845 			   struct drm_buf_desc *request)
846 {
847 	struct drm_device_dma *dma = dev->dma;
848 	int count;
849 	int order;
850 	int size;
851 	int total;
852 	int page_order;
853 	struct drm_buf_entry *entry;
854 	drm_dma_handle_t *dmah;
855 	struct drm_buf *buf;
856 	int alignment;
857 	unsigned long offset;
858 	int i;
859 	int byte_count;
860 	int page_count;
861 	unsigned long *temp_pagelist;
862 	struct drm_buf **temp_buflist;
863 
864 	if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
865 		return -EOPNOTSUPP;
866 
867 	if (!dma)
868 		return -EINVAL;
869 
870 	if (!capable(CAP_SYS_ADMIN))
871 		return -EPERM;
872 
873 	count = request->count;
874 	order = order_base_2(request->size);
875 	size = 1 << order;
876 
877 	DRM_DEBUG("count=%d, size=%d (%d), order=%d\n",
878 		  request->count, request->size, size, order);
879 
880 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
881 		return -EINVAL;
882 
883 	alignment = (request->flags & _DRM_PAGE_ALIGN)
884 	    ? PAGE_ALIGN(size) : size;
885 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
886 	total = PAGE_SIZE << page_order;
887 
888 	spin_lock(&dev->buf_lock);
889 	if (dev->buf_use) {
890 		spin_unlock(&dev->buf_lock);
891 		return -EBUSY;
892 	}
893 	atomic_inc(&dev->buf_alloc);
894 	spin_unlock(&dev->buf_lock);
895 
896 	mutex_lock(&dev->struct_mutex);
897 	entry = &dma->bufs[order];
898 	if (entry->buf_count) {
899 		mutex_unlock(&dev->struct_mutex);
900 		atomic_dec(&dev->buf_alloc);
901 		return -ENOMEM;	/* May only call once for each order */
902 	}
903 
904 	if (count < 0 || count > 4096) {
905 		mutex_unlock(&dev->struct_mutex);
906 		atomic_dec(&dev->buf_alloc);
907 		return -EINVAL;
908 	}
909 
910 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
911 	if (!entry->buflist) {
912 		mutex_unlock(&dev->struct_mutex);
913 		atomic_dec(&dev->buf_alloc);
914 		return -ENOMEM;
915 	}
916 
917 	entry->seglist = kcalloc(count, sizeof(*entry->seglist), GFP_KERNEL);
918 	if (!entry->seglist) {
919 		kfree(entry->buflist);
920 		mutex_unlock(&dev->struct_mutex);
921 		atomic_dec(&dev->buf_alloc);
922 		return -ENOMEM;
923 	}
924 
925 	/* Keep the original pagelist until we know all the allocations
926 	 * have succeeded
927 	 */
928 	temp_pagelist = kmalloc_array(dma->page_count + (count << page_order),
929 				      sizeof(*dma->pagelist),
930 				      GFP_KERNEL);
931 	if (!temp_pagelist) {
932 		kfree(entry->buflist);
933 		kfree(entry->seglist);
934 		mutex_unlock(&dev->struct_mutex);
935 		atomic_dec(&dev->buf_alloc);
936 		return -ENOMEM;
937 	}
938 	memcpy(temp_pagelist,
939 	       dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
940 	DRM_DEBUG("pagelist: %d entries\n",
941 		  dma->page_count + (count << page_order));
942 
943 	entry->buf_size = size;
944 	entry->page_order = page_order;
945 	byte_count = 0;
946 	page_count = 0;
947 
948 	while (entry->buf_count < count) {
949 
950 		dmah = drm_pci_alloc(dev, PAGE_SIZE << page_order, 0x1000);
951 
952 		if (!dmah) {
953 			/* Set count correctly so we free the proper amount. */
954 			entry->buf_count = count;
955 			entry->seg_count = count;
956 			drm_cleanup_buf_error(dev, entry);
957 			kfree(temp_pagelist);
958 			mutex_unlock(&dev->struct_mutex);
959 			atomic_dec(&dev->buf_alloc);
960 			return -ENOMEM;
961 		}
962 		entry->seglist[entry->seg_count++] = dmah;
963 		for (i = 0; i < (1 << page_order); i++) {
964 			DRM_DEBUG("page %d @ 0x%08lx\n",
965 				  dma->page_count + page_count,
966 				  (unsigned long)dmah->vaddr + PAGE_SIZE * i);
967 			temp_pagelist[dma->page_count + page_count++]
968 				= (unsigned long)dmah->vaddr + PAGE_SIZE * i;
969 		}
970 		for (offset = 0;
971 		     offset + size <= total && entry->buf_count < count;
972 		     offset += alignment, ++entry->buf_count) {
973 			buf = &entry->buflist[entry->buf_count];
974 			buf->idx = dma->buf_count + entry->buf_count;
975 			buf->total = alignment;
976 			buf->order = order;
977 			buf->used = 0;
978 			buf->offset = (dma->byte_count + byte_count + offset);
979 			buf->address = (void *)(dmah->vaddr + offset);
980 			buf->bus_address = dmah->busaddr + offset;
981 			buf->next = NULL;
982 			buf->waiting = 0;
983 			buf->pending = 0;
984 			buf->file_priv = NULL;
985 
986 			buf->dev_priv_size = dev->driver->dev_priv_size;
987 			buf->dev_private = kzalloc(buf->dev_priv_size,
988 						GFP_KERNEL);
989 			if (!buf->dev_private) {
990 				/* Set count correctly so we free the proper amount. */
991 				entry->buf_count = count;
992 				entry->seg_count = count;
993 				drm_cleanup_buf_error(dev, entry);
994 				kfree(temp_pagelist);
995 				mutex_unlock(&dev->struct_mutex);
996 				atomic_dec(&dev->buf_alloc);
997 				return -ENOMEM;
998 			}
999 
1000 			DRM_DEBUG("buffer %d @ %p\n",
1001 				  entry->buf_count, buf->address);
1002 		}
1003 		byte_count += PAGE_SIZE << page_order;
1004 	}
1005 
1006 	temp_buflist = krealloc(dma->buflist,
1007 				(dma->buf_count + entry->buf_count) *
1008 				sizeof(*dma->buflist), GFP_KERNEL);
1009 	if (!temp_buflist) {
1010 		/* Free the entry because it isn't valid */
1011 		drm_cleanup_buf_error(dev, entry);
1012 		kfree(temp_pagelist);
1013 		mutex_unlock(&dev->struct_mutex);
1014 		atomic_dec(&dev->buf_alloc);
1015 		return -ENOMEM;
1016 	}
1017 	dma->buflist = temp_buflist;
1018 
1019 	for (i = 0; i < entry->buf_count; i++) {
1020 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1021 	}
1022 
1023 	/* No allocations failed, so now we can replace the original pagelist
1024 	 * with the new one.
