[PATCH] riscv: add a warning when physical memory address overflows

[Alexandre Ghiti]

Hi Yunhui,

On 14/08/2024 08:26, Yunhui Cui wrote:
> The part of physical memory that exceeds the size of the linear mapping
> will be discarded. When the system starts up normally, a warning message
> will be printed to prevent confusion caused by the mismatch between the
> system memory and the actual physical memory.
>
> Signed-off-by: Yunhui Cui <cuiyunhui at bytedance.com>
> ---
>   arch/riscv/mm/init.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 52290c9bd04bd..c93164dc51658 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -236,8 +236,12 @@ static void __init setup_bootmem(void)
>   	 */
>   	if (IS_ENABLED(CONFIG_64BIT)) {
>   		max_mapped_addr = __pa(PAGE_OFFSET) + KERN_VIRT_SIZE;
> -		memblock_cap_memory_range(phys_ram_base,
> -					  max_mapped_addr - phys_ram_base);
> +		if (memblock_end_of_DRAM() > max_mapped_addr) {
> +			memblock_cap_memory_range(phys_ram_base,
> +						  max_mapped_addr - phys_ram_base);
> +			pr_warn("Physical memory overflows the linear mapping size: region above 0x%llx removed",
> +				max_mapped_addr);
> +		}
>   	}
>   
>   


A bit weird to review and test my own patch, but here it is anyway :)

Reviewed-by: Alexandre Ghiti <alexghiti at rivosinc.com>

Tested-by: Alexandre Ghiti <alexghiti at rivosinc.com>

Thanks,

Alex