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1/*
2 * Copyright © 2008 Intel Corporation
3 *
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:
10 *
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
13 * Software.
14 *
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
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 * Eric Anholt <eric@anholt.net>
25 *
26 */
27
28#include <linux/types.h>
29#include <linux/slab.h>
30#include <linux/mm.h>
31#include <linux/uaccess.h>
32#include <linux/fs.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 "drmP.h"
39
40/** @file drm_gem.c
41 *
42 * This file provides some of the base ioctls and library routines for
43 * the graphics memory manager implemented by each device driver.
44 *
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.
52 *
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
55 * two major failings:
56 * - Process limits prevent more than 1024 or so being used at a time by
57 * default.
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.
60 *
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.
66 */
67
68/*
69 * We make up offsets for buffer objects so we can recognize them at
70 * mmap time.
71 */
72
73/* pgoff in mmap is an unsigned long, so we need to make sure that
74 * the faked up offset will fit
75 */
76
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)
80#else
81#define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
82#define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
83#endif
84
85/**
86 * Initialize the GEM device fields
87 */
88
89int
90drm_gem_init(struct drm_device *dev)
91{
92 struct drm_gem_mm *mm;
93
94 spin_lock_init(&dev->object_name_lock);
95 idr_init(&dev->object_name_idr);
96
97 mm = kzalloc(sizeof(struct drm_gem_mm), GFP_KERNEL);
98 if (!mm) {
99 DRM_ERROR("out of memory\n");
100 return -ENOMEM;
101 }
102
103 dev->mm_private = mm;
104
105 if (drm_ht_create(&mm->offset_hash, 12)) {
106 kfree(mm);
107 return -ENOMEM;
108 }
109
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);
113 kfree(mm);
114 return -ENOMEM;
115 }
116
117 return 0;
118}
119
120void
121drm_gem_destroy(struct drm_device *dev)
122{
123 struct drm_gem_mm *mm = dev->mm_private;
124
125 drm_mm_takedown(&mm->offset_manager);
126 drm_ht_remove(&mm->offset_hash);
127 kfree(mm);
128 dev->mm_private = NULL;
129}
130
131/**
132 * Initialize an already allocated GEM object of the specified size with
133 * shmfs backing store.
134 */
135int drm_gem_object_init(struct drm_device *dev,
136 struct drm_gem_object *obj, size_t size)
137{
138 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
139
140 obj->dev = dev;
141 obj->filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
142 if (IS_ERR(obj->filp))
143 return -ENOMEM;
144
145 kref_init(&obj->refcount);
146 atomic_set(&obj->handle_count, 0);
147 obj->size = size;
148
149 return 0;
150}
151EXPORT_SYMBOL(drm_gem_object_init);
152
153/**
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.
157 */
158int drm_gem_private_object_init(struct drm_device *dev,
159 struct drm_gem_object *obj, size_t size)
160{
161 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
162
163 obj->dev = dev;
164 obj->filp = NULL;
165
166 kref_init(&obj->refcount);
167 atomic_set(&obj->handle_count, 0);
168 obj->size = size;
169
170 return 0;
171}
172EXPORT_SYMBOL(drm_gem_private_object_init);
173
174/**
175 * Allocate a GEM object of the specified size with shmfs backing store
176 */
177struct drm_gem_object *
178drm_gem_object_alloc(struct drm_device *dev, size_t size)
179{
180 struct drm_gem_object *obj;
181
182 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
183 if (!obj)
184 goto free;
185
186 if (drm_gem_object_init(dev, obj, size) != 0)
187 goto free;
188
189 if (dev->driver->gem_init_object != NULL &&
190 dev->driver->gem_init_object(obj) != 0) {
191 goto fput;
192 }
193 return obj;
194fput:
195 /* Object_init mangles the global counters - readjust them. */
196 fput(obj->filp);
197free:
198 kfree(obj);
199 return NULL;
200}
201EXPORT_SYMBOL(drm_gem_object_alloc);
202
203/**
204 * Removes the mapping from handle to filp for this object.
205 */
206int
207drm_gem_handle_delete(struct drm_file *filp, u32 handle)
208{
209 struct drm_device *dev;
210 struct drm_gem_object *obj;
211
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.
220 */
221 spin_lock(&filp->table_lock);
222
223 /* Check if we currently have a reference on the object */
224 obj = idr_find(&filp->object_idr, handle);
225 if (obj == NULL) {
226 spin_unlock(&filp->table_lock);
227 return -EINVAL;
228 }
229 dev = obj->dev;
230
231 /* Release reference and decrement refcount. */
232 idr_remove(&filp->object_idr, handle);
233 spin_unlock(&filp->table_lock);
234
235 if (dev->driver->gem_close_object)
236 dev->driver->gem_close_object(obj, filp);
237 drm_gem_object_handle_unreference_unlocked(obj);
238
239 return 0;
240}
241EXPORT_SYMBOL(drm_gem_handle_delete);
242
243/**
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.
247 */
248int
249drm_gem_handle_create(struct drm_file *file_priv,
250 struct drm_gem_object *obj,
251 u32 *handlep)
252{
253 struct drm_device *dev = obj->dev;
254 int ret;
255
256 /*
257 * Get the user-visible handle using idr.
258 */
259again:
260 /* ensure there is space available to allocate a handle */
261 if (idr_pre_get(&file_priv->object_idr, GFP_KERNEL) == 0)
262 return -ENOMEM;
263
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);
268 if (ret == -EAGAIN)
269 goto again;
270
271 if (ret != 0)
272 return ret;
273
274 drm_gem_object_handle_reference(obj);
275
276 if (dev->driver->gem_open_object) {
277 ret = dev->driver->gem_open_object(obj, file_priv);
278 if (ret) {
279 drm_gem_handle_delete(file_priv, *handlep);
280 return ret;
281 }
282 }
283
284 return 0;
285}
286EXPORT_SYMBOL(drm_gem_handle_create);
287
288/** Returns a reference to the object named by the handle. */
289struct drm_gem_object *
290drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
291 u32 handle)
292{
293 struct drm_gem_object *obj;
294
295 spin_lock(&filp->table_lock);
296
297 /* Check if we currently have a reference on the object */
298 obj = idr_find(&filp->object_idr, handle);
299 if (obj == NULL) {
300 spin_unlock(&filp->table_lock);
301 return NULL;
302 }
303
304 drm_gem_object_reference(obj);
305
306 spin_unlock(&filp->table_lock);
307
308 return obj;
309}
310EXPORT_SYMBOL(drm_gem_object_lookup);
311
312/**
313 * Releases the handle to an mm object.
