*/
#include <linux/module.h>
+#include <linux/bitmap.h>
#include <linux/genalloc.h>
-/*
- * Create a new special memory pool.
- *
+/**
+ * gen_pool_create - create a new special memory pool
* @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
* @nid: node id of the node the pool structure should be allocated on, or -1
+ *
+ * Create a new special memory pool that can be used to manage special purpose
+ * memory not managed by the regular kmalloc/kfree interface.
*/
struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
{
}
EXPORT_SYMBOL(gen_pool_create);
-
-/*
- * Add a new chunk of memory to the specified pool.
- *
+/**
+ * gen_pool_add - add a new chunk of special memory to the pool
* @pool: pool to add new memory chunk to
* @addr: starting address of memory chunk to add to pool
* @size: size in bytes of the memory chunk to add to pool
* @nid: node id of the node the chunk structure and bitmap should be
* allocated on, or -1
+ *
+ * Add a new chunk of special memory to the specified pool.
*/
int gen_pool_add(struct gen_pool *pool, unsigned long addr, size_t size,
int nid)
int nbytes = sizeof(struct gen_pool_chunk) +
(nbits + BITS_PER_BYTE - 1) / BITS_PER_BYTE;
- chunk = kmalloc_node(nbytes, GFP_KERNEL, nid);
+ chunk = kmalloc_node(nbytes, GFP_KERNEL | __GFP_ZERO, nid);
if (unlikely(chunk == NULL))
return -1;
- memset(chunk, 0, nbytes);
spin_lock_init(&chunk->lock);
chunk->start_addr = addr;
chunk->end_addr = addr + size;
}
EXPORT_SYMBOL(gen_pool_add);
-
-/*
- * Destroy a memory pool. Verifies that there are no outstanding allocations.
- *
+/**
+ * gen_pool_destroy - destroy a special memory pool
* @pool: pool to destroy
+ *
+ * Destroy the specified special memory pool. Verifies that there are no
+ * outstanding allocations.
*/
void gen_pool_destroy(struct gen_pool *pool)
{
int bit, end_bit;
- write_lock(&pool->lock);
list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
list_del(&chunk->next_chunk);
}
EXPORT_SYMBOL(gen_pool_destroy);
-
-/*
- * Allocate the requested number of bytes from the specified pool.
- * Uses a first-fit algorithm.
- *
+/**
+ * gen_pool_alloc - allocate special memory from the pool
* @pool: pool to allocate from
* @size: number of bytes to allocate from the pool
+ *
+ * Allocate the requested number of bytes from the specified pool.
+ * Uses a first-fit algorithm.
*/
unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
{
struct gen_pool_chunk *chunk;
unsigned long addr, flags;
int order = pool->min_alloc_order;
- int nbits, bit, start_bit, end_bit;
+ int nbits, start_bit, end_bit;
if (size == 0)
return 0;
end_bit -= nbits + 1;
spin_lock_irqsave(&chunk->lock, flags);
- bit = -1;
- while (bit + 1 < end_bit) {
- bit = find_next_zero_bit(chunk->bits, end_bit, bit + 1);
- if (bit >= end_bit)
- break;
-
- start_bit = bit;
- if (nbits > 1) {
- bit = find_next_bit(chunk->bits, bit + nbits,
- bit + 1);
- if (bit - start_bit < nbits)
- continue;
- }
-
- addr = chunk->start_addr +
- ((unsigned long)start_bit << order);
- while (nbits--)
- __set_bit(start_bit++, &chunk->bits);
+ start_bit = bitmap_find_next_zero_area(chunk->bits, end_bit, 0,
+ nbits, 0);
+ if (start_bit >= end_bit) {
spin_unlock_irqrestore(&chunk->lock, flags);
- read_unlock(&pool->lock);
- return addr;
+ continue;
}
+
+ addr = chunk->start_addr + ((unsigned long)start_bit << order);
+
+ bitmap_set(chunk->bits, start_bit, nbits);
spin_unlock_irqrestore(&chunk->lock, flags);
+ read_unlock(&pool->lock);
+ return addr;
}
read_unlock(&pool->lock);
return 0;
}
EXPORT_SYMBOL(gen_pool_alloc);
-
-/*
- * Free the specified memory back to the specified pool.
- *
+/**
+ * gen_pool_free - free allocated special memory back to the pool
* @pool: pool to free to
* @addr: starting address of memory to free back to pool
* @size: size in bytes of memory to free
+ *
+ * Free previously allocated special memory back to the specified pool.
*/
void gen_pool_free(struct gen_pool *pool, unsigned long addr, size_t size)
{
spin_lock_irqsave(&chunk->lock, flags);
bit = (addr - chunk->start_addr) >> order;
while (nbits--)
- __clear_bit(bit++, &chunk->bits);
+ __clear_bit(bit++, chunk->bits);
spin_unlock_irqrestore(&chunk->lock, flags);
break;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff