Re: [PATCH v2 1/2] riscv: errata: fix T-Head dcache.cva encoding

Drew Fustini
2023-09-04T19:43:31Z

On Sun, Aug 27, 2023 at 05:08:12PM +0800, Jisheng Zhang wrote:
> From: Icenowy Zheng <uwu@icenowy.me>
>
> The dcache.cva encoding shown in the comments are wrong, it's for
> dcache.cval1 (which is restricted to L1) instead.
>
> Fix this in the comment and in the hardcoded instruction.
>
> Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
> Tested-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com>
> Reviewed-by: Heiko Stuebner <heiko@sntech.de>
> Reviewed-by: Guo Ren <guoren@kernel.org>
> ---
> arch/riscv/include/asm/errata_list.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h
> index fb1a810f3d8c..feab334dd832 100644
> --- a/arch/riscv/include/asm/errata_list.h
> +++ b/arch/riscv/include/asm/errata_list.h
> @@ -100,7 +100,7 @@ asm volatile(ALTERNATIVE( \
> * | 31 - 25 | 24 - 20 | 19 - 15 | 14 - 12 | 11 - 7 | 6 - 0 |
> * 0000001 01001 rs1 000 00000 0001011
> * dcache.cva rs1 (clean, virtual address)
> - * 0000001 00100 rs1 000 00000 0001011
> + * 0000001 00101 rs1 000 00000 0001011
> *
> * dcache.cipa rs1 (clean then invalidate, physical address)
> * | 31 - 25 | 24 - 20 | 19 - 15 | 14 - 12 | 11 - 7 | 6 - 0 |
> @@ -113,7 +113,7 @@ asm volatile(ALTERNATIVE( \
> * 0000000 11001 00000 000 00000 0001011
> */
> #define THEAD_inval_A0 ".long 0x0265000b"
> -#define THEAD_clean_A0 ".long 0x0245000b"
> +#define THEAD_clean_A0 ".long 0x0255000b"
> #define THEAD_flush_A0 ".long 0x0275000b"
> #define THEAD_SYNC_S ".long 0x0190000b"
>
> --
> 2.40.1
>

Tested-by: Drew Fustini <dfustini@baylibre.com>

I applied this on top of the emmc series [1] and the dma-noncoherent dts
patch [2]. SDMA is now working with this patch applied. Before this
patch, the filesystems on the emmc were corrupted after mounting. It
makes sense that problem is solved by the correct cache clean
instruction being used.

Thanks,
Drew

[1] https://lore.kernel.org/linux-riscv/20230724-th1520-emmc-v2-0-132ed2e2171e@baylibre.com/
[2] https://lore.kernel.org/linux-riscv/ZOIBQI3L4kP7c%2FT1@xhacker/