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 * Copyright (c) 2011 The FreeBSD Foundation
29 * All rights reserved.
31 * This software was developed by Konstantin Belousov under sponsorship from
32 * the FreeBSD Foundation.
34 * Redistribution and use in source and binary forms, with or without
35 * modification, are permitted provided that the following conditions
37 * 1. Redistributions of source code must retain the above copyright
38 * notice, this list of conditions and the following disclaimer.
39 * 2. Redistributions in binary form must reproduce the above copyright
40 * notice, this list of conditions and the following disclaimer in the
41 * documentation and/or other materials provided with the distribution.
43 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
44 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
45 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
46 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
47 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
48 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
49 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 #include <sys/param.h>
59 #include <sys/systm.h>
60 #include <sys/limits.h>
62 #include <sys/mutex.h>
66 #include <vm/vm_page.h>
68 #include <linux/types.h>
70 #include <linux/module.h>
72 #include <drm/drm_vma_manager.h>
73 #include <drm/drm_gem.h>
74 #include "drm_internal.h"
78 * This file provides some of the base ioctls and library routines for
79 * the graphics memory manager implemented by each device driver.
81 * Because various devices have different requirements in terms of
82 * synchronization and migration strategies, implementing that is left up to
83 * the driver, and all that the general API provides should be generic --
84 * allocating objects, reading/writing data with the cpu, freeing objects.
85 * Even there, platform-dependent optimizations for reading/writing data with
86 * the CPU mean we'll likely hook those out to driver-specific calls. However,
87 * the DRI2 implementation wants to have at least allocate/mmap be generic.
89 * The goal was to have swap-backed object allocation managed through
90 * struct file. However, file descriptors as handles to a struct file have
92 * - Process limits prevent more than 1024 or so being used at a time by
94 * - Inability to allocate high fds will aggravate the X Server's select()
95 * handling, and likely that of many GL client applications as well.
97 * This led to a plan of using our own integer IDs (called handles, following
98 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
99 * ioctls. The objects themselves will still include the struct file so
100 * that we can transition to fds if the required kernel infrastructure shows
101 * up at a later date, and as our interface with shmfs for memory allocation.
105 * We make up offsets for buffer objects so we can recognize them at
109 /* pgoff in mmap is an unsigned long, so we need to make sure that
110 * the faked up offset will fit
113 #if BITS_PER_LONG == 64
114 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
115 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
117 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
118 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
122 * drm_gem_init - Initialize the GEM device fields
123 * @dev: drm_devic structure to initialize
126 drm_gem_init(struct drm_device *dev)
128 struct drm_gem_mm *mm;
130 lockinit(&dev->object_name_lock, "objnam", 0, LK_CANRECURSE);
131 idr_init(&dev->object_name_idr);
133 mm = kzalloc(sizeof(struct drm_gem_mm), GFP_KERNEL);
135 DRM_ERROR("out of memory\n");
139 dev->mm_private = mm;
141 if (drm_ht_create(&mm->offset_hash, 12)) {
146 mm->idxunr = new_unrhdr(0, DRM_GEM_MAX_IDX, NULL);
147 drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START,
148 DRM_FILE_PAGE_OFFSET_SIZE);
149 drm_vma_offset_manager_init(&mm->vma_manager,
150 DRM_FILE_PAGE_OFFSET_START,
151 DRM_FILE_PAGE_OFFSET_SIZE);
157 drm_gem_destroy(struct drm_device *dev)
159 struct drm_gem_mm *mm = dev->mm_private;
161 drm_mm_takedown(&mm->offset_manager);
162 drm_ht_remove(&mm->offset_hash);
164 drm_vma_offset_manager_destroy(&mm->vma_manager);
165 delete_unrhdr(mm->idxunr);
167 dev->mm_private = NULL;
171 * Initialize an already allocated GEM object of the specified size with
172 * shmfs backing store.
174 int drm_gem_object_init(struct drm_device *dev,
175 struct drm_gem_object *obj, size_t size)
177 drm_gem_private_object_init(dev, obj, size);
179 obj->vm_obj = default_pager_alloc(NULL, size,
180 VM_PROT_READ | VM_PROT_WRITE, 0);
184 EXPORT_SYMBOL(drm_gem_object_init);
187 * drm_gem_object_init - initialize an allocated private GEM object
188 * @dev: drm_device the object should be initialized for
189 * @obj: drm_gem_object to initialize
192 * Initialize an already allocated GEM object of the specified size with
193 * no GEM provided backing store. Instead the caller is responsible for
194 * backing the object and handling it.
196 void drm_gem_private_object_init(struct drm_device *dev,
197 struct drm_gem_object *obj, size_t size)
199 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
204 kref_init(&obj->refcount);
205 obj->handle_count = 0;
207 drm_vma_node_reset(&obj->vma_node);
209 EXPORT_SYMBOL(drm_gem_private_object_init);
212 drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
215 if (obj->import_attach) {
216 drm_prime_remove_buf_handle(&filp->prime,
217 obj->import_attach->dmabuf);
219 if (obj->export_dma_buf) {
220 drm_prime_remove_buf_handle(&filp->prime,
221 obj->export_dma_buf);
226 static void drm_gem_object_ref_bug(struct kref *list_kref)
232 * drm_gem_object_free - release resources bound to userspace handles
233 * @obj: GEM object to clean up.
235 * Called after the last handle to the object has been closed
237 * Removes any name for the object. Note that this must be
238 * called before drm_gem_object_free or we'll be touching
241 static void drm_gem_object_handle_free(struct drm_gem_object *obj)
243 struct drm_device *dev = obj->dev;
245 /* Remove any name for this object */
247 idr_remove(&dev->object_name_idr, obj->name);
250 * The object name held a reference to this object, drop
253 * This cannot be the last reference, since the handle holds one too.
255 kref_put(&obj->refcount, drm_gem_object_ref_bug);
260 static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
262 /* Unbreak the reference cycle if we have an exported dma_buf. */
264 dma_buf_put(obj->dma_buf);
271 drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj)
273 if (WARN_ON(obj->handle_count == 0))
277 * Must bump handle count first as this may be the last
278 * ref, in which case the object would disappear before we
282 mutex_lock(&obj->dev->object_name_lock);
283 if (--obj->handle_count == 0)
284 drm_gem_object_handle_free(obj);
285 mutex_unlock(&obj->dev->object_name_lock);
287 drm_gem_object_unreference_unlocked(obj);
291 * drm_gem_handle_delete - deletes the given file-private handle
292 * @filp: drm file-private structure to use for the handle look up
293 * @handle: userspace handle to delete
295 * Removes the GEM handle from the @filp lookup table and if this is the last
296 * handle also cleans up linked resources like GEM names.
299 drm_gem_handle_delete(struct drm_file *filp, u32 handle)
301 struct drm_device *dev;
302 struct drm_gem_object *obj;
304 /* This is gross. The idr system doesn't let us try a delete and
305 * return an error code. It just spews if you fail at deleting.
306 * So, we have to grab a lock around finding the object and then
307 * doing the delete on it and dropping the refcount, or the user
308 * could race us to double-decrement the refcount and cause a
309 * use-after-free later. Given the frequency of our handle lookups,
310 * we may want to use ida for number allocation and a hash table
311 * for the pointers, anyway.
313 lockmgr(&filp->table_lock, LK_EXCLUSIVE);
315 /* Check if we currently have a reference on the object */
316 obj = idr_find(&filp->object_idr, handle);
318 lockmgr(&filp->table_lock, LK_RELEASE);
323 /* Release reference and decrement refcount. */
324 idr_remove(&filp->object_idr, handle);
325 lockmgr(&filp->table_lock, LK_RELEASE);
327 drm_gem_remove_prime_handles(obj, filp);
329 if (dev->driver->gem_close_object)
330 dev->driver->gem_close_object(obj, filp);
331 drm_gem_object_handle_unreference_unlocked(obj);
335 EXPORT_SYMBOL(drm_gem_handle_delete);
338 * drm_gem_dumb_destroy - dumb fb callback helper for gem based drivers
339 * @file: drm file-private structure to remove the dumb handle from
340 * @dev: corresponding drm_device
341 * @handle: the dumb handle to remove
343 * This implements the ->dumb_destroy kms driver callback for drivers which use
344 * gem to manage their backing storage.
346 int drm_gem_dumb_destroy(struct drm_file *file,
347 struct drm_device *dev,
350 return drm_gem_handle_delete(file, handle);
352 EXPORT_SYMBOL(drm_gem_dumb_destroy);
355 * Create a handle for this object. This adds a handle reference
356 * to the object, which includes a regular reference count. Callers
357 * will likely want to dereference the object afterwards.
360 drm_gem_handle_create(struct drm_file *file_priv,
361 struct drm_gem_object *obj,
364 struct drm_device *dev = obj->dev;
368 * Get the user-visible handle using idr.
370 idr_preload(GFP_KERNEL);
371 lockmgr(&dev->object_name_lock, LK_EXCLUSIVE);
372 lockmgr(&file_priv->table_lock, LK_EXCLUSIVE);
374 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
375 drm_gem_object_reference(obj);
377 lockmgr(&file_priv->table_lock, LK_RELEASE);
378 lockmgr(&dev->object_name_lock, LK_RELEASE);
381 drm_gem_object_handle_unreference_unlocked(obj);
387 if (dev->driver->gem_open_object) {
388 ret = dev->driver->gem_open_object(obj, file_priv);
390 drm_gem_handle_delete(file_priv, *handlep);
397 EXPORT_SYMBOL(drm_gem_handle_create);
401 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
402 * @obj: obj in question
404 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
407 drm_gem_free_mmap_offset(struct drm_gem_object *obj)
409 struct drm_device *dev = obj->dev;
410 struct drm_gem_mm *mm = dev->mm_private;
411 struct drm_hash_item *list;
415 list = &obj->map_list;
417 drm_ht_remove_item(&mm->offset_hash, list);
418 free_unr(mm->idxunr, list->key);
421 drm_vma_offset_remove(&mm->vma_manager, &obj->vma_node);
423 EXPORT_SYMBOL(drm_gem_free_mmap_offset);
426 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object
427 * @obj: obj in question
428 * @size: the virtual size
430 * GEM memory mapping works by handing back to userspace a fake mmap offset
431 * it can use in a subsequent mmap(2) call. The DRM core code then looks
432 * up the object based on the offset and sets up the various memory mapping
435 * This routine allocates and attaches a fake offset for @obj, in cases where
436 * the virtual size differs from the physical size (ie. obj->size). Otherwise
437 * just use drm_gem_create_mmap_offset().
440 drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
442 struct drm_device *dev = obj->dev;
443 struct drm_gem_mm *mm = dev->mm_private;
449 obj->map_list.key = alloc_unr(mm->idxunr);
450 ret = drm_ht_insert_item(&mm->offset_hash, &obj->map_list);
452 DRM_ERROR("failed to add to map hash\n");
453 free_unr(mm->idxunr, obj->map_list.key);
459 return drm_vma_offset_add(&mm->vma_manager, &obj->vma_node,
462 EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
465 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
466 * @obj: obj in question
468 * GEM memory mapping works by handing back to userspace a fake mmap offset
469 * it can use in a subsequent mmap(2) call. The DRM core code then looks
470 * up the object based on the offset and sets up the various memory mapping
473 * This routine allocates and attaches a fake offset for @obj.
475 int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
477 return drm_gem_create_mmap_offset_size(obj, obj->size);
479 EXPORT_SYMBOL(drm_gem_create_mmap_offset);
481 /** Returns a reference to the object named by the handle. */
482 struct drm_gem_object *
483 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
486 struct drm_gem_object *obj;
488 lockmgr(&filp->table_lock, LK_EXCLUSIVE);
490 /* Check if we currently have a reference on the object */
491 obj = idr_find(&filp->object_idr, handle);
493 lockmgr(&filp->table_lock, LK_RELEASE);
497 drm_gem_object_reference(obj);
499 lockmgr(&filp->table_lock, LK_RELEASE);
503 EXPORT_SYMBOL(drm_gem_object_lookup);
506 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
509 * @file_priv: drm file-private structure
511 * Releases the handle to an mm object.
514 drm_gem_close_ioctl(struct drm_device *dev, void *data,
515 struct drm_file *file_priv)
517 struct drm_gem_close *args = data;
520 if (!drm_core_check_feature(dev, DRIVER_GEM))
523 ret = drm_gem_handle_delete(file_priv, args->handle);
529 * Create a global name for an object, returning the name.
531 * Note that the name does not hold a reference; when the object
532 * is freed, the name goes away.
535 drm_gem_flink_ioctl(struct drm_device *dev, void *data,
536 struct drm_file *file_priv)
538 struct drm_gem_flink *args = data;
539 struct drm_gem_object *obj;
542 if (!drm_core_check_feature(dev, DRIVER_GEM))
545 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
549 idr_preload(GFP_KERNEL);
550 lockmgr(&dev->object_name_lock, LK_EXCLUSIVE);
551 /* prevent races with concurrent gem_close. */
552 if (obj->handle_count == 0) {
558 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_NOWAIT);
564 /* Allocate a reference for the name table. */
565 drm_gem_object_reference(obj);
568 args->name = (uint64_t) obj->name;
572 lockmgr(&dev->object_name_lock, LK_RELEASE);
574 drm_gem_object_unreference_unlocked(obj);
579 * drm_gem_open - implementation of the GEM_OPEN ioctl
582 * @file_priv: drm file-private structure
584 * Open an object using the global name, returning a handle and the size.
586 * This handle (of course) holds a reference to the object, so the object
587 * will not go away until the handle is deleted.
