From de9e14eebf33a60712a52a0bc6e08c043c0aba53 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Mon, 13 Oct 2014 15:51:09 -0700 Subject: drivers: dma-contiguous: add initialization from device tree Add a function to create CMA region from previously reserved memory and add support for handling 'shared-dma-pool' reserved-memory device tree nodes. Based on previous code provided by Josh Cartwright Signed-off-by: Marek Szyprowski Cc: Arnd Bergmann Cc: Michal Nazarewicz Cc: Grant Likely Cc: Laura Abbott Cc: Josh Cartwright Cc: Joonsoo Kim Cc: Kyungmin Park Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/cma.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 51 insertions(+), 11 deletions(-) (limited to 'mm/cma.c') diff --git a/mm/cma.c b/mm/cma.c index a951a3b3ed36..963bc4add9af 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -142,6 +142,54 @@ static int __init cma_init_reserved_areas(void) } core_initcall(cma_init_reserved_areas); +/** + * cma_init_reserved_mem() - create custom contiguous area from reserved memory + * @base: Base address of the reserved area + * @size: Size of the reserved area (in bytes), + * @order_per_bit: Order of pages represented by one bit on bitmap. + * @res_cma: Pointer to store the created cma region. + * + * This function creates custom contiguous area from already reserved memory. + */ +int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, + int order_per_bit, struct cma **res_cma) +{ + struct cma *cma; + phys_addr_t alignment; + + /* Sanity checks */ + if (cma_area_count == ARRAY_SIZE(cma_areas)) { + pr_err("Not enough slots for CMA reserved regions!\n"); + return -ENOSPC; + } + + if (!size || !memblock_is_region_reserved(base, size)) + return -EINVAL; + + /* ensure minimal alignment requied by mm core */ + alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order); + + /* alignment should be aligned with order_per_bit */ + if (!IS_ALIGNED(alignment >> PAGE_SHIFT, 1 << order_per_bit)) + return -EINVAL; + + if (ALIGN(base, alignment) != base || ALIGN(size, alignment) != size) + return -EINVAL; + + /* + * Each reserved area must be initialised later, when more kernel + * subsystems (like slab allocator) are available. + */ + cma = &cma_areas[cma_area_count]; + cma->base_pfn = PFN_DOWN(base); + cma->count = size >> PAGE_SHIFT; + cma->order_per_bit = order_per_bit; + *res_cma = cma; + cma_area_count++; + + return 0; +} + /** * cma_declare_contiguous() - reserve custom contiguous area * @base: Base address of the reserved area optional, use 0 for any @@ -165,7 +213,6 @@ int __init cma_declare_contiguous(phys_addr_t base, phys_addr_t alignment, unsigned int order_per_bit, bool fixed, struct cma **res_cma) { - struct cma *cma; phys_addr_t memblock_end = memblock_end_of_DRAM(); phys_addr_t highmem_start = __pa(high_memory); int ret = 0; @@ -237,16 +284,9 @@ int __init cma_declare_contiguous(phys_addr_t base, } } - /* - * Each reserved area must be initialised later, when more kernel - * subsystems (like slab allocator) are available. - */ - cma = &cma_areas[cma_area_count]; - cma->base_pfn = PFN_DOWN(base); - cma->count = size >> PAGE_SHIFT; - cma->order_per_bit = order_per_bit; - *res_cma = cma; - cma_area_count++; + ret = cma_init_reserved_mem(base, size, order_per_bit, res_cma); + if (ret) + goto err; pr_info("Reserved %ld MiB at %08lx\n", (unsigned long)size / SZ_1M, (unsigned long)base); -- cgit v1.2.3-59-g8ed1b