In host control mode the host is the originator of map requests. To not
flood the device with map requests, use a simple throttling mechanism
that limits the number of inflight map requests.
Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
---
drivers/scsi/ufs/ufshpb.c | 11 +++++++++++
drivers/scsi/ufs/ufshpb.h | 1 +
2 files changed, 12 insertions(+)
diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index 4639d3b5ddc0..f755f5a7775c 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -21,6 +21,7 @@
#define READ_TO_MS 1000
#define READ_TO_EXPIRIES 100
#define POLLING_INTERVAL_MS 200
+#define THROTTLE_MAP_REQ_DEFAULT 1
/* memory management */
static struct kmem_cache *ufshpb_mctx_cache;
@@ -747,6 +748,14 @@ static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
struct ufshpb_req *map_req;
struct bio *bio;
+ if (hpb->is_hcm &&
+ hpb->num_inflight_map_req >= THROTTLE_MAP_REQ_DEFAULT) {
+ dev_info(&hpb->sdev_ufs_lu->sdev_dev,
+ "map_req throttle. inflight %d throttle %d",
+ hpb->num_inflight_map_req, THROTTLE_MAP_REQ_DEFAULT);
+ return NULL;
+ }
+
map_req = ufshpb_get_req(hpb, srgn->rgn_idx, REQ_OP_SCSI_IN, false);
if (!map_req)
return NULL;
@@ -761,6 +770,7 @@ static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
map_req->rb.srgn_idx = srgn->srgn_idx;
map_req->rb.mctx = srgn->mctx;
+ hpb->num_inflight_map_req++;
return map_req;
}
@@ -770,6 +780,7 @@ static void ufshpb_put_map_req(struct ufshpb_lu *hpb,
{
bio_put(map_req->bio);
ufshpb_put_req(hpb, map_req);
+ hpb->num_inflight_map_req--;
}
static int ufshpb_clear_dirty_bitmap(struct ufshpb_lu *hpb,
diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
index c2821504a2d8..c9b8ee540704 100644
--- a/drivers/scsi/ufs/ufshpb.h
+++ b/drivers/scsi/ufs/ufshpb.h
@@ -213,6 +213,7 @@ struct ufshpb_lu {
struct ufshpb_req *pre_req;
int num_inflight_pre_req;
int throttle_pre_req;
+ int num_inflight_map_req;
struct list_head lh_pre_req_free;
int cur_read_id;
int pre_req_min_tr_len;
--
2.25.1