1025 	 */
1026 	if (dma->page_count) {
1027 		kfree(dma->pagelist);
1028 	}
1029 	dma->pagelist = temp_pagelist;
1030 
1031 	dma->buf_count += entry->buf_count;
1032 	dma->seg_count += entry->seg_count;
1033 	dma->page_count += entry->seg_count << page_order;
1034 	dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);
1035 
1036 	mutex_unlock(&dev->struct_mutex);
1037 
1038 	request->count = entry->buf_count;
1039 	request->size = size;
1040 
1041 	if (request->flags & _DRM_PCI_BUFFER_RO)
1042 		dma->flags = _DRM_DMA_USE_PCI_RO;
1043 
1044 	atomic_dec(&dev->buf_alloc);
1045 	return 0;
1046 
1047 }
1048 EXPORT_SYMBOL(drm_legacy_addbufs_pci);
1049 
1050 static int drm_legacy_addbufs_sg(struct drm_device *dev,
1051 				 struct drm_buf_desc *request)
1052 {
1053 	struct drm_device_dma *dma = dev->dma;
1054 	struct drm_buf_entry *entry;
1055 	struct drm_buf *buf;
1056 	unsigned long offset;
1057 	unsigned long agp_offset;
1058 	int count;
1059 	int order;
1060 	int size;
1061 	int alignment;
1062 	int page_order;
1063 	int total;
1064 	int byte_count;
1065 	int i;
1066 	struct drm_buf **temp_buflist;
1067 
1068 	if (!drm_core_check_feature(dev, DRIVER_SG))
1069 		return -EOPNOTSUPP;
1070 
1071 	if (!dma)
1072 		return -EINVAL;
1073 
1074 	if (!capable(CAP_SYS_ADMIN))
1075 		return -EPERM;
1076 
1077 	count = request->count;
1078 	order = order_base_2(request->size);
1079 	size = 1 << order;
1080 
1081 	alignment = (request->flags & _DRM_PAGE_ALIGN)
1082 	    ? PAGE_ALIGN(size) : size;
1083 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
1084 	total = PAGE_SIZE << page_order;
1085 
1086 	byte_count = 0;
1087 	agp_offset = request->agp_start;
1088 
1089 	DRM_DEBUG("count:      %d\n", count);
1090 	DRM_DEBUG("order:      %d\n", order);
1091 	DRM_DEBUG("size:       %d\n", size);
1092 	DRM_DEBUG("agp_offset: %lu\n", agp_offset);
1093 	DRM_DEBUG("alignment:  %d\n", alignment);
1094 	DRM_DEBUG("page_order: %d\n", page_order);
1095 	DRM_DEBUG("total:      %d\n", total);
1096 
1097 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1098 		return -EINVAL;
1099 
1100 	spin_lock(&dev->buf_lock);
1101 	if (dev->buf_use) {
1102 		spin_unlock(&dev->buf_lock);
1103 		return -EBUSY;
1104 	}
1105 	atomic_inc(&dev->buf_alloc);
1106 	spin_unlock(&dev->buf_lock);
1107 
1108 	mutex_lock(&dev->struct_mutex);
1109 	entry = &dma->bufs[order];
1110 	if (entry->buf_count) {
1111 		mutex_unlock(&dev->struct_mutex);
1112 		atomic_dec(&dev->buf_alloc);
1113 		return -ENOMEM;	/* May only call once for each order */
1114 	}
1115 
1116 	if (count < 0 || count > 4096) {
1117 		mutex_unlock(&dev->struct_mutex);
1118 		atomic_dec(&dev->buf_alloc);
1119 		return -EINVAL;
1120 	}
1121 
1122 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
1123 	if (!entry->buflist) {
1124 		mutex_unlock(&dev->struct_mutex);
1125 		atomic_dec(&dev->buf_alloc);
1126 		return -ENOMEM;
1127 	}
1128 
1129 	entry->buf_size = size;
1130 	entry->page_order = page_order;
1131 
1132 	offset = 0;
1133 
1134 	while (entry->buf_count < count) {
1135 		buf = &entry->buflist[entry->buf_count];
1136 		buf->idx = dma->buf_count + entry->buf_count;
1137 		buf->total = alignment;
1138 		buf->order = order;
1139 		buf->used = 0;
1140 
1141 		buf->offset = (dma->byte_count + offset);
1142 		buf->bus_address = agp_offset + offset;
1143 		buf->address = (void *)(agp_offset + offset
1144 					+ (unsigned long)dev->sg->virtual);
1145 		buf->next = NULL;
1146 		buf->waiting = 0;
1147 		buf->pending = 0;
1148 		buf->file_priv = NULL;
1149 
