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/debugfs.h>
 37#include <linux/highmem.h>
 38#include <linux/sched/mm.h>
 39
 40#ifdef CONFIG_X86
 41#include <asm/set_memory.h>
 42#endif
 43
 44#include <drm/ttm/ttm_pool.h>
 
 45#include <drm/ttm/ttm_tt.h>
 46#include <drm/ttm/ttm_bo.h>
 47
 48#include "ttm_module.h"
 49
 50/**
 51 * struct ttm_pool_dma - Helper object for coherent DMA mappings
 52 *
 53 * @addr: original DMA address returned for the mapping
 54 * @vaddr: original vaddr return for the mapping and order in the lower bits
 55 */
 56struct ttm_pool_dma {
 57	dma_addr_t addr;
 58	unsigned long vaddr;
 59};
 60
 61static unsigned long page_pool_size;
 62
 63MODULE_PARM_DESC(page_pool_size, "Number of pages in the WC/UC/DMA pool");
 64module_param(page_pool_size, ulong, 0644);
 65
 66static atomic_long_t allocated_pages;
 67
 68static struct ttm_pool_type global_write_combined[NR_PAGE_ORDERS];
 69static struct ttm_pool_type global_uncached[NR_PAGE_ORDERS];
 70
 71static struct ttm_pool_type global_dma32_write_combined[NR_PAGE_ORDERS];
 72static struct ttm_pool_type global_dma32_uncached[NR_PAGE_ORDERS];
 73
 74static spinlock_t shrinker_lock;
 75static struct list_head shrinker_list;
 76static struct shrinker *mm_shrinker;
 77static DECLARE_RWSEM(pool_shrink_rwsem);
 78
 79/* Allocate pages of size 1 << order with the given gfp_flags */
 80static struct page *ttm_pool_alloc_page(struct ttm_pool *pool, gfp_t gfp_flags,
 81					unsigned int order)
 82{
 83	unsigned long attr = DMA_ATTR_FORCE_CONTIGUOUS;
 84	struct ttm_pool_dma *dma;
 85	struct page *p;
 86	void *vaddr;
 87
 88	/* Don't set the __GFP_COMP flag for higher order allocations.
 89	 * Mapping pages directly into an userspace process and calling
 90	 * put_page() on a TTM allocated page is illegal.
 91	 */
 92	if (order)
 93		gfp_flags |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN |
 94			__GFP_THISNODE;
 95
 96	if (!pool->use_dma_alloc) {
 97		p = alloc_pages_node(pool->nid, gfp_flags, order);
 98		if (p)
 99			p->private = order;
100		return p;
101	}
102
103	dma = kmalloc(sizeof(*dma), GFP_KERNEL);
104	if (!dma)
105		return NULL;
106
107	if (order)
108		attr |= DMA_ATTR_NO_WARN;
109
110	vaddr = dma_alloc_attrs(pool->dev, (1ULL << order) * PAGE_SIZE,
111				&dma->addr, gfp_flags, attr);
112	if (!vaddr)
113		goto error_free;
114
115	/* TODO: This is an illegal abuse of the DMA API, but we need to rework
116	 * TTM page fault handling and extend the DMA API to clean this up.
117	 */
118	if (is_vmalloc_addr(vaddr))
119		p = vmalloc_to_page(vaddr);
120	else
121		p = virt_to_page(vaddr);
122
123	dma->vaddr = (unsigned long)vaddr | order;
124	p->private = (unsigned long)dma;
125	return p;
126
127error_free:
128	kfree(dma);
129	return NULL;
130}
131
132/* Reset the caching and pages of size 1 << order */
133static void ttm_pool_free_page(struct ttm_pool *pool, enum ttm_caching caching,
134			       unsigned int order, struct page *p)
135{
136	unsigned long attr = DMA_ATTR_FORCE_CONTIGUOUS;
137	struct ttm_pool_dma *dma;
138	void *vaddr;
139
140#ifdef CONFIG_X86
141	/* We don't care that set_pages_wb is inefficient here. This is only
142	 * used when we have to shrink and CPU overhead is irrelevant then.
