Nam Cao <namcao@xxxxxxxxxxxxx> writes:
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index fa34cf55037b..f600cfee0aef 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -197,7 +197,6 @@ early_param("mem", early_mem);
> static void __init setup_bootmem(void)
> {
> phys_addr_t vmlinux_end = __pa_symbol(&_end);
> - phys_addr_t max_mapped_addr;
> phys_addr_t phys_ram_end, vmlinux_start;
>
> if (IS_ENABLED(CONFIG_XIP_KERNEL))
> @@ -238,17 +237,9 @@ static void __init setup_bootmem(void)
> /*
> * memblock allocator is not aware of the fact that last 4K bytes of
> * the addressable memory can not be mapped because of IS_ERR_VALUE
> - * macro. Make sure that last 4k bytes are not usable by memblock
> - * if end of dram is equal to maximum addressable memory. For 64-bit
> - * kernel, this problem can't happen here as the end of the virtual
> - * address space is occupied by the kernel mapping then this check must
> - * be done as soon as the kernel mapping base address is determined.
> + * macro. Make sure that last 4k bytes are not usable by memblock.
> */
> - if (!IS_ENABLED(CONFIG_64BIT)) {
> - max_mapped_addr = __pa(~(ulong)0);
> - if (max_mapped_addr == (phys_ram_end - 1))
> - memblock_set_current_limit(max_mapped_addr - 4096);
> - }
> + memblock_reserve(__pa(-PAGE_SIZE), PAGE_SIZE);
>
> min_low_pfn = PFN_UP(phys_ram_base);
> max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
Nice! Would you mind submitting this as a proper fix (unless there's a
way to do it non-arch specific like Matthew pointed out).
Björn
