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/sched.h>
36#include <linux/shmem_fs.h>
37#include <linux/file.h>
38#include <linux/module.h>
39#include <drm/drm_cache.h>
40#include <drm/drm_device.h>
41#include <drm/drm_util.h>
42#include <drm/ttm/ttm_bo.h>
43#include <drm/ttm/ttm_tt.h>
44
45#include "ttm_module.h"
46
47static unsigned long ttm_pages_limit;
48
49MODULE_PARM_DESC(pages_limit, "Limit for the allocated pages");
50module_param_named(pages_limit, ttm_pages_limit, ulong, 0644);
51
52static unsigned long ttm_dma32_pages_limit;
53
54MODULE_PARM_DESC(dma32_pages_limit, "Limit for the allocated DMA32 pages");
55module_param_named(dma32_pages_limit, ttm_dma32_pages_limit, ulong, 0644);
56
57static atomic_long_t ttm_pages_allocated;
58static atomic_long_t ttm_dma32_pages_allocated;
59
60/*
61 * Allocates a ttm structure for the given BO.
62 */
63int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
64{
65 struct ttm_device *bdev = bo->bdev;
66 struct drm_device *ddev = bo->base.dev;
67 uint32_t page_flags = 0;
68
69 dma_resv_assert_held(bo->base.resv);
70
71 if (bo->ttm)
72 return 0;
73
74 switch (bo->type) {
75 case ttm_bo_type_device:
76 if (zero_alloc)
77 page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
78 break;
79 case ttm_bo_type_kernel:
80 break;
81 case ttm_bo_type_sg:
82 page_flags |= TTM_TT_FLAG_EXTERNAL;
83 break;
84 default:
85 pr_err("Illegal buffer object type\n");
86 return -EINVAL;
87 }
88 /*
89 * When using dma_alloc_coherent with memory encryption the
90 * mapped TT pages need to be decrypted or otherwise the drivers
91 * will end up sending encrypted mem to the gpu.
92 */
93 if (bdev->pool.use_dma_alloc && cc_platform_has(attr: CC_ATTR_GUEST_MEM_ENCRYPT)) {
94 page_flags |= TTM_TT_FLAG_DECRYPTED;
95 drm_info(ddev, "TT memory decryption enabled.");
96 }
97
98 bo->ttm = bdev->funcs->ttm_tt_create(bo, page_flags);
99 if (unlikely(bo->ttm == NULL))
100 return -ENOMEM;
101
102 WARN_ON(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE &&
103 !(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL));
104
105 return 0;
106}
107EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_create);
108
109/*
110 * Allocates storage for pointers to the pages that back the ttm.
111 */
112static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
113{
114 ttm->pages = kvcalloc(n: ttm->num_pages, size: sizeof(void*), GFP_KERNEL);
115 if (!ttm->pages)
116 return -ENOMEM;
117
118 return 0;
119}
120
121static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
122{
123 ttm->pages = kvcalloc(n: ttm->num_pages, size: sizeof(*ttm->pages) +
124 sizeof(*ttm->dma_address), GFP_KERNEL);
125 if (!ttm->pages)
126 return -ENOMEM;
127
128 ttm->dma_address = (void *)(ttm->pages + ttm->num_pages);
129 return 0;
130}
131
132static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
133{
134 ttm->dma_address = kvcalloc(n: ttm->num_pages, size: sizeof(*ttm->dma_address),
135 GFP_KERNEL);
136 if (!ttm->dma_address)
137 return -ENOMEM;
138
139 return 0;
140}
141
142void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
143{
144 bdev->funcs->ttm_tt_destroy(bdev, ttm);
145}
146EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_destroy);
147
148static void ttm_tt_init_fields(struct ttm_tt *ttm,
149 struct ttm_buffer_object *bo,
150 uint32_t page_flags,
151 enum ttm_caching caching,
152 unsigned long extra_pages)
153{
154 ttm->num_pages = (PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT) + extra_pages;
155 ttm->page_flags = page_flags;
156 ttm->dma_address = NULL;
157 ttm->swap_storage = NULL;
158 ttm->sg = bo->sg;
159 ttm->caching = caching;
160}
161
162int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
163 uint32_t page_flags, enum ttm_caching caching,
164 unsigned long extra_pages)
165{
166 ttm_tt_init_fields(ttm, bo, page_flags, caching, extra_pages);
167
168 if (ttm_tt_alloc_page_directory(ttm)) {
169 pr_err("Failed allocating page table\n");
170 return -ENOMEM;
171 }
172 return 0;
173}
