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>
42 * This file provides some of the base ioctls and library routines for
43 * the graphics memory manager implemented by each device driver.
45 * Because various devices have different requirements in terms of
46 * synchronization and migration strategies, implementing that is left up to
47 * the driver, and all that the general API provides should be generic --
48 * allocating objects, reading/writing data with the cpu, freeing objects.
49 * Even there, platform-dependent optimizations for reading/writing data with
50 * the CPU mean we'll likely hook those out to driver-specific calls. However,
51 * the DRI2 implementation wants to have at least allocate/mmap be generic.
53 * The goal was to have swap-backed object allocation managed through
54 * struct file. However, file descriptors as handles to a struct file have
56 * - Process limits prevent more than 1024 or so being used at a time by
58 * - Inability to allocate high fds will aggravate the X Server's select()
59 * handling, and likely that of many GL client applications as well.
61 * This led to a plan of using our own integer IDs (called handles, following
62 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
63 * ioctls. The objects themselves will still include the struct file so
64 * that we can transition to fds if the required kernel infrastructure shows
65 * up at a later date, and as our interface with shmfs for memory allocation.
69 * We make up offsets for buffer objects so we can recognize them at
73 /* pgoff in mmap is an unsigned long, so we need to make sure that
74 * the faked up offset will fit
77 #if BITS_PER_LONG == 64
78 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
79 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
81 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
82 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
86 * Initialize the GEM device fields
90 drm_gem_init(struct drm_device
*dev
)
92 struct drm_gem_mm
*mm
;
94 spin_lock_init(&dev
->object_name_lock
);
95 idr_init(&dev
->object_name_idr
);
97 mm
= kzalloc(sizeof(struct drm_gem_mm
), GFP_KERNEL
);
99 DRM_ERROR("out of memory\n");
103 dev
->mm_private
= mm
;
105 if (drm_ht_create(&mm
->offset_hash
, 12)) {
110 if (drm_mm_init(&mm
->offset_manager
, DRM_FILE_PAGE_OFFSET_START
,
111 DRM_FILE_PAGE_OFFSET_SIZE
)) {
112 drm_ht_remove(&mm
->offset_hash
);
121 drm_gem_destroy(struct drm_device
*dev
)
123 struct drm_gem_mm
*mm
= dev
->mm_private
;
125 drm_mm_takedown(&mm
->offset_manager
);
126 drm_ht_remove(&mm
->offset_hash
);
128 dev
->mm_private
= NULL
;
132 * Initialize an already allocated GEM object of the specified size with
133 * shmfs backing store.
135 int drm_gem_object_init(struct drm_device
*dev
,
136 struct drm_gem_object
*obj
, size_t size
)
138 BUG_ON((size
& (PAGE_SIZE
- 1)) != 0);
141 obj
->filp
= shmem_file_setup("drm mm object", size
, VM_NORESERVE
);
142 if (IS_ERR(obj
->filp
))
145 kref_init(&obj
->refcount
);
146 atomic_set(&obj
->handle_count
, 0);
151 EXPORT_SYMBOL(drm_gem_object_init
);
154 * Initialize an already allocated GEM object of the specified size with
155 * no GEM provided backing store. Instead the caller is responsible for
156 * backing the object and handling it.
158 int drm_gem_private_object_init(struct drm_device
*dev
,
159 struct drm_gem_object
*obj
, size_t size
)
161 BUG_ON((size
& (PAGE_SIZE
- 1)) != 0);
166 kref_init(&obj
->refcount
);
167 atomic_set(&obj
->handle_count
, 0);
172 EXPORT_SYMBOL(drm_gem_private_object_init
);
175 * Allocate a GEM object of the specified size with shmfs backing store
177 struct drm_gem_object
*
178 drm_gem_object_alloc(struct drm_device
*dev
, size_t size
)
180 struct drm_gem_object
*obj
;
182 obj
= kzalloc(sizeof(*obj
), GFP_KERNEL
);
186 if (drm_gem_object_init(dev
, obj
, size
) != 0)
189 if (dev
->driver
->gem_init_object
!= NULL
&&
190 dev
->driver
->gem_init_object(obj
) != 0) {
195 /* Object_init mangles the global counters - readjust them. */
201 EXPORT_SYMBOL(drm_gem_object_alloc
);
204 * Removes the mapping from handle to filp for this object.
