/* * Copyright 2011 (c) Oracle Corp. * 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 AUTHORS OR COPYRIGHT HOLDERS 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. * * Author: Konrad Rzeszutek Wilk * * $FreeBSD: head/sys/dev/drm2/ttm/ttm_page_alloc_dma.c 247835 2013-03-05 09:49:34Z kib $ */ /* * A simple DMA pool losely based on dmapool.c. It has certain advantages * over the DMA pools: * - Pool collects resently freed pages for reuse (and hooks up to * the shrinker). * - Tracks currently in use pages * - Tracks whether the page is UC, WB or cached (and reverts to WB * when freed). */ #define pr_fmt(fmt) "[TTM] " fmt #include #include #include /* for seq_printf */ #include #include #include #include #include #include #include #include #include #include #include #ifdef TTM_HAS_AGP #include #endif #define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *)) #define SMALL_ALLOCATION 4 #define FREE_ALL_PAGES (~0U) /* times are in msecs */ #define IS_UNDEFINED (0) #define IS_WC (1<<1) #define IS_UC (1<<2) #define IS_CACHED (1<<3) #define IS_DMA32 (1<<4) enum pool_type { POOL_IS_UNDEFINED, POOL_IS_WC = IS_WC, POOL_IS_UC = IS_UC, POOL_IS_CACHED = IS_CACHED, POOL_IS_WC_DMA32 = IS_WC | IS_DMA32, POOL_IS_UC_DMA32 = IS_UC | IS_DMA32, POOL_IS_CACHED_DMA32 = IS_CACHED | IS_DMA32, }; /* * The pool structure. There are usually six pools: * - generic (not restricted to DMA32): * - write combined, uncached, cached. * - dma32 (up to 2^32 - so up 4GB): * - write combined, uncached, cached. * for each 'struct device'. The 'cached' is for pages that are actively used. * The other ones can be shrunk by the shrinker API if neccessary. * @pools: The 'struct device->dma_pools' link. * @type: Type of the pool * @lock: Protects the inuse_list and free_list from concurrnet access. Must be * used with irqsave/irqrestore variants because pool allocator maybe called * from delayed work. * @inuse_list: Pool of pages that are in use. The order is very important and * it is in the order that the TTM pages that are put back are in. * @free_list: Pool of pages that are free to be used. No order requirements. * @dev: The device that is associated with these pools. * @size: Size used during DMA allocation. * @npages_free: Count of available pages for re-use. * @npages_in_use: Count of pages that are in use. * @nfrees: Stats when pool is shrinking. * @nrefills: Stats when the pool is grown. * @gfp_flags: Flags to pass for alloc_page. * @name: Name of the pool. * @dev_name: Name derieved from dev - similar to how dev_info works. * Used during shutdown as the dev_info during release is unavailable. */ struct dma_pool { struct list_head pools; /* The 'struct device->dma_pools link */ enum pool_type type; spinlock_t lock; struct list_head inuse_list; struct list_head free_list; struct device *dev; unsigned size; unsigned npages_free; unsigned npages_in_use; unsigned long nfrees; /* Stats when shrunk. */ unsigned long nrefills; /* Stats when grown. */ gfp_t gfp_flags; char name[13]; /* "cached dma32" */ char dev_name[64]; /* Constructed from dev */ }; /* * The accounting page keeping track of the allocated page along with * the DMA address. * @page_list: The link to the 'page_list' in 'struct dma_pool'. * @vaddr: The virtual address of the page * @dma: The bus address of the page. If the page is not allocated * via the DMA API, it will be -1. */ struct dma_page { struct list_head page_list; void *vaddr; struct page *p; dma_addr_t dma; }; /* * Limits for the pool. They are handled without locks because only place where * they may change is in sysfs store. They won't have immediate effect anyway * so forcing serialization to access them is pointless. */ struct ttm_pool_opts { unsigned alloc_size; unsigned max_size; unsigned small; }; /* * Contains the list of all of the 'struct device' and their corresponding * DMA pools. Guarded by _mutex->lock. * @pools: The link to 'struct ttm_pool_manager->pools' * @dev: The 'struct device' associated with the 'pool' * @pool: The 'struct dma_pool' associated with the 'dev' */ struct device_pools { struct list_head pools; struct device *dev; struct dma_pool *pool; }; /* * struct ttm_pool_manager - Holds memory pools for fast allocation * * @lock: Lock used when adding/removing from pools * @pools: List of 'struct device' and 'struct dma_pool' tuples. * @options: Limits for the pool. * @npools: Total amount of pools in existence. * @shrinker: The structure used by [un|]register_shrinker */ struct ttm_pool_manager { struct mutex lock; struct list_head pools; struct ttm_pool_opts options; unsigned npools; struct shrinker mm_shrink; struct kobject kobj; }; static struct ttm_pool_manager *_manager; static struct attribute ttm_page_pool_max = { .name = "pool_max_size", .mode = S_IRUGO | S_IWUSR }; static struct attribute ttm_page_pool_small = { .name = "pool_small_allocation", .mode = S_IRUGO | S_IWUSR }; static struct attribute ttm_page_pool_alloc_size = { .name = "pool_allocation_size", .mode = S_IRUGO | S_IWUSR }; static struct attribute *ttm_pool_attrs[] = { &ttm_page_pool_max, &ttm_page_pool_small, &ttm_page_pool_alloc_size, NULL }; static void ttm_pool_kobj_release(struct kobject *kobj) { struct ttm_pool_manager *m = container_of(kobj, struct ttm_pool_manager, kobj); kfree(m); } static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr, const char *buffer, size_t size) { struct ttm_pool_manager *m = container_of(kobj, struct ttm_pool_manager, kobj); int chars; unsigned val; chars = sscanf(buffer, "%u", &val); if (chars == 0) return size; /* Convert kb to number of pages */ val = val / (PAGE_SIZE >> 10); if (attr == &ttm_page_pool_max) m->options.max_size = val; else if (attr == &ttm_page_pool_small) m->options.small = val; else if (attr == &ttm_page_pool_alloc_size) { if (val > NUM_PAGES_TO_ALLOC*8) { pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n", NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7), NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10)); return size; } else if (val > NUM_PAGES_TO_ALLOC) { pr_warn("Setting allocation size to larger than %lu is not recommended\n", NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10)); } m->options.alloc_size = val; } return size; } static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr, char *buffer) { struct ttm_pool_manager *m = container_of(kobj, struct ttm_pool_manager, kobj); unsigned val = 0; if (attr == &ttm_page_pool_max) val = m->options.max_size; else if (attr == &ttm_page_pool_small) val = m->options.small; else if (attr == &ttm_page_pool_alloc_size) val = m->options.alloc_size; val = val * (PAGE_SIZE >> 10); return snprintf(buffer, PAGE_SIZE, "%u\n", val); } static const struct sysfs_ops ttm_pool_sysfs_ops = { .show = &ttm_pool_show, .store = &ttm_pool_store, }; static struct kobj_type ttm_pool_kobj_type = { .release = &ttm_pool_kobj_release, .sysfs_ops = &ttm_pool_sysfs_ops, .default_attrs = ttm_pool_attrs, }; #ifndef CONFIG_X86 static int set_pages_array_wb(struct page **pages, int addrinarray) { #ifdef TTM_HAS_AGP int i; for (i = 0; i < addrinarray; i++) unmap_page_from_agp(pages[i]); #endif return 0; } static int set_pages_array_wc(struct page **pages, int addrinarray) { #ifdef TTM_HAS_AGP int i; for (i = 0; i < addrinarray; i++) map_page_into_agp(pages[i]); #endif return 0; } static int set_pages_array_uc(struct page **pages, int addrinarray) { #ifdef TTM_HAS_AGP int i; for (i = 0; i < addrinarray; i++) map_page_into_agp(pages[i]); #endif return 0; } #endif /* for !CONFIG_X86 */ static int ttm_set_pages_caching(struct dma_pool *pool, struct page **pages, unsigned cpages) { int r = 0; /* Set page caching */ if (pool->type & IS_UC) { r = set_pages_array_uc(pages, cpages); if (r) pr_err("%s: Failed to set %d pages to uc!