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/dma-buf.h>
29#include <linux/file.h>
30#include <linux/fs.h>
31#include <linux/iosys-map.h>
32#include <linux/mem_encrypt.h>
33#include <linux/mm.h>
34#include <linux/mman.h>
35#include <linux/module.h>
36#include <linux/pagemap.h>
37#include <linux/pagevec.h>
38#include <linux/shmem_fs.h>
39#include <linux/slab.h>
40#include <linux/string_helpers.h>
41#include <linux/types.h>
42#include <linux/uaccess.h>
43
44#include <drm/drm.h>
45#include <drm/drm_device.h>
46#include <drm/drm_drv.h>
47#include <drm/drm_file.h>
48#include <drm/drm_gem.h>
49#include <drm/drm_managed.h>
50#include <drm/drm_print.h>
51#include <drm/drm_vma_manager.h>
52
53#include "drm_internal.h"
54
55/** @file drm_gem.c
56 *
57 * This file provides some of the base ioctls and library routines for
58 * the graphics memory manager implemented by each device driver.
59 *
60 * Because various devices have different requirements in terms of
61 * synchronization and migration strategies, implementing that is left up to
62 * the driver, and all that the general API provides should be generic --
63 * allocating objects, reading/writing data with the cpu, freeing objects.
64 * Even there, platform-dependent optimizations for reading/writing data with
65 * the CPU mean we'll likely hook those out to driver-specific calls. However,
66 * the DRI2 implementation wants to have at least allocate/mmap be generic.
67 *
68 * The goal was to have swap-backed object allocation managed through
69 * struct file. However, file descriptors as handles to a struct file have
70 * two major failings:
71 * - Process limits prevent more than 1024 or so being used at a time by
72 * default.
73 * - Inability to allocate high fds will aggravate the X Server's select()
74 * handling, and likely that of many GL client applications as well.
75 *
76 * This led to a plan of using our own integer IDs (called handles, following
77 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
78 * ioctls. The objects themselves will still include the struct file so
79 * that we can transition to fds if the required kernel infrastructure shows
80 * up at a later date, and as our interface with shmfs for memory allocation.
81 */
82
83static void
84drm_gem_init_release(struct drm_device *dev, void *ptr)
85{
86 drm_vma_offset_manager_destroy(mgr: dev->vma_offset_manager);
87}
88
89/**
90 * drm_gem_init - Initialize the GEM device fields
91 * @dev: drm_devic structure to initialize
92 */
93int
94drm_gem_init(struct drm_device *dev)
95{
96 struct drm_vma_offset_manager *vma_offset_manager;
97
98 mutex_init(&dev->object_name_lock);
99 idr_init_base(idr: &dev->object_name_idr, base: 1);
100
101 vma_offset_manager = drmm_kzalloc(dev, size: sizeof(*vma_offset_manager),
102 GFP_KERNEL);
103 if (!vma_offset_manager) {
104 DRM_ERROR("out of memory\n");
105 return -ENOMEM;
106 }
107
108 dev->vma_offset_manager = vma_offset_manager;
109 drm_vma_offset_manager_init(mgr: vma_offset_manager,
110 DRM_FILE_PAGE_OFFSET_START,
111 DRM_FILE_PAGE_OFFSET_SIZE);
112
113 return drmm_add_action(dev, drm_gem_init_release, NULL);
114}
115
116/**
117 * drm_gem_object_init_with_mnt - initialize an allocated shmem-backed GEM
118 * object in a given shmfs mountpoint
119 *
120 * @dev: drm_device the object should be initialized for
121 * @obj: drm_gem_object to initialize
122 * @size: object size
123 * @gemfs: tmpfs mount where the GEM object will be created. If NULL, use
124 * the usual tmpfs mountpoint (`shm_mnt`).
125 *
126 * Initialize an already allocated GEM object of the specified size with
127 * shmfs backing store.
128 */
129int drm_gem_object_init_with_mnt(struct drm_device *dev,
130 struct drm_gem_object *obj, size_t size,
131 struct vfsmount *gemfs)
132{
133 struct file *filp;
134
135 drm_gem_private_object_init(dev, obj, size);
136
137 if (gemfs)
138 filp = shmem_file_setup_with_mnt(mnt: gemfs, name: "drm mm object", size,
139 VM_NORESERVE);
140 else
141 filp = shmem_file_setup(name: "drm mm object", size, VM_NORESERVE);
142
143 if (IS_ERR(ptr: filp))
144 return PTR_ERR(ptr: filp);
145
146 obj->filp = filp;
147
148 return 0;
149}
150EXPORT_SYMBOL(drm_gem_object_init_with_mnt);
151
152/**
153 * drm_gem_object_init - initialize an allocated shmem-backed 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 * shmfs backing store.
160 */
161int drm_gem_object_init(struct drm_device *dev, struct drm_gem_object *obj,
162 size_t size)
163{
164 return drm_gem_object_init_with_mnt(dev, obj, size, NULL);
165}
166EXPORT_SYMBOL(drm_gem_object_init);
167
168/**
169 * drm_gem_private_object_init - initialize an allocated private GEM object
170 * @dev: drm_device the object should be initialized for
171 * @obj: drm_gem_object to initialize
172 * @size: object size
173 *
174 * Initialize an already allocated GEM object of the specified size with
175 * no GEM provided backing store. Instead the caller is responsible for
176 * backing the object and handling it.
177 */
178void drm_gem_private_object_init(struct drm_device *dev,
179 struct drm_gem_object *obj, size_t size)
180{
181 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
182
183 obj->dev = dev;
184 obj->filp = NULL;
185
186 kref_init(kref: &obj->refcount);
187 obj->handle_count = 0;
188 obj->size = size;
189 dma_resv_init(obj: &obj->_resv);
190 if (!obj->resv)
191 obj->resv = &obj->_resv;
192
193 if (drm_core_check_feature(dev, feature: DRIVER_GEM_GPUVA))
194 drm_gem_gpuva_init(obj);
195
196 drm_vma_node_reset(node: &obj->vma_node);
197 INIT_LIST_HEAD(list: &obj->lru_node);
198}
199EXPORT_SYMBOL(drm_gem_private_object_init);
200
201/**
202 * drm_gem_private_object_fini - Finalize a failed drm_gem_object
203 * @obj: drm_gem_object
204 *
205 * Uninitialize an already allocated GEM object when it initialized failed
206 */
207void drm_gem_private_object_fini(struct drm_gem_object *obj)
208{
209 WARN_ON(obj->dma_buf);
210
211 dma_resv_fini(obj: &obj->_resv);
212}
213EXPORT_SYMBOL(drm_gem_private_object_fini);
214
215/**
216 * drm_gem_object_handle_free - release resources bound to userspace handles
217 * @obj: GEM object to clean up.
