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>
40 #include <drm/drm_vma_manager.h>
44 * This file provides some of the base ioctls and library routines for
45 * the graphics memory manager implemented by each device driver.
47 * Because various devices have different requirements in terms of
48 * synchronization and migration strategies, implementing that is left up to
49 * the driver, and all that the general API provides should be generic --
50 * allocating objects, reading/writing data with the cpu, freeing objects.
51 * Even there, platform-dependent optimizations for reading/writing data with
52 * the CPU mean we'll likely hook those out to driver-specific calls. However,
53 * the DRI2 implementation wants to have at least allocate/mmap be generic.
55 * The goal was to have swap-backed object allocation managed through
56 * struct file. However, file descriptors as handles to a struct file have
58 * - Process limits prevent more than 1024 or so being used at a time by
60 * - Inability to allocate high fds will aggravate the X Server's select()
61 * handling, and likely that of many GL client applications as well.
63 * This led to a plan of using our own integer IDs (called handles, following
64 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
65 * ioctls. The objects themselves will still include the struct file so
66 * that we can transition to fds if the required kernel infrastructure shows
67 * up at a later date, and as our interface with shmfs for memory allocation.
71 * We make up offsets for buffer objects so we can recognize them at
75 /* pgoff in mmap is an unsigned long, so we need to make sure that
76 * the faked up offset will fit
79 #if BITS_PER_LONG == 64
80 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
81 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
83 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
84 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
88 * Initialize the GEM device fields
92 drm_gem_init(struct drm_device
*dev
)
94 struct drm_gem_mm
*mm
;
96 spin_lock_init(&dev
->object_name_lock
);
97 idr_init(&dev
->object_name_idr
);
99 mm
= kzalloc(sizeof(struct drm_gem_mm
), GFP_KERNEL
);
101 DRM_ERROR("out of memory\n");
105 dev
->mm_private
= mm
;
106 drm_vma_offset_manager_init(&mm
->vma_manager
,
107 DRM_FILE_PAGE_OFFSET_START
,
108 DRM_FILE_PAGE_OFFSET_SIZE
);
114 drm_gem_destroy(struct drm_device
*dev
)
116 struct drm_gem_mm
*mm
= dev
->mm_private
;
118 drm_vma_offset_manager_destroy(&mm
->vma_manager
);
120 dev
->mm_private
= NULL
;
124 * Initialize an already allocated GEM object of the specified size with
125 * shmfs backing store.
127 int drm_gem_object_init(struct drm_device
*dev
,
128 struct drm_gem_object
*obj
, size_t size
)
132 filp
= shmem_file_setup("drm mm object", size
, VM_NORESERVE
);
134 return PTR_ERR(filp
);
136 drm_gem_private_object_init(dev
, obj
, size
);
141 EXPORT_SYMBOL(drm_gem_object_init
);
144 * Initialize an already allocated GEM object of the specified size with
145 * no GEM provided backing store. Instead the caller is responsible for
146 * backing the object and handling it.
148 void drm_gem_private_object_init(struct drm_device
*dev
,
149 struct drm_gem_object
*obj
, size_t size
)
151 BUG_ON((size
& (PAGE_SIZE
- 1)) != 0);
156 kref_init(&obj
->refcount
);
157 atomic_set(&obj
->handle_count
, 0);
160 EXPORT_SYMBOL(drm_gem_private_object_init
);
163 * Allocate a GEM object of the specified size with shmfs backing store
165 struct drm_gem_object
*
166 drm_gem_object_alloc(struct drm_device
*dev
, size_t size
)
168 struct drm_gem_object
*obj
;
170 obj
= kzalloc(sizeof(*obj
), GFP_KERNEL
);
174 if (drm_gem_object_init(dev
, obj
, size
) != 0)
177 if (dev
->driver
->gem_init_object
!= NULL
&&
178 dev
->driver
->gem_init_object(obj
) != 0) {
183 /* Object_init mangles the global counters - readjust them. */
189 EXPORT_SYMBOL(drm_gem_object_alloc
);
192 drm_gem_remove_prime_handles(struct drm_gem_object
*obj
, struct drm_file
*filp
)
194 if (obj
->import_attach
) {
195 drm_prime_remove_buf_handle(&filp
->prime
,
196 obj
->import_attach
->dmabuf
);
198 if (obj
->export_dma_buf
) {
199 drm_prime_remove_buf_handle(&filp
->prime
,
200 obj
->export_dma_buf
);
205 * Removes the mapping from handle to filp for this object.
