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)
141 filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
143 return PTR_ERR(filp);
145 drm_gem_private_object_init(dev, obj, size);
150 EXPORT_SYMBOL(drm_gem_object_init);
153 * Initialize an already allocated GEM object of the specified size with
154 * no GEM provided backing store. Instead the caller is responsible for
155 * backing the object and handling it.
157 void drm_gem_private_object_init(struct drm_device *dev,
158 struct drm_gem_object *obj, size_t size)
160 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
165 kref_init(&obj->refcount);
166 atomic_set(&obj->handle_count, 0);
169 EXPORT_SYMBOL(drm_gem_private_object_init);
172 * Allocate a GEM object of the specified size with shmfs backing store
174 struct drm_gem_object *
175 drm_gem_object_alloc(struct drm_device *dev, size_t size)
177 struct drm_gem_object *obj;
179 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
183 if (drm_gem_object_init(dev, obj, size) != 0)
186 if (dev->driver->gem_init_object != NULL &&
187 dev->driver->gem_init_object(obj) != 0) {
192 /* Object_init mangles the global counters - readjust them. */
198 EXPORT_SYMBOL(drm_gem_object_alloc);
201 drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
203 if (obj->import_attach) {
204 drm_prime_remove_buf_handle(&filp->prime,
205 obj->import_attach->dmabuf);
207 if (obj->export_dma_buf) {
208 drm_prime_remove_buf_handle(&filp->prime,
209 obj->export_dma_buf);
214 * Removes the mapping from handle to filp for this object.
217 drm_gem_handle_delete(struct drm_file *filp, u32 handle)
219 struct drm_device *dev;
220 struct drm_gem_object *obj;
222 /* This is gross. The idr system doesn't let us try a delete and
223 * return an error code. It just spews if you fail at deleting.
224 * So, we have to grab a lock around finding the object and then
225 * doing the delete on it and dropping the refcount, or the user
226 * could race us to double-decrement the refcount and cause a
227 * use-after-free later. Given the frequency of our handle lookups,
228 * we may want to use ida for number allocation and a hash table
229 * for the pointers, anyway.
231 spin_lock(&filp->table_lock);
233 /* Check if we currently have a reference on the object */
234 obj = idr_find(&filp->object_idr, handle);
236 spin_unlock(&filp->table_lock);
241 DRM_DEBUG("%s:hdl[%d]obj[0x%x]\n", __func__, handle, (int)obj);
243 /* Release reference and decrement refcount. */
244 idr_remove(&filp->object_idr, handle);
245 spin_unlock(&filp->table_lock);
247 drm_gem_remove_prime_handles(obj, filp);
249 if (dev->driver->gem_close_object)
250 dev->driver->gem_close_object(obj, filp);
251 drm_gem_object_handle_unreference_unlocked(obj);
255 EXPORT_SYMBOL(drm_gem_handle_delete);
258 * Create a handle for this object. This adds a handle reference
259 * to the object, which includes a regular reference count. Callers
260 * will likely want to dereference the object afterwards.
263 drm_gem_handle_create(struct drm_file *file_priv,
264 struct drm_gem_object *obj,
267 struct drm_device *dev = obj->dev;
271 * Get the user-visible handle using idr. Preload and perform
272 * allocation under our spinlock.
274 idr_preload(GFP_KERNEL);
275 spin_lock(&file_priv->table_lock);
277 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
279 spin_unlock(&file_priv->table_lock);
285 drm_gem_object_handle_reference(obj);
287 if (dev->driver->gem_open_object) {
288 ret = dev->driver->gem_open_object(obj, file_priv);
290 drm_gem_handle_delete(file_priv, *handlep);
297 EXPORT_SYMBOL(drm_gem_handle_create);
301 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
302 * @obj: obj in question
304 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
307 drm_gem_free_mmap_offset(struct drm_gem_object *obj)
309 struct drm_device *dev = obj->dev;
310 struct drm_gem_mm *mm = dev->mm_private;
311 struct drm_map_list *list = &obj->map_list;
313 drm_ht_remove_item(&mm->offset_hash, &list->hash);
314 drm_mm_put_block(list->file_offset_node);
318 EXPORT_SYMBOL(drm_gem_free_mmap_offset);
321 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
322 * @obj: obj in question
324 * GEM memory mapping works by handing back to userspace a fake mmap offset
325 * it can use in a subsequent mmap(2) call. The DRM core code then looks
326 * up the object based on the offset and sets up the various memory mapping
329 * This routine allocates and attaches a fake offset for @obj.
332 drm_gem_create_mmap_offset(struct drm_gem_object *obj)
334 struct drm_device *dev = obj->dev;
335 struct drm_gem_mm *mm = dev->mm_private;
336 struct drm_map_list *list;
337 struct drm_local_map *map;
340 /* Set the object up for mmap'ing */
341 list = &obj->map_list;
342 list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);
347 map->type = _DRM_GEM;
348 map->size = obj->size;
351 /* Get a DRM GEM mmap offset allocated... */
352 list->file_offset_node = drm_mm_search_free(&mm->offset_manager,
353 obj->size / PAGE_SIZE, 0, false);
355 if (!list->file_offset_node) {
356 DRM_ERROR("failed to allocate offset for bo %d\n", obj->name);
361 list->file_offset_node = drm_mm_get_block(list->file_offset_node,
362 obj->size / PAGE_SIZE, 0);
363 if (!list->file_offset_node) {
368 list->hash.key = list->file_offset_node->start;
369 ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);
371 DRM_ERROR("failed to add to map hash\n");
378 drm_mm_put_block(list->file_offset_node);
385 EXPORT_SYMBOL(drm_gem_create_mmap_offset);
387 /** Returns a reference to the object named by the handle. */
388 struct drm_gem_object *
389 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
392 struct drm_gem_object *obj;
394 spin_lock(&filp->table_lock);
396 /* Check if we currently have a reference on the object */
397 obj = idr_find(&filp->object_idr, handle);
399 spin_unlock(&filp->table_lock);
403 drm_gem_object_reference(obj);
405 spin_unlock(&filp->table_lock);
409 EXPORT_SYMBOL(drm_gem_object_lookup);
412 * Releases the handle to an mm object.
415 drm_gem_close_ioctl(struct drm_device *dev, void *data,
416 struct drm_file *file_priv)
418 struct drm_gem_close *args = data;
421 if (!(dev->driver->driver_features & DRIVER_GEM))
424 ret = drm_gem_handle_delete(file_priv, args->handle);
430 * Create a global name for an object, returning the name.
432 * Note that the name does not hold a reference; when the object
433 * is freed, the name goes away.
436 drm_gem_flink_ioctl(struct drm_device *dev, void *data,
437 struct drm_file *file_priv)
439 struct drm_gem_flink *args = data;
440 struct drm_gem_object *obj;
443 if (!(dev->driver->driver_features & DRIVER_GEM))
446 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
450 idr_preload(GFP_KERNEL);
451 spin_lock(&dev->object_name_lock);
453 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_NOWAIT);
459 /* Allocate a reference for the name table. */
460 drm_gem_object_reference(obj);
463 args->name = (uint64_t) obj->name;
467 spin_unlock(&dev->object_name_lock);
469 drm_gem_object_unreference_unlocked(obj);
471 DRM_DEBUG("%s:hdl[%d]obj[0x%x]name[%d]\n",
472 __func__, (int) args->handle, (int)obj, args->name);
478 * Open an object using the global name, returning a handle and the size.
480 * This handle (of course) holds a reference to the object, so the object
481 * will not go away until the handle is deleted.
484 drm_gem_open_ioctl(struct drm_device *dev, void *data,
485 struct drm_file *file_priv)
487 struct drm_gem_open *args = data;
488 struct drm_gem_object *obj;
492 if (!(dev->driver->driver_features & DRIVER_GEM))
495 spin_lock(&dev->object_name_lock);
496 obj = idr_find(&dev->object_name_idr, (int) args->name);
498 drm_gem_object_reference(obj);
499 spin_unlock(&dev->object_name_lock);
503 ret = drm_gem_handle_create(file_priv, obj, &handle);
504 drm_gem_object_unreference_unlocked(obj);
508 args->handle = handle;
509 args->size = obj->size;
511 DRM_DEBUG("%s:name[%d]obj[0x%x]hdl[%d]sz[%d]\n",
512 __func__, (int) args->name, (int)obj,
513 args->handle, (int)args->size);
519 * Called at device open time, sets up the structure for handling refcounting
523 drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
525 idr_init(&file_private->object_idr);
526 spin_lock_init(&file_private->table_lock);
530 * Called at device close to release the file's
531 * handle references on objects.
534 drm_gem_object_release_handle(int id, void *ptr, void *data)
536 struct drm_file *file_priv = data;
537 struct drm_gem_object *obj = ptr;
538 struct drm_device *dev = obj->dev;
540 drm_gem_remove_prime_handles(obj, file_priv);
542 if (dev->driver->gem_close_object)
543 dev->driver->gem_close_object(obj, file_priv);
545 drm_gem_object_handle_unreference_unlocked(obj);
551 * Called at close time when the filp is going away.
553 * Releases any remaining references on objects by this filp.
556 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
558 idr_for_each(&file_private->object_idr,
559 &drm_gem_object_release_handle, file_private);
560 idr_destroy(&file_private->object_idr);
564 drm_gem_object_release(struct drm_gem_object *obj)
569 EXPORT_SYMBOL(drm_gem_object_release);
572 * Called after the last reference to the object has been lost.
573 * Must be called holding struct_ mutex
578 drm_gem_object_free(struct kref *kref)
580 struct drm_gem_object *obj = (struct drm_gem_object *) kref;
581 struct drm_device *dev = obj->dev;
583 BUG_ON(!mutex_is_locked(&dev->struct_mutex));
585 if (dev->driver->gem_free_object != NULL)
586 dev->driver->gem_free_object(obj);
588 EXPORT_SYMBOL(drm_gem_object_free);
590 static void drm_gem_object_ref_bug(struct kref *list_kref)
596 * Called after the last handle to the object has been closed
598 * Removes any name for the object. Note that this must be
599 * called before drm_gem_object_free or we'll be touching
602 void drm_gem_object_handle_free(struct drm_gem_object *obj)
604 struct drm_device *dev = obj->dev;
606 /* Remove any name for this object */
607 spin_lock(&dev->object_name_lock);
609 idr_remove(&dev->object_name_idr, obj->name);
611 spin_unlock(&dev->object_name_lock);
613 * The object name held a reference to this object, drop
616 * This cannot be the last reference, since the handle holds one too.
618 kref_put(&obj->refcount, drm_gem_object_ref_bug);
620 spin_unlock(&dev->object_name_lock);
623 EXPORT_SYMBOL(drm_gem_object_handle_free);
625 void drm_gem_vm_open(struct vm_area_struct *vma)
627 struct drm_gem_object *obj = vma->vm_private_data;
629 drm_gem_object_reference(obj);
631 mutex_lock(&obj->dev->struct_mutex);
632 drm_vm_open_locked(obj->dev, vma);
633 mutex_unlock(&obj->dev->struct_mutex);
635 EXPORT_SYMBOL(drm_gem_vm_open);
637 void drm_gem_vm_close(struct vm_area_struct *vma)
639 struct drm_gem_object *obj = vma->vm_private_data;
640 struct drm_device *dev = obj->dev;
642 mutex_lock(&dev->struct_mutex);
643 drm_vm_close_locked(obj->dev, vma);
644 drm_gem_object_unreference(obj);
645 mutex_unlock(&dev->struct_mutex);
647 EXPORT_SYMBOL(drm_gem_vm_close);
650 * drm_gem_mmap_obj - memory map a GEM object
651 * @obj: the GEM object to map
652 * @obj_size: the object size to be mapped, in bytes
653 * @vma: VMA for the area to be mapped
655 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
656 * provided by the driver. Depending on their requirements, drivers can either
657 * provide a fault handler in their gem_vm_ops (in which case any accesses to
658 * the object will be trapped, to perform migration, GTT binding, surface
659 * register allocation, or performance monitoring), or mmap the buffer memory
660 * synchronously after calling drm_gem_mmap_obj.
662 * This function is mainly intended to implement the DMABUF mmap operation, when
663 * the GEM object is not looked up based on its fake offset. To implement the
664 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
666 * NOTE: This function has to be protected with dev->struct_mutex
668 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
669 * size, or if no gem_vm_ops are provided.
671 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
672 struct vm_area_struct *vma)
674 struct drm_device *dev = obj->dev;
676 lockdep_assert_held(&dev->struct_mutex);
678 /* Check for valid size. */
679 if (obj_size < vma->vm_end - vma->vm_start)
682 if (!dev->driver->gem_vm_ops)
685 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
686 vma->vm_ops = dev->driver->gem_vm_ops;
687 vma->vm_private_data = obj;
688 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
690 /* Take a ref for this mapping of the object, so that the fault
691 * handler can dereference the mmap offset's pointer to the object.
692 * This reference is cleaned up by the corresponding vm_close
693 * (which should happen whether the vma was created by this call, or
694 * by a vm_open due to mremap or partial unmap or whatever).
696 drm_gem_object_reference(obj);
698 drm_vm_open_locked(dev, vma);
701 EXPORT_SYMBOL(drm_gem_mmap_obj);
704 * drm_gem_mmap - memory map routine for GEM objects
705 * @filp: DRM file pointer
706 * @vma: VMA for the area to be mapped
708 * If a driver supports GEM object mapping, mmap calls on the DRM file
709 * descriptor will end up here.
711 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
712 * contain the fake offset we created when the GTT map ioctl was called on
713 * the object) and map it with a call to drm_gem_mmap_obj().
715 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
717 struct drm_file *priv = filp->private_data;
718 struct drm_device *dev = priv->minor->dev;
719 struct drm_gem_mm *mm = dev->mm_private;
720 struct drm_local_map *map = NULL;
721 struct drm_hash_item *hash;
724 if (drm_device_is_unplugged(dev))
727 mutex_lock(&dev->struct_mutex);
729 if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) {
730 mutex_unlock(&dev->struct_mutex);
731 return drm_mmap(filp, vma);
734 map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
736 ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) {
741 ret = drm_gem_mmap_obj(map->handle, map->size, vma);
744 mutex_unlock(&dev->struct_mutex);
748 EXPORT_SYMBOL(drm_gem_mmap);