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path: root/drivers/nvme/host/hwmon.c
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-rw-r--r--drivers/nvme/host/hwmon.c259
1 files changed, 259 insertions, 0 deletions
diff --git a/drivers/nvme/host/hwmon.c b/drivers/nvme/host/hwmon.c
new file mode 100644
index 000000000000..a5af21f5d370
--- /dev/null
+++ b/drivers/nvme/host/hwmon.c
@@ -0,0 +1,259 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVM Express hardware monitoring support
+ * Copyright (c) 2019, Guenter Roeck
+ */
+
+#include <linux/hwmon.h>
+#include <asm/unaligned.h>
+
+#include "nvme.h"
+
+/* These macros should be moved to linux/temperature.h */
+#define MILLICELSIUS_TO_KELVIN(t) DIV_ROUND_CLOSEST((t) + 273150, 1000)
+#define KELVIN_TO_MILLICELSIUS(t) ((t) * 1000L - 273150)
+
+struct nvme_hwmon_data {
+ struct nvme_ctrl *ctrl;
+ struct nvme_smart_log log;
+ struct mutex read_lock;
+};
+
+static int nvme_get_temp_thresh(struct nvme_ctrl *ctrl, int sensor, bool under,
+ long *temp)
+{
+ unsigned int threshold = sensor << NVME_TEMP_THRESH_SELECT_SHIFT;
+ u32 status;
+ int ret;
+
+ if (under)
+ threshold |= NVME_TEMP_THRESH_TYPE_UNDER;
+
+ ret = nvme_get_features(ctrl, NVME_FEAT_TEMP_THRESH, threshold, NULL, 0,
+ &status);
+ if (ret > 0)
+ return -EIO;
+ if (ret < 0)
+ return ret;
+ *temp = KELVIN_TO_MILLICELSIUS(status & NVME_TEMP_THRESH_MASK);
+
+ return 0;
+}
+
+static int nvme_set_temp_thresh(struct nvme_ctrl *ctrl, int sensor, bool under,
+ long temp)
+{
+ unsigned int threshold = sensor << NVME_TEMP_THRESH_SELECT_SHIFT;
+ int ret;
+
+ temp = MILLICELSIUS_TO_KELVIN(temp);
+ threshold |= clamp_val(temp, 0, NVME_TEMP_THRESH_MASK);
+
+ if (under)
+ threshold |= NVME_TEMP_THRESH_TYPE_UNDER;
+
+ ret = nvme_set_features(ctrl, NVME_FEAT_TEMP_THRESH, threshold, NULL, 0,
+ NULL);
+ if (ret > 0)
+ return -EIO;
+
+ return ret;
+}
+
+static int nvme_hwmon_get_smart_log(struct nvme_hwmon_data *data)
+{
+ int ret;
+
+ ret = nvme_get_log(data->ctrl, NVME_NSID_ALL, NVME_LOG_SMART, 0,
+ &data->log, sizeof(data->log), 0);
+
+ return ret <= 0 ? ret : -EIO;
+}
+
+static int nvme_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct nvme_hwmon_data *data = dev_get_drvdata(dev);
+ struct nvme_smart_log *log = &data->log;
+ int temp;
+ int err;
+
+ /*
+ * First handle attributes which don't require us to read
+ * the smart log.