143	 */
144	if (caching != ttm_cached && !PageHighMem(p))
145		set_pages_wb(p, 1 << order);
146#endif
147
148	if (!pool || !pool->use_dma_alloc) {
149		__free_pages(p, order);
150		return;
151	}
152
153	if (order)
154		attr |= DMA_ATTR_NO_WARN;
155
156	dma = (void *)p->private;
157	vaddr = (void *)(dma->vaddr & PAGE_MASK);
158	dma_free_attrs(pool->dev, (1UL << order) * PAGE_SIZE, vaddr, dma->addr,
159		       attr);
160	kfree(dma);
161}
162
163/* Apply a new caching to an array of pages */
164static int ttm_pool_apply_caching(struct page **first, struct page **last,
165				  enum ttm_caching caching)
166{
167#ifdef CONFIG_X86
168	unsigned int num_pages = last - first;
169
170	if (!num_pages)
171		return 0;
172
173	switch (caching) {
174	case ttm_cached:
175		break;
176	case ttm_write_combined:
177		return set_pages_array_wc(first, num_pages);
178	case ttm_uncached:
179		return set_pages_array_uc(first, num_pages);
180	}
181#endif
182	return 0;
183}
184
185/* Map pages of 1 << order size and fill the DMA address array  */
186static int ttm_pool_map(struct ttm_pool *pool, unsigned int order,
187			struct page *p, dma_addr_t **dma_addr)
188{
189	dma_addr_t addr;
190	unsigned int i;
191
192	if (pool->use_dma_alloc) {
193		struct ttm_pool_dma *dma = (void *)p->private;
194
195		addr = dma->addr;
196	} else {
197		size_t size = (1ULL << order) * PAGE_SIZE;
198
199		addr = dma_map_page(pool->dev, p, 0, size, DMA_BIDIRECTIONAL);
200		if (dma_mapping_error(pool->dev, addr))
201			return -EFAULT;
202	}
203
204	for (i = 1 << order; i ; --i) {
205		*(*dma_addr)++ = addr;
206		addr += PAGE_SIZE;
207	}
208
209	return 0;
210}
211
212/* Unmap pages of 1 << order size */
213static void ttm_pool_unmap(struct ttm_pool *pool, dma_addr_t dma_addr,
214			   unsigned int num_pages)
215{
216	/* Unmapped while freeing the page */
217	if (pool->use_dma_alloc)
218		return;
219
220	dma_unmap_page(pool->dev, dma_addr, (long)num_pages << PAGE_SHIFT,
221		       DMA_BIDIRECTIONAL);
222}
223
224/* Give pages into a specific pool_type */
225static void ttm_pool_type_give(struct ttm_pool_type *pt, struct page *p)
226{
227	unsigned int i, num_pages = 1 << pt->order;
228
229	for (i = 0; i < num_pages; ++i) {
230		if (PageHighMem(p))
231			clear_highpage(p + i);
232		else
233			clear_page(page_address(p + i));
234	}
235
236	spin_lock(&pt->lock);
237	list_add(&p->lru, &pt->pages);
238	spin_unlock(&pt->lock);
239	atomic_long_add(1 << pt->order, &allocated_pages);
240}
241
242/* Take pages from a specific pool_type, return NULL when nothing available */
243static struct page *ttm_pool_type_take(struct ttm_pool_type *pt)
244{
245	struct page *p;
246
247	spin_lock(&pt->lock);
248	p = list_first_entry_or_null(&pt->pages, typeof(*p), lru);
249	if (p) {
250		atomic_long_sub(1 << pt->order, &allocated_pages);
251		list_del(&p->lru);
252	}
253	spin_unlock(&pt->lock);
254
255	return p;
256}
257
258/* Initialize and add a pool type to the global shrinker list */
259static void ttm_pool_type_init(struct ttm_pool_type *pt, struct ttm_pool *pool,
260			       enum ttm_caching caching, unsigned int order)
261{
262	pt->pool = pool;
263	pt->caching = caching;
264	pt->order = order;
265	spin_lock_init(&pt->lock);
266	INIT_LIST_HEAD(&pt->pages);
