1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /*
3 * Copyright 2020 Advanced Micro Devices, Inc.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21 * OTHER DEALINGS IN THE SOFTWARE.
22 *
23 * Authors: Christian König
24 */
25
26 /* Pooling of allocated pages is necessary because changing the caching
27 * attributes on x86 of the linear mapping requires a costly cross CPU TLB
28 * invalidate for those addresses.
29 *
30 * Additional to that allocations from the DMA coherent API are pooled as well
31 * cause they are rather slow compared to alloc_pages+map.
32 */
33
34 #include <linux/module.h>
35 #include <linux/dma-mapping.h>
36 #include <linux/highmem.h>
37 #include <linux/sched/mm.h>
38
39 #ifdef CONFIG_X86
40 #include <asm/set_memory.h>
41 #endif
42
43 #include <drm/ttm/ttm_pool.h>
44 #include <drm/ttm/ttm_bo_driver.h>
45 #include <drm/ttm/ttm_tt.h>
46
47 #include "ttm_module.h"
48
49 /**
50 * struct ttm_pool_dma - Helper object for coherent DMA mappings
51 *
52 * @addr: original DMA address returned for the mapping
53 * @vaddr: original vaddr return for the mapping and order in the lower bits
54 */
55 struct ttm_pool_dma {
56 dma_addr_t addr;
57 unsigned long vaddr;
58 };
59
60 static unsigned long page_pool_size;
61
62 MODULE_PARM_DESC(page_pool_size, "Number of pages in the WC/UC/DMA pool");
63 module_param(page_pool_size, ulong, 0644);
64
65 static atomic_long_t allocated_pages;
66
67 static struct ttm_pool_type global_write_combined[MAX_ORDER];
68 static struct ttm_pool_type global_uncached[MAX_ORDER];
69
70 static struct ttm_pool_type global_dma32_write_combined[MAX_ORDER];
71 static struct ttm_pool_type global_dma32_uncached[MAX_ORDER];
72
73 static struct mutex shrinker_lock;
74 static struct list_head shrinker_list;
75 static struct shrinker mm_shrinker;
76
77 /* Allocate pages of size 1 << order with the given gfp_flags */
ttm_pool_alloc_page(struct ttm_pool * pool,gfp_t gfp_flags,unsigned int order)78 static struct page *ttm_pool_alloc_page(struct ttm_pool *pool, gfp_t gfp_flags,
79 unsigned int order)
80 {
81 unsigned long attr = DMA_ATTR_FORCE_CONTIGUOUS;
82 struct ttm_pool_dma *dma;
83 struct page *p;
84 void *vaddr;
85
86 /* Don't set the __GFP_COMP flag for higher order allocations.
87 * Mapping pages directly into an userspace process and calling
88 * put_page() on a TTM allocated page is illegal.
89 */
90 if (order)
91 gfp_flags |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN |
92 __GFP_KSWAPD_RECLAIM;
93
94 if (!pool->use_dma_alloc) {
95 p = alloc_pages(gfp_flags, order);
96 if (p)
97 p->private = order;
98 return p;
99 }
100
101 dma = kmalloc(sizeof(*dma), GFP_KERNEL);
102 if (!dma)
103 return NULL;
104
105 if (order)
106 attr |= DMA_ATTR_NO_WARN;
107
108 vaddr = dma_alloc_attrs(pool->dev, (1ULL << order) * PAGE_SIZE,
109 &dma->addr, gfp_flags, attr);
110 if (!vaddr)
111 goto error_free;
112
113 /* TODO: This is an illegal abuse of the DMA API, but we need to rework
114 * TTM page fault handling and extend the DMA API to clean this up.