1150 		buf->dev_priv_size = dev->driver->dev_priv_size;
1151 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
1152 		if (!buf->dev_private) {
1153 			/* Set count correctly so we free the proper amount. */
1154 			entry->buf_count = count;
1155 			drm_cleanup_buf_error(dev, entry);
1156 			mutex_unlock(&dev->struct_mutex);
1157 			atomic_dec(&dev->buf_alloc);
1158 			return -ENOMEM;
1159 		}
1160 
1161 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
1162 
1163 		offset += alignment;
1164 		entry->buf_count++;
1165 		byte_count += PAGE_SIZE << page_order;
1166 	}
1167 
1168 	DRM_DEBUG("byte_count: %d\n", byte_count);
1169 
1170 	temp_buflist = krealloc(dma->buflist,
1171 				(dma->buf_count + entry->buf_count) *
1172 				sizeof(*dma->buflist), GFP_KERNEL);
1173 	if (!temp_buflist) {
1174 		/* Free the entry because it isn't valid */
1175 		drm_cleanup_buf_error(dev, entry);
1176 		mutex_unlock(&dev->struct_mutex);
1177 		atomic_dec(&dev->buf_alloc);
1178 		return -ENOMEM;
1179 	}
1180 	dma->buflist = temp_buflist;
1181 
1182 	for (i = 0; i < entry->buf_count; i++) {
1183 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1184 	}
1185 
1186 	dma->buf_count += entry->buf_count;
1187 	dma->seg_count += entry->seg_count;
1188 	dma->page_count += byte_count >> PAGE_SHIFT;
1189 	dma->byte_count += byte_count;
1190 
1191 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
1192 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
1193 
1194 	mutex_unlock(&dev->struct_mutex);
1195 
1196 	request->count = entry->buf_count;
1197 	request->size = size;
1198 
1199 	dma->flags = _DRM_DMA_USE_SG;
1200 
1201 	atomic_dec(&dev->buf_alloc);
1202 	return 0;
1203 }
1204 
1205 /**
1206  * Add buffers for DMA transfers (ioctl).
1207  *
1208  * \param inode device inode.
1209  * \param file_priv DRM file private.
1210  * \param cmd command.
1211  * \param arg pointer to a struct drm_buf_desc request.
1212  * \return zero on success or a negative number on failure.
1213  *
1214  * According with the memory type specified in drm_buf_desc::flags and the
1215  * build options, it dispatches the call either to addbufs_agp(),
1216  * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
1217  * PCI memory respectively.
1218  */
1219 int drm_legacy_addbufs(struct drm_device *dev, void *data,
1220 		       struct drm_file *file_priv)
1221 {
1222 	struct drm_buf_desc *request = data;
1223 	int ret;
1224 
1225 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1226 		return -EOPNOTSUPP;
1227 
1228 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1229 		return -EOPNOTSUPP;
1230 
1231 #if IS_ENABLED(CONFIG_AGP)
1232 	if (request->flags & _DRM_AGP_BUFFER)
1233 		ret = drm_legacy_addbufs_agp(dev, request);
1234 	else
1235 #endif
1236 	if (request->flags & _DRM_SG_BUFFER)
1237 		ret = drm_legacy_addbufs_sg(dev, request);
1238 	else if (request->flags & _DRM_FB_BUFFER)
1239 		ret = -EINVAL;
1240 	else
1241 		ret = drm_legacy_addbufs_pci(dev, request);
1242 
1243 	return ret;
1244 }
1245 
1246 /**
1247  * Get information about the buffer mappings.
1248  *
1249  * This was originally mean for debugging purposes, or by a sophisticated
1250  * client library to determine how best to use the available buffers (e.g.,
1251  * large buffers can be used for image transfer).
1252  *
1253  * \param inode device inode.
1254  * \param file_priv DRM file private.
1255  * \param cmd command.
1256  * \param arg pointer to a drm_buf_info structure.
1257  * \return zero on success or a negative number on failure.
