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>

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 0bfdca3..4a00c24 100644 (file)
--- 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 460d2b4..41d85b6 100644 (file)
--- 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: