xref: /openbmc/linux/drivers/gpu/drm/drm_bufs.c (revision f20c7d91)
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/export.h>
32 #include <linux/log2.h>
33 #include <linux/mm.h>
34 #include <linux/mman.h>
35 #include <linux/nospec.h>
36 #include <linux/pci.h>
37 #include <linux/slab.h>
38 #include <linux/uaccess.h>
39 #include <linux/vmalloc.h>
40 
41 #include <asm/shmparam.h>
42 
43 #include <drm/drm_agpsupport.h>
44 #include <drm/drm_device.h>
45 #include <drm/drm_drv.h>
46 #include <drm/drm_file.h>
47 #include <drm/drm_print.h>
48 
49 #include "drm_legacy.h"
50 
51 
52 static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
53 						  struct drm_local_map *map)
54 {
55 	struct drm_map_list *entry;
56 	list_for_each_entry(entry, &dev->maplist, head) {
57 		/*
58 		 * Because the kernel-userspace ABI is fixed at a 32-bit offset
59 		 * while PCI resources may live above that, we only compare the
60 		 * lower 32 bits of the map offset for maps of type
61 		 * _DRM_FRAMEBUFFER or _DRM_REGISTERS.
62 		 * It is assumed that if a driver have more than one resource
63 		 * of each type, the lower 32 bits are different.
64 		 */
65 		if (!entry->map ||
66 		    map->type != entry->map->type ||
67 		    entry->master != dev->master)
68 			continue;
69 		switch (map->type) {
70 		case _DRM_SHM:
71 			if (map->flags != _DRM_CONTAINS_LOCK)
72 				break;
73 			return entry;
74 		case _DRM_REGISTERS:
75 		case _DRM_FRAME_BUFFER:
76 			if ((entry->map->offset & 0xffffffff) ==
77 			    (map->offset & 0xffffffff))
78 				return entry;
79 		default: /* Make gcc happy */
80 			;
81 		}
82 		if (entry->map->offset == map->offset)
83 			return entry;
84 	}
85 
86 	return NULL;
87 }
88 
89 static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
90 			  unsigned long user_token, int hashed_handle, int shm)
91 {
92 	int use_hashed_handle, shift;
93 	unsigned long add;
94 
95 #if (BITS_PER_LONG == 64)
96 	use_hashed_handle = ((user_token & 0xFFFFFFFF00000000UL) || hashed_handle);
97 #elif (BITS_PER_LONG == 32)
98 	use_hashed_handle = hashed_handle;
99 #else
100 #error Unsupported long size. Neither 64 nor 32 bits.
101 #endif
102 
103 	if (!use_hashed_handle) {
104 		int ret;
105 		hash->key = user_token >> PAGE_SHIFT;
106 		ret = drm_ht_insert_item(&dev->map_hash, hash);
107 		if (ret != -EINVAL)
108 			return ret;
109 	}
110 
111 	shift = 0;
112 	add = DRM_MAP_HASH_OFFSET >> PAGE_SHIFT;
113 	if (shm && (SHMLBA > PAGE_SIZE)) {
114 		int bits = ilog2(SHMLBA >> PAGE_SHIFT) + 1;
115 
116 		/* For shared memory, we have to preserve the SHMLBA
117 		 * bits of the eventual vma->vm_pgoff value during
118 		 * mmap().  Otherwise we run into cache aliasing problems
119 		 * on some platforms.  On these platforms, the pgoff of
120 		 * a mmap() request is used to pick a suitable virtual
121 		 * address for the mmap() region such that it will not
122 		 * cause cache aliasing problems.
123 		 *
124 		 * Therefore, make sure the SHMLBA relevant bits of the
125 		 * hash value we use are equal to those in the original
126 		 * kernel virtual address.
127 		 */
128 		shift = bits;
129 		add |= ((user_token >> PAGE_SHIFT) & ((1UL << bits) - 1UL));
130 	}
131 
132 	return drm_ht_just_insert_please(&dev->map_hash, hash,
133 					 user_token, 32 - PAGE_SHIFT - 3,
134 					 shift, add);
135 }
136 
137 /*
138  * Core function to create a range of memory available for mapping by a
139  * non-root process.
140  *
141  * Adjusts the memory offset to its absolute value according to the mapping
142  * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
143  * applicable and if supported by the kernel.
144  */
145 static int drm_addmap_core(struct drm_device *dev, resource_size_t offset,
146 			   unsigned int size, enum drm_map_type type,
147 			   enum drm_map_flags flags,
148 			   struct drm_map_list **maplist)
149 {
150 	struct drm_local_map *map;
151 	struct drm_map_list *list;
152 	unsigned long user_token;
153 	int ret;
154 
155 	map = kmalloc(sizeof(*map), GFP_KERNEL);
156 	if (!map)
157 		return -ENOMEM;
158 
159 	map->offset = offset;
160 	map->size = size;
161 	map->flags = flags;
162 	map->type = type;
163 
164 	/* Only allow shared memory to be removable since we only keep enough
165 	 * book keeping information about shared memory to allow for removal
166 	 * when processes fork.
167 	 */
168 	if ((map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM) {
169 		kfree(map);
170 		return -EINVAL;
171 	}
172 	DRM_DEBUG("offset = 0x%08llx, size = 0x%08lx, type = %d\n",
173 		  (unsigned long long)map->offset, map->size, map->type);
174 
175 	/* page-align _DRM_SHM maps. They are allocated here so there is no security
176 	 * hole created by that and it works around various broken drivers that use
177 	 * a non-aligned quantity to map the SAREA. --BenH
178 	 */
179 	if (map->type == _DRM_SHM)
180 		map->size = PAGE_ALIGN(map->size);
181 
182 	if ((map->offset & (~(resource_size_t)PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
183 		kfree(map);
184 		return -EINVAL;
185 	}
186 	map->mtrr = -1;
187 	map->handle = NULL;
188 
189 	switch (map->type) {
190 	case _DRM_REGISTERS:
191 	case _DRM_FRAME_BUFFER:
192 #if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__) && !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__arm__)
193 		if (map->offset + (map->size-1) < map->offset ||
194 		    map->offset < virt_to_phys(high_memory)) {
195 			kfree(map);
196 			return -EINVAL;
197 		}
198 #endif
199 		/* Some drivers preinitialize some maps, without the X Server
200 		 * needing to be aware of it.  Therefore, we just return success
201 		 * when the server tries to create a duplicate map.