207 drm_gem_handle_delete(struct drm_file
*filp
, u32 handle
)
209 struct drm_device
*dev
;
210 struct drm_gem_object
*obj
;
212 /* This is gross. The idr system doesn't let us try a delete and
213 * return an error code. It just spews if you fail at deleting.
214 * So, we have to grab a lock around finding the object and then
215 * doing the delete on it and dropping the refcount, or the user
216 * could race us to double-decrement the refcount and cause a
217 * use-after-free later. Given the frequency of our handle lookups,
218 * we may want to use ida for number allocation and a hash table
219 * for the pointers, anyway.
221 spin_lock(&filp
->table_lock
);
223 /* Check if we currently have a reference on the object */
224 obj
= idr_find(&filp
->object_idr
, handle
);
226 spin_unlock(&filp
->table_lock
);
231 /* Release reference and decrement refcount. */
232 idr_remove(&filp
->object_idr
, handle
);
233 spin_unlock(&filp
->table_lock
);
235 if (dev
->driver
->gem_close_object
)
236 dev
->driver
->gem_close_object(obj
, filp
);
237 drm_gem_object_handle_unreference_unlocked(obj
);
241 EXPORT_SYMBOL(drm_gem_handle_delete
);
244 * Create a handle for this object. This adds a handle reference
245 * to the object, which includes a regular reference count. Callers
246 * will likely want to dereference the object afterwards.
249 drm_gem_handle_create(struct drm_file
*file_priv
,
250 struct drm_gem_object
*obj
,
253 struct drm_device
*dev
= obj
->dev
;
257 * Get the user-visible handle using idr.
260 /* ensure there is space available to allocate a handle */
261 if (idr_pre_get(&file_priv
->object_idr
, GFP_KERNEL
) == 0)
264 /* do the allocation under our spinlock */
265 spin_lock(&file_priv
->table_lock
);
266 ret
= idr_get_new_above(&file_priv
->object_idr
, obj
, 1, (int *)handlep
);
267 spin_unlock(&file_priv
->table_lock
);
274 drm_gem_object_handle_reference(obj
);
276 if (dev
->driver
->gem_open_object
) {
277 ret
= dev
->driver
->gem_open_object(obj
, file_priv
);
279 drm_gem_handle_delete(file_priv
, *handlep
);
286 EXPORT_SYMBOL(drm_gem_handle_create
);
288 /** Returns a reference to the object named by the handle. */
289 struct drm_gem_object
*
290 drm_gem_object_lookup(struct drm_device
*dev
, struct drm_file
*filp
,
293 struct drm_gem_object
*obj
;
295 spin_lock(&filp
->table_lock
);
297 /* Check if we currently have a reference on the object */
298 obj
= idr_find(&filp
->object_idr
, handle
);
300 spin_unlock(&filp
->table_lock
);
304 drm_gem_object_reference(obj
);
306 spin_unlock(&filp
->table_lock
);
310 EXPORT_SYMBOL(drm_gem_object_lookup
);
313 * Releases the handle to an mm object.
316 drm_gem_close_ioctl(struct drm_device
*dev
, void *data
,
317 struct drm_file
*file_priv
)
319 struct drm_gem_close
*args
= data
;
322 if (!(dev
->driver
->driver_features
& DRIVER_GEM
))
325 ret
= drm_gem_handle_delete(file_priv
, args
->handle
);
331 * Create a global name for an object, returning the name.
333 * Note that the name does not hold a reference; when the object
334 * is freed, the name goes away.
