drivers/nvme/host/hwmon.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * NVM Express hardware monitoring support
   4  * Copyright (c) 2019, Guenter Roeck
   5  */
   6
   7 #include <linux/hwmon.h>
   8 #include <linux/units.h>
   9 #include <asm/unaligned.h>
  10
  11 #include "nvme.h"
  12
  13 struct nvme_hwmon_data {
  14         struct nvme_ctrl *ctrl;
  15         struct nvme_smart_log log;
  16         struct mutex read_lock;
  17 };
  18
  19 static int nvme_get_temp_thresh(struct nvme_ctrl *ctrl, int sensor, bool under,
  20                                 long *temp)
  21 {
  22         unsigned int threshold = sensor << NVME_TEMP_THRESH_SELECT_SHIFT;
  23         u32 status;
  24         int ret;
  25
  26         if (under)
  27                 threshold |= NVME_TEMP_THRESH_TYPE_UNDER;
  28
  29         ret = nvme_get_features(ctrl, NVME_FEAT_TEMP_THRESH, threshold, NULL, 0,
  30                                 &status);
  31         if (ret > 0)
  32                 return -EIO;
  33         if (ret < 0)
  34                 return ret;
  35         *temp = kelvin_to_millicelsius(status & NVME_TEMP_THRESH_MASK);
  36
  37         return 0;
  38 }
  39
  40 static int nvme_set_temp_thresh(struct nvme_ctrl *ctrl, int sensor, bool under,
  41                                 long temp)
  42 {
  43         unsigned int threshold = sensor << NVME_TEMP_THRESH_SELECT_SHIFT;
  44         int ret;
  45
  46         temp = millicelsius_to_kelvin(temp);
  47         threshold |= clamp_val(temp, 0, NVME_TEMP_THRESH_MASK);
  48
  49         if (under)
  50                 threshold |= NVME_TEMP_THRESH_TYPE_UNDER;
  51
  52         ret = nvme_set_features(ctrl, NVME_FEAT_TEMP_THRESH, threshold, NULL, 0,
  53                                 NULL);
  54         if (ret > 0)
  55                 return -EIO;
  56
  57         return ret;
  58 }
  59
  60 static int nvme_hwmon_get_smart_log(struct nvme_hwmon_data *data)
  61 {
  62         int ret;
  63
  64         ret = nvme_get_log(data->ctrl, NVME_NSID_ALL, NVME_LOG_SMART, 0,
  65                            &data->log, sizeof(data->log), 0);
  66
  67         return ret <= 0 ? ret : -EIO;
  68 }
  69
  70 static int nvme_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
  71                            u32 attr, int channel, long *val)
  72 {
  73         struct nvme_hwmon_data *data = dev_get_drvdata(dev);
  74         struct nvme_smart_log *log = &data->log;
  75         int temp;
  76         int err;
  77
  78         /*
  79          * First handle attributes which don't require us to read
  80          * the smart log.
  81          */
  82         switch (attr) {
  83         case hwmon_temp_max:
  84                 return nvme_get_temp_thresh(data->ctrl, channel, false, val);
  85         case hwmon_temp_min:
  86                 return nvme_get_temp_thresh(data->ctrl, channel, true, val);
  87         case hwmon_temp_crit:
  88                 *val = kelvin_to_millicelsius(data->ctrl->cctemp);
  89                 return 0;
  90         default:
  91                 break;
  92         }
  93
  94         mutex_lock(&data->read_lock);
  95         err = nvme_hwmon_get_smart_log(data);
  96         if (err)
  97                 goto unlock;
  98
  99         switch (attr) {
 100         case hwmon_temp_input:
 101                 if (!channel)
 102                         temp = get_unaligned_le16(log->temperature);
 103                 else
 104                         temp = le16_to_cpu(log->temp_sensor[channel - 1]);
 105                 *val = kelvin_to_millicelsius(temp);
 106                 break;
 107         case hwmon_temp_alarm:
 108                 *val = !!(log->critical_warning & NVME_SMART_CRIT_TEMPERATURE);
 109                 break;
 110         default:
 111                 err = -EOPNOTSUPP;
 112                 break;
 113         }
 114 unlock:
 115         mutex_unlock(&data->read_lock);
 116         return err;
 117 }
 118
 119 static int nvme_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
 120                             u32 attr, int channel, long val)
 121 {
 122         struct nvme_hwmon_data *data = dev_get_drvdata(dev);
 123
 124         switch (attr) {
 125         case hwmon_temp_max:
 126                 return nvme_set_temp_thresh(data->ctrl, channel, false, val);
 127         case hwmon_temp_min:
 128                 return nvme_set_temp_thresh(data->ctrl, channel, true, val);
 129         default:
 130                 break;
 131         }
 132
 133         return -EOPNOTSUPP;
 134 }
 135
 136 static const char * const nvme_hwmon_sensor_names[] = {
 137         "Composite",
 138         "Sensor 1",
 139         "Sensor 2",
