In host mode, eviction is considered an extreme measure.
verify that the entering region has enough reads, and the exiting
region has much less reads.
Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
Reviewed-by: Daejun Park <daejun7.park@xxxxxxxxxxx>
---
drivers/scsi/ufs/ufshpb.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index b080bd9ca35a..f9efef35316e 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -17,6 +17,7 @@
#include "../sd.h"
#define ACTIVATION_THRESHOLD 8 /* 8 IOs */
+#define EVICTION_THRESHOLD (ACTIVATION_THRESHOLD << 5) /* 256 IOs */
/* memory management */
static struct kmem_cache *ufshpb_mctx_cache;
@@ -1057,6 +1058,13 @@ static struct ufshpb_region *ufshpb_victim_lru_info(struct ufshpb_lu *hpb)
if (ufshpb_check_srgns_issue_state(hpb, rgn))
continue;
+ /*
+ * in host control mode, verify that the exiting region
+ * has less reads
+ */
+ if (hpb->is_hcm && rgn->reads > (EVICTION_THRESHOLD >> 1))
+ continue;
+
victim_rgn = rgn;
break;
}
@@ -1229,7 +1237,7 @@ static int ufshpb_issue_map_req(struct ufshpb_lu *hpb,
static int ufshpb_add_region(struct ufshpb_lu *hpb, struct ufshpb_region *rgn)
{
- struct ufshpb_region *victim_rgn;
+ struct ufshpb_region *victim_rgn = NULL;
struct victim_select_info *lru_info = &hpb->lru_info;
unsigned long flags;
int ret = 0;
@@ -1256,7 +1264,15 @@ static int ufshpb_add_region(struct ufshpb_lu *hpb, struct ufshpb_region *rgn)
* It is okay to evict the least recently used region,
* because the device could detect this region
* by not issuing HPB_READ
+ *
+ * in host control mode, verify that the entering
+ * region has enough reads
*/
+ if (hpb->is_hcm && rgn->reads < EVICTION_THRESHOLD) {
+ ret = -EACCES;
+ goto out;
+ }
+
victim_rgn = ufshpb_victim_lru_info(hpb);
if (!victim_rgn) {
dev_warn(&hpb->sdev_ufs_lu->sdev_dev,
--
2.25.1