202 		 */
203 		list = drm_find_matching_map(dev, map);
204 		if (list != NULL) {
205 			if (list->map->size != map->size) {
206 				DRM_DEBUG("Matching maps of type %d with "
207 					  "mismatched sizes, (%ld vs %ld)\n",
208 					  map->type, map->size,
209 					  list->map->size);
210 				list->map->size = map->size;
211 			}
212 
213 			kfree(map);
214 			*maplist = list;
215 			return 0;
216 		}
217 
218 		if (map->type == _DRM_FRAME_BUFFER ||
219 		    (map->flags & _DRM_WRITE_COMBINING)) {
220 			map->mtrr =
221 				arch_phys_wc_add(map->offset, map->size);
222 		}
223 		if (map->type == _DRM_REGISTERS) {
224 			if (map->flags & _DRM_WRITE_COMBINING)
225 				map->handle = ioremap_wc(map->offset,
226 							 map->size);
227 			else
228 				map->handle = ioremap(map->offset, map->size);
229 			if (!map->handle) {
230 				kfree(map);
231 				return -ENOMEM;
232 			}
233 		}
234 
235 		break;
236 	case _DRM_SHM:
237 		list = drm_find_matching_map(dev, map);
238 		if (list != NULL) {
239 			if (list->map->size != map->size) {
240 				DRM_DEBUG("Matching maps of type %d with "
241 					  "mismatched sizes, (%ld vs %ld)\n",
242 					  map->type, map->size, list->map->size);
243 				list->map->size = map->size;
244 			}
245 
246 			kfree(map);
247 			*maplist = list;
248 			return 0;
249 		}
250 		map->handle = vmalloc_user(map->size);
251 		DRM_DEBUG("%lu %d %p\n",
252 			  map->size, order_base_2(map->size), map->handle);
253 		if (!map->handle) {
254 			kfree(map);
255 			return -ENOMEM;
256 		}
257 		map->offset = (unsigned long)map->handle;
258 		if (map->flags & _DRM_CONTAINS_LOCK) {
259 			/* Prevent a 2nd X Server from creating a 2nd lock */
260 			if (dev->master->lock.hw_lock != NULL) {
261 				vfree(map->handle);
262 				kfree(map);
263 				return -EBUSY;
264 			}
265 			dev->sigdata.lock = dev->master->lock.hw_lock = map->handle;	/* Pointer to lock */
266 		}
267 		break;
268 	case _DRM_AGP: {
269 		struct drm_agp_mem *entry;
270 		int valid = 0;
271 
272 		if (!dev->agp) {
273 			kfree(map);
274 			return -EINVAL;
275 		}
276 #ifdef __alpha__
277 		map->offset += dev->hose->mem_space->start;
278 #endif
279 		/* In some cases (i810 driver), user space may have already
280 		 * added the AGP base itself, because dev->agp->base previously
281 		 * only got set during AGP enable.  So, only add the base
282 		 * address if the map's offset isn't already within the
283 		 * aperture.
284 		 */
285 		if (map->offset < dev->agp->base ||
286 		    map->offset > dev->agp->base +
287 		    dev->agp->agp_info.aper_size * 1024 * 1024 - 1) {
288 			map->offset += dev->agp->base;
289 		}
290 		map->mtrr = dev->agp->agp_mtrr;	/* for getmap */
291 
292 		/* This assumes the DRM is in total control of AGP space.
293 		 * It's not always the case as AGP can be in the control
294 		 * of user space (i.e. i810 driver). So this loop will get
295 		 * skipped and we double check that dev->agp->memory is
296 		 * actually set as well as being invalid before EPERM'ing
297 		 */
298 		list_for_each_entry(entry, &dev->agp->memory, head) {
299 			if ((map->offset >= entry->bound) &&
300 			    (map->offset + map->size <= entry->bound + entry->pages * PAGE_SIZE)) {
301 				valid = 1;
302 				break;
303 			}
304 		}
305 		if (!list_empty(&dev->agp->memory) && !valid) {
306 			kfree(map);
307 			return -EPERM;
308 		}
309 		DRM_DEBUG("AGP offset = 0x%08llx, size = 0x%08lx\n",
310 			  (unsigned long long)map->offset, map->size);
311 
312 		break;
313 	}
314 	case _DRM_SCATTER_GATHER:
315 		if (!dev->sg) {
316 			kfree(map);
317 			return -EINVAL;
318 		}
319 		map->offset += (unsigned long)dev->sg->virtual;
320 		break;
321 	case _DRM_CONSISTENT:
322 		/* dma_addr_t is 64bit on i386 with CONFIG_HIGHMEM64G,
323 		 * As we're limiting the address to 2^32-1 (or less),
324 		 * casting it down to 32 bits is no problem, but we
325 		 * need to point to a 64bit variable first. */
326 		map->handle = dma_alloc_coherent(&dev->pdev->dev,
327 						 map->size,
328 						 &map->offset,
329 						 GFP_KERNEL);
330 		if (!map->handle) {
331 			kfree(map);
332 			return -ENOMEM;
333 		}
334 		break;
335 	default:
336 		kfree(map);
337 		return -EINVAL;
338 	}
339 
340 	list = kzalloc(sizeof(*list), GFP_KERNEL);
341 	if (!list) {
342 		if (map->type == _DRM_REGISTERS)
343 			iounmap(map->handle);
344 		kfree(map);
345 		return -EINVAL;
346 	}
347 	list->map = map;
348 
349 	mutex_lock(&dev->struct_mutex);
350 	list_add(&list->head, &dev->maplist);
351 
352 	/* Assign a 32-bit handle */
353 	/* We do it here so that dev->struct_mutex protects the increment */
354 	user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle :
355 		map->offset;
356 	ret = drm_map_handle(dev, &list->hash, user_token, 0,
357 			     (map->type == _DRM_SHM));
358 	if (ret) {
359 		if (map->type == _DRM_REGISTERS)
360 			iounmap(map->handle);
361 		kfree(map);
362 		kfree(list);
363 		mutex_unlock(&dev->struct_mutex);
364 		return ret;
365 	}
366 
367 	list->user_token = list->hash.key << PAGE_SHIFT;
368 	mutex_unlock(&dev->struct_mutex);
369 
370 	if (!(map->flags & _DRM_DRIVER))
371 		list->master = dev->master;
372 	*maplist = list;
373 	return 0;
374 }
375 
376 int drm_legacy_addmap(struct drm_device *dev, resource_size_t offset,
377 		      unsigned int size, enum drm_map_type type,
378 		      enum drm_map_flags flags, struct drm_local_map **map_ptr)
379 {
380 	struct drm_map_list *list;
381 	int rc;
382 
383 	rc = drm_addmap_core(dev, offset, size, type, flags, &list);
384 	if (!rc)
385 		*map_ptr = list->map;
386 	return rc;
387 }
388 EXPORT_SYMBOL(drm_legacy_addmap);
389 
390 struct drm_local_map *drm_legacy_findmap(struct drm_device *dev,
391 					 unsigned int token)
392 {
393 	struct drm_map_list *_entry;
394 	list_for_each_entry(_entry, &dev->maplist, head)
395 		if (_entry->user_token == token)
396 			return _entry->map;
397 	return NULL;
398 }
399 EXPORT_SYMBOL(drm_legacy_findmap);
400 
401 /*
402  * Ioctl to specify a range of memory that is available for mapping by a
403  * non-root process.
404  *
405  * \param inode device inode.
406  * \param file_priv DRM file private.
407  * \param cmd command.
408  * \param arg pointer to a drm_map structure.
409  * \return zero on success or a negative value on error.
