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, 664 insertions, 0 deletions

diff --git a/drivers/watchdog/wdt.c b/drivers/watchdog/wdt.c
new file mode 100644
index 000000000..183876156
--- /dev/null
+++ b/drivers/watchdog/wdt.c
@@ -0,0 +1,664 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	Industrial Computer Source WDT501 driver
+ *
+ *	(c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ *						All Rights Reserved.
+ *
+ *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
+ *	warranty for any of this software. This material is provided
+ *	"AS-IS" and at no charge.
+ *
+ *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ *	Release 0.10.
+ *
+ *	Fixes
+ *		Dave Gregorich	:	Modularisation and minor bugs
+ *		Alan Cox	:	Added the watchdog ioctl() stuff
+ *		Alan Cox	:	Fixed the reboot problem (as noted by
+ *					Matt Crocker).
+ *		Alan Cox	:	Added wdt= boot option
+ *		Alan Cox	:	Cleaned up copy/user stuff
+ *		Tim Hockin	:	Added insmod parameters, comment
+ *					cleanup, parameterized timeout
+ *		Tigran Aivazian	:	Restructured wdt_init() to handle
+ *					failures
+ *		Joel Becker	:	Added WDIOC_GET/SETTIMEOUT
+ *		Matt Domsch	:	Added nowayout module option
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
+#include <linux/ioport.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#include "wd501p.h"
+
+static unsigned long wdt_is_open;
+static char expect_close;
+
+/*
+ *	Module parameters
+ */
+
+#define WD_TIMO 60			/* Default heartbeat = 60 seconds */
+
+static int heartbeat = WD_TIMO;
+static int wd_heartbeat;
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat,
+	"Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
+				__MODULE_STRING(WD_TIMO) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+	"Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+/* You must set these - there is no sane way to probe for this board. */
+static int io = 0x240;
+static int irq = 11;
+
+static DEFINE_SPINLOCK(wdt_lock);
+
+module_param_hw(io, int, ioport, 0);
+MODULE_PARM_DESC(io, "WDT io port (default=0x240)");
+module_param_hw(irq, int, irq, 0);
+MODULE_PARM_DESC(irq, "WDT irq (default=11)");
+
+/* Support for the Fan Tachometer on the WDT501-P */
+static int tachometer;
+module_param(tachometer, int, 0);
+MODULE_PARM_DESC(tachometer,
+		"WDT501-P Fan Tachometer support (0=disable, default=0)");
+
+static int type = 500;
+module_param(type, int, 0);
+MODULE_PARM_DESC(type,
+		"WDT501-P Card type (500 or 501, default=500)");
+
+/*
+ *	Programming support
+ */
+
+static void wdt_ctr_mode(int ctr, int mode)
+{
+	ctr <<= 6;
+	ctr |= 0x30;
+	ctr |= (mode << 1);
+	outb_p(ctr, WDT_CR);
+}
+
+static void wdt_ctr_load(int ctr, int val)
+{
+	outb_p(val&0xFF, WDT_COUNT0+ctr);
+	outb_p(val>>8, WDT_COUNT0+ctr);
+}
+
+/**
+ *	wdt_start:
+ *
+ *	Start the watchdog driver.
+ */
+
+static int wdt_start(void)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&wdt_lock, flags);
+	inb_p(WDT_DC);			/* Disable watchdog */
+	wdt_ctr_mode(0, 3);		/* Program CTR0 for Mode 3:
+						Square Wave Generator */
+	wdt_ctr_mode(1, 2);		/* Program CTR1 for Mode 2:
+						Rate Generator */
+	wdt_ctr_mode(2, 0);		/* Program CTR2 for Mode 0:
+						Pulse on Terminal Count */
+	wdt_ctr_load(0, 8948);		/* Count at 100Hz */
+	wdt_ctr_load(1, wd_heartbeat);	/* Heartbeat */
+	wdt_ctr_load(2, 65535);		/* Length of reset pulse */
+	outb_p(0, WDT_DC);		/* Enable watchdog */
+	spin_unlock_irqrestore(&wdt_lock, flags);
+	return 0;
+}
+
+/**
+ *	wdt_stop:
+ *
+ *	Stop the watchdog driver.
+ */
+
+static int wdt_stop(void)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&wdt_lock, flags);
+	/* Turn the card off */
+	inb_p(WDT_DC);			/* Disable watchdog */
+	wdt_ctr_load(2, 0);		/* 0 length reset pulses now */
+	spin_unlock_irqrestore(&wdt_lock, flags);
+	return 0;
+}
+
+/**
+ *	wdt_ping:
+ *
+ *	Reload counter one with the watchdog heartbeat. We don't bother
+ *	reloading the cascade counter.
+ */
+
+static void wdt_ping(void)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&wdt_lock, flags);
+	/* Write a watchdog value */
+	inb_p(WDT_DC);			/* Disable watchdog */
+	wdt_ctr_mode(1, 2);		/* Re-Program CTR1 for Mode 2:
+							Rate Generator */
+	wdt_ctr_load(1, wd_heartbeat);	/* Heartbeat */
+	outb_p(0, WDT_DC);		/* Enable watchdog */
+	spin_unlock_irqrestore(&wdt_lock, flags);
+}
+
+/**
+ *	wdt_set_heartbeat:
+ *	@t:		the new heartbeat value that needs to be set.
+ *
+ *	Set a new heartbeat value for the watchdog device. If the heartbeat
+ *	value is incorrect we keep the old value and return -EINVAL. If
+ *	successful we return 0.
+ */
+
+static int wdt_set_heartbeat(int t)
+{
+	if (t < 1 || t > 65535)
+		return -EINVAL;
+
+	heartbeat = t;
+	wd_heartbeat = t * 100;
+	return 0;
+}
+
+/**
+ *	wdt_get_status:
+ *
+ *	Extract the status information from a WDT watchdog device. There are
+ *	several board variants so we have to know which bits are valid. Some
+ *	bits default to one and some to zero in order to be maximally painful.
+ *
+ *	we then map the bits onto the status ioctl flags.
+ */
+
+static int wdt_get_status(void)
+{
+	unsigned char new_status;
+	int status = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&wdt_lock, flags);
+	new_status = inb_p(WDT_SR);
+	spin_unlock_irqrestore(&wdt_lock, flags);
+
+	if (new_status & WDC_SR_ISOI0)
+		status |= WDIOF_EXTERN1;
+	if (new_status & WDC_SR_ISII1)
+		status |= WDIOF_EXTERN2;
+	if (type == 501) {
+		if (!(new_status & WDC_SR_TGOOD))
+			status |= WDIOF_OVERHEAT;
+		if (!(new_status & WDC_SR_PSUOVER))
+			status |= WDIOF_POWEROVER;
+		if (!(new_status & WDC_SR_PSUUNDR))
+			status |= WDIOF_POWERUNDER;
+		if (tachometer) {
+			if (!(new_status & WDC_SR_FANGOOD))
+				status |= WDIOF_FANFAULT;
+		}
+	}
+	return status;
+}
+
+/**
+ *	wdt_get_temperature:
+ *
+ *	Reports the temperature in degrees Fahrenheit. The API is in
+ *	farenheit. It was designed by an imperial measurement luddite.
+ */
+
+static int wdt_get_temperature(void)
+{
+	unsigned short c;
+	unsigned long flags;
+
+	spin_lock_irqsave(&wdt_lock, flags);
+	c = inb_p(WDT_RT);
+	spin_unlock_irqrestore(&wdt_lock, flags);
+	return (c * 11 / 15) + 7;
+}
+
+static void wdt_decode_501(int status)
+{
+	if (!(status & WDC_SR_TGOOD))
+		pr_crit("Overheat alarm (%d)\n", inb_p(WDT_RT));
+	if (!(status & WDC_SR_PSUOVER))
+		pr_crit("PSU over voltage\n");
+	if (!(status & WDC_SR_PSUUNDR))
+		pr_crit("PSU under voltage\n");
+}
+
+/**
+ *	wdt_interrupt:
+ *	@irq:		Interrupt number
+ *	@dev_id:	Unused as we don't allow multiple devices.
+ *
+ *	Handle an interrupt from the board. These are raised when the status
+ *	map changes in what the board considers an interesting way. That means
+ *	a failure condition occurring.
+ */
+
+static irqreturn_t wdt_interrupt(int irq, void *dev_id)
+{
+	/*
+	 *	Read the status register see what is up and
+	 *	then printk it.
+	 */
+	unsigned char status;
+
+	spin_lock(&wdt_lock);
+	status = inb_p(WDT_SR);
+
+	pr_crit("WDT status %d\n", status);
+
+	if (type == 501) {
+		wdt_decode_501(status);
+		if (tachometer) {
+			if (!(status & WDC_SR_FANGOOD))
+				pr_crit("Possible fan fault\n");
+		}
+	}
+	if (!(status & WDC_SR_WCCR)) {
+#ifdef SOFTWARE_REBOOT
+#ifdef ONLY_TESTING
+		pr_crit("Would Reboot\n");
+#else
+		pr_crit("Initiating system reboot\n");
+		emergency_restart();
+#endif
+#else
+		pr_crit("Reset in 5ms\n");
+#endif
+	}
+	spin_unlock(&wdt_lock);
+	return IRQ_HANDLED;
+}
+
+
+/**
+ *	wdt_write:
+ *	@file: file handle to the watchdog
+ *	@buf: buffer to write (unused as data does not matter here
+ *	@count: count of bytes
+ *	@ppos: pointer to the position to write. No seeks allowed
+ *
+ *	A write to a watchdog device is defined as a keepalive signal. Any
+ *	write of data will do, as we we don't define content meaning.
+ */
+
+static ssize_t wdt_write(struct file *file, const char __user *buf,
+						size_t count, loff_t *ppos)
+{
+	if (count) {
+		if (!nowayout) {
+			size_t i;
+
+			/* In case it was set long ago */
+			expect_close = 0;
+
+			for (i = 0; i != count; i++) {
+				char c;
+				if (get_user(c, buf + i))
+					return -EFAULT;
+				if (c == 'V')
+					expect_close = 42;
+			}
+		}
+		wdt_ping();
+	}
+	return count;
+}
+
+/**
+ *	wdt_ioctl:
+ *	@file: file handle to the device
+ *	@cmd: watchdog command
+ *	@arg: argument pointer
+ *
+ *	The watchdog API defines a common set of functions for all watchdogs
+ *	according to their available features. We only actually usefully support
+ *	querying capabilities and current status.
+ */
+
+static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	int new_heartbeat;
+	int status;
+
+	struct watchdog_info ident = {
+		.options =		WDIOF_SETTIMEOUT|
+					WDIOF_MAGICCLOSE|
+					WDIOF_KEEPALIVEPING,
+		.firmware_version =	1,
+		.identity =		"WDT500/501",
+	};
+
+	/* Add options according to the card we have */
+	ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
+	if (type == 501) {
+		ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
+							WDIOF_POWEROVER);
+		if (tachometer)
+			ident.options |= WDIOF_FANFAULT;
+	}
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+	case WDIOC_GETSTATUS:
+		status = wdt_get_status();
+		return put_user(status, p);
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(0, p);
+	case WDIOC_KEEPALIVE:
+		wdt_ping();
+		return 0;
+	case WDIOC_SETTIMEOUT:
+		if (get_user(new_heartbeat, p))
+			return -EFAULT;
+		if (wdt_set_heartbeat(new_heartbeat))
+			return -EINVAL;
+		wdt_ping();
+		fallthrough;
+	case WDIOC_GETTIMEOUT:
+		return put_user(heartbeat, p);
+	default:
+		return -ENOTTY;
+	}
+}
+
+/**
+ *	wdt_open:
+ *	@inode: inode of device
+ *	@file: file handle to device
+ *
+ *	The watchdog device has been opened. The watchdog device is single
+ *	open and on opening we load the counters. Counter zero is a 100Hz
+ *	cascade, into counter 1 which downcounts to reboot. When the counter
+ *	triggers counter 2 downcounts the length of the reset pulse which
+ *	set set to be as long as possible.
+ */
+
+static int wdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &wdt_is_open))
+		return -EBUSY;
+	/*
+	 *	Activate
+	 */
+	wdt_start();
+	return stream_open(inode, file);
+}
+
+/**
+ *	wdt_release:
+ *	@inode: inode to board
+ *	@file: file handle to board
+ *
+ *	The watchdog has a configurable API. There is a religious dispute
+ *	between people who want their watchdog to be able to shut down and
+ *	those who want to be sure if the watchdog manager dies the machine
+ *	reboots. In the former case we disable the counters, in the latter
+ *	case you have to open it again very soon.
+ */
+
+static int wdt_release(struct inode *inode, struct file *file)
+{
+	if (expect_close == 42) {
+		wdt_stop();
+		clear_bit(0, &wdt_is_open);
+	} else {
+		pr_crit("WDT device closed unexpectedly.  WDT will not stop!\n");
+		wdt_ping();
+	}
+	expect_close = 0;
+	return 0;
+}
+
+/**
+ *	wdt_temp_read:
+ *	@file: file handle to the watchdog board
+ *	@buf: buffer to write 1 byte into
+ *	@count: length of buffer
+ *	@ptr: offset (no seek allowed)
+ *
+ *	Temp_read reports the temperature in degrees Fahrenheit. The API is in
+ *	farenheit. It was designed by an imperial measurement luddite.
+ */
+
+static ssize_t wdt_temp_read(struct file *file, char __user *buf,
+						size_t count, loff_t *ptr)
+{
+	int temperature = wdt_get_temperature();
+
+	if (copy_to_user(buf, &temperature, 1))
+		return -EFAULT;
+
+	return 1;
+}
+
+/**
+ *	wdt_temp_open:
+ *	@inode: inode of device
+ *	@file: file handle to device
+ *
+ *	The temperature device has been opened.
+ */
+
+static int wdt_temp_open(struct inode *inode, struct file *file)
+{
+	return stream_open(inode, file);
+}
+
+/**
+ *	wdt_temp_release:
+ *	@inode: inode to board
+ *	@file: file handle to board
+ *
+ *	The temperature device has been closed.
