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 * drm_gem_handle_create_tail - internal functions to create a handle
356 * @file_priv: drm file-private structure to register the handle for
357 * @obj: object to register
358 * @handlep: pointer to return the created handle to the caller
360 * This expects the dev->object_name_lock to be held already and will drop it
361 * before returning. Used to avoid races in establishing new handles when
362 * importing an object from either an flink name or a dma-buf.
365 drm_gem_handle_create_tail(struct drm_file *file_priv,
366 struct drm_gem_object *obj,
369 struct drm_device *dev = obj->dev;
372 WARN_ON(!mutex_is_locked(&dev->object_name_lock));
375 * Get the user-visible handle using idr. Preload and perform
376 * allocation under our spinlock.
378 idr_preload(GFP_KERNEL);
379 lockmgr(&file_priv->table_lock, LK_EXCLUSIVE);
381 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
382 drm_gem_object_reference(obj);
384 lockmgr(&file_priv->table_lock, LK_RELEASE);
386 mutex_unlock(&dev->object_name_lock);
388 drm_gem_object_handle_unreference_unlocked(obj);
394 ret = drm_vma_node_allow(&obj->vma_node, file_priv->filp);
396 drm_gem_handle_delete(file_priv, *handlep);
401 if (dev->driver->gem_open_object) {
402 ret = dev->driver->gem_open_object(obj, file_priv);
404 drm_gem_handle_delete(file_priv, *handlep);
413 * drm_gem_handle_create - create a gem handle for an object
414 * @file_priv: drm file-private structure to register the handle for
415 * @obj: object to register
416 * @handlep: pionter to return the created handle to the caller
418 * Create a handle for this object. This adds a handle reference
419 * to the object, which includes a regular reference count. Callers
420 * will likely want to dereference the object afterwards.
422 int drm_gem_handle_create(struct drm_file *file_priv,
423 struct drm_gem_object *obj,
426 mutex_lock(&obj->dev->object_name_lock);
428 return drm_gem_handle_create_tail(file_priv, obj, handlep);
430 EXPORT_SYMBOL(drm_gem_handle_create);
433 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
434 * @obj: obj in question
436 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
439 drm_gem_free_mmap_offset(struct drm_gem_object *obj)
441 struct drm_device *dev = obj->dev;
442 struct drm_gem_mm *mm = dev->mm_private;
443 struct drm_hash_item *list;
447 list = &obj->map_list;
449 drm_ht_remove_item(&mm->offset_hash, list);
450 free_unr(mm->idxunr, list->key);
453 drm_vma_offset_remove(&mm->vma_manager, &obj->vma_node);
455 EXPORT_SYMBOL(drm_gem_free_mmap_offset);
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
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
467 * This routine allocates and attaches a fake offset for @obj, in cases where
468 * the virtual size differs from the physical size (ie. obj->size). Otherwise
469 * just use drm_gem_create_mmap_offset().
472 drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
474 struct drm_device *dev = obj->dev;
475 struct drm_gem_mm *mm = dev->mm_private;
481 obj->map_list.key = alloc_unr(mm->idxunr);
482 ret = drm_ht_insert_item(&mm->offset_hash, &obj->map_list);
484 DRM_ERROR("failed to add to map hash\n");
485 free_unr(mm->idxunr, obj->map_list.key);
491 return drm_vma_offset_add(&mm->vma_manager, &obj->vma_node,
494 EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
497 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
498 * @obj: obj in question
500 * GEM memory mapping works by handing back to userspace a fake mmap offset
501 * it can use in a subsequent mmap(2) call. The DRM core code then looks
502 * up the object based on the offset and sets up the various memory mapping
505 * This routine allocates and attaches a fake offset for @obj.
507 int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
509 return drm_gem_create_mmap_offset_size(obj, obj->size);
511 EXPORT_SYMBOL(drm_gem_create_mmap_offset);
513 /** Returns a reference to the object named by the handle. */
514 struct drm_gem_object *
515 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
518 struct drm_gem_object *obj;
520 lockmgr(&filp->table_lock, LK_EXCLUSIVE);
522 /* Check if we currently have a reference on the object */
523 obj = idr_find(&filp->object_idr, handle);
525 lockmgr(&filp->table_lock, LK_RELEASE);
529 drm_gem_object_reference(obj);
531 lockmgr(&filp->table_lock, LK_RELEASE);
535 EXPORT_SYMBOL(drm_gem_object_lookup);
538 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
541 * @file_priv: drm file-private structure
543 * Releases the handle to an mm object.
546 drm_gem_close_ioctl(struct drm_device *dev, void *data,
547 struct drm_file *file_priv)
549 struct drm_gem_close *args = data;
552 if (!drm_core_check_feature(dev, DRIVER_GEM))
555 ret = drm_gem_handle_delete(file_priv, args->handle);
561 * Create a global name for an object, returning the name.
563 * Note that the name does not hold a reference; when the object
564 * is freed, the name goes away.
