[PATCH v4 3/3] nvme: notify thermal framework when temperature threshold events occur

[Akinobu Mita <akinobu.mita@gmail.com>]

The NVMe controller supports the temperature threshold feature (Feature
Identifier 04h) that enables to configure the asynchronous event request
command to complete when the temperature is crossed its corresponding
temperature threshold.

This enables the reporting of asynchronous events from the controller when
the temperature reached or exceeded a temperature threshold.
In the case of the temperature threshold conditions, this notifies the
thermal framework.

The main purpose of this is to turn on a fan when overheated without
polling the device for the smart log that could prevent the lower power
state transitions.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Minwoo Im <minwoo.im.dev@gmail.com>
Cc: Kenneth Heitke <kenneth.heitke@intel.com>
Cc: Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
---
* v4
- support DT thermal zone device.
- use bitmap to iterate over implemented sensors

 drivers/nvme/host/core.c    | 14 ++++++++++++++
 drivers/nvme/host/nvme.h    |  5 +++++
 drivers/nvme/host/thermal.c | 12 ++++++++++++
 include/linux/nvme.h        |  7 +++++++
 4 files changed, 38 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 4be339b..44dadbb 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1186,6 +1186,9 @@ static void nvme_enable_aen(struct nvme_ctrl *ctrl)
 	u32 result, supported_aens = ctrl->oaes & NVME_AEN_SUPPORTED;
 	int status;
 
+	if (IS_ENABLED(CONFIG_THERMAL))
+		supported_aens |= NVME_SMART_CRIT_TEMPERATURE;
+
 	if (!supported_aens)
 		return;
 
@@ -3561,6 +3564,16 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl)
 }
 EXPORT_SYMBOL_GPL(nvme_remove_namespaces);
 
+static void nvme_handle_aen_smart(struct nvme_ctrl *ctrl, u32 result)
+{
+	u32 aer_type = result & NVME_AER_TYPE_MASK;
+	u32 aer_info = (result >> NVME_AER_INFO_SHIFT) & NVME_AER_INFO_MASK;
+
+	if (aer_type == NVME_AER_SMART &&
+	    aer_info == NVME_AER_SMART_TEMP_THRESH)
+		nvme_thermal_notify_framework(ctrl);
+}
+
 static void nvme_aen_uevent(struct nvme_ctrl *ctrl)
 {
 	char *envp[2] = { NULL, NULL };
@@ -3582,6 +3595,7 @@ static void nvme_async_event_work(struct work_struct *work)
 	struct nvme_ctrl *ctrl =
 		container_of(work, struct nvme_ctrl, async_event_work);
 
+	nvme_handle_aen_smart(ctrl, ctrl->aen_result);
 	nvme_aen_uevent(ctrl);
 	ctrl->ops->submit_async_event(ctrl);
 }
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index a9c63ea..40325b6 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -605,6 +605,7 @@ static inline struct nvme_ns *nvme_get_ns_from_dev(struct device *dev)
 
 int nvme_thermal_zones_register(struct nvme_ctrl *ctrl);
 void nvme_thermal_zones_unregister(struct nvme_ctrl *ctrl);
+void nvme_thermal_notify_framework(struct nvme_ctrl *ctrl);
 
 #else
 
@@ -617,6 +618,10 @@ static inline void nvme_thermal_zones_unregister(struct nvme_ctrl *ctrl)
 {
 }
 
+static inline void nvme_thermal_notify_framework(struct nvme_ctrl *ctrl)
+{
+}
+
 #endif /* CONFIG_THERMAL */
 
 #endif /* _NVME_H */
diff --git a/drivers/nvme/host/thermal.c b/drivers/nvme/host/thermal.c
index 18d0e4c..b5e835d 100644
--- a/drivers/nvme/host/thermal.c
+++ b/drivers/nvme/host/thermal.c
@@ -309,3 +309,15 @@ void nvme_thermal_zones_unregister(struct nvme_ctrl *ctrl)
 		__clear_bit(i, ctrl->tz_enabled);
 	}
 }
+
+void nvme_thermal_notify_framework(struct nvme_ctrl *ctrl)
+{
+	int i;
+
+	for_each_set_bit(i, ctrl->tz_enabled, ARRAY_SIZE(ctrl->tz)) {
+		if (ctrl->tz[i].dev)
+			thermal_notify_framework(ctrl->tz[i].dev, 0);
+		if (ctrl->tz[i].of_dev)
+			thermal_notify_framework(ctrl->tz[i].of_dev, 0);
+	}
+}
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index f29728b..069b962 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -476,6 +476,7 @@ enum {
 };
 
 enum {
+	NVME_AER_TYPE_MASK		= 0x7,
 	NVME_AER_ERROR			= 0,
 	NVME_AER_SMART			= 1,
 	NVME_AER_NOTICE			= 2,
@@ -484,6 +485,12 @@ enum {
 };
 
 enum {
+	NVME_AER_INFO_SHIFT		= 8,
+	NVME_AER_INFO_MASK		= 0xff,
+	NVME_AER_SMART_TEMP_THRESH	= 0x01,
+};
+
+enum {
 	NVME_AER_NOTICE_NS_CHANGED	= 0x00,
 	NVME_AER_NOTICE_FW_ACT_STARTING = 0x01,
 	NVME_AER_NOTICE_ANA		= 0x03,
-- 
2.7.4