On Thu, Mar 21, 2019 at 09:47:58AM +0000, Anup Patel wrote:
> 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);
Sorry for misleading you here, but this can be done outside the loop as
well as the calculation of vmlinux_{start,end}.
> 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
>
--
Sincerely yours,
Mike.