+ */
+
+static int wdt_temp_release(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+/**
+ *	wdt_notify_sys:
+ *	@this: our notifier block
+ *	@code: the event being reported
+ *	@unused: unused
+ *
+ *	Our notifier is called on system shutdowns. We want to turn the card
+ *	off at reboot otherwise the machine will reboot again during memory
+ *	test or worse yet during the following fsck. This would suck, in fact
+ *	trust me - if it happens it does suck.
+ */
+
+static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
+	void *unused)
+{
+	if (code == SYS_DOWN || code == SYS_HALT)
+		wdt_stop();
+	return NOTIFY_DONE;
+}
+
+/*
+ *	Kernel Interfaces
+ */
+
+
+static const struct file_operations wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= wdt_write,
+	.unlocked_ioctl	= wdt_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+	.open		= wdt_open,
+	.release	= wdt_release,
+};
+
+static struct miscdevice wdt_miscdev = {
+	.minor	= WATCHDOG_MINOR,
+	.name	= "watchdog",
+	.fops	= &wdt_fops,
+};
+
+static const struct file_operations wdt_temp_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.read		= wdt_temp_read,
+	.open		= wdt_temp_open,
+	.release	= wdt_temp_release,
+};
+
+static struct miscdevice temp_miscdev = {
+	.minor	= TEMP_MINOR,
+	.name	= "temperature",
+	.fops	= &wdt_temp_fops,
+};
+
+/*
+ *	The WDT card needs to learn about soft shutdowns in order to
+ *	turn the timebomb registers off.
+ */
+
+static struct notifier_block wdt_notifier = {
+	.notifier_call = wdt_notify_sys,
+};
+
+/**
+ *	wdt_exit:
+ *
+ *	Unload the watchdog. You cannot do this with any file handles open.
+ *	If your watchdog is set to continue ticking on close and you unload
+ *	it, well it keeps ticking. We won't get the interrupt but the board
+ *	will not touch PC memory so all is fine. You just have to load a new
+ *	module in 60 seconds or reboot.
+ */
+
+static void __exit wdt_exit(void)
+{
+	misc_deregister(&wdt_miscdev);
+	if (type == 501)
+		misc_deregister(&temp_miscdev);
+	unregister_reboot_notifier(&wdt_notifier);
+	free_irq(irq, NULL);
+	release_region(io, 8);
+}
+
+/**
+ *	wdt_init:
+ *
+ *	Set up the WDT watchdog board. All we have to do is grab the
+ *	resources we require and bitch if anyone beat us to them.
+ *	The open() function will actually kick the board off.
+ */
+
+static int __init wdt_init(void)
+{
+	int ret;
+
+	if (type != 500 && type != 501) {
+		pr_err("unknown card type '%d'\n", type);
+		return -ENODEV;
+	}
+
+	/* Check that the heartbeat value is within it's range;
+	   if not reset to the default */
+	if (wdt_set_heartbeat(heartbeat)) {
+		wdt_set_heartbeat(WD_TIMO);
+		pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n",
+			WD_TIMO);
+	}
+
+	if (!request_region(io, 8, "wdt501p")) {
+		pr_err("I/O address 0x%04x already in use\n", io);
+		ret = -EBUSY;
+		goto out;
+	}
+
+	ret = request_irq(irq, wdt_interrupt, 0, "wdt501p", NULL);
+	if (ret) {
+		pr_err("IRQ %d is not free\n", irq);
+		goto outreg;
+	}
+
+	ret = register_reboot_notifier(&wdt_notifier);
+	if (ret) {
+		pr_err("cannot register reboot notifier (err=%d)\n", ret);
+		goto outirq;
+	}
+
+	if (type == 501) {
+		ret = misc_register(&temp_miscdev);
+		if (ret) {
+			pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+			       TEMP_MINOR, ret);
+			goto outrbt;
+		}
+	}
+
+	ret = misc_register(&wdt_miscdev);
+	if (ret) {
+		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+		       WATCHDOG_MINOR, ret);
+		goto outmisc;
+	}
+
+	pr_info("WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n",
+		io, irq, heartbeat, nowayout);
+	if (type == 501)
+		pr_info("Fan Tachometer is %s\n",
+			tachometer ? "Enabled" : "Disabled");
+	return 0;
+
+outmisc:
+	if (type == 501)
+		misc_deregister(&temp_miscdev);
+outrbt:
+	unregister_reboot_notifier(&wdt_notifier);
+outirq:
+	free_irq(irq, NULL);
+outreg:
+	release_region(io, 8);
+out:
+	return ret;
+}
+
+module_init(wdt_init);
+module_exit(wdt_exit);
+
+MODULE_AUTHOR("Alan Cox");
+MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
+MODULE_LICENSE("GPL");