From: Igor Opaniuk igor.opaniuk@toradex.com
Add support for setting linux,usable-memory property in the memory node of device tree for the kernel [1].
This property holds a base address and size, describing a limited region in which memory may be considered available for use by the kernel. Memory outside of this range is not available for use.
[1] https://www.kernel.org/doc/Documentation/devicetree/bindings/chosen.txt
Signed-off-by: Igor Opaniuk igor.opaniuk@toradex.com Signed-off-by: Sanchayan Maity maitysanchayan@gmail.com Signed-off-by: Stefan Agner stefan.agner@toradex.com Reviewed-by: Oleksandr Suvorov oleksandr.suvorov@toradex.com ---
common/fdt_support.c | 35 +++++++++++++++++++++++++++++++++++ include/fdt_support.h | 1 + 2 files changed, 36 insertions(+)
diff --git a/common/fdt_support.c b/common/fdt_support.c index 6834399039..02cf5c6241 100644 --- a/common/fdt_support.c +++ b/common/fdt_support.c @@ -467,6 +467,41 @@ int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[], int banks) } return 0; } + +int fdt_set_usable_memory(void *blob, u64 start[], u64 size[], int areas) +{ + int err, nodeoffset; + int len; + u8 tmp[8 * 16]; /* Up to 64-bit address + 64-bit size */ + + if (areas > 8) { + printf("%s: num areas %d exceeds hardcoded limit %d\n", + __func__, areas, 8); + return -1; + } + + err = fdt_check_header(blob); + if (err < 0) { + printf("%s: %s\n", __func__, fdt_strerror(err)); + return err; + } + + /* find or create "/memory" node. */ + nodeoffset = fdt_find_or_add_subnode(blob, 0, "memory"); + if (nodeoffset < 0) + return nodeoffset; + + len = fdt_pack_reg(blob, tmp, start, size, areas); + + err = fdt_setprop(blob, nodeoffset, "linux,usable-memory", tmp, len); + if (err < 0) { + printf("WARNING: could not set %s %s.\n", + "reg", fdt_strerror(err)); + return err; + } + + return 0; +} #endif
int fdt_fixup_memory(void *blob, u64 start, u64 size) diff --git a/include/fdt_support.h b/include/fdt_support.h index cefb2b2cce..2286ea7793 100644 --- a/include/fdt_support.h +++ b/include/fdt_support.h @@ -94,6 +94,7 @@ int fdt_fixup_memory(void *blob, u64 start, u64 size); */ #ifdef CONFIG_ARCH_FIXUP_FDT_MEMORY int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[], int banks); +int fdt_set_usable_memory(void *blob, u64 start[], u64 size[], int banks); #else static inline int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[], int banks)