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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
111struct 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
131static 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
152static inline bool ata_id_smart_supported(u16 *id)
153{
154 return id[ATA_ID_COMMAND_SET_1] & BIT(0);
155}
156
157static inline bool ata_id_smart_enabled(u16 *id)
158{
159 return id[ATA_ID_CFS_ENABLE_1] & BIT(0);
160}
161
162static 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 int err;
169
170 memset(scsi_cmd, 0, sizeof(scsi_cmd));
171 scsi_cmd[0] = ATA_16;
172 if (ata_command == ATA_CMD_SMART && feature == SMART_WRITE_LOG) {
173 scsi_cmd[1] = (5 << 1); /* PIO Data-out */
174 /*
175 * No off.line or cc, write to dev, block count in sector count
176 * field.
177 */
178 scsi_cmd[2] = 0x06;
179 op = REQ_OP_DRV_OUT;
180 } else {
181 scsi_cmd[1] = (4 << 1); /* PIO Data-in */
182 /*
183 * No off.line or cc, read from dev, block count in sector count
184 * field.
185 */
186 scsi_cmd[2] = 0x0e;
187 op = REQ_OP_DRV_IN;
188 }
189 scsi_cmd[4] = feature;
190 scsi_cmd[6] = 1; /* 1 sector */
191 scsi_cmd[8] = lba_low;
192 scsi_cmd[10] = lba_mid;
193 scsi_cmd[12] = lba_high;
194 scsi_cmd[14] = ata_command;
195
196 err = scsi_execute_cmd(st->sdev, scsi_cmd, op, st->smartdata,
197 ATA_SECT_SIZE, 10 * HZ, 5, NULL);
198 if (err > 0)
199 err = -EIO;
200 return err;
201}
202
203static int drivetemp_ata_command(struct drivetemp_data *st, u8 feature,
204 u8 select)
205{
206 return drivetemp_scsi_command(st, ATA_CMD_SMART, feature, select,
207 ATA_SMART_LBAM_PASS, ATA_SMART_LBAH_PASS);
208}
209
210static int drivetemp_get_smarttemp(struct drivetemp_data *st, u32 attr,
211 long *temp)
212{
213 u8 *buf = st->smartdata;
214 bool have_temp = false;
215 u8 temp_raw;
216 u8 csum;
217 int err;
218 int i;
219
220 err = drivetemp_ata_command(st, ATA_SMART_READ_VALUES, 0);
221 if (err)
222 return err;
223
224 /* Checksum the read value table */
225 csum = 0;
226 for (i = 0; i < ATA_SECT_SIZE; i++)
227 csum += buf[i];
228 if (csum) {
229 dev_dbg(&st->sdev->sdev_gendev,
230 "checksum error reading SMART values\n");
231 return -EIO;
232 }
233
234 for (i = 0; i < ATA_MAX_SMART_ATTRS; i++) {
235 u8 *attr = buf + i * 12;
236 int id = attr[2];
237
238 if (!id)
239 continue;
240
241 if (id == SMART_TEMP_PROP_190) {
242 temp_raw = attr[7];
243 have_temp = true;
244 }
245 if (id == SMART_TEMP_PROP_194) {
246 temp_raw = attr[7];
247 have_temp = true;
248 break;
249 }
250 }
251
252 if (have_temp) {
253 *temp = temp_raw * 1000;
254 return 0;
255 }
256
257 return -ENXIO;
258}
259
260static int drivetemp_get_scttemp(struct drivetemp_data *st, u32 attr, long *val)
261{
262 u8 *buf = st->smartdata;
263 int err;
264
265 err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_STATUS_REQ_ADDR);
266 if (err)
267 return err;
268 switch (attr) {
269 case hwmon_temp_input:
270 if (!temp_is_valid(buf[SCT_STATUS_TEMP]))
271 return -ENODATA;
272 *val = temp_from_sct(buf[SCT_STATUS_TEMP]);
273 break;
274 case hwmon_temp_lowest:
275 if (!temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST]))
276 return -ENODATA;
277 *val = temp_from_sct(buf[SCT_STATUS_TEMP_LOWEST]);
278 break;
279 case hwmon_temp_highest:
280 if (!temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST]))
281 return -ENODATA;
282 *val = temp_from_sct(buf[SCT_STATUS_TEMP_HIGHEST]);
283 break;
284 default:
285 err = -EINVAL;
286 break;
287 }
288 return err;
289}
290
291static const char * const sct_avoid_models[] = {
292/*
293 * These drives will have WRITE FPDMA QUEUED command timeouts and sometimes just
294 * freeze until power-cycled under heavy write loads when their temperature is
295 * getting polled in SCT mode. The SMART mode seems to be fine, though.
296 *
297 * While only the 3 TB model (DT01ACA3) was actually caught exhibiting the
298 * problem let's play safe here to avoid data corruption and ban the whole
299 * DT01ACAx family.
300
301 * The models from this array are prefix-matched.
