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) 151 152 static inline bool ata_id_smart_supported(u16 *id) 153 { 154 return id[ATA_ID_COMMAND_SET_1] & BIT(0); 155 } 156 157 static inline bool ata_id_smart_enabled(u16 *id) 158 { 159 return id[ATA_ID_CFS_ENABLE_1] & BIT(0); 160 } 161 162 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 int data_dir; 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 data_dir = DMA_TO_DEVICE; 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 data_dir = DMA_FROM_DEVICE; 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_req(st->sdev, scsi_cmd, data_dir, 196 st->smartdata, ATA_SECT_SIZE, NULL, HZ, 5, 197 NULL); 198 } 199 200 static int drivetemp_ata_command(struct drivetemp_data *st, u8 feature, 201 u8 select) 202 { 203 return drivetemp_scsi_command(st, ATA_CMD_SMART, feature, select, 204 ATA_SMART_LBAM_PASS, ATA_SMART_LBAH_PASS); 205 } 206 207 static int drivetemp_get_smarttemp(struct drivetemp_data *st, u32 attr, 208 long *temp) 209 { 210 u8 *buf = st->smartdata; 211 bool have_temp = false; 212 u8 temp_raw; 213 u8 csum; 214 int err; 215 int i; 216 217 err = drivetemp_ata_command(st, ATA_SMART_READ_VALUES, 0); 218 if (err) 219 return err; 220 221 /* Checksum the read value table */ 222 csum = 0; 223 for (i = 0; i < ATA_SECT_SIZE; i++) 224 csum += buf[i]; 225 if (csum) { 226 dev_dbg(&st->sdev->sdev_gendev, 227 "checksum error reading SMART values\n"); 228 return -EIO; 229 } 230 231 for (i = 0; i < ATA_MAX_SMART_ATTRS; i++) { 232 u8 *attr = buf + i * 12; 233 int id = attr[2]; 234 235 if (!id) 236 continue; 237 238 if (id == SMART_TEMP_PROP_190) { 239 temp_raw = attr[7]; 240 have_temp = true; 241 } 242 if (id == SMART_TEMP_PROP_194) { 243 temp_raw = attr[7]; 244 have_temp = true; 245 break; 246 } 247 } 248 249 if (have_temp) { 250 *temp = temp_raw * 1000; 251 return 0; 252 } 253 254 return -ENXIO; 255 } 256 257 static int drivetemp_get_scttemp(struct drivetemp_data *st, u32 attr, long *val) 258 { 259 u8 *buf = st->smartdata; 260 int err; 261 262 err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_STATUS_REQ_ADDR); 263 if (err) 264 return err; 265 switch (attr) { 266 case hwmon_temp_input: 267 if (!temp_is_valid(buf[SCT_STATUS_TEMP])) 268 return -ENODATA; 269 *val = temp_from_sct(buf[SCT_STATUS_TEMP]); 270 break; 271 case hwmon_temp_lowest: 272 if (!temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST])) 273 return -ENODATA; 274 *val = temp_from_sct(buf[SCT_STATUS_TEMP_LOWEST]); 275 break; 276 case hwmon_temp_highest: 277 if (!temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST])) 278 return -ENODATA; 279 *val = temp_from_sct(buf[SCT_STATUS_TEMP_HIGHEST]); 280 break; 281 default: 282 err = -EINVAL; 283 break; 284 } 285 return err; 286 } 287 288 static const char * const sct_avoid_models[] = { 289 /* 290 * These drives will have WRITE FPDMA QUEUED command timeouts and sometimes just 291 * freeze until power-cycled under heavy write loads when their temperature is 292 * getting polled in SCT mode. The SMART mode seems to be fine, though. 293 * 294 * While only the 3 TB model (DT01ACA3) was actually caught exhibiting the 295 * problem let's play safe here to avoid data corruption and ban the whole 296 * DT01ACAx family. 297 298 * The models from this array are prefix-matched. 299 */ 300 "TOSHIBA DT01ACA", 301 }; 302 303 static bool drivetemp_sct_avoid(struct drivetemp_data *st) 304 { 305 struct scsi_device *sdev = st->sdev; 306 unsigned int ctr; 307 308 if (!sdev->model) 309 return false; 310 311 /* 312 * The "model" field contains just the raw SCSI INQUIRY response 313 * "product identification" field, which has a width of 16 bytes. 314 * This field is space-filled, but is NOT NULL-terminated. 