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dmapool: create/destroy cleanup

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Set the 'empty' bool directly from the result of the function that
determines its value instead of adding additional logic.

Link: https://lkml.kernel.org/r/20230126215125.4069751-13-kbusch@meta.com
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Keith Busch 2023-01-26 13:51:25 -08:00 • committed by Andrew Morton
parent a4de12a032
commit 2d55c16c0c
1 changed files with 208 additions and 205 deletions
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393
mm/dmapool.c
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@ -15,7 +15,7 @@
* represented by the 'struct dma_pool' which keeps a doubly-linked list of * 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 * 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 * least 'size' bytes. Free blocks are tracked in an unsorted singly-linked
* list of free blocks across all pages. Used blocks aren't tracked, but we * list of free blocks within the page. Used blocks aren't tracked, but we
* keep a count of how many are currently allocated from each page. * keep a count of how many are currently allocated from each page.
*/ */
@ -40,22 +40,13 @@
#define DMAPOOL_DEBUG 1 #define DMAPOOL_DEBUG 1
#endif #endif
struct dma_block {
struct dma_block *next_block;
dma_addr_t dma;
};
struct dma_pool { /* the pool */ struct dma_pool { /* the pool */
struct list_head page_list; struct list_head page_list;
spinlock_t lock; spinlock_t lock;
struct dma_block *next_block; size_t size;
size_t nr_blocks;
size_t nr_active;
size_t nr_pages;
struct device *dev; struct device *dev;
unsigned int size; size_t allocation;
unsigned int allocation; size_t boundary;
unsigned int boundary;
char name[32]; char name[32];
struct list_head pools; struct list_head pools;
}; };
@ -64,6 +55,8 @@ struct dma_page { /* cacheable header for 'allocation' bytes */
struct list_head page_list; struct list_head page_list;
void *vaddr; void *vaddr;
dma_addr_t dma; dma_addr_t dma;
unsigned int in_use;
unsigned int offset;
}; };
static DEFINE_MUTEX(pools_lock); static DEFINE_MUTEX(pools_lock);
@ -71,133 +64,46 @@ static DEFINE_MUTEX(pools_reg_lock);
static ssize_t pools_show(struct device *dev, struct device_attribute *attr, char *buf) static ssize_t pools_show(struct device *dev, struct device_attribute *attr, char *buf)
{ {
struct dma_pool *pool; unsigned temp;
unsigned size; unsigned size;
char *next;
struct dma_page *page;
struct dma_pool *pool;
size = sysfs_emit(buf, "poolinfo - 0.1\n"); next = buf;
size = PAGE_SIZE;
temp = scnprintf(next, size, "poolinfo - 0.1\n");
size -= temp;
next += temp;
mutex_lock(&pools_lock); mutex_lock(&pools_lock);
list_for_each_entry(pool, &dev->dma_pools, pools) { 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 */ /* per-pool info, no real statistics yet */
size += sysfs_emit_at(buf, size, "%-16s %4zu %4zu %4u %2zu\n", temp = scnprintf(next, size, "%-16s %4u %4zu %4zu %2u\n",
pool->name, pool->nr_active, pool->name, blocks,
pool->nr_blocks, pool->size, pages * (pool->allocation / pool->size),
pool->nr_pages); pool->size, pages);
size -= temp;
next += temp;
} }
mutex_unlock(&pools_lock); mutex_unlock(&pools_lock);
return size; return PAGE_SIZE - size;
} }
static DEVICE_ATTR_RO(pools); 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. * dma_pool_create - Creates a pool of consistent memory blocks, for dma.
* @name: name of pool, for diagnostics * @name: name of pool, for diagnostics
@ -228,18 +134,15 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
size_t allocation; size_t allocation;
bool empty = false; bool empty = false;
if (!dev)
return NULL;
if (align == 0) if (align == 0)
align = 1; align = 1;
else if (align & (align - 1)) else if (align & (align - 1))
return NULL; return NULL;
if (size == 0 || size > INT_MAX) if (size == 0)
return NULL; return NULL;
if (size < sizeof(struct dma_block)) else if (size < 4)
size = sizeof(struct dma_block); size = 4;
size = ALIGN(size, align); size = ALIGN(size, align);
allocation = max_t(size_t, size, PAGE_SIZE); allocation = max_t(size_t, size, PAGE_SIZE);
@ -249,9 +152,7 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
else if ((boundary < size) || (boundary & (boundary - 1))) else if ((boundary < size) || (boundary & (boundary - 1)))
return NULL; return NULL;
boundary = min(boundary, allocation); retval = kmalloc(sizeof(*retval), GFP_KERNEL);
retval = kzalloc(sizeof(*retval), GFP_KERNEL);
if (!retval) if (!retval)
return retval; return retval;
@ -264,6 +165,7 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
retval->size = size; retval->size = size;
retval->boundary = boundary; retval->boundary = boundary;
retval->allocation = allocation; retval->allocation = allocation;
INIT_LIST_HEAD(&retval->pools); INIT_LIST_HEAD(&retval->pools);
/* /*
@ -300,36 +202,18 @@ EXPORT_SYMBOL(dma_pool_create);
static void pool_initialise_page(struct dma_pool *pool, struct dma_page *page) static void pool_initialise_page(struct dma_pool *pool, struct dma_page *page)
{ {
