RE: [PATCH v21 3/4] scsi: ufs: Prepare HPB read for cached sub-region

[Avri Altman <Avri.Altman@wdc.com>]

> +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.

Thanks,
Avri

> +}
> +