Merge tag 'mm-stable-2023-05-06-10-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull dmapool updates - again - from Andrew Morton:
"Reinstate the dmapool changes which were accidentally removed by a
mishap on the last commit in the previous attempt at the series"
Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup").
[ The whole old series: def8574308ed..2d55c16c0c54 results in an empty
diff because that last commit ended up being just a revert of all that
came everything before it. - Linus ]
* tag 'mm-stable-2023-05-06-10-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
dmapool: link blocks across pages
dmapool: don't memset on free twice
dmapool: simplify freeing
dmapool: consolidate page initialization
dmapool: rearrange page alloc failure handling
dmapool: move debug code to own functions
dmapool: speedup DMAPOOL_DEBUG with init_on_alloc
dmapool: cleanup integer types
dmapool: use sysfs_emit() instead of scnprintf()
dmapool: remove checks for dev == NULL
diff --git a/mm/dmapool.c b/mm/dmapool.c
index a7eb5d0..d2b0f8f 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -15,7 +15,7 @@
* 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.
*/
@@ -40,13 +40,22 @@
#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;
- size_t size;
+ struct dma_block *next_block;
+ size_t nr_blocks;
+ size_t nr_active;
+ size_t nr_pages;
struct device *dev;
- size_t allocation;
- size_t boundary;
+ unsigned int size;
+ unsigned int allocation;
+ unsigned int boundary;
char name[32];
struct list_head pools;
};
@@ -55,8 +64,6 @@
struct list_head page_list;
void *vaddr;
dma_addr_t dma;
- unsigned int in_use;
- unsigned int offset;
};
static DEFINE_MUTEX(pools_lock);
@@ -64,46 +71,133 @@
static ssize_t pools_show(struct device *dev, struct device_attribute *attr, char *buf)
{
- unsigned temp;
- unsigned size;
- char *next;
- struct dma_page *page;
struct dma_pool *pool;
+ unsigned size;
- next = buf;
- size = PAGE_SIZE;
-
- temp = scnprintf(next, size, "poolinfo - 0.1\n");
- size -= temp;
- next += temp;
+ size = sysfs_emit(buf, "poolinfo - 0.1\n");
mutex_lock(&pools_lock);
list_for_each_entry(pool, &dev->dma_pools, pools) {
- unsigned pages = 0;
- unsigned 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 */
- temp = scnprintf(next, size, "%-16s %4u %4zu %4zu %2u\n",
- pool->name, blocks,
- pages * (pool->allocation / pool->size),
- pool->size, pages);
- size -= temp;
- next += temp;
+ 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);
- return PAGE_SIZE - size;
+ return size;
}
static DEVICE_ATTR_RO(pools);
+#ifdef DMAPOOL_DEBUG
+static void pool_check_block(struct dma_pool *pool, struct dma_block *block,
+ gfp_t mem_flags)
+{
+ u8 *data = (void *)block;
+ int 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, block);
+
+ /*
+ * Dump the first 4 bytes even if they are not
+ * POOL_POISON_FREED
+ */
+ print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,
+ data, pool->size, 1);
+ break;
+ }
+
+ if (!want_init_on_alloc(mem_flags))
+ 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_block_err(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
+{
+ struct dma_block *block = pool->next_block;
+ struct dma_page *page;
+
+ 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 (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;
+}
+
+static void pool_init_page(struct dma_pool *pool, struct dma_page *page)
+{
+ memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
+}
+#else
+static void pool_check_block(struct dma_pool *pool, struct dma_block *block,
+ gfp_t mem_flags)
+{
+}
+
+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;
+}
+
+static void pool_init_page(struct dma_pool *pool, struct dma_page *page)
+{
+}
+#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
@@ -134,15 +228,18 @@
size_t allocation;
bool empty = false;
+ if (!dev)
+ return NULL;
+
if (align == 0)
align = 1;
else if (align & (align - 1))
return NULL;
- if (size == 0)
+ 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);
@@ -152,7 +249,9 @@
else if ((boundary < size) || (boundary & (boundary - 1)))
return NULL;
- retval = kmalloc(sizeof(*retval), GFP_KERNEL);
+ boundary = min(boundary, allocation);
+
+ retval = kzalloc(sizeof(*retval), GFP_KERNEL);
if (!retval)
return retval;
@@ -165,7 +264,6 @@
retval->size = size;
retval->boundary = boundary;
retval->allocation = allocation;
-
INIT_LIST_HEAD(&retval->pools);
/*
@@ -202,18 +300,36 @@
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)
@@ -223,39 +339,17 @@
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) {
-#ifdef DMAPOOL_DEBUG
- memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
-#endif
- 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;
-
-#ifdef DMAPOOL_DEBUG
- 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
@@ -267,7 +361,7 @@
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;
@@ -275,26 +369,24 @@
mutex_lock(&pools_reg_lock);
mutex_lock(&pools_lock);
list_del(&pool->pools);
- if (pool->dev && list_empty(&pool->dev->dma_pools))
+ if (list_empty(&pool->dev->dma_pools))
empty = true;
mutex_unlock(&pools_lock);
if (empty)
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)) {
- if (pool->dev)
- dev_err(pool->dev, "%s %s, %p busy\n", __func__,
- pool->name, page->vaddr);
- else
- pr_err("%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);
@@ -314,84 +406,40 @@
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;
- size_t 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;
- }
+ block = pool_block_pop(pool);
+ if (!block) {
+ /*
+ * pool_alloc_page() might sleep, so temporarily drop
+ * &pool->lock
+ */
+ spin_unlock_irqrestore(&pool->lock, flags);
- /* pool_alloc_page() might sleep, so temporarily drop &pool->lock */
+ page = pool_alloc_page(pool, mem_flags & (~__GFP_ZERO));
+ if (!page)
+ return NULL;
+
+ spin_lock_irqsave(&pool->lock, flags);
+ pool_initialise_page(pool, page);
+ block = pool_block_pop(pool);
+ }
spin_unlock_irqrestore(&pool->lock, flags);
- page = pool_alloc_page(pool, mem_flags & (~__GFP_ZERO));
- if (!page)
- return NULL;
-
- spin_lock_irqsave(&pool->lock, flags);
-
- 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;
-#ifdef DMAPOOL_DEBUG
- {
- int i;
- u8 *data = retval;
- /* page->offset is stored in first 4 bytes */
- for (i = sizeof(page->offset); i < pool->size; i++) {
- if (data[i] == POOL_POISON_FREED)
- continue;
- if (pool->dev)
- dev_err(pool->dev, "%s %s, %p (corrupted)\n",
- __func__, pool->name, retval);
- else
- pr_err("%s %s, %p (corrupted)\n",
- __func__, pool->name, retval);
-
- /*
- * Dump the first 4 bytes even if they are not
- * POOL_POISON_FREED
- */
- print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,
- data, pool->size, 1);
- break;
- }
- }
- if (!(mem_flags & __GFP_ZERO))
- memset(retval, POOL_POISON_ALLOCATED, pool->size);
-#endif
- 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
@@ -403,65 +451,14 @@
*/
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;
- unsigned int offset;
spin_lock_irqsave(&pool->lock, flags);
- page = pool_find_page(pool, dma);
- if (!page) {
- spin_unlock_irqrestore(&pool->lock, flags);
- if (pool->dev)
- dev_err(pool->dev, "%s %s, %p/%pad (bad dma)\n",
- __func__, pool->name, vaddr, &dma);
- else
- pr_err("%s %s, %p/%pad (bad dma)\n",
- __func__, pool->name, vaddr, &dma);
- return;
+ if (!pool_block_err(pool, vaddr, dma)) {
+ pool_block_push(pool, block, dma);
+ pool->nr_active--;
}
-
- offset = vaddr - page->vaddr;
- if (want_init_on_free())
- memset(vaddr, 0, pool->size);
-#ifdef DMAPOOL_DEBUG
- if ((dma - page->dma) != offset) {
- spin_unlock_irqrestore(&pool->lock, flags);
- if (pool->dev)
- dev_err(pool->dev, "%s %s, %p (bad vaddr)/%pad\n",
- __func__, pool->name, vaddr, &dma);
- else
- pr_err("%s %s, %p (bad vaddr)/%pad\n",
- __func__, pool->name, vaddr, &dma);
- return;
- }
- {
- unsigned int chain = page->offset;
- while (chain < pool->allocation) {
- if (chain != offset) {
- chain = *(int *)(page->vaddr + chain);
- continue;
- }
- spin_unlock_irqrestore(&pool->lock, flags);
- if (pool->dev)
- dev_err(pool->dev, "%s %s, dma %pad already free\n",
- __func__, pool->name, &dma);
- else
- pr_err("%s %s, dma %pad already free\n",
- __func__, pool->name, &dma);
- return;
- }
- }
- memset(vaddr, POOL_POISON_FREED, pool->size);
-#endif
-
- page->in_use--;
- *(int *)vaddr = page->offset;
- page->offset = offset;
- /*
- * 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);
