1/* SPDX-License-Identifier: GPL-2.0 OR MIT */
2/**************************************************************************
3 *
4 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
5 * All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the
9 * "Software"), to deal in the Software without restriction, including
10 * without limitation the rights to use, copy, modify, merge, publish,
11 * distribute, sub license, and/or sell copies of the Software, and to
12 * permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the
16 * next paragraph) shall be included in all copies or substantial portions
17 * of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
22 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
23 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
24 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
25 * USE OR OTHER DEALINGS IN THE SOFTWARE.
26 *
27 **************************************************************************/
28/*
29 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
30 */
31
32#define pr_fmt(fmt) "[TTM] " fmt
33
34#include <linux/cc_platform.h>
35#include <linux/debugfs.h>
36#include <linux/export.h>
37#include <linux/file.h>
38#include <linux/module.h>
39#include <linux/sched.h>
40#include <linux/shmem_fs.h>
41#include <drm/drm_cache.h>
42#include <drm/drm_device.h>
43#include <drm/drm_print.h>
44#include <drm/drm_util.h>
45#include <drm/ttm/ttm_backup.h>
46#include <drm/ttm/ttm_bo.h>
47#include <drm/ttm/ttm_tt.h>
48
49#include "ttm_module.h"
50#include "ttm_pool_internal.h"
51
52static unsigned long ttm_pages_limit;
53
54MODULE_PARM_DESC(pages_limit, "Limit for the allocated pages");
55module_param_named(pages_limit, ttm_pages_limit, ulong, 0644);
56
57static unsigned long ttm_dma32_pages_limit;
58
59MODULE_PARM_DESC(dma32_pages_limit, "Limit for the allocated DMA32 pages");
60module_param_named(dma32_pages_limit, ttm_dma32_pages_limit, ulong, 0644);
61
62static atomic_long_t ttm_pages_allocated;
63static atomic_long_t ttm_dma32_pages_allocated;
64
65/*
66 * Allocates a ttm structure for the given BO.
67 */
68int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
69{
70 struct ttm_device *bdev = bo->bdev;
71 struct drm_device *ddev = bo->base.dev;
72 uint32_t page_flags = 0;
73
74 dma_resv_assert_held(bo->base.resv);
75
76 if (bo->ttm)
77 return 0;
78
79 switch (bo->type) {
80 case ttm_bo_type_device:
81 if (zero_alloc)
82 page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
83 break;
84 case ttm_bo_type_kernel:
85 break;
86 case ttm_bo_type_sg:
87 page_flags |= TTM_TT_FLAG_EXTERNAL;
88 break;
89 default:
90 pr_err("Illegal buffer object type\n");
91 return -EINVAL;
92 }
93 /*
94 * When using dma_alloc_coherent with memory encryption the
95 * mapped TT pages need to be decrypted or otherwise the drivers
96 * will end up sending encrypted mem to the gpu.
97 */
98 if (ttm_pool_uses_dma_alloc(pool: &bdev->pool) &&
99 cc_platform_has(attr: CC_ATTR_GUEST_MEM_ENCRYPT)) {
100 page_flags |= TTM_TT_FLAG_DECRYPTED;
101 drm_info_once(ddev, "TT memory decryption enabled.");
102 }
103
104 bo->ttm = bdev->funcs->ttm_tt_create(bo, page_flags);
105 if (unlikely(bo->ttm == NULL))
106 return -ENOMEM;
107
108 WARN_ON(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE &&
109 !(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL));
110
111 return 0;
112}
113EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_create);
114
115/*
116 * Allocates storage for pointers to the pages that back the ttm.
