From 6c59cb501b86f8cddc486d6846732375f7baef24 Mon Sep 17 00:00:00 2001 From: Avri Altman Date: Mon, 12 Jul 2021 12:50:32 +0300 Subject: [PATCH] scsi: ufs: ufshpb: Make eviction depend on region's reads In host mode, eviction is considered an extreme measure. Verify that the entering region has enough reads, and the exiting region has fewer reads. Link: https://lore.kernel.org/r/20210712095039.8093-6-avri.altman@wdc.com Reviewed-by: Daejun Park Signed-off-by: Avri Altman Signed-off-by: Martin K. Petersen --- 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 a330c4922965..912bc6e5f3f8 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; @@ -1056,6 +1057,13 @@ 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 fewer reads + */ + if (hpb->is_hcm && rgn->reads > (EVICTION_THRESHOLD >> 1)) + continue; + victim_rgn = rgn; break; } @@ -1223,7 +1231,7 @@ 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; @@ -1250,7 +1258,15 @@ 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,