xref: /openbmc/linux/drivers/gpu/drm/drm_bufs.c (revision 9be08a27)
1 /*
2  * Legacy: Generic DRM Buffer Management
3  *
4  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
6  * All Rights Reserved.
7  *
8  * Author: Rickard E. (Rik) Faith <faith@valinux.com>
9  * Author: Gareth Hughes <gareth@valinux.com>
10  *
11  * Permission is hereby granted, free of charge, to any person obtaining a
12  * copy of this software and associated documentation files (the "Software"),
13  * to deal in the Software without restriction, including without limitation
14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15  * and/or sell copies of the Software, and to permit persons to whom the
16  * Software is furnished to do so, subject to the following conditions:
17  *
18  * The above copyright notice and this permission notice (including the next
19  * paragraph) shall be included in all copies or substantial portions of the
20  * Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
25  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
26  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
27  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28  * OTHER DEALINGS IN THE SOFTWARE.
29  */
30 
31 #include <linux/vmalloc.h>
32 #include <linux/slab.h>
33 #include <linux/log2.h>
34 #include <linux/export.h>
35 #include <asm/shmparam.h>
36 #include <drm/drmP.h>
37 #include "drm_legacy.h"
38 
39 static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
40 						  struct drm_local_map *map)
41 {
42 	struct drm_map_list *entry;
43 	list_for_each_entry(entry, &dev->maplist, head) {
44 		/*
45 		 * Because the kernel-userspace ABI is fixed at a 32-bit offset
46 		 * while PCI resources may live above that, we only compare the
47 		 * lower 32 bits of the map offset for maps of type
48 		 * _DRM_FRAMEBUFFER or _DRM_REGISTERS.
49 		 * It is assumed that if a driver have more than one resource
50 		 * of each type, the lower 32 bits are different.
51 		 */
52 		if (!entry->map ||
53 		    map->type != entry->map->type ||
54 		    entry->master != dev->master)
55 			continue;
56 		switch (map->type) {
57 		case _DRM_SHM:
58 			if (map->flags != _DRM_CONTAINS_LOCK)
59 				break;
60 			return entry;
61 		case _DRM_REGISTERS:
62 		case _DRM_FRAME_BUFFER:
63 			if ((entry->map->offset & 0xffffffff) ==
64 			    (map->offset & 0xffffffff))
65 				return entry;
66 		default: /* Make gcc happy */
67 			;
68 		}
69 		if (entry->map->offset == map->offset)
70 			return entry;
71 	}
72 
73 	return NULL;
74 }
75 
76 static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
77 			  unsigned long user_token, int hashed_handle, int shm)
78 {
79 	int use_hashed_handle, shift;
80 	unsigned long add;
81 
82 #if (BITS_PER_LONG == 64)
83 	use_hashed_handle = ((user_token & 0xFFFFFFFF00000000UL) || hashed_handle);
84 #elif (BITS_PER_LONG == 32)
85 	use_hashed_handle = hashed_handle;
86 #else
87 #error Unsupported long size. Neither 64 nor 32 bits.
88 #endif
89 
90 	if (!use_hashed_handle) {
91 		int ret;
92 		hash->key = user_token >> PAGE_SHIFT;
93 		ret = drm_ht_insert_item(&dev->map_hash, hash);
94 		if (ret != -EINVAL)
95 			return ret;
96 	}
97 
98 	shift = 0;
99 	add = DRM_MAP_HASH_OFFSET >> PAGE_SHIFT;
100 	if (shm && (SHMLBA > PAGE_SIZE)) {
101 		int bits = ilog2(SHMLBA >> PAGE_SHIFT) + 1;
102 
103 		/* For shared memory, we have to preserve the SHMLBA
104 		 * bits of the eventual vma->vm_pgoff value during
105 		 * mmap().  Otherwise we run into cache aliasing problems
106 		 * on some platforms.  On these platforms, the pgoff of
107 		 * a mmap() request is used to pick a suitable virtual
108 		 * address for the mmap() region such that it will not
109 		 * cause cache aliasing problems.
110 		 *
111 		 * Therefore, make sure the SHMLBA relevant bits of the
112 		 * hash value we use are equal to those in the original
113 		 * kernel virtual address.
114 		 */
115 		shift = bits;
116 		add |= ((user_token >> PAGE_SHIFT) & ((1UL << bits) - 1UL));
117 	}
118 
119 	return drm_ht_just_insert_please(&dev->map_hash, hash,
120 					 user_token, 32 - PAGE_SHIFT - 3,
121 					 shift, add);
122 }
123 
124 /**
125  * Core function to create a range of memory available for mapping by a
126  * non-root process.
127  *
128  * Adjusts the memory offset to its absolute value according to the mapping
129  * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
130  * applicable and if supported by the kernel.
131  */
132 static int drm_addmap_core(struct drm_device *dev, resource_size_t offset,
133 			   unsigned int size, enum drm_map_type type,
134 			   enum drm_map_flags flags,
135 			   struct drm_map_list **maplist)
136 {
137 	struct drm_local_map *map;
138 	struct drm_map_list *list;
139 	drm_dma_handle_t *dmah;
140 	unsigned long user_token;
141 	int ret;
142 
143 	map = kmalloc(sizeof(*map), GFP_KERNEL);
144 	if (!map)
145 		return -ENOMEM;
146 
147 	map->offset = offset;
148 	map->size = size;
149 	map->flags = flags;
150 	map->type = type;
151 
152 	/* Only allow shared memory to be removable since we only keep enough
153 	 * book keeping information about shared memory to allow for removal
154 	 * when processes fork.
155 	 */
156 	if ((map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM) {
157 		kfree(map);
158 		return -EINVAL;
159 	}
160 	DRM_DEBUG("offset = 0x%08llx, size = 0x%08lx, type = %d\n",
161 		  (unsigned long long)map->offset, map->size, map->type);
162 
163 	/* page-align _DRM_SHM maps. They are allocated here so there is no security
164 	 * hole created by that and it works around various broken drivers that use
165 	 * a non-aligned quantity to map the SAREA. --BenH
166 	 */
167 	if (map->type == _DRM_SHM)
168 		map->size = PAGE_ALIGN(map->size);
169 
170 	if ((map->offset & (~(resource_size_t)PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
171 		kfree(map);
172 		return -EINVAL;
173 	}
174 	map->mtrr = -1;
175 	map->handle = NULL;
176 
177 	switch (map->type) {
178 	case _DRM_REGISTERS:
179 	case _DRM_FRAME_BUFFER:
180 #if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__) && !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__arm__)
181 		if (map->offset + (map->size-1) < map->offset ||
182 		    map->offset < virt_to_phys(high_memory)) {
183 			kfree(map);
184 			return -EINVAL;
185 		}
186 #endif
187 		/* Some drivers preinitialize some maps, without the X Server
188 		 * needing to be aware of it.  Therefore, we just return success
189 		 * when the server tries to create a duplicate map.
190 		 */
191 		list = drm_find_matching_map(dev, map);
192 		if (list != NULL) {
193 			if (list->map->size != map->size) {
194 				DRM_DEBUG("Matching maps of type %d with "
195 					  "mismatched sizes, (%ld vs %ld)\n",
196 					  map->type, map->size,
197 					  list->map->size);
198 				list->map->size = map->size;
199 			}
200 
201 			kfree(map);
202 			*maplist = list;
203 			return 0;
204 		}
205 
206 		if (map->type == _DRM_FRAME_BUFFER ||
207 		    (map->flags & _DRM_WRITE_COMBINING)) {
208 			map->mtrr =
209 				arch_phys_wc_add(map->offset, map->size);
210 		}
211 		if (map->type == _DRM_REGISTERS) {
212 			if (map->flags & _DRM_WRITE_COMBINING)
213 				map->handle = ioremap_wc(map->offset,
214 							 map->size);
215 			else
216 				map->handle = ioremap(map->offset, map->size);
217 			if (!map->handle) {
218 				kfree(map);
219 				return -ENOMEM;
220 			}
221 		}
222 
223 		break;
224 	case _DRM_SHM:
225 		list = drm_find_matching_map(dev, map);
226 		if (list != NULL) {
227 			if (list->map->size != map->size) {
228 				DRM_DEBUG("Matching maps of type %d with "
229 					  "mismatched sizes, (%ld vs %ld)\n",
230 					  map->type, map->size, list->map->size);
231 				list->map->size = map->size;
232 			}
233 
234 			kfree(map);
235 			*maplist = list;
236 			return 0;
237 		}
238 		map->handle = vmalloc_user(map->size);
239 		DRM_DEBUG("%lu %d %p\n",
240 			  map->size, order_base_2(map->size), map->handle);
241 		if (!map->handle) {
242 			kfree(map);
243 			return -ENOMEM;
244 		}
245 		map->offset = (unsigned long)map->handle;
246 		if (map->flags & _DRM_CONTAINS_LOCK) {
247 			/* Prevent a 2nd X Server from creating a 2nd lock */
248 			if (dev->master->lock.hw_lock != NULL) {
249 				vfree(map->handle);
250 				kfree(map);
251 				return -EBUSY;
252 			}
253 			dev->sigdata.lock = dev->master->lock.hw_lock = map->handle;	/* Pointer to lock */
254 		}
255 		break;
256 	case _DRM_AGP: {
257 		struct drm_agp_mem *entry;
258 		int valid = 0;
259 
260 		if (!dev->agp) {
261 			kfree(map);
262 			return -EINVAL;
263 		}
264 #ifdef __alpha__
265 		map->offset += dev->hose->mem_space->start;
266 #endif
267 		/* In some cases (i810 driver), user space may have already
268 		 * added the AGP base itself, because dev->agp->base previously
269 		 * only got set during AGP enable.  So, only add the base
270 		 * address if the map's offset isn't already within the
271 		 * aperture.
272 		 */
273 		if (map->offset < dev->agp->base ||
274 		    map->offset > dev->agp->base +
275 		    dev->agp->agp_info.aper_size * 1024 * 1024 - 1) {
276 			map->offset += dev->agp->base;
277 		}
278 		map->mtrr = dev->agp->agp_mtrr;	/* for getmap */
279 
280 		/* This assumes the DRM is in total control of AGP space.
281 		 * It's not always the case as AGP can be in the control
282 		 * of user space (i.e. i810 driver). So this loop will get
283 		 * skipped and we double check that dev->agp->memory is
284 		 * actually set as well as being invalid before EPERM'ing
285 		 */
286 		list_for_each_entry(entry, &dev->agp->memory, head) {
287 			if ((map->offset >= entry->bound) &&
288 			    (map->offset + map->size <= entry->bound + entry->pages * PAGE_SIZE)) {
289 				valid = 1;
290 				break;
291 			}
292 		}
293 		if (!list_empty(&dev->agp->memory) && !valid) {
294 			kfree(map);
295 			return -EPERM;
296 		}
297 		DRM_DEBUG("AGP offset = 0x%08llx, size = 0x%08lx\n",
298 			  (unsigned long long)map->offset, map->size);
299 
300 		break;
301 	}
302 	case _DRM_SCATTER_GATHER:
303 		if (!dev->sg) {
304 			kfree(map);
305 			return -EINVAL;
306 		}
307 		map->offset += (unsigned long)dev->sg->virtual;
308 		break;
309 	case _DRM_CONSISTENT:
310 		/* dma_addr_t is 64bit on i386 with CONFIG_HIGHMEM64G,
311 		 * As we're limiting the address to 2^32-1 (or less),
312 		 * casting it down to 32 bits is no problem, but we
313 		 * need to point to a 64bit variable first. */
314 		dmah = drm_pci_alloc(dev, map->size, map->size);
315 		if (!dmah) {
316 			kfree(map);
317 			return -ENOMEM;
318 		}
319 		map->handle = dmah->vaddr;
320 		map->offset = (unsigned long)dmah->busaddr;
321 		kfree(dmah);
322 		break;
323 	default:
324 		kfree(map);
325 		return -EINVAL;
326 	}
327 
328 	list = kzalloc(sizeof(*list), GFP_KERNEL);
329 	if (!list) {
330 		if (map->type == _DRM_REGISTERS)
331 			iounmap(map->handle);
332 		kfree(map);
333 		return -EINVAL;
334 	}
335 	list->map = map;
336 
337 	mutex_lock(&dev->struct_mutex);
338 	list_add(&list->head, &dev->maplist);
339 
340 	/* Assign a 32-bit handle */
341 	/* We do it here so that dev->struct_mutex protects the increment */
342 	user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle :
343 		map->offset;
344 	ret = drm_map_handle(dev, &list->hash, user_token, 0,
345 			     (map->type == _DRM_SHM));
346 	if (ret) {
347 		if (map->type == _DRM_REGISTERS)
348 			iounmap(map->handle);
349 		kfree(map);
350 		kfree(list);
351 		mutex_unlock(&dev->struct_mutex);
352 		return ret;
353 	}
354 
355 	list->user_token = list->hash.key << PAGE_SHIFT;
356 	mutex_unlock(&dev->struct_mutex);
357 
358 	if (!(map->flags & _DRM_DRIVER))
359 		list->master = dev->master;
360 	*maplist = list;
361 	return 0;
362 }
363 
364 int drm_legacy_addmap(struct drm_device *dev, resource_size_t offset,
365 		      unsigned int size, enum drm_map_type type,
366 		      enum drm_map_flags flags, struct drm_local_map **map_ptr)
367 {
368 	struct drm_map_list *list;
369 	int rc;
370 
371 	rc = drm_addmap_core(dev, offset, size, type, flags, &list);
372 	if (!rc)
373 		*map_ptr = list->map;
374 	return rc;
375 }
376 EXPORT_SYMBOL(drm_legacy_addmap);
377 
378 /**
379  * Ioctl to specify a range of memory that is available for mapping by a
380  * non-root process.
381  *
382  * \param inode device inode.
383  * \param file_priv DRM file private.
384  * \param cmd command.
385  * \param arg pointer to a drm_map structure.
386  * \return zero on success or a negative value on error.
387  *
388  */
389 int drm_legacy_addmap_ioctl(struct drm_device *dev, void *data,
390 			    struct drm_file *file_priv)
391 {
392 	struct drm_map *map = data;
393 	struct drm_map_list *maplist;
394 	int err;
395 
396 	if (!(capable(CAP_SYS_ADMIN) || map->type == _DRM_AGP || map->type == _DRM_SHM))
397 		return -EPERM;
398 
399 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
400 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
401 		return -EINVAL;
402 
403 	err = drm_addmap_core(dev, map->offset, map->size, map->type,
404 			      map->flags, &maplist);
405 
406 	if (err)
407 		return err;
408 
409 	/* avoid a warning on 64-bit, this casting isn't very nice, but the API is set so too late */
410 	map->handle = (void *)(unsigned long)maplist->user_token;
411 
412 	/*
413 	 * It appears that there are no users of this value whatsoever --
414 	 * drmAddMap just discards it.  Let's not encourage its use.
415 	 * (Keeping drm_addmap_core's returned mtrr value would be wrong --
416 	 *  it's not a real mtrr index anymore.)
417 	 */
418 	map->mtrr = -1;
419 
420 	return 0;
421 }
422 
423 /*
424  * Get a mapping information.
425  *
426  * \param inode device inode.
427  * \param file_priv DRM file private.
428  * \param cmd command.
429  * \param arg user argument, pointing to a drm_map structure.
430  *
431  * \return zero on success or a negative number on failure.
432  *
433  * Searches for the mapping with the specified offset and copies its information
434  * into userspace
435  */
436 int drm_legacy_getmap_ioctl(struct drm_device *dev, void *data,
437 			    struct drm_file *file_priv)
438 {
439 	struct drm_map *map = data;
440 	struct drm_map_list *r_list = NULL;
441 	struct list_head *list;
442 	int idx;
443 	int i;
444 
445 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
446 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
447 		return -EINVAL;
448 
449 	idx = map->offset;
450 	if (idx < 0)
451 		return -EINVAL;
452 
453 	i = 0;
454 	mutex_lock(&dev->struct_mutex);
455 	list_for_each(list, &dev->maplist) {
456 		if (i == idx) {
457 			r_list = list_entry(list, struct drm_map_list, head);
458 			break;
459 		}
460 		i++;
461 	}
462 	if (!r_list || !r_list->map) {
463 		mutex_unlock(&dev->struct_mutex);
464 		return -EINVAL;
465 	}
466 
467 	map->offset = r_list->map->offset;
468 	map->size = r_list->map->size;
469 	map->type = r_list->map->type;
470 	map->flags = r_list->map->flags;
471 	map->handle = (void *)(unsigned long) r_list->user_token;
472 	map->mtrr = arch_phys_wc_index(r_list->map->mtrr);
473 
474 	mutex_unlock(&dev->struct_mutex);
475 
476 	return 0;
477 }
478 
479 /**
480  * Remove a map private from list and deallocate resources if the mapping
481  * isn't in use.
482  *
483  * Searches the map on drm_device::maplist, removes it from the list, see if
484  * its being used, and free any associate resource (such as MTRR's) if it's not
485  * being on use.
486  *
487  * \sa drm_legacy_addmap
488  */
489 int drm_legacy_rmmap_locked(struct drm_device *dev, struct drm_local_map *map)
490 {
491 	struct drm_map_list *r_list = NULL, *list_t;
492 	drm_dma_handle_t dmah;
493 	int found = 0;
494 	struct drm_master *master;
495 
496 	/* Find the list entry for the map and remove it */
497 	list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
498 		if (r_list->map == map) {
499 			master = r_list->master;
500 			list_del(&r_list->head);
501 			drm_ht_remove_key(&dev->map_hash,
502 					  r_list->user_token >> PAGE_SHIFT);
503 			kfree(r_list);
504 			found = 1;
505 			break;
506 		}
507 	}
508 
509 	if (!found)
510 		return -EINVAL;
511 
512 	switch (map->type) {
513 	case _DRM_REGISTERS:
514 		iounmap(map->handle);
515 		/* FALLTHROUGH */
516 	case _DRM_FRAME_BUFFER:
517 		arch_phys_wc_del(map->mtrr);
518 		break;
519 	case _DRM_SHM:
520 		vfree(map->handle);
521 		if (master) {
522 			if (dev->sigdata.lock == master->lock.hw_lock)
523 				dev->sigdata.lock = NULL;
524 			master->lock.hw_lock = NULL;   /* SHM removed */
525 			master->lock.file_priv = NULL;
526 			wake_up_interruptible_all(&master->lock.lock_queue);
527 		}
528 		break;
529 	case _DRM_AGP:
530 	case _DRM_SCATTER_GATHER:
531 		break;
532 	case _DRM_CONSISTENT:
533 		dmah.vaddr = map->handle;
534 		dmah.busaddr = map->offset;
535 		dmah.size = map->size;
536 		__drm_legacy_pci_free(dev, &dmah);
537 		break;
538 	}
539 	kfree(map);
540 
541 	return 0;
542 }
543 EXPORT_SYMBOL(drm_legacy_rmmap_locked);
544 
545 void drm_legacy_rmmap(struct drm_device *dev, struct drm_local_map *map)
546 {
547 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
548 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
549 		return;
550 
551 	mutex_lock(&dev->struct_mutex);
552 	drm_legacy_rmmap_locked(dev, map);
553 	mutex_unlock(&dev->struct_mutex);
554 }
555 EXPORT_SYMBOL(drm_legacy_rmmap);
556 
557 void drm_legacy_master_rmmaps(struct drm_device *dev, struct drm_master *master)
558 {
559 	struct drm_map_list *r_list, *list_temp;
560 
561 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
562 		return;
563 
564 	mutex_lock(&dev->struct_mutex);
565 	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
566 		if (r_list->master == master) {
567 			drm_legacy_rmmap_locked(dev, r_list->map);
568 			r_list = NULL;
569 		}
570 	}
571 	mutex_unlock(&dev->struct_mutex);
572 }
573 
574 /* The rmmap ioctl appears to be unnecessary.  All mappings are torn down on
575  * the last close of the device, and this is necessary for cleanup when things
576  * exit uncleanly.  Therefore, having userland manually remove mappings seems
577  * like a pointless exercise since they're going away anyway.
578  *
579  * One use case might be after addmap is allowed for normal users for SHM and
580  * gets used by drivers that the server doesn't need to care about.  This seems
581  * unlikely.
582  *
583  * \param inode device inode.
584  * \param file_priv DRM file private.
585  * \param cmd command.
586  * \param arg pointer to a struct drm_map structure.
587  * \return zero on success or a negative value on error.
