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, 426 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c
new file mode 100644
index 000000000..a79c8ac0a
--- /dev/null
+++ b/drivers/usb/host/ehci-timer.c
@@ -0,0 +1,426 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2012 by Alan Stern
+ */
+
+/* This file is part of ehci-hcd.c */
+
+/*-------------------------------------------------------------------------*/
+
+/* Set a bit in the USBCMD register */
+static void ehci_set_command_bit(struct ehci_hcd *ehci, u32 bit)
+{
+	ehci->command |= bit;
+	ehci_writel(ehci, ehci->command, &ehci->regs->command);
+
+	/* unblock posted write */
+	ehci_readl(ehci, &ehci->regs->command);
+}
+
+/* Clear a bit in the USBCMD register */
+static void ehci_clear_command_bit(struct ehci_hcd *ehci, u32 bit)
+{
+	ehci->command &= ~bit;
+	ehci_writel(ehci, ehci->command, &ehci->regs->command);
+
+	/* unblock posted write */
+	ehci_readl(ehci, &ehci->regs->command);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * EHCI timer support...  Now using hrtimers.
+ *
+ * Lots of different events are triggered from ehci->hrtimer.  Whenever
+ * the timer routine runs, it checks each possible event; events that are
+ * currently enabled and whose expiration time has passed get handled.
+ * The set of enabled events is stored as a collection of bitflags in
+ * ehci->enabled_hrtimer_events, and they are numbered in order of
+ * increasing delay values (ranging between 1 ms and 100 ms).
+ *
+ * Rather than implementing a sorted list or tree of all pending events,
+ * we keep track only of the lowest-numbered pending event, in
+ * ehci->next_hrtimer_event.  Whenever ehci->hrtimer gets restarted, its
+ * expiration time is set to the timeout value for this event.
+ *
+ * As a result, events might not get handled right away; the actual delay
+ * could be anywhere up to twice the requested delay.  This doesn't
+ * matter, because none of the events are especially time-critical.  The
+ * ones that matter most all have a delay of 1 ms, so they will be
+ * handled after 2 ms at most, which is okay.  In addition to this, we
+ * allow for an expiration range of 1 ms.
+ */
+
+/*
+ * Delay lengths for the hrtimer event types.
+ * Keep this list sorted by delay length, in the same order as
+ * the event types indexed by enum ehci_hrtimer_event in ehci.h.
+ */
+static unsigned event_delays_ns[] = {
+	1 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_POLL_ASS */
+	1 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_POLL_PSS */
+	1 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_POLL_DEAD */
+	1125 * NSEC_PER_USEC,	/* EHCI_HRTIMER_UNLINK_INTR */
+	2 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_FREE_ITDS */
+	2 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_ACTIVE_UNLINK */
+	5 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_START_UNLINK_INTR */
+	6 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_ASYNC_UNLINKS */
+	10 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_IAA_WATCHDOG */
+	10 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_DISABLE_PERIODIC */
+	15 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_DISABLE_ASYNC */
+	100 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_IO_WATCHDOG */
+};
+
+/* Enable a pending hrtimer event */
+static void ehci_enable_event(struct ehci_hcd *ehci, unsigned event,
+		bool resched)
+{
+	ktime_t		*timeout = &ehci->hr_timeouts[event];
+
+	if (resched)
+		*timeout = ktime_add(ktime_get(), event_delays_ns[event]);
+	ehci->enabled_hrtimer_events |= (1 << event);
+
+	/* Track only the lowest-numbered pending event */
+	if (event < ehci->next_hrtimer_event) {
+		ehci->next_hrtimer_event = event;
+		hrtimer_start_range_ns(&ehci->hrtimer, *timeout,
+				NSEC_PER_MSEC, HRTIMER_MODE_ABS);
+	}
+}
+
+
+/* Poll the STS_ASS status bit; see when it agrees with CMD_ASE */
+static void ehci_poll_ASS(struct ehci_hcd *ehci)
+{
+	unsigned	actual, want;
+
+	/* Don't enable anything if the controller isn't running (e.g., died) */
+	if (ehci->rh_state != EHCI_RH_RUNNING)
+		return;
+
+	want = (ehci->command & CMD_ASE) ? STS_ASS : 0;
+	actual = ehci_readl(ehci, &ehci->regs->status) & STS_ASS;
+
+	if (want != actual) {
+
+		/* Poll again later, but give up after about 2-4 ms */
+		if (ehci->ASS_poll_count++ < 2) {
+			ehci_enable_event(ehci, EHCI_HRTIMER_POLL_ASS, true);
+			return;
+		}
+		ehci_dbg(ehci, "Waited too long for the async schedule status (%x/%x), giving up\n",
+				want, actual);
+	}
+	ehci->ASS_poll_count = 0;
+
+	/* The status is up-to-date; restart or stop the schedule as needed */
+	if (want == 0) {	/* Stopped */
+		if (ehci->async_count > 0)
+			ehci_set_command_bit(ehci, CMD_ASE);
+
+	} else {		/* Running */
+		if (ehci->async_count == 0) {
+
+			/* Turn off the schedule after a while */
+			ehci_enable_event(ehci, EHCI_HRTIMER_DISABLE_ASYNC,
+					true);
+		}
+	}
+}
+
+/* Turn off the async schedule after a brief delay */
+static void ehci_disable_ASE(struct ehci_hcd *ehci)
+{
+	ehci_clear_command_bit(ehci, CMD_ASE);
+}
+
+
+/* Poll the STS_PSS status bit; see when it agrees with CMD_PSE */
+static void ehci_poll_PSS(struct ehci_hcd *ehci)
+{
+	unsigned	actual, want;
+
+	/* Don't do anything if the controller isn't running (e.g., died) */
+	if (ehci->rh_state != EHCI_RH_RUNNING)
+		return;
+
+	want = (ehci->command & CMD_PSE) ? STS_PSS : 0;
+	actual = ehci_readl(ehci, &ehci->regs->status) & STS_PSS;
+
+	if (want != actual) {
+
+		/* Poll again later, but give up after about 2-4 ms */
+		if (ehci->PSS_poll_count++ < 2) {
+			ehci_enable_event(ehci, EHCI_HRTIMER_POLL_PSS, true);
+			return;
+		}
+		ehci_dbg(ehci, "Waited too long for the periodic schedule status (%x/%x), giving up\n",
+				want, actual);
+	}
+	ehci->PSS_poll_count = 0;
+
+	/* The status is up-to-date; restart or stop the schedule as needed */
+	if (want == 0) {	/* Stopped */
+		if (ehci->periodic_count > 0)
+			ehci_set_command_bit(ehci, CMD_PSE);
+
+	} else {		/* Running */
+		if (ehci->periodic_count == 0) {
+
+			/* Turn off the schedule after a while */
+			ehci_enable_event(ehci, EHCI_HRTIMER_DISABLE_PERIODIC,
+					true);
+		}
+	}
+}
+
+/* Turn off the periodic schedule after a brief delay */
+static void ehci_disable_PSE(struct ehci_hcd *ehci)
+{
+	ehci_clear_command_bit(ehci, CMD_PSE);
+}
+
+
+/* Poll the STS_HALT status bit; see when a dead controller stops */
+static void ehci_handle_controller_death(struct ehci_hcd *ehci)
+{
+	if (!(ehci_readl(ehci, &ehci->regs->status) & STS_HALT)) {
+
+		/* Give up after a few milliseconds */
+		if (ehci->died_poll_count++ < 5) {
+			/* Try again later */
+			ehci_enable_event(ehci, EHCI_HRTIMER_POLL_DEAD, true);
+			return;
+		}
+		ehci_warn(ehci, "Waited too long for the controller to stop, giving up\n");
+	}
+
+	/* Clean up the mess */
+	ehci->rh_state = EHCI_RH_HALTED;
+	ehci_writel(ehci, 0, &ehci->regs->configured_flag);
+	ehci_writel(ehci, 0, &ehci->regs->intr_enable);
+	ehci_work(ehci);
+	end_unlink_async(ehci);
+
+	/* Not in process context, so don't try to reset the controller */
+}
+
+/* start to unlink interrupt QHs  */
+static void ehci_handle_start_intr_unlinks(struct ehci_hcd *ehci)
+{
+	bool		stopped = (ehci->rh_state < EHCI_RH_RUNNING);
+
+	/*
+	 * Process all the QHs on the intr_unlink list that were added
+	 * before the current unlink cycle began.  The list is in
+	 * temporal order, so stop when we reach the first entry in the
+	 * current cycle.  But if the root hub isn't running then
+	 * process all the QHs on the list.
+	 */
+	while (!list_empty(&ehci->intr_unlink_wait)) {
+		struct ehci_qh	*qh;
+
+		qh = list_first_entry(&ehci->intr_unlink_wait,
+				struct ehci_qh, unlink_node);
+		if (!stopped && (qh->unlink_cycle ==
+				ehci->intr_unlink_wait_cycle))
+			break;
+		list_del_init(&qh->unlink_node);
+		qh->unlink_reason |= QH_UNLINK_QUEUE_EMPTY;
+		start_unlink_intr(ehci, qh);
+	}
+
+	/* Handle remaining entries later */
+	if (!list_empty(&ehci->intr_unlink_wait)) {
+		ehci_enable_event(ehci, EHCI_HRTIMER_START_UNLINK_INTR, true);
+		++ehci->intr_unlink_wait_cycle;
+	}
+}
+
+/* Handle unlinked interrupt QHs once they are gone from the hardware */
+static void ehci_handle_intr_unlinks(struct ehci_hcd *ehci)
+{
+	bool		stopped = (ehci->rh_state < EHCI_RH_RUNNING);
+
+	/*
+	 * Process all the QHs on the intr_unlink list that were added
+	 * before the current unlink cycle began.  The list is in
+	 * temporal order, so stop when we reach the first entry in the
+	 * current cycle.  But if the root hub isn't running then
+	 * process all the QHs on the list.
+	 */
+	ehci->intr_unlinking = true;
+	while (!list_empty(&ehci->intr_unlink)) {
+		struct ehci_qh	*qh;
+
+		qh = list_first_entry(&ehci->intr_unlink, struct ehci_qh,
+				unlink_node);
+		if (!stopped && qh->unlink_cycle == ehci->intr_unlink_cycle)
+			break;
+		list_del_init(&qh->unlink_node);
+		end_unlink_intr(ehci, qh);
+	}
+
+	/* Handle remaining entries later */
+	if (!list_empty(&ehci->intr_unlink)) {
+		ehci_enable_event(ehci, EHCI_HRTIMER_UNLINK_INTR, true);
+		++ehci->intr_unlink_cycle;
+	}
+	ehci->intr_unlinking = false;
+}
+
+
+/* Start another free-iTDs/siTDs cycle */
+static void start_free_itds(struct ehci_hcd *ehci)
+{
+	if (!(ehci->enabled_hrtimer_events & BIT(EHCI_HRTIMER_FREE_ITDS))) {
+		ehci->last_itd_to_free = list_entry(
+				ehci->cached_itd_list.prev,
+				struct ehci_itd, itd_list);
+		ehci->last_sitd_to_free = list_entry(
+				ehci->cached_sitd_list.prev,
+				struct ehci_sitd, sitd_list);
+		ehci_enable_event(ehci, EHCI_HRTIMER_FREE_ITDS, true);
+	}
+}
+
+/* Wait for controller to stop using old iTDs and siTDs */
+static void end_free_itds(struct ehci_hcd *ehci)
+{
+	struct ehci_itd		*itd, *n;
+	struct ehci_sitd	*sitd, *sn;
+
+	if (ehci->rh_state < EHCI_RH_RUNNING) {
+		ehci->last_itd_to_free = NULL;
+		ehci->last_sitd_to_free = NULL;
+	}
+
+	list_for_each_entry_safe(itd, n, &ehci->cached_itd_list, itd_list) {
+		list_del(&itd->itd_list);
+		dma_pool_free(ehci->itd_pool, itd, itd->itd_dma);
+		if (itd == ehci->last_itd_to_free)
+			break;
+	}
+	list_for_each_entry_safe(sitd, sn, &ehci->cached_sitd_list, sitd_list) {
+		list_del(&sitd->sitd_list);
+		dma_pool_free(ehci->sitd_pool, sitd, sitd->sitd_dma);
+		if (sitd == ehci->last_sitd_to_free)
+			break;
+	}
+
+	if (!list_empty(&ehci->cached_itd_list) ||
+			!list_empty(&ehci->cached_sitd_list))
+		start_free_itds(ehci);
+}
+
+
+/* Handle lost (or very late) IAA interrupts */
+static void ehci_iaa_watchdog(struct ehci_hcd *ehci)
+{
+	u32 cmd, status;
+
+	/*
+	 * Lost IAA irqs wedge things badly; seen first with a vt8235.
+	 * So we need this watchdog, but must protect it against both
+	 * (a) SMP races against real IAA firing and retriggering, and
+	 * (b) clean HC shutdown, when IAA watchdog was pending.
+	 */
+	if (!ehci->iaa_in_progress || ehci->rh_state != EHCI_RH_RUNNING)
+		return;
+
+	/* If we get here, IAA is *REALLY* late.  It's barely
+	 * conceivable that the system is so busy that CMD_IAAD
+	 * is still legitimately set, so let's be sure it's
+	 * clear before we read STS_IAA.  (The HC should clear
+	 * CMD_IAAD when it sets STS_IAA.)
+	 */
+	cmd = ehci_readl(ehci, &ehci->regs->command);
+
+	/*
+	 * If IAA is set here it either legitimately triggered
+	 * after the watchdog timer expired (_way_ late, so we'll
+	 * still count it as lost) ... or a silicon erratum:
+	 * - VIA seems to set IAA without triggering the IRQ;
+	 * - IAAD potentially cleared without setting IAA.
+	 */
+	status = ehci_readl(ehci, &ehci->regs->status);
+	if ((status & STS_IAA) || !(cmd & CMD_IAAD)) {
+		INCR(ehci->stats.lost_iaa);
+		ehci_writel(ehci, STS_IAA, &ehci->regs->status);
+	}
+
+	ehci_dbg(ehci, "IAA watchdog: status %x cmd %x\n", status, cmd);
+	end_iaa_cycle(ehci);
+}
+
+
+/* Enable the I/O watchdog, if appropriate */
+static void turn_on_io_watchdog(struct ehci_hcd *ehci)
+{
+	/* Not needed if the controller isn't running or it's already enabled */
+	if (ehci->rh_state != EHCI_RH_RUNNING ||
+			(ehci->enabled_hrtimer_events &
+				BIT(EHCI_HRTIMER_IO_WATCHDOG)))
+		return;
+
+	/*
+	 * Isochronous transfers always need the watchdog.
+	 * For other sorts we use it only if the flag is set.
+	 */
+	if (ehci->isoc_count > 0 || (ehci->need_io_watchdog &&
+			ehci->async_count + ehci->intr_count > 0))
+		ehci_enable_event(ehci, EHCI_HRTIMER_IO_WATCHDOG, true);
+}
+
+
+/*
+ * Handler functions for the hrtimer event types.
+ * Keep this array in the same order as the event types indexed by
+ * enum ehci_hrtimer_event in ehci.h.
+ */
+static void (*event_handlers[])(struct ehci_hcd *) = {
+	ehci_poll_ASS,			/* EHCI_HRTIMER_POLL_ASS */
+	ehci_poll_PSS,			/* EHCI_HRTIMER_POLL_PSS */
+	ehci_handle_controller_death,	/* EHCI_HRTIMER_POLL_DEAD */
+	ehci_handle_intr_unlinks,	/* EHCI_HRTIMER_UNLINK_INTR */
+	end_free_itds,			/* EHCI_HRTIMER_FREE_ITDS */
+	end_unlink_async,		/* EHCI_HRTIMER_ACTIVE_UNLINK */
+	ehci_handle_start_intr_unlinks,	/* EHCI_HRTIMER_START_UNLINK_INTR */
+	unlink_empty_async,		/* EHCI_HRTIMER_ASYNC_UNLINKS */
+	ehci_iaa_watchdog,		/* EHCI_HRTIMER_IAA_WATCHDOG */
+	ehci_disable_PSE,		/* EHCI_HRTIMER_DISABLE_PERIODIC */
+	ehci_disable_ASE,		/* EHCI_HRTIMER_DISABLE_ASYNC */
+	ehci_work,			/* EHCI_HRTIMER_IO_WATCHDOG */
+};
+
+static enum hrtimer_restart ehci_hrtimer_func(struct hrtimer *t)
+{
+	struct ehci_hcd	*ehci = container_of(t, struct ehci_hcd, hrtimer);
+	ktime_t		now;
+	unsigned long	events;
+	unsigned long	flags;
+	unsigned	e;
+
+	spin_lock_irqsave(&ehci->lock, flags);
+
+	events = ehci->enabled_hrtimer_events;
+	ehci->enabled_hrtimer_events = 0;
+	ehci->next_hrtimer_event = EHCI_HRTIMER_NO_EVENT;
+
+	/*
+	 * Check each pending event.  If its time has expired, handle
+	 * the event; otherwise re-enable it.
+	 */
+	now = ktime_get();
+	for_each_set_bit(e, &events, EHCI_HRTIMER_NUM_EVENTS) {
+		if (ktime_compare(now, ehci->hr_timeouts[e]) >= 0)
+			event_handlers[e](ehci);
+		else
+			ehci_enable_event(ehci, e, false);
+	}
+
+	spin_unlock_irqrestore(&ehci->lock, flags);
+	return HRTIMER_NORESTART;
+}