2 * Copyright © 2008 Intel Corporation
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:
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
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
24 * Eric Anholt <eric@anholt.net>
28 #include <linux/types.h>
29 #include <linux/slab.h>
31 #include <linux/uaccess.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/mem_encrypt.h>
41 #include <drm/drm_vma_manager.h>
42 #include <drm/drm_gem.h>
43 #include "drm_internal.h"
47 * This file provides some of the base ioctls and library routines for
48 * the graphics memory manager implemented by each device driver.
50 * Because various devices have different requirements in terms of
51 * synchronization and migration strategies, implementing that is left up to
52 * the driver, and all that the general API provides should be generic --
53 * allocating objects, reading/writing data with the cpu, freeing objects.
54 * Even there, platform-dependent optimizations for reading/writing data with
55 * the CPU mean we'll likely hook those out to driver-specific calls. However,
56 * the DRI2 implementation wants to have at least allocate/mmap be generic.
58 * The goal was to have swap-backed object allocation managed through
59 * struct file. However, file descriptors as handles to a struct file have
61 * - Process limits prevent more than 1024 or so being used at a time by
63 * - Inability to allocate high fds will aggravate the X Server's select()
64 * handling, and likely that of many GL client applications as well.
66 * This led to a plan of using our own integer IDs (called handles, following
67 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
68 * ioctls. The objects themselves will still include the struct file so
69 * that we can transition to fds if the required kernel infrastructure shows
70 * up at a later date, and as our interface with shmfs for memory allocation.
74 * We make up offsets for buffer objects so we can recognize them at
78 /* pgoff in mmap is an unsigned long, so we need to make sure that
79 * the faked up offset will fit
82 #if BITS_PER_LONG == 64
83 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
84 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
86 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
87 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
91 * drm_gem_init - Initialize the GEM device fields
92 * @dev: drm_devic structure to initialize
95 drm_gem_init(struct drm_device
*dev
)
97 struct drm_vma_offset_manager
*vma_offset_manager
;
99 mutex_init(&dev
->object_name_lock
);
100 idr_init(&dev
->object_name_idr
);
102 vma_offset_manager
= kzalloc(sizeof(*vma_offset_manager
), GFP_KERNEL
);
103 if (!vma_offset_manager
) {
104 DRM_ERROR("out of memory\n");
108 dev
->vma_offset_manager
= vma_offset_manager
;
109 drm_vma_offset_manager_init(vma_offset_manager
,
110 DRM_FILE_PAGE_OFFSET_START
,
111 DRM_FILE_PAGE_OFFSET_SIZE
);
117 drm_gem_destroy(struct drm_device
*dev
)
120 drm_vma_offset_manager_destroy(dev
->vma_offset_manager
);
121 kfree(dev
->vma_offset_manager
);
122 dev
->vma_offset_manager
= NULL
;
126 * drm_gem_object_init - initialize an allocated shmem-backed GEM object
127 * @dev: drm_device the object should be initialized for
128 * @obj: drm_gem_object to initialize
131 * Initialize an already allocated GEM object of the specified size with
132 * shmfs backing store.
134 int drm_gem_object_init(struct drm_device
*dev
,
135 struct drm_gem_object
*obj
, size_t size
)
139 drm_gem_private_object_init(dev
, obj
, size
);
141 filp
= shmem_file_setup("drm mm object", size
, VM_NORESERVE
);
143 return PTR_ERR(filp
);
149 EXPORT_SYMBOL(drm_gem_object_init
);
152 * drm_gem_private_object_init - initialize an allocated private GEM object
153 * @dev: drm_device the object should be initialized for
154 * @obj: drm_gem_object to initialize
157 * Initialize an already allocated GEM object of the specified size with
158 * no GEM provided backing store. Instead the caller is responsible for
159 * backing the object and handling it.
161 void drm_gem_private_object_init(struct drm_device
*dev
,
162 struct drm_gem_object
*obj
, size_t size
)
164 BUG_ON((size
& (PAGE_SIZE
- 1)) != 0);
169 kref_init(&obj
->refcount
);
170 obj
->handle_count
= 0;
172 drm_vma_node_reset(&obj
->vma_node
);
174 EXPORT_SYMBOL(drm_gem_private_object_init
);
177 drm_gem_remove_prime_handles(struct drm_gem_object
*obj
, struct drm_file
*filp
)
180 * Note: obj->dma_buf can't disappear as long as we still hold a
181 * handle reference in obj->handle_count.
183 mutex_lock(&filp
->prime
.lock
);
185 drm_prime_remove_buf_handle_locked(&filp
->prime
,
188 mutex_unlock(&filp
->prime
.lock
);
192 * drm_gem_object_handle_free - release resources bound to userspace handles
193 * @obj: GEM object to clean up.
195 * Called after the last handle to the object has been closed
197 * Removes any name for the object. Note that this must be
198 * called before drm_gem_object_free or we'll be touching
201 static void drm_gem_object_handle_free(struct drm_gem_object
*obj
)
203 struct drm_device
*dev
= obj
->dev
;
205 /* Remove any name for this object */
207 idr_remove(&dev
->object_name_idr
, obj
->name
);
212 static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object
*obj
)
214 /* Unbreak the reference cycle if we have an exported dma_buf. */
216 dma_buf_put(obj
->dma_buf
);
222 drm_gem_object_handle_put_unlocked(struct drm_gem_object
*obj
)
224 struct drm_device
*dev
= obj
->dev
;
227 if (WARN_ON(obj
->handle_count
== 0))
231 * Must bump handle count first as this may be the last
232 * ref, in which case the object would disappear before we
236 mutex_lock(&dev
->object_name_lock
);
237 if (--obj
->handle_count
== 0) {
238 drm_gem_object_handle_free(obj
);
239 drm_gem_object_exported_dma_buf_free(obj
);
242 mutex_unlock(&dev
->object_name_lock
);
245 drm_gem_object_put_unlocked(obj
);
249 * Called at device or object close to release the file's
250 * handle references on objects.
253 drm_gem_object_release_handle(int id
, void *ptr
, void *data
)
255 struct drm_file
*file_priv
= data
;
256 struct drm_gem_object
*obj
= ptr
;
257 struct drm_device
*dev
= obj
->dev
;
259 if (dev
->driver
->gem_close_object
)
260 dev
->driver
->gem_close_object(obj
, file_priv
);
262 if (drm_core_check_feature(dev
, DRIVER_PRIME
))
263 drm_gem_remove_prime_handles(obj
, file_priv
);
264 drm_vma_node_revoke(&obj
->vma_node
, file_priv
);
266 drm_gem_object_handle_put_unlocked(obj
);
272 * drm_gem_handle_delete - deletes the given file-private handle
273 * @filp: drm file-private structure to use for the handle look up
274 * @handle: userspace handle to delete
276 * Removes the GEM handle from the @filp lookup table which has been added with
277 * drm_gem_handle_create(). If this is the last handle also cleans up linked
278 * resources like GEM names.
281 drm_gem_handle_delete(struct drm_file
*filp
, u32 handle
)
283 struct drm_gem_object
*obj
;
285 spin_lock(&filp
->table_lock
);
287 /* Check if we currently have a reference on the object */
288 obj
= idr_replace(&filp
->object_idr
, NULL
, handle
);
289 spin_unlock(&filp
->table_lock
);
290 if (IS_ERR_OR_NULL(obj
))
293 /* Release driver's reference and decrement refcount. */
294 drm_gem_object_release_handle(handle
, obj
, filp
);
296 /* And finally make the handle available for future allocations. */
297 spin_lock(&filp
->table_lock
);
298 idr_remove(&filp
->object_idr
, handle
);
299 spin_unlock(&filp
->table_lock
);
303 EXPORT_SYMBOL(drm_gem_handle_delete
);
306 * drm_gem_dumb_map_offset - return the fake mmap offset for a gem object
307 * @file: drm file-private structure containing the gem object
308 * @dev: corresponding drm_device
309 * @handle: gem object handle
310 * @offset: return location for the fake mmap offset
312 * This implements the &drm_driver.dumb_map_offset kms driver callback for
313 * drivers which use gem to manage their backing storage.
316 * 0 on success or a negative error code on failure.
318 int drm_gem_dumb_map_offset(struct drm_file
*file
, struct drm_device
*dev
,
319 u32 handle
, u64
*offset
)
321 struct drm_gem_object
*obj
;
324 obj
= drm_gem_object_lookup(file
, handle
);
328 /* Don't allow imported objects to be mapped */
329 if (obj
->import_attach
) {
334 ret
= drm_gem_create_mmap_offset(obj
);
338 *offset
= drm_vma_node_offset_addr(&obj
->vma_node
);
340 drm_gem_object_put_unlocked(obj
);
344 EXPORT_SYMBOL_GPL(drm_gem_dumb_map_offset
);
347 * drm_gem_dumb_destroy - dumb fb callback helper for gem based drivers
348 * @file: drm file-private structure to remove the dumb handle from
349 * @dev: corresponding drm_device
350 * @handle: the dumb handle to remove
352 * This implements the &drm_driver.dumb_destroy kms driver callback for drivers
353 * which use gem to manage their backing storage.
355 int drm_gem_dumb_destroy(struct drm_file
*file
,
356 struct drm_device
*dev
,
359 return drm_gem_handle_delete(file
, handle
);
361 EXPORT_SYMBOL(drm_gem_dumb_destroy
);
364 * drm_gem_handle_create_tail - internal functions to create a handle
365 * @file_priv: drm file-private structure to register the handle for
366 * @obj: object to register
367 * @handlep: pointer to return the created handle to the caller
369 * This expects the &drm_device.object_name_lock to be held already and will
370 * drop it before returning. Used to avoid races in establishing new handles
371 * when importing an object from either an flink name or a dma-buf.
373 * Handles must be release again through drm_gem_handle_delete(). This is done
374 * when userspace closes @file_priv for all attached handles, or through the
375 * GEM_CLOSE ioctl for individual handles.
378 drm_gem_handle_create_tail(struct drm_file
*file_priv
,
379 struct drm_gem_object
*obj
,
382 struct drm_device
*dev
= obj
->dev
;
386 WARN_ON(!mutex_is_locked(&dev
->object_name_lock
));
387 if (obj
->handle_count
++ == 0)
388 drm_gem_object_get(obj
);
391 * Get the user-visible handle using idr. Preload and perform
392 * allocation under our spinlock.
394 idr_preload(GFP_KERNEL
);
395 spin_lock(&file_priv
->table_lock
);
397 ret
= idr_alloc(&file_priv
->object_idr
, obj
, 1, 0, GFP_NOWAIT
);
399 spin_unlock(&file_priv
->table_lock
);
402 mutex_unlock(&dev
->object_name_lock
);
408 ret
= drm_vma_node_allow(&obj
->vma_node
, file_priv
);
412 if (dev
->driver
->gem_open_object
) {
413 ret
= dev
->driver
->gem_open_object(obj
, file_priv
);
422 drm_vma_node_revoke(&obj
->vma_node
, file_priv
);
424 spin_lock(&file_priv
->table_lock
);
425 idr_remove(&file_priv
->object_idr
, handle
);
426 spin_unlock(&file_priv
->table_lock
);
428 drm_gem_object_handle_put_unlocked(obj
);
433 * drm_gem_handle_create - create a gem handle for an object
434 * @file_priv: drm file-private structure to register the handle for
435 * @obj: object to register
436 * @handlep: pionter to return the created handle to the caller
438 * Create a handle for this object. This adds a handle reference
439 * to the object, which includes a regular reference count. Callers
440 * will likely want to dereference the object afterwards.
442 int drm_gem_handle_create(struct drm_file
*file_priv
,
443 struct drm_gem_object
*obj
,
446 mutex_lock(&obj
->dev
->object_name_lock
);
448 return drm_gem_handle_create_tail(file_priv
, obj
, handlep
);
450 EXPORT_SYMBOL(drm_gem_handle_create
);
454 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
455 * @obj: obj in question
457 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
459 * Note that drm_gem_object_release() already calls this function, so drivers
460 * don't have to take care of releasing the mmap offset themselves when freeing
464 drm_gem_free_mmap_offset(struct drm_gem_object
*obj
)
466 struct drm_device
*dev
= obj
->dev
;
468 drm_vma_offset_remove(dev
->vma_offset_manager
, &obj
->vma_node
);
470 EXPORT_SYMBOL(drm_gem_free_mmap_offset
);
473 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object
474 * @obj: obj in question
475 * @size: the virtual size
477 * GEM memory mapping works by handing back to userspace a fake mmap offset
478 * it can use in a subsequent mmap(2) call. The DRM core code then looks
479 * up the object based on the offset and sets up the various memory mapping
482 * This routine allocates and attaches a fake offset for @obj, in cases where
483 * the virtual size differs from the physical size (ie. &drm_gem_object.size).