302 */
303 "TOSHIBA DT01ACA",
304};
305
306static bool drivetemp_sct_avoid(struct drivetemp_data *st)
307{
308 struct scsi_device *sdev = st->sdev;
309 unsigned int ctr;
310
311 if (!sdev->model)
312 return false;
313
314 /*
315 * The "model" field contains just the raw SCSI INQUIRY response
316 * "product identification" field, which has a width of 16 bytes.
317 * This field is space-filled, but is NOT NULL-terminated.
318 */
319 for (ctr = 0; ctr < ARRAY_SIZE(sct_avoid_models); ctr++)
320 if (!strncmp(sdev->model, sct_avoid_models[ctr],
321 strlen(sct_avoid_models[ctr])))
322 return true;
323
324 return false;
325}
326
327static int drivetemp_identify_sata(struct drivetemp_data *st)
328{
329 struct scsi_device *sdev = st->sdev;
330 u8 *buf = st->smartdata;
331 struct scsi_vpd *vpd;
332 bool is_ata, is_sata;
333 bool have_sct_data_table;
334 bool have_sct_temp;
335 bool have_smart;
336 bool have_sct;
337 u16 *ata_id;
338 u16 version;
339 long temp;
340 int err;
341
342 /* SCSI-ATA Translation present? */
343 rcu_read_lock();
344 vpd = rcu_dereference(sdev->vpd_pg89);
345
346 /*
347 * Verify that ATA IDENTIFY DEVICE data is included in ATA Information
348 * VPD and that the drive implements the SATA protocol.
349 */
350 if (!vpd || vpd->len < 572 || vpd->data[56] != ATA_CMD_ID_ATA ||
351 vpd->data[36] != 0x34) {
352 rcu_read_unlock();
353 return -ENODEV;
354 }
355 ata_id = (u16 *)&vpd->data[60];
356 is_ata = ata_id_is_ata(ata_id);
357 is_sata = ata_id_is_sata(ata_id);
358 have_sct = ata_id_sct_supported(ata_id);
359 have_sct_data_table = ata_id_sct_data_tables(ata_id);
360 have_smart = ata_id_smart_supported(ata_id) &&
361 ata_id_smart_enabled(ata_id);
362
363 rcu_read_unlock();
364
365 /* bail out if this is not a SATA device */
366 if (!is_ata || !is_sata)
367 return -ENODEV;
368
369 if (have_sct && drivetemp_sct_avoid(st)) {
370 dev_notice(&sdev->sdev_gendev,
371 "will avoid using SCT for temperature monitoring\n");
372 have_sct = false;
373 }
374
375 if (!have_sct)
376 goto skip_sct;
377
378 err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_STATUS_REQ_ADDR);
379 if (err)
380 goto skip_sct;
381
382 version = (buf[SCT_STATUS_VERSION_HIGH] << 8) |
383 buf[SCT_STATUS_VERSION_LOW];
384 if (version != 2 && version != 3)
385 goto skip_sct;
386
387 have_sct_temp = temp_is_valid(buf[SCT_STATUS_TEMP]);
388 if (!have_sct_temp)
389 goto skip_sct;
390
391 st->have_temp_lowest = temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST]);
392 st->have_temp_highest = temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST]);
393
394 if (!have_sct_data_table)
395 goto skip_sct_data;
396
397 /* Request and read temperature history table */
398 memset(buf, '\0', sizeof(st->smartdata));
399 buf[0] = 5; /* data table command */
400 buf[2] = 1; /* read table */
401 buf[4] = 2; /* temperature history table */
402
403 err = drivetemp_ata_command(st, SMART_WRITE_LOG, SCT_STATUS_REQ_ADDR);
404 if (err)
405 goto skip_sct_data;
406
407 err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_READ_LOG_ADDR);
408 if (err)
409 goto skip_sct_data;
410
411 /*
412 * Temperature limits per AT Attachment 8 -
413 * ATA/ATAPI Command Set (ATA8-ACS)
414 */
415 st->have_temp_max = temp_is_valid(buf[6]);
416 st->have_temp_crit = temp_is_valid(buf[7]);
417 st->have_temp_min = temp_is_valid(buf[8]);
418 st->have_temp_lcrit = temp_is_valid(buf[9]);
419
420 st->temp_max = temp_from_sct(buf[6]);
421 st->temp_crit = temp_from_sct(buf[7]);
422 st->temp_min = temp_from_sct(buf[8]);
423 st->temp_lcrit = temp_from_sct(buf[9]);
424
425skip_sct_data:
426 if (have_sct_temp) {
427 st->get_temp = drivetemp_get_scttemp;
428 return 0;
429 }
430skip_sct:
431 if (!have_smart)
432 return -ENODEV;
433 st->get_temp = drivetemp_get_smarttemp;
434 return drivetemp_get_smarttemp(st, hwmon_temp_input, &temp);
435}
436
437static int drivetemp_identify(struct drivetemp_data *st)
438{
439 struct scsi_device *sdev = st->sdev;
440
441 /* Bail out immediately if there is no inquiry data */
442 if (!sdev->inquiry || sdev->inquiry_len < 16)
443 return -ENODEV;
444
445 /* Disk device? */