267
268	spin_lock(&shrinker_lock);
269	list_add_tail(&pt->shrinker_list, &shrinker_list);
270	spin_unlock(&shrinker_lock);
271}
272
273/* Remove a pool_type from the global shrinker list and free all pages */
274static void ttm_pool_type_fini(struct ttm_pool_type *pt)
275{
276	struct page *p;
277
278	spin_lock(&shrinker_lock);
279	list_del(&pt->shrinker_list);
280	spin_unlock(&shrinker_lock);
281
282	while ((p = ttm_pool_type_take(pt)))
283		ttm_pool_free_page(pt->pool, pt->caching, pt->order, p);
284}
285
286/* Return the pool_type to use for the given caching and order */
287static struct ttm_pool_type *ttm_pool_select_type(struct ttm_pool *pool,
288						  enum ttm_caching caching,
289						  unsigned int order)
290{
291	if (pool->use_dma_alloc)
292		return &pool->caching[caching].orders[order];
293
294#ifdef CONFIG_X86
295	switch (caching) {
296	case ttm_write_combined:
297		if (pool->nid != NUMA_NO_NODE)
298			return &pool->caching[caching].orders[order];
299
300		if (pool->use_dma32)
301			return &global_dma32_write_combined[order];
302
303		return &global_write_combined[order];
304	case ttm_uncached:
305		if (pool->nid != NUMA_NO_NODE)
306			return &pool->caching[caching].orders[order];
307
308		if (pool->use_dma32)
309			return &global_dma32_uncached[order];
310
311		return &global_uncached[order];
312	default:
313		break;
314	}
315#endif
316
317	return NULL;
318}
319
320/* Free pages using the global shrinker list */
321static unsigned int ttm_pool_shrink(void)
322{
323	struct ttm_pool_type *pt;
324	unsigned int num_pages;
325	struct page *p;
326
327	down_read(&pool_shrink_rwsem);
328	spin_lock(&shrinker_lock);
329	pt = list_first_entry(&shrinker_list, typeof(*pt), shrinker_list);
330	list_move_tail(&pt->shrinker_list, &shrinker_list);
331	spin_unlock(&shrinker_lock);
332
333	p = ttm_pool_type_take(pt);
334	if (p) {
335		ttm_pool_free_page(pt->pool, pt->caching, pt->order, p);
336		num_pages = 1 << pt->order;
337	} else {
338		num_pages = 0;
339	}
340	up_read(&pool_shrink_rwsem);
341
342	return num_pages;
343}
344
345/* Return the allocation order based for a page */
346static unsigned int ttm_pool_page_order(struct ttm_pool *pool, struct page *p)
347{
348	if (pool->use_dma_alloc) {
349		struct ttm_pool_dma *dma = (void *)p->private;
350
351		return dma->vaddr & ~PAGE_MASK;
352	}
353
354	return p->private;
355}
356
357/* Called when we got a page, either from a pool or newly allocated */
358static int ttm_pool_page_allocated(struct ttm_pool *pool, unsigned int order,
359				   struct page *p, dma_addr_t **dma_addr,
360				   unsigned long *num_pages,
361				   struct page ***pages)
362{
363	unsigned int i;
364	int r;
365
366	if (*dma_addr) {
367		r = ttm_pool_map(pool, order, p, dma_addr);
368		if (r)
369			return r;
370	}
371
372	*num_pages -= 1 << order;
373	for (i = 1 << order; i; --i, ++(*pages), ++p)
374		**pages = p;
375
376	return 0;
377}
378
379/**
380 * ttm_pool_free_range() - Free a range of TTM pages
381 * @pool: The pool used for allocating.
382 * @tt: The struct ttm_tt holding the page pointers.
383 * @caching: The page caching mode used by the range.
384 * @start_page: index for first page to free.
385 * @end_page: index for last page to free + 1.
386 *
387 * During allocation the ttm_tt page-vector may be populated with ranges of
388 * pages with different attributes if allocation hit an error without being
389 * able to completely fulfill the allocation. This function can be used
390 * to free these individual ranges.
391 */
392static void ttm_pool_free_range(struct ttm_pool *pool, struct ttm_tt *tt,
393				enum ttm_caching caching,
394				pgoff_t start_page, pgoff_t end_page)
395{
396	struct page **pages = &tt->pages[start_page];
397	unsigned int order;
398	pgoff_t i, nr;
399
400	for (i = start_page; i < end_page; i += nr, pages += nr) {
401		struct ttm_pool_type *pt = NULL;
402
403		order = ttm_pool_page_order(pool, *pages);
404		nr = (1UL << order);
405		if (tt->dma_address)
406			ttm_pool_unmap(pool, tt->dma_address[i], nr);
407
408		pt = ttm_pool_select_type(pool, caching, order);
409		if (pt)
410			ttm_pool_type_give(pt, *pages);
411		else
412			ttm_pool_free_page(pool, caching, order, *pages);
413	}
414}
415
416/**
417 * ttm_pool_alloc - Fill a ttm_tt object
418 *
419 * @pool: ttm_pool to use
420 * @tt: ttm_tt object to fill
421 * @ctx: operation context
422 *
423 * Fill the ttm_tt object with pages and also make sure to DMA map them when
424 * necessary.
425 *
426 * Returns: 0 on successe, negative error code otherwise.
427 */
428int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
429		   struct ttm_operation_ctx *ctx)
430{
431	pgoff_t num_pages = tt->num_pages;
432	dma_addr_t *dma_addr = tt->dma_address;
433	struct page **caching = tt->pages;
434	struct page **pages = tt->pages;
435	enum ttm_caching page_caching;
436	gfp_t gfp_flags = GFP_USER;
437	pgoff_t caching_divide;
438	unsigned int order;
439	struct page *p;
440	int r;
441
442	WARN_ON(!num_pages || ttm_tt_is_populated(tt));
443	WARN_ON(dma_addr && !pool->dev);
444
445	if (tt->page_flags & TTM_TT_FLAG_ZERO_ALLOC)
446		gfp_flags |= __GFP_ZERO;
447
448	if (ctx->gfp_retry_mayfail)
449		gfp_flags |= __GFP_RETRY_MAYFAIL;
450
451	if (pool->use_dma32)
452		gfp_flags |= GFP_DMA32;
453	else
454		gfp_flags |= GFP_HIGHUSER;
455
456	for (order = min_t(unsigned int, MAX_PAGE_ORDER, __fls(num_pages));
457	     num_pages;
458	     order = min_t(unsigned int, order, __fls(num_pages))) {
459		struct ttm_pool_type *pt;
460
461		page_caching = tt->caching;
462		pt = ttm_pool_select_type(pool, tt->caching, order);
463		p = pt ? ttm_pool_type_take(pt) : NULL;
464		if (p) {
465			r = ttm_pool_apply_caching(caching, pages,
466						   tt->caching);
467			if (r)
468				goto error_free_page;
469
470			caching = pages;
471			do {
472				r = ttm_pool_page_allocated(pool, order, p,
473							    &dma_addr,
474							    &num_pages,
475							    &pages);
476				if (r)
477					goto error_free_page;
478
479				caching = pages;
480				if (num_pages < (1 << order))
481					break;
482
483				p = ttm_pool_type_take(pt);
484			} while (p);
 
485		}
486
487		page_caching = ttm_cached;
488		while (num_pages >= (1 << order) &&
489		       (p = ttm_pool_alloc_page(pool, gfp_flags, order))) {
490
491			if (PageHighMem(p)) {
492				r = ttm_pool_apply_caching(caching, pages,
493							   tt->caching);
494				if (r)
495					goto error_free_page;
496				caching = pages;
497			}
498			r = ttm_pool_page_allocated(pool, order, p, &dma_addr,
499						    &num_pages, &pages);
500			if (r)
501				goto error_free_page;
502			if (PageHighMem(p))
503				caching = pages;
504		}
505
506		if (!p) {
507			if (order) {
508				--order;
509				continue;
510			}
511			r = -ENOMEM;
512			goto error_free_all;
513		}
514	}
515
516	r = ttm_pool_apply_caching(caching, pages, tt->caching);
517	if (r)
518		goto error_free_all;
519
520	return 0;
521
522error_free_page:
523	ttm_pool_free_page(pool, page_caching, order, p);
524
525error_free_all:
526	num_pages = tt->num_pages - num_pages;
527	caching_divide = caching - tt->pages;
528	ttm_pool_free_range(pool, tt, tt->caching, 0, caching_divide);
529	ttm_pool_free_range(pool, tt, ttm_cached, caching_divide, num_pages);
 
 
530
531	return r;
532}
533EXPORT_SYMBOL(ttm_pool_alloc);
534
535/**
536 * ttm_pool_free - Free the backing pages from a ttm_tt object
537 *
538 * @pool: Pool to give pages back to.