410  *
411  */
412 int drm_legacy_addmap_ioctl(struct drm_device *dev, void *data,
413 			    struct drm_file *file_priv)
414 {
415 	struct drm_map *map = data;
416 	struct drm_map_list *maplist;
417 	int err;
418 
419 	if (!(capable(CAP_SYS_ADMIN) || map->type == _DRM_AGP || map->type == _DRM_SHM))
420 		return -EPERM;
421 
422 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
423 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
424 		return -EOPNOTSUPP;
425 
426 	err = drm_addmap_core(dev, map->offset, map->size, map->type,
427 			      map->flags, &maplist);
428 
429 	if (err)
430 		return err;
431 
432 	/* avoid a warning on 64-bit, this casting isn't very nice, but the API is set so too late */
433 	map->handle = (void *)(unsigned long)maplist->user_token;
434 
435 	/*
436 	 * It appears that there are no users of this value whatsoever --
437 	 * drmAddMap just discards it.  Let's not encourage its use.
438 	 * (Keeping drm_addmap_core's returned mtrr value would be wrong --
439 	 *  it's not a real mtrr index anymore.)
440 	 */
441 	map->mtrr = -1;
442 
443 	return 0;
444 }
445 
446 /*
447  * Get a mapping information.
448  *
449  * \param inode device inode.
450  * \param file_priv DRM file private.
451  * \param cmd command.
452  * \param arg user argument, pointing to a drm_map structure.
453  *
454  * \return zero on success or a negative number on failure.
455  *
456  * Searches for the mapping with the specified offset and copies its information
457  * into userspace
458  */
459 int drm_legacy_getmap_ioctl(struct drm_device *dev, void *data,
460 			    struct drm_file *file_priv)
461 {
462 	struct drm_map *map = data;
463 	struct drm_map_list *r_list = NULL;
464 	struct list_head *list;
465 	int idx;
466 	int i;
467 
468 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
469 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
470 		return -EOPNOTSUPP;
471 
472 	idx = map->offset;
473 	if (idx < 0)
474 		return -EINVAL;
475 
476 	i = 0;
477 	mutex_lock(&dev->struct_mutex);
478 	list_for_each(list, &dev->maplist) {
479 		if (i == idx) {
480 			r_list = list_entry(list, struct drm_map_list, head);
481 			break;
482 		}
483 		i++;
484 	}
485 	if (!r_list || !r_list->map) {
486 		mutex_unlock(&dev->struct_mutex);
487 		return -EINVAL;
488 	}
489 
490 	map->offset = r_list->map->offset;
491 	map->size = r_list->map->size;
492 	map->type = r_list->map->type;
493 	map->flags = r_list->map->flags;
494 	map->handle = (void *)(unsigned long) r_list->user_token;
495 	map->mtrr = arch_phys_wc_index(r_list->map->mtrr);
496 
497 	mutex_unlock(&dev->struct_mutex);
498 
499 	return 0;
500 }
501 
502 /*
503  * Remove a map private from list and deallocate resources if the mapping
504  * isn't in use.
505  *
506  * Searches the map on drm_device::maplist, removes it from the list, see if
507  * it's being used, and free any associated resource (such as MTRR's) if it's not
508  * being on use.
509  *
510  * \sa drm_legacy_addmap
511  */
512 int drm_legacy_rmmap_locked(struct drm_device *dev, struct drm_local_map *map)
513 {
514 	struct drm_map_list *r_list = NULL, *list_t;
515 	int found = 0;
516 	struct drm_master *master;
517 
518 	/* Find the list entry for the map and remove it */
519 	list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
520 		if (r_list->map == map) {
521 			master = r_list->master;
522 			list_del(&r_list->head);
523 			drm_ht_remove_key(&dev->map_hash,
524 					  r_list->user_token >> PAGE_SHIFT);
525 			kfree(r_list);
526 			found = 1;
527 			break;
528 		}
529 	}
530 
531 	if (!found)
532 		return -EINVAL;
533 
534 	switch (map->type) {
535 	case _DRM_REGISTERS:
536 		iounmap(map->handle);
537 		/* FALLTHROUGH */
538 	case _DRM_FRAME_BUFFER:
539 		arch_phys_wc_del(map->mtrr);
540 		break;
541 	case _DRM_SHM:
542 		vfree(map->handle);
543 		if (master) {
544 			if (dev->sigdata.lock == master->lock.hw_lock)
545 				dev->sigdata.lock = NULL;
546 			master->lock.hw_lock = NULL;   /* SHM removed */
547 			master->lock.file_priv = NULL;
548 			wake_up_interruptible_all(&master->lock.lock_queue);
549 		}
550 		break;
551 	case _DRM_AGP:
552 	case _DRM_SCATTER_GATHER:
553 		break;
554 	case _DRM_CONSISTENT:
555 		dma_free_coherent(&dev->pdev->dev,
556 				  map->size,
557 				  map->handle,
558 				  map->offset);
559 		break;
560 	}
561 	kfree(map);
562 
563 	return 0;
564 }
565 EXPORT_SYMBOL(drm_legacy_rmmap_locked);
566 
567 void drm_legacy_rmmap(struct drm_device *dev, struct drm_local_map *map)
568 {
569 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
570 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
571 		return;
572 
573 	mutex_lock(&dev->struct_mutex);
574 	drm_legacy_rmmap_locked(dev, map);
575 	mutex_unlock(&dev->struct_mutex);
576 }
577 EXPORT_SYMBOL(drm_legacy_rmmap);
578 
579 void drm_legacy_master_rmmaps(struct drm_device *dev, struct drm_master *master)
580 {
581 	struct drm_map_list *r_list, *list_temp;
582 
583 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
584 		return;
585 
586 	mutex_lock(&dev->struct_mutex);
587 	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
588 		if (r_list->master == master) {
589 			drm_legacy_rmmap_locked(dev, r_list->map);
590 			r_list = NULL;
591 		}
592 	}
593 	mutex_unlock(&dev->struct_mutex);
594 }
595 
596 void drm_legacy_rmmaps(struct drm_device *dev)
597 {
598 	struct drm_map_list *r_list, *list_temp;
599 
600 	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
601 		drm_legacy_rmmap(dev, r_list->map);
602 }
603 
604 /* The rmmap ioctl appears to be unnecessary.  All mappings are torn down on
605  * the last close of the device, and this is necessary for cleanup when things
606  * exit uncleanly.  Therefore, having userland manually remove mappings seems
607  * like a pointless exercise since they're going away anyway.
608  *
609  * One use case might be after addmap is allowed for normal users for SHM and
610  * gets used by drivers that the server doesn't need to care about.  This seems
611  * unlikely.
612  *
613  * \param inode device inode.
614  * \param file_priv DRM file private.
615  * \param cmd command.
616  * \param arg pointer to a struct drm_map structure.
617  * \return zero on success or a negative value on error.
618  */
619 int drm_legacy_rmmap_ioctl(struct drm_device *dev, void *data,
620 			   struct drm_file *file_priv)
621 {
622 	struct drm_map *request = data;
623 	struct drm_local_map *map = NULL;
624 	struct drm_map_list *r_list;
625 	int ret;
626 
627 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
628 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
629 		return -EOPNOTSUPP;
630 
631 	mutex_lock(&dev->struct_mutex);
632 	list_for_each_entry(r_list, &dev->maplist, head) {
633 		if (r_list->map &&
634 		    r_list->user_token == (unsigned long)request->handle &&
635 		    r_list->map->flags & _DRM_REMOVABLE) {
636 			map = r_list->map;
637 			break;
638 		}
639 	}
640 
641 	/* List has wrapped around to the head pointer, or it's empty we didn't
642 	 * find anything.
