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diff --git a/drivers/hwmon/drivetemp.c b/drivers/hwmon/drivetemp.c
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+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hwmon client for disk and solid state drives with temperature sensors
+ * Copyright (C) 2019 Zodiac Inflight Innovations
+ *
+ * With input from:
+ * Hwmon client for S.M.A.R.T. hard disk drives with temperature sensors.
+ * (C) 2018 Linus Walleij
+ *
+ * hwmon: Driver for SCSI/ATA temperature sensors
+ * by Constantin Baranov <const@mimas.ru>, submitted September 2009
+ *
+ * This drive supports reporting the temperature of SATA drives. It can be
+ * easily extended to report the temperature of SCSI drives.
+ *
+ * The primary means to read drive temperatures and temperature limits
+ * for ATA drives is the SCT Command Transport feature set as specified in
+ * ATA8-ACS.
+ * It can be used to read the current drive temperature, temperature limits,
+ * and historic minimum and maximum temperatures. The SCT Command Transport
+ * feature set is documented in "AT Attachment 8 - ATA/ATAPI Command Set
+ * (ATA8-ACS)".
+ *
+ * If the SCT Command Transport feature set is not available, drive temperatures
+ * may be readable through SMART attributes. Since SMART attributes are not well
+ * defined, this method is only used as fallback mechanism.
+ *
+ * There are three SMART attributes which may report drive temperatures.
+ * Those are defined as follows (from
+ * http://www.cropel.com/library/smart-attribute-list.aspx).
+ *
+ * 190 Temperature Temperature, monitored by a sensor somewhere inside
+ * the drive. Raw value typicaly holds the actual
+ * temperature (hexadecimal) in its rightmost two digits.
+ *
+ * 194 Temperature Temperature, monitored by a sensor somewhere inside
+ * the drive. Raw value typicaly holds the actual
+ * temperature (hexadecimal) in its rightmost two digits.
+ *
+ * 231 Temperature Temperature, monitored by a sensor somewhere inside
+ * the drive. Raw value typicaly holds the actual
+ * temperature (hexadecimal) in its rightmost two digits.
+ *
+ * Wikipedia defines attributes a bit differently.
+ *
+ * 190 Temperature Value is equal to (100-temp. °C), allowing manufacturer
+ * Difference or to set a minimum threshold which corresponds to a
+ * Airflow maximum temperature. This also follows the convention of
+ * Temperature 100 being a best-case value and lower values being
+ * undesirable. However, some older drives may instead
+ * report raw Temperature (identical to 0xC2) or
+ * Temperature minus 50 here.
+ * 194 Temperature or Indicates the device temperature, if the appropriate
+ * Temperature sensor is fitted. Lowest byte of the raw value contains
+ * Celsius the exact temperature value (Celsius degrees).
+ * 231 Life Left Indicates the approximate SSD life left, in terms of
+ * (SSDs) or program/erase cycles or available reserved blocks.
+ * Temperature A normalized value of 100 represents a new drive, with
+ * a threshold value at 10 indicating a need for
+ * replacement. A value of 0 may mean that the drive is
+ * operating in read-only mode to allow data recovery.
+ * Previously (pre-2010) occasionally used for Drive
+ * Temperature (more typically reported at 0xC2).
+ *
+ * Common denominator is that the first raw byte reports the temperature
+ * in degrees C on almost all drives. Some drives may report a fractional
+ * temperature in the second raw byte.
+ *
+ * Known exceptions (from libatasmart):
+ * - SAMSUNG SV0412H and SAMSUNG SV1204H) report the temperature in 10th
+ * degrees C in the first two raw bytes.
+ * - A few Maxtor drives report an unknown or bad value in attribute 194.
+ * - Certain Apple SSD drives report an unknown value in attribute 190.
+ * Only certain firmware versions are affected.
+ *
+ * Those exceptions affect older ATA drives and are currently ignored.
+ * Also, the second raw byte (possibly reporting the fractional temperature)
+ * is currently ignored.
+ *
+ * Many drives also report temperature limits in additional SMART data raw
+ * bytes. The format of those is not well defined and varies widely.
+ * The driver does not currently attempt to report those limits.
+ *
+ * According to data in smartmontools, attribute 231 is rarely used to report
+ * drive temperatures. At the same time, several drives report SSD life left
+ * in attribute 231, but do not support temperature sensors. For this reason,
+ * attribute 231 is currently ignored.