484 * Otherwise just use drm_gem_create_mmap_offset().
486 * This function is idempotent and handles an already allocated mmap offset
487 * transparently. Drivers do not need to check for this case.
490 drm_gem_create_mmap_offset_size(struct drm_gem_object
*obj
, size_t size
)
492 struct drm_device
*dev
= obj
->dev
;
494 return drm_vma_offset_add(dev
->vma_offset_manager
, &obj
->vma_node
,
497 EXPORT_SYMBOL(drm_gem_create_mmap_offset_size
);
500 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
501 * @obj: obj in question
503 * GEM memory mapping works by handing back to userspace a fake mmap offset
504 * it can use in a subsequent mmap(2) call. The DRM core code then looks
505 * up the object based on the offset and sets up the various memory mapping
508 * This routine allocates and attaches a fake offset for @obj.
510 * Drivers can call drm_gem_free_mmap_offset() before freeing @obj to release
511 * the fake offset again.
513 int drm_gem_create_mmap_offset(struct drm_gem_object
*obj
)
515 return drm_gem_create_mmap_offset_size(obj
, obj
->size
);
517 EXPORT_SYMBOL(drm_gem_create_mmap_offset
);
520 * drm_gem_get_pages - helper to allocate backing pages for a GEM object
522 * @obj: obj in question
524 * This reads the page-array of the shmem-backing storage of the given gem
525 * object. An array of pages is returned. If a page is not allocated or
526 * swapped-out, this will allocate/swap-in the required pages. Note that the
527 * whole object is covered by the page-array and pinned in memory.
529 * Use drm_gem_put_pages() to release the array and unpin all pages.
531 * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()).
532 * If you require other GFP-masks, you have to do those allocations yourself.
534 * Note that you are not allowed to change gfp-zones during runtime. That is,
535 * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as
536 * set during initialization. If you have special zone constraints, set them
537 * after drm_gem_init_object() via mapping_set_gfp_mask(). shmem-core takes care
538 * to keep pages in the required zone during swap-in.
540 struct page
**drm_gem_get_pages(struct drm_gem_object
*obj
)
542 struct address_space
*mapping
;
543 struct page
*p
, **pages
;
546 /* This is the shared memory object that backs the GEM resource */
547 mapping
= obj
->filp
->f_mapping
;
549 /* We already BUG_ON() for non-page-aligned sizes in
550 * drm_gem_object_init(), so we should never hit this unless
551 * driver author is doing something really wrong:
553 WARN_ON((obj
->size
& (PAGE_SIZE
- 1)) != 0);
555 npages
= obj
->size
>> PAGE_SHIFT
;
557 pages
= kvmalloc_array(npages
, sizeof(struct page
*), GFP_KERNEL
);
559 return ERR_PTR(-ENOMEM
);
561 for (i
= 0; i
< npages
; i
++) {
562 p
= shmem_read_mapping_page(mapping
, i
);
567 /* Make sure shmem keeps __GFP_DMA32 allocated pages in the
568 * correct region during swapin. Note that this requires
569 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping)
570 * so shmem can relocate pages during swapin if required.
