1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Hwmon client for disk and solid state drives with temperature sensors
4 * Copyright (C) 2019 Zodiac Inflight Innovations
5 *
6 * With input from:
7 * Hwmon client for S.M.A.R.T. hard disk drives with temperature sensors.
8 * (C) 2018 Linus Walleij
9 *
10 * hwmon: Driver for SCSI/ATA temperature sensors
11 * by Constantin Baranov <const@mimas.ru>, submitted September 2009
12 *
13 * This drive supports reporting the temperature of SATA drives. It can be
14 * easily extended to report the temperature of SCSI drives.
15 *
16 * The primary means to read drive temperatures and temperature limits
17 * for ATA drives is the SCT Command Transport feature set as specified in
18 * ATA8-ACS.
19 * It can be used to read the current drive temperature, temperature limits,
20 * and historic minimum and maximum temperatures. The SCT Command Transport
21 * feature set is documented in "AT Attachment 8 - ATA/ATAPI Command Set
22 * (ATA8-ACS)".
23 *
24 * If the SCT Command Transport feature set is not available, drive temperatures
25 * may be readable through SMART attributes. Since SMART attributes are not well
26 * defined, this method is only used as fallback mechanism.
27 *
28 * There are three SMART attributes which may report drive temperatures.
29 * Those are defined as follows (from
30 * http://www.cropel.com/library/smart-attribute-list.aspx).
31 *
32 * 190 Temperature Temperature, monitored by a sensor somewhere inside
33 * the drive. Raw value typicaly holds the actual
34 * temperature (hexadecimal) in its rightmost two digits.
35 *
36 * 194 Temperature Temperature, monitored by a sensor somewhere inside
37 * the drive. Raw value typicaly holds the actual
38 * temperature (hexadecimal) in its rightmost two digits.
39 *
40 * 231 Temperature Temperature, monitored by a sensor somewhere inside
41 * the drive. Raw value typicaly holds the actual
42 * temperature (hexadecimal) in its rightmost two digits.
43 *
44 * Wikipedia defines attributes a bit differently.
45 *
46 * 190 Temperature Value is equal to (100-temp. °C), allowing manufacturer
47 * Difference or to set a minimum threshold which corresponds to a
48 * Airflow maximum temperature. This also follows the convention of
49 * Temperature 100 being a best-case value and lower values being
50 * undesirable. However, some older drives may instead
51 * report raw Temperature (identical to 0xC2) or
52 * Temperature minus 50 here.
53 * 194 Temperature or Indicates the device temperature, if the appropriate
54 * Temperature sensor is fitted. Lowest byte of the raw value contains
55 * Celsius the exact temperature value (Celsius degrees).
56 * 231 Life Left Indicates the approximate SSD life left, in terms of
57 * (SSDs) or program/erase cycles or available reserved blocks.
58 * Temperature A normalized value of 100 represents a new drive, with
59 * a threshold value at 10 indicating a need for
60 * replacement. A value of 0 may mean that the drive is
61 * operating in read-only mode to allow data recovery.
62 * Previously (pre-2010) occasionally used for Drive
63 * Temperature (more typically reported at 0xC2).
64 *
65 * Common denominator is that the first raw byte reports the temperature
66 * in degrees C on almost all drives. Some drives may report a fractional
67 * temperature in the second raw byte.
68 *
69 * Known exceptions (from libatasmart):
70 * - SAMSUNG SV0412H and SAMSUNG SV1204H) report the temperature in 10th
71 * degrees C in the first two raw bytes.
72 * - A few Maxtor drives report an unknown or bad value in attribute 194.
73 * - Certain Apple SSD drives report an unknown value in attribute 190.
74 * Only certain firmware versions are affected.
75 *
76 * Those exceptions affect older ATA drives and are currently ignored.
77 * Also, the second raw byte (possibly reporting the fractional temperature)
78 * is currently ignored.
79 *
80 * Many drives also report temperature limits in additional SMART data raw
81 * bytes. The format of those is not well defined and varies widely.