643 	 */
644 	if (list_empty(&dev->maplist) || !map) {
645 		mutex_unlock(&dev->struct_mutex);
646 		return -EINVAL;
647 	}
648 
649 	/* Register and framebuffer maps are permanent */
650 	if ((map->type == _DRM_REGISTERS) || (map->type == _DRM_FRAME_BUFFER)) {
651 		mutex_unlock(&dev->struct_mutex);
652 		return 0;
653 	}
654 
655 	ret = drm_legacy_rmmap_locked(dev, map);
656 
657 	mutex_unlock(&dev->struct_mutex);
658 
659 	return ret;
660 }
661 
662 /*
663  * Cleanup after an error on one of the addbufs() functions.
664  *
665  * \param dev DRM device.
666  * \param entry buffer entry where the error occurred.
667  *
668  * Frees any pages and buffers associated with the given entry.
669  */
670 static void drm_cleanup_buf_error(struct drm_device *dev,
671 				  struct drm_buf_entry *entry)
672 {
673 	int i;
674 
675 	if (entry->seg_count) {
676 		for (i = 0; i < entry->seg_count; i++) {
677 			if (entry->seglist[i]) {
678 				drm_pci_free(dev, entry->seglist[i]);
679 			}
680 		}
681 		kfree(entry->seglist);
682 
683 		entry->seg_count = 0;
684 	}
685 
686 	if (entry->buf_count) {
687 		for (i = 0; i < entry->buf_count; i++) {
688 			kfree(entry->buflist[i].dev_private);
689 		}
690 		kfree(entry->buflist);
691 
692 		entry->buf_count = 0;
693 	}
694 }
695 
696 #if IS_ENABLED(CONFIG_AGP)
697 /*
698  * Add AGP buffers for DMA transfers.
699  *
700  * \param dev struct drm_device to which the buffers are to be added.
701  * \param request pointer to a struct drm_buf_desc describing the request.
702  * \return zero on success or a negative number on failure.
703  *
704  * After some sanity checks creates a drm_buf structure for each buffer and
705  * reallocates the buffer list of the same size order to accommodate the new
706  * buffers.
707  */
708 int drm_legacy_addbufs_agp(struct drm_device *dev,
709 			   struct drm_buf_desc *request)
710 {
711 	struct drm_device_dma *dma = dev->dma;
712 	struct drm_buf_entry *entry;
713 	struct drm_agp_mem *agp_entry;
714 	struct drm_buf *buf;
715 	unsigned long offset;
716 	unsigned long agp_offset;
717 	int count;
718 	int order;
719 	int size;
720 	int alignment;
721 	int page_order;
722 	int total;
723 	int byte_count;
724 	int i, valid;
725 	struct drm_buf **temp_buflist;
726 
727 	if (!dma)
728 		return -EINVAL;
729 
730 	count = request->count;
731 	order = order_base_2(request->size);
732 	size = 1 << order;
733 
734 	alignment = (request->flags & _DRM_PAGE_ALIGN)
735 	    ? PAGE_ALIGN(size) : size;
736 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
737 	total = PAGE_SIZE << page_order;
738 
739 	byte_count = 0;
740 	agp_offset = dev->agp->base + request->agp_start;
741 
742 	DRM_DEBUG("count:      %d\n", count);
743 	DRM_DEBUG("order:      %d\n", order);
744 	DRM_DEBUG("size:       %d\n", size);
745 	DRM_DEBUG("agp_offset: %lx\n", agp_offset);
746 	DRM_DEBUG("alignment:  %d\n", alignment);
747 	DRM_DEBUG("page_order: %d\n", page_order);
748 	DRM_DEBUG("total:      %d\n", total);
749 
750 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
751 		return -EINVAL;
752 
753 	/* Make sure buffers are located in AGP memory that we own */
754 	valid = 0;
755 	list_for_each_entry(agp_entry, &dev->agp->memory, head) {
756 		if ((agp_offset >= agp_entry->bound) &&
757 		    (agp_offset + total * count <= agp_entry->bound + agp_entry->pages * PAGE_SIZE)) {
758 			valid = 1;
759 			break;
760 		}
761 	}
762 	if (!list_empty(&dev->agp->memory) && !valid) {
763 		DRM_DEBUG("zone invalid\n");
764 		return -EINVAL;
765 	}
766 	spin_lock(&dev->buf_lock);
767 	if (dev->buf_use) {
768 		spin_unlock(&dev->buf_lock);
769 		return -EBUSY;
770 	}
771 	atomic_inc(&dev->buf_alloc);
772 	spin_unlock(&dev->buf_lock);
773 
774 	mutex_lock(&dev->struct_mutex);
775 	entry = &dma->bufs[order];
776 	if (entry->buf_count) {
777 		mutex_unlock(&dev->struct_mutex);
778 		atomic_dec(&dev->buf_alloc);
779 		return -ENOMEM;	/* May only call once for each order */
780 	}
781 
782 	if (count < 0 || count > 4096) {
783 		mutex_unlock(&dev->struct_mutex);
784 		atomic_dec(&dev->buf_alloc);
785 		return -EINVAL;
786 	}
787 
788 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
789 	if (!entry->buflist) {
790 		mutex_unlock(&dev->struct_mutex);
791 		atomic_dec(&dev->buf_alloc);
792 		return -ENOMEM;
793 	}
794 
795 	entry->buf_size = size;
796 	entry->page_order = page_order;
797 
798 	offset = 0;
799 
800 	while (entry->buf_count < count) {
801 		buf = &entry->buflist[entry->buf_count];
802 		buf->idx = dma->buf_count + entry->buf_count;
803 		buf->total = alignment;
804 		buf->order = order;
805 		buf->used = 0;
806 
807 		buf->offset = (dma->byte_count + offset);
808 		buf->bus_address = agp_offset + offset;
809 		buf->address = (void *)(agp_offset + offset);
810 		buf->next = NULL;
811 		buf->waiting = 0;
812 		buf->pending = 0;
813 		buf->file_priv = NULL;
814 
815 		buf->dev_priv_size = dev->driver->dev_priv_size;
816 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
817 		if (!buf->dev_private) {
818 			/* Set count correctly so we free the proper amount. */
819 			entry->buf_count = count;
820 			drm_cleanup_buf_error(dev, entry);
821 			mutex_unlock(&dev->struct_mutex);
822 			atomic_dec(&dev->buf_alloc);
823 			return -ENOMEM;
824 		}
825 
826 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
827 
828 		offset += alignment;
829 		entry->buf_count++;
830 		byte_count += PAGE_SIZE << page_order;
831 	}
832 
833 	DRM_DEBUG("byte_count: %d\n", byte_count);
834 
835 	temp_buflist = krealloc(dma->buflist,
836 				(dma->buf_count + entry->buf_count) *
837 				sizeof(*dma->buflist), GFP_KERNEL);
838 	if (!temp_buflist) {
839 		/* Free the entry because it isn't valid */
840 		drm_cleanup_buf_error(dev, entry);
841 		mutex_unlock(&dev->struct_mutex);
842 		atomic_dec(&dev->buf_alloc);
843 		return -ENOMEM;
844 	}
845 	dma->buflist = temp_buflist;
846 
847 	for (i = 0; i < entry->buf_count; i++) {
848 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
849 	}
850 
851 	dma->buf_count += entry->buf_count;
852 	dma->seg_count += entry->seg_count;
853 	dma->page_count += byte_count >> PAGE_SHIFT;
854 	dma->byte_count += byte_count;
855 
856 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
857 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
858 
859 	mutex_unlock(&dev->struct_mutex);
860 
861 	request->count = entry->buf_count;
862 	request->size = size;
863 
864 	dma->flags = _DRM_DMA_USE_AGP;
865 
866 	atomic_dec(&dev->buf_alloc);
867 	return 0;
868 }
869 EXPORT_SYMBOL(drm_legacy_addbufs_agp);
870 #endif /* CONFIG_AGP */
871 
872 int drm_legacy_addbufs_pci(struct drm_device *dev,
873 			   struct drm_buf_desc *request)
874 {
875 	struct drm_device_dma *dma = dev->dma;
876 	int count;
877 	int order;
878 	int size;
879 	int total;
880 	int page_order;
881 	struct drm_buf_entry *entry;
882 	drm_dma_handle_t *dmah;
883 	struct drm_buf *buf;
884 	int alignment;
885 	unsigned long offset;
886 	int i;
887 	int byte_count;
888 	int page_count;
889 	unsigned long *temp_pagelist;
890 	struct drm_buf **temp_buflist;
891 
892 	if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
893 		return -EOPNOTSUPP;
894 
895 	if (!dma)
896 		return -EINVAL;
897 
898 	if (!capable(CAP_SYS_ADMIN))
899 		return -EPERM;
900 
901 	count = request->count;
902 	order = order_base_2(request->size);
903 	size = 1 << order;
904 
905 	DRM_DEBUG("count=%d, size=%d (%d), order=%d\n",
906 		  request->count, request->size, size, order);
907 
908 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
909 		return -EINVAL;
910 
911 	alignment = (request->flags & _DRM_PAGE_ALIGN)
912 	    ? PAGE_ALIGN(size) : size;
913 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
914 	total = PAGE_SIZE << page_order;
915 
916 	spin_lock(&dev->buf_lock);
917 	if (dev->buf_use) {
918 		spin_unlock(&dev->buf_lock);
919 		return -EBUSY;
920 	}
921 	atomic_inc(&dev->buf_alloc);
922 	spin_unlock(&dev->buf_lock);
923 
924 	mutex_lock(&dev->struct_mutex);
925 	entry = &dma->bufs[order];
926 	if (entry->buf_count) {
927 		mutex_unlock(&dev->struct_mutex);
928 		atomic_dec(&dev->buf_alloc);
929 		return -ENOMEM;	/* May only call once for each order */
930 	}
931 
932 	if (count < 0 || count > 4096) {
933 		mutex_unlock(&dev->struct_mutex);
934 		atomic_dec(&dev->buf_alloc);
935 		return -EINVAL;
936 	}
937 
938 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
939 	if (!entry->buflist) {
940 		mutex_unlock(&dev->struct_mutex);
941 		atomic_dec(&dev->buf_alloc);
942 		return -ENOMEM;
943 	}
944 
945 	entry->seglist = kcalloc(count, sizeof(*entry->seglist), GFP_KERNEL);
946 	if (!entry->seglist) {
947 		kfree(entry->buflist);
948 		mutex_unlock(&dev->struct_mutex);
949 		atomic_dec(&dev->buf_alloc);
950 		return -ENOMEM;
951 	}
952 
953 	/* Keep the original pagelist until we know all the allocations
954 	 * have succeeded
955 	 */
956 	temp_pagelist = kmalloc_array(dma->page_count + (count << page_order),
957 				      sizeof(*dma->pagelist),
958 				      GFP_KERNEL);
959 	if (!temp_pagelist) {
960 		kfree(entry->buflist);
961 		kfree(entry->seglist);
962 		mutex_unlock(&dev->struct_mutex);
963 		atomic_dec(&dev->buf_alloc);
964 		return -ENOMEM;
965 	}
966 	memcpy(temp_pagelist,
967 	       dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
968 	DRM_DEBUG("pagelist: %d entries\n",
969 		  dma->page_count + (count << page_order));
970 
971 	entry->buf_size = size;
972 	entry->page_order = page_order;
973 	byte_count = 0;
974 	page_count = 0;
975 
976 	while (entry->buf_count < count) {
977 
978 		dmah = drm_pci_alloc(dev, PAGE_SIZE << page_order, 0x1000);
979 
980 		if (!dmah) {
981 			/* Set count correctly so we free the proper amount. */
982 			entry->buf_count = count;
983 			entry->seg_count = count;
984 			drm_cleanup_buf_error(dev, entry);
985 			kfree(temp_pagelist);
986 			mutex_unlock(&dev->struct_mutex);
987 			atomic_dec(&dev->buf_alloc);
988 			return -ENOMEM;
989 		}
990 		entry->seglist[entry->seg_count++] = dmah;
991 		for (i = 0; i < (1 << page_order); i++) {
992 			DRM_DEBUG("page %d @ 0x%08lx\n",
993 				  dma->page_count + page_count,
994 				  (unsigned long)dmah->vaddr + PAGE_SIZE * i);
995 			temp_pagelist[dma->page_count + page_count++]
996 				= (unsigned long)dmah->vaddr + PAGE_SIZE * i;
997 		}
998 		for (offset = 0;
999 		     offset + size <= total && entry->buf_count < count;
1000 		     offset += alignment, ++entry->buf_count) {
1001 			buf = &entry->buflist[entry->buf_count];
1002 			buf->idx = dma->buf_count + entry->buf_count;
1003 			buf->total = alignment;
1004 			buf->order = order;
1005 			buf->used = 0;
1006 			buf->offset = (dma->byte_count + byte_count + offset);
1007 			buf->address = (void *)(dmah->vaddr + offset);
1008 			buf->bus_address = dmah->busaddr + offset;
1009 			buf->next = NULL;
1010 			buf->waiting = 0;
1011 			buf->pending = 0;
1012 			buf->file_priv = NULL;
1013 
1014 			buf->dev_priv_size = dev->driver->dev_priv_size;
1015 			buf->dev_private = kzalloc(buf->dev_priv_size,
1016 						GFP_KERNEL);
1017 			if (!buf->dev_private) {
1018 				/* Set count correctly so we free the proper amount. */
1019 				entry->buf_count = count;
1020 				entry->seg_count = count;
1021 				drm_cleanup_buf_error(dev, entry);
1022 				kfree(temp_pagelist);
1023 				mutex_unlock(&dev->struct_mutex);
1024 				atomic_dec(&dev->buf_alloc);
1025 				return -ENOMEM;
1026 			}
1027 
1028 			DRM_DEBUG("buffer %d @ %p\n",
1029 				  entry->buf_count, buf->address);
1030 		}
1031 		byte_count += PAGE_SIZE << page_order;
1032 	}
1033 
1034 	temp_buflist = krealloc(dma->buflist,
1035 				(dma->buf_count + entry->buf_count) *
1036 				sizeof(*dma->buflist), GFP_KERNEL);
1037 	if (!temp_buflist) {
1038 		/* Free the entry because it isn't valid */
1039 		drm_cleanup_buf_error(dev, entry);
1040 		kfree(temp_pagelist);
1041 		mutex_unlock(&dev->struct_mutex);
1042 		atomic_dec(&dev->buf_alloc);
1043 		return -ENOMEM;
1044 	}
1045 	dma->buflist = temp_buflist;
1046 
1047 	for (i = 0; i < entry->buf_count; i++) {
1048 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1049 	}
1050 
1051 	/* No allocations failed, so now we can replace the original pagelist
1052 	 * with the new one.
1053 	 */
1054 	if (dma->page_count) {
1055 		kfree(dma->pagelist);
1056 	}
1057 	dma->pagelist = temp_pagelist;
1058 
1059 	dma->buf_count += entry->buf_count;
1060 	dma->seg_count += entry->seg_count;
1061 	dma->page_count += entry->seg_count << page_order;
1062 	dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);
1063 
1064 	mutex_unlock(&dev->struct_mutex);
1065 
1066 	request->count = entry->buf_count;
1067 	request->size = size;
1068 
1069 	if (request->flags & _DRM_PCI_BUFFER_RO)
1070 		dma->flags = _DRM_DMA_USE_PCI_RO;
1071 
1072 	atomic_dec(&dev->buf_alloc);
1073 	return 0;
1074 
1075 }
1076 EXPORT_SYMBOL(drm_legacy_addbufs_pci);
1077 
1078 static int drm_legacy_addbufs_sg(struct drm_device *dev,
1079 				 struct drm_buf_desc *request)
1080 {
1081 	struct drm_device_dma *dma = dev->dma;
1082 	struct drm_buf_entry *entry;
1083 	struct drm_buf *buf;
1084 	unsigned long offset;
1085 	unsigned long agp_offset;
1086 	int count;
1087 	int order;
1088 	int size;
1089 	int alignment;
1090 	int page_order;
1091 	int total;
1092 	int byte_count;
1093 	int i;
1094 	struct drm_buf **temp_buflist;
1095 
1096 	if (!drm_core_check_feature(dev, DRIVER_SG))
1097 		return -EOPNOTSUPP;
1098 
1099 	if (!dma)
1100 		return -EINVAL;
1101 
1102 	if (!capable(CAP_SYS_ADMIN))
1103 		return -EPERM;
1104 
1105 	count = request->count;
1106 	order = order_base_2(request->size);
1107 	size = 1 << order;
1108 
1109 	alignment = (request->flags & _DRM_PAGE_ALIGN)
1110 	    ? PAGE_ALIGN(size) : size;
1111 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
1112 	total = PAGE_SIZE << page_order;
1113 
1114 	byte_count = 0;
1115 	agp_offset = request->agp_start;
1116 
1117 	DRM_DEBUG("count:      %d\n", count);
1118 	DRM_DEBUG("order:      %d\n", order);
1119 	DRM_DEBUG("size:       %d\n", size);
1120 	DRM_DEBUG("agp_offset: %lu\n", agp_offset);
1121 	DRM_DEBUG("alignment:  %d\n", alignment);
1122 	DRM_DEBUG("page_order: %d\n", page_order);
1123 	DRM_DEBUG("total:      %d\n", total);
1124 
1125 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1126 		return -EINVAL;
1127 
1128 	spin_lock(&dev->buf_lock);
1129 	if (dev->buf_use) {
1130 		spin_unlock(&dev->buf_lock);
1131 		return -EBUSY;
1132 	}
1133 	atomic_inc(&dev->buf_alloc);
1134 	spin_unlock(&dev->buf_lock);
1135 
1136 	mutex_lock(&dev->struct_mutex);
1137 	entry = &dma->bufs[order];
1138 	if (entry->buf_count) {
1139 		mutex_unlock(&dev->struct_mutex);
1140 		atomic_dec(&dev->buf_alloc);
1141 		return -ENOMEM;	/* May only call once for each order */
1142 	}
1143 
1144 	if (count < 0 || count > 4096) {
1145 		mutex_unlock(&dev->struct_mutex);
1146 		atomic_dec(&dev->buf_alloc);
1147 		return -EINVAL;
1148 	}
1149 
1150 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
1151 	if (!entry->buflist) {
1152 		mutex_unlock(&dev->struct_mutex);
1153 		atomic_dec(&dev->buf_alloc);
1154 		return -ENOMEM;
1155 	}
1156 
1157 	entry->buf_size = size;
1158 	entry->page_order = page_order;
1159 
1160 	offset = 0;
1161 
1162 	while (entry->buf_count < count) {
1163 		buf = &entry->buflist[entry->buf_count];
1164 		buf->idx = dma->buf_count + entry->buf_count;
1165 		buf->total = alignment;
1166 		buf->order = order;
1167 		buf->used = 0;
1168 
1169 		buf->offset = (dma->byte_count + offset);
1170 		buf->bus_address = agp_offset + offset;
1171 		buf->address = (void *)(agp_offset + offset
1172 					+ (unsigned long)dev->sg->virtual);
1173 		buf->next = NULL;
1174 		buf->waiting = 0;
1175 		buf->pending = 0;
1176 		buf->file_priv = NULL;
1177 
1178 		buf->dev_priv_size = dev->driver->dev_priv_size;
1179 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
1180 		if (!buf->dev_private) {
1181 			/* Set count correctly so we free the proper amount. */
1182 			entry->buf_count = count;
1183 			drm_cleanup_buf_error(dev, entry);
1184 			mutex_unlock(&dev->struct_mutex);
1185 			atomic_dec(&dev->buf_alloc);
1186 			return -ENOMEM;
1187 		}
1188 
1189 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
1190 
1191 		offset += alignment;
1192 		entry->buf_count++;
1193 		byte_count += PAGE_SIZE << page_order;
1194 	}
1195 
1196 	DRM_DEBUG("byte_count: %d\n", byte_count);
1197 
1198 	temp_buflist = krealloc(dma->buflist,
1199 				(dma->buf_count + entry->buf_count) *
1200 				sizeof(*dma->buflist), GFP_KERNEL);
1201 	if (!temp_buflist) {
1202 		/* Free the entry because it isn't valid */
1203 		drm_cleanup_buf_error(dev, entry);
1204 		mutex_unlock(&dev->struct_mutex);
1205 		atomic_dec(&dev->buf_alloc);
1206 		return -ENOMEM;
1207 	}
1208 	dma->buflist = temp_buflist;
1209 
1210 	for (i = 0; i < entry->buf_count; i++) {
1211 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1212 	}
1213 
1214 	dma->buf_count += entry->buf_count;
1215 	dma->seg_count += entry->seg_count;
1216 	dma->page_count += byte_count >> PAGE_SHIFT;
1217 	dma->byte_count += byte_count;
1218 
1219 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
1220 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
1221 
1222 	mutex_unlock(&dev->struct_mutex);
1223 
1224 	request->count = entry->buf_count;
1225 	request->size = size;
1226 
1227 	dma->flags = _DRM_DMA_USE_SG;
1228 
1229 	atomic_dec(&dev->buf_alloc);
1230 	return 0;
1231 }
1232 
1233 /*
1234  * Add buffers for DMA transfers (ioctl).