218 *
219 * Called after the last handle to the object has been closed
220 *
221 * Removes any name for the object. Note that this must be
222 * called before drm_gem_object_free or we'll be touching
223 * freed memory
224 */
225static void drm_gem_object_handle_free(struct drm_gem_object *obj)
226{
227 struct drm_device *dev = obj->dev;
228
229 /* Remove any name for this object */
230 if (obj->name) {
231 idr_remove(&dev->object_name_idr, id: obj->name);
232 obj->name = 0;
233 }
234}
235
236static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
237{
238 /* Unbreak the reference cycle if we have an exported dma_buf. */
239 if (obj->dma_buf) {
240 dma_buf_put(dmabuf: obj->dma_buf);
241 obj->dma_buf = NULL;
242 }
243}
244
245static void
246drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj)
247{
248 struct drm_device *dev = obj->dev;
249 bool final = false;
250
251 if (WARN_ON(READ_ONCE(obj->handle_count) == 0))
252 return;
253
254 /*
255 * Must bump handle count first as this may be the last
256 * ref, in which case the object would disappear before we
257 * checked for a name
258 */
259
260 mutex_lock(&dev->object_name_lock);
261 if (--obj->handle_count == 0) {
262 drm_gem_object_handle_free(obj);
263 drm_gem_object_exported_dma_buf_free(obj);
264 final = true;
265 }
266 mutex_unlock(lock: &dev->object_name_lock);
267
268 if (final)
269 drm_gem_object_put(obj);
270}
271
272/*
273 * Called at device or object close to release the file's
274 * handle references on objects.
275 */
276static int
277drm_gem_object_release_handle(int id, void *ptr, void *data)
278{
279 struct drm_file *file_priv = data;
280 struct drm_gem_object *obj = ptr;
281
282 if (obj->funcs->close)
283 obj->funcs->close(obj, file_priv);
284
285 drm_prime_remove_buf_handle(prime_fpriv: &file_priv->prime, handle: id);
286 drm_vma_node_revoke(node: &obj->vma_node, tag: file_priv);
287
288 drm_gem_object_handle_put_unlocked(obj);
289
290 return 0;
291}
292
293/**
294 * drm_gem_handle_delete - deletes the given file-private handle
295 * @filp: drm file-private structure to use for the handle look up
296 * @handle: userspace handle to delete
297 *
298 * Removes the GEM handle from the @filp lookup table which has been added with
299 * drm_gem_handle_create(). If this is the last handle also cleans up linked
300 * resources like GEM names.
301 */
302int
303drm_gem_handle_delete(struct drm_file *filp, u32 handle)
304{
305 struct drm_gem_object *obj;
306
307 spin_lock(lock: &filp->table_lock);
308
309 /* Check if we currently have a reference on the object */
310 obj = idr_replace(&filp->object_idr, NULL, id: handle);
311 spin_unlock(lock: &filp->table_lock);
312 if (IS_ERR_OR_NULL(ptr: obj))
313 return -EINVAL;
314
315 /* Release driver's reference and decrement refcount. */
316 drm_gem_object_release_handle(id: handle, ptr: obj, data: filp);
317
318 /* And finally make the handle available for future allocations. */
319 spin_lock(lock: &filp->table_lock);
320 idr_remove(&filp->object_idr, id: handle);
321 spin_unlock(lock: &filp->table_lock);
322
323 return 0;
324}
325EXPORT_SYMBOL(drm_gem_handle_delete);
326
327/**
328 * drm_gem_dumb_map_offset - return the fake mmap offset for a gem object
329 * @file: drm file-private structure containing the gem object
330 * @dev: corresponding drm_device
331 * @handle: gem object handle
332 * @offset: return location for the fake mmap offset
333 *
334 * This implements the &drm_driver.dumb_map_offset kms driver callback for
335 * drivers which use gem to manage their backing storage.
336 *
337 * Returns:
338 * 0 on success or a negative error code on failure.
339 */
340int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
341 u32 handle, u64 *offset)
342{
343 struct drm_gem_object *obj;
344 int ret;
345
346 obj = drm_gem_object_lookup(filp: file, handle);
347 if (!obj)
348 return -ENOENT;
349
350 /* Don't allow imported objects to be mapped */
351 if (drm_gem_is_imported(obj)) {
352 ret = -EINVAL;
353 goto out;
354 }
355
356 ret = drm_gem_create_mmap_offset(obj);
357 if (ret)
358 goto out;
359
360 *offset = drm_vma_node_offset_addr(node: &obj->vma_node);
361out:
362 drm_gem_object_put(obj);
363
364 return ret;
365}
366EXPORT_SYMBOL_GPL(drm_gem_dumb_map_offset);
367
368/**
369 * drm_gem_handle_create_tail - internal functions to create a handle
370 * @file_priv: drm file-private structure to register the handle for
371 * @obj: object to register
372 * @handlep: pointer to return the created handle to the caller
373 *
374 * This expects the &drm_device.object_name_lock to be held already and will
375 * drop it before returning. Used to avoid races in establishing new handles
376 * when importing an object from either an flink name or a dma-buf.
377 *
378 * Handles must be release again through drm_gem_handle_delete(). This is done
379 * when userspace closes @file_priv for all attached handles, or through the
380 * GEM_CLOSE ioctl for individual handles.
381 */
382int
383drm_gem_handle_create_tail(struct drm_file *file_priv,
384 struct drm_gem_object *obj,
385 u32 *handlep)
386{
387 struct drm_device *dev = obj->dev;
388 u32 handle;
389 int ret;
390
391 WARN_ON(!mutex_is_locked(&dev->object_name_lock));
392 if (obj->handle_count++ == 0)
393 drm_gem_object_get(obj);
394
395 /*
396 * Get the user-visible handle using idr. Preload and perform
397 * allocation under our spinlock.
