ttm_tt.c

  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/debugfs.h>
 36#include <linux/export.h>
 37#include <linux/file.h>
 38#include <linux/module.h>
 39#include <linux/sched.h>
 40#include <linux/shmem_fs.h>
 41#include <drm/drm_cache.h>
 42#include <drm/drm_device.h>
 43#include <drm/drm_print.h>
 44#include <drm/drm_util.h>
 45#include <drm/ttm/ttm_backup.h>
 46#include <drm/ttm/ttm_bo.h>
 47#include <drm/ttm/ttm_tt.h>
 48
 49#include "ttm_module.h"
 50#include "ttm_pool_internal.h"
 51
 52static unsigned long ttm_pages_limit;
 53
 54MODULE_PARM_DESC(pages_limit, "Limit for the allocated pages");
 55module_param_named(pages_limit, ttm_pages_limit, ulong, 0644);
 56
 57static unsigned long ttm_dma32_pages_limit;
 58
 59MODULE_PARM_DESC(dma32_pages_limit, "Limit for the allocated DMA32 pages");
 60module_param_named(dma32_pages_limit, ttm_dma32_pages_limit, ulong, 0644);
 61
 62static atomic_long_t ttm_pages_allocated;
 63static atomic_long_t ttm_dma32_pages_allocated;
 64
 65/*
 66 * Allocates a ttm structure for the given BO.
 67 */
 68int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
 69{
 70	struct ttm_device *bdev = bo->bdev;
 71	struct drm_device *ddev = bo->base.dev;
 72	uint32_t page_flags = 0;
 73
 74	dma_resv_assert_held(bo->base.resv);
 75
 76	if (bo->ttm)
 77		return 0;
 78
 79	switch (bo->type) {
 80	case ttm_bo_type_device:
 81		if (zero_alloc)
 82			page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
 83		break;
 84	case ttm_bo_type_kernel:
 85		break;
 86	case ttm_bo_type_sg:
 87		page_flags |= TTM_TT_FLAG_EXTERNAL;
 88		break;
 89	default:
 90		pr_err("Illegal buffer object type\n");
 91		return -EINVAL;
 92	}
 93	/*
 94	 * When using dma_alloc_coherent with memory encryption the
 95	 * mapped TT pages need to be decrypted or otherwise the drivers
 96	 * will end up sending encrypted mem to the gpu.
 97	 */
 98	if (ttm_pool_uses_dma_alloc(&bdev->pool) &&
 99	    cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
100		page_flags |= TTM_TT_FLAG_DECRYPTED;
101		drm_info_once(ddev, "TT memory decryption enabled.");
102	}
103
104	bo->ttm = bdev->funcs->ttm_tt_create(bo, page_flags);
105	if (unlikely(bo->ttm == NULL))
106		return -ENOMEM;
107
108	WARN_ON(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE &&
109		!(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL));
110
111	return 0;
112}
113EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_create);
114
115/*
116 * Allocates storage for pointers to the pages that back the ttm.
117 */
118static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
119{
120	ttm->pages = kvcalloc(ttm->num_pages, sizeof(void*), GFP_KERNEL);
121	if (!ttm->pages)
122		return -ENOMEM;
123
124	return 0;
125}
126
127static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
128{
129	ttm->pages = kvcalloc(ttm->num_pages, sizeof(*ttm->pages) +
130			      sizeof(*ttm->dma_address), GFP_KERNEL);
131	if (!ttm->pages)
132		return -ENOMEM;
133
134	ttm->dma_address = (void *)(ttm->pages + ttm->num_pages);
135	return 0;
136}
137
138static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
139{
140	ttm->dma_address = kvcalloc(ttm->num_pages, sizeof(*ttm->dma_address),
141				    GFP_KERNEL);
142	if (!ttm->dma_address)
143		return -ENOMEM;
144
145	return 0;
146}
147
148void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
149{
150	bdev->funcs->ttm_tt_destroy(bdev, ttm);
151}
152EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_destroy);
153
154static void ttm_tt_init_fields(struct ttm_tt *ttm,
155			       struct ttm_buffer_object *bo,
156			       uint32_t page_flags,
157			       enum ttm_caching caching,
158			       unsigned long extra_pages)
159{
160	ttm->num_pages = (PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT) + extra_pages;
161	ttm->page_flags = page_flags;