+ *
+ * Following above definitions, temperatures are reported as follows.
+ * If SCT Command Transport is supported, it is used to read the
+ * temperature and, if available, temperature limits.
+ * - Otherwise, if SMART attribute 194 is supported, it is used to read
+ * the temperature.
+ * - Otherwise, if SMART attribute 190 is supported, it is used to read
+ * the temperature.
+ */
+
+#include <linux/ata.h>
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/hwmon.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_driver.h>
+#include <scsi/scsi_proto.h>
+
+struct drivetemp_data {
+ struct list_head list; /* list of instantiated devices */
+ struct mutex lock; /* protect data buffer accesses */
+ struct scsi_device *sdev; /* SCSI device */
+ struct device *dev; /* instantiating device */
+ struct device *hwdev; /* hardware monitoring device */
+ u8 smartdata[ATA_SECT_SIZE]; /* local buffer */
+ int (*get_temp)(struct drivetemp_data *st, u32 attr, long *val);
+ bool have_temp_lowest; /* lowest temp in SCT status */
+ bool have_temp_highest; /* highest temp in SCT status */
+ bool have_temp_min; /* have min temp */
+ bool have_temp_max; /* have max temp */
+ bool have_temp_lcrit; /* have lower critical limit */
+ bool have_temp_crit; /* have critical limit */
+ int temp_min; /* min temp */
+ int temp_max; /* max temp */
+ int temp_lcrit; /* lower critical limit */
+ int temp_crit; /* critical limit */
+};
+
+static LIST_HEAD(drivetemp_devlist);
+
+#define ATA_MAX_SMART_ATTRS 30
+#define SMART_TEMP_PROP_190 190
+#define SMART_TEMP_PROP_194 194
+
+#define SCT_STATUS_REQ_ADDR 0xe0
+#define SCT_STATUS_VERSION_LOW 0 /* log byte offsets */
+#define SCT_STATUS_VERSION_HIGH 1
+#define SCT_STATUS_TEMP 200
+#define SCT_STATUS_TEMP_LOWEST 201
+#define SCT_STATUS_TEMP_HIGHEST 202
+#define SCT_READ_LOG_ADDR 0xe1
+#define SMART_READ_LOG 0xd5
+#define SMART_WRITE_LOG 0xd6
+
+#define INVALID_TEMP 0x80
+
+#define temp_is_valid(temp) ((temp) != INVALID_TEMP)
+#define temp_from_sct(temp) (((s8)(temp)) * 1000)
+
+static inline bool ata_id_smart_supported(u16 *id)
+{
+ return id[ATA_ID_COMMAND_SET_1] & BIT(0);
+}
+
+static inline bool ata_id_smart_enabled(u16 *id)
+{
+ return id[ATA_ID_CFS_ENABLE_1] & BIT(0);
+}
+
+static int drivetemp_scsi_command(struct drivetemp_data *st,
+ u8 ata_command, u8 feature,
+ u8 lba_low, u8 lba_mid, u8 lba_high)
+{
+ u8 scsi_cmd[MAX_COMMAND_SIZE];
+ int data_dir;
+
+ memset(scsi_cmd, 0, sizeof(scsi_cmd));
+ scsi_cmd[0] = ATA_16;
+ if (ata_command == ATA_CMD_SMART && feature == SMART_WRITE_LOG) {
+ scsi_cmd[1] = (5 << 1); /* PIO Data-out */
+ /*
+ * No off.line or cc, write to dev, block count in sector count
+ * field.
+ */
+ scsi_cmd[2] = 0x06;
+ data_dir = DMA_TO_DEVICE;
+ } else {
+ scsi_cmd[1] = (4 << 1); /* PIO Data-in */
+ /*
+ * No off.line or cc, read from dev, block count in sector count
+ * field.