398 */
399 idr_preload(GFP_KERNEL);
400 spin_lock(lock: &file_priv->table_lock);
401
402 ret = idr_alloc(&file_priv->object_idr, ptr: obj, start: 1, end: 0, GFP_NOWAIT);
403
404 spin_unlock(lock: &file_priv->table_lock);
405 idr_preload_end();
406
407 mutex_unlock(lock: &dev->object_name_lock);
408 if (ret < 0)
409 goto err_unref;
410
411 handle = ret;
412
413 ret = drm_vma_node_allow(node: &obj->vma_node, tag: file_priv);
414 if (ret)
415 goto err_remove;
416
417 if (obj->funcs->open) {
418 ret = obj->funcs->open(obj, file_priv);
419 if (ret)
420 goto err_revoke;
421 }
422
423 *handlep = handle;
424 return 0;
425
426err_revoke:
427 drm_vma_node_revoke(node: &obj->vma_node, tag: file_priv);
428err_remove:
429 spin_lock(lock: &file_priv->table_lock);
430 idr_remove(&file_priv->object_idr, id: handle);
431 spin_unlock(lock: &file_priv->table_lock);
432err_unref:
433 drm_gem_object_handle_put_unlocked(obj);
434 return ret;
435}
436
437/**
438 * drm_gem_handle_create - create a gem handle for an object
439 * @file_priv: drm file-private structure to register the handle for
440 * @obj: object to register
441 * @handlep: pointer to return the created handle to the caller
442 *
443 * Create a handle for this object. This adds a handle reference to the object,
444 * which includes a regular reference count. Callers will likely want to
445 * dereference the object afterwards.
446 *
447 * Since this publishes @obj to userspace it must be fully set up by this point,
448 * drivers must call this last in their buffer object creation callbacks.
449 */
450int drm_gem_handle_create(struct drm_file *file_priv,
451 struct drm_gem_object *obj,
452 u32 *handlep)
453{
454 mutex_lock(&obj->dev->object_name_lock);
455
456 return drm_gem_handle_create_tail(file_priv, obj, handlep);
457}
458EXPORT_SYMBOL(drm_gem_handle_create);
459
460
461/**
462 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
463 * @obj: obj in question
464 *
465 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
466 *
467 * Note that drm_gem_object_release() already calls this function, so drivers
468 * don't have to take care of releasing the mmap offset themselves when freeing
469 * the GEM object.
470 */
471void
472drm_gem_free_mmap_offset(struct drm_gem_object *obj)
473{
474 struct drm_device *dev = obj->dev;
475
476 drm_vma_offset_remove(mgr: dev->vma_offset_manager, node: &obj->vma_node);
477}
478EXPORT_SYMBOL(drm_gem_free_mmap_offset);
479
480/**
481 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object
482 * @obj: obj in question
483 * @size: the virtual size
484 *
485 * GEM memory mapping works by handing back to userspace a fake mmap offset
486 * it can use in a subsequent mmap(2) call. The DRM core code then looks
487 * up the object based on the offset and sets up the various memory mapping
488 * structures.
489 *
490 * This routine allocates and attaches a fake offset for @obj, in cases where
491 * the virtual size differs from the physical size (ie. &drm_gem_object.size).
492 * Otherwise just use drm_gem_create_mmap_offset().
493 *
494 * This function is idempotent and handles an already allocated mmap offset
495 * transparently. Drivers do not need to check for this case.
496 */
497int
498drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
499{
500 struct drm_device *dev = obj->dev;
501
502 return drm_vma_offset_add(mgr: dev->vma_offset_manager, node: &obj->vma_node,
503 pages: size / PAGE_SIZE);
504}
505EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
506
507/**
508 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
509 * @obj: obj in question
510 *
511 * GEM memory mapping works by handing back to userspace a fake mmap offset
512 * it can use in a subsequent mmap(2) call. The DRM core code then looks
513 * up the object based on the offset and sets up the various memory mapping
514 * structures.
515 *
516 * This routine allocates and attaches a fake offset for @obj.
517 *
518 * Drivers can call drm_gem_free_mmap_offset() before freeing @obj to release
519 * the fake offset again.
520 */
521int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
522{
523 return drm_gem_create_mmap_offset_size(obj, obj->size);
524}
525EXPORT_SYMBOL(drm_gem_create_mmap_offset);
526
527/*
528 * Move folios to appropriate lru and release the folios, decrementing the
529 * ref count of those folios.
530 */
531static void drm_gem_check_release_batch(struct folio_batch *fbatch)
532{
533 check_move_unevictable_folios(fbatch);
534 __folio_batch_release(pvec: fbatch);
535 cond_resched();
536}
537
538/**
539 * drm_gem_get_pages - helper to allocate backing pages for a GEM object
540 * from shmem
541 * @obj: obj in question
542 *
543 * This reads the page-array of the shmem-backing storage of the given gem
544 * object. An array of pages is returned. If a page is not allocated or
545 * swapped-out, this will allocate/swap-in the required pages. Note that the
546 * whole object is covered by the page-array and pinned in memory.
547 *
548 * Use drm_gem_put_pages() to release the array and unpin all pages.
549 *
550 * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()).
551 * If you require other GFP-masks, you have to do those allocations yourself.
552 *
553 * Note that you are not allowed to change gfp-zones during runtime. That is,
554 * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as
555 * set during initialization. If you have special zone constraints, set them
556 * after drm_gem_object_init() via mapping_set_gfp_mask(). shmem-core takes care
557 * to keep pages in the required zone during swap-in.
558 *
559 * This function is only valid on objects initialized with
560 * drm_gem_object_init(), but not for those initialized with
561 * drm_gem_private_object_init() only.
562 */
563struct page **drm_gem_get_pages(struct drm_gem_object *obj)
564{
565 struct address_space *mapping;
566 struct page **pages;
567 struct folio *folio;
568 struct folio_batch fbatch;
569 long i, j, npages;
570
571 if (WARN_ON(!obj->filp))
572 return ERR_PTR(error: -EINVAL);
573
574 /* This is the shared memory object that backs the GEM resource */
575 mapping = obj->filp->f_mapping;
576
577 /* We already BUG_ON() for non-page-aligned sizes in
578 * drm_gem_object_init(), so we should never hit this unless
579 * driver author is doing something really wrong:
580 */
581 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
582
583 npages = obj->size >> PAGE_SHIFT;
584
585 pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
586 if (pages == NULL)
587 return ERR_PTR(error: -ENOMEM);
588
589 mapping_set_unevictable(mapping);
590
591 i = 0;
592 while (i < npages) {
593 long nr;
594 folio = shmem_read_folio_gfp(mapping, index: i,
595 gfp: mapping_gfp_mask(mapping));
596 if (IS_ERR(ptr: folio))
597 goto fail;
598 nr = min(npages - i, folio_nr_pages(folio));
599 for (j = 0; j < nr; j++, i++)
600 pages[i] = folio_file_page(folio, index: i);
601
602 /* Make sure shmem keeps __GFP_DMA32 allocated pages in the
603 * correct region during swapin. Note that this requires
604 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping)
605 * so shmem can relocate pages during swapin if required.
