summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/ttm/ttm_tt.c
blob: 3d47a2c12322173fa3621e9cb5886408dcb1c19e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
/**************************************************************************
 *
 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/
/*
 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 */

#include <linux/vmalloc.h>
#include <linux/sched.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/file.h>
#include <linux/swap.h>
#include "drm_cache.h"
#include "ttm/ttm_module.h"
#include "ttm/ttm_bo_driver.h"
#include "ttm/ttm_placement.h"

static int ttm_tt_swapin(struct ttm_tt *ttm);

/**
 * Allocates storage for pointers to the pages that back the ttm.
 *
 * Uses kmalloc if possible. Otherwise falls back to vmalloc.
 */
static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
{
	unsigned long size = ttm->num_pages * sizeof(*ttm->pages);
	ttm->pages = NULL;

	if (size <= PAGE_SIZE)
		ttm->pages = kzalloc(size, GFP_KERNEL);

	if (!ttm->pages) {
		ttm->pages = vmalloc_user(size);
		if (ttm->pages)
			ttm->page_flags |= TTM_PAGE_FLAG_VMALLOC;
	}
}

static void ttm_tt_free_page_directory(struct ttm_tt *ttm)
{
	if (ttm->page_flags & TTM_PAGE_FLAG_VMALLOC) {
		vfree(ttm->pages);
		ttm->page_flags &= ~TTM_PAGE_FLAG_VMALLOC;
	} else {
		kfree(ttm->pages);
	}
	ttm->pages = NULL;
}

static struct page *ttm_tt_alloc_page(unsigned page_flags)
{
	gfp_t gfp_flags = GFP_USER;

	if (page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
		gfp_flags |= __GFP_ZERO;

	if (page_flags & TTM_PAGE_FLAG_DMA32)
		gfp_flags |= __GFP_DMA32;
	else
		gfp_flags |= __GFP_HIGHMEM;

	return alloc_page(gfp_flags);
}

static void ttm_tt_free_user_pages(struct ttm_tt *ttm)
{
	int write;
	int dirty;
	struct page *page;
	int i;
	struct ttm_backend *be = ttm->be;

	BUG_ON(!(ttm->page_flags & TTM_PAGE_FLAG_USER));
	write = ((ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0);
	dirty = ((ttm->page_flags & TTM_PAGE_FLAG_USER_DIRTY) != 0);

	if (be)
		be->func->clear(be);

	for (i = 0; i < ttm->num_pages; ++i) {
		page = ttm->pages[i];
		if (page == NULL)
			continue;

		if (page == ttm->dummy_read_page) {
			BUG_ON(write);
			continue;
		}

		if (write && dirty && !PageReserved(page))
			set_page_dirty_lock(page);

		ttm->pages[i] = NULL;
		ttm_mem_global_free(ttm->glob->mem_glob, PAGE_SIZE);
		put_page(page);
	}
	ttm->state = tt_unpopulated;
	ttm->first_himem_page = ttm->num_pages;
	ttm->last_lomem_page = -1;
}

static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
{
	struct page *p;
	struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
	int ret;

	while (NULL == (p = ttm->pages[index])) {
		p = ttm_tt_alloc_page(ttm->page_flags);

		if (!p)
			return NULL;

		ret = ttm_mem_global_alloc_page(mem_glob, p, false, false);
		if (unlikely(ret != 0))
			goto out_err;

		if (PageHighMem(p))
			ttm->pages[--ttm->first_himem_page] = p;
		else
			ttm->pages[++ttm->last_lomem_page] = p;
	}
	return p;
out_err:
	put_page(p);
	return NULL;
}

struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index)
{
	int ret;

	if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
		ret = ttm_tt_swapin(ttm);
		if (unlikely(ret != 0))
			return NULL;
	}
	return __ttm_tt_get_page(ttm, index);
}

int ttm_tt_populate(struct ttm_tt *ttm)
{
	struct page *page;
	unsigned long i;
	struct ttm_backend *be;
	int ret;