337 drm_gem_flink_ioctl(struct drm_device
*dev
, void *data
,
338 struct drm_file
*file_priv
)
340 struct drm_gem_flink
*args
= data
;
341 struct drm_gem_object
*obj
;
344 if (!(dev
->driver
->driver_features
& DRIVER_GEM
))
347 obj
= drm_gem_object_lookup(dev
, file_priv
, args
->handle
);
352 if (idr_pre_get(&dev
->object_name_idr
, GFP_KERNEL
) == 0) {
357 spin_lock(&dev
->object_name_lock
);
359 ret
= idr_get_new_above(&dev
->object_name_idr
, obj
, 1,
361 args
->name
= (uint64_t) obj
->name
;
362 spin_unlock(&dev
->object_name_lock
);
370 /* Allocate a reference for the name table. */
371 drm_gem_object_reference(obj
);
373 args
->name
= (uint64_t) obj
->name
;
374 spin_unlock(&dev
->object_name_lock
);
379 drm_gem_object_unreference_unlocked(obj
);
384 * Open an object using the global name, returning a handle and the size.
386 * This handle (of course) holds a reference to the object, so the object
387 * will not go away until the handle is deleted.
390 drm_gem_open_ioctl(struct drm_device
*dev
, void *data
,
391 struct drm_file
*file_priv
)
393 struct drm_gem_open
*args
= data
;
394 struct drm_gem_object
*obj
;
398 if (!(dev
->driver
->driver_features
& DRIVER_GEM
))
401 spin_lock(&dev
->object_name_lock
);
402 obj
= idr_find(&dev
->object_name_idr
, (int) args
->name
);
404 drm_gem_object_reference(obj
);
405 spin_unlock(&dev
->object_name_lock
);
409 ret
= drm_gem_handle_create(file_priv
, obj
, &handle
);
410 drm_gem_object_unreference_unlocked(obj
);
414 args
->handle
= handle
;
415 args
->size
= obj
->size
;
421 * Called at device open time, sets up the structure for handling refcounting
425 drm_gem_open(struct drm_device
*dev
, struct drm_file
*file_private
)
427 idr_init(&file_private
->object_idr
);
428 spin_lock_init(&file_private
->table_lock
);
432 * Called at device close to release the file's
433 * handle references on objects.
436 drm_gem_object_release_handle(int id
, void *ptr
, void *data
)
438 struct drm_file
*file_priv
= data
;
439 struct drm_gem_object
*obj
= ptr
;
440 struct drm_device
*dev
= obj
->dev
;
442 if (dev
->driver
->gem_close_object
)
443 dev
->driver
->gem_close_object(obj
, file_priv
);
445 drm_gem_object_handle_unreference_unlocked(obj
);
451 * Called at close time when the filp is going away.
453 * Releases any remaining references on objects by this filp.
456 drm_gem_release(struct drm_device
*dev
, struct drm_file
*file_private
)
458 idr_for_each(&file_private
->object_idr
,
459 &drm_gem_object_release_handle
, file_private
);
461 idr_remove_all(&file_private
->object_idr
);
462 idr_destroy(&file_private
->object_idr
);
466 drm_gem_object_release(struct drm_gem_object
*obj
)
471 EXPORT_SYMBOL(drm_gem_object_release
);
474 * Called after the last reference to the object has been lost.
475 * Must be called holding struct_ mutex
480 drm_gem_object_free(struct kref
*kref
)
482 struct drm_gem_object
*obj
= (struct drm_gem_object
*) kref
;
483 struct drm_device
*dev
= obj
->dev
;
485 BUG_ON(!mutex_is_locked(&dev
->struct_mutex
));
487 if (dev
->driver
->gem_free_object
!= NULL
)
488 dev
->driver
->gem_free_object(obj
);
490 EXPORT_SYMBOL(drm_gem_object_free
);
492 static void drm_gem_object_ref_bug(struct kref
*list_kref
)
498 * Called after the last handle to the object has been closed
500 * Removes any name for the object. Note that this must be
501 * called before drm_gem_object_free or we'll be touching
504 void drm_gem_object_handle_free(struct drm_gem_object
*obj
)
506 struct drm_device
*dev
= obj
->dev
;
508 /* Remove any name for this object */
509 spin_lock(&dev
->object_name_lock
);
511 idr_remove(&dev
->object_name_idr
, obj
->name
);
513 spin_unlock(&dev
->object_name_lock
);
515 * The object name held a reference to this object, drop
518 * This cannot be the last reference, since the handle holds one too.
