[PATCH 4/4] riscv: Parse all memory blocks to remove unusable memory
Palmer Dabbelt
palmer at dabbelt.com
Sat Jul 25 01:12:42 EDT 2020
On Wed, 15 Jul 2020 16:30:09 PDT (-0700), Atish Patra wrote:
> Currently, maximum physical memory allowed is equal to -PAGE_OFFSET.
> That's why we remove any memory blocks spanning beyond that size. However,
> it is done only for memblock containing linux kernel which will not work
> if there are multiple memblocks.
>
> Process all memory blocks to figure out how much memory needs to be removed
> and remove at the end instead of updating the memblock list in place.
>
> Signed-off-by: Atish Patra <atish.patra at wdc.com>
> ---
> arch/riscv/mm/init.c | 31 +++++++++++++++++--------------
> 1 file changed, 17 insertions(+), 14 deletions(-)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index f818a47a72d1..79e9d55bdf1a 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -147,26 +147,29 @@ void __init setup_bootmem(void)
> {
> struct memblock_region *reg;
> phys_addr_t mem_size = 0;
> + phys_addr_t total_mem = 0;
> + phys_addr_t mem_start, end = 0;
> phys_addr_t vmlinux_end = __pa_symbol(&_end);
> phys_addr_t vmlinux_start = __pa_symbol(&_start);
>
> /* Find the memory region containing the kernel */
> for_each_memblock(memory, reg) {
> - phys_addr_t end = reg->base + reg->size;
> -
> - if (reg->base <= vmlinux_start && vmlinux_end <= end) {
> - mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
> -
> - /*
> - * Remove memblock from the end of usable area to the
> - * end of region
> - */
> - if (reg->base + mem_size < end)
> - memblock_remove(reg->base + mem_size,
> - end - reg->base - mem_size);
> - }
> + end = reg->base + reg->size;
> + if (!total_mem)
> + mem_start = reg->base;
> + if (reg->base <= vmlinux_start && vmlinux_end <= end)
> + BUG_ON(reg->size == 0);
> + total_mem = total_mem + reg->size;
> }
> - BUG_ON(mem_size == 0);
> +
> + /*
> + * Remove memblock from the end of usable area to the
> + * end of region
> + */
> + mem_size = min(total_mem, (phys_addr_t)-PAGE_OFFSET);
> + if (mem_start + mem_size < end)
> + memblock_remove(mem_start + mem_size,
> + end - mem_start - mem_size);
>
> /* Reserve from the start of the kernel to the end of the kernel */
> memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
Thanks, this one is also on fixes.
More information about the linux-riscv
mailing list