117 */
118static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
119{
120 ttm->pages = kvcalloc(ttm->num_pages, sizeof(void*), GFP_KERNEL);
121 if (!ttm->pages)
122 return -ENOMEM;
123
124 return 0;
125}
126
127static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
128{
129 ttm->pages = kvcalloc(ttm->num_pages, sizeof(*ttm->pages) +
130 sizeof(*ttm->dma_address), GFP_KERNEL);
131 if (!ttm->pages)
132 return -ENOMEM;
133
134 ttm->dma_address = (void *)(ttm->pages + ttm->num_pages);
135 return 0;
136}
137
138static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
139{
140 ttm->dma_address = kvcalloc(ttm->num_pages, sizeof(*ttm->dma_address),
141 GFP_KERNEL);
142 if (!ttm->dma_address)
143 return -ENOMEM;
144
145 return 0;
146}
147
148void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
149{
150 bdev->funcs->ttm_tt_destroy(bdev, ttm);
151}
152EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_destroy);
153
154static void ttm_tt_init_fields(struct ttm_tt *ttm,
155 struct ttm_buffer_object *bo,
156 uint32_t page_flags,
157 enum ttm_caching caching,
158 unsigned long extra_pages)
159{
160 ttm->num_pages = (PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT) + extra_pages;
161 ttm->page_flags = page_flags;
162 ttm->dma_address = NULL;
163 ttm->swap_storage = NULL;
164 ttm->sg = bo->sg;
165 ttm->caching = caching;
166 ttm->restore = NULL;
167 ttm->backup = NULL;
168}
169
170int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
171 uint32_t page_flags, enum ttm_caching caching,
172 unsigned long extra_pages)
173{
174 ttm_tt_init_fields(ttm, bo, page_flags, caching, extra_pages);
175
176 if (ttm_tt_alloc_page_directory(ttm)) {
177 pr_err("Failed allocating page table\n");
178 return -ENOMEM;
179 }
180 return 0;
181}
182EXPORT_SYMBOL(ttm_tt_init);
183
184void ttm_tt_fini(struct ttm_tt *ttm)
185{
186 WARN_ON(ttm->page_flags & TTM_TT_FLAG_PRIV_POPULATED);
187
188 if (ttm->swap_storage)
189 fput(ttm->swap_storage);
190 ttm->swap_storage = NULL;
191
192 if (ttm_tt_is_backed_up(tt: ttm))
193 ttm_pool_drop_backed_up(tt: ttm);
194 if (ttm->backup) {
195 ttm_backup_fini(backup: ttm->backup);
196 ttm->backup = NULL;
197 }
198
199 if (ttm->pages)
200 kvfree(addr: ttm->pages);
201 else
202 kvfree(addr: ttm->dma_address);
203 ttm->pages = NULL;
204 ttm->dma_address = NULL;
205}
206EXPORT_SYMBOL(ttm_tt_fini);
207
208int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
209 uint32_t page_flags, enum ttm_caching caching)
210{
211 int ret;
212
213 ttm_tt_init_fields(ttm, bo, page_flags, caching, extra_pages: 0);
214
215 if (page_flags & TTM_TT_FLAG_EXTERNAL)
216 ret = ttm_sg_tt_alloc_page_directory(ttm);
217 else
218 ret = ttm_dma_tt_alloc_page_directory(ttm);
219 if (ret) {
220 pr_err("Failed allocating page table\n");
221 return -ENOMEM;
222 }
223 return 0;
224}
225EXPORT_SYMBOL(ttm_sg_tt_init);
226
227int ttm_tt_swapin(struct ttm_tt *ttm)
228{
229 struct address_space *swap_space;
230 struct file *swap_storage;
231 struct page *from_page;
232 struct page *to_page;
233 gfp_t gfp_mask;
234 int i, ret;
235
236 swap_storage = ttm->swap_storage;
237 BUG_ON(swap_storage == NULL);
238
239 swap_space = swap_storage->f_mapping;
240 gfp_mask = mapping_gfp_mask(mapping: swap_space);
241
242 for (i = 0; i < ttm->num_pages; ++i) {
243 from_page = shmem_read_mapping_page_gfp(mapping: swap_space, index: i,
244 gfp_mask);
245 if (IS_ERR(ptr: from_page)) {
246 ret = PTR_ERR(ptr: from_page);
247 goto out_err;
248 }
249 to_page = ttm->pages[i];
250 if (unlikely(to_page == NULL)) {
251 ret = -ENOMEM;
252 goto out_err;
253 }
254
255 copy_highpage(to: to_page, from: from_page);
256 put_page(page: from_page);
257 }
258
259 fput(swap_storage);
260 ttm->swap_storage = NULL;
261 ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
262
263 return 0;
264
265out_err:
266 return ret;
267}
268EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_swapin);
269
270/**
271 * ttm_tt_backup() - Helper to back up a struct ttm_tt.
272 * @bdev: The TTM device.
273 * @tt: The struct ttm_tt.
274 * @flags: Flags that govern the backup behaviour.
275 *
276 * Update the page accounting and call ttm_pool_shrink_tt to free pages
277 * or back them up.
278 *
279 * Return: Number of pages freed or swapped out, or negative error code on
280 * error.
