Commit | Line | Data |
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673a394b EA |
1 | /* |
2 | * Copyright © 2008 Intel Corporation | |
3 | * | |
4 | * Permission is hereby granted, free of charge, to any person obtaining a | |
5 | * copy of this software and associated documentation files (the "Software"), | |
6 | * to deal in the Software without restriction, including without limitation | |
7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
8 | * and/or sell copies of the Software, and to permit persons to whom the | |
9 | * Software is furnished to do so, subject to the following conditions: | |
10 | * | |
11 | * The above copyright notice and this permission notice (including the next | |
12 | * paragraph) shall be included in all copies or substantial portions of the | |
13 | * Software. | |
14 | * | |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
18 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
19 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
20 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
21 | * IN THE SOFTWARE. | |
22 | * | |
23 | * Authors: | |
24 | * Eric Anholt <eric@anholt.net> | |
25 | * | |
26 | */ | |
27 | ||
28 | #include <linux/types.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/mm.h> | |
31 | #include <linux/uaccess.h> | |
32 | #include <linux/fs.h> | |
33 | #include <linux/file.h> | |
34 | #include <linux/module.h> | |
35 | #include <linux/mman.h> | |
36 | #include <linux/pagemap.h> | |
5949eac4 | 37 | #include <linux/shmem_fs.h> |
673a394b EA |
38 | #include "drmP.h" |
39 | ||
40 | /** @file drm_gem.c | |
41 | * | |
42 | * This file provides some of the base ioctls and library routines for | |
43 | * the graphics memory manager implemented by each device driver. | |
44 | * | |
45 | * Because various devices have different requirements in terms of | |
46 | * synchronization and migration strategies, implementing that is left up to | |
47 | * the driver, and all that the general API provides should be generic -- | |
48 | * allocating objects, reading/writing data with the cpu, freeing objects. | |
49 | * Even there, platform-dependent optimizations for reading/writing data with | |
50 | * the CPU mean we'll likely hook those out to driver-specific calls. However, | |
51 | * the DRI2 implementation wants to have at least allocate/mmap be generic. | |
52 | * | |
53 | * The goal was to have swap-backed object allocation managed through | |
54 | * struct file. However, file descriptors as handles to a struct file have | |
55 | * two major failings: | |
56 | * - Process limits prevent more than 1024 or so being used at a time by | |
57 | * default. | |
58 | * - Inability to allocate high fds will aggravate the X Server's select() | |
59 | * handling, and likely that of many GL client applications as well. | |
60 | * | |
61 | * This led to a plan of using our own integer IDs (called handles, following | |
62 | * DRM terminology) to mimic fds, and implement the fd syscalls we need as | |
63 | * ioctls. The objects themselves will still include the struct file so | |
64 | * that we can transition to fds if the required kernel infrastructure shows | |
65 | * up at a later date, and as our interface with shmfs for memory allocation. | |
66 | */ | |
