xref: /openbmc/linux/drivers/gpu/drm/ttm/ttm_tt.c (revision f2a89d3b)
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4  * All Rights Reserved.
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9  * without limitation the rights to use, copy, modify, merge, publish,
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11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
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14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
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19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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27 /*
28  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29  */
30 
31 #define pr_fmt(fmt) "[TTM] " fmt
32 
33 #include <linux/sched.h>
34 #include <linux/highmem.h>
35 #include <linux/pagemap.h>
36 #include <linux/shmem_fs.h>
37 #include <linux/file.h>
38 #include <linux/swap.h>
39 #include <linux/slab.h>
40 #include <linux/export.h>
41 #include <drm/drm_cache.h>
42 #include <drm/drm_mem_util.h>
43 #include <drm/ttm/ttm_module.h>
44 #include <drm/ttm/ttm_bo_driver.h>
45 #include <drm/ttm/ttm_placement.h>
46 #include <drm/ttm/ttm_page_alloc.h>
47 
48 /**
49  * Allocates storage for pointers to the pages that back the ttm.
50  */
51 static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
52 {
53 	ttm->pages = drm_calloc_large(ttm->num_pages, sizeof(void*));
54 }
55 
56 static void ttm_dma_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
57 {
58 	ttm->ttm.pages = drm_calloc_large(ttm->ttm.num_pages,
59 					  sizeof(*ttm->ttm.pages) +
60 					  sizeof(*ttm->dma_address) +
61 					  sizeof(*ttm->cpu_address));
62 	ttm->cpu_address = (void *) (ttm->ttm.pages + ttm->ttm.num_pages);
63 	ttm->dma_address = (void *) (ttm->cpu_address + ttm->ttm.num_pages);
64 }
65 
66 #ifdef CONFIG_X86
67 static inline int ttm_tt_set_page_caching(struct page *p,
68 					  enum ttm_caching_state c_old,
69 					  enum ttm_caching_state c_new)
70 {
71 	int ret = 0;
72 
73 	if (PageHighMem(p))
74 		return 0;
75 
76 	if (c_old != tt_cached) {
77 		/* p isn't in the default caching state, set it to
78 		 * writeback first to free its current memtype. */
79 
80 		ret = set_pages_wb(p, 1);
81 		if (ret)
82 			return ret;
83 	}
84 
85 	if (c_new == tt_wc)
86 		ret = set_memory_wc((unsigned long) page_address(p), 1);
87 	else if (c_new == tt_uncached)
88 		ret = set_pages_uc(p, 1);
89 
90 	return ret;
91 }
92 #else /* CONFIG_X86 */
93 static inline int ttm_tt_set_page_caching(struct page *p,
94 					  enum ttm_caching_state c_old,
95 					  enum ttm_caching_state c_new)
96 {
97 	return 0;
98 }
99 #endif /* CONFIG_X86 */
100 
101 /*
102  * Change caching policy for the linear kernel map
103  * for range of pages in a ttm.
