scsi: ufs: core: Add device level exception support

The ufs device JEDEC specification version 4.1 adds support for the
device level exception events. To support this new device level
exception feature, expose two new sysfs nodes below to provide the user
space access to the device level exception information.

/sys/bus/platform/drivers/ufshcd/*/device_lvl_exception_count
/sys/bus/platform/drivers/ufshcd/*/device_lvl_exception_id

The device_lvl_exception_count sysfs node reports the number of device
level exceptions that have occurred since the last time this variable is
reset. Writing a value of 0 will reset it.  The device_lvl_exception_id
reports the exception ID which is the qDeviceLevelExceptionID attribute
of the device JEDEC specifications version 4.1 and later. The user space
application can query these sysfs nodes to get more information about
the device level exception.

Signed-off-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>
Link: https://lore.kernel.org/r/6278d7c125b2f0cf5056f4a647a4b9c1fdd24fc7.1743198325.git.quic_nguyenb@quicinc.com
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Arthur Simchaev <arthur.simchaev@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Documentation/ABI/testing/sysfs-driver-ufs

@@ -1604,3 +1604,35 @@ Description:
 		prevent the UFS from frequently performing clock gating/ungating.
 
 		The attribute is read/write.
+
+What:		/sys/bus/platform/drivers/ufshcd/*/device_lvl_exception_count
+What:		/sys/bus/platform/devices/*.ufs/device_lvl_exception_count
+Date:		March 2025
+Contact:	Bao D. Nguyen <quic_nguyenb@quicinc.com>
+Description:
+		This attribute is applicable to ufs devices compliant to the
+		JEDEC specifications version 4.1 or later. The
+		device_lvl_exception_count is a counter indicating the number of
+		times the device level exceptions have occurred since the last
+		time this variable is reset.  Writing a 0 value to this
+		attribute will reset the device_lvl_exception_count.  If the
+		device_lvl_exception_count reads a positive value, the user
+		application should read the device_lvl_exception_id attribute to
+		know more information about the exception.
+
+		The attribute is read/write.
+
+What:		/sys/bus/platform/drivers/ufshcd/*/device_lvl_exception_id
+What:		/sys/bus/platform/devices/*.ufs/device_lvl_exception_id
+Date:		March 2025
+Contact:	Bao D. Nguyen <quic_nguyenb@quicinc.com>
+Description:
+		Reading the device_lvl_exception_id returns the
+		qDeviceLevelExceptionID attribute of the ufs device JEDEC
+		specification version 4.1. The definition of the
+		qDeviceLevelExceptionID is the ufs device vendor specific
+		implementation.  Refer to the device manufacturer datasheet for
+		more information on the meaning of the qDeviceLevelExceptionID
+		attribute value.
+
+		The attribute is read only.

drivers/ufs/core/ufs-sysfs.c

@@ -466,6 +466,56 @@ static ssize_t critical_health_show(struct device *dev,
 	return sysfs_emit(buf, "%d\n", hba->critical_health_count);
 }
 
+static ssize_t device_lvl_exception_count_show(struct device *dev,
+					       struct device_attribute *attr,
+					       char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+
+	if (hba->dev_info.wspecversion < 0x410)
+		return -EOPNOTSUPP;
+
+	return sysfs_emit(buf, "%u\n", atomic_read(&hba->dev_lvl_exception_count));
+}
+
+static ssize_t device_lvl_exception_count_store(struct device *dev,
+						struct device_attribute *attr,
+						const char *buf, size_t count)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	unsigned int value;
+
+	if (kstrtouint(buf, 0, &value))
+		return -EINVAL;
+
+	/* the only supported usecase is to reset the dev_lvl_exception_count */
+	if (value)
+		return -EINVAL;
+
+	atomic_set(&hba->dev_lvl_exception_count, 0);
+
+	return count;
+}
+
+static ssize_t device_lvl_exception_id_show(struct device *dev,
+					    struct device_attribute *attr,
+					    char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	u64 exception_id;
+	int err;
+
+	ufshcd_rpm_get_sync(hba);
+	err = ufshcd_read_device_lvl_exception_id(hba, &exception_id);
+	ufshcd_rpm_put_sync(hba);
+
+	if (err)
+		return err;
+
+	hba->dev_lvl_exception_id = exception_id;
+	return sysfs_emit(buf, "%llu\n", exception_id);
+}
+
 static DEVICE_ATTR_RW(rpm_lvl);
 static DEVICE_ATTR_RO(rpm_target_dev_state);
 static DEVICE_ATTR_RO(rpm_target_link_state);
@@ -479,6 +529,8 @@ static DEVICE_ATTR_RW(wb_flush_threshold);
 static DEVICE_ATTR_RW(rtc_update_ms);
 static DEVICE_ATTR_RW(pm_qos_enable);
 static DEVICE_ATTR_RO(critical_health);
+static DEVICE_ATTR_RW(device_lvl_exception_count);
+static DEVICE_ATTR_RO(device_lvl_exception_id);
 
 static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_rpm_lvl.attr,
@@ -494,6 +546,8 @@ static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_rtc_update_ms.attr,
 	&dev_attr_pm_qos_enable.attr,
 	&dev_attr_critical_health.attr,
+	&dev_attr_device_lvl_exception_count.attr,
+	&dev_attr_device_lvl_exception_id.attr,
 	NULL
 };
 

drivers/ufs/core/ufshcd-priv.h

@@ -94,6 +94,7 @@ 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_read_device_lvl_exception_id(struct ufs_hba *hba, u64 *exception_id);
 
 /* Wrapper functions for safely calling variant operations */
 static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)

drivers/ufs/core/ufshcd.c

@@ -5998,6 +5998,42 @@ static void ufshcd_bkops_exception_event_handler(struct ufs_hba *hba)
 				__func__, err);
 }
 
+int ufshcd_read_device_lvl_exception_id(struct ufs_hba *hba, u64 *exception_id)
+{
+	struct utp_upiu_query_v4_0 *upiu_resp;
+	struct ufs_query_req *request = NULL;
+	struct ufs_query_res *response = NULL;
+	int err;
+
+	if (hba->dev_info.wspecversion < 0x410)
+		return -EOPNOTSUPP;
+
+	ufshcd_hold(hba);
+	mutex_lock(&hba->dev_cmd.lock);
+
+	ufshcd_init_query(hba, &request, &response,
+			  UPIU_QUERY_OPCODE_READ_ATTR,
+			  QUERY_ATTR_IDN_DEV_LVL_EXCEPTION_ID, 0, 0);
+
+	request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
+
+	err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);
+
+	if (err) {
+		dev_err(hba->dev, "%s: failed to read device level exception %d\n",
+			__func__, err);
+		goto out;
+	}
+
+	upiu_resp = (struct utp_upiu_query_v4_0 *)response;
+	*exception_id = get_unaligned_be64(&upiu_resp->osf3);
+out:
+	mutex_unlock(&hba->dev_cmd.lock);
+	ufshcd_release(hba);
+
+	return err;
+}
+
 static int __ufshcd_wb_toggle(struct ufs_hba *hba, bool set, enum flag_idn idn)
 {
 	u8 index;
@@ -6223,6 +6259,11 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
 		sysfs_notify(&hba->dev->kobj, NULL, "critical_health");
 	}
 
+	if (status & hba->ee_drv_mask & MASK_EE_DEV_LVL_EXCEPTION) {
+		atomic_inc(&hba->dev_lvl_exception_count);
+		sysfs_notify(&hba->dev->kobj, NULL, "device_lvl_exception_count");
+	}
+
 	ufs_debugfs_exception_event(hba, status);
 }
 
@@ -8122,6 +8163,22 @@ static void ufshcd_temp_notif_probe(struct ufs_hba *hba, const u8 *desc_buf)
 	}
 }
 
+static void ufshcd_device_lvl_exception_probe(struct ufs_hba *hba, u8 *desc_buf)
+{
+	u32 ext_ufs_feature;
+
+	if (hba->dev_info.wspecversion < 0x410)
+		return;
+
+	ext_ufs_feature = get_unaligned_be32(desc_buf +
+				DEVICE_DESC_PARAM_EXT_UFS_FEATURE_SUP);
+	if (!(ext_ufs_feature & UFS_DEV_LVL_EXCEPTION_SUP))
+		return;
+
+	atomic_set(&hba->dev_lvl_exception_count, 0);
+	ufshcd_enable_ee(hba, MASK_EE_DEV_LVL_EXCEPTION);
+}
+
 static void ufshcd_set_rtt(struct ufs_hba *hba)
 {
 	struct ufs_dev_info *dev_info = &hba->dev_info;
@@ -8322,6 +8379,8 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
 
 	ufs_init_rtc(hba, desc_buf);
 
+	ufshcd_device_lvl_exception_probe(hba, desc_buf);
+
 	/*
 	 * ufshcd_read_string_desc returns size of the string
 	 * reset the error value

include/ufs/ufs.h

@@ -180,7 +180,8 @@ enum attr_idn {
 	QUERY_ATTR_IDN_AVAIL_WB_BUFF_SIZE       = 0x1D,
 	QUERY_ATTR_IDN_WB_BUFF_LIFE_TIME_EST    = 0x1E,
 	QUERY_ATTR_IDN_CURR_WB_BUFF_SIZE        = 0x1F,
-	QUERY_ATTR_IDN_TIMESTAMP		= 0x30
+	QUERY_ATTR_IDN_TIMESTAMP		= 0x30,
+	QUERY_ATTR_IDN_DEV_LVL_EXCEPTION_ID     = 0x34,
 };
 
 /* Descriptor idn for Query requests */
@@ -390,6 +391,7 @@ enum {
 	UFS_DEV_EXT_TEMP_NOTIF		= BIT(6),
 	UFS_DEV_HPB_SUPPORT		= BIT(7),
 	UFS_DEV_WRITE_BOOSTER_SUP	= BIT(8),
+	UFS_DEV_LVL_EXCEPTION_SUP       = BIT(12),
 };
 #define UFS_DEV_HPB_SUPPORT_VERSION		0x310
 
@@ -419,6 +421,7 @@ enum {
 	MASK_EE_TOO_LOW_TEMP		= BIT(4),
 	MASK_EE_WRITEBOOSTER_EVENT	= BIT(5),
 	MASK_EE_PERFORMANCE_THROTTLING	= BIT(6),
+	MASK_EE_DEV_LVL_EXCEPTION       = BIT(7),
 	MASK_EE_HEALTH_CRITICAL		= BIT(9),
 };
 #define MASK_EE_URGENT_TEMP (MASK_EE_TOO_HIGH_TEMP | MASK_EE_TOO_LOW_TEMP)

include/ufs/ufshcd.h

@@ -968,6 +968,9 @@ enum ufshcd_mcq_opr {
  * @pm_qos_req: PM QoS request handle
  * @pm_qos_enabled: flag to check if pm qos is enabled
  * @critical_health_count: count of critical health exceptions
+ * @dev_lvl_exception_count: count of device level exceptions since last reset
+ * @dev_lvl_exception_id: vendor specific information about the
+ * device level exception event.
  */
 struct ufs_hba {
 	void __iomem *mmio_base;
@@ -1138,6 +1141,8 @@ struct ufs_hba {
 	bool pm_qos_enabled;
 
 	int critical_health_count;
+	atomic_t dev_lvl_exception_count;
+	u64 dev_lvl_exception_id;
 };
 
 /**