diff options
Diffstat (limited to 'arch/arm64/mm/init.c')
| -rw-r--r-- | arch/arm64/mm/init.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index e19e06593e37..290794b1a0f1 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -188,10 +188,45 @@ static int __init early_mem(char *p) } early_param("mem", early_mem); +static int __init early_init_dt_scan_usablemem(unsigned long node, + const char *uname, int depth, void *data) +{ + struct memblock_region *usablemem = data; + const __be32 *reg; + int len; + + if (depth != 1 || strcmp(uname, "chosen") != 0) + return 0; + + reg = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); + if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) + return 1; + + usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®); + usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®); + + return 1; +} + +static void __init fdt_enforce_memory_region(void) +{ + struct memblock_region reg = { + .size = 0, + }; + + of_scan_flat_dt(early_init_dt_scan_usablemem, ®); + + if (reg.size) + memblock_cap_memory_range(reg.base, reg.size); +} + void __init arm64_memblock_init(void) { const s64 linear_region_size = -(s64)PAGE_OFFSET; + /* Handle linux,usable-memory-range property */ + fdt_enforce_memory_region(); + /* * Ensure that the linear region takes up exactly half of the kernel * virtual address space. This way, we can distinguish a linear address |