115 */
116 if (is_vmalloc_addr(vaddr))
117 p = vmalloc_to_page(vaddr);
118 else
119 p = virt_to_page(vaddr);
120
121 dma->vaddr = (unsigned long)vaddr | order;
122 p->private = (unsigned long)dma;
123 return p;
124
125 error_free:
126 kfree(dma);
127 return NULL;
128 }
129
130 /* Reset the caching and pages of size 1 << order */
ttm_pool_free_page(struct ttm_pool * pool,enum ttm_caching caching,unsigned int order,struct page * p)131 static void ttm_pool_free_page(struct ttm_pool *pool, enum ttm_caching caching,
132 unsigned int order, struct page *p)
133 {
134 unsigned long attr = DMA_ATTR_FORCE_CONTIGUOUS;
135 struct ttm_pool_dma *dma;
136 void *vaddr;
137
138 #ifdef CONFIG_X86
139 /* We don't care that set_pages_wb is inefficient here. This is only
140 * used when we have to shrink and CPU overhead is irrelevant then.
141 */
142 if (caching != ttm_cached && !PageHighMem(p))
143 set_pages_wb(p, 1 << order);
144 #endif
145
146 if (!pool || !pool->use_dma_alloc) {
147 __free_pages(p, order);
148 return;
149 }
150
151 if (order)
152 attr |= DMA_ATTR_NO_WARN;
153
154 dma = (void *)p->private;
155 vaddr = (void *)(dma->vaddr & PAGE_MASK);
156 dma_free_attrs(pool->dev, (1UL << order) * PAGE_SIZE, vaddr, dma->addr,
157 attr);
158 kfree(dma);
159 }
160
161 /* Apply a new caching to an array of pages */
ttm_pool_apply_caching(struct page ** first,struct page ** last,enum ttm_caching caching)162 static int ttm_pool_apply_caching(struct page **first, struct page **last,
163 enum ttm_caching caching)
164 {
165 #ifdef CONFIG_X86
166 unsigned int num_pages = last - first;
167
168 if (!num_pages)
169 return 0;
170
171 switch (caching) {
172 case ttm_cached:
173 break;
174 case ttm_write_combined:
175 return set_pages_array_wc(first, num_pages);
176 case ttm_uncached:
177 return set_pages_array_uc(first, num_pages);
178 }
179 #endif
180 return 0;
181 }
182
183 /* Map pages of 1 << order size and fill the DMA address array */
ttm_pool_map(struct ttm_pool * pool,unsigned int order,struct page * p,dma_addr_t ** dma_addr)184 static int ttm_pool_map(struct ttm_pool *pool, unsigned int order,
185 struct page *p, dma_addr_t **dma_addr)
186 {
187 dma_addr_t addr;
188 unsigned int i;
189
190 if (pool->use_dma_alloc) {
191 struct ttm_pool_dma *dma = (void *)p->private;
192
193 addr = dma->addr;
194 } else {
195 size_t size = (1ULL << order) * PAGE_SIZE;
196
197 addr = dma_map_page(pool->dev, p, 0, size, DMA_BIDIRECTIONAL);
198 if (dma_mapping_error(pool->dev, addr))
199 return -EFAULT;
200 }
201
202 for (i = 1 << order; i ; --i) {
203 *(*dma_addr)++ = addr;
204 addr += PAGE_SIZE;
205 }
206
207 return 0;
208 }
209
210 /* Unmap pages of 1 << order size */
ttm_pool_unmap(struct ttm_pool * pool,dma_addr_t dma_addr,unsigned int num_pages)211 static void ttm_pool_unmap(struct ttm_pool *pool, dma_addr_t dma_addr,
212 unsigned int num_pages)
213 {
214 /* Unmapped while freeing the page */
215 if (pool->use_dma_alloc)
216 return;
217
218 dma_unmap_page(pool->dev, dma_addr, (long)num_pages << PAGE_SHIFT,
219 DMA_BIDIRECTIONAL);
220 }
221
222 /* Give pages into a specific pool_type */
ttm_pool_type_give(struct ttm_pool_type * pt,struct page * p)223 static void ttm_pool_type_give(struct ttm_pool_type *pt, struct page *p)
224 {
225 unsigned int i, num_pages = 1 << pt->order;
226
227 for (i = 0; i < num_pages; ++i) {
228 if (PageHighMem(p))
229 clear_highpage(p + i);
230 else
231 clear_page(page_address(p + i));
232 }
233
234 spin_lock(&pt->lock);
235 list_add(&p->lru, &pt->pages);
236 spin_unlock(&pt->lock);
237 atomic_long_add(1 << pt->order, &allocated_pages);
238 }
239
240 /* Take pages from a specific pool_type, return NULL when nothing available */
ttm_pool_type_take(struct ttm_pool_type * pt)241 static struct page *ttm_pool_type_take(struct ttm_pool_type *pt)
242 {
243 struct page *p;
244
245 spin_lock(&pt->lock);
246 p = list_first_entry_or_null(&pt->pages, typeof(*p), lru);
247 if (p) {
248 atomic_long_sub(1 << pt->order, &allocated_pages);
249 list_del(&p->lru);
250 }
251 spin_unlock(&pt->lock);
252
253 return p;
254 }
255
256 /* Initialize and add a pool type to the global shrinker list */
ttm_pool_type_init(struct ttm_pool_type * pt,struct ttm_pool * pool,enum ttm_caching caching,unsigned int order)257 static void ttm_pool_type_init(struct ttm_pool_type *pt, struct ttm_pool *pool,
258 enum ttm_caching caching, unsigned int order)
259 {
260 pt->pool = pool;
261 pt->caching = caching;
262 pt->order = order;
263 spin_lock_init(&pt->lock);
264 INIT_LIST_HEAD(&pt->pages);
265
266 mutex_lock(&shrinker_lock);
267 list_add_tail(&pt->shrinker_list, &shrinker_list);
268 mutex_unlock(&shrinker_lock);
269 }
270
271 /* Remove a pool_type from the global shrinker list and free all pages */
ttm_pool_type_fini(struct ttm_pool_type * pt)272 static void ttm_pool_type_fini(struct ttm_pool_type *pt)
273 {
274 struct page *p;
275
276 mutex_lock(&shrinker_lock);
277 list_del(&pt->shrinker_list);
278 mutex_unlock(&shrinker_lock);
279
280 while ((p = ttm_pool_type_take(pt)))
281 ttm_pool_free_page(pt->pool, pt->caching, pt->order, p);
282 }
283
284 /* Return the pool_type to use for the given caching and order */
ttm_pool_select_type(struct ttm_pool * pool,enum ttm_caching caching,unsigned int order)285 static struct ttm_pool_type *ttm_pool_select_type(struct ttm_pool *pool,
286 enum ttm_caching caching,
287 unsigned int order)
288 {
289 if (pool->use_dma_alloc)
290 return &pool->caching[caching].orders[order];
291
292 #ifdef CONFIG_X86
293 switch (caching) {
294 case ttm_write_combined:
295 if (pool->use_dma32)
296 return &global_dma32_write_combined[order];
297
298 return &global_write_combined[order];
299 case ttm_uncached:
300 if (pool->use_dma32)
301 return &global_dma32_uncached[order];
302
303 return &global_uncached[order];
304 default:
305 break;
306 }
307 #endif
308
309 return NULL;
310 }
311
312 /* Free pages using the global shrinker list */
ttm_pool_shrink(void)313 static unsigned int ttm_pool_shrink(void)
314 {
315 struct ttm_pool_type *pt;
316 unsigned int num_freed;
317 struct page *p;
318
319 mutex_lock(&shrinker_lock);
320 pt = list_first_entry(&shrinker_list, typeof(*pt), shrinker_list);
321
322 p = ttm_pool_type_take(pt);
323 if (p) {
324 ttm_pool_free_page(pt->pool, pt->caching, pt->order, p);
325 num_freed = 1 << pt->order;
326 } else {
327 num_freed = 0;
328 }
329
330 list_move_tail(&pt->shrinker_list, &shrinker_list);
331 mutex_unlock(&shrinker_lock);
332
333 return num_freed;
334 }
335
336 /* Return the allocation order based for a page */
ttm_pool_page_order(struct ttm_pool * pool,struct page * p)337 static unsigned int ttm_pool_page_order(struct ttm_pool *pool, struct page *p)
338 {
339 if (pool->use_dma_alloc) {
340 struct ttm_pool_dma *dma = (void *)p->private;
341
342 return dma->vaddr & ~PAGE_MASK;
343 }
344
345 return p->private;
346 }
347
348 /**
349 * ttm_pool_alloc - Fill a ttm_tt object
350 *
351 * @pool: ttm_pool to use
352 * @tt: ttm_tt object to fill
353 * @ctx: operation context
354 *
355 * Fill the ttm_tt object with pages and also make sure to DMA map them when
356 * necessary.