315 */ 316 for (ctr = 0; ctr < ARRAY_SIZE(sct_avoid_models); ctr++) 317 if (!strncmp(sdev->model, sct_avoid_models[ctr], 318 strlen(sct_avoid_models[ctr]))) 319 return true; 320 321 return false; 322 } 323 324 static int drivetemp_identify_sata(struct drivetemp_data *st) 325 { 326 struct scsi_device *sdev = st->sdev; 327 u8 *buf = st->smartdata; 328 struct scsi_vpd *vpd; 329 bool is_ata, is_sata; 330 bool have_sct_data_table; 331 bool have_sct_temp; 332 bool have_smart; 333 bool have_sct; 334 u16 *ata_id; 335 u16 version; 336 long temp; 337 int err; 338 339 /* SCSI-ATA Translation present? */ 340 rcu_read_lock(); 341 vpd = rcu_dereference(sdev->vpd_pg89); 342 343 /* 344 * Verify that ATA IDENTIFY DEVICE data is included in ATA Information 345 * VPD and that the drive implements the SATA protocol. 346 */ 347 if (!vpd || vpd->len < 572 || vpd->data[56] != ATA_CMD_ID_ATA || 348 vpd->data[36] != 0x34) { 349 rcu_read_unlock(); 350 return -ENODEV; 351 } 352 ata_id = (u16 *)&vpd->data[60]; 353 is_ata = ata_id_is_ata(ata_id); 354 is_sata = ata_id_is_sata(ata_id); 355 have_sct = ata_id_sct_supported(ata_id); 356 have_sct_data_table = ata_id_sct_data_tables(ata_id); 357 have_smart = ata_id_smart_supported(ata_id) && 358 ata_id_smart_enabled(ata_id); 359 360 rcu_read_unlock(); 361 362 /* bail out if this is not a SATA device */ 363 if (!is_ata || !is_sata) 364 return -ENODEV; 365 366 if (have_sct && drivetemp_sct_avoid(st)) { 367 dev_notice(&sdev->sdev_gendev, 368 "will avoid using SCT for temperature monitoring\n"); 369 have_sct = false; 370 } 371 372 if (!have_sct) 373 goto skip_sct; 374 375 err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_STATUS_REQ_ADDR); 376 if (err) 377 goto skip_sct; 378 379 version = (buf[SCT_STATUS_VERSION_HIGH] << 8) | 380 buf[SCT_STATUS_VERSION_LOW]; 381 if (version != 2 && version != 3) 382 goto skip_sct; 383 384 have_sct_temp = temp_is_valid(buf[SCT_STATUS_TEMP]); 385 if (!have_sct_temp) 386 goto skip_sct; 387 388 st->have_temp_lowest = temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST]); 389 st->have_temp_highest = temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST]); 390 391 if (!have_sct_data_table) 392 goto skip_sct_data; 393 394 /* Request and read temperature history table */ 395 memset(buf, '\0', sizeof(st->smartdata)); 396 buf[0] = 5; /* data table command */ 397 buf[2] = 1; /* read table */ 398 buf[4] = 2; /* temperature history table */ 399 400 err = drivetemp_ata_command(st, SMART_WRITE_LOG, SCT_STATUS_REQ_ADDR); 401 if (err) 402 goto skip_sct_data; 403 404 err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_READ_LOG_ADDR); 405 if (err) 406 goto skip_sct_data; 407 408 /* 409 * Temperature limits per AT Attachment 8 - 410 * ATA/ATAPI Command Set (ATA8-ACS) 411 */ 412 st->have_temp_max = temp_is_valid(buf[6]); 413 st->have_temp_crit = temp_is_valid(buf[7]); 414 st->have_temp_min = temp_is_valid(buf[8]); 415 st->have_temp_lcrit = temp_is_valid(buf[9]); 416 417 st->temp_max = temp_from_sct(buf[6]); 418 st->temp_crit = temp_from_sct(buf[7]); 419 st->temp_min = temp_from_sct(buf[8]); 420 st->temp_lcrit = temp_from_sct(buf[9]); 421 422 skip_sct_data: 423 if (have_sct_temp) { 424 st->get_temp = drivetemp_get_scttemp; 425 return 0; 426 } 427 skip_sct: 428 if (!have_smart) 429 return -ENODEV; 430 st->get_temp = drivetemp_get_smarttemp; 431 return drivetemp_get_smarttemp(st, hwmon_temp_input, &temp); 432 } 433 434 static int drivetemp_identify(struct drivetemp_data *st) 435 { 436 struct scsi_device *sdev = st->sdev; 437 438 /* Bail out immediately if there is no inquiry data */ 439 if (!sdev->inquiry || sdev->inquiry_len < 16) 440 return -ENODEV; 441 442 /* Disk device? */ 443 if (sdev->type != TYPE_DISK && sdev->type != TYPE_ZBC) 444 return -ENODEV; 445 446 return drivetemp_identify_sata(st); 447 } 448 449 static int drivetemp_read(struct device *dev, enum hwmon_sensor_types type, 450 u32 attr, int channel, long *val) 451 { 452 struct drivetemp_data *st = dev_get_drvdata(dev); 