diff options
Diffstat (limited to 'drivers/of/reserved-mem.c')
-rw-r--r-- | drivers/of/reserved-mem.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/of/reserved-mem.c b/drivers/of/reserved-mem.c new file mode 100644 index 0000000000..34e61dfea3 --- /dev/null +++ b/drivers/of/reserved-mem.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0-only +// SPDX-FileCopyrightText: 2021 Rouven Czerwinski <r.czerwinski@pengutronix.de>, Pengutronix + +#include <stdio.h> +#include <of.h> +#include <of_address.h> + +#define MEMRESERVE_NCELLS 2 +#define MEMRESERVE_FLAGS (IORESOURCE_MEM | IORESOURCE_EXCLUSIVE) + +int of_reserved_mem_walk(int (*handler)(const struct resource *res)) +{ + struct device_node *node, *child; + int ncells = 0; + const __be32 *reg; + int ret; + + node = of_find_node_by_path("/reserved-memory"); + if (node) { + for_each_available_child_of_node(node, child) { + struct resource resource = {}; + + /* skip e.g. linux,cma */ + if (!of_get_property(child, "reg", NULL)) + continue; + + of_address_to_resource(child, 0, &resource); + + resource.name = child->name; + resource.flags = MEMRESERVE_FLAGS; + + ret = handler(&resource); + if (ret) + return ret; + } + } + + node = of_find_node_by_path("/memreserve"); + reg = of_get_property(node, "reg", &ncells); + ncells /= sizeof(__be32); + if (reg) { + char name[sizeof "fdt-memreserve-4294967295"]; + int i = 0, n = 0; + + while (i < ncells) { + struct resource resource = {}; + u64 size; + + snprintf(name, sizeof(name), "fdt-memreserve-%u", n++); + resource.name = name; + resource.flags = MEMRESERVE_FLAGS; + + resource.start = of_read_number(reg + i, MEMRESERVE_NCELLS); + i += MEMRESERVE_NCELLS; + + size = of_read_number(reg + i, MEMRESERVE_NCELLS); + i += MEMRESERVE_NCELLS; + + if (!size) + continue; + + resource.end = resource.start + size - 1; + + ret = handler(&resource); + if (ret) + return ret; + } + } + + return 0; +} |