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/cc_platform.h>
35#include <linux/sched.h>
36#include <linux/shmem_fs.h>
37#include <linux/file.h>
38#include <linux/module.h>
39#include <drm/drm_cache.h>
40#include <drm/drm_device.h>
41#include <drm/drm_util.h>
42#include <drm/ttm/ttm_bo.h>
43#include <drm/ttm/ttm_tt.h>
44
45#include "ttm_module.h"
46
47static unsigned long ttm_pages_limit;
48
49MODULE_PARM_DESC(pages_limit, "Limit for the allocated pages");
50module_param_named(pages_limit, ttm_pages_limit, ulong, 0644);
51
52static unsigned long ttm_dma32_pages_limit;
53
54MODULE_PARM_DESC(dma32_pages_limit, "Limit for the allocated DMA32 pages");
55module_param_named(dma32_pages_limit, ttm_dma32_pages_limit, ulong, 0644);
56
57static atomic_long_t ttm_pages_allocated;
58static atomic_long_t ttm_dma32_pages_allocated;
59
60/*
61 * Allocates a ttm structure for the given BO.
62 */
63int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
64{
65	struct ttm_device *bdev = bo->bdev;
66	struct drm_device *ddev = bo->base.dev;
67	uint32_t page_flags = 0;
68
69	dma_resv_assert_held(bo->base.resv);
70
71	if (bo->ttm)
72		return 0;
73
74	switch (bo->type) {
75	case ttm_bo_type_device:
76		if (zero_alloc)
77			page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
78		break;
79	case ttm_bo_type_kernel:
80		break;
81	case ttm_bo_type_sg:
82		page_flags |= TTM_TT_FLAG_EXTERNAL;
83		break;
84	default:
85		pr_err("Illegal buffer object type\n");
86		return -EINVAL;
87	}
88	/*
89	 * When using dma_alloc_coherent with memory encryption the
90	 * mapped TT pages need to be decrypted or otherwise the drivers
91	 * will end up sending encrypted mem to the gpu.
92	 */
93	if (bdev->pool.use_dma_alloc && cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
94		page_flags |= TTM_TT_FLAG_DECRYPTED;
95		drm_info(ddev, "TT memory decryption enabled.");
96	}
97
98	bo->ttm = bdev->funcs->ttm_tt_create(bo, page_flags);
99	if (unlikely(bo->ttm == NULL))
100		return -ENOMEM;
101
102	WARN_ON(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE &&
103		!(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL));
104
105	return 0;
106}
107EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_create);
108
109/*
110 * Allocates storage for pointers to the pages that back the ttm.
111 */
112static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
113{
114	ttm->pages = kvcalloc(ttm->num_pages, sizeof(void*), GFP_KERNEL);
115	if (!ttm->pages)
116		return -ENOMEM;
117
118	return 0;
119}
120
121static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
122{
123	ttm->pages = kvcalloc(ttm->num_pages, sizeof(*ttm->pages) +
124			      sizeof(*ttm->dma_address), GFP_KERNEL);
125	if (!ttm->pages)
126		return -ENOMEM;
127
128	ttm->dma_address = (void *)(ttm->pages + ttm->num_pages);
129	return 0;
130}
131
132static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
133{
134	ttm->dma_address = kvcalloc(ttm->num_pages, sizeof(*ttm->dma_address),
135				    GFP_KERNEL);
136	if (!ttm->dma_address)
137		return -ENOMEM;
138
139	return 0;
140}
141
142void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
143{
144	bdev->funcs->ttm_tt_destroy(bdev, ttm);
145}
146EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_destroy);
147
148static void ttm_tt_init_fields(struct ttm_tt *ttm,
149			       struct ttm_buffer_object *bo,
150			       uint32_t page_flags,
151			       enum ttm_caching caching,
152			       unsigned long extra_pages)
153{
154	ttm->num_pages = (PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT) + extra_pages;
155	ttm->page_flags = page_flags;
156	ttm->dma_address = NULL;
157	ttm->swap_storage = NULL;
158	ttm->sg = bo->sg;
159	ttm->caching = caching;
160}
161
162int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
163		uint32_t page_flags, enum ttm_caching caching,
164		unsigned long extra_pages)
165{
166	ttm_tt_init_fields(ttm, bo, page_flags, caching, extra_pages);
167
168	if (ttm_tt_alloc_page_directory(ttm)) {
