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>
41 * This file provides some of the base ioctls and library routines for
42 * the graphics memory manager implemented by each device driver.
44 * Because various devices have different requirements in terms of
45 * synchronization and migration strategies, implementing that is left up to
46 * the driver, and all that the general API provides should be generic --
47 * allocating objects, reading/writing data with the cpu, freeing objects.
48 * Even there, platform-dependent optimizations for reading/writing data with
49 * the CPU mean we'll likely hook those out to driver-specific calls. However,
50 * the DRI2 implementation wants to have at least allocate/mmap be generic.
52 * The goal was to have swap-backed object allocation managed through
53 * struct file. However, file descriptors as handles to a struct file have
55 * - Process limits prevent more than 1024 or so being used at a time by
57 * - Inability to allocate high fds will aggravate the X Server's select()
58 * handling, and likely that of many GL client applications as well.
60 * This led to a plan of using our own integer IDs (called handles, following
61 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
62 * ioctls. The objects themselves will still include the struct file so
63 * that we can transition to fds if the required kernel infrastructure shows
64 * up at a later date, and as our interface with shmfs for memory allocation.
68 * We make up offsets for buffer objects so we can recognize them at
71 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
72 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
75 * Initialize the GEM device fields
79 drm_gem_init(struct drm_device *dev)
81 struct drm_gem_mm *mm;
83 spin_lock_init(&dev->object_name_lock);
84 idr_init(&dev->object_name_idr);
85 atomic_set(&dev->object_count, 0);
86 atomic_set(&dev->object_memory, 0);
87 atomic_set(&dev->pin_count, 0);
88 atomic_set(&dev->pin_memory, 0);
89 atomic_set(&dev->gtt_count, 0);
90 atomic_set(&dev->gtt_memory, 0);
92 mm = drm_calloc(1, sizeof(struct drm_gem_mm), DRM_MEM_MM);
94 DRM_ERROR("out of memory\n");
100 if (drm_ht_create(&mm->offset_hash, 19)) {
101 drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM);
105 if (drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START,
106 DRM_FILE_PAGE_OFFSET_SIZE)) {
107 drm_ht_remove(&mm->offset_hash);
108 drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM);
116 drm_gem_destroy(struct drm_device *dev)
118 struct drm_gem_mm *mm = dev->mm_private;
120 drm_mm_takedown(&mm->offset_manager);
121 drm_ht_remove(&mm->offset_hash);
122 drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM);
123 dev->mm_private = NULL;
127 * Allocate a GEM object of the specified size with shmfs backing store
129 struct drm_gem_object *
130 drm_gem_object_alloc(struct drm_device *dev, size_t size)
132 struct drm_gem_object *obj;
134 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
136 obj = kcalloc(1, sizeof(*obj), GFP_KERNEL);
139 obj->filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
140 if (IS_ERR(obj->filp)) {
145 kref_init(&obj->refcount);
146 kref_init(&obj->handlecount);
148 if (dev->driver->gem_init_object != NULL &&
149 dev->driver->gem_init_object(obj) != 0) {
154 atomic_inc(&dev->object_count);
155 atomic_add(obj->size, &dev->object_memory);
158 EXPORT_SYMBOL(drm_gem_object_alloc);
161 * Removes the mapping from handle to filp for this object.
164 drm_gem_handle_delete(struct drm_file *filp, int handle)
166 struct drm_device *dev;
167 struct drm_gem_object *obj;
169 /* This is gross. The idr system doesn't let us try a delete and
170 * return an error code. It just spews if you fail at deleting.
171 * So, we have to grab a lock around finding the object and then
172 * doing the delete on it and dropping the refcount, or the user
173 * could race us to double-decrement the refcount and cause a
174 * use-after-free later. Given the frequency of our handle lookups,
175 * we may want to use ida for number allocation and a hash table
176 * for the pointers, anyway.
178 spin_lock(&filp->table_lock);
180 /* Check if we currently have a reference on the object */
181 obj = idr_find(&filp->object_idr, handle);
183 spin_unlock(&filp->table_lock);
188 /* Release reference and decrement refcount. */
189 idr_remove(&filp->object_idr, handle);
190 spin_unlock(&filp->table_lock);
192 mutex_lock(&dev->struct_mutex);
193 drm_gem_object_handle_unreference(obj);
194 mutex_unlock(&dev->struct_mutex);
200 * Create a handle for this object. This adds a handle reference
201 * to the object, which includes a regular reference count. Callers
202 * will likely want to dereference the object afterwards.
205 drm_gem_handle_create(struct drm_file *file_priv,
206 struct drm_gem_object *obj,
212 * Get the user-visible handle using idr.
215 /* ensure there is space available to allocate a handle */
216 if (idr_pre_get(&file_priv->object_idr, GFP_KERNEL) == 0)
219 /* do the allocation under our spinlock */
220 spin_lock(&file_priv->table_lock);
221 ret = idr_get_new_above(&file_priv->object_idr, obj, 1, handlep);
222 spin_unlock(&file_priv->table_lock);
229 drm_gem_object_handle_reference(obj);
232 EXPORT_SYMBOL(drm_gem_handle_create);
234 /** Returns a reference to the object named by the handle. */
235 struct drm_gem_object *
236 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
239 struct drm_gem_object *obj;
241 spin_lock(&filp->table_lock);
243 /* Check if we currently have a reference on the object */
244 obj = idr_find(&filp->object_idr, handle);
246 spin_unlock(&filp->table_lock);
250 drm_gem_object_reference(obj);
252 spin_unlock(&filp->table_lock);
256 EXPORT_SYMBOL(drm_gem_object_lookup);
259 * Releases the handle to an mm object.
262 drm_gem_close_ioctl(struct drm_device *dev, void *data,
263 struct drm_file *file_priv)
265 struct drm_gem_close *args = data;
268 if (!(dev->driver->driver_features & DRIVER_GEM))
271 ret = drm_gem_handle_delete(file_priv, args->handle);
277 * Create a global name for an object, returning the name.
279 * Note that the name does not hold a reference; when the object
280 * is freed, the name goes away.
283 drm_gem_flink_ioctl(struct drm_device *dev, void *data,
284 struct drm_file *file_priv)
286 struct drm_gem_flink *args = data;
287 struct drm_gem_object *obj;
290 if (!(dev->driver->driver_features & DRIVER_GEM))
293 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
298 if (idr_pre_get(&dev->object_name_idr, GFP_KERNEL) == 0) {
303 spin_lock(&dev->object_name_lock);
305 args->name = obj->name;
306 spin_unlock(&dev->object_name_lock);
309 ret = idr_get_new_above(&dev->object_name_idr, obj, 1,
311 spin_unlock(&dev->object_name_lock);
319 * Leave the reference from the lookup around as the
320 * name table now holds one
322 args->name = (uint64_t) obj->name;
327 mutex_lock(&dev->struct_mutex);
328 drm_gem_object_unreference(obj);
329 mutex_unlock(&dev->struct_mutex);
334 * Open an object using the global name, returning a handle and the size.
336 * This handle (of course) holds a reference to the object, so the object
337 * will not go away until the handle is deleted.
340 drm_gem_open_ioctl(struct drm_device *dev, void *data,
341 struct drm_file *file_priv)
343 struct drm_gem_open *args = data;
344 struct drm_gem_object *obj;
348 if (!(dev->driver->driver_features & DRIVER_GEM))
351 spin_lock(&dev->object_name_lock);
352 obj = idr_find(&dev->object_name_idr, (int) args->name);
354 drm_gem_object_reference(obj);
355 spin_unlock(&dev->object_name_lock);
359 ret = drm_gem_handle_create(file_priv, obj, &handle);
360 mutex_lock(&dev->struct_mutex);
361 drm_gem_object_unreference(obj);
362 mutex_unlock(&dev->struct_mutex);
366 args->handle = handle;
367 args->size = obj->size;
373 * Called at device open time, sets up the structure for handling refcounting
377 drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
379 idr_init(&file_private->object_idr);
380 spin_lock_init(&file_private->table_lock);
384 * Called at device close to release the file's
385 * handle references on objects.
388 drm_gem_object_release_handle(int id, void *ptr, void *data)
390 struct drm_gem_object *obj = ptr;
392 drm_gem_object_handle_unreference(obj);
398 * Called at close time when the filp is going away.
400 * Releases any remaining references on objects by this filp.
403 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
405 mutex_lock(&dev->struct_mutex);
406 idr_for_each(&file_private->object_idr,
407 &drm_gem_object_release_handle, NULL);
409 idr_destroy(&file_private->object_idr);
410 mutex_unlock(&dev->struct_mutex);
414 * Called after the last reference to the object has been lost.
419 drm_gem_object_free(struct kref *kref)
421 struct drm_gem_object *obj = (struct drm_gem_object *) kref;
422 struct drm_device *dev = obj->dev;
424 BUG_ON(!mutex_is_locked(&dev->struct_mutex));
426 if (dev->driver->gem_free_object != NULL)
427 dev->driver->gem_free_object(obj);
430 atomic_dec(&dev->object_count);
431 atomic_sub(obj->size, &dev->object_memory);
434 EXPORT_SYMBOL(drm_gem_object_free);
437 * Called after the last handle to the object has been closed
439 * Removes any name for the object. Note that this must be
440 * called before drm_gem_object_free or we'll be touching
444 drm_gem_object_handle_free(struct kref *kref)
446 struct drm_gem_object *obj = container_of(kref,
447 struct drm_gem_object,
449 struct drm_device *dev = obj->dev;
451 /* Remove any name for this object */
452 spin_lock(&dev->object_name_lock);
454 idr_remove(&dev->object_name_idr, obj->name);
455 spin_unlock(&dev->object_name_lock);
457 * The object name held a reference to this object, drop
460 drm_gem_object_unreference(obj);
462 spin_unlock(&dev->object_name_lock);
465 EXPORT_SYMBOL(drm_gem_object_handle_free);
468 * drm_gem_mmap - memory map routine for GEM objects
469 * @filp: DRM file pointer
470 * @vma: VMA for the area to be mapped
472 * If a driver supports GEM object mapping, mmap calls on the DRM file
473 * descriptor will end up here.
475 * If we find the object based on the offset passed in (vma->vm_pgoff will
476 * contain the fake offset we created when the GTT map ioctl was called on
477 * the object), we set up the driver fault handler so that any accesses
478 * to the object can be trapped, to perform migration, GTT binding, surface
479 * register allocation, or performance monitoring.
481 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
483 struct drm_file *priv = filp->private_data;
484 struct drm_device *dev = priv->minor->dev;
485 struct drm_gem_mm *mm = dev->mm_private;
486 struct drm_map *map = NULL;
487 struct drm_gem_object *obj;
488 struct drm_hash_item *hash;
492 mutex_lock(&dev->struct_mutex);
494 if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) {
495 mutex_unlock(&dev->struct_mutex);
496 return drm_mmap(filp, vma);
499 map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
501 ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) {
506 /* Check for valid size. */
507 if (map->size < vma->vm_end - vma->vm_start) {
513 if (!obj->dev->driver->gem_vm_ops) {
518 vma->vm_flags |= VM_RESERVED | VM_IO | VM_PFNMAP | VM_DONTEXPAND;
519 vma->vm_ops = obj->dev->driver->gem_vm_ops;
520 vma->vm_private_data = map->handle;
521 /* FIXME: use pgprot_writecombine when available */
522 prot = pgprot_val(vma->vm_page_prot);
524 prot |= _PAGE_CACHE_WC;
526 vma->vm_page_prot = __pgprot(prot);
528 vma->vm_file = filp; /* Needed for drm_vm_open() */
529 drm_vm_open_locked(vma);
532 mutex_unlock(&dev->struct_mutex);
536 EXPORT_SYMBOL(drm_gem_mmap);