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/sched.h>
35 #include <linux/pagemap.h>
36 #include <linux/shmem_fs.h>
37 #include <linux/file.h>
38 #include <drm/drm_cache.h>
39 #include <drm/ttm/ttm_bo_driver.h>
40
41 #include "ttm_module.h"
42
43 static unsigned long ttm_pages_limit;
44
45 MODULE_PARM_DESC(pages_limit, "Limit for the allocated pages");
46 module_param_named(pages_limit, ttm_pages_limit, ulong, 0644);
47
48 static unsigned long ttm_dma32_pages_limit;
49
50 MODULE_PARM_DESC(dma32_pages_limit, "Limit for the allocated DMA32 pages");
51 module_param_named(dma32_pages_limit, ttm_dma32_pages_limit, ulong, 0644);
52
53 static atomic_long_t ttm_pages_allocated;
54 static atomic_long_t ttm_dma32_pages_allocated;
55
56 /*
57 * Allocates a ttm structure for the given BO.
58 */
ttm_tt_create(struct ttm_buffer_object * bo,bool zero_alloc)59 int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
60 {
61 struct ttm_device *bdev = bo->bdev;
62 uint32_t page_flags = 0;
63
64 dma_resv_assert_held(bo->base.resv);
65
66 if (bo->ttm)
67 return 0;
68
69 switch (bo->type) {
70 case ttm_bo_type_device:
71 if (zero_alloc)
72 page_flags |= TTM_PAGE_FLAG_ZERO_ALLOC;
73 break;
74 case ttm_bo_type_kernel:
75 break;
76 case ttm_bo_type_sg:
77 page_flags |= TTM_PAGE_FLAG_SG;
78 break;
79 default:
80 pr_err("Illegal buffer object type\n");
81 return -EINVAL;
82 }
83
84 bo->ttm = bdev->funcs->ttm_tt_create(bo, page_flags);
85 if (unlikely(bo->ttm == NULL))
86 return -ENOMEM;
87
88 return 0;
89 }
90
91 /*
92 * Allocates storage for pointers to the pages that back the ttm.
93 */
ttm_tt_alloc_page_directory(struct ttm_tt * ttm)94 static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
95 {
96 ttm->pages = kvmalloc_array(ttm->num_pages, sizeof(void*),
97 GFP_KERNEL | __GFP_ZERO);
98 if (!ttm->pages)
99 return -ENOMEM;
100 return 0;
101 }
102
ttm_dma_tt_alloc_page_directory(struct ttm_tt * ttm)103 static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
104 {
105 ttm->pages = kvmalloc_array(ttm->num_pages,
106 sizeof(*ttm->pages) +
107 sizeof(*ttm->dma_address),
108 GFP_KERNEL | __GFP_ZERO);
109 if (!ttm->pages)
110 return -ENOMEM;
111
112 ttm->dma_address = (void *)(ttm->pages + ttm->num_pages);
113 return 0;
114 }
115
ttm_sg_tt_alloc_page_directory(struct ttm_tt * ttm)116 static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
117 {
118 ttm->dma_address = kvmalloc_array(ttm->num_pages,
119 sizeof(*ttm->dma_address),
120 GFP_KERNEL | __GFP_ZERO);
121 if (!ttm->dma_address)
122 return -ENOMEM;
123 return 0;
124 }
125
ttm_tt_destroy_common(struct ttm_device * bdev,struct ttm_tt * ttm)126 void ttm_tt_destroy_common(struct ttm_device *bdev, struct ttm_tt *ttm)
127 {
128 ttm_tt_unpopulate(bdev, ttm);
129
130 if (ttm->swap_storage)
131 fput(ttm->swap_storage);
132
133 ttm->swap_storage = NULL;
134 }
135 EXPORT_SYMBOL(ttm_tt_destroy_common);
136
ttm_tt_destroy(struct ttm_device * bdev,struct ttm_tt * ttm)137 void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
138 {
139 bdev->funcs->ttm_tt_destroy(bdev, ttm);
140 }
141
