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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 <linux/shmem_fs.h>
38#include <linux/dma-buf.h>
39#include <drm/drmP.h>
40#include <drm/drm_vma_manager.h>
41#include <drm/drm_gem.h>
42#include "drm_internal.h"
43
44/** @file drm_gem.c
45 *
46 * This file provides some of the base ioctls and library routines for
47 * the graphics memory manager implemented by each device driver.
48 *
49 * Because various devices have different requirements in terms of
50 * synchronization and migration strategies, implementing that is left up to
51 * the driver, and all that the general API provides should be generic --
52 * allocating objects, reading/writing data with the cpu, freeing objects.
53 * Even there, platform-dependent optimizations for reading/writing data with
54 * the CPU mean we'll likely hook those out to driver-specific calls. However,
55 * the DRI2 implementation wants to have at least allocate/mmap be generic.
56 *
57 * The goal was to have swap-backed object allocation managed through
58 * struct file. However, file descriptors as handles to a struct file have
59 * two major failings:
60 * - Process limits prevent more than 1024 or so being used at a time by
61 * default.
62 * - Inability to allocate high fds will aggravate the X Server's select()
63 * handling, and likely that of many GL client applications as well.
64 *
65 * This led to a plan of using our own integer IDs (called handles, following
66 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
67 * ioctls. The objects themselves will still include the struct file so
68 * that we can transition to fds if the required kernel infrastructure shows
69 * up at a later date, and as our interface with shmfs for memory allocation.
70 */
71
72/*
73 * We make up offsets for buffer objects so we can recognize them at
74 * mmap time.
75 */
76
77/* pgoff in mmap is an unsigned long, so we need to make sure that
78 * the faked up offset will fit
79 */
80
81#if BITS_PER_LONG == 64
82#define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
83#define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
84#else
85#define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
86#define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
87#endif
88
89/**
90 * drm_gem_init - Initialize the GEM device fields
91 * @dev: drm_devic structure to initialize
92 */
93int
94drm_gem_init(struct drm_device *dev)
95{
96 struct drm_vma_offset_manager *vma_offset_manager;
97
98 mutex_init(&dev->object_name_lock);
99 idr_init(&dev->object_name_idr);
100
101 vma_offset_manager = kzalloc(sizeof(*vma_offset_manager), GFP_KERNEL);
102 if (!vma_offset_manager) {
103 DRM_ERROR("out of memory\n");
104 return -ENOMEM;
105 }
106
107 dev->vma_offset_manager = vma_offset_manager;
108 drm_vma_offset_manager_init(vma_offset_manager,
109 DRM_FILE_PAGE_OFFSET_START,
110 DRM_FILE_PAGE_OFFSET_SIZE);
111
112 return 0;
113}
114
115void
116drm_gem_destroy(struct drm_device *dev)
117{
118
119 drm_vma_offset_manager_destroy(dev->vma_offset_manager);
120 kfree(dev->vma_offset_manager);
121 dev->vma_offset_manager = NULL;
122}
123
124/**
125 * drm_gem_object_init - initialize an allocated shmem-backed GEM object
126 * @dev: drm_device the object should be initialized for
127 * @obj: drm_gem_object to initialize
128 * @size: object size
129 *
130 * Initialize an already allocated GEM object of the specified size with
131 * shmfs backing store.
132 */
133int drm_gem_object_init(struct drm_device *dev,
134 struct drm_gem_object *obj, size_t size)
135{
136 struct file *filp;
137
138 drm_gem_private_object_init(dev, obj, size);
139
140 filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
141 if (IS_ERR(filp))
142 return PTR_ERR(filp);
143
144 obj->filp = filp;
145
146 return 0;
147}
148EXPORT_SYMBOL(drm_gem_object_init);
149
150/**
151 * drm_gem_private_object_init - initialize an allocated private GEM object
152 * @dev: drm_device the object should be initialized for
153 * @obj: drm_gem_object to initialize
154 * @size: object size
155 *
156 * Initialize an already allocated GEM object of the specified size with
157 * no GEM provided backing store. Instead the caller is responsible for
158 * backing the object and handling it.
159 */
160void drm_gem_private_object_init(struct drm_device *dev,
161 struct drm_gem_object *obj, size_t size)
162{
163 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
164
165 obj->dev = dev;
166 obj->filp = NULL;
167
168 kref_init(&obj->refcount);
169 obj->handle_count = 0;
170 obj->size = size;
171 drm_vma_node_reset(&obj->vma_node);
172}
173EXPORT_SYMBOL(drm_gem_private_object_init);
174
175static void
176drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
177{
178 /*
179 * Note: obj->dma_buf can't disappear as long as we still hold a
180 * handle reference in obj->handle_count.
181 */
182 mutex_lock(&filp->prime.lock);
183 if (obj->dma_buf) {
184 drm_prime_remove_buf_handle_locked(&filp->prime,
185 obj->dma_buf);
186 }
187 mutex_unlock(&filp->prime.lock);
188}
189
190/**
191 * drm_gem_object_handle_free - release resources bound to userspace handles
192 * @obj: GEM object to clean up.
193 *
194 * Called after the last handle to the object has been closed
195 *
196 * Removes any name for the object. Note that this must be
197 * called before drm_gem_object_free or we'll be touching
198 * freed memory
199 */
200static void drm_gem_object_handle_free(struct drm_gem_object *obj)
201{
202 struct drm_device *dev = obj->dev;
203
204 /* Remove any name for this object */
205 if (obj->name) {
206 idr_remove(&dev->object_name_idr, obj->name);
207 obj->name = 0;
208 }
209}
210
211static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
212{
213 /* Unbreak the reference cycle if we have an exported dma_buf. */
214 if (obj->dma_buf) {
215 dma_buf_put(obj->dma_buf);
216 obj->dma_buf = NULL;
217 }
218}
219
220static void
221drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj)
222{
223 struct drm_device *dev = obj->dev;
224 bool final = false;
225
226 if (WARN_ON(obj->handle_count == 0))
227 return;
228
229 /*
230 * Must bump handle count first as this may be the last
231 * ref, in which case the object would disappear before we
232 * checked for a name
233 */
234
235 mutex_lock(&dev->object_name_lock);
236 if (--obj->handle_count == 0) {
237 drm_gem_object_handle_free(obj);
238 drm_gem_object_exported_dma_buf_free(obj);
239 final = true;
240 }
241 mutex_unlock(&dev->object_name_lock);
242
243 if (final)
244 drm_gem_object_unreference_unlocked(obj);
245}
246
247/*
248 * Called at device or object close to release the file's
249 * handle references on objects.
250 */
251static int
252drm_gem_object_release_handle(int id, void *ptr, void *data)
253{
254 struct drm_file *file_priv = data;
255 struct drm_gem_object *obj = ptr;
256 struct drm_device *dev = obj->dev;
257
258 if (drm_core_check_feature(dev, DRIVER_PRIME))
259 drm_gem_remove_prime_handles(obj, file_priv);
260 drm_vma_node_revoke(&obj->vma_node, file_priv->filp);
261
262 if (dev->driver->gem_close_object)
263 dev->driver->gem_close_object(obj, file_priv);
264
265 drm_gem_object_handle_unreference_unlocked(obj);
266
267 return 0;
268}
269
270/**
271 * drm_gem_handle_delete - deletes the given file-private handle
272 * @filp: drm file-private structure to use for the handle look up
273 * @handle: userspace handle to delete
274 *
275 * Removes the GEM handle from the @filp lookup table which has been added with
276 * drm_gem_handle_create(). If this is the last handle also cleans up linked
277 * resources like GEM names.
278 */
279int
280drm_gem_handle_delete(struct drm_file *filp, u32 handle)
281{
282 struct drm_device *dev;
283 struct drm_gem_object *obj;
284
285 /* This is gross. The idr system doesn't let us try a delete and
286 * return an error code. It just spews if you fail at deleting.
287 * So, we have to grab a lock around finding the object and then
288 * doing the delete on it and dropping the refcount, or the user
289 * could race us to double-decrement the refcount and cause a
290 * use-after-free later. Given the frequency of our handle lookups,
291 * we may want to use ida for number allocation and a hash table
292 * for the pointers, anyway.
293 */
294 spin_lock(&filp->table_lock);
295
296 /* Check if we currently have a reference on the object */
297 obj = idr_find(&filp->object_idr, handle);
298 if (obj == NULL) {
299 spin_unlock(&filp->table_lock);
300 return -EINVAL;
301 }
302 dev = obj->dev;
303
304 /* Release reference and decrement refcount. */
305 idr_remove(&filp->object_idr, handle);
306 spin_unlock(&filp->table_lock);
307
308 drm_gem_object_release_handle(handle, obj, filp);
309 return 0;
310}
311EXPORT_SYMBOL(drm_gem_handle_delete);
312
313/**
314 * drm_gem_dumb_destroy - dumb fb callback helper for gem based drivers
315 * @file: drm file-private structure to remove the dumb handle from
316 * @dev: corresponding drm_device
317 * @handle: the dumb handle to remove
318 *
319 * This implements the ->dumb_destroy kms driver callback for drivers which use
320 * gem to manage their backing storage.
321 */
322int drm_gem_dumb_destroy(struct drm_file *file,
323 struct drm_device *dev,
324 uint32_t handle)
325{
326 return drm_gem_handle_delete(file, handle);
327}
328EXPORT_SYMBOL(drm_gem_dumb_destroy);
329
330/**
331 * drm_gem_handle_create_tail - internal functions to create a handle
332 * @file_priv: drm file-private structure to register the handle for
333 * @obj: object to register
334 * @handlep: pointer to return the created handle to the caller
335 *
336 * This expects the dev->object_name_lock to be held already and will drop it
337 * before returning. Used to avoid races in establishing new handles when
338 * importing an object from either an flink name or a dma-buf.
339 *
340 * Handles must be release again through drm_gem_handle_delete(). This is done
341 * when userspace closes @file_priv for all attached handles, or through the
342 * GEM_CLOSE ioctl for individual handles.
343 */
344int
345drm_gem_handle_create_tail(struct drm_file *file_priv,
346 struct drm_gem_object *obj,
347 u32 *handlep)
348{
349 struct drm_device *dev = obj->dev;
350 u32 handle;
351 int ret;
352
353 WARN_ON(!mutex_is_locked(&dev->object_name_lock));
354 if (obj->handle_count++ == 0)
355 drm_gem_object_reference(obj);
356
357 /*
358 * Get the user-visible handle using idr. Preload and perform
359 * allocation under our spinlock.
360 */
361 idr_preload(GFP_KERNEL);
362 spin_lock(&file_priv->table_lock);
363
364 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
365
366 spin_unlock(&file_priv->table_lock);
367 idr_preload_end();
368
369 mutex_unlock(&dev->object_name_lock);
370 if (ret < 0)
371 goto err_unref;
372
373 handle = ret;
374
375 ret = drm_vma_node_allow(&obj->vma_node, file_priv->filp);
376 if (ret)
377 goto err_remove;
378
379 if (dev->driver->gem_open_object) {
380 ret = dev->driver->gem_open_object(obj, file_priv);
381 if (ret)
382 goto err_revoke;
383 }
384
385 *handlep = handle;
386 return 0;
387
388err_revoke:
389 drm_vma_node_revoke(&obj->vma_node, file_priv->filp);
390err_remove:
391 spin_lock(&file_priv->table_lock);
392 idr_remove(&file_priv->object_idr, handle);
393 spin_unlock(&file_priv->table_lock);
394err_unref:
395 drm_gem_object_handle_unreference_unlocked(obj);
396 return ret;
397}
398
399/**
400 * drm_gem_handle_create - create a gem handle for an object
401 * @file_priv: drm file-private structure to register the handle for
402 * @obj: object to register
403 * @handlep: pionter to return the created handle to the caller
404 *
405 * Create a handle for this object. This adds a handle reference
406 * to the object, which includes a regular reference count. Callers
407 * will likely want to dereference the object afterwards.
408 */
409int drm_gem_handle_create(struct drm_file *file_priv,
410 struct drm_gem_object *obj,
411 u32 *handlep)
412{
413 mutex_lock(&obj->dev->object_name_lock);
414
415 return drm_gem_handle_create_tail(file_priv, obj, handlep);
416}
417EXPORT_SYMBOL(drm_gem_handle_create);
418
419
420/**
421 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
422 * @obj: obj in question
423 *
424 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
425 */
426void
427drm_gem_free_mmap_offset(struct drm_gem_object *obj)
428{
429 struct drm_device *dev = obj->dev;
430
431 drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node);
432}
433EXPORT_SYMBOL(drm_gem_free_mmap_offset);
434
435/**
436 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object
437 * @obj: obj in question
438 * @size: the virtual size
439 *
440 * GEM memory mapping works by handing back to userspace a fake mmap offset
441 * it can use in a subsequent mmap(2) call. The DRM core code then looks
442 * up the object based on the offset and sets up the various memory mapping
443 * structures.
444 *
445 * This routine allocates and attaches a fake offset for @obj, in cases where
446 * the virtual size differs from the physical size (ie. obj->size). Otherwise
447 * just use drm_gem_create_mmap_offset().
448 */
449int
450drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
451{
452 struct drm_device *dev = obj->dev;
453
454 return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node,
455 size / PAGE_SIZE);
456}
457EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
458
459/**
460 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
461 * @obj: obj in question
462 *
463 * GEM memory mapping works by handing back to userspace a fake mmap offset
464 * it can use in a subsequent mmap(2) call. The DRM core code then looks
465 * up the object based on the offset and sets up the various memory mapping
466 * structures.
467 *
468 * This routine allocates and attaches a fake offset for @obj.
469 */
470int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
471{
472 return drm_gem_create_mmap_offset_size(obj, obj->size);
473}
474EXPORT_SYMBOL(drm_gem_create_mmap_offset);
475
476/**
477 * drm_gem_get_pages - helper to allocate backing pages for a GEM object
478 * from shmem
479 * @obj: obj in question
480 *
481 * This reads the page-array of the shmem-backing storage of the given gem
482 * object. An array of pages is returned. If a page is not allocated or
483 * swapped-out, this will allocate/swap-in the required pages. Note that the
484 * whole object is covered by the page-array and pinned in memory.
485 *
486 * Use drm_gem_put_pages() to release the array and unpin all pages.
487 *
488 * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()).
489 * If you require other GFP-masks, you have to do those allocations yourself.
490 *
491 * Note that you are not allowed to change gfp-zones during runtime. That is,
492 * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as
493 * set during initialization. If you have special zone constraints, set them
494 * after drm_gem_init_object() via mapping_set_gfp_mask(). shmem-core takes care
495 * to keep pages in the required zone during swap-in.
496 */
497struct page **drm_gem_get_pages(struct drm_gem_object *obj)
498{
499 struct address_space *mapping;
500 struct page *p, **pages;
501 int i, npages;
502
503 /* This is the shared memory object that backs the GEM resource */
504 mapping = file_inode(obj->filp)->i_mapping;
505
506 /* We already BUG_ON() for non-page-aligned sizes in
507 * drm_gem_object_init(), so we should never hit this unless
508 * driver author is doing something really wrong:
509 */
510 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
511
512 npages = obj->size >> PAGE_SHIFT;
513
514 pages = drm_malloc_ab(npages, sizeof(struct page *));
515 if (pages == NULL)
516 return ERR_PTR(-ENOMEM);
517
518 for (i = 0; i < npages; i++) {
519 p = shmem_read_mapping_page(mapping, i);
520 if (IS_ERR(p))
521 goto fail;
522 pages[i] = p;
523
524 /* Make sure shmem keeps __GFP_DMA32 allocated pages in the
525 * correct region during swapin. Note that this requires
526 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping)
527 * so shmem can relocate pages during swapin if required.
528 */
529 BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) &&
530 (page_to_pfn(p) >= 0x00100000UL));
531 }
532
533 return pages;
534
535fail:
536 while (i--)
537 put_page(pages[i]);
538
539 drm_free_large(pages);
540 return ERR_CAST(p);
541}
542EXPORT_SYMBOL(drm_gem_get_pages);
543
544/**
545 * drm_gem_put_pages - helper to free backing pages for a GEM object
546 * @obj: obj in question
547 * @pages: pages to free
548 * @dirty: if true, pages will be marked as dirty
549 * @accessed: if true, the pages will be marked as accessed
550 */
551void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
552 bool dirty, bool accessed)
553{
554 int i, npages;
555
556 /* We already BUG_ON() for non-page-aligned sizes in
557 * drm_gem_object_init(), so we should never hit this unless
558 * driver author is doing something really wrong:
559 */
560 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
561
562 npages = obj->size >> PAGE_SHIFT;
563
564 for (i = 0; i < npages; i++) {
565 if (dirty)
566 set_page_dirty(pages[i]);
567
568 if (accessed)
569 mark_page_accessed(pages[i]);
570
571 /* Undo the reference we took when populating the table */
572 put_page(pages[i]);
573 }
574
575 drm_free_large(pages);
576}
577EXPORT_SYMBOL(drm_gem_put_pages);
578
579/**
580 * drm_gem_object_lookup - look up a GEM object from it's handle
581 * @dev: DRM device
582 * @filp: DRM file private date
583 * @handle: userspace handle
584 *
585 * Returns:
586 *
587 * A reference to the object named by the handle if such exists on @filp, NULL
588 * otherwise.
