[PATCH v2] riscv: mm: update T-Head memory type definitions

Palmer Dabbelt palmer at dabbelt.com
Sun Nov 5 14:18:48 PST 2023


On Wed, 04 Oct 2023 05:07:35 PDT (-0700), jszhang at kernel.org wrote:
> On Tue, Sep 12, 2023 at 03:25:10PM +0800, Jisheng Zhang wrote:
>> Update T-Head memory type definitions according to C910 doc [1]
>> For NC and IO, SH property isn't configurable, hardcoded as SH,
>> so set SH for NOCACHE and IO.
>>
>> And also set bit[61](Bufferable) for NOCACHE according to the
>> table 6.1 in the doc [1].
>>
>> Link: https://github.com/T-head-Semi/openc910 [1]
>> Signed-off-by: Jisheng Zhang <jszhang at kernel.org>
>> Reviewed-by: Guo Ren <guoren at kernel.org>
>> Tested-by: Drew Fustini <dfustini at baylibre.com>
>
> Hi Palmer,
>
> I believe this is a fix, could you please review and take it for 6.6
> fix?

Sorry for being slow, I'm still pretty behind from getting COVID and such.
This LGTM, it's queued up for testing and it'll show up on for-next assuming
everything passes.

>
> Thanks
>
>> ---
>>
>> Since v1:
>>  - collect Reviewed-by and Tested-by tag
>>  - rebase on linux 6.6-rc1
>>
>>  arch/riscv/include/asm/pgtable-64.h | 14 +++++++++-----
>>  1 file changed, 9 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
>> index 7a5097202e15..9a2c780a11e9 100644
>> --- a/arch/riscv/include/asm/pgtable-64.h
>> +++ b/arch/riscv/include/asm/pgtable-64.h
>> @@ -126,14 +126,18 @@ enum napot_cont_order {
>>
>>  /*
>>   * [63:59] T-Head Memory Type definitions:
>> - *
>> - * 00000 - NC   Weakly-ordered, Non-cacheable, Non-bufferable, Non-shareable, Non-trustable
>> + * bit[63] SO - Strong Order
>> + * bit[62] C - Cacheable
>> + * bit[61] B - Bufferable
>> + * bit[60] SH - Shareable
>> + * bit[59] Sec - Trustable
>> + * 00110 - NC   Weakly-ordered, Non-cacheable, Bufferable, Shareable, Non-trustable
>>   * 01110 - PMA  Weakly-ordered, Cacheable, Bufferable, Shareable, Non-trustable
>> - * 10000 - IO   Strongly-ordered, Non-cacheable, Non-bufferable, Non-shareable, Non-trustable
>> + * 10010 - IO   Strongly-ordered, Non-cacheable, Non-bufferable, Shareable, Non-trustable
>>   */
>>  #define _PAGE_PMA_THEAD		((1UL << 62) | (1UL << 61) | (1UL << 60))
>> -#define _PAGE_NOCACHE_THEAD	0UL
>> -#define _PAGE_IO_THEAD		(1UL << 63)
>> +#define _PAGE_NOCACHE_THEAD	((1UL < 61) | (1UL << 60))
>> +#define _PAGE_IO_THEAD		((1UL << 63) | (1UL << 60))
>>  #define _PAGE_MTMASK_THEAD	(_PAGE_PMA_THEAD | _PAGE_IO_THEAD | (1UL << 59))
>>
>>  static inline u64 riscv_page_mtmask(void)
>> --
>> 2.40.1
>>
>>
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