\n", pool->dev_name, cpages); } if (pool->type & IS_WC) { r = set_pages_array_wc(pages, cpages); if (r) pr_err("%s: Failed to set %d pages to wc!\n", pool->dev_name, cpages); } return r; } static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page) { dma_addr_t dma = d_page->dma; dma_free_coherent(pool->dev, pool->size, d_page->vaddr, dma); kfree(d_page); d_page = NULL; } static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool) { struct dma_page *d_page; d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL); if (!d_page) return NULL; d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size, &d_page->dma, pool->gfp_flags); if (d_page->vaddr) d_page->p = virt_to_page(d_page->vaddr); else { kfree(d_page); d_page = NULL; } return d_page; } static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate) { enum pool_type type = IS_UNDEFINED; if (flags & TTM_PAGE_FLAG_DMA32) type |= IS_DMA32; if (cstate == tt_cached) type |= IS_CACHED; else if (cstate == tt_uncached) type |= IS_UC; else type |= IS_WC; return type; } static void ttm_pool_update_free_locked(struct dma_pool *pool, unsigned freed_pages) { pool->npages_free -= freed_pages; pool->nfrees += freed_pages; } /* set memory back to wb and free the pages. */ static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages, struct page *pages[], unsigned npages) { struct dma_page *d_page, *tmp; /* Don't set WB on WB page pool. */ if (npages && !(pool->type & IS_CACHED) && set_pages_array_wb(pages, npages)) pr_err("%s: Failed to set %d pages to wb!\n", pool->dev_name, npages); list_for_each_entry_safe(d_page, tmp, d_pages, page_list) { list_del(&d_page->page_list); __ttm_dma_free_page(pool, d_page); } } static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page) { /* Don't set WB on WB page pool. */ if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1)) pr_err("%s: Failed to set %d pages to wb!\n", pool->dev_name, 1); list_del(&d_page->page_list); __ttm_dma_free_page(pool, d_page); } /* * Free pages from pool. * * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC * number of pages in one go. * * @pool: to free the pages from * @nr_free: If set to true will free all pages in pool **/ static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free) { unsigned long irq_flags; struct dma_page *dma_p, *tmp; struct page **pages_to_free; struct list_head d_pages; unsigned freed_pages = 0, npages_to_free = nr_free; if (NUM_PAGES_TO_ALLOC < nr_free) npages_to_free = NUM_PAGES_TO_ALLOC; #if 0 if (nr_free > 1) { pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n", pool->dev_name, pool->name, current->pid, npages_to_free, nr_free); } #endif pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), GFP_KERNEL); if (!pages_to_free) { pr_err("%s: Failed to allocate memory for pool free operation\n", pool->dev_name); return 0; } INIT_LIST_HEAD(&d_pages); restart: spin_lock_irqsave(&pool->lock, irq_flags); /* We picking the oldest ones off the list */ list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list, page_list) { if (freed_pages >= npages_to_free) break; /* Move the dma_page from one list to another. */ list_move(&dma_p->page_list, &d_pages); pages_to_free[freed_pages++] = dma_p->p; /* We can only remove NUM_PAGES_TO_ALLOC at a time. */ if (freed_pages >= NUM_PAGES_TO_ALLOC) { ttm_pool_update_free_locked(pool, freed_pages); /** * Because changing page caching is costly * we unlock the pool to prevent stalling. */ spin_unlock_irqrestore(&pool->lock, irq_flags); ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages); INIT_LIST_HEAD(&d_pages); if (likely(nr_free != FREE_ALL_PAGES)) nr_free -= freed_pages; if (NUM_PAGES_TO_ALLOC >= nr_free) npages_to_free = nr_free; else npages_to_free = NUM_PAGES_TO_ALLOC; freed_pages = 0; /* free all so restart the processing */ if (nr_free) goto restart; /* Not allowed to fall through or break because * following context is inside spinlock while we are * outside here. */ goto out; } } /* remove range of pages from the pool */ if (freed_pages) { ttm_pool_update_free_locked(pool, freed_pages); nr_free -= freed_pages; } spin_unlock_irqrestore(&pool->lock, irq_flags); if (freed_pages) ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages); out: kfree(pages_to_free); return nr_free; } static void ttm_dma_free_pool(struct device *dev, enum pool_type type) { struct device_pools *p; struct dma_pool *pool; if (!dev) return; mutex_lock(&_manager->lock); list_for_each_entry_reverse(p, &_manager->pools, pools) { if (p->dev != dev) continue; pool = p->pool; if (pool->type != type) continue; list_del(&p->pools); kfree(p); _manager->npools--; break; } list_for_each_entry_reverse(pool, &dev->dma_pools, pools) { if (pool->type != type) continue; /* Takes a spinlock.. */ ttm_dma_page_pool_free(pool, FREE_ALL_PAGES); WARN_ON(((pool->npages_in_use + pool->npages_free) != 0)); /* This code path is called after _all_ references to the * struct device has been dropped - so nobody should be * touching it. In case somebody is trying to _add_ we are * guarded by the mutex. */ list_del(&pool->pools); kfree(pool); break; } mutex_unlock(&_manager->lock); } /* * On free-ing of the 'struct device' this deconstructor is run. * Albeit the pool might have already been freed earlier. */ static void ttm_dma_pool_release(struct device *dev, void *res) { struct dma_pool *pool = *(struct dma_pool **)res; if (pool) ttm_dma_free_pool(dev, pool->type); } static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data) { return *(struct dma_pool **)res == match_data; } static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags, enum pool_type type) { char *n[] = {"wc", "uc", "cached", " dma32", "unknown",}; enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_UNDEFINED}; struct device_pools *sec_pool = NULL; struct dma_pool *pool = NULL, **ptr; unsigned i; int ret = -ENODEV; char *p; if (!dev) return NULL; ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL); if (!ptr) return NULL; ret = -ENOMEM; pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL, dev_to_node(dev)); if (!pool) goto err_mem; sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL, dev_to_node(dev)); if (!sec_pool) goto err_mem; INIT_LIST_HEAD(&sec_pool->pools); sec_pool->dev = dev; sec_pool->pool = pool; INIT_LIST_HEAD(&pool->free_list); INIT_LIST_HEAD(&pool->inuse_list); INIT_LIST_HEAD(&pool->pools); spin_lock_init(&pool->lock); pool->dev = dev; pool->npages_free = pool->npages_in_use = 0; pool->nfrees = 0; pool->gfp_flags = flags; pool->size = PAGE_SIZE; pool->type = type; pool->nrefills = 0; p = pool->name; for (i = 0; i < 5; i++) { if (type & t[i]) { p += snprintf(p, sizeof(pool->name) - (p - pool->name), "%s", n[i]); } } *p = 0; /* We copy the name for pr_ calls b/c when dma_pool_destroy is called * - the kobj->name has already been deallocated.*/ snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s", dev_driver_string(dev), dev_name(dev)); mutex_lock(&_manager->lock); /* You can get the dma_pool from either the global: */ list_add(&sec_pool->pools, &_manager->pools); _manager->npools++; /* or from 'struct device': */ list_add(&pool->pools, &dev->dma_pools); mutex_unlock(&_manager->lock); *ptr = pool; devres_add(dev, ptr); return pool; err_mem: devres_free(ptr); kfree(sec_pool); kfree(pool); return ERR_PTR(ret); } static struct dma_pool *ttm_dma_find_pool(struct device *dev, enum pool_type type) { struct dma_pool *pool, *tmp, *found = NULL; if (type == IS_UNDEFINED) return found; /* NB: We iterate on the 'struct dev' which has no spinlock, but * it does have a kref which we have taken. The kref is taken during * graphic driver loading - in the drm_pci_init it calls either * pci_dev_get or pci_register_driver which both