2 * Copyright 2011 (c) Oracle Corp.
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5 * copy of this software and associated documentation files (the "Software"),
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15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
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21 * DEALINGS IN THE SOFTWARE.
23 * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
27 * A simple DMA pool losely based on dmapool.c. It has certain advantages
29 * - Pool collects resently freed pages for reuse (and hooks up to
31 * - Tracks currently in use pages
32 * - Tracks whether the page is UC, WB or cached (and reverts to WB
36 #include <linux/dma-mapping.h>
37 #include <linux/list.h>
38 #include <linux/seq_file.h> /* for seq_printf */
39 #include <linux/slab.h>
40 #include <linux/spinlock.h>
41 #include <linux/highmem.h>
42 #include <linux/mm_types.h>
43 #include <linux/module.h>
45 #include <linux/atomic.h>
46 #include <linux/device.h>
47 #include <linux/kthread.h>
48 #include "ttm/ttm_bo_driver.h"
49 #include "ttm/ttm_page_alloc.h"
54 #define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *))
55 #define SMALL_ALLOCATION 4
56 #define FREE_ALL_PAGES (~0U)
57 /* times are in msecs */
58 #define IS_UNDEFINED (0)
61 #define IS_CACHED (1<<3)
62 #define IS_DMA32 (1<<4)
68 POOL_IS_CACHED = IS_CACHED,
69 POOL_IS_WC_DMA32 = IS_WC | IS_DMA32,
70 POOL_IS_UC_DMA32 = IS_UC | IS_DMA32,
71 POOL_IS_CACHED_DMA32 = IS_CACHED | IS_DMA32,
74 * The pool structure. There are usually six pools:
75 * - generic (not restricted to DMA32):
76 * - write combined, uncached, cached.
77 * - dma32 (up to 2^32 - so up 4GB):
78 * - write combined, uncached, cached.
79 * for each 'struct device'. The 'cached' is for pages that are actively used.
80 * The other ones can be shrunk by the shrinker API if neccessary.
81 * @pools: The 'struct device->dma_pools' link.
82 * @type: Type of the pool
83 * @lock: Protects the inuse_list and free_list from concurrnet access. Must be
84 * used with irqsave/irqrestore variants because pool allocator maybe called
86 * @inuse_list: Pool of pages that are in use. The order is very important and
87 * it is in the order that the TTM pages that are put back are in.
88 * @free_list: Pool of pages that are free to be used. No order requirements.
89 * @dev: The device that is associated with these pools.
90 * @size: Size used during DMA allocation.
91 * @npages_free: Count of available pages for re-use.
92 * @npages_in_use: Count of pages that are in use.
93 * @nfrees: Stats when pool is shrinking.
94 * @nrefills: Stats when the pool is grown.
95 * @gfp_flags: Flags to pass for alloc_page.
96 * @name: Name of the pool.
97 * @dev_name: Name derieved from dev - similar to how dev_info works.
98 * Used during shutdown as the dev_info during release is unavailable.
101 struct list_head pools; /* The 'struct device->dma_pools link */
104 struct list_head inuse_list;
105 struct list_head free_list;
108 unsigned npages_free;
109 unsigned npages_in_use;
110 unsigned long nfrees; /* Stats when shrunk. */
111 unsigned long nrefills; /* Stats when grown. */
113 char name[13]; /* "cached dma32" */
114 char dev_name[64]; /* Constructed from dev */
118 * The accounting page keeping track of the allocated page along with
120 * @page_list: The link to the 'page_list' in 'struct dma_pool'.
121 * @vaddr: The virtual address of the page
122 * @dma: The bus address of the page. If the page is not allocated
123 * via the DMA API, it will be -1.
126 struct list_head page_list;
133 * Limits for the pool. They are handled without locks because only place where
134 * they may change is in sysfs store. They won't have immediate effect anyway
135 * so forcing serialization to access them is pointless.