104  */
105 
106 static int ttm_tt_set_caching(struct ttm_tt *ttm,
107 			      enum ttm_caching_state c_state)
108 {
109 	int i, j;
110 	struct page *cur_page;
111 	int ret;
112 
113 	if (ttm->caching_state == c_state)
114 		return 0;
115 
116 	if (ttm->state == tt_unpopulated) {
117 		/* Change caching but don't populate */
118 		ttm->caching_state = c_state;
119 		return 0;
120 	}
121 
122 	if (ttm->caching_state == tt_cached)
123 		drm_clflush_pages(ttm->pages, ttm->num_pages);
124 
125 	for (i = 0; i < ttm->num_pages; ++i) {
126 		cur_page = ttm->pages[i];
127 		if (likely(cur_page != NULL)) {
128 			ret = ttm_tt_set_page_caching(cur_page,
129 						      ttm->caching_state,
130 						      c_state);
131 			if (unlikely(ret != 0))
132 				goto out_err;
133 		}
134 	}
135 
136 	ttm->caching_state = c_state;
137 
138 	return 0;
139 
140 out_err:
141 	for (j = 0; j < i; ++j) {
142 		cur_page = ttm->pages[j];
143 		if (likely(cur_page != NULL)) {
144 			(void)ttm_tt_set_page_caching(cur_page, c_state,
145 						      ttm->caching_state);
146 		}
147 	}
148 
149 	return ret;
150 }
151 
152 int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
153 {
154 	enum ttm_caching_state state;
155 
156 	if (placement & TTM_PL_FLAG_WC)
157 		state = tt_wc;
158 	else if (placement & TTM_PL_FLAG_UNCACHED)
159 		state = tt_uncached;
160 	else
161 		state = tt_cached;
162 
163 	return ttm_tt_set_caching(ttm, state);
164 }
165 EXPORT_SYMBOL(ttm_tt_set_placement_caching);
166 
167 void ttm_tt_destroy(struct ttm_tt *ttm)
168 {
169 	if (ttm == NULL)
170 		return;
171 
172 	ttm_tt_unbind(ttm);
173 
174 	if (ttm->state == tt_unbound)
175 		ttm_tt_unpopulate(ttm);
176 
177 	if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP) &&
178 	    ttm->swap_storage)
179 		fput(ttm->swap_storage);
180 
181 	ttm->swap_storage = NULL;
182 	ttm->func->destroy(ttm);
183 }
184 
185 int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
186 		unsigned long size, uint32_t page_flags,
187 		struct page *dummy_read_page)
188 {
189 	ttm->bdev = bdev;
190 	ttm->glob = bdev->glob;
191 	ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
192 	ttm->caching_state = tt_cached;
193 	ttm->page_flags = page_flags;
194 	ttm->dummy_read_page = dummy_read_page;
195 	ttm->state = tt_unpopulated;
196 	ttm->swap_storage = NULL;
197 
198 	ttm_tt_alloc_page_directory(ttm);
199 	if (!ttm->pages) {
200 		ttm_tt_destroy(ttm);
201 		pr_err("Failed allocating page table\n");
202 		return -ENOMEM;
203 	}
204 	return 0;
205 }
206 EXPORT_SYMBOL(ttm_tt_init);
207 
208 void ttm_tt_fini(struct ttm_tt *ttm)
209 {
210 	drm_free_large(ttm->pages);
211 	ttm->pages = NULL;
212 }
213 EXPORT_SYMBOL(ttm_tt_fini);
214 
215 int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
216 		unsigned long size, uint32_t page_flags,
217 		struct page *dummy_read_page)
218 {
219 	struct ttm_tt *ttm = &ttm_dma->ttm;
220 
221 	ttm->bdev = bdev;
222 	ttm->glob = bdev->glob;
223 	ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
224 	ttm->caching_state = tt_cached;
225 	ttm->page_flags = page_flags;
226 	ttm->dummy_read_page = dummy_read_page;
227 	ttm->state = tt_unpopulated;
228 	ttm->swap_storage = NULL;
229 
230 	INIT_LIST_HEAD(&ttm_dma->pages_list);
231 	ttm_dma_tt_alloc_page_directory(ttm_dma);
232 	if (!ttm->pages) {
233 		ttm_tt_destroy(ttm);
234 		pr_err("Failed allocating page table\n");
235 		return -ENOMEM;
236 	}
237 	return 0;
238 }
239 EXPORT_SYMBOL(ttm_dma_tt_init);
240 
241 void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma)
242 {
243 	struct ttm_tt *ttm = &ttm_dma->ttm;
244 
245 	drm_free_large(ttm->pages);
246 	ttm->pages = NULL;
247 	ttm_dma->cpu_address = NULL;
248 	ttm_dma->dma_address = NULL;