1235  *
1236  * \param inode device inode.
1237  * \param file_priv DRM file private.
1238  * \param cmd command.
1239  * \param arg pointer to a struct drm_buf_desc request.
1240  * \return zero on success or a negative number on failure.
1241  *
1242  * According with the memory type specified in drm_buf_desc::flags and the
1243  * build options, it dispatches the call either to addbufs_agp(),
1244  * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
1245  * PCI memory respectively.
1246  */
1247 int drm_legacy_addbufs(struct drm_device *dev, void *data,
1248 		       struct drm_file *file_priv)
1249 {
1250 	struct drm_buf_desc *request = data;
1251 	int ret;
1252 
1253 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1254 		return -EOPNOTSUPP;
1255 
1256 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1257 		return -EOPNOTSUPP;
1258 
1259 #if IS_ENABLED(CONFIG_AGP)
1260 	if (request->flags & _DRM_AGP_BUFFER)
1261 		ret = drm_legacy_addbufs_agp(dev, request);
1262 	else
1263 #endif
1264 	if (request->flags & _DRM_SG_BUFFER)
1265 		ret = drm_legacy_addbufs_sg(dev, request);
1266 	else if (request->flags & _DRM_FB_BUFFER)
1267 		ret = -EINVAL;
1268 	else
1269 		ret = drm_legacy_addbufs_pci(dev, request);
1270 
1271 	return ret;
1272 }
1273 
1274 /*
1275  * Get information about the buffer mappings.
1276  *
1277  * This was originally mean for debugging purposes, or by a sophisticated
1278  * client library to determine how best to use the available buffers (e.g.,
1279  * large buffers can be used for image transfer).
1280  *
1281  * \param inode device inode.
1282  * \param file_priv DRM file private.
1283  * \param cmd command.
1284  * \param arg pointer to a drm_buf_info structure.
1285  * \return zero on success or a negative number on failure.
1286  *
1287  * Increments drm_device::buf_use while holding the drm_device::buf_lock
1288  * lock, preventing of allocating more buffers after this call. Information
1289  * about each requested buffer is then copied into user space.
1290  */
1291 int __drm_legacy_infobufs(struct drm_device *dev,
1292 			void *data, int *p,
1293 			int (*f)(void *, int, struct drm_buf_entry *))
1294 {
1295 	struct drm_device_dma *dma = dev->dma;
1296 	int i;
1297 	int count;
1298 
1299 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1300 		return -EOPNOTSUPP;
1301 
1302 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1303 		return -EOPNOTSUPP;
1304 
1305 	if (!dma)
1306 		return -EINVAL;
1307 
1308 	spin_lock(&dev->buf_lock);
1309 	if (atomic_read(&dev->buf_alloc)) {
1310 		spin_unlock(&dev->buf_lock);
1311 		return -EBUSY;
1312 	}
1313 	++dev->buf_use;		/* Can't allocate more after this call */
1314 	spin_unlock(&dev->buf_lock);
1315 
1316 	for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1317 		if (dma->bufs[i].buf_count)
1318 			++count;
1319 	}
1320 
1321 	DRM_DEBUG("count = %d\n", count);
1322 
1323 	if (*p >= count) {
1324 		for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1325 			struct drm_buf_entry *from = &dma->bufs[i];
1326 			if (from->buf_count) {
1327 				if (f(data, count, from) < 0)
1328 					return -EFAULT;
1329 				DRM_DEBUG("%d %d %d %d %d\n",
1330 					  i,
1331 					  dma->bufs[i].buf_count,
1332 					  dma->bufs[i].buf_size,
1333 					  dma->bufs[i].low_mark,
1334 					  dma->bufs[i].high_mark);
1335 				++count;
1336 			}
1337 		}
1338 	}
1339 	*p = count;
1340 
1341 	return 0;
1342 }
1343 
1344 static int copy_one_buf(void *data, int count, struct drm_buf_entry *from)
1345 {
1346 	struct drm_buf_info *request = data;
1347 	struct drm_buf_desc __user *to = &request->list[count];
1348 	struct drm_buf_desc v = {.count = from->buf_count,
1349 				 .size = from->buf_size,
1350 				 .low_mark = from->low_mark,
1351 				 .high_mark = from->high_mark};
1352 
1353 	if (copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags)))
1354 		return -EFAULT;
1355 	return 0;
1356 }
1357 
1358 int drm_legacy_infobufs(struct drm_device *dev, void *data,
1359 			struct drm_file *file_priv)
1360 {
1361 	struct drm_buf_info *request = data;
1362 	return __drm_legacy_infobufs(dev, data, &request->count, copy_one_buf);
1363 }
1364 
1365 /*
1366  * Specifies a low and high water mark for buffer allocation
1367  *
1368  * \param inode device inode.
1369  * \param file_priv DRM file private.
1370  * \param cmd command.
1371  * \param arg a pointer to a drm_buf_desc structure.
1372  * \return zero on success or a negative number on failure.
1373  *
1374  * Verifies that the size order is bounded between the admissible orders and
1375  * updates the respective drm_device_dma::bufs entry low and high water mark.
1376  *
1377  * \note This ioctl is deprecated and mostly never used.
1378  */
1379 int drm_legacy_markbufs(struct drm_device *dev, void *data,
1380 			struct drm_file *file_priv)
1381 {
1382 	struct drm_device_dma *dma = dev->dma;
1383 	struct drm_buf_desc *request = data;
1384 	int order;
1385 	struct drm_buf_entry *entry;
1386 
1387 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1388 		return -EOPNOTSUPP;
1389 
1390 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1391 		return -EOPNOTSUPP;
1392 
1393 	if (!dma)
1394 		return -EINVAL;
1395 
1396 	DRM_DEBUG("%d, %d, %d\n",
1397 		  request->size, request->low_mark, request->high_mark);
1398 	order = order_base_2(request->size);
1399 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1400 		return -EINVAL;
1401 	entry = &dma->bufs[order];
1402 
1403 	if (request->low_mark < 0 || request->low_mark > entry->buf_count)
1404 		return -EINVAL;
1405 	if (request->high_mark < 0 || request->high_mark > entry->buf_count)
1406 		return -EINVAL;
1407 
1408 	entry->low_mark = request->low_mark;
1409 	entry->high_mark = request->high_mark;
1410 
1411 	return 0;
1412 }
1413 
1414 /*
1415  * Unreserve the buffers in list, previously reserved using drmDMA.
1416  *
1417  * \param inode device inode.
1418  * \param file_priv DRM file private.