588  */
589 int drm_legacy_rmmap_ioctl(struct drm_device *dev, void *data,
590 			   struct drm_file *file_priv)
591 {
592 	struct drm_map *request = data;
593 	struct drm_local_map *map = NULL;
594 	struct drm_map_list *r_list;
595 	int ret;
596 
597 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
598 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
599 		return -EINVAL;
600 
601 	mutex_lock(&dev->struct_mutex);
602 	list_for_each_entry(r_list, &dev->maplist, head) {
603 		if (r_list->map &&
604 		    r_list->user_token == (unsigned long)request->handle &&
605 		    r_list->map->flags & _DRM_REMOVABLE) {
606 			map = r_list->map;
607 			break;
608 		}
609 	}
610 
611 	/* List has wrapped around to the head pointer, or its empty we didn't
612 	 * find anything.
613 	 */
614 	if (list_empty(&dev->maplist) || !map) {
615 		mutex_unlock(&dev->struct_mutex);
616 		return -EINVAL;
617 	}
618 
619 	/* Register and framebuffer maps are permanent */
620 	if ((map->type == _DRM_REGISTERS) || (map->type == _DRM_FRAME_BUFFER)) {
621 		mutex_unlock(&dev->struct_mutex);
622 		return 0;
623 	}
624 
625 	ret = drm_legacy_rmmap_locked(dev, map);
626 
627 	mutex_unlock(&dev->struct_mutex);
628 
629 	return ret;
630 }
631 
632 /**
633  * Cleanup after an error on one of the addbufs() functions.
634  *
635  * \param dev DRM device.
636  * \param entry buffer entry where the error occurred.
637  *
638  * Frees any pages and buffers associated with the given entry.
639  */
640 static void drm_cleanup_buf_error(struct drm_device *dev,
641 				  struct drm_buf_entry *entry)
642 {
643 	int i;
644 
645 	if (entry->seg_count) {
646 		for (i = 0; i < entry->seg_count; i++) {
647 			if (entry->seglist[i]) {
648 				drm_pci_free(dev, entry->seglist[i]);
649 			}
650 		}
651 		kfree(entry->seglist);
652 
653 		entry->seg_count = 0;
654 	}
655 
656 	if (entry->buf_count) {
657 		for (i = 0; i < entry->buf_count; i++) {
658 			kfree(entry->buflist[i].dev_private);
659 		}
660 		kfree(entry->buflist);
661 
662 		entry->buf_count = 0;
663 	}
664 }
665 
666 #if IS_ENABLED(CONFIG_AGP)
667 /**
668  * Add AGP buffers for DMA transfers.
669  *
670  * \param dev struct drm_device to which the buffers are to be added.
671  * \param request pointer to a struct drm_buf_desc describing the request.
672  * \return zero on success or a negative number on failure.
673  *
674  * After some sanity checks creates a drm_buf structure for each buffer and
675  * reallocates the buffer list of the same size order to accommodate the new
676  * buffers.
677  */
678 int drm_legacy_addbufs_agp(struct drm_device *dev,
679 			   struct drm_buf_desc *request)
680 {
681 	struct drm_device_dma *dma = dev->dma;
682 	struct drm_buf_entry *entry;
683 	struct drm_agp_mem *agp_entry;
684 	struct drm_buf *buf;
685 	unsigned long offset;
686 	unsigned long agp_offset;
687 	int count;
688 	int order;
689 	int size;
690 	int alignment;
691 	int page_order;
692 	int total;
693 	int byte_count;
694 	int i, valid;
695 	struct drm_buf **temp_buflist;
696 
697 	if (!dma)
698 		return -EINVAL;
699 
700 	count = request->count;
701 	order = order_base_2(request->size);
702 	size = 1 << order;
703 
704 	alignment = (request->flags & _DRM_PAGE_ALIGN)
705 	    ? PAGE_ALIGN(size) : size;
706 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
707 	total = PAGE_SIZE << page_order;
708 
709 	byte_count = 0;
710 	agp_offset = dev->agp->base + request->agp_start;
711 
712 	DRM_DEBUG("count:      %d\n", count);
713 	DRM_DEBUG("order:      %d\n", order);
714 	DRM_DEBUG("size:       %d\n", size);
715 	DRM_DEBUG("agp_offset: %lx\n", agp_offset);
716 	DRM_DEBUG("alignment:  %d\n", alignment);
717 	DRM_DEBUG("page_order: %d\n", page_order);
718 	DRM_DEBUG("total:      %d\n", total);
719 
720 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
721 		return -EINVAL;
722 
723 	/* Make sure buffers are located in AGP memory that we own */
724 	valid = 0;
725 	list_for_each_entry(agp_entry, &dev->agp->memory, head) {
726 		if ((agp_offset >= agp_entry->bound) &&
727 		    (agp_offset + total * count <= agp_entry->bound + agp_entry->pages * PAGE_SIZE)) {
728 			valid = 1;
729 			break;
730 		}
731 	}
732 	if (!list_empty(&dev->agp->memory) && !valid) {
733 		DRM_DEBUG("zone invalid\n");
734 		return -EINVAL;
735 	}
736 	spin_lock(&dev->buf_lock);
737 	if (dev->buf_use) {
738 		spin_unlock(&dev->buf_lock);
739 		return -EBUSY;
740 	}
741 	atomic_inc(&dev->buf_alloc);
742 	spin_unlock(&dev->buf_lock);
743 
744 	mutex_lock(&dev->struct_mutex);
745 	entry = &dma->bufs[order];
746 	if (entry->buf_count) {
747 		mutex_unlock(&dev->struct_mutex);
748 		atomic_dec(&dev->buf_alloc);
749 		return -ENOMEM;	/* May only call once for each order */
750 	}
751 
752 	if (count < 0 || count > 4096) {
753 		mutex_unlock(&dev->struct_mutex);
754 		atomic_dec(&dev->buf_alloc);
755 		return -EINVAL;
756 	}
757 
758 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
759 	if (!entry->buflist) {
760 		mutex_unlock(&dev->struct_mutex);
761 		atomic_dec(&dev->buf_alloc);
762 		return -ENOMEM;
763 	}
764 
765 	entry->buf_size = size;
766 	entry->page_order = page_order;
767 
768 	offset = 0;
769 
770 	while (entry->buf_count < count) {
771 		buf = &entry->buflist[entry->buf_count];
772 		buf->idx = dma->buf_count + entry->buf_count;
773 		buf->total = alignment;
774 		buf->order = order;
775 		buf->used = 0;
776 
777 		buf->offset = (dma->byte_count + offset);
778 		buf->bus_address = agp_offset + offset;
779 		buf->address = (void *)(agp_offset + offset);
780 		buf->next = NULL;
781 		buf->waiting = 0;
782 		buf->pending = 0;
783 		buf->file_priv = NULL;
784 
785 		buf->dev_priv_size = dev->driver->dev_priv_size;
786 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
787 		if (!buf->dev_private) {
788 			/* Set count correctly so we free the proper amount. */
789 			entry->buf_count = count;
790 			drm_cleanup_buf_error(dev, entry);
791 			mutex_unlock(&dev->struct_mutex);
792 			atomic_dec(&dev->buf_alloc);
793 			return -ENOMEM;
794 		}
795 
796 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
797 
798 		offset += alignment;
799 		entry->buf_count++;
800 		byte_count += PAGE_SIZE << page_order;
801 	}
802 
803 	DRM_DEBUG("byte_count: %d\n", byte_count);
804 
805 	temp_buflist = krealloc(dma->buflist,
806 				(dma->buf_count + entry->buf_count) *
807 				sizeof(*dma->buflist), GFP_KERNEL);
808 	if (!temp_buflist) {
809 		/* Free the entry because it isn't valid */
810 		drm_cleanup_buf_error(dev, entry);
811 		mutex_unlock(&dev->struct_mutex);
812 		atomic_dec(&dev->buf_alloc);
813 		return -ENOMEM;
814 	}
815 	dma->buflist = temp_buflist;
816 
817 	for (i = 0; i < entry->buf_count; i++) {
818 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
819 	}
820 
821 	dma->buf_count += entry->buf_count;
822 	dma->seg_count += entry->seg_count;
823 	dma->page_count += byte_count >> PAGE_SHIFT;
824 	dma->byte_count += byte_count;
825 
826 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
827 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
828 
829 	mutex_unlock(&dev->struct_mutex);
830 
831 	request->count = entry->buf_count;
832 	request->size = size;
833 
834 	dma->flags = _DRM_DMA_USE_AGP;
835 
836 	atomic_dec(&dev->buf_alloc);
837 	return 0;
838 }
839 EXPORT_SYMBOL(drm_legacy_addbufs_agp);
840 #endif /* CONFIG_AGP */
841 
842 int drm_legacy_addbufs_pci(struct drm_device *dev,
843 			   struct drm_buf_desc *request)
844 {
845 	struct drm_device_dma *dma = dev->dma;
846 	int count;
847 	int order;
848 	int size;
849 	int total;
850 	int page_order;
851 	struct drm_buf_entry *entry;
852 	drm_dma_handle_t *dmah;
853 	struct drm_buf *buf;
854 	int alignment;
855 	unsigned long offset;
856 	int i;
857 	int byte_count;
858 	int page_count;
859 	unsigned long *temp_pagelist;
860 	struct drm_buf **temp_buflist;
861 
862 	if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
863 		return -EINVAL;
864 
865 	if (!dma)
866 		return -EINVAL;
867 
868 	if (!capable(CAP_SYS_ADMIN))
869 		return -EPERM;
870 
871 	count = request->count;
872 	order = order_base_2(request->size);
873 	size = 1 << order;
874 
875 	DRM_DEBUG("count=%d, size=%d (%d), order=%d\n",
876 		  request->count, request->size, size, order);
877 
878 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
879 		return -EINVAL;
880 
881 	alignment = (request->flags & _DRM_PAGE_ALIGN)
882 	    ? PAGE_ALIGN(size) : size;
883 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
884 	total = PAGE_SIZE << page_order;
885 
886 	spin_lock(&dev->buf_lock);
887 	if (dev->buf_use) {
888 		spin_unlock(&dev->buf_lock);
889 		return -EBUSY;
890 	}
891 	atomic_inc(&dev->buf_alloc);
892 	spin_unlock(&dev->buf_lock);
893 
894 	mutex_lock(&dev->struct_mutex);
895 	entry = &dma->bufs[order];
896 	if (entry->buf_count) {
897 		mutex_unlock(&dev->struct_mutex);
898 		atomic_dec(&dev->buf_alloc);
899 		return -ENOMEM;	/* May only call once for each order */
900 	}
901 
902 	if (count < 0 || count > 4096) {
903 		mutex_unlock(&dev->struct_mutex);
904 		atomic_dec(&dev->buf_alloc);
905 		return -EINVAL;
906 	}
907 
908 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
909 	if (!entry->buflist) {
910 		mutex_unlock(&dev->struct_mutex);
911 		atomic_dec(&dev->buf_alloc);
912 		return -ENOMEM;
913 	}
914 
915 	entry->seglist = kcalloc(count, sizeof(*entry->seglist), GFP_KERNEL);
916 	if (!entry->seglist) {
917 		kfree(entry->buflist);
918 		mutex_unlock(&dev->struct_mutex);
919 		atomic_dec(&dev->buf_alloc);
920 		return -ENOMEM;
921 	}
922 
923 	/* Keep the original pagelist until we know all the allocations
924 	 * have succeeded
925 	 */
926 	temp_pagelist = kmalloc_array(dma->page_count + (count << page_order),
927 				      sizeof(*dma->pagelist),
928 				      GFP_KERNEL);
929 	if (!temp_pagelist) {
930 		kfree(entry->buflist);
931 		kfree(entry->seglist);
932 		mutex_unlock(&dev->struct_mutex);
933 		atomic_dec(&dev->buf_alloc);
934 		return -ENOMEM;
935 	}
936 	memcpy(temp_pagelist,
937 	       dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
938 	DRM_DEBUG("pagelist: %d entries\n",
939 		  dma->page_count + (count << page_order));
940 
941 	entry->buf_size = size;
942 	entry->page_order = page_order;
943 	byte_count = 0;
944 	page_count = 0;
945 
946 	while (entry->buf_count < count) {
947 
948 		dmah = drm_pci_alloc(dev, PAGE_SIZE << page_order, 0x1000);
949 
950 		if (!dmah) {
951 			/* Set count correctly so we free the proper amount. */
952 			entry->buf_count = count;
953 			entry->seg_count = count;
954 			drm_cleanup_buf_error(dev, entry);
955 			kfree(temp_pagelist);
956 			mutex_unlock(&dev->struct_mutex);
957 			atomic_dec(&dev->buf_alloc);
958 			return -ENOMEM;
959 		}
960 		entry->seglist[entry->seg_count++] = dmah;
961 		for (i = 0; i < (1 << page_order); i++) {
962 			DRM_DEBUG("page %d @ 0x%08lx\n",
963 				  dma->page_count + page_count,
964 				  (unsigned long)dmah->vaddr + PAGE_SIZE * i);
965 			temp_pagelist[dma->page_count + page_count++]
966 				= (unsigned long)dmah->vaddr + PAGE_SIZE * i;
967 		}
968 		for (offset = 0;
969 		     offset + size <= total && entry->buf_count < count;
970 		     offset += alignment, ++entry->buf_count) {
971 			buf = &entry->buflist[entry->buf_count];
972 			buf->idx = dma->buf_count + entry->buf_count;
973 			buf->total = alignment;
974 			buf->order = order;
975 			buf->used = 0;
976 			buf->offset = (dma->byte_count + byte_count + offset);
977 			buf->address = (void *)(dmah->vaddr + offset);
978 			buf->bus_address = dmah->busaddr + offset;
979 			buf->next = NULL;
980 			buf->waiting = 0;
981 			buf->pending = 0;
982 			buf->file_priv = NULL;
983 
984 			buf->dev_priv_size = dev->driver->dev_priv_size;
985 			buf->dev_private = kzalloc(buf->dev_priv_size,
986 						GFP_KERNEL);
987 			if (!buf->dev_private) {
988 				/* Set count correctly so we free the proper amount. */
989 				entry->buf_count = count;
990 				entry->seg_count = count;
991 				drm_cleanup_buf_error(dev, entry);
992 				kfree(temp_pagelist);
993 				mutex_unlock(&dev->struct_mutex);
994 				atomic_dec(&dev->buf_alloc);
995 				return -ENOMEM;
996 			}
997 
998 			DRM_DEBUG("buffer %d @ %p\n",
999 				  entry->buf_count, buf->address);
1000 		}
1001 		byte_count += PAGE_SIZE << page_order;
1002 	}
1003 
1004 	temp_buflist = krealloc(dma->buflist,
1005 				(dma->buf_count + entry->buf_count) *
1006 				sizeof(*dma->buflist), GFP_KERNEL);
1007 	if (!temp_buflist) {
1008 		/* Free the entry because it isn't valid */
1009 		drm_cleanup_buf_error(dev, entry);
1010 		kfree(temp_pagelist);
1011 		mutex_unlock(&dev->struct_mutex);
1012 		atomic_dec(&dev->buf_alloc);
1013 		return -ENOMEM;
1014 	}
1015 	dma->buflist = temp_buflist;
1016 
1017 	for (i = 0; i < entry->buf_count; i++) {
1018 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1019 	}
1020 
1021 	/* No allocations failed, so now we can replace the original pagelist
1022 	 * with the new one.
1023 	 */
1024 	if (dma->page_count) {
1025 		kfree(dma->pagelist);
1026 	}
1027 	dma->pagelist = temp_pagelist;
1028 
1029 	dma->buf_count += entry->buf_count;
1030 	dma->seg_count += entry->seg_count;
1031 	dma->page_count += entry->seg_count << page_order;
1032 	dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);
1033 
1034 	mutex_unlock(&dev->struct_mutex);
1035 
1036 	request->count = entry->buf_count;
1037 	request->size = size;
1038 
1039 	if (request->flags & _DRM_PCI_BUFFER_RO)
1040 		dma->flags = _DRM_DMA_USE_PCI_RO;
1041 
1042 	atomic_dec(&dev->buf_alloc);
1043 	return 0;
1044 
1045 }
1046 EXPORT_SYMBOL(drm_legacy_addbufs_pci);
1047 
1048 static int drm_legacy_addbufs_sg(struct drm_device *dev,
1049 				 struct drm_buf_desc *request)
1050 {
1051 	struct drm_device_dma *dma = dev->dma;
1052 	struct drm_buf_entry *entry;
1053 	struct drm_buf *buf;
1054 	unsigned long offset;
1055 	unsigned long agp_offset;
1056 	int count;
1057 	int order;
1058 	int size;
1059 	int alignment;
1060 	int page_order;
1061 	int total;
1062 	int byte_count;
1063 	int i;
1064 	struct drm_buf **temp_buflist;
1065 
1066 	if (!drm_core_check_feature(dev, DRIVER_SG))
1067 		return -EINVAL;
1068 
1069 	if (!dma)
1070 		return -EINVAL;
1071 
1072 	if (!capable(CAP_SYS_ADMIN))
1073 		return -EPERM;
1074 
1075 	count = request->count;
1076 	order = order_base_2(request->size);
1077 	size = 1 << order;
1078 
1079 	alignment = (request->flags & _DRM_PAGE_ALIGN)
1080 	    ? PAGE_ALIGN(size) : size;
1081 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
1082 	total = PAGE_SIZE << page_order;
1083 
1084 	byte_count = 0;
1085 	agp_offset = request->agp_start;
1086 
1087 	DRM_DEBUG("count:      %d\n", count);
1088 	DRM_DEBUG("order:      %d\n", order);
1089 	DRM_DEBUG("size:       %d\n", size);
1090 	DRM_DEBUG("agp_offset: %lu\n", agp_offset);
1091 	DRM_DEBUG("alignment:  %d\n", alignment);
1092 	DRM_DEBUG("page_order: %d\n", page_order);
1093 	DRM_DEBUG("total:      %d\n", total);
1094 
1095 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1096 		return -EINVAL;
1097 
1098 	spin_lock(&dev->buf_lock);
1099 	if (dev->buf_use) {
1100 		spin_unlock(&dev->buf_lock);
1101 		return -EBUSY;
1102 	}
1103 	atomic_inc(&dev->buf_alloc);
1104 	spin_unlock(&dev->buf_lock);
1105 
1106 	mutex_lock(&dev->struct_mutex);
1107 	entry = &dma->bufs[order];
1108 	if (entry->buf_count) {
1109 		mutex_unlock(&dev->struct_mutex);
1110 		atomic_dec(&dev->buf_alloc);
1111 		return -ENOMEM;	/* May only call once for each order */
1112 	}
1113 
1114 	if (count < 0 || count > 4096) {
1115 		mutex_unlock(&dev->struct_mutex);
1116 		atomic_dec(&dev->buf_alloc);
1117 		return -EINVAL;
1118 	}
1119 
1120 	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
1121 	if (!entry->buflist) {
1122 		mutex_unlock(&dev->struct_mutex);
1123 		atomic_dec(&dev->buf_alloc);
1124 		return -ENOMEM;
1125 	}
1126 
1127 	entry->buf_size = size;
1128 	entry->page_order = page_order;
1129 
1130 	offset = 0;
1131 
1132 	while (entry->buf_count < count) {
1133 		buf = &entry->buflist[entry->buf_count];
1134 		buf->idx = dma->buf_count + entry->buf_count;
1135 		buf->total = alignment;
1136 		buf->order = order;
1137 		buf->used = 0;
1138 
1139 		buf->offset = (dma->byte_count + offset);
1140 		buf->bus_address = agp_offset + offset;
1141 		buf->address = (void *)(agp_offset + offset
1142 					+ (unsigned long)dev->sg->virtual);
1143 		buf->next = NULL;
1144 		buf->waiting = 0;
1145 		buf->pending = 0;
1146 		buf->file_priv = NULL;
1147 
1148 		buf->dev_priv_size = dev->driver->dev_priv_size;
1149 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
1150 		if (!buf->dev_private) {
1151 			/* Set count correctly so we free the proper amount. */
1152 			entry->buf_count = count;
1153 			drm_cleanup_buf_error(dev, entry);
1154 			mutex_unlock(&dev->struct_mutex);
1155 			atomic_dec(&dev->buf_alloc);
1156 			return -ENOMEM;
1157 		}
1158 
1159 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
1160 
1161 		offset += alignment;
1162 		entry->buf_count++;
1163 		byte_count += PAGE_SIZE << page_order;
1164 	}
1165 
1166 	DRM_DEBUG("byte_count: %d\n", byte_count);
1167 
1168 	temp_buflist = krealloc(dma->buflist,
1169 				(dma->buf_count + entry->buf_count) *
1170 				sizeof(*dma->buflist), GFP_KERNEL);
1171 	if (!temp_buflist) {
1172 		/* Free the entry because it isn't valid */
1173 		drm_cleanup_buf_error(dev, entry);
1174 		mutex_unlock(&dev->struct_mutex);
1175 		atomic_dec(&dev->buf_alloc);
1176 		return -ENOMEM;
1177 	}
1178 	dma->buflist = temp_buflist;
1179 
1180 	for (i = 0; i < entry->buf_count; i++) {
1181 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1182 	}
1183 
1184 	dma->buf_count += entry->buf_count;
1185 	dma->seg_count += entry->seg_count;
1186 	dma->page_count += byte_count >> PAGE_SHIFT;
1187 	dma->byte_count += byte_count;
1188 
1189 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
1190 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
1191 
1192 	mutex_unlock(&dev->struct_mutex);
1193 
1194 	request->count = entry->buf_count;
1195 	request->size = size;
1196 
1197 	dma->flags = _DRM_DMA_USE_SG;
1198 
1199 	atomic_dec(&dev->buf_alloc);
1200 	return 0;
1201 }
1202 
1203 /**
1204  * Add buffers for DMA transfers (ioctl).
1205  *
1206  * \param inode device inode.
1207  * \param file_priv DRM file private.
1208  * \param cmd command.
1209  * \param arg pointer to a struct drm_buf_desc request.
1210  * \return zero on success or a negative number on failure.
1211  *
1212  * According with the memory type specified in drm_buf_desc::flags and the
1213  * build options, it dispatches the call either to addbufs_agp(),
1214  * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
1215  * PCI memory respectively.
1216  */
1217 int drm_legacy_addbufs(struct drm_device *dev, void *data,
1218 		       struct drm_file *file_priv)
1219 {
1220 	struct drm_buf_desc *request = data;
1221 	int ret;
1222 
1223 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1224 		return -EINVAL;
1225 
1226 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1227 		return -EINVAL;
1228 
1229 #if IS_ENABLED(CONFIG_AGP)
1230 	if (request->flags & _DRM_AGP_BUFFER)
1231 		ret = drm_legacy_addbufs_agp(dev, request);
1232 	else
1233 #endif
1234 	if (request->flags & _DRM_SG_BUFFER)
1235 		ret = drm_legacy_addbufs_sg(dev, request);
1236 	else if (request->flags & _DRM_FB_BUFFER)
1237 		ret = -EINVAL;
1238 	else
1239 		ret = drm_legacy_addbufs_pci(dev, request);
1240 
1241 	return ret;
1242 }
1243 
1244 /**
1245  * Get information about the buffer mappings.
1246  *
1247  * This was originally mean for debugging purposes, or by a sophisticated
1248  * client library to determine how best to use the available buffers (e.g.,
1249  * large buffers can be used for image transfer).
1250  *
1251  * \param inode device inode.
1252  * \param file_priv DRM file private.
1253  * \param cmd command.
1254  * \param arg pointer to a drm_buf_info structure.
1255  * \return zero on success or a negative number on failure.
1256  *
1257  * Increments drm_device::buf_use while holding the drm_device::buf_lock
1258  * lock, preventing of allocating more buffers after this call. Information
1259  * about each requested buffer is then copied into user space.
1260  */
1261 int __drm_legacy_infobufs(struct drm_device *dev,
1262 			void *data, int *p,
1263 			int (*f)(void *, int, struct drm_buf_entry *))
1264 {
1265 	struct drm_device_dma *dma = dev->dma;
1266 	int i;
1267 	int count;
1268 
1269 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1270 		return -EINVAL;
1271 
1272 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1273 		return -EINVAL;
1274 
1275 	if (!dma)
1276 		return -EINVAL;
1277 
1278 	spin_lock(&dev->buf_lock);
1279 	if (atomic_read(&dev->buf_alloc)) {
1280 		spin_unlock(&dev->buf_lock);
1281 		return -EBUSY;
1282 	}
1283 	++dev->buf_use;		/* Can't allocate more after this call */
1284 	spin_unlock(&dev->buf_lock);
1285 
1286 	for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1287 		if (dma->bufs[i].buf_count)
1288 			++count;
1289 	}
1290 
1291 	DRM_DEBUG("count = %d\n", count);
1292 
1293 	if (*p >= count) {
1294 		for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1295 			struct drm_buf_entry *from = &dma->bufs[i];
1296 			if (from->buf_count) {
1297 				if (f(data, count, from) < 0)
1298 					return -EFAULT;
1299 				DRM_DEBUG("%d %d %d %d %d\n",
1300 					  i,
1301 					  dma->bufs[i].buf_count,
1302 					  dma->bufs[i].buf_size,
1303 					  dma->bufs[i].low_mark,
1304 					  dma->bufs[i].high_mark);
1305 				++count;
1306 			}
1307 		}
1308 	}
1309 	*p = count;
1310 
1311 	return 0;
1312 }
1313 
1314 static int copy_one_buf(void *data, int count, struct drm_buf_entry *from)
1315 {
1316 	struct drm_buf_info *request = data;
1317 	struct drm_buf_desc __user *to = &request->list[count];
1318 	struct drm_buf_desc v = {.count = from->buf_count,
1319 				 .size = from->buf_size,
1320 				 .low_mark = from->low_mark,
1321 				 .high_mark = from->high_mark};
1322 	return copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags));
1323 }
1324 
1325 int drm_legacy_infobufs(struct drm_device *dev, void *data,
1326 			struct drm_file *file_priv)
1327 {
1328 	struct drm_buf_info *request = data;
1329 	return __drm_legacy_infobufs(dev, data, &request->count, copy_one_buf);
1330 }
1331 
1332 /**
1333  * Specifies a low and high water mark for buffer allocation
1334  *
1335  * \param inode device inode.
1336  * \param file_priv DRM file private.
1337  * \param cmd command.
1338  * \param arg a pointer to a drm_buf_desc structure.
1339  * \return zero on success or a negative number on failure.
1340  *
1341  * Verifies that the size order is bounded between the admissible orders and
1342  * updates the respective drm_device_dma::bufs entry low and high water mark.
1343  *
1344  * \note This ioctl is deprecated and mostly never used.
1345  */
1346 int drm_legacy_markbufs(struct drm_device *dev, void *data,
1347 			struct drm_file *file_priv)
1348 {
1349 	struct drm_device_dma *dma = dev->dma;
1350 	struct drm_buf_desc *request = data;
1351 	int order;
1352 	struct drm_buf_entry *entry;
1353 
1354 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1355 		return -EINVAL;
1356 
1357 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1358 		return -EINVAL;
1359 
1360 	if (!dma)
1361 		return -EINVAL;
1362 
1363 	DRM_DEBUG("%d, %d, %d\n",
1364 		  request->size, request->low_mark, request->high_mark);
1365 	order = order_base_2(request->size);
1366 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1367 		return -EINVAL;
1368 	entry = &dma->bufs[order];
1369 
1370 	if (request->low_mark < 0 || request->low_mark > entry->buf_count)
1371 		return -EINVAL;
1372 	if (request->high_mark < 0 || request->high_mark > entry->buf_count)
1373 		return -EINVAL;
1374 
1375 	entry->low_mark = request->low_mark;
1376 	entry->high_mark = request->high_mark;
1377 
1378 	return 0;
1379 }
1380 
1381 /**
1382  * Unreserve the buffers in list, previously reserved using drmDMA.
