* represented by the 'struct dma_pool' which keeps a doubly-linked list of
* allocated pages. Each page in the page_list is split into blocks of at
* least 'size' bytes. Free blocks are tracked in an unsorted singly-linked
- * list of free blocks within the page. Used blocks aren't tracked, but we
+ * list of free blocks across all pages. Used blocks aren't tracked, but we
* keep a count of how many are currently allocated from each page.
*/
#define DMAPOOL_DEBUG 1
#endif
+struct dma_block {
+ struct dma_block *next_block;
+ dma_addr_t dma;
+};
+
struct dma_pool { /* the pool */
struct list_head page_list;
spinlock_t lock;
+ struct dma_block *next_block;
+ size_t nr_blocks;
+ size_t nr_active;
+ size_t nr_pages;
struct device *dev;
unsigned int size;
unsigned int allocation;
struct list_head page_list;
void *vaddr;
dma_addr_t dma;
- unsigned int in_use;
- unsigned int offset;
};
static DEFINE_MUTEX(pools_lock);
static ssize_t pools_show(struct device *dev, struct device_attribute *attr, char *buf)
{
- int size;
- struct dma_page *page;
struct dma_pool *pool;
+ unsigned size;
size = sysfs_emit(buf, "poolinfo - 0.1\n");
mutex_lock(&pools_lock);
list_for_each_entry(pool, &dev->dma_pools, pools) {
- unsigned pages = 0;
- size_t blocks = 0;
-
- spin_lock_irq(&pool->lock);
- list_for_each_entry(page, &pool->page_list, page_list) {
- pages++;
- blocks += page->in_use;
- }
- spin_unlock_irq(&pool->lock);
-
/* per-pool info, no real statistics yet */
- size += sysfs_emit_at(buf, size, "%-16s %4zu %4zu %4u %2u\n",
- pool->name, blocks,
- (size_t) pages *
- (pool->allocation / pool->size),
- pool->size, pages);
+ size += sysfs_emit_at(buf, size, "%-16s %4zu %4zu %4u %2zu\n",
+ pool->name, pool->nr_active,
+ pool->nr_blocks, pool->size,
+ pool->nr_pages);
}
mutex_unlock(&pools_lock);
static DEVICE_ATTR_RO(pools);
#ifdef DMAPOOL_DEBUG
-static void pool_check_block(struct dma_pool *pool, void *retval,
- unsigned int offset, gfp_t mem_flags)
+static void pool_check_block(struct dma_pool *pool, struct dma_block *block,
+ gfp_t mem_flags)
{
+ u8 *data = (void *)block;
int i;
- u8 *data = retval;
- /* page->offset is stored in first 4 bytes */
- for (i = sizeof(offset); i < pool->size; i++) {
+
+ for (i = sizeof(struct dma_block); i < pool->size; i++) {
if (data[i] == POOL_POISON_FREED)
continue;
- dev_err(pool->dev, "%s %s, %p (corrupted)\n",
- __func__, pool->name, retval);
+ dev_err(pool->dev, "%s %s, %p (corrupted)\n", __func__,
+ pool->name, block);
/*
* Dump the first 4 bytes even if they are not
data, pool->size, 1);
break;
}
+
if (!want_init_on_alloc(mem_flags))
- memset(retval, POOL_POISON_ALLOCATED, pool->size);
+ memset(block, POOL_POISON_ALLOCATED, pool->size);
+}
+
+static struct dma_page *pool_find_page(struct dma_pool *pool, dma_addr_t dma)
+{
+ struct dma_page *page;
+
+ list_for_each_entry(page, &pool->page_list, page_list) {
+ if (dma < page->dma)
+ continue;
+ if ((dma - page->dma) < pool->allocation)
+ return page;
+ }
+ return NULL;
}
-static bool pool_page_err(struct dma_pool *pool, struct dma_page *page,
- void *vaddr, dma_addr_t dma)
+static bool pool_block_err(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
{
- unsigned int offset = vaddr - page->vaddr;
- unsigned int chain = page->offset;
+ struct dma_block *block = pool->next_block;
+ struct dma_page *page;
- if ((dma - page->dma) != offset) {
- dev_err(pool->dev, "%s %s, %p (bad vaddr)/%pad\n",
+ page = pool_find_page(pool, dma);
+ if (!page) {
+ dev_err(pool->dev, "%s %s, %p/%pad (bad dma)\n",
__func__, pool->name, vaddr, &dma);
return true;
}
- while (chain < pool->allocation) {
- if (chain != offset) {
- chain = *(int *)(page->vaddr + chain);
+ while (block) {
+ if (block != vaddr) {
+ block = block->next_block;
continue;
}
dev_err(pool->dev, "%s %s, dma %pad already free\n",
__func__, pool->name, &dma);
return true;
}
+
memset(vaddr, POOL_POISON_FREED, pool->size);
return false;
}
memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
}
#else
-static void pool_check_block(struct dma_pool *pool, void *retval,
- unsigned int offset, gfp_t mem_flags)
-
+static void pool_check_block(struct dma_pool *pool, struct dma_block *block,
+ gfp_t mem_flags)
{
}
-static bool pool_page_err(struct dma_pool *pool, struct dma_page *page,
- void *vaddr, dma_addr_t dma)
+static bool pool_block_err(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
{
+ if (want_init_on_free())
+ memset(vaddr, 0, pool->size);
return false;
}
}
#endif
+static struct dma_block *pool_block_pop(struct dma_pool *pool)
+{
+ struct dma_block *block = pool->next_block;
+
+ if (block) {
+ pool->next_block = block->next_block;
+ pool->nr_active++;
+ }
+ return block;
+}
+
+static void pool_block_push(struct dma_pool *pool, struct dma_block *block,
+ dma_addr_t dma)
+{
+ block->dma = dma;
+ block->next_block = pool->next_block;
+ pool->next_block = block;
+}
+
+
/**
* dma_pool_create - Creates a pool of consistent memory blocks, for dma.
* @name: name of pool, for diagnostics
if (size == 0 || size > INT_MAX)
return NULL;
- else if (size < 4)
- size = 4;
+ if (size < sizeof(struct dma_block))
+ size = sizeof(struct dma_block);
size = ALIGN(size, align);
allocation = max_t(size_t, size, PAGE_SIZE);
boundary = min(boundary, allocation);
- retval = kmalloc(sizeof(*retval), GFP_KERNEL);
+ retval = kzalloc(sizeof(*retval), GFP_KERNEL);
if (!retval)
return retval;
retval->size = size;
retval->boundary = boundary;
retval->allocation = allocation;
-
INIT_LIST_HEAD(&retval->pools);
/*
static void pool_initialise_page(struct dma_pool *pool, struct dma_page *page)
{
- unsigned int offset = 0;
- unsigned int next_boundary = pool->boundary;
+ unsigned int next_boundary = pool->boundary, offset = 0;
+ struct dma_block *block, *first = NULL, *last = NULL;
- do {
- unsigned int next = offset + pool->size;
- if (unlikely((next + pool->size) >= next_boundary)) {
- next = next_boundary;
+ pool_init_page(pool, page);
+ while (offset + pool->size <= pool->allocation) {
+ if (offset + pool->size > next_boundary) {
+ offset = next_boundary;
next_boundary += pool->boundary;
+ continue;
}
- *(int *)(page->vaddr + offset) = next;
- offset = next;
- } while (offset < pool->allocation);
+
+ block = page->vaddr + offset;
+ block->dma = page->dma + offset;
+ block->next_block = NULL;
+
+ if (last)
+ last->next_block = block;
+ else
+ first = block;
+ last = block;
+
+ offset += pool->size;
+ pool->nr_blocks++;
+ }
+
+ last->next_block = pool->next_block;
+ pool->next_block = first;
+
+ list_add(&page->page_list, &pool->page_list);
+ pool->nr_pages++;
}
static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags)
page = kmalloc(sizeof(*page), mem_flags);
if (!page)
return NULL;
+
page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation,
&page->dma, mem_flags);
- if (page->vaddr) {
- pool_init_page(pool, page);
- pool_initialise_page(pool, page);
- page->in_use = 0;
- page->offset = 0;
- } else {
+ if (!page->vaddr) {
kfree(page);
- page = NULL;
+ return NULL;
}
- return page;
-}
-
-static inline bool is_page_busy(struct dma_page *page)
-{
- return page->in_use != 0;
-}
-
-static void pool_free_page(struct dma_pool *pool, struct dma_page *page)
-{
- dma_addr_t dma = page->dma;
- pool_init_page(pool, page);
- dma_free_coherent(pool->dev, pool->allocation, page->vaddr, dma);
- list_del(&page->page_list);
- kfree(page);
+ return page;
}
/**
void dma_pool_destroy(struct dma_pool *pool)
{
struct dma_page *page, *tmp;
- bool empty = false;
+ bool empty = false, busy = false;
if (unlikely(!pool))
return;
device_remove_file(pool->dev, &dev_attr_pools);
mutex_unlock(&pools_reg_lock);
+ if (pool->nr_active) {
+ dev_err(pool->dev, "%s %s busy\n", __func__, pool->name);
+ busy = true;
+ }
+
list_for_each_entry_safe(page, tmp, &pool->page_list, page_list) {
- if (is_page_busy(page)) {
- dev_err(pool->dev, "%s %s, %p busy\n", __func__,
- pool->name, page->vaddr);
- /* leak the still-in-use consistent memory */
- list_del(&page->page_list);
- kfree(page);
- } else
- pool_free_page(pool, page);
+ if (!busy)
+ dma_free_coherent(pool->dev, pool->allocation,
+ page->vaddr, page->dma);
+ list_del(&page->page_list);
+ kfree(page);
}
kfree(pool);
void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
dma_addr_t *handle)
{
- unsigned long flags;
+ struct dma_block *block;
struct dma_page *page;
- unsigned int offset;
- void *retval;
+ unsigned long flags;
might_alloc(mem_flags);
spin_lock_irqsave(&pool->lock, flags);
- list_for_each_entry(page, &pool->page_list, page_list) {
- if (page->offset < pool->allocation)
- goto ready;
- }
-
- /* pool_alloc_page() might sleep, so temporarily drop &pool->lock */
- spin_unlock_irqrestore(&pool->lock, flags);
-
- page = pool_alloc_page(pool, mem_flags & (~__GFP_ZERO));
- if (!page)
- return NULL;
+ block = pool_block_pop(pool);
+ if (!block) {
+ /*
+ * pool_alloc_page() might sleep, so temporarily drop
+ * &pool->lock
+ */
+ spin_unlock_irqrestore(&pool->lock, flags);
- spin_lock_irqsave(&pool->lock, flags);
+ page = pool_alloc_page(pool, mem_flags & (~__GFP_ZERO));
+ if (!page)
+ return NULL;
- list_add(&page->page_list, &pool->page_list);
- ready:
- page->in_use++;
- offset = page->offset;
- page->offset = *(int *)(page->vaddr + offset);
- retval = offset + page->vaddr;
- *handle = offset + page->dma;
- pool_check_block(pool, retval, offset, mem_flags);
+ spin_lock_irqsave(&pool->lock, flags);
+ pool_initialise_page(pool, page);
+ block = pool_block_pop(pool);
+ }
spin_unlock_irqrestore(&pool->lock, flags);
+ *handle = block->dma;
+ pool_check_block(pool, block, mem_flags);
if (want_init_on_alloc(mem_flags))
- memset(retval, 0, pool->size);
+ memset(block, 0, pool->size);
- return retval;
+ return block;
}
EXPORT_SYMBOL(dma_pool_alloc);
-static struct dma_page *pool_find_page(struct dma_pool *pool, dma_addr_t dma)
-{
- struct dma_page *page;
-
- list_for_each_entry(page, &pool->page_list, page_list) {
- if (dma < page->dma)
- continue;
- if ((dma - page->dma) < pool->allocation)
- return page;
- }
- return NULL;
-}
-
/**
* dma_pool_free - put block back into dma pool
* @pool: the dma pool holding the block
*/
void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
{
- struct dma_page *page;
+ struct dma_block *block = vaddr;
unsigned long flags;
spin_lock_irqsave(&pool->lock, flags);
- page = pool_find_page(pool, dma);
- if (!page) {
- spin_unlock_irqrestore(&pool->lock, flags);
- dev_err(pool->dev, "%s %s, %p/%pad (bad dma)\n",
- __func__, pool->name, vaddr, &dma);
- return;
- }
-
- if (want_init_on_free())
- memset(vaddr, 0, pool->size);
- if (pool_page_err(pool, page, vaddr, dma)) {
- spin_unlock_irqrestore(&pool->lock, flags);
- return;
+ if (!pool_block_err(pool, vaddr, dma)) {
+ pool_block_push(pool, block, dma);
+ pool->nr_active--;
}
-
- page->in_use--;
- *(int *)vaddr = page->offset;
- page->offset = vaddr - page->vaddr;
- /*
- * Resist a temptation to do
- * if (!is_page_busy(page)) pool_free_page(pool, page);
- * Better have a few empty pages hang around.
- */
spin_unlock_irqrestore(&pool->lock, flags);
}
EXPORT_SYMBOL(dma_pool_free);
projects / linux-block.git / blobdiff