82 * The driver does not currently attempt to report those limits.
83 *
84 * According to data in smartmontools, attribute 231 is rarely used to report
85 * drive temperatures. At the same time, several drives report SSD life left
86 * in attribute 231, but do not support temperature sensors. For this reason,
87 * attribute 231 is currently ignored.
88 *
89 * Following above definitions, temperatures are reported as follows.
90 * If SCT Command Transport is supported, it is used to read the
91 * temperature and, if available, temperature limits.
92 * - Otherwise, if SMART attribute 194 is supported, it is used to read
93 * the temperature.
94 * - Otherwise, if SMART attribute 190 is supported, it is used to read
95 * the temperature.
96 */
97
98 #include <linux/ata.h>
99 #include <linux/bits.h>
100 #include <linux/device.h>
101 #include <linux/hwmon.h>
102 #include <linux/kernel.h>
103 #include <linux/list.h>
104 #include <linux/module.h>
105 #include <linux/mutex.h>
106 #include <scsi/scsi_cmnd.h>
107 #include <scsi/scsi_device.h>
108 #include <scsi/scsi_driver.h>
109 #include <scsi/scsi_proto.h>
110
111 struct drivetemp_data {
112 struct list_head list; /* list of instantiated devices */
113 struct mutex lock; /* protect data buffer accesses */
114 struct scsi_device *sdev; /* SCSI device */
115 struct device *dev; /* instantiating device */
116 struct device *hwdev; /* hardware monitoring device */
117 u8 smartdata[ATA_SECT_SIZE]; /* local buffer */
118 int (*get_temp)(struct drivetemp_data *st, u32 attr, long *val);
119 bool have_temp_lowest; /* lowest temp in SCT status */
120 bool have_temp_highest; /* highest temp in SCT status */
121 bool have_temp_min; /* have min temp */
122 bool have_temp_max; /* have max temp */
123 bool have_temp_lcrit; /* have lower critical limit */
124 bool have_temp_crit; /* have critical limit */
125 int temp_min; /* min temp */
126 int temp_max; /* max temp */
127 int temp_lcrit; /* lower critical limit */
128 int temp_crit; /* critical limit */
129 };
130
131 static LIST_HEAD(drivetemp_devlist);
132
133 #define ATA_MAX_SMART_ATTRS 30
134 #define SMART_TEMP_PROP_190 190
135 #define SMART_TEMP_PROP_194 194
136
137 #define SCT_STATUS_REQ_ADDR 0xe0
138 #define SCT_STATUS_VERSION_LOW 0 /* log byte offsets */
139 #define SCT_STATUS_VERSION_HIGH 1
140 #define SCT_STATUS_TEMP 200
141 #define SCT_STATUS_TEMP_LOWEST 201
142 #define SCT_STATUS_TEMP_HIGHEST 202
143 #define SCT_READ_LOG_ADDR 0xe1
144 #define SMART_READ_LOG 0xd5
145 #define SMART_WRITE_LOG 0xd6
146
147 #define INVALID_TEMP 0x80
148
149 #define temp_is_valid(temp) ((temp) != INVALID_TEMP)
150 #define temp_from_sct(temp) (((s8)(temp)) * 1000)
151
ata_id_smart_supported(u16 * id)152 static inline bool ata_id_smart_supported(u16 *id)
153 {
154 return id[ATA_ID_COMMAND_SET_1] & BIT(0);
155 }
156
ata_id_smart_enabled(u16 * id)157 static inline bool ata_id_smart_enabled(u16 *id)
158 {
159 return id[ATA_ID_CFS_ENABLE_1] & BIT(0);
160 }
161
drivetemp_scsi_command(struct drivetemp_data * st,u8 ata_command,u8 feature,u8 lba_low,u8 lba_mid,u8 lba_high)162 static int drivetemp_scsi_command(struct drivetemp_data *st,
163 u8 ata_command, u8 feature,
164 u8 lba_low, u8 lba_mid, u8 lba_high)
165 {
166 u8 scsi_cmd[MAX_COMMAND_SIZE];
167 enum req_op op;
168
169 memset(scsi_cmd, 0, sizeof(scsi_cmd));
170 scsi_cmd[0] = ATA_16;
171 if (ata_command == ATA_CMD_SMART && feature == SMART_WRITE_LOG) {
172 scsi_cmd[1] = (5 << 1); /* PIO Data-out */
173 /*
174 * No off.line or cc, write to dev, block count in sector count
175 * field.
