diff options
Diffstat (limited to 'drivers/of/fdt.c')
| -rw-r--r-- | drivers/of/fdt.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index ecc7a02d868..9aa012e6ea0 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -26,6 +26,54 @@ #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ #include <asm/page.h> +/* + * of_fdt_limit_memory - limit the number of regions in the /memory node + * @limit: maximum entries + * + * Adjust the flattened device tree to have at most 'limit' number of + * memory entries in the /memory node. This function may be called + * any time after initial_boot_param is set. + */ +void of_fdt_limit_memory(int limit) +{ + int memory; + int len; + const void *val; + int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; + int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; + const uint32_t *addr_prop; + const uint32_t *size_prop; + int root_offset; + int cell_size; + + root_offset = fdt_path_offset(initial_boot_params, "/"); + if (root_offset < 0) + return; + + addr_prop = fdt_getprop(initial_boot_params, root_offset, + "#address-cells", NULL); + if (addr_prop) + nr_address_cells = fdt32_to_cpu(*addr_prop); + + size_prop = fdt_getprop(initial_boot_params, root_offset, + "#size-cells", NULL); + if (size_prop) + nr_size_cells = fdt32_to_cpu(*size_prop); + + cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells); + + memory = fdt_path_offset(initial_boot_params, "/memory"); + if (memory > 0) { + val = fdt_getprop(initial_boot_params, memory, "reg", &len); + if (len > limit*cell_size) { + len = limit*cell_size; + pr_debug("Limiting number of entries to %d\n", limit); + fdt_setprop(initial_boot_params, memory, "reg", val, + len); + } + } +} + /** * of_fdt_is_compatible - Return true if given node from the given blob has * compat in its compatible list |