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

From: Avri Altman
Date: Tue Apr 06 2021 - 03:19:26 EST

> >>
> >> On 2021-04-06 13:20, Avri Altman wrote:
> >> >> > -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).
> >> > OK.
> >>
> >> Hi Avri,
> >>
> >> Checked on my setup, this lead to compilation error. Will you fix it
> >> in
> >> next version?
> >>
> >> warning: variable 'flags' is uninitialized when used here
> >> [-Wuninitialized]
> > Yeah - I will pass it to __ufshpb_evict_region and drop the
> > lockdep_assert call.
> >
>
> Please paste the sample code/change here so that I can move forward
> quickly.
Thanks a lot. Also attaching the patch if its more convenient.

Thanks,
Avri

$ git show 5d33d36e8704
commit 5d33d36e87047d27a546ad3529cb7837186b47b2
Author: Avri Altman <avri.altman@xxxxxxx>
Date: Tue Jun 30 15:14:31 2020 +0300

scsi: ufshpb: Region inactivation in host mode

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.altman@xxxxxxx>
Reviewed-by: Daejun Park <daejun7.park@xxxxxxxxxxx>
Change-Id: I1a6696b38d4abfb4d9fbe44e84016a6238825125

diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index aefb6dc160ee..54a3ea9f5732 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 +1111,35 @@ 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,
+ unsigned long flags)
{
struct victim_select_info *lru_info;
struct ufshpb_subregion *srgn;
int srgn_idx;

+ if (hpb->is_hcm) {
+ int ret;
+
+ spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
+ 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 +1148,8 @@ 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 +1171,7 @@ 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, flags);
}
out:
spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
@@ -1285,7 +1305,9 @@ 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, flags);
+ if (ret)
+ goto out;
}

/*
@@ -1856,6 +1878,7 @@ 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 +1887,7 @@ 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 +2012,7 @@ 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 {

Attachment: v8-0006-scsi-ufshpb-Region-inactivation-in-host-mode.patch
Description: v8-0006-scsi-ufshpb-Region-inactivation-in-host-mode.patch