[PATCH] add gen_pool_destroy()

From: Dean Nelson
Date: Thu Sep 28 2006 - 09:16:45 EST


Modules using the genpool allocator need to be able to kfree() the memory
used for the genpool data structures when unloading.

Signed-off-by: Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dean Nelson <dcn@xxxxxxx>

---

Hi Linus,

Would you please accept this patch against the genpool allocator?

There is still an issue with the block comments not being up to
kernel-doc standards that plagues the entire file, which I will
remedy in a followup patch.

Thanks,
Dean

include/linux/genalloc.h | 1 +
lib/genalloc.c | 37 +++++++++++++++++++++++++++++++++----
2 files changed, 34 insertions(+), 4 deletions(-)


Index: linux-2.6/lib/genalloc.c
===================================================================
--- linux-2.6.orig/lib/genalloc.c 2006-09-27 13:42:35.000000000 -0500
+++ linux-2.6/lib/genalloc.c 2006-09-28 07:49:05.948568928 -0500
@@ -71,6 +71,35 @@


/*
+ * Destroy a memory pool. Verifies that there are no outstanding allocations.
+ *
+ * @pool: pool to destroy
+ */
+void gen_pool_destroy(struct gen_pool *pool)
+{
+ struct list_head *_chunk, *_next_chunk;
+ struct gen_pool_chunk *chunk;
+ int order = pool->min_alloc_order;
+ 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);
+
+ end_bit = (chunk->end_addr - chunk->start_addr) >> order;
+ bit = find_next_bit(chunk->bits, end_bit, 0);
+ BUG_ON(bit < end_bit);
+
+ kfree(chunk);
+ }
+ kfree(pool);
+ return;
+}
+EXPORT_SYMBOL(gen_pool_destroy);
+
+
+/*
* Allocate the requested number of bytes from the specified pool.
* Uses a first-fit algorithm.
*
@@ -79,7 +108,7 @@
*/
unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
{
- struct list_head *_chunk;
+ struct list_head *_chunk, *_next_chunk;
struct gen_pool_chunk *chunk;
unsigned long addr, flags;
int order = pool->min_alloc_order;
@@ -91,7 +120,7 @@
nbits = (size + (1UL << order) - 1) >> order;

read_lock(&pool->lock);
- list_for_each(_chunk, &pool->chunks) {
+ list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);

end_bit = (chunk->end_addr - chunk->start_addr) >> order;
@@ -137,7 +166,7 @@
*/
void gen_pool_free(struct gen_pool *pool, unsigned long addr, size_t size)
{
- struct list_head *_chunk;
+ struct list_head *_chunk, *_next_chunk;
struct gen_pool_chunk *chunk;
unsigned long flags;
int order = pool->min_alloc_order;
@@ -146,7 +175,7 @@
nbits = (size + (1UL << order) - 1) >> order;

read_lock(&pool->lock);
- list_for_each(_chunk, &pool->chunks) {
+ list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);

if (addr >= chunk->start_addr && addr < chunk->end_addr) {
Index: linux-2.6/include/linux/genalloc.h
===================================================================
--- linux-2.6.orig/include/linux/genalloc.h 2006-09-27 13:42:34.000000000 -0500
+++ linux-2.6/include/linux/genalloc.h 2006-09-27 14:18:31.807816652 -0500
@@ -31,5 +31,6 @@

extern struct gen_pool *gen_pool_create(int, int);
extern int gen_pool_add(struct gen_pool *, unsigned long, size_t, int);
+extern void gen_pool_destroy(struct gen_pool *);
extern unsigned long gen_pool_alloc(struct gen_pool *, size_t);
extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);
-
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