From 2af2b50acf9b9c38080a45f32a9c162e2a0f2de2 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 11 Aug 2021 10:51:02 +0200 Subject: of: fdt: Add generic support for handling usable memory range property Add support for handling the "linux,usable-memory-range" property in the "/chosen" node to the FDT core code. This can co-exist safely with the architecture-specific handling, until the latter has been removed. Signed-off-by: Geert Uytterhoeven Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/3bd69bada93ee59b7d23c38b3527fc1654e19343.1628670468.git.geert+renesas@glider.be --- drivers/of/fdt.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'drivers/of') 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) -- cgit v1.2.3