539 * @tt: ttm_tt object to unpopulate
540 *
541 * Give the packing pages back to a pool or free them
542 */
543void ttm_pool_free(struct ttm_pool *pool, struct ttm_tt *tt)
544{
545	ttm_pool_free_range(pool, tt, tt->caching, 0, tt->num_pages);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
546
547	while (atomic_long_read(&allocated_pages) > page_pool_size)
548		ttm_pool_shrink();
549}
550EXPORT_SYMBOL(ttm_pool_free);
551
552/**
553 * ttm_pool_init - Initialize a pool
554 *
555 * @pool: the pool to initialize
556 * @dev: device for DMA allocations and mappings
557 * @nid: NUMA node to use for allocations
558 * @use_dma_alloc: true if coherent DMA alloc should be used
559 * @use_dma32: true if GFP_DMA32 should be used
560 *
561 * Initialize the pool and its pool types.
562 */
563void ttm_pool_init(struct ttm_pool *pool, struct device *dev,
564		   int nid, bool use_dma_alloc, bool use_dma32)
565{
566	unsigned int i, j;
567
568	WARN_ON(!dev && use_dma_alloc);
569
570	pool->dev = dev;
571	pool->nid = nid;
572	pool->use_dma_alloc = use_dma_alloc;
573	pool->use_dma32 = use_dma32;
574
575	for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
576		for (j = 0; j < NR_PAGE_ORDERS; ++j) {
577			struct ttm_pool_type *pt;
578
579			/* Initialize only pool types which are actually used */
580			pt = ttm_pool_select_type(pool, i, j);
581			if (pt != &pool->caching[i].orders[j])
582				continue;
583
584			ttm_pool_type_init(pt, pool, i, j);
585		}
586	}
587}
588EXPORT_SYMBOL(ttm_pool_init);
589
590/**
591 * ttm_pool_synchronize_shrinkers - Wait for all running shrinkers to complete.
592 *
593 * This is useful to guarantee that all shrinker invocations have seen an
594 * update, before freeing memory, similar to rcu.
595 */
596static void ttm_pool_synchronize_shrinkers(void)
597{
598	down_write(&pool_shrink_rwsem);
599	up_write(&pool_shrink_rwsem);
600}
601
602/**
603 * ttm_pool_fini - Cleanup a pool
604 *
605 * @pool: the pool to clean up
606 *
607 * Free all pages in the pool and unregister the types from the global
608 * shrinker.
609 */
610void ttm_pool_fini(struct ttm_pool *pool)
611{
612	unsigned int i, j;
613
614	for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
615		for (j = 0; j < NR_PAGE_ORDERS; ++j) {
616			struct ttm_pool_type *pt;
617
618			pt = ttm_pool_select_type(pool, i, j);
619			if (pt != &pool->caching[i].orders[j])
620				continue;
621
622			ttm_pool_type_fini(pt);
623		}
624	}
625
626	/* We removed the pool types from the LRU, but we need to also make sure
627	 * that no shrinker is concurrently freeing pages from the pool.