208 drm_gem_handle_delete(struct drm_file
*filp
, u32 handle
)
210 struct drm_device
*dev
;
211 struct drm_gem_object
*obj
;
213 /* This is gross. The idr system doesn't let us try a delete and
214 * return an error code. It just spews if you fail at deleting.
215 * So, we have to grab a lock around finding the object and then
216 * doing the delete on it and dropping the refcount, or the user
217 * could race us to double-decrement the refcount and cause a
218 * use-after-free later. Given the frequency of our handle lookups,
219 * we may want to use ida for number allocation and a hash table
220 * for the pointers, anyway.
222 spin_lock(&filp
->table_lock
);
224 /* Check if we currently have a reference on the object */
225 obj
= idr_find(&filp
->object_idr
, handle
);
227 spin_unlock(&filp
->table_lock
);
232 /* Release reference and decrement refcount. */
233 idr_remove(&filp
->object_idr
, handle
);
234 spin_unlock(&filp
->table_lock
);
236 drm_gem_remove_prime_handles(obj
, filp
);
238 if (dev
->driver
->gem_close_object
)
239 dev
->driver
->gem_close_object(obj
, filp
);
240 drm_gem_object_handle_unreference_unlocked(obj
);
244 EXPORT_SYMBOL(drm_gem_handle_delete
);
247 * Create a handle for this object. This adds a handle reference
248 * to the object, which includes a regular reference count. Callers
249 * will likely want to dereference the object afterwards.
252 drm_gem_handle_create(struct drm_file
*file_priv
,
253 struct drm_gem_object
*obj
,
256 struct drm_device
*dev
= obj
->dev
;
260 * Get the user-visible handle using idr. Preload and perform
261 * allocation under our spinlock.
263 idr_preload(GFP_KERNEL
);
264 spin_lock(&file_priv
->table_lock
);
266 ret
= idr_alloc(&file_priv
->object_idr
, obj
, 1, 0, GFP_NOWAIT
);
268 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
);
290 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
291 * @obj: obj in question
293 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
296 drm_gem_free_mmap_offset(struct drm_gem_object
*obj
)
298 struct drm_device
*dev
= obj
->dev
;
299 struct drm_gem_mm
*mm
= dev
->mm_private
;
301 drm_vma_offset_remove(&mm
->vma_manager
, &obj
->vma_node
);
303 EXPORT_SYMBOL(drm_gem_free_mmap_offset
);
306 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
307 * @obj: obj in question
309 * GEM memory mapping works by handing back to userspace a fake mmap offset
310 * it can use in a subsequent mmap(2) call. The DRM core code then looks
311 * up the object based on the offset and sets up the various memory mapping
314 * This routine allocates and attaches a fake offset for @obj.
317 drm_gem_create_mmap_offset(struct drm_gem_object
*obj
)
319 struct drm_device
*dev
= obj
->dev
;
320 struct drm_gem_mm
*mm
= dev
->mm_private
;
322 return drm_vma_offset_add(&mm
->vma_manager
, &obj
->vma_node
,
323 obj
->size
/ PAGE_SIZE
);
325 EXPORT_SYMBOL(drm_gem_create_mmap_offset
);
327 /** Returns a reference to the object named by the handle. */
328 struct drm_gem_object
*
329 drm_gem_object_lookup(struct drm_device
*dev
, struct drm_file
*filp
,
332 struct drm_gem_object
*obj
;
334 spin_lock(&filp
->table_lock
);
336 /* Check if we currently have a reference on the object */
337 obj
= idr_find(&filp
->object_idr
, handle
);
339 spin_unlock(&filp
->table_lock
);
343 drm_gem_object_reference(obj
);
345 spin_unlock(&filp
->table_lock
);
349 EXPORT_SYMBOL(drm_gem_object_lookup
);
352 * Releases the handle to an mm object.
355 drm_gem_close_ioctl(struct drm_device
*dev
, void *data
,
356 struct drm_file
*file_priv
)
358 struct drm_gem_close
*args
= data
;
361 if (!(dev
->driver
->driver_features
& DRIVER_GEM
))
364 ret
= drm_gem_handle_delete(file_priv
, args
->handle
);
370 * Create a global name for an object, returning the name.
372 * Note that the name does not hold a reference; when the object
373 * is freed, the name goes away.