1258  *
1259  * Increments drm_device::buf_use while holding the drm_device::buf_lock
1260  * lock, preventing of allocating more buffers after this call. Information
1261  * about each requested buffer is then copied into user space.
1262  */
1263 int __drm_legacy_infobufs(struct drm_device *dev,
1264 			void *data, int *p,
1265 			int (*f)(void *, int, struct drm_buf_entry *))
1266 {
1267 	struct drm_device_dma *dma = dev->dma;
1268 	int i;
1269 	int count;
1270 
1271 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1272 		return -EOPNOTSUPP;
1273 
1274 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1275 		return -EOPNOTSUPP;
1276 
1277 	if (!dma)
1278 		return -EINVAL;
1279 
1280 	spin_lock(&dev->buf_lock);
1281 	if (atomic_read(&dev->buf_alloc)) {
1282 		spin_unlock(&dev->buf_lock);
1283 		return -EBUSY;
1284 	}
1285 	++dev->buf_use;		/* Can't allocate more after this call */
1286 	spin_unlock(&dev->buf_lock);
1287 
1288 	for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1289 		if (dma->bufs[i].buf_count)
1290 			++count;
1291 	}
1292 
1293 	DRM_DEBUG("count = %d\n", count);
1294 
1295 	if (*p >= count) {
1296 		for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1297 			struct drm_buf_entry *from = &dma->bufs[i];
1298 			if (from->buf_count) {
1299 				if (f(data, count, from) < 0)
1300 					return -EFAULT;
1301 				DRM_DEBUG("%d %d %d %d %d\n",
1302 					  i,
1303 					  dma->bufs[i].buf_count,
1304 					  dma->bufs[i].buf_size,
1305 					  dma->bufs[i].low_mark,
1306 					  dma->bufs[i].high_mark);
1307 				++count;
1308 			}
1309 		}
1310 	}
1311 	*p = count;
1312 
1313 	return 0;
1314 }
1315 
1316 static int copy_one_buf(void *data, int count, struct drm_buf_entry *from)
1317 {
1318 	struct drm_buf_info *request = data;
1319 	struct drm_buf_desc __user *to = &request->list[count];
1320 	struct drm_buf_desc v = {.count = from->buf_count,
1321 				 .size = from->buf_size,
1322 				 .low_mark = from->low_mark,
1323 				 .high_mark = from->high_mark};
1324 	return copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags));
1325 }
1326 
1327 int drm_legacy_infobufs(struct drm_device *dev, void *data,
1328 			struct drm_file *file_priv)
1329 {
1330 	struct drm_buf_info *request = data;
1331 	return __drm_legacy_infobufs(dev, data, &request->count, copy_one_buf);
1332 }
1333 
1334 /**
1335  * Specifies a low and high water mark for buffer allocation
1336  *
1337  * \param inode device inode.
1338  * \param file_priv DRM file private.
1339  * \param cmd command.
1340  * \param arg a pointer to a drm_buf_desc structure.
1341  * \return zero on success or a negative number on failure.
1342  *
1343  * Verifies that the size order is bounded between the admissible orders and
1344  * updates the respective drm_device_dma::bufs entry low and high water mark.
1345  *
1346  * \note This ioctl is deprecated and mostly never used.
1347  */
1348 int drm_legacy_markbufs(struct drm_device *dev, void *data,
1349 			struct drm_file *file_priv)
1350 {
1351 	struct drm_device_dma *dma = dev->dma;
1352 	struct drm_buf_desc *request = data;
1353 	int order;
1354 	struct drm_buf_entry *entry;
1355 
1356 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1357 		return -EOPNOTSUPP;
1358 
1359 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1360 		return -EOPNOTSUPP;
1361 
1362 	if (!dma)
1363 		return -EINVAL;
1364 
1365 	DRM_DEBUG("%d, %d, %d\n",
1366 		  request->size, request->low_mark, request->high_mark);
1367 	order = order_base_2(request->size);
1368 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1369 		return -EINVAL;
1370 	entry = &dma->bufs[order];
1371 
1372 	if (request->low_mark < 0 || request->low_mark > entry->buf_count)
1373 		return -EINVAL;
1374 	if (request->high_mark < 0 || request->high_mark > entry->buf_count)
1375 		return -EINVAL;
1376 
1377 	entry->low_mark = request->low_mark;
1378 	entry->high_mark = request->high_mark;
1379 
1380 	return 0;
1381 }
1382 
1383 /**
1384  * Unreserve the buffers in list, previously reserved using drmDMA.