ttm_tt_init_fields(struct ttm_tt * ttm,struct ttm_buffer_object * bo,uint32_t page_flags,enum ttm_caching caching)142 static void ttm_tt_init_fields(struct ttm_tt *ttm,
143 struct ttm_buffer_object *bo,
144 uint32_t page_flags,
145 enum ttm_caching caching)
146 {
147 ttm->num_pages = PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT;
148 ttm->caching = ttm_cached;
149 ttm->page_flags = page_flags;
150 ttm->dma_address = NULL;
151 ttm->swap_storage = NULL;
152 ttm->sg = bo->sg;
153 ttm->caching = caching;
154 }
155
ttm_tt_init(struct ttm_tt * ttm,struct ttm_buffer_object * bo,uint32_t page_flags,enum ttm_caching caching)156 int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
157 uint32_t page_flags, enum ttm_caching caching)
158 {
159 ttm_tt_init_fields(ttm, bo, page_flags, caching);
160
161 if (ttm_tt_alloc_page_directory(ttm)) {
162 pr_err("Failed allocating page table\n");
163 return -ENOMEM;
164 }
165 return 0;
166 }
167 EXPORT_SYMBOL(ttm_tt_init);
168
ttm_tt_fini(struct ttm_tt * ttm)169 void ttm_tt_fini(struct ttm_tt *ttm)
170 {
171 if (ttm->pages)
172 kvfree(ttm->pages);
173 else
174 kvfree(ttm->dma_address);
175 ttm->pages = NULL;
176 ttm->dma_address = NULL;
177 }
178 EXPORT_SYMBOL(ttm_tt_fini);
179
ttm_sg_tt_init(struct ttm_tt * ttm,struct ttm_buffer_object * bo,uint32_t page_flags,enum ttm_caching caching)180 int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
181 uint32_t page_flags, enum ttm_caching caching)
182 {
183 int ret;
184
185 ttm_tt_init_fields(ttm, bo, page_flags, caching);
186
187 if (page_flags & TTM_PAGE_FLAG_SG)
188 ret = ttm_sg_tt_alloc_page_directory(ttm);
189 else
190 ret = ttm_dma_tt_alloc_page_directory(ttm);
191 if (ret) {
192 pr_err("Failed allocating page table\n");
193 return -ENOMEM;
194 }
195 return 0;
196 }
197 EXPORT_SYMBOL(ttm_sg_tt_init);
198
ttm_tt_swapin(struct ttm_tt * ttm)199 int ttm_tt_swapin(struct ttm_tt *ttm)
200 {
201 struct address_space *swap_space;
202 struct file *swap_storage;
203 struct page *from_page;
204 struct page *to_page;
205 gfp_t gfp_mask;
206 int i, ret;
207
208 swap_storage = ttm->swap_storage;
209 BUG_ON(swap_storage == NULL);
210
211 swap_space = swap_storage->f_mapping;
212 gfp_mask = mapping_gfp_mask(swap_space);
213
214 for (i = 0; i < ttm->num_pages; ++i) {
215 from_page = shmem_read_mapping_page_gfp(swap_space, i,
216 gfp_mask);
217 if (IS_ERR(from_page)) {
218 ret = PTR_ERR(from_page);
219 goto out_err;
220 }
221 to_page = ttm->pages[i];
222 if (unlikely(to_page == NULL)) {
223 ret = -ENOMEM;
224 goto out_err;
225 }
226
227 copy_highpage(to_page, from_page);
228 put_page(from_page);
229 }
230
231 fput(swap_storage);
232 ttm->swap_storage = NULL;
233 ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
234
235 return 0;
236
237 out_err:
238 return ret;
239 }
240
241 /**
242 * ttm_tt_swapout - swap out tt object
243 *
244 * @bdev: TTM device structure.
245 * @ttm: The struct ttm_tt.
246 * @gfp_flags: Flags to use for memory allocation.
247 *
248 * Swapout a TT object to a shmem_file, return number of pages swapped out or
249 * negative error code.