1419  * \param cmd command.
1420  * \param arg pointer to a drm_buf_free structure.
1421  * \return zero on success or a negative number on failure.
1422  *
1423  * Calls free_buffer() for each used buffer.
1424  * This function is primarily used for debugging.
1425  */
1426 int drm_legacy_freebufs(struct drm_device *dev, void *data,
1427 			struct drm_file *file_priv)
1428 {
1429 	struct drm_device_dma *dma = dev->dma;
1430 	struct drm_buf_free *request = data;
1431 	int i;
1432 	int idx;
1433 	struct drm_buf *buf;
1434 
1435 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1436 		return -EOPNOTSUPP;
1437 
1438 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1439 		return -EOPNOTSUPP;
1440 
1441 	if (!dma)
1442 		return -EINVAL;
1443 
1444 	DRM_DEBUG("%d\n", request->count);
1445 	for (i = 0; i < request->count; i++) {
1446 		if (copy_from_user(&idx, &request->list[i], sizeof(idx)))
1447 			return -EFAULT;
1448 		if (idx < 0 || idx >= dma->buf_count) {
1449 			DRM_ERROR("Index %d (of %d max)\n",
1450 				  idx, dma->buf_count - 1);
1451 			return -EINVAL;
1452 		}
1453 		idx = array_index_nospec(idx, dma->buf_count);
1454 		buf = dma->buflist[idx];
1455 		if (buf->file_priv != file_priv) {
1456 			DRM_ERROR("Process %d freeing buffer not owned\n",
1457 				  task_pid_nr(current));
1458 			return -EINVAL;
1459 		}
1460 		drm_legacy_free_buffer(dev, buf);
1461 	}
1462 
1463 	return 0;
1464 }
1465 
1466 /*
1467  * Maps all of the DMA buffers into client-virtual space (ioctl).
1468  *
1469  * \param inode device inode.
1470  * \param file_priv DRM file private.
1471  * \param cmd command.
1472  * \param arg pointer to a drm_buf_map structure.
1473  * \return zero on success or a negative number on failure.
1474  *
1475  * Maps the AGP, SG or PCI buffer region with vm_mmap(), and copies information
1476  * about each buffer into user space. For PCI buffers, it calls vm_mmap() with
1477  * offset equal to 0, which drm_mmap() interpretes as PCI buffers and calls
1478  * drm_mmap_dma().
1479  */
1480 int __drm_legacy_mapbufs(struct drm_device *dev, void *data, int *p,
1481 			 void __user **v,
1482 			 int (*f)(void *, int, unsigned long,
1483 				 struct drm_buf *),
1484 				 struct drm_file *file_priv)
1485 {
1486 	struct drm_device_dma *dma = dev->dma;
1487 	int retcode = 0;
1488 	unsigned long virtual;
1489 	int i;
1490 
1491 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1492 		return -EOPNOTSUPP;
1493 
1494 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1495 		return -EOPNOTSUPP;
1496 
1497 	if (!dma)
1498 		return -EINVAL;
1499 
1500 	spin_lock(&dev->buf_lock);
1501 	if (atomic_read(&dev->buf_alloc)) {
1502 		spin_unlock(&dev->buf_lock);
1503 		return -EBUSY;
1504 	}
1505 	dev->buf_use++;		/* Can't allocate more after this call */
1506 	spin_unlock(&dev->buf_lock);
1507 
1508 	if (*p >= dma->buf_count) {
1509 		if ((dev->agp && (dma->flags & _DRM_DMA_USE_AGP))
1510 		    || (drm_core_check_feature(dev, DRIVER_SG)
1511 			&& (dma->flags & _DRM_DMA_USE_SG))) {
1512 			struct drm_local_map *map = dev->agp_buffer_map;
1513 			unsigned long token = dev->agp_buffer_token;
1514 
1515 			if (!map) {
1516 				retcode = -EINVAL;
1517 				goto done;
1518 			}
1519 			virtual = vm_mmap(file_priv->filp, 0, map->size,
1520 					  PROT_READ | PROT_WRITE,
1521 					  MAP_SHARED,
1522 					  token);
1523 		} else {
1524 			virtual = vm_mmap(file_priv->filp, 0, dma->byte_count,
1525 					  PROT_READ | PROT_WRITE,
1526 					  MAP_SHARED, 0);
1527 		}
1528 		if (virtual > -1024UL) {
1529 			/* Real error */
1530 			retcode = (signed long)virtual;
1531 			goto done;
1532 		}
1533 		*v = (void __user *)virtual;
1534 
1535 		for (i = 0; i < dma->buf_count; i++) {
1536 			if (f(data, i, virtual, dma->buflist[i]) < 0) {
1537 				retcode = -EFAULT;
1538 				goto done;
1539 			}
1540 		}
1541 	}
1542       done:
1543 	*p = dma->buf_count;
1544 	DRM_DEBUG("%d buffers, retcode = %d\n", *p, retcode);
1545 
1546 	return retcode;
1547 }
1548 
1549 static int map_one_buf(void *data, int idx, unsigned long virtual,
1550 			struct drm_buf *buf)
1551 {
1552 	struct drm_buf_map *request = data;
1553 	unsigned long address = virtual + buf->offset;	/* *** */
1554 
1555 	if (copy_to_user(&request->list[idx].idx, &buf->idx,
1556 			 sizeof(request->list[0].idx)))
1557 		return -EFAULT;
1558 	if (copy_to_user(&request->list[idx].total, &buf->total,
1559 			 sizeof(request->list[0].total)))
1560 		return -EFAULT;
1561 	if (clear_user(&request->list[idx].used, sizeof(int)))
1562 		return -EFAULT;
1563 	if (copy_to_user(&request->list[idx].address, &address,
1564 			 sizeof(address)))
1565 		return -EFAULT;
1566 	return 0;
1567 }
1568 
1569 int drm_legacy_mapbufs(struct drm_device *dev, void *data,
1570 		       struct drm_file *file_priv)
1571 {
1572 	struct drm_buf_map *request = data;
1573 	return __drm_legacy_mapbufs(dev, data, &request->count,
1574 				    &request->virtual, map_one_buf,
1575 				    file_priv);
1576 }
1577 
1578 int drm_legacy_dma_ioctl(struct drm_device *dev, void *data,
1579 		  struct drm_file *file_priv)
1580 {
1581 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1582 		return -EOPNOTSUPP;
1583 
1584 	if (dev->driver->dma_ioctl)
1585 		return dev->driver->dma_ioctl(dev, data, file_priv);
1586 	else
1587 		return -EINVAL;
1588 }
1589 
1590 struct drm_local_map *drm_legacy_getsarea(struct drm_device *dev)
1591 {
1592 	struct drm_map_list *entry;
1593 
1594 	list_for_each_entry(entry, &dev->maplist, head) {
1595 		if (entry->map && entry->map->type == _DRM_SHM &&
1596 		    (entry->map->flags & _DRM_CONTAINS_LOCK)) {
1597 			return entry->map;
1598 		}
1599 	}
1600 	return NULL;
1601 }
1602 EXPORT_SYMBOL(drm_legacy_getsarea);
1603