357 *
358 * Returns: 0 on successe, negative error code otherwise.
359 */
ttm_pool_alloc(struct ttm_pool * pool,struct ttm_tt * tt,struct ttm_operation_ctx * ctx)360 int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
361 struct ttm_operation_ctx *ctx)
362 {
363 unsigned long num_pages = tt->num_pages;
364 dma_addr_t *dma_addr = tt->dma_address;
365 struct page **caching = tt->pages;
366 struct page **pages = tt->pages;
367 gfp_t gfp_flags = GFP_USER;
368 unsigned int i, order;
369 struct page *p;
370 int r;
371
372 WARN_ON(!num_pages || ttm_tt_is_populated(tt));
373 WARN_ON(dma_addr && !pool->dev);
374
375 if (tt->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
376 gfp_flags |= __GFP_ZERO;
377
378 if (ctx->gfp_retry_mayfail)
379 gfp_flags |= __GFP_RETRY_MAYFAIL;
380
381 if (pool->use_dma32)
382 gfp_flags |= GFP_DMA32;
383 else
384 gfp_flags |= GFP_HIGHUSER;
385
386 for (order = min(MAX_ORDER - 1UL, __fls(num_pages)); num_pages;
387 order = min_t(unsigned int, order, __fls(num_pages))) {
388 bool apply_caching = false;
389 struct ttm_pool_type *pt;
390
391 pt = ttm_pool_select_type(pool, tt->caching, order);
392 p = pt ? ttm_pool_type_take(pt) : NULL;
393 if (p) {
394 apply_caching = true;
395 } else {
396 p = ttm_pool_alloc_page(pool, gfp_flags, order);
397 if (p && PageHighMem(p))
398 apply_caching = true;
399 }
400
401 if (!p) {
402 if (order) {
403 --order;
404 continue;
405 }
406 r = -ENOMEM;
407 goto error_free_all;
408 }
409
410 if (apply_caching) {
411 r = ttm_pool_apply_caching(caching, pages,
412 tt->caching);
413 if (r)
414 goto error_free_page;
415 caching = pages + (1 << order);
416 }
417
418 if (dma_addr) {
419 r = ttm_pool_map(pool, order, p, &dma_addr);
420 if (r)
421 goto error_free_page;
422 }
423
424 num_pages -= 1 << order;
425 for (i = 1 << order; i; --i)
426 *(pages++) = p++;
427 }
428
429 r = ttm_pool_apply_caching(caching, pages, tt->caching);
430 if (r)
431 goto error_free_all;
432
433 return 0;
434
435 error_free_page:
436 ttm_pool_free_page(pool, tt->caching, order, p);
437
438 error_free_all:
439 num_pages = tt->num_pages - num_pages;
440 for (i = 0; i < num_pages; ) {
441 order = ttm_pool_page_order(pool, tt->pages[i]);
442 ttm_pool_free_page(pool, tt->caching, order, tt->pages[i]);
443 i += 1 << order;
444 }
445
446 return r;
447 }
448 EXPORT_SYMBOL(ttm_pool_alloc);
449
450 /**
451 * ttm_pool_free - Free the backing pages from a ttm_tt object
452 *
453 * @pool: Pool to give pages back to.
454 * @tt: ttm_tt object to unpopulate
455 *
456 * Give the packing pages back to a pool or free them
457 */
ttm_pool_free(struct ttm_pool * pool,struct ttm_tt * tt)458 void ttm_pool_free(struct ttm_pool *pool, struct ttm_tt *tt)
459 {
460 unsigned int i;
461
462 for (i = 0; i < tt->num_pages; ) {
463 struct page *p = tt->pages[i];
464 unsigned int order, num_pages;
465 struct ttm_pool_type *pt;
466
467 order = ttm_pool_page_order(pool, p);
468 num_pages = 1ULL << order;
469 if (tt->dma_address)
470 ttm_pool_unmap(pool, tt->dma_address[i], num_pages);
471
472 pt = ttm_pool_select_type(pool, tt->caching, order);
473 if (pt)
474 ttm_pool_type_give(pt, tt->pages[i]);
475 else
476 ttm_pool_free_page(pool, tt->caching, order,
477 tt->pages[i]);
478
479 i += num_pages;
480 }
481
482 while (atomic_long_read(&allocated_pages) > page_pool_size)
483 ttm_pool_shrink();
484 }
485 EXPORT_SYMBOL(ttm_pool_free);
486
487 /**
488 * ttm_pool_init - Initialize a pool
489 *
490 * @pool: the pool to initialize
491 * @dev: device for DMA allocations and mappings
492 * @use_dma_alloc: true if coherent DMA alloc should be used
493 * @use_dma32: true if GFP_DMA32 should be used
494 *
495 * Initialize the pool and its pool types.
496 */
ttm_pool_init(struct ttm_pool * pool,struct device * dev,bool use_dma_alloc,bool use_dma32)497 void ttm_pool_init(struct ttm_pool *pool, struct device *dev,
498 bool use_dma_alloc, bool use_dma32)
499 {
500 unsigned int i, j;
501
502 WARN_ON(!dev && use_dma_alloc);
503
504 pool->dev = dev;
505 pool->use_dma_alloc = use_dma_alloc;
506 pool->use_dma32 = use_dma32;
507
508 if (use_dma_alloc) {
509 for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
510 for (j = 0; j < MAX_ORDER; ++j)
511 ttm_pool_type_init(&pool->caching[i].orders[j],
512 pool, i, j);
513 }
514 }
515
516 /**
517 * ttm_pool_fini - Cleanup a pool
518 *
519 * @pool: the pool to clean up
520 *
521 * Free all pages in the pool and unregister the types from the global
522 * shrinker.