138 struct ttm_pool_opts {
145 * Contains the list of all of the 'struct device' and their corresponding
146 * DMA pools. Guarded by _mutex->lock.
147 * @pools: The link to 'struct ttm_pool_manager->pools'
148 * @dev: The 'struct device' associated with the 'pool'
149 * @pool: The 'struct dma_pool' associated with the 'dev'
151 struct device_pools {
152 struct list_head pools;
154 struct dma_pool *pool;
158 * struct ttm_pool_manager - Holds memory pools for fast allocation
160 * @lock: Lock used when adding/removing from pools
161 * @pools: List of 'struct device' and 'struct dma_pool' tuples.
162 * @options: Limits for the pool.
163 * @npools: Total amount of pools in existence.
164 * @shrinker: The structure used by [un|]register_shrinker
166 struct ttm_pool_manager {
168 struct list_head pools;
169 struct ttm_pool_opts options;
171 struct shrinker mm_shrink;
175 static struct ttm_pool_manager *_manager;
177 static struct attribute ttm_page_pool_max = {
178 .name = "pool_max_size",
179 .mode = S_IRUGO | S_IWUSR
181 static struct attribute ttm_page_pool_small = {
182 .name = "pool_small_allocation",
183 .mode = S_IRUGO | S_IWUSR
185 static struct attribute ttm_page_pool_alloc_size = {
186 .name = "pool_allocation_size",
187 .mode = S_IRUGO | S_IWUSR
190 static struct attribute *ttm_pool_attrs[] = {
192 &ttm_page_pool_small,
193 &ttm_page_pool_alloc_size,
197 static void ttm_pool_kobj_release(struct kobject *kobj)
199 struct ttm_pool_manager *m =
200 container_of(kobj, struct ttm_pool_manager, kobj);
204 static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr,
205 const char *buffer, size_t size)
207 struct ttm_pool_manager *m =
208 container_of(kobj, struct ttm_pool_manager, kobj);
211 chars = sscanf(buffer, "%u", &val);
215 /* Convert kb to number of pages */
216 val = val / (PAGE_SIZE >> 10);
218 if (attr == &ttm_page_pool_max)
219 m->options.max_size = val;
220 else if (attr == &ttm_page_pool_small)
221 m->options.small = val;
222 else if (attr == &ttm_page_pool_alloc_size) {
223 if (val > NUM_PAGES_TO_ALLOC*8) {
224 printk(KERN_ERR TTM_PFX
225 "Setting allocation size to %lu "
226 "is not allowed. Recommended size is "
228 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
229 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
231 } else if (val > NUM_PAGES_TO_ALLOC) {
232 printk(KERN_WARNING TTM_PFX
233 "Setting allocation size to "
234 "larger than %lu is not recommended.\n",
235 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
237 m->options.alloc_size = val;
243 static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr,
246 struct ttm_pool_manager *m =
247 container_of(kobj, struct ttm_pool_manager, kobj);
250 if (attr == &ttm_page_pool_max)
251 val = m->options.max_size;
252 else if (attr == &ttm_page_pool_small)
253 val = m->options.small;
254 else if (attr == &ttm_page_pool_alloc_size)
255 val = m->options.alloc_size;
257 val = val * (PAGE_SIZE >> 10);
259 return snprintf(buffer, PAGE_SIZE, "%u\n", val);
262 static const struct sysfs_ops ttm_pool_sysfs_ops = {
263 .show = &ttm_pool_show,
264 .store = &ttm_pool_store,
267 static struct kobj_type ttm_pool_kobj_type = {
268 .release = &ttm_pool_kobj_release,
269 .sysfs_ops = &ttm_pool_sysfs_ops,
270 .default_attrs = ttm_pool_attrs,
274 static int set_pages_array_wb(struct page **pages, int addrinarray)
279 for (i = 0; i < addrinarray; i++)
280 unmap_page_from_agp(pages[i]);
285 static int set_pages_array_wc(struct page **pages, int addrinarray)
290 for (i = 0; i < addrinarray; i++)
291 map_page_into_agp(pages[i]);
296 static int set_pages_array_uc(struct page **pages, int addrinarray)
