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Message-ID: <b7527fc3-8750-69b8-40fa-214962ef50ed@intel.com>
Date:   Tue, 8 Nov 2022 08:13:57 -0800
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Subject: Re: [PATCH 1/3] dmaengine: idxd: Add descriptor definitions for 16
 bytes of pattern in memory fill operation
Content-Language: en-US
To:     Fenghua Yu <fenghua.yu@intel.com>, Vinod Koul <vkoul@kernel.org>
Cc:     dmaengine@vger.kernel.org,
        linux-kernel <linux-kernel@vger.kernel.org>
References: <20221108003944.2095567-1-fenghua.yu@intel.com>
 <20221108003944.2095567-2-fenghua.yu@intel.com>
From:   Dave Jiang <dave.jiang@intel.com>
In-Reply-To: <20221108003944.2095567-2-fenghua.yu@intel.com>
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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@intel.com>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
>   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));