unsigned int next_boundary = pool->boundary, offset = 0; unsigned int offset = 0;
struct dma_block *block, *first = NULL, *last = NULL; unsigned int next_boundary = pool->boundary;
pool_init_page(pool, page); do {
while (offset + pool->size <= pool->allocation) { unsigned int next = offset + pool->size;
if (offset + pool->size > next_boundary) { if (unlikely((next + pool->size) >= next_boundary)) {
offset = next_boundary; next = next_boundary;
next_boundary += pool->boundary; next_boundary += pool->boundary;
continue;
} }
*(int *)(page->vaddr + offset) = next;
block = page->vaddr + offset; offset = next;
block->dma = page->dma + offset; } while (offset < pool->allocation);
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) static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags)
@ -339,15 +223,37 @@ static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags)
page = kmalloc(sizeof(*page), mem_flags); page = kmalloc(sizeof(*page), mem_flags);
if (!page) if (!page)
return NULL; return NULL;
page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation, page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation,
&page->dma, mem_flags); &page->dma, mem_flags);
if (!page->vaddr) { 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 {
kfree(page); kfree(page);
return NULL; page = NULL;
}
return page;
} }
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);
} }
/** /**
@ -361,7 +267,7 @@ static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags)
void dma_pool_destroy(struct dma_pool *pool) void dma_pool_destroy(struct dma_pool *pool)
{ {
struct dma_page *page, *tmp; struct dma_page *page, *tmp;
bool empty = false, busy = false; bool empty = false;
if (unlikely(!pool)) if (unlikely(!pool))
return; return;
@ -369,24 +275,26 @@ void dma_pool_destroy(struct dma_pool *pool)
mutex_lock(&pools_reg_lock); mutex_lock(&pools_reg_lock);
mutex_lock(&pools_lock); mutex_lock(&pools_lock);
list_del(&pool->pools); list_del(&pool->pools);
if (list_empty(&pool->dev->dma_pools)) if (pool->dev && list_empty(&pool->dev->dma_pools))
empty = true; empty = true;
mutex_unlock(&pools_lock); mutex_unlock(&pools_lock);
if (empty) if (empty)
device_remove_file(pool->dev, &dev_attr_pools); device_remove_file(pool->dev, &dev_attr_pools);
mutex_unlock(&pools_reg_lock); 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) { list_for_each_entry_safe(page, tmp, &pool->page_list, page_list) {
if (!busy) if (is_page_busy(page)) {
dma_free_coherent(pool->dev, pool->allocation, if (pool->dev)
page->vaddr, page->dma); 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); list_del(&page->page_list);
kfree(page); kfree(page);
} else
pool_free_page(pool, page);
} }
kfree(pool); kfree(pool);
@ -406,19 +314,20 @@ EXPORT_SYMBOL(dma_pool_destroy);
void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
dma_addr_t *handle) dma_addr_t *handle)
{ {
struct dma_block *block;
struct dma_page *page;
unsigned long flags; unsigned long flags;
struct dma_page *page;
size_t offset;
void *retval;
might_alloc(mem_flags); might_alloc(mem_flags);
spin_lock_irqsave(&pool->lock, flags); spin_lock_irqsave(&pool->lock, flags);
block = pool_block_pop(pool); list_for_each_entry(page, &pool->page_list, page_list) {
if (!block) { if (page->offset < pool->allocation)
/* goto ready;
* pool_alloc_page() might sleep, so temporarily drop }
* &pool->lock
*/ /* pool_alloc_page() might sleep, so temporarily drop &pool->lock */
spin_unlock_irqrestore(&pool->lock, flags); spin_unlock_irqrestore(&pool->lock, flags);
page = pool_alloc_page(pool, mem_flags & (~__GFP_ZERO)); page = pool_alloc_page(pool, mem_flags & (~__GFP_ZERO));
@ -426,20 +335,63 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
return NULL; return NULL;
spin_lock_irqsave(&pool->lock, flags); spin_lock_irqsave(&pool->lock, flags);
pool_initialise_page(pool, page);
block = pool_block_pop(pool); 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); spin_unlock_irqrestore(&pool->lock, flags);
*handle = block->dma;
pool_check_block(pool, block, mem_flags);
if (want_init_on_alloc(mem_flags)) if (want_init_on_alloc(mem_flags))
memset(block, 0, pool->size); memset(retval, 0, pool->size);
return block; return retval;
} }
EXPORT_SYMBOL(dma_pool_alloc); 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 * dma_pool_free - put block back into dma pool
* @pool: the dma pool holding the block * @pool: the dma pool holding the block
@ -451,14 +403,65 @@ EXPORT_SYMBOL(dma_pool_alloc);
*/ */
void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma) void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
{ {
struct dma_block *block = vaddr; struct dma_page *page;
unsigned long flags; unsigned long flags;
unsigned int offset;
spin_lock_irqsave(&pool->lock, flags); spin_lock_irqsave(&pool->lock, flags);
if (!pool_block_err(pool, vaddr, dma)) { page = pool_find_page(pool, dma);
pool_block_push(pool, block, dma); if (!page) {
pool->nr_active--; 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;
} }
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); spin_unlock_irqrestore(&pool->lock, flags);
} }
EXPORT_SYMBOL(dma_pool_free); EXPORT_SYMBOL(dma_pool_free);