176 */
177 scsi_cmd[2] = 0x06;
178 op = REQ_OP_DRV_OUT;
179 } else {
180 scsi_cmd[1] = (4 << 1); /* PIO Data-in */
181 /*
182 * No off.line or cc, read from dev, block count in sector count
183 * field.
184 */
185 scsi_cmd[2] = 0x0e;
186 op = REQ_OP_DRV_IN;
187 }
188 scsi_cmd[4] = feature;
189 scsi_cmd[6] = 1; /* 1 sector */
190 scsi_cmd[8] = lba_low;
191 scsi_cmd[10] = lba_mid;
192 scsi_cmd[12] = lba_high;
193 scsi_cmd[14] = ata_command;
194
195 return scsi_execute_cmd(st->sdev, scsi_cmd, op, st->smartdata,
196 ATA_SECT_SIZE, HZ, 5, NULL);
197 }
198
drivetemp_ata_command(struct drivetemp_data * st,u8 feature,u8 select)199 static int drivetemp_ata_command(struct drivetemp_data *st, u8 feature,
200 u8 select)
201 {
202 return drivetemp_scsi_command(st, ATA_CMD_SMART, feature, select,
203 ATA_SMART_LBAM_PASS, ATA_SMART_LBAH_PASS);
204 }
205
drivetemp_get_smarttemp(struct drivetemp_data * st,u32 attr,long * temp)206 static int drivetemp_get_smarttemp(struct drivetemp_data *st, u32 attr,
207 long *temp)
208 {
209 u8 *buf = st->smartdata;
210 bool have_temp = false;
211 u8 temp_raw;
212 u8 csum;
213 int err;
214 int i;
215
216 err = drivetemp_ata_command(st, ATA_SMART_READ_VALUES, 0);
217 if (err)
218 return err;
219
220 /* Checksum the read value table */
221 csum = 0;
222 for (i = 0; i < ATA_SECT_SIZE; i++)
223 csum += buf[i];
224 if (csum) {
225 dev_dbg(&st->sdev->sdev_gendev,
226 "checksum error reading SMART values\n");
227 return -EIO;
228 }
229
230 for (i = 0; i < ATA_MAX_SMART_ATTRS; i++) {
231 u8 *attr = buf + i * 12;
232 int id = attr[2];
233
234 if (!id)
235 continue;
236
237 if (id == SMART_TEMP_PROP_190) {
238 temp_raw = attr[7];
239 have_temp = true;
240 }
241 if (id == SMART_TEMP_PROP_194) {
242 temp_raw = attr[7];
243 have_temp = true;
244 break;
245 }
246 }
247
248 if (have_temp) {
249 *temp = temp_raw * 1000;
250 return 0;
251 }
252
253 return -ENXIO;
254 }
255
drivetemp_get_scttemp(struct drivetemp_data * st,u32 attr,long * val)256 static int drivetemp_get_scttemp(struct drivetemp_data *st, u32 attr, long *val)
257 {
258 u8 *buf = st->smartdata;
259 int err;
260
261 err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_STATUS_REQ_ADDR);
262 if (err)
263 return err;
264 switch (attr) {
265 case hwmon_temp_input:
266 if (!temp_is_valid(buf[SCT_STATUS_TEMP]))
267 return -ENODATA;
268 *val = temp_from_sct(buf[SCT_STATUS_TEMP]);
269 break;
270 case hwmon_temp_lowest:
271 if (!temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST]))
272 return -ENODATA;
273 *val = temp_from_sct(buf[SCT_STATUS_TEMP_LOWEST]);
274 break;
275 case hwmon_temp_highest:
276 if (!temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST]))
277 return -ENODATA;
278 *val = temp_from_sct(buf[SCT_STATUS_TEMP_HIGHEST]);
279 break;
280 default:
281 err = -EINVAL;
282 break;
283 }
284 return err;
285 }
286
287 static const char * const sct_avoid_models[] = {
288 /*
289 * These drives will have WRITE FPDMA QUEUED command timeouts and sometimes just
290 * freeze until power-cycled under heavy write loads when their temperature is
291 * getting polled in SCT mode. The SMART mode seems to be fine, though.