606 */
607 BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) &&
608 (folio_pfn(folio) >= 0x00100000UL));
609 }
610
611 return pages;
612
613fail:
614 mapping_clear_unevictable(mapping);
615 folio_batch_init(fbatch: &fbatch);
616 j = 0;
617 while (j < i) {
618 struct folio *f = page_folio(pages[j]);
619 if (!folio_batch_add(fbatch: &fbatch, folio: f))
620 drm_gem_check_release_batch(fbatch: &fbatch);
621 j += folio_nr_pages(folio: f);
622 }
623 if (fbatch.nr)
624 drm_gem_check_release_batch(fbatch: &fbatch);
625
626 kvfree(addr: pages);
627 return ERR_CAST(ptr: folio);
628}
629EXPORT_SYMBOL(drm_gem_get_pages);
630
631/**
632 * drm_gem_put_pages - helper to free backing pages for a GEM object
633 * @obj: obj in question
634 * @pages: pages to free
635 * @dirty: if true, pages will be marked as dirty
636 * @accessed: if true, the pages will be marked as accessed
637 */
638void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
639 bool dirty, bool accessed)
640{
641 int i, npages;
642 struct address_space *mapping;
643 struct folio_batch fbatch;
644
645 mapping = file_inode(f: obj->filp)->i_mapping;
646 mapping_clear_unevictable(mapping);
647
648 /* We already BUG_ON() for non-page-aligned sizes in
649 * drm_gem_object_init(), so we should never hit this unless
650 * driver author is doing something really wrong:
651 */
652 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
653
654 npages = obj->size >> PAGE_SHIFT;
655
656 folio_batch_init(fbatch: &fbatch);
657 for (i = 0; i < npages; i++) {
658 struct folio *folio;
659
660 if (!pages[i])
661 continue;
662 folio = page_folio(pages[i]);
663
664 if (dirty)
665 folio_mark_dirty(folio);
666
667 if (accessed)
668 folio_mark_accessed(folio);
669
670 /* Undo the reference we took when populating the table */
671 if (!folio_batch_add(fbatch: &fbatch, folio))
672 drm_gem_check_release_batch(fbatch: &fbatch);
673 i += folio_nr_pages(folio) - 1;
674 }
675 if (folio_batch_count(fbatch: &fbatch))
676 drm_gem_check_release_batch(fbatch: &fbatch);
677
678 kvfree(addr: pages);
679}
680EXPORT_SYMBOL(drm_gem_put_pages);
681
682static int objects_lookup(struct drm_file *filp, u32 *handle, int count,
683 struct drm_gem_object **objs)
684{
685 int i, ret = 0;
686 struct drm_gem_object *obj;
687
688 spin_lock(lock: &filp->table_lock);
689
690 for (i = 0; i < count; i++) {
691 /* Check if we currently have a reference on the object */
692 obj = idr_find(&filp->object_idr, id: handle[i]);
693 if (!obj) {
694 ret = -ENOENT;
695 break;
696 }
697 drm_gem_object_get(obj);
698 objs[i] = obj;
699 }
700 spin_unlock(lock: &filp->table_lock);
701
702 return ret;
703}
704
705/**
706 * drm_gem_objects_lookup - look up GEM objects from an array of handles
707 * @filp: DRM file private date
708 * @bo_handles: user pointer to array of userspace handle
709 * @count: size of handle array
710 * @objs_out: returned pointer to array of drm_gem_object pointers
711 *
712 * Takes an array of userspace handles and returns a newly allocated array of
713 * GEM objects.
714 *
715 * For a single handle lookup, use drm_gem_object_lookup().
716 *
717 * Returns:
718 * @objs filled in with GEM object pointers. Returned GEM objects need to be
719 * released with drm_gem_object_put(). -ENOENT is returned on a lookup
720 * failure. 0 is returned on success.
721 *
722 */
723int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
724 int count, struct drm_gem_object ***objs_out)
725{
726 int ret;
727 u32 *handles;
728 struct drm_gem_object **objs;
729
730 if (!count)
731 return 0;
732
733 objs = kvmalloc_array(count, sizeof(struct drm_gem_object *),
734 GFP_KERNEL | __GFP_ZERO);
735 if (!objs)
736 return -ENOMEM;
737
738 *objs_out = objs;
739
740 handles = kvmalloc_array(count, sizeof(u32), GFP_KERNEL);
741 if (!handles) {
742 ret = -ENOMEM;
743 goto out;
744 }
745
746 if (copy_from_user(to: handles, from: bo_handles, n: count * sizeof(u32))) {
747 ret = -EFAULT;
748 DRM_DEBUG("Failed to copy in GEM handles\n");
749 goto out;
750 }
751
752 ret = objects_lookup(filp, handle: handles, count, objs);
753out:
754 kvfree(addr: handles);
755 return ret;
756
757}
758EXPORT_SYMBOL(drm_gem_objects_lookup);
759
760/**
761 * drm_gem_object_lookup - look up a GEM object from its handle
762 * @filp: DRM file private date
763 * @handle: userspace handle
764 *
765 * If looking up an array of handles, use drm_gem_objects_lookup().
766 *
767 * Returns:
768 * A reference to the object named by the handle if such exists on @filp, NULL
769 * otherwise.
770 */
771struct drm_gem_object *
772drm_gem_object_lookup(struct drm_file *filp, u32 handle)
773{
774 struct drm_gem_object *obj = NULL;
775
776 objects_lookup(filp, handle: &handle, count: 1, objs: &obj);
777 return obj;
778}
779EXPORT_SYMBOL(drm_gem_object_lookup);
780
781/**
782 * drm_gem_dma_resv_wait - Wait on GEM object's reservation's objects
783 * shared and/or exclusive fences.
784 * @filep: DRM file private date
785 * @handle: userspace handle
786 * @wait_all: if true, wait on all fences, else wait on just exclusive fence
787 * @timeout: timeout value in jiffies or zero to return immediately
788 *
789 * Returns:
790 * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or
791 * greater than 0 on success.