523 */
ttm_pool_fini(struct ttm_pool * pool)524 void ttm_pool_fini(struct ttm_pool *pool)
525 {
526 unsigned int i, j;
527
528 if (pool->use_dma_alloc) {
529 for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
530 for (j = 0; j < MAX_ORDER; ++j)
531 ttm_pool_type_fini(&pool->caching[i].orders[j]);
532 }
533 }
534
535 /* As long as pages are available make sure to release at least one */
ttm_pool_shrinker_scan(struct shrinker * shrink,struct shrink_control * sc)536 static unsigned long ttm_pool_shrinker_scan(struct shrinker *shrink,
537 struct shrink_control *sc)
538 {
539 unsigned long num_freed = 0;
540
541 do
542 num_freed += ttm_pool_shrink();
543 while (!num_freed && atomic_long_read(&allocated_pages));
544
545 return num_freed;
546 }
547
548 /* Return the number of pages available or SHRINK_EMPTY if we have none */
ttm_pool_shrinker_count(struct shrinker * shrink,struct shrink_control * sc)549 static unsigned long ttm_pool_shrinker_count(struct shrinker *shrink,
550 struct shrink_control *sc)
551 {
552 unsigned long num_pages = atomic_long_read(&allocated_pages);
553
554 return num_pages ? num_pages : SHRINK_EMPTY;
555 }
556
557 #ifdef CONFIG_DEBUG_FS
558 /* Count the number of pages available in a pool_type */
ttm_pool_type_count(struct ttm_pool_type * pt)559 static unsigned int ttm_pool_type_count(struct ttm_pool_type *pt)
560 {
561 unsigned int count = 0;
562 struct page *p;
563
564 spin_lock(&pt->lock);
565 /* Only used for debugfs, the overhead doesn't matter */
566 list_for_each_entry(p, &pt->pages, lru)
567 ++count;
568 spin_unlock(&pt->lock);
569
570 return count;
571 }
572
573 /* Print a nice header for the order */
ttm_pool_debugfs_header(struct seq_file * m)574 static void ttm_pool_debugfs_header(struct seq_file *m)
575 {
576 unsigned int i;
577
578 seq_puts(m, "\t ");
579 for (i = 0; i < MAX_ORDER; ++i)
580 seq_printf(m, " ---%2u---", i);
581 seq_puts(m, "\n");
582 }
583
584 /* Dump information about the different pool types */
ttm_pool_debugfs_orders(struct ttm_pool_type * pt,struct seq_file * m)585 static void ttm_pool_debugfs_orders(struct ttm_pool_type *pt,
586 struct seq_file *m)
587 {
588 unsigned int i;
589
590 for (i = 0; i < MAX_ORDER; ++i)
591 seq_printf(m, " %8u", ttm_pool_type_count(&pt[i]));
592 seq_puts(m, "\n");
593 }
594
595 /* Dump the total amount of allocated pages */
ttm_pool_debugfs_footer(struct seq_file * m)596 static void ttm_pool_debugfs_footer(struct seq_file *m)
597 {
598 seq_printf(m, "\ntotal\t: %8lu of %8lu\n",
599 atomic_long_read(&allocated_pages), page_pool_size);
600 }
601
602 /* Dump the information for the global pools */
ttm_pool_debugfs_globals_show(struct seq_file * m,void * data)603 static int ttm_pool_debugfs_globals_show(struct seq_file *m, void *data)
604 {
605 ttm_pool_debugfs_header(m);
606
607 mutex_lock(&shrinker_lock);
608 seq_puts(m, "wc\t:");
609 ttm_pool_debugfs_orders(global_write_combined, m);
610 seq_puts(m, "uc\t:");
611 ttm_pool_debugfs_orders(global_uncached, m);
612 seq_puts(m, "wc 32\t:");
613 ttm_pool_debugfs_orders(global_dma32_write_combined, m);
614 seq_puts(m, "uc 32\t:");
615 ttm_pool_debugfs_orders(global_dma32_uncached, m);
616 mutex_unlock(&shrinker_lock);
617
618 ttm_pool_debugfs_footer(m);
619
620 return 0;
621 }
622 DEFINE_SHOW_ATTRIBUTE(ttm_pool_debugfs_globals);
623
624 /**
625 * ttm_pool_debugfs - Debugfs dump function for a pool
626 *
627 * @pool: the pool to dump the information for
628 * @m: seq_file to dump to
629 *
630 * Make a debugfs dump with the per pool and global information.
