Re: [RFC PATCH v3 1/4] ufs: core: prepare ufs for multi circular queue support

[Asutosh Das (asd)]

Hello Bean
Thanks for your comments. Responses inline.

On 9/5/2022 5:26 AM, Bean Huo wrote:
> Asutosh,
[...]
> >   static inline
> > -void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
> > +void ufshcd_send_command(struct ufs_hba *hba, struct ufshcd_lrb
> > *lrbp)
> >   {
> > -       struct ufshcd_lrb *lrbp = &hba->lrb[task_tag];
> > +       int task_tag = lrbp->task_tag;
> >          unsigned long flags;
> >   
> >          lrbp->issue_time_stamp = ktime_get();
> >          lrbp->compl_time_stamp = ktime_set(0, 0);
> > -       ufshcd_add_command_trace(hba, task_tag, UFS_CMD_SEND);
> > +       ufshcd_add_command_trace(hba, lrbp, UFS_CMD_SEND);
> >          ufshcd_clk_scaling_start_busy(hba);
> >          if (unlikely(ufshcd_should_inform_monitor(hba, lrbp)))
> >                  ufshcd_start_monitor(hba, lrbp);
> > @@ -2553,9 +2554,10 @@ void ufshcd_prepare_utp_scsi_cmd_upiu(struct
> > ufshcd_lrb *lrbp, u8 upiu_flags)
> >          /* command descriptor fields */
> >          ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
> >                                  UPIU_TRANSACTION_COMMAND, upiu_flags,
> > -                               lrbp->lun, lrbp->task_tag);
> > +                               lrbp->lun, lrbp->task_tag & 0xff);
> >          ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
> > -                               UPIU_COMMAND_SET_TYPE_SCSI, 0, 0, 0);
> > +                               UPIU_COMMAND_SET_TYPE_SCSI, 0, 0,
> > +                               (lrbp->task_tag & 0xf00) << 4);
> >   
>
> Are you sure here "(lrbp->task_tag & 0xf00) << 4" is correct?
EXT_IID is the higher nibble in DWORD1. So this looks correct to me.

COMMAND UPIU
0 	    1 	  2 	3
xx000001b Flags LUN Task Tag
4 			5 	6 	7
IID Command Set Type Reserved Reserved EXT_IID | Reserved
> this will overwrite other fields, see UPIU_HEADER_DWORD:
>
> #define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
>                          cpu_to_be32((byte3 << 24) | (byte2 << 16) |\
>                           (byte1 << 8) | (byte0))
>
>
>
> >   
> > -       ufshcd_send_command(hba, tag);
> > +       ufshcd_send_command(hba, lrbp);
> >          err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);
> >          ufshcd_add_query_upiu_trace(hba, err ? UFS_QUERY_ERR :
> > UFS_QUERY_COMP,
> >                                      (struct utp_upiu_req *)lrbp-
> > > ucd_rsp_ptr);
> > @@ -4513,6 +4515,7 @@ int ufshcd_make_hba_operational(struct ufs_hba
> > *hba)
> >                          REG_UTP_TRANSFER_REQ_LIST_BASE_L);
> >          ufshcd_writel(hba, upper_32_bits(hba->utrdl_dma_addr),
> >                          REG_UTP_TRANSFER_REQ_LIST_BASE_H);
> > +
> >          ufshcd_writel(hba, lower_32_bits(hba->utmrdl_dma_addr),
> >                          REG_UTP_TASK_REQ_LIST_BASE_L);
> >          ufshcd_writel(hba, upper_32_bits(hba->utmrdl_dma_addr),
> > @@ -5320,6 +5323,32 @@ static void ufshcd_release_scsi_cmd(struct
> > ufs_hba *hba,
> >          ufshcd_clk_scaling_update_busy(hba);
> >   }
> >   
> > +void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag)
>
> This function does only complete one task. What does cqe stand for?
CQE - Completion Queue Entry. The term 'task' is used for TM commands in 
scsi, hence there was a comment to change it to CQE.

> > +{
> > +       struct ufshcd_lrb *lrbp;
> > +       struct scsi_cmnd *cmd;
> > +
> > +       lrbp = &hba->lrb[task_tag];
> > +       lrbp->compl_time_stamp = ktime_get();
> > +       cmd = lrbp->cmd;
> > +       if (cmd) {
> > +               if (unlikely(ufshcd_should_inform_monitor(hba,
> > lrbp)))
> > +                       ufshcd_update_monitor(hba, lrbp);
> > +               ufshcd_add_command_trace(hba, lrbp, UFS_CMD_COMP);
> > +               cmd->result = ufshcd_transfer_rsp_status(hba, lrbp);
> > +               ufshcd_release_scsi_cmd(hba, lrbp);
> > +               /* Do not touch lrbp after scsi done */
> > +               scsi_done(cmd);
> > +       } else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE ||
> > +                  lrbp->command_type == UTP_CMD_TYPE_UFS_STORAGE) {
> > +               if (hba->dev_cmd.complete) {
> > +                       ufshcd_add_command_trace(hba, lrbp,
> > UFS_DEV_COMP);
> > +                       complete(hba->dev_cmd.complete);
> > +                       ufshcd_clk_scaling_update_busy(hba);
> > +               }
> > +       }
> > +}
> > +
>
>
> Kind regards,
> Bean