249 }
250 EXPORT_SYMBOL(ttm_dma_tt_fini);
251 
252 void ttm_tt_unbind(struct ttm_tt *ttm)
253 {
254 	int ret;
255 
256 	if (ttm->state == tt_bound) {
257 		ret = ttm->func->unbind(ttm);
258 		BUG_ON(ret);
259 		ttm->state = tt_unbound;
260 	}
261 }
262 
263 int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
264 {
265 	int ret = 0;
266 
267 	if (!ttm)
268 		return -EINVAL;
269 
270 	if (ttm->state == tt_bound)
271 		return 0;
272 
273 	ret = ttm->bdev->driver->ttm_tt_populate(ttm);
274 	if (ret)
275 		return ret;
276 
277 	ret = ttm->func->bind(ttm, bo_mem);
278 	if (unlikely(ret != 0))
279 		return ret;
280 
281 	ttm->state = tt_bound;
282 
283 	return 0;
284 }
285 EXPORT_SYMBOL(ttm_tt_bind);
286 
287 int ttm_tt_swapin(struct ttm_tt *ttm)
288 {
289 	struct address_space *swap_space;
290 	struct file *swap_storage;
291 	struct page *from_page;
292 	struct page *to_page;
293 	int i;
294 	int ret = -ENOMEM;
295 
296 	swap_storage = ttm->swap_storage;
297 	BUG_ON(swap_storage == NULL);
298 
299 	swap_space = swap_storage->f_mapping;
300 
301 	for (i = 0; i < ttm->num_pages; ++i) {
302 		from_page = shmem_read_mapping_page(swap_space, i);
303 		if (IS_ERR(from_page)) {
304 			ret = PTR_ERR(from_page);
305 			goto out_err;
306 		}
307 		to_page = ttm->pages[i];
308 		if (unlikely(to_page == NULL))
309 			goto out_err;
310 
311 		copy_highpage(to_page, from_page);
312 		put_page(from_page);
313 	}
314 
315 	if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP))
316 		fput(swap_storage);
317 	ttm->swap_storage = NULL;
318 	ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
319 
320 	return 0;
321 out_err:
322 	return ret;
323 }
324 
325 int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistent_swap_storage)
326 {
327 	struct address_space *swap_space;
328 	struct file *swap_storage;
329 	struct page *from_page;
330 	struct page *to_page;
331 	int i;
332 	int ret = -ENOMEM;
333 
334 	BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
335 	BUG_ON(ttm->caching_state != tt_cached);
336 
337 	if (!persistent_swap_storage) {
338 		swap_storage = shmem_file_setup("ttm swap",
339 						ttm->num_pages << PAGE_SHIFT,
340 						0);
341 		if (IS_ERR(swap_storage)) {
342 			pr_err("Failed allocating swap storage\n");
343 			return PTR_ERR(swap_storage);
344 		}
345 	} else
346 		swap_storage = persistent_swap_storage;
347 
348 	swap_space = swap_storage->f_mapping;
349 
350 	for (i = 0; i < ttm->num_pages; ++i) {
351 		from_page = ttm->pages[i];
352 		if (unlikely(from_page == NULL))
353 			continue;
354 		to_page = shmem_read_mapping_page(swap_space, i);
355 		if (IS_ERR(to_page)) {
356 			ret = PTR_ERR(to_page);
357 			goto out_err;
358 		}
359 		copy_highpage(to_page, from_page);
360 		set_page_dirty(to_page);
361 		mark_page_accessed(to_page);
362 		put_page(to_page);
363 	}
364 
365 	ttm_tt_unpopulate(ttm);
366 	ttm->swap_storage = swap_storage;
367 	ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
368 	if (persistent_swap_storage)
369 		ttm->page_flags |= TTM_PAGE_FLAG_PERSISTENT_SWAP;
370 
371 	return 0;
372 out_err:
373 	if (!persistent_swap_storage)
374 		fput(swap_storage);
375 
376 	return ret;
377 }
378 
379 static void ttm_tt_clear_mapping(struct ttm_tt *ttm)
380 {
381 	pgoff_t i;
382 	struct page **page = ttm->pages;
383 
384 	if (ttm->page_flags & TTM_PAGE_FLAG_SG)
385 		return;
386 
387 	for (i = 0; i < ttm->num_pages; ++i) {
388 		(*page)->mapping = NULL;
389 		(*page++)->index = 0;
390 	}
391 }
392 
393 void ttm_tt_unpopulate(struct ttm_tt *ttm)
394 {
395 	if (ttm->state == tt_unpopulated)
396 		return;
397 
398 	ttm_tt_clear_mapping(ttm);
399 	ttm->bdev->driver->ttm_tt_unpopulate(ttm);
400 }
401