590 drm_gem_open_ioctl(struct drm_device *dev, void *data,
591 struct drm_file *file_priv)
593 struct drm_gem_open *args = data;
594 struct drm_gem_object *obj;
598 if (!drm_core_check_feature(dev, DRIVER_GEM))
601 lockmgr(&dev->object_name_lock, LK_EXCLUSIVE);
602 obj = idr_find(&dev->object_name_idr, (int) args->name);
604 drm_gem_object_reference(obj);
605 lockmgr(&dev->object_name_lock, LK_RELEASE);
609 ret = drm_gem_handle_create(file_priv, obj, &handle);
610 drm_gem_object_unreference_unlocked(obj);
614 args->handle = handle;
615 args->size = obj->size;
621 * gem_gem_open - initalizes GEM file-private structures at devnode open time
622 * @dev: drm_device which is being opened by userspace
623 * @file_private: drm file-private structure to set up
625 * Called at device open time, sets up the structure for handling refcounting
629 drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
631 idr_init(&file_private->object_idr);
632 lockinit(&file_private->table_lock, "fptab", 0, LK_CANRECURSE);
636 * Called at device close to release the file's
637 * handle references on objects.
640 drm_gem_object_release_handle(int id, void *ptr, void *data)
642 struct drm_file *file_priv = data;
643 struct drm_gem_object *obj = ptr;
644 struct drm_device *dev = obj->dev;
646 drm_gem_remove_prime_handles(obj, file_priv);
648 if (dev->driver->gem_close_object)
649 dev->driver->gem_close_object(obj, file_priv);
651 drm_gem_object_handle_unreference_unlocked(obj);
657 * drm_gem_release - release file-private GEM resources
658 * @dev: drm_device which is being closed by userspace
659 * @file_private: drm file-private structure to clean up
661 * Called at close time when the filp is going away.
663 * Releases any remaining references on objects by this filp.
666 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
668 idr_for_each(&file_private->object_idr,
669 &drm_gem_object_release_handle, file_private);
670 idr_destroy(&file_private->object_idr);
674 drm_gem_object_release(struct drm_gem_object *obj)
678 * obj->vm_obj can be NULL for private gem objects.
680 vm_object_deallocate(obj->vm_obj);
682 EXPORT_SYMBOL(drm_gem_object_release);
685 * drm_gem_object_free - free a GEM object
686 * @kref: kref of the object to free
688 * Called after the last reference to the object has been lost.
689 * Must be called holding struct_ mutex
694 drm_gem_object_free(struct kref *kref)
696 struct drm_gem_object *obj = (struct drm_gem_object *) kref;
697 struct drm_device *dev = obj->dev;
699 BUG_ON(!mutex_is_locked(&dev->struct_mutex));
701 if (dev->driver->gem_free_object != NULL)
702 dev->driver->gem_free_object(obj);
704 EXPORT_SYMBOL(drm_gem_object_free);
706 static struct drm_gem_object *
707 drm_gem_object_from_offset(struct drm_device *dev, vm_ooffset_t offset)
709 struct drm_gem_object *obj;
710 struct drm_gem_mm *mm = dev->mm_private;
711 struct drm_hash_item *hash;
713 if ((offset & DRM_GEM_MAPPING_MASK) != DRM_GEM_MAPPING_KEY)
715 offset &= ~DRM_GEM_MAPPING_KEY;
717 if (drm_ht_find_item(&mm->offset_hash, DRM_GEM_MAPPING_IDX(offset),
721 obj = container_of(hash, struct drm_gem_object, map_list);
726 drm_gem_mmap_single(struct drm_device *dev, vm_ooffset_t *offset, vm_size_t size,
727 struct vm_object **obj_res, int nprot)
729 struct drm_gem_object *gem_obj;
730 struct vm_object *vm_obj;
733 gem_obj = drm_gem_object_from_offset(dev, *offset);
734 if (gem_obj == NULL) {
739 drm_gem_object_reference(gem_obj);
741 vm_obj = cdev_pager_allocate(gem_obj, OBJT_MGTDEVICE,
742 dev->driver->gem_pager_ops, size, nprot,
743 DRM_GEM_MAPPING_MAPOFF(*offset), curthread->td_ucred);
744 if (vm_obj == NULL) {
745 drm_gem_object_unreference_unlocked(gem_obj);
748 *offset = DRM_GEM_MAPPING_MAPOFF(*offset);
754 drm_gem_pager_dtr(void *handle)
756 struct drm_gem_object *obj;
757 struct drm_device *dev;
763 drm_gem_free_mmap_offset(obj);
764 drm_gem_object_unreference(obj);