diff options
Diffstat (limited to 'drivers/base/dmapool.c')
| -rw-r--r-- | drivers/base/dmapool.c | 481 |
1 files changed, 0 insertions, 481 deletions
diff --git a/drivers/base/dmapool.c b/drivers/base/dmapool.c deleted file mode 100644 index b5034dc72a05..000000000000 --- a/drivers/base/dmapool.c +++ /dev/null @@ -1,481 +0,0 @@ - -#include <linux/device.h> -#include <linux/mm.h> -#include <asm/io.h> /* Needed for i386 to build */ -#include <linux/dma-mapping.h> -#include <linux/dmapool.h> -#include <linux/slab.h> -#include <linux/module.h> -#include <linux/poison.h> -#include <linux/sched.h> - -/* - * Pool allocator ... wraps the dma_alloc_coherent page allocator, so - * small blocks are easily used by drivers for bus mastering controllers. - * This should probably be sharing the guts of the slab allocator. - */ - -struct dma_pool { /* the pool */ - struct list_head page_list; - spinlock_t lock; - size_t blocks_per_page; - size_t size; - struct device *dev; - size_t allocation; - char name [32]; - wait_queue_head_t waitq; - struct list_head pools; -}; - -struct dma_page { /* cacheable header for 'allocation' bytes */ - struct list_head page_list; - void *vaddr; - dma_addr_t dma; - unsigned in_use; - unsigned long bitmap [0]; -}; - -#define POOL_TIMEOUT_JIFFIES ((100 /* msec */ * HZ) / 1000) - -static DEFINE_MUTEX (pools_lock); - -static ssize_t -show_pools (struct device *dev, struct device_attribute *attr, char *buf) -{ - unsigned temp; - unsigned size; - char *next; - struct dma_page *page; - struct dma_pool *pool; - - next = buf; - size = PAGE_SIZE; - - temp = scnprintf(next, size, "poolinfo - 0.1\n"); - size -= temp; - next += temp; - - mutex_lock(&pools_lock); - list_for_each_entry(pool, &dev->dma_pools, pools) { - unsigned pages = 0; - unsigned blocks = 0; - - list_for_each_entry(page, &pool->page_list, page_list) { - pages++; - blocks += page->in_use; - } - - /* per-pool info, no real statistics yet */ - temp = scnprintf(next, size, "%-16s %4u %4Zu %4Zu %2u\n", - pool->name, - blocks, pages * pool->blocks_per_page, - pool->size, pages); - size -= temp; - next += temp; - } - mutex_unlock(&pools_lock); - - return PAGE_SIZE - size; -} -static DEVICE_ATTR (pools, S_IRUGO, show_pools, NULL); - -/** - * dma_pool_create - Creates a pool of consistent memory blocks, for dma. - * @name: name of pool, for diagnostics - * @dev: device that will be doing the DMA - * @size: size of the blocks in this pool. - * @align: alignment requirement for blocks; must be a power of two - * @allocation: returned blocks won't cross this boundary (or zero) - * Context: !in_interrupt() - * - * Returns a dma allocation pool with the requested characteristics, or - * null if one can't be created. Given one of these pools, dma_pool_alloc() - * may be used to allocate memory. Such memory will all have "consistent" - * DMA mappings, accessible by the device and its driver without using - * cache flushing primitives. The actual size of blocks allocated may be - * larger than requested because of alignment. - * - * If allocation is nonzero, objects returned from dma_pool_alloc() won't - * cross that size boundary. This is useful for devices which have - * addressing restrictions on individual DMA transfers, such as not crossing - * boundaries of 4KBytes. - */ -struct dma_pool * -dma_pool_create (const char *name, struct device *dev, - size_t size, size_t align, size_t allocation) -{ - struct dma_pool *retval; - - if (align == 0) - align = 1; - if (size == 0) - return NULL; - else if (size < align) - size = align; - else if ((size % align) != 0) { - size += align + 1; - size &= ~(align - 1); - } - - if (allocation == 0) { - if (PAGE_SIZE < size) - allocation = size; - else - allocation = PAGE_SIZE; - // FIXME: round up for less fragmentation - } else if (allocation < size) - return NULL; - - if (!