572 BUG_ON(mapping_gfp_constraint(mapping
, __GFP_DMA32
) &&
573 (page_to_pfn(p
) >= 0x00100000UL
));
585 EXPORT_SYMBOL(drm_gem_get_pages
);
588 * drm_gem_put_pages - helper to free backing pages for a GEM object
589 * @obj: obj in question
590 * @pages: pages to free
591 * @dirty: if true, pages will be marked as dirty
592 * @accessed: if true, the pages will be marked as accessed
594 void drm_gem_put_pages(struct drm_gem_object
*obj
, struct page
**pages
,
595 bool dirty
, bool accessed
)
599 /* We already BUG_ON() for non-page-aligned sizes in
600 * drm_gem_object_init(), so we should never hit this unless
601 * driver author is doing something really wrong:
603 WARN_ON((obj
->size
& (PAGE_SIZE
- 1)) != 0);
605 npages
= obj
->size
>> PAGE_SHIFT
;
607 for (i
= 0; i
< npages
; i
++) {
609 set_page_dirty(pages
[i
]);
612 mark_page_accessed(pages
[i
]);
614 /* Undo the reference we took when populating the table */
620 EXPORT_SYMBOL(drm_gem_put_pages
);
623 * drm_gem_object_lookup - look up a GEM object from it's handle
624 * @filp: DRM file private date
625 * @handle: userspace handle
629 * A reference to the object named by the handle if such exists on @filp, NULL
632 struct drm_gem_object
*
633 drm_gem_object_lookup(struct drm_file
*filp
, u32 handle
)
635 struct drm_gem_object
*obj
;
637 spin_lock(&filp
->table_lock
);
639 /* Check if we currently have a reference on the object */
640 obj
= idr_find(&filp
->object_idr
, handle
);
642 drm_gem_object_get(obj
);
644 spin_unlock(&filp
->table_lock
);
648 EXPORT_SYMBOL(drm_gem_object_lookup
);
651 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
654 * @file_priv: drm file-private structure
656 * Releases the handle to an mm object.
659 drm_gem_close_ioctl(struct drm_device
*dev
, void *data
,
660 struct drm_file
*file_priv
)
662 struct drm_gem_close
*args
= data
;
665 if (!drm_core_check_feature(dev
, DRIVER_GEM
))
668 ret
= drm_gem_handle_delete(file_priv
, args
->handle
);
674 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl
677 * @file_priv: drm file-private structure
679 * Create a global name for an object, returning the name.
681 * Note that the name does not hold a reference; when the object
682 * is freed, the name goes away.
685 drm_gem_flink_ioctl(struct drm_device
*dev
, void *data
,
686 struct drm_file
*file_priv
)
688 struct drm_gem_flink
*args
= data
;
689 struct drm_gem_object
*obj
;
692 if (!drm_core_check_feature(dev
, DRIVER_GEM
))
695 obj
= drm_gem_object_lookup(file_priv
, args
->handle
);
699 mutex_lock(&dev
->object_name_lock
);
700 /* prevent races with concurrent gem_close. */
701 if (obj
->handle_count
== 0) {
707 ret
= idr_alloc(&dev
->object_name_idr
, obj
, 1, 0, GFP_KERNEL
);
714 args
->name
= (uint64_t) obj
->name
;
718 mutex_unlock(&dev
->object_name_lock
);
719 drm_gem_object_put_unlocked(obj
);
724 * drm_gem_open - implementation of the GEM_OPEN ioctl
727 * @file_priv: drm file-private structure
729 * Open an object using the global name, returning a handle and the size.
731 * This handle (of course) holds a reference to the object, so the object
732 * will not go away until the handle is deleted.
735 drm_gem_open_ioctl(struct drm_device
*dev
, void *data
,
736 struct drm_file
*file_priv
)
738 struct drm_gem_open
*args
= data
;
739 struct drm_gem_object
*obj
;
743 if (!drm_core_check_feature(dev
, DRIVER_GEM
))
746 mutex_lock(&dev
->object_name_lock
);
747 obj
= idr_find(&dev
->object_name_idr
, (int) args
->name
);
749 drm_gem_object_get(obj
);
751 mutex_unlock(&dev
->object_name_lock
);
755 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
756 ret
= drm_gem_handle_create_tail(file_priv
, obj
, &handle
);
757 drm_gem_object_put_unlocked(obj
);
761 args
->handle
= handle
;
762 args
->size
= obj
->size
;
768 * gem_gem_open - initalizes GEM file-private structures at devnode open time
769 * @dev: drm_device which is being opened by userspace
770 * @file_private: drm file-private structure to set up
772 * Called at device open time, sets up the structure for handling refcounting
776 drm_gem_open(struct drm_device
*dev
, struct drm_file
*file_private
)
778 idr_init(&file_private
->object_idr
);
779 spin_lock_init(&file_private
->table_lock
);
783 * drm_gem_release - release file-private GEM resources
784 * @dev: drm_device which is being closed by userspace
785 * @file_private: drm file-private structure to clean up
787 * Called at close time when the filp is going away.
789 * Releases any remaining references on objects by this filp.
792 drm_gem_release(struct drm_device
*dev
, struct drm_file
*file_private
)
794 idr_for_each(&file_private
->object_idr
,
795 &drm_gem_object_release_handle
, file_private
);
796 idr_destroy(&file_private
->object_idr
);
800 * drm_gem_object_release - release GEM buffer object resources
801 * @obj: GEM buffer object
803 * This releases any structures and resources used by @obj and is the invers of
804 * drm_gem_object_init().
807 drm_gem_object_release(struct drm_gem_object
*obj
)
809 WARN_ON(obj
->dma_buf
);
814 drm_gem_free_mmap_offset(obj
);
816 EXPORT_SYMBOL(drm_gem_object_release
);
819 * drm_gem_object_free - free a GEM object
820 * @kref: kref of the object to free
822 * Called after the last reference to the object has been lost.
823 * Must be called holding &drm_device.struct_mutex.
828 drm_gem_object_free(struct kref
*kref
)
830 struct drm_gem_object
*obj
=
831 container_of(kref
, struct drm_gem_object
, refcount
);
832 struct drm_device
*dev
= obj
->dev
;
834 if (dev
->driver
->gem_free_object_unlocked
) {
835 dev
->driver
->gem_free_object_unlocked(obj
);
836 } else if (dev
->driver
->gem_free_object
) {
837 WARN_ON(!mutex_is_locked(&dev
->struct_mutex
));
839 dev
->driver
->gem_free_object(obj
);
842 EXPORT_SYMBOL(drm_gem_object_free
);
845 * drm_gem_object_put_unlocked - drop a GEM buffer object reference
846 * @obj: GEM buffer object
848 * This releases a reference to @obj. Callers must not hold the
849 * &drm_device.struct_mutex lock when calling this function.
851 * See also __drm_gem_object_put().
854 drm_gem_object_put_unlocked(struct drm_gem_object
*obj
)
856 struct drm_device
*dev
;
863 if (dev
->driver
->gem_free_object_unlocked
) {
864 kref_put(&obj
->refcount
, drm_gem_object_free
);
866 might_lock(&dev
->struct_mutex
);
867 if (kref_put_mutex(&obj
->refcount
, drm_gem_object_free
,
869 mutex_unlock(&dev
->struct_mutex
);
872 EXPORT_SYMBOL(drm_gem_object_put_unlocked
);
875 * drm_gem_object_put - release a GEM buffer object reference
876 * @obj: GEM buffer object
878 * This releases a reference to @obj. Callers must hold the
879 * &drm_device.struct_mutex lock when calling this function, even when the
880 * driver doesn't use &drm_device.struct_mutex for anything.
882 * For drivers not encumbered with legacy locking use
883 * drm_gem_object_put_unlocked() instead.
886 drm_gem_object_put(struct drm_gem_object
*obj
)
889 WARN_ON(!mutex_is_locked(&obj
->dev
->struct_mutex
));
891 kref_put(&obj
->refcount
, drm_gem_object_free
);
894 EXPORT_SYMBOL(drm_gem_object_put
);
897 * drm_gem_vm_open - vma->ops->open implementation for GEM
898 * @vma: VM area structure
900 * This function implements the #vm_operations_struct open() callback for GEM
901 * drivers. This must be used together with drm_gem_vm_close().
903 void drm_gem_vm_open(struct vm_area_struct
*vma
)
905 struct drm_gem_object
*obj
= vma
->vm_private_data
;
907 drm_gem_object_get(obj
);
909 EXPORT_SYMBOL(drm_gem_vm_open
);
912 * drm_gem_vm_close - vma->ops->close implementation for GEM
913 * @vma: VM area structure
915 * This function implements the #vm_operations_struct close() callback for GEM
916 * drivers. This must be used together with drm_gem_vm_open().
918 void drm_gem_vm_close(struct vm_area_struct
*vma
)
920 struct drm_gem_object
*obj
= vma
->vm_private_data
;
922 drm_gem_object_put_unlocked(obj
);
924 EXPORT_SYMBOL(drm_gem_vm_close
);
927 * drm_gem_mmap_obj - memory map a GEM object
928 * @obj: the GEM object to map
929 * @obj_size: the object size to be mapped, in bytes
930 * @vma: VMA for the area to be mapped
932 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
933 * provided by the driver. Depending on their requirements, drivers can either
934 * provide a fault handler in their gem_vm_ops (in which case any accesses to
935 * the object will be trapped, to perform migration, GTT binding, surface
936 * register allocation, or performance monitoring), or mmap the buffer memory
937 * synchronously after calling drm_gem_mmap_obj.
939 * This function is mainly intended to implement the DMABUF mmap operation, when
940 * the GEM object is not looked up based on its fake offset. To implement the
941 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
943 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while
944 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So
945 * callers must verify access restrictions before calling this helper.
947 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
948 * size, or if no gem_vm_ops are provided.
950 int drm_gem_mmap_obj(struct drm_gem_object
*obj
, unsigned long obj_size
,
951 struct vm_area_struct
*vma
)
953 struct drm_device
*dev
= obj
->dev
;
955 /* Check for valid size. */
956 if (obj_size
< vma
->vm_end
- vma
->vm_start
)
959 if (!dev
->driver
->gem_vm_ops
)
962 vma
->vm_flags
|= VM_IO
| VM_PFNMAP
| VM_DONTEXPAND
| VM_DONTDUMP
;
963 vma
->vm_ops
= dev
->driver
->gem_vm_ops
;
964 vma
->vm_private_data
= obj
;
965 vma
->vm_page_prot
= pgprot_writecombine(vm_get_page_prot(vma
->vm_flags
));
966 vma
->vm_page_prot
= pgprot_decrypted(vma
->vm_page_prot
);
968 /* Take a ref for this mapping of the object, so that the fault
969 * handler can dereference the mmap offset's pointer to the object.
970 * This reference is cleaned up by the corresponding vm_close
971 * (which should happen whether the vma was created by this call, or
972 * by a vm_open due to mremap or partial unmap or whatever).
974 drm_gem_object_get(obj
);
978 EXPORT_SYMBOL(drm_gem_mmap_obj
);
981 * drm_gem_mmap - memory map routine for GEM objects
982 * @filp: DRM file pointer
983 * @vma: VMA for the area to be mapped
985 * If a driver supports GEM object mapping, mmap calls on the DRM file
986 * descriptor will end up here.
988 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
989 * contain the fake offset we created when the GTT map ioctl was called on
990 * the object) and map it with a call to drm_gem_mmap_obj().
992 * If the caller is not granted access to the buffer object, the mmap will fail
993 * with EACCES. Please see the vma manager for more information.
995 int drm_gem_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
997 struct drm_file
*priv
= filp
->private_data
;
998 struct drm_device
*dev
= priv
->minor
->dev
;
999 struct drm_gem_object
*obj
= NULL
;
1000 struct drm_vma_offset_node
*node
;
1003 if (drm_dev_is_unplugged(dev
))
1006 drm_vma_offset_lock_lookup(dev
->vma_offset_manager
);
1007 node
= drm_vma_offset_exact_lookup_locked(dev
->vma_offset_manager
,
1011 obj
= container_of(node
, struct drm_gem_object
, vma_node
);
1013 * When the object is being freed, after it hits 0-refcnt it
1014 * proceeds to tear down the object. In the process it will
1015 * attempt to remove the VMA offset and so acquire this
1016 * mgr->vm_lock. Therefore if we find an object with a 0-refcnt
1017 * that matches our range, we know it is in the process of being
1018 * destroyed and will be freed as soon as we release the lock -
1019 * so we have to check for the 0-refcnted object and treat it as
1022 if (!kref_get_unless_zero(&obj
->refcount
))
1025 drm_vma_offset_unlock_lookup(dev
->vma_offset_manager
);
1030 if (!drm_vma_node_is_allowed(node
, priv
)) {
1031 drm_gem_object_put_unlocked(obj
);
1035 ret
= drm_gem_mmap_obj(obj
, drm_vma_node_size(node
) << PAGE_SHIFT
,
1038 drm_gem_object_put_unlocked(obj
);
1042 EXPORT_SYMBOL(drm_gem_mmap
);