+ */
+ scsi_cmd[2] = 0x0e;
+ data_dir = DMA_FROM_DEVICE;
+ }
+ scsi_cmd[4] = feature;
+ scsi_cmd[6] = 1; /* 1 sector */
+ scsi_cmd[8] = lba_low;
+ scsi_cmd[10] = lba_mid;
+ scsi_cmd[12] = lba_high;
+ scsi_cmd[14] = ata_command;
+
+ return scsi_execute_req(st->sdev, scsi_cmd, data_dir,
+ st->smartdata, ATA_SECT_SIZE, NULL, HZ, 5,
+ NULL);
+}
+
+static int drivetemp_ata_command(struct drivetemp_data *st, u8 feature,
+ u8 select)
+{
+ return drivetemp_scsi_command(st, ATA_CMD_SMART, feature, select,
+ ATA_SMART_LBAM_PASS, ATA_SMART_LBAH_PASS);
+}
+
+static int drivetemp_get_smarttemp(struct drivetemp_data *st, u32 attr,
+ long *temp)
+{
+ u8 *buf = st->smartdata;
+ bool have_temp = false;
+ u8 temp_raw;
+ u8 csum;
+ int err;
+ int i;
+
+ err = drivetemp_ata_command(st, ATA_SMART_READ_VALUES, 0);
+ if (err)
+ return err;
+
+ /* Checksum the read value table */
+ csum = 0;
+ for (i = 0; i < ATA_SECT_SIZE; i++)
+ csum += buf[i];
+ if (csum) {
+ dev_dbg(&st->sdev->sdev_gendev,
+ "checksum error reading SMART values\n");
+ return -EIO;
+ }
+
+ for (i = 0; i < ATA_MAX_SMART_ATTRS; i++) {
+ u8 *attr = buf + i * 12;
+ int id = attr[2];
+
+ if (!id)
+ continue;
+
+ if (id == SMART_TEMP_PROP_190) {
+ temp_raw = attr[7];
+ have_temp = true;
+ }
+ if (id == SMART_TEMP_PROP_194) {
+ temp_raw = attr[7];
+ have_temp = true;
+ break;
+ }
+ }
+
+ if (have_temp) {
+ *temp = temp_raw * 1000;
+ return 0;
+ }
+
+ return -ENXIO;
+}
+
+static int drivetemp_get_scttemp(struct drivetemp_data *st, u32 attr, long *val)
+{
+ u8 *buf = st->smartdata;
+ int err;
+
+ err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_STATUS_REQ_ADDR);
+ if (err)
+ return err;
+ switch (attr) {
+ case hwmon_temp_input:
+ if (!temp_is_valid(buf[SCT_STATUS_TEMP]))
+ return -ENODATA;
+ *val = temp_from_sct(buf[SCT_STATUS_TEMP]);
+ break;
+ case hwmon_temp_lowest:
+ if (!temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST]))
+ return -ENODATA;
+ *val = temp_from_sct(buf[SCT_STATUS_TEMP_LOWEST]);
+ break;
+ case hwmon_temp_highest:
+ if (!temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST]))
+ return -ENODATA;
+ *val = temp_from_sct(buf[SCT_STATUS_TEMP_HIGHEST]);
+ break;
+ default:
+ err = -EINVAL;
+ break;
+ }
+ return err;
+}
+
+static const char * const sct_avoid_models[] = {
+/*
+ * These drives will have WRITE FPDMA QUEUED command timeouts and sometimes just
+ * freeze until power-cycled under heavy write loads when their temperature is
+ * getting polled in SCT mode. The SMART mode seems to be fine, though.
+ *
+ * While only the 3 TB model (DT01ACA3) was actually caught exhibiting the
+ * problem let's play safe here to avoid data corruption and ban the whole
+ * DT01ACAx family.
+
+ * The models from this array are prefix-matched.
+ */
+ "TOSHIBA DT01ACA",
+};
+
+static bool drivetemp_sct_avoid(struct drivetemp_data *st)
+{
+ struct scsi_device *sdev = st->sdev;
+ unsigned int ctr;
+
+ if (!sdev->model)
+ return false;
+
+ /*
+ * The "model" field contains just the raw SCSI INQUIRY response
+ * "product identification" field, which has a width of 16 bytes.
+ * This field is space-filled, but is NOT NULL-terminated.
+ */
+ for (ctr = 0; ctr < ARRAY_SIZE(sct_avoid_models); ctr++)
+ if (!strncmp(sdev->model, sct_avoid_models[ctr],
+ strlen(sct_avoid_models[ctr])))
+ return true;
+
+ return false;
+}
+
+static int drivetemp_identify_sata(struct drivetemp_data *st)
+{
+ struct scsi_device *sdev = st->sdev;
+ u8 *buf = st->smartdata;
+ struct scsi_vpd *vpd;
+ bool is_ata, is_sata;
+ bool have_sct_data_table;
+ bool have_sct_temp;
+ bool have_smart;
+ bool have_sct;
+ u16 *ata_id;
+ u16 version;
+ long temp;
+ int err;
+
+ /* SCSI-ATA Translation present? */
+ rcu_read_lock();
+ vpd = rcu_dereference(sdev->vpd_pg89);
+
+ /*
+ * Verify that ATA IDENTIFY DEVICE data is included in ATA Information
+ * VPD and that the drive implements the SATA protocol.
