Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 624 insertions, 0 deletions

diff --git a/drivers/hwmon/drivetemp.c b/drivers/hwmon/drivetemp.c
new file mode 100644
index 000000000..5bac2b0fc
--- /dev/null
+++ b/drivers/hwmon/drivetemp.c
@@ -0,0 +1,624 @@
+// 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");