[v2,4/5] scsi: ufshpb: Add handing of device reset HPB regions Infos in HPB device mode

From: Bean Huo <beanhuo@micron.com>

In UFS HPB Spec JESD220-3A,

"5.8. Active and inactive information upon power cycle
...
When the device is powered off by the host, the device may restore L2P map data
upon power up or build from the host’s HPB READ command. In case device powered
up and lost HPB information, device can signal to the host through HPB Sense data,
by setting HPB Operation as ‘2’ which will inform the host that device reset HPB
information."

Therefore, for HPB device control mode, if the UFS device is reset via the RST_N
pin, the active region information in the device will be reset. If the host side
receives this notification from the device side, it is recommended to inactivate
all active regions in the host's HPB cache.

Signed-off-by: Bean Huo <beanhuo@micron.com>
---
 drivers/scsi/ufs/ufshpb.c | 73 ++++++++++++++++++++++++++++-----------
 1 file changed, 53 insertions(+), 20 deletions(-)

Hi Bean,

>From: Bean Huo <beanhuo@micron.com>
> 
>In UFS HPB Spec JESD220-3A,
> 
>"5.8. Active and inactive information upon power cycle
>...
>When the device is powered off by the host, the device may restore L2P map data
>upon power up or build from the host’s HPB READ command. In case device powered
>up and lost HPB information, device can signal to the host through HPB Sense data,
>by setting HPB Operation as ‘2’ which will inform the host that device reset HPB
>information."
> 
>Therefore, for HPB device control mode, if the UFS device is reset via the RST_N
>pin, the active region information in the device will be reset. If the host side
>receives this notification from the device side, it is recommended to inactivate
>all active regions in the host's HPB cache.
> 
>Signed-off-by: Bean Huo <beanhuo@micron.com>
>---
> drivers/scsi/ufs/ufshpb.c | 73 ++++++++++++++++++++++++++++-----------
> 1 file changed, 53 insertions(+), 20 deletions(-)
> 
>diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
>index 4538164fc493..4b15fa862beb 100644
>--- a/drivers/scsi/ufs/ufshpb.c
>+++ b/drivers/scsi/ufs/ufshpb.c
>@@ -1143,6 +1143,39 @@ static int ufshpb_add_region(struct ufshpb_lu *hpb, struct ufshpb_region *rgn)
>         spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
>         return ret;
> }
>+/**
>+ *ufshpb_submit_region_inactive() - submit a region to be inactivated later
>+ *@hpb: per-LU HPB instance
>+ *@region_index: the index associated with the region that will be inactivated later
>+ */
>+static void ufshpb_submit_region_inactive(struct ufshpb_lu *hpb, int region_index)
>+{
>+        int subregion_index;
>+        struct ufshpb_region *rgn;
>+        struct ufshpb_subregion *srgn;
>+
>+        /*
>+         * Remove this region from active region list and add it to inactive list
>+         */
>+        spin_lock(&hpb->rsp_list_lock);
>+        ufshpb_update_inactive_info(hpb, region_index);
How about separating the "hpb->stats.rb_inactive_cnt++" code from ufshpb_update_inactive_info()?
Because I think this code should only be used in ufshpb_rsp_req_region_update().

>+        spin_unlock(&hpb->rsp_list_lock);
>+
>+        rgn = hpb->rgn_tbl + region_index;
>+
>+        /*
>+         * Set subregion state to be HPB_SRGN_INVALID, there will no HPB read on this subregion
>+         */
>+        spin_lock(&hpb->rgn_state_lock);
>+        if (rgn->rgn_state != HPB_RGN_INACTIVE) {
>+                for (subregion_index = 0; subregion_index < rgn->srgn_cnt; subregion_index++) {
>+                        srgn = rgn->srgn_tbl + subregion_index;
>+                        if (srgn->srgn_state == HPB_SRGN_VALID)
>+                                srgn->srgn_state = HPB_SRGN_INVALID;
>+                }
>+        }
>+        spin_unlock(&hpb->rgn_state_lock);
>+}
> 
> static void ufshpb_rsp_req_region_update(struct ufshpb_lu *hpb,
>                                          struct utp_hpb_rsp *rsp_field)
>@@ -1202,25 +1235,8 @@ static void ufshpb_rsp_req_region_update(struct ufshpb_lu *hpb,
> 
>         for (i = 0; i < rsp_field->inactive_rgn_cnt; i++) {
>                 rgn_i = be16_to_cpu(rsp_field->hpb_inactive_field[i]);
>-                dev_dbg(&hpb->sdev_ufs_lu->sdev_dev,
>-                        "inactivate(%d) region %d\n", i, rgn_i);
>-
>-                spin_lock(&hpb->rsp_list_lock);
>-                ufshpb_update_inactive_info(hpb, rgn_i);
>-                spin_unlock(&hpb->rsp_list_lock);
>-
>-                rgn = hpb->rgn_tbl + rgn_i;
>-
>-                spin_lock(&hpb->rgn_state_lock);
>-                if (rgn->rgn_state != HPB_RGN_INACTIVE) {
>-                        for (srgn_i = 0; srgn_i < rgn->srgn_cnt; srgn_i++) {
>-                                srgn = rgn->srgn_tbl + srgn_i;
>-                                if (srgn->srgn_state == HPB_SRGN_VALID)
>-                                        srgn->srgn_state = HPB_SRGN_INVALID;
>-                        }
>-                }
>-                spin_unlock(&hpb->rgn_state_lock);
>-
>+                dev_dbg(&hpb->sdev_ufs_lu->sdev_dev, "inactivate(%d) region %d\n", i, rgn_i);
>+                ufshpb_submit_region_inactive(hpb, rgn_i);
>         }
> 
> out:
>@@ -1255,7 +1271,10 @@ static void ufshpb_dev_reset_handler(struct ufs_hba *hba)
> 
>         __shost_for_each_device(sdev, hba->host) {
>                 hpb = ufshpb_get_hpb_data(sdev);
>-                if (hpb && hpb->is_hcm)
>+                if (!hpb)
>+                        continue;
>+
>+                if (hpb->is_hcm) {
>                         /*
>                          * For the HPB host mode, in case device powered up and lost HPB
For the HPB host control mode, ...

>                          * information, we will set the region flag to be RGN_FLAG_UPDATE,
>@@ -1263,6 +1282,20 @@ static void ufshpb_dev_reset_handler(struct ufs_hba *hba)
>                          * in the UFS device).
>                          */
>                         ufshpb_set_regions_update(hpb);
>+                } else {
>+                        /*
>+                         * For the HPB device mode, we add all active regions to inactive list,
For the HPB device control mode, ...

>+                         * they will be inactivated later in ufshpb_map_work_handler()
>+                         */
>+                        struct victim_select_info *lru_info = &hpb->lru_info;
>+                        struct ufshpb_region *rgn;
>+
>+                        list_for_each_entry(rgn, &lru_info->lh_lru_rgn, list_lru_rgn)
>+                                ufshpb_submit_region_inactive(hpb, rgn->rgn_idx);
>+
>+                        if (ufshpb_get_state(hpb) == HPB_PRESENT)
>+                                queue_work(ufshpb_wq, &hpb->map_work);
>+                }
>         }
> }
> 
>-- 
>2.34.1
> 
> 

Best Regards,
Keoseong Park