xref: /netbsd-src/sys/external/bsd/drm2/dist/drm/drm_bufs.c (revision cef8759bd76c1b621f8eab8faa6f208faabc2e15)
1 /*	$NetBSD: drm_bufs.c,v 1.12 2020/02/14 14:34:57 maya Exp $	*/
2 
3 /*
4  * Legacy: Generic DRM Buffer Management
5  *
6  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
7  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
8  * All Rights Reserved.
9  *
10  * Author: Rickard E. (Rik) Faith <faith@valinux.com>
11  * Author: Gareth Hughes <gareth@valinux.com>
12  *
13  * Permission is hereby granted, free of charge, to any person obtaining a
14  * copy of this software and associated documentation files (the "Software"),
15  * to deal in the Software without restriction, including without limitation
16  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
17  * and/or sell copies of the Software, and to permit persons to whom the
18  * Software is furnished to do so, subject to the following conditions:
19  *
20  * The above copyright notice and this permission notice (including the next
21  * paragraph) shall be included in all copies or substantial portions of the
22  * Software.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
26  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
27  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
28  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
29  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
30  * OTHER DEALINGS IN THE SOFTWARE.
31  */
32 
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: drm_bufs.c,v 1.12 2020/02/14 14:34:57 maya Exp $");
35 
36 #include <linux/vmalloc.h>
37 #include <linux/slab.h>
38 #include <linux/log2.h>
39 #include <linux/export.h>
40 #include <asm/shmparam.h>
41 #include <drm/drmP.h>
42 #include "drm_legacy.h"
43 
44 static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
45 						  struct drm_local_map *map)
46 {
47 	struct drm_map_list *entry;
48 	list_for_each_entry(entry, &dev->maplist, head) {
49 		/*
50 		 * Because the kernel-userspace ABI is fixed at a 32-bit offset
51 		 * while PCI resources may live above that, we only compare the
52 		 * lower 32 bits of the map offset for maps of type
53 		 * _DRM_FRAMEBUFFER or _DRM_REGISTERS.
54 		 * It is assumed that if a driver have more than one resource
55 		 * of each type, the lower 32 bits are different.
56 		 */
57 		if (!entry->map ||
58 		    map->type != entry->map->type ||
59 		    entry->master != dev->primary->master)
60 			continue;
61 		switch (map->type) {
62 		case _DRM_SHM:
63 			if (map->flags != _DRM_CONTAINS_LOCK)
64 				break;
65 			return entry;
66 		case _DRM_REGISTERS:
67 		case _DRM_FRAME_BUFFER:
68 			if ((entry->map->offset & 0xffffffff) ==
69 			    (map->offset & 0xffffffff))
70 				return entry;
71 		default: /* Make gcc happy */
72 			;
73 		}
74 		if (entry->map->offset == map->offset)
75 			return entry;
76 	}
77 
78 	return NULL;
79 }
80 
81 static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
82 			  unsigned long user_token, int hashed_handle, int shm)
83 {
84 	int use_hashed_handle, shift;
85 	unsigned long add;
86 
87 	use_hashed_handle = (user_token &~ 0xffffffffUL) || hashed_handle;
88 	if (!use_hashed_handle) {
89 		int ret;
90 		hash->key = user_token >> PAGE_SHIFT;
91 		ret = drm_ht_insert_item(&dev->map_hash, hash);
92 		if (ret != -EINVAL)
93 			return ret;
94 	}
95 
96 	shift = 0;
97 	add = DRM_MAP_HASH_OFFSET >> PAGE_SHIFT;
98 	if (shm && (SHMLBA > PAGE_SIZE)) {
99 		int bits = ilog2(SHMLBA >> PAGE_SHIFT) + 1;
100 
101 		/* For shared memory, we have to preserve the SHMLBA
102 		 * bits of the eventual vma->vm_pgoff value during
103 		 * mmap().  Otherwise we run into cache aliasing problems
104 		 * on some platforms.  On these platforms, the pgoff of
105 		 * a mmap() request is used to pick a suitable virtual
106 		 * address for the mmap() region such that it will not
107 		 * cause cache aliasing problems.
108 		 *
109 		 * Therefore, make sure the SHMLBA relevant bits of the
110 		 * hash value we use are equal to those in the original
111 		 * kernel virtual address.
112 		 */
113 		shift = bits;
114 		add |= ((user_token >> PAGE_SHIFT) & ((1UL << bits) - 1UL));
115 	}
116 
117 	return drm_ht_just_insert_please(&dev->map_hash, hash,
118 					 user_token, 32 - PAGE_SHIFT - 3,
119 					 shift, add);
120 }
121 
122 /**
123  * Core function to create a range of memory available for mapping by a
124  * non-root process.
125  *
126  * Adjusts the memory offset to its absolute value according to the mapping
127  * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
128  * applicable and if supported by the kernel.
129  */
130 static int drm_addmap_core(struct drm_device * dev, resource_size_t offset,
131 			   unsigned int size, enum drm_map_type type,
132 			   enum drm_map_flags flags,
133 			   struct drm_map_list ** maplist)
134 {
135 	struct drm_local_map *map;
136 	struct drm_map_list *list;
137 	drm_dma_handle_t *dmah;
138 	unsigned long user_token;
139 	int ret;
140 
141 	map = kmalloc(sizeof(*map), GFP_KERNEL);
142 	if (!map)
143 		return -ENOMEM;
144 
145 	map->offset = offset;
146 	map->size = size;
147 	map->flags = flags;
148 	map->type = type;
149 
150 	/* Only allow shared memory to be removable since we only keep enough
151 	 * book keeping information about shared memory to allow for removal
152 	 * when processes fork.
