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