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>
43 * This file provides some of the base ioctls and library routines for
44 * the graphics memory manager implemented by each device driver.
46 * Because various devices have different requirements in terms of
47 * synchronization and migration strategies, implementing that is left up to
48 * the driver, and all that the general API provides should be generic --
49 * allocating objects, reading/writing data with the cpu, freeing objects.
50 * Even there, platform-dependent optimizations for reading/writing data with
51 * the CPU mean we'll likely hook those out to driver-specific calls. However,
52 * the DRI2 implementation wants to have at least allocate/mmap be generic.
54 * The goal was to have swap-backed object allocation managed through
55 * struct file. However, file descriptors as handles to a struct file have
57 * - Process limits prevent more than 1024 or so being used at a time by
59 * - Inability to allocate high fds will aggravate the X Server's select()
60 * handling, and likely that of many GL client applications as well.
62 * This led to a plan of using our own integer IDs (called handles, following
63 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
64 * ioctls. The objects themselves will still include the struct file so
65 * that we can transition to fds if the required kernel infrastructure shows
66 * up at a later date, and as our interface with shmfs for memory allocation.
70 * We make up offsets for buffer objects so we can recognize them at
74 /* pgoff in mmap is an unsigned long, so we need to make sure that
75 * the faked up offset will fit
78 #if BITS_PER_LONG == 64
79 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
80 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
82 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
83 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
87 * Initialize the GEM device fields
91 drm_gem_init(struct drm_device *dev)
93 struct drm_gem_mm *mm;
95 spin_lock_init(&dev->object_name_lock);
96 idr_init(&dev->object_name_idr);
98 mm = kzalloc(sizeof(struct drm_gem_mm), GFP_KERNEL);
100 DRM_ERROR("out of memory\n");
104 dev->mm_private = mm;
106 if (drm_ht_create(&mm->offset_hash, 12)) {
111 if (drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START,
112 DRM_FILE_PAGE_OFFSET_SIZE)) {
113 drm_ht_remove(&mm->offset_hash);
122 drm_gem_destroy(struct drm_device *dev)
124 struct drm_gem_mm *mm = dev->mm_private;
126 drm_mm_takedown(&mm->offset_manager);
127 drm_ht_remove(&mm->offset_hash);
129 dev->mm_private = NULL;
133 * Initialize an already allocated GEM object of the specified size with
134 * shmfs backing store.
136 int drm_gem_object_init(struct drm_device *dev,
137 struct drm_gem_object *obj, size_t size)
139 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
142 obj->filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
143 if (IS_ERR(obj->filp))
144 return PTR_ERR(obj->filp);
146 kref_init(&obj->refcount);
147 atomic_set(&obj->handle_count, 0);
152 EXPORT_SYMBOL(drm_gem_object_init);
155 * Initialize an already allocated GEM object of the specified size with
156 * no GEM provided backing store. Instead the caller is responsible for
157 * backing the object and handling it.
159 int drm_gem_private_object_init(struct drm_device *dev,
160 struct drm_gem_object *obj, size_t size)
162 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
167 kref_init(&obj->refcount);
168 atomic_set(&obj->handle_count, 0);
173 EXPORT_SYMBOL(drm_gem_private_object_init);
176 * Allocate a GEM object of the specified size with shmfs backing store
178 struct drm_gem_object *
179 drm_gem_object_alloc(struct drm_device *dev, size_t size)
181 struct drm_gem_object *obj;
183 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
187 if (drm_gem_object_init(dev, obj, size) != 0)
190 if (dev->driver->gem_init_object != NULL &&
191 dev->driver->gem_init_object(obj) != 0) {
196 /* Object_init mangles the global counters - readjust them. */
202 EXPORT_SYMBOL(drm_gem_object_alloc);
205 drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
207 if (obj->import_attach) {
208 drm_prime_remove_buf_handle(&filp->prime,
209 obj->import_attach->dmabuf);
211 if (obj->export_dma_buf) {
212 drm_prime_remove_buf_handle(&filp->prime,
213 obj->export_dma_buf);
218 * Removes the mapping from handle to filp for this object.