446 if (sdev->type != TYPE_DISK && sdev->type != TYPE_ZBC)
447 return -ENODEV;
448
449 return drivetemp_identify_sata(st);
450}
451
452static int drivetemp_read(struct device *dev, enum hwmon_sensor_types type,
453 u32 attr, int channel, long *val)
454{
455 struct drivetemp_data *st = dev_get_drvdata(dev);
456 int err = 0;
457
458 if (type != hwmon_temp)
459 return -EINVAL;
460
461 switch (attr) {
462 case hwmon_temp_input:
463 case hwmon_temp_lowest:
464 case hwmon_temp_highest:
465 mutex_lock(&st->lock);
466 err = st->get_temp(st, attr, val);
467 mutex_unlock(&st->lock);
468 break;
469 case hwmon_temp_lcrit:
470 *val = st->temp_lcrit;
471 break;
472 case hwmon_temp_min:
473 *val = st->temp_min;
474 break;
475 case hwmon_temp_max:
476 *val = st->temp_max;
477 break;
478 case hwmon_temp_crit:
479 *val = st->temp_crit;
480 break;
481 default:
482 err = -EINVAL;
483 break;
484 }
485 return err;
486}
487
488static umode_t drivetemp_is_visible(const void *data,
489 enum hwmon_sensor_types type,
490 u32 attr, int channel)
491{
492 const struct drivetemp_data *st = data;
493
494 switch (type) {
495 case hwmon_temp:
496 switch (attr) {
497 case hwmon_temp_input:
498 return 0444;
499 case hwmon_temp_lowest:
500 if (st->have_temp_lowest)
501 return 0444;
502 break;
503 case hwmon_temp_highest:
504 if (st->have_temp_highest)
505 return 0444;
506 break;
507 case hwmon_temp_min:
508 if (st->have_temp_min)
509 return 0444;
510 break;
511 case hwmon_temp_max:
512 if (st->have_temp_max)
513 return 0444;
514 break;
515 case hwmon_temp_lcrit:
516 if (st->have_temp_lcrit)
517 return 0444;
518 break;
519 case hwmon_temp_crit:
520 if (st->have_temp_crit)
521 return 0444;
522 break;
523 default:
524 break;
525 }
526 break;
527 default:
528 break;
529 }
530 return 0;
531}
532
533static const struct hwmon_channel_info * const drivetemp_info[] = {
534 HWMON_CHANNEL_INFO(chip,
535 HWMON_C_REGISTER_TZ),
536 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT |
537 HWMON_T_LOWEST | HWMON_T_HIGHEST |
538 HWMON_T_MIN | HWMON_T_MAX |
539 HWMON_T_LCRIT | HWMON_T_CRIT),
540 NULL
541};
542
543static const struct hwmon_ops drivetemp_ops = {
544 .is_visible = drivetemp_is_visible,
545 .read = drivetemp_read,
546};
547
548static const struct hwmon_chip_info drivetemp_chip_info = {
549 .ops = &drivetemp_ops,
550 .info = drivetemp_info,
551};
552
553/*
554 * The device argument points to sdev->sdev_dev. Its parent is
555 * sdev->sdev_gendev, which we can use to get the scsi_device pointer.
556 */
557static int drivetemp_add(struct device *dev)
558{
559 struct scsi_device *sdev = to_scsi_device(dev->parent);
560 struct drivetemp_data *st;
561 int err;
562
563 st = kzalloc(sizeof(*st), GFP_KERNEL);
564 if (!st)
565 return -ENOMEM;
566
567 st->sdev = sdev;
568 st->dev = dev;
569 mutex_init(&st->lock);
570
571 if (drivetemp_identify(st)) {
572 err = -ENODEV;
573 goto abort;
574 }
575
576 st->hwdev = hwmon_device_register_with_info(dev->parent, "drivetemp",
577 st, &drivetemp_chip_info,
578 NULL);
579 if (IS_ERR(st->hwdev)) {
580 err = PTR_ERR(st->hwdev);
581 goto abort;
582 }
583
584 list_add(&st->list, &drivetemp_devlist);
585 return 0;
586
587abort:
588 kfree(st);
589 return err;
590}
591
592static void drivetemp_remove(struct device *dev)
593{
594 struct drivetemp_data *st, *tmp;
595
596 list_for_each_entry_safe(st, tmp, &drivetemp_devlist, list) {
597 if (st->dev == dev) {
598 list_del(&st->list);
599 hwmon_device_unregister(st->hwdev);
600 kfree(st);
601 break;
602 }
603 }
604}
605
606static struct class_interface drivetemp_interface = {
607 .add_dev = drivetemp_add,
608 .remove_dev = drivetemp_remove,
609};
610
611static int __init drivetemp_init(void)
612{
613 return scsi_register_interface(&drivetemp_interface);
614}
615
616static void __exit drivetemp_exit(void)
617{
618 scsi_unregister_interface(&drivetemp_interface);
619}
620
621module_init(drivetemp_init);
622module_exit(drivetemp_exit);
623
624MODULE_AUTHOR("Guenter Roeck <linus@roeck-us.net>");
625MODULE_DESCRIPTION("Hard drive temperature monitor");
626MODULE_LICENSE("GPL");
627MODULE_ALIAS("platform:drivetemp");