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Subject: RE: RE: [PATCH v21 3/4] scsi: ufs: Prepare HPB read for cached
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Reply-To: daejun7.park@samsung.com
Sender: Daejun Park <daejun7.park@samsung.com>
From:   Daejun Park <daejun7.park@samsung.com>
To:     Avri Altman <Avri.Altman@wdc.com>,
        Daejun Park <daejun7.park@samsung.com>,
        Greg KH <gregkh@linuxfoundation.org>,
        "jejb@linux.ibm.com" <jejb@linux.ibm.com>,
        "martin.petersen@oracle.com" <martin.petersen@oracle.com>,
        "asutoshd@codeaurora.org" <asutoshd@codeaurora.org>,
        "stanley.chu@mediatek.com" <stanley.chu@mediatek.com>,
        "cang@codeaurora.org" <cang@codeaurora.org>,
        "bvanassche@acm.org" <bvanassche@acm.org>,
        "huobean@gmail.com" <huobean@gmail.com>,
        ALIM AKHTAR <alim.akhtar@samsung.com>
CC:     "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        JinHwan Park <jh.i.park@samsung.com>,
        Javier Gonzalez <javier.gonz@samsung.com>,
        SEUNGUK SHIN <seunguk.shin@samsung.com>,
        Sung-Jun Park <sungjun07.park@samsung.com>,
        yongmyung lee <ymhungry.lee@samsung.com>,
        Jinyoung CHOI <j-young.choi@samsung.com>,
        BoRam Shin <boram.shin@samsung.com>
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Message-ID: <20210222082038epcms2p761e3c08ed3ec77854a693d48dc9f1357@epcms2p7>
Date:   Mon, 22 Feb 2021 17:20:38 +0900
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> +static u64 ufshpb_get_ppn(struct ufshpb_lu *hpb,
> > +                         struct ufshpb_map_ctx *mctx, int pos, int *error)
> > +{
> > +       u64 *ppn_table;
> > +       struct page *page;
> > +       int index, offset;
> > +
> > +       index = pos / (PAGE_SIZE / HPB_ENTRY_SIZE);
> > +       offset = pos % (PAGE_SIZE / HPB_ENTRY_SIZE);
> > +
> > +       page = mctx->m_page[index];
> > +       if (unlikely(!page)) {
> > +               *error = -ENOMEM;
> > +               dev_err(&hpb->sdev_ufs_lu->sdev_dev,
> > +                       "error. cannot find page in mctx\n");
> > +               return 0;
> > +       }
> > +
> > +       ppn_table = page_address(page);
> > +       if (unlikely(!ppn_table)) {
> > +               *error = -ENOMEM;
> > +               dev_err(&hpb->sdev_ufs_lu->sdev_dev,
> > +                       "error. cannot get ppn_table\n");
> > +               return 0;
> > +       }
> > +
> > +       return ppn_table[offset];
> How about memcpy here as well?
> This way it is clear that the host is not manipulating the physical addresses in any way,
> And you won't need to invent the new ufshpb_fill_ppn_from_page.
>  
I changed the code to use ufshpb_fill_ppn_from_page() because it is more
genenal for use than ufshpb_get_ppn(). And I fixed to use memcpy for
setting cdb of HPB read.

Thanks,
Daejun