301 for (i = 0; i < addrinarray; i++)
302 map_page_into_agp(pages[i]);
306 #endif /* for !CONFIG_X86 */
308 static int ttm_set_pages_caching(struct dma_pool *pool,
309 struct page **pages, unsigned cpages)
312 /* Set page caching */
313 if (pool->type & IS_UC) {
314 r = set_pages_array_uc(pages, cpages);
317 "%s: Failed to set %d pages to uc!\n",
318 pool->dev_name, cpages);
320 if (pool->type & IS_WC) {
321 r = set_pages_array_wc(pages, cpages);
324 "%s: Failed to set %d pages to wc!\n",
325 pool->dev_name, cpages);
330 static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page)
332 dma_addr_t dma = d_page->dma;
333 dma_free_coherent(pool->dev, pool->size, d_page->vaddr, dma);
338 static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
340 struct dma_page *d_page;
342 d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
346 d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size,
350 d_page->p = virt_to_page(d_page->vaddr);
357 static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate)
359 enum pool_type type = IS_UNDEFINED;
361 if (flags & TTM_PAGE_FLAG_DMA32)
363 if (cstate == tt_cached)
365 else if (cstate == tt_uncached)
373 static void ttm_pool_update_free_locked(struct dma_pool *pool,
374 unsigned freed_pages)
376 pool->npages_free -= freed_pages;
377 pool->nfrees += freed_pages;
381 /* set memory back to wb and free the pages. */
382 static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages,
383 struct page *pages[], unsigned npages)
385 struct dma_page *d_page, *tmp;
387 /* Don't set WB on WB page pool. */
388 if (npages && !(pool->type & IS_CACHED) &&
389 set_pages_array_wb(pages, npages))
390 pr_err(TTM_PFX "%s: Failed to set %d pages to wb!\n",
391 pool->dev_name, npages);
393 list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
394 list_del(&d_page->page_list);
395 __ttm_dma_free_page(pool, d_page);
399 static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
401 /* Don't set WB on WB page pool. */
402 if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1))
403 pr_err(TTM_PFX "%s: Failed to set %d pages to wb!\n",
406 list_del(&d_page->page_list);
407 __ttm_dma_free_page(pool, d_page);
411 * Free pages from pool.
413 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
414 * number of pages in one go.
416 * @pool: to free the pages from
417 * @nr_free: If set to true will free all pages in pool
419 static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free)
421 unsigned long irq_flags;
422 struct dma_page *dma_p, *tmp;
423 struct page **pages_to_free;
424 struct list_head d_pages;
425 unsigned freed_pages = 0,
426 npages_to_free = nr_free;
428 if (NUM_PAGES_TO_ALLOC < nr_free)
429 npages_to_free = NUM_PAGES_TO_ALLOC;
432 pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n",
433 pool->dev_name, pool->name, current->pid,
434 npages_to_free, nr_free);
437 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
440 if (!pages_to_free) {
442 "%s: Failed to allocate memory for pool free operation.\n",
446 INIT_LIST_HEAD(&d_pages);
448 spin_lock_irqsave(&pool->lock, irq_flags);
450 /* We picking the oldest ones off the list */
451 list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list,
453 if (freed_pages >= npages_to_free)
456 /* Move the dma_page from one list to another. */
457 list_move(&dma_p->page_list, &d_pages);
459 pages_to_free[freed_pages++] = dma_p->p;
460 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
461 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
463 ttm_pool_update_free_locked(pool, freed_pages);
465 * Because changing page caching is costly
466 * we unlock the pool to prevent stalling.
