android_kernel_xiaomi_sm8350/include/linux/genalloc.h
Dean Nelson 929f97276b [PATCH] change gen_pool allocator to not touch managed memory
Modify the gen_pool allocator (lib/genalloc.c) to utilize a bitmap scheme
instead of the buddy scheme.  The purpose of this change is to eliminate
the touching of the actual memory being allocated.

Since the change modifies the interface, a change to the uncached allocator
(arch/ia64/kernel/uncached.c) is also required.

Both Andrey Volkov and Jes Sorenson have expressed a desire that the
gen_pool allocator not write to the memory being managed. See the
following:

  http://marc.theaimsgroup.com/?l=linux-kernel&m=113518602713125&w=2
  http://marc.theaimsgroup.com/?l=linux-kernel&m=113533568827916&w=2

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Andrey Volkov <avolkov@varma-el.com>
Acked-by: Jes Sorensen <jes@trained-monkey.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:42:49 -07:00

36 lines
1.1 KiB
C

/*
* Basic general purpose allocator for managing special purpose memory
* not managed by the regular kmalloc/kfree interface.
* Uses for this includes on-device special memory, uncached memory
* etc.
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
/*
* General purpose special memory pool descriptor.
*/
struct gen_pool {
rwlock_t lock;
struct list_head chunks; /* list of chunks in this pool */
int min_alloc_order; /* minimum allocation order */
};
/*
* General purpose special memory pool chunk descriptor.
*/
struct gen_pool_chunk {
spinlock_t lock;
struct list_head next_chunk; /* next chunk in pool */
unsigned long start_addr; /* starting address of memory chunk */
unsigned long end_addr; /* ending address of memory chunk */
unsigned long bits[0]; /* bitmap for allocating memory chunk */
};
extern struct gen_pool *gen_pool_create(int, int);
extern int gen_pool_add(struct gen_pool *, unsigned long, size_t, int);
extern unsigned long gen_pool_alloc(struct gen_pool *, size_t);
extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);