Currently, the setup_bootmem() reserves memory from RAM start to the kernel end. This prevents us from exploring ways to use the RAM below (or before) the kernel start hence this patch updates setup_bootmem() to only reserve memory from the kernel start to the kernel end.
Signed-off-by: Mike Rapoport <[email protected]> Signed-off-by: Anup Patel <[email protected]> --- arch/riscv/mm/init.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 2e2f2567964c..99b42380d17d 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -18,6 +18,8 @@ #include <asm/pgtable.h> #include <asm/io.h> +extern char _start[]; + static void __init zone_sizes_init(void) { unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, }; @@ -93,15 +95,17 @@ void __init setup_bootmem(void) /* Find the memory region containing the kernel */ for_each_memblock(memory, reg) { - phys_addr_t vmlinux_end = __pa(_end); + phys_addr_t vmlinux_end = __pa(&_end); + phys_addr_t vmlinux_start = __pa(&_start); phys_addr_t end = reg->base + reg->size; if (reg->base <= vmlinux_end && vmlinux_end <= end) { /* - * Reserve from the start of the region to the end of + * Reserve from the start of the kernel to the end of * the kernel */ - memblock_reserve(reg->base, vmlinux_end - reg->base); + memblock_reserve(vmlinux_start, + vmlinux_end - vmlinux_start); mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET); } } @@ -177,7 +181,6 @@ struct mapping_ops { static inline void *__load_addr(void *ptr, uintptr_t load_pa) { - extern char _start; uintptr_t va = (uintptr_t)ptr; uintptr_t sz = (uintptr_t)(&_end) - (uintptr_t)(&_start); -- 2.17.1
