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>
40 #include <drm/drm_vma_manager.h>
41 #include <drm/drm_gem.h>
42 #include "drm_internal.h"
46 * This file provides some of the base ioctls and library routines for
47 * the graphics memory manager implemented by each device driver.
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.
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
60 * - Process limits prevent more than 1024 or so being used at a time by
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.
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.
73 * We make up offsets for buffer objects so we can recognize them at
77 /* pgoff in mmap is an unsigned long, so we need to make sure that
78 * the faked up offset will fit
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)
85 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
86 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
90 * drm_gem_init - Initialize the GEM device fields
91 * @dev: drm_devic structure to initialize
94 drm_gem_init(struct drm_device *dev)
96 struct drm_vma_offset_manager *vma_offset_manager;
98 mutex_init(&dev->object_name_lock);
99 idr_init(&dev->object_name_idr);
101 vma_offset_manager = kzalloc(sizeof(*vma_offset_manager), GFP_KERNEL);
102 if (!vma_offset_manager) {
103 DRM_ERROR("out of memory\n");
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);
116 drm_gem_destroy(struct drm_device *dev)
119 drm_vma_offset_manager_destroy(dev->vma_offset_manager);
120 kfree(dev->vma_offset_manager);
121 dev->vma_offset_manager = NULL;
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
130 * Initialize an already allocated GEM object of the specified size with
131 * shmfs backing store.
133 int drm_gem_object_init(struct drm_device *dev,
134 struct drm_gem_object *obj, size_t size)
138 drm_gem_private_object_init(dev, obj, size);
140 filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
142 return PTR_ERR(filp);
148 EXPORT_SYMBOL(drm_gem_object_init);
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
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.
160 void drm_gem_private_object_init(struct drm_device *dev,
161 struct drm_gem_object *obj, size_t size)
163 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
168 kref_init(&obj->refcount);
169 obj->handle_count = 0;
171 drm_vma_node_reset(&obj->vma_node);
173 EXPORT_SYMBOL(drm_gem_private_object_init);
176 drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
179 * Note: obj->dma_buf can't disappear as long as we still hold a
180 * handle reference in obj->handle_count.
182 mutex_lock(&filp->prime.lock);
184 drm_prime_remove_buf_handle_locked(&filp->prime,
187 mutex_unlock(&filp->prime.lock);
191 * drm_gem_object_handle_free - release resources bound to userspace handles
192 * @obj: GEM object to clean up.
194 * Called after the last handle to the object has been closed
196 * Removes any name for the object. Note that this must be
197 * called before drm_gem_object_free or we'll be touching
200 static void drm_gem_object_handle_free(struct drm_gem_object *obj)
202 struct drm_device *dev = obj->dev;
204 /* Remove any name for this object */
206 idr_remove(&dev->object_name_idr, obj->name);
211 static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
213 /* Unbreak the reference cycle if we have an exported dma_buf. */
215 dma_buf_put(obj->dma_buf);
221 drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj)
223 struct drm_device *dev = obj->dev;
226 if (WARN_ON(obj->handle_count == 0))
230 * Must bump handle count first as this may be the last
231 * ref, in which case the object would disappear before we
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);
241 mutex_unlock(&dev->object_name_lock);
244 drm_gem_object_unreference_unlocked(obj);
248 * drm_gem_handle_delete - deletes the given file-private handle
249 * @filp: drm file-private structure to use for the handle look up
250 * @handle: userspace handle to delete
252 * Removes the GEM handle from the @filp lookup table which has been added with
253 * drm_gem_handle_create(). If this is the last handle also cleans up linked
254 * resources like GEM names.
257 drm_gem_handle_delete(struct drm_file *filp, u32 handle)
259 struct drm_device *dev;
260 struct drm_gem_object *obj;
262 /* This is gross. The idr system doesn't let us try a delete and
263 * return an error code. It just spews if you fail at deleting.
264 * So, we have to grab a lock around finding the object and then
265 * doing the delete on it and dropping the refcount, or the user
266 * could race us to double-decrement the refcount and cause a
267 * use-after-free later. Given the frequency of our handle lookups,
268 * we may want to use ida for number allocation and a hash table
269 * for the pointers, anyway.
271 spin_lock(&filp->table_lock);
273 /* Check if we currently have a reference on the object */
274 obj = idr_find(&filp->object_idr, handle);
276 spin_unlock(&filp->table_lock);
281 /* Release reference and decrement refcount. */
282 idr_remove(&filp->object_idr, handle);
283 spin_unlock(&filp->table_lock);
285 if (drm_core_check_feature(dev, DRIVER_PRIME))
286 drm_gem_remove_prime_handles(obj, filp);
287 drm_vma_node_revoke(&obj->vma_node, filp->filp);
289 if (dev->driver->gem_close_object)
290 dev->driver->gem_close_object(obj, filp);
291 drm_gem_object_handle_unreference_unlocked(obj);
295 EXPORT_SYMBOL(drm_gem_handle_delete);
298 * drm_gem_dumb_destroy - dumb fb callback helper for gem based drivers
299 * @file: drm file-private structure to remove the dumb handle from
300 * @dev: corresponding drm_device
301 * @handle: the dumb handle to remove
303 * This implements the ->dumb_destroy kms driver callback for drivers which use
304 * gem to manage their backing storage.
306 int drm_gem_dumb_destroy(struct drm_file *file,
307 struct drm_device *dev,
310 return drm_gem_handle_delete(file, handle);
312 EXPORT_SYMBOL(drm_gem_dumb_destroy);
315 * drm_gem_handle_create_tail - internal functions to create a handle
316 * @file_priv: drm file-private structure to register the handle for
317 * @obj: object to register
318 * @handlep: pointer to return the created handle to the caller
320 * This expects the dev->object_name_lock to be held already and will drop it
321 * before returning. Used to avoid races in establishing new handles when
322 * importing an object from either an flink name or a dma-buf.
324 * Handles must be release again through drm_gem_handle_delete(). This is done
325 * when userspace closes @file_priv for all attached handles, or through the
326 * GEM_CLOSE ioctl for individual handles.
329 drm_gem_handle_create_tail(struct drm_file *file_priv,
330 struct drm_gem_object *obj,
333 struct drm_device *dev = obj->dev;
337 WARN_ON(!mutex_is_locked(&dev->object_name_lock));
338 if (obj->handle_count++ == 0)
339 drm_gem_object_reference(obj);
342 * Get the user-visible handle using idr. Preload and perform
343 * allocation under our spinlock.
345 idr_preload(GFP_KERNEL);
346 spin_lock(&file_priv->table_lock);
348 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
350 spin_unlock(&file_priv->table_lock);
353 mutex_unlock(&dev->object_name_lock);
359 ret = drm_vma_node_allow(&obj->vma_node, file_priv->filp);
363 if (dev->driver->gem_open_object) {
364 ret = dev->driver->gem_open_object(obj, file_priv);
373 drm_vma_node_revoke(&obj->vma_node, file_priv->filp);
375 spin_lock(&file_priv->table_lock);
376 idr_remove(&file_priv->object_idr, handle);
377 spin_unlock(&file_priv->table_lock);
379 drm_gem_object_handle_unreference_unlocked(obj);
384 * drm_gem_handle_create - create a gem handle for an object
385 * @file_priv: drm file-private structure to register the handle for
386 * @obj: object to register
387 * @handlep: pionter to return the created handle to the caller
389 * Create a handle for this object. This adds a handle reference
390 * to the object, which includes a regular reference count. Callers
391 * will likely want to dereference the object afterwards.
393 int drm_gem_handle_create(struct drm_file *file_priv,
394 struct drm_gem_object *obj,
397 mutex_lock(&obj->dev->object_name_lock);
399 return drm_gem_handle_create_tail(file_priv, obj, handlep);
401 EXPORT_SYMBOL(drm_gem_handle_create);
405 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
406 * @obj: obj in question
408 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
411 drm_gem_free_mmap_offset(struct drm_gem_object *obj)
413 struct drm_device *dev = obj->dev;
415 drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node);
417 EXPORT_SYMBOL(drm_gem_free_mmap_offset);
420 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object
421 * @obj: obj in question
422 * @size: the virtual size
424 * GEM memory mapping works by handing back to userspace a fake mmap offset
425 * it can use in a subsequent mmap(2) call. The DRM core code then looks
426 * up the object based on the offset and sets up the various memory mapping
429 * This routine allocates and attaches a fake offset for @obj, in cases where
430 * the virtual size differs from the physical size (ie. obj->size). Otherwise
431 * just use drm_gem_create_mmap_offset().
434 drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
436 struct drm_device *dev = obj->dev;
438 return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node,
441 EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
444 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
445 * @obj: obj in question
447 * GEM memory mapping works by handing back to userspace a fake mmap offset
448 * it can use in a subsequent mmap(2) call. The DRM core code then looks
449 * up the object based on the offset and sets up the various memory mapping
452 * This routine allocates and attaches a fake offset for @obj.
454 int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
456 return drm_gem_create_mmap_offset_size(obj, obj->size);
458 EXPORT_SYMBOL(drm_gem_create_mmap_offset);
461 * drm_gem_get_pages - helper to allocate backing pages for a GEM object
463 * @obj: obj in question
465 * This reads the page-array of the shmem-backing storage of the given gem
466 * object. An array of pages is returned. If a page is not allocated or
467 * swapped-out, this will allocate/swap-in the required pages. Note that the
468 * whole object is covered by the page-array and pinned in memory.
470 * Use drm_gem_put_pages() to release the array and unpin all pages.
472 * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()).
473 * If you require other GFP-masks, you have to do those allocations yourself.
475 * Note that you are not allowed to change gfp-zones during runtime. That is,
476 * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as
477 * set during initialization. If you have special zone constraints, set them
478 * after drm_gem_init_object() via mapping_set_gfp_mask(). shmem-core takes care
479 * to keep pages in the required zone during swap-in.
481 struct page **drm_gem_get_pages(struct drm_gem_object *obj)
483 struct address_space *mapping;
484 struct page *p, **pages;
487 /* This is the shared memory object that backs the GEM resource */
488 mapping = file_inode(obj->filp)->i_mapping;
490 /* We already BUG_ON() for non-page-aligned sizes in
491 * drm_gem_object_init(), so we should never hit this unless
492 * driver author is doing something really wrong:
494 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
496 npages = obj->size >> PAGE_SHIFT;
498 pages = drm_malloc_ab(npages, sizeof(struct page *));
500 return ERR_PTR(-ENOMEM);
502 for (i = 0; i < npages; i++) {
503 p = shmem_read_mapping_page(mapping, i);
508 /* Make sure shmem keeps __GFP_DMA32 allocated pages in the
509 * correct region during swapin. Note that this requires
510 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping)
511 * so shmem can relocate pages during swapin if required.
513 BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) &&
514 (page_to_pfn(p) >= 0x00100000UL));
521 page_cache_release(pages[i]);
523 drm_free_large(pages);
526 EXPORT_SYMBOL(drm_gem_get_pages);
529 * drm_gem_put_pages - helper to free backing pages for a GEM object
530 * @obj: obj in question
531 * @pages: pages to free
532 * @dirty: if true, pages will be marked as dirty
533 * @accessed: if true, the pages will be marked as accessed
535 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
536 bool dirty, bool accessed)
540 /* We already BUG_ON() for non-page-aligned sizes in
541 * drm_gem_object_init(), so we should never hit this unless
542 * driver author is doing something really wrong:
544 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
546 npages = obj->size >> PAGE_SHIFT;
548 for (i = 0; i < npages; i++) {
550 set_page_dirty(pages[i]);
553 mark_page_accessed(pages[i]);
555 /* Undo the reference we took when populating the table */
556 page_cache_release(pages[i]);
559 drm_free_large(pages);
561 EXPORT_SYMBOL(drm_gem_put_pages);
564 * drm_gem_object_lookup - look up a GEM object from it's handle
566 * @filp: DRM file private date
567 * @handle: userspace handle
571 * A reference to the object named by the handle if such exists on @filp, NULL
574 struct drm_gem_object *
575 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
578 struct drm_gem_object *obj;
580 spin_lock(&filp->table_lock);
582 /* Check if we currently have a reference on the object */
583 obj = idr_find(&filp->object_idr, handle);
585 spin_unlock(&filp->table_lock);
589 drm_gem_object_reference(obj);
591 spin_unlock(&filp->table_lock);
595 EXPORT_SYMBOL(drm_gem_object_lookup);
598 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
601 * @file_priv: drm file-private structure
603 * Releases the handle to an mm object.
606 drm_gem_close_ioctl(struct drm_device *dev, void *data,
607 struct drm_file *file_priv)
609 struct drm_gem_close *args = data;
612 if (!drm_core_check_feature(dev, DRIVER_GEM))
615 ret = drm_gem_handle_delete(file_priv, args->handle);
621 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl
624 * @file_priv: drm file-private structure
626 * Create a global name for an object, returning the name.
628 * Note that the name does not hold a reference; when the object
629 * is freed, the name goes away.
632 drm_gem_flink_ioctl(struct drm_device *dev, void *data,
633 struct drm_file *file_priv)
635 struct drm_gem_flink *args = data;
636 struct drm_gem_object *obj;
639 if (!drm_core_check_feature(dev, DRIVER_GEM))
642 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
646 mutex_lock(&dev->object_name_lock);
647 /* prevent races with concurrent gem_close. */
648 if (obj->handle_count == 0) {
654 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_KERNEL);
661 args->name = (uint64_t) obj->name;
665 mutex_unlock(&dev->object_name_lock);
666 drm_gem_object_unreference_unlocked(obj);
671 * drm_gem_open - implementation of the GEM_OPEN ioctl
674 * @file_priv: drm file-private structure
676 * Open an object using the global name, returning a handle and the size.
678 * This handle (of course) holds a reference to the object, so the object
679 * will not go away until the handle is deleted.
682 drm_gem_open_ioctl(struct drm_device *dev, void *data,
683 struct drm_file *file_priv)
685 struct drm_gem_open *args = data;
686 struct drm_gem_object *obj;
690 if (!drm_core_check_feature(dev, DRIVER_GEM))
693 mutex_lock(&dev->object_name_lock);
694 obj = idr_find(&dev->object_name_idr, (int) args->name);
696 drm_gem_object_reference(obj);
698 mutex_unlock(&dev->object_name_lock);
702 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
703 ret = drm_gem_handle_create_tail(file_priv, obj, &handle);
704 drm_gem_object_unreference_unlocked(obj);
708 args->handle = handle;
709 args->size = obj->size;
715 * gem_gem_open - initalizes GEM file-private structures at devnode open time
716 * @dev: drm_device which is being opened by userspace
717 * @file_private: drm file-private structure to set up
719 * Called at device open time, sets up the structure for handling refcounting
723 drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
725 idr_init(&file_private->object_idr);
726 spin_lock_init(&file_private->table_lock);
730 * Called at device close to release the file's
731 * handle references on objects.
734 drm_gem_object_release_handle(int id, void *ptr, void *data)
736 struct drm_file *file_priv = data;
737 struct drm_gem_object *obj = ptr;
738 struct drm_device *dev = obj->dev;
740 if (drm_core_check_feature(dev, DRIVER_PRIME))
741 drm_gem_remove_prime_handles(obj, file_priv);
742 drm_vma_node_revoke(&obj->vma_node, file_priv->filp);
744 if (dev->driver->gem_close_object)
745 dev->driver->gem_close_object(obj, file_priv);
747 drm_gem_object_handle_unreference_unlocked(obj);
753 * drm_gem_release - release file-private GEM resources
754 * @dev: drm_device which is being closed by userspace
755 * @file_private: drm file-private structure to clean up
757 * Called at close time when the filp is going away.
759 * Releases any remaining references on objects by this filp.
762 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
764 idr_for_each(&file_private->object_idr,
765 &drm_gem_object_release_handle, file_private);
766 idr_destroy(&file_private->object_idr);
770 drm_gem_object_release(struct drm_gem_object *obj)
772 WARN_ON(obj->dma_buf);
777 drm_gem_free_mmap_offset(obj);
779 EXPORT_SYMBOL(drm_gem_object_release);
782 * drm_gem_object_free - free a GEM object
783 * @kref: kref of the object to free
785 * Called after the last reference to the object has been lost.
786 * Must be called holding struct_ mutex
791 drm_gem_object_free(struct kref *kref)
793 struct drm_gem_object *obj =
794 container_of(kref, struct drm_gem_object, refcount);
795 struct drm_device *dev = obj->dev;
797 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
799 if (dev->driver->gem_free_object != NULL)
800 dev->driver->gem_free_object(obj);
802 EXPORT_SYMBOL(drm_gem_object_free);
805 * drm_gem_vm_open - vma->ops->open implementation for GEM
806 * @vma: VM area structure
808 * This function implements the #vm_operations_struct open() callback for GEM
809 * drivers. This must be used together with drm_gem_vm_close().
