Re: [PATCH v5 06/10] scsi: ufshpb: Add hpb dev reset response

[Can Guo]

On 2021-03-17 19:23, Avri Altman wrote:
> > On 2021-03-02 21:24, Avri Altman wrote:
> > > The spec does not define what is the host's recommended response when
> > > the device send hpb dev reset response (oper 0x2).
> > >
> > > We will update all active hpb regions: mark them and do that on the
> > > next
> > > read.
> > >
> > > Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
> > > ---
> > >  drivers/scsi/ufs/ufshpb.c | 47
> > ++++++++++++++++++++++++++++++++++++---
> > >  drivers/scsi/ufs/ufshpb.h |  2 ++
> > >  2 files changed, 46 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
> > > index 0744feb4d484..0034fa03fdc6 100644
> > > --- a/drivers/scsi/ufs/ufshpb.c
> > > +++ b/drivers/scsi/ufs/ufshpb.c
> > > @@ -642,7 +642,8 @@ int ufshpb_prep(struct ufs_hba *hba, struct
> > > ufshcd_lrb *lrbp)
> > >               if (rgn->reads == ACTIVATION_THRESHOLD)
> > >                       activate = true;
> > >               spin_unlock_irqrestore(&rgn->rgn_lock, flags);
> > > -             if (activate) {
> > > +             if (activate ||
> > > +                 test_and_clear_bit(RGN_FLAG_UPDATE, &rgn->rgn_flags)) {
> > >                       spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> > >                       ufshpb_update_active_info(hpb, rgn_idx, srgn_idx);
> > >                       hpb->stats.rb_active_cnt++;
> > > @@ -1480,6 +1481,20 @@ void ufshpb_rsp_upiu(struct ufs_hba *hba,
> > > struct ufshcd_lrb *lrbp)
> > >       case HPB_RSP_DEV_RESET:
> > >               dev_warn(&hpb->sdev_ufs_lu->sdev_dev,
> > >                        "UFS device lost HPB information during PM.\n");
> > > +
> > > +             if (hpb->is_hcm) {
> > > +                     struct scsi_device *sdev;
> > > +
> > > +                     __shost_for_each_device(sdev, hba->host) {
> > > +                             struct ufshpb_lu *h = sdev->hostdata;
> > > +
> > > +                             if (!h)
> > > +                                     continue;
> > > +
> > > +                             schedule_work(&hpb->ufshpb_lun_reset_work);
> > > +                     }
> > > +             }
> > > +
> > >               break;
> > >       default:
> > >               dev_notice(&hpb->sdev_ufs_lu->sdev_dev,
> > > @@ -1594,6 +1609,25 @@ static void
> > > ufshpb_run_inactive_region_list(struct ufshpb_lu *hpb)
> > >       spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
> > >  }
> > >
> > > +static void ufshpb_reset_work_handler(struct work_struct *work)
> >
> > Just curious, directly doing below things inside ufshpb_rsp_upiu() 
> > does
> > not
> > seem a problem to me, does this really deserve a separate work?
> I don't know, I never even consider of doing this.
> The active region list may contain up to few thousands of regions -
> It is not rare to see configurations that covers the entire device.

Yes, true, it can be a huge list. But what does the ops 
"HPB_RSP_DEV_RESET"
really mean? The specs says "Device reset HPB Regions information", but 
I
don't know what is really happening. Could you please elaborate?

Thanks,
Can Guo.

> But yes, I can do that.
> Better to get ack from Daejun first.
>
> Thanks,
> Avri
>
> > Thanks,
> > Can Guo.
> >
> > > +{
> > > +     struct ufshpb_lu *hpb;
> > > +     struct victim_select_info *lru_info;
> > > +     struct ufshpb_region *rgn;
> > > +     unsigned long flags;
> > > +
> > > +     hpb = container_of(work, struct ufshpb_lu, ufshpb_lun_reset_work);
> > > +
> > > +     lru_info = &hpb->lru_info;
> > > +
> > > +     spin_lock_irqsave(&hpb->rgn_state_lock, flags);
> > > +
> > > +     list_for_each_entry(rgn, &lru_info->lh_lru_rgn, list_lru_rgn)
> > > +             set_bit(RGN_FLAG_UPDATE, &rgn->rgn_flags);
> > > +
> > > +     spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> > > +}
> > > +
> > >  static void ufshpb_normalization_work_handler(struct work_struct
> > > *work)
> > >  {
> > >       struct ufshpb_lu *hpb;
> > > @@ -1798,6 +1832,8 @@ static int ufshpb_alloc_region_tbl(struct
> > > ufs_hba *hba, struct ufshpb_lu *hpb)
> > >               } else {
> > >                       rgn->rgn_state = HPB_RGN_INACTIVE;
> > >               }
> > > +
> > > +             rgn->rgn_flags = 0;
> > >       }
> > >
> > >       return 0;
> > > @@ -2012,9 +2048,12 @@ static int ufshpb_lu_hpb_init(struct ufs_hba
> > > *hba, struct ufshpb_lu *hpb)
> > >       INIT_LIST_HEAD(&hpb->list_hpb_lu);
> > >
> > >       INIT_WORK(&hpb->map_work, ufshpb_map_work_handler);
> > > -     if (hpb->is_hcm)
> > > +     if (hpb->is_hcm) {
> > >               INIT_WORK(&hpb->ufshpb_normalization_work,
> > >                         ufshpb_normalization_work_handler);
> > > +             INIT_WORK(&hpb->ufshpb_lun_reset_work,
> > > +                       ufshpb_reset_work_handler);
> > > +     }
> > >
> > >       hpb->map_req_cache = kmem_cache_create("ufshpb_req_cache",
> > >                         sizeof(struct ufshpb_req), 0, 0, NULL);
> > > @@ -2114,8 +2153,10 @@ static void ufshpb_discard_rsp_lists(struct
> > > ufshpb_lu *hpb)
> > >
> > >  static void ufshpb_cancel_jobs(struct ufshpb_lu *hpb)
> > >  {
> > > -     if (hpb->is_hcm)
> > > +     if (hpb->is_hcm) {
> > > +             cancel_work_sync(&hpb->ufshpb_lun_reset_work);
> > >               cancel_work_sync(&hpb->ufshpb_normalization_work);
> > > +     }
> > >       cancel_work_sync(&hpb->map_work);
> > >  }
> > >
> > > diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
> > > index 84598a317897..37c1b0ea0c0a 100644
> > > --- a/drivers/scsi/ufs/ufshpb.h
> > > +++ b/drivers/scsi/ufs/ufshpb.h
> > > @@ -121,6 +121,7 @@ struct ufshpb_region {
> > >       struct list_head list_lru_rgn;
> > >       unsigned long rgn_flags;
> > >  #define RGN_FLAG_DIRTY 0
> > > +#define RGN_FLAG_UPDATE 1
> > >
> > >       /* region reads - for host mode */
> > >       spinlock_t rgn_lock;
> > > @@ -217,6 +218,7 @@ struct ufshpb_lu {
> > >       /* for selecting victim */
> > >       struct victim_select_info lru_info;
> > >       struct work_struct ufshpb_normalization_work;
> > > +     struct work_struct ufshpb_lun_reset_work;
> > >
> > >       /* pinned region information */
> > >       u32 lu_pinned_start;