+ */
+ if (!vpd || vpd->len < 572 || vpd->data[56] != ATA_CMD_ID_ATA ||
+ vpd->data[36] != 0x34) {
+ rcu_read_unlock();
+ return -ENODEV;
+ }
+ ata_id = (u16 *)&vpd->data[60];
+ is_ata = ata_id_is_ata(ata_id);
+ is_sata = ata_id_is_sata(ata_id);
+ have_sct = ata_id_sct_supported(ata_id);
+ have_sct_data_table = ata_id_sct_data_tables(ata_id);
+ have_smart = ata_id_smart_supported(ata_id) &&
+ ata_id_smart_enabled(ata_id);
+
+ rcu_read_unlock();
+
+ /* bail out if this is not a SATA device */
+ if (!is_ata || !is_sata)
+ return -ENODEV;
+
+ if (have_sct && drivetemp_sct_avoid(st)) {
+ dev_notice(&sdev->sdev_gendev,
+ "will avoid using SCT for temperature monitoring\n");
+ have_sct = false;
+ }
+
+ if (!have_sct)
+ goto skip_sct;
+
+ err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_STATUS_REQ_ADDR);
+ if (err)
+ goto skip_sct;
+
+ version = (buf[SCT_STATUS_VERSION_HIGH] << 8) |
+ buf[SCT_STATUS_VERSION_LOW];
+ if (version != 2 && version != 3)
+ goto skip_sct;
+
+ have_sct_temp = temp_is_valid(buf[SCT_STATUS_TEMP]);
+ if (!have_sct_temp)
+ goto skip_sct;
+
+ st->have_temp_lowest = temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST]);
+ st->have_temp_highest = temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST]);
+
+ if (!have_sct_data_table)
+ goto skip_sct_data;
+
+ /* Request and read temperature history table */
+ memset(buf, '\0', sizeof(st->smartdata));
+ buf[0] = 5; /* data table command */
+ buf[2] = 1; /* read table */
+ buf[4] = 2; /* temperature history table */
+
+ err = drivetemp_ata_command(st, SMART_WRITE_LOG, SCT_STATUS_REQ_ADDR);
+ if (err)
+ goto skip_sct_data;
+
+ err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_READ_LOG_ADDR);
+ if (err)
+ goto skip_sct_data;
+
+ /*
+ * Temperature limits per AT Attachment 8 -
+ * ATA/ATAPI Command Set (ATA8-ACS)
+ */
+ st->have_temp_max = temp_is_valid(buf[6]);
+ st->have_temp_crit = temp_is_valid(buf[7]);
+ st->have_temp_min = temp_is_valid(buf[8]);
+ st->have_temp_lcrit = temp_is_valid(buf[9]);
+
+ st->temp_max = temp_from_sct(buf[6]);
+ st->temp_crit = temp_from_sct(buf[7]);
+ st->temp_min = temp_from_sct(buf[8]);
+ st->temp_lcrit = temp_from_sct(buf[9]);
+
+skip_sct_data:
+ if (have_sct_temp) {
+ st->get_temp = drivetemp_get_scttemp;
+ return 0;
+ }
+skip_sct:
+ if (!have_smart)
+ return -ENODEV;
+ st->get_temp = drivetemp_get_smarttemp;
+ return drivetemp_get_smarttemp(st, hwmon_temp_input, &temp);
+}
+
+static int drivetemp_identify(struct drivetemp_data *st)
+{
+ struct scsi_device *sdev = st->sdev;
+
+ /* Bail out immediately if there is no inquiry data */
+ if (!sdev->inquiry || sdev->inquiry_len < 16)
+ return -ENODEV;
+
+ /* Disk device? */
+ if (sdev->type != TYPE_DISK && sdev->type != TYPE_ZBC)
+ return -ENODEV;
+
+ return drivetemp_identify_sata(st);
+}
+
+static int drivetemp_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct drivetemp_data *st = dev_get_drvdata(dev);
+ int err = 0;
+
+ if (type != hwmon_temp)
+ return -EINVAL;
+
+ switch (attr) {
+ case hwmon_temp_input:
+ case hwmon_temp_lowest:
+ case hwmon_temp_highest:
+ mutex_lock(&st->lock);
+ err = st->get_temp(st, attr, val);
+ mutex_unlock(&st->lock);
+ break;
+ case hwmon_temp_lcrit:
+ *val = st->temp_lcrit;
+ break;
+ case hwmon_temp_min:
+ *val = st->temp_min;
+ break;
+ case hwmon_temp_max:
+ *val = st->temp_max;
+ break;
+ case hwmon_temp_crit:
+ *val = st->temp_crit;
+ break;
+ default:
+ err = -EINVAL;
+ break;
+ }
+ return err;
+}
+
+static umode_t drivetemp_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ const struct drivetemp_data *st = data;
+
+ switch (type) {
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_input:
+ return 0444;
+ case hwmon_temp_lowest:
+ if (st->have_temp_lowest)
+ return 0444;
+ break;
+ case hwmon_temp_highest:
+ if (st->have_temp_highest)
+ return 0444;
+ break;
+ case hwmon_temp_min:
+ if (st->have_temp_min)
+ return 0444;
+ break;
+ case hwmon_temp_max:
+ if (st->have_temp_max)
+ return 0444;
+ break;
+ case hwmon_temp_lcrit:
+ if (st->have_temp_lcrit)
+ return 0444;
+ break;
+ case hwmon_temp_crit:
+ if (st->have_temp_crit)
+ return 0444;
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+
+static const struct hwmon_channel_info *drivetemp_info[] = {
+ HWMON_CHANNEL_INFO(chip,
+ HWMON_C_REGISTER_TZ),
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT |
+ HWMON_T_LOWEST | HWMON_T_HIGHEST |
+ HWMON_T_MIN | HWMON_T_MAX |
+ HWMON_T_LCRIT | HWMON_T_CRIT),
+ NULL
+};
+
+static const struct hwmon_ops drivetemp_ops = {
+ .is_visible = drivetemp_is_visible,
+ .read = drivetemp_read,
+};
+
+static const struct hwmon_chip_info drivetemp_chip_info = {
+ .ops = &drivetemp_ops,
+ .info = drivetemp_info,
+};
+
+/*
+ * The device argument points to sdev->sdev_dev. Its parent is
+ * sdev->sdev_gendev, which we can use to get the scsi_device pointer.
+ */
+static int drivetemp_add(struct device *dev, struct class_interface *intf)
+{
+ struct scsi_device *sdev = to_scsi_device(dev->parent);
+ struct drivetemp_data *st;
+ int err;
+
+ st = kzalloc(sizeof(*st), GFP_KERNEL);
+ if (!st)
+ return -ENOMEM;
+
+ st->sdev = sdev;
+ st->dev = dev;
+ mutex_init(&st->lock);
+
+ if (drivetemp_identify(st)) {
+ err = -ENODEV;
+ goto abort;
+ }
+
+ st->hwdev = hwmon_device_register_with_info(dev->parent, "drivetemp",
+ st, &drivetemp_chip_info,
+ NULL);
+ if (IS_ERR(st->hwdev)) {
+ err = PTR_ERR(st->hwdev);
+ goto abort;
+ }
+
+ list_add(&st->list, &drivetemp_devlist);
+ return 0;
+
+abort:
+ kfree(st);
+ return err;
+}
+
+static void drivetemp_remove(struct device *dev, struct class_interface *intf)
+{
+ struct drivetemp_data *st, *tmp;
+
+ list_for_each_entry_safe(st, tmp, &drivetemp_devlist, list) {
+ if (st->dev == dev) {
+ list_del(&st->list);
+ hwmon_device_unregister(st->hwdev);
+ kfree(st);
+ break;
+ }
+ }
+}
+
+static struct class_interface drivetemp_interface = {
+ .add_dev = drivetemp_add,
+ .remove_dev = drivetemp_remove,
+};
+
+static int __init drivetemp_init(void)
+{
+ return scsi_register_interface(&drivetemp_interface);
+}
+
+static void __exit drivetemp_exit(void)
+{
+ scsi_unregister_interface(&drivetemp_interface);
+}
+
+module_init(drivetemp_init);
+module_exit(drivetemp_exit);
+
+MODULE_AUTHOR("Guenter Roeck <linus@roeck-us.net>");
+MODULE_DESCRIPTION("Hard drive temperature monitor");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:drivetemp");