scsi: ufs: core: Critical health condition

Martin hi,

The UFS4.1 standard, released on January 8, 2025, added a new exception
event: HEALTH_CRITICAL, which notifies the host of a device's critical
health condition. This notification implies that the device is approaching
the end of its lifetime based on the amount of performed program/erase
cycles.

Once an EOL (End-of-Life) exception event is received, we increment a
designated member, which is exposed via a sysfs entry. This new entry, will
report the number of times a critical health event has been reported by a
UFS device.

To handle this new sysfs entry, userspace applications can use select(),
poll(), or epoll() to monitor changes in the critical_health attribute. The
kernel will call sysfs_notify() to signal changes, allowing the userspace
application to detect and respond to these changes efficiently.

The host can gain further insight into the specific issue by reading one of
the following attributes: bPreEOLInfo, bDeviceLifeTimeEstA,
bDeviceLifeTimeEstB, bWriteBoosterBufferLifeTimeEst, and
bRPMBLifeTimeEst. All those are available for reading via the driver's
sysfs entries or through an applicable utility. It is up to userspace to
read these attributes if needed.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Link: https://lore.kernel.org/r/20250211065813.58091-1-avri.altman@wdc.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Documentation/ABI/testing/sysfs-driver-ufs

@@ -1559,3 +1559,15 @@ Description:
 		Symbol - HCMID. This file shows the UFSHCD manufacturer id.
 		The Manufacturer ID is defined by JEDEC in JEDEC-JEP106.
 		The file is read only.
+
+What:		/sys/bus/platform/drivers/ufshcd/*/critical_health
+What:		/sys/bus/platform/devices/*.ufs/critical_health
+Date:		February 2025
+Contact:	Avri Altman <avri.altman@wdc.com>
+Description:	Report the number of times a critical health event has been
+		reported by a UFS device. Further insight into the specific
+		issue can be gained by reading one of: bPreEOLInfo,
+		bDeviceLifeTimeEstA, bDeviceLifeTimeEstB,
+		bWriteBoosterBufferLifeTimeEst, and bRPMBLifeTimeEst.
+
+		The file is read only.

drivers/ufs/core/ufs-sysfs.c

@@ -458,6 +458,14 @@ static ssize_t pm_qos_enable_store(struct device *dev,
 	return count;
 }
 
+static ssize_t critical_health_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->critical_health_count);
+}
+
 static DEVICE_ATTR_RW(rpm_lvl);
 static DEVICE_ATTR_RO(rpm_target_dev_state);
 static DEVICE_ATTR_RO(rpm_target_link_state);
@@ -470,6 +478,7 @@ static DEVICE_ATTR_RW(enable_wb_buf_flush);
 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 struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_rpm_lvl.attr,
@@ -484,6 +493,7 @@ static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_wb_flush_threshold.attr,
 	&dev_attr_rtc_update_ms.attr,
 	&dev_attr_pm_qos_enable.attr,
+	&dev_attr_critical_health.attr,
 	NULL
 };
 

drivers/ufs/core/ufshcd.c

@@ -6216,6 +6216,11 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
 	if (status & hba->ee_drv_mask & MASK_EE_URGENT_TEMP)
 		ufshcd_temp_exception_event_handler(hba, status);
 
+	if (status & hba->ee_drv_mask & MASK_EE_HEALTH_CRITICAL) {
+		hba->critical_health_count++;
+		sysfs_notify(&hba->dev->kobj, NULL, "critical_health");
+	}
+
 	ufs_debugfs_exception_event(hba, status);
 }
 
@@ -8308,6 +8313,11 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
 
 	ufshcd_temp_notif_probe(hba, desc_buf);
 
+	if (dev_info->wspecversion >= 0x410) {
+		hba->critical_health_count = 0;
+		ufshcd_enable_ee(hba, MASK_EE_HEALTH_CRITICAL);
+	}
+
 	ufs_init_rtc(hba, desc_buf);
 
 	/*

include/ufs/ufs.h

@@ -419,6 +419,7 @@ enum {
 	MASK_EE_TOO_LOW_TEMP		= BIT(4),
 	MASK_EE_WRITEBOOSTER_EVENT	= BIT(5),
 	MASK_EE_PERFORMANCE_THROTTLING	= BIT(6),
+	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

@@ -962,6 +962,7 @@ enum ufshcd_mcq_opr {
  * @ufs_rtc_update_work: A work for UFS RTC periodic update
  * @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
  */
 struct ufs_hba {
 	void __iomem *mmio_base;
@@ -1130,6 +1131,8 @@ struct ufs_hba {
 	struct delayed_work ufs_rtc_update_work;
 	struct pm_qos_request pm_qos_req;
 	bool pm_qos_enabled;
+
+	int critical_health_count;
 };
 
 /**