xref: /openbmc/linux/drivers/gpu/drm/drm_bufs.c (revision cf8698df)
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_device.h>
44 #include <drm/drm_drv.h>
45 #include <drm/drm_file.h>
46 #include <drm/drm_print.h>
47 
48 #include "drm_legacy.h"
49 
50 
drm_find_matching_map(struct drm_device * dev,struct drm_local_map * map)51 static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
52 						  struct drm_local_map *map)
53 {
54 	struct drm_map_list *entry;
55 
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 			break;
80 		default: /* Make gcc happy */
81 			break;
82 		}
83 		if (entry->map->offset == map->offset)
84 			return entry;
85 	}
86 
87 	return NULL;
88 }
89 
drm_map_handle(struct drm_device * dev,struct drm_hash_item * hash,unsigned long user_token,int hashed_handle,int shm)90 static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
91 			  unsigned long user_token, int hashed_handle, int shm)
92 {
93 	int use_hashed_handle, shift;
94 	unsigned long add;
95 
96 #if (BITS_PER_LONG == 64)
97 	use_hashed_handle = ((user_token & 0xFFFFFFFF00000000UL) || hashed_handle);
98 #elif (BITS_PER_LONG == 32)
99 	use_hashed_handle = hashed_handle;
100 #else
101 #error Unsupported long size. Neither 64 nor 32 bits.
102 #endif
103 
104 	if (!use_hashed_handle) {
105 		int ret;
106 
107 		hash->key = user_token >> PAGE_SHIFT;
108 		ret = drm_ht_insert_item(&dev->map_hash, hash);
109 		if (ret != -EINVAL)
110 			return ret;
111 	}
112 
113 	shift = 0;
114 	add = DRM_MAP_HASH_OFFSET >> PAGE_SHIFT;
115 	if (shm && (SHMLBA > PAGE_SIZE)) {
116 		int bits = ilog2(SHMLBA >> PAGE_SHIFT) + 1;
117 
118 		/* For shared memory, we have to preserve the SHMLBA
119 		 * bits of the eventual vma->vm_pgoff value during
120 		 * mmap().  Otherwise we run into cache aliasing problems
121 		 * on some platforms.  On these platforms, the pgoff of
122 		 * a mmap() request is used to pick a suitable virtual
123 		 * address for the mmap() region such that it will not
124 		 * cause cache aliasing problems.
125 		 *
126 		 * Therefore, make sure the SHMLBA relevant bits of the
127 		 * hash value we use are equal to those in the original
128 		 * kernel virtual address.
129 		 */
130 		shift = bits;
131 		add |= ((user_token >> PAGE_SHIFT) & ((1UL << bits) - 1UL));
132 	}
133 
134 	return drm_ht_just_insert_please(&dev->map_hash, hash,
135 					 user_token, 32 - PAGE_SHIFT - 3,
136 					 shift, add);
137 }
138 
139 /*
140  * Core function to create a range of memory available for mapping by a
141  * non-root process.
142  *
143  * Adjusts the memory offset to its absolute value according to the mapping
144  * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
145  * applicable and if supported by the kernel.
146  */
drm_addmap_core(struct drm_device * dev,resource_size_t offset,unsigned int size,enum drm_map_type type,enum drm_map_flags flags,struct drm_map_list ** maplist)147 static int drm_addmap_core(struct drm_device *dev, resource_size_t offset,
148 			   unsigned int size, enum drm_map_type type,
149 			   enum drm_map_flags flags,
150 			   struct drm_map_list **maplist)
151 {
152 	struct drm_local_map *map;
153 	struct drm_map_list *list;
154 	unsigned long user_token;
155 	int ret;
156 
157 	map = kmalloc(sizeof(*map), GFP_KERNEL);
158 	if (!map)
159 		return -ENOMEM;
160 
161 	map->offset = offset;
162 	map->size = size;
163 	map->flags = flags;
164 	map->type = type;
165 
166 	/* Only allow shared memory to be removable since we only keep enough
167 	 * book keeping information about shared memory to allow for removal
168 	 * when processes fork.
169 	 */
170 	if ((map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM) {
171 		kfree(map);
172 		return -EINVAL;
173 	}
174 	DRM_DEBUG("offset = 0x%08llx, size = 0x%08lx, type = %d\n",
175 		  (unsigned long long)map->offset, map->size, map->type);
176 
177 	/* page-align _DRM_SHM maps. They are allocated here so there is no security
178 	 * hole created by that and it works around various broken drivers that use
179 	 * a non-aligned quantity to map the SAREA. --BenH
180 	 */
181 	if (map->type == _DRM_SHM)
182 		map->size = PAGE_ALIGN(map->size);
183 
184 	if ((map->offset & (~(resource_size_t)PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
185 		kfree(map);
186 		return -EINVAL;
187 	}
188 	map->mtrr = -1;
189 	map->handle = NULL;
190 
191 	switch (map->type) {
192 	case _DRM_REGISTERS:
193 	case _DRM_FRAME_BUFFER:
194 #if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__) && !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__arm__)
195 		if (map->offset + (map->size-1) < map->offset ||
196 		    map->offset < virt_to_phys(high_memory)) {
197 			kfree(map);
198 			return -EINVAL;
199 		}
200 #endif
201 		/* Some drivers preinitialize some maps, without the X Server
202 		 * needing to be aware of it.  Therefore, we just return success
203 		 * when the server tries to create a duplicate map.
204 		 */
205 		list = drm_find_matching_map(dev, map);
206 		if (list != NULL) {
207 			if (list->map->size != map->size) {
208 				DRM_DEBUG("Matching maps of type %d with "
209 					  "mismatched sizes, (%ld vs %ld)\n",
210 					  map->type, map->size,
211 					  list->map->size);
212 				list->map->size = map->size;
213 			}
214 
215 			kfree(map);
216 			*maplist = list;
217 			return 0;
218 		}
219 
220 		if (map->type == _DRM_FRAME_BUFFER ||
221 		    (map->flags & _DRM_WRITE_COMBINING)) {
222 			map->mtrr =
223 				arch_phys_wc_add(map->offset, map->size);
224 		}
225 		if (map->type == _DRM_REGISTERS) {
226 			if (map->flags & _DRM_WRITE_COMBINING)
227 				map->handle = ioremap_wc(map->offset,
228 							 map->size);
229 			else
230 				map->handle = ioremap(map->offset, map->size);
231 			if (!map->handle) {
232 				kfree(map);
233 				return -ENOMEM;
234 			}
235 		}
236 
237 		break;
238 	case _DRM_SHM:
239 		list = drm_find_matching_map(dev, map);
240 		if (list != NULL) {
241 			if (list->map->size != map->size) {
242 				DRM_DEBUG("Matching maps of type %d with "
243 					  "mismatched sizes, (%ld vs %ld)\n",
244 					  map->type, map->size, list->map->size);
245 				list->map->size = map->size;
246 			}
247 
248 			kfree(map);
249 			*maplist = list;
250 			return 0;
251 		}
252 		map->handle = vmalloc_user(map->size);
253 		DRM_DEBUG("%lu %d %p\n",
254 			  map->size, order_base_2(map->size), map->handle);
255 		if (!map->handle) {
256 			kfree(map);
257 			return -ENOMEM;
258 		}
259 		map->offset = (unsigned long)map->handle;
260 		if (map->flags & _DRM_CONTAINS_LOCK) {
261 			/* Prevent a 2nd X Server from creating a 2nd lock */
262 			if (dev->master->lock.hw_lock != NULL) {
263 				vfree(map->handle);
264 				kfree(map);
265 				return -EBUSY;
266 			}
267 			dev->sigdata.lock = dev->master->lock.hw_lock = map->handle;	/* Pointer to lock */
268 		}
269 		break;
270 	case _DRM_AGP: {
271 		struct drm_agp_mem *entry;
272 		int valid = 0;
273 
274 		if (!dev->agp) {
275 			kfree(map);
276 			return -EINVAL;
277 		}
278 #ifdef __alpha__
279 		map->offset += dev->hose->mem_space->start;
280 #endif
281 		/* In some cases (i810 driver), user space may have already
282 		 * added the AGP base itself, because dev->agp->base previously
283 		 * only got set during AGP enable.  So, only add the base
284 		 * address if the map's offset isn't already within the
285 		 * aperture.
286 		 */
287 		if (map->offset < dev->agp->base ||
288 		    map->offset > dev->agp->base +
289 		    dev->agp->agp_info.aper_size * 1024 * 1024 - 1) {
290 			map->offset += dev->agp->base;
291 		}
292 		map->mtrr = dev->agp->agp_mtrr;	/* for getmap */
293 
294 		/* This assumes the DRM is in total control of AGP space.
295 		 * It's not always the case as AGP can be in the control
296 		 * of user space (i.e. i810 driver). So this loop will get
297 		 * skipped and we double check that dev->agp->memory is
298 		 * actually set as well as being invalid before EPERM'ing
299 		 */
300 		list_for_each_entry(entry, &dev->agp->memory, head) {
301 			if ((map->offset >= entry->bound) &&
302 			    (map->offset + map->size <= entry->bound + entry->pages * PAGE_SIZE)) {
303 				valid = 1;
304 				break;
305 			}
306 		}
307 		if (!list_empty(&dev->agp->memory) && !valid) {
308 			kfree(map);
309 			return -EPERM;
310 		}
311 		DRM_DEBUG("AGP offset = 0x%08llx, size = 0x%08lx\n",
312 			  (unsigned long long)map->offset, map->size);
313 
314 		break;
315 	}
316 	case _DRM_SCATTER_GATHER:
317 		if (!dev->sg) {
318 			kfree(map);
319 			return -EINVAL;
320 		}
321 		map->offset += (unsigned long)dev->sg->virtual;
322 		break;
323 	case _DRM_CONSISTENT:
324 		/* dma_addr_t is 64bit on i386 with CONFIG_HIGHMEM64G,
325 		 * As we're limiting the address to 2^32-1 (or less),
326 		 * casting it down to 32 bits is no problem, but we
327 		 * need to point to a 64bit variable first.
328 		 */
329 		map->handle = dma_alloc_coherent(dev->dev,
330 						 map->size,
331 						 &map->offset,
332 						 GFP_KERNEL);
333 		if (!map->handle) {
334 			kfree(map);
335 			return -ENOMEM;
336 		}
337 		break;
338 	default:
339 		kfree(map);
340 		return -EINVAL;
341 	}
342 
343 	list = kzalloc(sizeof(*list), GFP_KERNEL);
344 	if (!list) {
345 		if (map->type == _DRM_REGISTERS)
346 			iounmap(map->handle);
347 		kfree(map);
348 		return -EINVAL;
349 	}
350 	list->map = map;
351 
352 	mutex_lock(&dev->struct_mutex);
353 	list_add(&list->head, &dev->maplist);
354 
355 	/* Assign a 32-bit handle */
356 	/* We do it here so that dev->struct_mutex protects the increment */
357 	user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle :
358 		map->offset;
359 	ret = drm_map_handle(dev, &list->hash, user_token, 0,
360 			     (map->type == _DRM_SHM));
361 	if (ret) {
362 		if (map->type == _DRM_REGISTERS)
363 			iounmap(map->handle);
364 		kfree(map);
365 		kfree(list);
366 		mutex_unlock(&dev->struct_mutex);
367 		return ret;
368 	}
369 
370 	list->user_token = list->hash.key << PAGE_SHIFT;
371 	mutex_unlock(&dev->struct_mutex);
372 
373 	if (!(map->flags & _DRM_DRIVER))
374 		list->master = dev->master;
375 	*maplist = list;
376 	return 0;
377 }
378 
drm_legacy_addmap(struct drm_device * dev,resource_size_t offset,unsigned int size,enum drm_map_type type,enum drm_map_flags flags,struct drm_local_map ** map_ptr)379 int drm_legacy_addmap(struct drm_device *dev, resource_size_t offset,
380 		      unsigned int size, enum drm_map_type type,
381 		      enum drm_map_flags flags, struct drm_local_map **map_ptr)
382 {
383 	struct drm_map_list *list;
384 	int rc;
385 
386 	rc = drm_addmap_core(dev, offset, size, type, flags, &list);
387 	if (!rc)
388 		*map_ptr = list->map;
389 	return rc;
390 }
391 EXPORT_SYMBOL(drm_legacy_addmap);
392 
drm_legacy_findmap(struct drm_device * dev,unsigned int token)393 struct drm_local_map *drm_legacy_findmap(struct drm_device *dev,
394 					 unsigned int token)
395 {
396 	struct drm_map_list *_entry;
397 
398 	list_for_each_entry(_entry, &dev->maplist, head)
399 		if (_entry->user_token == token)
400 			return _entry->map;
401 	return NULL;
402 }
403 EXPORT_SYMBOL(drm_legacy_findmap);
404 
405 /*
406  * Ioctl to specify a range of memory that is available for mapping by a
407  * non-root process.
408  *
409  * \param inode device inode.
410  * \param file_priv DRM file private.
411  * \param cmd command.
412  * \param arg pointer to a drm_map structure.
413  * \return zero on success or a negative value on error.
414  *
415  */
drm_legacy_addmap_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)416 int drm_legacy_addmap_ioctl(struct drm_device *dev, void *data,
417 			    struct drm_file *file_priv)
418 {
419 	struct drm_map *map = data;
420 	struct drm_map_list *maplist;
421 	int err;
422 
423 	if (!(capable(CAP_SYS_ADMIN) || map->type == _DRM_AGP || map->type == _DRM_SHM))
424 		return -EPERM;
425 
426 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
427 		return -EOPNOTSUPP;
428 
429 	err = drm_addmap_core(dev, map->offset, map->size, map->type,
430 			      map->flags, &maplist);
431 
432 	if (err)
433 		return err;
434 
435 	/* avoid a warning on 64-bit, this casting isn't very nice, but the API is set so too late */
436 	map->handle = (void *)(unsigned long)maplist->user_token;
437 
438 	/*
439 	 * It appears that there are no users of this value whatsoever --
440 	 * drmAddMap just discards it.  Let's not encourage its use.
441 	 * (Keeping drm_addmap_core's returned mtrr value would be wrong --
442 	 *  it's not a real mtrr index anymore.)
443 	 */
444 	map->mtrr = -1;
445 
446 	return 0;
447 }
448 
449 /*
450  * Get a mapping information.
451  *
452  * \param inode device inode.
453  * \param file_priv DRM file private.
454  * \param cmd command.
455  * \param arg user argument, pointing to a drm_map structure.
456  *
457  * \return zero on success or a negative number on failure.
458  *
459  * Searches for the mapping with the specified offset and copies its information
460  * into userspace
461  */
drm_legacy_getmap_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)462 int drm_legacy_getmap_ioctl(struct drm_device *dev, void *data,
463 			    struct drm_file *file_priv)
464 {
465 	struct drm_map *map = data;
466 	struct drm_map_list *r_list = NULL;
467 	struct list_head *list;
468 	int idx;
469 	int i;
470 
471 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
472 		return -EOPNOTSUPP;
473 
474 	idx = map->offset;
475 	if (idx < 0)
476 		return -EINVAL;
477 
478 	i = 0;
479 	mutex_lock(&dev->struct_mutex);
480 	list_for_each(list, &dev->maplist) {
481 		if (i == idx) {
482 			r_list = list_entry(list, struct drm_map_list, head);
483 			break;
484 		}
485 		i++;
486 	}
487 	if (!r_list || !r_list->map) {
488 		mutex_unlock(&dev->struct_mutex);
489 		return -EINVAL;
490 	}
491 
492 	map->offset = r_list->map->offset;
493 	map->size = r_list->map->size;
494 	map->type = r_list->map->type;
495 	map->flags = r_list->map->flags;
496 	map->handle = (void *)(unsigned long) r_list->user_token;
497 	map->mtrr = arch_phys_wc_index(r_list->map->mtrr);
498 
499 	mutex_unlock(&dev->struct_mutex);
500 
501 	return 0;
502 }
503 
504 /*
505  * Remove a map private from list and deallocate resources if the mapping
506  * isn't in use.
507  *
508  * Searches the map on drm_device::maplist, removes it from the list, see if
509  * it's being used, and free any associated resource (such as MTRR's) if it's not
510  * being on use.
511  *
512  * \sa drm_legacy_addmap
513  */
drm_legacy_rmmap_locked(struct drm_device * dev,struct drm_local_map * map)514 int drm_legacy_rmmap_locked(struct drm_device *dev, struct drm_local_map *map)
515 {
516 	struct drm_map_list *r_list = NULL, *list_t;
517 	int found = 0;
518 	struct drm_master *master;
519 
520 	/* Find the list entry for the map and remove it */
521 	list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
522 		if (r_list->map == map) {
523 			master = r_list->master;
524 			list_del(&r_list->head);
525 			drm_ht_remove_key(&dev->map_hash,
526 					  r_list->user_token >> PAGE_SHIFT);
527 			kfree(r_list);
528 			found = 1;
529 			break;
530 		}
531 	}
532 
533 	if (!found)
534 		return -EINVAL;
535 
536 	switch (map->type) {
537 	case _DRM_REGISTERS:
538 		iounmap(map->handle);
539 		fallthrough;
540 	case _DRM_FRAME_BUFFER:
541 		arch_phys_wc_del(map->mtrr);
542 		break;
543 	case _DRM_SHM:
544 		vfree(map->handle);
545 		if (master) {
546 			if (dev->sigdata.lock == master->lock.hw_lock)
547 				dev->sigdata.lock = NULL;
548 			master->lock.hw_lock = NULL;   /* SHM removed */
549 			master->lock.file_priv = NULL;
550 			wake_up_interruptible_all(&master->lock.lock_queue);
551 		}
552 		break;
553 	case _DRM_AGP:
554 	case _DRM_SCATTER_GATHER:
555 		break;
556 	case _DRM_CONSISTENT:
557 		dma_free_coherent(dev->dev,
558 				  map->size,
559 				  map->handle,
560 				  map->offset);
561 		break;
562 	}
563 	kfree(map);
564 
565 	return 0;
566 }
567 EXPORT_SYMBOL(drm_legacy_rmmap_locked);
568 
drm_legacy_rmmap(struct drm_device * dev,struct drm_local_map * map)569 void drm_legacy_rmmap(struct drm_device *dev, struct drm_local_map *map)
570 {
571 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
572 		return;
573 
574 	mutex_lock(&dev->struct_mutex);
575 	drm_legacy_rmmap_locked(dev, map);
576 	mutex_unlock(&dev->struct_mutex);
577 }
578 EXPORT_SYMBOL(drm_legacy_rmmap);
579 
drm_legacy_master_rmmaps(struct drm_device * dev,struct drm_master * master)580 void drm_legacy_master_rmmaps(struct drm_device *dev, struct drm_master *master)
581 {
582 	struct drm_map_list *r_list, *list_temp;
583 
584 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
585 		return;
586 
587 	mutex_lock(&dev->struct_mutex);
588 	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
589 		if (r_list->master == master) {
590 			drm_legacy_rmmap_locked(dev, r_list->map);
591 			r_list = NULL;
592 		}
593 	}
594 	mutex_unlock(&dev->struct_mutex);
595 }
596 
drm_legacy_rmmaps(struct drm_device * dev)597 void drm_legacy_rmmaps(struct drm_device *dev)
598 {
599 	struct drm_map_list *r_list, *list_temp;
600 
601 	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
602 		drm_legacy_rmmap(dev, r_list->map);
603 }
604 
605 /* The rmmap ioctl appears to be unnecessary.  All mappings are torn down on
606  * the last close of the device, and this is necessary for cleanup when things
607  * exit uncleanly.  Therefore, having userland manually remove mappings seems
608  * like a pointless exercise since they're going away anyway.
609  *
610  * One use case might be after addmap is allowed for normal users for SHM and
611  * gets used by drivers that the server doesn't need to care about.  This seems
612  * unlikely.
613  *
614  * \param inode device inode.
615  * \param file_priv DRM file private.
616  * \param cmd command.
617  * \param arg pointer to a struct drm_map structure.
618  * \return zero on success or a negative value on error.
619  */
drm_legacy_rmmap_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)620 int drm_legacy_rmmap_ioctl(struct drm_device *dev, void *data,
621 			   struct drm_file *file_priv)
622 {
623 	struct drm_map *request = data;
624 	struct drm_local_map *map = NULL;
625 	struct drm_map_list *r_list;
626 	int ret;
627 
628 	if (!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  */
drm_cleanup_buf_error(struct drm_device * dev,struct drm_buf_entry * entry)670 static void drm_cleanup_buf_error(struct drm_device *dev,
671 				  struct drm_buf_entry *entry)
672 {
673 	drm_dma_handle_t *dmah;
674 	int i;
675 
676 	if (entry->seg_count) {
677 		for (i = 0; i < entry->seg_count; i++) {
678 			if (entry->seglist[i]) {
679 				dmah = entry->seglist[i];
680 				dma_free_coherent(dev->dev,
681 						  dmah->size,
682 						  dmah->vaddr,
683 						  dmah->busaddr);
684 				kfree(dmah);
685 			}
686 		}
687 		kfree(entry->seglist);
688 
689 		entry->seg_count = 0;
690 	}
691 
692 	if (entry->buf_count) {
693 		for (i = 0; i < entry->buf_count; i++) {
694 			kfree(entry->buflist[i].dev_private);
695 		}
696 		kfree(entry->buflist);
697 
698 		entry->buf_count = 0;
699 	}
700 }
701 
702 #if IS_ENABLED(CONFIG_AGP)
703 /*
704  * Add AGP buffers for DMA transfers.
705  *
706  * \param dev struct drm_device to which the buffers are to be added.
707  * \param request pointer to a struct drm_buf_desc describing the request.
708  * \return zero on success or a negative number on failure.
709  *
710  * After some sanity checks creates a drm_buf structure for each buffer and
711  * reallocates the buffer list of the same size order to accommodate the new
712  * buffers.
713  */
drm_legacy_addbufs_agp(struct drm_device * dev,struct drm_buf_desc * request)714 int drm_legacy_addbufs_agp(struct drm_device *dev,
715 			   struct drm_buf_desc *request)
716 {
717 	struct drm_device_dma *dma = dev->dma;
718 	struct drm_buf_entry *entry;
719 	struct drm_agp_mem *agp_entry;
720 	struct drm_buf *buf;
721 	unsigned long offset;
722 	unsigned long agp_offset;
723 	int count;
724 	int order;
725 	int size;
726 	int alignment;
727 	int page_order;
728 	int total;
729 	int byte_count;
730 	int i, valid;
731 	struct drm_buf **temp_buflist;
732 
733 	if (!dma)
734 		return -EINVAL;
735 
736 	count = request->count;
737 	order = order_base_2(request->size);
738 	size = 1 << order;
739 
740 	alignment = (request->flags & _DRM_PAGE_ALIGN)
741 	    ? PAGE_ALIGN(size) : size;
742 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
743 	total = PAGE_SIZE << page_order;
744 
745 	byte_count = 0;
746 	agp_offset = dev->agp->base + request->agp_start;
747 
748 	DRM_DEBUG("count:      %d\n", count);
749 	DRM_DEBUG("order:      %d\n", order);
750 	DRM_DEBUG("size:       %d\n", size);
751 	DRM_DEBUG("agp_offset: %lx\n", agp_offset);
752 	DRM_DEBUG("alignment:  %d\n", alignment);
753 	DRM_DEBUG("page_order: %d\n", page_order);
754 	DRM_DEBUG("total:      %d\n", total);
755 
756 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
757 		return -EINVAL;
758 
759 	/* Make sure buffers are located in AGP memory that we own */
760 	valid = 0;
761 	list_for_each_entry(agp_entry, &dev->agp->memory, head) {
762 		if ((agp_offset >= agp_entry->bound) &&
763 		    (agp_offset + total * count <= agp_entry->bound + agp_entry->pages * PAGE_SIZE)) {
764 			valid = 1;
765 			break;
766 		}
767 	}
768 	if (!list_empty(&dev->agp->memory) && !valid) {
769 		DRM_DEBUG("zone invalid\n");
770 		return -EINVAL;
771 	}
772 	spin_lock(&dev->buf_lock);
773 	if (dev->buf_use) {
774 		spin_unlock(&dev->buf_lock);
775 		return -EBUSY;
776 	}
777 	atomic_inc(&dev->buf_alloc);
778 	spin_unlock(&dev->buf_lock);
779 
780 	mutex_lock(&dev->struct_mutex);
781 	entry = &dma->bufs[order];
782 	if (entry->buf_count) {
783 		mutex_unlock(&dev->struct_mutex);
784 		atomic_dec(&dev->buf_alloc);
785 		return -ENOMEM;	/* May only call once for each order */
786 	}
787 
788 	if (count < 0 || count > 4096) {
789 		mutex_unlock(&dev->struct_mutex);
790 		atomic_dec(&dev->buf_alloc);
791 		return -EINVAL;
792 	}
793 
794 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
795 	if (!entry->buflist) {
796 		mutex_unlock(&dev->struct_mutex);
797 		atomic_dec(&dev->buf_alloc);
798 		return -ENOMEM;
799 	}
800 
801 	entry->buf_size = size;
802 	entry->page_order = page_order;
803 
804 	offset = 0;
805 
806 	while (entry->buf_count < count) {
807 		buf = &entry->buflist[entry->buf_count];
808 		buf->idx = dma->buf_count + entry->buf_count;
809 		buf->total = alignment;
810 		buf->order = order;
811 		buf->used = 0;
812 
813 		buf->offset = (dma->byte_count + offset);
814 		buf->bus_address = agp_offset + offset;
815 		buf->address = (void *)(agp_offset + offset);
816 		buf->next = NULL;
817 		buf->waiting = 0;
818 		buf->pending = 0;
819 		buf->file_priv = NULL;
820 
821 		buf->dev_priv_size = dev->driver->dev_priv_size;
822 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
823 		if (!buf->dev_private) {
824 			/* Set count correctly so we free the proper amount. */
825 			entry->buf_count = count;
826 			drm_cleanup_buf_error(dev, entry);
827 			mutex_unlock(&dev->struct_mutex);
828 			atomic_dec(&dev->buf_alloc);
829 			return -ENOMEM;
830 		}
831 
832 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
833 
834 		offset += alignment;
835 		entry->buf_count++;
836 		byte_count += PAGE_SIZE << page_order;
837 	}
838 
839 	DRM_DEBUG("byte_count: %d\n", byte_count);
840 
841 	temp_buflist = krealloc(dma->buflist,
842 				(dma->buf_count + entry->buf_count) *
843 				sizeof(*dma->buflist), GFP_KERNEL);
844 	if (!temp_buflist) {
845 		/* Free the entry because it isn't valid */
846 		drm_cleanup_buf_error(dev, entry);
847 		mutex_unlock(&dev->struct_mutex);
848 		atomic_dec(&dev->buf_alloc);
849 		return -ENOMEM;
850 	}
851 	dma->buflist = temp_buflist;
852 
853 	for (i = 0; i < entry->buf_count; i++) {
854 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
855 	}
856 
857 	dma->buf_count += entry->buf_count;
858 	dma->seg_count += entry->seg_count;
859 	dma->page_count += byte_count >> PAGE_SHIFT;
860 	dma->byte_count += byte_count;
861 
862 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
863 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
864 
865 	mutex_unlock(&dev->struct_mutex);
866 
867 	request->count = entry->buf_count;
868 	request->size = size;
869 
870 	dma->flags = _DRM_DMA_USE_AGP;
871 
872 	atomic_dec(&dev->buf_alloc);
873 	return 0;
874 }
875 EXPORT_SYMBOL(drm_legacy_addbufs_agp);
876 #endif /* CONFIG_AGP */
877 
drm_legacy_addbufs_pci(struct drm_device * dev,struct drm_buf_desc * request)878 int drm_legacy_addbufs_pci(struct drm_device *dev,
879 			   struct drm_buf_desc *request)
880 {
881 	struct drm_device_dma *dma = dev->dma;
882 	int count;
883 	int order;
884 	int size;
885 	int total;
886 	int page_order;
887 	struct drm_buf_entry *entry;
888 	drm_dma_handle_t *dmah;
889 	struct drm_buf *buf;
890 	int alignment;
891 	unsigned long offset;
892 	int i;
893 	int byte_count;
894 	int page_count;
895 	unsigned long *temp_pagelist;
896 	struct drm_buf **temp_buflist;
897 
898 	if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
899 		return -EOPNOTSUPP;
900 
901 	if (!dma)
902 		return -EINVAL;
903 
904 	if (!capable(CAP_SYS_ADMIN))
905 		return -EPERM;
906 
907 	count = request->count;
908 	order = order_base_2(request->size);
909 	size = 1 << order;
910 
911 	DRM_DEBUG("count=%d, size=%d (%d), order=%d\n",
912 		  request->count, request->size, size, order);
913 
914 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
915 		return -EINVAL;
916 
917 	alignment = (request->flags & _DRM_PAGE_ALIGN)
918 	    ? PAGE_ALIGN(size) : size;
919 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
920 	total = PAGE_SIZE << page_order;
921 
922 	spin_lock(&dev->buf_lock);
923 	if (dev->buf_use) {
924 		spin_unlock(&dev->buf_lock);
925 		return -EBUSY;
926 	}
927 	atomic_inc(&dev->buf_alloc);
928 	spin_unlock(&dev->buf_lock);
929 
930 	mutex_lock(&dev->struct_mutex);
931 	entry = &dma->bufs[order];
932 	if (entry->buf_count) {
933 		mutex_unlock(&dev->struct_mutex);
934 		atomic_dec(&dev->buf_alloc);
935 		return -ENOMEM;	/* May only call once for each order */
936 	}
937 
938 	if (count < 0 || count > 4096) {
939 		mutex_unlock(&dev->struct_mutex);
940 		atomic_dec(&dev->buf_alloc);
941 		return -EINVAL;
942 	}
943 
944 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
945 	if (!entry->buflist) {
946 		mutex_unlock(&dev->struct_mutex);
947 		atomic_dec(&dev->buf_alloc);
948 		return -ENOMEM;
949 	}
950 
951 	entry->seglist = kcalloc(count, sizeof(*entry->seglist), GFP_KERNEL);
952 	if (!entry->seglist) {
953 		kfree(entry->buflist);
954 		mutex_unlock(&dev->struct_mutex);
955 		atomic_dec(&dev->buf_alloc);
956 		return -ENOMEM;
957 	}
958 
959 	/* Keep the original pagelist until we know all the allocations
960 	 * have succeeded
961 	 */
962 	temp_pagelist = kmalloc_array(dma->page_count + (count << page_order),
963 				      sizeof(*dma->pagelist),
964 				      GFP_KERNEL);
965 	if (!temp_pagelist) {
966 		kfree(entry->buflist);
967 		kfree(entry->seglist);
968 		mutex_unlock(&dev->struct_mutex);
969 		atomic_dec(&dev->buf_alloc);
970 		return -ENOMEM;
971 	}
972 	memcpy(temp_pagelist,
973 	       dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
974 	DRM_DEBUG("pagelist: %d entries\n",
975 		  dma->page_count + (count << page_order));
976 
977 	entry->buf_size = size;
978 	entry->page_order = page_order;
979 	byte_count = 0;
980 	page_count = 0;
981 
982 	while (entry->buf_count < count) {
983 		dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
984 		if (!dmah) {
985 			/* Set count correctly so we free the proper amount. */
986 			entry->buf_count = count;
987 			entry->seg_count = count;
988 			drm_cleanup_buf_error(dev, entry);
989 			kfree(temp_pagelist);
990 			mutex_unlock(&dev->struct_mutex);
991 			atomic_dec(&dev->buf_alloc);
992 			return -ENOMEM;
993 		}
994 
995 		dmah->size = total;
996 		dmah->vaddr = dma_alloc_coherent(dev->dev,
997 						 dmah->size,
998 						 &dmah->busaddr,
999 						 GFP_KERNEL);
1000 		if (!dmah->vaddr) {
1001 			kfree(dmah);
1002 
1003 			/* Set count correctly so we free the proper amount. */
1004 			entry->buf_count = count;
1005 			entry->seg_count = count;
1006 			drm_cleanup_buf_error(dev, entry);
1007 			kfree(temp_pagelist);
1008 			mutex_unlock(&dev->struct_mutex);
1009 			atomic_dec(&dev->buf_alloc);
1010 			return -ENOMEM;
1011 		}
1012 		entry->seglist[entry->seg_count++] = dmah;
1013 		for (i = 0; i < (1 << page_order); i++) {
1014 			DRM_DEBUG("page %d @ 0x%08lx\n",
1015 				  dma->page_count + page_count,
1016 				  (unsigned long)dmah->vaddr + PAGE_SIZE * i);
1017 			temp_pagelist[dma->page_count + page_count++]
1018 				= (unsigned long)dmah->vaddr + PAGE_SIZE * i;
1019 		}
1020 		for (offset = 0;
1021 		     offset + size <= total && entry->buf_count < count;
1022 		     offset += alignment, ++entry->buf_count) {
1023 			buf = &entry->buflist[entry->buf_count];
1024 			buf->idx = dma->buf_count + entry->buf_count;
1025 			buf->total = alignment;
1026 			buf->order = order;
1027 			buf->used = 0;
1028 			buf->offset = (dma->byte_count + byte_count + offset);
1029 			buf->address = (void *)(dmah->vaddr + offset);
1030 			buf->bus_address = dmah->busaddr + offset;
1031 			buf->next = NULL;
1032 			buf->waiting = 0;
1033 			buf->pending = 0;
1034 			buf->file_priv = NULL;
1035 
1036 			buf->dev_priv_size = dev->driver->dev_priv_size;
1037 			buf->dev_private = kzalloc(buf->dev_priv_size,
1038 						GFP_KERNEL);
1039 			if (!buf->dev_private) {
1040 				/* Set count correctly so we free the proper amount. */
1041 				entry->buf_count = count;
1042 				entry->seg_count = count;
1043 				drm_cleanup_buf_error(dev, entry);
1044 				kfree(temp_pagelist);
1045 				mutex_unlock(&dev->struct_mutex);
1046 				atomic_dec(&dev->buf_alloc);
1047 				return -ENOMEM;
1048 			}
1049 
1050 			DRM_DEBUG("buffer %d @ %p\n",
1051 				  entry->buf_count, buf->address);
1052 		}
1053 		byte_count += PAGE_SIZE << page_order;
1054 	}
1055 
1056 	temp_buflist = krealloc(dma->buflist,
1057 				(dma->buf_count + entry->buf_count) *
1058 				sizeof(*dma->buflist), GFP_KERNEL);
1059 	if (!temp_buflist) {
1060 		/* Free the entry because it isn't valid */
1061 		drm_cleanup_buf_error(dev, entry);
1062 		kfree(temp_pagelist);
1063 		mutex_unlock(&dev->struct_mutex);
1064 		atomic_dec(&dev->buf_alloc);
1065 		return -ENOMEM;
1066 	}
1067 	dma->buflist = temp_buflist;
1068 
1069 	for (i = 0; i < entry->buf_count; i++) {
1070 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1071 	}
1072 
1073 	/* No allocations failed, so now we can replace the original pagelist
1074 	 * with the new one.
1075 	 */
1076 	if (dma->page_count) {
1077 		kfree(dma->pagelist);
1078 	}
1079 	dma->pagelist = temp_pagelist;
1080 
1081 	dma->buf_count += entry->buf_count;
1082 	dma->seg_count += entry->seg_count;
1083 	dma->page_count += entry->seg_count << page_order;
1084 	dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);
1085 
1086 	mutex_unlock(&dev->struct_mutex);
1087 
1088 	request->count = entry->buf_count;
1089 	request->size = size;
1090 
1091 	if (request->flags & _DRM_PCI_BUFFER_RO)
1092 		dma->flags = _DRM_DMA_USE_PCI_RO;
1093 
1094 	atomic_dec(&dev->buf_alloc);
1095 	return 0;
1096 
1097 }
1098 EXPORT_SYMBOL(drm_legacy_addbufs_pci);
1099 
drm_legacy_addbufs_sg(struct drm_device * dev,struct drm_buf_desc * request)1100 static int drm_legacy_addbufs_sg(struct drm_device *dev,
1101 				 struct drm_buf_desc *request)
1102 {
1103 	struct drm_device_dma *dma = dev->dma;
1104 	struct drm_buf_entry *entry;
1105 	struct drm_buf *buf;
1106 	unsigned long offset;
1107 	unsigned long agp_offset;
1108 	int count;
1109 	int order;
1110 	int size;
1111 	int alignment;
1112 	int page_order;
1113 	int total;
1114 	int byte_count;
1115 	int i;
1116 	struct drm_buf **temp_buflist;
1117 
1118 	if (!drm_core_check_feature(dev, DRIVER_SG))
1119 		return -EOPNOTSUPP;
1120 
1121 	if (!dma)
1122 		return -EINVAL;
1123 
1124 	if (!capable(CAP_SYS_ADMIN))
1125 		return -EPERM;
1126 
1127 	count = request->count;
1128 	order = order_base_2(request->size);
1129 	size = 1 << order;
1130 
1131 	alignment = (request->flags & _DRM_PAGE_ALIGN)
1132 	    ? PAGE_ALIGN(size) : size;
1133 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
1134 	total = PAGE_SIZE << page_order;
1135 
1136 	byte_count = 0;
1137 	agp_offset = request->agp_start;
1138 
1139 	DRM_DEBUG("count:      %d\n", count);
1140 	DRM_DEBUG("order:      %d\n", order);
1141 	DRM_DEBUG("size:       %d\n", size);
1142 	DRM_DEBUG("agp_offset: %lu\n", agp_offset);
1143 	DRM_DEBUG("alignment:  %d\n", alignment);
1144 	DRM_DEBUG("page_order: %d\n", page_order);
1145 	DRM_DEBUG("total:      %d\n", total);
1146 
1147 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1148 		return -EINVAL;
1149 
1150 	spin_lock(&dev->buf_lock);
1151 	if (dev->buf_use) {
1152 		spin_unlock(&dev->buf_lock);
1153 		return -EBUSY;
1154 	}
1155 	atomic_inc(&dev->buf_alloc);
1156 	spin_unlock(&dev->buf_lock);
1157 
1158 	mutex_lock(&dev->struct_mutex);
1159 	entry = &dma->bufs[order];
1160 	if (entry->buf_count) {
1161 		mutex_unlock(&dev->struct_mutex);
1162 		atomic_dec(&dev->buf_alloc);
1163 		return -ENOMEM;	/* May only call once for each order */
1164 	}
1165 
1166 	if (count < 0 || count > 4096) {
1167 		mutex_unlock(&dev->struct_mutex);
1168 		atomic_dec(&dev->buf_alloc);
1169 		return -EINVAL;
1170 	}
1171 
1172 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
1173 	if (!entry->buflist) {
1174 		mutex_unlock(&dev->struct_mutex);
1175 		atomic_dec(&dev->buf_alloc);
1176 		return -ENOMEM;
1177 	}
1178 
1179 	entry->buf_size = size;
1180 	entry->page_order = page_order;
1181 
1182 	offset = 0;
1183 
1184 	while (entry->buf_count < count) {
1185 		buf = &entry->buflist[entry->buf_count];
1186 		buf->idx = dma->buf_count + entry->buf_count;
1187 		buf->total = alignment;
1188 		buf->order = order;
1189 		buf->used = 0;
1190 
1191 		buf->offset = (dma->byte_count + offset);
1192 		buf->bus_address = agp_offset + offset;
1193 		buf->address = (void *)(agp_offset + offset
1194 					+ (unsigned long)dev->sg->virtual);
1195 		buf->next = NULL;
1196 		buf->waiting = 0;
1197 		buf->pending = 0;
1198 		buf->file_priv = NULL;
1199 
1200 		buf->dev_priv_size = dev->driver->dev_priv_size;
1201 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
1202 		if (!buf->dev_private) {
1203 			/* Set count correctly so we free the proper amount. */
1204 			entry->buf_count = count;
1205 			drm_cleanup_buf_error(dev, entry);
1206 			mutex_unlock(&dev->struct_mutex);
1207 			atomic_dec(&dev->buf_alloc);
1208 			return -ENOMEM;
1209 		}
1210 
1211 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
1212 
1213 		offset += alignment;
1214 		entry->buf_count++;
1215 		byte_count += PAGE_SIZE << page_order;
1216 	}
1217 
1218 	DRM_DEBUG("byte_count: %d\n", byte_count);
1219 
1220 	temp_buflist = krealloc(dma->buflist,
1221 				(dma->buf_count + entry->buf_count) *
1222 				sizeof(*dma->buflist), GFP_KERNEL);
1223 	if (!temp_buflist) {
1224 		/* Free the entry because it isn't valid */
1225 		drm_cleanup_buf_error(dev, entry);
1226 		mutex_unlock(&dev->struct_mutex);
1227 		atomic_dec(&dev->buf_alloc);
1228 		return -ENOMEM;
1229 	}
1230 	dma->buflist = temp_buflist;
1231 
1232 	for (i = 0; i < entry->buf_count; i++) {
1233 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1234 	}
1235 
1236 	dma->buf_count += entry->buf_count;
1237 	dma->seg_count += entry->seg_count;
1238 	dma->page_count += byte_count >> PAGE_SHIFT;
1239 	dma->byte_count += byte_count;
1240 
1241 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
1242 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
1243 
1244 	mutex_unlock(&dev->struct_mutex);
1245 
1246 	request->count = entry->buf_count;
1247 	request->size = size;
1248 
1249 	dma->flags = _DRM_DMA_USE_SG;
1250 
1251 	atomic_dec(&dev->buf_alloc);
1252 	return 0;
1253 }
1254 
1255 /*
1256  * Add buffers for DMA transfers (ioctl).
1257  *
1258  * \param inode device inode.
1259  * \param file_priv DRM file private.
1260  * \param cmd command.
1261  * \param arg pointer to a struct drm_buf_desc request.
1262  * \return zero on success or a negative number on failure.
1263  *
1264  * According with the memory type specified in drm_buf_desc::flags and the
1265  * build options, it dispatches the call either to addbufs_agp(),
1266  * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
1267  * PCI memory respectively.
1268  */
drm_legacy_addbufs(struct drm_device * dev,void * data,struct drm_file * file_priv)1269 int drm_legacy_addbufs(struct drm_device *dev, void *data,
1270 		       struct drm_file *file_priv)
1271 {
1272 	struct drm_buf_desc *request = data;
1273 	int ret;
1274 
1275 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1276 		return -EOPNOTSUPP;
1277 
1278 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1279 		return -EOPNOTSUPP;
1280 
1281 #if IS_ENABLED(CONFIG_AGP)
1282 	if (request->flags & _DRM_AGP_BUFFER)
1283 		ret = drm_legacy_addbufs_agp(dev, request);
1284 	else
1285 #endif
1286 	if (request->flags & _DRM_SG_BUFFER)
1287 		ret = drm_legacy_addbufs_sg(dev, request);
1288 	else if (request->flags & _DRM_FB_BUFFER)
1289 		ret = -EINVAL;
1290 	else
1291 		ret = drm_legacy_addbufs_pci(dev, request);
1292 
1293 	return ret;
1294 }
1295 
1296 /*
1297  * Get information about the buffer mappings.
1298  *
1299  * This was originally mean for debugging purposes, or by a sophisticated
1300  * client library to determine how best to use the available buffers (e.g.,
1301  * large buffers can be used for image transfer).
1302  *
1303  * \param inode device inode.
1304  * \param file_priv DRM file private.
1305  * \param cmd command.
1306  * \param arg pointer to a drm_buf_info structure.
1307  * \return zero on success or a negative number on failure.
1308  *
1309  * Increments drm_device::buf_use while holding the drm_device::buf_lock
1310  * lock, preventing of allocating more buffers after this call. Information
1311  * about each requested buffer is then copied into user space.
1312  */
__drm_legacy_infobufs(struct drm_device * dev,void * data,int * p,int (* f)(void *,int,struct drm_buf_entry *))1313 int __drm_legacy_infobufs(struct drm_device *dev,
1314 			void *data, int *p,
1315 			int (*f)(void *, int, struct drm_buf_entry *))
1316 {
1317 	struct drm_device_dma *dma = dev->dma;
1318 	int i;
1319 	int count;
1320 
1321 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1322 		return -EOPNOTSUPP;
1323 
1324 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1325 		return -EOPNOTSUPP;
1326 
1327 	if (!dma)
1328 		return -EINVAL;
1329 
1330 	spin_lock(&dev->buf_lock);
1331 	if (atomic_read(&dev->buf_alloc)) {
1332 		spin_unlock(&dev->buf_lock);
1333 		return -EBUSY;
1334 	}
1335 	++dev->buf_use;		/* Can't allocate more after this call */
1336 	spin_unlock(&dev->buf_lock);
1337 
1338 	for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1339 		if (dma->bufs[i].buf_count)
1340 			++count;
1341 	}
1342 
1343 	DRM_DEBUG("count = %d\n", count);
1344 
1345 	if (*p >= count) {
1346 		for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1347 			struct drm_buf_entry *from = &dma->bufs[i];
1348 
1349 			if (from->buf_count) {
1350 				if (f(data, count, from) < 0)
1351 					return -EFAULT;
1352 				DRM_DEBUG("%d %d %d %d %d\n",
1353 					  i,
1354 					  dma->bufs[i].buf_count,
1355 					  dma->bufs[i].buf_size,
1356 					  dma->bufs[i].low_mark,
1357 					  dma->bufs[i].high_mark);
1358 				++count;
1359 			}
1360 		}
1361 	}
1362 	*p = count;
1363 
1364 	return 0;
1365 }
1366 
copy_one_buf(void * data,int count,struct drm_buf_entry * from)1367 static int copy_one_buf(void *data, int count, struct drm_buf_entry *from)
1368 {
1369 	struct drm_buf_info *request = data;
1370 	struct drm_buf_desc __user *to = &request->list[count];
1371 	struct drm_buf_desc v = {.count = from->buf_count,
1372 				 .size = from->buf_size,
1373 				 .low_mark = from->low_mark,
1374 				 .high_mark = from->high_mark};
1375 
1376 	if (copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags)))
1377 		return -EFAULT;
1378 	return 0;
1379 }
1380 
drm_legacy_infobufs(struct drm_device * dev,void * data,struct drm_file * file_priv)1381 int drm_legacy_infobufs(struct drm_device *dev, void *data,
1382 			struct drm_file *file_priv)
1383 {
1384 	struct drm_buf_info *request = data;
1385 
1386 	return __drm_legacy_infobufs(dev, data, &request->count, copy_one_buf);
1387 }
1388 
1389 /*
1390  * Specifies a low and high water mark for buffer allocation
1391  *
1392  * \param inode device inode.
1393  * \param file_priv DRM file private.
1394  * \param cmd command.
1395  * \param arg a pointer to a drm_buf_desc structure.
1396  * \return zero on success or a negative number on failure.
1397  *
1398  * Verifies that the size order is bounded between the admissible orders and
1399  * updates the respective drm_device_dma::bufs entry low and high water mark.
1400  *
1401  * \note This ioctl is deprecated and mostly never used.
1402  */
drm_legacy_markbufs(struct drm_device * dev,void * data,struct drm_file * file_priv)1403 int drm_legacy_markbufs(struct drm_device *dev, void *data,
1404 			struct drm_file *file_priv)
1405 {
1406 	struct drm_device_dma *dma = dev->dma;
1407 	struct drm_buf_desc *request = data;
1408 	int order;
1409 	struct drm_buf_entry *entry;
1410 
1411 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1412 		return -EOPNOTSUPP;
1413 
1414 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1415 		return -EOPNOTSUPP;
1416 
1417 	if (!dma)
1418 		return -EINVAL;
1419 
1420 	DRM_DEBUG("%d, %d, %d\n",
1421 		  request->size, request->low_mark, request->high_mark);
1422 	order = order_base_2(request->size);
1423 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1424 		return -EINVAL;
1425 	entry = &dma->bufs[order];
1426 
1427 	if (request->low_mark < 0 || request->low_mark > entry->buf_count)
1428 		return -EINVAL;
1429 	if (request->high_mark < 0 || request->high_mark > entry->buf_count)
1430 		return -EINVAL;
1431 
1432 	entry->low_mark = request->low_mark;
1433 	entry->high_mark = request->high_mark;
1434 
1435 	return 0;
1436 }
1437 
1438 /*
1439  * Unreserve the buffers in list, previously reserved using drmDMA.
1440  *
1441  * \param inode device inode.
1442  * \param file_priv DRM file private.
1443  * \param cmd command.
1444  * \param arg pointer to a drm_buf_free structure.
1445  * \return zero on success or a negative number on failure.
1446  *
1447  * Calls free_buffer() for each used buffer.
1448  * This function is primarily used for debugging.
1449  */
drm_legacy_freebufs(struct drm_device * dev,void * data,struct drm_file * file_priv)1450 int drm_legacy_freebufs(struct drm_device *dev, void *data,
1451 			struct drm_file *file_priv)
1452 {
1453 	struct drm_device_dma *dma = dev->dma;
1454 	struct drm_buf_free *request = data;
1455 	int i;
1456 	int idx;
1457 	struct drm_buf *buf;
1458 
1459 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1460 		return -EOPNOTSUPP;
1461 
1462 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1463 		return -EOPNOTSUPP;
1464 
1465 	if (!dma)
1466 		return -EINVAL;
1467 
1468 	DRM_DEBUG("%d\n", request->count);
1469 	for (i = 0; i < request->count; i++) {
1470 		if (copy_from_user(&idx, &request->list[i], sizeof(idx)))
1471 			return -EFAULT;
1472 		if (idx < 0 || idx >= dma->buf_count) {
1473 			DRM_ERROR("Index %d (of %d max)\n",
1474 				  idx, dma->buf_count - 1);
1475 			return -EINVAL;
1476 		}
1477 		idx = array_index_nospec(idx, dma->buf_count);
1478 		buf = dma->buflist[idx];
1479 		if (buf->file_priv != file_priv) {
1480 			DRM_ERROR("Process %d freeing buffer not owned\n",
1481 				  task_pid_nr(current));
1482 			return -EINVAL;
1483 		}
1484 		drm_legacy_free_buffer(dev, buf);
1485 	}
1486 
1487 	return 0;
1488 }
1489 
1490 /*
1491  * Maps all of the DMA buffers into client-virtual space (ioctl).
1492  *
1493  * \param inode device inode.
1494  * \param file_priv DRM file private.
1495  * \param cmd command.
1496  * \param arg pointer to a drm_buf_map structure.
1497  * \return zero on success or a negative number on failure.
1498  *
1499  * Maps the AGP, SG or PCI buffer region with vm_mmap(), and copies information
1500  * about each buffer into user space. For PCI buffers, it calls vm_mmap() with
1501  * offset equal to 0, which drm_mmap() interprets as PCI buffers and calls
1502  * drm_mmap_dma().
1503  */
__drm_legacy_mapbufs(struct drm_device * dev,void * data,int * p,void __user ** v,int (* f)(void *,int,unsigned long,struct drm_buf *),struct drm_file * file_priv)1504 int __drm_legacy_mapbufs(struct drm_device *dev, void *data, int *p,
1505 			 void __user **v,
1506 			 int (*f)(void *, int, unsigned long,
1507 				 struct drm_buf *),
1508 				 struct drm_file *file_priv)
1509 {
1510 	struct drm_device_dma *dma = dev->dma;
1511 	int retcode = 0;
1512 	unsigned long virtual;
1513 	int i;
1514 
1515 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1516 		return -EOPNOTSUPP;
1517 
1518 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1519 		return -EOPNOTSUPP;
1520 
1521 	if (!dma)
1522 		return -EINVAL;
1523 
1524 	spin_lock(&dev->buf_lock);
1525 	if (atomic_read(&dev->buf_alloc)) {
1526 		spin_unlock(&dev->buf_lock);
1527 		return -EBUSY;
1528 	}
1529 	dev->buf_use++;		/* Can't allocate more after this call */
1530 	spin_unlock(&dev->buf_lock);
1531 
1532 	if (*p >= dma->buf_count) {
1533 		if ((dev->agp && (dma->flags & _DRM_DMA_USE_AGP))
1534 		    || (drm_core_check_feature(dev, DRIVER_SG)
1535 			&& (dma->flags & _DRM_DMA_USE_SG))) {
1536 			struct drm_local_map *map = dev->agp_buffer_map;
1537 			unsigned long token = dev->agp_buffer_token;
1538 
1539 			if (!map) {
1540 				retcode = -EINVAL;
1541 				goto done;
1542 			}
1543 			virtual = vm_mmap(file_priv->filp, 0, map->size,
1544 					  PROT_READ | PROT_WRITE,
1545 					  MAP_SHARED,
1546 					  token);
1547 		} else {
1548 			virtual = vm_mmap(file_priv->filp, 0, dma->byte_count,
1549 					  PROT_READ | PROT_WRITE,
1550 					  MAP_SHARED, 0);
1551 		}
1552 		if (virtual > -1024UL) {
1553 			/* Real error */
1554 			retcode = (signed long)virtual;
1555 			goto done;
1556 		}
1557 		*v = (void __user *)virtual;
1558 
1559 		for (i = 0; i < dma->buf_count; i++) {
1560 			if (f(data, i, virtual, dma->buflist[i]) < 0) {
1561 				retcode = -EFAULT;
1562 				goto done;
1563 			}
1564 		}
1565 	}
1566       done:
1567 	*p = dma->buf_count;
1568 	DRM_DEBUG("%d buffers, retcode = %d\n", *p, retcode);
1569 
1570 	return retcode;
1571 }
1572 
map_one_buf(void * data,int idx,unsigned long virtual,struct drm_buf * buf)1573 static int map_one_buf(void *data, int idx, unsigned long virtual,
1574 			struct drm_buf *buf)
1575 {
1576 	struct drm_buf_map *request = data;
1577 	unsigned long address = virtual + buf->offset;	/* *** */
1578 
1579 	if (copy_to_user(&request->list[idx].idx, &buf->idx,
1580 			 sizeof(request->list[0].idx)))
1581 		return -EFAULT;
1582 	if (copy_to_user(&request->list[idx].total, &buf->total,
1583 			 sizeof(request->list[0].total)))
1584 		return -EFAULT;
1585 	if (clear_user(&request->list[idx].used, sizeof(int)))
1586 		return -EFAULT;
1587 	if (copy_to_user(&request->list[idx].address, &address,
1588 			 sizeof(address)))
1589 		return -EFAULT;
1590 	return 0;
1591 }
1592 
drm_legacy_mapbufs(struct drm_device * dev,void * data,struct drm_file * file_priv)1593 int drm_legacy_mapbufs(struct drm_device *dev, void *data,
1594 		       struct drm_file *file_priv)
1595 {
1596 	struct drm_buf_map *request = data;
1597 
1598 	return __drm_legacy_mapbufs(dev, data, &request->count,
1599 				    &request->virtual, map_one_buf,
1600 				    file_priv);
1601 }
1602 
drm_legacy_dma_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)1603 int drm_legacy_dma_ioctl(struct drm_device *dev, void *data,
1604 		  struct drm_file *file_priv)
1605 {
1606 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1607 		return -EOPNOTSUPP;
1608 
1609 	if (dev->driver->dma_ioctl)
1610 		return dev->driver->dma_ioctl(dev, data, file_priv);
1611 	else
1612 		return -EINVAL;
1613 }
1614 
drm_legacy_getsarea(struct drm_device * dev)1615 struct drm_local_map *drm_legacy_getsarea(struct drm_device *dev)
1616 {
1617 	struct drm_map_list *entry;
1618 
1619 	list_for_each_entry(entry, &dev->maplist, head) {
1620 		if (entry->map && entry->map->type == _DRM_SHM &&
1621 		    (entry->map->flags & _DRM_CONTAINS_LOCK)) {
1622 			return entry->map;
1623 		}
1624 	}
1625 	return NULL;
1626 }
1627 EXPORT_SYMBOL(drm_legacy_getsarea);
1628