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Date:   Fri, 30 Sep 2022 13:41:31 -0700
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Subject: Re: [PATCH v1 13/16] ufs: mcq: Add completion support of a cqe
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To:     Asutosh Das <quic_asutoshd@quicinc.com>, mani@kernel.org,
        quic_nguyenb@quicinc.com, quic_xiaosenh@quicinc.com,
        quic_cang@quicinc.com, quic_nitirawa@quicinc.com,
        quic_rampraka@quicinc.com, quic_richardp@quicinc.com,
        stanley.chu@mediatek.com, adrian.hunter@intel.com,
        avri.altman@wdc.com, beanhuo@micron.com, martin.petersen@oracle.com
Cc:     linux-scsi@vger.kernel.org, Alim Akhtar <alim.akhtar@samsung.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Kiwoong Kim <kwmad.kim@samsung.com>,
        open list <linux-kernel@vger.kernel.org>,
        "open list:ARM/QUALCOMM SUPPORT" <linux-arm-msm@vger.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-arm-kernel@lists.infradead.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>
References: <cover.1663894792.git.quic_asutoshd@quicinc.com>
 <80b24ce43aadac3bf561a60a65303f36ae8c0c21.1663894792.git.quic_asutoshd@quicinc.com>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <80b24ce43aadac3bf561a60a65303f36ae8c0c21.1663894792.git.quic_asutoshd@quicinc.com>
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Precedence: bulk

On 9/22/22 18:05, Asutosh Das wrote:
> +static int ufshcd_mcq_get_tag(struct ufs_hba *hba,
> +				     struct ufs_hw_queue *hwq,
> +				     struct cq_entry *cqe)
> +{
> +	dma_addr_t dma_addr;
> +
> +	/* Bits 63:7 UCD base address, 6:5 are reserved, 4:0 is SQ ID */
> +	dma_addr = le64_to_cpu(cqe->command_desc_base_addr) & CQE_UCD_BA;
> +
> +	return (dma_addr - hba->ucdl_dma_addr) /
> +		sizeof(struct utp_transfer_cmd_desc);
> +}

Since the above code only works correctly if the size of struct 
utp_transfer_cmd_desc is a multiple of 1 << 7, please add a 
BUILD_BUG_ON() statement that verifies that the size of 
utp_transfer_cmd_desc is a multiple of 128.

Thanks,

Bart.