[PATCH v2] RISC-V: Mark IORESOURCE_EXCLUSIVE for reserved mem instead of IORESOURCE_BUSY

[Xianting Tian]

Hi

Could I get any comments for the v2 patch, thanks

在 2022/5/12 下午2:09, Xianting Tian 写道:
> Commit 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree")
> marked IORESOURCE_BUSY for reserved memory, which casued resource map
> failed in subsequent operations of related driver, so remove the
> IORESOURCE_BUSY flag. In order to prohibit userland mapping reserved
> memory, mark IORESOURCE_EXCLUSIVE for it.
>
> The code to reproduce the issue,
> dts:
>          mem0: memory at a0000000 {
>                  reg = <0x0 0xa0000000 0 0x1000000>;
>                  no-map;
>          };
>
>          &test {
>                  status = "okay";
>                  memory-region = <&mem0>;
>          };
>
> code:
>          np = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
>          ret = of_address_to_resource(np, 0, &r);
>          base = devm_ioremap_resource(&pdev->dev, &r);
>          // base = -EBUSY
>
> Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree")
> Reported-by: Huaming Jiang <jianghuaming.jhm at alibaba-inc.com>
> Reviewed-by: Guo Ren <guoren at kernel.org>
> Reviewed-by: Nick Kossifidis <mick at ics.forth.gr>
> Signed-off-by: Xianting Tian <xianting.tian at linux.alibaba.com>
> ---
>   arch/riscv/kernel/setup.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index 834eb652a7b9..e0a00739bd13 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -189,7 +189,7 @@ static void __init init_resources(void)
>   		res = &mem_res[res_idx--];
>   
>   		res->name = "Reserved";
> -		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
> +		res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
>   		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
>   		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
>   
> @@ -214,7 +214,7 @@ static void __init init_resources(void)
>   
>   		if (unlikely(memblock_is_nomap(region))) {
>   			res->name = "Reserved";
> -			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
> +			res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
>   		} else {
>   			res->name = "System RAM";
>   			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;