end up taking a kref * on 'struct device'. * * On teardown, the graphic drivers end up quiescing the TTM (put_pages) * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice * thing is at that point of time there are no pages associated with the * driver so this function will not be called. */ list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) { if (pool->type != type) continue; found = pool; break; } return found; } /* * Free pages the pages that failed to change the caching state. If there * are pages that have changed their caching state already put them to the * pool. */ static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool, struct list_head *d_pages, struct page **failed_pages, unsigned cpages) { struct dma_page *d_page, *tmp; struct page *p; unsigned i = 0; p = failed_pages[0]; if (!p) return; /* Find the failed page. */ list_for_each_entry_safe(d_page, tmp, d_pages, page_list) { if (d_page->p != p) continue; /* .. and then progress over the full list. */ list_del(&d_page->page_list); __ttm_dma_free_page(pool, d_page); if (++i < cpages) p = failed_pages[i]; else break; } } /* * Allocate 'count' pages, and put 'need' number of them on the * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset. * The full list of pages should also be on 'd_pages'. * We return zero for success, and negative numbers as errors. */ static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool, struct list_head *d_pages, unsigned count) { struct page **caching_array; struct dma_page *dma_p; struct page *p; int r = 0; unsigned i, cpages; unsigned max_cpages = min(count, (unsigned)(PAGE_SIZE/sizeof(struct page *))); /* allocate array for page caching change */ caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL); if (!caching_array) { pr_err("%s: Unable to allocate table for new pages\n", pool->dev_name); return -ENOMEM; } if (count > 1) { pr_debug("%s: (%s:%d) Getting %d pages\n", pool->dev_name, pool->name, current->pid, count); } for (i = 0, cpages = 0; i < count; ++i) { dma_p = __ttm_dma_alloc_page(pool); if (!dma_p) { pr_err("%s: Unable to get page %u\n", pool->dev_name, i); /* store already allocated pages in the pool after * setting the caching state */ if (cpages) { r = ttm_set_pages_caching(pool, caching_array, cpages); if (r) ttm_dma_handle_caching_state_failure( pool, d_pages, caching_array, cpages); } r = -ENOMEM; goto out; } p = dma_p->p; #ifdef CONFIG_HIGHMEM /* gfp flags of highmem page should never be dma32 so we * we should be fine in such case */ if (!PageHighMem(p)) #endif { caching_array[cpages++] = p; if (cpages == max_cpages) { /* Note: Cannot hold the spinlock */ r = ttm_set_pages_caching(pool, caching_array, cpages); if (r) { ttm_dma_handle_caching_state_failure( pool, d_pages, caching_array, cpages); goto out; } cpages = 0; } } list_add(&dma_p->page_list, d_pages); } if (cpages) { r = ttm_set_pages_caching(pool, caching_array, cpages); if (r) ttm_dma_handle_caching_state_failure(pool, d_pages, caching_array, cpages); } out: kfree(caching_array); return r; } /* * @return count of pages still required to fulfill the request. */ static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool, unsigned long *irq_flags) { unsigned count = _manager->options.small; int r = pool->npages_free; if (count > pool->npages_free) { struct list_head d_pages; INIT_LIST_HEAD(&d_pages); spin_unlock_irqrestore(&pool->lock, *irq_flags); /* Returns how many more are neccessary to fulfill the * request. */ r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count); spin_lock_irqsave(&pool->lock, *irq_flags); if (!r) { /* Add the fresh to the end.. */ list_splice(&d_pages, &pool->free_list); ++pool->nrefills; pool->npages_free += count; r = count; } else { struct dma_page *d_page; unsigned cpages = 0; pr_err("%s: Failed to fill %s pool (r:%d)!\n", pool->dev_name, pool->name, r); list_for_each_entry(d_page, &d_pages, page_list) { cpages++; } list_splice_tail(&d_pages, &pool->free_list); pool->npages_free += cpages; r = cpages; } } return r; } /* * @return count of pages still required to fulfill the request. * The populate list is actually a stack (not that is matters as TTM * allocates one page at a time. */ static int ttm_dma_pool_get_pages(struct dma_pool *pool, struct ttm_dma_tt *ttm_dma, unsigned index) { struct dma_page *d_page; struct ttm_tt *ttm = &ttm_dma->ttm; unsigned long irq_flags; int count, r = -ENOMEM; spin_lock_irqsave(&pool->lock, irq_flags); count = ttm_dma_page_pool_fill_locked(pool, &irq_flags); if (count) { d_page = list_first_entry(&pool->free_list, struct dma_page, page_list); ttm->pages[index] = d_page->p; ttm_dma->dma_address[index] = d_page->dma; list_move_tail(&d_page->page_list, &ttm_dma->pages_list); r = 0; pool->npages_in_use += 1; pool->npages_free -= 1; } spin_unlock_irqrestore(&pool->lock, irq_flags); return r; } /* * On success pages list will hold count number of correctly * cached pages. On failure will hold the negative return value (-ENOMEM, etc). */ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev) { struct ttm_tt *ttm = &ttm_dma->ttm; struct ttm_mem_global *mem_glob = ttm->glob->mem_glob; struct dma_pool *pool; enum pool_type type; unsigned i; gfp_t gfp_flags; int ret; if (ttm->state != tt_unpopulated) return 0; type = ttm_to_type(ttm->page_flags, ttm->caching_state); if (ttm->page_flags & TTM_PAGE_FLAG_DMA32) gfp_flags = GFP_USER | GFP_DMA32; else gfp_flags = GFP_HIGHUSER; if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC) gfp_flags |= __GFP_ZERO; pool = ttm_dma_find_pool(dev, type); if (!pool) { pool = ttm_dma_pool_init(dev, gfp_flags, type); if (IS_ERR_OR_NULL(pool)) { return -ENOMEM; } } INIT_LIST_HEAD(&ttm_dma->pages_list); for (i = 0; i < ttm->num_pages; ++i) { ret = ttm_dma_pool_get_pages(pool, ttm_dma, i); if (ret != 0) { ttm_dma_unpopulate(ttm_dma, dev); return -ENOMEM; } ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i], false, false); if (unlikely(ret != 0)) { ttm_dma_unpopulate(ttm_dma, dev); return -ENOMEM; } } if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) { ret = ttm_tt_swapin(ttm); if (unlikely(ret != 0)) { ttm_dma_unpopulate(ttm_dma, dev); return ret; } } ttm->state = tt_unbound; return 0; } EXPORT_SYMBOL_GPL(ttm_dma_populate); /* Get good estimation how many pages are free in pools */ static int ttm_dma_pool_get_num_unused_pages(void) { struct device_pools *p; unsigned total = 0; mutex_lock(&_manager->lock); list_for_each_entry(p, &_manager->pools, pools) total += p->pool->npages_free; mutex_unlock(&_manager->lock); return total; } /* Put all pages in pages list to correct pool to wait for reuse */ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) { struct ttm_tt *ttm = &ttm_dma->ttm; struct dma_pool *pool; struct dma_page *d_page, *next; enum pool_type type; bool is_cached = false; unsigned count = 0, i, npages = 0; unsigned long irq_flags; type = ttm_to_type(ttm->page_flags, ttm->caching_state); pool = ttm_dma_find_pool(dev, type); if (!pool) return; is_cached = (ttm_dma_find_pool(pool->dev, ttm_to_type(ttm->page_flags, tt_cached)) == pool); /* make sure pages array match list and count number of pages */ list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) { ttm->pages[count] = d_page->p; count++; } spin_lock_irqsave(&pool->lock, irq_flags); pool->npages_in_use -= count; if (is_cached) { pool->nfrees += count; } else { pool->npages_free += count; list_splice(&ttm_dma->pages_list, &pool->free_list); npages = count; if (pool->npages_free > _manager->options.max_size) { npages = pool->npages_free - _manager->options.max_size; /* free at least NUM_PAGES_TO_ALLOC number of pages * to reduce calls to set_memory_wb */ if (npages < NUM_PAGES_TO_ALLOC) npages = NUM_PAGES_TO_ALLOC; } } spin_unlock_irqrestore(&pool->lock, irq_flags); if (is_cached) { list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list, page_list) { ttm_mem_global_free_page(ttm->glob->mem_glob, d_page->p); ttm_dma_page_put(pool, d_page); } } else { for (i = 0; i < count; i++) { ttm_mem_global_free_page(ttm->glob->mem_glob, ttm->pages[i]); } } INIT_LIST_HEAD(&ttm_dma->pages_list); for (i = 0; i < ttm->num_pages; i++) { ttm->pages[i] = NULL; ttm_dma->dma_address[i] = 0; } /* shrink pool if necessary (only on !is_cached pools)*/ if (npages) ttm_dma_page_pool_free(pool, npages); ttm->state = tt_unpopulated; } EXPORT_SYMBOL_GPL(ttm_dma_unpopulate); /** * Callback for mm to request pool to reduce number of page held. */ static int ttm_dma_pool_mm_shrink(struct shrinker *shrink, struct shrink_control *sc) { static atomic_t start_pool = ATOMIC_INIT(0); unsigned idx = 0; unsigned pool_offset = atomic_add_return(1, &start_pool); unsigned shrink_pages = sc->nr_to_scan; struct device_pools *p; if (list_empty(&_manager->pools)) return 0; mutex_lock(&_manager->lock); pool_offset = pool_offset % _manager->npools; list_for_each_entry(p, &_manager->pools, pools) { unsigned nr_free; if (!p->dev) continue; if (shrink_pages == 0) break; /* Do it in round-robin fashion. */ if (++idx < pool_offset) continue; nr_free = shrink_pages; shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free); pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n", p->pool->dev_name, p->pool->name, current->pid, nr_free, shrink_pages); } mutex_unlock(&_manager->lock); /* return estimated number of unused pages in pool */ return ttm_dma_pool_get_num_unused_pages(); } static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager) { manager->mm_shrink.shrink = &ttm_dma_pool_mm_shrink; manager->mm_shrink.seeks = 1; register_shrinker(&manager->mm_shrink); } static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager) { unregister_shrinker(&manager->mm_shrink); } int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages) { int ret = -ENOMEM; WARN_ON(_manager); pr_info("Initializing DMA pool allocator\n"); _manager = kzalloc(sizeof(*_manager), GFP_KERNEL); if (!_manager) goto err; mutex_init(&_manager->lock); INIT_LIST_HEAD(&_manager->pools); _manager->options.max_size = max_pages; _manager->options.small = SMALL_ALLOCATION; _manager->options.alloc_size = NUM_PAGES_TO_ALLOC; /* This takes care of auto-freeing the _manager */ ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type, &glob->kobj, "dma_pool"); if (unlikely(ret != 0)) { kobject_put(&_manager->kobj); goto err; } ttm_dma_pool_mm_shrink_init(_manager); return 0; err: return ret; } void ttm_dma_page_alloc_fini(void) { struct device_pools *p, *t; pr_info("Finalizing DMA pool allocator\n"); ttm_dma_pool_mm_shrink_fini(_manager); list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) { dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name, current->pid); WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release, ttm_dma_pool_match, p->pool)); ttm_dma_free_pool(p->dev, p->pool->type); } kobject_put(&_manager->kobj); _manager = NULL; } int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data) { struct device_pools *p; struct dma_pool *pool = NULL; char *h[] = {"pool", "refills", "pages freed", "inuse", "available", "name", "virt", "busaddr"}; if (!_manager) { seq_printf(m, "No pool allocator running.\n"); return 0; } seq_printf(m, "%13s %12s %13s %8s %8s %8s\n", h[0], h[1], h[2], h[3], h[4], h[5]); mutex_lock(&_manager->lock); list_for_each_entry(p, &_manager->pools, pools) { struct device *dev = p->dev; if (!dev) continue; pool = p->pool; seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n", pool->name, pool->nrefills, pool->nfrees, pool->npages_in_use, pool->npages_free, pool->dev_name); } mutex_unlock(&_manager->lock); return 0; } EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs);