scsi: ufs: Add checking lifetime attribute for WriteBooster

Because WB performs writes in SLC mode, it is not possible to use
WriteBooster indefinitely. Vendors can set a lifetime limit in the device.
If the lifetime exceeds this limit, the device ican disable the WB feature.

The feature is defined in the "bWriteBoosterBufferLifeTimeEst (IDN = 1E)"
attribute.

With lifetime exceeding the limit value, the current driver continuously
performs the following query:

	- Write Flag: WB_ENABLE / DISABLE
	- Read attr: Available Buffer Size
	- Read attr: Current Buffer Size

This patch recognizes that WriteBooster is no longer supported by the
device, and prevents unnecessary queries.

Link: https://lore.kernel.org/r/1891546521.01643252701746.JavaMail.epsvc@epcpadp3
Reviewed-by: Asutosh Das <quic_asutoshd@quicinc.com>
Acked-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Jinyoung Choi <j-young.choi@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 0bfdca3e648e..4a00c24a3209 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -43,6 +43,12 @@
 /* WriteBooster buffer is available only for the logical unit from 0 to 7 */
 #define UFS_UPIU_MAX_WB_LUN_ID	8
 
+/*
+ * WriteBooster buffer lifetime has a limit setted by vendor.
+ * If it is over the limit, WriteBooster feature will be disabled.
+ */
+#define UFS_WB_EXCEED_LIFETIME		0x0B
+
 /* Well known logical unit id in LUN field of UPIU */
 enum {
 	UFS_UPIU_REPORT_LUNS_WLUN	= 0x81,