(retval = kmalloc_node (sizeof *retval, GFP_KERNEL, dev_to_node(dev)))) - return retval; - - strlcpy (retval->name, name, sizeof retval->name); - - retval->dev = dev; - - INIT_LIST_HEAD (&retval->page_list); - spin_lock_init (&retval->lock); - retval->size = size; - retval->allocation = allocation; - retval->blocks_per_page = allocation / size; - init_waitqueue_head (&retval->waitq); - - if (dev) { - int ret; - - mutex_lock(&pools_lock); - if (list_empty (&dev->dma_pools)) - ret = device_create_file (dev, &dev_attr_pools); - else - ret = 0; - /* note: not currently insisting "name" be unique */ - if (!ret) - list_add (&retval->pools, &dev->dma_pools); - else { - kfree(retval); - retval = NULL; - } - mutex_unlock(&pools_lock); - } else - INIT_LIST_HEAD (&retval->pools); - - return retval; -} - - -static struct dma_page * -pool_alloc_page (struct dma_pool *pool, gfp_t mem_flags) -{ - struct dma_page *page; - int mapsize; - - mapsize = pool->blocks_per_page; - mapsize = (mapsize + BITS_PER_LONG - 1) / BITS_PER_LONG; - mapsize *= sizeof (long); - - page = kmalloc(mapsize + sizeof *page, mem_flags); - if (!page) - return NULL; - page->vaddr = dma_alloc_coherent (pool->dev, - pool->allocation, - &page->dma, - mem_flags); - if (page->vaddr) { - memset (page->bitmap, 0xff, mapsize); // bit set == free -#ifdef CONFIG_DEBUG_SLAB - memset (page->vaddr, POOL_POISON_FREED, pool->allocation); -#endif - list_add (&page->page_list, &pool->page_list); - page->in_use = 0; - } else { - kfree (page); - page = NULL; - } - return page; -} - - -static inline int -is_page_busy (int blocks, unsigned long *bitmap) -{ - while (blocks > 0) { - if (*bitmap++ != ~0UL) - return 1; - blocks -= BITS_PER_LONG; - } - return 0; -} - -static void -pool_free_page (struct dma_pool *pool, struct dma_page *page) -{ - dma_addr_t dma = page->dma; - -#ifdef CONFIG_DEBUG_SLAB - memset (page->vaddr, POOL_POISON_FREED, pool->allocation); -#endif - dma_free_coherent (pool->dev, pool->allocation, page->vaddr, dma); - list_del (&page->page_list); - kfree (page); -} - - -/** - * dma_pool_destroy - destroys a pool of dma memory blocks. - * @pool: dma pool that will be destroyed - * Context: !in_interrupt() - * - * Caller guarantees that no more memory from the pool is in use, - * and that nothing will try to use the pool after this call. - */ -void -dma_pool_destroy (struct dma_pool *pool) -{ - mutex_lock(&pools_lock); - list_del (&pool->pools); - if (pool->dev && list_empty (&pool->dev->dma_pools)) - device_remove_file (pool->dev, &dev_attr_pools); - mutex_unlock(&pools_lock); - - while (!list_empty (&pool->page_list)) { - struct dma_page *page; - page = list_entry (pool->page_list.next, - struct dma_page, page_list); - if (is_page_busy (pool->blocks_per_page, page->bitmap)) { - if (pool->dev) - dev_err(pool->dev, "dma_pool_destroy %s, %p busy\n", - pool->name, page->vaddr); - else - printk (KERN_ERR "dma_pool_destroy %s, %p busy\n", - pool->name, page->vaddr); - /* leak the still-in-use consistent memory */ - list_del (&page->page_list); - kfree (page); - } else - pool_free_page (pool, page); - } - - kfree (pool); -} - - -/** - * dma_pool_alloc - get a block of consistent memory - * @pool: dma pool that will produce the block - * @mem_flags: GFP_* bitmask - * @handle: pointer to dma address of block - * - * This returns the kernel virtual address of a currently unused block, - * and reports its dma address through the handle. - * If such a memory block can't be allocated, null is returned. - */ -void * -dma_pool_alloc (struct dma_pool *pool, gfp_t mem_flags, dma_addr_t *handle) -{ - unsigned long flags; - struct dma_page *page; - int map, block; - size_t offset; - void *retval; - -restart: - spin_lock_irqsave (&pool->lock, flags); - list_for_each_entry(page, &pool->page_list, page_list) { - int i; - /* only cachable accesses here ... */ - for (map = 0, i = 0; - i < pool->blocks_per_page; - i += BITS_PER_LONG, map++) { - if (page->bitmap [map] == 0) - continue; - block = ffz (~ page->bitmap [map]); - if ((i + block) < pool->blocks_per_page) { - clear_bit (block, &page->bitmap [map]); - offset = (BITS_PER_LONG * map) + block; - offset *= pool->size; - goto ready; - } - } - } - if (!(page = pool_alloc_page (pool, GFP_ATOMIC))) { - if (mem_flags & __GFP_WAIT) { - DECLARE_WAITQUEUE (wait, current); - - __set_current_state(TASK_INTERRUPTIBLE); - add_wait_queue (&pool->waitq, &wait); - spin_unlock_irqrestore (&pool->lock, flags); - - schedule_timeout (POOL_TIMEOUT_JIFFIES); - - remove_wait_queue (&pool->waitq, &wait); - goto restart; - } - retval = NULL; - goto done; - } - - clear_bit (0, &page->bitmap [0]); - offset = 0; -ready: - page->in_use++; - retval = offset + page->vaddr; - *handle = offset + page->dma; -#ifdef CONFIG_DEBUG_SLAB - memset (retval, POOL_POISON_ALLOCATED, pool->size); -#endif -done: - spin_unlock_irqrestore (&pool->lock, flags); - return retval; -} - - -static struct dma_page * -pool_find_page (struct dma_pool *pool, dma_addr_t dma) -{ - unsigned long flags; - struct dma_page *page; - - spin_lock_irqsave (&pool->lock, flags); - list_for_each_entry(page, &pool->page_list, page_list) { - if (dma < page->dma) - continue; - if (dma < (page->dma + pool->allocation)) - goto done; - } - page = NULL; -done: - spin_unlock_irqrestore (&pool->lock, flags); - return page; -} - - -/** - * dma_pool_free - put block back into dma pool - * @pool: the dma pool holding the block - * @vaddr: virtual address of block - * @dma: dma address of block - * - * Caller promises neither device nor driver will again touch this block - * unless it is first re-allocated. - */ -void -dma_pool_free (struct dma_pool *pool, void *vaddr, dma_addr_t dma) -{ - struct dma_page *page; - unsigned long flags; - int map, block; - - if ((page = pool_find_page(pool, dma)) == NULL) { - if (pool->dev) - dev_err(pool->dev, "dma_pool_free %s, %p/%lx (bad dma)\n", - pool->name, vaddr, (unsigned long) dma); - else - printk (KERN_ERR "dma_pool_free %s, %p/%lx (bad dma)\n", - pool->name, vaddr, (unsigned long) dma); - return; - } - - block = dma - page->dma; - block /= pool->size; - map = block / BITS_PER_LONG; - block %= BITS_PER_LONG; - -#ifdef CONFIG_DEBUG_SLAB - if (((dma - page->dma) + (void *)page->vaddr) != vaddr) { - if (pool->dev) - dev_err(pool->dev, "dma_pool_free %s, %p (bad vaddr)/%Lx\n", - pool->name, vaddr, (unsigned long long) dma); - else - printk (KERN_ERR "dma_pool_free %s, %p (bad vaddr)/%Lx\n", - pool->name, vaddr, (unsigned long long) dma); - return; - } - if (page->bitmap [map] & (1UL << block)) { - if (pool->dev) - dev_err(pool->dev, "dma_pool_free %s, dma %Lx already free\n", - pool->name, (unsigned long long)dma); - else - printk (KERN_ERR "dma_pool_free %s, dma %Lx already free\n", - pool->name, (unsigned long long)dma); - return; - } - memset (vaddr, POOL_POISON_FREED, pool->size); -#endif - - spin_lock_irqsave (&pool->lock, flags); - page->in_use--; - set_bit (block, &page->bitmap [map]); - if (waitqueue_active (&pool->waitq)) - wake_up (&pool->waitq); - /* - * Resist a temptation to do - * if (!is_page_busy(bpp, page->bitmap)) pool_free_page(pool, page); - * Better have a few empty pages hang around. - */ - spin_unlock_irqrestore (&pool->lock, flags); -} - -/* - * Managed DMA pool - */ -static void dmam_pool_release(struct device *dev, void *res) -{ - struct dma_pool *pool = *(struct dma_pool **)res; - - dma_pool_destroy(pool); -} - -static int dmam_pool_match(struct device *dev, void *res, void *match_data) -{ - return *(struct dma_pool **)res == match_data; -} - -/** - * dmam_pool_create - Managed dma_pool_create() - * @name: name of pool, for diagnostics - * @dev: device that will be doing the DMA - * @size: size of the blocks in this pool. - * @align: alignment requirement for blocks; must be a power of two - * @allocation: returned blocks won't cross this boundary (or zero) - * - * Managed dma_pool_create(). DMA pool created with this function is - * automatically destroyed on driver detach. - */ -struct dma_pool *dmam_pool_create(const char *name, struct device *dev, - size_t size, size_t align, size_t allocation) -{ - struct dma_pool **ptr, *pool; - - ptr = devres_alloc(dmam_pool_release, sizeof(*ptr), GFP_KERNEL); - if (!ptr) - return NULL; - - pool = *ptr = dma_pool_create(name, dev, size, align, allocation); - if (pool) - devres_add(dev, ptr); - else - devres_free(ptr); - - return pool; -} - -/** - * dmam_pool_destroy - Managed dma_pool_destroy() - * @pool: dma pool that will be destroyed - * - * Managed dma_pool_destroy(). - */ -void dmam_pool_destroy(struct dma_pool *pool) -{ - struct device *dev = pool->dev; - - dma_pool_destroy(pool); - WARN_ON(devres_destroy(dev, dmam_pool_release, dmam_pool_match, pool)); -} - -EXPORT_SYMBOL (dma_pool_create); -EXPORT_SYMBOL (dma_pool_destroy); -EXPORT_SYMBOL (dma_pool_alloc); -EXPORT_SYMBOL (dma_pool_free); -EXPORT_SYMBOL (dmam_pool_create); -EXPORT_SYMBOL (dmam_pool_destroy); |