[PATCH 2/2] scsi: ufs: Add support for critical health notification

[Avri Altman]

The UFS 4.1 standard, released on January 8, 2025, introduces several
new features, including a new exception event: HEALTH_CRITICAL. This
event notifies the host of a device's critical health condition,
indicating that the device is approaching the end of its lifetime based
on the number of program/erase cycles performed.

We utilize the hwmon (hardware monitoring) subsystem to propagate this
information via the chip alarm channel.

The host can gain further insight into the specific issue by reading one
of the following attributes: bPreEOLInfo, bDeviceLifeTimeEstA,
bDeviceLifeTimeEstB, bWriteBoosterBufferLifeTimeEst, and
bRPMBLifeTimeEst. However, we do not provide the corresponding .read
method in the hwmon subsystem. This is intentional: all other
end-of-life (EOL) signals are available for reading via the driver's
sysfs entries or through an applicable utility. It is up to user-space
to read these attributes if needed. It is not the kernel's
responsibility to interpret any EOL signals, as they may vary from
vendor to vendor.

Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
---
 drivers/ufs/core/ufs-hwmon.c |  4 ++++
 drivers/ufs/core/ufshcd.c    | 15 +++++++++++++++
 include/ufs/ufs.h            |  1 +
 3 files changed, 20 insertions(+)

diff --git a/drivers/ufs/core/ufs-hwmon.c b/drivers/ufs/core/ufs-hwmon.c
index db28f456b923..410dc6568de5 100644
--- a/drivers/ufs/core/ufs-hwmon.c
+++ b/drivers/ufs/core/ufs-hwmon.c
@@ -149,6 +149,7 @@ static umode_t ufs_hwmon_is_visible(const void *data,
 
 static const struct hwmon_channel_info *const ufs_hwmon_info[] = {
 	HWMON_CHANNEL_INFO(temp, HWMON_T_ENABLE | HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_LCRIT),
+	HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS),
 	NULL
 };
 
@@ -209,4 +210,7 @@ void ufs_hwmon_notify_event(struct ufs_hba *hba, u16 ee_mask)
 
 	if (ee_mask & MASK_EE_TOO_LOW_TEMP)
 		hwmon_notify_event(hba->hwmon_device, hwmon_temp, hwmon_temp_min_alarm, 0);
+
+	if (ee_mask & MASK_EE_HEALTH_CRITICAL)
+		hwmon_notify_event(hba->hwmon_device, hwmon_chip, hwmon_chip_alarms, 0);
 }
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 9fbaf74b0fef..407dc1acca0f 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -6198,6 +6198,9 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
 	if (status & hba->ee_drv_mask & MASK_EE_URGENT_TEMP)
 		ufs_hwmon_notify_event(hba, status & MASK_EE_URGENT_TEMP);
 
+	if (status & hba->ee_drv_mask & MASK_EE_HEALTH_CRITICAL)
+		ufs_hwmon_notify_event(hba, status & MASK_EE_HEALTH_CRITICAL);
+
 	ufs_debugfs_exception_event(hba, status);
 }
 
@@ -8091,12 +8094,24 @@ static void ufshcd_temp_notif_probe(struct ufs_hba *hba, const u8 *desc_buf, u16
 		*mask |= MASK_EE_TOO_HIGH_TEMP;
 }
 
+static void ufshcd_critical_health_probe(struct ufs_hba *hba, u16 *mask)
+{
+	struct ufs_dev_info *dev_info = &hba->dev_info;
+
+	if (dev_info->wspecversion < 0x410)
+		return;
+
+	*mask |= MASK_EE_HEALTH_CRITICAL;
+}
+
 static void ufshcd_hwmon_probe(struct ufs_hba *hba, const u8 *desc_buf)
 {
 	u16 mask = 0;
 
 	ufshcd_temp_notif_probe(hba, desc_buf, &mask);
 
+	ufshcd_critical_health_probe(hba, &mask);
+
 	if (mask) {
 		ufshcd_enable_ee(hba, mask);
 		ufs_hwmon_probe(hba, mask);
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index f151feb0ca8c..8a24ed59ec46 100644
--- a/include/ufs/ufs.h
+++ b/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)
 
-- 
2.25.1