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
);