On Fri, 2021-02-05 at 11:29 +0800, Can Guo wrote: > > + return ppn_table[offset]; > > +} > > + > > +static void > > +ufshpb_get_pos_from_lpn(struct ufshpb_lu *hpb, unsigned long lpn, > > int > > *rgn_idx, > > + int *srgn_idx, int *offset) > > +{ > > + int rgn_offset; > > + > > + *rgn_idx = lpn >> hpb->entries_per_rgn_shift; > > + rgn_offset = lpn & hpb->entries_per_rgn_mask; > > + *srgn_idx = rgn_offset >> hpb->entries_per_srgn_shift; > > + *offset = rgn_offset & hpb->entries_per_srgn_mask; > > +} > > + > > +static void > > +ufshpb_set_hpb_read_to_upiu(struct ufshpb_lu *hpb, struct > > ufshcd_lrb > > *lrbp, > > + u32 lpn, u64 ppn, unsigned int > > transfer_len) > > +{ > > + unsigned char *cdb = lrbp->cmd->cmnd; > > + > > + cdb[0] = UFSHPB_READ; > > + > > + put_unaligned_be64(ppn, &cdb[6]); > > You are assuming the HPB entries read out by "HPB Read Buffer" cmd > are > in Little > Endian, which is why you are using put_unaligned_be64 here. > Actaully, here uses put_unaligned_be64 is no problem. SCSI command should be big-endian filled. I Think the problem is that geting ppn from HPB cache in ufshpb_get_ppn(). ... e0000001f: 12 34 56 78 90 fa de ef ... + +static u64 ufshpb_get_ppn(struct ufshpb_lu *hpb, + struct ufshpb_map_ctx *mctx, int pos, int *error) +{ + u64 *ppn_table; // It s a 64 bits pointer + 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]; +} > this assumption > is not right for all the other flash vendors - HPB entries read out > by > "HPB Read Buffer" > cmd may come in Big Endian, if so, their random read performance are > screwed. > Actually, I have seen at least two flash vendors acting so. I had to > modify this line > to get the code work properly on my setups. > > Meanwhile, in your cover letter, you mentioned that the performance > data > is collected > on a UFS2.1 device. Please re-collect the data on a real UFS3.1 > device > and let me > know the part number. Otherwise, the data is not quite convincing to > us. > > Regards, > Can Guo.