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
13struct nvme_hwmon_data {
14	struct nvme_ctrl *ctrl;
15	struct nvme_smart_log *log;
16	struct mutex read_lock;
17};
18
19static 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
40static 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
60static 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
66static 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	}
110unlock:
111	mutex_unlock(&data->read_lock);
112	return err;
113}
114
115static 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
132static 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
144static 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
152static 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		     !(data->ctrl->quirks &
168		       NVME_QUIRK_NO_SECONDARY_TEMP_THRESH))) {
169			if (data->ctrl->quirks &
170			    NVME_QUIRK_NO_TEMP_THRESH_CHANGE)
171				return 0444;
172			return 0644;
173		}
174		break;
175	case hwmon_temp_alarm:
176		if (!channel)
177			return 0444;
178		break;
179	case hwmon_temp_input:
180	case hwmon_temp_label:
181		if (!channel || data->log->temp_sensor[channel - 1])
182			return 0444;
183		break;
184	default:
185		break;
186	}
187	return 0;
188}
189
190static const struct hwmon_channel_info *const nvme_hwmon_info[] = {
191	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
192	HWMON_CHANNEL_INFO(temp,
193			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
194				HWMON_T_CRIT | HWMON_T_LABEL | HWMON_T_ALARM,
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			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
210				HWMON_T_LABEL),
211	NULL
212};
213
214static const struct hwmon_ops nvme_hwmon_ops = {
215	.is_visible	= nvme_hwmon_is_visible,
216	.read		= nvme_hwmon_read,
217	.read_string	= nvme_hwmon_read_string,
218	.write		= nvme_hwmon_write,
219};
220
221static const struct hwmon_chip_info nvme_hwmon_chip_info = {
222	.ops	= &nvme_hwmon_ops,
223	.info	= nvme_hwmon_info,
224};
225
226int nvme_hwmon_init(struct nvme_ctrl *ctrl)
227{
228	struct device *dev = ctrl->device;
229	struct nvme_hwmon_data *data;
230	struct device *hwmon;
231	int err;
232
233	data = kzalloc(sizeof(*data), GFP_KERNEL);
234	if (!data)
235		return -ENOMEM;
236
237	data->log = kzalloc(sizeof(*data->log), GFP_KERNEL);
238	if (!data->log) {
239		err = -ENOMEM;
240		goto err_free_data;
241	}
242
243	data->ctrl = ctrl;
244	mutex_init(&data->read_lock);
245
246	err = nvme_hwmon_get_smart_log(data);
247	if (err) {
248		dev_warn(dev, "Failed to read smart log (error %d)\n", err);
249		goto err_free_log;
250	}
251
252	hwmon = hwmon_device_register_with_info(dev, "nvme",
253						data, &nvme_hwmon_chip_info,
254						NULL);
255	if (IS_ERR(hwmon)) {
256		dev_warn(dev, "Failed to instantiate hwmon device\n");
257		err = PTR_ERR(hwmon);
258		goto err_free_log;
259	}
260	ctrl->hwmon_device = hwmon;
261	return 0;
262
263err_free_log:
264	kfree(data->log);
265err_free_data:
266	kfree(data);
267	return err;
268}
269
270void nvme_hwmon_exit(struct nvme_ctrl *ctrl)
271{
272	if (ctrl->hwmon_device) {
273		struct nvme_hwmon_data *data =
274			dev_get_drvdata(ctrl->hwmon_device);
275
276		hwmon_device_unregister(ctrl->hwmon_device);
277		ctrl->hwmon_device = NULL;
278		kfree(data->log);
279		kfree(data);
280	}
281}
282