792 */
793long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle,
794 bool wait_all, unsigned long timeout)
795{
796 long ret;
797 struct drm_gem_object *obj;
798
799 obj = drm_gem_object_lookup(filep, handle);
800 if (!obj) {
801 DRM_DEBUG("Failed to look up GEM BO %d\n", handle);
802 return -EINVAL;
803 }
804
805 ret = dma_resv_wait_timeout(obj: obj->resv, usage: dma_resv_usage_rw(write: wait_all),
806 intr: true, timeout);
807 if (ret == 0)
808 ret = -ETIME;
809 else if (ret > 0)
810 ret = 0;
811
812 drm_gem_object_put(obj);
813
814 return ret;
815}
816EXPORT_SYMBOL(drm_gem_dma_resv_wait);
817
818/**
819 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
820 * @dev: drm_device
821 * @data: ioctl data
822 * @file_priv: drm file-private structure
823 *
824 * Releases the handle to an mm object.
825 */
826int
827drm_gem_close_ioctl(struct drm_device *dev, void *data,
828 struct drm_file *file_priv)
829{
830 struct drm_gem_close *args = data;
831 int ret;
832
833 if (!drm_core_check_feature(dev, feature: DRIVER_GEM))
834 return -EOPNOTSUPP;
835
836 ret = drm_gem_handle_delete(file_priv, args->handle);
837
838 return ret;
839}
840
841/**
842 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl
843 * @dev: drm_device
844 * @data: ioctl data
845 * @file_priv: drm file-private structure
846 *
847 * Create a global name for an object, returning the name.
848 *
849 * Note that the name does not hold a reference; when the object
850 * is freed, the name goes away.
851 */
852int
853drm_gem_flink_ioctl(struct drm_device *dev, void *data,
854 struct drm_file *file_priv)
855{
856 struct drm_gem_flink *args = data;
857 struct drm_gem_object *obj;
858 int ret;
859
860 if (!drm_core_check_feature(dev, feature: DRIVER_GEM))
861 return -EOPNOTSUPP;
862
863 obj = drm_gem_object_lookup(file_priv, args->handle);
864 if (obj == NULL)
865 return -ENOENT;
866
867 mutex_lock(&dev->object_name_lock);
868 /* prevent races with concurrent gem_close. */
869 if (obj->handle_count == 0) {
870 ret = -ENOENT;
871 goto err;
872 }
873
874 if (!obj->name) {
875 ret = idr_alloc(&dev->object_name_idr, ptr: obj, start: 1, end: 0, GFP_KERNEL);
876 if (ret < 0)
877 goto err;
878
879 obj->name = ret;
880 }
881
882 args->name = (uint64_t) obj->name;
883 ret = 0;
884
885err:
886 mutex_unlock(lock: &dev->object_name_lock);
887 drm_gem_object_put(obj);
888 return ret;
889}
890
891/**
892 * drm_gem_open_ioctl - implementation of the GEM_OPEN ioctl
893 * @dev: drm_device
894 * @data: ioctl data
895 * @file_priv: drm file-private structure
896 *
897 * Open an object using the global name, returning a handle and the size.
898 *
899 * This handle (of course) holds a reference to the object, so the object
900 * will not go away until the handle is deleted.
901 */
902int
903drm_gem_open_ioctl(struct drm_device *dev, void *data,
904 struct drm_file *file_priv)
905{
906 struct drm_gem_open *args = data;
907 struct drm_gem_object *obj;
908 int ret;
909 u32 handle;
910
911 if (!drm_core_check_feature(dev, feature: DRIVER_GEM))
912 return -EOPNOTSUPP;
913
914 mutex_lock(&dev->object_name_lock);
915 obj = idr_find(&dev->object_name_idr, id: (int) args->name);
916 if (obj) {
917 drm_gem_object_get(obj);
918 } else {
919 mutex_unlock(lock: &dev->object_name_lock);
920 return -ENOENT;
921 }
922
923 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
924 ret = drm_gem_handle_create_tail(file_priv, obj, handlep: &handle);
925 if (ret)
926 goto err;
927
928 args->handle = handle;
929 args->size = obj->size;
930
931err:
932 drm_gem_object_put(obj);
933 return ret;
934}
935
936/**
937 * drm_gem_open - initializes GEM file-private structures at devnode open time
938 * @dev: drm_device which is being opened by userspace
939 * @file_private: drm file-private structure to set up
940 *
941 * Called at device open time, sets up the structure for handling refcounting
942 * of mm objects.
943 */
944void
945drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
946{
947 idr_init_base(idr: &file_private->object_idr, base: 1);
948 spin_lock_init(&file_private->table_lock);
949}
950
951/**
952 * drm_gem_release - release file-private GEM resources
953 * @dev: drm_device which is being closed by userspace
954 * @file_private: drm file-private structure to clean up
955 *
956 * Called at close time when the filp is going away.
957 *
958 * Releases any remaining references on objects by this filp.
959 */
960void
961drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
962{
963 idr_for_each(&file_private->object_idr,
964 fn: &drm_gem_object_release_handle, data: file_private);
965 idr_destroy(&file_private->object_idr);
966}
967
968/**
969 * drm_gem_object_release - release GEM buffer object resources
970 * @obj: GEM buffer object
971 *
972 * This releases any structures and resources used by @obj and is the inverse of
973 * drm_gem_object_init().
974 */
975void
976drm_gem_object_release(struct drm_gem_object *obj)
977{
978 if (obj->filp)
979 fput(obj->filp);
980
981 drm_gem_private_object_fini(obj);
982
983 drm_gem_free_mmap_offset(obj);
984 drm_gem_lru_remove(obj);
985}
986EXPORT_SYMBOL(drm_gem_object_release);
987
988/**
989 * drm_gem_object_free - free a GEM object
990 * @kref: kref of the object to free
991 *
992 * Called after the last reference to the object has been lost.
993 *
994 * Frees the object
995 */
996void
997drm_gem_object_free(struct kref *kref)
998{
999 struct drm_gem_object *obj =
1000 container_of(kref, struct drm_gem_object, refcount);
1001
1002 if (WARN_ON(!obj->funcs->free))
1003 return;
1004
1005 obj->funcs->free(obj);
1006}
1007EXPORT_SYMBOL(drm_gem_object_free);
1008
1009/**
1010 * drm_gem_vm_open - vma->ops->open implementation for GEM
1011 * @vma: VM area structure
1012 *
1013 * This function implements the #vm_operations_struct open() callback for GEM
1014 * drivers. This must be used together with drm_gem_vm_close().