169		pr_err("Failed allocating page table\n");
170		return -ENOMEM;
171	}
172	return 0;
173}
174EXPORT_SYMBOL(ttm_tt_init);
175
176void ttm_tt_fini(struct ttm_tt *ttm)
177{
178	WARN_ON(ttm->page_flags & TTM_TT_FLAG_PRIV_POPULATED);
179
180	if (ttm->swap_storage)
181		fput(ttm->swap_storage);
182	ttm->swap_storage = NULL;
183
184	if (ttm->pages)
185		kvfree(ttm->pages);
186	else
187		kvfree(ttm->dma_address);
188	ttm->pages = NULL;
189	ttm->dma_address = NULL;
190}
191EXPORT_SYMBOL(ttm_tt_fini);
192
193int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
194		   uint32_t page_flags, enum ttm_caching caching)
195{
196	int ret;
197
198	ttm_tt_init_fields(ttm, bo, page_flags, caching, 0);
199
200	if (page_flags & TTM_TT_FLAG_EXTERNAL)
201		ret = ttm_sg_tt_alloc_page_directory(ttm);
202	else
203		ret = ttm_dma_tt_alloc_page_directory(ttm);
204	if (ret) {
205		pr_err("Failed allocating page table\n");
206		return -ENOMEM;
207	}
208	return 0;
209}
210EXPORT_SYMBOL(ttm_sg_tt_init);
211
212int ttm_tt_swapin(struct ttm_tt *ttm)
213{
214	struct address_space *swap_space;
215	struct file *swap_storage;
216	struct page *from_page;
217	struct page *to_page;
218	gfp_t gfp_mask;
219	int i, ret;
220
221	swap_storage = ttm->swap_storage;
222	BUG_ON(swap_storage == NULL);
223
224	swap_space = swap_storage->f_mapping;
225	gfp_mask = mapping_gfp_mask(swap_space);
226
227	for (i = 0; i < ttm->num_pages; ++i) {
228		from_page = shmem_read_mapping_page_gfp(swap_space, i,
229							gfp_mask);
230		if (IS_ERR(from_page)) {
231			ret = PTR_ERR(from_page);
232			goto out_err;
233		}
234		to_page = ttm->pages[i];
235		if (unlikely(to_page == NULL)) {
236			ret = -ENOMEM;
237			goto out_err;
238		}
239
240		copy_highpage(to_page, from_page);
241		put_page(from_page);
242	}
243
244	fput(swap_storage);
245	ttm->swap_storage = NULL;
246	ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
247
248	return 0;
249
250out_err:
251	return ret;
252}
253
254/**
255 * ttm_tt_swapout - swap out tt object
256 *
257 * @bdev: TTM device structure.
258 * @ttm: The struct ttm_tt.
259 * @gfp_flags: Flags to use for memory allocation.
260 *
261 * Swapout a TT object to a shmem_file, return number of pages swapped out or
262 * negative error code.
263 */
264int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
265		   gfp_t gfp_flags)
266{
267	loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT;
268	struct address_space *swap_space;
269	struct file *swap_storage;
270	struct page *from_page;
271	struct page *to_page;
272	int i, ret;
273
274	swap_storage = shmem_file_setup("ttm swap", size, 0);
275	if (IS_ERR(swap_storage)) {
276		pr_err("Failed allocating swap storage\n");
277		return PTR_ERR(swap_storage);
278	}
279
280	swap_space = swap_storage->f_mapping;
281	gfp_flags &= mapping_gfp_mask(swap_space);
282
283	for (i = 0; i < ttm->num_pages; ++i) {
284		from_page = ttm->pages[i];
285		if (unlikely(from_page == NULL))
286			continue;
287
288		to_page = shmem_read_mapping_page_gfp(swap_space, i, gfp_flags);
289		if (IS_ERR(to_page)) {
290			ret = PTR_ERR(to_page);
291			goto out_err;
292		}
293		copy_highpage(to_page, from_page);
294		set_page_dirty(to_page);
295		mark_page_accessed(to_page);
296		put_page(to_page);
297	}
298
299	ttm_tt_unpopulate(bdev, ttm);
300	ttm->swap_storage = swap_storage;
301	ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
302
303	return ttm->num_pages;
304
305out_err:
306	fput(swap_storage);
307
308	return ret;
309}
310
311int ttm_tt_populate(struct ttm_device *bdev,
312		    struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
313{
314	int ret;
315
316	if (!ttm)
317		return -EINVAL;
318
319	if (ttm_tt_is_populated(ttm))
320		return 0;
321
322	if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
323		atomic_long_add(ttm->num_pages, &ttm_pages_allocated);
324		if (bdev->pool.use_dma32)
325			atomic_long_add(ttm->num_pages,
326					&ttm_dma32_pages_allocated);
327	}
328
329	while (atomic_long_read(&ttm_pages_allocated) > ttm_pages_limit ||
330	       atomic_long_read(&ttm_dma32_pages_allocated) >
331	       ttm_dma32_pages_limit) {
332
333		ret = ttm_global_swapout(ctx, GFP_KERNEL);
334		if (ret == 0)
335			break;
336		if (ret < 0)
337			goto error;
338	}
339
340	if (bdev->funcs->ttm_tt_populate)
341		ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx);
342	else
343		ret = ttm_pool_alloc(&bdev->pool, ttm, ctx);
344	if (ret)
345		goto error;
346
347	ttm->page_flags |= TTM_TT_FLAG_PRIV_POPULATED;
348	if (unlikely(ttm->page_flags & TTM_TT_FLAG_SWAPPED)) {
349		ret = ttm_tt_swapin(ttm);
350		if (unlikely(ret != 0)) {
351			ttm_tt_unpopulate(bdev, ttm);
352			return ret;
353		}
354	}
355
356	return 0;
357
358error:
359	if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
360		atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
361		if (bdev->pool.use_dma32)
362			atomic_long_sub(ttm->num_pages,
363					&ttm_dma32_pages_allocated);
364	}
365	return ret;
366}
367EXPORT_SYMBOL(ttm_tt_populate);
368
369void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
370{
371	if (!ttm_tt_is_populated(ttm))
372		return;
373
374	if (bdev->funcs->ttm_tt_unpopulate)
375		bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
376	else
377		ttm_pool_free(&bdev->pool, ttm);
378
379	if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
380		atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
381		if (bdev->pool.use_dma32)
382			atomic_long_sub(ttm->num_pages,
383					&ttm_dma32_pages_allocated);
384	}
385
386	ttm->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
387}
388
389#ifdef CONFIG_DEBUG_FS
390
391/* Test the shrinker functions and dump the result */
392static int ttm_tt_debugfs_shrink_show(struct seq_file *m, void *data)
393{
394	struct ttm_operation_ctx ctx = { false, false };
395
396	seq_printf(m, "%d\n", ttm_global_swapout(&ctx, GFP_KERNEL));
397	return 0;
398}
399DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink);
400
401#endif
402
403
404/*
405 * ttm_tt_mgr_init - register with the MM shrinker
406 *
407 * Register with the MM shrinker for swapping out BOs.
408 */
409void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
410{
411#ifdef CONFIG_DEBUG_FS
412	debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL,
413			    &ttm_tt_debugfs_shrink_fops);
414#endif
415
416	if (!ttm_pages_limit)
417		ttm_pages_limit = num_pages;
418
419	if (!ttm_dma32_pages_limit)
420		ttm_dma32_pages_limit = num_dma32_pages;
421}
422
423static void ttm_kmap_iter_tt_map_local(struct ttm_kmap_iter *iter,
424				       struct iosys_map *dmap,
425				       pgoff_t i)
426{
427	struct ttm_kmap_iter_tt *iter_tt =
428		container_of(iter, typeof(*iter_tt), base);
429
430	iosys_map_set_vaddr(dmap, kmap_local_page_prot(iter_tt->tt->pages[i],
431						       iter_tt->prot));
432}
433
434static void ttm_kmap_iter_tt_unmap_local(struct ttm_kmap_iter *iter,
435					 struct iosys_map *map)
436{
437	kunmap_local(map->vaddr);
438}
439
440static const struct ttm_kmap_iter_ops ttm_kmap_iter_tt_ops = {
441	.map_local = ttm_kmap_iter_tt_map_local,
442	.unmap_local = ttm_kmap_iter_tt_unmap_local,
443	.maps_tt = true,
444};
445
446/**
447 * ttm_kmap_iter_tt_init - Initialize a struct ttm_kmap_iter_tt
448 * @iter_tt: The struct ttm_kmap_iter_tt to initialize.
449 * @tt: Struct ttm_tt holding page pointers of the struct ttm_resource.
450 *
451 * Return: Pointer to the embedded struct ttm_kmap_iter.
452 */
453struct ttm_kmap_iter *
454ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
455		      struct ttm_tt *tt)
456{
457	iter_tt->base.ops = &ttm_kmap_iter_tt_ops;
458	iter_tt->tt = tt;
459	if (tt)
460		iter_tt->prot = ttm_prot_from_caching(tt->caching, PAGE_KERNEL);
461	else
462		iter_tt->prot = PAGE_KERNEL;
463
464	return &iter_tt->base;
465}
466EXPORT_SYMBOL(ttm_kmap_iter_tt_init);
467
468unsigned long ttm_tt_pages_limit(void)
469{
470	return ttm_pages_limit;
471}
472EXPORT_SYMBOL(ttm_tt_pages_limit);
473