453 int err = 0; 454 455 if (type != hwmon_temp) 456 return -EINVAL; 457 458 switch (attr) { 459 case hwmon_temp_input: 460 case hwmon_temp_lowest: 461 case hwmon_temp_highest: 462 mutex_lock(&st->lock); 463 err = st->get_temp(st, attr, val); 464 mutex_unlock(&st->lock); 465 break; 466 case hwmon_temp_lcrit: 467 *val = st->temp_lcrit; 468 break; 469 case hwmon_temp_min: 470 *val = st->temp_min; 471 break; 472 case hwmon_temp_max: 473 *val = st->temp_max; 474 break; 475 case hwmon_temp_crit: 476 *val = st->temp_crit; 477 break; 478 default: 479 err = -EINVAL; 480 break; 481 } 482 return err; 483 } 484 485 static umode_t drivetemp_is_visible(const void *data, 486 enum hwmon_sensor_types type, 487 u32 attr, int channel) 488 { 489 const struct drivetemp_data *st = data; 490 491 switch (type) { 492 case hwmon_temp: 493 switch (attr) { 494 case hwmon_temp_input: 495 return 0444; 496 case hwmon_temp_lowest: 497 if (st->have_temp_lowest) 498 return 0444; 499 break; 500 case hwmon_temp_highest: 501 if (st->have_temp_highest) 502 return 0444; 503 break; 504 case hwmon_temp_min: 505 if (st->have_temp_min) 506 return 0444; 507 break; 508 case hwmon_temp_max: 509 if (st->have_temp_max) 510 return 0444; 511 break; 512 case hwmon_temp_lcrit: 513 if (st->have_temp_lcrit) 514 return 0444; 515 break; 516 case hwmon_temp_crit: 517 if (st->have_temp_crit) 518 return 0444; 519 break; 520 default: 521 break; 522 } 523 break; 524 default: 525 break; 526 } 527 return 0; 528 } 529 530 static const struct hwmon_channel_info *drivetemp_info[] = { 531 HWMON_CHANNEL_INFO(chip, 532 HWMON_C_REGISTER_TZ), 533 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | 534 HWMON_T_LOWEST | HWMON_T_HIGHEST | 535 HWMON_T_MIN | HWMON_T_MAX | 536 HWMON_T_LCRIT | HWMON_T_CRIT), 537 NULL 538 }; 539 540 static const struct hwmon_ops drivetemp_ops = { 541 .is_visible = drivetemp_is_visible, 542 .read = drivetemp_read, 543 }; 544 545 static const struct hwmon_chip_info drivetemp_chip_info = { 546 .ops = &drivetemp_ops, 547 .info = drivetemp_info, 548 }; 549 550 /* 551 * The device argument points to sdev->sdev_dev. Its parent is 552 * sdev->sdev_gendev, which we can use to get the scsi_device pointer. 553 */ 554 static int drivetemp_add(struct device *dev, struct class_interface *intf) 555 { 556 struct scsi_device *sdev = to_scsi_device(dev->parent); 557 struct drivetemp_data *st; 558 int err; 559 560 st = kzalloc(sizeof(*st), GFP_KERNEL); 561 if (!st) 562 return -ENOMEM; 563 564 st->sdev = sdev; 565 st->dev = dev; 566 mutex_init(&st->lock); 567 568 if (drivetemp_identify(st)) { 569 err = -ENODEV; 570 goto abort; 571 } 572 573 st->hwdev = hwmon_device_register_with_info(dev->parent, "drivetemp", 574 st, &drivetemp_chip_info, 575 NULL); 576 if (IS_ERR(st->hwdev)) { 577 err = PTR_ERR(st->hwdev); 578 goto abort; 579 } 580 581 list_add(&st->list, &drivetemp_devlist); 582 return 0; 583 584 abort: 585 kfree(st); 586 return err; 587 } 588 589 static void drivetemp_remove(struct device *dev, struct class_interface *intf) 590 { 591 struct drivetemp_data *st, *tmp; 592 593 list_for_each_entry_safe(st, tmp, &drivetemp_devlist, list) { 594 if (st->dev == dev) { 595 list_del(&st->list); 596 hwmon_device_unregister(st->hwdev); 597 kfree(st); 598 break; 599 } 600 } 601 } 602 603 static struct class_interface drivetemp_interface = { 604 .add_dev = drivetemp_add, 605 .remove_dev = drivetemp_remove, 606 }; 607 608 static int __init drivetemp_init(void) 609 { 610 return scsi_register_interface(&drivetemp_interface); 611 } 612 613 static void __exit drivetemp_exit(void) 614 { 615 scsi_unregister_interface(&drivetemp_interface); 616 } 617 618 module_init(drivetemp_init); 619 module_exit(drivetemp_exit); 620 621 MODULE_AUTHOR("Guenter Roeck <linus@roeck-us.net>"); 622 MODULE_DESCRIPTION("Hard drive temperature monitor"); 623 MODULE_LICENSE("GPL"); 624