628	 */
629	ttm_pool_synchronize_shrinkers();
630}
631EXPORT_SYMBOL(ttm_pool_fini);
632
633/* As long as pages are available make sure to release at least one */
634static unsigned long ttm_pool_shrinker_scan(struct shrinker *shrink,
635					    struct shrink_control *sc)
636{
637	unsigned long num_freed = 0;
638
639	do
640		num_freed += ttm_pool_shrink();
641	while (!num_freed && atomic_long_read(&allocated_pages));
642
643	return num_freed;
644}
645
646/* Return the number of pages available or SHRINK_EMPTY if we have none */
647static unsigned long ttm_pool_shrinker_count(struct shrinker *shrink,
648					     struct shrink_control *sc)
649{
650	unsigned long num_pages = atomic_long_read(&allocated_pages);
651
652	return num_pages ? num_pages : SHRINK_EMPTY;
653}
654
655#ifdef CONFIG_DEBUG_FS
656/* Count the number of pages available in a pool_type */
657static unsigned int ttm_pool_type_count(struct ttm_pool_type *pt)
658{
659	unsigned int count = 0;
660	struct page *p;
661
662	spin_lock(&pt->lock);
663	/* Only used for debugfs, the overhead doesn't matter */
664	list_for_each_entry(p, &pt->pages, lru)
665		++count;
666	spin_unlock(&pt->lock);
667
668	return count;
669}
670
671/* Print a nice header for the order */
672static void ttm_pool_debugfs_header(struct seq_file *m)
673{
674	unsigned int i;
675
676	seq_puts(m, "\t ");
677	for (i = 0; i < NR_PAGE_ORDERS; ++i)
678		seq_printf(m, " ---%2u---", i);
679	seq_puts(m, "\n");
680}
681
682/* Dump information about the different pool types */
683static void ttm_pool_debugfs_orders(struct ttm_pool_type *pt,
684				    struct seq_file *m)
685{
686	unsigned int i;
687
688	for (i = 0; i < NR_PAGE_ORDERS; ++i)
689		seq_printf(m, " %8u", ttm_pool_type_count(&pt[i]));
690	seq_puts(m, "\n");
691}
692
693/* Dump the total amount of allocated pages */
694static void ttm_pool_debugfs_footer(struct seq_file *m)
695{
696	seq_printf(m, "\ntotal\t: %8lu of %8lu\n",
697		   atomic_long_read(&allocated_pages), page_pool_size);
698}
699
700/* Dump the information for the global pools */
701static int ttm_pool_debugfs_globals_show(struct seq_file *m, void *data)
702{
703	ttm_pool_debugfs_header(m);
704
705	spin_lock(&shrinker_lock);
706	seq_puts(m, "wc\t:");
707	ttm_pool_debugfs_orders(global_write_combined, m);
708	seq_puts(m, "uc\t:");
709	ttm_pool_debugfs_orders(global_uncached, m);
710	seq_puts(m, "wc 32\t:");
711	ttm_pool_debugfs_orders(global_dma32_write_combined, m);
712	seq_puts(m, "uc 32\t:");
713	ttm_pool_debugfs_orders(global_dma32_uncached, m);
714	spin_unlock(&shrinker_lock);
715
716	ttm_pool_debugfs_footer(m);
717
718	return 0;
719}
720DEFINE_SHOW_ATTRIBUTE(ttm_pool_debugfs_globals);
721
722/**
723 * ttm_pool_debugfs - Debugfs dump function for a pool
724 *
725 * @pool: the pool to dump the information for
726 * @m: seq_file to dump to
727 *
728 * Make a debugfs dump with the per pool and global information.