281 */
282long ttm_tt_backup(struct ttm_device *bdev, struct ttm_tt *tt,
283 const struct ttm_backup_flags flags)
284{
285 long ret;
286
287 if (WARN_ON(IS_ERR_OR_NULL(tt->backup)))
288 return 0;
289
290 ret = ttm_pool_backup(pool: &bdev->pool, ttm: tt, flags: &flags);
291 if (ret > 0) {
292 tt->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
293 tt->page_flags |= TTM_TT_FLAG_BACKED_UP;
294 }
295
296 return ret;
297}
298
299int ttm_tt_restore(struct ttm_device *bdev, struct ttm_tt *tt,
300 const struct ttm_operation_ctx *ctx)
301{
302 int ret = ttm_pool_restore_and_alloc(pool: &bdev->pool, tt, ctx);
303
304 if (ret)
305 return ret;
306
307 tt->page_flags &= ~TTM_TT_FLAG_BACKED_UP;
308
309 return 0;
310}
311EXPORT_SYMBOL(ttm_tt_restore);
312
313/**
314 * ttm_tt_swapout - swap out tt object
315 *
316 * @bdev: TTM device structure.
317 * @ttm: The struct ttm_tt.
318 * @gfp_flags: Flags to use for memory allocation.
319 *
320 * Swapout a TT object to a shmem_file, return number of pages swapped out or
321 * negative error code.
322 */
323int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
324 gfp_t gfp_flags)
325{
326 loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT;
327 struct address_space *swap_space;
328 struct file *swap_storage;
329 struct page *from_page;
330 struct page *to_page;
331 int i, ret;
332
333 swap_storage = shmem_file_setup(name: "ttm swap", size, flags: 0);
334 if (IS_ERR(ptr: swap_storage)) {
335 pr_err("Failed allocating swap storage\n");
336 return PTR_ERR(ptr: swap_storage);
337 }
338
339 swap_space = swap_storage->f_mapping;
340 gfp_flags &= mapping_gfp_mask(mapping: swap_space);
341
342 for (i = 0; i < ttm->num_pages; ++i) {
343 from_page = ttm->pages[i];
344 if (unlikely(from_page == NULL))
345 continue;
346
347 to_page = shmem_read_mapping_page_gfp(mapping: swap_space, index: i, gfp_mask: gfp_flags);
348 if (IS_ERR(ptr: to_page)) {
349 ret = PTR_ERR(ptr: to_page);
350 goto out_err;
351 }
352 copy_highpage(to: to_page, from: from_page);
353 set_page_dirty(to_page);
354 mark_page_accessed(to_page);
355 put_page(page: to_page);
356 }
357
358 ttm_tt_unpopulate(bdev, ttm);
359 ttm->swap_storage = swap_storage;
360 ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
361
362 return ttm->num_pages;
363
364out_err:
365 fput(swap_storage);
366
367 return ret;
368}
369EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_swapout);
370
371int ttm_tt_populate(struct ttm_device *bdev,
372 struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
373{
374 int ret;
375
376 if (!ttm)
377 return -EINVAL;
378
379 if (ttm_tt_is_populated(tt: ttm))
380 return 0;
381
382 if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
383 atomic_long_add(i: ttm->num_pages, v: &ttm_pages_allocated);
384 if (ttm_pool_uses_dma32(pool: &bdev->pool))
385 atomic_long_add(i: ttm->num_pages,
386 v: &ttm_dma32_pages_allocated);
387 }
388
389 while (atomic_long_read(v: &ttm_pages_allocated) > ttm_pages_limit ||
390 atomic_long_read(v: &ttm_dma32_pages_allocated) >
391 ttm_dma32_pages_limit) {
392
393 ret = ttm_global_swapout(ctx, GFP_KERNEL);
394 if (ret == 0)
395 break;
396 if (ret < 0)
397 goto error;
398 }
399
400 if (bdev->funcs->ttm_tt_populate)
401 ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx);
402 else
403 ret = ttm_pool_alloc(pool: &bdev->pool, tt: ttm, ctx);
404 if (ret)
405 goto error;
406
407 ttm->page_flags |= TTM_TT_FLAG_PRIV_POPULATED;
408 ttm->page_flags &= ~TTM_TT_FLAG_BACKED_UP;
409 if (unlikely(ttm->page_flags & TTM_TT_FLAG_SWAPPED)) {
410 ret = ttm_tt_swapin(ttm);
411 if (unlikely(ret != 0)) {
412 ttm_tt_unpopulate(bdev, ttm);
413 return ret;
414 }
415 }
416
417 return 0;
418
419error:
420 if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
421 atomic_long_sub(i: ttm->num_pages, v: &ttm_pages_allocated);
422 if (ttm_pool_uses_dma32(pool: &bdev->pool))
423 atomic_long_sub(i: ttm->num_pages,
424 v: &ttm_dma32_pages_allocated);
425 }
426 return ret;
427}
428
429#if IS_ENABLED(CONFIG_DRM_TTM_KUNIT_TEST)
430EXPORT_SYMBOL(ttm_tt_populate);
431#endif
432
433void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
434{
435 if (!ttm_tt_is_populated(tt: ttm))
436 return;
437
438 if (bdev->funcs->ttm_tt_unpopulate)
439 bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
440 else
441 ttm_pool_free(pool: &bdev->pool, tt: ttm);
442
443 if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
444 atomic_long_sub(i: ttm->num_pages, v: &ttm_pages_allocated);
445 if (ttm_pool_uses_dma32(pool: &bdev->pool))
446 atomic_long_sub(i: ttm->num_pages,
447 v: &ttm_dma32_pages_allocated);
448 }
449
450 ttm->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
451}
452EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_unpopulate);
453
454#ifdef CONFIG_DEBUG_FS
455
456/* Test the shrinker functions and dump the result */
457static int ttm_tt_debugfs_shrink_show(struct seq_file *m, void *data)
458{
459 struct ttm_operation_ctx ctx = { false, false };
460
461 seq_printf(m, fmt: "%d\n", ttm_global_swapout(ctx: &ctx, GFP_KERNEL));
462 return 0;
463}
464DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink);
465
466#endif
467
468
469/*
470 * ttm_tt_mgr_init - register with the MM shrinker
471 *
472 * Register with the MM shrinker for swapping out BOs.