589 */
590struct drm_gem_object *
591drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
592 u32 handle)
593{
594 struct drm_gem_object *obj;
595
596 spin_lock(&filp->table_lock);
597
598 /* Check if we currently have a reference on the object */
599 obj = idr_find(&filp->object_idr, handle);
600 if (obj == NULL) {
601 spin_unlock(&filp->table_lock);
602 return NULL;
603 }
604
605 drm_gem_object_reference(obj);
606
607 spin_unlock(&filp->table_lock);
608
609 return obj;
610}
611EXPORT_SYMBOL(drm_gem_object_lookup);
612
613/**
614 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
615 * @dev: drm_device
616 * @data: ioctl data
617 * @file_priv: drm file-private structure
618 *
619 * Releases the handle to an mm object.
620 */
621int
622drm_gem_close_ioctl(struct drm_device *dev, void *data,
623 struct drm_file *file_priv)
624{
625 struct drm_gem_close *args = data;
626 int ret;
627
628 if (!drm_core_check_feature(dev, DRIVER_GEM))
629 return -ENODEV;
630
631 ret = drm_gem_handle_delete(file_priv, args->handle);
632
633 return ret;
634}
635
636/**
637 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl
638 * @dev: drm_device
639 * @data: ioctl data
640 * @file_priv: drm file-private structure
641 *
642 * Create a global name for an object, returning the name.
643 *
644 * Note that the name does not hold a reference; when the object
645 * is freed, the name goes away.
646 */
647int
648drm_gem_flink_ioctl(struct drm_device *dev, void *data,
649 struct drm_file *file_priv)
650{
651 struct drm_gem_flink *args = data;
652 struct drm_gem_object *obj;
653 int ret;
654
655 if (!drm_core_check_feature(dev, DRIVER_GEM))
656 return -ENODEV;
657
658 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
659 if (obj == NULL)
660 return -ENOENT;
661
662 mutex_lock(&dev->object_name_lock);
663 /* prevent races with concurrent gem_close. */
664 if (obj->handle_count == 0) {
665 ret = -ENOENT;
666 goto err;
667 }
668
669 if (!obj->name) {
670 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_KERNEL);
671 if (ret < 0)
672 goto err;
673
674 obj->name = ret;
675 }
676
677 args->name = (uint64_t) obj->name;
678 ret = 0;
679
680err:
681 mutex_unlock(&dev->object_name_lock);
682 drm_gem_object_unreference_unlocked(obj);
683 return ret;
684}
685
686/**
687 * drm_gem_open - implementation of the GEM_OPEN ioctl
688 * @dev: drm_device
689 * @data: ioctl data
690 * @file_priv: drm file-private structure
691 *
692 * Open an object using the global name, returning a handle and the size.
693 *
694 * This handle (of course) holds a reference to the object, so the object
695 * will not go away until the handle is deleted.
696 */
697int
698drm_gem_open_ioctl(struct drm_device *dev, void *data,
699 struct drm_file *file_priv)
700{
701 struct drm_gem_open *args = data;
702 struct drm_gem_object *obj;
703 int ret;
704 u32 handle;
705
706 if (!drm_core_check_feature(dev, DRIVER_GEM))
707 return -ENODEV;
708
709 mutex_lock(&dev->object_name_lock);
710 obj = idr_find(&dev->object_name_idr, (int) args->name);
711 if (obj) {
712 drm_gem_object_reference(obj);
713 } else {
714 mutex_unlock(&dev->object_name_lock);
715 return -ENOENT;
716 }
717
718 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
719 ret = drm_gem_handle_create_tail(file_priv, obj, &handle);
720 drm_gem_object_unreference_unlocked(obj);
721 if (ret)
722 return ret;
723
724 args->handle = handle;
725 args->size = obj->size;
726
727 return 0;
728}
729
730/**
731 * gem_gem_open - initalizes GEM file-private structures at devnode open time
732 * @dev: drm_device which is being opened by userspace
733 * @file_private: drm file-private structure to set up
734 *
735 * Called at device open time, sets up the structure for handling refcounting
736 * of mm objects.
737 */
738void
739drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
740{
741 idr_init(&file_private->object_idr);
742 spin_lock_init(&file_private->table_lock);
743}
744
745/**
746 * drm_gem_release - release file-private GEM resources
747 * @dev: drm_device which is being closed by userspace
748 * @file_private: drm file-private structure to clean up
749 *
750 * Called at close time when the filp is going away.
751 *
752 * Releases any remaining references on objects by this filp.
753 */
754void
755drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
756{
757 idr_for_each(&file_private->object_idr,
758 &drm_gem_object_release_handle, file_private);
759 idr_destroy(&file_private->object_idr);
760}
761
762void
763drm_gem_object_release(struct drm_gem_object *obj)
764{
765 WARN_ON(obj->dma_buf);
766
767 if (obj->filp)
768 fput(obj->filp);
769
770 drm_gem_free_mmap_offset(obj);
771}
772EXPORT_SYMBOL(drm_gem_object_release);
773
774/**
775 * drm_gem_object_free - free a GEM object
776 * @kref: kref of the object to free
777 *
778 * Called after the last reference to the object has been lost.
779 * Must be called holding struct_ mutex
780 *
781 * Frees the object
782 */
783void
784drm_gem_object_free(struct kref *kref)
785{
786 struct drm_gem_object *obj =
787 container_of(kref, struct drm_gem_object, refcount);
788 struct drm_device *dev = obj->dev;
789
790 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
791
792 if (dev->driver->gem_free_object != NULL)
793 dev->driver->gem_free_object(obj);
794}
795EXPORT_SYMBOL(drm_gem_object_free);
796
797/**
798 * drm_gem_vm_open - vma->ops->open implementation for GEM
799 * @vma: VM area structure
800 *
801 * This function implements the #vm_operations_struct open() callback for GEM
802 * drivers. This must be used together with drm_gem_vm_close().
803 */
804void drm_gem_vm_open(struct vm_area_struct *vma)
805{
806 struct drm_gem_object *obj = vma->vm_private_data;
807
808 drm_gem_object_reference(obj);
809}
810EXPORT_SYMBOL(drm_gem_vm_open);
811
812/**
813 * drm_gem_vm_close - vma->ops->close implementation for GEM
814 * @vma: VM area structure
815 *
816 * This function implements the #vm_operations_struct close() callback for GEM
817 * drivers. This must be used together with drm_gem_vm_open().
818 */
819void drm_gem_vm_close(struct vm_area_struct *vma)
820{
821 struct drm_gem_object *obj = vma->vm_private_data;
822
823 drm_gem_object_unreference_unlocked(obj);
824}
825EXPORT_SYMBOL(drm_gem_vm_close);
826
827/**
828 * drm_gem_mmap_obj - memory map a GEM object
829 * @obj: the GEM object to map
830 * @obj_size: the object size to be mapped, in bytes
831 * @vma: VMA for the area to be mapped
832 *
833 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
834 * provided by the driver. Depending on their requirements, drivers can either
835 * provide a fault handler in their gem_vm_ops (in which case any accesses to
836 * the object will be trapped, to perform migration, GTT binding, surface
837 * register allocation, or performance monitoring), or mmap the buffer memory
838 * synchronously after calling drm_gem_mmap_obj.
839 *
840 * This function is mainly intended to implement the DMABUF mmap operation, when
841 * the GEM object is not looked up based on its fake offset. To implement the
842 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
843 *
844 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while
845 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So
846 * callers must verify access restrictions before calling this helper.
847 *
848 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
849 * size, or if no gem_vm_ops are provided.
850 */
851int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
852 struct vm_area_struct *vma)
853{
854 struct drm_device *dev = obj->dev;
855
856 /* Check for valid size. */
857 if (obj_size < vma->vm_end - vma->vm_start)
858 return -EINVAL;
859
860 if (!dev->driver->gem_vm_ops)
861 return -EINVAL;
862
863 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
864 vma->vm_ops = dev->driver->gem_vm_ops;
865 vma->vm_private_data = obj;
866 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
867
868 /* Take a ref for this mapping of the object, so that the fault
869 * handler can dereference the mmap offset's pointer to the object.
870 * This reference is cleaned up by the corresponding vm_close
871 * (which should happen whether the vma was created by this call, or
872 * by a vm_open due to mremap or partial unmap or whatever).
873 */
874 drm_gem_object_reference(obj);
875
876 return 0;
877}
878EXPORT_SYMBOL(drm_gem_mmap_obj);
879
880/**
881 * drm_gem_mmap - memory map routine for GEM objects
882 * @filp: DRM file pointer
883 * @vma: VMA for the area to be mapped
884 *
885 * If a driver supports GEM object mapping, mmap calls on the DRM file
886 * descriptor will end up here.
887 *
888 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
889 * contain the fake offset we created when the GTT map ioctl was called on
890 * the object) and map it with a call to drm_gem_mmap_obj().
891 *
892 * If the caller is not granted access to the buffer object, the mmap will fail
893 * with EACCES. Please see the vma manager for more information.