729 */
730int ttm_pool_debugfs(struct ttm_pool *pool, struct seq_file *m)
731{
732	unsigned int i;
733
734	if (!pool->use_dma_alloc) {
735		seq_puts(m, "unused\n");
736		return 0;
737	}
738
739	ttm_pool_debugfs_header(m);
740
741	spin_lock(&shrinker_lock);
742	for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
743		seq_puts(m, "DMA ");
744		switch (i) {
745		case ttm_cached:
746			seq_puts(m, "\t:");
747			break;
748		case ttm_write_combined:
749			seq_puts(m, "wc\t:");
750			break;
751		case ttm_uncached:
752			seq_puts(m, "uc\t:");
753			break;
754		}
755		ttm_pool_debugfs_orders(pool->caching[i].orders, m);
756	}
757	spin_unlock(&shrinker_lock);
758
759	ttm_pool_debugfs_footer(m);
760	return 0;
761}
762EXPORT_SYMBOL(ttm_pool_debugfs);
763
764/* Test the shrinker functions and dump the result */
765static int ttm_pool_debugfs_shrink_show(struct seq_file *m, void *data)
766{
767	struct shrink_control sc = { .gfp_mask = GFP_NOFS };
768
769	fs_reclaim_acquire(GFP_KERNEL);
770	seq_printf(m, "%lu/%lu\n", ttm_pool_shrinker_count(mm_shrinker, &sc),
771		   ttm_pool_shrinker_scan(mm_shrinker, &sc));
772	fs_reclaim_release(GFP_KERNEL);
773
774	return 0;
775}
776DEFINE_SHOW_ATTRIBUTE(ttm_pool_debugfs_shrink);
777
778#endif
779
780/**
781 * ttm_pool_mgr_init - Initialize globals
782 *
783 * @num_pages: default number of pages
784 *
785 * Initialize the global locks and lists for the MM shrinker.
786 */
787int ttm_pool_mgr_init(unsigned long num_pages)
788{
789	unsigned int i;
790
791	if (!page_pool_size)
792		page_pool_size = num_pages;
793
794	spin_lock_init(&shrinker_lock);
795	INIT_LIST_HEAD(&shrinker_list);
796
797	for (i = 0; i < NR_PAGE_ORDERS; ++i) {
798		ttm_pool_type_init(&global_write_combined[i], NULL,
799				   ttm_write_combined, i);
800		ttm_pool_type_init(&global_uncached[i], NULL, ttm_uncached, i);
801
802		ttm_pool_type_init(&global_dma32_write_combined[i], NULL,
803				   ttm_write_combined, i);
804		ttm_pool_type_init(&global_dma32_uncached[i], NULL,
805				   ttm_uncached, i);
806	}
807
808#ifdef CONFIG_DEBUG_FS
809	debugfs_create_file("page_pool", 0444, ttm_debugfs_root, NULL,
810			    &ttm_pool_debugfs_globals_fops);
811	debugfs_create_file("page_pool_shrink", 0400, ttm_debugfs_root, NULL,
812			    &ttm_pool_debugfs_shrink_fops);
813#endif
814
815	mm_shrinker = shrinker_alloc(0, "drm-ttm_pool");
816	if (!mm_shrinker)
817		return -ENOMEM;
818
819	mm_shrinker->count_objects = ttm_pool_shrinker_count;
820	mm_shrinker->scan_objects = ttm_pool_shrinker_scan;
821	mm_shrinker->seeks = 1;
822
823	shrinker_register(mm_shrinker);
824
825	return 0;
826}
827
828/**
829 * ttm_pool_mgr_fini - Finalize globals
830 *
831 * Cleanup the global pools and unregister the MM shrinker.
832 */
833void ttm_pool_mgr_fini(void)
834{
835	unsigned int i;
836
837	for (i = 0; i < NR_PAGE_ORDERS; ++i) {
838		ttm_pool_type_fini(&global_write_combined[i]);
839		ttm_pool_type_fini(&global_uncached[i]);
840
841		ttm_pool_type_fini(&global_dma32_write_combined[i]);
842		ttm_pool_type_fini(&global_dma32_uncached[i]);
843	}
844
845	shrinker_free(mm_shrinker);
846	WARN_ON(!list_empty(&shrinker_list));
847}