376 drm_gem_flink_ioctl(struct drm_device
*dev
, void *data
,
377 struct drm_file
*file_priv
)
379 struct drm_gem_flink
*args
= data
;
380 struct drm_gem_object
*obj
;
383 if (!(dev
->driver
->driver_features
& DRIVER_GEM
))
386 obj
= drm_gem_object_lookup(dev
, file_priv
, args
->handle
);
390 idr_preload(GFP_KERNEL
);
391 spin_lock(&dev
->object_name_lock
);
393 ret
= idr_alloc(&dev
->object_name_idr
, obj
, 1, 0, GFP_NOWAIT
);
399 /* Allocate a reference for the name table. */
400 drm_gem_object_reference(obj
);
403 args
->name
= (uint64_t) obj
->name
;
407 spin_unlock(&dev
->object_name_lock
);
409 drm_gem_object_unreference_unlocked(obj
);
414 * Open an object using the global name, returning a handle and the size.
416 * This handle (of course) holds a reference to the object, so the object
417 * will not go away until the handle is deleted.
420 drm_gem_open_ioctl(struct drm_device
*dev
, void *data
,
421 struct drm_file
*file_priv
)
423 struct drm_gem_open
*args
= data
;
424 struct drm_gem_object
*obj
;
428 if (!(dev
->driver
->driver_features
& DRIVER_GEM
))
431 spin_lock(&dev
->object_name_lock
);
432 obj
= idr_find(&dev
->object_name_idr
, (int) args
->name
);
434 drm_gem_object_reference(obj
);
435 spin_unlock(&dev
->object_name_lock
);
439 ret
= drm_gem_handle_create(file_priv
, obj
, &handle
);
440 drm_gem_object_unreference_unlocked(obj
);
444 args
->handle
= handle
;
445 args
->size
= obj
->size
;
451 * Called at device open time, sets up the structure for handling refcounting
455 drm_gem_open(struct drm_device
*dev
, struct drm_file
*file_private
)
457 idr_init(&file_private
->object_idr
);
458 spin_lock_init(&file_private
->table_lock
);
462 * Called at device close to release the file's
463 * handle references on objects.
466 drm_gem_object_release_handle(int id
, void *ptr
, void *data
)
468 struct drm_file
*file_priv
= data
;
469 struct drm_gem_object
*obj
= ptr
;
470 struct drm_device
*dev
= obj
->dev
;
472 drm_gem_remove_prime_handles(obj
, file_priv
);
474 if (dev
->driver
->gem_close_object
)
475 dev
->driver
->gem_close_object(obj
, file_priv
);
477 drm_gem_object_handle_unreference_unlocked(obj
);
483 * Called at close time when the filp is going away.
485 * Releases any remaining references on objects by this filp.
488 drm_gem_release(struct drm_device
*dev
, struct drm_file
*file_private
)
490 idr_for_each(&file_private
->object_idr
,
491 &drm_gem_object_release_handle
, file_private
);
492 idr_destroy(&file_private
->object_idr
);
496 drm_gem_object_release(struct drm_gem_object
*obj
)
501 EXPORT_SYMBOL(drm_gem_object_release
);
504 * Called after the last reference to the object has been lost.
505 * Must be called holding struct_ mutex
510 drm_gem_object_free(struct kref
*kref
)
512 struct drm_gem_object
*obj
= (struct drm_gem_object
*) kref
;
513 struct drm_device
*dev
= obj
->dev
;
515 BUG_ON(!mutex_is_locked(&dev
->struct_mutex
));
517 if (dev
->driver
->gem_free_object
!= NULL
)
518 dev
->driver
->gem_free_object(obj
);
520 EXPORT_SYMBOL(drm_gem_object_free
);
522 static void drm_gem_object_ref_bug(struct kref
*list_kref
)
528 * Called after the last handle to the object has been closed
530 * Removes any name for the object. Note that this must be
531 * called before drm_gem_object_free or we'll be touching
534 void drm_gem_object_handle_free(struct drm_gem_object
*obj
)
536 struct drm_device
*dev
= obj
->dev
;
538 /* Remove any name for this object */
539 spin_lock(&dev
->object_name_lock
);
541 idr_remove(&dev
->object_name_idr
, obj
->name
);
543 spin_unlock(&dev
->object_name_lock
);
545 * The object name held a reference to this object, drop
548 * This cannot be the last reference, since the handle holds one too.