314 */
315int
316drm_gem_close_ioctl(struct drm_device *dev, void *data,
317 struct drm_file *file_priv)
318{
319 struct drm_gem_close *args = data;
320 int ret;
321
322 if (!(dev->driver->driver_features & DRIVER_GEM))
323 return -ENODEV;
324
325 ret = drm_gem_handle_delete(file_priv, args->handle);
326
327 return ret;
328}
329
330/**
331 * Create a global name for an object, returning the name.
332 *
333 * Note that the name does not hold a reference; when the object
334 * is freed, the name goes away.
335 */
336int
337drm_gem_flink_ioctl(struct drm_device *dev, void *data,
338 struct drm_file *file_priv)
339{
340 struct drm_gem_flink *args = data;
341 struct drm_gem_object *obj;
342 int ret;
343
344 if (!(dev->driver->driver_features & DRIVER_GEM))
345 return -ENODEV;
346
347 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
348 if (obj == NULL)
349 return -ENOENT;
350
351again:
352 if (idr_pre_get(&dev->object_name_idr, GFP_KERNEL) == 0) {
353 ret = -ENOMEM;
354 goto err;
355 }
356
357 spin_lock(&dev->object_name_lock);
358 if (!obj->name) {
359 ret = idr_get_new_above(&dev->object_name_idr, obj, 1,
360 &obj->name);
361 args->name = (uint64_t) obj->name;
362 spin_unlock(&dev->object_name_lock);
363
364 if (ret == -EAGAIN)
365 goto again;
366
367 if (ret != 0)
368 goto err;
369
370 /* Allocate a reference for the name table. */
371 drm_gem_object_reference(obj);
372 } else {
373 args->name = (uint64_t) obj->name;
374 spin_unlock(&dev->object_name_lock);
375 ret = 0;
376 }
377
378err:
379 drm_gem_object_unreference_unlocked(obj);
380 return ret;
381}
382
383/**
384 * Open an object using the global name, returning a handle and the size.
385 *
386 * This handle (of course) holds a reference to the object, so the object
387 * will not go away until the handle is deleted.
388 */
389int
390drm_gem_open_ioctl(struct drm_device *dev, void *data,
391 struct drm_file *file_priv)
392{
393 struct drm_gem_open *args = data;
394 struct drm_gem_object *obj;
395 int ret;
396 u32 handle;
397
398 if (!(dev->driver->driver_features & DRIVER_GEM))
399 return -ENODEV;
400
401 spin_lock(&dev->object_name_lock);
402 obj = idr_find(&dev->object_name_idr, (int) args->name);
403 if (obj)
404 drm_gem_object_reference(obj);
405 spin_unlock(&dev->object_name_lock);
406 if (!obj)
407 return -ENOENT;
408
409 ret = drm_gem_handle_create(file_priv, obj, &handle);
410 drm_gem_object_unreference_unlocked(obj);
411 if (ret)
412 return ret;
413
414 args->handle = handle;
415 args->size = obj->size;
416
417 return 0;
418}
419
420/**
421 * Called at device open time, sets up the structure for handling refcounting
422 * of mm objects.
423 */
424void
425drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
426{
427 idr_init(&file_private->object_idr);
428 spin_lock_init(&file_private->table_lock);
429}
430
431/**
432 * Called at device close to release the file's
433 * handle references on objects.
434 */
435static int
436drm_gem_object_release_handle(int id, void *ptr, void *data)
437{
438 struct drm_file *file_priv = data;
439 struct drm_gem_object *obj = ptr;
440 struct drm_device *dev = obj->dev;
441
442 if (dev->driver->gem_close_object)
443 dev->driver->gem_close_object(obj, file_priv);
444
445 drm_gem_object_handle_unreference_unlocked(obj);
446
447 return 0;
448}
449
450/**
451 * Called at close time when the filp is going away.
452 *
453 * Releases any remaining references on objects by this filp.
454 */
455void
456drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
457{
458 idr_for_each(&file_private->object_idr,
459 &drm_gem_object_release_handle, file_private);
460
461 idr_remove_all(&file_private->object_idr);
462 idr_destroy(&file_private->object_idr);
463}
464
465void
466drm_gem_object_release(struct drm_gem_object *obj)
467{
468 if (obj->filp)
469 fput(obj->filp);
470}
471EXPORT_SYMBOL(drm_gem_object_release);
472
473/**
474 * Called after the last reference to the object has been lost.
475 * Must be called holding struct_ mutex
476 *
477 * Frees the object
478 */
479void
480drm_gem_object_free(struct kref *kref)
481{
482 struct drm_gem_object *obj = (struct drm_gem_object *) kref;
483 struct drm_device *dev = obj->dev;
484
485 BUG_ON(!mutex_is_locked(&dev->struct_mutex));
486
487 if (dev->driver->gem_free_object != NULL)
488 dev->driver->gem_free_object(obj);
489}
490EXPORT_SYMBOL(drm_gem_object_free);
491
492static void drm_gem_object_ref_bug(struct kref *list_kref)
493{
494 BUG();
495}
496
497/**
498 * Called after the last handle to the object has been closed
499 *
500 * Removes any name for the object. Note that this must be
501 * called before drm_gem_object_free or we'll be touching
502 * freed memory
503 */
504void drm_gem_object_handle_free(struct drm_gem_object *obj)
505{
506 struct drm_device *dev = obj->dev;
507
508 /* Remove any name for this object */
509 spin_lock(&dev->object_name_lock);
510 if (obj->name) {
511 idr_remove(&dev->object_name_idr, obj->name);
512 obj->name = 0;
513 spin_unlock(&dev->object_name_lock);
514 /*
515 * The object name held a reference to this object, drop
516 * that now.
517 *
518 * This cannot be the last reference, since the handle holds one too.
519 */
520 kref_put(&obj->refcount, drm_gem_object_ref_bug);
521 } else
522 spin_unlock(&dev->object_name_lock);
523
524}
525EXPORT_SYMBOL(drm_gem_object_handle_free);
526
527void drm_gem_vm_open(struct vm_area_struct *vma)
528{
529 struct drm_gem_object *obj = vma->vm_private_data;
530
531 drm_gem_object_reference(obj);
532
533 mutex_lock(&obj->dev->struct_mutex);
534 drm_vm_open_locked(vma);
535 mutex_unlock(&obj->dev->struct_mutex);
536}
537EXPORT_SYMBOL(drm_gem_vm_open);
538
539void drm_gem_vm_close(struct vm_area_struct *vma)
540{
541 struct drm_gem_object *obj = vma->vm_private_data;
542 struct drm_device *dev = obj->dev;
543
544 mutex_lock(&dev->struct_mutex);
545 drm_vm_close_locked(vma);
546 drm_gem_object_unreference(obj);
547 mutex_unlock(&dev->struct_mutex);
548}
549EXPORT_SYMBOL(drm_gem_vm_close);
550
551
552/**
553 * drm_gem_mmap - memory map routine for GEM objects
554 * @filp: DRM file pointer
555 * @vma: VMA for the area to be mapped
556 *
557 * If a driver supports GEM object mapping, mmap calls on the DRM file
558 * descriptor will end up here.
559 *
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.
565 */
566int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
567{
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;
574 int ret = 0;
575
576 mutex_lock(&dev->struct_mutex);
577
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);
581 }
582
583 map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
584 if (!map ||
585 ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) {
586 ret = -EPERM;
587 goto out_unlock;
588 }
589
590 /* Check for valid size. */
591 if (map->size < vma->vm_end - vma->vm_start) {
592 ret = -EINVAL;
593 goto out_unlock;
594 }
595
596 obj = map->handle;
597 if (!obj->dev->driver->gem_vm_ops) {
598 ret = -EINVAL;
599 goto out_unlock;
600 }
601
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));
606
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).
612 */
613 drm_gem_object_reference(obj);
614
615 vma->vm_file = filp; /* Needed for drm_vm_open() */
616 drm_vm_open_locked(vma);
617
618out_unlock:
619 mutex_unlock(&dev->struct_mutex);
620
621 return ret;
622}
623EXPORT_SYMBOL(drm_gem_mmap);
1/*
2 * Copyright © 2008 Intel Corporation
3 *
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:
10 *
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
13 * Software.
14 *
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
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 * Eric Anholt <eric@anholt.net>
25 *
26 */
27
28#include <linux/types.h>
29#include <linux/slab.h>
30#include <linux/mm.h>
31#include <linux/uaccess.h>
32#include <linux/fs.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>
39#include <linux/mem_encrypt.h>
40#include <drm/drmP.h>
41#include <drm/drm_vma_manager.h>
42#include <drm/drm_gem.h>
43#include <drm/drm_print.h>
44#include "drm_internal.h"
45
46/** @file drm_gem.c
47 *
48 * This file provides some of the base ioctls and library routines for
49 * the graphics memory manager implemented by each device driver.
50 *
51 * Because various devices have different requirements in terms of
52 * synchronization and migration strategies, implementing that is left up to
53 * the driver, and all that the general API provides should be generic --
54 * allocating objects, reading/writing data with the cpu, freeing objects.
55 * Even there, platform-dependent optimizations for reading/writing data with
56 * the CPU mean we'll likely hook those out to driver-specific calls. However,
57 * the DRI2 implementation wants to have at least allocate/mmap be generic.
58 *
59 * The goal was to have swap-backed object allocation managed through
60 * struct file. However, file descriptors as handles to a struct file have
61 * two major failings:
62 * - Process limits prevent more than 1024 or so being used at a time by
63 * default.
64 * - Inability to allocate high fds will aggravate the X Server's select()
65 * handling, and likely that of many GL client applications as well.
66 *
67 * This led to a plan of using our own integer IDs (called handles, following
68 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
69 * ioctls. The objects themselves will still include the struct file so
70 * that we can transition to fds if the required kernel infrastructure shows
71 * up at a later date, and as our interface with shmfs for memory allocation.
72 */
73
74/*
75 * We make up offsets for buffer objects so we can recognize them at
76 * mmap time.
77 */
78
79/* pgoff in mmap is an unsigned long, so we need to make sure that
80 * the faked up offset will fit
81 */
82
83#if BITS_PER_LONG == 64
84#define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
85#define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
86#else
87#define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
88#define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
89#endif
90
91/**
92 * drm_gem_init - Initialize the GEM device fields
93 * @dev: drm_devic structure to initialize
94 */
95int
96drm_gem_init(struct drm_device *dev)
97{
98 struct drm_vma_offset_manager *vma_offset_manager;
99
100 mutex_init(&dev->object_name_lock);
101 idr_init_base(&dev->object_name_idr, 1);
102
103 vma_offset_manager = kzalloc(sizeof(*vma_offset_manager), GFP_KERNEL);
104 if (!vma_offset_manager) {
105 DRM_ERROR("out of memory\n");
106 return -ENOMEM;
107 }
108
109 dev->vma_offset_manager = vma_offset_manager;
110 drm_vma_offset_manager_init(vma_offset_manager,
111 DRM_FILE_PAGE_OFFSET_START,
112 DRM_FILE_PAGE_OFFSET_SIZE);
113
114 return 0;
115}
116
117void
118drm_gem_destroy(struct drm_device *dev)
119{
120
121 drm_vma_offset_manager_destroy(dev->vma_offset_manager);
122 kfree(dev->vma_offset_manager);
123 dev->vma_offset_manager = NULL;
124}
125
126/**
127 * drm_gem_object_init - initialize an allocated shmem-backed GEM object
128 * @dev: drm_device the object should be initialized for
129 * @obj: drm_gem_object to initialize
130 * @size: object size
131 *
132 * Initialize an already allocated GEM object of the specified size with
133 * shmfs backing store.