 140         "Sensor 3",
 141         "Sensor 4",
 142         "Sensor 5",
 143         "Sensor 6",
 144         "Sensor 7",
 145         "Sensor 8",
 146 };
 147
 148 static int nvme_hwmon_read_string(struct device *dev,
 149                                   enum hwmon_sensor_types type, u32 attr,
 150                                   int channel, const char **str)
 151 {
 152         *str = nvme_hwmon_sensor_names[channel];
 153         return 0;
 154 }
 155
 156 static umode_t nvme_hwmon_is_visible(const void *_data,
 157                                      enum hwmon_sensor_types type,
 158                                      u32 attr, int channel)
 159 {
 160         const struct nvme_hwmon_data *data = _data;
 161
 162         switch (attr) {
 163         case hwmon_temp_crit:
 164                 if (!channel && data->ctrl->cctemp)
 165                         return 0444;
 166                 break;
 167         case hwmon_temp_max:
 168         case hwmon_temp_min:
 169                 if ((!channel && data->ctrl->wctemp) ||
 170                     (channel && data->log.temp_sensor[channel - 1])) {
 171                         if (data->ctrl->quirks &
 172                             NVME_QUIRK_NO_TEMP_THRESH_CHANGE)
 173                                 return 0444;
 174                         return 0644;
 175                 }
 176                 break;
 177         case hwmon_temp_alarm:
 178                 if (!channel)
 179                         return 0444;
 180                 break;
 181         case hwmon_temp_input:
 182         case hwmon_temp_label:
 183                 if (!channel || data->log.temp_sensor[channel - 1])
 184                         return 0444;
 185                 break;
 186         default:
 187                 break;
 188         }
 189         return 0;
 190 }
 191
 192 static const struct hwmon_channel_info *nvme_hwmon_info[] = {
 193         HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
 194         HWMON_CHANNEL_INFO(temp,
 195                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 196                                 HWMON_T_CRIT | HWMON_T_LABEL | HWMON_T_ALARM,
 197                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 198                                 HWMON_T_LABEL,
 199                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 200                                 HWMON_T_LABEL,
 201                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 202                                 HWMON_T_LABEL,
 203                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 204                                 HWMON_T_LABEL,
 205                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 206                                 HWMON_T_LABEL,
 207                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 208                                 HWMON_T_LABEL,
 209                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 210                                 HWMON_T_LABEL,
 211                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 212                                 HWMON_T_LABEL),
 213         NULL
 214 };
 215
 216 static const struct hwmon_ops nvme_hwmon_ops = {
 217         .is_visible     = nvme_hwmon_is_visible,
 218         .read           = nvme_hwmon_read,
 219         .read_string    = nvme_hwmon_read_string,
 220         .write          = nvme_hwmon_write,
 221 };
 222
 223 static const struct hwmon_chip_info nvme_hwmon_chip_info = {
 224         .ops    = &nvme_hwmon_ops,
 225         .info   = nvme_hwmon_info,
 226 };
 227
 228 void nvme_hwmon_init(struct nvme_ctrl *ctrl)
 229 {
 230         struct device *dev = ctrl->dev;
 231         struct nvme_hwmon_data *data;
 232         struct device *hwmon;
 233         int err;
 234
 235         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 236         if (!data)
 237                 return;
 238
 239         data->ctrl = ctrl;
 240         mutex_init(&data->read_lock);
 241
 242         err = nvme_hwmon_get_smart_log(data);
 243         if (err) {
 244                 dev_warn(dev, "Failed to read smart log (error %d)\n", err);
 245                 devm_kfree(dev, data);
 246                 return;
 247         }
 248
 249         hwmon = devm_hwmon_device_register_with_info(dev, "nvme", data,
 250                                                      &nvme_hwmon_chip_info,
 251                                                      NULL);
 252         if (IS_ERR(hwmon)) {
 253                 dev_warn(dev, "Failed to instantiate hwmon device\n");
 254                 devm_kfree(dev, data);
 255         }
 256 }