From: Jinyoung Choi <j-young.choi@samsung.com>
Date: Thu, 27 Jan 2022 12:00:25 +0900
Subject: [PATCH] scsi: ufs: Add checking lifetime attribute for WriteBooster
Git-commit: f681d1078d456ef4aea8da1bf5ccbd4081b0fbed
Patch-mainline: v5.18-rc1
References: jsc#PED-818

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>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/scsi/ufs/ufs.h    |  6 +++++
 drivers/scsi/ufs/ufshcd.c | 52 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)

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,
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 460d2b440d2e..41d85b69fa50 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5778,6 +5778,47 @@ static bool ufshcd_wb_presrv_usrspc_keep_vcc_on(struct ufs_hba *hba,
 	return false;
 }
 
+static void ufshcd_wb_force_disable(struct ufs_hba *hba)
+{
+	if (!(hba->quirks & UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL))
+		ufshcd_wb_toggle_flush(hba, false);
+
+	ufshcd_wb_toggle_flush_during_h8(hba, false);
+	ufshcd_wb_toggle(hba, false);
+	hba->caps &= ~UFSHCD_CAP_WB_EN;
+
+	dev_info(hba->dev, "%s: WB force disabled\n", __func__);
+}
+
+static bool ufshcd_is_wb_buf_lifetime_available(struct ufs_hba *hba)
+{
+	u32 lifetime;
+	int ret;
+	u8 index;
+
+	index = ufshcd_wb_get_query_index(hba);
+	ret = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+				      QUERY_ATTR_IDN_WB_BUFF_LIFE_TIME_EST,
+				      index, 0, &lifetime);
+	if (ret) {
+		dev_err(hba->dev,
+			"%s: bWriteBoosterBufferLifeTimeEst read failed %d\n",
+			__func__, ret);
+		return false;
+	}
+
+	if (lifetime == UFS_WB_EXCEED_LIFETIME) {
+		dev_err(hba->dev, "%s: WB buf lifetime is exhausted 0x%02X\n",
+			__func__, lifetime);
+		return false;
+	}
+
+	dev_dbg(hba->dev, "%s: WB buf lifetime is 0x%02X\n",
+		__func__, lifetime);
+
+	return true;
+}
+
 static bool ufshcd_wb_need_flush(struct ufs_hba *hba)
 {
 	int ret;
@@ -5786,6 +5827,12 @@ static bool ufshcd_wb_need_flush(struct ufs_hba *hba)
 
 	if (!ufshcd_is_wb_allowed(hba))
 		return false;
+
+	if (!ufshcd_is_wb_buf_lifetime_available(hba)) {
+		ufshcd_wb_force_disable(hba);
+		return false;
+	}
+
 	/*
 	 * The ufs device needs the vcc to be ON to flush.
 	 * With user-space reduction enabled, it's enough to enable flush
@@ -7486,6 +7533,7 @@ static void ufshcd_wb_probe(struct ufs_hba *hba, u8 *desc_buf)
 
 	if (!ufshcd_is_wb_allowed(hba))
 		return;
+
 	/*
 	 * Probe WB only for UFS-2.2 and UFS-3.1 (and later) devices or
 	 * UFS devices with quirk UFS_DEVICE_QUIRK_SUPPORT_EXTENDED_FEATURES
@@ -7537,6 +7585,10 @@ static void ufshcd_wb_probe(struct ufs_hba *hba, u8 *desc_buf)
 		if (!d_lu_wb_buf_alloc)
 			goto wb_disabled;
 	}
+
+	if (!ufshcd_is_wb_buf_lifetime_available(hba))
+		goto wb_disabled;
+
 	return;
 
 wb_disabled:
-- 
2.35.3