Re: [PATCH] riscv,entry: fix misaligned base for excp_vect_table

From: Anup Patel
Date: Wed Mar 17 2021 - 04:31:51 EST


On Wed, Mar 17, 2021 at 1:48 PM Zihao Yu <yuzihao@xxxxxxxxx> wrote:
>
> * In RV64, the size of each entry in excp_vect_table is 8 bytes. If the
> base of the table is not 8-byte aligned, loading an entry in the table
> will raise a misaligned exception. Although such exception will be
> handled by opensbi/bbl, this still causes performance degradation.
>
> Signed-off-by: Zihao Yu <yuzihao@xxxxxxxxx>

Looks good to me.

Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>

Regards,
Anup

> ---
> arch/riscv/kernel/entry.S | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
> index 744f3209c..76274a4a1 100644
> --- a/arch/riscv/kernel/entry.S
> +++ b/arch/riscv/kernel/entry.S
> @@ -447,6 +447,7 @@ ENDPROC(__switch_to)
> #endif
>
> .section ".rodata"
> + .align LGREG
> /* Exception vector table */
> ENTRY(excp_vect_table)
> RISCV_PTR do_trap_insn_misaligned
> --
> 2.20.1
>
>
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