[PATCH v2] scsi: ufs: wb: Add Manual Flush sysfs and cleanup toggle functions

[Jinyoung CHOI <j-young.choi@xxxxxxxxxxx>]

There is the following quirk to bypass "WB Manual Flush" in Write Booster.

	- UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL

If this quirk is not set, there is no knob that can control "WB Manual Flush".

There are three flags that control Write Booster Feature.
	1. WB ON/OFF
	2. WB Hibern Flush ON/OFF
	3. WB Flush ON/OFF

The sysfs that controls the WB was implemented. (1)

In the case of "Hibern Flush", it is always good to turn on.
Control may not be required. (2)

Finally, "Manual flush" may be necessary because the Auto-Hibern8 is not
supported in a specific environment.
So the sysfs that controls this is necessary. (3)

In addition, toggle functions for controlling the above flags are cleaned.

V2:
	- modify commit message
	- move & modify err messages
	- remove unnesscessary debug messages

Signed-off-by: Jinyoung Choi <j-young.choi@xxxxxxxxxxx>
---
 drivers/ufs/core/ufs-sysfs.c | 46 +++++++++++++++++++++++-
 drivers/ufs/core/ufshcd.c    | 69 +++++++++++++++++-------------------
 include/ufs/ufshcd.h         |  7 ++++
 3 files changed, 84 insertions(+), 38 deletions(-)

diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index 0a088b47d557..b1c51d8df9f4 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -230,7 +230,7 @@ static ssize_t wb_on_store(struct device *dev, struct device_attribute *attr,
 		 * If the platform supports UFSHCD_CAP_CLK_SCALING, turn WB
 		 * on/off will be done while clock scaling up/down.
 		 */
-		dev_warn(dev, "To control WB through wb_on is not allowed!\n");
+		dev_warn(dev, "It is not allowed to control WB!\n");
 		return -EOPNOTSUPP;
 	}
 
@@ -254,6 +254,48 @@ static ssize_t wb_on_store(struct device *dev, struct device_attribute *attr,
 	return res < 0 ? res : count;
 }
 
+static ssize_t wb_buf_flush_en_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", hba->dev_info.wb_buf_flush_enabled);
+}
+
+static ssize_t wb_buf_flush_en_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	unsigned int wb_buf_flush_en;
+	ssize_t res;
+
+	if (!ufshcd_is_wb_buf_flush_allowed(hba)) {
+		dev_warn(dev, "It is not allowed to control WB buf flush!\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (kstrtouint(buf, 0, &wb_buf_flush_en))
+		return -EINVAL;
+
+	if (wb_buf_flush_en != 0 && wb_buf_flush_en != 1)
+		return -EINVAL;
+
+	down(&hba->host_sem);
+	if (!ufshcd_is_user_access_allowed(hba)) {
+		res = -EBUSY;
+		goto out;
+	}
+
+	ufshcd_rpm_get_sync(hba);
+	res = ufshcd_wb_toggle_buf_flush(hba, wb_buf_flush_en);
+	ufshcd_rpm_put_sync(hba);
+out:
+	up(&hba->host_sem);
+	return res < 0 ? res : count;
+}
+
 static DEVICE_ATTR_RW(rpm_lvl);
 static DEVICE_ATTR_RO(rpm_target_dev_state);
 static DEVICE_ATTR_RO(rpm_target_link_state);
@@ -262,6 +304,7 @@ static DEVICE_ATTR_RO(spm_target_dev_state);
 static DEVICE_ATTR_RO(spm_target_link_state);
 static DEVICE_ATTR_RW(auto_hibern8);
 static DEVICE_ATTR_RW(wb_on);
+static DEVICE_ATTR_RW(wb_buf_flush_en);
 
 static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_rpm_lvl.attr,
@@ -272,6 +315,7 @@ static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_spm_target_link_state.attr,
 	&dev_attr_auto_hibern8.attr,
 	&dev_attr_wb_on.attr,
+	&dev_attr_wb_buf_flush_en.attr,
 	NULL
 };
 
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index f5d5dde497ac..439f6cb15084 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -268,8 +268,7 @@ static int ufshcd_setup_vreg(struct ufs_hba *hba, bool on);
 static inline int ufshcd_config_vreg_hpm(struct ufs_hba *hba,
 					 struct ufs_vreg *vreg);
 static int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag);
-static void ufshcd_wb_toggle_flush_during_h8(struct ufs_hba *hba, bool set);
-static inline void ufshcd_wb_toggle_flush(struct ufs_hba *hba, bool enable);
+static void ufshcd_wb_toggle_buf_flush_during_h8(struct ufs_hba *hba, bool set);
 static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba);
 static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba);
 
@@ -289,16 +288,16 @@ static inline void ufshcd_disable_irq(struct ufs_hba *hba)
 	}
 }
 
-static inline void ufshcd_wb_config(struct ufs_hba *hba)
+static void ufshcd_wb_set_default_flags(struct ufs_hba *hba)
 {
 	if (!ufshcd_is_wb_allowed(hba))
 		return;
 
 	ufshcd_wb_toggle(hba, true);
+	ufshcd_wb_toggle_buf_flush_during_h8(hba, true);
 
-	ufshcd_wb_toggle_flush_during_h8(hba, true);
-	if (!(hba->quirks & UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL))
-		ufshcd_wb_toggle_flush(hba, true);
+	if (ufshcd_is_wb_buf_flush_allowed(hba))
+		ufshcd_wb_toggle_buf_flush(hba, true);
 }
 
 static void ufshcd_scsi_unblock_requests(struct ufs_hba *hba)
@@ -1289,9 +1288,10 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
 		}
 	}
 
-	/* Enable Write Booster if we have scaled up else disable it */
 	downgrade_write(&hba->clk_scaling_lock);
 	is_writelock = false;
+
+	/* Enable Write Booster if we have scaled up else disable it */
 	ufshcd_wb_toggle(hba, scale_up);
 
 out_unprepare:
@@ -5714,6 +5714,9 @@ static int __ufshcd_wb_toggle(struct ufs_hba *hba, bool set, enum flag_idn idn)
 	enum query_opcode opcode = set ? UPIU_QUERY_OPCODE_SET_FLAG :
 				   UPIU_QUERY_OPCODE_CLEAR_FLAG;
 
+	if (!ufshcd_is_wb_allowed(hba))
+		return -EPERM;
+
 	index = ufshcd_wb_get_query_index(hba);
 	return ufshcd_query_flag_retry(hba, opcode, idn, index, NULL);
 }
@@ -5722,60 +5725,50 @@ int ufshcd_wb_toggle(struct ufs_hba *hba, bool enable)
 {
 	int ret;
 
-	if (!ufshcd_is_wb_allowed(hba))
-		return 0;
-
-	if (!(enable ^ hba->dev_info.wb_enabled))
+	if (hba->dev_info.wb_enabled == enable)
 		return 0;
 
 	ret = __ufshcd_wb_toggle(hba, enable, QUERY_FLAG_IDN_WB_EN);
 	if (ret) {
-		dev_err(hba->dev, "%s Write Booster %s failed %d\n",
+		dev_err(hba->dev, "%s: failed to %s WB %d\n",
 			__func__, enable ? "enable" : "disable", ret);
 		return ret;
 	}
 
 	hba->dev_info.wb_enabled = enable;
-	dev_info(hba->dev, "%s Write Booster %s\n",
-			__func__, enable ? "enabled" : "disabled");
 
 	return ret;
 }
 
-static void ufshcd_wb_toggle_flush_during_h8(struct ufs_hba *hba, bool set)
+static void ufshcd_wb_toggle_buf_flush_during_h8(struct ufs_hba *hba,
+						 bool enable)
 {
 	int ret;
 
-	ret = __ufshcd_wb_toggle(hba, set,
-			QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8);
-	if (ret) {
-		dev_err(hba->dev, "%s: WB-Buf Flush during H8 %s failed: %d\n",
-			__func__, set ? "enable" : "disable", ret);
-		return;
-	}
-	dev_dbg(hba->dev, "%s WB-Buf Flush during H8 %s\n",
-			__func__, set ? "enabled" : "disabled");
+	ret = __ufshcd_wb_toggle(hba, enable,
+				 QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8);
+	if (ret)
+		dev_err(hba->dev, "%s: failed to %s WB buf flush during H8 %d\n",
+			__func__, enable ? "enable" : "disable", ret);
 }
 
-static inline void ufshcd_wb_toggle_flush(struct ufs_hba *hba, bool enable)
+int ufshcd_wb_toggle_buf_flush(struct ufs_hba *hba, bool enable)
 {
 	int ret;
 
-	if (!ufshcd_is_wb_allowed(hba) ||
-	    hba->dev_info.wb_buf_flush_enabled == enable)
-		return;
+	if (hba->dev_info.wb_buf_flush_enabled == enable)
+		return 0;
 
 	ret = __ufshcd_wb_toggle(hba, enable, QUERY_FLAG_IDN_WB_BUFF_FLUSH_EN);
 	if (ret) {
-		dev_err(hba->dev, "%s WB-Buf Flush %s failed %d\n", __func__,
-			enable ? "enable" : "disable", ret);
-		return;
+		dev_err(hba->dev, "%s: failed to %s WB buf flush %d\n",
+			__func__, enable ? "enable" : "disable", ret);
+		return ret;
 	}
 
 	hba->dev_info.wb_buf_flush_enabled = enable;
 
-	dev_dbg(hba->dev, "%s WB-Buf Flush %s\n",
-			__func__, enable ? "enabled" : "disabled");
+	return ret;
 }
 
 static bool ufshcd_wb_presrv_usrspc_keep_vcc_on(struct ufs_hba *hba,
@@ -5806,10 +5799,10 @@ static bool ufshcd_wb_presrv_usrspc_keep_vcc_on(struct ufs_hba *hba,
 
 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);
+	if (ufshcd_is_wb_buf_flush_allowed(hba))
+		ufshcd_wb_toggle_buf_flush(hba, false);
 
-	ufshcd_wb_toggle_flush_during_h8(hba, false);
+	ufshcd_wb_toggle_buf_flush_during_h8(hba, false);
 	ufshcd_wb_toggle(hba, false);
 	hba->caps &= ~UFSHCD_CAP_WB_EN;
 
@@ -8195,7 +8188,9 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool init_dev_params)
 	 */
 	ufshcd_set_active_icc_lvl(hba);
 
-	ufshcd_wb_config(hba);
+	/* Enable UFS Write Booster if supported */
+	ufshcd_wb_set_default_flags(hba);
+
 	if (hba->ee_usr_mask)
 		ufshcd_write_ee_control(hba);
 	/* Enable Auto-Hibernate if configured */
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index b5c9064a11d9..8c9461d45606 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -1017,6 +1017,12 @@ static inline bool ufshcd_is_wb_allowed(struct ufs_hba *hba)
 	return hba->caps & UFSHCD_CAP_WB_EN;
 }
 
+static inline bool ufshcd_is_wb_buf_flush_allowed(struct ufs_hba *hba)
+{
+	return ufshcd_is_wb_allowed(hba) &&
+		!(hba->quirks & UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL);
+}
+
 #define ufshcd_writel(hba, val, reg)	\
 	writel((val), (hba)->mmio_base + (reg))
 #define ufshcd_readl(hba, reg)	\
@@ -1211,6 +1217,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
 			     enum query_opcode desc_op);
 
 int ufshcd_wb_toggle(struct ufs_hba *hba, bool enable);
+int ufshcd_wb_toggle_buf_flush(struct ufs_hba *hba, bool enable);
 int ufshcd_suspend_prepare(struct device *dev);
 int __ufshcd_suspend_prepare(struct device *dev, bool rpm_ok_for_spm);
 void ufshcd_resume_complete(struct device *dev);
-- 
2.25.1