153 	 */
154 	if ((map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM) {
155 		kfree(map);
156 		return -EINVAL;
157 	}
158 	DRM_DEBUG("offset = 0x%08llx, size = 0x%08lx, type = %d\n",
159 		  (unsigned long long)map->offset, map->size, map->type);
160 
161 	/* page-align _DRM_SHM maps. They are allocated here so there is no security
162 	 * hole created by that and it works around various broken drivers that use
163 	 * a non-aligned quantity to map the SAREA. --BenH
164 	 */
165 	if (map->type == _DRM_SHM)
166 		map->size = PAGE_ALIGN(map->size);
167 
168 	if ((map->offset & (~(resource_size_t)PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
169 		kfree(map);
170 		return -EINVAL;
171 	}
172 	map->mtrr = -1;
173 	map->handle = NULL;
174 
175 	switch (map->type) {
176 	case _DRM_REGISTERS:
177 	case _DRM_FRAME_BUFFER:
178 #ifndef __NetBSD__		/* XXX No idea what this is for...  */
179 #if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__) && !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__arm__)
180 		if (map->offset + (map->size-1) < map->offset ||
181 		    map->offset < virt_to_phys(high_memory)) {
182 			kfree(map);
183 			return -EINVAL;
184 		}
185 #endif
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 #ifdef __NetBSD__
213 			drm_legacy_ioremap(map, dev);
214 #else
215 			if (map->flags & _DRM_WRITE_COMBINING)
216 				map->handle = ioremap_wc(map->offset,
217 							 map->size);
218 			else
219 				map->handle = ioremap(map->offset, map->size);
220 #endif
221 			if (!map->handle) {
222 				kfree(map);
223 				return -ENOMEM;
224 			}
225 		}
226 
227 		break;
228 	case _DRM_SHM:
229 		list = drm_find_matching_map(dev, map);
230 		if (list != NULL) {
231 			if(list->map->size != map->size) {
232 				DRM_DEBUG("Matching maps of type %d with "
233 					  "mismatched sizes, (%ld vs %ld)\n",
234 					  map->type, map->size, list->map->size);
235 				list->map->size = map->size;
236 			}
237 
238 			kfree(map);
239 			*maplist = list;
240 			return 0;
241 		}
242 		map->handle = vmalloc_user(map->size);
243 		DRM_DEBUG("%lu %d %p\n",
244 			  map->size, order_base_2(map->size), map->handle);
245 		if (!map->handle) {
246 			kfree(map);
247 			return -ENOMEM;
248 		}
249 		map->offset = (unsigned long)map->handle;
250 		if (map->flags & _DRM_CONTAINS_LOCK) {
251 			/* Prevent a 2nd X Server from creating a 2nd lock */
252 			spin_lock(&dev->primary->master->lock.spinlock);
253 			if (dev->primary->master->lock.hw_lock != NULL) {
254 				vfree(map->handle);
255 				kfree(map);
256 				spin_unlock(&dev->primary->master->lock.spinlock);
257 				return -EBUSY;
258 			}
259 			dev->sigdata.lock = dev->primary->master->lock.hw_lock = map->handle;	/* Pointer to lock */
260 			spin_unlock(&dev->primary->master->lock.spinlock);
261 		}
262 		break;
263 	case _DRM_AGP: {
264 		struct drm_agp_mem *entry;
265 		int valid = 0;
266 
267 		if (!dev->agp) {
268 			kfree(map);
269 			return -EINVAL;
270 		}
271 #ifdef __alpha__
272 		map->offset += dev->hose->mem_space->start;
273 #endif
274 		/* In some cases (i810 driver), user space may have already
275 		 * added the AGP base itself, because dev->agp->base previously
276 		 * only got set during AGP enable.  So, only add the base
277 		 * address if the map's offset isn't already within the
278 		 * aperture.
279 		 */
280 #ifdef __NetBSD__
281 		if (map->offset < dev->agp->base ||
282 		    map->offset > dev->agp->base +
283 		    dev->agp->agp_info.aki_info.ai_aperture_size - 1) {
284 			map->offset += dev->agp->base;
285 		}
286 #else
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 #endif
293 		map->mtrr = dev->agp->agp_mtrr;	/* for getmap */
294 
295 		/* This assumes the DRM is in total control of AGP space.
296 		 * It's not always the case as AGP can be in the control
297 		 * of user space (i.e. i810 driver). So this loop will get
298 		 * skipped and we double check that dev->agp->memory is
299 		 * actually set as well as being invalid before EPERM'ing
300 		 */
301 		list_for_each_entry(entry, &dev->agp->memory, head) {
302 			if ((map->offset >= entry->bound) &&
303 			    (map->offset + map->size <= entry->bound + entry->pages * PAGE_SIZE)) {
304 				valid = 1;
305 				break;
306 			}
307 		}
308 		if (!list_empty(&dev->agp->memory) && !valid) {
309 			kfree(map);
310 			return -EPERM;
311 		}
312 		DRM_DEBUG("AGP offset = 0x%08llx, size = 0x%08lx\n",
313 			  (unsigned long long)map->offset, map->size);
314 
315 		break;
316 	}
317 	case _DRM_SCATTER_GATHER:
318 		if (!dev->sg) {
319 			kfree(map);
320 			return -EINVAL;
321 		}
322 		map->offset += (unsigned long)dev->sg->virtual;
323 		break;
324 	case _DRM_CONSISTENT:
325 		/* dma_addr_t is 64bit on i386 with CONFIG_HIGHMEM64G,
326 		 * As we're limiting the address to 2^32-1 (or less),
327 		 * casting it down to 32 bits is no problem, but we
328 		 * need to point to a 64bit variable first. */
329 		dmah = drm_pci_alloc(dev, map->size, map->size);
330 		if (!dmah) {
331 			kfree(map);
332 			return -ENOMEM;
333 		}
334 		map->handle = dmah->vaddr;
335 		map->offset = (unsigned long)dmah->busaddr;
336 #ifdef __NetBSD__
337 		map->lm_data.dmah = dmah;
338 #else
339 		kfree(dmah);
340 #endif
341 		break;
342 	default:
343 		kfree(map);
344 		return -EINVAL;
345 	}
346 
347 	list = kzalloc(sizeof(*list), GFP_KERNEL);
348 	if (!list) {
349 		if (map->type == _DRM_REGISTERS)
350 #ifdef __NetBSD__
351 			drm_legacy_ioremapfree(map, dev);
352 #else
353 			iounmap(map->handle);
354 #endif
355 		kfree(map);
356 		return -EINVAL;
357 	}
358 	list->map = map;
359 
360 	mutex_lock(&dev->struct_mutex);
361 	list_add(&list->head, &dev->maplist);
362 
363 	/* Assign a 32-bit handle */
364 	/* We do it here so that dev->struct_mutex protects the increment */
365 	user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle :
366 		map->offset;
367 	ret = drm_map_handle(dev, &list->hash, user_token, 0,
368 			     (map->type == _DRM_SHM));
369 	if (ret) {
370 		if (map->type == _DRM_REGISTERS)
371 #ifdef __NetBSD__		/* XXX What about other map types...?  */
372 			drm_legacy_ioremapfree(map, dev);
373 #else
374 			iounmap(map->handle);
375 #endif
376 		kfree(map);
377 		kfree(list);
378 		mutex_unlock(&dev->struct_mutex);
379 		return ret;
380 	}
381 
382 	list->user_token = list->hash.key << PAGE_SHIFT;
383 	mutex_unlock(&dev->struct_mutex);
384 
385 	if (!(map->flags & _DRM_DRIVER))
386 		list->master = dev->primary->master;
387 	*maplist = list;
388 	return 0;
389 }
390 
391 int drm_legacy_addmap(struct drm_device * dev, resource_size_t offset,
392 		      unsigned int size, enum drm_map_type type,
393 		      enum drm_map_flags flags, struct drm_local_map **map_ptr)
394 {
395 	struct drm_map_list *list;
396 	int rc;
397 
398 	rc = drm_addmap_core(dev, offset, size, type, flags, &list);
399 	if (!rc)
400 		*map_ptr = list->map;
401 	return rc;
402 }
403 EXPORT_SYMBOL(drm_legacy_addmap);
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  */
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 	err = drm_addmap_core(dev, map->offset, map->size, map->type,
427 			      map->flags, &maplist);
428 
429 	if (err)
430 		return err;
431 
432 	/* avoid a warning on 64-bit, this casting isn't very nice, but the API is set so too late */
433 	map->handle = (void *)(unsigned long)maplist->user_token;
434 
435 	/*
436 	 * It appears that there are no users of this value whatsoever --
437 	 * drmAddMap just discards it.  Let's not encourage its use.