	if (ttm->state != tt_unpopulated)
		return 0;

	if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
		ret = ttm_tt_swapin(ttm);
		if (unlikely(ret != 0))
			return ret;
	}

	be = ttm->be;

	for (i = 0; i < ttm->num_pages; ++i) {
		page = __ttm_tt_get_page(ttm, i);
		if (!page)
			return -ENOMEM;
	}

	be->func->populate(be, ttm->num_pages, ttm->pages,
			   ttm->dummy_read_page);
	ttm->state = tt_unbound;
	return 0;
}
EXPORT_SYMBOL(ttm_tt_populate);

#ifdef CONFIG_X86
static inline int ttm_tt_set_page_caching(struct page *p,
					  enum ttm_caching_state c_old,
					  enum ttm_caching_state c_new)
{
	int ret = 0;

	if (PageHighMem(p))
		return 0;

	if (c_old != tt_cached) {
		/* p isn't in the default caching state, set it to
		 * writeback first to free its current memtype. */

		ret = set_pages_wb(p, 1);
		if (ret)
			return ret;
	}

	if (c_new == tt_wc)
		ret = set_memory_wc((unsigned long) page_address(p), 1);
	else if (c_new == tt_uncached)
		ret = set_pages_uc(p, 1);

	return ret;
}
#else /* CONFIG_X86 */
static inline int ttm_tt_set_page_caching(struct page *p,
					  enum ttm_caching_state c_old,
					  enum ttm_caching_state c_new)
{
	return 0;
}
#endif /* CONFIG_X86 */

/*
 * Change caching policy for the linear kernel map
 * for range of pages in a ttm.
 */

static int ttm_tt_set_caching(struct ttm_tt *ttm,
			      enum ttm_caching_state c_state)
{
	int i, j;
	struct page *cur_page;
	int ret;

	if (ttm->caching_state == c_state)
		return 0;

	if (c_state != tt_cached) {
		ret = ttm_tt_populate(ttm);
		if (unlikely(ret != 0))
			return ret;
	}

	if (ttm->caching_state == tt_cached)
		drm_clflush_pages(ttm->pages, ttm->num_pages);

	for (i = 0; i < ttm->num_pages; ++i) {
		cur_page = ttm->pages[i];
		if (likely(cur_page != NULL)) {
			ret = ttm_tt_set_page_caching(cur_page,
						      ttm->caching_state,
						      c_state);
			if (unlikely(ret != 0))
				goto out_err;
		}
	}

	ttm->caching_state = c_state;

	return 0;

out_err:
	for (j = 0; j < i; ++j) {
		cur_page = ttm->pages[j];
		if (likely(cur_page != NULL)) {
			(void)ttm_tt_set_page_caching(cur_page, c_state,
						      ttm->caching_state);
		}
	}

	return ret;
}

int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
{
	enum ttm_caching_state state;

	if (placement & TTM_PL_FLAG_WC)
		state = tt_wc;
	else if (placement & TTM_PL_FLAG_UNCACHED)
		state = tt_uncached;
	else
		state = tt_cached;

	return ttm_tt_set_caching(ttm, state);
}
EXPORT_SYMBOL(ttm_tt_set_placement_caching);

static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
{
	int i;
	struct page *cur_page;
	struct ttm_backend *be = ttm->be;

	if (be)
		be->func->clear(be);
	(void)ttm_tt_set_caching(ttm, tt_cached);
	for (i = 0; i < ttm->num_pages; ++i) {
		cur_page = ttm->pages[i];
		ttm->pages[i] = NULL;
		if (cur_page) {
			if (page_count(cur_page) != 1)
				printk(KERN_ERR TTM_PFX
				       "Erroneous page count. "
				       "Leaking pages.\n");
			ttm_mem_global_free_page(ttm->glob->mem_glob,
						 cur_page);
			__free_page(cur_page);
		}
	}
	ttm->state = tt_unpopulated;
	ttm->first_himem_page = ttm->num_pages;
	ttm->last_lomem_page = -1;
}

void ttm_tt_destroy(struct ttm_tt *ttm)
{
	struct ttm_backend *be;

	if (unlikely(ttm == NULL))
		return;

	be = ttm->be;
	if (likely(be != NULL)) {
		be->func->destroy(be);
		ttm->be = NULL;
	}

	if (likely(ttm->pages != NULL)) {
		if (ttm->page_flags & TTM_PAGE_FLAG_USER)
			ttm_tt_free_user_pages(ttm);
		else
			ttm_tt_free_alloced_pages(ttm);

		ttm_tt_free_page_directory(ttm);
	}

	if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP) &&
	    ttm->swap_storage)
		fput(ttm->swap_storage);

	kfree(ttm);
}

int ttm_tt_set_user(struct ttm_tt *ttm,
		    struct task_struct *tsk,
		    unsigned long start, unsigned long num_pages)
{
	struct mm_struct *mm = tsk->mm;
	int ret;
	int write = (ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0;
	struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;

	BUG_ON(num_pages != ttm->num_pages);
	BUG_ON((ttm->page_flags & TTM_PAGE_FLAG_USER) == 0);

	/**
	 * Account user pages as lowmem pages for now.
	 */

	ret = ttm_mem_global_alloc(mem_glob, num_pages * PAGE_SIZE,
				   false, false);
	if (unlikely(ret != 0))
		return ret;

	down_read(&mm->mmap_sem);
	ret = get_user_pages(tsk, mm, start, num_pages,
			     write, 0, ttm->pages, NULL);
	up_read(&mm->mmap_sem);

	if (ret != num_pages && write) {
		ttm_tt_free_user_pages(ttm);
		ttm_mem_global_free(mem_glob, num_pages * PAGE_SIZE);
		return -ENOMEM;
	}

	ttm->tsk = tsk;
	ttm->start = start;
	ttm->state = tt_unbound;

	return 0;
}

struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
			     uint32_t page_flags, struct page *dummy_read_page)
{
	struct ttm_bo_driver *bo_driver = bdev->driver;
	struct ttm_tt *ttm;

	if (!bo_driver)
		return NULL;

	ttm = kzalloc(sizeof(*ttm), GFP_KERNEL);
	if (!ttm)
		return NULL;

	ttm->glob = bdev->glob;
	ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
	ttm->first_himem_page = ttm->num_pages;
	ttm->last_lomem_page = -1;
	ttm->caching_state = tt_cached;
	ttm->page_flags = page_flags;

	ttm->dummy_read_page = dummy_read_page;

	ttm_tt_alloc_page_directory(ttm);
	if (!ttm->pages) {
		ttm_tt_destroy(ttm);
		printk(KERN_ERR TTM_PFX "Failed allocating page table\n");
		return NULL;
	}
	ttm->be = bo_driver->create_ttm_backend_entry(bdev);
	if (!ttm->be) {
		ttm_tt_destroy(ttm);
		printk(KERN_ERR TTM_PFX "Failed creating ttm backend entry\n");
		return NULL;
	}
	ttm->state = tt_unpopulated;
	return ttm;
}

void ttm_tt_unbind(struct ttm_tt *ttm)
{
	int ret;
	struct ttm_backend *be = ttm->be;

	if (ttm->state == tt_bound) {
		ret = be->func->unbind(be);
		BUG_ON(ret);
		ttm->state = tt_unbound;
	}
}

int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
{
	int ret = 0;
	struct ttm_backend *be;

	if (!ttm)
		return -EINVAL;

	if (ttm->state == tt_bound)
		return 0;

	be = ttm->be;

	ret = ttm_tt_populate(ttm);
	if (ret)
		return ret;

	ret = be->func->bind(be, bo_mem);
	if (ret) {
		printk(KERN_ERR TTM_PFX "Couldn't bind backend.\n");
		return ret;
	}

