diff options
Diffstat (limited to 'mm/cma.c')
| -rw-r--r-- | mm/cma.c | 131 |
1 files changed, 107 insertions, 24 deletions
@@ -32,6 +32,7 @@ #include <linux/slab.h> #include <linux/log2.h> #include <linux/cma.h> +#include <linux/highmem.h> struct cma { unsigned long base_pfn; @@ -57,7 +58,9 @@ unsigned long cma_get_size(struct cma *cma) static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order) { - return (1UL << (align_order >> cma->order_per_bit)) - 1; + if (align_order <= cma->order_per_bit) + return 0; + return (1UL << (align_order - cma->order_per_bit)) - 1; } static unsigned long cma_bitmap_maxno(struct cma *cma) @@ -121,6 +124,7 @@ static int __init cma_activate_area(struct cma *cma) err: kfree(cma->bitmap); + cma->count = 0; return -EINVAL; } @@ -140,6 +144,54 @@ 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 * @size: Size of the reserved area (in bytes), @@ -162,12 +214,12 @@ 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; - pr_debug("%s(size %lx, base %08lx, limit %08lx alignment %08lx)\n", - __func__, (unsigned long)size, (unsigned long)base, - (unsigned long)limit, (unsigned long)alignment); + pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n", + __func__, &size, &base, &limit, &alignment); if (cma_area_count == ARRAY_SIZE(cma_areas)) { pr_err("Not enough slots for CMA reserved regions!\n"); @@ -192,41 +244,72 @@ int __init cma_declare_contiguous(phys_addr_t base, size = ALIGN(size, alignment); limit &= ~(alignment - 1); + if (!base) + fixed = false; + /* size should be aligned with order_per_bit */ if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit)) return -EINVAL; + /* + * If allocating at a fixed base the request region must not cross the + * low/high memory boundary. + */ + if (fixed && base < highmem_start && base + size > highmem_start) { + ret = -EINVAL; + pr_err("Region at %pa defined on low/high memory boundary (%pa)\n", + &base, &highmem_start); + goto err; + } + + /* + * If the limit is unspecified or above the memblock end, its effective + * value will be the memblock end. Set it explicitly to simplify further + * checks. + */ + if (limit == 0 || limit > memblock_end) + limit = memblock_end; + /* Reserve memory */ - if (base && fixed) { + if (fixed) { if (memblock_is_region_reserved(base, size) || memblock_reserve(base, size) < 0) { ret = -EBUSY; goto err; } } else { - phys_addr_t addr = memblock_alloc_range(size, alignment, base, - limit); + phys_addr_t addr = 0; + + /* + * All pages in the reserved area must come from the same zone. + * If the requested region crosses the low/high memory boundary, + * try allocating from high memory first and fall back to low + * memory in case of failure. + */ + if (base < highmem_start && limit > highmem_start) { + addr = memblock_alloc_range(size, alignment, + highmem_start, limit); + limit = highmem_start; + } + if (!addr) { - ret = -ENOMEM; - goto err; - } else { - base = addr; + addr = memblock_alloc_range(size, alignment, base, + limit); + if (!addr) { + ret = -ENOMEM; + goto err; + } } + + base = addr; } - /* - * 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); + pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M, + &base); return 0; err: |