From b26981c8f743d3cb64a6907eb1f5c6c4ba6ca672 Mon Sep 17 00:00:00 2001 From: Zhao Qiang Date: Mon, 30 Nov 2015 10:48:53 +0800 Subject: [PATCH] genalloc:support allocating specific region Add new algo for genalloc, it reserve a specific region of memory Signed-off-by: Zhao Qiang Signed-off-by: Scott Wood --- include/linux/genalloc.h | 11 +++++++++++ lib/genalloc.c | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+) diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h index 3c676ce46ee0..29d4385903d4 100644 --- a/include/linux/genalloc.h +++ b/include/linux/genalloc.h @@ -84,6 +84,13 @@ struct genpool_data_align { int align; /* alignment by bytes for starting address */ }; +/* + * gen_pool data descriptor for gen_pool_fixed_alloc. + */ +struct genpool_data_fixed { + unsigned long offset; /* The offset of the specific region */ +}; + extern struct gen_pool *gen_pool_create(int, int); extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long); extern int gen_pool_add_virt(struct gen_pool *, unsigned long, phys_addr_t, @@ -124,6 +131,10 @@ extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size, unsigned long start, unsigned int nr, void *data, struct gen_pool *pool); +extern unsigned long gen_pool_fixed_alloc(unsigned long *map, + unsigned long size, unsigned long start, unsigned int nr, + void *data, struct gen_pool *pool); + extern unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long size, unsigned long start, unsigned int nr, void *data, struct gen_pool *pool); diff --git a/lib/genalloc.c b/lib/genalloc.c index b8cf89d9e17d..5ec83cd93284 100644 --- a/lib/genalloc.c +++ b/lib/genalloc.c @@ -555,6 +555,38 @@ unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long size, } EXPORT_SYMBOL(gen_pool_first_fit_align); +/** + * gen_pool_fixed_alloc - reserve a specific region + * @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: data for alignment + * @pool: pool to get order from + */ +unsigned long gen_pool_fixed_alloc(unsigned long *map, unsigned long size, + unsigned long start, unsigned int nr, void *data, + struct gen_pool *pool) +{ + struct genpool_data_fixed *fixed_data; + int order; + unsigned long offset_bit; + unsigned long start_bit; + + fixed_data = data; + order = pool->min_alloc_order; + offset_bit = fixed_data->offset >> order; + if (WARN_ON(fixed_data->offset & (1UL << order - 1))) + return size; + + start_bit = bitmap_find_next_zero_area(map, size, + start + offset_bit, nr, 0); + if (start_bit != offset_bit) + start_bit = size; + return start_bit; +} +EXPORT_SYMBOL(gen_pool_fixed_alloc); + /** * gen_pool_first_fit_order_align - find the first available region * of memory matching the size requirement. The region will be aligned -- 2.34.1