+ */
+ switch (attr) {
+ case hwmon_temp_max:
+ return nvme_get_temp_thresh(data->ctrl, channel, false, val);
+ case hwmon_temp_min:
+ return nvme_get_temp_thresh(data->ctrl, channel, true, val);
+ case hwmon_temp_crit:
+ *val = KELVIN_TO_MILLICELSIUS(data->ctrl->cctemp);
+ return 0;
+ default:
+ break;
+ }
+
+ mutex_lock(&data->read_lock);
+ err = nvme_hwmon_get_smart_log(data);
+ if (err)
+ goto unlock;
+
+ switch (attr) {
+ case hwmon_temp_input:
+ if (!channel)
+ temp = get_unaligned_le16(log->temperature);
+ else
+ temp = le16_to_cpu(log->temp_sensor[channel - 1]);
+ *val = KELVIN_TO_MILLICELSIUS(temp);
+ break;
+ case hwmon_temp_alarm:
+ *val = !!(log->critical_warning & NVME_SMART_CRIT_TEMPERATURE);
+ break;
+ default:
+ err = -EOPNOTSUPP;
+ break;
+ }
+unlock:
+ mutex_unlock(&data->read_lock);
+ return err;
+}
+
+static int nvme_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long val)
+{
+ struct nvme_hwmon_data *data = dev_get_drvdata(dev);
+
+ switch (attr) {
+ case hwmon_temp_max:
+ return nvme_set_temp_thresh(data->ctrl, channel, false, val);
+ case hwmon_temp_min:
+ return nvme_set_temp_thresh(data->ctrl, channel, true, val);
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static const char * const nvme_hwmon_sensor_names[] = {
+ "Composite",
+ "Sensor 1",
+ "Sensor 2",
+ "Sensor 3",
+ "Sensor 4",
+ "Sensor 5",
+ "Sensor 6",
+ "Sensor 7",
+ "Sensor 8",
+};
+
+static int nvme_hwmon_read_string(struct device *dev,
+ enum hwmon_sensor_types type, u32 attr,
+ int channel, const char **str)
+{
+ *str = nvme_hwmon_sensor_names[channel];
+ return 0;
+}
+
+static umode_t nvme_hwmon_is_visible(const void *_data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ const struct nvme_hwmon_data *data = _data;
+
+ switch (attr) {
+ case hwmon_temp_crit:
+ if (!channel && data->ctrl->cctemp)
+ return 0444;
+ break;
+ case hwmon_temp_max:
+ case hwmon_temp_min:
+ if ((!channel && data->ctrl->wctemp) ||
+ (channel && data->log.temp_sensor[channel - 1])) {
+ if (data->ctrl->quirks &
+ NVME_QUIRK_NO_TEMP_THRESH_CHANGE)
+ return 0444;
+ return 0644;
+ }
+ break;
+ case hwmon_temp_alarm:
+ if (!channel)
+ return 0444;
+ break;
+ case hwmon_temp_input:
+ case hwmon_temp_label:
+ if (!channel || data->log.temp_sensor[channel - 1])
+ return 0444;
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+
+static const struct hwmon_channel_info *nvme_hwmon_info[] = {
+ HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
+ HWMON_CHANNEL_INFO(temp,
+ HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
+ HWMON_T_CRIT | HWMON_T_LABEL | HWMON_T_ALARM,
+ HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
+ HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
+ HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
+ HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
+ HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
+ HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
+ HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
+ HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
+ HWMON_T_LABEL),
+ NULL
+};
+
+static const struct hwmon_ops nvme_hwmon_ops = {
+ .is_visible = nvme_hwmon_is_visible,
+ .read = nvme_hwmon_read,
+ .read_string = nvme_hwmon_read_string,
+ .write = nvme_hwmon_write,
+};
+
+static const struct hwmon_chip_info nvme_hwmon_chip_info = {
+ .ops = &nvme_hwmon_ops,
+ .info = nvme_hwmon_info,
+};
+
+void nvme_hwmon_init(struct nvme_ctrl *ctrl)
+{
+ struct device *dev = ctrl->dev;
+ struct nvme_hwmon_data *data;
+ struct device *hwmon;
+ int err;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return;
+
+ data->ctrl = ctrl;
+ mutex_init(&data->read_lock);
+
+ err = nvme_hwmon_get_smart_log(data);
+ if (err) {
+ dev_warn(dev, "Failed to read smart log (error %d)\n", err);
+ devm_kfree(dev, data);
+ return;
+ }
+
+ hwmon = devm_hwmon_device_register_with_info(dev, "nvme", data,
+ &nvme_hwmon_chip_info,
+ NULL);
+ if (IS_ERR(hwmon)) {
+ dev_warn(dev, "Failed to instantiate hwmon device\n");
+ devm_kfree(dev, data);
+ }
+}