Commit 505e3be6 authored by Laura Abbott's avatar Laura Abbott Committed by Linus Torvalds
Browse files

lib/genalloc.c: add power aligned algorithm 



One of the more common algorithms used for allocation is to align the
start address of the allocation to the order of size requested.  Add this
as an algorithm option for genalloc.

Signed-off-by: default avatarLaura Abbott <lauraa@codeaurora.org>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Acked-by: default avatarOlof Johansson <olof@lixom.net>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Riley <davidriley@chromium.org>
Cc: Ritesh Harjain <ritesh.harjani@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6a33979d

include/linux/genalloc.h

+4 −0
Original line number Diff line number Diff line
@@ -110,6 +110,10 @@ extern void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, 
extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,

		unsigned long start, unsigned int nr, void *data);



extern unsigned long gen_pool_first_fit_order_align(unsigned long *map,

		unsigned long size, unsigned long start, unsigned int nr,

		void *data);



extern unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size,

		unsigned long start, unsigned int nr, void *data);

lib/genalloc.c

+20 −0
Original line number Diff line number Diff line
@@ -480,6 +480,26 @@ unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size, 
}

EXPORT_SYMBOL(gen_pool_first_fit);



/**

 * gen_pool_first_fit_order_align - find the first available region

 * of memory matching the size requirement. The region will be aligned

 * to the order of the size specified.

 * @map: The address to base the search on

 * @size: The bitmap size in bits

 * @start: The bitnumber to start searching at

 * @nr: The number of zeroed bits we're looking for

 * @data: additional data - unused

 */

unsigned long gen_pool_first_fit_order_align(unsigned long *map,

		unsigned long size, unsigned long start,

		unsigned int nr, void *data)

{

	unsigned long align_mask = roundup_pow_of_two(nr) - 1;



	return bitmap_find_next_zero_area(map, size, start, nr, align_mask);

}

EXPORT_SYMBOL(gen_pool_first_fit_order_align);



/**

 * gen_pool_best_fit - find the best fitting region of memory

 * macthing the size requirement (no alignment constraint)

CRA Git | Maintained and supported by SUSTech CRA and CCSE