221 drm_gem_handle_delete(struct drm_file *filp, u32 handle)
223 struct drm_device *dev;
224 struct drm_gem_object *obj;
226 /* This is gross. The idr system doesn't let us try a delete and
227 * return an error code. It just spews if you fail at deleting.
228 * So, we have to grab a lock around finding the object and then
229 * doing the delete on it and dropping the refcount, or the user
230 * could race us to double-decrement the refcount and cause a
231 * use-after-free later. Given the frequency of our handle lookups,
232 * we may want to use ida for number allocation and a hash table
233 * for the pointers, anyway.
235 spin_lock(&filp->table_lock);
237 /* Check if we currently have a reference on the object */
238 obj = idr_find(&filp->object_idr, handle);
240 spin_unlock(&filp->table_lock);
245 /* Release reference and decrement refcount. */
246 idr_remove(&filp->object_idr, handle);
247 spin_unlock(&filp->table_lock);
249 drm_gem_remove_prime_handles(obj, filp);
251 if (dev->driver->gem_close_object)
252 dev->driver->gem_close_object(obj, filp);
253 drm_gem_object_handle_unreference_unlocked(obj);
257 EXPORT_SYMBOL(drm_gem_handle_delete);
260 * Create a handle for this object. This adds a handle reference
261 * to the object, which includes a regular reference count. Callers
262 * will likely want to dereference the object afterwards.
265 drm_gem_handle_create(struct drm_file *file_priv,
266 struct drm_gem_object *obj,
269 struct drm_device *dev = obj->dev;
273 * Get the user-visible handle using idr. Preload and perform
274 * allocation under our spinlock.
276 idr_preload(GFP_KERNEL);
277 spin_lock(&file_priv->table_lock);
279 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
281 spin_unlock(&file_priv->table_lock);
287 drm_gem_object_handle_reference(obj);
289 if (dev->driver->gem_open_object) {
290 ret = dev->driver->gem_open_object(obj, file_priv);
292 drm_gem_handle_delete(file_priv, *handlep);
299 EXPORT_SYMBOL(drm_gem_handle_create);
303 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
304 * @obj: obj in question
306 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
309 drm_gem_free_mmap_offset(struct drm_gem_object *obj)
311 struct drm_device *dev = obj->dev;
312 struct drm_gem_mm *mm = dev->mm_private;
313 struct drm_map_list *list = &obj->map_list;
315 drm_ht_remove_item(&mm->offset_hash, &list->hash);
316 drm_mm_put_block(list->file_offset_node);
320 EXPORT_SYMBOL(drm_gem_free_mmap_offset);
323 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
324 * @obj: obj in question
326 * GEM memory mapping works by handing back to userspace a fake mmap offset
327 * it can use in a subsequent mmap(2) call. The DRM core code then looks
328 * up the object based on the offset and sets up the various memory mapping
331 * This routine allocates and attaches a fake offset for @obj.
334 drm_gem_create_mmap_offset(struct drm_gem_object *obj)
336 struct drm_device *dev = obj->dev;
337 struct drm_gem_mm *mm = dev->mm_private;
338 struct drm_map_list *list;
339 struct drm_local_map *map;
342 /* Set the object up for mmap'ing */
343 list = &obj->map_list;
344 list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);
349 map->type = _DRM_GEM;
350 map->size = obj->size;
353 /* Get a DRM GEM mmap offset allocated... */
354 list->file_offset_node = drm_mm_search_free(&mm->offset_manager,
355 obj->size / PAGE_SIZE, 0, false);
357 if (!list->file_offset_node) {
358 DRM_ERROR("failed to allocate offset for bo %d\n", obj->name);
363 list->file_offset_node = drm_mm_get_block(list->file_offset_node,
364 obj->size / PAGE_SIZE, 0);
365 if (!list->file_offset_node) {
370 list->hash.key = list->file_offset_node->start;
371 ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);
373 DRM_ERROR("failed to add to map hash\n");
380 drm_mm_put_block(list->file_offset_node);
387 EXPORT_SYMBOL(drm_gem_create_mmap_offset);
389 /** Returns a reference to the object named by the handle. */
390 struct drm_gem_object *
391 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
394 struct drm_gem_object *obj;
396 spin_lock(&filp->table_lock);
398 /* Check if we currently have a reference on the object */
399 obj = idr_find(&filp->object_idr, handle);
401 spin_unlock(&filp->table_lock);
405 drm_gem_object_reference(obj);
407 spin_unlock(&filp->table_lock);
411 EXPORT_SYMBOL(drm_gem_object_lookup);
414 * Releases the handle to an mm object.
417 drm_gem_close_ioctl(struct drm_device *dev, void *data,
418 struct drm_file *file_priv)
420 struct drm_gem_close *args = data;
423 if (!(dev->driver->driver_features & DRIVER_GEM))
426 ret = drm_gem_handle_delete(file_priv, args->handle);
432 * Create a global name for an object, returning the name.
434 * Note that the name does not hold a reference; when the object
435 * is freed, the name goes away.
438 drm_gem_flink_ioctl(struct drm_device *dev, void *data,
439 struct drm_file *file_priv)
441 struct drm_gem_flink *args = data;
442 struct drm_gem_object *obj;
445 if (!(dev->driver->driver_features & DRIVER_GEM))
448 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
452 idr_preload(GFP_KERNEL);
453 spin_lock(&dev->object_name_lock);
455 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_NOWAIT);
461 /* Allocate a reference for the name table. */
462 drm_gem_object_reference(obj);
465 args->name = (uint64_t) obj->name;
469 spin_unlock(&dev->object_name_lock);
471 drm_gem_object_unreference_unlocked(obj);
476 * Open an object using the global name, returning a handle and the size.
478 * This handle (of course) holds a reference to the object, so the object
479 * will not go away until the handle is deleted.
482 drm_gem_open_ioctl(struct drm_device *dev, void *data,
483 struct drm_file *file_priv)
485 struct drm_gem_open *args = data;
486 struct drm_gem_object *obj;
490 if (!(dev->driver->driver_features & DRIVER_GEM))
493 spin_lock(&dev->object_name_lock);
494 obj = idr_find(&dev->object_name_idr, (int) args->name);
496 drm_gem_object_reference(obj);
497 spin_unlock(&dev->object_name_lock);
501 ret = drm_gem_handle_create(file_priv, obj, &handle);
502 drm_gem_object_unreference_unlocked(obj);
506 args->handle = handle;
507 args->size = obj->size;
513 * Called at device open time, sets up the structure for handling refcounting
517 drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
519 idr_init(&file_private->object_idr);
520 spin_lock_init(&file_private->table_lock);
524 * Called at device close to release the file's
525 * handle references on objects.
528 drm_gem_object_release_handle(int id, void *ptr, void *data)
530 struct drm_file *file_priv = data;
531 struct drm_gem_object *obj = ptr;
532 struct drm_device *dev = obj->dev;
534 drm_gem_remove_prime_handles(obj, file_priv);
536 if (dev->driver->gem_close_object)
537 dev->driver->gem_close_object(obj, file_priv);
539 drm_gem_object_handle_unreference_unlocked(obj);
545 * Called at close time when the filp is going away.
547 * Releases any remaining references on objects by this filp.
550 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
552 idr_for_each(&file_private->object_idr,
553 &drm_gem_object_release_handle, file_private);
554 idr_destroy(&file_private->object_idr);
558 drm_gem_object_release(struct drm_gem_object *obj)
563 EXPORT_SYMBOL(drm_gem_object_release);
566 * Called after the last reference to the object has been lost.
567 * Must be called holding struct_ mutex
572 drm_gem_object_free(struct kref *kref)
574 struct drm_gem_object *obj = (struct drm_gem_object *) kref;
575 struct drm_device *dev = obj->dev;
577 BUG_ON(!mutex_is_locked(&dev->struct_mutex));
579 if (dev->driver->gem_free_object != NULL)
580 dev->driver->gem_free_object(obj);
582 EXPORT_SYMBOL(drm_gem_object_free);
584 static void drm_gem_object_ref_bug(struct kref *list_kref)
590 * Called after the last handle to the object has been closed
592 * Removes any name for the object. Note that this must be
593 * called before drm_gem_object_free or we'll be touching
596 void drm_gem_object_handle_free(struct drm_gem_object *obj)
598 struct drm_device *dev = obj->dev;
600 /* Remove any name for this object */
601 spin_lock(&dev->object_name_lock);
603 idr_remove(&dev->object_name_idr, obj->name);
605 spin_unlock(&dev->object_name_lock);
607 * The object name held a reference to this object, drop
610 * This cannot be the last reference, since the handle holds one too.