134 */
135int drm_gem_object_init(struct drm_device *dev,
136 struct drm_gem_object *obj, size_t size)
137{
138 struct file *filp;
139
140 drm_gem_private_object_init(dev, obj, size);
141
142 filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
143 if (IS_ERR(filp))
144 return PTR_ERR(filp);
145
146 obj->filp = filp;
147
148 return 0;
149}
150EXPORT_SYMBOL(drm_gem_object_init);
151
152/**
153 * drm_gem_private_object_init - initialize an allocated private GEM object
154 * @dev: drm_device the object should be initialized for
155 * @obj: drm_gem_object to initialize
156 * @size: object size
157 *
158 * Initialize an already allocated GEM object of the specified size with
159 * no GEM provided backing store. Instead the caller is responsible for
160 * backing the object and handling it.
161 */
162void drm_gem_private_object_init(struct drm_device *dev,
163 struct drm_gem_object *obj, size_t size)
164{
165 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
166
167 obj->dev = dev;
168 obj->filp = NULL;
169
170 kref_init(&obj->refcount);
171 obj->handle_count = 0;
172 obj->size = size;
173 drm_vma_node_reset(&obj->vma_node);
174}
175EXPORT_SYMBOL(drm_gem_private_object_init);
176
177static void
178drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
179{
180 /*
181 * Note: obj->dma_buf can't disappear as long as we still hold a
182 * handle reference in obj->handle_count.
183 */
184 mutex_lock(&filp->prime.lock);
185 if (obj->dma_buf) {
186 drm_prime_remove_buf_handle_locked(&filp->prime,
187 obj->dma_buf);
188 }
189 mutex_unlock(&filp->prime.lock);
190}
191
192/**
193 * drm_gem_object_handle_free - release resources bound to userspace handles
194 * @obj: GEM object to clean up.
195 *
196 * Called after the last handle to the object has been closed
197 *
198 * Removes any name for the object. Note that this must be
199 * called before drm_gem_object_free or we'll be touching
200 * freed memory
201 */
202static void drm_gem_object_handle_free(struct drm_gem_object *obj)
203{
204 struct drm_device *dev = obj->dev;
205
206 /* Remove any name for this object */
207 if (obj->name) {
208 idr_remove(&dev->object_name_idr, obj->name);
209 obj->name = 0;
210 }
211}
212
213static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
214{
215 /* Unbreak the reference cycle if we have an exported dma_buf. */
216 if (obj->dma_buf) {
217 dma_buf_put(obj->dma_buf);
218 obj->dma_buf = NULL;
219 }
220}
221
222static void
223drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj)
224{
225 struct drm_device *dev = obj->dev;
226 bool final = false;
227
228 if (WARN_ON(obj->handle_count == 0))
229 return;
230
231 /*
232 * Must bump handle count first as this may be the last
233 * ref, in which case the object would disappear before we
234 * checked for a name
235 */
236
237 mutex_lock(&dev->object_name_lock);
238 if (--obj->handle_count == 0) {
239 drm_gem_object_handle_free(obj);
240 drm_gem_object_exported_dma_buf_free(obj);
241 final = true;
242 }
243 mutex_unlock(&dev->object_name_lock);
244
245 if (final)
246 drm_gem_object_put_unlocked(obj);
247}
248
249/*
250 * Called at device or object close to release the file's
251 * handle references on objects.
252 */
253static int
254drm_gem_object_release_handle(int id, void *ptr, void *data)
255{
256 struct drm_file *file_priv = data;
257 struct drm_gem_object *obj = ptr;
258 struct drm_device *dev = obj->dev;
259
260 if (dev->driver->gem_close_object)
261 dev->driver->gem_close_object(obj, file_priv);
262
263 if (drm_core_check_feature(dev, DRIVER_PRIME))
264 drm_gem_remove_prime_handles(obj, file_priv);
265 drm_vma_node_revoke(&obj->vma_node, file_priv);
266
267 drm_gem_object_handle_put_unlocked(obj);
268
269 return 0;
270}
271
272/**
273 * drm_gem_handle_delete - deletes the given file-private handle
274 * @filp: drm file-private structure to use for the handle look up
275 * @handle: userspace handle to delete
276 *
277 * Removes the GEM handle from the @filp lookup table which has been added with
278 * drm_gem_handle_create(). If this is the last handle also cleans up linked
279 * resources like GEM names.
280 */
281int
282drm_gem_handle_delete(struct drm_file *filp, u32 handle)
283{
284 struct drm_gem_object *obj;
285
286 spin_lock(&filp->table_lock);
287
288 /* Check if we currently have a reference on the object */
289 obj = idr_replace(&filp->object_idr, NULL, handle);
290 spin_unlock(&filp->table_lock);
291 if (IS_ERR_OR_NULL(obj))
292 return -EINVAL;
293
294 /* Release driver's reference and decrement refcount. */
295 drm_gem_object_release_handle(handle, obj, filp);
296
297 /* And finally make the handle available for future allocations. */
298 spin_lock(&filp->table_lock);
299 idr_remove(&filp->object_idr, handle);
300 spin_unlock(&filp->table_lock);
301
302 return 0;
303}
304EXPORT_SYMBOL(drm_gem_handle_delete);
305
306/**
307 * drm_gem_dumb_map_offset - return the fake mmap offset for a gem object
308 * @file: drm file-private structure containing the gem object
309 * @dev: corresponding drm_device
310 * @handle: gem object handle
311 * @offset: return location for the fake mmap offset
312 *
313 * This implements the &drm_driver.dumb_map_offset kms driver callback for
314 * drivers which use gem to manage their backing storage.
315 *
316 * Returns:
317 * 0 on success or a negative error code on failure.
318 */
319int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
320 u32 handle, u64 *offset)
321{
322 struct drm_gem_object *obj;
323 int ret;
324
325 obj = drm_gem_object_lookup(file, handle);
326 if (!obj)
327 return -ENOENT;
328
329 /* Don't allow imported objects to be mapped */
330 if (obj->import_attach) {
331 ret = -EINVAL;
332 goto out;
333 }
334
335 ret = drm_gem_create_mmap_offset(obj);
336 if (ret)
337 goto out;
338
339 *offset = drm_vma_node_offset_addr(&obj->vma_node);
340out:
341 drm_gem_object_put_unlocked(obj);
342
343 return ret;
344}
345EXPORT_SYMBOL_GPL(drm_gem_dumb_map_offset);
346
347/**
348 * drm_gem_dumb_destroy - dumb fb callback helper for gem based drivers
349 * @file: drm file-private structure to remove the dumb handle from
350 * @dev: corresponding drm_device
351 * @handle: the dumb handle to remove
352 *
353 * This implements the &drm_driver.dumb_destroy kms driver callback for drivers
354 * which use gem to manage their backing storage.
355 */
356int drm_gem_dumb_destroy(struct drm_file *file,
357 struct drm_device *dev,
358 uint32_t handle)
359{
360 return drm_gem_handle_delete(file, handle);
361}
362EXPORT_SYMBOL(drm_gem_dumb_destroy);
363
364/**
365 * drm_gem_handle_create_tail - internal functions to create a handle
366 * @file_priv: drm file-private structure to register the handle for
367 * @obj: object to register
368 * @handlep: pointer to return the created handle to the caller
369 *
370 * This expects the &drm_device.object_name_lock to be held already and will
371 * drop it before returning. Used to avoid races in establishing new handles
372 * when importing an object from either an flink name or a dma-buf.
373 *
374 * Handles must be release again through drm_gem_handle_delete(). This is done
375 * when userspace closes @file_priv for all attached handles, or through the
376 * GEM_CLOSE ioctl for individual handles.
377 */
378int
379drm_gem_handle_create_tail(struct drm_file *file_priv,
380 struct drm_gem_object *obj,
381 u32 *handlep)
382{
383 struct drm_device *dev = obj->dev;
384 u32 handle;
385 int ret;
386
387 WARN_ON(!mutex_is_locked(&dev->object_name_lock));
388 if (obj->handle_count++ == 0)
389 drm_gem_object_get(obj);
390
391 /*
392 * Get the user-visible handle using idr. Preload and perform
393 * allocation under our spinlock.
394 */
395 idr_preload(GFP_KERNEL);
396 spin_lock(&file_priv->table_lock);
397
398 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
399
400 spin_unlock(&file_priv->table_lock);
401 idr_preload_end();
402
403 mutex_unlock(&dev->object_name_lock);
404 if (ret < 0)
405 goto err_unref;
406
407 handle = ret;
408
409 ret = drm_vma_node_allow(&obj->vma_node, file_priv);
410 if (ret)
411 goto err_remove;
412
413 if (dev->driver->gem_open_object) {
414 ret = dev->driver->gem_open_object(obj, file_priv);
415 if (ret)
416 goto err_revoke;
417 }
418
419 *handlep = handle;
420 return 0;
421
422err_revoke:
423 drm_vma_node_revoke(&obj->vma_node, file_priv);
424err_remove:
425 spin_lock(&file_priv->table_lock);
426 idr_remove(&file_priv->object_idr, handle);
427 spin_unlock(&file_priv->table_lock);
428err_unref:
429 drm_gem_object_handle_put_unlocked(obj);
430 return ret;
431}
432
433/**
434 * drm_gem_handle_create - create a gem handle for an object
435 * @file_priv: drm file-private structure to register the handle for
436 * @obj: object to register
437 * @handlep: pionter to return the created handle to the caller
438 *
439 * Create a handle for this object. This adds a handle reference
440 * to the object, which includes a regular reference count. Callers
441 * will likely want to dereference the object afterwards.
442 */
443int drm_gem_handle_create(struct drm_file *file_priv,
444 struct drm_gem_object *obj,
445 u32 *handlep)
446{
447 mutex_lock(&obj->dev->object_name_lock);
448
449 return drm_gem_handle_create_tail(file_priv, obj, handlep);
450}
451EXPORT_SYMBOL(drm_gem_handle_create);
452
453
454/**
455 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
456 * @obj: obj in question
457 *
458 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
459 *
460 * Note that drm_gem_object_release() already calls this function, so drivers
461 * don't have to take care of releasing the mmap offset themselves when freeing
462 * the GEM object.
463 */
464void
465drm_gem_free_mmap_offset(struct drm_gem_object *obj)
466{
467 struct drm_device *dev = obj->dev;
468
469 drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node);
470}
471EXPORT_SYMBOL(drm_gem_free_mmap_offset);
472
473/**
474 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object
475 * @obj: obj in question
476 * @size: the virtual size
477 *
478 * GEM memory mapping works by handing back to userspace a fake mmap offset
479 * it can use in a subsequent mmap(2) call. The DRM core code then looks
480 * up the object based on the offset and sets up the various memory mapping
481 * structures.
482 *
483 * This routine allocates and attaches a fake offset for @obj, in cases where
484 * the virtual size differs from the physical size (ie. &drm_gem_object.size).
485 * Otherwise just use drm_gem_create_mmap_offset().
486 *
487 * This function is idempotent and handles an already allocated mmap offset
488 * transparently. Drivers do not need to check for this case.
489 */
490int
491drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
492{
493 struct drm_device *dev = obj->dev;
494
495 return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node,
496 size / PAGE_SIZE);
497}
498EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
499
500/**
501 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
502 * @obj: obj in question
503 *
504 * GEM memory mapping works by handing back to userspace a fake mmap offset
505 * it can use in a subsequent mmap(2) call. The DRM core code then looks
506 * up the object based on the offset and sets up the various memory mapping
507 * structures.
508 *
509 * This routine allocates and attaches a fake offset for @obj.
510 *
511 * Drivers can call drm_gem_free_mmap_offset() before freeing @obj to release
512 * the fake offset again.
513 */
514int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
515{
516 return drm_gem_create_mmap_offset_size(obj, obj->size);
517}
518EXPORT_SYMBOL(drm_gem_create_mmap_offset);
519
520/**
521 * drm_gem_get_pages - helper to allocate backing pages for a GEM object
522 * from shmem
523 * @obj: obj in question
524 *
525 * This reads the page-array of the shmem-backing storage of the given gem
526 * object. An array of pages is returned. If a page is not allocated or
527 * swapped-out, this will allocate/swap-in the required pages. Note that the
528 * whole object is covered by the page-array and pinned in memory.
529 *
530 * Use drm_gem_put_pages() to release the array and unpin all pages.
531 *
532 * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()).
533 * If you require other GFP-masks, you have to do those allocations yourself.
534 *
535 * Note that you are not allowed to change gfp-zones during runtime. That is,
536 * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as
537 * set during initialization. If you have special zone constraints, set them
538 * after drm_gem_object_init() via mapping_set_gfp_mask(). shmem-core takes care
539 * to keep pages in the required zone during swap-in.
540 */
541struct page **drm_gem_get_pages(struct drm_gem_object *obj)
542{
543 struct address_space *mapping;
544 struct page *p, **pages;
545 int i, npages;
546
547 /* This is the shared memory object that backs the GEM resource */
548 mapping = obj->filp->f_mapping;
549
550 /* We already BUG_ON() for non-page-aligned sizes in
551 * drm_gem_object_init(), so we should never hit this unless
552 * driver author is doing something really wrong:
553 */
554 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
555
556 npages = obj->size >> PAGE_SHIFT;
557
558 pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
559 if (pages == NULL)
560 return ERR_PTR(-ENOMEM);
561
562 for (i = 0; i < npages; i++) {
563 p = shmem_read_mapping_page(mapping, i);
564 if (IS_ERR(p))
565 goto fail;
566 pages[i] = p;
567
568 /* Make sure shmem keeps __GFP_DMA32 allocated pages in the
569 * correct region during swapin. Note that this requires
570 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping)
571 * so shmem can relocate pages during swapin if required.
572 */
573 BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) &&
574 (page_to_pfn(p) >= 0x00100000UL));
575 }
576
577 return pages;
578
579fail:
580 while (i--)
581 put_page(pages[i]);
582
583 kvfree(pages);
584 return ERR_CAST(p);
585}
586EXPORT_SYMBOL(drm_gem_get_pages);
587
588/**
589 * drm_gem_put_pages - helper to free backing pages for a GEM object
590 * @obj: obj in question
591 * @pages: pages to free
592 * @dirty: if true, pages will be marked as dirty
593 * @accessed: if true, the pages will be marked as accessed
594 */
595void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
596 bool dirty, bool accessed)
597{
598 int i, npages;
599
600 /* We already BUG_ON() for non-page-aligned sizes in
601 * drm_gem_object_init(), so we should never hit this unless
602 * driver author is doing something really wrong:
603 */
604 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
605
606 npages = obj->size >> PAGE_SHIFT;
607
608 for (i = 0; i < npages; i++) {
609 if (dirty)
610 set_page_dirty(pages[i]);
611
612 if (accessed)
613 mark_page_accessed(pages[i]);
614
615 /* Undo the reference we took when populating the table */
616 put_page(pages[i]);
617 }
618
619 kvfree(pages);
620}
621EXPORT_SYMBOL(drm_gem_put_pages);
622
623/**
624 * drm_gem_object_lookup - look up a GEM object from it's handle
625 * @filp: DRM file private date
626 * @handle: userspace handle
627 *
628 * Returns:
629 *
630 * A reference to the object named by the handle if such exists on @filp, NULL
631 * otherwise.
632 */
633struct drm_gem_object *
634drm_gem_object_lookup(struct drm_file *filp, u32 handle)
635{
636 struct drm_gem_object *obj;
637
638 spin_lock(&filp->table_lock);
639
640 /* Check if we currently have a reference on the object */
641 obj = idr_find(&filp->object_idr, handle);
642 if (obj)
643 drm_gem_object_get(obj);
644
645 spin_unlock(&filp->table_lock);
646
647 return obj;
648}
649EXPORT_SYMBOL(drm_gem_object_lookup);
650
651/**
652 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
653 * @dev: drm_device
654 * @data: ioctl data
655 * @file_priv: drm file-private structure
656 *
657 * Releases the handle to an mm object.
658 */
659int
660drm_gem_close_ioctl(struct drm_device *dev, void *data,
661 struct drm_file *file_priv)
662{
663 struct drm_gem_close *args = data;
664 int ret;
665
666 if (!drm_core_check_feature(dev, DRIVER_GEM))
667 return -ENODEV;
668
669 ret = drm_gem_handle_delete(file_priv, args->handle);
670
671 return ret;
672}
673
674/**
675 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl
676 * @dev: drm_device
677 * @data: ioctl data
678 * @file_priv: drm file-private structure
679 *
680 * Create a global name for an object, returning the name.
681 *
682 * Note that the name does not hold a reference; when the object
683 * is freed, the name goes away.
684 */
685int
686drm_gem_flink_ioctl(struct drm_device *dev, void *data,
687 struct drm_file *file_priv)
688{
689 struct drm_gem_flink *args = data;
690 struct drm_gem_object *obj;
691 int ret;
692
693 if (!drm_core_check_feature(dev, DRIVER_GEM))
694 return -ENODEV;
695
696 obj = drm_gem_object_lookup(file_priv, args->handle);
697 if (obj == NULL)
698 return -ENOENT;
699
700 mutex_lock(&dev->object_name_lock);
701 /* prevent races with concurrent gem_close. */
702 if (obj->handle_count == 0) {
703 ret = -ENOENT;
704 goto err;
705 }
706
707 if (!obj->name) {
708 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_KERNEL);
709 if (ret < 0)
710 goto err;
711
712 obj->name = ret;
713 }
714
715 args->name = (uint64_t) obj->name;
716 ret = 0;
717
718err:
719 mutex_unlock(&dev->object_name_lock);
720 drm_gem_object_put_unlocked(obj);
721 return ret;
722}
723
724/**
725 * drm_gem_open - implementation of the GEM_OPEN ioctl
726 * @dev: drm_device
727 * @data: ioctl data
728 * @file_priv: drm file-private structure
729 *
730 * Open an object using the global name, returning a handle and the size.
731 *
732 * This handle (of course) holds a reference to the object, so the object
733 * will not go away until the handle is deleted.
734 */
735int
736drm_gem_open_ioctl(struct drm_device *dev, void *data,
737 struct drm_file *file_priv)
738{
739 struct drm_gem_open *args = data;
740 struct drm_gem_object *obj;
741 int ret;
742 u32 handle;
743
744 if (!drm_core_check_feature(dev, DRIVER_GEM))
745 return -ENODEV;
746
747 mutex_lock(&dev->object_name_lock);
748 obj = idr_find(&dev->object_name_idr, (int) args->name);
749 if (obj) {
750 drm_gem_object_get(obj);
751 } else {
752 mutex_unlock(&dev->object_name_lock);
753 return -ENOENT;
754 }
755
756 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
757 ret = drm_gem_handle_create_tail(file_priv, obj, &handle);
758 drm_gem_object_put_unlocked(obj);
759 if (ret)
760 return ret;
761
762 args->handle = handle;
763 args->size = obj->size;
764
765 return 0;
766}
767
768/**
769 * gem_gem_open - initalizes GEM file-private structures at devnode open time
770 * @dev: drm_device which is being opened by userspace
771 * @file_private: drm file-private structure to set up
772 *
773 * Called at device open time, sets up the structure for handling refcounting
774 * of mm objects.
775 */
776void
777drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
778{
779 idr_init_base(&file_private->object_idr, 1);
780 spin_lock_init(&file_private->table_lock);
781}
782
783/**
784 * drm_gem_release - release file-private GEM resources
785 * @dev: drm_device which is being closed by userspace
786 * @file_private: drm file-private structure to clean up
787 *
788 * Called at close time when the filp is going away.
789 *
790 * Releases any remaining references on objects by this filp.
791 */
792void
793drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
794{
795 idr_for_each(&file_private->object_idr,
796 &drm_gem_object_release_handle, file_private);
797 idr_destroy(&file_private->object_idr);
798}
799
800/**
801 * drm_gem_object_release - release GEM buffer object resources
802 * @obj: GEM buffer object
803 *
804 * This releases any structures and resources used by @obj and is the invers of
805 * drm_gem_object_init().
806 */
807void
808drm_gem_object_release(struct drm_gem_object *obj)
809{
810 WARN_ON(obj->dma_buf);
811
812 if (obj->filp)
813 fput(obj->filp);
814
815 drm_gem_free_mmap_offset(obj);
816}
817EXPORT_SYMBOL(drm_gem_object_release);
818
819/**
820 * drm_gem_object_free - free a GEM object
821 * @kref: kref of the object to free
822 *
823 * Called after the last reference to the object has been lost.
824 * Must be called holding &drm_device.struct_mutex.
825 *
826 * Frees the object
827 */
828void
829drm_gem_object_free(struct kref *kref)
830{
831 struct drm_gem_object *obj =
832 container_of(kref, struct drm_gem_object, refcount);
833 struct drm_device *dev = obj->dev;
834
835 if (dev->driver->gem_free_object_unlocked) {
836 dev->driver->gem_free_object_unlocked(obj);
837 } else if (dev->driver->gem_free_object) {
838 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
839
840 dev->driver->gem_free_object(obj);
841 }
842}
843EXPORT_SYMBOL(drm_gem_object_free);
844
845/**
846 * drm_gem_object_put_unlocked - drop a GEM buffer object reference
847 * @obj: GEM buffer object
848 *
849 * This releases a reference to @obj. Callers must not hold the
850 * &drm_device.struct_mutex lock when calling this function.
851 *
852 * See also __drm_gem_object_put().
853 */
854void
855drm_gem_object_put_unlocked(struct drm_gem_object *obj)
856{
857 struct drm_device *dev;
858
859 if (!obj)
860 return;
861
862 dev = obj->dev;
863
864 if (dev->driver->gem_free_object_unlocked) {
865 kref_put(&obj->refcount, drm_gem_object_free);
866 } else {
867 might_lock(&dev->struct_mutex);
868 if (kref_put_mutex(&obj->refcount, drm_gem_object_free,
869 &dev->struct_mutex))
870 mutex_unlock(&dev->struct_mutex);
871 }
872}
873EXPORT_SYMBOL(drm_gem_object_put_unlocked);
874
875/**
876 * drm_gem_object_put - release a GEM buffer object reference
877 * @obj: GEM buffer object
878 *
879 * This releases a reference to @obj. Callers must hold the
880 * &drm_device.struct_mutex lock when calling this function, even when the
881 * driver doesn't use &drm_device.struct_mutex for anything.
882 *
883 * For drivers not encumbered with legacy locking use
884 * drm_gem_object_put_unlocked() instead.
885 */
886void
887drm_gem_object_put(struct drm_gem_object *obj)
888{
889 if (obj) {
890 WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
891
892 kref_put(&obj->refcount, drm_gem_object_free);
893 }
894}
895EXPORT_SYMBOL(drm_gem_object_put);
896
897/**
898 * drm_gem_vm_open - vma->ops->open implementation for GEM
899 * @vma: VM area structure
900 *
901 * This function implements the #vm_operations_struct open() callback for GEM
902 * drivers. This must be used together with drm_gem_vm_close().
903 */
904void drm_gem_vm_open(struct vm_area_struct *vma)
905{
906 struct drm_gem_object *obj = vma->vm_private_data;
907
908 drm_gem_object_get(obj);
909}
910EXPORT_SYMBOL(drm_gem_vm_open);
911
912/**
913 * drm_gem_vm_close - vma->ops->close implementation for GEM
914 * @vma: VM area structure
915 *
916 * This function implements the #vm_operations_struct close() callback for GEM
917 * drivers. This must be used together with drm_gem_vm_open().
918 */
919void drm_gem_vm_close(struct vm_area_struct *vma)
920{
921 struct drm_gem_object *obj = vma->vm_private_data;
922
923 drm_gem_object_put_unlocked(obj);
924}
925EXPORT_SYMBOL(drm_gem_vm_close);
926
927/**
928 * drm_gem_mmap_obj - memory map a GEM object
929 * @obj: the GEM object to map
930 * @obj_size: the object size to be mapped, in bytes
931 * @vma: VMA for the area to be mapped
932 *
933 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
934 * provided by the driver. Depending on their requirements, drivers can either
935 * provide a fault handler in their gem_vm_ops (in which case any accesses to
936 * the object will be trapped, to perform migration, GTT binding, surface
937 * register allocation, or performance monitoring), or mmap the buffer memory
938 * synchronously after calling drm_gem_mmap_obj.
939 *
940 * This function is mainly intended to implement the DMABUF mmap operation, when
941 * the GEM object is not looked up based on its fake offset. To implement the
942 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
943 *
944 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while
945 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So
946 * callers must verify access restrictions before calling this helper.
947 *
948 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
949 * size, or if no gem_vm_ops are provided.
950 */
951int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
952 struct vm_area_struct *vma)
953{
954 struct drm_device *dev = obj->dev;
955
956 /* Check for valid size. */
957 if (obj_size < vma->vm_end - vma->vm_start)
958 return -EINVAL;
959
960 if (!dev->driver->gem_vm_ops)
961 return -EINVAL;
962
963 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
964 vma->vm_ops = dev->driver->gem_vm_ops;
965 vma->vm_private_data = obj;
966 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
967 vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
968
969 /* Take a ref for this mapping of the object, so that the fault
970 * handler can dereference the mmap offset's pointer to the object.
971 * This reference is cleaned up by the corresponding vm_close
972 * (which should happen whether the vma was created by this call, or
973 * by a vm_open due to mremap or partial unmap or whatever).
974 */
975 drm_gem_object_get(obj);
976
977 return 0;
978}
979EXPORT_SYMBOL(drm_gem_mmap_obj);
980
981/**
982 * drm_gem_mmap - memory map routine for GEM objects
983 * @filp: DRM file pointer
984 * @vma: VMA for the area to be mapped
985 *
986 * If a driver supports GEM object mapping, mmap calls on the DRM file
987 * descriptor will end up here.
988 *
989 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
990 * contain the fake offset we created when the GTT map ioctl was called on
991 * the object) and map it with a call to drm_gem_mmap_obj().
992 *
993 * If the caller is not granted access to the buffer object, the mmap will fail
994 * with EACCES. Please see the vma manager for more information.
995 */
996int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
997{
998 struct drm_file *priv = filp->private_data;
999 struct drm_device *dev = priv->minor->dev;
1000 struct drm_gem_object *obj = NULL;
1001 struct drm_vma_offset_node *node;
1002 int ret;
1003
1004 if (drm_dev_is_unplugged(dev))
1005 return -ENODEV;
1006
1007 drm_vma_offset_lock_lookup(dev->vma_offset_manager);
1008 node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
1009 vma->vm_pgoff,
1010 vma_pages(vma));
1011 if (likely(node)) {
1012 obj = container_of(node, struct drm_gem_object, vma_node);
1013 /*
1014 * When the object is being freed, after it hits 0-refcnt it
1015 * proceeds to tear down the object. In the process it will
1016 * attempt to remove the VMA offset and so acquire this
1017 * mgr->vm_lock. Therefore if we find an object with a 0-refcnt
1018 * that matches our range, we know it is in the process of being
1019 * destroyed and will be freed as soon as we release the lock -
1020 * so we have to check for the 0-refcnted object and treat it as
1021 * invalid.
1022 */
1023 if (!kref_get_unless_zero(&obj->refcount))
1024 obj = NULL;
1025 }
1026 drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
1027
1028 if (!obj)
1029 return -EINVAL;
1030
1031 if (!drm_vma_node_is_allowed(node, priv)) {
1032 drm_gem_object_put_unlocked(obj);
1033 return -EACCES;
1034 }
1035
1036 ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT,
1037 vma);
1038
1039 drm_gem_object_put_unlocked(obj);
1040
1041 return ret;
1042}
1043EXPORT_SYMBOL(drm_gem_mmap);
1044
1045void drm_gem_print_info(struct drm_printer *p, unsigned int indent,
1046 const struct drm_gem_object *obj)
1047{
1048 drm_printf_indent(p, indent, "name=%d\n", obj->name);
1049 drm_printf_indent(p, indent, "refcount=%u\n",
1050 kref_read(&obj->refcount));
1051 drm_printf_indent(p, indent, "start=%08lx\n",
1052 drm_vma_node_start(&obj->vma_node));
1053 drm_printf_indent(p, indent, "size=%zu\n", obj->size);
1054 drm_printf_indent(p, indent, "imported=%s\n",
1055 obj->import_attach ? "yes" : "no");
1056
1057 if (obj->dev->driver->gem_print_info)
1058 obj->dev->driver->gem_print_info(p, indent, obj);
1059}