diff options
-rw-r--r-- | Documentation/devicetree/bindings/chosen.txt | 6 | ||||
-rw-r--r-- | drivers/of/fdt.c | 30 |
2 files changed, 33 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt index 5b0b94eb2d04..1cc3aa10dcb1 100644 --- a/Documentation/devicetree/bindings/chosen.txt +++ b/Documentation/devicetree/bindings/chosen.txt @@ -79,9 +79,9 @@ a different secondary CPU release mechanism) linux,usable-memory-range ------------------------- -This property (arm64 only) 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. +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. This property describes a limitation: memory within this range is only valid when also described through another mechanism that the kernel diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index a421c90c83fb..6c0cdee03deb 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -972,6 +972,32 @@ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) elfcorehdr_addr, elfcorehdr_size); } +static phys_addr_t cap_mem_addr; +static phys_addr_t cap_mem_size; + +/** + * early_init_dt_check_for_usable_mem_range - Decode usable memory range + * location from flat tree + * @node: reference to node containing usable memory range location ('chosen') + */ +static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) +{ + const __be32 *prop; + int len; + + pr_debug("Looking for usable-memory-range property... "); + + prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); + if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) + return; + + cap_mem_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); + cap_mem_size = dt_mem_next_cell(dt_root_size_cells, &prop); + + pr_debug("cap_mem_start=%pa cap_mem_size=%pa\n", &cap_mem_addr, + &cap_mem_size); +} + #ifdef CONFIG_SERIAL_EARLYCON int __init early_init_dt_scan_chosen_stdout(void) @@ -1120,6 +1146,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, early_init_dt_check_for_initrd(node); early_init_dt_check_for_elfcorehdr(node); + early_init_dt_check_for_usable_mem_range(node); /* Retrieve command line */ p = of_get_flat_dt_prop(node, "bootargs", &l); @@ -1253,6 +1280,9 @@ void __init early_init_dt_scan_nodes(void) /* Setup memory, calling early_init_dt_add_memory_arch */ of_scan_flat_dt(early_init_dt_scan_memory, NULL); + + /* Handle linux,usable-memory-range property */ + memblock_cap_memory_range(cap_mem_addr, cap_mem_size); } bool __init early_init_dt_scan(void *params) |