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, 545 insertions, 0 deletions

diff --git a/drivers/watchdog/kempld_wdt.c b/drivers/watchdog/kempld_wdt.c
new file mode 100644
index 000000000..e6c7a2906
--- /dev/null
+++ b/drivers/watchdog/kempld_wdt.c
@@ -0,0 +1,545 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Kontron PLD watchdog driver
+ *
+ * Copyright (c) 2010-2013 Kontron Europe GmbH
+ * Author: Michael Brunner <michael.brunner@kontron.com>
+ *
+ * Note: From the PLD watchdog point of view timeout and pretimeout are
+ *       defined differently than in the kernel.
+ *       First the pretimeout stage runs out before the timeout stage gets
+ *       active.
+ *
+ * Kernel/API:                     P-----| pretimeout
+ *               |-----------------------T timeout
+ * Watchdog:     |-----------------P       pretimeout_stage
+ *                                 |-----T timeout_stage
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/kempld.h>
+
+#define KEMPLD_WDT_STAGE_TIMEOUT(x)	(0x1b + (x) * 4)
+#define KEMPLD_WDT_STAGE_CFG(x)		(0x18 + (x))
+#define STAGE_CFG_GET_PRESCALER(x)	(((x) & 0x30) >> 4)
+#define STAGE_CFG_SET_PRESCALER(x)	(((x) & 0x3) << 4)
+#define STAGE_CFG_PRESCALER_MASK	0x30
+#define STAGE_CFG_ACTION_MASK		0x7
+#define STAGE_CFG_ASSERT		(1 << 3)
+
+#define KEMPLD_WDT_MAX_STAGES		2
+#define KEMPLD_WDT_KICK			0x16
+#define KEMPLD_WDT_CFG			0x17
+#define KEMPLD_WDT_CFG_ENABLE		0x10
+#define KEMPLD_WDT_CFG_ENABLE_LOCK	0x8
+#define KEMPLD_WDT_CFG_GLOBAL_LOCK	0x80
+
+enum {
+	ACTION_NONE = 0,
+	ACTION_RESET,
+	ACTION_NMI,
+	ACTION_SMI,
+	ACTION_SCI,
+	ACTION_DELAY,
+};
+
+enum {
+	STAGE_TIMEOUT = 0,
+	STAGE_PRETIMEOUT,
+};
+
+enum {
+	PRESCALER_21 = 0,
+	PRESCALER_17,
+	PRESCALER_12,
+};
+
+static const u32 kempld_prescaler[] = {
+	[PRESCALER_21] = (1 << 21) - 1,
+	[PRESCALER_17] = (1 << 17) - 1,
+	[PRESCALER_12] = (1 << 12) - 1,
+	0,
+};
+
+struct kempld_wdt_stage {
+	unsigned int	id;
+	u32		mask;
+};
+
+struct kempld_wdt_data {
+	struct kempld_device_data	*pld;
+	struct watchdog_device		wdd;
+	unsigned int			pretimeout;
+	struct kempld_wdt_stage		stage[KEMPLD_WDT_MAX_STAGES];
+	u8				pm_status_store;
+};
+
+#define DEFAULT_TIMEOUT		30 /* seconds */
+#define DEFAULT_PRETIMEOUT	0
+
+static unsigned int timeout = DEFAULT_TIMEOUT;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+	"Watchdog timeout in seconds. (>=0, default="
+	__MODULE_STRING(DEFAULT_TIMEOUT) ")");
+
+static unsigned int pretimeout = DEFAULT_PRETIMEOUT;
+module_param(pretimeout, uint, 0);
+MODULE_PARM_DESC(pretimeout,
+	"Watchdog pretimeout in seconds. (>=0, default="
+	__MODULE_STRING(DEFAULT_PRETIMEOUT) ")");
+
+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) ")");
+
+static int kempld_wdt_set_stage_action(struct kempld_wdt_data *wdt_data,
+					struct kempld_wdt_stage *stage,
+					u8 action)
+{
+	struct kempld_device_data *pld = wdt_data->pld;
+	u8 stage_cfg;
+
+	if (!stage || !stage->mask)
+		return -EINVAL;
+
+	kempld_get_mutex(pld);
+	stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id));
+	stage_cfg &= ~STAGE_CFG_ACTION_MASK;
+	stage_cfg |= (action & STAGE_CFG_ACTION_MASK);
+
+	if (action == ACTION_RESET)
+		stage_cfg |= STAGE_CFG_ASSERT;
+	else
+		stage_cfg &= ~STAGE_CFG_ASSERT;
+
+	kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->id), stage_cfg);
+	kempld_release_mutex(pld);
+
+	return 0;
+}
+
+static int kempld_wdt_set_stage_timeout(struct kempld_wdt_data *wdt_data,
+					struct kempld_wdt_stage *stage,
+					unsigned int timeout)
+{
+	struct kempld_device_data *pld = wdt_data->pld;
+	u32 prescaler;
+	u64 stage_timeout64;
+	u32 stage_timeout;
+	u32 remainder;
+	u8 stage_cfg;
+
+	prescaler = kempld_prescaler[PRESCALER_21];
+
+	if (!stage)
+		return -EINVAL;
+
+	stage_timeout64 = (u64)timeout * pld->pld_clock;
+	remainder = do_div(stage_timeout64, prescaler);
+	if (remainder)
+		stage_timeout64++;
+
+	if (stage_timeout64 > stage->mask)
+		return -EINVAL;
+
+	stage_timeout = stage_timeout64 & stage->mask;
+
+	kempld_get_mutex(pld);
+	stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id));
+	stage_cfg &= ~STAGE_CFG_PRESCALER_MASK;
+	stage_cfg |= STAGE_CFG_SET_PRESCALER(PRESCALER_21);
+	kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->id), stage_cfg);
+	kempld_write32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->id),
+			stage_timeout);
+	kempld_release_mutex(pld);
+
+	return 0;
+}
+
+/*
+ * kempld_get_mutex must be called prior to calling this function.
+ */
+static unsigned int kempld_wdt_get_timeout(struct kempld_wdt_data *wdt_data,
+						struct kempld_wdt_stage *stage)
+{
+	struct kempld_device_data *pld = wdt_data->pld;
+	unsigned int timeout;
+	u64 stage_timeout;
+	u32 prescaler;
+	u32 remainder;
+	u8 stage_cfg;
+
+	if (!stage->mask)
+		return 0;
+
+	stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id));
+	stage_timeout = kempld_read32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->id));
+	prescaler = kempld_prescaler[STAGE_CFG_GET_PRESCALER(stage_cfg)];
+
+	stage_timeout = (stage_timeout & stage->mask) * prescaler;
+	remainder = do_div(stage_timeout, pld->pld_clock);
+	if (remainder)
+		stage_timeout++;
+
+	timeout = stage_timeout;
+	WARN_ON_ONCE(timeout != stage_timeout);
+
+	return timeout;
+}
+
+static int kempld_wdt_set_timeout(struct watchdog_device *wdd,
+					unsigned int timeout)
+{
+	struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
+	struct kempld_wdt_stage *pretimeout_stage;
+	struct kempld_wdt_stage *timeout_stage;
+	int ret;
+
+	timeout_stage = &wdt_data->stage[STAGE_TIMEOUT];
+	pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT];
+
+	if (pretimeout_stage->mask && wdt_data->pretimeout > 0)
+		timeout = wdt_data->pretimeout;
+
+	ret = kempld_wdt_set_stage_action(wdt_data, timeout_stage,
+						ACTION_RESET);
+	if (ret)
+		return ret;
+	ret = kempld_wdt_set_stage_timeout(wdt_data, timeout_stage,
+						timeout);
+	if (ret)
+		return ret;
+
+	wdd->timeout = timeout;
+	return 0;
+}
+
+static int kempld_wdt_set_pretimeout(struct watchdog_device *wdd,
+					unsigned int pretimeout)
+{
+	struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
+	struct kempld_wdt_stage *pretimeout_stage;
+	u8 action = ACTION_NONE;
+	int ret;
+
+	pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT];
+
+	if (!pretimeout_stage->mask)
+		return -ENXIO;
+
+	if (pretimeout > wdd->timeout)
+		return -EINVAL;
+
+	if (pretimeout > 0)
+		action = ACTION_NMI;
+
+	ret = kempld_wdt_set_stage_action(wdt_data, pretimeout_stage,
+						action);
+	if (ret)
+		return ret;
+	ret = kempld_wdt_set_stage_timeout(wdt_data, pretimeout_stage,
+						wdd->timeout - pretimeout);
+	if (ret)
+		return ret;
+
+	wdt_data->pretimeout = pretimeout;
+	return 0;
+}
+
+static void kempld_wdt_update_timeouts(struct kempld_wdt_data *wdt_data)
+{
+	struct kempld_device_data *pld = wdt_data->pld;
+	struct kempld_wdt_stage *pretimeout_stage;
+	struct kempld_wdt_stage *timeout_stage;
+	unsigned int pretimeout, timeout;
+
+	pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT];
+	timeout_stage = &wdt_data->stage[STAGE_TIMEOUT];
+
+	kempld_get_mutex(pld);
+	pretimeout = kempld_wdt_get_timeout(wdt_data, pretimeout_stage);
+	timeout = kempld_wdt_get_timeout(wdt_data, timeout_stage);
+	kempld_release_mutex(pld);
+
+	if (pretimeout)
+		wdt_data->pretimeout = timeout;
+	else
+		wdt_data->pretimeout = 0;
+
+	wdt_data->wdd.timeout = pretimeout + timeout;
+}
+
+static int kempld_wdt_start(struct watchdog_device *wdd)
+{
+	struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
+	struct kempld_device_data *pld = wdt_data->pld;
+	u8 status;
+	int ret;
+
+	ret = kempld_wdt_set_timeout(wdd, wdd->timeout);
+	if (ret)
+		return ret;
+
+	kempld_get_mutex(pld);
+	status = kempld_read8(pld, KEMPLD_WDT_CFG);
+	status |= KEMPLD_WDT_CFG_ENABLE;
+	kempld_write8(pld, KEMPLD_WDT_CFG, status);
+	status = kempld_read8(pld, KEMPLD_WDT_CFG);
+	kempld_release_mutex(pld);
+
+	/* Check if the watchdog was enabled */
+	if (!(status & KEMPLD_WDT_CFG_ENABLE))
+		return -EACCES;
+
+	return 0;
+}
+
+static int kempld_wdt_stop(struct watchdog_device *wdd)
+{
+	struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
+	struct kempld_device_data *pld = wdt_data->pld;
+	u8 status;
+
+	kempld_get_mutex(pld);
+	status = kempld_read8(pld, KEMPLD_WDT_CFG);
+	status &= ~KEMPLD_WDT_CFG_ENABLE;
+	kempld_write8(pld, KEMPLD_WDT_CFG, status);
+	status = kempld_read8(pld, KEMPLD_WDT_CFG);
+	kempld_release_mutex(pld);
+
+	/* Check if the watchdog was disabled */
+	if (status & KEMPLD_WDT_CFG_ENABLE)
+		return -EACCES;
+
+	return 0;
+}
+
+static int kempld_wdt_keepalive(struct watchdog_device *wdd)
+{
+	struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
+	struct kempld_device_data *pld = wdt_data->pld;
+
+	kempld_get_mutex(pld);
+	kempld_write8(pld, KEMPLD_WDT_KICK, 'K');
+	kempld_release_mutex(pld);
+
+	return 0;
+}
+
+static long kempld_wdt_ioctl(struct watchdog_device *wdd, unsigned int cmd,
+				unsigned long arg)
+{
+	struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
+	void __user *argp = (void __user *)arg;
+	int ret = -ENOIOCTLCMD;
+	int __user *p = argp;
+	int new_value;
+
+	switch (cmd) {
+	case WDIOC_SETPRETIMEOUT:
+		if (get_user(new_value, p))
+			return -EFAULT;
+		ret = kempld_wdt_set_pretimeout(wdd, new_value);
+		if (ret)
+			return ret;
+		ret = kempld_wdt_keepalive(wdd);
+		break;
+	case WDIOC_GETPRETIMEOUT:
+		ret = put_user(wdt_data->pretimeout, (int __user *)arg);
+		break;
+	}
+
+	return ret;
+}
+
+static int kempld_wdt_probe_stages(struct watchdog_device *wdd)
+{
+	struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
+	struct kempld_device_data *pld = wdt_data->pld;
+	struct kempld_wdt_stage *pretimeout_stage;
+	struct kempld_wdt_stage *timeout_stage;
+	u8 index, data, data_orig;
+	u32 mask;
+	int i, j;
+
+	pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT];
+	timeout_stage = &wdt_data->stage[STAGE_TIMEOUT];
+
+	pretimeout_stage->mask = 0;
+	timeout_stage->mask = 0;
+
+	for (i = 0; i < 3; i++) {
+		index = KEMPLD_WDT_STAGE_TIMEOUT(i);
+		mask = 0;
+
+		kempld_get_mutex(pld);
+		/* Probe each byte individually. */
+		for (j = 0; j < 4; j++) {
+			data_orig = kempld_read8(pld, index + j);
+			kempld_write8(pld, index + j, 0x00);
+			data = kempld_read8(pld, index + j);
+			/* A failed write means this byte is reserved */
+			if (data != 0x00)
+				break;
+			kempld_write8(pld, index + j, data_orig);
+			mask |= 0xff << (j * 8);
+		}
+		kempld_release_mutex(pld);
+
+		/* Assign available stages to timeout and pretimeout */
+		if (!timeout_stage->mask) {
+			timeout_stage->mask = mask;
+			timeout_stage->id = i;
+		} else {
+			if (pld->feature_mask & KEMPLD_FEATURE_BIT_NMI) {
+				pretimeout_stage->mask = timeout_stage->mask;
+				timeout_stage->mask = mask;
+				pretimeout_stage->id = timeout_stage->id;
+				timeout_stage->id = i;
+			}
+			break;
+		}
+	}
+
+	if (!timeout_stage->mask)
+		return -ENODEV;
+
+	return 0;
+}
+
+static const struct watchdog_info kempld_wdt_info = {
+	.identity	= "KEMPLD Watchdog",
+	.options	= WDIOF_SETTIMEOUT |
+			WDIOF_KEEPALIVEPING |
+			WDIOF_MAGICCLOSE |
+			WDIOF_PRETIMEOUT
+};
+
+static const struct watchdog_ops kempld_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= kempld_wdt_start,
+	.stop		= kempld_wdt_stop,
+	.ping		= kempld_wdt_keepalive,
+	.set_timeout	= kempld_wdt_set_timeout,
+	.ioctl		= kempld_wdt_ioctl,
+};
+
+static int kempld_wdt_probe(struct platform_device *pdev)
+{
+	struct kempld_device_data *pld = dev_get_drvdata(pdev->dev.parent);
+	struct kempld_wdt_data *wdt_data;
+	struct device *dev = &pdev->dev;
+	struct watchdog_device *wdd;
+	u8 status;
+	int ret = 0;
+
+	wdt_data = devm_kzalloc(dev, sizeof(*wdt_data), GFP_KERNEL);
+	if (!wdt_data)
+		return -ENOMEM;
+
+	wdt_data->pld = pld;
+	wdd = &wdt_data->wdd;
+	wdd->parent = dev;
+
+	kempld_get_mutex(pld);
+	status = kempld_read8(pld, KEMPLD_WDT_CFG);
+	kempld_release_mutex(pld);
+
+	/* Enable nowayout if watchdog is already locked */
+	if (status & (KEMPLD_WDT_CFG_ENABLE_LOCK |
+			KEMPLD_WDT_CFG_GLOBAL_LOCK)) {
+		if (!nowayout)
+			dev_warn(dev,
+				 "Forcing nowayout - watchdog lock enabled!\n");
+		nowayout = true;
+	}
+
+	wdd->info = &kempld_wdt_info;
+	wdd->ops = &kempld_wdt_ops;
+
+	watchdog_set_drvdata(wdd, wdt_data);
+	watchdog_set_nowayout(wdd, nowayout);
+
+	ret = kempld_wdt_probe_stages(wdd);
+	if (ret)
+		return ret;
+
+	kempld_wdt_set_timeout(wdd, timeout);
+	kempld_wdt_set_pretimeout(wdd, pretimeout);
+
+	/* Check if watchdog is already enabled */
+	if (status & KEMPLD_WDT_CFG_ENABLE) {
+		/* Get current watchdog settings */
+		kempld_wdt_update_timeouts(wdt_data);
+		dev_info(dev, "Watchdog was already enabled\n");
+	}
+
+	platform_set_drvdata(pdev, wdt_data);
+	watchdog_stop_on_reboot(wdd);
+	watchdog_stop_on_unregister(wdd);
+	ret = devm_watchdog_register_device(dev, wdd);
+	if (ret)
+		return ret;
+
+	dev_info(dev, "Watchdog registered with %ds timeout\n", wdd->timeout);
+
+	return 0;
+}
+
+/* Disable watchdog if it is active during suspend */
+static int kempld_wdt_suspend(struct platform_device *pdev,
+				pm_message_t message)
+{
+	struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev);
+	struct kempld_device_data *pld = wdt_data->pld;
+	struct watchdog_device *wdd = &wdt_data->wdd;
+
+	kempld_get_mutex(pld);
+	wdt_data->pm_status_store = kempld_read8(pld, KEMPLD_WDT_CFG);
+	kempld_release_mutex(pld);
+
+	kempld_wdt_update_timeouts(wdt_data);
+
+	if (wdt_data->pm_status_store & KEMPLD_WDT_CFG_ENABLE)
+		return kempld_wdt_stop(wdd);
+
+	return 0;
+}
+
+/* Enable watchdog and configure it if necessary */
+static int kempld_wdt_resume(struct platform_device *pdev)
+{
+	struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev);
+	struct watchdog_device *wdd = &wdt_data->wdd;
+
+	/*
+	 * If watchdog was stopped before suspend be sure it gets disabled
+	 * again, for the case BIOS has enabled it during resume
+	 */
+	if (wdt_data->pm_status_store & KEMPLD_WDT_CFG_ENABLE)
+		return kempld_wdt_start(wdd);
+	else
+		return kempld_wdt_stop(wdd);
+}
+
+static struct platform_driver kempld_wdt_driver = {
+	.driver		= {
+		.name	= "kempld-wdt",
+	},
+	.probe		= kempld_wdt_probe,
+	.suspend	= pm_ptr(kempld_wdt_suspend),
+	.resume		= pm_ptr(kempld_wdt_resume),
+};
+
+module_platform_driver(kempld_wdt_driver);
+
+MODULE_DESCRIPTION("KEM PLD Watchdog Driver");
+MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>");
+MODULE_LICENSE("GPL");