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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  
nvme_get_temp_thresh(struct nvme_ctrl * ctrl,int sensor,bool under,long * temp)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  
nvme_set_temp_thresh(struct nvme_ctrl * ctrl,int sensor,bool under,long temp)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  
nvme_hwmon_get_smart_log(struct nvme_hwmon_data * data)60  static int nvme_hwmon_get_smart_log(struct nvme_hwmon_data *data)
61  {
62  	return nvme_get_log(data->ctrl, NVME_NSID_ALL, NVME_LOG_SMART, 0,
63  			   NVME_CSI_NVM, &data->log, sizeof(data->log), 0);
64  }
65  
nvme_hwmon_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)66  static int nvme_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
67  			   u32 attr, int channel, long *val)
68  {
69  	struct nvme_hwmon_data *data = dev_get_drvdata(dev);
70  	struct nvme_smart_log *log = &data->log;
71  	int temp;
72  	int err;
73  
74  	/*
75  	 * First handle attributes which don't require us to read
76  	 * the smart log.
77  	 */
78  	switch (attr) {
79  	case hwmon_temp_max:
80  		return nvme_get_temp_thresh(data->ctrl, channel, false, val);
81  	case hwmon_temp_min:
82  		return nvme_get_temp_thresh(data->ctrl, channel, true, val);
83  	case hwmon_temp_crit:
84  		*val = kelvin_to_millicelsius(data->ctrl->cctemp);
85  		return 0;
86  	default:
87  		break;
88  	}
89  
90  	mutex_lock(&data->read_lock);
91  	err = nvme_hwmon_get_smart_log(data);
92  	if (err)
93  		goto unlock;
94  
95  	switch (attr) {
96  	case hwmon_temp_input:
97  		if (!channel)
98  			temp = get_unaligned_le16(log->temperature);
99  		else
100  			temp = le16_to_cpu(log->temp_sensor[channel - 1]);
101  		*val = kelvin_to_millicelsius(temp);
102  		break;
103  	case hwmon_temp_alarm:
104  		*val = !!(log->critical_warning & NVME_SMART_CRIT_TEMPERATURE);
105  		break;
106  	default:
107  		err = -EOPNOTSUPP;
108  		break;
109  	}
110  unlock:
111  	mutex_unlock(&data->read_lock);
112  	return err;
113  }
114  
nvme_hwmon_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)115  static int nvme_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
116  			    u32 attr, int channel, long val)
117  {
118  	struct nvme_hwmon_data *data = dev_get_drvdata(dev);
119  
120  	switch (attr) {
121  	case hwmon_temp_max:
122  		return nvme_set_temp_thresh(data->ctrl, channel, false, val);
123  	case hwmon_temp_min:
124  		return nvme_set_temp_thresh(data->ctrl, channel, true, val);
125  	default:
126  		break;
127  	}
128  
129  	return -EOPNOTSUPP;
130  }
131  
132  static const char * const nvme_hwmon_sensor_names[] = {
133  	"Composite",
134  	"Sensor 1",
135  	"Sensor 2",
136  	"Sensor 3",
137  	"Sensor 4",
138  	"Sensor 5",
139  	"Sensor 6",
140  	"Sensor 7",
141  	"Sensor 8",
142  };
143  
nvme_hwmon_read_string(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,const char ** str)144  static int nvme_hwmon_read_string(struct device *dev,
145  				  enum hwmon_sensor_types type, u32 attr,
146  				  int channel, const char **str)
147  {
148  	*str = nvme_hwmon_sensor_names[channel];
149  	return 0;
150  }
151  
nvme_hwmon_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)152  static umode_t nvme_hwmon_is_visible(const void *_data,
153  				     enum hwmon_sensor_types type,
154  				     u32 attr, int channel)
155  {
156  	const struct nvme_hwmon_data *data = _data;
157  
158  	switch (attr) {
159  	case hwmon_temp_crit:
160  		if (!channel && data->ctrl->cctemp)
161  			return 0444;
162  		break;
163  	case hwmon_temp_max:
164  	case hwmon_temp_min:
165  		if ((!channel && data->ctrl->wctemp) ||
166  		    (channel && data->log.temp_sensor[channel - 1])) {
167  			if (data->ctrl->quirks &
168  			    NVME_QUIRK_NO_TEMP_THRESH_CHANGE)
169  				return 0444;
170  			return 0644;
171  		}
172  		break;
173  	case hwmon_temp_alarm:
174  		if (!channel)
175  			return 0444;
176  		break;
177  	case hwmon_temp_input:
178  	case hwmon_temp_label:
179  		if (!channel || data->log.temp_sensor[channel - 1])
180  			return 0444;
181  		break;
182  	default:
183  		break;
184  	}
185  	return 0;
186  }
187  
188  static const struct hwmon_channel_info *nvme_hwmon_info[] = {
189  	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
190  	HWMON_CHANNEL_INFO(temp,
191  			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
192  				HWMON_T_CRIT | HWMON_T_LABEL | HWMON_T_ALARM,
193  			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
194  				HWMON_T_LABEL,
195  			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
196  				HWMON_T_LABEL,
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  	NULL
210  };
211  
212  static const struct hwmon_ops nvme_hwmon_ops = {
213  	.is_visible	= nvme_hwmon_is_visible,
214  	.read		= nvme_hwmon_read,
215  	.read_string	= nvme_hwmon_read_string,
216  	.write		= nvme_hwmon_write,
217  };
218  
219  static const struct hwmon_chip_info nvme_hwmon_chip_info = {
220  	.ops	= &nvme_hwmon_ops,
221  	.info	= nvme_hwmon_info,
222  };
223  
nvme_hwmon_init(struct nvme_ctrl * ctrl)224  int nvme_hwmon_init(struct nvme_ctrl *ctrl)
225  {
226  	struct device *dev = ctrl->dev;
227  	struct nvme_hwmon_data *data;
228  	struct device *hwmon;
229  	int err;
230  
231  	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
232  	if (!data)
233  		return 0;
234  
235  	data->ctrl = ctrl;
236  	mutex_init(&data->read_lock);
237  
238  	err = nvme_hwmon_get_smart_log(data);
239  	if (err) {
240  		dev_warn(ctrl->device,
241  			"Failed to read smart log (error %d)\n", err);
242  		devm_kfree(dev, data);
243  		return err;
244  	}
245  
246  	hwmon = devm_hwmon_device_register_with_info(dev, "nvme", data,
247  						     &nvme_hwmon_chip_info,
248  						     NULL);
249  	if (IS_ERR(hwmon)) {
250  		dev_warn(dev, "Failed to instantiate hwmon device\n");
251  		devm_kfree(dev, data);
252  	}
253  
254  	return 0;
255  }
256