250 */
ttm_tt_swapout(struct ttm_device * bdev,struct ttm_tt * ttm,gfp_t gfp_flags)251 int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
252 gfp_t gfp_flags)
253 {
254 loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT;
255 struct address_space *swap_space;
256 struct file *swap_storage;
257 struct page *from_page;
258 struct page *to_page;
259 int i, ret;
260
261 swap_storage = shmem_file_setup("ttm swap", size, 0);
262 if (IS_ERR(swap_storage)) {
263 pr_err("Failed allocating swap storage\n");
264 return PTR_ERR(swap_storage);
265 }
266
267 swap_space = swap_storage->f_mapping;
268 gfp_flags &= mapping_gfp_mask(swap_space);
269
270 for (i = 0; i < ttm->num_pages; ++i) {
271 from_page = ttm->pages[i];
272 if (unlikely(from_page == NULL))
273 continue;
274
275 to_page = shmem_read_mapping_page_gfp(swap_space, i, gfp_flags);
276 if (IS_ERR(to_page)) {
277 ret = PTR_ERR(to_page);
278 goto out_err;
279 }
280 copy_highpage(to_page, from_page);
281 set_page_dirty(to_page);
282 mark_page_accessed(to_page);
283 put_page(to_page);
284 }
285
286 ttm_tt_unpopulate(bdev, ttm);
287 ttm->swap_storage = swap_storage;
288 ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
289
290 return ttm->num_pages;
291
292 out_err:
293 fput(swap_storage);
294
295 return ret;
296 }
297
ttm_tt_add_mapping(struct ttm_device * bdev,struct ttm_tt * ttm)298 static void ttm_tt_add_mapping(struct ttm_device *bdev, struct ttm_tt *ttm)
299 {
300 pgoff_t i;
301
302 if (ttm->page_flags & TTM_PAGE_FLAG_SG)
303 return;
304
305 for (i = 0; i < ttm->num_pages; ++i)
306 ttm->pages[i]->mapping = bdev->dev_mapping;
307 }
308
ttm_tt_populate(struct ttm_device * bdev,struct ttm_tt * ttm,struct ttm_operation_ctx * ctx)309 int ttm_tt_populate(struct ttm_device *bdev,
310 struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
311 {
312 int ret;
313
314 if (!ttm)
315 return -EINVAL;
316
317 if (ttm_tt_is_populated(ttm))
318 return 0;
319
320 if (!(ttm->page_flags & TTM_PAGE_FLAG_SG)) {
321 atomic_long_add(ttm->num_pages, &ttm_pages_allocated);
322 if (bdev->pool.use_dma32)
323 atomic_long_add(ttm->num_pages,
324 &ttm_dma32_pages_allocated);
325 }
326
327 while (atomic_long_read(&ttm_pages_allocated) > ttm_pages_limit ||
328 atomic_long_read(&ttm_dma32_pages_allocated) >
329 ttm_dma32_pages_limit) {
330
331 ret = ttm_global_swapout(ctx, GFP_KERNEL);
332 if (ret == 0)
333 break;
334 if (ret < 0)
335 goto error;
336 }
337
338 if (bdev->funcs->ttm_tt_populate)
339 ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx);
340 else
341 ret = ttm_pool_alloc(&bdev->pool, ttm, ctx);
342 if (ret)
343 goto error;
344
345 ttm_tt_add_mapping(bdev, ttm);
346 ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
347 if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
348 ret = ttm_tt_swapin(ttm);
349 if (unlikely(ret != 0)) {
350 ttm_tt_unpopulate(bdev, ttm);
351 return ret;
352 }
353 }
354
355 return 0;
356
357 error:
358 if (!(ttm->page_flags & TTM_PAGE_FLAG_SG)) {
359 atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
360 if (bdev->pool.use_dma32)
361 atomic_long_sub(ttm->num_pages,
362 &ttm_dma32_pages_allocated);
363 }
364 return ret;
365 }
366 EXPORT_SYMBOL(ttm_tt_populate);
367
ttm_tt_clear_mapping(struct ttm_tt * ttm)368 static void ttm_tt_clear_mapping(struct ttm_tt *ttm)
369 {
370 pgoff_t i;
371 struct page **page = ttm->pages;
372
373 if (ttm->page_flags & TTM_PAGE_FLAG_SG)
374 return;
375
376 for (i = 0; i < ttm->num_pages; ++i) {
377 (*page)->mapping = NULL;
378 (*page++)->index = 0;
379 }
380 }
381
ttm_tt_unpopulate(struct ttm_device * bdev,struct ttm_tt * ttm)382 void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
383 {
384 if (!ttm_tt_is_populated(ttm))
385 return;
386
387 ttm_tt_clear_mapping(ttm);
388 if (bdev->funcs->ttm_tt_unpopulate)
389 bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
390 else
391 ttm_pool_free(&bdev->pool, ttm);
392
393 if (!(ttm->page_flags & TTM_PAGE_FLAG_SG)) {
394 atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
395 if (bdev->pool.use_dma32)
396 atomic_long_sub(ttm->num_pages,
397 &ttm_dma32_pages_allocated);
398 }
399
400 ttm->page_flags &= ~TTM_PAGE_FLAG_PRIV_POPULATED;
401 }
402
403 /**
404 * ttm_tt_mgr_init - register with the MM shrinker
405 *
406 * Register with the MM shrinker for swapping out BOs.
407 */
ttm_tt_mgr_init(unsigned long num_pages,unsigned long num_dma32_pages)408 void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
409 {
410 if (!ttm_pages_limit)
411 ttm_pages_limit = num_pages;
412
413 if (!ttm_dma32_pages_limit)
414 ttm_dma32_pages_limit = num_dma32_pages;
415 }
416