550 kref_put(&obj
->refcount
, drm_gem_object_ref_bug
);
552 spin_unlock(&dev
->object_name_lock
);
555 EXPORT_SYMBOL(drm_gem_object_handle_free
);
557 void drm_gem_vm_open(struct vm_area_struct
*vma
)
559 struct drm_gem_object
*obj
= vma
->vm_private_data
;
561 drm_gem_object_reference(obj
);
563 mutex_lock(&obj
->dev
->struct_mutex
);
564 drm_vm_open_locked(obj
->dev
, vma
);
565 mutex_unlock(&obj
->dev
->struct_mutex
);
567 EXPORT_SYMBOL(drm_gem_vm_open
);
569 void drm_gem_vm_close(struct vm_area_struct
*vma
)
571 struct drm_gem_object
*obj
= vma
->vm_private_data
;
572 struct drm_device
*dev
= obj
->dev
;
574 mutex_lock(&dev
->struct_mutex
);
575 drm_vm_close_locked(obj
->dev
, vma
);
576 drm_gem_object_unreference(obj
);
577 mutex_unlock(&dev
->struct_mutex
);
579 EXPORT_SYMBOL(drm_gem_vm_close
);
582 * drm_gem_mmap_obj - memory map a GEM object
583 * @obj: the GEM object to map
584 * @obj_size: the object size to be mapped, in bytes
585 * @vma: VMA for the area to be mapped
587 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
588 * provided by the driver. Depending on their requirements, drivers can either
589 * provide a fault handler in their gem_vm_ops (in which case any accesses to
590 * the object will be trapped, to perform migration, GTT binding, surface
591 * register allocation, or performance monitoring), or mmap the buffer memory
592 * synchronously after calling drm_gem_mmap_obj.
594 * This function is mainly intended to implement the DMABUF mmap operation, when
595 * the GEM object is not looked up based on its fake offset. To implement the
596 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
598 * NOTE: This function has to be protected with dev->struct_mutex
600 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
601 * size, or if no gem_vm_ops are provided.
603 int drm_gem_mmap_obj(struct drm_gem_object
*obj
, unsigned long obj_size
,
604 struct vm_area_struct
*vma
)
606 struct drm_device
*dev
= obj
->dev
;
608 lockdep_assert_held(&dev
->struct_mutex
);
610 /* Check for valid size. */
611 if (obj_size
< vma
->vm_end
- vma
->vm_start
)
614 if (!dev
->driver
->gem_vm_ops
)
617 vma
->vm_flags
|= VM_IO
| VM_PFNMAP
| VM_DONTEXPAND
| VM_DONTDUMP
;
618 vma
->vm_ops
= dev
->driver
->gem_vm_ops
;
619 vma
->vm_private_data
= obj
;
620 vma
->vm_page_prot
= pgprot_writecombine(vm_get_page_prot(vma
->vm_flags
));
622 /* Take a ref for this mapping of the object, so that the fault
623 * handler can dereference the mmap offset's pointer to the object.
624 * This reference is cleaned up by the corresponding vm_close
625 * (which should happen whether the vma was created by this call, or
626 * by a vm_open due to mremap or partial unmap or whatever).
628 drm_gem_object_reference(obj
);
630 drm_vm_open_locked(dev
, vma
);
633 EXPORT_SYMBOL(drm_gem_mmap_obj
);
636 * drm_gem_mmap - memory map routine for GEM objects
637 * @filp: DRM file pointer
638 * @vma: VMA for the area to be mapped
640 * If a driver supports GEM object mapping, mmap calls on the DRM file
641 * descriptor will end up here.
643 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
644 * contain the fake offset we created when the GTT map ioctl was called on
645 * the object) and map it with a call to drm_gem_mmap_obj().
647 int drm_gem_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
649 struct drm_file
*priv
= filp
->private_data
;
650 struct drm_device
*dev
= priv
->minor
->dev
;
651 struct drm_gem_mm
*mm
= dev
->mm_private
;
652 struct drm_gem_object
*obj
;
653 struct drm_vma_offset_node
*node
;
656 if (drm_device_is_unplugged(dev
))
659 mutex_lock(&dev
->struct_mutex
);
661 node
= drm_vma_offset_exact_lookup(&mm
->vma_manager
, vma
->vm_pgoff
,
664 mutex_unlock(&dev
->struct_mutex
);
665 return drm_mmap(filp
, vma
);
668 obj
= container_of(node
, struct drm_gem_object
, vma_node
);
669 ret
= drm_gem_mmap_obj(obj
, drm_vma_node_size(node
), vma
);
671 mutex_unlock(&dev
->struct_mutex
);
675 EXPORT_SYMBOL(drm_gem_mmap
);