438 	 * (Keeping drm_addmap_core's returned mtrr value would be wrong --
439 	 *  it's not a real mtrr index anymore.)
440 	 */
441 	map->mtrr = -1;
442 
443 	return 0;
444 }
445 
446 /**
447  * Remove a map private from list and deallocate resources if the mapping
448  * isn't in use.
449  *
450  * Searches the map on drm_device::maplist, removes it from the list, see if
451  * its being used, and free any associate resource (such as MTRR's) if it's not
452  * being on use.
453  *
454  * \sa drm_legacy_addmap
455  */
456 int drm_legacy_rmmap_locked(struct drm_device *dev, struct drm_local_map *map)
457 {
458 	struct drm_map_list *r_list = NULL, *list_t;
459 #ifndef __NetBSD__
460 	drm_dma_handle_t dmah;
461 #endif
462 	int found = 0;
463 	struct drm_master *master;
464 
465 	/* Find the list entry for the map and remove it */
466 	list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
467 		if (r_list->map == map) {
468 			master = r_list->master;
469 			list_del(&r_list->head);
470 			drm_ht_remove_key(&dev->map_hash,
471 					  r_list->user_token >> PAGE_SHIFT);
472 			kfree(r_list);
473 			found = 1;
474 			break;
475 		}
476 	}
477 
478 	if (!found)
479 		return -EINVAL;
480 
481 	switch (map->type) {
482 	case _DRM_REGISTERS:
483 #ifdef __NetBSD__
484 		drm_legacy_ioremapfree(map, dev);
485 #else
486 		iounmap(map->handle);
487 #endif
488 		/* FALLTHROUGH */
489 	case _DRM_FRAME_BUFFER:
490 		arch_phys_wc_del(map->mtrr);
491 		break;
492 	case _DRM_SHM:
493 		if (master && (map->flags & _DRM_CONTAINS_LOCK)) {
494 			spin_lock(&master->lock.spinlock);
495 			/*
496 			 * If we successfully removed this mapping,
497 			 * then the mapping must have been there in the
498 			 * first place, and we must have had a
499 			 * heavyweight lock, so we assert here instead
500 			 * of just checking and failing.
501 			 *
502 			 * XXX What about the _DRM_CONTAINS_LOCK flag?
503 			 * Where is that supposed to be set?  Is it
504 			 * equivalent to having a master set?
505 			 *
506 			 * XXX There is copypasta of this in
507 			 * drm_fops.c.
508 			 */
509 			BUG_ON(master->lock.hw_lock == NULL);
510 			if (dev->sigdata.lock == master->lock.hw_lock)
511 				dev->sigdata.lock = NULL;
512 			master->lock.hw_lock = NULL;   /* SHM removed */
513 			master->lock.file_priv = NULL;
514 #ifdef __NetBSD__
515 			DRM_SPIN_WAKEUP_ALL(&master->lock.lock_queue,
516 			    &master->lock.spinlock);
517 #else
518 			wake_up_interruptible_all(&master->lock.lock_queue);
519 #endif
520 			spin_unlock(&master->lock.spinlock);
521 		}
522 		vfree(map->handle);
523 		break;
524 	case _DRM_AGP:
525 	case _DRM_SCATTER_GATHER:
526 		break;
527 	case _DRM_CONSISTENT:
528 #ifdef __NetBSD__
529 		drm_pci_free(dev, map->lm_data.dmah);
530 #else
531 		dmah.vaddr = map->handle;
532 		dmah.busaddr = map->offset;
533 		dmah.size = map->size;
534 		__drm_legacy_pci_free(dev, &dmah);
535 #endif
536 		break;
537 	}
538 	kfree(map);
539 
540 	return 0;
541 }
542 EXPORT_SYMBOL(drm_legacy_rmmap_locked);
543 
544 int drm_legacy_rmmap(struct drm_device *dev, struct drm_local_map *map)
545 {
546 	int ret;
547 
548 	mutex_lock(&dev->struct_mutex);
549 	ret = drm_legacy_rmmap_locked(dev, map);
550 	mutex_unlock(&dev->struct_mutex);
551 
552 	return ret;
553 }
554 EXPORT_SYMBOL(drm_legacy_rmmap);
555 
556 /* The rmmap ioctl appears to be unnecessary.  All mappings are torn down on
557  * the last close of the device, and this is necessary for cleanup when things
558  * exit uncleanly.  Therefore, having userland manually remove mappings seems
559  * like a pointless exercise since they're going away anyway.
560  *
561  * One use case might be after addmap is allowed for normal users for SHM and
562  * gets used by drivers that the server doesn't need to care about.  This seems
563  * unlikely.
564  *
565  * \param inode device inode.
566  * \param file_priv DRM file private.
567  * \param cmd command.
568  * \param arg pointer to a struct drm_map structure.
569  * \return zero on success or a negative value on error.
570  */
571 int drm_legacy_rmmap_ioctl(struct drm_device *dev, void *data,
572 			   struct drm_file *file_priv)
573 {
574 	struct drm_map *request = data;
575 	struct drm_local_map *map = NULL;
576 	struct drm_map_list *r_list;
577 	int ret;
578 
579 	mutex_lock(&dev->struct_mutex);
580 	list_for_each_entry(r_list, &dev->maplist, head) {
581 		if (r_list->map &&
582 		    r_list->user_token == (unsigned long)request->handle &&
583 		    r_list->map->flags & _DRM_REMOVABLE) {
584 			map = r_list->map;
585 			break;
586 		}
587 	}
588 
589 	/* List has wrapped around to the head pointer, or its empty we didn't
590 	 * find anything.
591 	 */
592 	if (list_empty(&dev->maplist) || !map) {
593 		mutex_unlock(&dev->struct_mutex);
594 		return -EINVAL;
595 	}
596 
597 	/* Register and framebuffer maps are permanent */
598 	if ((map->type == _DRM_REGISTERS) || (map->type == _DRM_FRAME_BUFFER)) {
599 		mutex_unlock(&dev->struct_mutex);
600 		return 0;
601 	}
602 
603 	ret = drm_legacy_rmmap_locked(dev, map);
604 
605 	mutex_unlock(&dev->struct_mutex);
606 
607 	return ret;
608 }
609 
610 /**
611  * Cleanup after an error on one of the addbufs() functions.