1385  *
1386  * \param inode device inode.
1387  * \param file_priv DRM file private.
1388  * \param cmd command.
1389  * \param arg pointer to a drm_buf_free structure.
1390  * \return zero on success or a negative number on failure.
1391  *
1392  * Calls free_buffer() for each used buffer.
1393  * This function is primarily used for debugging.
1394  */
1395 int drm_legacy_freebufs(struct drm_device *dev, void *data,
1396 			struct drm_file *file_priv)
1397 {
1398 	struct drm_device_dma *dma = dev->dma;
1399 	struct drm_buf_free *request = data;
1400 	int i;
1401 	int idx;
1402 	struct drm_buf *buf;
1403 
1404 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1405 		return -EOPNOTSUPP;
1406 
1407 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1408 		return -EOPNOTSUPP;
1409 
1410 	if (!dma)
1411 		return -EINVAL;
1412 
1413 	DRM_DEBUG("%d\n", request->count);
1414 	for (i = 0; i < request->count; i++) {
1415 		if (copy_from_user(&idx, &request->list[i], sizeof(idx)))
1416 			return -EFAULT;
1417 		if (idx < 0 || idx >= dma->buf_count) {
1418 			DRM_ERROR("Index %d (of %d max)\n",
1419 				  idx, dma->buf_count - 1);
1420 			return -EINVAL;
1421 		}
1422 		idx = array_index_nospec(idx, dma->buf_count);
1423 		buf = dma->buflist[idx];
1424 		if (buf->file_priv != file_priv) {
1425 			DRM_ERROR("Process %d freeing buffer not owned\n",
1426 				  task_pid_nr(current));
1427 			return -EINVAL;
1428 		}
1429 		drm_legacy_free_buffer(dev, buf);
1430 	}
1431 
1432 	return 0;
1433 }
1434 
1435 /**
1436  * Maps all of the DMA buffers into client-virtual space (ioctl).
1437  *
1438  * \param inode device inode.
1439  * \param file_priv DRM file private.
1440  * \param cmd command.
1441  * \param arg pointer to a drm_buf_map structure.
1442  * \return zero on success or a negative number on failure.
1443  *
1444  * Maps the AGP, SG or PCI buffer region with vm_mmap(), and copies information
1445  * about each buffer into user space. For PCI buffers, it calls vm_mmap() with
1446  * offset equal to 0, which drm_mmap() interpretes as PCI buffers and calls
1447  * drm_mmap_dma().
