Re: [PATCH v7 06/11] scsi: ufshpb: Region inactivation in host mode

[Can Guo]

On 2021-03-31 15:39, Avri Altman wrote:
In host mode, the host is expected to send HPB-WRITE-BUFFER with
buffer-id = 0x1 when it inactivates a region.
Use the map-requests pool as there is no point in assigning a
designated cache for umap-requests.

Signed-off-by: Avri Altman <avri.alt...@wdc.com>
---
 drivers/scsi/ufs/ufshpb.c | 35 +++++++++++++++++++++++++++++++----
 drivers/scsi/ufs/ufshpb.h |  1 +
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index aefb6dc160ee..fcc954f51bcf 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -914,6 +914,7 @@ static int ufshpb_execute_umap_req(struct ufshpb_lu 
*hpb,

        blk_execute_rq_nowait(NULL, req, 1, ufshpb_umap_req_compl_fn);

+       hpb->stats.umap_req_cnt++;
        return 0;
 }

@@ -1110,18 +1111,37 @@ static int ufshpb_issue_umap_req(struct 
ufshpb_lu *hpb,
        return -EAGAIN;
 }

+static int ufshpb_issue_umap_single_req(struct ufshpb_lu *hpb,
+                                       struct ufshpb_region *rgn)
+{
+       return ufshpb_issue_umap_req(hpb, rgn);
+}
+
 static int ufshpb_issue_umap_all_req(struct ufshpb_lu *hpb)
 {
        return ufshpb_issue_umap_req(hpb, NULL);
 }

-static void __ufshpb_evict_region(struct ufshpb_lu *hpb,
-                                 struct ufshpb_region *rgn)
+static int __ufshpb_evict_region(struct ufshpb_lu *hpb,
+                                struct ufshpb_region *rgn)
 {
        struct victim_select_info *lru_info;
        struct ufshpb_subregion *srgn;
        int srgn_idx;

+       lockdep_assert_held(&hpb->rgn_state_lock);
+
+       if (hpb->is_hcm) {
+               unsigned long flags;
+               int ret;
+
+               spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);

Never seen a usage like this... Here flags is used without being 
intialized.
The flag is needed when spin_unlock_irqrestore -> 
local_irq_restore(flags) to
restore the DAIF register (in terms of ARM).

Thanks,

Can Guo.

+               ret = ufshpb_issue_umap_single_req(hpb, rgn);
+               spin_lock_irqsave(&hpb->rgn_state_lock, flags);
+               if (ret)
+                       return ret;
+       }
+
        lru_info = &hpb->lru_info;

 	dev_dbg(&hpb->sdev_ufs_lu->sdev_dev, "evict region %d\n", 
rgn->rgn_idx);
@@ -1130,6 +1150,8 @@ static void __ufshpb_evict_region(struct 
ufshpb_lu *hpb,

        for_each_sub_region(rgn, srgn_idx, srgn)
                ufshpb_purge_active_subregion(hpb, srgn);
+
+       return 0;
 }

 static int ufshpb_evict_region(struct ufshpb_lu *hpb, struct
ufshpb_region *rgn)
@@ -1151,7 +1173,7 @@ static int ufshpb_evict_region(struct ufshpb_lu
*hpb, struct ufshpb_region *rgn)
                        goto out;
                }

-               __ufshpb_evict_region(hpb, rgn);
+               ret = __ufshpb_evict_region(hpb, rgn);
        }
 out:
        spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
@@ -1285,7 +1307,9 @@ static int ufshpb_add_region(struct ufshpb_lu
*hpb, struct ufshpb_region *rgn)
                                "LRU full (%d), choose victim %d\n",
                                atomic_read(&lru_info->active_cnt),
                                victim_rgn->rgn_idx);
-                       __ufshpb_evict_region(hpb, victim_rgn);
+                       ret = __ufshpb_evict_region(hpb, victim_rgn);
+                       if (ret)
+                               goto out;
                }

                /*
@@ -1856,6 +1880,7 @@ ufshpb_sysfs_attr_show_func(rb_noti_cnt);
 ufshpb_sysfs_attr_show_func(rb_active_cnt);
 ufshpb_sysfs_attr_show_func(rb_inactive_cnt);
 ufshpb_sysfs_attr_show_func(map_req_cnt);
+ufshpb_sysfs_attr_show_func(umap_req_cnt);

 static struct attribute *hpb_dev_stat_attrs[] = {
        &dev_attr_hit_cnt.attr,
@@ -1864,6 +1889,7 @@ static struct attribute *hpb_dev_stat_attrs[] = {
        &dev_attr_rb_active_cnt.attr,
        &dev_attr_rb_inactive_cnt.attr,
        &dev_attr_map_req_cnt.attr,
+       &dev_attr_umap_req_cnt.attr,
        NULL,
 };

@@ -1988,6 +2014,7 @@ static void ufshpb_stat_init(struct ufshpb_lu 
*hpb)
        hpb->stats.rb_active_cnt = 0;
        hpb->stats.rb_inactive_cnt = 0;
        hpb->stats.map_req_cnt = 0;
+       hpb->stats.umap_req_cnt = 0;
 }

 static void ufshpb_param_init(struct ufshpb_lu *hpb)
diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
index 87495e59fcf1..1ea58c17a4de 100644
--- a/drivers/scsi/ufs/ufshpb.h
+++ b/drivers/scsi/ufs/ufshpb.h
@@ -191,6 +191,7 @@ struct ufshpb_stats {
        u64 rb_inactive_cnt;
        u64 map_req_cnt;
        u64 pre_req_cnt;
+       u64 umap_req_cnt;
 };

 struct ufshpb_lu {