520 kref_put(&obj
->refcount
, drm_gem_object_ref_bug
);
522 spin_unlock(&dev
->object_name_lock
);
525 EXPORT_SYMBOL(drm_gem_object_handle_free
);
527 void drm_gem_vm_open(struct vm_area_struct
*vma
)
529 struct drm_gem_object
*obj
= vma
->vm_private_data
;
531 drm_gem_object_reference(obj
);
533 mutex_lock(&obj
->dev
->struct_mutex
);
534 drm_vm_open_locked(vma
);
535 mutex_unlock(&obj
->dev
->struct_mutex
);
537 EXPORT_SYMBOL(drm_gem_vm_open
);
539 void drm_gem_vm_close(struct vm_area_struct
*vma
)
541 struct drm_gem_object
*obj
= vma
->vm_private_data
;
542 struct drm_device
*dev
= obj
->dev
;
544 mutex_lock(&dev
->struct_mutex
);
545 drm_vm_close_locked(vma
);
546 drm_gem_object_unreference(obj
);
547 mutex_unlock(&dev
->struct_mutex
);
549 EXPORT_SYMBOL(drm_gem_vm_close
);
553 * drm_gem_mmap - memory map routine for GEM objects
554 * @filp: DRM file pointer
555 * @vma: VMA for the area to be mapped
557 * If a driver supports GEM object mapping, mmap calls on the DRM file
558 * descriptor will end up here.
560 * If we find the object based on the offset passed in (vma->vm_pgoff will
561 * contain the fake offset we created when the GTT map ioctl was called on
562 * the object), we set up the driver fault handler so that any accesses
563 * to the object can be trapped, to perform migration, GTT binding, surface
564 * register allocation, or performance monitoring.
566 int drm_gem_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
568 struct drm_file
*priv
= filp
->private_data
;
569 struct drm_device
*dev
= priv
->minor
->dev
;
570 struct drm_gem_mm
*mm
= dev
->mm_private
;
571 struct drm_local_map
*map
= NULL
;
572 struct drm_gem_object
*obj
;
573 struct drm_hash_item
*hash
;
576 mutex_lock(&dev
->struct_mutex
);
578 if (drm_ht_find_item(&mm
->offset_hash
, vma
->vm_pgoff
, &hash
)) {
579 mutex_unlock(&dev
->struct_mutex
);
580 return drm_mmap(filp
, vma
);
583 map
= drm_hash_entry(hash
, struct drm_map_list
, hash
)->map
;
585 ((map
->flags
& _DRM_RESTRICTED
) && !capable(CAP_SYS_ADMIN
))) {
590 /* Check for valid size. */
591 if (map
->size
< vma
->vm_end
- vma
->vm_start
) {
597 if (!obj
->dev
->driver
->gem_vm_ops
) {
602 vma
->vm_flags
|= VM_RESERVED
| VM_IO
| VM_PFNMAP
| VM_DONTEXPAND
;
603 vma
->vm_ops
= obj
->dev
->driver
->gem_vm_ops
;
604 vma
->vm_private_data
= map
->handle
;
605 vma
->vm_page_prot
= pgprot_writecombine(vm_get_page_prot(vma
->vm_flags
));
607 /* Take a ref for this mapping of the object, so that the fault
608 * handler can dereference the mmap offset's pointer to the object.
609 * This reference is cleaned up by the corresponding vm_close
610 * (which should happen whether the vma was created by this call, or
611 * by a vm_open due to mremap or partial unmap or whatever).
613 drm_gem_object_reference(obj
);
615 vma
->vm_file
= filp
; /* Needed for drm_vm_open() */
616 drm_vm_open_locked(vma
);
619 mutex_unlock(&dev
->struct_mutex
);
623 EXPORT_SYMBOL(drm_gem_mmap
);