1015 */
1016void drm_gem_vm_open(struct vm_area_struct *vma)
1017{
1018 struct drm_gem_object *obj = vma->vm_private_data;
1019
1020 drm_gem_object_get(obj);
1021}
1022EXPORT_SYMBOL(drm_gem_vm_open);
1023
1024/**
1025 * drm_gem_vm_close - vma->ops->close implementation for GEM
1026 * @vma: VM area structure
1027 *
1028 * This function implements the #vm_operations_struct close() callback for GEM
1029 * drivers. This must be used together with drm_gem_vm_open().
1030 */
1031void drm_gem_vm_close(struct vm_area_struct *vma)
1032{
1033 struct drm_gem_object *obj = vma->vm_private_data;
1034
1035 drm_gem_object_put(obj);
1036}
1037EXPORT_SYMBOL(drm_gem_vm_close);
1038
1039/**
1040 * drm_gem_mmap_obj - memory map a GEM object
1041 * @obj: the GEM object to map
1042 * @obj_size: the object size to be mapped, in bytes
1043 * @vma: VMA for the area to be mapped
1044 *
1045 * Set up the VMA to prepare mapping of the GEM object using the GEM object's
1046 * vm_ops. Depending on their requirements, GEM objects can either
1047 * provide a fault handler in their vm_ops (in which case any accesses to
1048 * the object will be trapped, to perform migration, GTT binding, surface
1049 * register allocation, or performance monitoring), or mmap the buffer memory
1050 * synchronously after calling drm_gem_mmap_obj.
1051 *
1052 * This function is mainly intended to implement the DMABUF mmap operation, when
1053 * the GEM object is not looked up based on its fake offset. To implement the
1054 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
1055 *
1056 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while
1057 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So
1058 * callers must verify access restrictions before calling this helper.
1059 *
1060 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
1061 * size, or if no vm_ops are provided.
1062 */
1063int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
1064 struct vm_area_struct *vma)
1065{
1066 int ret;
1067
1068 /* Check for valid size. */
1069 if (obj_size < vma->vm_end - vma->vm_start)
1070 return -EINVAL;
1071
1072 /* Take a ref for this mapping of the object, so that the fault
1073 * handler can dereference the mmap offset's pointer to the object.
1074 * This reference is cleaned up by the corresponding vm_close
1075 * (which should happen whether the vma was created by this call, or
1076 * by a vm_open due to mremap or partial unmap or whatever).
1077 */
1078 drm_gem_object_get(obj);
1079
1080 vma->vm_private_data = obj;
1081 vma->vm_ops = obj->funcs->vm_ops;
1082
1083 if (obj->funcs->mmap) {
1084 ret = obj->funcs->mmap(obj, vma);
1085 if (ret)
1086 goto err_drm_gem_object_put;
1087 WARN_ON(!(vma->vm_flags & VM_DONTEXPAND));
1088 } else {
1089 if (!vma->vm_ops) {
1090 ret = -EINVAL;
1091 goto err_drm_gem_object_put;
1092 }
1093
1094 vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
1095 vma->vm_page_prot = pgprot_writecombine(prot: vm_get_page_prot(vm_flags: vma->vm_flags));
1096 vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
1097 }
1098
1099 return 0;
1100
1101err_drm_gem_object_put:
1102 drm_gem_object_put(obj);
1103 return ret;
1104}
1105EXPORT_SYMBOL(drm_gem_mmap_obj);
1106
1107/**
1108 * drm_gem_mmap - memory map routine for GEM objects
1109 * @filp: DRM file pointer
1110 * @vma: VMA for the area to be mapped
1111 *
1112 * If a driver supports GEM object mapping, mmap calls on the DRM file
1113 * descriptor will end up here.
1114 *
1115 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
1116 * contain the fake offset we created when the GTT map ioctl was called on
1117 * the object) and map it with a call to drm_gem_mmap_obj().
1118 *
1119 * If the caller is not granted access to the buffer object, the mmap will fail
1120 * with EACCES. Please see the vma manager for more information.
1121 */
1122int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
1123{
1124 struct drm_file *priv = filp->private_data;
1125 struct drm_device *dev = priv->minor->dev;
1126 struct drm_gem_object *obj = NULL;
1127 struct drm_vma_offset_node *node;
1128 int ret;
1129
1130 if (drm_dev_is_unplugged(dev))
1131 return -ENODEV;
1132
1133 drm_vma_offset_lock_lookup(mgr: dev->vma_offset_manager);
1134 node = drm_vma_offset_exact_lookup_locked(mgr: dev->vma_offset_manager,
1135 start: vma->vm_pgoff,
1136 pages: vma_pages(vma));
1137 if (likely(node)) {
1138 obj = container_of(node, struct drm_gem_object, vma_node);
1139 /*
1140 * When the object is being freed, after it hits 0-refcnt it
1141 * proceeds to tear down the object. In the process it will
1142 * attempt to remove the VMA offset and so acquire this
1143 * mgr->vm_lock. Therefore if we find an object with a 0-refcnt
1144 * that matches our range, we know it is in the process of being
1145 * destroyed and will be freed as soon as we release the lock -
1146 * so we have to check for the 0-refcnted object and treat it as
1147 * invalid.
