diff options
| -rw-r--r-- | mm/cma.c | 49 |
1 files changed, 33 insertions, 16 deletions
@@ -253,23 +253,24 @@ int __init cma_declare_contiguous(phys_addr_t base, return -EINVAL; /* - * adjust limit to avoid crossing low/high memory boundary for - * automatically allocated regions + * If allocating at a fixed base the request region must not cross the + * low/high memory boundary. */ - if (((limit == 0 || limit > memblock_end) && - (memblock_end - size < highmem_start && - memblock_end > highmem_start)) || - (!fixed && limit > highmem_start && limit - size < highmem_start)) { - limit = highmem_start; - } - - if (fixed && base < highmem_start && base+size > highmem_start) { + if (fixed && base < highmem_start && base + size > highmem_start) { ret = -EINVAL; pr_err("Region at %08lx defined on low/high memory boundary (%08lx)\n", (unsigned long)base, (unsigned long)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 (fixed) { if (memblock_is_region_reserved(base, size) || @@ -278,14 +279,30 @@ int __init cma_declare_contiguous(phys_addr_t base, 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; } ret = cma_init_reserved_mem(base, size, order_per_bit, res_cma); |