811 void drm_gem_vm_open(struct vm_area_struct *vma)
813 struct drm_gem_object *obj = vma->vm_private_data;
815 drm_gem_object_reference(obj);
817 EXPORT_SYMBOL(drm_gem_vm_open);
820 * drm_gem_vm_close - vma->ops->close implementation for GEM
821 * @vma: VM area structure
823 * This function implements the #vm_operations_struct close() callback for GEM
824 * drivers. This must be used together with drm_gem_vm_open().
826 void drm_gem_vm_close(struct vm_area_struct *vma)
828 struct drm_gem_object *obj = vma->vm_private_data;
830 drm_gem_object_unreference_unlocked(obj);
832 EXPORT_SYMBOL(drm_gem_vm_close);
835 * drm_gem_mmap_obj - memory map a GEM object
836 * @obj: the GEM object to map
837 * @obj_size: the object size to be mapped, in bytes
838 * @vma: VMA for the area to be mapped
840 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
841 * provided by the driver. Depending on their requirements, drivers can either
842 * provide a fault handler in their gem_vm_ops (in which case any accesses to
843 * the object will be trapped, to perform migration, GTT binding, surface
844 * register allocation, or performance monitoring), or mmap the buffer memory
845 * synchronously after calling drm_gem_mmap_obj.
847 * This function is mainly intended to implement the DMABUF mmap operation, when
848 * the GEM object is not looked up based on its fake offset. To implement the
849 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
851 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while
852 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So
853 * callers must verify access restrictions before calling this helper.
855 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
856 * size, or if no gem_vm_ops are provided.
858 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
859 struct vm_area_struct *vma)
861 struct drm_device *dev = obj->dev;
863 /* Check for valid size. */
864 if (obj_size < vma->vm_end - vma->vm_start)
867 if (!dev->driver->gem_vm_ops)
870 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
871 vma->vm_ops = dev->driver->gem_vm_ops;
872 vma->vm_private_data = obj;
873 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
875 /* Take a ref for this mapping of the object, so that the fault
876 * handler can dereference the mmap offset's pointer to the object.
877 * This reference is cleaned up by the corresponding vm_close
878 * (which should happen whether the vma was created by this call, or
879 * by a vm_open due to mremap or partial unmap or whatever).
881 drm_gem_object_reference(obj);
885 EXPORT_SYMBOL(drm_gem_mmap_obj);
888 * drm_gem_mmap - memory map routine for GEM objects
889 * @filp: DRM file pointer
890 * @vma: VMA for the area to be mapped
892 * If a driver supports GEM object mapping, mmap calls on the DRM file
893 * descriptor will end up here.
895 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
896 * contain the fake offset we created when the GTT map ioctl was called on
897 * the object) and map it with a call to drm_gem_mmap_obj().
899 * If the caller is not granted access to the buffer object, the mmap will fail
900 * with EACCES. Please see the vma manager for more information.
902 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
904 struct drm_file *priv = filp->private_data;
905 struct drm_device *dev = priv->minor->dev;
906 struct drm_gem_object *obj = NULL;
907 struct drm_vma_offset_node *node;
910 if (drm_device_is_unplugged(dev))
913 drm_vma_offset_lock_lookup(dev->vma_offset_manager);
914 node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
918 obj = container_of(node, struct drm_gem_object, vma_node);
920 * When the object is being freed, after it hits 0-refcnt it
921 * proceeds to tear down the object. In the process it will
922 * attempt to remove the VMA offset and so acquire this
923 * mgr->vm_lock. Therefore if we find an object with a 0-refcnt
924 * that matches our range, we know it is in the process of being
925 * destroyed and will be freed as soon as we release the lock -
926 * so we have to check for the 0-refcnted object and treat it as
929 if (!kref_get_unless_zero(&obj->refcount))
932 drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
937 if (!drm_vma_node_is_allowed(node, filp)) {
938 drm_gem_object_unreference_unlocked(obj);
942 ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT,
945 drm_gem_object_unreference_unlocked(obj);
949 EXPORT_SYMBOL(drm_gem_mmap);