Re: [PATCH v5 05/10] scsi: ufshpb: Region inactivation in host mode

[Can Guo <cang@xxxxxxxxxxxxxx>]

On 2021-03-15 12:02, Can Guo wrote:
> On 2021-03-02 21:24, Avri Altman wrote:
> > I 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>
> > ---
> >  drivers/scsi/ufs/ufshpb.c | 14 ++++++++++++++
> >  drivers/scsi/ufs/ufshpb.h |  1 +
> >  2 files changed, 15 insertions(+)
> >
> > diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
> > index 6f4fd22eaf2f..0744feb4d484 100644
> > --- a/drivers/scsi/ufs/ufshpb.c
> > +++ b/drivers/scsi/ufs/ufshpb.c
> > @@ -907,6 +907,7 @@ static int ufshpb_execute_umap_req(struct 
> > ufshpb_lu *hpb,
> >
> >  	blk_execute_rq_nowait(q, NULL, req, 1, ufshpb_umap_req_compl_fn);
> >
> > +	hpb->stats.umap_req_cnt++;
> >  	return 0;
> >  }
> >
> > @@ -1103,6 +1104,12 @@ 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);
> > @@ -1115,6 +1122,10 @@ static void __ufshpb_evict_region(struct 
> > ufshpb_lu *hpb,
> >  	struct ufshpb_subregion *srgn;
> >  	int srgn_idx;
> >
> > +
> > +	if (hpb->is_hcm && ufshpb_issue_umap_single_req(hpb, rgn))
>
> __ufshpb_evict_region() is called with rgn_state_lock held and IRQ 
> disabled,
> when ufshpb_issue_umap_single_req() invokes blk_execute_rq_nowait(), 
> below
> warning shall pop up every time, fix it?
>
> void blk_execute_rq_nowait(struct request_queue *q, struct gendisk 
> *bd_disk,
> 		   struct request *rq, int at_head,
> 			   rq_end_io_fn *done)
> {
> 	WARN_ON(irqs_disabled());
> ...

Moreover, since we are here with rgn_state_lock held and IRQ disabled,
in ufshpb_get_req(), rq = kmem_cache_alloc(hpb->map_req_cache, 
GFP_KERNEL)
has the GFP_KERNEL flag, scheduling while atomic???

Can Guo.

> Thanks.
> Can Guo.
>
> > +		return;
> > +
> >  	lru_info = &hpb->lru_info;
> >
> >  	dev_dbg(&hpb->sdev_ufs_lu->sdev_dev, "evict region %d\n", 
> > rgn->rgn_idx);
> > @@ -1855,6 +1866,7 @@ 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,
> > @@ -1863,6 +1875,7 @@ 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,
> >  };
> >
> > @@ -1978,6 +1991,7 @@ 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 bd4308010466..84598a317897 100644
> > --- a/drivers/scsi/ufs/ufshpb.h
> > +++ b/drivers/scsi/ufs/ufshpb.h
> > @@ -186,6 +186,7 @@ struct ufshpb_stats {
> >  	u64 rb_inactive_cnt;
> >  	u64 map_req_cnt;
> >  	u64 pre_req_cnt;
> > +	u64 umap_req_cnt;
> >  };
> >
> >  struct ufshpb_lu {