612  *
613  * \param dev DRM device.
614  * \param entry buffer entry where the error occurred.
615  *
616  * Frees any pages and buffers associated with the given entry.
617  */
618 static void drm_cleanup_buf_error(struct drm_device * dev,
619 				  struct drm_buf_entry * entry)
620 {
621 	int i;
622 
623 	if (entry->seg_count) {
624 		for (i = 0; i < entry->seg_count; i++) {
625 			if (entry->seglist[i]) {
626 				drm_pci_free(dev, entry->seglist[i]);
627 			}
628 		}
629 		kfree(entry->seglist);
630 
631 		entry->seg_count = 0;
632 	}
633 
634 	if (entry->buf_count) {
635 		for (i = 0; i < entry->buf_count; i++) {
636 			kfree(entry->buflist[i].dev_private);
637 		}
638 		kfree(entry->buflist);
639 
640 		entry->buf_count = 0;
641 	}
642 }
643 
644 #if IS_ENABLED(CONFIG_AGP)
645 /**
646  * Add AGP buffers for DMA transfers.
647  *
648  * \param dev struct drm_device to which the buffers are to be added.
649  * \param request pointer to a struct drm_buf_desc describing the request.
650  * \return zero on success or a negative number on failure.
651  *
652  * After some sanity checks creates a drm_buf structure for each buffer and
653  * reallocates the buffer list of the same size order to accommodate the new
654  * buffers.
655  */
656 int drm_legacy_addbufs_agp(struct drm_device *dev,
657 			   struct drm_buf_desc *request)
658 {
659 	struct drm_device_dma *dma = dev->dma;
660 	struct drm_buf_entry *entry;
661 	struct drm_agp_mem *agp_entry;
662 	struct drm_buf *buf;
663 	unsigned long offset;
664 	unsigned long agp_offset;
665 	int count;
666 	int order;
667 	int size;
668 	int alignment;
669 	int page_order;
670 	int total;
671 	int byte_count;
672 	int i, valid;
673 	struct drm_buf **temp_buflist;
674 
675 	if (!dma)
676 		return -EINVAL;
677 
678 	count = request->count;
679 	order = order_base_2(request->size);
680 	size = 1 << order;
681 
682 	alignment = (request->flags & _DRM_PAGE_ALIGN)
683 	    ? PAGE_ALIGN(size) : size;
684 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
685 	total = PAGE_SIZE << page_order;
686 
687 	byte_count = 0;
688 	agp_offset = dev->agp->base + request->agp_start;
689 
690 	DRM_DEBUG("count:      %d\n", count);
691 	DRM_DEBUG("order:      %d\n", order);
692 	DRM_DEBUG("size:       %d\n", size);
693 	DRM_DEBUG("agp_offset: %lx\n", agp_offset);
694 	DRM_DEBUG("alignment:  %d\n", alignment);
695 	DRM_DEBUG("page_order: %d\n", page_order);
696 	DRM_DEBUG("total:      %d\n", total);
697 
698 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
699 		return -EINVAL;
700 
701 	/* Make sure buffers are located in AGP memory that we own */
702 	valid = 0;
703 	list_for_each_entry(agp_entry, &dev->agp->memory, head) {
704 		if ((agp_offset >= agp_entry->bound) &&
705 		    (agp_offset + total * count <= agp_entry->bound + agp_entry->pages * PAGE_SIZE)) {
706 			valid = 1;
707 			break;
708 		}
709 	}
710 	if (!list_empty(&dev->agp->memory) && !valid) {
711 		DRM_DEBUG("zone invalid\n");
712 		return -EINVAL;
713 	}
714 	spin_lock(&dev->buf_lock);
715 	if (dev->buf_use) {
716 		spin_unlock(&dev->buf_lock);
717 		return -EBUSY;
718 	}
719 	atomic_inc(&dev->buf_alloc);
720 	spin_unlock(&dev->buf_lock);
721 
722 	mutex_lock(&dev->struct_mutex);
723 	entry = &dma->bufs[order];
724 	if (entry->buf_count) {
725 		mutex_unlock(&dev->struct_mutex);
726 		atomic_dec(&dev->buf_alloc);
727 		return -ENOMEM;	/* May only call once for each order */
728 	}
729 
730 	if (count < 0 || count > 4096) {
731 		mutex_unlock(&dev->struct_mutex);
732 		atomic_dec(&dev->buf_alloc);
733 		return -EINVAL;
734 	}
735 
736 	entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
737 	if (!entry->buflist) {
738 		mutex_unlock(&dev->struct_mutex);
739 		atomic_dec(&dev->buf_alloc);
740 		return -ENOMEM;
741 	}
742 
743 	entry->buf_size = size;
744 	entry->page_order = page_order;
745 
746 	offset = 0;
747 
748 	while (entry->buf_count < count) {
749 		buf = &entry->buflist[entry->buf_count];
750 		buf->idx = dma->buf_count + entry->buf_count;
751 		buf->total = alignment;
752 		buf->order = order;
753 		buf->used = 0;
754 
755 		buf->offset = (dma->byte_count + offset);
756 		buf->bus_address = agp_offset + offset;
757 		buf->address = (void *)(agp_offset + offset);
758 		buf->next = NULL;
759 		buf->waiting = 0;
760 		buf->pending = 0;
761 		buf->file_priv = NULL;
762 
763 		buf->dev_priv_size = dev->driver->dev_priv_size;
764 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
765 		if (!buf->dev_private) {
766 			/* Set count correctly so we free the proper amount. */
767 			entry->buf_count = count;
768 			drm_cleanup_buf_error(dev, entry);
769 			mutex_unlock(&dev->struct_mutex);
770 			atomic_dec(&dev->buf_alloc);
771 			return -ENOMEM;
772 		}
773 
774 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
775 
776 		offset += alignment;
777 		entry->buf_count++;
778 		byte_count += PAGE_SIZE << page_order;
779 	}
780 
781 	DRM_DEBUG("byte_count: %d\n", byte_count);
782 
783 	temp_buflist = krealloc(dma->buflist,
784 				(dma->buf_count + entry->buf_count) *
785 				sizeof(*dma->buflist), GFP_KERNEL);
786 	if (!temp_buflist) {
787 		/* Free the entry because it isn't valid */
788 		drm_cleanup_buf_error(dev, entry);
789 		mutex_unlock(&dev->struct_mutex);
790 		atomic_dec(&dev->buf_alloc);
791 		return -ENOMEM;
792 	}
793 	dma->buflist = temp_buflist;
794 
795 	for (i = 0; i < entry->buf_count; i++) {
796 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
797 	}
798 
799 	dma->buf_count += entry->buf_count;
800 	dma->seg_count += entry->seg_count;
801 	dma->page_count += byte_count >> PAGE_SHIFT;
802 	dma->byte_count += byte_count;
803 
804 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
805 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
806 
807 	mutex_unlock(&dev->struct_mutex);
808 
809 	request->count = entry->buf_count;
810 	request->size = size;
811 
812 	dma->flags = _DRM_DMA_USE_AGP;
813 
814 	atomic_dec(&dev->buf_alloc);
815 	return 0;
816 }
817 EXPORT_SYMBOL(drm_legacy_addbufs_agp);
818 #endif /* CONFIG_AGP */
819 
820 int drm_legacy_addbufs_pci(struct drm_device *dev,
821 			   struct drm_buf_desc *request)
822 {
823 	struct drm_device_dma *dma = dev->dma;
824 	int count;
825 	int order;
826 	int size;
827 	int total;
828 	int page_order;
829 	struct drm_buf_entry *entry;
830 	drm_dma_handle_t *dmah;
831 	struct drm_buf *buf;
832 	int alignment;
833 	unsigned long offset;
834 	int i;
835 	int byte_count;
836 	int page_count;
837 	unsigned long *temp_pagelist;
838 	struct drm_buf **temp_buflist;
839 
840 	if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
841 		return -EINVAL;
842 
843 	if (!dma)
844 		return -EINVAL;
845 
846 	if (!capable(CAP_SYS_ADMIN))
847 		return -EPERM;
848 
849 	count = request->count;
850 	order = order_base_2(request->size);
851 	size = 1 << order;
852 
853 	DRM_DEBUG("count=%d, size=%d (%d), order=%d\n",
854 		  request->count, request->size, size, order);
855 
856 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
857 		return -EINVAL;
858 
859 	alignment = (request->flags & _DRM_PAGE_ALIGN)
860 	    ? PAGE_ALIGN(size) : size;
861 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
862 	total = PAGE_SIZE << page_order;
863 
864 	spin_lock(&dev->buf_lock);
865 	if (dev->buf_use) {
866 		spin_unlock(&dev->buf_lock);
867 		return -EBUSY;
868 	}
869 	atomic_inc(&dev->buf_alloc);
870 	spin_unlock(&dev->buf_lock);
871 
872 	mutex_lock(&dev->struct_mutex);
873 	entry = &dma->bufs[order];
874 	if (entry->buf_count) {
875 		mutex_unlock(&dev->struct_mutex);
876 		atomic_dec(&dev->buf_alloc);
877 		return -ENOMEM;	/* May only call once for each order */
878 	}
879 
880 	if (count < 0 || count > 4096) {
881 		mutex_unlock(&dev->struct_mutex);
882 		atomic_dec(&dev->buf_alloc);
883 		return -EINVAL;
884 	}
885 
886 	entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
887 	if (!entry->buflist) {
888 		mutex_unlock(&dev->struct_mutex);
889 		atomic_dec(&dev->buf_alloc);
890 		return -ENOMEM;
891 	}
892 
893 	entry->seglist = kzalloc(count * sizeof(*entry->seglist), GFP_KERNEL);
894 	if (!entry->seglist) {
895 		kfree(entry->buflist);
896 		mutex_unlock(&dev->struct_mutex);
897 		atomic_dec(&dev->buf_alloc);
898 		return -ENOMEM;
899 	}
900 
901 	/* Keep the original pagelist until we know all the allocations
902 	 * have succeeded
903 	 */
904 	temp_pagelist = kmalloc((dma->page_count + (count << page_order)) *
905 			       sizeof(*dma->pagelist), GFP_KERNEL);
906 	if (!temp_pagelist) {
907 		kfree(entry->buflist);
908 		kfree(entry->seglist);
909 		mutex_unlock(&dev->struct_mutex);
910 		atomic_dec(&dev->buf_alloc);
911 		return -ENOMEM;
912 	}
913 	memcpy(temp_pagelist,
914 	       dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
915 	DRM_DEBUG("pagelist: %d entries\n",
916 		  dma->page_count + (count << page_order));
917 
918 	entry->buf_size = size;
919 	entry->page_order = page_order;
920 	byte_count = 0;
921 	page_count = 0;
922 
923 	while (entry->buf_count < count) {
924 
925 		dmah = drm_pci_alloc(dev, PAGE_SIZE << page_order, 0x1000);
926 
927 		if (!dmah) {
928 			/* Set count correctly so we free the proper amount. */
929 			entry->buf_count = count;
930 			entry->seg_count = count;
931 			drm_cleanup_buf_error(dev, entry);
932 			kfree(temp_pagelist);
933 			mutex_unlock(&dev->struct_mutex);
934 			atomic_dec(&dev->buf_alloc);
935 			return -ENOMEM;
936 		}
937 		entry->seglist[entry->seg_count++] = dmah;
938 		for (i = 0; i < (1 << page_order); i++) {
939 			DRM_DEBUG("page %d @ 0x%08lx\n",
940 				  dma->page_count + page_count,
941 				  (unsigned long)dmah->vaddr + PAGE_SIZE * i);
942 			temp_pagelist[dma->page_count + page_count++]
943 				= (unsigned long)dmah->vaddr + PAGE_SIZE * i;
944 		}
945 		for (offset = 0;
946 		     offset + size <= total && entry->buf_count < count;
947 		     offset += alignment, ++entry->buf_count) {
948 			buf = &entry->buflist[entry->buf_count];
949 			buf->idx = dma->buf_count + entry->buf_count;
950 			buf->total = alignment;
951 			buf->order = order;
952 			buf->used = 0;
953 			buf->offset = (dma->byte_count + byte_count + offset);
954 			buf->address = (void *)(dmah->vaddr + offset);
955 			buf->bus_address = dmah->busaddr + offset;
956 			buf->next = NULL;
957 			buf->waiting = 0;
958 			buf->pending = 0;
959 			buf->file_priv = NULL;
960 
961 			buf->dev_priv_size = dev->driver->dev_priv_size;
962 			buf->dev_private = kzalloc(buf->dev_priv_size,
963 						GFP_KERNEL);
964 			if (!buf->dev_private) {
965 				/* Set count correctly so we free the proper amount. */
966 				entry->buf_count = count;
967 				entry->seg_count = count;
968 				drm_cleanup_buf_error(dev, entry);
969 				kfree(temp_pagelist);
970 				mutex_unlock(&dev->struct_mutex);
971 				atomic_dec(&dev->buf_alloc);
972 				return -ENOMEM;
973 			}
974 
975 			DRM_DEBUG("buffer %d @ %p\n",
976 				  entry->buf_count, buf->address);
977 		}
978 		byte_count += PAGE_SIZE << page_order;
979 	}
980 
981 	temp_buflist = krealloc(dma->buflist,
982 				(dma->buf_count + entry->buf_count) *
983 				sizeof(*dma->buflist), GFP_KERNEL);
984 	if (!temp_buflist) {
985 		/* Free the entry because it isn't valid */
986 		drm_cleanup_buf_error(dev, entry);
987 		kfree(temp_pagelist);
988 		mutex_unlock(&dev->struct_mutex);
989 		atomic_dec(&dev->buf_alloc);
990 		return -ENOMEM;
991 	}
992 	dma->buflist = temp_buflist;
993 
994 	for (i = 0; i < entry->buf_count; i++) {
995 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
996 	}
997 
998 	/* No allocations failed, so now we can replace the original pagelist
999 	 * with the new one.