	ttm->state = tt_bound;

	if (ttm->page_flags & TTM_PAGE_FLAG_USER)
		ttm->page_flags |= TTM_PAGE_FLAG_USER_DIRTY;
	return 0;
}
EXPORT_SYMBOL(ttm_tt_bind);

static int ttm_tt_swapin(struct ttm_tt *ttm)
{
	struct address_space *swap_space;
	struct file *swap_storage;
	struct page *from_page;
	struct page *to_page;
	void *from_virtual;
	void *to_virtual;
	int i;
	int ret;

	if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
		ret = ttm_tt_set_user(ttm, ttm->tsk, ttm->start,
				      ttm->num_pages);
		if (unlikely(ret != 0))
			return ret;

		ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
		return 0;
	}

	swap_storage = ttm->swap_storage;
	BUG_ON(swap_storage == NULL);

	swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;

	for (i = 0; i < ttm->num_pages; ++i) {
		from_page = read_mapping_page(swap_space, i, NULL);
		if (IS_ERR(from_page))
			goto out_err;
		to_page = __ttm_tt_get_page(ttm, i);
		if (unlikely(to_page == NULL))
			goto out_err;

		preempt_disable();
		from_virtual = kmap_atomic(from_page, KM_USER0);
		to_virtual = kmap_atomic(to_page, KM_USER1);
		memcpy(to_virtual, from_virtual, PAGE_SIZE);
		kunmap_atomic(to_virtual, KM_USER1);
		kunmap_atomic(from_virtual, KM_USER0);
		preempt_enable();
		page_cache_release(from_page);
	}

	if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP))
		fput(swap_storage);
	ttm->swap_storage = NULL;
	ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;

	return 0;
out_err:
	ttm_tt_free_alloced_pages(ttm);
	return -ENOMEM;
}

int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistant_swap_storage)
{
	struct address_space *swap_space;
	struct file *swap_storage;
	struct page *from_page;
	struct page *to_page;
	void *from_virtual;
	void *to_virtual;
	int i;

	BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
	BUG_ON(ttm->caching_state != tt_cached);

	/*
	 * For user buffers, just unpin the pages, as there should be
	 * vma references.
	 */

	if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
		ttm_tt_free_user_pages(ttm);
		ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
		ttm->swap_storage = NULL;
		return 0;
	}

	if (!persistant_swap_storage) {
		swap_storage = shmem_file_setup("ttm swap",
						ttm->num_pages << PAGE_SHIFT,
						0);
		if (unlikely(IS_ERR(swap_storage))) {
			printk(KERN_ERR "Failed allocating swap storage.\n");
			return -ENOMEM;
		}
	} else
		swap_storage = persistant_swap_storage;

	swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;

	for (i = 0; i < ttm->num_pages; ++i) {
		from_page = ttm->pages[i];
		if (unlikely(from_page == NULL))
			continue;
		to_page = read_mapping_page(swap_space, i, NULL);
		if (unlikely(to_page == NULL))
			goto out_err;

		preempt_disable();
		from_virtual = kmap_atomic(from_page, KM_USER0);
		to_virtual = kmap_atomic(to_page, KM_USER1);
		memcpy(to_virtual, from_virtual, PAGE_SIZE);
		kunmap_atomic(to_virtual, KM_USER1);
		kunmap_atomic(from_virtual, KM_USER0);
		preempt_enable();
		set_page_dirty(to_page);
		mark_page_accessed(to_page);
		page_cache_release(to_page);
	}

	ttm_tt_free_alloced_pages(ttm);
	ttm->swap_storage = swap_storage;
	ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
	if (persistant_swap_storage)
		ttm->page_flags |= TTM_PAGE_FLAG_PERSISTANT_SWAP;

	return 0;
out_err:
	if (!persistant_swap_storage)
		fput(swap_storage);

	return -ENOMEM;
}
OpenPOWER on IntegriCloud