174EXPORT_SYMBOL(ttm_tt_init);
175
176void ttm_tt_fini(struct ttm_tt *ttm)
177{
178 WARN_ON(ttm->page_flags & TTM_TT_FLAG_PRIV_POPULATED);
179
180 if (ttm->swap_storage)
181 fput(ttm->swap_storage);
182 ttm->swap_storage = NULL;
183
184 if (ttm->pages)
185 kvfree(addr: ttm->pages);
186 else
187 kvfree(addr: ttm->dma_address);
188 ttm->pages = NULL;
189 ttm->dma_address = NULL;
190}
191EXPORT_SYMBOL(ttm_tt_fini);
192
193int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
194 uint32_t page_flags, enum ttm_caching caching)
195{
196 int ret;
197
198 ttm_tt_init_fields(ttm, bo, page_flags, caching, extra_pages: 0);
199
200 if (page_flags & TTM_TT_FLAG_EXTERNAL)
201 ret = ttm_sg_tt_alloc_page_directory(ttm);
202 else
203 ret = ttm_dma_tt_alloc_page_directory(ttm);
204 if (ret) {
205 pr_err("Failed allocating page table\n");
206 return -ENOMEM;
207 }
208 return 0;
209}
210EXPORT_SYMBOL(ttm_sg_tt_init);
211
212int ttm_tt_swapin(struct ttm_tt *ttm)
213{
214 struct address_space *swap_space;
215 struct file *swap_storage;
216 struct page *from_page;
217 struct page *to_page;
218 gfp_t gfp_mask;
219 int i, ret;
220
221 swap_storage = ttm->swap_storage;
222 BUG_ON(swap_storage == NULL);
223
224 swap_space = swap_storage->f_mapping;
225 gfp_mask = mapping_gfp_mask(mapping: swap_space);
226
227 for (i = 0; i < ttm->num_pages; ++i) {
228 from_page = shmem_read_mapping_page_gfp(mapping: swap_space, index: i,
229 gfp_mask);
230 if (IS_ERR(ptr: from_page)) {
231 ret = PTR_ERR(ptr: from_page);
232 goto out_err;
233 }
234 to_page = ttm->pages[i];
235 if (unlikely(to_page == NULL)) {
236 ret = -ENOMEM;
237 goto out_err;
238 }
239
240 copy_highpage(to: to_page, from: from_page);
241 put_page(page: from_page);
242 }
243
244 fput(swap_storage);
245 ttm->swap_storage = NULL;
246 ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
247
248 return 0;
249
250out_err:
251 return ret;
252}
253
254/**
255 * ttm_tt_swapout - swap out tt object
256 *
257 * @bdev: TTM device structure.
258 * @ttm: The struct ttm_tt.
259 * @gfp_flags: Flags to use for memory allocation.
260 *
261 * Swapout a TT object to a shmem_file, return number of pages swapped out or
262 * negative error code.
263 */
264int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
265 gfp_t gfp_flags)
266{
267 loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT;
268 struct address_space *swap_space;
269 struct file *swap_storage;
270 struct page *from_page;
271 struct page *to_page;
272 int i, ret;
273
274 swap_storage = shmem_file_setup(name: "ttm swap", size, flags: 0);
275 if (IS_ERR(ptr: swap_storage)) {
276 pr_err("Failed allocating swap storage\n");
277 return PTR_ERR(ptr: swap_storage);
278 }
279
280 swap_space = swap_storage->f_mapping;
281 gfp_flags &= mapping_gfp_mask(mapping: swap_space);
282
283 for (i = 0; i < ttm->num_pages; ++i) {
284 from_page = ttm->pages[i];
285 if (unlikely(from_page == NULL))
286 continue;
287
288 to_page = shmem_read_mapping_page_gfp(mapping: swap_space, index: i, gfp_mask: gfp_flags);
289 if (IS_ERR(ptr: to_page)) {
290 ret = PTR_ERR(ptr: to_page);
291 goto out_err;
292 }
293 copy_highpage(to: to_page, from: from_page);
294 set_page_dirty(to_page);
295 mark_page_accessed(to_page);
296 put_page(page: to_page);
297 }
298
299 ttm_tt_unpopulate(bdev, ttm);
300 ttm->swap_storage = swap_storage;
301 ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
302
303 return ttm->num_pages;
304
305out_err:
306 fput(swap_storage);
307
308 return ret;
309}
310
311int ttm_tt_populate(struct ttm_device *bdev,
312 struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
313{
314 int ret;
315
316 if (!ttm)
317 return -EINVAL;
318
319 if (ttm_tt_is_populated(tt: ttm))
320 return 0;
321
322 if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
323 atomic_long_add(i: ttm->num_pages, v: &ttm_pages_allocated);
324 if (bdev->pool.use_dma32)
325 atomic_long_add(i: ttm->num_pages,
326 v: &ttm_dma32_pages_allocated);
327 }
328
329 while (atomic_long_read(v: &ttm_pages_allocated) > ttm_pages_limit ||