894 */
895int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
896{
897 struct drm_file *priv = filp->private_data;
898 struct drm_device *dev = priv->minor->dev;
899 struct drm_gem_object *obj = NULL;
900 struct drm_vma_offset_node *node;
901 int ret;
902
903 if (drm_device_is_unplugged(dev))
904 return -ENODEV;
905
906 drm_vma_offset_lock_lookup(dev->vma_offset_manager);
907 node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
908 vma->vm_pgoff,
909 vma_pages(vma));
910 if (likely(node)) {
911 obj = container_of(node, struct drm_gem_object, vma_node);
912 /*
913 * When the object is being freed, after it hits 0-refcnt it
914 * proceeds to tear down the object. In the process it will
915 * attempt to remove the VMA offset and so acquire this
916 * mgr->vm_lock. Therefore if we find an object with a 0-refcnt
917 * that matches our range, we know it is in the process of being
918 * destroyed and will be freed as soon as we release the lock -
919 * so we have to check for the 0-refcnted object and treat it as
920 * invalid.
921 */
922 if (!kref_get_unless_zero(&obj->refcount))
923 obj = NULL;
924 }
925 drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
926
927 if (!obj)
928 return -EINVAL;
929
930 if (!drm_vma_node_is_allowed(node, filp)) {
931 drm_gem_object_unreference_unlocked(obj);
932 return -EACCES;
933 }
934
935 ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT,
936 vma);
937
938 drm_gem_object_unreference_unlocked(obj);
939
940 return ret;
941}
942EXPORT_SYMBOL(drm_gem_mmap);
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 <linux/shmem_fs.h>
38#include <linux/dma-buf.h>
39#include <linux/dma-buf-map.h>
40#include <linux/mem_encrypt.h>
41#include <linux/pagevec.h>
42
43#include <drm/drm.h>
44#include <drm/drm_device.h>
45#include <drm/drm_drv.h>
46#include <drm/drm_file.h>
47#include <drm/drm_gem.h>
48#include <drm/drm_managed.h>
49#include <drm/drm_print.h>
50#include <drm/drm_vma_manager.h>
51
52#include "drm_internal.h"
53
54/** @file drm_gem.c
55 *
56 * This file provides some of the base ioctls and library routines for
57 * the graphics memory manager implemented by each device driver.
58 *
59 * Because various devices have different requirements in terms of
60 * synchronization and migration strategies, implementing that is left up to
61 * the driver, and all that the general API provides should be generic --
62 * allocating objects, reading/writing data with the cpu, freeing objects.
63 * Even there, platform-dependent optimizations for reading/writing data with
64 * the CPU mean we'll likely hook those out to driver-specific calls. However,
65 * the DRI2 implementation wants to have at least allocate/mmap be generic.
66 *
67 * The goal was to have swap-backed object allocation managed through
68 * struct file. However, file descriptors as handles to a struct file have
69 * two major failings:
70 * - Process limits prevent more than 1024 or so being used at a time by
71 * default.
72 * - Inability to allocate high fds will aggravate the X Server's select()
73 * handling, and likely that of many GL client applications as well.
74 *
75 * This led to a plan of using our own integer IDs (called handles, following
76 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
77 * ioctls. The objects themselves will still include the struct file so
78 * that we can transition to fds if the required kernel infrastructure shows
79 * up at a later date, and as our interface with shmfs for memory allocation.
80 */
81
82static void
83drm_gem_init_release(struct drm_device *dev, void *ptr)
84{
85 drm_vma_offset_manager_destroy(dev->vma_offset_manager);
86}
87
88/**
89 * drm_gem_init - Initialize the GEM device fields
90 * @dev: drm_devic structure to initialize
91 */
92int
93drm_gem_init(struct drm_device *dev)
94{
95 struct drm_vma_offset_manager *vma_offset_manager;
96
97 mutex_init(&dev->object_name_lock);
98 idr_init_base(&dev->object_name_idr, 1);
99
100 vma_offset_manager = drmm_kzalloc(dev, sizeof(*vma_offset_manager),
101 GFP_KERNEL);
102 if (!vma_offset_manager) {
103 DRM_ERROR("out of memory\n");
104 return -ENOMEM;
105 }
106
107 dev->vma_offset_manager = vma_offset_manager;
108 drm_vma_offset_manager_init(vma_offset_manager,
109 DRM_FILE_PAGE_OFFSET_START,
110 DRM_FILE_PAGE_OFFSET_SIZE);
111
112 return drmm_add_action(dev, drm_gem_init_release, NULL);
113}
114
115/**
116 * drm_gem_object_init - initialize an allocated shmem-backed GEM object
117 * @dev: drm_device the object should be initialized for
118 * @obj: drm_gem_object to initialize
119 * @size: object size
120 *
121 * Initialize an already allocated GEM object of the specified size with
122 * shmfs backing store.
123 */
124int drm_gem_object_init(struct drm_device *dev,
125 struct drm_gem_object *obj, size_t size)
126{
127 struct file *filp;
128
129 drm_gem_private_object_init(dev, obj, size);
130
131 filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
132 if (IS_ERR(filp))
133 return PTR_ERR(filp);
134
135 obj->filp = filp;
136
137 return 0;
138}
139EXPORT_SYMBOL(drm_gem_object_init);
140
141/**
142 * drm_gem_private_object_init - initialize an allocated private GEM object
143 * @dev: drm_device the object should be initialized for
144 * @obj: drm_gem_object to initialize
145 * @size: object size
146 *
147 * Initialize an already allocated GEM object of the specified size with
148 * no GEM provided backing store. Instead the caller is responsible for
149 * backing the object and handling it.
150 */
151void drm_gem_private_object_init(struct drm_device *dev,
152 struct drm_gem_object *obj, size_t size)
153{
154 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
155
156 obj->dev = dev;
157 obj->filp = NULL;
158
159 kref_init(&obj->refcount);
160 obj->handle_count = 0;
161 obj->size = size;
162 dma_resv_init(&obj->_resv);
163 if (!obj->resv)
164 obj->resv = &obj->_resv;
165
166 drm_vma_node_reset(&obj->vma_node);
167}
168EXPORT_SYMBOL(drm_gem_private_object_init);
169
170static void
171drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
172{
173 /*
174 * Note: obj->dma_buf can't disappear as long as we still hold a
175 * handle reference in obj->handle_count.
176 */
177 mutex_lock(&filp->prime.lock);
178 if (obj->dma_buf) {
179 drm_prime_remove_buf_handle_locked(&filp->prime,
180 obj->dma_buf);
181 }
182 mutex_unlock(&filp->prime.lock);
183}
184
185/**
186 * drm_gem_object_handle_free - release resources bound to userspace handles
187 * @obj: GEM object to clean up.
188 *
189 * Called after the last handle to the object has been closed
190 *
191 * Removes any name for the object. Note that this must be
192 * called before drm_gem_object_free or we'll be touching
193 * freed memory
194 */
195static void drm_gem_object_handle_free(struct drm_gem_object *obj)
196{
197 struct drm_device *dev = obj->dev;
198
199 /* Remove any name for this object */
200 if (obj->name) {
201 idr_remove(&dev->object_name_idr, obj->name);
202 obj->name = 0;
203 }
204}
205
206static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
207{
208 /* Unbreak the reference cycle if we have an exported dma_buf. */
209 if (obj->dma_buf) {
210 dma_buf_put(obj->dma_buf);
211 obj->dma_buf = NULL;
212 }
213}
214
215static void
216drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj)
217{
218 struct drm_device *dev = obj->dev;
219 bool final = false;
220
221 if (WARN_ON(READ_ONCE(obj->handle_count) == 0))
222 return;
223
224 /*
225 * Must bump handle count first as this may be the last
226 * ref, in which case the object would disappear before we
227 * checked for a name
228 */
229
230 mutex_lock(&dev->object_name_lock);
231 if (--obj->handle_count == 0) {
232 drm_gem_object_handle_free(obj);
233 drm_gem_object_exported_dma_buf_free(obj);
234 final = true;
235 }
236 mutex_unlock(&dev->object_name_lock);
237
238 if (final)
239 drm_gem_object_put(obj);
240}
241
242/*
243 * Called at device or object close to release the file's
244 * handle references on objects.
245 */
246static int
247drm_gem_object_release_handle(int id, void *ptr, void *data)
248{
249 struct drm_file *file_priv = data;
250 struct drm_gem_object *obj = ptr;
251
252 if (obj->funcs->close)
253 obj->funcs->close(obj, file_priv);
254
255 drm_gem_remove_prime_handles(obj, file_priv);
256 drm_vma_node_revoke(&obj->vma_node, file_priv);
257
258 drm_gem_object_handle_put_unlocked(obj);
259
260 return 0;
261}
262
263/**
264 * drm_gem_handle_delete - deletes the given file-private handle
265 * @filp: drm file-private structure to use for the handle look up
266 * @handle: userspace handle to delete
267 *
268 * Removes the GEM handle from the @filp lookup table which has been added with
269 * drm_gem_handle_create(). If this is the last handle also cleans up linked
270 * resources like GEM names.
271 */
272int
273drm_gem_handle_delete(struct drm_file *filp, u32 handle)
274{
275 struct drm_gem_object *obj;
276
277 spin_lock(&filp->table_lock);
278
279 /* Check if we currently have a reference on the object */
280 obj = idr_replace(&filp->object_idr, NULL, handle);
281 spin_unlock(&filp->table_lock);
282 if (IS_ERR_OR_NULL(obj))
283 return -EINVAL;
284
285 /* Release driver's reference and decrement refcount. */
286 drm_gem_object_release_handle(handle, obj, filp);
287
288 /* And finally make the handle available for future allocations. */
289 spin_lock(&filp->table_lock);
290 idr_remove(&filp->object_idr, handle);
291 spin_unlock(&filp->table_lock);
292
293 return 0;
294}
295EXPORT_SYMBOL(drm_gem_handle_delete);
296
297/**
298 * drm_gem_dumb_map_offset - return the fake mmap offset for a gem object
299 * @file: drm file-private structure containing the gem object
300 * @dev: corresponding drm_device
301 * @handle: gem object handle
302 * @offset: return location for the fake mmap offset
303 *
304 * This implements the &drm_driver.dumb_map_offset kms driver callback for
305 * drivers which use gem to manage their backing storage.
306 *
307 * Returns:
308 * 0 on success or a negative error code on failure.
309 */
310int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
311 u32 handle, u64 *offset)
312{
313 struct drm_gem_object *obj;
314 int ret;
315
316 obj = drm_gem_object_lookup(file, handle);
317 if (!obj)
318 return -ENOENT;
319
320 /* Don't allow imported objects to be mapped */
321 if (obj->import_attach) {
322 ret = -EINVAL;
323 goto out;
324 }
325
326 ret = drm_gem_create_mmap_offset(obj);
327 if (ret)
328 goto out;
329
330 *offset = drm_vma_node_offset_addr(&obj->vma_node);
331out:
332 drm_gem_object_put(obj);
333
334 return ret;
335}
336EXPORT_SYMBOL_GPL(drm_gem_dumb_map_offset);
337
338int drm_gem_dumb_destroy(struct drm_file *file,
339 struct drm_device *dev,
340 u32 handle)
341{
342 return drm_gem_handle_delete(file, handle);
343}
344
345/**
346 * drm_gem_handle_create_tail - internal functions to create a handle
347 * @file_priv: drm file-private structure to register the handle for
348 * @obj: object to register
349 * @handlep: pointer to return the created handle to the caller
350 *
351 * This expects the &drm_device.object_name_lock to be held already and will
352 * drop it before returning. Used to avoid races in establishing new handles
353 * when importing an object from either an flink name or a dma-buf.
354 *
355 * Handles must be release again through drm_gem_handle_delete(). This is done
356 * when userspace closes @file_priv for all attached handles, or through the
357 * GEM_CLOSE ioctl for individual handles.
358 */
359int
360drm_gem_handle_create_tail(struct drm_file *file_priv,
361 struct drm_gem_object *obj,
362 u32 *handlep)
363{
364 struct drm_device *dev = obj->dev;
365 u32 handle;
366 int ret;
367
368 WARN_ON(!mutex_is_locked(&dev->object_name_lock));
369 if (obj->handle_count++ == 0)
370 drm_gem_object_get(obj);
371
372 /*
373 * Get the user-visible handle using idr. Preload and perform
374 * allocation under our spinlock.
375 */
376 idr_preload(GFP_KERNEL);
377 spin_lock(&file_priv->table_lock);
378
379 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
380
381 spin_unlock(&file_priv->table_lock);
382 idr_preload_end();
383
384 mutex_unlock(&dev->object_name_lock);
385 if (ret < 0)
386 goto err_unref;
387
388 handle = ret;
389
390 ret = drm_vma_node_allow(&obj->vma_node, file_priv);
391 if (ret)
392 goto err_remove;
393
394 if (obj->funcs->open) {
395 ret = obj->funcs->open(obj, file_priv);
396 if (ret)
397 goto err_revoke;
398 }
399
400 *handlep = handle;
401 return 0;
402
403err_revoke:
404 drm_vma_node_revoke(&obj->vma_node, file_priv);
405err_remove:
406 spin_lock(&file_priv->table_lock);
407 idr_remove(&file_priv->object_idr, handle);
408 spin_unlock(&file_priv->table_lock);
409err_unref:
410 drm_gem_object_handle_put_unlocked(obj);
411 return ret;
412}
413
414/**
415 * drm_gem_handle_create - create a gem handle for an object
416 * @file_priv: drm file-private structure to register the handle for
417 * @obj: object to register
418 * @handlep: pointer to return the created handle to the caller
419 *
420 * Create a handle for this object. This adds a handle reference to the object,
421 * which includes a regular reference count. Callers will likely want to
422 * dereference the object afterwards.
423 *
424 * Since this publishes @obj to userspace it must be fully set up by this point,
425 * drivers must call this last in their buffer object creation callbacks.
426 */
427int drm_gem_handle_create(struct drm_file *file_priv,
428 struct drm_gem_object *obj,
429 u32 *handlep)
430{
431 mutex_lock(&obj->dev->object_name_lock);
432
433 return drm_gem_handle_create_tail(file_priv, obj, handlep);
434}
435EXPORT_SYMBOL(drm_gem_handle_create);
436
437
438/**
439 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
440 * @obj: obj in question
441 *
442 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
443 *
444 * Note that drm_gem_object_release() already calls this function, so drivers
445 * don't have to take care of releasing the mmap offset themselves when freeing
446 * the GEM object.
447 */
448void
449drm_gem_free_mmap_offset(struct drm_gem_object *obj)
450{
451 struct drm_device *dev = obj->dev;
452
453 drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node);
454}
455EXPORT_SYMBOL(drm_gem_free_mmap_offset);
456
457/**
458 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object
459 * @obj: obj in question
460 * @size: the virtual size
461 *
462 * GEM memory mapping works by handing back to userspace a fake mmap offset
463 * it can use in a subsequent mmap(2) call. The DRM core code then looks
464 * up the object based on the offset and sets up the various memory mapping
465 * structures.
466 *
467 * This routine allocates and attaches a fake offset for @obj, in cases where
468 * the virtual size differs from the physical size (ie. &drm_gem_object.size).
469 * Otherwise just use drm_gem_create_mmap_offset().
470 *
471 * This function is idempotent and handles an already allocated mmap offset
472 * transparently. Drivers do not need to check for this case.
473 */
474int
475drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
476{
477 struct drm_device *dev = obj->dev;
478
479 return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node,
480 size / PAGE_SIZE);
481}
482EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
483
484/**
485 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
486 * @obj: obj in question
487 *
488 * GEM memory mapping works by handing back to userspace a fake mmap offset
489 * it can use in a subsequent mmap(2) call. The DRM core code then looks
490 * up the object based on the offset and sets up the various memory mapping
491 * structures.
492 *
493 * This routine allocates and attaches a fake offset for @obj.
494 *
495 * Drivers can call drm_gem_free_mmap_offset() before freeing @obj to release
496 * the fake offset again.
497 */
498int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
499{
500 return drm_gem_create_mmap_offset_size(obj, obj->size);
501}
502EXPORT_SYMBOL(drm_gem_create_mmap_offset);
503
504/*
505 * Move pages to appropriate lru and release the pagevec, decrementing the
506 * ref count of those pages.
507 */
508static void drm_gem_check_release_pagevec(struct pagevec *pvec)
509{
510 check_move_unevictable_pages(pvec);
511 __pagevec_release(pvec);
512 cond_resched();
513}
514
515/**
516 * drm_gem_get_pages - helper to allocate backing pages for a GEM object
517 * from shmem
518 * @obj: obj in question
519 *
520 * This reads the page-array of the shmem-backing storage of the given gem
521 * object. An array of pages is returned. If a page is not allocated or
522 * swapped-out, this will allocate/swap-in the required pages. Note that the
523 * whole object is covered by the page-array and pinned in memory.
524 *
525 * Use drm_gem_put_pages() to release the array and unpin all pages.
526 *
527 * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()).
528 * If you require other GFP-masks, you have to do those allocations yourself.
529 *
530 * Note that you are not allowed to change gfp-zones during runtime. That is,
531 * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as
532 * set during initialization. If you have special zone constraints, set them
533 * after drm_gem_object_init() via mapping_set_gfp_mask(). shmem-core takes care
534 * to keep pages in the required zone during swap-in.
535 *
536 * This function is only valid on objects initialized with
537 * drm_gem_object_init(), but not for those initialized with
538 * drm_gem_private_object_init() only.
539 */
540struct page **drm_gem_get_pages(struct drm_gem_object *obj)
541{
542 struct address_space *mapping;
543 struct page *p, **pages;
544 struct pagevec pvec;
545 int i, npages;
546
547
548 if (WARN_ON(!obj->filp))
549 return ERR_PTR(-EINVAL);
550
551 /* This is the shared memory object that backs the GEM resource */
552 mapping = obj->filp->f_mapping;
553
554 /* We already BUG_ON() for non-page-aligned sizes in
555 * drm_gem_object_init(), so we should never hit this unless
556 * driver author is doing something really wrong:
557 */
558 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
559
560 npages = obj->size >> PAGE_SHIFT;
561
562 pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
563 if (pages == NULL)
564 return ERR_PTR(-ENOMEM);
565
566 mapping_set_unevictable(mapping);
567
568 for (i = 0; i < npages; i++) {
569 p = shmem_read_mapping_page(mapping, i);
570 if (IS_ERR(p))
571 goto fail;
572 pages[i] = p;
573
574 /* Make sure shmem keeps __GFP_DMA32 allocated pages in the
575 * correct region during swapin. Note that this requires
576 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping)
577 * so shmem can relocate pages during swapin if required.
578 */
579 BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) &&
580 (page_to_pfn(p) >= 0x00100000UL));
581 }
582
583 return pages;
584
585fail:
586 mapping_clear_unevictable(mapping);
587 pagevec_init(&pvec);
588 while (i--) {
589 if (!pagevec_add(&pvec, pages[i]))
590 drm_gem_check_release_pagevec(&pvec);
591 }
592 if (pagevec_count(&pvec))
593 drm_gem_check_release_pagevec(&pvec);
594
595 kvfree(pages);
596 return ERR_CAST(p);
597}
598EXPORT_SYMBOL(drm_gem_get_pages);
599
600/**
601 * drm_gem_put_pages - helper to free backing pages for a GEM object
602 * @obj: obj in question
603 * @pages: pages to free
604 * @dirty: if true, pages will be marked as dirty
605 * @accessed: if true, the pages will be marked as accessed
606 */
607void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
608 bool dirty, bool accessed)
609{
610 int i, npages;
611 struct address_space *mapping;
612 struct pagevec pvec;
613
614 mapping = file_inode(obj->filp)->i_mapping;
615 mapping_clear_unevictable(mapping);
616
617 /* We already BUG_ON() for non-page-aligned sizes in
618 * drm_gem_object_init(), so we should never hit this unless
619 * driver author is doing something really wrong:
620 */
621 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
622
623 npages = obj->size >> PAGE_SHIFT;
624
625 pagevec_init(&pvec);
626 for (i = 0; i < npages; i++) {
627 if (!pages[i])
628 continue;
629
630 if (dirty)
631 set_page_dirty(pages[i]);
632
633 if (accessed)
634 mark_page_accessed(pages[i]);
635
636 /* Undo the reference we took when populating the table */
637 if (!pagevec_add(&pvec, pages[i]))
638 drm_gem_check_release_pagevec(&pvec);
639 }
640 if (pagevec_count(&pvec))
641 drm_gem_check_release_pagevec(&pvec);
642
643 kvfree(pages);
644}
645EXPORT_SYMBOL(drm_gem_put_pages);
646
647static int objects_lookup(struct drm_file *filp, u32 *handle, int count,
648 struct drm_gem_object **objs)
649{
650 int i, ret = 0;
651 struct drm_gem_object *obj;
652
653 spin_lock(&filp->table_lock);
654
655 for (i = 0; i < count; i++) {
656 /* Check if we currently have a reference on the object */
657 obj = idr_find(&filp->object_idr, handle[i]);
658 if (!obj) {
659 ret = -ENOENT;
660 break;
661 }
662 drm_gem_object_get(obj);
663 objs[i] = obj;
664 }
665 spin_unlock(&filp->table_lock);
666
667 return ret;
668}
669
670/**
671 * drm_gem_objects_lookup - look up GEM objects from an array of handles
672 * @filp: DRM file private date
673 * @bo_handles: user pointer to array of userspace handle
674 * @count: size of handle array
675 * @objs_out: returned pointer to array of drm_gem_object pointers
676 *
677 * Takes an array of userspace handles and returns a newly allocated array of
678 * GEM objects.
679 *
680 * For a single handle lookup, use drm_gem_object_lookup().
681 *
682 * Returns:
683 *
684 * @objs filled in with GEM object pointers. Returned GEM objects need to be
685 * released with drm_gem_object_put(). -ENOENT is returned on a lookup
686 * failure. 0 is returned on success.
687 *
688 */
689int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
690 int count, struct drm_gem_object ***objs_out)
691{
692 int ret;
693 u32 *handles;
694 struct drm_gem_object **objs;
695
696 if (!count)
697 return 0;
698
699 objs = kvmalloc_array(count, sizeof(struct drm_gem_object *),
700 GFP_KERNEL | __GFP_ZERO);
701 if (!objs)
702 return -ENOMEM;
703
704 *objs_out = objs;
705
706 handles = kvmalloc_array(count, sizeof(u32), GFP_KERNEL);
707 if (!handles) {
708 ret = -ENOMEM;
709 goto out;
710 }
711
712 if (copy_from_user(handles, bo_handles, count * sizeof(u32))) {
713 ret = -EFAULT;
714 DRM_DEBUG("Failed to copy in GEM handles\n");
715 goto out;
716 }
717
718 ret = objects_lookup(filp, handles, count, objs);
719out:
720 kvfree(handles);
721 return ret;
722
723}
724EXPORT_SYMBOL(drm_gem_objects_lookup);
725
726/**
727 * drm_gem_object_lookup - look up a GEM object from its handle
728 * @filp: DRM file private date
729 * @handle: userspace handle
730 *
731 * Returns:
732 *
733 * A reference to the object named by the handle if such exists on @filp, NULL
734 * otherwise.
735 *
736 * If looking up an array of handles, use drm_gem_objects_lookup().
737 */
738struct drm_gem_object *
739drm_gem_object_lookup(struct drm_file *filp, u32 handle)
740{
741 struct drm_gem_object *obj = NULL;
742
743 objects_lookup(filp, &handle, 1, &obj);
744 return obj;
745}
746EXPORT_SYMBOL(drm_gem_object_lookup);
747
748/**
749 * drm_gem_dma_resv_wait - Wait on GEM object's reservation's objects
750 * shared and/or exclusive fences.
751 * @filep: DRM file private date
752 * @handle: userspace handle
753 * @wait_all: if true, wait on all fences, else wait on just exclusive fence
754 * @timeout: timeout value in jiffies or zero to return immediately
755 *
756 * Returns:
757 *
758 * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or
759 * greater than 0 on success.
760 */
761long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle,
762 bool wait_all, unsigned long timeout)
763{
764 long ret;
765 struct drm_gem_object *obj;
766
767 obj = drm_gem_object_lookup(filep, handle);
768 if (!obj) {
769 DRM_DEBUG("Failed to look up GEM BO %d\n", handle);
770 return -EINVAL;
771 }
772
773 ret = dma_resv_wait_timeout(obj->resv, wait_all, true, timeout);
774 if (ret == 0)
775 ret = -ETIME;
776 else if (ret > 0)
777 ret = 0;
778
779 drm_gem_object_put(obj);
780
781 return ret;
782}
783EXPORT_SYMBOL(drm_gem_dma_resv_wait);
784
785/**
786 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
787 * @dev: drm_device
788 * @data: ioctl data
789 * @file_priv: drm file-private structure
790 *
791 * Releases the handle to an mm object.
792 */
793int
794drm_gem_close_ioctl(struct drm_device *dev, void *data,
795 struct drm_file *file_priv)
796{
797 struct drm_gem_close *args = data;
798 int ret;
799
800 if (!drm_core_check_feature(dev, DRIVER_GEM))
801 return -EOPNOTSUPP;
802
803 ret = drm_gem_handle_delete(file_priv, args->handle);
804
805 return ret;
806}
807
808/**
809 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl
810 * @dev: drm_device
811 * @data: ioctl data
812 * @file_priv: drm file-private structure
813 *
814 * Create a global name for an object, returning the name.
815 *
816 * Note that the name does not hold a reference; when the object
817 * is freed, the name goes away.
818 */
819int
820drm_gem_flink_ioctl(struct drm_device *dev, void *data,
821 struct drm_file *file_priv)
822{
823 struct drm_gem_flink *args = data;
824 struct drm_gem_object *obj;
825 int ret;
826
827 if (!drm_core_check_feature(dev, DRIVER_GEM))
828 return -EOPNOTSUPP;
829
830 obj = drm_gem_object_lookup(file_priv, args->handle);
831 if (obj == NULL)
832 return -ENOENT;
833
834 mutex_lock(&dev->object_name_lock);
835 /* prevent races with concurrent gem_close. */
836 if (obj->handle_count == 0) {
837 ret = -ENOENT;
838 goto err;
839 }
840
841 if (!obj->name) {
842 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_KERNEL);
843 if (ret < 0)
844 goto err;
845
846 obj->name = ret;
847 }
848
849 args->name = (uint64_t) obj->name;
850 ret = 0;
851
852err:
853 mutex_unlock(&dev->object_name_lock);
854 drm_gem_object_put(obj);
855 return ret;
856}
857
858/**
859 * drm_gem_open_ioctl - implementation of the GEM_OPEN ioctl
860 * @dev: drm_device
861 * @data: ioctl data
862 * @file_priv: drm file-private structure
863 *
864 * Open an object using the global name, returning a handle and the size.
865 *
866 * This handle (of course) holds a reference to the object, so the object
867 * will not go away until the handle is deleted.
868 */
869int
870drm_gem_open_ioctl(struct drm_device *dev, void *data,
871 struct drm_file *file_priv)
872{
873 struct drm_gem_open *args = data;
874 struct drm_gem_object *obj;
875 int ret;
876 u32 handle;
877
878 if (!drm_core_check_feature(dev, DRIVER_GEM))
879 return -EOPNOTSUPP;
880
881 mutex_lock(&dev->object_name_lock);
882 obj = idr_find(&dev->object_name_idr, (int) args->name);
883 if (obj) {
884 drm_gem_object_get(obj);
885 } else {
886 mutex_unlock(&dev->object_name_lock);
887 return -ENOENT;
888 }
889
890 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
891 ret = drm_gem_handle_create_tail(file_priv, obj, &handle);
892 if (ret)
893 goto err;
894
895 args->handle = handle;
896 args->size = obj->size;
897
898err:
899 drm_gem_object_put(obj);
900 return ret;
901}
902
903/**
904 * drm_gem_open - initalizes GEM file-private structures at devnode open time
905 * @dev: drm_device which is being opened by userspace
906 * @file_private: drm file-private structure to set up
907 *
908 * Called at device open time, sets up the structure for handling refcounting
909 * of mm objects.
910 */
911void
912drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
913{
914 idr_init_base(&file_private->object_idr, 1);
915 spin_lock_init(&file_private->table_lock);
916}
917
918/**
919 * drm_gem_release - release file-private GEM resources
920 * @dev: drm_device which is being closed by userspace
921 * @file_private: drm file-private structure to clean up
922 *
923 * Called at close time when the filp is going away.
924 *
925 * Releases any remaining references on objects by this filp.
926 */
927void
928drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
929{
930 idr_for_each(&file_private->object_idr,
931 &drm_gem_object_release_handle, file_private);
932 idr_destroy(&file_private->object_idr);
933}
934
935/**
936 * drm_gem_object_release - release GEM buffer object resources
937 * @obj: GEM buffer object
938 *
939 * This releases any structures and resources used by @obj and is the invers of
940 * drm_gem_object_init().
941 */
942void
943drm_gem_object_release(struct drm_gem_object *obj)
944{
945 WARN_ON(obj->dma_buf);
946
947 if (obj->filp)
948 fput(obj->filp);
949
950 dma_resv_fini(&obj->_resv);
951 drm_gem_free_mmap_offset(obj);
952}
953EXPORT_SYMBOL(drm_gem_object_release);
954
955/**
956 * drm_gem_object_free - free a GEM object
957 * @kref: kref of the object to free
958 *
959 * Called after the last reference to the object has been lost.
960 *
961 * Frees the object
962 */
963void
964drm_gem_object_free(struct kref *kref)
965{
966 struct drm_gem_object *obj =
967 container_of(kref, struct drm_gem_object, refcount);
968
969 if (WARN_ON(!obj->funcs->free))
970 return;
971
972 obj->funcs->free(obj);
973}
974EXPORT_SYMBOL(drm_gem_object_free);
975
976/**
977 * drm_gem_object_put_locked - release a GEM buffer object reference
978 * @obj: GEM buffer object
979 *
980 * This releases a reference to @obj. Callers must hold the
981 * &drm_device.struct_mutex lock when calling this function, even when the
982 * driver doesn't use &drm_device.struct_mutex for anything.
983 *
984 * For drivers not encumbered with legacy locking use
985 * drm_gem_object_put() instead.
986 */
987void
988drm_gem_object_put_locked(struct drm_gem_object *obj)
989{
990 if (obj) {
991 WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
992
993 kref_put(&obj->refcount, drm_gem_object_free);
994 }
995}
996EXPORT_SYMBOL(drm_gem_object_put_locked);
997
998/**
999 * drm_gem_vm_open - vma->ops->open implementation for GEM
1000 * @vma: VM area structure
1001 *
1002 * This function implements the #vm_operations_struct open() callback for GEM
1003 * drivers. This must be used together with drm_gem_vm_close().
1004 */
1005void drm_gem_vm_open(struct vm_area_struct *vma)
1006{
1007 struct drm_gem_object *obj = vma->vm_private_data;
1008
1009 drm_gem_object_get(obj);
1010}
1011EXPORT_SYMBOL(drm_gem_vm_open);
1012
1013/**
1014 * drm_gem_vm_close - vma->ops->close implementation for GEM
1015 * @vma: VM area structure
1016 *
1017 * This function implements the #vm_operations_struct close() callback for GEM
1018 * drivers. This must be used together with drm_gem_vm_open().
1019 */
1020void drm_gem_vm_close(struct vm_area_struct *vma)
1021{
1022 struct drm_gem_object *obj = vma->vm_private_data;
1023
1024 drm_gem_object_put(obj);
1025}
1026EXPORT_SYMBOL(drm_gem_vm_close);
1027
1028/**
1029 * drm_gem_mmap_obj - memory map a GEM object
1030 * @obj: the GEM object to map
1031 * @obj_size: the object size to be mapped, in bytes
1032 * @vma: VMA for the area to be mapped
1033 *
1034 * Set up the VMA to prepare mapping of the GEM object using the GEM object's
1035 * vm_ops. Depending on their requirements, GEM objects can either
1036 * provide a fault handler in their vm_ops (in which case any accesses to
1037 * the object will be trapped, to perform migration, GTT binding, surface
1038 * register allocation, or performance monitoring), or mmap the buffer memory
1039 * synchronously after calling drm_gem_mmap_obj.
1040 *
1041 * This function is mainly intended to implement the DMABUF mmap operation, when
1042 * the GEM object is not looked up based on its fake offset. To implement the
1043 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
1044 *
1045 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while
1046 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So
1047 * callers must verify access restrictions before calling this helper.
1048 *
1049 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
1050 * size, or if no vm_ops are provided.
1051 */
1052int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
1053 struct vm_area_struct *vma)
1054{
1055 int ret;
1056
1057 /* Check for valid size. */
1058 if (obj_size < vma->vm_end - vma->vm_start)
1059 return -EINVAL;
1060
1061 /* Take a ref for this mapping of the object, so that the fault
1062 * handler can dereference the mmap offset's pointer to the object.
1063 * This reference is cleaned up by the corresponding vm_close
1064 * (which should happen whether the vma was created by this call, or
1065 * by a vm_open due to mremap or partial unmap or whatever).
1066 */
1067 drm_gem_object_get(obj);
1068
1069 vma->vm_private_data = obj;
1070 vma->vm_ops = obj->funcs->vm_ops;
1071
1072 if (obj->funcs->mmap) {
1073 ret = obj->funcs->mmap(obj, vma);
1074 if (ret)
1075 goto err_drm_gem_object_put;
1076 WARN_ON(!(vma->vm_flags & VM_DONTEXPAND));
1077 } else {
1078 if (!vma->vm_ops) {
1079 ret = -EINVAL;
1080 goto err_drm_gem_object_put;
1081 }
1082
1083 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
1084 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
1085 vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
1086 }
1087
1088 return 0;
1089
1090err_drm_gem_object_put:
1091 drm_gem_object_put(obj);
1092 return ret;
1093}
1094EXPORT_SYMBOL(drm_gem_mmap_obj);
1095
1096/**
1097 * drm_gem_mmap - memory map routine for GEM objects
1098 * @filp: DRM file pointer
1099 * @vma: VMA for the area to be mapped
1100 *
1101 * If a driver supports GEM object mapping, mmap calls on the DRM file
1102 * descriptor will end up here.
1103 *
1104 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
1105 * contain the fake offset we created when the GTT map ioctl was called on
1106 * the object) and map it with a call to drm_gem_mmap_obj().
1107 *
1108 * If the caller is not granted access to the buffer object, the mmap will fail
1109 * with EACCES. Please see the vma manager for more information.
1110 */
1111int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
1112{
1113 struct drm_file *priv = filp->private_data;
1114 struct drm_device *dev = priv->minor->dev;
1115 struct drm_gem_object *obj = NULL;
1116 struct drm_vma_offset_node *node;
1117 int ret;
1118
1119 if (drm_dev_is_unplugged(dev))
1120 return -ENODEV;
1121
1122 drm_vma_offset_lock_lookup(dev->vma_offset_manager);
1123 node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
1124 vma->vm_pgoff,
1125 vma_pages(vma));
1126 if (likely(node)) {
1127 obj = container_of(node, struct drm_gem_object, vma_node);
1128 /*
1129 * When the object is being freed, after it hits 0-refcnt it
1130 * proceeds to tear down the object. In the process it will
1131 * attempt to remove the VMA offset and so acquire this
1132 * mgr->vm_lock. Therefore if we find an object with a 0-refcnt
1133 * that matches our range, we know it is in the process of being
1134 * destroyed and will be freed as soon as we release the lock -
1135 * so we have to check for the 0-refcnted object and treat it as
1136 * invalid.
1137 */
1138 if (!kref_get_unless_zero(&obj->refcount))
1139 obj = NULL;
1140 }
1141 drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
1142
1143 if (!obj)
1144 return -EINVAL;
1145
1146 if (!drm_vma_node_is_allowed(node, priv)) {
1147 drm_gem_object_put(obj);
1148 return -EACCES;
1149 }
1150
1151 if (node->readonly) {
1152 if (vma->vm_flags & VM_WRITE) {
1153 drm_gem_object_put(obj);
1154 return -EINVAL;
1155 }
1156
1157 vma->vm_flags &= ~VM_MAYWRITE;
1158 }
1159
1160 ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT,
1161 vma);
1162
1163 drm_gem_object_put(obj);
1164
1165 return ret;
1166}
1167EXPORT_SYMBOL(drm_gem_mmap);
1168
1169void drm_gem_print_info(struct drm_printer *p, unsigned int indent,
1170 const struct drm_gem_object *obj)
1171{
1172 drm_printf_indent(p, indent, "name=%d\n", obj->name);
1173 drm_printf_indent(p, indent, "refcount=%u\n",
1174 kref_read(&obj->refcount));
1175 drm_printf_indent(p, indent, "start=%08lx\n",
1176 drm_vma_node_start(&obj->vma_node));
1177 drm_printf_indent(p, indent, "size=%zu\n", obj->size);
1178 drm_printf_indent(p, indent, "imported=%s\n",
1179 obj->import_attach ? "yes" : "no");
1180
1181 if (obj->funcs->print_info)
1182 obj->funcs->print_info(p, indent, obj);
1183}
1184
1185int drm_gem_pin(struct drm_gem_object *obj)
1186{
1187 if (obj->funcs->pin)
1188 return obj->funcs->pin(obj);
1189 else
1190 return 0;
1191}
1192
1193void drm_gem_unpin(struct drm_gem_object *obj)
1194{
1195 if (obj->funcs->unpin)
1196 obj->funcs->unpin(obj);
1197}
1198
1199int drm_gem_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
1200{
1201 int ret;
1202
1203 if (!obj->funcs->vmap)
1204 return -EOPNOTSUPP;
1205
1206 ret = obj->funcs->vmap(obj, map);
1207 if (ret)
1208 return ret;
1209 else if (dma_buf_map_is_null(map))
1210 return -ENOMEM;
1211
1212 return 0;
1213}
1214EXPORT_SYMBOL(drm_gem_vmap);
1215
1216void drm_gem_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
1217{
1218 if (dma_buf_map_is_null(map))
1219 return;
1220
1221 if (obj->funcs->vunmap)
1222 obj->funcs->vunmap(obj, map);
1223
1224 /* Always set the mapping to NULL. Callers may rely on this. */
1225 dma_buf_map_clear(map);
1226}
1227EXPORT_SYMBOL(drm_gem_vunmap);
1228
1229/**
1230 * drm_gem_lock_reservations - Sets up the ww context and acquires
1231 * the lock on an array of GEM objects.
1232 *
1233 * Once you've locked your reservations, you'll want to set up space
1234 * for your shared fences (if applicable), submit your job, then
1235 * drm_gem_unlock_reservations().
1236 *
1237 * @objs: drm_gem_objects to lock
1238 * @count: Number of objects in @objs
1239 * @acquire_ctx: struct ww_acquire_ctx that will be initialized as
1240 * part of tracking this set of locked reservations.
1241 */
1242int
1243drm_gem_lock_reservations(struct drm_gem_object **objs, int count,
1244 struct ww_acquire_ctx *acquire_ctx)
1245{
1246 int contended = -1;
1247 int i, ret;
1248
1249 ww_acquire_init(acquire_ctx, &reservation_ww_class);
1250
1251retry:
1252 if (contended != -1) {
1253 struct drm_gem_object *obj = objs[contended];
1254
1255 ret = dma_resv_lock_slow_interruptible(obj->resv,
1256 acquire_ctx);
1257 if (ret) {
1258 ww_acquire_done(acquire_ctx);
1259 return ret;
1260 }
1261 }
1262
1263 for (i = 0; i < count; i++) {
1264 if (i == contended)
1265 continue;
1266
1267 ret = dma_resv_lock_interruptible(objs[i]->resv,
1268 acquire_ctx);
1269 if (ret) {
1270 int j;
1271
1272 for (j = 0; j < i; j++)
1273 dma_resv_unlock(objs[j]->resv);
1274
1275 if (contended != -1 && contended >= i)
1276 dma_resv_unlock(objs[contended]->resv);
1277
1278 if (ret == -EDEADLK) {
1279 contended = i;
1280 goto retry;
1281 }
1282
1283 ww_acquire_done(acquire_ctx);
1284 return ret;
1285 }
1286 }
1287
1288 ww_acquire_done(acquire_ctx);
1289
1290 return 0;
1291}
1292EXPORT_SYMBOL(drm_gem_lock_reservations);
1293
1294void
1295drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
1296 struct ww_acquire_ctx *acquire_ctx)
1297{
1298 int i;
1299
1300 for (i = 0; i < count; i++)
1301 dma_resv_unlock(objs[i]->resv);
1302
1303 ww_acquire_fini(acquire_ctx);
1304}
1305EXPORT_SYMBOL(drm_gem_unlock_reservations);
1306
1307/**
1308 * drm_gem_fence_array_add - Adds the fence to an array of fences to be
1309 * waited on, deduplicating fences from the same context.
1310 *
1311 * @fence_array: array of dma_fence * for the job to block on.
1312 * @fence: the dma_fence to add to the list of dependencies.
1313 *
1314 * Returns:
1315 * 0 on success, or an error on failing to expand the array.
1316 */
1317int drm_gem_fence_array_add(struct xarray *fence_array,
1318 struct dma_fence *fence)
1319{
1320 struct dma_fence *entry;
1321 unsigned long index;
1322 u32 id = 0;
1323 int ret;
1324
1325 if (!fence)
1326 return 0;
1327
1328 /* Deduplicate if we already depend on a fence from the same context.
1329 * This lets the size of the array of deps scale with the number of
1330 * engines involved, rather than the number of BOs.
1331 */
1332 xa_for_each(fence_array, index, entry) {
1333 if (entry->context != fence->context)
1334 continue;
1335
1336 if (dma_fence_is_later(fence, entry)) {
1337 dma_fence_put(entry);
1338 xa_store(fence_array, index, fence, GFP_KERNEL);
1339 } else {
1340 dma_fence_put(fence);
1341 }
1342 return 0;
1343 }
1344
1345 ret = xa_alloc(fence_array, &id, fence, xa_limit_32b, GFP_KERNEL);
1346 if (ret != 0)
1347 dma_fence_put(fence);
1348
1349 return ret;
1350}
1351EXPORT_SYMBOL(drm_gem_fence_array_add);
1352
1353/**
1354 * drm_gem_fence_array_add_implicit - Adds the implicit dependencies tracked
1355 * in the GEM object's reservation object to an array of dma_fences for use in
1356 * scheduling a rendering job.
1357 *
1358 * This should be called after drm_gem_lock_reservations() on your array of
1359 * GEM objects used in the job but before updating the reservations with your
1360 * own fences.
1361 *
1362 * @fence_array: array of dma_fence * for the job to block on.
1363 * @obj: the gem object to add new dependencies from.
1364 * @write: whether the job might write the object (so we need to depend on
1365 * shared fences in the reservation object).
1366 */
1367int drm_gem_fence_array_add_implicit(struct xarray *fence_array,
1368 struct drm_gem_object *obj,
1369 bool write)
1370{
1371 int ret;
1372 struct dma_fence **fences;
1373 unsigned int i, fence_count;
1374
1375 if (!write) {
1376 struct dma_fence *fence =
1377 dma_resv_get_excl_unlocked(obj->resv);
1378
1379 return drm_gem_fence_array_add(fence_array, fence);
1380 }
1381
1382 ret = dma_resv_get_fences(obj->resv, NULL,
1383 &fence_count, &fences);
1384 if (ret || !fence_count)
1385 return ret;
1386
1387 for (i = 0; i < fence_count; i++) {
1388 ret = drm_gem_fence_array_add(fence_array, fences[i]);
1389 if (ret)
1390 break;
1391 }
1392
1393 for (; i < fence_count; i++)
1394 dma_fence_put(fences[i]);
1395 kfree(fences);
1396 return ret;
1397}
1398EXPORT_SYMBOL(drm_gem_fence_array_add_implicit);