1148 */
1149 if (!kref_get_unless_zero(kref: &obj->refcount))
1150 obj = NULL;
1151 }
1152 drm_vma_offset_unlock_lookup(mgr: dev->vma_offset_manager);
1153
1154 if (!obj)
1155 return -EINVAL;
1156
1157 if (!drm_vma_node_is_allowed(node, tag: priv)) {
1158 drm_gem_object_put(obj);
1159 return -EACCES;
1160 }
1161
1162 ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT,
1163 vma);
1164
1165 drm_gem_object_put(obj);
1166
1167 return ret;
1168}
1169EXPORT_SYMBOL(drm_gem_mmap);
1170
1171void drm_gem_print_info(struct drm_printer *p, unsigned int indent,
1172 const struct drm_gem_object *obj)
1173{
1174 drm_printf_indent(p, indent, "name=%d\n", obj->name);
1175 drm_printf_indent(p, indent, "refcount=%u\n",
1176 kref_read(&obj->refcount));
1177 drm_printf_indent(p, indent, "start=%08lx\n",
1178 drm_vma_node_start(&obj->vma_node));
1179 drm_printf_indent(p, indent, "size=%zu\n", obj->size);
1180 drm_printf_indent(p, indent, "imported=%s\n",
1181 str_yes_no(drm_gem_is_imported(obj)));
1182
1183 if (obj->funcs->print_info)
1184 obj->funcs->print_info(p, indent, obj);
1185}
1186
1187int drm_gem_pin_locked(struct drm_gem_object *obj)
1188{
1189 if (obj->funcs->pin)
1190 return obj->funcs->pin(obj);
1191
1192 return 0;
1193}
1194
1195void drm_gem_unpin_locked(struct drm_gem_object *obj)
1196{
1197 if (obj->funcs->unpin)
1198 obj->funcs->unpin(obj);
1199}
1200
1201int drm_gem_pin(struct drm_gem_object *obj)
1202{
1203 int ret;
1204
1205 dma_resv_lock(obj: obj->resv, NULL);
1206 ret = drm_gem_pin_locked(obj);
1207 dma_resv_unlock(obj: obj->resv);
1208
1209 return ret;
1210}
1211
1212void drm_gem_unpin(struct drm_gem_object *obj)
1213{
1214 dma_resv_lock(obj: obj->resv, NULL);
1215 drm_gem_unpin_locked(obj);
1216 dma_resv_unlock(obj: obj->resv);
1217}
1218
1219int drm_gem_vmap_locked(struct drm_gem_object *obj, struct iosys_map *map)
1220{
1221 int ret;
1222
1223 dma_resv_assert_held(obj->resv);
1224
1225 if (!obj->funcs->vmap)
1226 return -EOPNOTSUPP;
1227
1228 ret = obj->funcs->vmap(obj, map);
1229 if (ret)
1230 return ret;
1231 else if (iosys_map_is_null(map))
1232 return -ENOMEM;
1233
1234 return 0;
1235}
1236EXPORT_SYMBOL(drm_gem_vmap_locked);
1237
1238void drm_gem_vunmap_locked(struct drm_gem_object *obj, struct iosys_map *map)
1239{
1240 dma_resv_assert_held(obj->resv);
1241
1242 if (iosys_map_is_null(map))
1243 return;
1244
1245 if (obj->funcs->vunmap)
1246 obj->funcs->vunmap(obj, map);
1247
1248 /* Always set the mapping to NULL. Callers may rely on this. */
1249 iosys_map_clear(map);
1250}
1251EXPORT_SYMBOL(drm_gem_vunmap_locked);
1252
1253void drm_gem_lock(struct drm_gem_object *obj)
1254{
1255 dma_resv_lock(obj: obj->resv, NULL);
1256}
1257EXPORT_SYMBOL(drm_gem_lock);
1258
1259void drm_gem_unlock(struct drm_gem_object *obj)
1260{
1261 dma_resv_unlock(obj: obj->resv);
1262}
1263EXPORT_SYMBOL(drm_gem_unlock);
1264
1265int drm_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map)
1266{
1267 int ret;
1268
1269 dma_resv_lock(obj: obj->resv, NULL);
1270 ret = drm_gem_vmap_locked(obj, map);
1271 dma_resv_unlock(obj: obj->resv);
1272
1273 return ret;
1274}
1275EXPORT_SYMBOL(drm_gem_vmap);
1276
1277void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map)
1278{
1279 dma_resv_lock(obj: obj->resv, NULL);
1280 drm_gem_vunmap_locked(obj, map);
1281 dma_resv_unlock(obj: obj->resv);
1282}
1283EXPORT_SYMBOL(drm_gem_vunmap);
1284
1285/**
1286 * drm_gem_lock_reservations - Sets up the ww context and acquires
1287 * the lock on an array of GEM objects.
1288 *
1289 * Once you've locked your reservations, you'll want to set up space
1290 * for your shared fences (if applicable), submit your job, then
1291 * drm_gem_unlock_reservations().
1292 *
1293 * @objs: drm_gem_objects to lock
1294 * @count: Number of objects in @objs
1295 * @acquire_ctx: struct ww_acquire_ctx that will be initialized as
1296 * part of tracking this set of locked reservations.
1297 */
1298int
1299drm_gem_lock_reservations(struct drm_gem_object **objs, int count,
1300 struct ww_acquire_ctx *acquire_ctx)
1301{
1302 int contended = -1;
1303 int i, ret;
1304
1305 ww_acquire_init(ctx: acquire_ctx, ww_class: &reservation_ww_class);
1306
1307retry:
1308 if (contended != -1) {
1309 struct drm_gem_object *obj = objs[contended];
1310
1311 ret = dma_resv_lock_slow_interruptible(obj: obj->resv,
1312 ctx: acquire_ctx);
1313 if (ret) {
1314 ww_acquire_fini(ctx: acquire_ctx);
1315 return ret;
1316 }
1317 }
1318
1319 for (i = 0; i < count; i++) {
1320 if (i == contended)
1321 continue;
1322
1323 ret = dma_resv_lock_interruptible(obj: objs[i]->resv,
1324 ctx: acquire_ctx);
1325 if (ret) {
1326 int j;
1327
1328 for (j = 0; j < i; j++)
1329 dma_resv_unlock(obj: objs[j]->resv);
1330
1331 if (contended != -1 && contended >= i)
1332 dma_resv_unlock(obj: objs[contended]->resv);
1333
1334 if (ret == -EDEADLK) {
1335 contended = i;
1336 goto retry;
1337 }
1338
1339 ww_acquire_fini(ctx: acquire_ctx);
1340 return ret;
1341 }
1342 }
1343
1344 ww_acquire_done(ctx: acquire_ctx);
1345
1346 return 0;
1347}
1348EXPORT_SYMBOL(drm_gem_lock_reservations);
1349
1350void
1351drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
1352 struct ww_acquire_ctx *acquire_ctx)
1353{
1354 int i;
1355
1356 for (i = 0; i < count; i++)
1357 dma_resv_unlock(obj: objs[i]->resv);
1358
1359 ww_acquire_fini(ctx: acquire_ctx);
1360}
1361EXPORT_SYMBOL(drm_gem_unlock_reservations);
1362
1363/**
1364 * drm_gem_lru_init - initialize a LRU
1365 *
1366 * @lru: The LRU to initialize
1367 * @lock: The lock protecting the LRU
1368 */
1369void
1370drm_gem_lru_init(struct drm_gem_lru *lru, struct mutex *lock)
1371{
1372 lru->lock = lock;
1373 lru->count = 0;
1374 INIT_LIST_HEAD(list: &lru->list);
1375}
1376EXPORT_SYMBOL(drm_gem_lru_init);
1377
1378static void
1379drm_gem_lru_remove_locked(struct drm_gem_object *obj)
1380{
1381 obj->lru->count -= obj->size >> PAGE_SHIFT;
1382 WARN_ON(obj->lru->count < 0);
1383 list_del(entry: &obj->lru_node);
1384 obj->lru = NULL;
1385}
1386
1387/**
1388 * drm_gem_lru_remove - remove object from whatever LRU it is in
1389 *
1390 * If the object is currently in any LRU, remove it.