67 | ||
a2c0a97b JB |
68 | /* |
69 | * We make up offsets for buffer objects so we can recognize them at | |
70 | * mmap time. | |
71 | */ | |
05269a3a JC |
72 | |
73 | /* pgoff in mmap is an unsigned long, so we need to make sure that | |
74 | * the faked up offset will fit | |
75 | */ | |
76 | ||
77 | #if BITS_PER_LONG == 64 | |
a2c0a97b JB |
78 | #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1) |
79 | #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16) | |
05269a3a JC |
80 | #else |
81 | #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1) | |
82 | #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16) | |
83 | #endif | |
a2c0a97b | 84 | |
673a394b EA |
85 | /** |
86 | * Initialize the GEM device fields | |
87 | */ | |
88 | ||
89 | int | |
90 | drm_gem_init(struct drm_device *dev) | |
91 | { | |
a2c0a97b JB |
92 | struct drm_gem_mm *mm; |
93 | ||
673a394b EA |
94 | spin_lock_init(&dev->object_name_lock); |
95 | idr_init(&dev->object_name_idr); | |
a2c0a97b | 96 | |
9a298b2a | 97 | mm = kzalloc(sizeof(struct drm_gem_mm), GFP_KERNEL); |
a2c0a97b JB |
98 | if (!mm) { |
99 | DRM_ERROR("out of memory\n"); | |
100 | return -ENOMEM; | |
101 | } | |
102 | ||
103 | dev->mm_private = mm; | |
104 | ||
4cb81ac2 | 105 | if (drm_ht_create(&mm->offset_hash, 12)) { |
9a298b2a | 106 | kfree(mm); |
a2c0a97b JB |
107 | return -ENOMEM; |
108 | } | |
109 | ||
110 | if (drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START, | |
111 | DRM_FILE_PAGE_OFFSET_SIZE)) { | |
a2c0a97b | 112 | drm_ht_remove(&mm->offset_hash); |
9a298b2a | 113 | kfree(mm); |
a2c0a97b JB |
114 | return -ENOMEM; |
115 | } | |
116 | ||
673a394b EA |
117 | return 0; |
118 | } | |
119 | ||
a2c0a97b JB |
120 | void |
121 | drm_gem_destroy(struct drm_device *dev) | |
122 | { | |
123 | struct drm_gem_mm *mm = dev->mm_private; | |
124 | ||
125 | drm_mm_takedown(&mm->offset_manager); | |
126 | drm_ht_remove(&mm->offset_hash); | |
9a298b2a | 127 | kfree(mm); |
a2c0a97b JB |
128 | dev->mm_private = NULL; |
129 | } | |
130 | ||
1d397043 | 131 | /** |
62cb7011 | 132 | * Initialize an already allocated GEM object of the specified size with |
1d397043 DV |
133 | * shmfs backing store. |
134 | */ | |
135 | int drm_gem_object_init(struct drm_device *dev, | |
136 | struct drm_gem_object *obj, size_t size) | |
137 | { | |
138 | BUG_ON((size & (PAGE_SIZE - 1)) != 0); | |
139 | ||
140 | obj->dev = dev; | |
141 | obj->filp = shmem_file_setup("drm mm object", size, VM_NORESERVE); | |
142 | if (IS_ERR(obj->filp)) | |
143 | return -ENOMEM; | |
144 | ||
145 | kref_init(&obj->refcount); | |
29d08b3e | 146 | atomic_set(&obj->handle_count, 0); |
1d397043 DV |
147 | obj->size = size; |
148 | ||
1d397043 DV |
149 | return 0; |
150 | } | |
151 | EXPORT_SYMBOL(drm_gem_object_init); | |
152 | ||
62cb7011 AC |
153 | /** |
154 | * Initialize an already allocated GEM object of the specified size with | |
155 | * no GEM provided backing store. Instead the caller is responsible for | |
156 | * backing the object and handling it. | |
157 | */ | |
158 | int drm_gem_private_object_init(struct drm_device *dev, | |
159 | struct drm_gem_object *obj, size_t size) | |
160 | { | |
161 | BUG_ON((size & (PAGE_SIZE - 1)) != 0); | |
162 | ||
163 | obj->dev = dev; | |
164 | obj->filp = NULL; | |
165 | ||
166 | kref_init(&obj->refcount); | |
167 | atomic_set(&obj->handle_count, 0); | |
168 | obj->size = size; | |
169 | ||
170 | return 0; | |
171 | } | |
172 | EXPORT_SYMBOL(drm_gem_private_object_init); | |
173 | ||
673a394b EA |
174 | /** |
175 | * Allocate a GEM object of the specified size with shmfs backing store | |
176 | */ | |
177 | struct drm_gem_object * | |
178 | drm_gem_object_alloc(struct drm_device *dev, size_t size) | |
179 | { | |
180 | struct drm_gem_object *obj; | |
181 | ||
b798b1fe | 182 | obj = kzalloc(sizeof(*obj), GFP_KERNEL); |
845792d9 JS |
183 | if (!obj) |
184 | goto free; | |
673a394b | 185 | |
1d397043 | 186 | if (drm_gem_object_init(dev, obj, size) != 0) |
845792d9 | 187 | goto free; |
673a394b | 188 | |
673a394b EA |
189 | if (dev->driver->gem_init_object != NULL && |
190 | dev->driver->gem_init_object(obj) != 0) { | |
845792d9 | 191 | goto fput; |
673a394b | 192 | } |
673a394b | 193 | return obj; |
845792d9 | 194 | fput: |
1d397043 | 195 | /* Object_init mangles the global counters - readjust them. */ |
845792d9 JS |
196 | fput(obj->filp); |
197 | free: | |
198 | kfree(obj); | |
199 | return NULL; | |
673a394b EA |
200 | } |
201 | EXPORT_SYMBOL(drm_gem_object_alloc); | |
202 | ||
203 | /** | |
204 | * Removes the mapping from handle to filp for this object. | |
205 | */ | |
ff72145b | 206 | int |
a1a2d1d3 | 207 | drm_gem_handle_delete(struct drm_file *filp, u32 handle) |
673a394b EA |
208 | { |
209 | struct drm_device *dev; | |
210 | struct drm_gem_object *obj; | |
211 | ||
212 | /* This is gross. The idr system doesn't let us try a delete and | |
213 | * return an error code. It just spews if you fail at deleting. | |
214 | * So, we have to grab a lock around finding the object and then | |
215 | * doing the delete on it and dropping the refcount, or the user | |
216 | * could race us to double-decrement the refcount and cause a | |
217 | * use-after-free later. Given the frequency of our handle lookups, | |
218 | * we may want to use ida for number allocation and a hash table | |
219 | * for the pointers, anyway. | |
220 | */ | |
221 | spin_lock(&filp->table_lock); | |
222 | ||
223 | /* Check if we currently have a reference on the object */ | |
224 | obj = idr_find(&filp->object_idr, handle); | |
225 | if (obj == NULL) { | |
226 | spin_unlock(&filp->table_lock); | |
227 | return -EINVAL; | |
228 | } | |
229 | dev = obj->dev; | |
230 | ||
231 | /* Release reference and decrement refcount. */ | |
232 | idr_remove(&filp->object_idr, handle); | |
233 | spin_unlock(&filp->table_lock); | |
234 | ||
304eda32 BS |
235 | if (dev->driver->gem_close_object) |
236 | dev->driver->gem_close_object(obj, filp); | |
bc9025bd | 237 | drm_gem_object_handle_unreference_unlocked(obj); |
673a394b EA |
238 | |
239 | return 0; | |
240 | } | |
ff72145b | 241 | EXPORT_SYMBOL(drm_gem_handle_delete); |
673a394b EA |
242 | |
243 | /** | |
244 | * Create a handle for this object. This adds a handle reference | |
245 | * to the object, which includes a regular reference count. Callers | |
246 | * will likely want to dereference the object afterwards. | |
247 | */ | |
248 | int | |
249 | drm_gem_handle_create(struct drm_file *file_priv, | |
250 | struct drm_gem_object *obj, | |
a1a2d1d3 | 251 | u32 *handlep) |
673a394b | 252 | { |
304eda32 BS |
253 | struct drm_device *dev = obj->dev; |
254 | int ret; | |
673a394b EA |
255 | |
256 | /* | |
257 | * Get the user-visible handle using idr. | |
258 | */ | |
259 | again: | |
260 | /* ensure there is space available to allocate a handle */ | |
261 | if (idr_pre_get(&file_priv->object_idr, GFP_KERNEL) == 0) | |
262 | return -ENOMEM; | |
263 | ||
264 | /* do the allocation under our spinlock */ | |
265 | spin_lock(&file_priv->table_lock); | |
a1a2d1d3 | 266 | ret = idr_get_new_above(&file_priv->object_idr, obj, 1, (int *)handlep); |
673a394b EA |
267 | spin_unlock(&file_priv->table_lock); |
268 | if (ret == -EAGAIN) | |
269 | goto again; | |
270 | ||
271 | if (ret != 0) | |
272 | return ret; | |
273 | ||
274 | drm_gem_object_handle_reference(obj); | |
304eda32 BS |
275 | |
276 | if (dev->driver->gem_open_object) { | |
277 | ret = dev->driver->gem_open_object(obj, file_priv); | |
278 | if (ret) { | |
279 | drm_gem_handle_delete(file_priv, *handlep); | |
280 | return ret; | |
281 | } | |
282 | } | |
283 | ||
673a394b EA |
284 | return 0; |
285 | } | |
286 | EXPORT_SYMBOL(drm_gem_handle_create); | |
287 | ||
288 | /** Returns a reference to the object named by the handle. */ | |
289 | struct drm_gem_object * | |
290 | drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp, | |
a1a2d1d3 | 291 | u32 handle) |
673a394b EA |
292 | { |
293 | struct drm_gem_object *obj; | |
294 | ||
295 | spin_lock(&filp->table_lock); | |
296 | ||
297 | /* Check if we currently have a reference on the object */ | |
298 | obj = idr_find(&filp->object_idr, handle); | |
299 | if (obj == NULL) { | |
300 | spin_unlock(&filp->table_lock); | |
301 | return NULL; | |
302 | } | |
303 | ||
304 | drm_gem_object_reference(obj); | |
305 | ||
306 | spin_unlock(&filp->table_lock); | |
307 | ||
308 | return obj; | |
309 | } | |
310 | EXPORT_SYMBOL(drm_gem_object_lookup); | |
311 | ||
312 | /** | |
313 | * Releases the handle to an mm object. | |
314 | */ | |
315 | int | |
316 | drm_gem_close_ioctl(struct drm_device *dev, void *data, | |
317 | struct drm_file *file_priv) | |
318 | { | |
319 | struct drm_gem_close *args = data; | |
320 | int ret; | |
321 | ||
322 | if (!(dev->driver->driver_features & DRIVER_GEM)) | |
323 | return -ENODEV; | |
324 | ||
325 | ret = drm_gem_handle_delete(file_priv, args->handle); | |
326 | ||
327 | return ret; | |
328 | } | |
329 | ||
330 | /** | |
331 | * Create a global name for an object, returning the name. | |
332 | * | |
333 | * Note that the name does not hold a reference; when the object | |
334 | * is freed, the name goes away. | |
335 | */ | |
336 | int | |
337 | drm_gem_flink_ioctl(struct drm_device *dev, void *data, | |
338 | struct drm_file *file_priv) | |
339 | { | |
340 | struct drm_gem_flink *args = data; | |
341 | struct drm_gem_object *obj; | |
342 | int ret; | |
343 | ||
344 | if (!(dev->driver->driver_features & DRIVER_GEM)) | |
345 | return -ENODEV; | |
346 | ||
347 | obj = drm_gem_object_lookup(dev, file_priv, args->handle); | |
348 | if (obj == NULL) | |
bf79cb91 | 349 | return -ENOENT; |
673a394b EA |
350 | |
351 | again: | |
3e49c4f4 CW |
352 | if (idr_pre_get(&dev->object_name_idr, GFP_KERNEL) == 0) { |
353 | ret = -ENOMEM; | |
354 | goto err; | |
355 | } | |
673a394b EA |
356 | |
357 | spin_lock(&dev->object_name_lock); | |
8d59bae5 CW |
358 | if (!obj->name) { |
359 | ret = idr_get_new_above(&dev->object_name_idr, obj, 1, | |
360 | &obj->name); | |
361 | args->name = (uint64_t) obj->name; | |
673a394b | 362 | spin_unlock(&dev->object_name_lock); |
673a394b | 363 | |
8d59bae5 CW |
364 | if (ret == -EAGAIN) |
365 | goto again; | |
673a394b | 366 | |
8d59bae5 CW |
367 | if (ret != 0) |
368 | goto err; | |
673a394b | 369 | |
8d59bae5 CW |
370 | /* Allocate a reference for the name table. */ |
371 | drm_gem_object_reference(obj); | |
372 | } else { | |
373 | args->name = (uint64_t) obj->name; | |
374 | spin_unlock(&dev->object_name_lock); | |
375 | ret = 0; | |
376 | } | |
3e49c4f4 CW |
377 | |
378 | err: | |
bc9025bd | 379 | drm_gem_object_unreference_unlocked(obj); |
3e49c4f4 | 380 | return ret; |
673a394b EA |
381 | } |
382 | ||
383 | /** | |
384 | * Open an object using the global name, returning a handle and the size. | |
385 | * | |
386 | * This handle (of course) holds a reference to the object, so the object | |
387 | * will not go away until the handle is deleted. | |
388 | */ | |
389 | int | |
390 | drm_gem_open_ioctl(struct drm_device *dev, void *data, | |
391 | struct drm_file *file_priv) | |
392 | { | |
393 | struct drm_gem_open *args = data; | |
394 | struct drm_gem_object *obj; | |
395 | int ret; | |
a1a2d1d3 | 396 | u32 handle; |
673a394b EA |
397 | |
398 | if (!(dev->driver->driver_features & DRIVER_GEM)) | |
399 | return -ENODEV; | |
400 | ||
401 | spin_lock(&dev->object_name_lock); | |
402 | obj = idr_find(&dev->object_name_idr, (int) args->name); | |
403 | if (obj) | |
404 | drm_gem_object_reference(obj); | |
405 | spin_unlock(&dev->object_name_lock); | |
406 | if (!obj) | |
407 | return -ENOENT; | |
408 | ||
409 | ret = drm_gem_handle_create(file_priv, obj, &handle); | |
bc9025bd | 410 | drm_gem_object_unreference_unlocked(obj); |
673a394b EA |
411 | if (ret) |
412 | return ret; | |
413 | ||
414 | args->handle = handle; | |
415 | args->size = obj->size; | |
416 | ||
417 | return 0; | |
418 | } | |
419 | ||
420 | /** | |
421 | * Called at device open time, sets up the structure for handling refcounting | |
422 | * of mm objects. | |
423 | */ | |
424 | void | |
425 | drm_gem_open(struct drm_device *dev, struct drm_file *file_private) | |
426 | { | |
427 | idr_init(&file_private->object_idr); | |
428 | spin_lock_init(&file_private->table_lock); | |
429 | } | |
430 | ||
431 | /** | |
432 | * Called at device close to release the file's | |
433 | * handle references on objects. | |
434 | */ | |
435 | static int | |
436 | drm_gem_object_release_handle(int id, void *ptr, void *data) | |
437 | { | |
304eda32 | 438 | struct drm_file *file_priv = data; |
673a394b | 439 | struct drm_gem_object *obj = ptr; |
304eda32 BS |
440 | struct drm_device *dev = obj->dev; |
441 | ||
442 | if (dev->driver->gem_close_object) | |
443 | dev->driver->gem_close_object(obj, file_priv); | |
673a394b | 444 | |
bc9025bd | 445 | drm_gem_object_handle_unreference_unlocked(obj); |
673a394b EA |
446 | |
447 | return 0; | |
448 | } | |
449 | ||
450 | /** | |
451 | * Called at close time when the filp is going away. | |
452 | * | |
453 | * Releases any remaining references on objects by this filp. | |
454 | */ | |
455 | void | |
456 | drm_gem_release(struct drm_device *dev, struct drm_file *file_private) | |
457 | { | |
673a394b | 458 | idr_for_each(&file_private->object_idr, |
304eda32 | 459 | &drm_gem_object_release_handle, file_private); |
673a394b | 460 | |
ddd3d069 | 461 | idr_remove_all(&file_private->object_idr); |
673a394b | 462 | idr_destroy(&file_private->object_idr); |
673a394b EA |
463 | } |
464 | ||
fd632aa3 DV |
465 | void |
466 | drm_gem_object_release(struct drm_gem_object *obj) | |
c3ae90c0 | 467 | { |
62cb7011 AC |
468 | if (obj->filp) |
469 | fput(obj->filp); | |
c3ae90c0 | 470 | } |
fd632aa3 | 471 | EXPORT_SYMBOL(drm_gem_object_release); |
c3ae90c0 | 472 | |
673a394b EA |
473 | /** |
474 | * Called after the last reference to the object has been lost. | |
c3ae90c0 | 475 | * Must be called holding struct_ mutex |
673a394b EA |
476 | * |
477 | * Frees the object | |
478 | */ | |
479 | void | |
480 | drm_gem_object_free(struct kref *kref) | |
481 | { | |
482 | struct drm_gem_object *obj = (struct drm_gem_object *) kref; | |
483 | struct drm_device *dev = obj->dev; | |
484 | ||
485 | BUG_ON(!mutex_is_locked(&dev->struct_mutex)); | |
486 | ||
487 | if (dev->driver->gem_free_object != NULL) | |
488 | dev->driver->gem_free_object(obj); | |
673a394b EA |
489 | } |
490 | EXPORT_SYMBOL(drm_gem_object_free); | |
491 | ||
c3ae90c0 LB |
492 | static void drm_gem_object_ref_bug(struct kref *list_kref) |
493 | { | |
494 | BUG(); | |
495 | } | |
496 | ||
673a394b EA |
497 | /** |
498 | * Called after the last handle to the object has been closed | |
499 | * | |
500 | * Removes any name for the object. Note that this must be | |
501 | * called before drm_gem_object_free or we'll be touching | |
502 | * freed memory | |
503 | */ | |
29d08b3e | 504 | void drm_gem_object_handle_free(struct drm_gem_object *obj) |
673a394b | 505 | { |
673a394b EA |
506 | struct drm_device *dev = obj->dev; |
507 | ||
508 | /* Remove any name for this object */ | |
509 | spin_lock(&dev->object_name_lock); | |
510 | if (obj->name) { | |
511 | idr_remove(&dev->object_name_idr, obj->name); | |
8d59bae5 | 512 | obj->name = 0; |
673a394b EA |
513 | spin_unlock(&dev->object_name_lock); |
514 | /* | |
515 | * The object name held a reference to this object, drop | |
516 | * that now. | |
c3ae90c0 LB |
517 | * |
518 | * This cannot be the last reference, since the handle holds one too. | |
673a394b | 519 | */ |
c3ae90c0 | 520 | kref_put(&obj->refcount, drm_gem_object_ref_bug); |
673a394b EA |
521 | } else |
522 | spin_unlock(&dev->object_name_lock); | |
523 | ||
524 | } | |
525 | EXPORT_SYMBOL(drm_gem_object_handle_free); | |
526 | ||
ab00b3e5 JB |
527 | void drm_gem_vm_open(struct vm_area_struct *vma) |
528 | { | |
529 | struct drm_gem_object *obj = vma->vm_private_data; | |
530 | ||
531 | drm_gem_object_reference(obj); | |
31dfbc93 CW |
532 | |
533 | mutex_lock(&obj->dev->struct_mutex); | |
534 | drm_vm_open_locked(vma); | |
535 | mutex_unlock(&obj->dev->struct_mutex); | |
ab00b3e5 JB |
536 | } |
537 | EXPORT_SYMBOL(drm_gem_vm_open); | |
538 | ||
539 | void drm_gem_vm_close(struct vm_area_struct *vma) | |
540 | { | |
541 | struct drm_gem_object *obj = vma->vm_private_data; | |
b74ad5ae | 542 | struct drm_device *dev = obj->dev; |
ab00b3e5 | 543 | |
b74ad5ae | 544 | mutex_lock(&dev->struct_mutex); |
31dfbc93 CW |
545 | drm_vm_close_locked(vma); |
546 | drm_gem_object_unreference(obj); | |
b74ad5ae | 547 | mutex_unlock(&dev->struct_mutex); |
ab00b3e5 JB |
548 | } |
549 | EXPORT_SYMBOL(drm_gem_vm_close); | |
550 | ||
551 | ||
a2c0a97b JB |
552 | /** |
553 | * drm_gem_mmap - memory map routine for GEM objects | |
554 | * @filp: DRM file pointer | |
555 | * @vma: VMA for the area to be mapped | |
556 | * | |
557 | * If a driver supports GEM object mapping, mmap calls on the DRM file | |
558 | * descriptor will end up here. | |
559 | * | |
560 | * If we find the object based on the offset passed in (vma->vm_pgoff will | |
561 | * contain the fake offset we created when the GTT map ioctl was called on | |
562 | * the object), we set up the driver fault handler so that any accesses | |
563 | * to the object can be trapped, to perform migration, GTT binding, surface | |
564 | * register allocation, or performance monitoring. | |
565 | */ | |
566 | int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma) | |
567 | { | |
568 | struct drm_file *priv = filp->private_data; | |
569 | struct drm_device *dev = priv->minor->dev; | |
570 | struct drm_gem_mm *mm = dev->mm_private; | |
f77d390c | 571 | struct drm_local_map *map = NULL; |
a2c0a97b JB |
572 | struct drm_gem_object *obj; |
573 | struct drm_hash_item *hash; | |
a2c0a97b JB |
574 | int ret = 0; |
575 | ||
576 | mutex_lock(&dev->struct_mutex); | |
577 | ||
578 | if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) { | |
579 | mutex_unlock(&dev->struct_mutex); | |
580 | return drm_mmap(filp, vma); | |
581 | } | |
582 | ||
583 | map = drm_hash_entry(hash, struct drm_map_list, hash)->map; | |
584 | if (!map || | |
585 | ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) { | |
586 | ret = -EPERM; | |
587 | goto out_unlock; | |
588 | } | |
589 | ||
590 | /* Check for valid size. */ | |
591 | if (map->size < vma->vm_end - vma->vm_start) { | |
592 | ret = -EINVAL; | |
593 | goto out_unlock; | |
594 | } | |
595 | ||
596 | obj = map->handle; | |
597 | if (!obj->dev->driver->gem_vm_ops) { | |
598 | ret = -EINVAL; | |
599 | goto out_unlock; | |
600 | } | |
601 | ||
602 | vma->vm_flags |= VM_RESERVED | VM_IO | VM_PFNMAP | VM_DONTEXPAND; | |
603 | vma->vm_ops = obj->dev->driver->gem_vm_ops; | |
604 | vma->vm_private_data = map->handle; | |
79cc304f | 605 | vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); |
a2c0a97b | 606 | |
ab00b3e5 JB |
607 | /* Take a ref for this mapping of the object, so that the fault |
608 | * handler can dereference the mmap offset's pointer to the object. | |
609 | * This reference is cleaned up by the corresponding vm_close | |
610 | * (which should happen whether the vma was created by this call, or | |
611 | * by a vm_open due to mremap or partial unmap or whatever). | |
612 | */ | |
613 | drm_gem_object_reference(obj); | |
614 | ||
a2c0a97b JB |
615 | vma->vm_file = filp; /* Needed for drm_vm_open() */ |
616 | drm_vm_open_locked(vma); | |
617 | ||
618 | out_unlock: | |
619 | mutex_unlock(&dev->struct_mutex); | |
620 | ||
621 | return ret; | |
622 | } | |
623 | EXPORT_SYMBOL(drm_gem_mmap); |