612 kref_put(&obj->refcount, drm_gem_object_ref_bug);
614 spin_unlock(&dev->object_name_lock);
617 EXPORT_SYMBOL(drm_gem_object_handle_free);
619 void drm_gem_vm_open(struct vm_area_struct *vma)
621 struct drm_gem_object *obj = vma->vm_private_data;
623 drm_gem_object_reference(obj);
625 mutex_lock(&obj->dev->struct_mutex);
626 drm_vm_open_locked(obj->dev, vma);
627 mutex_unlock(&obj->dev->struct_mutex);
629 EXPORT_SYMBOL(drm_gem_vm_open);
631 void drm_gem_vm_close(struct vm_area_struct *vma)
633 struct drm_gem_object *obj = vma->vm_private_data;
634 struct drm_device *dev = obj->dev;
636 mutex_lock(&dev->struct_mutex);
637 drm_vm_close_locked(obj->dev, vma);
638 drm_gem_object_unreference(obj);
639 mutex_unlock(&dev->struct_mutex);
641 EXPORT_SYMBOL(drm_gem_vm_close);
644 * drm_gem_mmap_obj - memory map a GEM object
645 * @obj: the GEM object to map
646 * @obj_size: the object size to be mapped, in bytes
647 * @vma: VMA for the area to be mapped
649 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
650 * provided by the driver. Depending on their requirements, drivers can either
651 * provide a fault handler in their gem_vm_ops (in which case any accesses to
652 * the object will be trapped, to perform migration, GTT binding, surface
653 * register allocation, or performance monitoring), or mmap the buffer memory
654 * synchronously after calling drm_gem_mmap_obj.
656 * This function is mainly intended to implement the DMABUF mmap operation, when
657 * the GEM object is not looked up based on its fake offset. To implement the
658 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
660 * NOTE: This function has to be protected with dev->struct_mutex
662 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
663 * size, or if no gem_vm_ops are provided.
665 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
666 struct vm_area_struct *vma)
668 struct drm_device *dev = obj->dev;
670 lockdep_assert_held(&dev->struct_mutex);
672 /* Check for valid size. */
673 if (obj_size < vma->vm_end - vma->vm_start)
676 if (!dev->driver->gem_vm_ops)
679 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
680 vma->vm_ops = dev->driver->gem_vm_ops;
681 vma->vm_private_data = obj;
682 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
684 /* Take a ref for this mapping of the object, so that the fault
685 * handler can dereference the mmap offset's pointer to the object.
686 * This reference is cleaned up by the corresponding vm_close
687 * (which should happen whether the vma was created by this call, or
688 * by a vm_open due to mremap or partial unmap or whatever).
690 drm_gem_object_reference(obj);
692 drm_vm_open_locked(dev, vma);
695 EXPORT_SYMBOL(drm_gem_mmap_obj);
698 * drm_gem_mmap - memory map routine for GEM objects
699 * @filp: DRM file pointer
700 * @vma: VMA for the area to be mapped
702 * If a driver supports GEM object mapping, mmap calls on the DRM file
703 * descriptor will end up here.
705 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
706 * contain the fake offset we created when the GTT map ioctl was called on
707 * the object) and map it with a call to drm_gem_mmap_obj().
709 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
711 struct drm_file *priv = filp->private_data;
712 struct drm_device *dev = priv->minor->dev;
713 struct drm_gem_mm *mm = dev->mm_private;
714 struct drm_local_map *map = NULL;
715 struct drm_hash_item *hash;
718 if (drm_device_is_unplugged(dev))
721 mutex_lock(&dev->struct_mutex);
723 if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) {
724 mutex_unlock(&dev->struct_mutex);
725 return drm_mmap(filp, vma);
728 map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
730 ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) {
735 ret = drm_gem_mmap_obj(map->handle, map->size, vma);
738 mutex_unlock(&dev->struct_mutex);
742 EXPORT_SYMBOL(drm_gem_mmap);