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