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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> | |
37 | #include "drmP.h" | |
38 | ||
39 | /** @file drm_gem.c | |
40 | * | |
41 | * This file provides some of the base ioctls and library routines for | |
42 | * the graphics memory manager implemented by each device driver. | |
43 | * | |
44 | * Because various devices have different requirements in terms of | |
45 | * synchronization and migration strategies, implementing that is left up to | |
46 | * the driver, and all that the general API provides should be generic -- | |
47 | * allocating objects, reading/writing data with the cpu, freeing objects. | |
48 | * Even there, platform-dependent optimizations for reading/writing data with | |
49 | * the CPU mean we'll likely hook those out to driver-specific calls. However, | |
50 | * the DRI2 implementation wants to have at least allocate/mmap be generic. | |
51 | * | |
52 | * The goal was to have swap-backed object allocation managed through | |
53 | * struct file. However, file descriptors as handles to a struct file have | |
54 | * two major failings: | |
55 | * - Process limits prevent more than 1024 or so being used at a time by | |
56 | * default. | |
57 | * - Inability to allocate high fds will aggravate the X Server's select() | |
58 | * handling, and likely that of many GL client applications as well. | |
59 | * | |
60 | * This led to a plan of using our own integer IDs (called handles, following | |
61 | * DRM terminology) to mimic fds, and implement the fd syscalls we need as | |
62 | * ioctls. The objects themselves will still include the struct file so | |
63 | * that we can transition to fds if the required kernel infrastructure shows | |
64 | * up at a later date, and as our interface with shmfs for memory allocation. | |
65 | */ | |
66 | ||
a2c0a97b JB |
67 | /* |
68 | * We make up offsets for buffer objects so we can recognize them at | |
69 | * mmap time. | |
70 | */ | |
71 | #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1) | |
72 | #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16) | |
73 | ||
673a394b EA |
74 | /** |
75 | * Initialize the GEM device fields | |
76 | */ | |
77 | ||
78 | int | |
79 | drm_gem_init(struct drm_device *dev) | |
80 | { | |
a2c0a97b JB |
81 | struct drm_gem_mm *mm; |
82 | ||
673a394b EA |
83 | spin_lock_init(&dev->object_name_lock); |
84 | idr_init(&dev->object_name_idr); | |
85 | atomic_set(&dev->object_count, 0); | |
86 | atomic_set(&dev->object_memory, 0); | |
87 | atomic_set(&dev->pin_count, 0); | |
88 | atomic_set(&dev->pin_memory, 0); | |
89 | atomic_set(&dev->gtt_count, 0); | |
90 | atomic_set(&dev->gtt_memory, 0); | |
a2c0a97b JB |
91 | |
92 | mm = drm_calloc(1, sizeof(struct drm_gem_mm), DRM_MEM_MM); | |
93 | if (!mm) { | |
94 | DRM_ERROR("out of memory\n"); | |
95 | return -ENOMEM; | |
96 | } | |
97 | ||
98 | dev->mm_private = mm; | |
99 | ||
100 | if (drm_ht_create(&mm->offset_hash, 19)) { | |
101 | drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM); | |
102 | return -ENOMEM; | |
103 | } | |
104 | ||
105 | if (drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START, | |
106 | DRM_FILE_PAGE_OFFSET_SIZE)) { | |
107 | drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM); | |
108 | drm_ht_remove(&mm->offset_hash); | |
109 | return -ENOMEM; | |
110 | } | |
111 | ||
673a394b EA |
112 | return 0; |
113 | } | |
114 | ||
a2c0a97b JB |
115 | void |
116 | drm_gem_destroy(struct drm_device *dev) | |
117 | { | |
118 | struct drm_gem_mm *mm = dev->mm_private; | |
119 | ||
120 | drm_mm_takedown(&mm->offset_manager); | |
121 | drm_ht_remove(&mm->offset_hash); | |
122 | drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM); | |
123 | dev->mm_private = NULL; | |
124 | } | |
125 | ||
673a394b EA |
126 | /** |
127 | * Allocate a GEM object of the specified size with shmfs backing store | |
128 | */ | |
129 | struct drm_gem_object * | |
130 | drm_gem_object_alloc(struct drm_device *dev, size_t size) | |
131 | { | |
132 | struct drm_gem_object *obj; | |
133 | ||
134 | BUG_ON((size & (PAGE_SIZE - 1)) != 0); | |
135 | ||
136 | obj = kcalloc(1, sizeof(*obj), GFP_KERNEL); | |
137 | ||
138 | obj->dev = dev; | |
fc8744ad | 139 | obj->filp = shmem_file_setup("drm mm object", size, VM_NORESERVE); |
673a394b EA |
140 | if (IS_ERR(obj->filp)) { |
141 | kfree(obj); | |
142 | return NULL; | |
143 | } | |
144 | ||
145 | kref_init(&obj->refcount); | |
146 | kref_init(&obj->handlecount); | |
147 | obj->size = size; | |
148 | if (dev->driver->gem_init_object != NULL && | |
149 | dev->driver->gem_init_object(obj) != 0) { | |
150 | fput(obj->filp); | |
151 | kfree(obj); | |
152 | return NULL; | |
153 | } | |
154 | atomic_inc(&dev->object_count); | |
155 | atomic_add(obj->size, &dev->object_memory); | |
156 | return obj; | |
157 | } | |
158 | EXPORT_SYMBOL(drm_gem_object_alloc); | |
159 | ||
160 | /** | |
161 | * Removes the mapping from handle to filp for this object. | |
162 | */ | |
163 | static int | |
164 | drm_gem_handle_delete(struct drm_file *filp, int handle) | |
165 | { | |
166 | struct drm_device *dev; | |
167 | struct drm_gem_object *obj; | |
168 | ||
169 | /* This is gross. The idr system doesn't let us try a delete and | |
170 | * return an error code. It just spews if you fail at deleting. | |
171 | * So, we have to grab a lock around finding the object and then | |
172 | * doing the delete on it and dropping the refcount, or the user | |
173 | * could race us to double-decrement the refcount and cause a | |
174 | * use-after-free later. Given the frequency of our handle lookups, | |
175 | * we may want to use ida for number allocation and a hash table | |
176 | * for the pointers, anyway. | |
177 | */ | |
178 | spin_lock(&filp->table_lock); | |
179 | ||
180 | /* Check if we currently have a reference on the object */ | |
181 | obj = idr_find(&filp->object_idr, handle); | |
182 | if (obj == NULL) { | |
183 | spin_unlock(&filp->table_lock); | |
184 | return -EINVAL; | |
185 | } | |
186 | dev = obj->dev; | |
187 | ||
188 | /* Release reference and decrement refcount. */ | |
189 | idr_remove(&filp->object_idr, handle); | |
190 | spin_unlock(&filp->table_lock); | |
191 | ||
192 | mutex_lock(&dev->struct_mutex); | |
193 | drm_gem_object_handle_unreference(obj); | |
194 | mutex_unlock(&dev->struct_mutex); | |
195 | ||
196 | return 0; | |
197 | } | |
198 | ||
199 | /** | |
200 | * Create a handle for this object. This adds a handle reference | |
201 | * to the object, which includes a regular reference count. Callers | |
202 | * will likely want to dereference the object afterwards. | |
203 | */ | |
204 | int | |
205 | drm_gem_handle_create(struct drm_file *file_priv, | |
206 | struct drm_gem_object *obj, | |
207 | int *handlep) | |
208 | { | |
209 | int ret; | |
210 | ||
211 | /* | |
212 | * Get the user-visible handle using idr. | |
213 | */ | |
214 | again: | |
215 | /* ensure there is space available to allocate a handle */ | |
216 | if (idr_pre_get(&file_priv->object_idr, GFP_KERNEL) == 0) | |
217 | return -ENOMEM; | |
218 | ||
219 | /* do the allocation under our spinlock */ | |
220 | spin_lock(&file_priv->table_lock); | |
221 | ret = idr_get_new_above(&file_priv->object_idr, obj, 1, handlep); | |
222 | spin_unlock(&file_priv->table_lock); | |
223 | if (ret == -EAGAIN) | |
224 | goto again; | |
225 | ||
226 | if (ret != 0) | |
227 | return ret; | |
228 | ||
229 | drm_gem_object_handle_reference(obj); | |
230 | return 0; | |
231 | } | |
232 | EXPORT_SYMBOL(drm_gem_handle_create); | |
233 | ||
234 | /** Returns a reference to the object named by the handle. */ | |
235 | struct drm_gem_object * | |
236 | drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp, | |
237 | int handle) | |
238 | { | |
239 | struct drm_gem_object *obj; | |
240 | ||
241 | spin_lock(&filp->table_lock); | |
242 | ||
243 | /* Check if we currently have a reference on the object */ | |
244 | obj = idr_find(&filp->object_idr, handle); | |
245 | if (obj == NULL) { | |
246 | spin_unlock(&filp->table_lock); | |
247 | return NULL; | |
248 | } | |
249 | ||
250 | drm_gem_object_reference(obj); | |
251 | ||
252 | spin_unlock(&filp->table_lock); | |
253 | ||
254 | return obj; | |
255 | } | |
256 | EXPORT_SYMBOL(drm_gem_object_lookup); | |
257 | ||
258 | /** | |
259 | * Releases the handle to an mm object. | |
260 | */ | |
261 | int | |
262 | drm_gem_close_ioctl(struct drm_device *dev, void *data, | |
263 | struct drm_file *file_priv) | |
264 | { | |
265 | struct drm_gem_close *args = data; | |
266 | int ret; | |
267 | ||
268 | if (!(dev->driver->driver_features & DRIVER_GEM)) | |
269 | return -ENODEV; | |
270 | ||
271 | ret = drm_gem_handle_delete(file_priv, args->handle); | |
272 | ||
273 | return ret; | |
274 | } | |
275 | ||
276 | /** | |
277 | * Create a global name for an object, returning the name. | |
278 | * | |
279 | * Note that the name does not hold a reference; when the object | |
280 | * is freed, the name goes away. | |
281 | */ | |
282 | int | |
283 | drm_gem_flink_ioctl(struct drm_device *dev, void *data, | |
284 | struct drm_file *file_priv) | |
285 | { | |
286 | struct drm_gem_flink *args = data; | |
287 | struct drm_gem_object *obj; | |
288 | int ret; | |
289 | ||
290 | if (!(dev->driver->driver_features & DRIVER_GEM)) | |
291 | return -ENODEV; | |
292 | ||
293 | obj = drm_gem_object_lookup(dev, file_priv, args->handle); | |
294 | if (obj == NULL) | |
d4e7b898 | 295 | return -EBADF; |
673a394b EA |
296 | |
297 | again: | |
298 | if (idr_pre_get(&dev->object_name_idr, GFP_KERNEL) == 0) | |
299 | return -ENOMEM; | |
300 | ||
301 | spin_lock(&dev->object_name_lock); | |
302 | if (obj->name) { | |
d4e7b898 | 303 | args->name = obj->name; |
673a394b | 304 | spin_unlock(&dev->object_name_lock); |
d4e7b898 | 305 | return 0; |
673a394b EA |
306 | } |
307 | ret = idr_get_new_above(&dev->object_name_idr, obj, 1, | |
308 | &obj->name); | |
309 | spin_unlock(&dev->object_name_lock); | |
310 | if (ret == -EAGAIN) | |
311 | goto again; | |
312 | ||
313 | if (ret != 0) { | |
314 | mutex_lock(&dev->struct_mutex); | |
315 | drm_gem_object_unreference(obj); | |
316 | mutex_unlock(&dev->struct_mutex); | |
317 | return ret; | |
318 | } | |
319 | ||
320 | /* | |
321 | * Leave the reference from the lookup around as the | |
322 | * name table now holds one | |
323 | */ | |
324 | args->name = (uint64_t) obj->name; | |
325 | ||
326 | return 0; | |
327 | } | |
328 | ||
329 | /** | |
330 | * Open an object using the global name, returning a handle and the size. | |
331 | * | |
332 | * This handle (of course) holds a reference to the object, so the object | |
333 | * will not go away until the handle is deleted. | |
334 | */ | |
335 | int | |
336 | drm_gem_open_ioctl(struct drm_device *dev, void *data, | |
337 | struct drm_file *file_priv) | |
338 | { | |
339 | struct drm_gem_open *args = data; | |
340 | struct drm_gem_object *obj; | |
341 | int ret; | |
342 | int handle; | |
343 | ||
344 | if (!(dev->driver->driver_features & DRIVER_GEM)) | |
345 | return -ENODEV; | |
346 | ||
347 | spin_lock(&dev->object_name_lock); | |
348 | obj = idr_find(&dev->object_name_idr, (int) args->name); | |
349 | if (obj) | |
350 | drm_gem_object_reference(obj); | |
351 | spin_unlock(&dev->object_name_lock); | |
352 | if (!obj) | |
353 | return -ENOENT; | |
354 | ||
355 | ret = drm_gem_handle_create(file_priv, obj, &handle); | |
356 | mutex_lock(&dev->struct_mutex); | |
357 | drm_gem_object_unreference(obj); | |
358 | mutex_unlock(&dev->struct_mutex); | |
359 | if (ret) | |
360 | return ret; | |
361 | ||
362 | args->handle = handle; | |
363 | args->size = obj->size; | |
364 | ||
365 | return 0; | |
366 | } | |
367 | ||
368 | /** | |
369 | * Called at device open time, sets up the structure for handling refcounting | |
370 | * of mm objects. | |
371 | */ | |
372 | void | |
373 | drm_gem_open(struct drm_device *dev, struct drm_file *file_private) | |
374 | { | |
375 | idr_init(&file_private->object_idr); | |
376 | spin_lock_init(&file_private->table_lock); | |
377 | } | |
378 | ||
379 | /** | |
380 | * Called at device close to release the file's | |
381 | * handle references on objects. | |
382 | */ | |
383 | static int | |
384 | drm_gem_object_release_handle(int id, void *ptr, void *data) | |
385 | { | |
386 | struct drm_gem_object *obj = ptr; | |
387 | ||
388 | drm_gem_object_handle_unreference(obj); | |
389 | ||
390 | return 0; | |
391 | } | |
392 | ||
393 | /** | |
394 | * Called at close time when the filp is going away. | |
395 | * | |
396 | * Releases any remaining references on objects by this filp. | |
397 | */ | |
398 | void | |
399 | drm_gem_release(struct drm_device *dev, struct drm_file *file_private) | |
400 | { | |
401 | mutex_lock(&dev->struct_mutex); | |
402 | idr_for_each(&file_private->object_idr, | |
403 | &drm_gem_object_release_handle, NULL); | |
404 | ||
405 | idr_destroy(&file_private->object_idr); | |
406 | mutex_unlock(&dev->struct_mutex); | |
407 | } | |
408 | ||
409 | /** | |
410 | * Called after the last reference to the object has been lost. | |
411 | * | |
412 | * Frees the object | |
413 | */ | |
414 | void | |
415 | drm_gem_object_free(struct kref *kref) | |
416 | { | |
417 | struct drm_gem_object *obj = (struct drm_gem_object *) kref; | |
418 | struct drm_device *dev = obj->dev; | |
419 | ||
420 | BUG_ON(!mutex_is_locked(&dev->struct_mutex)); | |
421 | ||
422 | if (dev->driver->gem_free_object != NULL) | |
423 | dev->driver->gem_free_object(obj); | |
424 | ||
425 | fput(obj->filp); | |
426 | atomic_dec(&dev->object_count); | |
427 | atomic_sub(obj->size, &dev->object_memory); | |
428 | kfree(obj); | |
429 | } | |
430 | EXPORT_SYMBOL(drm_gem_object_free); | |
431 | ||
432 | /** | |
433 | * Called after the last handle to the object has been closed | |
434 | * | |
435 | * Removes any name for the object. Note that this must be | |
436 | * called before drm_gem_object_free or we'll be touching | |
437 | * freed memory | |
438 | */ | |
439 | void | |
440 | drm_gem_object_handle_free(struct kref *kref) | |
441 | { | |
442 | struct drm_gem_object *obj = container_of(kref, | |
443 | struct drm_gem_object, | |
444 | handlecount); | |
445 | struct drm_device *dev = obj->dev; | |
446 | ||
447 | /* Remove any name for this object */ | |
448 | spin_lock(&dev->object_name_lock); | |
449 | if (obj->name) { | |
450 | idr_remove(&dev->object_name_idr, obj->name); | |
451 | spin_unlock(&dev->object_name_lock); | |
452 | /* | |
453 | * The object name held a reference to this object, drop | |
454 | * that now. | |
455 | */ | |
456 | drm_gem_object_unreference(obj); | |
457 | } else | |
458 | spin_unlock(&dev->object_name_lock); | |
459 | ||
460 | } | |
461 | EXPORT_SYMBOL(drm_gem_object_handle_free); | |
462 | ||
a2c0a97b JB |
463 | /** |
464 | * drm_gem_mmap - memory map routine for GEM objects | |
465 | * @filp: DRM file pointer | |
466 | * @vma: VMA for the area to be mapped | |
467 | * | |
468 | * If a driver supports GEM object mapping, mmap calls on the DRM file | |
469 | * descriptor will end up here. | |
470 | * | |
471 | * If we find the object based on the offset passed in (vma->vm_pgoff will | |
472 | * contain the fake offset we created when the GTT map ioctl was called on | |
473 | * the object), we set up the driver fault handler so that any accesses | |
474 | * to the object can be trapped, to perform migration, GTT binding, surface | |
475 | * register allocation, or performance monitoring. | |
476 | */ | |
477 | int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma) | |
478 | { | |
479 | struct drm_file *priv = filp->private_data; | |
480 | struct drm_device *dev = priv->minor->dev; | |
481 | struct drm_gem_mm *mm = dev->mm_private; | |
482 | struct drm_map *map = NULL; | |
483 | struct drm_gem_object *obj; | |
484 | struct drm_hash_item *hash; | |
485 | unsigned long prot; | |
486 | int ret = 0; | |
487 | ||
488 | mutex_lock(&dev->struct_mutex); | |
489 | ||
490 | if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) { | |
491 | mutex_unlock(&dev->struct_mutex); | |
492 | return drm_mmap(filp, vma); | |
493 | } | |
494 | ||
495 | map = drm_hash_entry(hash, struct drm_map_list, hash)->map; | |
496 | if (!map || | |
497 | ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) { | |
498 | ret = -EPERM; | |
499 | goto out_unlock; | |
500 | } | |
501 | ||
502 | /* Check for valid size. */ | |
503 | if (map->size < vma->vm_end - vma->vm_start) { | |
504 | ret = -EINVAL; | |
505 | goto out_unlock; | |
506 | } | |
507 | ||
508 | obj = map->handle; | |
509 | if (!obj->dev->driver->gem_vm_ops) { | |
510 | ret = -EINVAL; | |
511 | goto out_unlock; | |
512 | } | |
513 | ||
514 | vma->vm_flags |= VM_RESERVED | VM_IO | VM_PFNMAP | VM_DONTEXPAND; | |
515 | vma->vm_ops = obj->dev->driver->gem_vm_ops; | |
516 | vma->vm_private_data = map->handle; | |
517 | /* FIXME: use pgprot_writecombine when available */ | |
518 | prot = pgprot_val(vma->vm_page_prot); | |
ae14dc05 | 519 | #ifdef CONFIG_X86 |
a2c0a97b | 520 | prot |= _PAGE_CACHE_WC; |
ae14dc05 | 521 | #endif |
a2c0a97b JB |
522 | vma->vm_page_prot = __pgprot(prot); |
523 | ||
524 | vma->vm_file = filp; /* Needed for drm_vm_open() */ | |
525 | drm_vm_open_locked(vma); | |
526 | ||
527 | out_unlock: | |
528 | mutex_unlock(&dev->struct_mutex); | |
529 | ||
530 | return ret; | |
531 | } | |
532 | EXPORT_SYMBOL(drm_gem_mmap); |