xref: /openbmc/linux/drivers/gpu/drm/ttm/ttm_tt.c (revision d3402925)
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  */
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  */
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 
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 
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 
128 void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
129 {
130 	bdev->funcs->ttm_tt_destroy(bdev, ttm);
131 }
132 
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 
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 
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 
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 
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  */
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 
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 
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 */
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  */
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 
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 
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 *
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