[PATCH] lib: sbi: Refine the settings for switching to Virtual Supervisor Mode.

[Xiang W]

在 2024-04-09星期二的 17:23 +0800，Pope B.Lei写道：
> Although Mstatus.MPV is set, before executing mret, access to VS mode
> registers should use the actual register addresses, not the pseudonyms
> of S registers.
> 
> Signed-off-by: Pope B.Lei <popeblei at gmail.com>
> ---
Next time, please remember that v2 is missing from the subject.

otherwise look good to me.

Reviewed-by: Xiang W <wxjstz at 126.com>
> V1 -> V2: Simplify the if condition
> - 
>  lib/sbi/sbi_hart.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
> index 3d13694..ccdd12f 100644
> --- a/lib/sbi/sbi_hart.c
> +++ b/lib/sbi/sbi_hart.c
> @@ -1041,10 +1041,17 @@ sbi_hart_switch_mode(unsigned long arg0, unsigned long arg1,
>  	csr_write(CSR_MEPC, next_addr);
>  
>  	if (next_mode == PRV_S) {
> -		csr_write(CSR_STVEC, next_addr);
> -		csr_write(CSR_SSCRATCH, 0);
> -		csr_write(CSR_SIE, 0);
> -		csr_write(CSR_SATP, 0);
> +		if (next_virt) {
> +		    csr_write(CSR_VSTVEC, next_addr);
> +		    csr_write(CSR_VSSCRATCH, 0);
> +		    csr_write(CSR_VSIE, 0);
> +		    csr_write(CSR_VSATP, 0);
> +		} else {
> +		    csr_write(CSR_STVEC, next_addr);
> +		    csr_write(CSR_SSCRATCH, 0);
> +		    csr_write(CSR_SIE, 0);
> +		    csr_write(CSR_SATP, 0);
> +		}
>  	} else if (next_mode == PRV_U) {
>  		if (misa_extension('N')) {
>  			csr_write(CSR_UTVEC, next_addr);
> -- 
> 2.35.2.windows.1
> 
>