567 drm_gem_flink_ioctl(struct drm_device *dev, void *data,
568 struct drm_file *file_priv)
570 struct drm_gem_flink *args = data;
571 struct drm_gem_object *obj;
574 if (!drm_core_check_feature(dev, DRIVER_GEM))
577 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
581 idr_preload(GFP_KERNEL);
582 lockmgr(&dev->object_name_lock, LK_EXCLUSIVE);
583 /* prevent races with concurrent gem_close. */
584 if (obj->handle_count == 0) {
590 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_NOWAIT);
596 /* Allocate a reference for the name table. */
597 drm_gem_object_reference(obj);
600 args->name = (uint64_t) obj->name;
604 lockmgr(&dev->object_name_lock, LK_RELEASE);
606 drm_gem_object_unreference_unlocked(obj);
611 * drm_gem_open - implementation of the GEM_OPEN ioctl
614 * @file_priv: drm file-private structure
616 * Open an object using the global name, returning a handle and the size.
618 * This handle (of course) holds a reference to the object, so the object
619 * will not go away until the handle is deleted.
622 drm_gem_open_ioctl(struct drm_device *dev, void *data,
623 struct drm_file *file_priv)
625 struct drm_gem_open *args = data;
626 struct drm_gem_object *obj;
630 if (!drm_core_check_feature(dev, DRIVER_GEM))
633 lockmgr(&dev->object_name_lock, LK_EXCLUSIVE);
634 obj = idr_find(&dev->object_name_idr, (int) args->name);
636 drm_gem_object_reference(obj);
637 lockmgr(&dev->object_name_lock, LK_RELEASE);
641 ret = drm_gem_handle_create(file_priv, obj, &handle);
642 drm_gem_object_unreference_unlocked(obj);
646 args->handle = handle;
647 args->size = obj->size;
653 * gem_gem_open - initalizes GEM file-private structures at devnode open time
654 * @dev: drm_device which is being opened by userspace
655 * @file_private: drm file-private structure to set up
657 * Called at device open time, sets up the structure for handling refcounting
661 drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
663 idr_init(&file_private->object_idr);
664 lockinit(&file_private->table_lock, "fptab", 0, LK_CANRECURSE);
668 * Called at device close to release the file's
669 * handle references on objects.
672 drm_gem_object_release_handle(int id, void *ptr, void *data)
674 struct drm_file *file_priv = data;
675 struct drm_gem_object *obj = ptr;
676 struct drm_device *dev = obj->dev;
678 drm_gem_remove_prime_handles(obj, file_priv);
680 if (dev->driver->gem_close_object)
681 dev->driver->gem_close_object(obj, file_priv);
683 drm_gem_object_handle_unreference_unlocked(obj);
689 * drm_gem_release - release file-private GEM resources
690 * @dev: drm_device which is being closed by userspace
691 * @file_private: drm file-private structure to clean up
693 * Called at close time when the filp is going away.
695 * Releases any remaining references on objects by this filp.
698 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
700 idr_for_each(&file_private->object_idr,
701 &drm_gem_object_release_handle, file_private);
702 idr_destroy(&file_private->object_idr);
706 drm_gem_object_release(struct drm_gem_object *obj)
710 * obj->vm_obj can be NULL for private gem objects.
712 vm_object_deallocate(obj->vm_obj);
714 EXPORT_SYMBOL(drm_gem_object_release);
717 * drm_gem_object_free - free a GEM object
718 * @kref: kref of the object to free
720 * Called after the last reference to the object has been lost.
721 * Must be called holding struct_ mutex
726 drm_gem_object_free(struct kref *kref)
728 struct drm_gem_object *obj = (struct drm_gem_object *) kref;
729 struct drm_device *dev = obj->dev;
731 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
733 if (dev->driver->gem_free_object != NULL)
734 dev->driver->gem_free_object(obj);
736 EXPORT_SYMBOL(drm_gem_object_free);
738 static struct drm_gem_object *
739 drm_gem_object_from_offset(struct drm_device *dev, vm_ooffset_t offset)
741 struct drm_gem_object *obj;
742 struct drm_gem_mm *mm = dev->mm_private;
743 struct drm_hash_item *hash;
745 if ((offset & DRM_GEM_MAPPING_MASK) != DRM_GEM_MAPPING_KEY)
747 offset &= ~DRM_GEM_MAPPING_KEY;
749 if (drm_ht_find_item(&mm->offset_hash, DRM_GEM_MAPPING_IDX(offset),
753 obj = container_of(hash, struct drm_gem_object, map_list);
758 drm_gem_mmap_single(struct drm_device *dev, vm_ooffset_t *offset, vm_size_t size,
759 struct vm_object **obj_res, int nprot)
761 struct drm_gem_object *gem_obj;
762 struct vm_object *vm_obj;
765 gem_obj = drm_gem_object_from_offset(dev, *offset);
766 if (gem_obj == NULL) {
771 drm_gem_object_reference(gem_obj);
773 vm_obj = cdev_pager_allocate(gem_obj, OBJT_MGTDEVICE,
774 dev->driver->gem_pager_ops, size, nprot,
775 DRM_GEM_MAPPING_MAPOFF(*offset), curthread->td_ucred);
776 if (vm_obj == NULL) {
777 drm_gem_object_unreference_unlocked(gem_obj);
780 *offset = DRM_GEM_MAPPING_MAPOFF(*offset);
786 drm_gem_pager_dtr(void *handle)
788 struct drm_gem_object *obj;
789 struct drm_device *dev;
795 drm_gem_free_mmap_offset(obj);
796 drm_gem_object_unreference(obj);