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.
276 /* ensure there is space available to allocate a handle */
277 if (idr_pre_get(&file_priv->object_idr, GFP_KERNEL) == 0)
280 /* do the allocation under our spinlock */
281 spin_lock(&file_priv->table_lock);
282 ret = idr_get_new_above(&file_priv->object_idr, obj, 1, (int *)handlep);
283 spin_unlock(&file_priv->table_lock);
290 drm_gem_object_handle_reference(obj);
292 if (dev->driver->gem_open_object) {
293 ret = dev->driver->gem_open_object(obj, file_priv);
295 drm_gem_handle_delete(file_priv, *handlep);
302 EXPORT_SYMBOL(drm_gem_handle_create);
306 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
307 * @obj: obj in question
309 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
312 drm_gem_free_mmap_offset(struct drm_gem_object *obj)
314 struct drm_device *dev = obj->dev;
315 struct drm_gem_mm *mm = dev->mm_private;
316 struct drm_map_list *list = &obj->map_list;
318 drm_ht_remove_item(&mm->offset_hash, &list->hash);
319 drm_mm_put_block(list->file_offset_node);
323 EXPORT_SYMBOL(drm_gem_free_mmap_offset);
326 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
327 * @obj: obj in question
329 * GEM memory mapping works by handing back to userspace a fake mmap offset
330 * it can use in a subsequent mmap(2) call. The DRM core code then looks
331 * up the object based on the offset and sets up the various memory mapping
334 * This routine allocates and attaches a fake offset for @obj.
337 drm_gem_create_mmap_offset(struct drm_gem_object *obj)
339 struct drm_device *dev = obj->dev;
340 struct drm_gem_mm *mm = dev->mm_private;
341 struct drm_map_list *list;
342 struct drm_local_map *map;
345 /* Set the object up for mmap'ing */
346 list = &obj->map_list;
347 list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);
352 map->type = _DRM_GEM;
353 map->size = obj->size;
356 /* Get a DRM GEM mmap offset allocated... */
357 list->file_offset_node = drm_mm_search_free(&mm->offset_manager,
358 obj->size / PAGE_SIZE, 0, 0);
360 if (!list->file_offset_node) {
361 DRM_ERROR("failed to allocate offset for bo %d\n", obj->name);
366 list->file_offset_node = drm_mm_get_block(list->file_offset_node,
367 obj->size / PAGE_SIZE, 0);
368 if (!list->file_offset_node) {
373 list->hash.key = list->file_offset_node->start;
374 ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);
376 DRM_ERROR("failed to add to map hash\n");
383 drm_mm_put_block(list->file_offset_node);
390 EXPORT_SYMBOL(drm_gem_create_mmap_offset);
392 /** Returns a reference to the object named by the handle. */
393 struct drm_gem_object *
394 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
397 struct drm_gem_object *obj;
399 spin_lock(&filp->table_lock);
401 /* Check if we currently have a reference on the object */
402 obj = idr_find(&filp->object_idr, handle);
404 spin_unlock(&filp->table_lock);
408 drm_gem_object_reference(obj);
410 spin_unlock(&filp->table_lock);
414 EXPORT_SYMBOL(drm_gem_object_lookup);
417 * Releases the handle to an mm object.
420 drm_gem_close_ioctl(struct drm_device *dev, void *data,
421 struct drm_file *file_priv)
423 struct drm_gem_close *args = data;
426 if (!(dev->driver->driver_features & DRIVER_GEM))
429 ret = drm_gem_handle_delete(file_priv, args->handle);
435 * Create a global name for an object, returning the name.
437 * Note that the name does not hold a reference; when the object
438 * is freed, the name goes away.
441 drm_gem_flink_ioctl(struct drm_device *dev, void *data,
442 struct drm_file *file_priv)
444 struct drm_gem_flink *args = data;
445 struct drm_gem_object *obj;
448 if (!(dev->driver->driver_features & DRIVER_GEM))
451 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
456 if (idr_pre_get(&dev->object_name_idr, GFP_KERNEL) == 0) {
461 spin_lock(&dev->object_name_lock);
463 ret = idr_get_new_above(&dev->object_name_idr, obj, 1,
465 args->name = (uint64_t) obj->name;
466 spin_unlock(&dev->object_name_lock);
474 /* Allocate a reference for the name table. */
475 drm_gem_object_reference(obj);
477 args->name = (uint64_t) obj->name;
478 spin_unlock(&dev->object_name_lock);
483 drm_gem_object_unreference_unlocked(obj);
488 * Open an object using the global name, returning a handle and the size.
490 * This handle (of course) holds a reference to the object, so the object
491 * will not go away until the handle is deleted.
494 drm_gem_open_ioctl(struct drm_device *dev, void *data,
495 struct drm_file *file_priv)
497 struct drm_gem_open *args = data;
498 struct drm_gem_object *obj;
502 if (!(dev->driver->driver_features & DRIVER_GEM))
505 spin_lock(&dev->object_name_lock);
506 obj = idr_find(&dev->object_name_idr, (int) args->name);
508 drm_gem_object_reference(obj);
509 spin_unlock(&dev->object_name_lock);
513 ret = drm_gem_handle_create(file_priv, obj, &handle);
514 drm_gem_object_unreference_unlocked(obj);
518 args->handle = handle;
519 args->size = obj->size;
525 * Called at device open time, sets up the structure for handling refcounting
529 drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
531 idr_init(&file_private->object_idr);
532 spin_lock_init(&file_private->table_lock);
536 * Called at device close to release the file's
537 * handle references on objects.
540 drm_gem_object_release_handle(int id, void *ptr, void *data)
542 struct drm_file *file_priv = data;
543 struct drm_gem_object *obj = ptr;
544 struct drm_device *dev = obj->dev;
546 drm_gem_remove_prime_handles(obj, file_priv);
548 if (dev->driver->gem_close_object)
549 dev->driver->gem_close_object(obj, file_priv);
551 drm_gem_object_handle_unreference_unlocked(obj);
557 * Called at close time when the filp is going away.
559 * Releases any remaining references on objects by this filp.
562 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
564 idr_for_each(&file_private->object_idr,
565 &drm_gem_object_release_handle, file_private);
567 idr_remove_all(&file_private->object_idr);
568 idr_destroy(&file_private->object_idr);
572 drm_gem_object_release(struct drm_gem_object *obj)
577 EXPORT_SYMBOL(drm_gem_object_release);
580 * Called after the last reference to the object has been lost.
581 * Must be called holding struct_ mutex
586 drm_gem_object_free(struct kref *kref)
588 struct drm_gem_object *obj = (struct drm_gem_object *) kref;
589 struct drm_device *dev = obj->dev;
591 BUG_ON(!mutex_is_locked(&dev->struct_mutex));
593 if (dev->driver->gem_free_object != NULL)
594 dev->driver->gem_free_object(obj);
596 EXPORT_SYMBOL(drm_gem_object_free);
598 static void drm_gem_object_ref_bug(struct kref *list_kref)
604 * Called after the last handle to the object has been closed
606 * Removes any name for the object. Note that this must be
607 * called before drm_gem_object_free or we'll be touching
610 void drm_gem_object_handle_free(struct drm_gem_object *obj)
612 struct drm_device *dev = obj->dev;
614 /* Remove any name for this object */
615 spin_lock(&dev->object_name_lock);
617 idr_remove(&dev->object_name_idr, obj->name);
619 spin_unlock(&dev->object_name_lock);
621 * The object name held a reference to this object, drop
624 * This cannot be the last reference, since the handle holds one too.
626 kref_put(&obj->refcount, drm_gem_object_ref_bug);
628 spin_unlock(&dev->object_name_lock);
631 EXPORT_SYMBOL(drm_gem_object_handle_free);
633 void drm_gem_vm_open(struct vm_area_struct *vma)
635 struct drm_gem_object *obj = vma->vm_private_data;
637 drm_gem_object_reference(obj);
639 mutex_lock(&obj->dev->struct_mutex);
640 drm_vm_open_locked(vma);
641 mutex_unlock(&obj->dev->struct_mutex);
643 EXPORT_SYMBOL(drm_gem_vm_open);
645 void drm_gem_vm_close(struct vm_area_struct *vma)
647 struct drm_gem_object *obj = vma->vm_private_data;
648 struct drm_device *dev = obj->dev;
650 mutex_lock(&dev->struct_mutex);
651 drm_vm_close_locked(vma);
652 drm_gem_object_unreference(obj);
653 mutex_unlock(&dev->struct_mutex);
655 EXPORT_SYMBOL(drm_gem_vm_close);
659 * drm_gem_mmap - memory map routine for GEM objects
660 * @filp: DRM file pointer
661 * @vma: VMA for the area to be mapped
663 * If a driver supports GEM object mapping, mmap calls on the DRM file
664 * descriptor will end up here.
666 * If we find the object based on the offset passed in (vma->vm_pgoff will
667 * contain the fake offset we created when the GTT map ioctl was called on
668 * the object), we set up the driver fault handler so that any accesses
669 * to the object can be trapped, to perform migration, GTT binding, surface
670 * register allocation, or performance monitoring.
672 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
674 struct drm_file *priv = filp->private_data;
675 struct drm_device *dev = priv->minor->dev;
676 struct drm_gem_mm *mm = dev->mm_private;
677 struct drm_local_map *map = NULL;
678 struct drm_gem_object *obj;
679 struct drm_hash_item *hash;
682 if (drm_device_is_unplugged(dev))
685 mutex_lock(&dev->struct_mutex);
687 if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) {
688 mutex_unlock(&dev->struct_mutex);
689 return drm_mmap(filp, vma);
692 map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
694 ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) {
699 /* Check for valid size. */
700 if (map->size < vma->vm_end - vma->vm_start) {
706 if (!obj->dev->driver->gem_vm_ops) {
711 vma->vm_flags |= VM_RESERVED | VM_IO | VM_PFNMAP | VM_DONTEXPAND;
712 vma->vm_ops = obj->dev->driver->gem_vm_ops;
713 vma->vm_private_data = map->handle;
714 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
716 /* Take a ref for this mapping of the object, so that the fault
717 * handler can dereference the mmap offset's pointer to the object.
718 * This reference is cleaned up by the corresponding vm_close
719 * (which should happen whether the vma was created by this call, or
720 * by a vm_open due to mremap or partial unmap or whatever).
722 drm_gem_object_reference(obj);
724 drm_vm_open_locked(vma);
727 mutex_unlock(&dev->struct_mutex);
731 EXPORT_SYMBOL(drm_gem_mmap);