1000 	 */
1001 	if (dma->page_count) {
1002 		kfree(dma->pagelist);
1003 	}
1004 	dma->pagelist = temp_pagelist;
1005 
1006 	dma->buf_count += entry->buf_count;
1007 	dma->seg_count += entry->seg_count;
1008 	dma->page_count += entry->seg_count << page_order;
1009 	dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);
1010 
1011 	mutex_unlock(&dev->struct_mutex);
1012 
1013 	request->count = entry->buf_count;
1014 	request->size = size;
1015 
1016 	if (request->flags & _DRM_PCI_BUFFER_RO)
1017 		dma->flags = _DRM_DMA_USE_PCI_RO;
1018 
1019 	atomic_dec(&dev->buf_alloc);
1020 	return 0;
1021 
1022 }
1023 EXPORT_SYMBOL(drm_legacy_addbufs_pci);
1024 
1025 static int drm_legacy_addbufs_sg(struct drm_device *dev,
1026 				 struct drm_buf_desc *request)
1027 {
1028 	struct drm_device_dma *dma = dev->dma;
1029 	struct drm_buf_entry *entry;
1030 	struct drm_buf *buf;
1031 	unsigned long offset;
1032 	unsigned long agp_offset;
1033 	int count;
1034 	int order;
1035 	int size;
1036 	int alignment;
1037 	int page_order;
1038 	int total;
1039 	int byte_count;
1040 	int i;
1041 	struct drm_buf **temp_buflist;
1042 
1043 	if (!drm_core_check_feature(dev, DRIVER_SG))
1044 		return -EINVAL;
1045 
1046 	if (!dma)
1047 		return -EINVAL;
1048 
1049 	if (!capable(CAP_SYS_ADMIN))
1050 		return -EPERM;
1051 
1052 	count = request->count;
1053 	order = order_base_2(request->size);
1054 	size = 1 << order;
1055 
1056 	alignment = (request->flags & _DRM_PAGE_ALIGN)
1057 	    ? PAGE_ALIGN(size) : size;
1058 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
1059 	total = PAGE_SIZE << page_order;
1060 
1061 	byte_count = 0;
1062 	agp_offset = request->agp_start;
1063 
1064 	DRM_DEBUG("count:      %d\n", count);
1065 	DRM_DEBUG("order:      %d\n", order);
1066 	DRM_DEBUG("size:       %d\n", size);
1067 	DRM_DEBUG("agp_offset: %lu\n", agp_offset);
1068 	DRM_DEBUG("alignment:  %d\n", alignment);
1069 	DRM_DEBUG("page_order: %d\n", page_order);
1070 	DRM_DEBUG("total:      %d\n", total);
1071 
1072 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1073 		return -EINVAL;
1074 
1075 	spin_lock(&dev->buf_lock);
1076 	if (dev->buf_use) {
1077 		spin_unlock(&dev->buf_lock);
1078 		return -EBUSY;
1079 	}
1080 	atomic_inc(&dev->buf_alloc);
1081 	spin_unlock(&dev->buf_lock);
1082 
1083 	mutex_lock(&dev->struct_mutex);
1084 	entry = &dma->bufs[order];
1085 	if (entry->buf_count) {
1086 		mutex_unlock(&dev->struct_mutex);
1087 		atomic_dec(&dev->buf_alloc);
1088 		return -ENOMEM;	/* May only call once for each order */
1089 	}
1090 
1091 	if (count < 0 || count > 4096) {
1092 		mutex_unlock(&dev->struct_mutex);
1093 		atomic_dec(&dev->buf_alloc);
1094 		return -EINVAL;
1095 	}
1096 
1097 	entry->buflist = kzalloc(count * sizeof(*entry->buflist),
1098 				GFP_KERNEL);
1099 	if (!entry->buflist) {
1100 		mutex_unlock(&dev->struct_mutex);
1101 		atomic_dec(&dev->buf_alloc);
1102 		return -ENOMEM;
1103 	}
1104 
1105 	entry->buf_size = size;
1106 	entry->page_order = page_order;
1107 
1108 	offset = 0;
1109 
1110 	while (entry->buf_count < count) {
1111 		buf = &entry->buflist[entry->buf_count];
1112 		buf->idx = dma->buf_count + entry->buf_count;
1113 		buf->total = alignment;
1114 		buf->order = order;
1115 		buf->used = 0;
1116 
1117 		buf->offset = (dma->byte_count + offset);
1118 		buf->bus_address = agp_offset + offset;
1119 		buf->address = (void *)(agp_offset + offset
1120 					+ (unsigned long)dev->sg->virtual);
1121 		buf->next = NULL;
1122 		buf->waiting = 0;
1123 		buf->pending = 0;
1124 		buf->file_priv = NULL;
1125 
1126 		buf->dev_priv_size = dev->driver->dev_priv_size;
1127 		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
1128 		if (!buf->dev_private) {
1129 			/* Set count correctly so we free the proper amount. */
1130 			entry->buf_count = count;
1131 			drm_cleanup_buf_error(dev, entry);
1132 			mutex_unlock(&dev->struct_mutex);
1133 			atomic_dec(&dev->buf_alloc);
1134 			return -ENOMEM;
1135 		}
1136 
1137 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
1138 
1139 		offset += alignment;
1140 		entry->buf_count++;
1141 		byte_count += PAGE_SIZE << page_order;
1142 	}
1143 
1144 	DRM_DEBUG("byte_count: %d\n", byte_count);
1145 
1146 	temp_buflist = krealloc(dma->buflist,
1147 				(dma->buf_count + entry->buf_count) *
1148 				sizeof(*dma->buflist), GFP_KERNEL);
1149 	if (!temp_buflist) {
1150 		/* Free the entry because it isn't valid */
1151 		drm_cleanup_buf_error(dev, entry);
1152 		mutex_unlock(&dev->struct_mutex);
1153 		atomic_dec(&dev->buf_alloc);
1154 		return -ENOMEM;
1155 	}
1156 	dma->buflist = temp_buflist;
1157 
1158 	for (i = 0; i < entry->buf_count; i++) {
1159 		dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1160 	}
1161 
1162 	dma->buf_count += entry->buf_count;
1163 	dma->seg_count += entry->seg_count;
1164 	dma->page_count += byte_count >> PAGE_SHIFT;
1165 	dma->byte_count += byte_count;
1166 
1167 	DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
1168 	DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
1169 
1170 	mutex_unlock(&dev->struct_mutex);
1171 
1172 	request->count = entry->buf_count;
1173 	request->size = size;
1174 
1175 	dma->flags = _DRM_DMA_USE_SG;
1176 
1177 	atomic_dec(&dev->buf_alloc);
1178 	return 0;
1179 }
1180 
1181 /**
1182  * Add buffers for DMA transfers (ioctl).
1183  *
1184  * \param inode device inode.
1185  * \param file_priv DRM file private.
1186  * \param cmd command.
1187  * \param arg pointer to a struct drm_buf_desc request.
1188  * \return zero on success or a negative number on failure.
1189  *
1190  * According with the memory type specified in drm_buf_desc::flags and the
1191  * build options, it dispatches the call either to addbufs_agp(),
1192  * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
1193  * PCI memory respectively.
1194  */
1195 int drm_legacy_addbufs(struct drm_device *dev, void *data,
1196 		       struct drm_file *file_priv)
1197 {
1198 	struct drm_buf_desc *request = data;
1199 	int ret;
1200 
1201 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1202 		return -EINVAL;
1203 
1204 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1205 		return -EINVAL;
1206 
1207 #if IS_ENABLED(CONFIG_AGP)
1208 	if (request->flags & _DRM_AGP_BUFFER)
1209 		ret = drm_legacy_addbufs_agp(dev, request);
1210 	else
1211 #endif
1212 	if (request->flags & _DRM_SG_BUFFER)
1213 		ret = drm_legacy_addbufs_sg(dev, request);
1214 	else if (request->flags & _DRM_FB_BUFFER)
1215 		ret = -EINVAL;
1216 	else
1217 		ret = drm_legacy_addbufs_pci(dev, request);
1218 
1219 	return ret;
1220 }
1221 
1222 /**
1223  * Get information about the buffer mappings.
1224  *
1225  * This was originally mean for debugging purposes, or by a sophisticated
1226  * client library to determine how best to use the available buffers (e.g.,
1227  * large buffers can be used for image transfer).
1228  *
1229  * \param inode device inode.
1230  * \param file_priv DRM file private.
1231  * \param cmd command.
1232  * \param arg pointer to a drm_buf_info structure.
1233  * \return zero on success or a negative number on failure.
1234  *
1235  * Increments drm_device::buf_use while holding the drm_device::buf_lock
1236  * lock, preventing of allocating more buffers after this call. Information
1237  * about each requested buffer is then copied into user space.
1238  */
1239 int drm_legacy_infobufs(struct drm_device *dev, void *data,
1240 			struct drm_file *file_priv)
1241 {
1242 	struct drm_device_dma *dma = dev->dma;
1243 	struct drm_buf_info *request = data;
1244 	int i;
1245 	int count;
1246 
1247 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1248 		return -EINVAL;
1249 
1250 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1251 		return -EINVAL;
1252 
1253 	if (!dma)
1254 		return -EINVAL;
1255 
1256 	spin_lock(&dev->buf_lock);
1257 	if (atomic_read(&dev->buf_alloc)) {
1258 		spin_unlock(&dev->buf_lock);
1259 		return -EBUSY;
1260 	}
1261 	++dev->buf_use;		/* Can't allocate more after this call */
1262 	spin_unlock(&dev->buf_lock);
1263 
1264 	for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1265 		if (dma->bufs[i].buf_count)
1266 			++count;
1267 	}
1268 
1269 	DRM_DEBUG("count = %d\n", count);
1270 
1271 	if (request->count >= count) {
1272 		for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1273 			if (dma->bufs[i].buf_count) {
1274 				struct drm_buf_desc __user *to =
1275 				    &request->list[count];
1276 				struct drm_buf_entry *from = &dma->bufs[i];
1277 				if (copy_to_user(&to->count,
1278 						 &from->buf_count,
1279 						 sizeof(from->buf_count)) ||
1280 				    copy_to_user(&to->size,
1281 						 &from->buf_size,
1282 						 sizeof(from->buf_size)) ||
1283 				    copy_to_user(&to->low_mark,
1284 						 &from->low_mark,
1285 						 sizeof(from->low_mark)) ||
1286 				    copy_to_user(&to->high_mark,
1287 						 &from->high_mark,
1288 						 sizeof(from->high_mark)))
1289 					return -EFAULT;
1290 
1291 				DRM_DEBUG("%d %d %d %d %d\n",
1292 					  i,
1293 					  dma->bufs[i].buf_count,
1294 					  dma->bufs[i].buf_size,
1295 					  dma->bufs[i].low_mark,
1296 					  dma->bufs[i].high_mark);
1297 				++count;
1298 			}
1299 		}
1300 	}
1301 	request->count = count;
1302 
1303 	return 0;
1304 }
1305 
1306 /**
1307  * Specifies a low and high water mark for buffer allocation
1308  *
1309  * \param inode device inode.
1310  * \param file_priv DRM file private.
1311  * \param cmd command.
1312  * \param arg a pointer to a drm_buf_desc structure.
1313  * \return zero on success or a negative number on failure.
1314  *
1315  * Verifies that the size order is bounded between the admissible orders and
1316  * updates the respective drm_device_dma::bufs entry low and high water mark.
1317  *
1318  * \note This ioctl is deprecated and mostly never used.
1319  */
1320 int drm_legacy_markbufs(struct drm_device *dev, void *data,
1321 			struct drm_file *file_priv)
1322 {
1323 	struct drm_device_dma *dma = dev->dma;
1324 	struct drm_buf_desc *request = data;
1325 	int order;
1326 	struct drm_buf_entry *entry;
1327 
1328 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1329 		return -EINVAL;
1330 
1331 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1332 		return -EINVAL;
1333 
1334 	if (!dma)
1335 		return -EINVAL;
1336 
1337 	DRM_DEBUG("%d, %d, %d\n",
1338 		  request->size, request->low_mark, request->high_mark);
1339 	order = order_base_2(request->size);
1340 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1341 		return -EINVAL;
1342 	entry = &dma->bufs[order];
1343 
1344 	if (request->low_mark < 0 || request->low_mark > entry->buf_count)
1345 		return -EINVAL;
1346 	if (request->high_mark < 0 || request->high_mark > entry->buf_count)
1347 		return -EINVAL;
1348 
1349 	entry->low_mark = request->low_mark;
1350 	entry->high_mark = request->high_mark;
1351 
1352 	return 0;
1353 }
1354 
1355 /**
1356  * Unreserve the buffers in list, previously reserved using drmDMA.
1357  *
1358  * \param inode device inode.
1359  * \param file_priv DRM file private.
1360  * \param cmd command.
1361  * \param arg pointer to a drm_buf_free structure.
1362  * \return zero on success or a negative number on failure.
1363  *
1364  * Calls free_buffer() for each used buffer.
1365  * This function is primarily used for debugging.
1366  */
1367 int drm_legacy_freebufs(struct drm_device *dev, void *data,
1368 			struct drm_file *file_priv)
1369 {
1370 	struct drm_device_dma *dma = dev->dma;
1371 	struct drm_buf_free *request = data;
1372 	int i;
1373 	int idx;
1374 	struct drm_buf *buf;
1375 
1376 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1377 		return -EINVAL;
1378 
1379 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1380 		return -EINVAL;
1381 
1382 	if (!dma)
1383 		return -EINVAL;
1384 
1385 	DRM_DEBUG("%d\n", request->count);
1386 	for (i = 0; i < request->count; i++) {
1387 		if (copy_from_user(&idx, &request->list[i], sizeof(idx)))
1388 			return -EFAULT;
1389 		if (idx < 0 || idx >= dma->buf_count) {
1390 			DRM_ERROR("Index %d (of %d max)\n",
1391 				  idx, dma->buf_count - 1);
1392 			return -EINVAL;
1393 		}
1394 		buf = dma->buflist[idx];
1395 		if (buf->file_priv != file_priv) {
1396 			DRM_ERROR("Process %d freeing buffer not owned\n",
1397 				  task_pid_nr(current));
1398 			return -EINVAL;
1399 		}
1400 		drm_legacy_free_buffer(dev, buf);
1401 	}
1402 
1403 	return 0;
1404 }
1405 
1406 /**
1407  * Maps all of the DMA buffers into client-virtual space (ioctl).
1408  *
1409  * \param inode device inode.
1410  * \param file_priv DRM file private.
1411  * \param cmd command.
1412  * \param arg pointer to a drm_buf_map structure.
1413  * \return zero on success or a negative number on failure.
1414  *
1415  * Maps the AGP, SG or PCI buffer region with vm_mmap(), and copies information
1416  * about each buffer into user space. For PCI buffers, it calls vm_mmap() with
1417  * offset equal to 0, which drm_mmap() interpretes as PCI buffers and calls
1418  * drm_mmap_dma().
1419  */
1420 int drm_legacy_mapbufs(struct drm_device *dev, void *data,
1421 		       struct drm_file *file_priv)
1422 {
1423 	struct drm_device_dma *dma = dev->dma;
1424 	int retcode = 0;
1425 	const int zero = 0;
1426 	unsigned long virtual;
1427 	unsigned long address;
1428 	struct drm_buf_map *request = data;
1429 	int i;
1430 
1431 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1432 		return -EINVAL;
1433 
1434 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1435 		return -EINVAL;
1436 
1437 	if (!dma)
1438 		return -EINVAL;
1439 
1440 	spin_lock(&dev->buf_lock);
1441 	if (atomic_read(&dev->buf_alloc)) {
1442 		spin_unlock(&dev->buf_lock);
1443 		return -EBUSY;
1444 	}
1445 	dev->buf_use++;		/* Can't allocate more after this call */
1446 	spin_unlock(&dev->buf_lock);
1447 
1448 	if (request->count >= dma->buf_count) {
1449 		if ((dev->agp && (dma->flags & _DRM_DMA_USE_AGP))
1450 		    || (drm_core_check_feature(dev, DRIVER_SG)
1451 			&& (dma->flags & _DRM_DMA_USE_SG))) {
1452 			struct drm_local_map *map = dev->agp_buffer_map;
1453 			unsigned long token = dev->agp_buffer_token;
1454 
1455 			if (!map) {
1456 				retcode = -EINVAL;
1457 				goto done;
1458 			}
1459 			virtual = vm_mmap(file_priv->filp, 0, map->size,
1460 					  PROT_READ | PROT_WRITE,
1461 					  MAP_SHARED,
1462 					  token);
1463 		} else {
1464 			virtual = vm_mmap(file_priv->filp, 0, dma->byte_count,
1465 					  PROT_READ | PROT_WRITE,
1466 					  MAP_SHARED, 0);
1467 		}
1468 		if (virtual > -1024UL) {
1469 			/* Real error */
1470 			retcode = (signed long)virtual;
1471 			goto done;
1472 		}
1473 		request->virtual = (void __user *)virtual;
1474 
1475 		for (i = 0; i < dma->buf_count; i++) {
1476 			if (copy_to_user(&request->list[i].idx,
1477 					 &dma->buflist[i]->idx,
1478 					 sizeof(request->list[0].idx))) {
1479 				retcode = -EFAULT;
1480 				goto done;
1481 			}
1482 			if (copy_to_user(&request->list[i].total,
1483 					 &dma->buflist[i]->total,
1484 					 sizeof(request->list[0].total))) {
1485 				retcode = -EFAULT;
1486 				goto done;
1487 			}
1488 			if (copy_to_user(&request->list[i].used,
1489 					 &zero, sizeof(zero))) {
1490 				retcode = -EFAULT;
1491 				goto done;
1492 			}
1493 			address = virtual + dma->buflist[i]->offset;	/* *** */
1494 			if (copy_to_user(&request->list[i].address,
1495 					 &address, sizeof(address))) {
1496 				retcode = -EFAULT;
1497 				goto done;
1498 			}
1499 		}
1500 	}
1501       done:
1502 	request->count = dma->buf_count;
1503 	DRM_DEBUG("%d buffers, retcode = %d\n", request->count, retcode);
1504 
1505 	return retcode;
1506 }
1507 
1508 int drm_legacy_dma_ioctl(struct drm_device *dev, void *data,
1509 		  struct drm_file *file_priv)
1510 {
1511 	if (drm_core_check_feature(dev, DRIVER_MODESET))
1512 		return -EINVAL;
1513 
1514 	if (dev->driver->dma_ioctl)
1515 		return dev->driver->dma_ioctl(dev, data, file_priv);
1516 	else
1517 		return -EINVAL;
1518 }
1519 
1520 struct drm_local_map *drm_legacy_getsarea(struct drm_device *dev)
1521 {
1522 	struct drm_map_list *entry;
1523 
1524 	list_for_each_entry(entry, &dev->maplist, head) {
1525 		if (entry->map && entry->map->type == _DRM_SHM &&
1526 		    (entry->map->flags & _DRM_CONTAINS_LOCK)) {
1527 			return entry->map;
1528 		}
1529 	}
1530 	return NULL;
1531 }
1532 EXPORT_SYMBOL(drm_legacy_getsarea);
1533