292 *
293 * While only the 3 TB model (DT01ACA3) was actually caught exhibiting the
294 * problem let's play safe here to avoid data corruption and ban the whole
295 * DT01ACAx family.
296
297 * The models from this array are prefix-matched.
298 */
299 "TOSHIBA DT01ACA",
300 };
301
drivetemp_sct_avoid(struct drivetemp_data * st)302 static bool drivetemp_sct_avoid(struct drivetemp_data *st)
303 {
304 struct scsi_device *sdev = st->sdev;
305 unsigned int ctr;
306
307 if (!sdev->model)
308 return false;
309
310 /*
311 * The "model" field contains just the raw SCSI INQUIRY response
312 * "product identification" field, which has a width of 16 bytes.
313 * This field is space-filled, but is NOT NULL-terminated.
314 */
315 for (ctr = 0; ctr < ARRAY_SIZE(sct_avoid_models); ctr++)
316 if (!strncmp(sdev->model, sct_avoid_models[ctr],
317 strlen(sct_avoid_models[ctr])))
318 return true;
319
320 return false;
321 }
322
drivetemp_identify_sata(struct drivetemp_data * st)323 static int drivetemp_identify_sata(struct drivetemp_data *st)
324 {
325 struct scsi_device *sdev = st->sdev;
326 u8 *buf = st->smartdata;
327 struct scsi_vpd *vpd;
328 bool is_ata, is_sata;
329 bool have_sct_data_table;
330 bool have_sct_temp;
331 bool have_smart;
332 bool have_sct;
333 u16 *ata_id;
334 u16 version;
335 long temp;
336 int err;
337
338 /* SCSI-ATA Translation present? */
339 rcu_read_lock();
340 vpd = rcu_dereference(sdev->vpd_pg89);
341
342 /*
343 * Verify that ATA IDENTIFY DEVICE data is included in ATA Information
344 * VPD and that the drive implements the SATA protocol.
345 */
346 if (!vpd || vpd->len < 572 || vpd->data[56] != ATA_CMD_ID_ATA ||
347 vpd->data[36] != 0x34) {
348 rcu_read_unlock();
349 return -ENODEV;
350 }
351 ata_id = (u16 *)&vpd->data[60];
352 is_ata = ata_id_is_ata(ata_id);
353 is_sata = ata_id_is_sata(ata_id);
354 have_sct = ata_id_sct_supported(ata_id);
355 have_sct_data_table = ata_id_sct_data_tables(ata_id);
356 have_smart = ata_id_smart_supported(ata_id) &&
357 ata_id_smart_enabled(ata_id);
358
359 rcu_read_unlock();
360
361 /* bail out if this is not a SATA device */
362 if (!is_ata || !is_sata)
363 return -ENODEV;
364
365 if (have_sct && drivetemp_sct_avoid(st)) {
366 dev_notice(&sdev->sdev_gendev,
367 "will avoid using SCT for temperature monitoring\n");
368 have_sct = false;
369 }
370
371 if (!have_sct)
372 goto skip_sct;
373
374 err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_STATUS_REQ_ADDR);
375 if (err)
376 goto skip_sct;
377
378 version = (buf[SCT_STATUS_VERSION_HIGH] << 8) |
379 buf[SCT_STATUS_VERSION_LOW];
380 if (version != 2 && version != 3)
381 goto skip_sct;
382
383 have_sct_temp = temp_is_valid(buf[SCT_STATUS_TEMP]);
384 if (!have_sct_temp)
385 goto skip_sct;
386
387 st->have_temp_lowest = temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST]);
388 st->have_temp_highest = temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST]);
389
390 if (!have_sct_data_table)
391 goto skip_sct_data;