473 */
474void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
475{
476#ifdef CONFIG_DEBUG_FS
477 debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL,
478 &ttm_tt_debugfs_shrink_fops);
479#endif
480
481 if (!ttm_pages_limit)
482 ttm_pages_limit = num_pages;
483
484 if (!ttm_dma32_pages_limit)
485 ttm_dma32_pages_limit = num_dma32_pages;
486}
487
488static void ttm_kmap_iter_tt_map_local(struct ttm_kmap_iter *iter,
489 struct iosys_map *dmap,
490 pgoff_t i)
491{
492 struct ttm_kmap_iter_tt *iter_tt =
493 container_of(iter, typeof(*iter_tt), base);
494
495 iosys_map_set_vaddr(map: dmap, vaddr: kmap_local_page_prot(page: iter_tt->tt->pages[i],
496 prot: iter_tt->prot));
497}
498
499static void ttm_kmap_iter_tt_unmap_local(struct ttm_kmap_iter *iter,
500 struct iosys_map *map)
501{
502 kunmap_local(map->vaddr);
503}
504
505static const struct ttm_kmap_iter_ops ttm_kmap_iter_tt_ops = {
506 .map_local = ttm_kmap_iter_tt_map_local,
507 .unmap_local = ttm_kmap_iter_tt_unmap_local,
508 .maps_tt = true,
509};
510
511/**
512 * ttm_kmap_iter_tt_init - Initialize a struct ttm_kmap_iter_tt
513 * @iter_tt: The struct ttm_kmap_iter_tt to initialize.
514 * @tt: Struct ttm_tt holding page pointers of the struct ttm_resource.
515 *
516 * Return: Pointer to the embedded struct ttm_kmap_iter.
517 */
518struct ttm_kmap_iter *
519ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
520 struct ttm_tt *tt)
521{
522 iter_tt->base.ops = &ttm_kmap_iter_tt_ops;
523 iter_tt->tt = tt;
524 if (tt)
525 iter_tt->prot = ttm_prot_from_caching(caching: tt->caching, PAGE_KERNEL);
526 else
527 iter_tt->prot = PAGE_KERNEL;
528
529 return &iter_tt->base;
530}
531EXPORT_SYMBOL(ttm_kmap_iter_tt_init);
532
533unsigned long ttm_tt_pages_limit(void)
534{
535 return ttm_pages_limit;
536}
537EXPORT_SYMBOL(ttm_tt_pages_limit);
538
539/**
540 * ttm_tt_setup_backup() - Allocate and assign a backup structure for a ttm_tt
541 * @tt: The ttm_tt for wich to allocate and assign a backup structure.
542 *
543 * Assign a backup structure to be used for tt backup. This should
544 * typically be done at bo creation, to avoid allocations at shrinking
545 * time.
546 *
547 * Return: 0 on success, negative error code on failure.
548 */
549int ttm_tt_setup_backup(struct ttm_tt *tt)
550{
551 struct file *backup =
552 ttm_backup_shmem_create(size: ((loff_t)tt->num_pages) << PAGE_SHIFT);
553
554 if (WARN_ON_ONCE(!(tt->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE)))
555 return -EINVAL;
556
557 if (IS_ERR(ptr: backup))
558 return PTR_ERR(ptr: backup);
559
560 if (tt->backup)
561 ttm_backup_fini(backup: tt->backup);
562
563 tt->backup = backup;
564 return 0;
565}
566EXPORT_SYMBOL(ttm_tt_setup_backup);
567

source code of linux/drivers/gpu/drm/ttm/ttm_tt.c