631 */
ttm_pool_debugfs(struct ttm_pool * pool,struct seq_file * m)632 int ttm_pool_debugfs(struct ttm_pool *pool, struct seq_file *m)
633 {
634 unsigned int i;
635
636 if (!pool->use_dma_alloc) {
637 seq_puts(m, "unused\n");
638 return 0;
639 }
640
641 ttm_pool_debugfs_header(m);
642
643 mutex_lock(&shrinker_lock);
644 for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
645 seq_puts(m, "DMA ");
646 switch (i) {
647 case ttm_cached:
648 seq_puts(m, "\t:");
649 break;
650 case ttm_write_combined:
651 seq_puts(m, "wc\t:");
652 break;
653 case ttm_uncached:
654 seq_puts(m, "uc\t:");
655 break;
656 }
657 ttm_pool_debugfs_orders(pool->caching[i].orders, m);
658 }
659 mutex_unlock(&shrinker_lock);
660
661 ttm_pool_debugfs_footer(m);
662 return 0;
663 }
664 EXPORT_SYMBOL(ttm_pool_debugfs);
665
666 /* Test the shrinker functions and dump the result */
ttm_pool_debugfs_shrink_show(struct seq_file * m,void * data)667 static int ttm_pool_debugfs_shrink_show(struct seq_file *m, void *data)
668 {
669 struct shrink_control sc = { .gfp_mask = GFP_NOFS };
670
671 fs_reclaim_acquire(GFP_KERNEL);
672 seq_printf(m, "%lu/%lu\n", ttm_pool_shrinker_count(&mm_shrinker, &sc),
673 ttm_pool_shrinker_scan(&mm_shrinker, &sc));
674 fs_reclaim_release(GFP_KERNEL);
675
676 return 0;
677 }
678 DEFINE_SHOW_ATTRIBUTE(ttm_pool_debugfs_shrink);
679
680 #endif
681
682 /**
683 * ttm_pool_mgr_init - Initialize globals
684 *
685 * @num_pages: default number of pages
686 *
687 * Initialize the global locks and lists for the MM shrinker.
688 */
ttm_pool_mgr_init(unsigned long num_pages)689 int ttm_pool_mgr_init(unsigned long num_pages)
690 {
691 unsigned int i;
692
693 if (!page_pool_size)
694 page_pool_size = num_pages;
695
696 mutex_init(&shrinker_lock);
697 INIT_LIST_HEAD(&shrinker_list);
698
699 for (i = 0; i < MAX_ORDER; ++i) {
700 ttm_pool_type_init(&global_write_combined[i], NULL,
701 ttm_write_combined, i);
702 ttm_pool_type_init(&global_uncached[i], NULL, ttm_uncached, i);
703
704 ttm_pool_type_init(&global_dma32_write_combined[i], NULL,
705 ttm_write_combined, i);
706 ttm_pool_type_init(&global_dma32_uncached[i], NULL,
707 ttm_uncached, i);
708 }
709
710 #ifdef CONFIG_DEBUG_FS
711 debugfs_create_file("page_pool", 0444, ttm_debugfs_root, NULL,
712 &ttm_pool_debugfs_globals_fops);
713 debugfs_create_file("page_pool_shrink", 0400, ttm_debugfs_root, NULL,
714 &ttm_pool_debugfs_shrink_fops);
715 #endif
716
717 mm_shrinker.count_objects = ttm_pool_shrinker_count;
718 mm_shrinker.scan_objects = ttm_pool_shrinker_scan;
719 mm_shrinker.seeks = 1;
720 return register_shrinker(&mm_shrinker);
721 }
722
723 /**
724 * ttm_pool_mgr_fini - Finalize globals
725 *
726 * Cleanup the global pools and unregister the MM shrinker.
727 */
ttm_pool_mgr_fini(void)728 void ttm_pool_mgr_fini(void)
729 {
730 unsigned int i;
731
732 for (i = 0; i < MAX_ORDER; ++i) {
733 ttm_pool_type_fini(&global_write_combined[i]);
734 ttm_pool_type_fini(&global_uncached[i]);
735
736 ttm_pool_type_fini(&global_dma32_write_combined[i]);
737 ttm_pool_type_fini(&global_dma32_uncached[i]);
738 }
739
740 unregister_shrinker(&mm_shrinker);
741 WARN_ON(!list_empty(&shrinker_list));
742 }
743