1448  */
1449 int __drm_legacy_mapbufs(struct drm_device *dev, void *data, int *p,
1450 			 void __user **v,
1451 			 int (*f)(void *, int, unsigned long,
1452 				 struct drm_buf *),
1453 				 struct drm_file *file_priv)
1454 {
1455 	struct drm_device_dma *dma = dev->dma;
1456 	int retcode = 0;
1457 	unsigned long virtual;
1458 	int i;
1459 
1460 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1461 		return -EOPNOTSUPP;
1462 
1463 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1464 		return -EOPNOTSUPP;
1465 
1466 	if (!dma)
1467 		return -EINVAL;
1468 
1469 	spin_lock(&dev->buf_lock);
1470 	if (atomic_read(&dev->buf_alloc)) {
1471 		spin_unlock(&dev->buf_lock);
1472 		return -EBUSY;
1473 	}
1474 	dev->buf_use++;		/* Can't allocate more after this call */
1475 	spin_unlock(&dev->buf_lock);
1476 
1477 	if (*p >= dma->buf_count) {
1478 		if ((dev->agp && (dma->flags & _DRM_DMA_USE_AGP))
1479 		    || (drm_core_check_feature(dev, DRIVER_SG)
1480 			&& (dma->flags & _DRM_DMA_USE_SG))) {
1481 			struct drm_local_map *map = dev->agp_buffer_map;
1482 			unsigned long token = dev->agp_buffer_token;
1483 
1484 			if (!map) {
1485 				retcode = -EINVAL;
1486 				goto done;
1487 			}
1488 			virtual = vm_mmap(file_priv->filp, 0, map->size,
1489 					  PROT_READ | PROT_WRITE,
1490 					  MAP_SHARED,
1491 					  token);
1492 		} else {
1493 			virtual = vm_mmap(file_priv->filp, 0, dma->byte_count,
1494 					  PROT_READ | PROT_WRITE,
1495 					  MAP_SHARED, 0);
1496 		}
1497 		if (virtual > -1024UL) {
1498 			/* Real error */
1499 			retcode = (signed long)virtual;
1500 			goto done;
1501 		}
1502 		*v = (void __user *)virtual;
1503 
1504 		for (i = 0; i < dma->buf_count; i++) {
1505 			if (f(data, i, virtual, dma->buflist[i]) < 0) {
1506 				retcode = -EFAULT;
1507 				goto done;
1508 			}
1509 		}
1510 	}
1511       done:
1512 	*p = dma->buf_count;
1513 	DRM_DEBUG("%d buffers, retcode = %d\n", *p, retcode);
1514 
1515 	return retcode;
1516 }
1517 
1518 static int map_one_buf(void *data, int idx, unsigned long virtual,
1519 			struct drm_buf *buf)
1520 {
1521 	struct drm_buf_map *request = data;
1522 	unsigned long address = virtual + buf->offset;	/* *** */
1523 
1524 	if (copy_to_user(&request->list[idx].idx, &buf->idx,
1525 			 sizeof(request->list[0].idx)))
1526 		return -EFAULT;
1527 	if (copy_to_user(&request->list[idx].total, &buf->total,
1528 			 sizeof(request->list[0].total)))
1529 		return -EFAULT;
1530 	if (clear_user(&request->list[idx].used, sizeof(int)))
1531 		return -EFAULT;
1532 	if (copy_to_user(&request->list[idx].address, &address,
1533 			 sizeof(address)))
1534 		return -EFAULT;
1535 	return 0;
1536 }
1537 
1538 int drm_legacy_mapbufs(struct drm_device *dev, void *data,
1539 		       struct drm_file *file_priv)
1540 {
1541 	struct drm_buf_map *request = data;
1542 	return __drm_legacy_mapbufs(dev, data, &request->count,
1543 				    &request->virtual, map_one_buf,
1544 				    file_priv);
1545 }
1546 
1547 int drm_legacy_dma_ioctl(struct drm_device *dev, void *data,
1548 		  struct drm_file *file_priv)
1549 {
1550 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1551 		return -EOPNOTSUPP;
1552 
1553 	if (dev->driver->dma_ioctl)
1554 		return dev->driver->dma_ioctl(dev, data, file_priv);
1555 	else
1556 		return -EINVAL;
1557 }
1558 
1559 struct drm_local_map *drm_legacy_getsarea(struct drm_device *dev)
1560 {
1561 	struct drm_map_list *entry;
1562 
1563 	list_for_each_entry(entry, &dev->maplist, head) {
1564 		if (entry->map && entry->map->type == _DRM_SHM &&
1565 		    (entry->map->flags & _DRM_CONTAINS_LOCK)) {
1566 			return entry->map;
1567 		}
1568 	}
1569 	return NULL;
1570 }
1571 EXPORT_SYMBOL(drm_legacy_getsarea);
1572