1391 *
1392 * @obj: The GEM object to remove from current LRU
1393 */
1394void
1395drm_gem_lru_remove(struct drm_gem_object *obj)
1396{
1397 struct drm_gem_lru *lru = obj->lru;
1398
1399 if (!lru)
1400 return;
1401
1402 mutex_lock(lru->lock);
1403 drm_gem_lru_remove_locked(obj);
1404 mutex_unlock(lock: lru->lock);
1405}
1406EXPORT_SYMBOL(drm_gem_lru_remove);
1407
1408/**
1409 * drm_gem_lru_move_tail_locked - move the object to the tail of the LRU
1410 *
1411 * Like &drm_gem_lru_move_tail but lru lock must be held
1412 *
1413 * @lru: The LRU to move the object into.
1414 * @obj: The GEM object to move into this LRU
1415 */
1416void
1417drm_gem_lru_move_tail_locked(struct drm_gem_lru *lru, struct drm_gem_object *obj)
1418{
1419 lockdep_assert_held_once(lru->lock);
1420
1421 if (obj->lru)
1422 drm_gem_lru_remove_locked(obj);
1423
1424 lru->count += obj->size >> PAGE_SHIFT;
1425 list_add_tail(new: &obj->lru_node, head: &lru->list);
1426 obj->lru = lru;
1427}
1428EXPORT_SYMBOL(drm_gem_lru_move_tail_locked);
1429
1430/**
1431 * drm_gem_lru_move_tail - move the object to the tail of the LRU
1432 *
1433 * If the object is already in this LRU it will be moved to the
1434 * tail. Otherwise it will be removed from whichever other LRU
1435 * it is in (if any) and moved into this LRU.
1436 *
1437 * @lru: The LRU to move the object into.
1438 * @obj: The GEM object to move into this LRU
1439 */
1440void
1441drm_gem_lru_move_tail(struct drm_gem_lru *lru, struct drm_gem_object *obj)
1442{
1443 mutex_lock(lru->lock);
1444 drm_gem_lru_move_tail_locked(lru, obj);
1445 mutex_unlock(lock: lru->lock);
1446}
1447EXPORT_SYMBOL(drm_gem_lru_move_tail);
1448
1449/**
1450 * drm_gem_lru_scan - helper to implement shrinker.scan_objects
1451 *
1452 * If the shrink callback succeeds, it is expected that the driver
1453 * move the object out of this LRU.
1454 *
1455 * If the LRU possibly contain active buffers, it is the responsibility
1456 * of the shrink callback to check for this (ie. dma_resv_test_signaled())
1457 * or if necessary block until the buffer becomes idle.
1458 *
1459 * @lru: The LRU to scan
1460 * @nr_to_scan: The number of pages to try to reclaim
1461 * @remaining: The number of pages left to reclaim, should be initialized by caller
1462 * @shrink: Callback to try to shrink/reclaim the object.
1463 */
1464unsigned long
1465drm_gem_lru_scan(struct drm_gem_lru *lru,
1466 unsigned int nr_to_scan,
1467 unsigned long *remaining,
1468 bool (*shrink)(struct drm_gem_object *obj))
1469{
1470 struct drm_gem_lru still_in_lru;
1471 struct drm_gem_object *obj;
1472 unsigned freed = 0;
1473
1474 drm_gem_lru_init(&still_in_lru, lru->lock);
1475
1476 mutex_lock(lru->lock);
1477
1478 while (freed < nr_to_scan) {
1479 obj = list_first_entry_or_null(&lru->list, typeof(*obj), lru_node);
1480
1481 if (!obj)
1482 break;
1483
1484 drm_gem_lru_move_tail_locked(&still_in_lru, obj);
1485
1486 /*
1487 * If it's in the process of being freed, gem_object->free()
1488 * may be blocked on lock waiting to remove it. So just
1489 * skip it.
1490 */
1491 if (!kref_get_unless_zero(kref: &obj->refcount))
1492 continue;
1493
1494 /*
1495 * Now that we own a reference, we can drop the lock for the
1496 * rest of the loop body, to reduce contention with other
1497 * code paths that need the LRU lock
1498 */
1499 mutex_unlock(lock: lru->lock);
1500
1501 /*
1502 * Note that this still needs to be trylock, since we can
1503 * hit shrinker in response to trying to get backing pages
1504 * for this obj (ie. while it's lock is already held)
1505 */
1506 if (!dma_resv_trylock(obj: obj->resv)) {
1507 *remaining += obj->size >> PAGE_SHIFT;
1508 goto tail;
1509 }
1510
1511 if (shrink(obj)) {
1512 freed += obj->size >> PAGE_SHIFT;
1513
1514 /*
1515 * If we succeeded in releasing the object's backing
1516 * pages, we expect the driver to have moved the object
1517 * out of this LRU
1518 */
1519 WARN_ON(obj->lru == &still_in_lru);
1520 WARN_ON(obj->lru == lru);
1521 }
1522
1523 dma_resv_unlock(obj: obj->resv);
1524
1525tail:
1526 drm_gem_object_put(obj);
1527 mutex_lock(lru->lock);
1528 }
1529
1530 /*
1531 * Move objects we've skipped over out of the temporary still_in_lru
1532 * back into this LRU
1533 */
1534 list_for_each_entry (obj, &still_in_lru.list, lru_node)
1535 obj->lru = lru;
1536 list_splice_tail(list: &still_in_lru.list, head: &lru->list);
1537 lru->count += still_in_lru.count;
1538
1539 mutex_unlock(lock: lru->lock);
1540
1541 return freed;
1542}
1543EXPORT_SYMBOL(drm_gem_lru_scan);
1544
1545/**
1546 * drm_gem_evict_locked - helper to evict backing pages for a GEM object
1547 * @obj: obj in question
1548 */
1549int drm_gem_evict_locked(struct drm_gem_object *obj)
1550{
1551 dma_resv_assert_held(obj->resv);
1552
1553 if (!dma_resv_test_signaled(obj: obj->resv, usage: DMA_RESV_USAGE_READ))
1554 return -EBUSY;
1555
1556 if (obj->funcs->evict)
1557 return obj->funcs->evict(obj);
1558
1559 return 0;
1560}
1561EXPORT_SYMBOL(drm_gem_evict_locked);
1562

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source code of linux/drivers/gpu/drm/drm_gem.c