162	ttm->dma_address = NULL;
163	ttm->swap_storage = NULL;
164	ttm->sg = bo->sg;
165	ttm->caching = caching;
166	ttm->restore = NULL;
167	ttm->backup = NULL;
168}
169
170int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
171		uint32_t page_flags, enum ttm_caching caching,
172		unsigned long extra_pages)
173{
174	ttm_tt_init_fields(ttm, bo, page_flags, caching, extra_pages);
175
176	if (ttm_tt_alloc_page_directory(ttm)) {
177		pr_err("Failed allocating page table\n");
178		return -ENOMEM;
179	}
180	return 0;
181}
182EXPORT_SYMBOL(ttm_tt_init);
183
184void ttm_tt_fini(struct ttm_tt *ttm)
185{
186	WARN_ON(ttm->page_flags & TTM_TT_FLAG_PRIV_POPULATED);
187
188	if (ttm->swap_storage)
189		fput(ttm->swap_storage);
190	ttm->swap_storage = NULL;
191
192	if (ttm_tt_is_backed_up(ttm))
193		ttm_pool_drop_backed_up(ttm);
194	if (ttm->backup) {
195		ttm_backup_fini(ttm->backup);
196		ttm->backup = NULL;
197	}
198
199	if (ttm->pages)
200		kvfree(ttm->pages);
201	else
202		kvfree(ttm->dma_address);
203	ttm->pages = NULL;
204	ttm->dma_address = NULL;
205}
206EXPORT_SYMBOL(ttm_tt_fini);
207
208int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
209		   uint32_t page_flags, enum ttm_caching caching)
210{
211	int ret;
212
213	ttm_tt_init_fields(ttm, bo, page_flags, caching, 0);
214
215	if (page_flags & TTM_TT_FLAG_EXTERNAL)
216		ret = ttm_sg_tt_alloc_page_directory(ttm);
217	else
218		ret = ttm_dma_tt_alloc_page_directory(ttm);
219	if (ret) {
220		pr_err("Failed allocating page table\n");
221		return -ENOMEM;
222	}
223	return 0;
224}
225EXPORT_SYMBOL(ttm_sg_tt_init);
226
227int ttm_tt_swapin(struct ttm_tt *ttm)
228{
229	struct address_space *swap_space;
230	struct file *swap_storage;
231	struct page *from_page;
232	struct page *to_page;
233	gfp_t gfp_mask;
234	int i, ret;
235
236	swap_storage = ttm->swap_storage;
237	BUG_ON(swap_storage == NULL);
238
239	swap_space = swap_storage->f_mapping;
240	gfp_mask = mapping_gfp_mask(swap_space);
241
242	for (i = 0; i < ttm->num_pages; ++i) {
243		from_page = shmem_read_mapping_page_gfp(swap_space, i,
244							gfp_mask);
245		if (IS_ERR(from_page)) {
246			ret = PTR_ERR(from_page);
247			goto out_err;
248		}
249		to_page = ttm->pages[i];
250		if (unlikely(to_page == NULL)) {
251			ret = -ENOMEM;
252			goto out_err;
253		}
254
255		copy_highpage(to_page, from_page);
256		put_page(from_page);
257	}
258
259	fput(swap_storage);
260	ttm->swap_storage = NULL;
261	ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
262
263	return 0;
264
265out_err:
266	return ret;
267}
268EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_swapin);
269
270/**
271 * ttm_tt_backup() - Helper to back up a struct ttm_tt.
272 * @bdev: The TTM device.
273 * @tt: The struct ttm_tt.
274 * @flags: Flags that govern the backup behaviour.
275 *
276 * Update the page accounting and call ttm_pool_shrink_tt to free pages
277 * or back them up.
278 *
279 * Return: Number of pages freed or swapped out, or negative error code on
280 * error.
281 */
282long ttm_tt_backup(struct ttm_device *bdev, struct ttm_tt *tt,
283		   const struct ttm_backup_flags flags)
284{
285	long ret;
286
287	if (WARN_ON(IS_ERR_OR_NULL(tt->backup)))
288		return 0;
289
290	ret = ttm_pool_backup(&bdev->pool, tt, &flags);
291	if (ret > 0) {
292		tt->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
293		tt->page_flags |= TTM_TT_FLAG_BACKED_UP;
294	}
295
296	return ret;
297}
298
299int ttm_tt_restore(struct ttm_device *bdev, struct ttm_tt *tt,
300		   const struct ttm_operation_ctx *ctx)
301{
302	int ret = ttm_pool_restore_and_alloc(&bdev->pool, tt, ctx);
303
304	if (ret)
305		return ret;
306
307	tt->page_flags &= ~TTM_TT_FLAG_BACKED_UP;
308
309	return 0;
310}
311EXPORT_SYMBOL(ttm_tt_restore);
312
313/**
314 * ttm_tt_swapout - swap out tt object
315 *
316 * @bdev: TTM device structure.
317 * @ttm: The struct ttm_tt.
318 * @gfp_flags: Flags to use for memory allocation.
319 *
320 * Swapout a TT object to a shmem_file, return number of pages swapped out or
321 * negative error code.
322 */
323int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
324		   gfp_t gfp_flags)
325{
326	loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT;
327	struct address_space *swap_space;
328	struct file *swap_storage;
329	struct page *from_page;
330	struct page *to_page;
331	int i, ret;
332
333	swap_storage = shmem_file_setup("ttm swap", size, 0);
334	if (IS_ERR(swap_storage)) {
335		pr_err("Failed allocating swap storage\n");
336		return PTR_ERR(swap_storage);
337	}
338
339	swap_space = swap_storage->f_mapping;
340	gfp_flags &= mapping_gfp_mask(swap_space);
341
342	for (i = 0; i < ttm->num_pages; ++i) {
343		from_page = ttm->pages[i];
344		if (unlikely(from_page == NULL))
345			continue;
346
347		to_page = shmem_read_mapping_page_gfp(swap_space, i, gfp_flags);
348		if (IS_ERR(to_page)) {
349			ret = PTR_ERR(to_page);
350			goto out_err;
351		}
352		copy_highpage(to_page, from_page);
353		set_page_dirty(to_page);
354		mark_page_accessed(to_page);
355		put_page(to_page);
356	}
357
358	ttm_tt_unpopulate(bdev, ttm);
359	ttm->swap_storage = swap_storage;
360	ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
361
362	return ttm->num_pages;
363
364out_err:
365	fput(swap_storage);
366
367	return ret;
368}
369EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_swapout);
370
371int ttm_tt_populate(struct ttm_device *bdev,
372		    struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
373{
374	int ret;
375
376	if (!ttm)
377		return -EINVAL;
378
379	if (ttm_tt_is_populated(ttm))
380		return 0;
381
382	if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
383		atomic_long_add(ttm->num_pages, &ttm_pages_allocated);
384		if (ttm_pool_uses_dma32(&bdev->pool))
385			atomic_long_add(ttm->num_pages,
386					&ttm_dma32_pages_allocated);
387	}
388
389	while (atomic_long_read(&ttm_pages_allocated) > ttm_pages_limit ||
390	       atomic_long_read(&ttm_dma32_pages_allocated) >
391	       ttm_dma32_pages_limit) {
392
393		ret = ttm_global_swapout(ctx, GFP_KERNEL);
394		if (ret == 0)
395			break;
396		if (ret < 0)
397			goto error;
398	}
399
400	if (bdev->funcs->ttm_tt_populate)
401		ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx);
402	else
403		ret = ttm_pool_alloc(&bdev->pool, ttm, ctx);
404	if (ret)
405		goto error;
406
407	ttm->page_flags |= TTM_TT_FLAG_PRIV_POPULATED;
408	ttm->page_flags &= ~TTM_TT_FLAG_BACKED_UP;
409	if (unlikely(ttm->page_flags & TTM_TT_FLAG_SWAPPED)) {
410		ret = ttm_tt_swapin(ttm);
411		if (unlikely(ret != 0)) {
412			ttm_tt_unpopulate(bdev, ttm);
413			return ret;
414		}
415	}
416
417	return 0;
418
419error:
420	if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
421		atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
422		if (ttm_pool_uses_dma32(&bdev->pool))
423			atomic_long_sub(ttm->num_pages,
424					&ttm_dma32_pages_allocated);
425	}
426	return ret;
427}
428
429#if IS_ENABLED(CONFIG_DRM_TTM_KUNIT_TEST)
430EXPORT_SYMBOL(ttm_tt_populate);
431#endif
432
433void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
434{
435	if (!ttm_tt_is_populated(ttm))
436		return;
437
438	if (bdev->funcs->ttm_tt_unpopulate)
439		bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
440	else
441		ttm_pool_free(&bdev->pool, ttm);
442
443	if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
444		atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
445		if (ttm_pool_uses_dma32(&bdev->pool))
446			atomic_long_sub(ttm->num_pages,
447					&ttm_dma32_pages_allocated);
448	}
449
450	ttm->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
451}
452EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_unpopulate);
453
454#ifdef CONFIG_DEBUG_FS
455
456/* Test the shrinker functions and dump the result */
457static int ttm_tt_debugfs_shrink_show(struct seq_file *m, void *data)
458{
459	struct ttm_operation_ctx ctx = { false, false };
460
461	seq_printf(m, "%d\n", ttm_global_swapout(&ctx, GFP_KERNEL));
462	return 0;
463}
464DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink);
465
466#endif
467
468
469/*
470 * ttm_tt_mgr_init - register with the MM shrinker
471 *
472 * Register with the MM shrinker for swapping out BOs.
473 */
474void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
475{
476#ifdef CONFIG_DEBUG_FS
477	debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL,
478			    &ttm_tt_debugfs_shrink_fops);
479#endif
480
481	if (!ttm_pages_limit)
482		ttm_pages_limit = num_pages;
483
484	if (!ttm_dma32_pages_limit)
485		ttm_dma32_pages_limit = num_dma32_pages;
486}
487
488static void ttm_kmap_iter_tt_map_local(struct ttm_kmap_iter *iter,
489				       struct iosys_map *dmap,
490				       pgoff_t i)
491{
492	struct ttm_kmap_iter_tt *iter_tt =
493		container_of(iter, typeof(*iter_tt), base);
494
495	iosys_map_set_vaddr(dmap, kmap_local_page_prot(iter_tt->tt->pages[i],
496						       iter_tt->prot));
497}
498
499static void ttm_kmap_iter_tt_unmap_local(struct ttm_kmap_iter *iter,
500					 struct iosys_map *map)
501{
502	kunmap_local(map->vaddr);
503}
504
505static const struct ttm_kmap_iter_ops ttm_kmap_iter_tt_ops = {
506	.map_local = ttm_kmap_iter_tt_map_local,
507	.unmap_local = ttm_kmap_iter_tt_unmap_local,
508	.maps_tt = true,
509};
510
511/**
512 * ttm_kmap_iter_tt_init - Initialize a struct ttm_kmap_iter_tt
513 * @iter_tt: The struct ttm_kmap_iter_tt to initialize.
514 * @tt: Struct ttm_tt holding page pointers of the struct ttm_resource.
515 *
516 * Return: Pointer to the embedded struct ttm_kmap_iter.
517 */
518struct ttm_kmap_iter *
519ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
520		      struct ttm_tt *tt)
521{
522	iter_tt->base.ops = &ttm_kmap_iter_tt_ops;
523	iter_tt->tt = tt;
524	if (tt)
525		iter_tt->prot = ttm_prot_from_caching(tt->caching, PAGE_KERNEL);
526	else
527		iter_tt->prot = PAGE_KERNEL;
528
529	return &iter_tt->base;
530}
531EXPORT_SYMBOL(ttm_kmap_iter_tt_init);
532
533unsigned long ttm_tt_pages_limit(void)
534{
535	return ttm_pages_limit;
536}
537EXPORT_SYMBOL(ttm_tt_pages_limit);
538
539/**
540 * ttm_tt_setup_backup() - Allocate and assign a backup structure for a ttm_tt
541 * @tt: The ttm_tt for wich to allocate and assign a backup structure.
542 *
543 * Assign a backup structure to be used for tt backup. This should
544 * typically be done at bo creation, to avoid allocations at shrinking
545 * time.
546 *
547 * Return: 0 on success, negative error code on failure.
548 */
549int ttm_tt_setup_backup(struct ttm_tt *tt)
550{
551	struct file *backup =
552		ttm_backup_shmem_create(((loff_t)tt->num_pages) << PAGE_SHIFT);
553
554	if (WARN_ON_ONCE(!(tt->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE)))
555		return -EINVAL;
556
557	if (IS_ERR(backup))
558		return PTR_ERR(backup);
559
560	if (tt->backup)
561		ttm_backup_fini(tt->backup);
562
563	tt->backup = backup;
564	return 0;
565}
566EXPORT_SYMBOL(ttm_tt_setup_backup);