330 atomic_long_read(v: &ttm_dma32_pages_allocated) >
331 ttm_dma32_pages_limit) {
332
333 ret = ttm_global_swapout(ctx, GFP_KERNEL);
334 if (ret == 0)
335 break;
336 if (ret < 0)
337 goto error;
338 }
339
340 if (bdev->funcs->ttm_tt_populate)
341 ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx);
342 else
343 ret = ttm_pool_alloc(pool: &bdev->pool, tt: ttm, ctx);
344 if (ret)
345 goto error;
346
347 ttm->page_flags |= TTM_TT_FLAG_PRIV_POPULATED;
348 if (unlikely(ttm->page_flags & TTM_TT_FLAG_SWAPPED)) {
349 ret = ttm_tt_swapin(ttm);
350 if (unlikely(ret != 0)) {
351 ttm_tt_unpopulate(bdev, ttm);
352 return ret;
353 }
354 }
355
356 return 0;
357
358error:
359 if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
360 atomic_long_sub(i: ttm->num_pages, v: &ttm_pages_allocated);
361 if (bdev->pool.use_dma32)
362 atomic_long_sub(i: ttm->num_pages,
363 v: &ttm_dma32_pages_allocated);
364 }
365 return ret;
366}
367EXPORT_SYMBOL(ttm_tt_populate);
368
369void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
370{
371 if (!ttm_tt_is_populated(tt: ttm))
372 return;
373
374 if (bdev->funcs->ttm_tt_unpopulate)
375 bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
376 else
377 ttm_pool_free(pool: &bdev->pool, tt: ttm);
378
379 if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
380 atomic_long_sub(i: ttm->num_pages, v: &ttm_pages_allocated);
381 if (bdev->pool.use_dma32)
382 atomic_long_sub(i: ttm->num_pages,
383 v: &ttm_dma32_pages_allocated);
384 }
385
386 ttm->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
387}
388
389#ifdef CONFIG_DEBUG_FS
390
391/* Test the shrinker functions and dump the result */
392static int ttm_tt_debugfs_shrink_show(struct seq_file *m, void *data)
393{
394 struct ttm_operation_ctx ctx = { false, false };
395
396 seq_printf(m, fmt: "%d\n", ttm_global_swapout(ctx: &ctx, GFP_KERNEL));
397 return 0;
398}
399DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink);
400
401#endif
402
403
404/*
405 * ttm_tt_mgr_init - register with the MM shrinker
406 *
407 * Register with the MM shrinker for swapping out BOs.
408 */
409void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
410{
411#ifdef CONFIG_DEBUG_FS
412 debugfs_create_file(name: "tt_shrink", mode: 0400, parent: ttm_debugfs_root, NULL,
413 fops: &ttm_tt_debugfs_shrink_fops);
414#endif
415
416 if (!ttm_pages_limit)
417 ttm_pages_limit = num_pages;
418
419 if (!ttm_dma32_pages_limit)
420 ttm_dma32_pages_limit = num_dma32_pages;
421}
422
423static void ttm_kmap_iter_tt_map_local(struct ttm_kmap_iter *iter,
424 struct iosys_map *dmap,
425 pgoff_t i)
426{
427 struct ttm_kmap_iter_tt *iter_tt =
428 container_of(iter, typeof(*iter_tt), base);
429
430 iosys_map_set_vaddr(map: dmap, vaddr: kmap_local_page_prot(page: iter_tt->tt->pages[i],
431 prot: iter_tt->prot));
432}
433
434static void ttm_kmap_iter_tt_unmap_local(struct ttm_kmap_iter *iter,
435 struct iosys_map *map)
436{
437 kunmap_local(map->vaddr);
438}
439
440static const struct ttm_kmap_iter_ops ttm_kmap_iter_tt_ops = {
441 .map_local = ttm_kmap_iter_tt_map_local,
442 .unmap_local = ttm_kmap_iter_tt_unmap_local,
443 .maps_tt = true,
444};
445
446/**
447 * ttm_kmap_iter_tt_init - Initialize a struct ttm_kmap_iter_tt
448 * @iter_tt: The struct ttm_kmap_iter_tt to initialize.
449 * @tt: Struct ttm_tt holding page pointers of the struct ttm_resource.
450 *
451 * Return: Pointer to the embedded struct ttm_kmap_iter.
452 */
453struct ttm_kmap_iter *
454ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
455 struct ttm_tt *tt)
456{
457 iter_tt->base.ops = &ttm_kmap_iter_tt_ops;
458 iter_tt->tt = tt;
459 if (tt)
460 iter_tt->prot = ttm_prot_from_caching(caching: tt->caching, PAGE_KERNEL);
461 else
462 iter_tt->prot = PAGE_KERNEL;
463
464 return &iter_tt->base;
465}
466EXPORT_SYMBOL(ttm_kmap_iter_tt_init);
467
468unsigned long ttm_tt_pages_limit(void)
469{
470 return ttm_pages_limit;
471}
472EXPORT_SYMBOL(ttm_tt_pages_limit);
473

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