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, 402 insertions, 0 deletions

diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
new file mode 100644
index 000000000..b020ff17d
--- /dev/null
+++ b/arch/s390/kernel/irq.c
@@ -0,0 +1,402 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    Copyright IBM Corp. 2004, 2011
+ *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ *		 Holger Smolinski <Holger.Smolinski@de.ibm.com>,
+ *		 Thomas Spatzier <tspat@de.ibm.com>,
+ *
+ * This file contains interrupt related functions.
+ */
+
+#include <linux/kernel_stat.h>
+#include <linux/interrupt.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/profile.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/ftrace.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/irq.h>
+#include <linux/entry-common.h>
+#include <asm/irq_regs.h>
+#include <asm/cputime.h>
+#include <asm/lowcore.h>
+#include <asm/irq.h>
+#include <asm/hw_irq.h>
+#include <asm/stacktrace.h>
+#include <asm/softirq_stack.h>
+#include "entry.h"
+
+DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
+EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);
+
+struct irq_class {
+	int irq;
+	char *name;
+	char *desc;
+};
+
+/*
+ * The list of "main" irq classes on s390. This is the list of interrupts
+ * that appear both in /proc/stat ("intr" line) and /proc/interrupts.
+ * Historically only external and I/O interrupts have been part of /proc/stat.
+ * We can't add the split external and I/O sub classes since the first field
+ * in the "intr" line in /proc/stat is supposed to be the sum of all other
+ * fields.
+ * Since the external and I/O interrupt fields are already sums we would end
+ * up with having a sum which accounts each interrupt twice.
+ */
+static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
+	{.irq = EXT_INTERRUPT,	.name = "EXT"},
+	{.irq = IO_INTERRUPT,	.name = "I/O"},
+	{.irq = THIN_INTERRUPT, .name = "AIO"},
+};
+
+/*
+ * The list of split external and I/O interrupts that appear only in
+ * /proc/interrupts.
+ * In addition this list contains non external / I/O events like NMIs.
+ */
+static const struct irq_class irqclass_sub_desc[] = {
+	{.irq = IRQEXT_CLK, .name = "CLK", .desc = "[EXT] Clock Comparator"},
+	{.irq = IRQEXT_EXC, .name = "EXC", .desc = "[EXT] External Call"},
+	{.irq = IRQEXT_EMS, .name = "EMS", .desc = "[EXT] Emergency Signal"},
+	{.irq = IRQEXT_TMR, .name = "TMR", .desc = "[EXT] CPU Timer"},
+	{.irq = IRQEXT_TLA, .name = "TAL", .desc = "[EXT] Timing Alert"},
+	{.irq = IRQEXT_PFL, .name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
+	{.irq = IRQEXT_DSD, .name = "DSD", .desc = "[EXT] DASD Diag"},
+	{.irq = IRQEXT_VRT, .name = "VRT", .desc = "[EXT] Virtio"},
+	{.irq = IRQEXT_SCP, .name = "SCP", .desc = "[EXT] Service Call"},
+	{.irq = IRQEXT_IUC, .name = "IUC", .desc = "[EXT] IUCV"},
+	{.irq = IRQEXT_CMS, .name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
+	{.irq = IRQEXT_CMC, .name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
+	{.irq = IRQEXT_FTP, .name = "FTP", .desc = "[EXT] HMC FTP Service"},
+	{.irq = IRQIO_CIO,  .name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
+	{.irq = IRQIO_DAS,  .name = "DAS", .desc = "[I/O] DASD"},
+	{.irq = IRQIO_C15,  .name = "C15", .desc = "[I/O] 3215"},
+	{.irq = IRQIO_C70,  .name = "C70", .desc = "[I/O] 3270"},
+	{.irq = IRQIO_TAP,  .name = "TAP", .desc = "[I/O] Tape"},
+	{.irq = IRQIO_VMR,  .name = "VMR", .desc = "[I/O] Unit Record Devices"},
+	{.irq = IRQIO_LCS,  .name = "LCS", .desc = "[I/O] LCS"},
+	{.irq = IRQIO_CTC,  .name = "CTC", .desc = "[I/O] CTC"},
+	{.irq = IRQIO_ADM,  .name = "ADM", .desc = "[I/O] EADM Subchannel"},
+	{.irq = IRQIO_CSC,  .name = "CSC", .desc = "[I/O] CHSC Subchannel"},
+	{.irq = IRQIO_VIR,  .name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
+	{.irq = IRQIO_QAI,  .name = "QAI", .desc = "[AIO] QDIO Adapter Interrupt"},
+	{.irq = IRQIO_APB,  .name = "APB", .desc = "[AIO] AP Bus"},
+	{.irq = IRQIO_PCF,  .name = "PCF", .desc = "[AIO] PCI Floating Interrupt"},
+	{.irq = IRQIO_PCD,  .name = "PCD", .desc = "[AIO] PCI Directed Interrupt"},
+	{.irq = IRQIO_MSI,  .name = "MSI", .desc = "[AIO] MSI Interrupt"},
+	{.irq = IRQIO_VAI,  .name = "VAI", .desc = "[AIO] Virtual I/O Devices AI"},
+	{.irq = IRQIO_GAL,  .name = "GAL", .desc = "[AIO] GIB Alert"},
+	{.irq = NMI_NMI,    .name = "NMI", .desc = "[NMI] Machine Check"},
+	{.irq = CPU_RST,    .name = "RST", .desc = "[CPU] CPU Restart"},
+};
+
+static void do_IRQ(struct pt_regs *regs, int irq)
+{
+	if (tod_after_eq(S390_lowcore.int_clock,
+			 S390_lowcore.clock_comparator))
+		/* Serve timer interrupts first. */
+		clock_comparator_work();
+	generic_handle_irq(irq);
+}
+
+static int on_async_stack(void)
+{
+	unsigned long frame = current_frame_address();
+
+	return ((S390_lowcore.async_stack ^ frame) & ~(THREAD_SIZE - 1)) == 0;
+}
+
+static void do_irq_async(struct pt_regs *regs, int irq)
+{
+	if (on_async_stack()) {
+		do_IRQ(regs, irq);
+	} else {
+		call_on_stack(2, S390_lowcore.async_stack, void, do_IRQ,
+			      struct pt_regs *, regs, int, irq);
+	}
+}
+
+static int irq_pending(struct pt_regs *regs)
+{
+	int cc;
+
+	asm volatile("tpi 0\n"
+		     "ipm %0" : "=d" (cc) : : "cc");
+	return cc >> 28;
+}
+
+void noinstr do_io_irq(struct pt_regs *regs)
+{
+	irqentry_state_t state = irqentry_enter(regs);
+	struct pt_regs *old_regs = set_irq_regs(regs);
+	bool from_idle;
+
+	irq_enter_rcu();
+
+	if (user_mode(regs)) {
+		update_timer_sys();
+		if (static_branch_likely(&cpu_has_bear))
+			current->thread.last_break = regs->last_break;
+	}
+
+	from_idle = test_and_clear_cpu_flag(CIF_ENABLED_WAIT);
+	if (from_idle)
+		account_idle_time_irq();
+
+	do {
+		regs->tpi_info = S390_lowcore.tpi_info;
+		if (S390_lowcore.tpi_info.adapter_IO)
+			do_irq_async(regs, THIN_INTERRUPT);
+		else
+			do_irq_async(regs, IO_INTERRUPT);
+	} while (MACHINE_IS_LPAR && irq_pending(regs));
+
+	irq_exit_rcu();
+
+	set_irq_regs(old_regs);
+	irqentry_exit(regs, state);
+
+	if (from_idle)
+		regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
+}
+
+void noinstr do_ext_irq(struct pt_regs *regs)
+{
+	irqentry_state_t state = irqentry_enter(regs);
+	struct pt_regs *old_regs = set_irq_regs(regs);
+	bool from_idle;
+
+	irq_enter_rcu();
+
+	if (user_mode(regs)) {
+		update_timer_sys();
+		if (static_branch_likely(&cpu_has_bear))
+			current->thread.last_break = regs->last_break;
+	}
+
+	regs->int_code = S390_lowcore.ext_int_code_addr;
+	regs->int_parm = S390_lowcore.ext_params;
+	regs->int_parm_long = S390_lowcore.ext_params2;
+
+	from_idle = test_and_clear_cpu_flag(CIF_ENABLED_WAIT);
+	if (from_idle)
+		account_idle_time_irq();
+
+	do_irq_async(regs, EXT_INTERRUPT);
+
+	irq_exit_rcu();
+	set_irq_regs(old_regs);
+	irqentry_exit(regs, state);
+
+	if (from_idle)
+		regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
+}
+
+static void show_msi_interrupt(struct seq_file *p, int irq)
+{
+	struct irq_desc *desc;
+	unsigned long flags;
+	int cpu;
+
+	rcu_read_lock();
+	desc = irq_to_desc(irq);
+	if (!desc)
+		goto out;
+
+	raw_spin_lock_irqsave(&desc->lock, flags);
+	seq_printf(p, "%3d: ", irq);
+	for_each_online_cpu(cpu)
+		seq_printf(p, "%10u ", irq_desc_kstat_cpu(desc, cpu));
+
+	if (desc->irq_data.chip)
+		seq_printf(p, " %8s", desc->irq_data.chip->name);
+
+	if (desc->action)
+		seq_printf(p, "  %s", desc->action->name);
+
+	seq_putc(p, '\n');
+	raw_spin_unlock_irqrestore(&desc->lock, flags);
+out:
+	rcu_read_unlock();
+}
+
+/*
+ * show_interrupts is needed by /proc/interrupts.
+ */
+int show_interrupts(struct seq_file *p, void *v)
+{
+	int index = *(loff_t *) v;
+	int cpu, irq;
+
+	cpus_read_lock();
+	if (index == 0) {
+		seq_puts(p, "           ");
+		for_each_online_cpu(cpu)
+			seq_printf(p, "CPU%-8d", cpu);
+		seq_putc(p, '\n');
+	}
+	if (index < NR_IRQS_BASE) {
+		seq_printf(p, "%s: ", irqclass_main_desc[index].name);
+		irq = irqclass_main_desc[index].irq;
+		for_each_online_cpu(cpu)
+			seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
+		seq_putc(p, '\n');
+		goto out;
+	}
+	if (index < nr_irqs) {
+		show_msi_interrupt(p, index);
+		goto out;
+	}
+	for (index = 0; index < NR_ARCH_IRQS; index++) {
+		seq_printf(p, "%s: ", irqclass_sub_desc[index].name);
+		irq = irqclass_sub_desc[index].irq;
+		for_each_online_cpu(cpu)
+			seq_printf(p, "%10u ",
+				   per_cpu(irq_stat, cpu).irqs[irq]);
+		if (irqclass_sub_desc[index].desc)
+			seq_printf(p, "  %s", irqclass_sub_desc[index].desc);
+		seq_putc(p, '\n');
+	}
+out:
+	cpus_read_unlock();
+	return 0;
+}
+
+unsigned int arch_dynirq_lower_bound(unsigned int from)
+{
+	return from < NR_IRQS_BASE ? NR_IRQS_BASE : from;
+}
+
+/*
+ * ext_int_hash[index] is the list head for all external interrupts that hash
+ * to this index.
+ */
+static struct hlist_head ext_int_hash[32] ____cacheline_aligned;
+
+struct ext_int_info {
+	ext_int_handler_t handler;
+	struct hlist_node entry;
+	struct rcu_head rcu;
+	u16 code;
+};
+
+/* ext_int_hash_lock protects the handler lists for external interrupts */
+static DEFINE_SPINLOCK(ext_int_hash_lock);
+
+static inline int ext_hash(u16 code)
+{
+	BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));
+
+	return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
+}
+
+int register_external_irq(u16 code, ext_int_handler_t handler)
+{
+	struct ext_int_info *p;
+	unsigned long flags;
+	int index;
+
+	p = kmalloc(sizeof(*p), GFP_ATOMIC);
+	if (!p)
+		return -ENOMEM;
+	p->code = code;
+	p->handler = handler;
+	index = ext_hash(code);
+
+	spin_lock_irqsave(&ext_int_hash_lock, flags);
+	hlist_add_head_rcu(&p->entry, &ext_int_hash[index]);
+	spin_unlock_irqrestore(&ext_int_hash_lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL(register_external_irq);
+
+int unregister_external_irq(u16 code, ext_int_handler_t handler)
+{
+	struct ext_int_info *p;
+	unsigned long flags;
+	int index = ext_hash(code);
+
+	spin_lock_irqsave(&ext_int_hash_lock, flags);
+	hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
+		if (p->code == code && p->handler == handler) {
+			hlist_del_rcu(&p->entry);
+			kfree_rcu(p, rcu);
+		}
+	}
+	spin_unlock_irqrestore(&ext_int_hash_lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL(unregister_external_irq);
+
+static irqreturn_t do_ext_interrupt(int irq, void *dummy)
+{
+	struct pt_regs *regs = get_irq_regs();
+	struct ext_code ext_code;
+	struct ext_int_info *p;
+	int index;
+
+	ext_code.int_code = regs->int_code;
+	if (ext_code.code != EXT_IRQ_CLK_COMP)
+		set_cpu_flag(CIF_NOHZ_DELAY);
+
+	index = ext_hash(ext_code.code);
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
+		if (unlikely(p->code != ext_code.code))
+			continue;
+		p->handler(ext_code, regs->int_parm, regs->int_parm_long);
+	}
+	rcu_read_unlock();
+	return IRQ_HANDLED;
+}
+
+static void __init init_ext_interrupts(void)
+{
+	int idx;
+
+	for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
+		INIT_HLIST_HEAD(&ext_int_hash[idx]);
+
+	irq_set_chip_and_handler(EXT_INTERRUPT,
+				 &dummy_irq_chip, handle_percpu_irq);
+	if (request_irq(EXT_INTERRUPT, do_ext_interrupt, 0, "EXT", NULL))
+		panic("Failed to register EXT interrupt\n");
+}
+
+void __init init_IRQ(void)
+{
+	BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS);
+	init_cio_interrupts();
+	init_airq_interrupts();
+	init_ext_interrupts();
+}
+
+static DEFINE_SPINLOCK(irq_subclass_lock);
+static unsigned char irq_subclass_refcount[64];
+
+void irq_subclass_register(enum irq_subclass subclass)
+{
+	spin_lock(&irq_subclass_lock);
+	if (!irq_subclass_refcount[subclass])
+		ctl_set_bit(0, subclass);
+	irq_subclass_refcount[subclass]++;
+	spin_unlock(&irq_subclass_lock);
+}
+EXPORT_SYMBOL(irq_subclass_register);
+
+void irq_subclass_unregister(enum irq_subclass subclass)
+{
+	spin_lock(&irq_subclass_lock);
+	irq_subclass_refcount[subclass]--;
+	if (!irq_subclass_refcount[subclass])
+		ctl_clear_bit(0, subclass);
+	spin_unlock(&irq_subclass_lock);
+}
+EXPORT_SYMBOL(irq_subclass_unregister);