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
72 /* pgoff in mmap is an unsigned long, so we need to make sure that
73 * the faked up offset will fit
76 #if BITS_PER_LONG == 64
77 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
78 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
80 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
81 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
85 * Initialize the GEM device fields
89 drm_gem_init(struct drm_device
*dev
)
91 struct drm_gem_mm
*mm
;
93 spin_lock_init(&dev
->object_name_lock
);
94 idr_init(&dev
->object_name_idr
);
96 mm
= kzalloc(sizeof(struct drm_gem_mm
), GFP_KERNEL
);
98 DRM_ERROR("out of memory\n");
102 dev
->mm_private
= mm
;
104 if (drm_ht_create(&mm
->offset_hash
, 12)) {
109 if (drm_mm_init(&mm
->offset_manager
, DRM_FILE_PAGE_OFFSET_START
,
110 DRM_FILE_PAGE_OFFSET_SIZE
)) {
111 drm_ht_remove(&mm
->offset_hash
);
120 drm_gem_destroy(struct drm_device
*dev
)
122 struct drm_gem_mm
*mm
= dev
->mm_private
;
124 drm_mm_takedown(&mm
->offset_manager
);
125 drm_ht_remove(&mm
->offset_hash
);
127 dev
->mm_private
= NULL
;
131 * Initialize an already allocate GEM object of the specified size with
132 * shmfs backing store.
134 int drm_gem_object_init(struct drm_device
*dev
,
135 struct drm_gem_object
*obj
, size_t size
)
137 BUG_ON((size
& (PAGE_SIZE
- 1)) != 0);
140 obj
->filp
= shmem_file_setup("drm mm object", size
, VM_NORESERVE
);
141 if (IS_ERR(obj
->filp
))
144 kref_init(&obj
->refcount
);
145 atomic_set(&obj
->handle_count
, 0);
150 EXPORT_SYMBOL(drm_gem_object_init
);
153 * Allocate a GEM object of the specified size with shmfs backing store
155 struct drm_gem_object
*
156 drm_gem_object_alloc(struct drm_device
*dev
, size_t size
)
158 struct drm_gem_object
*obj
;
160 obj
= kzalloc(sizeof(*obj
), GFP_KERNEL
);
164 if (drm_gem_object_init(dev
, obj
, size
) != 0)
167 if (dev
->driver
->gem_init_object
!= NULL
&&
168 dev
->driver
->gem_init_object(obj
) != 0) {
173 /* Object_init mangles the global counters - readjust them. */
179 EXPORT_SYMBOL(drm_gem_object_alloc
);
182 * Removes the mapping from handle to filp for this object.
185 drm_gem_handle_delete(struct drm_file
*filp
, u32 handle
)
187 struct drm_device
*dev
;
188 struct drm_gem_object
*obj
;
190 /* This is gross. The idr system doesn't let us try a delete and
191 * return an error code. It just spews if you fail at deleting.
192 * So, we have to grab a lock around finding the object and then
193 * doing the delete on it and dropping the refcount, or the user
194 * could race us to double-decrement the refcount and cause a
195 * use-after-free later. Given the frequency of our handle lookups,
196 * we may want to use ida for number allocation and a hash table
197 * for the pointers, anyway.
199 spin_lock(&filp
->table_lock
);
201 /* Check if we currently have a reference on the object */
202 obj
= idr_find(&filp
->object_idr
, handle
);
204 spin_unlock(&filp
->table_lock
);
209 /* Release reference and decrement refcount. */
210 idr_remove(&filp
->object_idr
, handle
);
211 spin_unlock(&filp
->table_lock
);
213 if (dev
->driver
->gem_close_object
)
214 dev
->driver
->gem_close_object(obj
, filp
);
215 drm_gem_object_handle_unreference_unlocked(obj
);
219 EXPORT_SYMBOL(drm_gem_handle_delete
);
222 * Create a handle for this object. This adds a handle reference
223 * to the object, which includes a regular reference count. Callers
224 * will likely want to dereference the object afterwards.
227 drm_gem_handle_create(struct drm_file
*file_priv
,
228 struct drm_gem_object
*obj
,
231 struct drm_device
*dev
= obj
->dev
;
235 * Get the user-visible handle using idr.
238 /* ensure there is space available to allocate a handle */
239 if (idr_pre_get(&file_priv
->object_idr
, GFP_KERNEL
) == 0)
242 /* do the allocation under our spinlock */
243 spin_lock(&file_priv
->table_lock
);
244 ret
= idr_get_new_above(&file_priv
->object_idr
, obj
, 1, (int *)handlep
);
245 spin_unlock(&file_priv
->table_lock
);
252 drm_gem_object_handle_reference(obj
);
254 if (dev
->driver
->gem_open_object
) {
255 ret
= dev
->driver
->gem_open_object(obj
, file_priv
);
257 drm_gem_handle_delete(file_priv
, *handlep
);
264 EXPORT_SYMBOL(drm_gem_handle_create
);
266 /** Returns a reference to the object named by the handle. */
267 struct drm_gem_object
*
268 drm_gem_object_lookup(struct drm_device
*dev
, struct drm_file
*filp
,
271 struct drm_gem_object
*obj
;
273 spin_lock(&filp
->table_lock
);
275 /* Check if we currently have a reference on the object */
276 obj
= idr_find(&filp
->object_idr
, handle
);
278 spin_unlock(&filp
->table_lock
);
282 drm_gem_object_reference(obj
);
284 spin_unlock(&filp
->table_lock
);
288 EXPORT_SYMBOL(drm_gem_object_lookup
);
291 * Releases the handle to an mm object.
294 drm_gem_close_ioctl(struct drm_device
*dev
, void *data
,
295 struct drm_file
*file_priv
)
297 struct drm_gem_close
*args
= data
;
300 if (!(dev
->driver
->driver_features
& DRIVER_GEM
))
303 ret
= drm_gem_handle_delete(file_priv
, args
->handle
);
309 * Create a global name for an object, returning the name.
311 * Note that the name does not hold a reference; when the object
312 * is freed, the name goes away.
315 drm_gem_flink_ioctl(struct drm_device
*dev
, void *data
,
316 struct drm_file
*file_priv
)
318 struct drm_gem_flink
*args
= data
;
319 struct drm_gem_object
*obj
;
322 if (!(dev
->driver
->driver_features
& DRIVER_GEM
))
325 obj
= drm_gem_object_lookup(dev
, file_priv
, args
->handle
);
330 if (idr_pre_get(&dev
->object_name_idr
, GFP_KERNEL
) == 0) {
335 spin_lock(&dev
->object_name_lock
);
337 ret
= idr_get_new_above(&dev
->object_name_idr
, obj
, 1,
339 args
->name
= (uint64_t) obj
->name
;
340 spin_unlock(&dev
->object_name_lock
);
348 /* Allocate a reference for the name table. */
349 drm_gem_object_reference(obj
);
351 args
->name
= (uint64_t) obj
->name
;
352 spin_unlock(&dev
->object_name_lock
);
357 drm_gem_object_unreference_unlocked(obj
);
362 * Open an object using the global name, returning a handle and the size.
364 * This handle (of course) holds a reference to the object, so the object
365 * will not go away until the handle is deleted.
368 drm_gem_open_ioctl(struct drm_device
*dev
, void *data
,
369 struct drm_file
*file_priv
)
371 struct drm_gem_open
*args
= data
;
372 struct drm_gem_object
*obj
;
376 if (!(dev
->driver
->driver_features
& DRIVER_GEM
))
379 spin_lock(&dev
->object_name_lock
);
380 obj
= idr_find(&dev
->object_name_idr
, (int) args
->name
);
382 drm_gem_object_reference(obj
);
383 spin_unlock(&dev
->object_name_lock
);
387 ret
= drm_gem_handle_create(file_priv
, obj
, &handle
);
388 drm_gem_object_unreference_unlocked(obj
);
392 args
->handle
= handle
;
393 args
->size
= obj
->size
;
399 * Called at device open time, sets up the structure for handling refcounting
403 drm_gem_open(struct drm_device
*dev
, struct drm_file
*file_private
)
405 idr_init(&file_private
->object_idr
);
406 spin_lock_init(&file_private
->table_lock
);
410 * Called at device close to release the file's
411 * handle references on objects.
414 drm_gem_object_release_handle(int id
, void *ptr
, void *data
)
416 struct drm_file
*file_priv
= data
;
417 struct drm_gem_object
*obj
= ptr
;
418 struct drm_device
*dev
= obj
->dev
;
420 if (dev
->driver
->gem_close_object
)
421 dev
->driver
->gem_close_object(obj
, file_priv
);
423 drm_gem_object_handle_unreference_unlocked(obj
);
429 * Called at close time when the filp is going away.
431 * Releases any remaining references on objects by this filp.
434 drm_gem_release(struct drm_device
*dev
, struct drm_file
*file_private
)
436 idr_for_each(&file_private
->object_idr
,
437 &drm_gem_object_release_handle
, file_private
);
439 idr_remove_all(&file_private
->object_idr
);
440 idr_destroy(&file_private
->object_idr
);
444 drm_gem_object_release(struct drm_gem_object
*obj
)
448 EXPORT_SYMBOL(drm_gem_object_release
);
451 * Called after the last reference to the object has been lost.
452 * Must be called holding struct_ mutex
457 drm_gem_object_free(struct kref
*kref
)
459 struct drm_gem_object
*obj
= (struct drm_gem_object
*) kref
;
460 struct drm_device
*dev
= obj
->dev
;
462 BUG_ON(!mutex_is_locked(&dev
->struct_mutex
));
464 if (dev
->driver
->gem_free_object
!= NULL
)
465 dev
->driver
->gem_free_object(obj
);
467 EXPORT_SYMBOL(drm_gem_object_free
);
469 static void drm_gem_object_ref_bug(struct kref
*list_kref
)
475 * Called after the last handle to the object has been closed
477 * Removes any name for the object. Note that this must be
478 * called before drm_gem_object_free or we'll be touching
481 void drm_gem_object_handle_free(struct drm_gem_object
*obj
)
483 struct drm_device
*dev
= obj
->dev
;
485 /* Remove any name for this object */
486 spin_lock(&dev
->object_name_lock
);
488 idr_remove(&dev
->object_name_idr
, obj
->name
);
490 spin_unlock(&dev
->object_name_lock
);
492 * The object name held a reference to this object, drop
495 * This cannot be the last reference, since the handle holds one too.
497 kref_put(&obj
->refcount
, drm_gem_object_ref_bug
);
499 spin_unlock(&dev
->object_name_lock
);
502 EXPORT_SYMBOL(drm_gem_object_handle_free
);
504 void drm_gem_vm_open(struct vm_area_struct
*vma
)
506 struct drm_gem_object
*obj
= vma
->vm_private_data
;
508 drm_gem_object_reference(obj
);
510 mutex_lock(&obj
->dev
->struct_mutex
);
511 drm_vm_open_locked(vma
);
512 mutex_unlock(&obj
->dev
->struct_mutex
);
514 EXPORT_SYMBOL(drm_gem_vm_open
);
516 void drm_gem_vm_close(struct vm_area_struct
*vma
)
518 struct drm_gem_object
*obj
= vma
->vm_private_data
;
519 struct drm_device
*dev
= obj
->dev
;
521 mutex_lock(&dev
->struct_mutex
);
522 drm_vm_close_locked(vma
);
523 drm_gem_object_unreference(obj
);
524 mutex_unlock(&dev
->struct_mutex
);
526 EXPORT_SYMBOL(drm_gem_vm_close
);
530 * drm_gem_mmap - memory map routine for GEM objects
531 * @filp: DRM file pointer
532 * @vma: VMA for the area to be mapped
534 * If a driver supports GEM object mapping, mmap calls on the DRM file
535 * descriptor will end up here.
537 * If we find the object based on the offset passed in (vma->vm_pgoff will
538 * contain the fake offset we created when the GTT map ioctl was called on
539 * the object), we set up the driver fault handler so that any accesses
540 * to the object can be trapped, to perform migration, GTT binding, surface
541 * register allocation, or performance monitoring.
543 int drm_gem_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
545 struct drm_file
*priv
= filp
->private_data
;
546 struct drm_device
*dev
= priv
->minor
->dev
;
547 struct drm_gem_mm
*mm
= dev
->mm_private
;
548 struct drm_local_map
*map
= NULL
;
549 struct drm_gem_object
*obj
;
550 struct drm_hash_item
*hash
;
553 mutex_lock(&dev
->struct_mutex
);
555 if (drm_ht_find_item(&mm
->offset_hash
, vma
->vm_pgoff
, &hash
)) {
556 mutex_unlock(&dev
->struct_mutex
);
557 return drm_mmap(filp
, vma
);
560 map
= drm_hash_entry(hash
, struct drm_map_list
, hash
)->map
;
562 ((map
->flags
& _DRM_RESTRICTED
) && !capable(CAP_SYS_ADMIN
))) {
567 /* Check for valid size. */
568 if (map
->size
< vma
->vm_end
- vma
->vm_start
) {
574 if (!obj
->dev
->driver
->gem_vm_ops
) {
579 vma
->vm_flags
|= VM_RESERVED
| VM_IO
| VM_PFNMAP
| VM_DONTEXPAND
;
580 vma
->vm_ops
= obj
->dev
->driver
->gem_vm_ops
;
581 vma
->vm_private_data
= map
->handle
;
582 vma
->vm_page_prot
= pgprot_writecombine(vm_get_page_prot(vma
->vm_flags
));
584 /* Take a ref for this mapping of the object, so that the fault
585 * handler can dereference the mmap offset's pointer to the object.
586 * This reference is cleaned up by the corresponding vm_close
587 * (which should happen whether the vma was created by this call, or
588 * by a vm_open due to mremap or partial unmap or whatever).
590 drm_gem_object_reference(obj
);
592 vma
->vm_file
= filp
; /* Needed for drm_vm_open() */
593 drm_vm_open_locked(vma
);
596 mutex_unlock(&dev
->struct_mutex
);
600 EXPORT_SYMBOL(drm_gem_mmap
);