468 spin_unlock_irqrestore(&pool->lock, irq_flags);
470 ttm_dma_pages_put(pool, &d_pages, pages_to_free,
473 INIT_LIST_HEAD(&d_pages);
475 if (likely(nr_free != FREE_ALL_PAGES))
476 nr_free -= freed_pages;
478 if (NUM_PAGES_TO_ALLOC >= nr_free)
479 npages_to_free = nr_free;
481 npages_to_free = NUM_PAGES_TO_ALLOC;
485 /* free all so restart the processing */
489 /* Not allowed to fall through or break because
490 * following context is inside spinlock while we are
498 /* remove range of pages from the pool */
500 ttm_pool_update_free_locked(pool, freed_pages);
501 nr_free -= freed_pages;
504 spin_unlock_irqrestore(&pool->lock, irq_flags);
507 ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages);
509 kfree(pages_to_free);
513 static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
515 struct device_pools *p;
516 struct dma_pool *pool;
521 mutex_lock(&_manager->lock);
522 list_for_each_entry_reverse(p, &_manager->pools, pools) {
526 if (pool->type != type)
534 list_for_each_entry_reverse(pool, &dev->dma_pools, pools) {
535 if (pool->type != type)
537 /* Takes a spinlock.. */
538 ttm_dma_page_pool_free(pool, FREE_ALL_PAGES);
539 WARN_ON(((pool->npages_in_use + pool->npages_free) != 0));
540 /* This code path is called after _all_ references to the
541 * struct device has been dropped - so nobody should be
542 * touching it. In case somebody is trying to _add_ we are
543 * guarded by the mutex. */
544 list_del(&pool->pools);
548 mutex_unlock(&_manager->lock);
552 * On free-ing of the 'struct device' this deconstructor is run.
553 * Albeit the pool might have already been freed earlier.
555 static void ttm_dma_pool_release(struct device *dev, void *res)
557 struct dma_pool *pool = *(struct dma_pool **)res;
560 ttm_dma_free_pool(dev, pool->type);
563 static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data)
565 return *(struct dma_pool **)res == match_data;
568 static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
571 char *n[] = {"wc", "uc", "cached", " dma32", "unknown",};
572 enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_UNDEFINED};
573 struct device_pools *sec_pool = NULL;
574 struct dma_pool *pool = NULL, **ptr;
582 ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL);
588 pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL,
593 sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL,
598 INIT_LIST_HEAD(&sec_pool->pools);
600 sec_pool->pool = pool;
602 INIT_LIST_HEAD(&pool->free_list);
603 INIT_LIST_HEAD(&pool->inuse_list);
604 INIT_LIST_HEAD(&pool->pools);
605 spin_lock_init(&pool->lock);
607 pool->npages_free = pool->npages_in_use = 0;
609 pool->gfp_flags = flags;
610 pool->size = PAGE_SIZE;
614 for (i = 0; i < 5; i++) {
616 p += snprintf(p, sizeof(pool->name) - (p - pool->name),
621 /* We copy the name for pr_ calls b/c when dma_pool_destroy is called
622 * - the kobj->name has already been deallocated.*/
623 snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s",
624 dev_driver_string(dev), dev_name(dev));
625 mutex_lock(&_manager->lock);
626 /* You can get the dma_pool from either the global: */
627 list_add(&sec_pool->pools, &_manager->pools);
629 /* or from 'struct device': */
630 list_add(&pool->pools, &dev->dma_pools);
631 mutex_unlock(&_manager->lock);
634 devres_add(dev, ptr);
644 static struct dma_pool *ttm_dma_find_pool(struct device *dev,
647 struct dma_pool *pool, *tmp, *found = NULL;
649 if (type == IS_UNDEFINED)
652 /* NB: We iterate on the 'struct dev' which has no spinlock, but
653 * it does have a kref which we have taken. The kref is taken during
654 * graphic driver loading - in the drm_pci_init it calls either
655 * pci_dev_get or pci_register_driver which both end up taking a kref
656 * on 'struct device'.
658 * On teardown, the graphic drivers end up quiescing the TTM (put_pages)
659 * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice
660 * thing is at that point of time there are no pages associated with the
661 * driver so this function will not be called.
663 list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) {
664 if (pool->type != type)
673 * Free pages the pages that failed to change the caching state. If there
674 * are pages that have changed their caching state already put them to the
677 static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool,
678 struct list_head *d_pages,
679 struct page **failed_pages,
682 struct dma_page *d_page, *tmp;
689 /* Find the failed page. */
690 list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
693 /* .. and then progress over the full list. */
694 list_del(&d_page->page_list);
695 __ttm_dma_free_page(pool, d_page);
705 * Allocate 'count' pages, and put 'need' number of them on the
706 * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset.
707 * The full list of pages should also be on 'd_pages'.
708 * We return zero for success, and negative numbers as errors.
710 static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
711 struct list_head *d_pages,
714 struct page **caching_array;
715 struct dma_page *dma_p;
719 unsigned max_cpages = min(count,
720 (unsigned)(PAGE_SIZE/sizeof(struct page *)));
722 /* allocate array for page caching change */
723 caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
725 if (!caching_array) {
727 "%s: Unable to allocate table for new pages.",
733 pr_debug("%s: (%s:%d) Getting %d pages\n",
734 pool->dev_name, pool->name, current->pid,
738 for (i = 0, cpages = 0; i < count; ++i) {
739 dma_p = __ttm_dma_alloc_page(pool);
741 pr_err(TTM_PFX "%s: Unable to get page %u.\n",
744 /* store already allocated pages in the pool after
745 * setting the caching state */
747 r = ttm_set_pages_caching(pool, caching_array,
750 ttm_dma_handle_caching_state_failure(
751 pool, d_pages, caching_array,
758 #ifdef CONFIG_HIGHMEM
759 /* gfp flags of highmem page should never be dma32 so we
760 * we should be fine in such case
765 caching_array[cpages++] = p;
766 if (cpages == max_cpages) {
767 /* Note: Cannot hold the spinlock */
768 r = ttm_set_pages_caching(pool, caching_array,
771 ttm_dma_handle_caching_state_failure(
772 pool, d_pages, caching_array,
779 list_add(&dma_p->page_list, d_pages);
783 r = ttm_set_pages_caching(pool, caching_array, cpages);
785 ttm_dma_handle_caching_state_failure(pool, d_pages,
786 caching_array, cpages);
789 kfree(caching_array);
794 * @return count of pages still required to fulfill the request.
796 static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool,
797 unsigned long *irq_flags)
799 unsigned count = _manager->options.small;
800 int r = pool->npages_free;
802 if (count > pool->npages_free) {
803 struct list_head d_pages;
805 INIT_LIST_HEAD(&d_pages);
807 spin_unlock_irqrestore(&pool->lock, *irq_flags);
809 /* Returns how many more are neccessary to fulfill the
811 r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count);
813 spin_lock_irqsave(&pool->lock, *irq_flags);
815 /* Add the fresh to the end.. */
816 list_splice(&d_pages, &pool->free_list);
818 pool->npages_free += count;
821 struct dma_page *d_page;
824 pr_err(TTM_PFX "%s: Failed to fill %s pool (r:%d)!\n",
825 pool->dev_name, pool->name, r);
827 list_for_each_entry(d_page, &d_pages, page_list) {
830 list_splice_tail(&d_pages, &pool->free_list);
831 pool->npages_free += cpages;
839 * @return count of pages still required to fulfill the request.
840 * The populate list is actually a stack (not that is matters as TTM
841 * allocates one page at a time.
843 static int ttm_dma_pool_get_pages(struct dma_pool *pool,
844 struct ttm_dma_tt *ttm_dma,
847 struct dma_page *d_page;
848 struct ttm_tt *ttm = &ttm_dma->ttm;
849 unsigned long irq_flags;
850 int count, r = -ENOMEM;
852 spin_lock_irqsave(&pool->lock, irq_flags);
853 count = ttm_dma_page_pool_fill_locked(pool, &irq_flags);
855 d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
856 ttm->pages[index] = d_page->p;
857 ttm_dma->dma_address[index] = d_page->dma;
858 list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
860 pool->npages_in_use += 1;
861 pool->npages_free -= 1;
863 spin_unlock_irqrestore(&pool->lock, irq_flags);
868 * On success pages list will hold count number of correctly
869 * cached pages. On failure will hold the negative return value (-ENOMEM, etc).
871 int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
873 struct ttm_tt *ttm = &ttm_dma->ttm;
874 struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
875 struct dma_pool *pool;
881 if (ttm->state != tt_unpopulated)
884 type = ttm_to_type(ttm->page_flags, ttm->caching_state);
885 if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
886 gfp_flags = GFP_USER | GFP_DMA32;
888 gfp_flags = GFP_HIGHUSER;
889 if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
890 gfp_flags |= __GFP_ZERO;
892 pool = ttm_dma_find_pool(dev, type);
894 pool = ttm_dma_pool_init(dev, gfp_flags, type);
895 if (IS_ERR_OR_NULL(pool)) {
900 INIT_LIST_HEAD(&ttm_dma->pages_list);
901 for (i = 0; i < ttm->num_pages; ++i) {
902 ret = ttm_dma_pool_get_pages(pool, ttm_dma, i);
904 ttm_dma_unpopulate(ttm_dma, dev);
908 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
910 if (unlikely(ret != 0)) {
911 ttm_dma_unpopulate(ttm_dma, dev);
916 if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
917 ret = ttm_tt_swapin(ttm);
918 if (unlikely(ret != 0)) {
919 ttm_dma_unpopulate(ttm_dma, dev);
924 ttm->state = tt_unbound;
927 EXPORT_SYMBOL_GPL(ttm_dma_populate);
929 /* Get good estimation how many pages are free in pools */
930 static int ttm_dma_pool_get_num_unused_pages(void)
932 struct device_pools *p;
935 mutex_lock(&_manager->lock);
936 list_for_each_entry(p, &_manager->pools, pools)
937 total += p->pool->npages_free;
938 mutex_unlock(&_manager->lock);
942 /* Put all pages in pages list to correct pool to wait for reuse */
943 void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
945 struct ttm_tt *ttm = &ttm_dma->ttm;
946 struct dma_pool *pool;
947 struct dma_page *d_page, *next;
949 bool is_cached = false;
950 unsigned count = 0, i, npages = 0;
951 unsigned long irq_flags;
953 type = ttm_to_type(ttm->page_flags, ttm->caching_state);
954 pool = ttm_dma_find_pool(dev, type);
958 is_cached = (ttm_dma_find_pool(pool->dev,
959 ttm_to_type(ttm->page_flags, tt_cached)) == pool);
961 /* make sure pages array match list and count number of pages */
962 list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) {
963 ttm->pages[count] = d_page->p;
967 spin_lock_irqsave(&pool->lock, irq_flags);
968 pool->npages_in_use -= count;
970 pool->nfrees += count;
972 pool->npages_free += count;
973 list_splice(&ttm_dma->pages_list, &pool->free_list);
975 if (pool->npages_free > _manager->options.max_size) {
976 npages = pool->npages_free - _manager->options.max_size;
977 /* free at least NUM_PAGES_TO_ALLOC number of pages
978 * to reduce calls to set_memory_wb */
979 if (npages < NUM_PAGES_TO_ALLOC)
980 npages = NUM_PAGES_TO_ALLOC;
983 spin_unlock_irqrestore(&pool->lock, irq_flags);
986 list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list, page_list) {
987 ttm_mem_global_free_page(ttm->glob->mem_glob,
989 ttm_dma_page_put(pool, d_page);
992 for (i = 0; i < count; i++) {
993 ttm_mem_global_free_page(ttm->glob->mem_glob,
998 INIT_LIST_HEAD(&ttm_dma->pages_list);
999 for (i = 0; i < ttm->num_pages; i++) {
1000 ttm->pages[i] = NULL;
1001 ttm_dma->dma_address[i] = 0;
1004 /* shrink pool if necessary (only on !is_cached pools)*/
1006 ttm_dma_page_pool_free(pool, npages);
1007 ttm->state = tt_unpopulated;
1009 EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
1012 * Callback for mm to request pool to reduce number of page held.
