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