1383  *
1384  * \param inode device inode.
1385  * \param file_priv DRM file private.
1386  * \param cmd command.
1387  * \param arg pointer to a drm_buf_free structure.
1388  * \return zero on success or a negative number on failure.
1389  *
1390  * Calls free_buffer() for each used buffer.
1391  * This function is primarily used for debugging.
1392  */
1393 int drm_legacy_freebufs(struct drm_device *dev, void *data,
1394 			struct drm_file *file_priv)
1395 {
1396 	struct drm_device_dma *dma = dev->dma;
1397 	struct drm_buf_free *request = data;
1398 	int i;
1399 	int idx;
1400 	struct drm_buf *buf;
1401 
1402 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1403 		return -EINVAL;
1404 
1405 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1406 		return -EINVAL;
1407 
1408 	if (!dma)
1409 		return -EINVAL;
1410 
1411 	DRM_DEBUG("%d\n", request->count);
1412 	for (i = 0; i < request->count; i++) {
1413 		if (copy_from_user(&idx, &request->list[i], sizeof(idx)))
1414 			return -EFAULT;
1415 		if (idx < 0 || idx >= dma->buf_count) {
1416 			DRM_ERROR("Index %d (of %d max)\n",
1417 				  idx, dma->buf_count - 1);
1418 			return -EINVAL;
1419 		}
1420 		buf = dma->buflist[idx];
1421 		if (buf->file_priv != file_priv) {
1422 			DRM_ERROR("Process %d freeing buffer not owned\n",
1423 				  task_pid_nr(current));
1424 			return -EINVAL;
1425 		}
1426 		drm_legacy_free_buffer(dev, buf);
1427 	}
1428 
1429 	return 0;
1430 }
1431 
1432 /**
1433  * Maps all of the DMA buffers into client-virtual space (ioctl).
1434  *
1435  * \param inode device inode.
1436  * \param file_priv DRM file private.
1437  * \param cmd command.
1438  * \param arg pointer to a drm_buf_map structure.
1439  * \return zero on success or a negative number on failure.
1440  *
1441  * Maps the AGP, SG or PCI buffer region with vm_mmap(), and copies information
1442  * about each buffer into user space. For PCI buffers, it calls vm_mmap() with
1443  * offset equal to 0, which drm_mmap() interpretes as PCI buffers and calls
1444  * drm_mmap_dma().
1445  */
1446 int __drm_legacy_mapbufs(struct drm_device *dev, void *data, int *p,
1447 			 void __user **v,
1448 			 int (*f)(void *, int, unsigned long,
1449 				 struct drm_buf *),
1450 				 struct drm_file *file_priv)
1451 {
1452 	struct drm_device_dma *dma = dev->dma;
1453 	int retcode = 0;
1454 	unsigned long virtual;
1455 	int i;
1456 
1457 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1458 		return -EINVAL;
1459 
1460 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1461 		return -EINVAL;
1462 
1463 	if (!dma)
1464 		return -EINVAL;
1465 
1466 	spin_lock(&dev->buf_lock);
1467 	if (atomic_read(&dev->buf_alloc)) {
1468 		spin_unlock(&dev->buf_lock);
1469 		return -EBUSY;
1470 	}
1471 	dev->buf_use++;		/* Can't allocate more after this call */
1472 	spin_unlock(&dev->buf_lock);
1473 
1474 	if (*p >= dma->buf_count) {
1475 		if ((dev->agp && (dma->flags & _DRM_DMA_USE_AGP))
1476 		    || (drm_core_check_feature(dev, DRIVER_SG)
1477 			&& (dma->flags & _DRM_DMA_USE_SG))) {
1478 			struct drm_local_map *map = dev->agp_buffer_map;
1479 			unsigned long token = dev->agp_buffer_token;
1480 
1481 			if (!map) {
1482 				retcode = -EINVAL;
1483 				goto done;
1484 			}
1485 			virtual = vm_mmap(file_priv->filp, 0, map->size,
1486 					  PROT_READ | PROT_WRITE,
1487 					  MAP_SHARED,
1488 					  token);
1489 		} else {
1490 			virtual = vm_mmap(file_priv->filp, 0, dma->byte_count,
1491 					  PROT_READ | PROT_WRITE,
1492 					  MAP_SHARED, 0);
1493 		}
1494 		if (virtual > -1024UL) {
1495 			/* Real error */
1496 			retcode = (signed long)virtual;
1497 			goto done;
1498 		}
1499 		*v = (void __user *)virtual;
1500 
1501 		for (i = 0; i < dma->buf_count; i++) {
1502 			if (f(data, i, virtual, dma->buflist[i]) < 0) {
1503 				retcode = -EFAULT;
1504 				goto done;
1505 			}
1506 		}
1507 	}
1508       done:
1509 	*p = dma->buf_count;
1510 	DRM_DEBUG("%d buffers, retcode = %d\n", *p, retcode);
1511 
1512 	return retcode;
1513 }
1514 
1515 static int map_one_buf(void *data, int idx, unsigned long virtual,
1516 			struct drm_buf *buf)
1517 {
1518 	struct drm_buf_map *request = data;
1519 	unsigned long address = virtual + buf->offset;	/* *** */
1520 
1521 	if (copy_to_user(&request->list[idx].idx, &buf->idx,
1522 			 sizeof(request->list[0].idx)))
1523 		return -EFAULT;
1524 	if (copy_to_user(&request->list[idx].total, &buf->total,
1525 			 sizeof(request->list[0].total)))
1526 		return -EFAULT;
1527 	if (clear_user(&request->list[idx].used, sizeof(int)))
1528 		return -EFAULT;
1529 	if (copy_to_user(&request->list[idx].address, &address,
1530 			 sizeof(address)))
1531 		return -EFAULT;
1532 	return 0;
1533 }
1534 
1535 int drm_legacy_mapbufs(struct drm_device *dev, void *data,
1536 		       struct drm_file *file_priv)
1537 {
1538 	struct drm_buf_map *request = data;
1539 	return __drm_legacy_mapbufs(dev, data, &request->count,
1540 				    &request->virtual, map_one_buf,
1541 				    file_priv);
1542 }
1543 
1544 int drm_legacy_dma_ioctl(struct drm_device *dev, void *data,
1545 		  struct drm_file *file_priv)
1546 {
1547 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1548 		return -EINVAL;
1549 
1550 	if (dev->driver->dma_ioctl)
1551 		return dev->driver->dma_ioctl(dev, data, file_priv);
1552 	else
1553 		return -EINVAL;
1554 }
1555 
1556 struct drm_local_map *drm_legacy_getsarea(struct drm_device *dev)
1557 {
1558 	struct drm_map_list *entry;
1559 
1560 	list_for_each_entry(entry, &dev->maplist, head) {
1561 		if (entry->map && entry->map->type == _DRM_SHM &&
1562 		    (entry->map->flags & _DRM_CONTAINS_LOCK)) {
1563 			return entry->map;
1564 		}
1565 	}
1566 	return NULL;
1567 }
1568 EXPORT_SYMBOL(drm_legacy_getsarea);
1569