1014 static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
1015 struct shrink_control *sc)
1017 static atomic_t start_pool = ATOMIC_INIT(0);
1019 unsigned pool_offset = atomic_add_return(1, &start_pool);
1020 unsigned shrink_pages = sc->nr_to_scan;
1021 struct device_pools *p;
1023 if (list_empty(&_manager->pools))
1026 mutex_lock(&_manager->lock);
1027 pool_offset = pool_offset % _manager->npools;
1028 list_for_each_entry(p, &_manager->pools, pools) {
1033 if (shrink_pages == 0)
1035 /* Do it in round-robin fashion. */
1036 if (++idx < pool_offset)
1038 nr_free = shrink_pages;
1039 shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free);
1040 pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
1041 p->pool->dev_name, p->pool->name, current->pid, nr_free,
1044 mutex_unlock(&_manager->lock);
1045 /* return estimated number of unused pages in pool */
1046 return ttm_dma_pool_get_num_unused_pages();
1049 static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
1051 manager->mm_shrink.shrink = &ttm_dma_pool_mm_shrink;
1052 manager->mm_shrink.seeks = 1;
1053 register_shrinker(&manager->mm_shrink);
1056 static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
1058 unregister_shrinker(&manager->mm_shrink);
1061 int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
1067 printk(KERN_INFO TTM_PFX "Initializing DMA pool allocator.\n");
1069 _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
1073 mutex_init(&_manager->lock);
1074 INIT_LIST_HEAD(&_manager->pools);
1076 _manager->options.max_size = max_pages;
1077 _manager->options.small = SMALL_ALLOCATION;
1078 _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
1080 /* This takes care of auto-freeing the _manager */
1081 ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
1082 &glob->kobj, "dma_pool");
1083 if (unlikely(ret != 0)) {
1084 kobject_put(&_manager->kobj);
1087 ttm_dma_pool_mm_shrink_init(_manager);
1096 void ttm_dma_page_alloc_fini(void)
1098 struct device_pools *p, *t;
1100 printk(KERN_INFO TTM_PFX "Finalizing DMA pool allocator.\n");
1101 ttm_dma_pool_mm_shrink_fini(_manager);
1103 list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) {
1104 dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name,
1106 WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release,
1107 ttm_dma_pool_match, p->pool));
1108 ttm_dma_free_pool(p->dev, p->pool->type);
1110 kobject_put(&_manager->kobj);
1114 int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data)
1116 struct device_pools *p;
1117 struct dma_pool *pool = NULL;
1118 char *h[] = {"pool", "refills", "pages freed", "inuse", "available",
1119 "name", "virt", "busaddr"};
1122 seq_printf(m, "No pool allocator running.\n");
1125 seq_printf(m, "%13s %12s %13s %8s %8s %8s\n",
1126 h[0], h[1], h[2], h[3], h[4], h[5]);
1127 mutex_lock(&_manager->lock);
1128 list_for_each_entry(p, &_manager->pools, pools) {
1129 struct device *dev = p->dev;
1133 seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n",
1134 pool->name, pool->nrefills,
1135 pool->nfrees, pool->npages_in_use,
1139 mutex_unlock(&_manager->lock);
1142 EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs);