Re: [PATCH 1/3] dmaengine: idxd: Add descriptor definitions for 16 bytes of pattern in memory fill operation

[Dave Jiang]

On 11/7/2022 4:39 PM, Fenghua Yu wrote:
> The memory fill operation (0x04) can fill in memory with either 8 bytes
> or 16 bytes of pattern. To fill in memory with 16 bytes of pattern, the
> first 8 bytes are provided in pattern lower in bytes 16-23 and the next
> 8 bytes are in pattern upper in bytes 40-47 in the descriptor. Currently
> only 8 bytes of pattern is enabled.
>
> Add descriptor definitions for pattern lower and pattern upper so that
> user can use 16 bytes of pattern to fill memory.
>
> Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
> Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> ---
>   include/uapi/linux/idxd.h | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/include/uapi/linux/idxd.h b/include/uapi/linux/idxd.h
> index 095299c75828..04a2f6411820 100644
> --- a/include/uapi/linux/idxd.h
> +++ b/include/uapi/linux/idxd.h
> @@ -179,6 +179,7 @@ struct dsa_hw_desc {
>   		uint64_t	rdback_addr;
>   		uint64_t	pattern;
>   		uint64_t	desc_list_addr;
> +		uint64_t	pattern_lower;
>   	};
>   	union {
>   		uint64_t	dst_addr;
> @@ -243,6 +244,11 @@ struct dsa_hw_desc {
>   			uint16_t	dest_app_tag_seed;
>   		};
>   
> +		/* Fill */
> +		struct {

I don't think the anon struct is needed here. If there are others, that 
can be added later with the next patch that needs it.

> +			uint64_t	pattern_upper;
> +		};
> +
>   		uint8_t		op_specific[24];
>   	};
>   } __attribute__((packed));