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

[Can Guo <cang@codeaurora.org>]

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@wdc.com>
>> > ---
>> >  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;