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