392
393 /* Request and read temperature history table */
394 memset(buf, '\0', sizeof(st->smartdata));
395 buf[0] = 5; /* data table command */
396 buf[2] = 1; /* read table */
397 buf[4] = 2; /* temperature history table */
398
399 err = drivetemp_ata_command(st, SMART_WRITE_LOG, SCT_STATUS_REQ_ADDR);
400 if (err)
401 goto skip_sct_data;
402
403 err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_READ_LOG_ADDR);
404 if (err)
405 goto skip_sct_data;
406
407 /*
408 * Temperature limits per AT Attachment 8 -
409 * ATA/ATAPI Command Set (ATA8-ACS)
410 */
411 st->have_temp_max = temp_is_valid(buf[6]);
412 st->have_temp_crit = temp_is_valid(buf[7]);
413 st->have_temp_min = temp_is_valid(buf[8]);
414 st->have_temp_lcrit = temp_is_valid(buf[9]);
415
416 st->temp_max = temp_from_sct(buf[6]);
417 st->temp_crit = temp_from_sct(buf[7]);
418 st->temp_min = temp_from_sct(buf[8]);
419 st->temp_lcrit = temp_from_sct(buf[9]);
420
421 skip_sct_data:
422 if (have_sct_temp) {
423 st->get_temp = drivetemp_get_scttemp;
424 return 0;
425 }
426 skip_sct:
427 if (!have_smart)
428 return -ENODEV;
429 st->get_temp = drivetemp_get_smarttemp;
430 return drivetemp_get_smarttemp(st, hwmon_temp_input, &temp);
431 }
432
drivetemp_identify(struct drivetemp_data * st)433 static int drivetemp_identify(struct drivetemp_data *st)
434 {
435 struct scsi_device *sdev = st->sdev;
436
437 /* Bail out immediately if there is no inquiry data */
438 if (!sdev->inquiry || sdev->inquiry_len < 16)
439 return -ENODEV;
440
441 /* Disk device? */
442 if (sdev->type != TYPE_DISK && sdev->type != TYPE_ZBC)
443 return -ENODEV;
444
445 return drivetemp_identify_sata(st);
446 }
447
drivetemp_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)448 static int drivetemp_read(struct device *dev, enum hwmon_sensor_types type,
449 u32 attr, int channel, long *val)
450 {
451 struct drivetemp_data *st = dev_get_drvdata(dev);
452 int err = 0;
453
454 if (type != hwmon_temp)
455 return -EINVAL;
456
457 switch (attr) {
458 case hwmon_temp_input:
459 case hwmon_temp_lowest:
460 case hwmon_temp_highest:
461 mutex_lock(&st->lock);
462 err = st->get_temp(st, attr, val);
463 mutex_unlock(&st->lock);
464 break;
465 case hwmon_temp_lcrit:
466 *val = st->temp_lcrit;
467 break;
468 case hwmon_temp_min:
469 *val = st->temp_min;
470 break;
471 case hwmon_temp_max:
472 *val = st->temp_max;
473 break;
474 case hwmon_temp_crit:
475 *val = st->temp_crit;
476 break;
477 default:
478 err = -EINVAL;
479 break;
480 }
481 return err;
482 }
483
drivetemp_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)484 static umode_t drivetemp_is_visible(const void *data,
485 enum hwmon_sensor_types type,
486 u32 attr, int channel)
487 {
488 const struct drivetemp_data *st = data;
489
490 switch (type) {
491 case hwmon_temp:
492 switch (attr) {
493 case hwmon_temp_input:
494 return 0444;
495 case hwmon_temp_lowest:
496 if (st->have_temp_lowest)
497 return 0444;
498 break;
499 case hwmon_temp_highest:
500 if (st->have_temp_highest)
501 return 0444;
502 break;
503 case hwmon_temp_min:
504 if (st->have_temp_min)
505 return 0444;
506 break;
507 case hwmon_temp_max:
508 if (st->have_temp_max)
509 return 0444;
510 break;
511 case hwmon_temp_lcrit:
512 if (st->have_temp_lcrit)
513 return 0444;
514 break;
515 case hwmon_temp_crit:
516 if (st->have_temp_crit)
517 return 0444;
518 break;
519 default:
520 break;
521 }
522 break;
523 default:
524 break;
525 }
526 return 0;
527 }
528
529 static const struct hwmon_channel_info * const drivetemp_info[] = {
530 HWMON_CHANNEL_INFO(chip,
531 HWMON_C_REGISTER_TZ),
532 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT |
533 HWMON_T_LOWEST | HWMON_T_HIGHEST |
534 HWMON_T_MIN | HWMON_T_MAX |
535 HWMON_T_LCRIT | HWMON_T_CRIT),
536 NULL
537 };
538
539 static const struct hwmon_ops drivetemp_ops = {
540 .is_visible = drivetemp_is_visible,
541 .read = drivetemp_read,
542 };
543
544 static const struct hwmon_chip_info drivetemp_chip_info = {
545 .ops = &drivetemp_ops,
546 .info = drivetemp_info,
547 };
548
549 /*
550 * The device argument points to sdev->sdev_dev. Its parent is
551 * sdev->sdev_gendev, which we can use to get the scsi_device pointer.
552 */
drivetemp_add(struct device * dev)553 static int drivetemp_add(struct device *dev)
554 {
555 struct scsi_device *sdev = to_scsi_device(dev->parent);
556 struct drivetemp_data *st;
557 int err;
558
559 st = kzalloc(sizeof(*st), GFP_KERNEL);
560 if (!st)
561 return -ENOMEM;
562
563 st->sdev = sdev;
564 st->dev = dev;
565 mutex_init(&st->lock);
566
567 if (drivetemp_identify(st)) {
568 err = -ENODEV;
569 goto abort;
570 }
571
572 st->hwdev = hwmon_device_register_with_info(dev->parent, "drivetemp",
573 st, &drivetemp_chip_info,
574 NULL);
575 if (IS_ERR(st->hwdev)) {
576 err = PTR_ERR(st->hwdev);
577 goto abort;
578 }
579
580 list_add(&st->list, &drivetemp_devlist);
581 return 0;
582
583 abort:
584 kfree(st);
585 return err;
586 }
587
drivetemp_remove(struct device * dev)588 static void drivetemp_remove(struct device *dev)
589 {
590 struct drivetemp_data *st, *tmp;
591
592 list_for_each_entry_safe(st, tmp, &drivetemp_devlist, list) {
593 if (st->dev == dev) {
594 list_del(&st->list);
595 hwmon_device_unregister(st->hwdev);
596 kfree(st);
597 break;
598 }
599 }
600 }
601
602 static struct class_interface drivetemp_interface = {
603 .add_dev = drivetemp_add,
604 .remove_dev = drivetemp_remove,
605 };
606
drivetemp_init(void)607 static int __init drivetemp_init(void)
608 {
609 return scsi_register_interface(&drivetemp_interface);
610 }
611
drivetemp_exit(void)612 static void __exit drivetemp_exit(void)
613 {
614 scsi_unregister_interface(&drivetemp_interface);
615 }
616
617 module_init(drivetemp_init);
618 module_exit(drivetemp_exit);
619
620 MODULE_AUTHOR("Guenter Roeck <linus@roeck-us.net>");
621 MODULE_DESCRIPTION("Hard drive temperature monitor");
622 MODULE_LICENSE("GPL");
623 MODULE_ALIAS("platform:drivetemp");
624
