Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

18 files changed, 11805 insertions, 0 deletions

diff --git a/arch/x86/kernel/apic/Makefile b/arch/x86/kernel/apic/Makefile
new file mode 100644
index 000000000..a6fcaf16c
--- /dev/null
+++ b/arch/x86/kernel/apic/Makefile
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for local APIC drivers and for the IO-APIC code
+#
+
+# Leads to non-deterministic coverage that is not a function of syscall inputs.
+# In particualr, smp_apic_timer_interrupt() is called in random places.
+KCOV_INSTRUMENT		:= n
+
+obj-$(CONFIG_X86_LOCAL_APIC)	+= apic.o apic_common.o apic_noop.o ipi.o vector.o
+obj-y				+= hw_nmi.o
+
+obj-$(CONFIG_X86_IO_APIC)	+= io_apic.o
+obj-$(CONFIG_PCI_MSI)		+= msi.o
+obj-$(CONFIG_SMP)		+= ipi.o
+
+ifeq ($(CONFIG_X86_64),y)
+# APIC probe will depend on the listing order here
+obj-$(CONFIG_X86_NUMACHIP)	+= apic_numachip.o
+obj-$(CONFIG_X86_UV)		+= x2apic_uv_x.o
+obj-$(CONFIG_X86_X2APIC)	+= x2apic_phys.o
+obj-$(CONFIG_X86_X2APIC)	+= x2apic_cluster.o
+obj-y				+= apic_flat_64.o
+endif
+
+# APIC probe will depend on the listing order here
+obj-$(CONFIG_X86_BIGSMP)	+= bigsmp_32.o
+
+# For 32bit, probe_32 need to be listed last
+obj-$(CONFIG_X86_LOCAL_APIC)	+= probe_$(BITS).o
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
new file mode 100644
index 000000000..770557110
--- /dev/null
+++ b/arch/x86/kernel/apic/apic.c
@@ -0,0 +1,3010 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *	Local APIC handling, local APIC timers
+ *
+ *	(c) 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
+ *
+ *	Fixes
+ *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
+ *					thanks to Eric Gilmore
+ *					and Rolf G. Tews
+ *					for testing these extensively.
+ *	Maciej W. Rozycki	:	Various updates and fixes.
+ *	Mikael Pettersson	:	Power Management for UP-APIC.
+ *	Pavel Machek and
+ *	Mikael Pettersson	:	PM converted to driver model.
+ */
+
+#include <linux/perf_event.h>
+#include <linux/kernel_stat.h>
+#include <linux/mc146818rtc.h>
+#include <linux/acpi_pmtmr.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/memblock.h>
+#include <linux/ftrace.h>
+#include <linux/ioport.h>
+#include <linux/export.h>
+#include <linux/syscore_ops.h>
+#include <linux/delay.h>
+#include <linux/timex.h>
+#include <linux/i8253.h>
+#include <linux/dmar.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/dmi.h>
+#include <linux/smp.h>
+#include <linux/mm.h>
+
+#include <asm/trace/irq_vectors.h>
+#include <asm/irq_remapping.h>
+#include <asm/pc-conf-reg.h>
+#include <asm/perf_event.h>
+#include <asm/x86_init.h>
+#include <linux/atomic.h>
+#include <asm/barrier.h>
+#include <asm/mpspec.h>
+#include <asm/i8259.h>
+#include <asm/proto.h>
+#include <asm/traps.h>
+#include <asm/apic.h>
+#include <asm/acpi.h>
+#include <asm/io_apic.h>
+#include <asm/desc.h>
+#include <asm/hpet.h>
+#include <asm/mtrr.h>
+#include <asm/time.h>
+#include <asm/smp.h>
+#include <asm/mce.h>
+#include <asm/tsc.h>
+#include <asm/hypervisor.h>
+#include <asm/cpu_device_id.h>
+#include <asm/intel-family.h>
+#include <asm/irq_regs.h>
+#include <asm/cpu.h>
+
+unsigned int num_processors;
+
+unsigned disabled_cpus;
+
+/* Processor that is doing the boot up */
+unsigned int boot_cpu_physical_apicid __ro_after_init = -1U;
+EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
+
+u8 boot_cpu_apic_version __ro_after_init;
+
+/*
+ * The highest APIC ID seen during enumeration.
+ */
+static unsigned int max_physical_apicid;
+
+/*
+ * Bitmask of physically existing CPUs:
+ */
+physid_mask_t phys_cpu_present_map;
+
+/*
+ * Processor to be disabled specified by kernel parameter
+ * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
+ * avoid undefined behaviour caused by sending INIT from AP to BSP.
+ */
+static unsigned int disabled_cpu_apicid __ro_after_init = BAD_APICID;
+
+/*
+ * This variable controls which CPUs receive external NMIs.  By default,
+ * external NMIs are delivered only to the BSP.
+ */
+static int apic_extnmi __ro_after_init = APIC_EXTNMI_BSP;
+
+/*
+ * Hypervisor supports 15 bits of APIC ID in MSI Extended Destination ID
+ */
+static bool virt_ext_dest_id __ro_after_init;
+
+/*
+ * Map cpu index to physical APIC ID
+ */
+DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID);
+DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid, BAD_APICID);
+DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
+EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
+EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
+EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
+
+#ifdef CONFIG_X86_32
+
+/*
+ * On x86_32, the mapping between cpu and logical apicid may vary
+ * depending on apic in use.  The following early percpu variable is
+ * used for the mapping.  This is where the behaviors of x86_64 and 32
+ * actually diverge.  Let's keep it ugly for now.
+ */
+DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);
+
+/* Local APIC was disabled by the BIOS and enabled by the kernel */
+static int enabled_via_apicbase __ro_after_init;
+
+/*
+ * Handle interrupt mode configuration register (IMCR).
+ * This register controls whether the interrupt signals
+ * that reach the BSP come from the master PIC or from the
+ * local APIC. Before entering Symmetric I/O Mode, either
+ * the BIOS or the operating system must switch out of
+ * PIC Mode by changing the IMCR.
+ */
+static inline void imcr_pic_to_apic(void)
+{
+	/* NMI and 8259 INTR go through APIC */
+	pc_conf_set(PC_CONF_MPS_IMCR, 0x01);
+}
+
+static inline void imcr_apic_to_pic(void)
+{
+	/* NMI and 8259 INTR go directly to BSP */
+	pc_conf_set(PC_CONF_MPS_IMCR, 0x00);
+}
+#endif
+
+/*
+ * Knob to control our willingness to enable the local APIC.
+ *
+ * +1=force-enable
+ */
+static int force_enable_local_apic __initdata;
+
+/*
+ * APIC command line parameters
+ */
+static int __init parse_lapic(char *arg)
+{
+	if (IS_ENABLED(CONFIG_X86_32) && !arg)
+		force_enable_local_apic = 1;
+	else if (arg && !strncmp(arg, "notscdeadline", 13))
+		setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
+	return 0;
+}
+early_param("lapic", parse_lapic);
+
+#ifdef CONFIG_X86_64
+static int apic_calibrate_pmtmr __initdata;
+static __init int setup_apicpmtimer(char *s)
+{
+	apic_calibrate_pmtmr = 1;
+	notsc_setup(NULL);
+	return 1;
+}
+__setup("apicpmtimer", setup_apicpmtimer);
+#endif
+
+unsigned long mp_lapic_addr __ro_after_init;
+int disable_apic __ro_after_init;
+/* Disable local APIC timer from the kernel commandline or via dmi quirk */
+static int disable_apic_timer __initdata;
+/* Local APIC timer works in C2 */
+int local_apic_timer_c2_ok __ro_after_init;
+EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
+
+/*
+ * Debug level, exported for io_apic.c
+ */
+int apic_verbosity __ro_after_init;
+
+int pic_mode __ro_after_init;
+
+/* Have we found an MP table */
+int smp_found_config __ro_after_init;
+
+static struct resource lapic_resource = {
+	.name = "Local APIC",
+	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
+};
+
+unsigned int lapic_timer_period = 0;
+
+static void apic_pm_activate(void);
+
+static unsigned long apic_phys __ro_after_init;
+
+/*
+ * Get the LAPIC version
+ */
+static inline int lapic_get_version(void)
+{
+	return GET_APIC_VERSION(apic_read(APIC_LVR));
+}
+
+/*
+ * Check, if the APIC is integrated or a separate chip
+ */
+static inline int lapic_is_integrated(void)
+{
+	return APIC_INTEGRATED(lapic_get_version());
+}
+
+/*
+ * Check, whether this is a modern or a first generation APIC
+ */
+static int modern_apic(void)
+{
+	/* AMD systems use old APIC versions, so check the CPU */
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+	    boot_cpu_data.x86 >= 0xf)
+		return 1;
+
+	/* Hygon systems use modern APIC */
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
+		return 1;
+
+	return lapic_get_version() >= 0x14;
+}
+
+/*
+ * right after this call apic become NOOP driven
+ * so apic->write/read doesn't do anything
+ */
+static void __init apic_disable(void)
+{
+	pr_info("APIC: switched to apic NOOP\n");
+	apic = &apic_noop;
+}
+
+void native_apic_wait_icr_idle(void)
+{
+	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
+		cpu_relax();
+}
+
+u32 native_safe_apic_wait_icr_idle(void)
+{
+	u32 send_status;
+	int timeout;
+
+	timeout = 0;
+	do {
+		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
+		if (!send_status)
+			break;
+		inc_irq_stat(icr_read_retry_count);
+		udelay(100);
+	} while (timeout++ < 1000);
+
+	return send_status;
+}
+
+void native_apic_icr_write(u32 low, u32 id)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	apic_write(APIC_ICR2, SET_XAPIC_DEST_FIELD(id));
+	apic_write(APIC_ICR, low);
+	local_irq_restore(flags);
+}
+
+u64 native_apic_icr_read(void)
+{
+	u32 icr1, icr2;
+
+	icr2 = apic_read(APIC_ICR2);
+	icr1 = apic_read(APIC_ICR);
+
+	return icr1 | ((u64)icr2 << 32);
+}
+
+#ifdef CONFIG_X86_32
+/**
+ * get_physical_broadcast - Get number of physical broadcast IDs
+ */
+int get_physical_broadcast(void)
+{
+	return modern_apic() ? 0xff : 0xf;
+}
+#endif
+
+/**
+ * lapic_get_maxlvt - get the maximum number of local vector table entries
+ */
+int lapic_get_maxlvt(void)
+{
+	/*
+	 * - we always have APIC integrated on 64bit mode
+	 * - 82489DXs do not report # of LVT entries
+	 */
+	return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 2;
+}
+
+/*
+ * Local APIC timer
+ */
+
+/* Clock divisor */
+#define APIC_DIVISOR 16
+#define TSC_DIVISOR  8
+
+/* i82489DX specific */
+#define		I82489DX_BASE_DIVIDER		(((0x2) << 18))
+
+/*
+ * This function sets up the local APIC timer, with a timeout of
+ * 'clocks' APIC bus clock. During calibration we actually call
+ * this function twice on the boot CPU, once with a bogus timeout
+ * value, second time for real. The other (noncalibrating) CPUs
+ * call this function only once, with the real, calibrated value.
+ *
+ * We do reads before writes even if unnecessary, to get around the
+ * P5 APIC double write bug.
+ */
+static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
+{
+	unsigned int lvtt_value, tmp_value;
+
+	lvtt_value = LOCAL_TIMER_VECTOR;
+	if (!oneshot)
+		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
+	else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
+		lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
+
+	/*
+	 * The i82489DX APIC uses bit 18 and 19 for the base divider.  This
+	 * overlaps with bit 18 on integrated APICs, but is not documented
+	 * in the SDM. No problem though. i82489DX equipped systems do not
+	 * have TSC deadline timer.
+	 */
+	if (!lapic_is_integrated())
+		lvtt_value |= I82489DX_BASE_DIVIDER;
+
+	if (!irqen)
+		lvtt_value |= APIC_LVT_MASKED;
+
+	apic_write(APIC_LVTT, lvtt_value);
+
+	if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
+		/*
+		 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
+		 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
+		 * According to Intel, MFENCE can do the serialization here.
+		 */
+		asm volatile("mfence" : : : "memory");
+		return;
+	}
+
+	/*
+	 * Divide PICLK by 16
+	 */
+	tmp_value = apic_read(APIC_TDCR);
+	apic_write(APIC_TDCR,
+		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
+		APIC_TDR_DIV_16);
+
+	if (!oneshot)
+		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
+}
+
+/*
+ * Setup extended LVT, AMD specific
+ *
+ * Software should use the LVT offsets the BIOS provides.  The offsets
+ * are determined by the subsystems using it like those for MCE
+ * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
+ * are supported. Beginning with family 10h at least 4 offsets are
+ * available.
+ *
+ * Since the offsets must be consistent for all cores, we keep track
+ * of the LVT offsets in software and reserve the offset for the same
+ * vector also to be used on other cores. An offset is freed by
+ * setting the entry to APIC_EILVT_MASKED.
+ *
+ * If the BIOS is right, there should be no conflicts. Otherwise a
+ * "[Firmware Bug]: ..." error message is generated. However, if
+ * software does not properly determines the offsets, it is not
+ * necessarily a BIOS bug.
+ */
+
+static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
+
+static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
+{
+	return (old & APIC_EILVT_MASKED)
+		|| (new == APIC_EILVT_MASKED)
+		|| ((new & ~APIC_EILVT_MASKED) == old);
+}
+
+static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
+{
+	unsigned int rsvd, vector;
+
+	if (offset >= APIC_EILVT_NR_MAX)
+		return ~0;
+
+	rsvd = atomic_read(&eilvt_offsets[offset]);
+	do {
+		vector = rsvd & ~APIC_EILVT_MASKED;	/* 0: unassigned */
+		if (vector && !eilvt_entry_is_changeable(vector, new))
+			/* may not change if vectors are different */
+			return rsvd;
+	} while (!atomic_try_cmpxchg(&eilvt_offsets[offset], &rsvd, new));
+
+	rsvd = new & ~APIC_EILVT_MASKED;
+	if (rsvd && rsvd != vector)
+		pr_info("LVT offset %d assigned for vector 0x%02x\n",
+			offset, rsvd);
+
+	return new;
+}
+
+/*
+ * If mask=1, the LVT entry does not generate interrupts while mask=0
+ * enables the vector. See also the BKDGs. Must be called with
+ * preemption disabled.
+ */
+
+int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
+{
+	unsigned long reg = APIC_EILVTn(offset);
+	unsigned int new, old, reserved;
+
+	new = (mask << 16) | (msg_type << 8) | vector;
+	old = apic_read(reg);
+	reserved = reserve_eilvt_offset(offset, new);
+
+	if (reserved != new) {
+		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
+		       "vector 0x%x, but the register is already in use for "
+		       "vector 0x%x on another cpu\n",
+		       smp_processor_id(), reg, offset, new, reserved);
+		return -EINVAL;
+	}
+
+	if (!eilvt_entry_is_changeable(old, new)) {
+		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
+		       "vector 0x%x, but the register is already in use for "
+		       "vector 0x%x on this cpu\n",
+		       smp_processor_id(), reg, offset, new, old);
+		return -EBUSY;
+	}
+
+	apic_write(reg, new);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
+
+/*
+ * Program the next event, relative to now
+ */
+static int lapic_next_event(unsigned long delta,
+			    struct clock_event_device *evt)
+{
+	apic_write(APIC_TMICT, delta);
+	return 0;
+}
+
+static int lapic_next_deadline(unsigned long delta,
+			       struct clock_event_device *evt)
+{
+	u64 tsc;
+
+	/* This MSR is special and need a special fence: */
+	weak_wrmsr_fence();
+
+	tsc = rdtsc();
+	wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
+	return 0;
+}
+
+static int lapic_timer_shutdown(struct clock_event_device *evt)
+{
+	unsigned int v;
+
+	/* Lapic used as dummy for broadcast ? */
+	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
+		return 0;
+
+	v = apic_read(APIC_LVTT);
+	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
+	apic_write(APIC_LVTT, v);
+	apic_write(APIC_TMICT, 0);
+	return 0;
+}
+
+static inline int
+lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
+{
+	/* Lapic used as dummy for broadcast ? */
+	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
+		return 0;
+
+	__setup_APIC_LVTT(lapic_timer_period, oneshot, 1);
+	return 0;
+}
+
+static int lapic_timer_set_periodic(struct clock_event_device *evt)
+{
+	return lapic_timer_set_periodic_oneshot(evt, false);
+}
+
+static int lapic_timer_set_oneshot(struct clock_event_device *evt)
+{
+	return lapic_timer_set_periodic_oneshot(evt, true);
+}
+
+/*
+ * Local APIC timer broadcast function
+ */
+static void lapic_timer_broadcast(const struct cpumask *mask)
+{
+#ifdef CONFIG_SMP
+	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
+#endif
+}
+
+
+/*
+ * The local apic timer can be used for any function which is CPU local.
+ */
+static struct clock_event_device lapic_clockevent = {
+	.name				= "lapic",
+	.features			= CLOCK_EVT_FEAT_PERIODIC |
+					  CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
+					  | CLOCK_EVT_FEAT_DUMMY,
+	.shift				= 32,
+	.set_state_shutdown		= lapic_timer_shutdown,
+	.set_state_periodic		= lapic_timer_set_periodic,
+	.set_state_oneshot		= lapic_timer_set_oneshot,
+	.set_state_oneshot_stopped	= lapic_timer_shutdown,
+	.set_next_event			= lapic_next_event,
+	.broadcast			= lapic_timer_broadcast,
+	.rating				= 100,
+	.irq				= -1,
+};
+static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
+
+static const struct x86_cpu_id deadline_match[] __initconst = {
+	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(HASWELL_X, X86_STEPPINGS(0x2, 0x2), 0x3a), /* EP */
+	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(HASWELL_X, X86_STEPPINGS(0x4, 0x4), 0x0f), /* EX */
+
+	X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_X,	0x0b000020),
+
+	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x2, 0x2), 0x00000011),
+	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x3, 0x3), 0x0700000e),
+	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x4, 0x4), 0x0f00000c),
+	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x5, 0x5), 0x0e000003),
+
+	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x3, 0x3), 0x01000136),
+	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x4, 0x4), 0x02000014),
+	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x5, 0xf), 0),
+
+	X86_MATCH_INTEL_FAM6_MODEL( HASWELL,		0x22),
+	X86_MATCH_INTEL_FAM6_MODEL( HASWELL_L,		0x20),
+	X86_MATCH_INTEL_FAM6_MODEL( HASWELL_G,		0x17),
+
+	X86_MATCH_INTEL_FAM6_MODEL( BROADWELL,		0x25),
+	X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_G,	0x17),
+
+	X86_MATCH_INTEL_FAM6_MODEL( SKYLAKE_L,		0xb2),
+	X86_MATCH_INTEL_FAM6_MODEL( SKYLAKE,		0xb2),
+
+	X86_MATCH_INTEL_FAM6_MODEL( KABYLAKE_L,		0x52),
+	X86_MATCH_INTEL_FAM6_MODEL( KABYLAKE,		0x52),
+
+	{},
+};
+
+static __init bool apic_validate_deadline_timer(void)
+{
+	const struct x86_cpu_id *m;
+	u32 rev;
+
+	if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
+		return false;
+	if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
+		return true;
+
+	m = x86_match_cpu(deadline_match);
+	if (!m)
+		return true;
+
+	rev = (u32)m->driver_data;
+
+	if (boot_cpu_data.microcode >= rev)
+		return true;
+
+	setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
+	pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
+	       "please update microcode to version: 0x%x (or later)\n", rev);
+	return false;
+}
+
+/*
+ * Setup the local APIC timer for this CPU. Copy the initialized values
+ * of the boot CPU and register the clock event in the framework.
+ */
+static void setup_APIC_timer(void)
+{
+	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
+
+	if (this_cpu_has(X86_FEATURE_ARAT)) {
+		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
+		/* Make LAPIC timer preferable over percpu HPET */
+		lapic_clockevent.rating = 150;
+	}
+
+	memcpy(levt, &lapic_clockevent, sizeof(*levt));
+	levt->cpumask = cpumask_of(smp_processor_id());
+
+	if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
+		levt->name = "lapic-deadline";
+		levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
+				    CLOCK_EVT_FEAT_DUMMY);
+		levt->set_next_event = lapic_next_deadline;
+		clockevents_config_and_register(levt,
+						tsc_khz * (1000 / TSC_DIVISOR),
+						0xF, ~0UL);
+	} else
+		clockevents_register_device(levt);
+}
+
+/*
+ * Install the updated TSC frequency from recalibration at the TSC
+ * deadline clockevent devices.
+ */
+static void __lapic_update_tsc_freq(void *info)
+{
+	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
+
+	if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
+		return;
+
+	clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
+}
+
+void lapic_update_tsc_freq(void)
+{
+	/*
+	 * The clockevent device's ->mult and ->shift can both be
+	 * changed. In order to avoid races, schedule the frequency
+	 * update code on each CPU.
+	 */
+	on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
+}
+
+/*
+ * In this functions we calibrate APIC bus clocks to the external timer.
+ *
+ * We want to do the calibration only once since we want to have local timer
+ * irqs synchronous. CPUs connected by the same APIC bus have the very same bus
+ * frequency.
+ *
+ * This was previously done by reading the PIT/HPET and waiting for a wrap
+ * around to find out, that a tick has elapsed. I have a box, where the PIT
+ * readout is broken, so it never gets out of the wait loop again. This was
+ * also reported by others.
+ *
+ * Monitoring the jiffies value is inaccurate and the clockevents
+ * infrastructure allows us to do a simple substitution of the interrupt
+ * handler.
+ *
+ * The calibration routine also uses the pm_timer when possible, as the PIT
+ * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
+ * back to normal later in the boot process).
+ */
+
+#define LAPIC_CAL_LOOPS		(HZ/10)
+
+static __initdata int lapic_cal_loops = -1;
+static __initdata long lapic_cal_t1, lapic_cal_t2;
+static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
+static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
+static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
+
+/*
+ * Temporary interrupt handler and polled calibration function.
+ */
+static void __init lapic_cal_handler(struct clock_event_device *dev)
+{
+	unsigned long long tsc = 0;
+	long tapic = apic_read(APIC_TMCCT);
+	unsigned long pm = acpi_pm_read_early();
+
+	if (boot_cpu_has(X86_FEATURE_TSC))
+		tsc = rdtsc();
+
+	switch (lapic_cal_loops++) {
+	case 0:
+		lapic_cal_t1 = tapic;
+		lapic_cal_tsc1 = tsc;
+		lapic_cal_pm1 = pm;
+		lapic_cal_j1 = jiffies;
+		break;
+
+	case LAPIC_CAL_LOOPS:
+		lapic_cal_t2 = tapic;
+		lapic_cal_tsc2 = tsc;
+		if (pm < lapic_cal_pm1)
+			pm += ACPI_PM_OVRRUN;
+		lapic_cal_pm2 = pm;
+		lapic_cal_j2 = jiffies;
+		break;
+	}
+}
+
+static int __init
+calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
+{
+	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
+	const long pm_thresh = pm_100ms / 100;
+	unsigned long mult;
+	u64 res;
+
+#ifndef CONFIG_X86_PM_TIMER
+	return -1;
+#endif
+
+	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
+
+	/* Check, if the PM timer is available */
+	if (!deltapm)
+		return -1;
+
+	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
+
+	if (deltapm > (pm_100ms - pm_thresh) &&
+	    deltapm < (pm_100ms + pm_thresh)) {
+		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
+		return 0;
+	}
+
+	res = (((u64)deltapm) *  mult) >> 22;
+	do_div(res, 1000000);
+	pr_warn("APIC calibration not consistent "
+		"with PM-Timer: %ldms instead of 100ms\n", (long)res);
+
+	/* Correct the lapic counter value */
+	res = (((u64)(*delta)) * pm_100ms);
+	do_div(res, deltapm);
+	pr_info("APIC delta adjusted to PM-Timer: "
+		"%lu (%ld)\n", (unsigned long)res, *delta);
+	*delta = (long)res;
+
+	/* Correct the tsc counter value */
+	if (boot_cpu_has(X86_FEATURE_TSC)) {
+		res = (((u64)(*deltatsc)) * pm_100ms);
+		do_div(res, deltapm);
+		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
+					  "PM-Timer: %lu (%ld)\n",
+					(unsigned long)res, *deltatsc);
+		*deltatsc = (long)res;
+	}
+
+	return 0;
+}
+
+static int __init lapic_init_clockevent(void)
+{
+	if (!lapic_timer_period)
+		return -1;
+
+	/* Calculate the scaled math multiplication factor */
+	lapic_clockevent.mult = div_sc(lapic_timer_period/APIC_DIVISOR,
+					TICK_NSEC, lapic_clockevent.shift);
+	lapic_clockevent.max_delta_ns =
+		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
+	lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
+	lapic_clockevent.min_delta_ns =
+		clockevent_delta2ns(0xF, &lapic_clockevent);
+	lapic_clockevent.min_delta_ticks = 0xF;
+
+	return 0;
+}
+
+bool __init apic_needs_pit(void)
+{
+	/*
+	 * If the frequencies are not known, PIT is required for both TSC
+	 * and apic timer calibration.
+	 */
+	if (!tsc_khz || !cpu_khz)
+		return true;
+
+	/* Is there an APIC at all or is it disabled? */
+	if (!boot_cpu_has(X86_FEATURE_APIC) || disable_apic)
+		return true;
+
+	/*
+	 * If interrupt delivery mode is legacy PIC or virtual wire without
+	 * configuration, the local APIC timer wont be set up. Make sure
+	 * that the PIT is initialized.
+	 */
+	if (apic_intr_mode == APIC_PIC ||
+	    apic_intr_mode == APIC_VIRTUAL_WIRE_NO_CONFIG)
+		return true;
+
+	/* Virt guests may lack ARAT, but still have DEADLINE */
+	if (!boot_cpu_has(X86_FEATURE_ARAT))
+		return true;
+
+	/* Deadline timer is based on TSC so no further PIT action required */
+	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
+		return false;
+
+	/* APIC timer disabled? */
+	if (disable_apic_timer)
+		return true;
+	/*
+	 * The APIC timer frequency is known already, no PIT calibration
+	 * required. If unknown, let the PIT be initialized.
+	 */
+	return lapic_timer_period == 0;
+}
+
+static int __init calibrate_APIC_clock(void)
+{
+	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
+	u64 tsc_perj = 0, tsc_start = 0;
+	unsigned long jif_start;
+	unsigned long deltaj;
+	long delta, deltatsc;
+	int pm_referenced = 0;
+
+	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
+		return 0;
+
+	/*
+	 * Check if lapic timer has already been calibrated by platform
+	 * specific routine, such as tsc calibration code. If so just fill
+	 * in the clockevent structure and return.
+	 */
+	if (!lapic_init_clockevent()) {
+		apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
+			    lapic_timer_period);
+		/*
+		 * Direct calibration methods must have an always running
+		 * local APIC timer, no need for broadcast timer.
+		 */
+		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
+		return 0;
+	}
+
+	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
+		    "calibrating APIC timer ...\n");
+
+	/*
+	 * There are platforms w/o global clockevent devices. Instead of
+	 * making the calibration conditional on that, use a polling based
+	 * approach everywhere.
+	 */
+	local_irq_disable();
+
+	/*
+	 * Setup the APIC counter to maximum. There is no way the lapic
+	 * can underflow in the 100ms detection time frame
+	 */
+	__setup_APIC_LVTT(0xffffffff, 0, 0);
+
+	/*
+	 * Methods to terminate the calibration loop:
+	 *  1) Global clockevent if available (jiffies)
+	 *  2) TSC if available and frequency is known
+	 */
+	jif_start = READ_ONCE(jiffies);
+
+	if (tsc_khz) {
+		tsc_start = rdtsc();
+		tsc_perj = div_u64((u64)tsc_khz * 1000, HZ);
+	}
+
+	/*
+	 * Enable interrupts so the tick can fire, if a global
+	 * clockevent device is available
+	 */
+	local_irq_enable();
+
+	while (lapic_cal_loops <= LAPIC_CAL_LOOPS) {
+		/* Wait for a tick to elapse */
+		while (1) {
+			if (tsc_khz) {
+				u64 tsc_now = rdtsc();
+				if ((tsc_now - tsc_start) >= tsc_perj) {
+					tsc_start += tsc_perj;
+					break;
+				}
+			} else {
+				unsigned long jif_now = READ_ONCE(jiffies);
+
+				if (time_after(jif_now, jif_start)) {
+					jif_start = jif_now;
+					break;
+				}
+			}
+			cpu_relax();
+		}
+
+		/* Invoke the calibration routine */
+		local_irq_disable();
+		lapic_cal_handler(NULL);
+		local_irq_enable();
+	}
+
+	local_irq_disable();
+
+	/* Build delta t1-t2 as apic timer counts down */
+	delta = lapic_cal_t1 - lapic_cal_t2;
+	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
+
+	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
+
+	/* we trust the PM based calibration if possible */
+	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
+					&delta, &deltatsc);
+
+	lapic_timer_period = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
+	lapic_init_clockevent();
+
+	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
+	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
+	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
+		    lapic_timer_period);
+
+	if (boot_cpu_has(X86_FEATURE_TSC)) {
+		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
+			    "%ld.%04ld MHz.\n",
+			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
+			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
+	}
+
+	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
+		    "%u.%04u MHz.\n",
+		    lapic_timer_period / (1000000 / HZ),
+		    lapic_timer_period % (1000000 / HZ));
+
+	/*
+	 * Do a sanity check on the APIC calibration result
+	 */
+	if (lapic_timer_period < (1000000 / HZ)) {
+		local_irq_enable();
+		pr_warn("APIC frequency too slow, disabling apic timer\n");
+		return -1;
+	}
+
+	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
+
+	/*
+	 * PM timer calibration failed or not turned on so lets try APIC
+	 * timer based calibration, if a global clockevent device is
+	 * available.
+	 */
+	if (!pm_referenced && global_clock_event) {
+		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
+
+		/*
+		 * Setup the apic timer manually
+		 */
+		levt->event_handler = lapic_cal_handler;
+		lapic_timer_set_periodic(levt);
+		lapic_cal_loops = -1;
+
+		/* Let the interrupts run */
+		local_irq_enable();
+
+		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
+			cpu_relax();
+
+		/* Stop the lapic timer */
+		local_irq_disable();
+		lapic_timer_shutdown(levt);
+
+		/* Jiffies delta */
+		deltaj = lapic_cal_j2 - lapic_cal_j1;
+		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
+
+		/* Check, if the jiffies result is consistent */
+		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
+			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
+		else
+			levt->features |= CLOCK_EVT_FEAT_DUMMY;
+	}
+	local_irq_enable();
+
+	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
+		pr_warn("APIC timer disabled due to verification failure\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * Setup the boot APIC
+ *
+ * Calibrate and verify the result.
+ */
+void __init setup_boot_APIC_clock(void)
+{
+	/*
+	 * The local apic timer can be disabled via the kernel
+	 * commandline or from the CPU detection code. Register the lapic
+	 * timer as a dummy clock event source on SMP systems, so the
+	 * broadcast mechanism is used. On UP systems simply ignore it.
+	 */
+	if (disable_apic_timer) {
+		pr_info("Disabling APIC timer\n");
+		/* No broadcast on UP ! */
+		if (num_possible_cpus() > 1) {
+			lapic_clockevent.mult = 1;
+			setup_APIC_timer();
+		}
+		return;
+	}
+
+	if (calibrate_APIC_clock()) {
+		/* No broadcast on UP ! */
+		if (num_possible_cpus() > 1)
+			setup_APIC_timer();
+		return;
+	}
+
+	/*
+	 * If nmi_watchdog is set to IO_APIC, we need the
+	 * PIT/HPET going.  Otherwise register lapic as a dummy
+	 * device.
+	 */
+	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
+
+	/* Setup the lapic or request the broadcast */
+	setup_APIC_timer();
+	amd_e400_c1e_apic_setup();
+}
+
+void setup_secondary_APIC_clock(void)
+{
+	setup_APIC_timer();
+	amd_e400_c1e_apic_setup();
+}
+
+/*
+ * The guts of the apic timer interrupt
+ */
+static void local_apic_timer_interrupt(void)
+{
+	struct clock_event_device *evt = this_cpu_ptr(&lapic_events);
+
+	/*
+	 * Normally we should not be here till LAPIC has been initialized but
+	 * in some cases like kdump, its possible that there is a pending LAPIC
+	 * timer interrupt from previous kernel's context and is delivered in
+	 * new kernel the moment interrupts are enabled.
+	 *
+	 * Interrupts are enabled early and LAPIC is setup much later, hence
+	 * its possible that when we get here evt->event_handler is NULL.
+	 * Check for event_handler being NULL and discard the interrupt as
+	 * spurious.
+	 */
+	if (!evt->event_handler) {
+		pr_warn("Spurious LAPIC timer interrupt on cpu %d\n",
+			smp_processor_id());
+		/* Switch it off */
+		lapic_timer_shutdown(evt);
+		return;
+	}
+
+	/*
+	 * the NMI deadlock-detector uses this.
+	 */
+	inc_irq_stat(apic_timer_irqs);
+
+	evt->event_handler(evt);
+}
+
+/*
+ * Local APIC timer interrupt. This is the most natural way for doing
+ * local interrupts, but local timer interrupts can be emulated by
+ * broadcast interrupts too. [in case the hw doesn't support APIC timers]
+ *
+ * [ if a single-CPU system runs an SMP kernel then we call the local
+ *   interrupt as well. Thus we cannot inline the local irq ... ]
+ */
+DEFINE_IDTENTRY_SYSVEC(sysvec_apic_timer_interrupt)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	ack_APIC_irq();
+	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
+	local_apic_timer_interrupt();
+	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
+
+	set_irq_regs(old_regs);
+}
+
+/*
+ * Local APIC start and shutdown
+ */
+
+/**
+ * clear_local_APIC - shutdown the local APIC
+ *
+ * This is called, when a CPU is disabled and before rebooting, so the state of
+ * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
+ * leftovers during boot.
+ */
+void clear_local_APIC(void)
+{
+	int maxlvt;
+	u32 v;
+
+	/* APIC hasn't been mapped yet */
+	if (!x2apic_mode && !apic_phys)
+		return;
+
+	maxlvt = lapic_get_maxlvt();
+	/*
+	 * Masking an LVT entry can trigger a local APIC error
+	 * if the vector is zero. Mask LVTERR first to prevent this.
+	 */
+	if (maxlvt >= 3) {
+		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
+		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
+	}
+	/*
+	 * Careful: we have to set masks only first to deassert
+	 * any level-triggered sources.
+	 */
+	v = apic_read(APIC_LVTT);
+	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
+	v = apic_read(APIC_LVT0);
+	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
+	v = apic_read(APIC_LVT1);
+	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
+	if (maxlvt >= 4) {
+		v = apic_read(APIC_LVTPC);
+		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
+	}
+
+	/* lets not touch this if we didn't frob it */
+#ifdef CONFIG_X86_THERMAL_VECTOR
+	if (maxlvt >= 5) {
+		v = apic_read(APIC_LVTTHMR);
+		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
+	}
+#endif
+#ifdef CONFIG_X86_MCE_INTEL
+	if (maxlvt >= 6) {
+		v = apic_read(APIC_LVTCMCI);
+		if (!(v & APIC_LVT_MASKED))
+			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
+	}
+#endif
+
+	/*
+	 * Clean APIC state for other OSs:
+	 */
+	apic_write(APIC_LVTT, APIC_LVT_MASKED);
+	apic_write(APIC_LVT0, APIC_LVT_MASKED);
+	apic_write(APIC_LVT1, APIC_LVT_MASKED);
+	if (maxlvt >= 3)
+		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
+	if (maxlvt >= 4)
+		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
+
+	/* Integrated APIC (!82489DX) ? */
+	if (lapic_is_integrated()) {
+		if (maxlvt > 3)
+			/* Clear ESR due to Pentium errata 3AP and 11AP */
+			apic_write(APIC_ESR, 0);
+		apic_read(APIC_ESR);
+	}
+}
+
+/**
+ * apic_soft_disable - Clears and software disables the local APIC on hotplug
+ *
+ * Contrary to disable_local_APIC() this does not touch the enable bit in
+ * MSR_IA32_APICBASE. Clearing that bit on systems based on the 3 wire APIC
+ * bus would require a hardware reset as the APIC would lose track of bus
+ * arbitration. On systems with FSB delivery APICBASE could be disabled,
+ * but it has to be guaranteed that no interrupt is sent to the APIC while
+ * in that state and it's not clear from the SDM whether it still responds
+ * to INIT/SIPI messages. Stay on the safe side and use software disable.
+ */
+void apic_soft_disable(void)
+{
+	u32 value;
+
+	clear_local_APIC();
+
+	/* Soft disable APIC (implies clearing of registers for 82489DX!). */
+	value = apic_read(APIC_SPIV);
+	value &= ~APIC_SPIV_APIC_ENABLED;
+	apic_write(APIC_SPIV, value);
+}
+
+/**
+ * disable_local_APIC - clear and disable the local APIC
+ */
+void disable_local_APIC(void)
+{
+	/* APIC hasn't been mapped yet */
+	if (!x2apic_mode && !apic_phys)
+		return;
+
+	apic_soft_disable();
+
+#ifdef CONFIG_X86_32
+	/*
+	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
+	 * restore the disabled state.
+	 */
+	if (enabled_via_apicbase) {
+		unsigned int l, h;
+
+		rdmsr(MSR_IA32_APICBASE, l, h);
+		l &= ~MSR_IA32_APICBASE_ENABLE;
+		wrmsr(MSR_IA32_APICBASE, l, h);
+	}
+#endif
+}
+
+/*
+ * If Linux enabled the LAPIC against the BIOS default disable it down before
+ * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
+ * not power-off.  Additionally clear all LVT entries before disable_local_APIC
+ * for the case where Linux didn't enable the LAPIC.
+ */
+void lapic_shutdown(void)
+{
+	unsigned long flags;
+
+	if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
+		return;
+
+	local_irq_save(flags);
+
+#ifdef CONFIG_X86_32
+	if (!enabled_via_apicbase)
+		clear_local_APIC();
+	else
+#endif
+		disable_local_APIC();
+
+
+	local_irq_restore(flags);
+}
+
+/**
+ * sync_Arb_IDs - synchronize APIC bus arbitration IDs
+ */
+void __init sync_Arb_IDs(void)
+{
+	/*
+	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
+	 * needed on AMD.
+	 */
+	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+		return;
+
+	/*
+	 * Wait for idle.
+	 */
+	apic_wait_icr_idle();
+
+	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
+	apic_write(APIC_ICR, APIC_DEST_ALLINC |
+			APIC_INT_LEVELTRIG | APIC_DM_INIT);
+}
+
+enum apic_intr_mode_id apic_intr_mode __ro_after_init;
+
+static int __init __apic_intr_mode_select(void)
+{
+	/* Check kernel option */
+	if (disable_apic) {
+		pr_info("APIC disabled via kernel command line\n");
+		return APIC_PIC;
+	}
+
+	/* Check BIOS */
+#ifdef CONFIG_X86_64
+	/* On 64-bit, the APIC must be integrated, Check local APIC only */
+	if (!boot_cpu_has(X86_FEATURE_APIC)) {
+		disable_apic = 1;
+		pr_info("APIC disabled by BIOS\n");
+		return APIC_PIC;
+	}
+#else
+	/* On 32-bit, the APIC may be integrated APIC or 82489DX */
+
+	/* Neither 82489DX nor integrated APIC ? */
+	if (!boot_cpu_has(X86_FEATURE_APIC) && !smp_found_config) {
+		disable_apic = 1;
+		return APIC_PIC;
+	}
+
+	/* If the BIOS pretends there is an integrated APIC ? */
+	if (!boot_cpu_has(X86_FEATURE_APIC) &&
+		APIC_INTEGRATED(boot_cpu_apic_version)) {
+		disable_apic = 1;
+		pr_err(FW_BUG "Local APIC %d not detected, force emulation\n",
+				       boot_cpu_physical_apicid);
+		return APIC_PIC;
+	}
+#endif
+
+	/* Check MP table or ACPI MADT configuration */
+	if (!smp_found_config) {
+		disable_ioapic_support();
+		if (!acpi_lapic) {
+			pr_info("APIC: ACPI MADT or MP tables are not detected\n");
+			return APIC_VIRTUAL_WIRE_NO_CONFIG;
+		}
+		return APIC_VIRTUAL_WIRE;
+	}
+
+#ifdef CONFIG_SMP
+	/* If SMP should be disabled, then really disable it! */
+	if (!setup_max_cpus) {
+		pr_info("APIC: SMP mode deactivated\n");
+		return APIC_SYMMETRIC_IO_NO_ROUTING;
+	}
+
+	if (read_apic_id() != boot_cpu_physical_apicid) {
+		panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
+		     read_apic_id(), boot_cpu_physical_apicid);
+		/* Or can we switch back to PIC here? */
+	}
+#endif
+
+	return APIC_SYMMETRIC_IO;
+}
+
+/* Select the interrupt delivery mode for the BSP */
+void __init apic_intr_mode_select(void)
+{
+	apic_intr_mode = __apic_intr_mode_select();
+}
+
+/*
+ * An initial setup of the virtual wire mode.
+ */
+void __init init_bsp_APIC(void)
+{
+	unsigned int value;
+
+	/*
+	 * Don't do the setup now if we have a SMP BIOS as the
+	 * through-I/O-APIC virtual wire mode might be active.
+	 */
+	if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
+		return;
+
+	/*
+	 * Do not trust the local APIC being empty at bootup.
+	 */
+	clear_local_APIC();
+
+	/*
+	 * Enable APIC.
+	 */
+	value = apic_read(APIC_SPIV);
+	value &= ~APIC_VECTOR_MASK;
+	value |= APIC_SPIV_APIC_ENABLED;
+
+#ifdef CONFIG_X86_32
+	/* This bit is reserved on P4/Xeon and should be cleared */
+	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
+	    (boot_cpu_data.x86 == 15))
+		value &= ~APIC_SPIV_FOCUS_DISABLED;
+	else
+#endif
+		value |= APIC_SPIV_FOCUS_DISABLED;
+	value |= SPURIOUS_APIC_VECTOR;
+	apic_write(APIC_SPIV, value);
+
+	/*
+	 * Set up the virtual wire mode.
+	 */
+	apic_write(APIC_LVT0, APIC_DM_EXTINT);
+	value = APIC_DM_NMI;
+	if (!lapic_is_integrated())		/* 82489DX */
+		value |= APIC_LVT_LEVEL_TRIGGER;
+	if (apic_extnmi == APIC_EXTNMI_NONE)
+		value |= APIC_LVT_MASKED;
+	apic_write(APIC_LVT1, value);
+}
+
+static void __init apic_bsp_setup(bool upmode);
+
+/* Init the interrupt delivery mode for the BSP */
+void __init apic_intr_mode_init(void)
+{
+	bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
+
+	switch (apic_intr_mode) {
+	case APIC_PIC:
+		pr_info("APIC: Keep in PIC mode(8259)\n");
+		return;
+	case APIC_VIRTUAL_WIRE:
+		pr_info("APIC: Switch to virtual wire mode setup\n");
+		break;
+	case APIC_VIRTUAL_WIRE_NO_CONFIG:
+		pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
+		upmode = true;
+		break;
+	case APIC_SYMMETRIC_IO:
+		pr_info("APIC: Switch to symmetric I/O mode setup\n");
+		break;
+	case APIC_SYMMETRIC_IO_NO_ROUTING:
+		pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
+		break;
+	}
+
+	default_setup_apic_routing();
+
+	if (x86_platform.apic_post_init)
+		x86_platform.apic_post_init();
+
+	apic_bsp_setup(upmode);
+}
+
+static void lapic_setup_esr(void)
+{
+	unsigned int oldvalue, value, maxlvt;
+
+	if (!lapic_is_integrated()) {
+		pr_info("No ESR for 82489DX.\n");
+		return;
+	}
+
+	if (apic->disable_esr) {
+		/*
+		 * Something untraceable is creating bad interrupts on
+		 * secondary quads ... for the moment, just leave the
+		 * ESR disabled - we can't do anything useful with the
+		 * errors anyway - mbligh
+		 */
+		pr_info("Leaving ESR disabled.\n");
+		return;
+	}
+
+	maxlvt = lapic_get_maxlvt();
+	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
+		apic_write(APIC_ESR, 0);
+	oldvalue = apic_read(APIC_ESR);
+
+	/* enables sending errors */
+	value = ERROR_APIC_VECTOR;
+	apic_write(APIC_LVTERR, value);
+
+	/*
+	 * spec says clear errors after enabling vector.
+	 */
+	if (maxlvt > 3)
+		apic_write(APIC_ESR, 0);
+	value = apic_read(APIC_ESR);
+	if (value != oldvalue)
+		apic_printk(APIC_VERBOSE, "ESR value before enabling "
+			"vector: 0x%08x  after: 0x%08x\n",
+			oldvalue, value);
+}
+
+#define APIC_IR_REGS		APIC_ISR_NR
+#define APIC_IR_BITS		(APIC_IR_REGS * 32)
+#define APIC_IR_MAPSIZE		(APIC_IR_BITS / BITS_PER_LONG)
+
+union apic_ir {
+	unsigned long	map[APIC_IR_MAPSIZE];
+	u32		regs[APIC_IR_REGS];
+};
+
+static bool apic_check_and_ack(union apic_ir *irr, union apic_ir *isr)
+{
+	int i, bit;
+
+	/* Read the IRRs */
+	for (i = 0; i < APIC_IR_REGS; i++)
+		irr->regs[i] = apic_read(APIC_IRR + i * 0x10);
+
+	/* Read the ISRs */
+	for (i = 0; i < APIC_IR_REGS; i++)
+		isr->regs[i] = apic_read(APIC_ISR + i * 0x10);
+
+	/*
+	 * If the ISR map is not empty. ACK the APIC and run another round
+	 * to verify whether a pending IRR has been unblocked and turned
+	 * into a ISR.
+	 */
+	if (!bitmap_empty(isr->map, APIC_IR_BITS)) {
+		/*
+		 * There can be multiple ISR bits set when a high priority
+		 * interrupt preempted a lower priority one. Issue an ACK
+		 * per set bit.
+		 */
+		for_each_set_bit(bit, isr->map, APIC_IR_BITS)
+			ack_APIC_irq();
+		return true;
+	}
+
+	return !bitmap_empty(irr->map, APIC_IR_BITS);
+}
+
+/*
+ * After a crash, we no longer service the interrupts and a pending
+ * interrupt from previous kernel might still have ISR bit set.
+ *
+ * Most probably by now the CPU has serviced that pending interrupt and it
+ * might not have done the ack_APIC_irq() because it thought, interrupt
+ * came from i8259 as ExtInt. LAPIC did not get EOI so it does not clear
+ * the ISR bit and cpu thinks it has already serviced the interrupt. Hence
+ * a vector might get locked. It was noticed for timer irq (vector
+ * 0x31). Issue an extra EOI to clear ISR.
+ *
+ * If there are pending IRR bits they turn into ISR bits after a higher
+ * priority ISR bit has been acked.
+ */
+static void apic_pending_intr_clear(void)
+{
+	union apic_ir irr, isr;
+	unsigned int i;
+
+	/* 512 loops are way oversized and give the APIC a chance to obey. */
+	for (i = 0; i < 512; i++) {
+		if (!apic_check_and_ack(&irr, &isr))
+			return;
+	}
+	/* Dump the IRR/ISR content if that failed */
+	pr_warn("APIC: Stale IRR: %256pb ISR: %256pb\n", irr.map, isr.map);
+}
+
+/**
+ * setup_local_APIC - setup the local APIC
+ *
+ * Used to setup local APIC while initializing BSP or bringing up APs.
+ * Always called with preemption disabled.
+ */
+static void setup_local_APIC(void)
+{
+	int cpu = smp_processor_id();
+	unsigned int value;
+
+	if (disable_apic) {
+		disable_ioapic_support();
+		return;
+	}
+
+	/*
+	 * If this comes from kexec/kcrash the APIC might be enabled in
+	 * SPIV. Soft disable it before doing further initialization.
+	 */
+	value = apic_read(APIC_SPIV);
+	value &= ~APIC_SPIV_APIC_ENABLED;
+	apic_write(APIC_SPIV, value);
+
+#ifdef CONFIG_X86_32
+	/* Pound the ESR really hard over the head with a big hammer - mbligh */
+	if (lapic_is_integrated() && apic->disable_esr) {
+		apic_write(APIC_ESR, 0);
+		apic_write(APIC_ESR, 0);
+		apic_write(APIC_ESR, 0);
+		apic_write(APIC_ESR, 0);
+	}
+#endif
+	/*
+	 * Double-check whether this APIC is really registered.
+	 * This is meaningless in clustered apic mode, so we skip it.
+	 */
+	BUG_ON(!apic->apic_id_registered());
+
+	/*
+	 * Intel recommends to set DFR, LDR and TPR before enabling
+	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
+	 * document number 292116).  So here it goes...
+	 */
+	apic->init_apic_ldr();
+
+#ifdef CONFIG_X86_32
+	if (apic->dest_mode_logical) {
+		int logical_apicid, ldr_apicid;
+
+		/*
+		 * APIC LDR is initialized.  If logical_apicid mapping was
+		 * initialized during get_smp_config(), make sure it matches
+		 * the actual value.
+		 */
+		logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
+		ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
+		if (logical_apicid != BAD_APICID)
+			WARN_ON(logical_apicid != ldr_apicid);
+		/* Always use the value from LDR. */
+		early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
+	}
+#endif
+
+	/*
+	 * Set Task Priority to 'accept all except vectors 0-31'.  An APIC
+	 * vector in the 16-31 range could be delivered if TPR == 0, but we
+	 * would think it's an exception and terrible things will happen.  We
+	 * never change this later on.
+	 */
+	value = apic_read(APIC_TASKPRI);
+	value &= ~APIC_TPRI_MASK;
+	value |= 0x10;
+	apic_write(APIC_TASKPRI, value);
+
+	/* Clear eventually stale ISR/IRR bits */
+	apic_pending_intr_clear();
+
+	/*
+	 * Now that we are all set up, enable the APIC
+	 */
+	value = apic_read(APIC_SPIV);
+	value &= ~APIC_VECTOR_MASK;
+	/*
+	 * Enable APIC
+	 */
+	value |= APIC_SPIV_APIC_ENABLED;
+
+#ifdef CONFIG_X86_32
+	/*
+	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
+	 * certain networking cards. If high frequency interrupts are
+	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
+	 * entry is masked/unmasked at a high rate as well then sooner or
+	 * later IOAPIC line gets 'stuck', no more interrupts are received
+	 * from the device. If focus CPU is disabled then the hang goes
+	 * away, oh well :-(
+	 *
+	 * [ This bug can be reproduced easily with a level-triggered
+	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
+	 *   BX chipset. ]
+	 */
+	/*
+	 * Actually disabling the focus CPU check just makes the hang less
+	 * frequent as it makes the interrupt distribution model be more
+	 * like LRU than MRU (the short-term load is more even across CPUs).
+	 */
+
+	/*
+	 * - enable focus processor (bit==0)
+	 * - 64bit mode always use processor focus
+	 *   so no need to set it
+	 */
+	value &= ~APIC_SPIV_FOCUS_DISABLED;
+#endif
+
+	/*
+	 * Set spurious IRQ vector
+	 */
+	value |= SPURIOUS_APIC_VECTOR;
+	apic_write(APIC_SPIV, value);
+
+	perf_events_lapic_init();
+
+	/*
+	 * Set up LVT0, LVT1:
+	 *
+	 * set up through-local-APIC on the boot CPU's LINT0. This is not
+	 * strictly necessary in pure symmetric-IO mode, but sometimes
+	 * we delegate interrupts to the 8259A.
+	 */
+	/*
+	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
+	 */
+	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
+	if (!cpu && (pic_mode || !value || skip_ioapic_setup)) {
+		value = APIC_DM_EXTINT;
+		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
+	} else {
+		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
+		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
+	}
+	apic_write(APIC_LVT0, value);
+
+	/*
+	 * Only the BSP sees the LINT1 NMI signal by default. This can be
+	 * modified by apic_extnmi= boot option.
+	 */
+	if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) ||
+	    apic_extnmi == APIC_EXTNMI_ALL)
+		value = APIC_DM_NMI;
+	else
+		value = APIC_DM_NMI | APIC_LVT_MASKED;
+
+	/* Is 82489DX ? */
+	if (!lapic_is_integrated())
+		value |= APIC_LVT_LEVEL_TRIGGER;
+	apic_write(APIC_LVT1, value);
+
+#ifdef CONFIG_X86_MCE_INTEL
+	/* Recheck CMCI information after local APIC is up on CPU #0 */
+	if (!cpu)
+		cmci_recheck();
+#endif
+}
+
+static void end_local_APIC_setup(void)
+{
+	lapic_setup_esr();
+
+#ifdef CONFIG_X86_32
+	{
+		unsigned int value;
+		/* Disable the local apic timer */
+		value = apic_read(APIC_LVTT);
+		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
+		apic_write(APIC_LVTT, value);
+	}
+#endif
+
+	apic_pm_activate();
+}
+
+/*
+ * APIC setup function for application processors. Called from smpboot.c
+ */
+void apic_ap_setup(void)
+{
+	setup_local_APIC();
+	end_local_APIC_setup();
+}
+
+#ifdef CONFIG_X86_X2APIC
+int x2apic_mode;
+EXPORT_SYMBOL_GPL(x2apic_mode);
+
+enum {
+	X2APIC_OFF,
+	X2APIC_DISABLED,
+	/* All states below here have X2APIC enabled */
+	X2APIC_ON,
+	X2APIC_ON_LOCKED
+};
+static int x2apic_state;
+
+static bool x2apic_hw_locked(void)
+{
+	u64 ia32_cap;
+	u64 msr;
+
+	ia32_cap = x86_read_arch_cap_msr();
+	if (ia32_cap & ARCH_CAP_XAPIC_DISABLE) {
+		rdmsrl(MSR_IA32_XAPIC_DISABLE_STATUS, msr);
+		return (msr & LEGACY_XAPIC_DISABLED);
+	}
+	return false;
+}
+
+static void __x2apic_disable(void)
+{
+	u64 msr;
+
+	if (!boot_cpu_has(X86_FEATURE_APIC))
+		return;
+
+	rdmsrl(MSR_IA32_APICBASE, msr);
+	if (!(msr & X2APIC_ENABLE))
+		return;
+	/* Disable xapic and x2apic first and then reenable xapic mode */
+	wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
+	wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
+	printk_once(KERN_INFO "x2apic disabled\n");
+}
+
+static void __x2apic_enable(void)
+{
+	u64 msr;
+
+	rdmsrl(MSR_IA32_APICBASE, msr);
+	if (msr & X2APIC_ENABLE)
+		return;
+	wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
+	printk_once(KERN_INFO "x2apic enabled\n");
+}
+
+static int __init setup_nox2apic(char *str)
+{
+	if (x2apic_enabled()) {
+		int apicid = native_apic_msr_read(APIC_ID);
+
+		if (apicid >= 255) {
+			pr_warn("Apicid: %08x, cannot enforce nox2apic\n",
+				apicid);
+			return 0;
+		}
+		if (x2apic_hw_locked()) {
+			pr_warn("APIC locked in x2apic mode, can't disable\n");
+			return 0;
+		}
+		pr_warn("x2apic already enabled.\n");
+		__x2apic_disable();
+	}
+	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
+	x2apic_state = X2APIC_DISABLED;
+	x2apic_mode = 0;
+	return 0;
+}
+early_param("nox2apic", setup_nox2apic);
+
+/* Called from cpu_init() to enable x2apic on (secondary) cpus */
+void x2apic_setup(void)
+{
+	/*
+	 * Try to make the AP's APIC state match that of the BSP,  but if the
+	 * BSP is unlocked and the AP is locked then there is a state mismatch.
+	 * Warn about the mismatch in case a GP fault occurs due to a locked AP
+	 * trying to be turned off.
+	 */
+	if (x2apic_state != X2APIC_ON_LOCKED && x2apic_hw_locked())
+		pr_warn("x2apic lock mismatch between BSP and AP.\n");
+	/*
+	 * If x2apic is not in ON or LOCKED state, disable it if already enabled
+	 * from BIOS.
+	 */
+	if (x2apic_state < X2APIC_ON) {
+		__x2apic_disable();
+		return;
+	}
+	__x2apic_enable();
+}
+
+static __init void x2apic_disable(void)
+{
+	u32 x2apic_id, state = x2apic_state;
+
+	x2apic_mode = 0;
+	x2apic_state = X2APIC_DISABLED;
+
+	if (state != X2APIC_ON)
+		return;
+
+	x2apic_id = read_apic_id();
+	if (x2apic_id >= 255)
+		panic("Cannot disable x2apic, id: %08x\n", x2apic_id);
+
+	if (x2apic_hw_locked()) {
+		pr_warn("Cannot disable locked x2apic, id: %08x\n", x2apic_id);
+		return;
+	}
+
+	__x2apic_disable();
+	register_lapic_address(mp_lapic_addr);
+}
+
+static __init void x2apic_enable(void)
+{
+	if (x2apic_state != X2APIC_OFF)
+		return;
+
+	x2apic_mode = 1;
+	x2apic_state = X2APIC_ON;
+	__x2apic_enable();
+}
+
+static __init void try_to_enable_x2apic(int remap_mode)
+{
+	if (x2apic_state == X2APIC_DISABLED)
+		return;
+
+	if (remap_mode != IRQ_REMAP_X2APIC_MODE) {
+		u32 apic_limit = 255;
+
+		/*
+		 * Using X2APIC without IR is not architecturally supported
+		 * on bare metal but may be supported in guests.
+		 */
+		if (!x86_init.hyper.x2apic_available()) {
+			pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
+			x2apic_disable();
+			return;
+		}
+
+		/*
+		 * If the hypervisor supports extended destination ID in
+		 * MSI, that increases the maximum APIC ID that can be
+		 * used for non-remapped IRQ domains.
+		 */
+		if (x86_init.hyper.msi_ext_dest_id()) {
+			virt_ext_dest_id = 1;
+			apic_limit = 32767;
+		}
+
+		/*
+		 * Without IR, all CPUs can be addressed by IOAPIC/MSI only
+		 * in physical mode, and CPUs with an APIC ID that cannot
+		 * be addressed must not be brought online.
+		 */
+		x2apic_set_max_apicid(apic_limit);
+		x2apic_phys = 1;
+	}
+	x2apic_enable();
+}
+
+void __init check_x2apic(void)
+{
+	if (x2apic_enabled()) {
+		pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n");
+		x2apic_mode = 1;
+		if (x2apic_hw_locked())
+			x2apic_state = X2APIC_ON_LOCKED;
+		else
+			x2apic_state = X2APIC_ON;
+	} else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
+		x2apic_state = X2APIC_DISABLED;
+	}
+}
+#else /* CONFIG_X86_X2APIC */
+void __init check_x2apic(void)
+{
+	if (!apic_is_x2apic_enabled())
+		return;
+	/*
+	 * Checkme: Can we simply turn off x2APIC here instead of disabling the APIC?
+	 */
+	pr_err("Kernel does not support x2APIC, please recompile with CONFIG_X86_X2APIC.\n");
+	pr_err("Disabling APIC, expect reduced performance and functionality.\n");
+
+	disable_apic = 1;
+	setup_clear_cpu_cap(X86_FEATURE_APIC);
+}
+
+static inline void try_to_enable_x2apic(int remap_mode) { }
+static inline void __x2apic_enable(void) { }
+#endif /* !CONFIG_X86_X2APIC */
+
+void __init enable_IR_x2apic(void)
+{
+	unsigned long flags;
+	int ret, ir_stat;
+
+	if (skip_ioapic_setup) {
+		pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
+		return;
+	}
+
+	ir_stat = irq_remapping_prepare();
+	if (ir_stat < 0 && !x2apic_supported())
+		return;
+
+	ret = save_ioapic_entries();
+	if (ret) {
+		pr_info("Saving IO-APIC state failed: %d\n", ret);
+		return;
+	}
+
+	local_irq_save(flags);
+	legacy_pic->mask_all();
+	mask_ioapic_entries();
+
+	/* If irq_remapping_prepare() succeeded, try to enable it */
+	if (ir_stat >= 0)
+		ir_stat = irq_remapping_enable();
+	/* ir_stat contains the remap mode or an error code */
+	try_to_enable_x2apic(ir_stat);
+
+	if (ir_stat < 0)
+		restore_ioapic_entries();
+	legacy_pic->restore_mask();
+	local_irq_restore(flags);
+}
+
+#ifdef CONFIG_X86_64
+/*
+ * Detect and enable local APICs on non-SMP boards.
+ * Original code written by Keir Fraser.
+ * On AMD64 we trust the BIOS - if it says no APIC it is likely
+ * not correctly set up (usually the APIC timer won't work etc.)
+ */
+static int __init detect_init_APIC(void)
+{
+	if (!boot_cpu_has(X86_FEATURE_APIC)) {
+		pr_info("No local APIC present\n");
+		return -1;
+	}
+
+	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
+	return 0;
+}
+#else
+
+static int __init apic_verify(void)
+{
+	u32 features, h, l;
+
+	/*
+	 * The APIC feature bit should now be enabled
+	 * in `cpuid'
+	 */
+	features = cpuid_edx(1);
+	if (!(features & (1 << X86_FEATURE_APIC))) {
+		pr_warn("Could not enable APIC!\n");
+		return -1;
+	}
+	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
+	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
+
+	/* The BIOS may have set up the APIC at some other address */
+	if (boot_cpu_data.x86 >= 6) {
+		rdmsr(MSR_IA32_APICBASE, l, h);
+		if (l & MSR_IA32_APICBASE_ENABLE)
+			mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
+	}
+
+	pr_info("Found and enabled local APIC!\n");
+	return 0;
+}
+
+int __init apic_force_enable(unsigned long addr)
+{
+	u32 h, l;
+
+	if (disable_apic)
+		return -1;
+
+	/*
+	 * Some BIOSes disable the local APIC in the APIC_BASE
+	 * MSR. This can only be done in software for Intel P6 or later
+	 * and AMD K7 (Model > 1) or later.
+	 */
+	if (boot_cpu_data.x86 >= 6) {
+		rdmsr(MSR_IA32_APICBASE, l, h);
+		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
+			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
+			l &= ~MSR_IA32_APICBASE_BASE;
+			l |= MSR_IA32_APICBASE_ENABLE | addr;
+			wrmsr(MSR_IA32_APICBASE, l, h);
+			enabled_via_apicbase = 1;
+		}
+	}
+	return apic_verify();
+}
+
+/*
+ * Detect and initialize APIC
+ */
+static int __init detect_init_APIC(void)
+{
+	/* Disabled by kernel option? */
+	if (disable_apic)
+		return -1;
+
+	switch (boot_cpu_data.x86_vendor) {
+	case X86_VENDOR_AMD:
+		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
+		    (boot_cpu_data.x86 >= 15))
+			break;
+		goto no_apic;
+	case X86_VENDOR_HYGON:
+		break;
+	case X86_VENDOR_INTEL:
+		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
+		    (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
+			break;
+		goto no_apic;
+	default:
+		goto no_apic;
+	}
+
+	if (!boot_cpu_has(X86_FEATURE_APIC)) {
+		/*
+		 * Over-ride BIOS and try to enable the local APIC only if
+		 * "lapic" specified.
+		 */
+		if (!force_enable_local_apic) {
+			pr_info("Local APIC disabled by BIOS -- "
+				"you can enable it with \"lapic\"\n");
+			return -1;
+		}
+		if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
+			return -1;
+	} else {
+		if (apic_verify())
+			return -1;
+	}
+
+	apic_pm_activate();
+
+	return 0;
+
+no_apic:
+	pr_info("No local APIC present or hardware disabled\n");
+	return -1;
+}
+#endif
+
+/**
+ * init_apic_mappings - initialize APIC mappings
+ */
+void __init init_apic_mappings(void)
+{
+	unsigned int new_apicid;
+
+	if (apic_validate_deadline_timer())
+		pr_info("TSC deadline timer available\n");
+
+	if (x2apic_mode) {
+		boot_cpu_physical_apicid = read_apic_id();
+		return;
+	}
+
+	/* If no local APIC can be found return early */
+	if (!smp_found_config && detect_init_APIC()) {
+		/* lets NOP'ify apic operations */
+		pr_info("APIC: disable apic facility\n");
+		apic_disable();
+	} else {
+		apic_phys = mp_lapic_addr;
+
+		/*
+		 * If the system has ACPI MADT tables or MP info, the LAPIC
+		 * address is already registered.
+		 */
+		if (!acpi_lapic && !smp_found_config)
+			register_lapic_address(apic_phys);
+	}
+
+	/*
+	 * Fetch the APIC ID of the BSP in case we have a
+	 * default configuration (or the MP table is broken).
+	 */
+	new_apicid = read_apic_id();
+	if (boot_cpu_physical_apicid != new_apicid) {
+		boot_cpu_physical_apicid = new_apicid;
+		/*
+		 * yeah -- we lie about apic_version
+		 * in case if apic was disabled via boot option
+		 * but it's not a problem for SMP compiled kernel
+		 * since apic_intr_mode_select is prepared for such
+		 * a case and disable smp mode
+		 */
+		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
+	}
+}
+
+void __init register_lapic_address(unsigned long address)
+{
+	mp_lapic_addr = address;
+
+	if (!x2apic_mode) {
+		set_fixmap_nocache(FIX_APIC_BASE, address);
+		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
+			    APIC_BASE, address);
+	}
+	if (boot_cpu_physical_apicid == -1U) {
+		boot_cpu_physical_apicid  = read_apic_id();
+		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
+	}
+}
+
+/*
+ * Local APIC interrupts
+ */
+
+/*
+ * Common handling code for spurious_interrupt and spurious_vector entry
+ * points below. No point in allowing the compiler to inline it twice.
+ */
+static noinline void handle_spurious_interrupt(u8 vector)
+{
+	u32 v;
+
+	trace_spurious_apic_entry(vector);
+
+	inc_irq_stat(irq_spurious_count);
+
+	/*
+	 * If this is a spurious interrupt then do not acknowledge
+	 */
+	if (vector == SPURIOUS_APIC_VECTOR) {
+		/* See SDM vol 3 */
+		pr_info("Spurious APIC interrupt (vector 0xFF) on CPU#%d, should never happen.\n",
+			smp_processor_id());
+		goto out;
+	}
+
+	/*
+	 * If it is a vectored one, verify it's set in the ISR. If set,
+	 * acknowledge it.
+	 */
+	v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
+	if (v & (1 << (vector & 0x1f))) {
+		pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Acked\n",
+			vector, smp_processor_id());
+		ack_APIC_irq();
+	} else {
+		pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Not pending!\n",
+			vector, smp_processor_id());
+	}
+out:
+	trace_spurious_apic_exit(vector);
+}
+
+/**
+ * spurious_interrupt - Catch all for interrupts raised on unused vectors
+ * @regs:	Pointer to pt_regs on stack
+ * @vector:	The vector number
+ *
+ * This is invoked from ASM entry code to catch all interrupts which
+ * trigger on an entry which is routed to the common_spurious idtentry
+ * point.
+ */
+DEFINE_IDTENTRY_IRQ(spurious_interrupt)
+{
+	handle_spurious_interrupt(vector);
+}
+
+DEFINE_IDTENTRY_SYSVEC(sysvec_spurious_apic_interrupt)
+{
+	handle_spurious_interrupt(SPURIOUS_APIC_VECTOR);
+}
+
+/*
+ * This interrupt should never happen with our APIC/SMP architecture
+ */
+DEFINE_IDTENTRY_SYSVEC(sysvec_error_interrupt)
+{
+	static const char * const error_interrupt_reason[] = {
+		"Send CS error",		/* APIC Error Bit 0 */
+		"Receive CS error",		/* APIC Error Bit 1 */
+		"Send accept error",		/* APIC Error Bit 2 */
+		"Receive accept error",		/* APIC Error Bit 3 */
+		"Redirectable IPI",		/* APIC Error Bit 4 */
+		"Send illegal vector",		/* APIC Error Bit 5 */
+		"Received illegal vector",	/* APIC Error Bit 6 */
+		"Illegal register address",	/* APIC Error Bit 7 */
+	};
+	u32 v, i = 0;
+
+	trace_error_apic_entry(ERROR_APIC_VECTOR);
+
+	/* First tickle the hardware, only then report what went on. -- REW */
+	if (lapic_get_maxlvt() > 3)	/* Due to the Pentium erratum 3AP. */
+		apic_write(APIC_ESR, 0);
+	v = apic_read(APIC_ESR);
+	ack_APIC_irq();
+	atomic_inc(&irq_err_count);
+
+	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x",
+		    smp_processor_id(), v);
+
+	v &= 0xff;
+	while (v) {
+		if (v & 0x1)
+			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
+		i++;
+		v >>= 1;
+	}
+
+	apic_printk(APIC_DEBUG, KERN_CONT "\n");
+
+	trace_error_apic_exit(ERROR_APIC_VECTOR);
+}
+
+/**
+ * connect_bsp_APIC - attach the APIC to the interrupt system
+ */
+static void __init connect_bsp_APIC(void)
+{
+#ifdef CONFIG_X86_32
+	if (pic_mode) {
+		/*
+		 * Do not trust the local APIC being empty at bootup.
+		 */
+		clear_local_APIC();
+		/*
+		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
+		 * local APIC to INT and NMI lines.
+		 */
+		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
+				"enabling APIC mode.\n");
+		imcr_pic_to_apic();
+	}
+#endif
+}
+
+/**
+ * disconnect_bsp_APIC - detach the APIC from the interrupt system
+ * @virt_wire_setup:	indicates, whether virtual wire mode is selected
+ *
+ * Virtual wire mode is necessary to deliver legacy interrupts even when the
+ * APIC is disabled.
+ */
+void disconnect_bsp_APIC(int virt_wire_setup)
+{
+	unsigned int value;
+
+#ifdef CONFIG_X86_32
+	if (pic_mode) {
+		/*
+		 * Put the board back into PIC mode (has an effect only on
+		 * certain older boards).  Note that APIC interrupts, including
+		 * IPIs, won't work beyond this point!  The only exception are
+		 * INIT IPIs.
+		 */
+		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
+				"entering PIC mode.\n");
+		imcr_apic_to_pic();
+		return;
+	}
+#endif
+
+	/* Go back to Virtual Wire compatibility mode */
+
+	/* For the spurious interrupt use vector F, and enable it */
+	value = apic_read(APIC_SPIV);
+	value &= ~APIC_VECTOR_MASK;
+	value |= APIC_SPIV_APIC_ENABLED;
+	value |= 0xf;
+	apic_write(APIC_SPIV, value);
+
+	if (!virt_wire_setup) {
+		/*
+		 * For LVT0 make it edge triggered, active high,
+		 * external and enabled
+		 */
+		value = apic_read(APIC_LVT0);
+		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
+			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
+			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
+		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
+		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
+		apic_write(APIC_LVT0, value);
+	} else {
+		/* Disable LVT0 */
+		apic_write(APIC_LVT0, APIC_LVT_MASKED);
+	}
+
+	/*
+	 * For LVT1 make it edge triggered, active high,
+	 * nmi and enabled
+	 */
+	value = apic_read(APIC_LVT1);
+	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
+			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
+			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
+	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
+	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
+	apic_write(APIC_LVT1, value);
+}
+
+/*
+ * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
+ * contiguously, it equals to current allocated max logical CPU ID plus 1.
+ * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
+ * so the maximum of nr_logical_cpuids is nr_cpu_ids.
+ *
+ * NOTE: Reserve 0 for BSP.
+ */
+static int nr_logical_cpuids = 1;
+
+/*
+ * Used to store mapping between logical CPU IDs and APIC IDs.
+ */
+static int cpuid_to_apicid[] = {
+	[0 ... NR_CPUS - 1] = -1,
+};
+
+bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return phys_id == cpuid_to_apicid[cpu];
+}
+
+#ifdef CONFIG_SMP
+/**
+ * apic_id_is_primary_thread - Check whether APIC ID belongs to a primary thread
+ * @apicid: APIC ID to check
+ */
+bool apic_id_is_primary_thread(unsigned int apicid)
+{
+	u32 mask;
+
+	if (smp_num_siblings == 1)
+		return true;
+	/* Isolate the SMT bit(s) in the APICID and check for 0 */
+	mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
+	return !(apicid & mask);
+}
+#endif
+
+/*
+ * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
+ * and cpuid_to_apicid[] synchronized.
+ */
+static int allocate_logical_cpuid(int apicid)
+{
+	int i;
+
+	/*
+	 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
+	 * check if the kernel has allocated a cpuid for it.
+	 */
+	for (i = 0; i < nr_logical_cpuids; i++) {
+		if (cpuid_to_apicid[i] == apicid)
+			return i;
+	}
+
+	/* Allocate a new cpuid. */
+	if (nr_logical_cpuids >= nr_cpu_ids) {
+		WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
+			     "Processor %d/0x%x and the rest are ignored.\n",
+			     nr_cpu_ids, nr_logical_cpuids, apicid);
+		return -EINVAL;
+	}
+
+	cpuid_to_apicid[nr_logical_cpuids] = apicid;
+	return nr_logical_cpuids++;
+}
+
+int generic_processor_info(int apicid, int version)
+{
+	int cpu, max = nr_cpu_ids;
+	bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
+				phys_cpu_present_map);
+
+	/*
+	 * boot_cpu_physical_apicid is designed to have the apicid
+	 * returned by read_apic_id(), i.e, the apicid of the
+	 * currently booting-up processor. However, on some platforms,
+	 * it is temporarily modified by the apicid reported as BSP
+	 * through MP table. Concretely:
+	 *
+	 * - arch/x86/kernel/mpparse.c: MP_processor_info()
+	 * - arch/x86/mm/amdtopology.c: amd_numa_init()
+	 *
+	 * This function is executed with the modified
+	 * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel
+	 * parameter doesn't work to disable APs on kdump 2nd kernel.
+	 *
+	 * Since fixing handling of boot_cpu_physical_apicid requires
+	 * another discussion and tests on each platform, we leave it
+	 * for now and here we use read_apic_id() directly in this
+	 * function, generic_processor_info().
+	 */
+	if (disabled_cpu_apicid != BAD_APICID &&
+	    disabled_cpu_apicid != read_apic_id() &&
+	    disabled_cpu_apicid == apicid) {
+		int thiscpu = num_processors + disabled_cpus;
+
+		pr_warn("APIC: Disabling requested cpu."
+			" Processor %d/0x%x ignored.\n", thiscpu, apicid);
+
+		disabled_cpus++;
+		return -ENODEV;
+	}
+
+	/*
+	 * If boot cpu has not been detected yet, then only allow upto
+	 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
+	 */
+	if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
+	    apicid != boot_cpu_physical_apicid) {
+		int thiscpu = max + disabled_cpus - 1;
+
+		pr_warn("APIC: NR_CPUS/possible_cpus limit of %i almost"
+			" reached. Keeping one slot for boot cpu."
+			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
+
+		disabled_cpus++;
+		return -ENODEV;
+	}
+
+	if (num_processors >= nr_cpu_ids) {
+		int thiscpu = max + disabled_cpus;
+
+		pr_warn("APIC: NR_CPUS/possible_cpus limit of %i reached. "
+			"Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
+
+		disabled_cpus++;
+		return -EINVAL;
+	}
+
+	if (apicid == boot_cpu_physical_apicid) {
+		/*
+		 * x86_bios_cpu_apicid is required to have processors listed
+		 * in same order as logical cpu numbers. Hence the first
+		 * entry is BSP, and so on.
+		 * boot_cpu_init() already hold bit 0 in cpu_present_mask
+		 * for BSP.
+		 */
+		cpu = 0;
+
+		/* Logical cpuid 0 is reserved for BSP. */
+		cpuid_to_apicid[0] = apicid;
+	} else {
+		cpu = allocate_logical_cpuid(apicid);
+		if (cpu < 0) {
+			disabled_cpus++;
+			return -EINVAL;
+		}
+	}
+
+	/*
+	 * Validate version
+	 */
+	if (version == 0x0) {
+		pr_warn("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
+			cpu, apicid);
+		version = 0x10;
+	}
+
+	if (version != boot_cpu_apic_version) {
+		pr_warn("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
+			boot_cpu_apic_version, cpu, version);
+	}
+
+	if (apicid > max_physical_apicid)
+		max_physical_apicid = apicid;
+
+#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
+	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
+	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
+#endif
+#ifdef CONFIG_X86_32
+	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
+		apic->x86_32_early_logical_apicid(cpu);
+#endif
+	set_cpu_possible(cpu, true);
+	physid_set(apicid, phys_cpu_present_map);
+	set_cpu_present(cpu, true);
+	num_processors++;
+
+	return cpu;
+}
+
+int hard_smp_processor_id(void)
+{
+	return read_apic_id();
+}
+
+void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg,
+			   bool dmar)
+{
+	memset(msg, 0, sizeof(*msg));
+
+	msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
+	msg->arch_addr_lo.dest_mode_logical = apic->dest_mode_logical;
+	msg->arch_addr_lo.destid_0_7 = cfg->dest_apicid & 0xFF;
+
+	msg->arch_data.delivery_mode = APIC_DELIVERY_MODE_FIXED;
+	msg->arch_data.vector = cfg->vector;
+
+	msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
+	/*
+	 * Only the IOMMU itself can use the trick of putting destination
+	 * APIC ID into the high bits of the address. Anything else would
+	 * just be writing to memory if it tried that, and needs IR to
+	 * address APICs which can't be addressed in the normal 32-bit
+	 * address range at 0xFFExxxxx. That is typically just 8 bits, but
+	 * some hypervisors allow the extended destination ID field in bits
+	 * 5-11 to be used, giving support for 15 bits of APIC IDs in total.
+	 */
+	if (dmar)
+		msg->arch_addr_hi.destid_8_31 = cfg->dest_apicid >> 8;
+	else if (virt_ext_dest_id && cfg->dest_apicid < 0x8000)
+		msg->arch_addr_lo.virt_destid_8_14 = cfg->dest_apicid >> 8;
+	else
+		WARN_ON_ONCE(cfg->dest_apicid > 0xFF);
+}
+
+u32 x86_msi_msg_get_destid(struct msi_msg *msg, bool extid)
+{
+	u32 dest = msg->arch_addr_lo.destid_0_7;
+
+	if (extid)
+		dest |= msg->arch_addr_hi.destid_8_31 << 8;
+	return dest;
+}
+EXPORT_SYMBOL_GPL(x86_msi_msg_get_destid);
+
+#ifdef CONFIG_X86_64
+void __init acpi_wake_cpu_handler_update(wakeup_cpu_handler handler)
+{
+	struct apic **drv;
+
+	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++)
+		(*drv)->wakeup_secondary_cpu_64 = handler;
+}
+#endif
+
+/*
+ * Override the generic EOI implementation with an optimized version.
+ * Only called during early boot when only one CPU is active and with
+ * interrupts disabled, so we know this does not race with actual APIC driver
+ * use.
+ */
+void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
+{
+	struct apic **drv;
+
+	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+		/* Should happen once for each apic */
+		WARN_ON((*drv)->eoi_write == eoi_write);
+		(*drv)->native_eoi_write = (*drv)->eoi_write;
+		(*drv)->eoi_write = eoi_write;
+	}
+}
+
+static void __init apic_bsp_up_setup(void)
+{
+#ifdef CONFIG_X86_64
+	apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
+#else
+	/*
+	 * Hack: In case of kdump, after a crash, kernel might be booting
+	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
+	 * might be zero if read from MP tables. Get it from LAPIC.
+	 */
+# ifdef CONFIG_CRASH_DUMP
+	boot_cpu_physical_apicid = read_apic_id();
+# endif
+#endif
+	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
+}
+
+/**
+ * apic_bsp_setup - Setup function for local apic and io-apic
+ * @upmode:		Force UP mode (for APIC_init_uniprocessor)
+ */
+static void __init apic_bsp_setup(bool upmode)
+{
+	connect_bsp_APIC();
+	if (upmode)
+		apic_bsp_up_setup();
+	setup_local_APIC();
+
+	enable_IO_APIC();
+	end_local_APIC_setup();
+	irq_remap_enable_fault_handling();
+	setup_IO_APIC();
+	lapic_update_legacy_vectors();
+}
+
+#ifdef CONFIG_UP_LATE_INIT
+void __init up_late_init(void)
+{
+	if (apic_intr_mode == APIC_PIC)
+		return;
+
+	/* Setup local timer */
+	x86_init.timers.setup_percpu_clockev();
+}
+#endif
+
+/*
+ * Power management
+ */
+#ifdef CONFIG_PM
+
+static struct {
+	/*
+	 * 'active' is true if the local APIC was enabled by us and
+	 * not the BIOS; this signifies that we are also responsible
+	 * for disabling it before entering apm/acpi suspend
+	 */
+	int active;
+	/* r/w apic fields */
+	unsigned int apic_id;
+	unsigned int apic_taskpri;
+	unsigned int apic_ldr;
+	unsigned int apic_dfr;
+	unsigned int apic_spiv;
+	unsigned int apic_lvtt;
+	unsigned int apic_lvtpc;
+	unsigned int apic_lvt0;
+	unsigned int apic_lvt1;
+	unsigned int apic_lvterr;
+	unsigned int apic_tmict;
+	unsigned int apic_tdcr;
+	unsigned int apic_thmr;
+	unsigned int apic_cmci;
+} apic_pm_state;
+
+static int lapic_suspend(void)
+{
+	unsigned long flags;
+	int maxlvt;
+
+	if (!apic_pm_state.active)
+		return 0;
+
+	maxlvt = lapic_get_maxlvt();
+
+	apic_pm_state.apic_id = apic_read(APIC_ID);
+	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
+	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
+	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
+	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
+	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
+	if (maxlvt >= 4)
+		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
+	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
+	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
+	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
+	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
+	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
+#ifdef CONFIG_X86_THERMAL_VECTOR
+	if (maxlvt >= 5)
+		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
+#endif
+#ifdef CONFIG_X86_MCE_INTEL
+	if (maxlvt >= 6)
+		apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI);
+#endif
+
+	local_irq_save(flags);
+
+	/*
+	 * Mask IOAPIC before disabling the local APIC to prevent stale IRR
+	 * entries on some implementations.
+	 */
+	mask_ioapic_entries();
+
+	disable_local_APIC();
+
+	irq_remapping_disable();
+
+	local_irq_restore(flags);
+	return 0;
+}
+
+static void lapic_resume(void)
+{
+	unsigned int l, h;
+	unsigned long flags;
+	int maxlvt;
+
+	if (!apic_pm_state.active)
+		return;
+
+	local_irq_save(flags);
+
+	/*
+	 * IO-APIC and PIC have their own resume routines.
+	 * We just mask them here to make sure the interrupt
+	 * subsystem is completely quiet while we enable x2apic
+	 * and interrupt-remapping.
+	 */
+	mask_ioapic_entries();
+	legacy_pic->mask_all();
+
+	if (x2apic_mode) {
+		__x2apic_enable();
+	} else {
+		/*
+		 * Make sure the APICBASE points to the right address
+		 *
+		 * FIXME! This will be wrong if we ever support suspend on
+		 * SMP! We'll need to do this as part of the CPU restore!
+		 */
+		if (boot_cpu_data.x86 >= 6) {
+			rdmsr(MSR_IA32_APICBASE, l, h);
+			l &= ~MSR_IA32_APICBASE_BASE;
+			l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
+			wrmsr(MSR_IA32_APICBASE, l, h);
+		}
+	}
+
+	maxlvt = lapic_get_maxlvt();
+	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
+	apic_write(APIC_ID, apic_pm_state.apic_id);
+	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
+	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
+	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
+	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
+	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
+	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
+#ifdef CONFIG_X86_THERMAL_VECTOR
+	if (maxlvt >= 5)
+		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
+#endif
+#ifdef CONFIG_X86_MCE_INTEL
+	if (maxlvt >= 6)
+		apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci);
+#endif
+	if (maxlvt >= 4)
+		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
+	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
+	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
+	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
+	apic_write(APIC_ESR, 0);
+	apic_read(APIC_ESR);
+	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
+	apic_write(APIC_ESR, 0);
+	apic_read(APIC_ESR);
+
+	irq_remapping_reenable(x2apic_mode);
+
+	local_irq_restore(flags);
+}
+
+/*
+ * This device has no shutdown method - fully functioning local APICs
+ * are needed on every CPU up until machine_halt/restart/poweroff.
+ */
+
+static struct syscore_ops lapic_syscore_ops = {
+	.resume		= lapic_resume,
+	.suspend	= lapic_suspend,
+};
+
+static void apic_pm_activate(void)
+{
+	apic_pm_state.active = 1;
+}
+
+static int __init init_lapic_sysfs(void)
+{
+	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
+	if (boot_cpu_has(X86_FEATURE_APIC))
+		register_syscore_ops(&lapic_syscore_ops);
+
+	return 0;
+}
+
+/* local apic needs to resume before other devices access its registers. */
+core_initcall(init_lapic_sysfs);
+
+#else	/* CONFIG_PM */
+
+static void apic_pm_activate(void) { }
+
+#endif	/* CONFIG_PM */
+
+#ifdef CONFIG_X86_64
+
+static int multi_checked;
+static int multi;
+
+static int set_multi(const struct dmi_system_id *d)
+{
+	if (multi)
+		return 0;
+	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
+	multi = 1;
+	return 0;
+}
+
+static const struct dmi_system_id multi_dmi_table[] = {
+	{
+		.callback = set_multi,
+		.ident = "IBM System Summit2",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
+		},
+	},
+	{}
+};
+
+static void dmi_check_multi(void)
+{
+	if (multi_checked)
+		return;
+
+	dmi_check_system(multi_dmi_table);
+	multi_checked = 1;
+}
+
+/*
+ * apic_is_clustered_box() -- Check if we can expect good TSC
+ *
+ * Thus far, the major user of this is IBM's Summit2 series:
+ * Clustered boxes may have unsynced TSC problems if they are
+ * multi-chassis.
+ * Use DMI to check them
+ */
+int apic_is_clustered_box(void)
+{
+	dmi_check_multi();
+	return multi;
+}
+#endif
+
+/*
+ * APIC command line parameters
+ */
+static int __init setup_disableapic(char *arg)
+{
+	disable_apic = 1;
+	setup_clear_cpu_cap(X86_FEATURE_APIC);
+	return 0;
+}
+early_param("disableapic", setup_disableapic);
+
+/* same as disableapic, for compatibility */
+static int __init setup_nolapic(char *arg)
+{
+	return setup_disableapic(arg);
+}
+early_param("nolapic", setup_nolapic);
+
+static int __init parse_lapic_timer_c2_ok(char *arg)
+{
+	local_apic_timer_c2_ok = 1;
+	return 0;
+}
+early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
+
+static int __init parse_disable_apic_timer(char *arg)
+{
+	disable_apic_timer = 1;
+	return 0;
+}
+early_param("noapictimer", parse_disable_apic_timer);
+
+static int __init parse_nolapic_timer(char *arg)
+{
+	disable_apic_timer = 1;
+	return 0;
+}
+early_param("nolapic_timer", parse_nolapic_timer);
+
+static int __init apic_set_verbosity(char *arg)
+{
+	if (!arg)  {
+#ifdef CONFIG_X86_64
+		skip_ioapic_setup = 0;
+		return 0;
+#endif
+		return -EINVAL;
+	}
+
+	if (strcmp("debug", arg) == 0)
+		apic_verbosity = APIC_DEBUG;
+	else if (strcmp("verbose", arg) == 0)
+		apic_verbosity = APIC_VERBOSE;
+#ifdef CONFIG_X86_64
+	else {
+		pr_warn("APIC Verbosity level %s not recognised"
+			" use apic=verbose or apic=debug\n", arg);
+		return -EINVAL;
+	}
+#endif
+
+	return 0;
+}
+early_param("apic", apic_set_verbosity);
+
+static int __init lapic_insert_resource(void)
+{
+	if (!apic_phys)
+		return -1;
+
+	/* Put local APIC into the resource map. */
+	lapic_resource.start = apic_phys;
+	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
+	insert_resource(&iomem_resource, &lapic_resource);
+
+	return 0;
+}
+
+/*
+ * need call insert after e820__reserve_resources()
+ * that is using request_resource
+ */
+late_initcall(lapic_insert_resource);
+
+static int __init apic_set_disabled_cpu_apicid(char *arg)
+{
+	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
+		return -EINVAL;
+
+	return 0;
+}
+early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
+
+static int __init apic_set_extnmi(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+
+	if (!strncmp("all", arg, 3))
+		apic_extnmi = APIC_EXTNMI_ALL;
+	else if (!strncmp("none", arg, 4))
+		apic_extnmi = APIC_EXTNMI_NONE;
+	else if (!strncmp("bsp", arg, 3))
+		apic_extnmi = APIC_EXTNMI_BSP;
+	else {
+		pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+early_param("apic_extnmi", apic_set_extnmi);
diff --git a/arch/x86/kernel/apic/apic_common.c b/arch/x86/kernel/apic/apic_common.c
new file mode 100644
index 000000000..02b483947
--- /dev/null
+++ b/arch/x86/kernel/apic/apic_common.c
@@ -0,0 +1,46 @@
+/*
+ * Common functions shared between the various APIC flavours
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+#include <linux/irq.h>
+#include <asm/apic.h>
+
+u32 apic_default_calc_apicid(unsigned int cpu)
+{
+	return per_cpu(x86_cpu_to_apicid, cpu);
+}
+
+u32 apic_flat_calc_apicid(unsigned int cpu)
+{
+	return 1U << cpu;
+}
+
+bool default_check_apicid_used(physid_mask_t *map, int apicid)
+{
+	return physid_isset(apicid, *map);
+}
+
+void default_ioapic_phys_id_map(physid_mask_t *phys_map, physid_mask_t *retmap)
+{
+	*retmap = *phys_map;
+}
+
+int default_cpu_present_to_apicid(int mps_cpu)
+{
+	if (mps_cpu < nr_cpu_ids && cpu_present(mps_cpu))
+		return (int)per_cpu(x86_bios_cpu_apicid, mps_cpu);
+	else
+		return BAD_APICID;
+}
+EXPORT_SYMBOL_GPL(default_cpu_present_to_apicid);
+
+int default_check_phys_apicid_present(int phys_apicid)
+{
+	return physid_isset(phys_apicid, phys_cpu_present_map);
+}
+
+int default_apic_id_valid(u32 apicid)
+{
+	return (apicid < 255);
+}
diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
new file mode 100644
index 000000000..8f72b4351
--- /dev/null
+++ b/arch/x86/kernel/apic/apic_flat_64.c
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2004 James Cleverdon, IBM.
+ *
+ * Flat APIC subarch code.
+ *
+ * Hacked for x86-64 by James Cleverdon from i386 architecture code by
+ * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
+ * James Cleverdon.
+ */
+#include <linux/cpumask.h>
+#include <linux/export.h>
+#include <linux/acpi.h>
+
+#include <asm/jailhouse_para.h>
+#include <asm/apic.h>
+
+#include "local.h"
+
+static struct apic apic_physflat;
+static struct apic apic_flat;
+
+struct apic *apic __ro_after_init = &apic_flat;
+EXPORT_SYMBOL_GPL(apic);
+
+static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+{
+	return 1;
+}
+
+/*
+ * Set up the logical destination ID.
+ *
+ * Intel recommends to set DFR, LDR and TPR before enabling
+ * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
+ * document number 292116).  So here it goes...
+ */
+void flat_init_apic_ldr(void)
+{
+	unsigned long val;
+	unsigned long num, id;
+
+	num = smp_processor_id();
+	id = 1UL << num;
+	apic_write(APIC_DFR, APIC_DFR_FLAT);
+	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
+	val |= SET_APIC_LOGICAL_ID(id);
+	apic_write(APIC_LDR, val);
+}
+
+static void _flat_send_IPI_mask(unsigned long mask, int vector)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__default_send_IPI_dest_field(mask, vector, APIC_DEST_LOGICAL);
+	local_irq_restore(flags);
+}
+
+static void flat_send_IPI_mask(const struct cpumask *cpumask, int vector)
+{
+	unsigned long mask = cpumask_bits(cpumask)[0];
+
+	_flat_send_IPI_mask(mask, vector);
+}
+
+static void
+flat_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector)
+{
+	unsigned long mask = cpumask_bits(cpumask)[0];
+	int cpu = smp_processor_id();
+
+	if (cpu < BITS_PER_LONG)
+		__clear_bit(cpu, &mask);
+
+	_flat_send_IPI_mask(mask, vector);
+}
+
+static unsigned int flat_get_apic_id(unsigned long x)
+{
+	return (x >> 24) & 0xFF;
+}
+
+static u32 set_apic_id(unsigned int id)
+{
+	return (id & 0xFF) << 24;
+}
+
+static unsigned int read_xapic_id(void)
+{
+	return flat_get_apic_id(apic_read(APIC_ID));
+}
+
+static int flat_apic_id_registered(void)
+{
+	return physid_isset(read_xapic_id(), phys_cpu_present_map);
+}
+
+static int flat_phys_pkg_id(int initial_apic_id, int index_msb)
+{
+	return initial_apic_id >> index_msb;
+}
+
+static int flat_probe(void)
+{
+	return 1;
+}
+
+static struct apic apic_flat __ro_after_init = {
+	.name				= "flat",
+	.probe				= flat_probe,
+	.acpi_madt_oem_check		= flat_acpi_madt_oem_check,
+	.apic_id_valid			= default_apic_id_valid,
+	.apic_id_registered		= flat_apic_id_registered,
+
+	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
+	.dest_mode_logical		= true,
+
+	.disable_esr			= 0,
+
+	.check_apicid_used		= NULL,
+	.init_apic_ldr			= flat_init_apic_ldr,
+	.ioapic_phys_id_map		= NULL,
+	.setup_apic_routing		= NULL,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= NULL,
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+	.phys_pkg_id			= flat_phys_pkg_id,
+
+	.get_apic_id			= flat_get_apic_id,
+	.set_apic_id			= set_apic_id,
+
+	.calc_dest_apicid		= apic_flat_calc_apicid,
+
+	.send_IPI			= default_send_IPI_single,
+	.send_IPI_mask			= flat_send_IPI_mask,
+	.send_IPI_mask_allbutself	= flat_send_IPI_mask_allbutself,
+	.send_IPI_allbutself		= default_send_IPI_allbutself,
+	.send_IPI_all			= default_send_IPI_all,
+	.send_IPI_self			= default_send_IPI_self,
+
+	.inquire_remote_apic		= default_inquire_remote_apic,
+
+	.read				= native_apic_mem_read,
+	.write				= native_apic_mem_write,
+	.eoi_write			= native_apic_mem_write,
+	.icr_read			= native_apic_icr_read,
+	.icr_write			= native_apic_icr_write,
+	.wait_icr_idle			= native_apic_wait_icr_idle,
+	.safe_wait_icr_idle		= native_safe_apic_wait_icr_idle,
+};
+
+/*
+ * Physflat mode is used when there are more than 8 CPUs on a system.
+ * We cannot use logical delivery in this case because the mask
+ * overflows, so use physical mode.
+ */
+static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+{
+#ifdef CONFIG_ACPI
+	/*
+	 * Quirk: some x86_64 machines can only use physical APIC mode
+	 * regardless of how many processors are present (x86_64 ES7000
+	 * is an example).
+	 */
+	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
+		(acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
+		printk(KERN_DEBUG "system APIC only can use physical flat");
+		return 1;
+	}
+
+	if (!strncmp(oem_id, "IBM", 3) && !strncmp(oem_table_id, "EXA", 3)) {
+		printk(KERN_DEBUG "IBM Summit detected, will use apic physical");
+		return 1;
+	}
+#endif
+
+	return 0;
+}
+
+static void physflat_init_apic_ldr(void)
+{
+	/*
+	 * LDR and DFR are not involved in physflat mode, rather:
+	 * "In physical destination mode, the destination processor is
+	 * specified by its local APIC ID [...]." (Intel SDM, 10.6.2.1)
+	 */
+}
+
+static int physflat_probe(void)
+{
+	if (apic == &apic_physflat || num_possible_cpus() > 8 ||
+	    jailhouse_paravirt())
+		return 1;
+
+	return 0;
+}
+
+static struct apic apic_physflat __ro_after_init = {
+
+	.name				= "physical flat",
+	.probe				= physflat_probe,
+	.acpi_madt_oem_check		= physflat_acpi_madt_oem_check,
+	.apic_id_valid			= default_apic_id_valid,
+	.apic_id_registered		= flat_apic_id_registered,
+
+	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
+	.dest_mode_logical		= false,
+
+	.disable_esr			= 0,
+
+	.check_apicid_used		= NULL,
+	.init_apic_ldr			= physflat_init_apic_ldr,
+	.ioapic_phys_id_map		= NULL,
+	.setup_apic_routing		= NULL,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= NULL,
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+	.phys_pkg_id			= flat_phys_pkg_id,
+
+	.get_apic_id			= flat_get_apic_id,
+	.set_apic_id			= set_apic_id,
+
+	.calc_dest_apicid		= apic_default_calc_apicid,
+
+	.send_IPI			= default_send_IPI_single_phys,
+	.send_IPI_mask			= default_send_IPI_mask_sequence_phys,
+	.send_IPI_mask_allbutself	= default_send_IPI_mask_allbutself_phys,
+	.send_IPI_allbutself		= default_send_IPI_allbutself,
+	.send_IPI_all			= default_send_IPI_all,
+	.send_IPI_self			= default_send_IPI_self,
+
+	.inquire_remote_apic		= default_inquire_remote_apic,
+
+	.read				= native_apic_mem_read,
+	.write				= native_apic_mem_write,
+	.eoi_write			= native_apic_mem_write,
+	.icr_read			= native_apic_icr_read,
+	.icr_write			= native_apic_icr_write,
+	.wait_icr_idle			= native_apic_wait_icr_idle,
+	.safe_wait_icr_idle		= native_safe_apic_wait_icr_idle,
+};
+
+/*
+ * We need to check for physflat first, so this order is important.
+ */
+apic_drivers(apic_physflat, apic_flat);
diff --git a/arch/x86/kernel/apic/apic_noop.c b/arch/x86/kernel/apic/apic_noop.c
new file mode 100644
index 000000000..fe78319e0
--- /dev/null
+++ b/arch/x86/kernel/apic/apic_noop.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NOOP APIC driver.
+ *
+ * Does almost nothing and should be substituted by a real apic driver via
+ * probe routine.
+ *
+ * Though in case if apic is disabled (for some reason) we try
+ * to not uglify the caller's code and allow to call (some) apic routines
+ * like self-ipi, etc...
+ */
+#include <linux/cpumask.h>
+#include <linux/thread_info.h>
+
+#include <asm/apic.h>
+
+static void noop_init_apic_ldr(void) { }
+static void noop_send_IPI(int cpu, int vector) { }
+static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { }
+static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { }
+static void noop_send_IPI_allbutself(int vector) { }
+static void noop_send_IPI_all(int vector) { }
+static void noop_send_IPI_self(int vector) { }
+static void noop_apic_wait_icr_idle(void) { }
+static void noop_apic_icr_write(u32 low, u32 id) { }
+
+static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip)
+{
+	return -1;
+}
+
+static u32 noop_safe_apic_wait_icr_idle(void)
+{
+	return 0;
+}
+
+static u64 noop_apic_icr_read(void)
+{
+	return 0;
+}
+
+static int noop_phys_pkg_id(int cpuid_apic, int index_msb)
+{
+	return 0;
+}
+
+static unsigned int noop_get_apic_id(unsigned long x)
+{
+	return 0;
+}
+
+static int noop_probe(void)
+{
+	/*
+	 * NOOP apic should not ever be
+	 * enabled via probe routine
+	 */
+	return 0;
+}
+
+static int noop_apic_id_registered(void)
+{
+	/*
+	 * if we would be really "pedantic"
+	 * we should pass read_apic_id() here
+	 * but since NOOP suppose APIC ID = 0
+	 * lets save a few cycles
+	 */
+	return physid_isset(0, phys_cpu_present_map);
+}
+
+static u32 noop_apic_read(u32 reg)
+{
+	WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !disable_apic);
+	return 0;
+}
+
+static void noop_apic_write(u32 reg, u32 v)
+{
+	WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !disable_apic);
+}
+
+#ifdef CONFIG_X86_32
+static int noop_x86_32_early_logical_apicid(int cpu)
+{
+	return BAD_APICID;
+}
+#endif
+
+struct apic apic_noop __ro_after_init = {
+	.name				= "noop",
+	.probe				= noop_probe,
+	.acpi_madt_oem_check		= NULL,
+
+	.apic_id_valid			= default_apic_id_valid,
+	.apic_id_registered		= noop_apic_id_registered,
+
+	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
+	.dest_mode_logical		= true,
+
+	.disable_esr			= 0,
+
+	.check_apicid_used		= default_check_apicid_used,
+	.init_apic_ldr			= noop_init_apic_ldr,
+	.ioapic_phys_id_map		= default_ioapic_phys_id_map,
+	.setup_apic_routing		= NULL,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= physid_set_mask_of_physid,
+
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+
+	.phys_pkg_id			= noop_phys_pkg_id,
+
+	.get_apic_id			= noop_get_apic_id,
+	.set_apic_id			= NULL,
+
+	.calc_dest_apicid		= apic_flat_calc_apicid,
+
+	.send_IPI			= noop_send_IPI,
+	.send_IPI_mask			= noop_send_IPI_mask,
+	.send_IPI_mask_allbutself	= noop_send_IPI_mask_allbutself,
+	.send_IPI_allbutself		= noop_send_IPI_allbutself,
+	.send_IPI_all			= noop_send_IPI_all,
+	.send_IPI_self			= noop_send_IPI_self,
+
+	.wakeup_secondary_cpu		= noop_wakeup_secondary_cpu,
+
+	.inquire_remote_apic		= NULL,
+
+	.read				= noop_apic_read,
+	.write				= noop_apic_write,
+	.eoi_write			= noop_apic_write,
+	.icr_read			= noop_apic_icr_read,
+	.icr_write			= noop_apic_icr_write,
+	.wait_icr_idle			= noop_apic_wait_icr_idle,
+	.safe_wait_icr_idle		= noop_safe_apic_wait_icr_idle,
+
+#ifdef CONFIG_X86_32
+	.x86_32_early_logical_apicid	= noop_x86_32_early_logical_apicid,
+#endif
+};
diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c
new file mode 100644
index 000000000..a54d817eb
--- /dev/null
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -0,0 +1,334 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Numascale NumaConnect-Specific APIC Code
+ *
+ * Copyright (C) 2011 Numascale AS. All rights reserved.
+ *
+ * Send feedback to <support@numascale.com>
+ *
+ */
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/pgtable.h>
+
+#include <asm/numachip/numachip.h>
+#include <asm/numachip/numachip_csr.h>
+
+
+#include "local.h"
+
+u8 numachip_system __read_mostly;
+static const struct apic apic_numachip1;
+static const struct apic apic_numachip2;
+static void (*numachip_apic_icr_write)(int apicid, unsigned int val) __read_mostly;
+
+static unsigned int numachip1_get_apic_id(unsigned long x)
+{
+	unsigned long value;
+	unsigned int id = (x >> 24) & 0xff;
+
+	if (static_cpu_has(X86_FEATURE_NODEID_MSR)) {
+		rdmsrl(MSR_FAM10H_NODE_ID, value);
+		id |= (value << 2) & 0xff00;
+	}
+
+	return id;
+}
+
+static u32 numachip1_set_apic_id(unsigned int id)
+{
+	return (id & 0xff) << 24;
+}
+
+static unsigned int numachip2_get_apic_id(unsigned long x)
+{
+	u64 mcfg;
+
+	rdmsrl(MSR_FAM10H_MMIO_CONF_BASE, mcfg);
+	return ((mcfg >> (28 - 8)) & 0xfff00) | (x >> 24);
+}
+
+static u32 numachip2_set_apic_id(unsigned int id)
+{
+	return id << 24;
+}
+
+static int numachip_apic_id_valid(u32 apicid)
+{
+	/* Trust what bootloader passes in MADT */
+	return 1;
+}
+
+static int numachip_apic_id_registered(void)
+{
+	return 1;
+}
+
+static int numachip_phys_pkg_id(int initial_apic_id, int index_msb)
+{
+	return initial_apic_id >> index_msb;
+}
+
+static void numachip1_apic_icr_write(int apicid, unsigned int val)
+{
+	write_lcsr(CSR_G3_EXT_IRQ_GEN, (apicid << 16) | val);
+}
+
+static void numachip2_apic_icr_write(int apicid, unsigned int val)
+{
+	numachip2_write32_lcsr(NUMACHIP2_APIC_ICR, (apicid << 12) | val);
+}
+
+static int numachip_wakeup_secondary(int phys_apicid, unsigned long start_rip)
+{
+	numachip_apic_icr_write(phys_apicid, APIC_DM_INIT);
+	numachip_apic_icr_write(phys_apicid, APIC_DM_STARTUP |
+		(start_rip >> 12));
+
+	return 0;
+}
+
+static void numachip_send_IPI_one(int cpu, int vector)
+{
+	int local_apicid, apicid = per_cpu(x86_cpu_to_apicid, cpu);
+	unsigned int dmode;
+
+	preempt_disable();
+	local_apicid = __this_cpu_read(x86_cpu_to_apicid);
+
+	/* Send via local APIC where non-local part matches */
+	if (!((apicid ^ local_apicid) >> NUMACHIP_LAPIC_BITS)) {
+		unsigned long flags;
+
+		local_irq_save(flags);
+		__default_send_IPI_dest_field(apicid, vector,
+			APIC_DEST_PHYSICAL);
+		local_irq_restore(flags);
+		preempt_enable();
+		return;
+	}
+	preempt_enable();
+
+	dmode = (vector == NMI_VECTOR) ? APIC_DM_NMI : APIC_DM_FIXED;
+	numachip_apic_icr_write(apicid, dmode | vector);
+}
+
+static void numachip_send_IPI_mask(const struct cpumask *mask, int vector)
+{
+	unsigned int cpu;
+
+	for_each_cpu(cpu, mask)
+		numachip_send_IPI_one(cpu, vector);
+}
+
+static void numachip_send_IPI_mask_allbutself(const struct cpumask *mask,
+						int vector)
+{
+	unsigned int this_cpu = smp_processor_id();
+	unsigned int cpu;
+
+	for_each_cpu(cpu, mask) {
+		if (cpu != this_cpu)
+			numachip_send_IPI_one(cpu, vector);
+	}
+}
+
+static void numachip_send_IPI_allbutself(int vector)
+{
+	unsigned int this_cpu = smp_processor_id();
+	unsigned int cpu;
+
+	for_each_online_cpu(cpu) {
+		if (cpu != this_cpu)
+			numachip_send_IPI_one(cpu, vector);
+	}
+}
+
+static void numachip_send_IPI_all(int vector)
+{
+	numachip_send_IPI_mask(cpu_online_mask, vector);
+}
+
+static void numachip_send_IPI_self(int vector)
+{
+	apic_write(APIC_SELF_IPI, vector);
+}
+
+static int __init numachip1_probe(void)
+{
+	return apic == &apic_numachip1;
+}
+
+static int __init numachip2_probe(void)
+{
+	return apic == &apic_numachip2;
+}
+
+static void fixup_cpu_id(struct cpuinfo_x86 *c, int node)
+{
+	u64 val;
+	u32 nodes = 1;
+
+	this_cpu_write(cpu_llc_id, node);
+
+	/* Account for nodes per socket in multi-core-module processors */
+	if (boot_cpu_has(X86_FEATURE_NODEID_MSR)) {
+		rdmsrl(MSR_FAM10H_NODE_ID, val);
+		nodes = ((val >> 3) & 7) + 1;
+	}
+
+	c->phys_proc_id = node / nodes;
+}
+
+static int __init numachip_system_init(void)
+{
+	/* Map the LCSR area and set up the apic_icr_write function */
+	switch (numachip_system) {
+	case 1:
+		init_extra_mapping_uc(NUMACHIP_LCSR_BASE, NUMACHIP_LCSR_SIZE);
+		numachip_apic_icr_write = numachip1_apic_icr_write;
+		break;
+	case 2:
+		init_extra_mapping_uc(NUMACHIP2_LCSR_BASE, NUMACHIP2_LCSR_SIZE);
+		numachip_apic_icr_write = numachip2_apic_icr_write;
+		break;
+	default:
+		return 0;
+	}
+
+	x86_cpuinit.fixup_cpu_id = fixup_cpu_id;
+	x86_init.pci.arch_init = pci_numachip_init;
+
+	return 0;
+}
+early_initcall(numachip_system_init);
+
+static int numachip1_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+{
+	if ((strncmp(oem_id, "NUMASC", 6) != 0) ||
+	    (strncmp(oem_table_id, "NCONNECT", 8) != 0))
+		return 0;
+
+	numachip_system = 1;
+
+	return 1;
+}
+
+static int numachip2_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+{
+	if ((strncmp(oem_id, "NUMASC", 6) != 0) ||
+	    (strncmp(oem_table_id, "NCONECT2", 8) != 0))
+		return 0;
+
+	numachip_system = 2;
+
+	return 1;
+}
+
+/* APIC IPIs are queued */
+static void numachip_apic_wait_icr_idle(void)
+{
+}
+
+/* APIC NMI IPIs are queued */
+static u32 numachip_safe_apic_wait_icr_idle(void)
+{
+	return 0;
+}
+
+static const struct apic apic_numachip1 __refconst = {
+	.name				= "NumaConnect system",
+	.probe				= numachip1_probe,
+	.acpi_madt_oem_check		= numachip1_acpi_madt_oem_check,
+	.apic_id_valid			= numachip_apic_id_valid,
+	.apic_id_registered		= numachip_apic_id_registered,
+
+	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
+	.dest_mode_logical		= false,
+
+	.disable_esr			= 0,
+
+	.check_apicid_used		= NULL,
+	.init_apic_ldr			= flat_init_apic_ldr,
+	.ioapic_phys_id_map		= NULL,
+	.setup_apic_routing		= NULL,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= NULL,
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+	.phys_pkg_id			= numachip_phys_pkg_id,
+
+	.get_apic_id			= numachip1_get_apic_id,
+	.set_apic_id			= numachip1_set_apic_id,
+
+	.calc_dest_apicid		= apic_default_calc_apicid,
+
+	.send_IPI			= numachip_send_IPI_one,
+	.send_IPI_mask			= numachip_send_IPI_mask,
+	.send_IPI_mask_allbutself	= numachip_send_IPI_mask_allbutself,
+	.send_IPI_allbutself		= numachip_send_IPI_allbutself,
+	.send_IPI_all			= numachip_send_IPI_all,
+	.send_IPI_self			= numachip_send_IPI_self,
+
+	.wakeup_secondary_cpu		= numachip_wakeup_secondary,
+	.inquire_remote_apic		= NULL, /* REMRD not supported */
+
+	.read				= native_apic_mem_read,
+	.write				= native_apic_mem_write,
+	.eoi_write			= native_apic_mem_write,
+	.icr_read			= native_apic_icr_read,
+	.icr_write			= native_apic_icr_write,
+	.wait_icr_idle			= numachip_apic_wait_icr_idle,
+	.safe_wait_icr_idle		= numachip_safe_apic_wait_icr_idle,
+};
+
+apic_driver(apic_numachip1);
+
+static const struct apic apic_numachip2 __refconst = {
+	.name				= "NumaConnect2 system",
+	.probe				= numachip2_probe,
+	.acpi_madt_oem_check		= numachip2_acpi_madt_oem_check,
+	.apic_id_valid			= numachip_apic_id_valid,
+	.apic_id_registered		= numachip_apic_id_registered,
+
+	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
+	.dest_mode_logical		= false,
+
+	.disable_esr			= 0,
+
+	.check_apicid_used		= NULL,
+	.init_apic_ldr			= flat_init_apic_ldr,
+	.ioapic_phys_id_map		= NULL,
+	.setup_apic_routing		= NULL,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= NULL,
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+	.phys_pkg_id			= numachip_phys_pkg_id,
+
+	.get_apic_id			= numachip2_get_apic_id,
+	.set_apic_id			= numachip2_set_apic_id,
+
+	.calc_dest_apicid		= apic_default_calc_apicid,
+
+	.send_IPI			= numachip_send_IPI_one,
+	.send_IPI_mask			= numachip_send_IPI_mask,
+	.send_IPI_mask_allbutself	= numachip_send_IPI_mask_allbutself,
+	.send_IPI_allbutself		= numachip_send_IPI_allbutself,
+	.send_IPI_all			= numachip_send_IPI_all,
+	.send_IPI_self			= numachip_send_IPI_self,
+
+	.wakeup_secondary_cpu		= numachip_wakeup_secondary,
+	.inquire_remote_apic		= NULL, /* REMRD not supported */
+
+	.read				= native_apic_mem_read,
+	.write				= native_apic_mem_write,
+	.eoi_write			= native_apic_mem_write,
+	.icr_read			= native_apic_icr_read,
+	.icr_write			= native_apic_icr_write,
+	.wait_icr_idle			= numachip_apic_wait_icr_idle,
+	.safe_wait_icr_idle		= numachip_safe_apic_wait_icr_idle,
+};
+
+apic_driver(apic_numachip2);
diff --git a/arch/x86/kernel/apic/bigsmp_32.c b/arch/x86/kernel/apic/bigsmp_32.c
new file mode 100644
index 000000000..77555f66c
--- /dev/null
+++ b/arch/x86/kernel/apic/bigsmp_32.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * APIC driver for "bigsmp" xAPIC machines with more than 8 virtual CPUs.
+ *
+ * Drives the local APIC in "clustered mode".
+ */
+#include <linux/cpumask.h>
+#include <linux/dmi.h>
+#include <linux/smp.h>
+
+#include <asm/apic.h>
+#include <asm/io_apic.h>
+
+#include "local.h"
+
+static unsigned bigsmp_get_apic_id(unsigned long x)
+{
+	return (x >> 24) & 0xFF;
+}
+
+static int bigsmp_apic_id_registered(void)
+{
+	return 1;
+}
+
+static bool bigsmp_check_apicid_used(physid_mask_t *map, int apicid)
+{
+	return false;
+}
+
+static int bigsmp_early_logical_apicid(int cpu)
+{
+	/* on bigsmp, logical apicid is the same as physical */
+	return early_per_cpu(x86_cpu_to_apicid, cpu);
+}
+
+/*
+ * bigsmp enables physical destination mode
+ * and doesn't use LDR and DFR
+ */
+static void bigsmp_init_apic_ldr(void)
+{
+}
+
+static void bigsmp_setup_apic_routing(void)
+{
+	printk(KERN_INFO
+		"Enabling APIC mode:  Physflat.  Using %d I/O APICs\n",
+		nr_ioapics);
+}
+
+static int bigsmp_cpu_present_to_apicid(int mps_cpu)
+{
+	if (mps_cpu < nr_cpu_ids)
+		return (int) per_cpu(x86_bios_cpu_apicid, mps_cpu);
+
+	return BAD_APICID;
+}
+
+static void bigsmp_ioapic_phys_id_map(physid_mask_t *phys_map, physid_mask_t *retmap)
+{
+	/* For clustered we don't have a good way to do this yet - hack */
+	physids_promote(0xFFL, retmap);
+}
+
+static int bigsmp_check_phys_apicid_present(int phys_apicid)
+{
+	return 1;
+}
+
+static int bigsmp_phys_pkg_id(int cpuid_apic, int index_msb)
+{
+	return cpuid_apic >> index_msb;
+}
+
+static void bigsmp_send_IPI_allbutself(int vector)
+{
+	default_send_IPI_mask_allbutself_phys(cpu_online_mask, vector);
+}
+
+static void bigsmp_send_IPI_all(int vector)
+{
+	default_send_IPI_mask_sequence_phys(cpu_online_mask, vector);
+}
+
+static int dmi_bigsmp; /* can be set by dmi scanners */
+
+static int hp_ht_bigsmp(const struct dmi_system_id *d)
+{
+	printk(KERN_NOTICE "%s detected: force use of apic=bigsmp\n", d->ident);
+	dmi_bigsmp = 1;
+
+	return 0;
+}
+
+
+static const struct dmi_system_id bigsmp_dmi_table[] = {
+	{ hp_ht_bigsmp, "HP ProLiant DL760 G2",
+		{	DMI_MATCH(DMI_BIOS_VENDOR, "HP"),
+			DMI_MATCH(DMI_BIOS_VERSION, "P44-"),
+		}
+	},
+
+	{ hp_ht_bigsmp, "HP ProLiant DL740",
+		{	DMI_MATCH(DMI_BIOS_VENDOR, "HP"),
+			DMI_MATCH(DMI_BIOS_VERSION, "P47-"),
+		}
+	},
+	{ } /* NULL entry stops DMI scanning */
+};
+
+static int probe_bigsmp(void)
+{
+	if (def_to_bigsmp)
+		dmi_bigsmp = 1;
+	else
+		dmi_check_system(bigsmp_dmi_table);
+
+	return dmi_bigsmp;
+}
+
+static struct apic apic_bigsmp __ro_after_init = {
+
+	.name				= "bigsmp",
+	.probe				= probe_bigsmp,
+	.acpi_madt_oem_check		= NULL,
+	.apic_id_valid			= default_apic_id_valid,
+	.apic_id_registered		= bigsmp_apic_id_registered,
+
+	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
+	.dest_mode_logical		= false,
+
+	.disable_esr			= 1,
+
+	.check_apicid_used		= bigsmp_check_apicid_used,
+	.init_apic_ldr			= bigsmp_init_apic_ldr,
+	.ioapic_phys_id_map		= bigsmp_ioapic_phys_id_map,
+	.setup_apic_routing		= bigsmp_setup_apic_routing,
+	.cpu_present_to_apicid		= bigsmp_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= physid_set_mask_of_physid,
+	.check_phys_apicid_present	= bigsmp_check_phys_apicid_present,
+	.phys_pkg_id			= bigsmp_phys_pkg_id,
+
+	.get_apic_id			= bigsmp_get_apic_id,
+	.set_apic_id			= NULL,
+
+	.calc_dest_apicid		= apic_default_calc_apicid,
+
+	.send_IPI			= default_send_IPI_single_phys,
+	.send_IPI_mask			= default_send_IPI_mask_sequence_phys,
+	.send_IPI_mask_allbutself	= NULL,
+	.send_IPI_allbutself		= bigsmp_send_IPI_allbutself,
+	.send_IPI_all			= bigsmp_send_IPI_all,
+	.send_IPI_self			= default_send_IPI_self,
+
+	.inquire_remote_apic		= default_inquire_remote_apic,
+
+	.read				= native_apic_mem_read,
+	.write				= native_apic_mem_write,
+	.eoi_write			= native_apic_mem_write,
+	.icr_read			= native_apic_icr_read,
+	.icr_write			= native_apic_icr_write,
+	.wait_icr_idle			= native_apic_wait_icr_idle,
+	.safe_wait_icr_idle		= native_safe_apic_wait_icr_idle,
+
+	.x86_32_early_logical_apicid	= bigsmp_early_logical_apicid,
+};
+
+void __init generic_bigsmp_probe(void)
+{
+	unsigned int cpu;
+
+	if (!probe_bigsmp())
+		return;
+
+	apic = &apic_bigsmp;
+
+	for_each_possible_cpu(cpu) {
+		if (early_per_cpu(x86_cpu_to_logical_apicid,
+				  cpu) == BAD_APICID)
+			continue;
+		early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
+			bigsmp_early_logical_apicid(cpu);
+	}
+
+	pr_info("Overriding APIC driver with %s\n", apic_bigsmp.name);
+}
+
+apic_driver(apic_bigsmp);
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
new file mode 100644
index 000000000..34a992e27
--- /dev/null
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  HW NMI watchdog support
+ *
+ *  started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
+ *
+ *  Arch specific calls to support NMI watchdog
+ *
+ *  Bits copied from original nmi.c file
+ *
+ */
+#include <linux/thread_info.h>
+#include <asm/apic.h>
+#include <asm/nmi.h>
+
+#include <linux/cpumask.h>
+#include <linux/kdebug.h>
+#include <linux/notifier.h>
+#include <linux/kprobes.h>
+#include <linux/nmi.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
+u64 hw_nmi_get_sample_period(int watchdog_thresh)
+{
+	return (u64)(cpu_khz) * 1000 * watchdog_thresh;
+}
+#endif
+
+#ifdef arch_trigger_cpumask_backtrace
+static void nmi_raise_cpu_backtrace(cpumask_t *mask)
+{
+	apic->send_IPI_mask(mask, NMI_VECTOR);
+}
+
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
+{
+	nmi_trigger_cpumask_backtrace(mask, exclude_self,
+				      nmi_raise_cpu_backtrace);
+}
+
+static int nmi_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs)
+{
+	if (nmi_cpu_backtrace(regs))
+		return NMI_HANDLED;
+
+	return NMI_DONE;
+}
+NOKPROBE_SYMBOL(nmi_cpu_backtrace_handler);
+
+static int __init register_nmi_cpu_backtrace_handler(void)
+{
+	register_nmi_handler(NMI_LOCAL, nmi_cpu_backtrace_handler,
+				0, "arch_bt");
+	return 0;
+}
+early_initcall(register_nmi_cpu_backtrace_handler);
+#endif
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
new file mode 100644
index 000000000..efa87b6bb
--- /dev/null
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -0,0 +1,3117 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *	Intel IO-APIC support for multi-Pentium hosts.
+ *
+ *	Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
+ *
+ *	Many thanks to Stig Venaas for trying out countless experimental
+ *	patches and reporting/debugging problems patiently!
+ *
+ *	(c) 1999, Multiple IO-APIC support, developed by
+ *	Ken-ichi Yaku <yaku@css1.kbnes.nec.co.jp> and
+ *      Hidemi Kishimoto <kisimoto@css1.kbnes.nec.co.jp>,
+ *	further tested and cleaned up by Zach Brown <zab@redhat.com>
+ *	and Ingo Molnar <mingo@redhat.com>
+ *
+ *	Fixes
+ *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
+ *					thanks to Eric Gilmore
+ *					and Rolf G. Tews
+ *					for testing these extensively
+ *	Paul Diefenbaugh	:	Added full ACPI support
+ *
+ * Historical information which is worth to be preserved:
+ *
+ * - SiS APIC rmw bug:
+ *
+ *	We used to have a workaround for a bug in SiS chips which
+ *	required to rewrite the index register for a read-modify-write
+ *	operation as the chip lost the index information which was
+ *	setup for the read already. We cache the data now, so that
+ *	workaround has been removed.
+ */
+
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/pci.h>
+#include <linux/mc146818rtc.h>
+#include <linux/compiler.h>
+#include <linux/acpi.h>
+#include <linux/export.h>
+#include <linux/syscore_ops.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+#include <linux/jiffies.h>	/* time_after() */
+#include <linux/slab.h>
+#include <linux/memblock.h>
+#include <linux/msi.h>
+
+#include <asm/irqdomain.h>
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/cpu.h>
+#include <asm/desc.h>
+#include <asm/proto.h>
+#include <asm/acpi.h>
+#include <asm/dma.h>
+#include <asm/timer.h>
+#include <asm/time.h>
+#include <asm/i8259.h>
+#include <asm/setup.h>
+#include <asm/irq_remapping.h>
+#include <asm/hw_irq.h>
+#include <asm/apic.h>
+#include <asm/pgtable.h>
+
+#define	for_each_ioapic(idx)		\
+	for ((idx) = 0; (idx) < nr_ioapics; (idx)++)
+#define	for_each_ioapic_reverse(idx)	\
+	for ((idx) = nr_ioapics - 1; (idx) >= 0; (idx)--)
+#define	for_each_pin(idx, pin)		\
+	for ((pin) = 0; (pin) < ioapics[(idx)].nr_registers; (pin)++)
+#define	for_each_ioapic_pin(idx, pin)	\
+	for_each_ioapic((idx))		\
+		for_each_pin((idx), (pin))
+#define for_each_irq_pin(entry, head) \
+	list_for_each_entry(entry, &head, list)
+
+static DEFINE_RAW_SPINLOCK(ioapic_lock);
+static DEFINE_MUTEX(ioapic_mutex);
+static unsigned int ioapic_dynirq_base;
+static int ioapic_initialized;
+
+struct irq_pin_list {
+	struct list_head list;
+	int apic, pin;
+};
+
+struct mp_chip_data {
+	struct list_head		irq_2_pin;
+	struct IO_APIC_route_entry	entry;
+	bool				is_level;
+	bool				active_low;
+	bool				isa_irq;
+	u32 count;
+};
+
+struct mp_ioapic_gsi {
+	u32 gsi_base;
+	u32 gsi_end;
+};
+
+static struct ioapic {
+	/*
+	 * # of IRQ routing registers
+	 */
+	int nr_registers;
+	/*
+	 * Saved state during suspend/resume, or while enabling intr-remap.
+	 */
+	struct IO_APIC_route_entry *saved_registers;
+	/* I/O APIC config */
+	struct mpc_ioapic mp_config;
+	/* IO APIC gsi routing info */
+	struct mp_ioapic_gsi  gsi_config;
+	struct ioapic_domain_cfg irqdomain_cfg;
+	struct irq_domain *irqdomain;
+	struct resource *iomem_res;
+} ioapics[MAX_IO_APICS];
+
+#define mpc_ioapic_ver(ioapic_idx)	ioapics[ioapic_idx].mp_config.apicver
+
+int mpc_ioapic_id(int ioapic_idx)
+{
+	return ioapics[ioapic_idx].mp_config.apicid;
+}
+
+unsigned int mpc_ioapic_addr(int ioapic_idx)
+{
+	return ioapics[ioapic_idx].mp_config.apicaddr;
+}
+
+static inline struct mp_ioapic_gsi *mp_ioapic_gsi_routing(int ioapic_idx)
+{
+	return &ioapics[ioapic_idx].gsi_config;
+}
+
+static inline int mp_ioapic_pin_count(int ioapic)
+{
+	struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(ioapic);
+
+	return gsi_cfg->gsi_end - gsi_cfg->gsi_base + 1;
+}
+
+static inline u32 mp_pin_to_gsi(int ioapic, int pin)
+{
+	return mp_ioapic_gsi_routing(ioapic)->gsi_base + pin;
+}
+
+static inline bool mp_is_legacy_irq(int irq)
+{
+	return irq >= 0 && irq < nr_legacy_irqs();
+}
+
+static inline struct irq_domain *mp_ioapic_irqdomain(int ioapic)
+{
+	return ioapics[ioapic].irqdomain;
+}
+
+int nr_ioapics;
+
+/* The one past the highest gsi number used */
+u32 gsi_top;
+
+/* MP IRQ source entries */
+struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCES];
+
+/* # of MP IRQ source entries */
+int mp_irq_entries;
+
+#ifdef CONFIG_EISA
+int mp_bus_id_to_type[MAX_MP_BUSSES];
+#endif
+
+DECLARE_BITMAP(mp_bus_not_pci, MAX_MP_BUSSES);
+
+int skip_ioapic_setup;
+
+/**
+ * disable_ioapic_support() - disables ioapic support at runtime
+ */
+void disable_ioapic_support(void)
+{
+#ifdef CONFIG_PCI
+	noioapicquirk = 1;
+	noioapicreroute = -1;
+#endif
+	skip_ioapic_setup = 1;
+}
+
+static int __init parse_noapic(char *str)
+{
+	/* disable IO-APIC */
+	disable_ioapic_support();
+	return 0;
+}
+early_param("noapic", parse_noapic);
+
+/* Will be called in mpparse/ACPI codes for saving IRQ info */
+void mp_save_irq(struct mpc_intsrc *m)
+{
+	int i;
+
+	apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
+		" IRQ %02x, APIC ID %x, APIC INT %02x\n",
+		m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbus,
+		m->srcbusirq, m->dstapic, m->dstirq);
+
+	for (i = 0; i < mp_irq_entries; i++) {
+		if (!memcmp(&mp_irqs[i], m, sizeof(*m)))
+			return;
+	}
+
+	memcpy(&mp_irqs[mp_irq_entries], m, sizeof(*m));
+	if (++mp_irq_entries == MAX_IRQ_SOURCES)
+		panic("Max # of irq sources exceeded!!\n");
+}
+
+static void alloc_ioapic_saved_registers(int idx)
+{
+	size_t size;
+
+	if (ioapics[idx].saved_registers)
+		return;
+
+	size = sizeof(struct IO_APIC_route_entry) * ioapics[idx].nr_registers;
+	ioapics[idx].saved_registers = kzalloc(size, GFP_KERNEL);
+	if (!ioapics[idx].saved_registers)
+		pr_err("IOAPIC %d: suspend/resume impossible!\n", idx);
+}
+
+static void free_ioapic_saved_registers(int idx)
+{
+	kfree(ioapics[idx].saved_registers);
+	ioapics[idx].saved_registers = NULL;
+}
+
+int __init arch_early_ioapic_init(void)
+{
+	int i;
+
+	if (!nr_legacy_irqs())
+		io_apic_irqs = ~0UL;
+
+	for_each_ioapic(i)
+		alloc_ioapic_saved_registers(i);
+
+	return 0;
+}
+
+struct io_apic {
+	unsigned int index;
+	unsigned int unused[3];
+	unsigned int data;
+	unsigned int unused2[11];
+	unsigned int eoi;
+};
+
+static __attribute_const__ struct io_apic __iomem *io_apic_base(int idx)
+{
+	return (void __iomem *) __fix_to_virt(FIX_IO_APIC_BASE_0 + idx)
+		+ (mpc_ioapic_addr(idx) & ~PAGE_MASK);
+}
+
+static inline void io_apic_eoi(unsigned int apic, unsigned int vector)
+{
+	struct io_apic __iomem *io_apic = io_apic_base(apic);
+	writel(vector, &io_apic->eoi);
+}
+
+unsigned int native_io_apic_read(unsigned int apic, unsigned int reg)
+{
+	struct io_apic __iomem *io_apic = io_apic_base(apic);
+	writel(reg, &io_apic->index);
+	return readl(&io_apic->data);
+}
+
+static void io_apic_write(unsigned int apic, unsigned int reg,
+			  unsigned int value)
+{
+	struct io_apic __iomem *io_apic = io_apic_base(apic);
+
+	writel(reg, &io_apic->index);
+	writel(value, &io_apic->data);
+}
+
+static struct IO_APIC_route_entry __ioapic_read_entry(int apic, int pin)
+{
+	struct IO_APIC_route_entry entry;
+
+	entry.w1 = io_apic_read(apic, 0x10 + 2 * pin);
+	entry.w2 = io_apic_read(apic, 0x11 + 2 * pin);
+
+	return entry;
+}
+
+static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin)
+{
+	struct IO_APIC_route_entry entry;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	entry = __ioapic_read_entry(apic, pin);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return entry;
+}
+
+/*
+ * When we write a new IO APIC routing entry, we need to write the high
+ * word first! If the mask bit in the low word is clear, we will enable
+ * the interrupt, and we need to make sure the entry is fully populated
+ * before that happens.
+ */
+static void __ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
+{
+	io_apic_write(apic, 0x11 + 2*pin, e.w2);
+	io_apic_write(apic, 0x10 + 2*pin, e.w1);
+}
+
+static void ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	__ioapic_write_entry(apic, pin, e);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+/*
+ * When we mask an IO APIC routing entry, we need to write the low
+ * word first, in order to set the mask bit before we change the
+ * high bits!
+ */
+static void ioapic_mask_entry(int apic, int pin)
+{
+	struct IO_APIC_route_entry e = { .masked = true };
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	io_apic_write(apic, 0x10 + 2*pin, e.w1);
+	io_apic_write(apic, 0x11 + 2*pin, e.w2);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+/*
+ * The common case is 1:1 IRQ<->pin mappings. Sometimes there are
+ * shared ISA-space IRQs, so we have to support them. We are super
+ * fast in the common case, and fast for shared ISA-space IRQs.
+ */
+static int __add_pin_to_irq_node(struct mp_chip_data *data,
+				 int node, int apic, int pin)
+{
+	struct irq_pin_list *entry;
+
+	/* don't allow duplicates */
+	for_each_irq_pin(entry, data->irq_2_pin)
+		if (entry->apic == apic && entry->pin == pin)
+			return 0;
+
+	entry = kzalloc_node(sizeof(struct irq_pin_list), GFP_ATOMIC, node);
+	if (!entry) {
+		pr_err("can not alloc irq_pin_list (%d,%d,%d)\n",
+		       node, apic, pin);
+		return -ENOMEM;
+	}
+	entry->apic = apic;
+	entry->pin = pin;
+	list_add_tail(&entry->list, &data->irq_2_pin);
+
+	return 0;
+}
+
+static void __remove_pin_from_irq(struct mp_chip_data *data, int apic, int pin)
+{
+	struct irq_pin_list *tmp, *entry;
+
+	list_for_each_entry_safe(entry, tmp, &data->irq_2_pin, list)
+		if (entry->apic == apic && entry->pin == pin) {
+			list_del(&entry->list);
+			kfree(entry);
+			return;
+		}
+}
+
+static void add_pin_to_irq_node(struct mp_chip_data *data,
+				int node, int apic, int pin)
+{
+	if (__add_pin_to_irq_node(data, node, apic, pin))
+		panic("IO-APIC: failed to add irq-pin. Can not proceed\n");
+}
+
+/*
+ * Reroute an IRQ to a different pin.
+ */
+static void __init replace_pin_at_irq_node(struct mp_chip_data *data, int node,
+					   int oldapic, int oldpin,
+					   int newapic, int newpin)
+{
+	struct irq_pin_list *entry;
+
+	for_each_irq_pin(entry, data->irq_2_pin) {
+		if (entry->apic == oldapic && entry->pin == oldpin) {
+			entry->apic = newapic;
+			entry->pin = newpin;
+			/* every one is different, right? */
+			return;
+		}
+	}
+
+	/* old apic/pin didn't exist, so just add new ones */
+	add_pin_to_irq_node(data, node, newapic, newpin);
+}
+
+static void io_apic_modify_irq(struct mp_chip_data *data, bool masked,
+			       void (*final)(struct irq_pin_list *entry))
+{
+	struct irq_pin_list *entry;
+
+	data->entry.masked = masked;
+
+	for_each_irq_pin(entry, data->irq_2_pin) {
+		io_apic_write(entry->apic, 0x10 + 2 * entry->pin, data->entry.w1);
+		if (final)
+			final(entry);
+	}
+}
+
+static void io_apic_sync(struct irq_pin_list *entry)
+{
+	/*
+	 * Synchronize the IO-APIC and the CPU by doing
+	 * a dummy read from the IO-APIC
+	 */
+	struct io_apic __iomem *io_apic;
+
+	io_apic = io_apic_base(entry->apic);
+	readl(&io_apic->data);
+}
+
+static void mask_ioapic_irq(struct irq_data *irq_data)
+{
+	struct mp_chip_data *data = irq_data->chip_data;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	io_apic_modify_irq(data, true, &io_apic_sync);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+static void __unmask_ioapic(struct mp_chip_data *data)
+{
+	io_apic_modify_irq(data, false, NULL);
+}
+
+static void unmask_ioapic_irq(struct irq_data *irq_data)
+{
+	struct mp_chip_data *data = irq_data->chip_data;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	__unmask_ioapic(data);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+/*
+ * IO-APIC versions below 0x20 don't support EOI register.
+ * For the record, here is the information about various versions:
+ *     0Xh     82489DX
+ *     1Xh     I/OAPIC or I/O(x)APIC which are not PCI 2.2 Compliant
+ *     2Xh     I/O(x)APIC which is PCI 2.2 Compliant
+ *     30h-FFh Reserved
+ *
+ * Some of the Intel ICH Specs (ICH2 to ICH5) documents the io-apic
+ * version as 0x2. This is an error with documentation and these ICH chips
+ * use io-apic's of version 0x20.
+ *
+ * For IO-APIC's with EOI register, we use that to do an explicit EOI.
+ * Otherwise, we simulate the EOI message manually by changing the trigger
+ * mode to edge and then back to level, with RTE being masked during this.
+ */
+static void __eoi_ioapic_pin(int apic, int pin, int vector)
+{
+	if (mpc_ioapic_ver(apic) >= 0x20) {
+		io_apic_eoi(apic, vector);
+	} else {
+		struct IO_APIC_route_entry entry, entry1;
+
+		entry = entry1 = __ioapic_read_entry(apic, pin);
+
+		/*
+		 * Mask the entry and change the trigger mode to edge.
+		 */
+		entry1.masked = true;
+		entry1.is_level = false;
+
+		__ioapic_write_entry(apic, pin, entry1);
+
+		/*
+		 * Restore the previous level triggered entry.
+		 */
+		__ioapic_write_entry(apic, pin, entry);
+	}
+}
+
+static void eoi_ioapic_pin(int vector, struct mp_chip_data *data)
+{
+	unsigned long flags;
+	struct irq_pin_list *entry;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	for_each_irq_pin(entry, data->irq_2_pin)
+		__eoi_ioapic_pin(entry->apic, entry->pin, vector);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
+{
+	struct IO_APIC_route_entry entry;
+
+	/* Check delivery_mode to be sure we're not clearing an SMI pin */
+	entry = ioapic_read_entry(apic, pin);
+	if (entry.delivery_mode == APIC_DELIVERY_MODE_SMI)
+		return;
+
+	/*
+	 * Make sure the entry is masked and re-read the contents to check
+	 * if it is a level triggered pin and if the remote-IRR is set.
+	 */
+	if (!entry.masked) {
+		entry.masked = true;
+		ioapic_write_entry(apic, pin, entry);
+		entry = ioapic_read_entry(apic, pin);
+	}
+
+	if (entry.irr) {
+		unsigned long flags;
+
+		/*
+		 * Make sure the trigger mode is set to level. Explicit EOI
+		 * doesn't clear the remote-IRR if the trigger mode is not
+		 * set to level.
+		 */
+		if (!entry.is_level) {
+			entry.is_level = true;
+			ioapic_write_entry(apic, pin, entry);
+		}
+		raw_spin_lock_irqsave(&ioapic_lock, flags);
+		__eoi_ioapic_pin(apic, pin, entry.vector);
+		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+	}
+
+	/*
+	 * Clear the rest of the bits in the IO-APIC RTE except for the mask
+	 * bit.
+	 */
+	ioapic_mask_entry(apic, pin);
+	entry = ioapic_read_entry(apic, pin);
+	if (entry.irr)
+		pr_err("Unable to reset IRR for apic: %d, pin :%d\n",
+		       mpc_ioapic_id(apic), pin);
+}
+
+void clear_IO_APIC (void)
+{
+	int apic, pin;
+
+	for_each_ioapic_pin(apic, pin)
+		clear_IO_APIC_pin(apic, pin);
+}
+
+#ifdef CONFIG_X86_32
+/*
+ * support for broken MP BIOSs, enables hand-redirection of PIRQ0-7 to
+ * specific CPU-side IRQs.
+ */
+
+#define MAX_PIRQS 8
+static int pirq_entries[MAX_PIRQS] = {
+	[0 ... MAX_PIRQS - 1] = -1
+};
+
+static int __init ioapic_pirq_setup(char *str)
+{
+	int i, max;
+	int ints[MAX_PIRQS+1];
+
+	get_options(str, ARRAY_SIZE(ints), ints);
+
+	apic_printk(APIC_VERBOSE, KERN_INFO
+			"PIRQ redirection, working around broken MP-BIOS.\n");
+	max = MAX_PIRQS;
+	if (ints[0] < MAX_PIRQS)
+		max = ints[0];
+
+	for (i = 0; i < max; i++) {
+		apic_printk(APIC_VERBOSE, KERN_DEBUG
+				"... PIRQ%d -> IRQ %d\n", i, ints[i+1]);
+		/*
+		 * PIRQs are mapped upside down, usually.
+		 */
+		pirq_entries[MAX_PIRQS-i-1] = ints[i+1];
+	}
+	return 1;
+}
+
+__setup("pirq=", ioapic_pirq_setup);
+#endif /* CONFIG_X86_32 */
+
+/*
+ * Saves all the IO-APIC RTE's
+ */
+int save_ioapic_entries(void)
+{
+	int apic, pin;
+	int err = 0;
+
+	for_each_ioapic(apic) {
+		if (!ioapics[apic].saved_registers) {
+			err = -ENOMEM;
+			continue;
+		}
+
+		for_each_pin(apic, pin)
+			ioapics[apic].saved_registers[pin] =
+				ioapic_read_entry(apic, pin);
+	}
+
+	return err;
+}
+
+/*
+ * Mask all IO APIC entries.
+ */
+void mask_ioapic_entries(void)
+{
+	int apic, pin;
+
+	for_each_ioapic(apic) {
+		if (!ioapics[apic].saved_registers)
+			continue;
+
+		for_each_pin(apic, pin) {
+			struct IO_APIC_route_entry entry;
+
+			entry = ioapics[apic].saved_registers[pin];
+			if (!entry.masked) {
+				entry.masked = true;
+				ioapic_write_entry(apic, pin, entry);
+			}
+		}
+	}
+}
+
+/*
+ * Restore IO APIC entries which was saved in the ioapic structure.
+ */
+int restore_ioapic_entries(void)
+{
+	int apic, pin;
+
+	for_each_ioapic(apic) {
+		if (!ioapics[apic].saved_registers)
+			continue;
+
+		for_each_pin(apic, pin)
+			ioapic_write_entry(apic, pin,
+					   ioapics[apic].saved_registers[pin]);
+	}
+	return 0;
+}
+
+/*
+ * Find the IRQ entry number of a certain pin.
+ */
+static int find_irq_entry(int ioapic_idx, int pin, int type)
+{
+	int i;
+
+	for (i = 0; i < mp_irq_entries; i++)
+		if (mp_irqs[i].irqtype == type &&
+		    (mp_irqs[i].dstapic == mpc_ioapic_id(ioapic_idx) ||
+		     mp_irqs[i].dstapic == MP_APIC_ALL) &&
+		    mp_irqs[i].dstirq == pin)
+			return i;
+
+	return -1;
+}
+
+/*
+ * Find the pin to which IRQ[irq] (ISA) is connected
+ */
+static int __init find_isa_irq_pin(int irq, int type)
+{
+	int i;
+
+	for (i = 0; i < mp_irq_entries; i++) {
+		int lbus = mp_irqs[i].srcbus;
+
+		if (test_bit(lbus, mp_bus_not_pci) &&
+		    (mp_irqs[i].irqtype == type) &&
+		    (mp_irqs[i].srcbusirq == irq))
+
+			return mp_irqs[i].dstirq;
+	}
+	return -1;
+}
+
+static int __init find_isa_irq_apic(int irq, int type)
+{
+	int i;
+
+	for (i = 0; i < mp_irq_entries; i++) {
+		int lbus = mp_irqs[i].srcbus;
+
+		if (test_bit(lbus, mp_bus_not_pci) &&
+		    (mp_irqs[i].irqtype == type) &&
+		    (mp_irqs[i].srcbusirq == irq))
+			break;
+	}
+
+	if (i < mp_irq_entries) {
+		int ioapic_idx;
+
+		for_each_ioapic(ioapic_idx)
+			if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic)
+				return ioapic_idx;
+	}
+
+	return -1;
+}
+
+static bool irq_active_low(int idx)
+{
+	int bus = mp_irqs[idx].srcbus;
+
+	/*
+	 * Determine IRQ line polarity (high active or low active):
+	 */
+	switch (mp_irqs[idx].irqflag & MP_IRQPOL_MASK) {
+	case MP_IRQPOL_DEFAULT:
+		/*
+		 * Conforms to spec, ie. bus-type dependent polarity.  PCI
+		 * defaults to low active. [E]ISA defaults to high active.
+		 */
+		return !test_bit(bus, mp_bus_not_pci);
+	case MP_IRQPOL_ACTIVE_HIGH:
+		return false;
+	case MP_IRQPOL_RESERVED:
+		pr_warn("IOAPIC: Invalid polarity: 2, defaulting to low\n");
+		fallthrough;
+	case MP_IRQPOL_ACTIVE_LOW:
+	default: /* Pointless default required due to do gcc stupidity */
+		return true;
+	}
+}
+
+#ifdef CONFIG_EISA
+/*
+ * EISA Edge/Level control register, ELCR
+ */
+static bool EISA_ELCR(unsigned int irq)
+{
+	if (irq < nr_legacy_irqs()) {
+		unsigned int port = PIC_ELCR1 + (irq >> 3);
+		return (inb(port) >> (irq & 7)) & 1;
+	}
+	apic_printk(APIC_VERBOSE, KERN_INFO
+			"Broken MPtable reports ISA irq %d\n", irq);
+	return false;
+}
+
+/*
+ * EISA interrupts are always active high and can be edge or level
+ * triggered depending on the ELCR value.  If an interrupt is listed as
+ * EISA conforming in the MP table, that means its trigger type must be
+ * read in from the ELCR.
+ */
+static bool eisa_irq_is_level(int idx, int bus, bool level)
+{
+	switch (mp_bus_id_to_type[bus]) {
+	case MP_BUS_PCI:
+	case MP_BUS_ISA:
+		return level;
+	case MP_BUS_EISA:
+		return EISA_ELCR(mp_irqs[idx].srcbusirq);
+	}
+	pr_warn("IOAPIC: Invalid srcbus: %d defaulting to level\n", bus);
+	return true;
+}
+#else
+static inline int eisa_irq_is_level(int idx, int bus, bool level)
+{
+	return level;
+}
+#endif
+
+static bool irq_is_level(int idx)
+{
+	int bus = mp_irqs[idx].srcbus;
+	bool level;
+
+	/*
+	 * Determine IRQ trigger mode (edge or level sensitive):
+	 */
+	switch (mp_irqs[idx].irqflag & MP_IRQTRIG_MASK) {
+	case MP_IRQTRIG_DEFAULT:
+		/*
+		 * Conforms to spec, ie. bus-type dependent trigger
+		 * mode. PCI defaults to level, ISA to edge.
+		 */
+		level = !test_bit(bus, mp_bus_not_pci);
+		/* Take EISA into account */
+		return eisa_irq_is_level(idx, bus, level);
+	case MP_IRQTRIG_EDGE:
+		return false;
+	case MP_IRQTRIG_RESERVED:
+		pr_warn("IOAPIC: Invalid trigger mode 2 defaulting to level\n");
+		fallthrough;
+	case MP_IRQTRIG_LEVEL:
+	default: /* Pointless default required due to do gcc stupidity */
+		return true;
+	}
+}
+
+static int __acpi_get_override_irq(u32 gsi, bool *trigger, bool *polarity)
+{
+	int ioapic, pin, idx;
+
+	if (skip_ioapic_setup)
+		return -1;
+
+	ioapic = mp_find_ioapic(gsi);
+	if (ioapic < 0)
+		return -1;
+
+	pin = mp_find_ioapic_pin(ioapic, gsi);
+	if (pin < 0)
+		return -1;
+
+	idx = find_irq_entry(ioapic, pin, mp_INT);
+	if (idx < 0)
+		return -1;
+
+	*trigger = irq_is_level(idx);
+	*polarity = irq_active_low(idx);
+	return 0;
+}
+
+#ifdef CONFIG_ACPI
+int acpi_get_override_irq(u32 gsi, int *is_level, int *active_low)
+{
+	*is_level = *active_low = 0;
+	return __acpi_get_override_irq(gsi, (bool *)is_level,
+				       (bool *)active_low);
+}
+#endif
+
+void ioapic_set_alloc_attr(struct irq_alloc_info *info, int node,
+			   int trigger, int polarity)
+{
+	init_irq_alloc_info(info, NULL);
+	info->type = X86_IRQ_ALLOC_TYPE_IOAPIC;
+	info->ioapic.node = node;
+	info->ioapic.is_level = trigger;
+	info->ioapic.active_low = polarity;
+	info->ioapic.valid = 1;
+}
+
+static void ioapic_copy_alloc_attr(struct irq_alloc_info *dst,
+				   struct irq_alloc_info *src,
+				   u32 gsi, int ioapic_idx, int pin)
+{
+	bool level, pol_low;
+
+	copy_irq_alloc_info(dst, src);
+	dst->type = X86_IRQ_ALLOC_TYPE_IOAPIC;
+	dst->devid = mpc_ioapic_id(ioapic_idx);
+	dst->ioapic.pin = pin;
+	dst->ioapic.valid = 1;
+	if (src && src->ioapic.valid) {
+		dst->ioapic.node = src->ioapic.node;
+		dst->ioapic.is_level = src->ioapic.is_level;
+		dst->ioapic.active_low = src->ioapic.active_low;
+	} else {
+		dst->ioapic.node = NUMA_NO_NODE;
+		if (__acpi_get_override_irq(gsi, &level, &pol_low) >= 0) {
+			dst->ioapic.is_level = level;
+			dst->ioapic.active_low = pol_low;
+		} else {
+			/*
+			 * PCI interrupts are always active low level
+			 * triggered.
+			 */
+			dst->ioapic.is_level = true;
+			dst->ioapic.active_low = true;
+		}
+	}
+}
+
+static int ioapic_alloc_attr_node(struct irq_alloc_info *info)
+{
+	return (info && info->ioapic.valid) ? info->ioapic.node : NUMA_NO_NODE;
+}
+
+static void mp_register_handler(unsigned int irq, bool level)
+{
+	irq_flow_handler_t hdl;
+	bool fasteoi;
+
+	if (level) {
+		irq_set_status_flags(irq, IRQ_LEVEL);
+		fasteoi = true;
+	} else {
+		irq_clear_status_flags(irq, IRQ_LEVEL);
+		fasteoi = false;
+	}
+
+	hdl = fasteoi ? handle_fasteoi_irq : handle_edge_irq;
+	__irq_set_handler(irq, hdl, 0, fasteoi ? "fasteoi" : "edge");
+}
+
+static bool mp_check_pin_attr(int irq, struct irq_alloc_info *info)
+{
+	struct mp_chip_data *data = irq_get_chip_data(irq);
+
+	/*
+	 * setup_IO_APIC_irqs() programs all legacy IRQs with default trigger
+	 * and polarity attributes. So allow the first user to reprogram the
+	 * pin with real trigger and polarity attributes.
+	 */
+	if (irq < nr_legacy_irqs() && data->count == 1) {
+		if (info->ioapic.is_level != data->is_level)
+			mp_register_handler(irq, info->ioapic.is_level);
+		data->entry.is_level = data->is_level = info->ioapic.is_level;
+		data->entry.active_low = data->active_low = info->ioapic.active_low;
+	}
+
+	return data->is_level == info->ioapic.is_level &&
+	       data->active_low == info->ioapic.active_low;
+}
+
+static int alloc_irq_from_domain(struct irq_domain *domain, int ioapic, u32 gsi,
+				 struct irq_alloc_info *info)
+{
+	bool legacy = false;
+	int irq = -1;
+	int type = ioapics[ioapic].irqdomain_cfg.type;
+
+	switch (type) {
+	case IOAPIC_DOMAIN_LEGACY:
+		/*
+		 * Dynamically allocate IRQ number for non-ISA IRQs in the first
+		 * 16 GSIs on some weird platforms.
+		 */
+		if (!ioapic_initialized || gsi >= nr_legacy_irqs())
+			irq = gsi;
+		legacy = mp_is_legacy_irq(irq);
+		break;
+	case IOAPIC_DOMAIN_STRICT:
+		irq = gsi;
+		break;
+	case IOAPIC_DOMAIN_DYNAMIC:
+		break;
+	default:
+		WARN(1, "ioapic: unknown irqdomain type %d\n", type);
+		return -1;
+	}
+
+	return __irq_domain_alloc_irqs(domain, irq, 1,
+				       ioapic_alloc_attr_node(info),
+				       info, legacy, NULL);
+}
+
+/*
+ * Need special handling for ISA IRQs because there may be multiple IOAPIC pins
+ * sharing the same ISA IRQ number and irqdomain only supports 1:1 mapping
+ * between IOAPIC pin and IRQ number. A typical IOAPIC has 24 pins, pin 0-15 are
+ * used for legacy IRQs and pin 16-23 are used for PCI IRQs (PIRQ A-H).
+ * When ACPI is disabled, only legacy IRQ numbers (IRQ0-15) are available, and
+ * some BIOSes may use MP Interrupt Source records to override IRQ numbers for
+ * PIRQs instead of reprogramming the interrupt routing logic. Thus there may be
+ * multiple pins sharing the same legacy IRQ number when ACPI is disabled.
+ */
+static int alloc_isa_irq_from_domain(struct irq_domain *domain,
+				     int irq, int ioapic, int pin,
+				     struct irq_alloc_info *info)
+{
+	struct mp_chip_data *data;
+	struct irq_data *irq_data = irq_get_irq_data(irq);
+	int node = ioapic_alloc_attr_node(info);
+
+	/*
+	 * Legacy ISA IRQ has already been allocated, just add pin to
+	 * the pin list associated with this IRQ and program the IOAPIC
+	 * entry. The IOAPIC entry
+	 */
+	if (irq_data && irq_data->parent_data) {
+		if (!mp_check_pin_attr(irq, info))
+			return -EBUSY;
+		if (__add_pin_to_irq_node(irq_data->chip_data, node, ioapic,
+					  info->ioapic.pin))
+			return -ENOMEM;
+	} else {
+		info->flags |= X86_IRQ_ALLOC_LEGACY;
+		irq = __irq_domain_alloc_irqs(domain, irq, 1, node, info, true,
+					      NULL);
+		if (irq >= 0) {
+			irq_data = irq_domain_get_irq_data(domain, irq);
+			data = irq_data->chip_data;
+			data->isa_irq = true;
+		}
+	}
+
+	return irq;
+}
+
+static int mp_map_pin_to_irq(u32 gsi, int idx, int ioapic, int pin,
+			     unsigned int flags, struct irq_alloc_info *info)
+{
+	int irq;
+	bool legacy = false;
+	struct irq_alloc_info tmp;
+	struct mp_chip_data *data;
+	struct irq_domain *domain = mp_ioapic_irqdomain(ioapic);
+
+	if (!domain)
+		return -ENOSYS;
+
+	if (idx >= 0 && test_bit(mp_irqs[idx].srcbus, mp_bus_not_pci)) {
+		irq = mp_irqs[idx].srcbusirq;
+		legacy = mp_is_legacy_irq(irq);
+		/*
+		 * IRQ2 is unusable for historical reasons on systems which
+		 * have a legacy PIC. See the comment vs. IRQ2 further down.
+		 *
+		 * If this gets removed at some point then the related code
+		 * in lapic_assign_system_vectors() needs to be adjusted as
+		 * well.
+		 */
+		if (legacy && irq == PIC_CASCADE_IR)
+			return -EINVAL;
+	}
+
+	mutex_lock(&ioapic_mutex);
+	if (!(flags & IOAPIC_MAP_ALLOC)) {
+		if (!legacy) {
+			irq = irq_find_mapping(domain, pin);
+			if (irq == 0)
+				irq = -ENOENT;
+		}
+	} else {
+		ioapic_copy_alloc_attr(&tmp, info, gsi, ioapic, pin);
+		if (legacy)
+			irq = alloc_isa_irq_from_domain(domain, irq,
+							ioapic, pin, &tmp);
+		else if ((irq = irq_find_mapping(domain, pin)) == 0)
+			irq = alloc_irq_from_domain(domain, ioapic, gsi, &tmp);
+		else if (!mp_check_pin_attr(irq, &tmp))
+			irq = -EBUSY;
+		if (irq >= 0) {
+			data = irq_get_chip_data(irq);
+			data->count++;
+		}
+	}
+	mutex_unlock(&ioapic_mutex);
+
+	return irq;
+}
+
+static int pin_2_irq(int idx, int ioapic, int pin, unsigned int flags)
+{
+	u32 gsi = mp_pin_to_gsi(ioapic, pin);
+
+	/*
+	 * Debugging check, we are in big trouble if this message pops up!
+	 */
+	if (mp_irqs[idx].dstirq != pin)
+		pr_err("broken BIOS or MPTABLE parser, ayiee!!\n");
+
+#ifdef CONFIG_X86_32
+	/*
+	 * PCI IRQ command line redirection. Yes, limits are hardcoded.
+	 */
+	if ((pin >= 16) && (pin <= 23)) {
+		if (pirq_entries[pin-16] != -1) {
+			if (!pirq_entries[pin-16]) {
+				apic_printk(APIC_VERBOSE, KERN_DEBUG
+						"disabling PIRQ%d\n", pin-16);
+			} else {
+				int irq = pirq_entries[pin-16];
+				apic_printk(APIC_VERBOSE, KERN_DEBUG
+						"using PIRQ%d -> IRQ %d\n",
+						pin-16, irq);
+				return irq;
+			}
+		}
+	}
+#endif
+
+	return  mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags, NULL);
+}
+
+int mp_map_gsi_to_irq(u32 gsi, unsigned int flags, struct irq_alloc_info *info)
+{
+	int ioapic, pin, idx;
+
+	ioapic = mp_find_ioapic(gsi);
+	if (ioapic < 0)
+		return -ENODEV;
+
+	pin = mp_find_ioapic_pin(ioapic, gsi);
+	idx = find_irq_entry(ioapic, pin, mp_INT);
+	if ((flags & IOAPIC_MAP_CHECK) && idx < 0)
+		return -ENODEV;
+
+	return mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags, info);
+}
+
+void mp_unmap_irq(int irq)
+{
+	struct irq_data *irq_data = irq_get_irq_data(irq);
+	struct mp_chip_data *data;
+
+	if (!irq_data || !irq_data->domain)
+		return;
+
+	data = irq_data->chip_data;
+	if (!data || data->isa_irq)
+		return;
+
+	mutex_lock(&ioapic_mutex);
+	if (--data->count == 0)
+		irq_domain_free_irqs(irq, 1);
+	mutex_unlock(&ioapic_mutex);
+}
+
+/*
+ * Find a specific PCI IRQ entry.
+ * Not an __init, possibly needed by modules
+ */
+int IO_APIC_get_PCI_irq_vector(int bus, int slot, int pin)
+{
+	int irq, i, best_ioapic = -1, best_idx = -1;
+
+	apic_printk(APIC_DEBUG,
+		    "querying PCI -> IRQ mapping bus:%d, slot:%d, pin:%d.\n",
+		    bus, slot, pin);
+	if (test_bit(bus, mp_bus_not_pci)) {
+		apic_printk(APIC_VERBOSE,
+			    "PCI BIOS passed nonexistent PCI bus %d!\n", bus);
+		return -1;
+	}
+
+	for (i = 0; i < mp_irq_entries; i++) {
+		int lbus = mp_irqs[i].srcbus;
+		int ioapic_idx, found = 0;
+
+		if (bus != lbus || mp_irqs[i].irqtype != mp_INT ||
+		    slot != ((mp_irqs[i].srcbusirq >> 2) & 0x1f))
+			continue;
+
+		for_each_ioapic(ioapic_idx)
+			if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic ||
+			    mp_irqs[i].dstapic == MP_APIC_ALL) {
+				found = 1;
+				break;
+			}
+		if (!found)
+			continue;
+
+		/* Skip ISA IRQs */
+		irq = pin_2_irq(i, ioapic_idx, mp_irqs[i].dstirq, 0);
+		if (irq > 0 && !IO_APIC_IRQ(irq))
+			continue;
+
+		if (pin == (mp_irqs[i].srcbusirq & 3)) {
+			best_idx = i;
+			best_ioapic = ioapic_idx;
+			goto out;
+		}
+
+		/*
+		 * Use the first all-but-pin matching entry as a
+		 * best-guess fuzzy result for broken mptables.
+		 */
+		if (best_idx < 0) {
+			best_idx = i;
+			best_ioapic = ioapic_idx;
+		}
+	}
+	if (best_idx < 0)
+		return -1;
+
+out:
+	return pin_2_irq(best_idx, best_ioapic, mp_irqs[best_idx].dstirq,
+			 IOAPIC_MAP_ALLOC);
+}
+EXPORT_SYMBOL(IO_APIC_get_PCI_irq_vector);
+
+static struct irq_chip ioapic_chip, ioapic_ir_chip;
+
+static void __init setup_IO_APIC_irqs(void)
+{
+	unsigned int ioapic, pin;
+	int idx;
+
+	apic_printk(APIC_VERBOSE, KERN_DEBUG "init IO_APIC IRQs\n");
+
+	for_each_ioapic_pin(ioapic, pin) {
+		idx = find_irq_entry(ioapic, pin, mp_INT);
+		if (idx < 0)
+			apic_printk(APIC_VERBOSE,
+				    KERN_DEBUG " apic %d pin %d not connected\n",
+				    mpc_ioapic_id(ioapic), pin);
+		else
+			pin_2_irq(idx, ioapic, pin,
+				  ioapic ? 0 : IOAPIC_MAP_ALLOC);
+	}
+}
+
+void ioapic_zap_locks(void)
+{
+	raw_spin_lock_init(&ioapic_lock);
+}
+
+static void io_apic_print_entries(unsigned int apic, unsigned int nr_entries)
+{
+	struct IO_APIC_route_entry entry;
+	char buf[256];
+	int i;
+
+	printk(KERN_DEBUG "IOAPIC %d:\n", apic);
+	for (i = 0; i <= nr_entries; i++) {
+		entry = ioapic_read_entry(apic, i);
+		snprintf(buf, sizeof(buf),
+			 " pin%02x, %s, %s, %s, V(%02X), IRR(%1d), S(%1d)",
+			 i,
+			 entry.masked ? "disabled" : "enabled ",
+			 entry.is_level ? "level" : "edge ",
+			 entry.active_low ? "low " : "high",
+			 entry.vector, entry.irr, entry.delivery_status);
+		if (entry.ir_format) {
+			printk(KERN_DEBUG "%s, remapped, I(%04X),  Z(%X)\n",
+			       buf,
+			       (entry.ir_index_15 << 15) | entry.ir_index_0_14,
+				entry.ir_zero);
+		} else {
+			printk(KERN_DEBUG "%s, %s, D(%02X%02X), M(%1d)\n", buf,
+			       entry.dest_mode_logical ? "logical " : "physical",
+			       entry.virt_destid_8_14, entry.destid_0_7,
+			       entry.delivery_mode);
+		}
+	}
+}
+
+static void __init print_IO_APIC(int ioapic_idx)
+{
+	union IO_APIC_reg_00 reg_00;
+	union IO_APIC_reg_01 reg_01;
+	union IO_APIC_reg_02 reg_02;
+	union IO_APIC_reg_03 reg_03;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	reg_00.raw = io_apic_read(ioapic_idx, 0);
+	reg_01.raw = io_apic_read(ioapic_idx, 1);
+	if (reg_01.bits.version >= 0x10)
+		reg_02.raw = io_apic_read(ioapic_idx, 2);
+	if (reg_01.bits.version >= 0x20)
+		reg_03.raw = io_apic_read(ioapic_idx, 3);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	printk(KERN_DEBUG "IO APIC #%d......\n", mpc_ioapic_id(ioapic_idx));
+	printk(KERN_DEBUG ".... register #00: %08X\n", reg_00.raw);
+	printk(KERN_DEBUG ".......    : physical APIC id: %02X\n", reg_00.bits.ID);
+	printk(KERN_DEBUG ".......    : Delivery Type: %X\n", reg_00.bits.delivery_type);
+	printk(KERN_DEBUG ".......    : LTS          : %X\n", reg_00.bits.LTS);
+
+	printk(KERN_DEBUG ".... register #01: %08X\n", *(int *)&reg_01);
+	printk(KERN_DEBUG ".......     : max redirection entries: %02X\n",
+		reg_01.bits.entries);
+
+	printk(KERN_DEBUG ".......     : PRQ implemented: %X\n", reg_01.bits.PRQ);
+	printk(KERN_DEBUG ".......     : IO APIC version: %02X\n",
+		reg_01.bits.version);
+
+	/*
+	 * Some Intel chipsets with IO APIC VERSION of 0x1? don't have reg_02,
+	 * but the value of reg_02 is read as the previous read register
+	 * value, so ignore it if reg_02 == reg_01.
+	 */
+	if (reg_01.bits.version >= 0x10 && reg_02.raw != reg_01.raw) {
+		printk(KERN_DEBUG ".... register #02: %08X\n", reg_02.raw);
+		printk(KERN_DEBUG ".......     : arbitration: %02X\n", reg_02.bits.arbitration);
+	}
+
+	/*
+	 * Some Intel chipsets with IO APIC VERSION of 0x2? don't have reg_02
+	 * or reg_03, but the value of reg_0[23] is read as the previous read
+	 * register value, so ignore it if reg_03 == reg_0[12].
+	 */
+	if (reg_01.bits.version >= 0x20 && reg_03.raw != reg_02.raw &&
+	    reg_03.raw != reg_01.raw) {
+		printk(KERN_DEBUG ".... register #03: %08X\n", reg_03.raw);
+		printk(KERN_DEBUG ".......     : Boot DT    : %X\n", reg_03.bits.boot_DT);
+	}
+
+	printk(KERN_DEBUG ".... IRQ redirection table:\n");
+	io_apic_print_entries(ioapic_idx, reg_01.bits.entries);
+}
+
+void __init print_IO_APICs(void)
+{
+	int ioapic_idx;
+	unsigned int irq;
+
+	printk(KERN_DEBUG "number of MP IRQ sources: %d.\n", mp_irq_entries);
+	for_each_ioapic(ioapic_idx)
+		printk(KERN_DEBUG "number of IO-APIC #%d registers: %d.\n",
+		       mpc_ioapic_id(ioapic_idx),
+		       ioapics[ioapic_idx].nr_registers);
+
+	/*
+	 * We are a bit conservative about what we expect.  We have to
+	 * know about every hardware change ASAP.
+	 */
+	printk(KERN_INFO "testing the IO APIC.......................\n");
+
+	for_each_ioapic(ioapic_idx)
+		print_IO_APIC(ioapic_idx);
+
+	printk(KERN_DEBUG "IRQ to pin mappings:\n");
+	for_each_active_irq(irq) {
+		struct irq_pin_list *entry;
+		struct irq_chip *chip;
+		struct mp_chip_data *data;
+
+		chip = irq_get_chip(irq);
+		if (chip != &ioapic_chip && chip != &ioapic_ir_chip)
+			continue;
+		data = irq_get_chip_data(irq);
+		if (!data)
+			continue;
+		if (list_empty(&data->irq_2_pin))
+			continue;
+
+		printk(KERN_DEBUG "IRQ%d ", irq);
+		for_each_irq_pin(entry, data->irq_2_pin)
+			pr_cont("-> %d:%d", entry->apic, entry->pin);
+		pr_cont("\n");
+	}
+
+	printk(KERN_INFO ".................................... done.\n");
+}
+
+/* Where if anywhere is the i8259 connect in external int mode */
+static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
+
+void __init enable_IO_APIC(void)
+{
+	int i8259_apic, i8259_pin;
+	int apic, pin;
+
+	if (skip_ioapic_setup)
+		nr_ioapics = 0;
+
+	if (!nr_legacy_irqs() || !nr_ioapics)
+		return;
+
+	for_each_ioapic_pin(apic, pin) {
+		/* See if any of the pins is in ExtINT mode */
+		struct IO_APIC_route_entry entry = ioapic_read_entry(apic, pin);
+
+		/* If the interrupt line is enabled and in ExtInt mode
+		 * I have found the pin where the i8259 is connected.
+		 */
+		if (!entry.masked &&
+		    entry.delivery_mode == APIC_DELIVERY_MODE_EXTINT) {
+			ioapic_i8259.apic = apic;
+			ioapic_i8259.pin  = pin;
+			goto found_i8259;
+		}
+	}
+ found_i8259:
+	/* Look to see what if the MP table has reported the ExtINT */
+	/* If we could not find the appropriate pin by looking at the ioapic
+	 * the i8259 probably is not connected the ioapic but give the
+	 * mptable a chance anyway.
+	 */
+	i8259_pin  = find_isa_irq_pin(0, mp_ExtINT);
+	i8259_apic = find_isa_irq_apic(0, mp_ExtINT);
+	/* Trust the MP table if nothing is setup in the hardware */
+	if ((ioapic_i8259.pin == -1) && (i8259_pin >= 0)) {
+		printk(KERN_WARNING "ExtINT not setup in hardware but reported by MP table\n");
+		ioapic_i8259.pin  = i8259_pin;
+		ioapic_i8259.apic = i8259_apic;
+	}
+	/* Complain if the MP table and the hardware disagree */
+	if (((ioapic_i8259.apic != i8259_apic) || (ioapic_i8259.pin != i8259_pin)) &&
+		(i8259_pin >= 0) && (ioapic_i8259.pin >= 0))
+	{
+		printk(KERN_WARNING "ExtINT in hardware and MP table differ\n");
+	}
+
+	/*
+	 * Do not trust the IO-APIC being empty at bootup
+	 */
+	clear_IO_APIC();
+}
+
+void native_restore_boot_irq_mode(void)
+{
+	/*
+	 * If the i8259 is routed through an IOAPIC
+	 * Put that IOAPIC in virtual wire mode
+	 * so legacy interrupts can be delivered.
+	 */
+	if (ioapic_i8259.pin != -1) {
+		struct IO_APIC_route_entry entry;
+		u32 apic_id = read_apic_id();
+
+		memset(&entry, 0, sizeof(entry));
+		entry.masked		= false;
+		entry.is_level		= false;
+		entry.active_low	= false;
+		entry.dest_mode_logical	= false;
+		entry.delivery_mode	= APIC_DELIVERY_MODE_EXTINT;
+		entry.destid_0_7	= apic_id & 0xFF;
+		entry.virt_destid_8_14	= apic_id >> 8;
+
+		/*
+		 * Add it to the IO-APIC irq-routing table:
+		 */
+		ioapic_write_entry(ioapic_i8259.apic, ioapic_i8259.pin, entry);
+	}
+
+	if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config())
+		disconnect_bsp_APIC(ioapic_i8259.pin != -1);
+}
+
+void restore_boot_irq_mode(void)
+{
+	if (!nr_legacy_irqs())
+		return;
+
+	x86_apic_ops.restore();
+}
+
+#ifdef CONFIG_X86_32
+/*
+ * function to set the IO-APIC physical IDs based on the
+ * values stored in the MPC table.
+ *
+ * by Matt Domsch <Matt_Domsch@dell.com>  Tue Dec 21 12:25:05 CST 1999
+ */
+void __init setup_ioapic_ids_from_mpc_nocheck(void)
+{
+	union IO_APIC_reg_00 reg_00;
+	physid_mask_t phys_id_present_map;
+	int ioapic_idx;
+	int i;
+	unsigned char old_id;
+	unsigned long flags;
+
+	/*
+	 * This is broken; anything with a real cpu count has to
+	 * circumvent this idiocy regardless.
+	 */
+	apic->ioapic_phys_id_map(&phys_cpu_present_map, &phys_id_present_map);
+
+	/*
+	 * Set the IOAPIC ID to the value stored in the MPC table.
+	 */
+	for_each_ioapic(ioapic_idx) {
+		/* Read the register 0 value */
+		raw_spin_lock_irqsave(&ioapic_lock, flags);
+		reg_00.raw = io_apic_read(ioapic_idx, 0);
+		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+		old_id = mpc_ioapic_id(ioapic_idx);
+
+		if (mpc_ioapic_id(ioapic_idx) >= get_physical_broadcast()) {
+			printk(KERN_ERR "BIOS bug, IO-APIC#%d ID is %d in the MPC table!...\n",
+				ioapic_idx, mpc_ioapic_id(ioapic_idx));
+			printk(KERN_ERR "... fixing up to %d. (tell your hw vendor)\n",
+				reg_00.bits.ID);
+			ioapics[ioapic_idx].mp_config.apicid = reg_00.bits.ID;
+		}
+
+		/*
+		 * Sanity check, is the ID really free? Every APIC in a
+		 * system must have a unique ID or we get lots of nice
+		 * 'stuck on smp_invalidate_needed IPI wait' messages.
+		 */
+		if (apic->check_apicid_used(&phys_id_present_map,
+					    mpc_ioapic_id(ioapic_idx))) {
+			printk(KERN_ERR "BIOS bug, IO-APIC#%d ID %d is already used!...\n",
+				ioapic_idx, mpc_ioapic_id(ioapic_idx));
+			for (i = 0; i < get_physical_broadcast(); i++)
+				if (!physid_isset(i, phys_id_present_map))
+					break;
+			if (i >= get_physical_broadcast())
+				panic("Max APIC ID exceeded!\n");
+			printk(KERN_ERR "... fixing up to %d. (tell your hw vendor)\n",
+				i);
+			physid_set(i, phys_id_present_map);
+			ioapics[ioapic_idx].mp_config.apicid = i;
+		} else {
+			physid_mask_t tmp;
+			apic->apicid_to_cpu_present(mpc_ioapic_id(ioapic_idx),
+						    &tmp);
+			apic_printk(APIC_VERBOSE, "Setting %d in the "
+					"phys_id_present_map\n",
+					mpc_ioapic_id(ioapic_idx));
+			physids_or(phys_id_present_map, phys_id_present_map, tmp);
+		}
+
+		/*
+		 * We need to adjust the IRQ routing table
+		 * if the ID changed.
+		 */
+		if (old_id != mpc_ioapic_id(ioapic_idx))
+			for (i = 0; i < mp_irq_entries; i++)
+				if (mp_irqs[i].dstapic == old_id)
+					mp_irqs[i].dstapic
+						= mpc_ioapic_id(ioapic_idx);
+
+		/*
+		 * Update the ID register according to the right value
+		 * from the MPC table if they are different.
+		 */
+		if (mpc_ioapic_id(ioapic_idx) == reg_00.bits.ID)
+			continue;
+
+		apic_printk(APIC_VERBOSE, KERN_INFO
+			"...changing IO-APIC physical APIC ID to %d ...",
+			mpc_ioapic_id(ioapic_idx));
+
+		reg_00.bits.ID = mpc_ioapic_id(ioapic_idx);
+		raw_spin_lock_irqsave(&ioapic_lock, flags);
+		io_apic_write(ioapic_idx, 0, reg_00.raw);
+		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+		/*
+		 * Sanity check
+		 */
+		raw_spin_lock_irqsave(&ioapic_lock, flags);
+		reg_00.raw = io_apic_read(ioapic_idx, 0);
+		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+		if (reg_00.bits.ID != mpc_ioapic_id(ioapic_idx))
+			pr_cont("could not set ID!\n");
+		else
+			apic_printk(APIC_VERBOSE, " ok.\n");
+	}
+}
+
+void __init setup_ioapic_ids_from_mpc(void)
+{
+
+	if (acpi_ioapic)
+		return;
+	/*
+	 * Don't check I/O APIC IDs for xAPIC systems.  They have
+	 * no meaning without the serial APIC bus.
+	 */
+	if (!(boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
+		|| APIC_XAPIC(boot_cpu_apic_version))
+		return;
+	setup_ioapic_ids_from_mpc_nocheck();
+}
+#endif
+
+int no_timer_check __initdata;
+
+static int __init notimercheck(char *s)
+{
+	no_timer_check = 1;
+	return 1;
+}
+__setup("no_timer_check", notimercheck);
+
+static void __init delay_with_tsc(void)
+{
+	unsigned long long start, now;
+	unsigned long end = jiffies + 4;
+
+	start = rdtsc();
+
+	/*
+	 * We don't know the TSC frequency yet, but waiting for
+	 * 40000000000/HZ TSC cycles is safe:
+	 * 4 GHz == 10 jiffies
+	 * 1 GHz == 40 jiffies
+	 */
+	do {
+		rep_nop();
+		now = rdtsc();
+	} while ((now - start) < 40000000000ULL / HZ &&
+		time_before_eq(jiffies, end));
+}
+
+static void __init delay_without_tsc(void)
+{
+	unsigned long end = jiffies + 4;
+	int band = 1;
+
+	/*
+	 * We don't know any frequency yet, but waiting for
+	 * 40940000000/HZ cycles is safe:
+	 * 4 GHz == 10 jiffies
+	 * 1 GHz == 40 jiffies
+	 * 1 << 1 + 1 << 2 +...+ 1 << 11 = 4094
+	 */
+	do {
+		__delay(((1U << band++) * 10000000UL) / HZ);
+	} while (band < 12 && time_before_eq(jiffies, end));
+}
+
+/*
+ * There is a nasty bug in some older SMP boards, their mptable lies
+ * about the timer IRQ. We do the following to work around the situation:
+ *
+ *	- timer IRQ defaults to IO-APIC IRQ
+ *	- if this function detects that timer IRQs are defunct, then we fall
+ *	  back to ISA timer IRQs
+ */
+static int __init timer_irq_works(void)
+{
+	unsigned long t1 = jiffies;
+
+	if (no_timer_check)
+		return 1;
+
+	local_irq_enable();
+	if (boot_cpu_has(X86_FEATURE_TSC))
+		delay_with_tsc();
+	else
+		delay_without_tsc();
+
+	/*
+	 * Expect a few ticks at least, to be sure some possible
+	 * glue logic does not lock up after one or two first
+	 * ticks in a non-ExtINT mode.  Also the local APIC
+	 * might have cached one ExtINT interrupt.  Finally, at
+	 * least one tick may be lost due to delays.
+	 */
+
+	local_irq_disable();
+
+	/* Did jiffies advance? */
+	return time_after(jiffies, t1 + 4);
+}
+
+/*
+ * In the SMP+IOAPIC case it might happen that there are an unspecified
+ * number of pending IRQ events unhandled. These cases are very rare,
+ * so we 'resend' these IRQs via IPIs, to the same CPU. It's much
+ * better to do it this way as thus we do not have to be aware of
+ * 'pending' interrupts in the IRQ path, except at this point.
+ */
+/*
+ * Edge triggered needs to resend any interrupt
+ * that was delayed but this is now handled in the device
+ * independent code.
+ */
+
+/*
+ * Starting up a edge-triggered IO-APIC interrupt is
+ * nasty - we need to make sure that we get the edge.
+ * If it is already asserted for some reason, we need
+ * return 1 to indicate that is was pending.
+ *
+ * This is not complete - we should be able to fake
+ * an edge even if it isn't on the 8259A...
+ */
+static unsigned int startup_ioapic_irq(struct irq_data *data)
+{
+	int was_pending = 0, irq = data->irq;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	if (irq < nr_legacy_irqs()) {
+		legacy_pic->mask(irq);
+		if (legacy_pic->irq_pending(irq))
+			was_pending = 1;
+	}
+	__unmask_ioapic(data->chip_data);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return was_pending;
+}
+
+atomic_t irq_mis_count;
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+static bool io_apic_level_ack_pending(struct mp_chip_data *data)
+{
+	struct irq_pin_list *entry;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	for_each_irq_pin(entry, data->irq_2_pin) {
+		struct IO_APIC_route_entry e;
+		int pin;
+
+		pin = entry->pin;
+		e.w1 = io_apic_read(entry->apic, 0x10 + pin*2);
+		/* Is the remote IRR bit set? */
+		if (e.irr) {
+			raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+			return true;
+		}
+	}
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return false;
+}
+
+static inline bool ioapic_prepare_move(struct irq_data *data)
+{
+	/* If we are moving the IRQ we need to mask it */
+	if (unlikely(irqd_is_setaffinity_pending(data))) {
+		if (!irqd_irq_masked(data))
+			mask_ioapic_irq(data);
+		return true;
+	}
+	return false;
+}
+
+static inline void ioapic_finish_move(struct irq_data *data, bool moveit)
+{
+	if (unlikely(moveit)) {
+		/* Only migrate the irq if the ack has been received.
+		 *
+		 * On rare occasions the broadcast level triggered ack gets
+		 * delayed going to ioapics, and if we reprogram the
+		 * vector while Remote IRR is still set the irq will never
+		 * fire again.
+		 *
+		 * To prevent this scenario we read the Remote IRR bit
+		 * of the ioapic.  This has two effects.
+		 * - On any sane system the read of the ioapic will
+		 *   flush writes (and acks) going to the ioapic from
+		 *   this cpu.
+		 * - We get to see if the ACK has actually been delivered.
+		 *
+		 * Based on failed experiments of reprogramming the
+		 * ioapic entry from outside of irq context starting
+		 * with masking the ioapic entry and then polling until
+		 * Remote IRR was clear before reprogramming the
+		 * ioapic I don't trust the Remote IRR bit to be
+		 * completely accurate.
+		 *
+		 * However there appears to be no other way to plug
+		 * this race, so if the Remote IRR bit is not
+		 * accurate and is causing problems then it is a hardware bug
+		 * and you can go talk to the chipset vendor about it.
+		 */
+		if (!io_apic_level_ack_pending(data->chip_data))
+			irq_move_masked_irq(data);
+		/* If the IRQ is masked in the core, leave it: */
+		if (!irqd_irq_masked(data))
+			unmask_ioapic_irq(data);
+	}
+}
+#else
+static inline bool ioapic_prepare_move(struct irq_data *data)
+{
+	return false;
+}
+static inline void ioapic_finish_move(struct irq_data *data, bool moveit)
+{
+}
+#endif
+
+static void ioapic_ack_level(struct irq_data *irq_data)
+{
+	struct irq_cfg *cfg = irqd_cfg(irq_data);
+	unsigned long v;
+	bool moveit;
+	int i;
+
+	irq_complete_move(cfg);
+	moveit = ioapic_prepare_move(irq_data);
+
+	/*
+	 * It appears there is an erratum which affects at least version 0x11
+	 * of I/O APIC (that's the 82093AA and cores integrated into various
+	 * chipsets).  Under certain conditions a level-triggered interrupt is
+	 * erroneously delivered as edge-triggered one but the respective IRR
+	 * bit gets set nevertheless.  As a result the I/O unit expects an EOI
+	 * message but it will never arrive and further interrupts are blocked
+	 * from the source.  The exact reason is so far unknown, but the
+	 * phenomenon was observed when two consecutive interrupt requests
+	 * from a given source get delivered to the same CPU and the source is
+	 * temporarily disabled in between.
+	 *
+	 * A workaround is to simulate an EOI message manually.  We achieve it
+	 * by setting the trigger mode to edge and then to level when the edge
+	 * trigger mode gets detected in the TMR of a local APIC for a
+	 * level-triggered interrupt.  We mask the source for the time of the
+	 * operation to prevent an edge-triggered interrupt escaping meanwhile.
+	 * The idea is from Manfred Spraul.  --macro
+	 *
+	 * Also in the case when cpu goes offline, fixup_irqs() will forward
+	 * any unhandled interrupt on the offlined cpu to the new cpu
+	 * destination that is handling the corresponding interrupt. This
+	 * interrupt forwarding is done via IPI's. Hence, in this case also
+	 * level-triggered io-apic interrupt will be seen as an edge
+	 * interrupt in the IRR. And we can't rely on the cpu's EOI
+	 * to be broadcasted to the IO-APIC's which will clear the remoteIRR
+	 * corresponding to the level-triggered interrupt. Hence on IO-APIC's
+	 * supporting EOI register, we do an explicit EOI to clear the
+	 * remote IRR and on IO-APIC's which don't have an EOI register,
+	 * we use the above logic (mask+edge followed by unmask+level) from
+	 * Manfred Spraul to clear the remote IRR.
+	 */
+	i = cfg->vector;
+	v = apic_read(APIC_TMR + ((i & ~0x1f) >> 1));
+
+	/*
+	 * We must acknowledge the irq before we move it or the acknowledge will
+	 * not propagate properly.
+	 */
+	ack_APIC_irq();
+
+	/*
+	 * Tail end of clearing remote IRR bit (either by delivering the EOI
+	 * message via io-apic EOI register write or simulating it using
+	 * mask+edge followed by unmask+level logic) manually when the
+	 * level triggered interrupt is seen as the edge triggered interrupt
+	 * at the cpu.
+	 */
+	if (!(v & (1 << (i & 0x1f)))) {
+		atomic_inc(&irq_mis_count);
+		eoi_ioapic_pin(cfg->vector, irq_data->chip_data);
+	}
+
+	ioapic_finish_move(irq_data, moveit);
+}
+
+static void ioapic_ir_ack_level(struct irq_data *irq_data)
+{
+	struct mp_chip_data *data = irq_data->chip_data;
+
+	/*
+	 * Intr-remapping uses pin number as the virtual vector
+	 * in the RTE. Actual vector is programmed in
+	 * intr-remapping table entry. Hence for the io-apic
+	 * EOI we use the pin number.
+	 */
+	apic_ack_irq(irq_data);
+	eoi_ioapic_pin(data->entry.vector, data);
+}
+
+/*
+ * The I/OAPIC is just a device for generating MSI messages from legacy
+ * interrupt pins. Various fields of the RTE translate into bits of the
+ * resulting MSI which had a historical meaning.
+ *
+ * With interrupt remapping, many of those bits have different meanings
+ * in the underlying MSI, but the way that the I/OAPIC transforms them
+ * from its RTE to the MSI message is the same. This function allows
+ * the parent IRQ domain to compose the MSI message, then takes the
+ * relevant bits to put them in the appropriate places in the RTE in
+ * order to generate that message when the IRQ happens.
+ *
+ * The setup here relies on a preconfigured route entry (is_level,
+ * active_low, masked) because the parent domain is merely composing the
+ * generic message routing information which is used for the MSI.
+ */
+static void ioapic_setup_msg_from_msi(struct irq_data *irq_data,
+				      struct IO_APIC_route_entry *entry)
+{
+	struct msi_msg msg;
+
+	/* Let the parent domain compose the MSI message */
+	irq_chip_compose_msi_msg(irq_data, &msg);
+
+	/*
+	 * - Real vector
+	 * - DMAR/IR: 8bit subhandle (ioapic.pin)
+	 * - AMD/IR:  8bit IRTE index
+	 */
+	entry->vector			= msg.arch_data.vector;
+	/* Delivery mode (for DMAR/IR all 0) */
+	entry->delivery_mode		= msg.arch_data.delivery_mode;
+	/* Destination mode or DMAR/IR index bit 15 */
+	entry->dest_mode_logical	= msg.arch_addr_lo.dest_mode_logical;
+	/* DMAR/IR: 1, 0 for all other modes */
+	entry->ir_format		= msg.arch_addr_lo.dmar_format;
+	/*
+	 * - DMAR/IR: index bit 0-14.
+	 *
+	 * - Virt: If the host supports x2apic without a virtualized IR
+	 *	   unit then bit 0-6 of dmar_index_0_14 are providing bit
+	 *	   8-14 of the destination id.
+	 *
+	 * All other modes have bit 0-6 of dmar_index_0_14 cleared and the
+	 * topmost 8 bits are destination id bit 0-7 (entry::destid_0_7).
+	 */
+	entry->ir_index_0_14		= msg.arch_addr_lo.dmar_index_0_14;
+}
+
+static void ioapic_configure_entry(struct irq_data *irqd)
+{
+	struct mp_chip_data *mpd = irqd->chip_data;
+	struct irq_pin_list *entry;
+
+	ioapic_setup_msg_from_msi(irqd, &mpd->entry);
+
+	for_each_irq_pin(entry, mpd->irq_2_pin)
+		__ioapic_write_entry(entry->apic, entry->pin, mpd->entry);
+}
+
+static int ioapic_set_affinity(struct irq_data *irq_data,
+			       const struct cpumask *mask, bool force)
+{
+	struct irq_data *parent = irq_data->parent_data;
+	unsigned long flags;
+	int ret;
+
+	ret = parent->chip->irq_set_affinity(parent, mask, force);
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE)
+		ioapic_configure_entry(irq_data);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return ret;
+}
+
+/*
+ * Interrupt shutdown masks the ioapic pin, but the interrupt might already
+ * be in flight, but not yet serviced by the target CPU. That means
+ * __synchronize_hardirq() would return and claim that everything is calmed
+ * down. So free_irq() would proceed and deactivate the interrupt and free
+ * resources.
+ *
+ * Once the target CPU comes around to service it it will find a cleared
+ * vector and complain. While the spurious interrupt is harmless, the full
+ * release of resources might prevent the interrupt from being acknowledged
+ * which keeps the hardware in a weird state.
+ *
+ * Verify that the corresponding Remote-IRR bits are clear.
+ */
+static int ioapic_irq_get_chip_state(struct irq_data *irqd,
+				   enum irqchip_irq_state which,
+				   bool *state)
+{
+	struct mp_chip_data *mcd = irqd->chip_data;
+	struct IO_APIC_route_entry rentry;
+	struct irq_pin_list *p;
+
+	if (which != IRQCHIP_STATE_ACTIVE)
+		return -EINVAL;
+
+	*state = false;
+	raw_spin_lock(&ioapic_lock);
+	for_each_irq_pin(p, mcd->irq_2_pin) {
+		rentry = __ioapic_read_entry(p->apic, p->pin);
+		/*
+		 * The remote IRR is only valid in level trigger mode. It's
+		 * meaning is undefined for edge triggered interrupts and
+		 * irrelevant because the IO-APIC treats them as fire and
+		 * forget.
+		 */
+		if (rentry.irr && rentry.is_level) {
+			*state = true;
+			break;
+		}
+	}
+	raw_spin_unlock(&ioapic_lock);
+	return 0;
+}
+
+static struct irq_chip ioapic_chip __read_mostly = {
+	.name			= "IO-APIC",
+	.irq_startup		= startup_ioapic_irq,
+	.irq_mask		= mask_ioapic_irq,
+	.irq_unmask		= unmask_ioapic_irq,
+	.irq_ack		= irq_chip_ack_parent,
+	.irq_eoi		= ioapic_ack_level,
+	.irq_set_affinity	= ioapic_set_affinity,
+	.irq_retrigger		= irq_chip_retrigger_hierarchy,
+	.irq_get_irqchip_state	= ioapic_irq_get_chip_state,
+	.flags			= IRQCHIP_SKIP_SET_WAKE |
+				  IRQCHIP_AFFINITY_PRE_STARTUP,
+};
+
+static struct irq_chip ioapic_ir_chip __read_mostly = {
+	.name			= "IR-IO-APIC",
+	.irq_startup		= startup_ioapic_irq,
+	.irq_mask		= mask_ioapic_irq,
+	.irq_unmask		= unmask_ioapic_irq,
+	.irq_ack		= irq_chip_ack_parent,
+	.irq_eoi		= ioapic_ir_ack_level,
+	.irq_set_affinity	= ioapic_set_affinity,
+	.irq_retrigger		= irq_chip_retrigger_hierarchy,
+	.irq_get_irqchip_state	= ioapic_irq_get_chip_state,
+	.flags			= IRQCHIP_SKIP_SET_WAKE |
+				  IRQCHIP_AFFINITY_PRE_STARTUP,
+};
+
+static inline void init_IO_APIC_traps(void)
+{
+	struct irq_cfg *cfg;
+	unsigned int irq;
+
+	for_each_active_irq(irq) {
+		cfg = irq_cfg(irq);
+		if (IO_APIC_IRQ(irq) && cfg && !cfg->vector) {
+			/*
+			 * Hmm.. We don't have an entry for this,
+			 * so default to an old-fashioned 8259
+			 * interrupt if we can..
+			 */
+			if (irq < nr_legacy_irqs())
+				legacy_pic->make_irq(irq);
+			else
+				/* Strange. Oh, well.. */
+				irq_set_chip(irq, &no_irq_chip);
+		}
+	}
+}
+
+/*
+ * The local APIC irq-chip implementation:
+ */
+
+static void mask_lapic_irq(struct irq_data *data)
+{
+	unsigned long v;
+
+	v = apic_read(APIC_LVT0);
+	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
+}
+
+static void unmask_lapic_irq(struct irq_data *data)
+{
+	unsigned long v;
+
+	v = apic_read(APIC_LVT0);
+	apic_write(APIC_LVT0, v & ~APIC_LVT_MASKED);
+}
+
+static void ack_lapic_irq(struct irq_data *data)
+{
+	ack_APIC_irq();
+}
+
+static struct irq_chip lapic_chip __read_mostly = {
+	.name		= "local-APIC",
+	.irq_mask	= mask_lapic_irq,
+	.irq_unmask	= unmask_lapic_irq,
+	.irq_ack	= ack_lapic_irq,
+};
+
+static void lapic_register_intr(int irq)
+{
+	irq_clear_status_flags(irq, IRQ_LEVEL);
+	irq_set_chip_and_handler_name(irq, &lapic_chip, handle_edge_irq,
+				      "edge");
+}
+
+/*
+ * This looks a bit hackish but it's about the only one way of sending
+ * a few INTA cycles to 8259As and any associated glue logic.  ICR does
+ * not support the ExtINT mode, unfortunately.  We need to send these
+ * cycles as some i82489DX-based boards have glue logic that keeps the
+ * 8259A interrupt line asserted until INTA.  --macro
+ */
+static inline void __init unlock_ExtINT_logic(void)
+{
+	int apic, pin, i;
+	struct IO_APIC_route_entry entry0, entry1;
+	unsigned char save_control, save_freq_select;
+	u32 apic_id;
+
+	pin  = find_isa_irq_pin(8, mp_INT);
+	if (pin == -1) {
+		WARN_ON_ONCE(1);
+		return;
+	}
+	apic = find_isa_irq_apic(8, mp_INT);
+	if (apic == -1) {
+		WARN_ON_ONCE(1);
+		return;
+	}
+
+	entry0 = ioapic_read_entry(apic, pin);
+	clear_IO_APIC_pin(apic, pin);
+
+	apic_id = hard_smp_processor_id();
+	memset(&entry1, 0, sizeof(entry1));
+
+	entry1.dest_mode_logical	= true;
+	entry1.masked			= false;
+	entry1.destid_0_7		= apic_id & 0xFF;
+	entry1.virt_destid_8_14		= apic_id >> 8;
+	entry1.delivery_mode		= APIC_DELIVERY_MODE_EXTINT;
+	entry1.active_low		= entry0.active_low;
+	entry1.is_level			= false;
+	entry1.vector = 0;
+
+	ioapic_write_entry(apic, pin, entry1);
+
+	save_control = CMOS_READ(RTC_CONTROL);
+	save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
+	CMOS_WRITE((save_freq_select & ~RTC_RATE_SELECT) | 0x6,
+		   RTC_FREQ_SELECT);
+	CMOS_WRITE(save_control | RTC_PIE, RTC_CONTROL);
+
+	i = 100;
+	while (i-- > 0) {
+		mdelay(10);
+		if ((CMOS_READ(RTC_INTR_FLAGS) & RTC_PF) == RTC_PF)
+			i -= 10;
+	}
+
+	CMOS_WRITE(save_control, RTC_CONTROL);
+	CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
+	clear_IO_APIC_pin(apic, pin);
+
+	ioapic_write_entry(apic, pin, entry0);
+}
+
+static int disable_timer_pin_1 __initdata;
+/* Actually the next is obsolete, but keep it for paranoid reasons -AK */
+static int __init disable_timer_pin_setup(char *arg)
+{
+	disable_timer_pin_1 = 1;
+	return 0;
+}
+early_param("disable_timer_pin_1", disable_timer_pin_setup);
+
+static int mp_alloc_timer_irq(int ioapic, int pin)
+{
+	int irq = -1;
+	struct irq_domain *domain = mp_ioapic_irqdomain(ioapic);
+
+	if (domain) {
+		struct irq_alloc_info info;
+
+		ioapic_set_alloc_attr(&info, NUMA_NO_NODE, 0, 0);
+		info.devid = mpc_ioapic_id(ioapic);
+		info.ioapic.pin = pin;
+		mutex_lock(&ioapic_mutex);
+		irq = alloc_isa_irq_from_domain(domain, 0, ioapic, pin, &info);
+		mutex_unlock(&ioapic_mutex);
+	}
+
+	return irq;
+}
+
+/*
+ * This code may look a bit paranoid, but it's supposed to cooperate with
+ * a wide range of boards and BIOS bugs.  Fortunately only the timer IRQ
+ * is so screwy.  Thanks to Brian Perkins for testing/hacking this beast
+ * fanatically on his truly buggy board.
+ *
+ * FIXME: really need to revamp this for all platforms.
+ */
+static inline void __init check_timer(void)
+{
+	struct irq_data *irq_data = irq_get_irq_data(0);
+	struct mp_chip_data *data = irq_data->chip_data;
+	struct irq_cfg *cfg = irqd_cfg(irq_data);
+	int node = cpu_to_node(0);
+	int apic1, pin1, apic2, pin2;
+	int no_pin1 = 0;
+
+	if (!global_clock_event)
+		return;
+
+	local_irq_disable();
+
+	/*
+	 * get/set the timer IRQ vector:
+	 */
+	legacy_pic->mask(0);
+
+	/*
+	 * As IRQ0 is to be enabled in the 8259A, the virtual
+	 * wire has to be disabled in the local APIC.  Also
+	 * timer interrupts need to be acknowledged manually in
+	 * the 8259A for the i82489DX when using the NMI
+	 * watchdog as that APIC treats NMIs as level-triggered.
+	 * The AEOI mode will finish them in the 8259A
+	 * automatically.
+	 */
+	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
+	legacy_pic->init(1);
+
+	pin1  = find_isa_irq_pin(0, mp_INT);
+	apic1 = find_isa_irq_apic(0, mp_INT);
+	pin2  = ioapic_i8259.pin;
+	apic2 = ioapic_i8259.apic;
+
+	apic_printk(APIC_QUIET, KERN_INFO "..TIMER: vector=0x%02X "
+		    "apic1=%d pin1=%d apic2=%d pin2=%d\n",
+		    cfg->vector, apic1, pin1, apic2, pin2);
+
+	/*
+	 * Some BIOS writers are clueless and report the ExtINTA
+	 * I/O APIC input from the cascaded 8259A as the timer
+	 * interrupt input.  So just in case, if only one pin
+	 * was found above, try it both directly and through the
+	 * 8259A.
+	 */
+	if (pin1 == -1) {
+		panic_if_irq_remap("BIOS bug: timer not connected to IO-APIC");
+		pin1 = pin2;
+		apic1 = apic2;
+		no_pin1 = 1;
+	} else if (pin2 == -1) {
+		pin2 = pin1;
+		apic2 = apic1;
+	}
+
+	if (pin1 != -1) {
+		/* Ok, does IRQ0 through the IOAPIC work? */
+		if (no_pin1) {
+			mp_alloc_timer_irq(apic1, pin1);
+		} else {
+			/*
+			 * for edge trigger, it's already unmasked,
+			 * so only need to unmask if it is level-trigger
+			 * do we really have level trigger timer?
+			 */
+			int idx = find_irq_entry(apic1, pin1, mp_INT);
+
+			if (idx != -1 && irq_is_level(idx))
+				unmask_ioapic_irq(irq_get_irq_data(0));
+		}
+		irq_domain_deactivate_irq(irq_data);
+		irq_domain_activate_irq(irq_data, false);
+		if (timer_irq_works()) {
+			if (disable_timer_pin_1 > 0)
+				clear_IO_APIC_pin(0, pin1);
+			goto out;
+		}
+		panic_if_irq_remap("timer doesn't work through Interrupt-remapped IO-APIC");
+		clear_IO_APIC_pin(apic1, pin1);
+		if (!no_pin1)
+			apic_printk(APIC_QUIET, KERN_ERR "..MP-BIOS bug: "
+				    "8254 timer not connected to IO-APIC\n");
+
+		apic_printk(APIC_QUIET, KERN_INFO "...trying to set up timer "
+			    "(IRQ0) through the 8259A ...\n");
+		apic_printk(APIC_QUIET, KERN_INFO
+			    "..... (found apic %d pin %d) ...\n", apic2, pin2);
+		/*
+		 * legacy devices should be connected to IO APIC #0
+		 */
+		replace_pin_at_irq_node(data, node, apic1, pin1, apic2, pin2);
+		irq_domain_deactivate_irq(irq_data);
+		irq_domain_activate_irq(irq_data, false);
+		legacy_pic->unmask(0);
+		if (timer_irq_works()) {
+			apic_printk(APIC_QUIET, KERN_INFO "....... works.\n");
+			goto out;
+		}
+		/*
+		 * Cleanup, just in case ...
+		 */
+		legacy_pic->mask(0);
+		clear_IO_APIC_pin(apic2, pin2);
+		apic_printk(APIC_QUIET, KERN_INFO "....... failed.\n");
+	}
+
+	apic_printk(APIC_QUIET, KERN_INFO
+		    "...trying to set up timer as Virtual Wire IRQ...\n");
+
+	lapic_register_intr(0);
+	apic_write(APIC_LVT0, APIC_DM_FIXED | cfg->vector);	/* Fixed mode */
+	legacy_pic->unmask(0);
+
+	if (timer_irq_works()) {
+		apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
+		goto out;
+	}
+	legacy_pic->mask(0);
+	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | cfg->vector);
+	apic_printk(APIC_QUIET, KERN_INFO "..... failed.\n");
+
+	apic_printk(APIC_QUIET, KERN_INFO
+		    "...trying to set up timer as ExtINT IRQ...\n");
+
+	legacy_pic->init(0);
+	legacy_pic->make_irq(0);
+	apic_write(APIC_LVT0, APIC_DM_EXTINT);
+	legacy_pic->unmask(0);
+
+	unlock_ExtINT_logic();
+
+	if (timer_irq_works()) {
+		apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
+		goto out;
+	}
+	apic_printk(APIC_QUIET, KERN_INFO "..... failed :(.\n");
+	if (apic_is_x2apic_enabled())
+		apic_printk(APIC_QUIET, KERN_INFO
+			    "Perhaps problem with the pre-enabled x2apic mode\n"
+			    "Try booting with x2apic and interrupt-remapping disabled in the bios.\n");
+	panic("IO-APIC + timer doesn't work!  Boot with apic=debug and send a "
+		"report.  Then try booting with the 'noapic' option.\n");
+out:
+	local_irq_enable();
+}
+
+/*
+ * Traditionally ISA IRQ2 is the cascade IRQ, and is not available
+ * to devices.  However there may be an I/O APIC pin available for
+ * this interrupt regardless.  The pin may be left unconnected, but
+ * typically it will be reused as an ExtINT cascade interrupt for
+ * the master 8259A.  In the MPS case such a pin will normally be
+ * reported as an ExtINT interrupt in the MP table.  With ACPI
+ * there is no provision for ExtINT interrupts, and in the absence
+ * of an override it would be treated as an ordinary ISA I/O APIC
+ * interrupt, that is edge-triggered and unmasked by default.  We
+ * used to do this, but it caused problems on some systems because
+ * of the NMI watchdog and sometimes IRQ0 of the 8254 timer using
+ * the same ExtINT cascade interrupt to drive the local APIC of the
+ * bootstrap processor.  Therefore we refrain from routing IRQ2 to
+ * the I/O APIC in all cases now.  No actual device should request
+ * it anyway.  --macro
+ */
+#define PIC_IRQS	(1UL << PIC_CASCADE_IR)
+
+static int mp_irqdomain_create(int ioapic)
+{
+	struct irq_domain *parent;
+	int hwirqs = mp_ioapic_pin_count(ioapic);
+	struct ioapic *ip = &ioapics[ioapic];
+	struct ioapic_domain_cfg *cfg = &ip->irqdomain_cfg;
+	struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(ioapic);
+	struct fwnode_handle *fn;
+	struct irq_fwspec fwspec;
+
+	if (cfg->type == IOAPIC_DOMAIN_INVALID)
+		return 0;
+
+	/* Handle device tree enumerated APICs proper */
+	if (cfg->dev) {
+		fn = of_node_to_fwnode(cfg->dev);
+	} else {
+		fn = irq_domain_alloc_named_id_fwnode("IO-APIC", mpc_ioapic_id(ioapic));
+		if (!fn)
+			return -ENOMEM;
+	}
+
+	fwspec.fwnode = fn;
+	fwspec.param_count = 1;
+	fwspec.param[0] = mpc_ioapic_id(ioapic);
+
+	parent = irq_find_matching_fwspec(&fwspec, DOMAIN_BUS_ANY);
+	if (!parent) {
+		if (!cfg->dev)
+			irq_domain_free_fwnode(fn);
+		return -ENODEV;
+	}
+
+	ip->irqdomain = irq_domain_create_linear(fn, hwirqs, cfg->ops,
+						 (void *)(long)ioapic);
+
+	if (!ip->irqdomain) {
+		/* Release fw handle if it was allocated above */
+		if (!cfg->dev)
+			irq_domain_free_fwnode(fn);
+		return -ENOMEM;
+	}
+
+	ip->irqdomain->parent = parent;
+
+	if (cfg->type == IOAPIC_DOMAIN_LEGACY ||
+	    cfg->type == IOAPIC_DOMAIN_STRICT)
+		ioapic_dynirq_base = max(ioapic_dynirq_base,
+					 gsi_cfg->gsi_end + 1);
+
+	return 0;
+}
+
+static void ioapic_destroy_irqdomain(int idx)
+{
+	struct ioapic_domain_cfg *cfg = &ioapics[idx].irqdomain_cfg;
+	struct fwnode_handle *fn = ioapics[idx].irqdomain->fwnode;
+
+	if (ioapics[idx].irqdomain) {
+		irq_domain_remove(ioapics[idx].irqdomain);
+		if (!cfg->dev)
+			irq_domain_free_fwnode(fn);
+		ioapics[idx].irqdomain = NULL;
+	}
+}
+
+void __init setup_IO_APIC(void)
+{
+	int ioapic;
+
+	if (skip_ioapic_setup || !nr_ioapics)
+		return;
+
+	io_apic_irqs = nr_legacy_irqs() ? ~PIC_IRQS : ~0UL;
+
+	apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
+	for_each_ioapic(ioapic)
+		BUG_ON(mp_irqdomain_create(ioapic));
+
+	/*
+         * Set up IO-APIC IRQ routing.
+         */
+	x86_init.mpparse.setup_ioapic_ids();
+
+	sync_Arb_IDs();
+	setup_IO_APIC_irqs();
+	init_IO_APIC_traps();
+	if (nr_legacy_irqs())
+		check_timer();
+
+	ioapic_initialized = 1;
+}
+
+static void resume_ioapic_id(int ioapic_idx)
+{
+	unsigned long flags;
+	union IO_APIC_reg_00 reg_00;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	reg_00.raw = io_apic_read(ioapic_idx, 0);
+	if (reg_00.bits.ID != mpc_ioapic_id(ioapic_idx)) {
+		reg_00.bits.ID = mpc_ioapic_id(ioapic_idx);
+		io_apic_write(ioapic_idx, 0, reg_00.raw);
+	}
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+static void ioapic_resume(void)
+{
+	int ioapic_idx;
+
+	for_each_ioapic_reverse(ioapic_idx)
+		resume_ioapic_id(ioapic_idx);
+
+	restore_ioapic_entries();
+}
+
+static struct syscore_ops ioapic_syscore_ops = {
+	.suspend = save_ioapic_entries,
+	.resume = ioapic_resume,
+};
+
+static int __init ioapic_init_ops(void)
+{
+	register_syscore_ops(&ioapic_syscore_ops);
+
+	return 0;
+}
+
+device_initcall(ioapic_init_ops);
+
+static int io_apic_get_redir_entries(int ioapic)
+{
+	union IO_APIC_reg_01	reg_01;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	reg_01.raw = io_apic_read(ioapic, 1);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	/* The register returns the maximum index redir index
+	 * supported, which is one less than the total number of redir
+	 * entries.
+	 */
+	return reg_01.bits.entries + 1;
+}
+
+unsigned int arch_dynirq_lower_bound(unsigned int from)
+{
+	unsigned int ret;
+
+	/*
+	 * dmar_alloc_hwirq() may be called before setup_IO_APIC(), so use
+	 * gsi_top if ioapic_dynirq_base hasn't been initialized yet.
+	 */
+	ret = ioapic_dynirq_base ? : gsi_top;
+
+	/*
+	 * For DT enabled machines ioapic_dynirq_base is irrelevant and
+	 * always 0. gsi_top can be 0 if there is no IO/APIC registered.
+	 * 0 is an invalid interrupt number for dynamic allocations. Return
+	 * @from instead.
+	 */
+	return ret ? : from;
+}
+
+#ifdef CONFIG_X86_32
+static int io_apic_get_unique_id(int ioapic, int apic_id)
+{
+	union IO_APIC_reg_00 reg_00;
+	static physid_mask_t apic_id_map = PHYSID_MASK_NONE;
+	physid_mask_t tmp;
+	unsigned long flags;
+	int i = 0;
+
+	/*
+	 * The P4 platform supports up to 256 APIC IDs on two separate APIC
+	 * buses (one for LAPICs, one for IOAPICs), where predecessors only
+	 * supports up to 16 on one shared APIC bus.
+	 *
+	 * TBD: Expand LAPIC/IOAPIC support on P4-class systems to take full
+	 *      advantage of new APIC bus architecture.
+	 */
+
+	if (physids_empty(apic_id_map))
+		apic->ioapic_phys_id_map(&phys_cpu_present_map, &apic_id_map);
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	reg_00.raw = io_apic_read(ioapic, 0);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	if (apic_id >= get_physical_broadcast()) {
+		printk(KERN_WARNING "IOAPIC[%d]: Invalid apic_id %d, trying "
+			"%d\n", ioapic, apic_id, reg_00.bits.ID);
+		apic_id = reg_00.bits.ID;
+	}
+
+	/*
+	 * Every APIC in a system must have a unique ID or we get lots of nice
+	 * 'stuck on smp_invalidate_needed IPI wait' messages.
+	 */
+	if (apic->check_apicid_used(&apic_id_map, apic_id)) {
+
+		for (i = 0; i < get_physical_broadcast(); i++) {
+			if (!apic->check_apicid_used(&apic_id_map, i))
+				break;
+		}
+
+		if (i == get_physical_broadcast())
+			panic("Max apic_id exceeded!\n");
+
+		printk(KERN_WARNING "IOAPIC[%d]: apic_id %d already used, "
+			"trying %d\n", ioapic, apic_id, i);
+
+		apic_id = i;
+	}
+
+	apic->apicid_to_cpu_present(apic_id, &tmp);
+	physids_or(apic_id_map, apic_id_map, tmp);
+
+	if (reg_00.bits.ID != apic_id) {
+		reg_00.bits.ID = apic_id;
+
+		raw_spin_lock_irqsave(&ioapic_lock, flags);
+		io_apic_write(ioapic, 0, reg_00.raw);
+		reg_00.raw = io_apic_read(ioapic, 0);
+		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+		/* Sanity check */
+		if (reg_00.bits.ID != apic_id) {
+			pr_err("IOAPIC[%d]: Unable to change apic_id!\n",
+			       ioapic);
+			return -1;
+		}
+	}
+
+	apic_printk(APIC_VERBOSE, KERN_INFO
+			"IOAPIC[%d]: Assigned apic_id %d\n", ioapic, apic_id);
+
+	return apic_id;
+}
+
+static u8 io_apic_unique_id(int idx, u8 id)
+{
+	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
+	    !APIC_XAPIC(boot_cpu_apic_version))
+		return io_apic_get_unique_id(idx, id);
+	else
+		return id;
+}
+#else
+static u8 io_apic_unique_id(int idx, u8 id)
+{
+	union IO_APIC_reg_00 reg_00;
+	DECLARE_BITMAP(used, 256);
+	unsigned long flags;
+	u8 new_id;
+	int i;
+
+	bitmap_zero(used, 256);
+	for_each_ioapic(i)
+		__set_bit(mpc_ioapic_id(i), used);
+
+	/* Hand out the requested id if available */
+	if (!test_bit(id, used))
+		return id;
+
+	/*
+	 * Read the current id from the ioapic and keep it if
+	 * available.
+	 */
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	reg_00.raw = io_apic_read(idx, 0);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+	new_id = reg_00.bits.ID;
+	if (!test_bit(new_id, used)) {
+		apic_printk(APIC_VERBOSE, KERN_INFO
+			"IOAPIC[%d]: Using reg apic_id %d instead of %d\n",
+			 idx, new_id, id);
+		return new_id;
+	}
+
+	/*
+	 * Get the next free id and write it to the ioapic.
+	 */
+	new_id = find_first_zero_bit(used, 256);
+	reg_00.bits.ID = new_id;
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	io_apic_write(idx, 0, reg_00.raw);
+	reg_00.raw = io_apic_read(idx, 0);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+	/* Sanity check */
+	BUG_ON(reg_00.bits.ID != new_id);
+
+	return new_id;
+}
+#endif
+
+static int io_apic_get_version(int ioapic)
+{
+	union IO_APIC_reg_01	reg_01;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	reg_01.raw = io_apic_read(ioapic, 1);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return reg_01.bits.version;
+}
+
+/*
+ * This function updates target affinity of IOAPIC interrupts to include
+ * the CPUs which came online during SMP bringup.
+ */
+#define IOAPIC_RESOURCE_NAME_SIZE 11
+
+static struct resource *ioapic_resources;
+
+static struct resource * __init ioapic_setup_resources(void)
+{
+	unsigned long n;
+	struct resource *res;
+	char *mem;
+	int i;
+
+	if (nr_ioapics == 0)
+		return NULL;
+
+	n = IOAPIC_RESOURCE_NAME_SIZE + sizeof(struct resource);
+	n *= nr_ioapics;
+
+	mem = memblock_alloc(n, SMP_CACHE_BYTES);
+	if (!mem)
+		panic("%s: Failed to allocate %lu bytes\n", __func__, n);
+	res = (void *)mem;
+
+	mem += sizeof(struct resource) * nr_ioapics;
+
+	for_each_ioapic(i) {
+		res[i].name = mem;
+		res[i].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+		snprintf(mem, IOAPIC_RESOURCE_NAME_SIZE, "IOAPIC %u", i);
+		mem += IOAPIC_RESOURCE_NAME_SIZE;
+		ioapics[i].iomem_res = &res[i];
+	}
+
+	ioapic_resources = res;
+
+	return res;
+}
+
+static void io_apic_set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
+{
+	pgprot_t flags = FIXMAP_PAGE_NOCACHE;
+
+	/*
+	 * Ensure fixmaps for IOAPIC MMIO respect memory encryption pgprot
+	 * bits, just like normal ioremap():
+	 */
+	flags = pgprot_decrypted(flags);
+
+	__set_fixmap(idx, phys, flags);
+}
+
+void __init io_apic_init_mappings(void)
+{
+	unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
+	struct resource *ioapic_res;
+	int i;
+
+	ioapic_res = ioapic_setup_resources();
+	for_each_ioapic(i) {
+		if (smp_found_config) {
+			ioapic_phys = mpc_ioapic_addr(i);
+#ifdef CONFIG_X86_32
+			if (!ioapic_phys) {
+				printk(KERN_ERR
+				       "WARNING: bogus zero IO-APIC "
+				       "address found in MPTABLE, "
+				       "disabling IO/APIC support!\n");
+				smp_found_config = 0;
+				skip_ioapic_setup = 1;
+				goto fake_ioapic_page;
+			}
+#endif
+		} else {
+#ifdef CONFIG_X86_32
+fake_ioapic_page:
+#endif
+			ioapic_phys = (unsigned long)memblock_alloc(PAGE_SIZE,
+								    PAGE_SIZE);
+			if (!ioapic_phys)
+				panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+				      __func__, PAGE_SIZE, PAGE_SIZE);
+			ioapic_phys = __pa(ioapic_phys);
+		}
+		io_apic_set_fixmap(idx, ioapic_phys);
+		apic_printk(APIC_VERBOSE, "mapped IOAPIC to %08lx (%08lx)\n",
+			__fix_to_virt(idx) + (ioapic_phys & ~PAGE_MASK),
+			ioapic_phys);
+		idx++;
+
+		ioapic_res->start = ioapic_phys;
+		ioapic_res->end = ioapic_phys + IO_APIC_SLOT_SIZE - 1;
+		ioapic_res++;
+	}
+}
+
+void __init ioapic_insert_resources(void)
+{
+	int i;
+	struct resource *r = ioapic_resources;
+
+	if (!r) {
+		if (nr_ioapics > 0)
+			printk(KERN_ERR
+				"IO APIC resources couldn't be allocated.\n");
+		return;
+	}
+
+	for_each_ioapic(i) {
+		insert_resource(&iomem_resource, r);
+		r++;
+	}
+}
+
+int mp_find_ioapic(u32 gsi)
+{
+	int i;
+
+	if (nr_ioapics == 0)
+		return -1;
+
+	/* Find the IOAPIC that manages this GSI. */
+	for_each_ioapic(i) {
+		struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(i);
+		if (gsi >= gsi_cfg->gsi_base && gsi <= gsi_cfg->gsi_end)
+			return i;
+	}
+
+	printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
+	return -1;
+}
+
+int mp_find_ioapic_pin(int ioapic, u32 gsi)
+{
+	struct mp_ioapic_gsi *gsi_cfg;
+
+	if (WARN_ON(ioapic < 0))
+		return -1;
+
+	gsi_cfg = mp_ioapic_gsi_routing(ioapic);
+	if (WARN_ON(gsi > gsi_cfg->gsi_end))
+		return -1;
+
+	return gsi - gsi_cfg->gsi_base;
+}
+
+static int bad_ioapic_register(int idx)
+{
+	union IO_APIC_reg_00 reg_00;
+	union IO_APIC_reg_01 reg_01;
+	union IO_APIC_reg_02 reg_02;
+
+	reg_00.raw = io_apic_read(idx, 0);
+	reg_01.raw = io_apic_read(idx, 1);
+	reg_02.raw = io_apic_read(idx, 2);
+
+	if (reg_00.raw == -1 && reg_01.raw == -1 && reg_02.raw == -1) {
+		pr_warn("I/O APIC 0x%x registers return all ones, skipping!\n",
+			mpc_ioapic_addr(idx));
+		return 1;
+	}
+
+	return 0;
+}
+
+static int find_free_ioapic_entry(void)
+{
+	int idx;
+
+	for (idx = 0; idx < MAX_IO_APICS; idx++)
+		if (ioapics[idx].nr_registers == 0)
+			return idx;
+
+	return MAX_IO_APICS;
+}
+
+/**
+ * mp_register_ioapic - Register an IOAPIC device
+ * @id:		hardware IOAPIC ID
+ * @address:	physical address of IOAPIC register area
+ * @gsi_base:	base of GSI associated with the IOAPIC
+ * @cfg:	configuration information for the IOAPIC
+ */
+int mp_register_ioapic(int id, u32 address, u32 gsi_base,
+		       struct ioapic_domain_cfg *cfg)
+{
+	bool hotplug = !!ioapic_initialized;
+	struct mp_ioapic_gsi *gsi_cfg;
+	int idx, ioapic, entries;
+	u32 gsi_end;
+
+	if (!address) {
+		pr_warn("Bogus (zero) I/O APIC address found, skipping!\n");
+		return -EINVAL;
+	}
+	for_each_ioapic(ioapic)
+		if (ioapics[ioapic].mp_config.apicaddr == address) {
+			pr_warn("address 0x%x conflicts with IOAPIC%d\n",
+				address, ioapic);
+			return -EEXIST;
+		}
+
+	idx = find_free_ioapic_entry();
+	if (idx >= MAX_IO_APICS) {
+		pr_warn("Max # of I/O APICs (%d) exceeded (found %d), skipping\n",
+			MAX_IO_APICS, idx);
+		return -ENOSPC;
+	}
+
+	ioapics[idx].mp_config.type = MP_IOAPIC;
+	ioapics[idx].mp_config.flags = MPC_APIC_USABLE;
+	ioapics[idx].mp_config.apicaddr = address;
+
+	io_apic_set_fixmap(FIX_IO_APIC_BASE_0 + idx, address);
+	if (bad_ioapic_register(idx)) {
+		clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
+		return -ENODEV;
+	}
+
+	ioapics[idx].mp_config.apicid = io_apic_unique_id(idx, id);
+	ioapics[idx].mp_config.apicver = io_apic_get_version(idx);
+
+	/*
+	 * Build basic GSI lookup table to facilitate gsi->io_apic lookups
+	 * and to prevent reprogramming of IOAPIC pins (PCI GSIs).
+	 */
+	entries = io_apic_get_redir_entries(idx);
+	gsi_end = gsi_base + entries - 1;
+	for_each_ioapic(ioapic) {
+		gsi_cfg = mp_ioapic_gsi_routing(ioapic);
+		if ((gsi_base >= gsi_cfg->gsi_base &&
+		     gsi_base <= gsi_cfg->gsi_end) ||
+		    (gsi_end >= gsi_cfg->gsi_base &&
+		     gsi_end <= gsi_cfg->gsi_end)) {
+			pr_warn("GSI range [%u-%u] for new IOAPIC conflicts with GSI[%u-%u]\n",
+				gsi_base, gsi_end,
+				gsi_cfg->gsi_base, gsi_cfg->gsi_end);
+			clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
+			return -ENOSPC;
+		}
+	}
+	gsi_cfg = mp_ioapic_gsi_routing(idx);
+	gsi_cfg->gsi_base = gsi_base;
+	gsi_cfg->gsi_end = gsi_end;
+
+	ioapics[idx].irqdomain = NULL;
+	ioapics[idx].irqdomain_cfg = *cfg;
+
+	/*
+	 * If mp_register_ioapic() is called during early boot stage when
+	 * walking ACPI/DT tables, it's too early to create irqdomain,
+	 * we are still using bootmem allocator. So delay it to setup_IO_APIC().
+	 */
+	if (hotplug) {
+		if (mp_irqdomain_create(idx)) {
+			clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
+			return -ENOMEM;
+		}
+		alloc_ioapic_saved_registers(idx);
+	}
+
+	if (gsi_cfg->gsi_end >= gsi_top)
+		gsi_top = gsi_cfg->gsi_end + 1;
+	if (nr_ioapics <= idx)
+		nr_ioapics = idx + 1;
+
+	/* Set nr_registers to mark entry present */
+	ioapics[idx].nr_registers = entries;
+
+	pr_info("IOAPIC[%d]: apic_id %d, version %d, address 0x%x, GSI %d-%d\n",
+		idx, mpc_ioapic_id(idx),
+		mpc_ioapic_ver(idx), mpc_ioapic_addr(idx),
+		gsi_cfg->gsi_base, gsi_cfg->gsi_end);
+
+	return 0;
+}
+
+int mp_unregister_ioapic(u32 gsi_base)
+{
+	int ioapic, pin;
+	int found = 0;
+
+	for_each_ioapic(ioapic)
+		if (ioapics[ioapic].gsi_config.gsi_base == gsi_base) {
+			found = 1;
+			break;
+		}
+	if (!found) {
+		pr_warn("can't find IOAPIC for GSI %d\n", gsi_base);
+		return -ENODEV;
+	}
+
+	for_each_pin(ioapic, pin) {
+		u32 gsi = mp_pin_to_gsi(ioapic, pin);
+		int irq = mp_map_gsi_to_irq(gsi, 0, NULL);
+		struct mp_chip_data *data;
+
+		if (irq >= 0) {
+			data = irq_get_chip_data(irq);
+			if (data && data->count) {
+				pr_warn("pin%d on IOAPIC%d is still in use.\n",
+					pin, ioapic);
+				return -EBUSY;
+			}
+		}
+	}
+
+	/* Mark entry not present */
+	ioapics[ioapic].nr_registers  = 0;
+	ioapic_destroy_irqdomain(ioapic);
+	free_ioapic_saved_registers(ioapic);
+	if (ioapics[ioapic].iomem_res)
+		release_resource(ioapics[ioapic].iomem_res);
+	clear_fixmap(FIX_IO_APIC_BASE_0 + ioapic);
+	memset(&ioapics[ioapic], 0, sizeof(ioapics[ioapic]));
+
+	return 0;
+}
+
+int mp_ioapic_registered(u32 gsi_base)
+{
+	int ioapic;
+
+	for_each_ioapic(ioapic)
+		if (ioapics[ioapic].gsi_config.gsi_base == gsi_base)
+			return 1;
+
+	return 0;
+}
+
+static void mp_irqdomain_get_attr(u32 gsi, struct mp_chip_data *data,
+				  struct irq_alloc_info *info)
+{
+	if (info && info->ioapic.valid) {
+		data->is_level = info->ioapic.is_level;
+		data->active_low = info->ioapic.active_low;
+	} else if (__acpi_get_override_irq(gsi, &data->is_level,
+					   &data->active_low) < 0) {
+		/* PCI interrupts are always active low level triggered. */
+		data->is_level = true;
+		data->active_low = true;
+	}
+}
+
+/*
+ * Configure the I/O-APIC specific fields in the routing entry.
+ *
+ * This is important to setup the I/O-APIC specific bits (is_level,
+ * active_low, masked) because the underlying parent domain will only
+ * provide the routing information and is oblivious of the I/O-APIC
+ * specific bits.
+ *
+ * The entry is just preconfigured at this point and not written into the
+ * RTE. This happens later during activation which will fill in the actual
+ * routing information.
+ */
+static void mp_preconfigure_entry(struct mp_chip_data *data)
+{
+	struct IO_APIC_route_entry *entry = &data->entry;
+
+	memset(entry, 0, sizeof(*entry));
+	entry->is_level		 = data->is_level;
+	entry->active_low	 = data->active_low;
+	/*
+	 * Mask level triggered irqs. Edge triggered irqs are masked
+	 * by the irq core code in case they fire.
+	 */
+	entry->masked		= data->is_level;
+}
+
+int mp_irqdomain_alloc(struct irq_domain *domain, unsigned int virq,
+		       unsigned int nr_irqs, void *arg)
+{
+	struct irq_alloc_info *info = arg;
+	struct mp_chip_data *data;
+	struct irq_data *irq_data;
+	int ret, ioapic, pin;
+	unsigned long flags;
+
+	if (!info || nr_irqs > 1)
+		return -EINVAL;
+	irq_data = irq_domain_get_irq_data(domain, virq);
+	if (!irq_data)
+		return -EINVAL;
+
+	ioapic = mp_irqdomain_ioapic_idx(domain);
+	pin = info->ioapic.pin;
+	if (irq_find_mapping(domain, (irq_hw_number_t)pin) > 0)
+		return -EEXIST;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, info);
+	if (ret < 0) {
+		kfree(data);
+		return ret;
+	}
+
+	INIT_LIST_HEAD(&data->irq_2_pin);
+	irq_data->hwirq = info->ioapic.pin;
+	irq_data->chip = (domain->parent == x86_vector_domain) ?
+			  &ioapic_chip : &ioapic_ir_chip;
+	irq_data->chip_data = data;
+	mp_irqdomain_get_attr(mp_pin_to_gsi(ioapic, pin), data, info);
+
+	add_pin_to_irq_node(data, ioapic_alloc_attr_node(info), ioapic, pin);
+
+	mp_preconfigure_entry(data);
+	mp_register_handler(virq, data->is_level);
+
+	local_irq_save(flags);
+	if (virq < nr_legacy_irqs())
+		legacy_pic->mask(virq);
+	local_irq_restore(flags);
+
+	apic_printk(APIC_VERBOSE, KERN_DEBUG
+		    "IOAPIC[%d]: Preconfigured routing entry (%d-%d -> IRQ %d Level:%i ActiveLow:%i)\n",
+		    ioapic, mpc_ioapic_id(ioapic), pin, virq,
+		    data->is_level, data->active_low);
+	return 0;
+}
+
+void mp_irqdomain_free(struct irq_domain *domain, unsigned int virq,
+		       unsigned int nr_irqs)
+{
+	struct irq_data *irq_data;
+	struct mp_chip_data *data;
+
+	BUG_ON(nr_irqs != 1);
+	irq_data = irq_domain_get_irq_data(domain, virq);
+	if (irq_data && irq_data->chip_data) {
+		data = irq_data->chip_data;
+		__remove_pin_from_irq(data, mp_irqdomain_ioapic_idx(domain),
+				      (int)irq_data->hwirq);
+		WARN_ON(!list_empty(&data->irq_2_pin));
+		kfree(irq_data->chip_data);
+	}
+	irq_domain_free_irqs_top(domain, virq, nr_irqs);
+}
+
+int mp_irqdomain_activate(struct irq_domain *domain,
+			  struct irq_data *irq_data, bool reserve)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	ioapic_configure_entry(irq_data);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+	return 0;
+}
+
+void mp_irqdomain_deactivate(struct irq_domain *domain,
+			     struct irq_data *irq_data)
+{
+	/* It won't be called for IRQ with multiple IOAPIC pins associated */
+	ioapic_mask_entry(mp_irqdomain_ioapic_idx(domain),
+			  (int)irq_data->hwirq);
+}
+
+int mp_irqdomain_ioapic_idx(struct irq_domain *domain)
+{
+	return (int)(long)domain->host_data;
+}
+
+const struct irq_domain_ops mp_ioapic_irqdomain_ops = {
+	.alloc		= mp_irqdomain_alloc,
+	.free		= mp_irqdomain_free,
+	.activate	= mp_irqdomain_activate,
+	.deactivate	= mp_irqdomain_deactivate,
+};
diff --git a/arch/x86/kernel/apic/ipi.c b/arch/x86/kernel/apic/ipi.c
new file mode 100644
index 000000000..2a6509e8c
--- /dev/null
+++ b/arch/x86/kernel/apic/ipi.c
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/cpumask.h>
+#include <linux/smp.h>
+#include <asm/io_apic.h>
+
+#include "local.h"
+
+DEFINE_STATIC_KEY_FALSE(apic_use_ipi_shorthand);
+
+#ifdef CONFIG_SMP
+static int apic_ipi_shorthand_off __ro_after_init;
+
+static __init int apic_ipi_shorthand(char *str)
+{
+	get_option(&str, &apic_ipi_shorthand_off);
+	return 1;
+}
+__setup("no_ipi_broadcast=", apic_ipi_shorthand);
+
+static int __init print_ipi_mode(void)
+{
+	pr_info("IPI shorthand broadcast: %s\n",
+		apic_ipi_shorthand_off ? "disabled" : "enabled");
+	return 0;
+}
+late_initcall(print_ipi_mode);
+
+void apic_smt_update(void)
+{
+	/*
+	 * Do not switch to broadcast mode if:
+	 * - Disabled on the command line
+	 * - Only a single CPU is online
+	 * - Not all present CPUs have been at least booted once
+	 *
+	 * The latter is important as the local APIC might be in some
+	 * random state and a broadcast might cause havoc. That's
+	 * especially true for NMI broadcasting.
+	 */
+	if (apic_ipi_shorthand_off || num_online_cpus() == 1 ||
+	    !cpumask_equal(cpu_present_mask, &cpus_booted_once_mask)) {
+		static_branch_disable(&apic_use_ipi_shorthand);
+	} else {
+		static_branch_enable(&apic_use_ipi_shorthand);
+	}
+}
+
+void apic_send_IPI_allbutself(unsigned int vector)
+{
+	if (num_online_cpus() < 2)
+		return;
+
+	if (static_branch_likely(&apic_use_ipi_shorthand))
+		apic->send_IPI_allbutself(vector);
+	else
+		apic->send_IPI_mask_allbutself(cpu_online_mask, vector);
+}
+
+/*
+ * Send a 'reschedule' IPI to another CPU. It goes straight through and
+ * wastes no time serializing anything. Worst case is that we lose a
+ * reschedule ...
+ */
+void native_smp_send_reschedule(int cpu)
+{
+	if (unlikely(cpu_is_offline(cpu))) {
+		WARN(1, "sched: Unexpected reschedule of offline CPU#%d!\n", cpu);
+		return;
+	}
+	apic->send_IPI(cpu, RESCHEDULE_VECTOR);
+}
+
+void native_send_call_func_single_ipi(int cpu)
+{
+	apic->send_IPI(cpu, CALL_FUNCTION_SINGLE_VECTOR);
+}
+
+void native_send_call_func_ipi(const struct cpumask *mask)
+{
+	if (static_branch_likely(&apic_use_ipi_shorthand)) {
+		unsigned int cpu = smp_processor_id();
+
+		if (!cpumask_or_equal(mask, cpumask_of(cpu), cpu_online_mask))
+			goto sendmask;
+
+		if (cpumask_test_cpu(cpu, mask))
+			apic->send_IPI_all(CALL_FUNCTION_VECTOR);
+		else if (num_online_cpus() > 1)
+			apic->send_IPI_allbutself(CALL_FUNCTION_VECTOR);
+		return;
+	}
+
+sendmask:
+	apic->send_IPI_mask(mask, CALL_FUNCTION_VECTOR);
+}
+
+#endif /* CONFIG_SMP */
+
+static inline int __prepare_ICR2(unsigned int mask)
+{
+	return SET_XAPIC_DEST_FIELD(mask);
+}
+
+static inline void __xapic_wait_icr_idle(void)
+{
+	while (native_apic_mem_read(APIC_ICR) & APIC_ICR_BUSY)
+		cpu_relax();
+}
+
+void __default_send_IPI_shortcut(unsigned int shortcut, int vector)
+{
+	/*
+	 * Subtle. In the case of the 'never do double writes' workaround
+	 * we have to lock out interrupts to be safe.  As we don't care
+	 * of the value read we use an atomic rmw access to avoid costly
+	 * cli/sti.  Otherwise we use an even cheaper single atomic write
+	 * to the APIC.
+	 */
+	unsigned int cfg;
+
+	/*
+	 * Wait for idle.
+	 */
+	if (unlikely(vector == NMI_VECTOR))
+		safe_apic_wait_icr_idle();
+	else
+		__xapic_wait_icr_idle();
+
+	/*
+	 * No need to touch the target chip field. Also the destination
+	 * mode is ignored when a shorthand is used.
+	 */
+	cfg = __prepare_ICR(shortcut, vector, 0);
+
+	/*
+	 * Send the IPI. The write to APIC_ICR fires this off.
+	 */
+	native_apic_mem_write(APIC_ICR, cfg);
+}
+
+/*
+ * This is used to send an IPI with no shorthand notation (the destination is
+ * specified in bits 56 to 63 of the ICR).
+ */
+void __default_send_IPI_dest_field(unsigned int mask, int vector, unsigned int dest)
+{
+	unsigned long cfg;
+
+	/*
+	 * Wait for idle.
+	 */
+	if (unlikely(vector == NMI_VECTOR))
+		safe_apic_wait_icr_idle();
+	else
+		__xapic_wait_icr_idle();
+
+	/*
+	 * prepare target chip field
+	 */
+	cfg = __prepare_ICR2(mask);
+	native_apic_mem_write(APIC_ICR2, cfg);
+
+	/*
+	 * program the ICR
+	 */
+	cfg = __prepare_ICR(0, vector, dest);
+
+	/*
+	 * Send the IPI. The write to APIC_ICR fires this off.
+	 */
+	native_apic_mem_write(APIC_ICR, cfg);
+}
+
+void default_send_IPI_single_phys(int cpu, int vector)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, cpu),
+				      vector, APIC_DEST_PHYSICAL);
+	local_irq_restore(flags);
+}
+
+void default_send_IPI_mask_sequence_phys(const struct cpumask *mask, int vector)
+{
+	unsigned long query_cpu;
+	unsigned long flags;
+
+	/*
+	 * Hack. The clustered APIC addressing mode doesn't allow us to send
+	 * to an arbitrary mask, so I do a unicast to each CPU instead.
+	 * - mbligh
+	 */
+	local_irq_save(flags);
+	for_each_cpu(query_cpu, mask) {
+		__default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid,
+				query_cpu), vector, APIC_DEST_PHYSICAL);
+	}
+	local_irq_restore(flags);
+}
+
+void default_send_IPI_mask_allbutself_phys(const struct cpumask *mask,
+						 int vector)
+{
+	unsigned int this_cpu = smp_processor_id();
+	unsigned int query_cpu;
+	unsigned long flags;
+
+	/* See Hack comment above */
+
+	local_irq_save(flags);
+	for_each_cpu(query_cpu, mask) {
+		if (query_cpu == this_cpu)
+			continue;
+		__default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid,
+				 query_cpu), vector, APIC_DEST_PHYSICAL);
+	}
+	local_irq_restore(flags);
+}
+
+/*
+ * Helper function for APICs which insist on cpumasks
+ */
+void default_send_IPI_single(int cpu, int vector)
+{
+	apic->send_IPI_mask(cpumask_of(cpu), vector);
+}
+
+void default_send_IPI_allbutself(int vector)
+{
+	__default_send_IPI_shortcut(APIC_DEST_ALLBUT, vector);
+}
+
+void default_send_IPI_all(int vector)
+{
+	__default_send_IPI_shortcut(APIC_DEST_ALLINC, vector);
+}
+
+void default_send_IPI_self(int vector)
+{
+	__default_send_IPI_shortcut(APIC_DEST_SELF, vector);
+}
+
+#ifdef CONFIG_X86_32
+
+void default_send_IPI_mask_sequence_logical(const struct cpumask *mask,
+						 int vector)
+{
+	unsigned long flags;
+	unsigned int query_cpu;
+
+	/*
+	 * Hack. The clustered APIC addressing mode doesn't allow us to send
+	 * to an arbitrary mask, so I do a unicasts to each CPU instead. This
+	 * should be modified to do 1 message per cluster ID - mbligh
+	 */
+
+	local_irq_save(flags);
+	for_each_cpu(query_cpu, mask)
+		__default_send_IPI_dest_field(
+			early_per_cpu(x86_cpu_to_logical_apicid, query_cpu),
+			vector, APIC_DEST_LOGICAL);
+	local_irq_restore(flags);
+}
+
+void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask,
+						 int vector)
+{
+	unsigned long flags;
+	unsigned int query_cpu;
+	unsigned int this_cpu = smp_processor_id();
+
+	/* See Hack comment above */
+
+	local_irq_save(flags);
+	for_each_cpu(query_cpu, mask) {
+		if (query_cpu == this_cpu)
+			continue;
+		__default_send_IPI_dest_field(
+			early_per_cpu(x86_cpu_to_logical_apicid, query_cpu),
+			vector, APIC_DEST_LOGICAL);
+		}
+	local_irq_restore(flags);
+}
+
+/*
+ * This is only used on smaller machines.
+ */
+void default_send_IPI_mask_logical(const struct cpumask *cpumask, int vector)
+{
+	unsigned long mask = cpumask_bits(cpumask)[0];
+	unsigned long flags;
+
+	if (!mask)
+		return;
+
+	local_irq_save(flags);
+	WARN_ON(mask & ~cpumask_bits(cpu_online_mask)[0]);
+	__default_send_IPI_dest_field(mask, vector, APIC_DEST_LOGICAL);
+	local_irq_restore(flags);
+}
+
+/* must come after the send_IPI functions above for inlining */
+static int convert_apicid_to_cpu(int apic_id)
+{
+	int i;
+
+	for_each_possible_cpu(i) {
+		if (per_cpu(x86_cpu_to_apicid, i) == apic_id)
+			return i;
+	}
+	return -1;
+}
+
+int safe_smp_processor_id(void)
+{
+	int apicid, cpuid;
+
+	if (!boot_cpu_has(X86_FEATURE_APIC))
+		return 0;
+
+	apicid = hard_smp_processor_id();
+	if (apicid == BAD_APICID)
+		return 0;
+
+	cpuid = convert_apicid_to_cpu(apicid);
+
+	return cpuid >= 0 ? cpuid : 0;
+}
+#endif
diff --git a/arch/x86/kernel/apic/local.h b/arch/x86/kernel/apic/local.h
new file mode 100644
index 000000000..a997d8495
--- /dev/null
+++ b/arch/x86/kernel/apic/local.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Historical copyright notices:
+ *
+ * Copyright 2004 James Cleverdon, IBM.
+ * (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
+ * (c) 1998-99, 2000 Ingo Molnar <mingo@redhat.com>
+ * (c) 2002,2003 Andi Kleen, SuSE Labs.
+ */
+
+#include <linux/jump_label.h>
+
+#include <asm/irq_vectors.h>
+#include <asm/apic.h>
+
+/* APIC flat 64 */
+void flat_init_apic_ldr(void);
+
+/* X2APIC */
+int x2apic_apic_id_valid(u32 apicid);
+int x2apic_apic_id_registered(void);
+void __x2apic_send_IPI_dest(unsigned int apicid, int vector, unsigned int dest);
+unsigned int x2apic_get_apic_id(unsigned long id);
+u32 x2apic_set_apic_id(unsigned int id);
+int x2apic_phys_pkg_id(int initial_apicid, int index_msb);
+void x2apic_send_IPI_self(int vector);
+void __x2apic_send_IPI_shorthand(int vector, u32 which);
+
+/* IPI */
+
+DECLARE_STATIC_KEY_FALSE(apic_use_ipi_shorthand);
+
+static inline unsigned int __prepare_ICR(unsigned int shortcut, int vector,
+					 unsigned int dest)
+{
+	unsigned int icr = shortcut | dest;
+
+	switch (vector) {
+	default:
+		icr |= APIC_DM_FIXED | vector;
+		break;
+	case NMI_VECTOR:
+		icr |= APIC_DM_NMI;
+		break;
+	}
+	return icr;
+}
+
+void __default_send_IPI_shortcut(unsigned int shortcut, int vector);
+
+/*
+ * This is used to send an IPI with no shorthand notation (the destination is
+ * specified in bits 56 to 63 of the ICR).
+ */
+void __default_send_IPI_dest_field(unsigned int mask, int vector, unsigned int dest);
+
+void default_send_IPI_single(int cpu, int vector);
+void default_send_IPI_single_phys(int cpu, int vector);
+void default_send_IPI_mask_sequence_phys(const struct cpumask *mask, int vector);
+void default_send_IPI_mask_allbutself_phys(const struct cpumask *mask, int vector);
+void default_send_IPI_allbutself(int vector);
+void default_send_IPI_all(int vector);
+void default_send_IPI_self(int vector);
+
+#ifdef CONFIG_X86_32
+void default_send_IPI_mask_sequence_logical(const struct cpumask *mask, int vector);
+void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask, int vector);
+void default_send_IPI_mask_logical(const struct cpumask *mask, int vector);
+#endif
diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
new file mode 100644
index 000000000..ab348aec8
--- /dev/null
+++ b/arch/x86/kernel/apic/msi.c
@@ -0,0 +1,348 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Support of MSI, HPET and DMAR interrupts.
+ *
+ * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
+ *	Moved from arch/x86/kernel/apic/io_apic.c.
+ * Jiang Liu <jiang.liu@linux.intel.com>
+ *	Convert to hierarchical irqdomain
+ */
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/pci.h>
+#include <linux/dmar.h>
+#include <linux/hpet.h>
+#include <linux/msi.h>
+#include <asm/irqdomain.h>
+#include <asm/hpet.h>
+#include <asm/hw_irq.h>
+#include <asm/apic.h>
+#include <asm/irq_remapping.h>
+#include <asm/xen/hypervisor.h>
+
+struct irq_domain *x86_pci_msi_default_domain __ro_after_init;
+
+static void irq_msi_update_msg(struct irq_data *irqd, struct irq_cfg *cfg)
+{
+	struct msi_msg msg[2] = { [1] = { }, };
+
+	__irq_msi_compose_msg(cfg, msg, false);
+	irq_data_get_irq_chip(irqd)->irq_write_msi_msg(irqd, msg);
+}
+
+static int
+msi_set_affinity(struct irq_data *irqd, const struct cpumask *mask, bool force)
+{
+	struct irq_cfg old_cfg, *cfg = irqd_cfg(irqd);
+	struct irq_data *parent = irqd->parent_data;
+	unsigned int cpu;
+	int ret;
+
+	/* Save the current configuration */
+	cpu = cpumask_first(irq_data_get_effective_affinity_mask(irqd));
+	old_cfg = *cfg;
+
+	/* Allocate a new target vector */
+	ret = parent->chip->irq_set_affinity(parent, mask, force);
+	if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)
+		return ret;
+
+	/*
+	 * For non-maskable and non-remapped MSI interrupts the migration
+	 * to a different destination CPU and a different vector has to be
+	 * done careful to handle the possible stray interrupt which can be
+	 * caused by the non-atomic update of the address/data pair.
+	 *
+	 * Direct update is possible when:
+	 * - The MSI is maskable (remapped MSI does not use this code path).
+	 *   The reservation mode bit is set in this case.
+	 * - The new vector is the same as the old vector
+	 * - The old vector is MANAGED_IRQ_SHUTDOWN_VECTOR (interrupt starts up)
+	 * - The interrupt is not yet started up
+	 * - The new destination CPU is the same as the old destination CPU
+	 */
+	if (!irqd_can_reserve(irqd) ||
+	    cfg->vector == old_cfg.vector ||
+	    old_cfg.vector == MANAGED_IRQ_SHUTDOWN_VECTOR ||
+	    !irqd_is_started(irqd) ||
+	    cfg->dest_apicid == old_cfg.dest_apicid) {
+		irq_msi_update_msg(irqd, cfg);
+		return ret;
+	}
+
+	/*
+	 * Paranoia: Validate that the interrupt target is the local
+	 * CPU.
+	 */
+	if (WARN_ON_ONCE(cpu != smp_processor_id())) {
+		irq_msi_update_msg(irqd, cfg);
+		return ret;
+	}
+
+	/*
+	 * Redirect the interrupt to the new vector on the current CPU
+	 * first. This might cause a spurious interrupt on this vector if
+	 * the device raises an interrupt right between this update and the
+	 * update to the final destination CPU.
+	 *
+	 * If the vector is in use then the installed device handler will
+	 * denote it as spurious which is no harm as this is a rare event
+	 * and interrupt handlers have to cope with spurious interrupts
+	 * anyway. If the vector is unused, then it is marked so it won't
+	 * trigger the 'No irq handler for vector' warning in
+	 * common_interrupt().
+	 *
+	 * This requires to hold vector lock to prevent concurrent updates to
+	 * the affected vector.
+	 */
+	lock_vector_lock();
+
+	/*
+	 * Mark the new target vector on the local CPU if it is currently
+	 * unused. Reuse the VECTOR_RETRIGGERED state which is also used in
+	 * the CPU hotplug path for a similar purpose. This cannot be
+	 * undone here as the current CPU has interrupts disabled and
+	 * cannot handle the interrupt before the whole set_affinity()
+	 * section is done. In the CPU unplug case, the current CPU is
+	 * about to vanish and will not handle any interrupts anymore. The
+	 * vector is cleaned up when the CPU comes online again.
+	 */
+	if (IS_ERR_OR_NULL(this_cpu_read(vector_irq[cfg->vector])))
+		this_cpu_write(vector_irq[cfg->vector], VECTOR_RETRIGGERED);
+
+	/* Redirect it to the new vector on the local CPU temporarily */
+	old_cfg.vector = cfg->vector;
+	irq_msi_update_msg(irqd, &old_cfg);
+
+	/* Now transition it to the target CPU */
+	irq_msi_update_msg(irqd, cfg);
+
+	/*
+	 * All interrupts after this point are now targeted at the new
+	 * vector/CPU.
+	 *
+	 * Drop vector lock before testing whether the temporary assignment
+	 * to the local CPU was hit by an interrupt raised in the device,
+	 * because the retrigger function acquires vector lock again.
+	 */
+	unlock_vector_lock();
+
+	/*
+	 * Check whether the transition raced with a device interrupt and
+	 * is pending in the local APICs IRR. It is safe to do this outside
+	 * of vector lock as the irq_desc::lock of this interrupt is still
+	 * held and interrupts are disabled: The check is not accessing the
+	 * underlying vector store. It's just checking the local APIC's
+	 * IRR.
+	 */
+	if (lapic_vector_set_in_irr(cfg->vector))
+		irq_data_get_irq_chip(irqd)->irq_retrigger(irqd);
+
+	return ret;
+}
+
+/*
+ * IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
+ * which implement the MSI or MSI-X Capability Structure.
+ */
+static struct irq_chip pci_msi_controller = {
+	.name			= "PCI-MSI",
+	.irq_unmask		= pci_msi_unmask_irq,
+	.irq_mask		= pci_msi_mask_irq,
+	.irq_ack		= irq_chip_ack_parent,
+	.irq_retrigger		= irq_chip_retrigger_hierarchy,
+	.irq_set_affinity	= msi_set_affinity,
+	.flags			= IRQCHIP_SKIP_SET_WAKE |
+				  IRQCHIP_AFFINITY_PRE_STARTUP,
+};
+
+int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
+		    msi_alloc_info_t *arg)
+{
+	init_irq_alloc_info(arg, NULL);
+	if (to_pci_dev(dev)->msix_enabled) {
+		arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSIX;
+	} else {
+		arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSI;
+		arg->flags |= X86_IRQ_ALLOC_CONTIGUOUS_VECTORS;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_msi_prepare);
+
+static struct msi_domain_ops pci_msi_domain_ops = {
+	.msi_prepare	= pci_msi_prepare,
+};
+
+static struct msi_domain_info pci_msi_domain_info = {
+	.flags		= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+			  MSI_FLAG_PCI_MSIX,
+	.ops		= &pci_msi_domain_ops,
+	.chip		= &pci_msi_controller,
+	.handler	= handle_edge_irq,
+	.handler_name	= "edge",
+};
+
+struct irq_domain * __init native_create_pci_msi_domain(void)
+{
+	struct fwnode_handle *fn;
+	struct irq_domain *d;
+
+	if (disable_apic)
+		return NULL;
+
+	fn = irq_domain_alloc_named_fwnode("PCI-MSI");
+	if (!fn)
+		return NULL;
+
+	d = pci_msi_create_irq_domain(fn, &pci_msi_domain_info,
+				      x86_vector_domain);
+	if (!d) {
+		irq_domain_free_fwnode(fn);
+		pr_warn("Failed to initialize PCI-MSI irqdomain.\n");
+	}
+	return d;
+}
+
+void __init x86_create_pci_msi_domain(void)
+{
+	x86_pci_msi_default_domain = x86_init.irqs.create_pci_msi_domain();
+}
+
+#ifdef CONFIG_IRQ_REMAP
+static struct irq_chip pci_msi_ir_controller = {
+	.name			= "IR-PCI-MSI",
+	.irq_unmask		= pci_msi_unmask_irq,
+	.irq_mask		= pci_msi_mask_irq,
+	.irq_ack		= irq_chip_ack_parent,
+	.irq_retrigger		= irq_chip_retrigger_hierarchy,
+	.flags			= IRQCHIP_SKIP_SET_WAKE |
+				  IRQCHIP_AFFINITY_PRE_STARTUP,
+};
+
+static struct msi_domain_info pci_msi_ir_domain_info = {
+	.flags		= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+			  MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX,
+	.ops		= &pci_msi_domain_ops,
+	.chip		= &pci_msi_ir_controller,
+	.handler	= handle_edge_irq,
+	.handler_name	= "edge",
+};
+
+struct irq_domain *arch_create_remap_msi_irq_domain(struct irq_domain *parent,
+						    const char *name, int id)
+{
+	struct fwnode_handle *fn;
+	struct irq_domain *d;
+
+	fn = irq_domain_alloc_named_id_fwnode(name, id);
+	if (!fn)
+		return NULL;
+	d = pci_msi_create_irq_domain(fn, &pci_msi_ir_domain_info, parent);
+	if (!d)
+		irq_domain_free_fwnode(fn);
+	return d;
+}
+#endif
+
+#ifdef CONFIG_DMAR_TABLE
+/*
+ * The Intel IOMMU (ab)uses the high bits of the MSI address to contain the
+ * high bits of the destination APIC ID. This can't be done in the general
+ * case for MSIs as it would be targeting real memory above 4GiB not the
+ * APIC.
+ */
+static void dmar_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	__irq_msi_compose_msg(irqd_cfg(data), msg, true);
+}
+
+static void dmar_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	dmar_msi_write(data->irq, msg);
+}
+
+static struct irq_chip dmar_msi_controller = {
+	.name			= "DMAR-MSI",
+	.irq_unmask		= dmar_msi_unmask,
+	.irq_mask		= dmar_msi_mask,
+	.irq_ack		= irq_chip_ack_parent,
+	.irq_set_affinity	= msi_domain_set_affinity,
+	.irq_retrigger		= irq_chip_retrigger_hierarchy,
+	.irq_compose_msi_msg	= dmar_msi_compose_msg,
+	.irq_write_msi_msg	= dmar_msi_write_msg,
+	.flags			= IRQCHIP_SKIP_SET_WAKE |
+				  IRQCHIP_AFFINITY_PRE_STARTUP,
+};
+
+static int dmar_msi_init(struct irq_domain *domain,
+			 struct msi_domain_info *info, unsigned int virq,
+			 irq_hw_number_t hwirq, msi_alloc_info_t *arg)
+{
+	irq_domain_set_info(domain, virq, arg->devid, info->chip, NULL,
+			    handle_edge_irq, arg->data, "edge");
+
+	return 0;
+}
+
+static struct msi_domain_ops dmar_msi_domain_ops = {
+	.msi_init	= dmar_msi_init,
+};
+
+static struct msi_domain_info dmar_msi_domain_info = {
+	.ops		= &dmar_msi_domain_ops,
+	.chip		= &dmar_msi_controller,
+	.flags		= MSI_FLAG_USE_DEF_DOM_OPS,
+};
+
+static struct irq_domain *dmar_get_irq_domain(void)
+{
+	static struct irq_domain *dmar_domain;
+	static DEFINE_MUTEX(dmar_lock);
+	struct fwnode_handle *fn;
+
+	mutex_lock(&dmar_lock);
+	if (dmar_domain)
+		goto out;
+
+	fn = irq_domain_alloc_named_fwnode("DMAR-MSI");
+	if (fn) {
+		dmar_domain = msi_create_irq_domain(fn, &dmar_msi_domain_info,
+						    x86_vector_domain);
+		if (!dmar_domain)
+			irq_domain_free_fwnode(fn);
+	}
+out:
+	mutex_unlock(&dmar_lock);
+	return dmar_domain;
+}
+
+int dmar_alloc_hwirq(int id, int node, void *arg)
+{
+	struct irq_domain *domain = dmar_get_irq_domain();
+	struct irq_alloc_info info;
+
+	if (!domain)
+		return -1;
+
+	init_irq_alloc_info(&info, NULL);
+	info.type = X86_IRQ_ALLOC_TYPE_DMAR;
+	info.devid = id;
+	info.hwirq = id;
+	info.data = arg;
+
+	return irq_domain_alloc_irqs(domain, 1, node, &info);
+}
+
+void dmar_free_hwirq(int irq)
+{
+	irq_domain_free_irqs(irq, 1);
+}
+#endif
+
+bool arch_restore_msi_irqs(struct pci_dev *dev)
+{
+	return xen_initdom_restore_msi(dev);
+}
diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
new file mode 100644
index 000000000..a61f642b1
--- /dev/null
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Default generic APIC driver. This handles up to 8 CPUs.
+ *
+ * Copyright 2003 Andi Kleen, SuSE Labs.
+ *
+ * Generic x86 APIC driver probe layer.
+ */
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/smp.h>
+
+#include <asm/io_apic.h>
+#include <asm/apic.h>
+#include <asm/acpi.h>
+
+#include "local.h"
+
+static int default_x86_32_early_logical_apicid(int cpu)
+{
+	return 1 << cpu;
+}
+
+static void setup_apic_flat_routing(void)
+{
+#ifdef CONFIG_X86_IO_APIC
+	printk(KERN_INFO
+		"Enabling APIC mode:  Flat.  Using %d I/O APICs\n",
+		nr_ioapics);
+#endif
+}
+
+static int default_apic_id_registered(void)
+{
+	return physid_isset(read_apic_id(), phys_cpu_present_map);
+}
+
+/*
+ * Set up the logical destination ID.  Intel recommends to set DFR, LDR and
+ * TPR before enabling an APIC.  See e.g. "AP-388 82489DX User's Manual"
+ * (Intel document number 292116).
+ */
+static void default_init_apic_ldr(void)
+{
+	unsigned long val;
+
+	apic_write(APIC_DFR, APIC_DFR_VALUE);
+	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
+	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
+	apic_write(APIC_LDR, val);
+}
+
+static int default_phys_pkg_id(int cpuid_apic, int index_msb)
+{
+	return cpuid_apic >> index_msb;
+}
+
+/* should be called last. */
+static int probe_default(void)
+{
+	return 1;
+}
+
+static struct apic apic_default __ro_after_init = {
+
+	.name				= "default",
+	.probe				= probe_default,
+	.acpi_madt_oem_check		= NULL,
+	.apic_id_valid			= default_apic_id_valid,
+	.apic_id_registered		= default_apic_id_registered,
+
+	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
+	.dest_mode_logical		= true,
+
+	.disable_esr			= 0,
+
+	.check_apicid_used		= default_check_apicid_used,
+	.init_apic_ldr			= default_init_apic_ldr,
+	.ioapic_phys_id_map		= default_ioapic_phys_id_map,
+	.setup_apic_routing		= setup_apic_flat_routing,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= physid_set_mask_of_physid,
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+	.phys_pkg_id			= default_phys_pkg_id,
+
+	.get_apic_id			= default_get_apic_id,
+	.set_apic_id			= NULL,
+
+	.calc_dest_apicid		= apic_flat_calc_apicid,
+
+	.send_IPI			= default_send_IPI_single,
+	.send_IPI_mask			= default_send_IPI_mask_logical,
+	.send_IPI_mask_allbutself	= default_send_IPI_mask_allbutself_logical,
+	.send_IPI_allbutself		= default_send_IPI_allbutself,
+	.send_IPI_all			= default_send_IPI_all,
+	.send_IPI_self			= default_send_IPI_self,
+
+	.inquire_remote_apic		= default_inquire_remote_apic,
+
+	.read				= native_apic_mem_read,
+	.write				= native_apic_mem_write,
+	.eoi_write			= native_apic_mem_write,
+	.icr_read			= native_apic_icr_read,
+	.icr_write			= native_apic_icr_write,
+	.wait_icr_idle			= native_apic_wait_icr_idle,
+	.safe_wait_icr_idle		= native_safe_apic_wait_icr_idle,
+
+	.x86_32_early_logical_apicid	= default_x86_32_early_logical_apicid,
+};
+
+apic_driver(apic_default);
+
+struct apic *apic __ro_after_init = &apic_default;
+EXPORT_SYMBOL_GPL(apic);
+
+static int cmdline_apic __initdata;
+static int __init parse_apic(char *arg)
+{
+	struct apic **drv;
+
+	if (!arg)
+		return -EINVAL;
+
+	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+		if (!strcmp((*drv)->name, arg)) {
+			apic = *drv;
+			cmdline_apic = 1;
+			return 0;
+		}
+	}
+
+	/* Parsed again by __setup for debug/verbose */
+	return 0;
+}
+early_param("apic", parse_apic);
+
+void __init default_setup_apic_routing(void)
+{
+	int version = boot_cpu_apic_version;
+
+	if (num_possible_cpus() > 8) {
+		switch (boot_cpu_data.x86_vendor) {
+		case X86_VENDOR_INTEL:
+			if (!APIC_XAPIC(version)) {
+				def_to_bigsmp = 0;
+				break;
+			}
+			/* P4 and above */
+			fallthrough;
+		case X86_VENDOR_HYGON:
+		case X86_VENDOR_AMD:
+			def_to_bigsmp = 1;
+		}
+	}
+
+#ifdef CONFIG_X86_BIGSMP
+	/*
+	 * This is used to switch to bigsmp mode when
+	 * - There is no apic= option specified by the user
+	 * - generic_apic_probe() has chosen apic_default as the sub_arch
+	 * - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support
+	 */
+
+	if (!cmdline_apic && apic == &apic_default)
+		generic_bigsmp_probe();
+#endif
+
+	if (apic->setup_apic_routing)
+		apic->setup_apic_routing();
+}
+
+void __init generic_apic_probe(void)
+{
+	if (!cmdline_apic) {
+		struct apic **drv;
+
+		for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+			if ((*drv)->probe()) {
+				apic = *drv;
+				break;
+			}
+		}
+		/* Not visible without early console */
+		if (drv == __apicdrivers_end)
+			panic("Didn't find an APIC driver");
+	}
+	printk(KERN_INFO "Using APIC driver %s\n", apic->name);
+}
+
+/* This function can switch the APIC even after the initial ->probe() */
+int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+{
+	struct apic **drv;
+
+	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+		if (!(*drv)->acpi_madt_oem_check)
+			continue;
+		if (!(*drv)->acpi_madt_oem_check(oem_id, oem_table_id))
+			continue;
+
+		if (!cmdline_apic) {
+			apic = *drv;
+			printk(KERN_INFO "Switched to APIC driver `%s'.\n",
+			       apic->name);
+		}
+		return 1;
+	}
+	return 0;
+}
diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
new file mode 100644
index 000000000..c46720f18
--- /dev/null
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2004 James Cleverdon, IBM.
+ *
+ * Generic APIC sub-arch probe layer.
+ *
+ * Hacked for x86-64 by James Cleverdon from i386 architecture code by
+ * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
+ * James Cleverdon.
+ */
+#include <linux/thread_info.h>
+#include <asm/apic.h>
+
+#include "local.h"
+
+/*
+ * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
+ */
+void __init default_setup_apic_routing(void)
+{
+	struct apic **drv;
+
+	enable_IR_x2apic();
+
+	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+		if ((*drv)->probe && (*drv)->probe()) {
+			if (apic != *drv) {
+				apic = *drv;
+				pr_info("Switched APIC routing to %s.\n",
+					apic->name);
+			}
+			break;
+		}
+	}
+}
+
+int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+{
+	struct apic **drv;
+
+	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+		if ((*drv)->acpi_madt_oem_check(oem_id, oem_table_id)) {
+			if (apic != *drv) {
+				apic = *drv;
+				pr_info("Setting APIC routing to %s.\n",
+					apic->name);
+			}
+			return 1;
+		}
+	}
+	return 0;
+}
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
new file mode 100644
index 000000000..3e6f6b448
--- /dev/null
+++ b/arch/x86/kernel/apic/vector.c
@@ -0,0 +1,1340 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Local APIC related interfaces to support IOAPIC, MSI, etc.
+ *
+ * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
+ *	Moved from arch/x86/kernel/apic/io_apic.c.
+ * Jiang Liu <jiang.liu@linux.intel.com>
+ *	Enable support of hierarchical irqdomains
+ */
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/compiler.h>
+#include <linux/slab.h>
+#include <asm/irqdomain.h>
+#include <asm/hw_irq.h>
+#include <asm/traps.h>
+#include <asm/apic.h>
+#include <asm/i8259.h>
+#include <asm/desc.h>
+#include <asm/irq_remapping.h>
+
+#include <asm/trace/irq_vectors.h>
+
+struct apic_chip_data {
+	struct irq_cfg		hw_irq_cfg;
+	unsigned int		vector;
+	unsigned int		prev_vector;
+	unsigned int		cpu;
+	unsigned int		prev_cpu;
+	unsigned int		irq;
+	struct hlist_node	clist;
+	unsigned int		move_in_progress	: 1,
+				is_managed		: 1,
+				can_reserve		: 1,
+				has_reserved		: 1;
+};
+
+struct irq_domain *x86_vector_domain;
+EXPORT_SYMBOL_GPL(x86_vector_domain);
+static DEFINE_RAW_SPINLOCK(vector_lock);
+static cpumask_var_t vector_searchmask;
+static struct irq_chip lapic_controller;
+static struct irq_matrix *vector_matrix;
+#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct hlist_head, cleanup_list);
+#endif
+
+void lock_vector_lock(void)
+{
+	/* Used to the online set of cpus does not change
+	 * during assign_irq_vector.
+	 */
+	raw_spin_lock(&vector_lock);
+}
+
+void unlock_vector_lock(void)
+{
+	raw_spin_unlock(&vector_lock);
+}
+
+void init_irq_alloc_info(struct irq_alloc_info *info,
+			 const struct cpumask *mask)
+{
+	memset(info, 0, sizeof(*info));
+	info->mask = mask;
+}
+
+void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src)
+{
+	if (src)
+		*dst = *src;
+	else
+		memset(dst, 0, sizeof(*dst));
+}
+
+static struct apic_chip_data *apic_chip_data(struct irq_data *irqd)
+{
+	if (!irqd)
+		return NULL;
+
+	while (irqd->parent_data)
+		irqd = irqd->parent_data;
+
+	return irqd->chip_data;
+}
+
+struct irq_cfg *irqd_cfg(struct irq_data *irqd)
+{
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+
+	return apicd ? &apicd->hw_irq_cfg : NULL;
+}
+EXPORT_SYMBOL_GPL(irqd_cfg);
+
+struct irq_cfg *irq_cfg(unsigned int irq)
+{
+	return irqd_cfg(irq_get_irq_data(irq));
+}
+
+static struct apic_chip_data *alloc_apic_chip_data(int node)
+{
+	struct apic_chip_data *apicd;
+
+	apicd = kzalloc_node(sizeof(*apicd), GFP_KERNEL, node);
+	if (apicd)
+		INIT_HLIST_NODE(&apicd->clist);
+	return apicd;
+}
+
+static void free_apic_chip_data(struct apic_chip_data *apicd)
+{
+	kfree(apicd);
+}
+
+static void apic_update_irq_cfg(struct irq_data *irqd, unsigned int vector,
+				unsigned int cpu)
+{
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+
+	lockdep_assert_held(&vector_lock);
+
+	apicd->hw_irq_cfg.vector = vector;
+	apicd->hw_irq_cfg.dest_apicid = apic->calc_dest_apicid(cpu);
+	irq_data_update_effective_affinity(irqd, cpumask_of(cpu));
+	trace_vector_config(irqd->irq, vector, cpu,
+			    apicd->hw_irq_cfg.dest_apicid);
+}
+
+static void apic_update_vector(struct irq_data *irqd, unsigned int newvec,
+			       unsigned int newcpu)
+{
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+	struct irq_desc *desc = irq_data_to_desc(irqd);
+	bool managed = irqd_affinity_is_managed(irqd);
+
+	lockdep_assert_held(&vector_lock);
+
+	trace_vector_update(irqd->irq, newvec, newcpu, apicd->vector,
+			    apicd->cpu);
+
+	/*
+	 * If there is no vector associated or if the associated vector is
+	 * the shutdown vector, which is associated to make PCI/MSI
+	 * shutdown mode work, then there is nothing to release. Clear out
+	 * prev_vector for this and the offlined target case.
+	 */
+	apicd->prev_vector = 0;
+	if (!apicd->vector || apicd->vector == MANAGED_IRQ_SHUTDOWN_VECTOR)
+		goto setnew;
+	/*
+	 * If the target CPU of the previous vector is online, then mark
+	 * the vector as move in progress and store it for cleanup when the
+	 * first interrupt on the new vector arrives. If the target CPU is
+	 * offline then the regular release mechanism via the cleanup
+	 * vector is not possible and the vector can be immediately freed
+	 * in the underlying matrix allocator.
+	 */
+	if (cpu_online(apicd->cpu)) {
+		apicd->move_in_progress = true;
+		apicd->prev_vector = apicd->vector;
+		apicd->prev_cpu = apicd->cpu;
+		WARN_ON_ONCE(apicd->cpu == newcpu);
+	} else {
+		irq_matrix_free(vector_matrix, apicd->cpu, apicd->vector,
+				managed);
+	}
+
+setnew:
+	apicd->vector = newvec;
+	apicd->cpu = newcpu;
+	BUG_ON(!IS_ERR_OR_NULL(per_cpu(vector_irq, newcpu)[newvec]));
+	per_cpu(vector_irq, newcpu)[newvec] = desc;
+}
+
+static void vector_assign_managed_shutdown(struct irq_data *irqd)
+{
+	unsigned int cpu = cpumask_first(cpu_online_mask);
+
+	apic_update_irq_cfg(irqd, MANAGED_IRQ_SHUTDOWN_VECTOR, cpu);
+}
+
+static int reserve_managed_vector(struct irq_data *irqd)
+{
+	const struct cpumask *affmsk = irq_data_get_affinity_mask(irqd);
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+	unsigned long flags;
+	int ret;
+
+	raw_spin_lock_irqsave(&vector_lock, flags);
+	apicd->is_managed = true;
+	ret = irq_matrix_reserve_managed(vector_matrix, affmsk);
+	raw_spin_unlock_irqrestore(&vector_lock, flags);
+	trace_vector_reserve_managed(irqd->irq, ret);
+	return ret;
+}
+
+static void reserve_irq_vector_locked(struct irq_data *irqd)
+{
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+
+	irq_matrix_reserve(vector_matrix);
+	apicd->can_reserve = true;
+	apicd->has_reserved = true;
+	irqd_set_can_reserve(irqd);
+	trace_vector_reserve(irqd->irq, 0);
+	vector_assign_managed_shutdown(irqd);
+}
+
+static int reserve_irq_vector(struct irq_data *irqd)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&vector_lock, flags);
+	reserve_irq_vector_locked(irqd);
+	raw_spin_unlock_irqrestore(&vector_lock, flags);
+	return 0;
+}
+
+static int
+assign_vector_locked(struct irq_data *irqd, const struct cpumask *dest)
+{
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+	bool resvd = apicd->has_reserved;
+	unsigned int cpu = apicd->cpu;
+	int vector = apicd->vector;
+
+	lockdep_assert_held(&vector_lock);
+
+	/*
+	 * If the current target CPU is online and in the new requested
+	 * affinity mask, there is no point in moving the interrupt from
+	 * one CPU to another.
+	 */
+	if (vector && cpu_online(cpu) && cpumask_test_cpu(cpu, dest))
+		return 0;
+
+	/*
+	 * Careful here. @apicd might either have move_in_progress set or
+	 * be enqueued for cleanup. Assigning a new vector would either
+	 * leave a stale vector on some CPU around or in case of a pending
+	 * cleanup corrupt the hlist.
+	 */
+	if (apicd->move_in_progress || !hlist_unhashed(&apicd->clist))
+		return -EBUSY;
+
+	vector = irq_matrix_alloc(vector_matrix, dest, resvd, &cpu);
+	trace_vector_alloc(irqd->irq, vector, resvd, vector);
+	if (vector < 0)
+		return vector;
+	apic_update_vector(irqd, vector, cpu);
+	apic_update_irq_cfg(irqd, vector, cpu);
+
+	return 0;
+}
+
+static int assign_irq_vector(struct irq_data *irqd, const struct cpumask *dest)
+{
+	unsigned long flags;
+	int ret;
+
+	raw_spin_lock_irqsave(&vector_lock, flags);
+	cpumask_and(vector_searchmask, dest, cpu_online_mask);
+	ret = assign_vector_locked(irqd, vector_searchmask);
+	raw_spin_unlock_irqrestore(&vector_lock, flags);
+	return ret;
+}
+
+static int assign_irq_vector_any_locked(struct irq_data *irqd)
+{
+	/* Get the affinity mask - either irq_default_affinity or (user) set */
+	const struct cpumask *affmsk = irq_data_get_affinity_mask(irqd);
+	int node = irq_data_get_node(irqd);
+
+	if (node != NUMA_NO_NODE) {
+		/* Try the intersection of @affmsk and node mask */
+		cpumask_and(vector_searchmask, cpumask_of_node(node), affmsk);
+		if (!assign_vector_locked(irqd, vector_searchmask))
+			return 0;
+	}
+
+	/* Try the full affinity mask */
+	cpumask_and(vector_searchmask, affmsk, cpu_online_mask);
+	if (!assign_vector_locked(irqd, vector_searchmask))
+		return 0;
+
+	if (node != NUMA_NO_NODE) {
+		/* Try the node mask */
+		if (!assign_vector_locked(irqd, cpumask_of_node(node)))
+			return 0;
+	}
+
+	/* Try the full online mask */
+	return assign_vector_locked(irqd, cpu_online_mask);
+}
+
+static int
+assign_irq_vector_policy(struct irq_data *irqd, struct irq_alloc_info *info)
+{
+	if (irqd_affinity_is_managed(irqd))
+		return reserve_managed_vector(irqd);
+	if (info->mask)
+		return assign_irq_vector(irqd, info->mask);
+	/*
+	 * Make only a global reservation with no guarantee. A real vector
+	 * is associated at activation time.
+	 */
+	return reserve_irq_vector(irqd);
+}
+
+static int
+assign_managed_vector(struct irq_data *irqd, const struct cpumask *dest)
+{
+	const struct cpumask *affmsk = irq_data_get_affinity_mask(irqd);
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+	int vector, cpu;
+
+	cpumask_and(vector_searchmask, dest, affmsk);
+
+	/* set_affinity might call here for nothing */
+	if (apicd->vector && cpumask_test_cpu(apicd->cpu, vector_searchmask))
+		return 0;
+	vector = irq_matrix_alloc_managed(vector_matrix, vector_searchmask,
+					  &cpu);
+	trace_vector_alloc_managed(irqd->irq, vector, vector);
+	if (vector < 0)
+		return vector;
+	apic_update_vector(irqd, vector, cpu);
+	apic_update_irq_cfg(irqd, vector, cpu);
+	return 0;
+}
+
+static void clear_irq_vector(struct irq_data *irqd)
+{
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+	bool managed = irqd_affinity_is_managed(irqd);
+	unsigned int vector = apicd->vector;
+
+	lockdep_assert_held(&vector_lock);
+
+	if (!vector)
+		return;
+
+	trace_vector_clear(irqd->irq, vector, apicd->cpu, apicd->prev_vector,
+			   apicd->prev_cpu);
+
+	per_cpu(vector_irq, apicd->cpu)[vector] = VECTOR_SHUTDOWN;
+	irq_matrix_free(vector_matrix, apicd->cpu, vector, managed);
+	apicd->vector = 0;
+
+	/* Clean up move in progress */
+	vector = apicd->prev_vector;
+	if (!vector)
+		return;
+
+	per_cpu(vector_irq, apicd->prev_cpu)[vector] = VECTOR_SHUTDOWN;
+	irq_matrix_free(vector_matrix, apicd->prev_cpu, vector, managed);
+	apicd->prev_vector = 0;
+	apicd->move_in_progress = 0;
+	hlist_del_init(&apicd->clist);
+}
+
+static void x86_vector_deactivate(struct irq_domain *dom, struct irq_data *irqd)
+{
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+	unsigned long flags;
+
+	trace_vector_deactivate(irqd->irq, apicd->is_managed,
+				apicd->can_reserve, false);
+
+	/* Regular fixed assigned interrupt */
+	if (!apicd->is_managed && !apicd->can_reserve)
+		return;
+	/* If the interrupt has a global reservation, nothing to do */
+	if (apicd->has_reserved)
+		return;
+
+	raw_spin_lock_irqsave(&vector_lock, flags);
+	clear_irq_vector(irqd);
+	if (apicd->can_reserve)
+		reserve_irq_vector_locked(irqd);
+	else
+		vector_assign_managed_shutdown(irqd);
+	raw_spin_unlock_irqrestore(&vector_lock, flags);
+}
+
+static int activate_reserved(struct irq_data *irqd)
+{
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+	int ret;
+
+	ret = assign_irq_vector_any_locked(irqd);
+	if (!ret) {
+		apicd->has_reserved = false;
+		/*
+		 * Core might have disabled reservation mode after
+		 * allocating the irq descriptor. Ideally this should
+		 * happen before allocation time, but that would require
+		 * completely convoluted ways of transporting that
+		 * information.
+		 */
+		if (!irqd_can_reserve(irqd))
+			apicd->can_reserve = false;
+	}
+
+	/*
+	 * Check to ensure that the effective affinity mask is a subset
+	 * the user supplied affinity mask, and warn the user if it is not
+	 */
+	if (!cpumask_subset(irq_data_get_effective_affinity_mask(irqd),
+			    irq_data_get_affinity_mask(irqd))) {
+		pr_warn("irq %u: Affinity broken due to vector space exhaustion.\n",
+			irqd->irq);
+	}
+
+	return ret;
+}
+
+static int activate_managed(struct irq_data *irqd)
+{
+	const struct cpumask *dest = irq_data_get_affinity_mask(irqd);
+	int ret;
+
+	cpumask_and(vector_searchmask, dest, cpu_online_mask);
+	if (WARN_ON_ONCE(cpumask_empty(vector_searchmask))) {
+		/* Something in the core code broke! Survive gracefully */
+		pr_err("Managed startup for irq %u, but no CPU\n", irqd->irq);
+		return -EINVAL;
+	}
+
+	ret = assign_managed_vector(irqd, vector_searchmask);
+	/*
+	 * This should not happen. The vector reservation got buggered.  Handle
+	 * it gracefully.
+	 */
+	if (WARN_ON_ONCE(ret < 0)) {
+		pr_err("Managed startup irq %u, no vector available\n",
+		       irqd->irq);
+	}
+	return ret;
+}
+
+static int x86_vector_activate(struct irq_domain *dom, struct irq_data *irqd,
+			       bool reserve)
+{
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+	unsigned long flags;
+	int ret = 0;
+
+	trace_vector_activate(irqd->irq, apicd->is_managed,
+			      apicd->can_reserve, reserve);
+
+	raw_spin_lock_irqsave(&vector_lock, flags);
+	if (!apicd->can_reserve && !apicd->is_managed)
+		assign_irq_vector_any_locked(irqd);
+	else if (reserve || irqd_is_managed_and_shutdown(irqd))
+		vector_assign_managed_shutdown(irqd);
+	else if (apicd->is_managed)
+		ret = activate_managed(irqd);
+	else if (apicd->has_reserved)
+		ret = activate_reserved(irqd);
+	raw_spin_unlock_irqrestore(&vector_lock, flags);
+	return ret;
+}
+
+static void vector_free_reserved_and_managed(struct irq_data *irqd)
+{
+	const struct cpumask *dest = irq_data_get_affinity_mask(irqd);
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+
+	trace_vector_teardown(irqd->irq, apicd->is_managed,
+			      apicd->has_reserved);
+
+	if (apicd->has_reserved)
+		irq_matrix_remove_reserved(vector_matrix);
+	if (apicd->is_managed)
+		irq_matrix_remove_managed(vector_matrix, dest);
+}
+
+static void x86_vector_free_irqs(struct irq_domain *domain,
+				 unsigned int virq, unsigned int nr_irqs)
+{
+	struct apic_chip_data *apicd;
+	struct irq_data *irqd;
+	unsigned long flags;
+	int i;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irqd = irq_domain_get_irq_data(x86_vector_domain, virq + i);
+		if (irqd && irqd->chip_data) {
+			raw_spin_lock_irqsave(&vector_lock, flags);
+			clear_irq_vector(irqd);
+			vector_free_reserved_and_managed(irqd);
+			apicd = irqd->chip_data;
+			irq_domain_reset_irq_data(irqd);
+			raw_spin_unlock_irqrestore(&vector_lock, flags);
+			free_apic_chip_data(apicd);
+		}
+	}
+}
+
+static bool vector_configure_legacy(unsigned int virq, struct irq_data *irqd,
+				    struct apic_chip_data *apicd)
+{
+	unsigned long flags;
+	bool realloc = false;
+
+	apicd->vector = ISA_IRQ_VECTOR(virq);
+	apicd->cpu = 0;
+
+	raw_spin_lock_irqsave(&vector_lock, flags);
+	/*
+	 * If the interrupt is activated, then it must stay at this vector
+	 * position. That's usually the timer interrupt (0).
+	 */
+	if (irqd_is_activated(irqd)) {
+		trace_vector_setup(virq, true, 0);
+		apic_update_irq_cfg(irqd, apicd->vector, apicd->cpu);
+	} else {
+		/* Release the vector */
+		apicd->can_reserve = true;
+		irqd_set_can_reserve(irqd);
+		clear_irq_vector(irqd);
+		realloc = true;
+	}
+	raw_spin_unlock_irqrestore(&vector_lock, flags);
+	return realloc;
+}
+
+static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
+				 unsigned int nr_irqs, void *arg)
+{
+	struct irq_alloc_info *info = arg;
+	struct apic_chip_data *apicd;
+	struct irq_data *irqd;
+	int i, err, node;
+
+	if (disable_apic)
+		return -ENXIO;
+
+	/* Currently vector allocator can't guarantee contiguous allocations */
+	if ((info->flags & X86_IRQ_ALLOC_CONTIGUOUS_VECTORS) && nr_irqs > 1)
+		return -ENOSYS;
+
+	/*
+	 * Catch any attempt to touch the cascade interrupt on a PIC
+	 * equipped system.
+	 */
+	if (WARN_ON_ONCE(info->flags & X86_IRQ_ALLOC_LEGACY &&
+			 virq == PIC_CASCADE_IR))
+		return -EINVAL;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irqd = irq_domain_get_irq_data(domain, virq + i);
+		BUG_ON(!irqd);
+		node = irq_data_get_node(irqd);
+		WARN_ON_ONCE(irqd->chip_data);
+		apicd = alloc_apic_chip_data(node);
+		if (!apicd) {
+			err = -ENOMEM;
+			goto error;
+		}
+
+		apicd->irq = virq + i;
+		irqd->chip = &lapic_controller;
+		irqd->chip_data = apicd;
+		irqd->hwirq = virq + i;
+		irqd_set_single_target(irqd);
+		/*
+		 * Prevent that any of these interrupts is invoked in
+		 * non interrupt context via e.g. generic_handle_irq()
+		 * as that can corrupt the affinity move state.
+		 */
+		irqd_set_handle_enforce_irqctx(irqd);
+
+		/* Don't invoke affinity setter on deactivated interrupts */
+		irqd_set_affinity_on_activate(irqd);
+
+		/*
+		 * Legacy vectors are already assigned when the IOAPIC
+		 * takes them over. They stay on the same vector. This is
+		 * required for check_timer() to work correctly as it might
+		 * switch back to legacy mode. Only update the hardware
+		 * config.
+		 */
+		if (info->flags & X86_IRQ_ALLOC_LEGACY) {
+			if (!vector_configure_legacy(virq + i, irqd, apicd))
+				continue;
+		}
+
+		err = assign_irq_vector_policy(irqd, info);
+		trace_vector_setup(virq + i, false, err);
+		if (err) {
+			irqd->chip_data = NULL;
+			free_apic_chip_data(apicd);
+			goto error;
+		}
+	}
+
+	return 0;
+
+error:
+	x86_vector_free_irqs(domain, virq, i);
+	return err;
+}
+
+#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
+static void x86_vector_debug_show(struct seq_file *m, struct irq_domain *d,
+				  struct irq_data *irqd, int ind)
+{
+	struct apic_chip_data apicd;
+	unsigned long flags;
+	int irq;
+
+	if (!irqd) {
+		irq_matrix_debug_show(m, vector_matrix, ind);
+		return;
+	}
+
+	irq = irqd->irq;
+	if (irq < nr_legacy_irqs() && !test_bit(irq, &io_apic_irqs)) {
+		seq_printf(m, "%*sVector: %5d\n", ind, "", ISA_IRQ_VECTOR(irq));
+		seq_printf(m, "%*sTarget: Legacy PIC all CPUs\n", ind, "");
+		return;
+	}
+
+	if (!irqd->chip_data) {
+		seq_printf(m, "%*sVector: Not assigned\n", ind, "");
+		return;
+	}
+
+	raw_spin_lock_irqsave(&vector_lock, flags);
+	memcpy(&apicd, irqd->chip_data, sizeof(apicd));
+	raw_spin_unlock_irqrestore(&vector_lock, flags);
+
+	seq_printf(m, "%*sVector: %5u\n", ind, "", apicd.vector);
+	seq_printf(m, "%*sTarget: %5u\n", ind, "", apicd.cpu);
+	if (apicd.prev_vector) {
+		seq_printf(m, "%*sPrevious vector: %5u\n", ind, "", apicd.prev_vector);
+		seq_printf(m, "%*sPrevious target: %5u\n", ind, "", apicd.prev_cpu);
+	}
+	seq_printf(m, "%*smove_in_progress: %u\n", ind, "", apicd.move_in_progress ? 1 : 0);
+	seq_printf(m, "%*sis_managed:       %u\n", ind, "", apicd.is_managed ? 1 : 0);
+	seq_printf(m, "%*scan_reserve:      %u\n", ind, "", apicd.can_reserve ? 1 : 0);
+	seq_printf(m, "%*shas_reserved:     %u\n", ind, "", apicd.has_reserved ? 1 : 0);
+	seq_printf(m, "%*scleanup_pending:  %u\n", ind, "", !hlist_unhashed(&apicd.clist));
+}
+#endif
+
+int x86_fwspec_is_ioapic(struct irq_fwspec *fwspec)
+{
+	if (fwspec->param_count != 1)
+		return 0;
+
+	if (is_fwnode_irqchip(fwspec->fwnode)) {
+		const char *fwname = fwnode_get_name(fwspec->fwnode);
+		return fwname && !strncmp(fwname, "IO-APIC-", 8) &&
+			simple_strtol(fwname+8, NULL, 10) == fwspec->param[0];
+	}
+	return to_of_node(fwspec->fwnode) &&
+		of_device_is_compatible(to_of_node(fwspec->fwnode),
+					"intel,ce4100-ioapic");
+}
+
+int x86_fwspec_is_hpet(struct irq_fwspec *fwspec)
+{
+	if (fwspec->param_count != 1)
+		return 0;
+
+	if (is_fwnode_irqchip(fwspec->fwnode)) {
+		const char *fwname = fwnode_get_name(fwspec->fwnode);
+		return fwname && !strncmp(fwname, "HPET-MSI-", 9) &&
+			simple_strtol(fwname+9, NULL, 10) == fwspec->param[0];
+	}
+	return 0;
+}
+
+static int x86_vector_select(struct irq_domain *d, struct irq_fwspec *fwspec,
+			     enum irq_domain_bus_token bus_token)
+{
+	/*
+	 * HPET and I/OAPIC cannot be parented in the vector domain
+	 * if IRQ remapping is enabled. APIC IDs above 15 bits are
+	 * only permitted if IRQ remapping is enabled, so check that.
+	 */
+	if (apic->apic_id_valid(32768))
+		return 0;
+
+	return x86_fwspec_is_ioapic(fwspec) || x86_fwspec_is_hpet(fwspec);
+}
+
+static const struct irq_domain_ops x86_vector_domain_ops = {
+	.select		= x86_vector_select,
+	.alloc		= x86_vector_alloc_irqs,
+	.free		= x86_vector_free_irqs,
+	.activate	= x86_vector_activate,
+	.deactivate	= x86_vector_deactivate,
+#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
+	.debug_show	= x86_vector_debug_show,
+#endif
+};
+
+int __init arch_probe_nr_irqs(void)
+{
+	int nr;
+
+	if (nr_irqs > (NR_VECTORS * nr_cpu_ids))
+		nr_irqs = NR_VECTORS * nr_cpu_ids;
+
+	nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids;
+#if defined(CONFIG_PCI_MSI)
+	/*
+	 * for MSI and HT dyn irq
+	 */
+	if (gsi_top <= NR_IRQS_LEGACY)
+		nr +=  8 * nr_cpu_ids;
+	else
+		nr += gsi_top * 16;
+#endif
+	if (nr < nr_irqs)
+		nr_irqs = nr;
+
+	/*
+	 * We don't know if PIC is present at this point so we need to do
+	 * probe() to get the right number of legacy IRQs.
+	 */
+	return legacy_pic->probe();
+}
+
+void lapic_assign_legacy_vector(unsigned int irq, bool replace)
+{
+	/*
+	 * Use assign system here so it wont get accounted as allocated
+	 * and moveable in the cpu hotplug check and it prevents managed
+	 * irq reservation from touching it.
+	 */
+	irq_matrix_assign_system(vector_matrix, ISA_IRQ_VECTOR(irq), replace);
+}
+
+void __init lapic_update_legacy_vectors(void)
+{
+	unsigned int i;
+
+	if (IS_ENABLED(CONFIG_X86_IO_APIC) && nr_ioapics > 0)
+		return;
+
+	/*
+	 * If the IO/APIC is disabled via config, kernel command line or
+	 * lack of enumeration then all legacy interrupts are routed
+	 * through the PIC. Make sure that they are marked as legacy
+	 * vectors. PIC_CASCADE_IRQ has already been marked in
+	 * lapic_assign_system_vectors().
+	 */
+	for (i = 0; i < nr_legacy_irqs(); i++) {
+		if (i != PIC_CASCADE_IR)
+			lapic_assign_legacy_vector(i, true);
+	}
+}
+
+void __init lapic_assign_system_vectors(void)
+{
+	unsigned int i, vector;
+
+	for_each_set_bit(vector, system_vectors, NR_VECTORS)
+		irq_matrix_assign_system(vector_matrix, vector, false);
+
+	if (nr_legacy_irqs() > 1)
+		lapic_assign_legacy_vector(PIC_CASCADE_IR, false);
+
+	/* System vectors are reserved, online it */
+	irq_matrix_online(vector_matrix);
+
+	/* Mark the preallocated legacy interrupts */
+	for (i = 0; i < nr_legacy_irqs(); i++) {
+		/*
+		 * Don't touch the cascade interrupt. It's unusable
+		 * on PIC equipped machines. See the large comment
+		 * in the IO/APIC code.
+		 */
+		if (i != PIC_CASCADE_IR)
+			irq_matrix_assign(vector_matrix, ISA_IRQ_VECTOR(i));
+	}
+}
+
+int __init arch_early_irq_init(void)
+{
+	struct fwnode_handle *fn;
+
+	fn = irq_domain_alloc_named_fwnode("VECTOR");
+	BUG_ON(!fn);
+	x86_vector_domain = irq_domain_create_tree(fn, &x86_vector_domain_ops,
+						   NULL);
+	BUG_ON(x86_vector_domain == NULL);
+	irq_set_default_host(x86_vector_domain);
+
+	BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL));
+
+	/*
+	 * Allocate the vector matrix allocator data structure and limit the
+	 * search area.
+	 */
+	vector_matrix = irq_alloc_matrix(NR_VECTORS, FIRST_EXTERNAL_VECTOR,
+					 FIRST_SYSTEM_VECTOR);
+	BUG_ON(!vector_matrix);
+
+	return arch_early_ioapic_init();
+}
+
+#ifdef CONFIG_SMP
+
+static struct irq_desc *__setup_vector_irq(int vector)
+{
+	int isairq = vector - ISA_IRQ_VECTOR(0);
+
+	/* Check whether the irq is in the legacy space */
+	if (isairq < 0 || isairq >= nr_legacy_irqs())
+		return VECTOR_UNUSED;
+	/* Check whether the irq is handled by the IOAPIC */
+	if (test_bit(isairq, &io_apic_irqs))
+		return VECTOR_UNUSED;
+	return irq_to_desc(isairq);
+}
+
+/* Online the local APIC infrastructure and initialize the vectors */
+void lapic_online(void)
+{
+	unsigned int vector;
+
+	lockdep_assert_held(&vector_lock);
+
+	/* Online the vector matrix array for this CPU */
+	irq_matrix_online(vector_matrix);
+
+	/*
+	 * The interrupt affinity logic never targets interrupts to offline
+	 * CPUs. The exception are the legacy PIC interrupts. In general
+	 * they are only targeted to CPU0, but depending on the platform
+	 * they can be distributed to any online CPU in hardware. The
+	 * kernel has no influence on that. So all active legacy vectors
+	 * must be installed on all CPUs. All non legacy interrupts can be
+	 * cleared.
+	 */
+	for (vector = 0; vector < NR_VECTORS; vector++)
+		this_cpu_write(vector_irq[vector], __setup_vector_irq(vector));
+}
+
+void lapic_offline(void)
+{
+	lock_vector_lock();
+	irq_matrix_offline(vector_matrix);
+	unlock_vector_lock();
+}
+
+static int apic_set_affinity(struct irq_data *irqd,
+			     const struct cpumask *dest, bool force)
+{
+	int err;
+
+	if (WARN_ON_ONCE(!irqd_is_activated(irqd)))
+		return -EIO;
+
+	raw_spin_lock(&vector_lock);
+	cpumask_and(vector_searchmask, dest, cpu_online_mask);
+	if (irqd_affinity_is_managed(irqd))
+		err = assign_managed_vector(irqd, vector_searchmask);
+	else
+		err = assign_vector_locked(irqd, vector_searchmask);
+	raw_spin_unlock(&vector_lock);
+	return err ? err : IRQ_SET_MASK_OK;
+}
+
+#else
+# define apic_set_affinity	NULL
+#endif
+
+static int apic_retrigger_irq(struct irq_data *irqd)
+{
+	struct apic_chip_data *apicd = apic_chip_data(irqd);
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&vector_lock, flags);
+	apic->send_IPI(apicd->cpu, apicd->vector);
+	raw_spin_unlock_irqrestore(&vector_lock, flags);
+
+	return 1;
+}
+
+void apic_ack_irq(struct irq_data *irqd)
+{
+	irq_move_irq(irqd);
+	ack_APIC_irq();
+}
+
+void apic_ack_edge(struct irq_data *irqd)
+{
+	irq_complete_move(irqd_cfg(irqd));
+	apic_ack_irq(irqd);
+}
+
+static void x86_vector_msi_compose_msg(struct irq_data *data,
+				       struct msi_msg *msg)
+{
+       __irq_msi_compose_msg(irqd_cfg(data), msg, false);
+}
+
+static struct irq_chip lapic_controller = {
+	.name			= "APIC",
+	.irq_ack		= apic_ack_edge,
+	.irq_set_affinity	= apic_set_affinity,
+	.irq_compose_msi_msg	= x86_vector_msi_compose_msg,
+	.irq_retrigger		= apic_retrigger_irq,
+};
+
+#ifdef CONFIG_SMP
+
+static void free_moved_vector(struct apic_chip_data *apicd)
+{
+	unsigned int vector = apicd->prev_vector;
+	unsigned int cpu = apicd->prev_cpu;
+	bool managed = apicd->is_managed;
+
+	/*
+	 * Managed interrupts are usually not migrated away
+	 * from an online CPU, but CPU isolation 'managed_irq'
+	 * can make that happen.
+	 * 1) Activation does not take the isolation into account
+	 *    to keep the code simple
+	 * 2) Migration away from an isolated CPU can happen when
+	 *    a non-isolated CPU which is in the calculated
+	 *    affinity mask comes online.
+	 */
+	trace_vector_free_moved(apicd->irq, cpu, vector, managed);
+	irq_matrix_free(vector_matrix, cpu, vector, managed);
+	per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
+	hlist_del_init(&apicd->clist);
+	apicd->prev_vector = 0;
+	apicd->move_in_progress = 0;
+}
+
+DEFINE_IDTENTRY_SYSVEC(sysvec_irq_move_cleanup)
+{
+	struct hlist_head *clhead = this_cpu_ptr(&cleanup_list);
+	struct apic_chip_data *apicd;
+	struct hlist_node *tmp;
+
+	ack_APIC_irq();
+	/* Prevent vectors vanishing under us */
+	raw_spin_lock(&vector_lock);
+
+	hlist_for_each_entry_safe(apicd, tmp, clhead, clist) {
+		unsigned int irr, vector = apicd->prev_vector;
+
+		/*
+		 * Paranoia: Check if the vector that needs to be cleaned
+		 * up is registered at the APICs IRR. If so, then this is
+		 * not the best time to clean it up. Clean it up in the
+		 * next attempt by sending another IRQ_MOVE_CLEANUP_VECTOR
+		 * to this CPU. IRQ_MOVE_CLEANUP_VECTOR is the lowest
+		 * priority external vector, so on return from this
+		 * interrupt the device interrupt will happen first.
+		 */
+		irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
+		if (irr & (1U << (vector % 32))) {
+			apic->send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR);
+			continue;
+		}
+		free_moved_vector(apicd);
+	}
+
+	raw_spin_unlock(&vector_lock);
+}
+
+static void __send_cleanup_vector(struct apic_chip_data *apicd)
+{
+	unsigned int cpu;
+
+	raw_spin_lock(&vector_lock);
+	apicd->move_in_progress = 0;
+	cpu = apicd->prev_cpu;
+	if (cpu_online(cpu)) {
+		hlist_add_head(&apicd->clist, per_cpu_ptr(&cleanup_list, cpu));
+		apic->send_IPI(cpu, IRQ_MOVE_CLEANUP_VECTOR);
+	} else {
+		apicd->prev_vector = 0;
+	}
+	raw_spin_unlock(&vector_lock);
+}
+
+void send_cleanup_vector(struct irq_cfg *cfg)
+{
+	struct apic_chip_data *apicd;
+
+	apicd = container_of(cfg, struct apic_chip_data, hw_irq_cfg);
+	if (apicd->move_in_progress)
+		__send_cleanup_vector(apicd);
+}
+
+void irq_complete_move(struct irq_cfg *cfg)
+{
+	struct apic_chip_data *apicd;
+
+	apicd = container_of(cfg, struct apic_chip_data, hw_irq_cfg);
+	if (likely(!apicd->move_in_progress))
+		return;
+
+	/*
+	 * If the interrupt arrived on the new target CPU, cleanup the
+	 * vector on the old target CPU. A vector check is not required
+	 * because an interrupt can never move from one vector to another
+	 * on the same CPU.
+	 */
+	if (apicd->cpu == smp_processor_id())
+		__send_cleanup_vector(apicd);
+}
+
+/*
+ * Called from fixup_irqs() with @desc->lock held and interrupts disabled.
+ */
+void irq_force_complete_move(struct irq_desc *desc)
+{
+	struct apic_chip_data *apicd;
+	struct irq_data *irqd;
+	unsigned int vector;
+
+	/*
+	 * The function is called for all descriptors regardless of which
+	 * irqdomain they belong to. For example if an IRQ is provided by
+	 * an irq_chip as part of a GPIO driver, the chip data for that
+	 * descriptor is specific to the irq_chip in question.
+	 *
+	 * Check first that the chip_data is what we expect
+	 * (apic_chip_data) before touching it any further.
+	 */
+	irqd = irq_domain_get_irq_data(x86_vector_domain,
+				       irq_desc_get_irq(desc));
+	if (!irqd)
+		return;
+
+	raw_spin_lock(&vector_lock);
+	apicd = apic_chip_data(irqd);
+	if (!apicd)
+		goto unlock;
+
+	/*
+	 * If prev_vector is empty, no action required.
+	 */
+	vector = apicd->prev_vector;
+	if (!vector)
+		goto unlock;
+
+	/*
+	 * This is tricky. If the cleanup of the old vector has not been
+	 * done yet, then the following setaffinity call will fail with
+	 * -EBUSY. This can leave the interrupt in a stale state.
+	 *
+	 * All CPUs are stuck in stop machine with interrupts disabled so
+	 * calling __irq_complete_move() would be completely pointless.
+	 *
+	 * 1) The interrupt is in move_in_progress state. That means that we
+	 *    have not seen an interrupt since the io_apic was reprogrammed to
+	 *    the new vector.
+	 *
+	 * 2) The interrupt has fired on the new vector, but the cleanup IPIs
+	 *    have not been processed yet.
+	 */
+	if (apicd->move_in_progress) {
+		/*
+		 * In theory there is a race:
+		 *
+		 * set_ioapic(new_vector) <-- Interrupt is raised before update
+		 *			      is effective, i.e. it's raised on
+		 *			      the old vector.
+		 *
+		 * So if the target cpu cannot handle that interrupt before
+		 * the old vector is cleaned up, we get a spurious interrupt
+		 * and in the worst case the ioapic irq line becomes stale.
+		 *
+		 * But in case of cpu hotplug this should be a non issue
+		 * because if the affinity update happens right before all
+		 * cpus rendezvous in stop machine, there is no way that the
+		 * interrupt can be blocked on the target cpu because all cpus
+		 * loops first with interrupts enabled in stop machine, so the
+		 * old vector is not yet cleaned up when the interrupt fires.
+		 *
+		 * So the only way to run into this issue is if the delivery
+		 * of the interrupt on the apic/system bus would be delayed
+		 * beyond the point where the target cpu disables interrupts
+		 * in stop machine. I doubt that it can happen, but at least
+		 * there is a theoretical chance. Virtualization might be
+		 * able to expose this, but AFAICT the IOAPIC emulation is not
+		 * as stupid as the real hardware.
+		 *
+		 * Anyway, there is nothing we can do about that at this point
+		 * w/o refactoring the whole fixup_irq() business completely.
+		 * We print at least the irq number and the old vector number,
+		 * so we have the necessary information when a problem in that
+		 * area arises.
+		 */
+		pr_warn("IRQ fixup: irq %d move in progress, old vector %d\n",
+			irqd->irq, vector);
+	}
+	free_moved_vector(apicd);
+unlock:
+	raw_spin_unlock(&vector_lock);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * Note, this is not accurate accounting, but at least good enough to
+ * prevent that the actual interrupt move will run out of vectors.
+ */
+int lapic_can_unplug_cpu(void)
+{
+	unsigned int rsvd, avl, tomove, cpu = smp_processor_id();
+	int ret = 0;
+
+	raw_spin_lock(&vector_lock);
+	tomove = irq_matrix_allocated(vector_matrix);
+	avl = irq_matrix_available(vector_matrix, true);
+	if (avl < tomove) {
+		pr_warn("CPU %u has %u vectors, %u available. Cannot disable CPU\n",
+			cpu, tomove, avl);
+		ret = -ENOSPC;
+		goto out;
+	}
+	rsvd = irq_matrix_reserved(vector_matrix);
+	if (avl < rsvd) {
+		pr_warn("Reserved vectors %u > available %u. IRQ request may fail\n",
+			rsvd, avl);
+	}
+out:
+	raw_spin_unlock(&vector_lock);
+	return ret;
+}
+#endif /* HOTPLUG_CPU */
+#endif /* SMP */
+
+static void __init print_APIC_field(int base)
+{
+	int i;
+
+	printk(KERN_DEBUG);
+
+	for (i = 0; i < 8; i++)
+		pr_cont("%08x", apic_read(base + i*0x10));
+
+	pr_cont("\n");
+}
+
+static void __init print_local_APIC(void *dummy)
+{
+	unsigned int i, v, ver, maxlvt;
+	u64 icr;
+
+	pr_debug("printing local APIC contents on CPU#%d/%d:\n",
+		 smp_processor_id(), hard_smp_processor_id());
+	v = apic_read(APIC_ID);
+	pr_info("... APIC ID:      %08x (%01x)\n", v, read_apic_id());
+	v = apic_read(APIC_LVR);
+	pr_info("... APIC VERSION: %08x\n", v);
+	ver = GET_APIC_VERSION(v);
+	maxlvt = lapic_get_maxlvt();
+
+	v = apic_read(APIC_TASKPRI);
+	pr_debug("... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);
+
+	/* !82489DX */
+	if (APIC_INTEGRATED(ver)) {
+		if (!APIC_XAPIC(ver)) {
+			v = apic_read(APIC_ARBPRI);
+			pr_debug("... APIC ARBPRI: %08x (%02x)\n",
+				 v, v & APIC_ARBPRI_MASK);
+		}
+		v = apic_read(APIC_PROCPRI);
+		pr_debug("... APIC PROCPRI: %08x\n", v);
+	}
+
+	/*
+	 * Remote read supported only in the 82489DX and local APIC for
+	 * Pentium processors.
+	 */
+	if (!APIC_INTEGRATED(ver) || maxlvt == 3) {
+		v = apic_read(APIC_RRR);
+		pr_debug("... APIC RRR: %08x\n", v);
+	}
+
+	v = apic_read(APIC_LDR);
+	pr_debug("... APIC LDR: %08x\n", v);
+	if (!x2apic_enabled()) {
+		v = apic_read(APIC_DFR);
+		pr_debug("... APIC DFR: %08x\n", v);
+	}
+	v = apic_read(APIC_SPIV);
+	pr_debug("... APIC SPIV: %08x\n", v);
+
+	pr_debug("... APIC ISR field:\n");
+	print_APIC_field(APIC_ISR);
+	pr_debug("... APIC TMR field:\n");
+	print_APIC_field(APIC_TMR);
+	pr_debug("... APIC IRR field:\n");
+	print_APIC_field(APIC_IRR);
+
+	/* !82489DX */
+	if (APIC_INTEGRATED(ver)) {
+		/* Due to the Pentium erratum 3AP. */
+		if (maxlvt > 3)
+			apic_write(APIC_ESR, 0);
+
+		v = apic_read(APIC_ESR);
+		pr_debug("... APIC ESR: %08x\n", v);
+	}
+
+	icr = apic_icr_read();
+	pr_debug("... APIC ICR: %08x\n", (u32)icr);
+	pr_debug("... APIC ICR2: %08x\n", (u32)(icr >> 32));
+
+	v = apic_read(APIC_LVTT);
+	pr_debug("... APIC LVTT: %08x\n", v);
+
+	if (maxlvt > 3) {
+		/* PC is LVT#4. */
+		v = apic_read(APIC_LVTPC);
+		pr_debug("... APIC LVTPC: %08x\n", v);
+	}
+	v = apic_read(APIC_LVT0);
+	pr_debug("... APIC LVT0: %08x\n", v);
+	v = apic_read(APIC_LVT1);
+	pr_debug("... APIC LVT1: %08x\n", v);
+
+	if (maxlvt > 2) {
+		/* ERR is LVT#3. */
+		v = apic_read(APIC_LVTERR);
+		pr_debug("... APIC LVTERR: %08x\n", v);
+	}
+
+	v = apic_read(APIC_TMICT);
+	pr_debug("... APIC TMICT: %08x\n", v);
+	v = apic_read(APIC_TMCCT);
+	pr_debug("... APIC TMCCT: %08x\n", v);
+	v = apic_read(APIC_TDCR);
+	pr_debug("... APIC TDCR: %08x\n", v);
+
+	if (boot_cpu_has(X86_FEATURE_EXTAPIC)) {
+		v = apic_read(APIC_EFEAT);
+		maxlvt = (v >> 16) & 0xff;
+		pr_debug("... APIC EFEAT: %08x\n", v);
+		v = apic_read(APIC_ECTRL);
+		pr_debug("... APIC ECTRL: %08x\n", v);
+		for (i = 0; i < maxlvt; i++) {
+			v = apic_read(APIC_EILVTn(i));
+			pr_debug("... APIC EILVT%d: %08x\n", i, v);
+		}
+	}
+	pr_cont("\n");
+}
+
+static void __init print_local_APICs(int maxcpu)
+{
+	int cpu;
+
+	if (!maxcpu)
+		return;
+
+	preempt_disable();
+	for_each_online_cpu(cpu) {
+		if (cpu >= maxcpu)
+			break;
+		smp_call_function_single(cpu, print_local_APIC, NULL, 1);
+	}
+	preempt_enable();
+}
+
+static void __init print_PIC(void)
+{
+	unsigned int v;
+	unsigned long flags;
+
+	if (!nr_legacy_irqs())
+		return;
+
+	pr_debug("\nprinting PIC contents\n");
+
+	raw_spin_lock_irqsave(&i8259A_lock, flags);
+
+	v = inb(0xa1) << 8 | inb(0x21);
+	pr_debug("... PIC  IMR: %04x\n", v);
+
+	v = inb(0xa0) << 8 | inb(0x20);
+	pr_debug("... PIC  IRR: %04x\n", v);
+
+	outb(0x0b, 0xa0);
+	outb(0x0b, 0x20);
+	v = inb(0xa0) << 8 | inb(0x20);
+	outb(0x0a, 0xa0);
+	outb(0x0a, 0x20);
+
+	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
+
+	pr_debug("... PIC  ISR: %04x\n", v);
+
+	v = inb(PIC_ELCR2) << 8 | inb(PIC_ELCR1);
+	pr_debug("... PIC ELCR: %04x\n", v);
+}
+
+static int show_lapic __initdata = 1;
+static __init int setup_show_lapic(char *arg)
+{
+	int num = -1;
+
+	if (strcmp(arg, "all") == 0) {
+		show_lapic = CONFIG_NR_CPUS;
+	} else {
+		get_option(&arg, &num);
+		if (num >= 0)
+			show_lapic = num;
+	}
+
+	return 1;
+}
+__setup("show_lapic=", setup_show_lapic);
+
+static int __init print_ICs(void)
+{
+	if (apic_verbosity == APIC_QUIET)
+		return 0;
+
+	print_PIC();
+
+	/* don't print out if apic is not there */
+	if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
+		return 0;
+
+	print_local_APICs(show_lapic);
+	print_IO_APICs();
+
+	return 0;
+}
+
+late_initcall(print_ICs);
diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c
new file mode 100644
index 000000000..e696e22d0
--- /dev/null
+++ b/arch/x86/kernel/apic/x2apic_cluster.c
@@ -0,0 +1,241 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/cpuhotplug.h>
+#include <linux/cpumask.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+
+#include <asm/apic.h>
+
+#include "local.h"
+
+struct cluster_mask {
+	unsigned int	clusterid;
+	int		node;
+	struct cpumask	mask;
+};
+
+/*
+ * __x2apic_send_IPI_mask() possibly needs to read
+ * x86_cpu_to_logical_apicid for all online cpus in a sequential way.
+ * Using per cpu variable would cost one cache line per cpu.
+ */
+static u32 *x86_cpu_to_logical_apicid __read_mostly;
+
+static DEFINE_PER_CPU(cpumask_var_t, ipi_mask);
+static DEFINE_PER_CPU_READ_MOSTLY(struct cluster_mask *, cluster_masks);
+static struct cluster_mask *cluster_hotplug_mask;
+
+static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+{
+	return x2apic_enabled();
+}
+
+static void x2apic_send_IPI(int cpu, int vector)
+{
+	u32 dest = x86_cpu_to_logical_apicid[cpu];
+
+	/* x2apic MSRs are special and need a special fence: */
+	weak_wrmsr_fence();
+	__x2apic_send_IPI_dest(dest, vector, APIC_DEST_LOGICAL);
+}
+
+static void
+__x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest)
+{
+	unsigned int cpu, clustercpu;
+	struct cpumask *tmpmsk;
+	unsigned long flags;
+	u32 dest;
+
+	/* x2apic MSRs are special and need a special fence: */
+	weak_wrmsr_fence();
+	local_irq_save(flags);
+
+	tmpmsk = this_cpu_cpumask_var_ptr(ipi_mask);
+	cpumask_copy(tmpmsk, mask);
+	/* If IPI should not be sent to self, clear current CPU */
+	if (apic_dest != APIC_DEST_ALLINC)
+		__cpumask_clear_cpu(smp_processor_id(), tmpmsk);
+
+	/* Collapse cpus in a cluster so a single IPI per cluster is sent */
+	for_each_cpu(cpu, tmpmsk) {
+		struct cluster_mask *cmsk = per_cpu(cluster_masks, cpu);
+
+		dest = 0;
+		for_each_cpu_and(clustercpu, tmpmsk, &cmsk->mask)
+			dest |= x86_cpu_to_logical_apicid[clustercpu];
+
+		if (!dest)
+			continue;
+
+		__x2apic_send_IPI_dest(dest, vector, APIC_DEST_LOGICAL);
+		/* Remove cluster CPUs from tmpmask */
+		cpumask_andnot(tmpmsk, tmpmsk, &cmsk->mask);
+	}
+
+	local_irq_restore(flags);
+}
+
+static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector)
+{
+	__x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC);
+}
+
+static void
+x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
+{
+	__x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT);
+}
+
+static void x2apic_send_IPI_allbutself(int vector)
+{
+	__x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLBUT);
+}
+
+static void x2apic_send_IPI_all(int vector)
+{
+	__x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLINC);
+}
+
+static u32 x2apic_calc_apicid(unsigned int cpu)
+{
+	return x86_cpu_to_logical_apicid[cpu];
+}
+
+static void init_x2apic_ldr(void)
+{
+	struct cluster_mask *cmsk = this_cpu_read(cluster_masks);
+	u32 cluster, apicid = apic_read(APIC_LDR);
+	unsigned int cpu;
+
+	x86_cpu_to_logical_apicid[smp_processor_id()] = apicid;
+
+	if (cmsk)
+		goto update;
+
+	cluster = apicid >> 16;
+	for_each_online_cpu(cpu) {
+		cmsk = per_cpu(cluster_masks, cpu);
+		/* Matching cluster found. Link and update it. */
+		if (cmsk && cmsk->clusterid == cluster)
+			goto update;
+	}
+	cmsk = cluster_hotplug_mask;
+	cmsk->clusterid = cluster;
+	cluster_hotplug_mask = NULL;
+update:
+	this_cpu_write(cluster_masks, cmsk);
+	cpumask_set_cpu(smp_processor_id(), &cmsk->mask);
+}
+
+static int alloc_clustermask(unsigned int cpu, int node)
+{
+	if (per_cpu(cluster_masks, cpu))
+		return 0;
+	/*
+	 * If a hotplug spare mask exists, check whether it's on the right
+	 * node. If not, free it and allocate a new one.
+	 */
+	if (cluster_hotplug_mask) {
+		if (cluster_hotplug_mask->node == node)
+			return 0;
+		kfree(cluster_hotplug_mask);
+	}
+
+	cluster_hotplug_mask = kzalloc_node(sizeof(*cluster_hotplug_mask),
+					    GFP_KERNEL, node);
+	if (!cluster_hotplug_mask)
+		return -ENOMEM;
+	cluster_hotplug_mask->node = node;
+	return 0;
+}
+
+static int x2apic_prepare_cpu(unsigned int cpu)
+{
+	if (alloc_clustermask(cpu, cpu_to_node(cpu)) < 0)
+		return -ENOMEM;
+	if (!zalloc_cpumask_var(&per_cpu(ipi_mask, cpu), GFP_KERNEL))
+		return -ENOMEM;
+	return 0;
+}
+
+static int x2apic_dead_cpu(unsigned int dead_cpu)
+{
+	struct cluster_mask *cmsk = per_cpu(cluster_masks, dead_cpu);
+
+	if (cmsk)
+		cpumask_clear_cpu(dead_cpu, &cmsk->mask);
+	free_cpumask_var(per_cpu(ipi_mask, dead_cpu));
+	return 0;
+}
+
+static int x2apic_cluster_probe(void)
+{
+	u32 slots;
+
+	if (!x2apic_mode)
+		return 0;
+
+	slots = max_t(u32, L1_CACHE_BYTES/sizeof(u32), nr_cpu_ids);
+	x86_cpu_to_logical_apicid = kcalloc(slots, sizeof(u32), GFP_KERNEL);
+	if (!x86_cpu_to_logical_apicid)
+		return 0;
+
+	if (cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "x86/x2apic:prepare",
+			      x2apic_prepare_cpu, x2apic_dead_cpu) < 0) {
+		pr_err("Failed to register X2APIC_PREPARE\n");
+		kfree(x86_cpu_to_logical_apicid);
+		x86_cpu_to_logical_apicid = NULL;
+		return 0;
+	}
+	init_x2apic_ldr();
+	return 1;
+}
+
+static struct apic apic_x2apic_cluster __ro_after_init = {
+
+	.name				= "cluster x2apic",
+	.probe				= x2apic_cluster_probe,
+	.acpi_madt_oem_check		= x2apic_acpi_madt_oem_check,
+	.apic_id_valid			= x2apic_apic_id_valid,
+	.apic_id_registered		= x2apic_apic_id_registered,
+
+	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
+	.dest_mode_logical		= true,
+
+	.disable_esr			= 0,
+
+	.check_apicid_used		= NULL,
+	.init_apic_ldr			= init_x2apic_ldr,
+	.ioapic_phys_id_map		= NULL,
+	.setup_apic_routing		= NULL,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= NULL,
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+	.phys_pkg_id			= x2apic_phys_pkg_id,
+
+	.get_apic_id			= x2apic_get_apic_id,
+	.set_apic_id			= x2apic_set_apic_id,
+
+	.calc_dest_apicid		= x2apic_calc_apicid,
+
+	.send_IPI			= x2apic_send_IPI,
+	.send_IPI_mask			= x2apic_send_IPI_mask,
+	.send_IPI_mask_allbutself	= x2apic_send_IPI_mask_allbutself,
+	.send_IPI_allbutself		= x2apic_send_IPI_allbutself,
+	.send_IPI_all			= x2apic_send_IPI_all,
+	.send_IPI_self			= x2apic_send_IPI_self,
+
+	.inquire_remote_apic		= NULL,
+
+	.read				= native_apic_msr_read,
+	.write				= native_apic_msr_write,
+	.eoi_write			= native_apic_msr_eoi_write,
+	.icr_read			= native_x2apic_icr_read,
+	.icr_write			= native_x2apic_icr_write,
+	.wait_icr_idle			= native_x2apic_wait_icr_idle,
+	.safe_wait_icr_idle		= native_safe_x2apic_wait_icr_idle,
+};
+
+apic_driver(apic_x2apic_cluster);
diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c
new file mode 100644
index 000000000..896bc41cb
--- /dev/null
+++ b/arch/x86/kernel/apic/x2apic_phys.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/cpumask.h>
+#include <linux/acpi.h>
+
+#include "local.h"
+
+int x2apic_phys;
+
+static struct apic apic_x2apic_phys;
+static u32 x2apic_max_apicid __ro_after_init;
+
+void __init x2apic_set_max_apicid(u32 apicid)
+{
+	x2apic_max_apicid = apicid;
+}
+
+static int __init set_x2apic_phys_mode(char *arg)
+{
+	x2apic_phys = 1;
+	return 0;
+}
+early_param("x2apic_phys", set_x2apic_phys_mode);
+
+static bool x2apic_fadt_phys(void)
+{
+#ifdef CONFIG_ACPI
+	if ((acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) &&
+		(acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
+		printk(KERN_DEBUG "System requires x2apic physical mode\n");
+		return true;
+	}
+#endif
+	return false;
+}
+
+static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+{
+	return x2apic_enabled() && (x2apic_phys || x2apic_fadt_phys());
+}
+
+static void x2apic_send_IPI(int cpu, int vector)
+{
+	u32 dest = per_cpu(x86_cpu_to_apicid, cpu);
+
+	/* x2apic MSRs are special and need a special fence: */
+	weak_wrmsr_fence();
+	__x2apic_send_IPI_dest(dest, vector, APIC_DEST_PHYSICAL);
+}
+
+static void
+__x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest)
+{
+	unsigned long query_cpu;
+	unsigned long this_cpu;
+	unsigned long flags;
+
+	/* x2apic MSRs are special and need a special fence: */
+	weak_wrmsr_fence();
+
+	local_irq_save(flags);
+
+	this_cpu = smp_processor_id();
+	for_each_cpu(query_cpu, mask) {
+		if (apic_dest == APIC_DEST_ALLBUT && this_cpu == query_cpu)
+			continue;
+		__x2apic_send_IPI_dest(per_cpu(x86_cpu_to_apicid, query_cpu),
+				       vector, APIC_DEST_PHYSICAL);
+	}
+	local_irq_restore(flags);
+}
+
+static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector)
+{
+	__x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC);
+}
+
+static void
+ x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
+{
+	__x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT);
+}
+
+static void x2apic_send_IPI_allbutself(int vector)
+{
+	__x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLBUT);
+}
+
+static void x2apic_send_IPI_all(int vector)
+{
+	__x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLINC);
+}
+
+static void init_x2apic_ldr(void)
+{
+}
+
+static int x2apic_phys_probe(void)
+{
+	if (!x2apic_mode)
+		return 0;
+
+	if (x2apic_phys || x2apic_fadt_phys())
+		return 1;
+
+	return apic == &apic_x2apic_phys;
+}
+
+/* Common x2apic functions, also used by x2apic_cluster */
+int x2apic_apic_id_valid(u32 apicid)
+{
+	if (x2apic_max_apicid && apicid > x2apic_max_apicid)
+		return 0;
+
+	return 1;
+}
+
+int x2apic_apic_id_registered(void)
+{
+	return 1;
+}
+
+void __x2apic_send_IPI_dest(unsigned int apicid, int vector, unsigned int dest)
+{
+	unsigned long cfg = __prepare_ICR(0, vector, dest);
+	native_x2apic_icr_write(cfg, apicid);
+}
+
+void __x2apic_send_IPI_shorthand(int vector, u32 which)
+{
+	unsigned long cfg = __prepare_ICR(which, vector, 0);
+
+	/* x2apic MSRs are special and need a special fence: */
+	weak_wrmsr_fence();
+	native_x2apic_icr_write(cfg, 0);
+}
+
+unsigned int x2apic_get_apic_id(unsigned long id)
+{
+	return id;
+}
+
+u32 x2apic_set_apic_id(unsigned int id)
+{
+	return id;
+}
+
+int x2apic_phys_pkg_id(int initial_apicid, int index_msb)
+{
+	return initial_apicid >> index_msb;
+}
+
+void x2apic_send_IPI_self(int vector)
+{
+	apic_write(APIC_SELF_IPI, vector);
+}
+
+static struct apic apic_x2apic_phys __ro_after_init = {
+
+	.name				= "physical x2apic",
+	.probe				= x2apic_phys_probe,
+	.acpi_madt_oem_check		= x2apic_acpi_madt_oem_check,
+	.apic_id_valid			= x2apic_apic_id_valid,
+	.apic_id_registered		= x2apic_apic_id_registered,
+
+	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
+	.dest_mode_logical		= false,
+
+	.disable_esr			= 0,
+
+	.check_apicid_used		= NULL,
+	.init_apic_ldr			= init_x2apic_ldr,
+	.ioapic_phys_id_map		= NULL,
+	.setup_apic_routing		= NULL,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= NULL,
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+	.phys_pkg_id			= x2apic_phys_pkg_id,
+
+	.get_apic_id			= x2apic_get_apic_id,
+	.set_apic_id			= x2apic_set_apic_id,
+
+	.calc_dest_apicid		= apic_default_calc_apicid,
+
+	.send_IPI			= x2apic_send_IPI,
+	.send_IPI_mask			= x2apic_send_IPI_mask,
+	.send_IPI_mask_allbutself	= x2apic_send_IPI_mask_allbutself,
+	.send_IPI_allbutself		= x2apic_send_IPI_allbutself,
+	.send_IPI_all			= x2apic_send_IPI_all,
+	.send_IPI_self			= x2apic_send_IPI_self,
+
+	.inquire_remote_apic		= NULL,
+
+	.read				= native_apic_msr_read,
+	.write				= native_apic_msr_write,
+	.eoi_write			= native_apic_msr_eoi_write,
+	.icr_read			= native_x2apic_icr_read,
+	.icr_write			= native_x2apic_icr_write,
+	.wait_icr_idle			= native_x2apic_wait_icr_idle,
+	.safe_wait_icr_idle		= native_safe_x2apic_wait_icr_idle,
+};
+
+apic_driver(apic_x2apic_phys);
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
new file mode 100644
index 000000000..482855227
--- /dev/null
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -0,0 +1,1839 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * SGI UV APIC functions (note: not an Intel compatible APIC)
+ *
+ * (C) Copyright 2020 Hewlett Packard Enterprise Development LP
+ * Copyright (C) 2007-2014 Silicon Graphics, Inc. All rights reserved.
+ */
+#include <linux/crash_dump.h>
+#include <linux/cpuhotplug.h>
+#include <linux/cpumask.h>
+#include <linux/proc_fs.h>
+#include <linux/memory.h>
+#include <linux/export.h>
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <linux/efi.h>
+
+#include <asm/e820/api.h>
+#include <asm/uv/uv_mmrs.h>
+#include <asm/uv/uv_hub.h>
+#include <asm/uv/bios.h>
+#include <asm/uv/uv.h>
+#include <asm/apic.h>
+
+static enum uv_system_type	uv_system_type;
+static int			uv_hubbed_system;
+static int			uv_hubless_system;
+static u64			gru_start_paddr, gru_end_paddr;
+static union uvh_apicid		uvh_apicid;
+static int			uv_node_id;
+
+/* Unpack AT/OEM/TABLE ID's to be NULL terminated strings */
+static u8 uv_archtype[UV_AT_SIZE + 1];
+static u8 oem_id[ACPI_OEM_ID_SIZE + 1];
+static u8 oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
+
+/* Information derived from CPUID and some UV MMRs */
+static struct {
+	unsigned int apicid_shift;
+	unsigned int apicid_mask;
+	unsigned int socketid_shift;	/* aka pnode_shift for UV2/3 */
+	unsigned int pnode_mask;
+	unsigned int nasid_shift;
+	unsigned int gpa_shift;
+	unsigned int gnode_shift;
+	unsigned int m_skt;
+	unsigned int n_skt;
+} uv_cpuid;
+
+static int uv_min_hub_revision_id;
+
+static struct apic apic_x2apic_uv_x;
+static struct uv_hub_info_s uv_hub_info_node0;
+
+/* Set this to use hardware error handler instead of kernel panic: */
+static int disable_uv_undefined_panic = 1;
+
+unsigned long uv_undefined(char *str)
+{
+	if (likely(!disable_uv_undefined_panic))
+		panic("UV: error: undefined MMR: %s\n", str);
+	else
+		pr_crit("UV: error: undefined MMR: %s\n", str);
+
+	/* Cause a machine fault: */
+	return ~0ul;
+}
+EXPORT_SYMBOL(uv_undefined);
+
+static unsigned long __init uv_early_read_mmr(unsigned long addr)
+{
+	unsigned long val, *mmr;
+
+	mmr = early_ioremap(UV_LOCAL_MMR_BASE | addr, sizeof(*mmr));
+	val = *mmr;
+	early_iounmap(mmr, sizeof(*mmr));
+
+	return val;
+}
+
+static inline bool is_GRU_range(u64 start, u64 end)
+{
+	if (!gru_start_paddr)
+		return false;
+
+	return start >= gru_start_paddr && end <= gru_end_paddr;
+}
+
+static bool uv_is_untracked_pat_range(u64 start, u64 end)
+{
+	return is_ISA_range(start, end) || is_GRU_range(start, end);
+}
+
+static void __init early_get_pnodeid(void)
+{
+	int pnode;
+
+	uv_cpuid.m_skt = 0;
+	if (UVH_RH10_GAM_ADDR_MAP_CONFIG) {
+		union uvh_rh10_gam_addr_map_config_u  m_n_config;
+
+		m_n_config.v = uv_early_read_mmr(UVH_RH10_GAM_ADDR_MAP_CONFIG);
+		uv_cpuid.n_skt = m_n_config.s.n_skt;
+		uv_cpuid.nasid_shift = 0;
+	} else if (UVH_RH_GAM_ADDR_MAP_CONFIG) {
+		union uvh_rh_gam_addr_map_config_u  m_n_config;
+
+	m_n_config.v = uv_early_read_mmr(UVH_RH_GAM_ADDR_MAP_CONFIG);
+		uv_cpuid.n_skt = m_n_config.s.n_skt;
+		if (is_uv(UV3))
+			uv_cpuid.m_skt = m_n_config.s3.m_skt;
+		if (is_uv(UV2))
+			uv_cpuid.m_skt = m_n_config.s2.m_skt;
+		uv_cpuid.nasid_shift = 1;
+	} else {
+		unsigned long GAM_ADDR_MAP_CONFIG = 0;
+
+		WARN(GAM_ADDR_MAP_CONFIG == 0,
+			"UV: WARN: GAM_ADDR_MAP_CONFIG is not available\n");
+		uv_cpuid.n_skt = 0;
+		uv_cpuid.nasid_shift = 0;
+	}
+
+	if (is_uv(UV4|UVY))
+		uv_cpuid.gnode_shift = 2; /* min partition is 4 sockets */
+
+	uv_cpuid.pnode_mask = (1 << uv_cpuid.n_skt) - 1;
+	pnode = (uv_node_id >> uv_cpuid.nasid_shift) & uv_cpuid.pnode_mask;
+	uv_cpuid.gpa_shift = 46;	/* Default unless changed */
+
+	pr_info("UV: n_skt:%d pnmsk:%x pn:%x\n",
+		uv_cpuid.n_skt, uv_cpuid.pnode_mask, pnode);
+}
+
+/* Running on a UV Hubbed system, determine which UV Hub Type it is */
+static int __init early_set_hub_type(void)
+{
+	union uvh_node_id_u node_id;
+
+	/*
+	 * The NODE_ID MMR is always at offset 0.
+	 * Contains the chip part # + revision.
+	 * Node_id field started with 15 bits,
+	 * ... now 7 but upper 8 are masked to 0.
+	 * All blades/nodes have the same part # and hub revision.
+	 */
+	node_id.v = uv_early_read_mmr(UVH_NODE_ID);
+	uv_node_id = node_id.sx.node_id;
+
+	switch (node_id.s.part_number) {
+
+	case UV5_HUB_PART_NUMBER:
+		uv_min_hub_revision_id = node_id.s.revision
+					 + UV5_HUB_REVISION_BASE;
+		uv_hub_type_set(UV5);
+		break;
+
+	/* UV4/4A only have a revision difference */
+	case UV4_HUB_PART_NUMBER:
+		uv_min_hub_revision_id = node_id.s.revision
+					 + UV4_HUB_REVISION_BASE - 1;
+		uv_hub_type_set(UV4);
+		if (uv_min_hub_revision_id == UV4A_HUB_REVISION_BASE)
+			uv_hub_type_set(UV4|UV4A);
+		break;
+
+	case UV3_HUB_PART_NUMBER:
+	case UV3_HUB_PART_NUMBER_X:
+		uv_min_hub_revision_id = node_id.s.revision
+					 + UV3_HUB_REVISION_BASE;
+		uv_hub_type_set(UV3);
+		break;
+
+	case UV2_HUB_PART_NUMBER:
+	case UV2_HUB_PART_NUMBER_X:
+		uv_min_hub_revision_id = node_id.s.revision
+					 + UV2_HUB_REVISION_BASE - 1;
+		uv_hub_type_set(UV2);
+		break;
+
+	default:
+		return 0;
+	}
+
+	pr_info("UV: part#:%x rev:%d rev_id:%d UVtype:0x%x\n",
+		node_id.s.part_number, node_id.s.revision,
+		uv_min_hub_revision_id, is_uv(~0));
+
+	return 1;
+}
+
+static void __init uv_tsc_check_sync(void)
+{
+	u64 mmr;
+	int sync_state;
+	int mmr_shift;
+	char *state;
+
+	/* UV5 guarantees synced TSCs; do not zero TSC_ADJUST */
+	if (!is_uv(UV2|UV3|UV4)) {
+		mark_tsc_async_resets("UV5+");
+		return;
+	}
+
+	/* UV2,3,4, UV BIOS TSC sync state available */
+	mmr = uv_early_read_mmr(UVH_TSC_SYNC_MMR);
+	mmr_shift =
+		is_uv2_hub() ? UVH_TSC_SYNC_SHIFT_UV2K : UVH_TSC_SYNC_SHIFT;
+	sync_state = (mmr >> mmr_shift) & UVH_TSC_SYNC_MASK;
+
+	/* Check if TSC is valid for all sockets */
+	switch (sync_state) {
+	case UVH_TSC_SYNC_VALID:
+		state = "in sync";
+		mark_tsc_async_resets("UV BIOS");
+		break;
+
+	/* If BIOS state unknown, don't do anything */
+	case UVH_TSC_SYNC_UNKNOWN:
+		state = "unknown";
+		break;
+
+	/* Otherwise, BIOS indicates problem with TSC */
+	default:
+		state = "unstable";
+		mark_tsc_unstable("UV BIOS");
+		break;
+	}
+	pr_info("UV: TSC sync state from BIOS:0%d(%s)\n", sync_state, state);
+}
+
+/* Selector for (4|4A|5) structs */
+#define uvxy_field(sname, field, undef) (	\
+	is_uv(UV4A) ? sname.s4a.field :		\
+	is_uv(UV4) ? sname.s4.field :		\
+	is_uv(UV3) ? sname.s3.field :		\
+	undef)
+
+/* [Copied from arch/x86/kernel/cpu/topology.c:detect_extended_topology()] */
+
+#define SMT_LEVEL			0	/* Leaf 0xb SMT level */
+#define INVALID_TYPE			0	/* Leaf 0xb sub-leaf types */
+#define SMT_TYPE			1
+#define CORE_TYPE			2
+#define LEAFB_SUBTYPE(ecx)		(((ecx) >> 8) & 0xff)
+#define BITS_SHIFT_NEXT_LEVEL(eax)	((eax) & 0x1f)
+
+static void set_x2apic_bits(void)
+{
+	unsigned int eax, ebx, ecx, edx, sub_index;
+	unsigned int sid_shift;
+
+	cpuid(0, &eax, &ebx, &ecx, &edx);
+	if (eax < 0xb) {
+		pr_info("UV: CPU does not have CPUID.11\n");
+		return;
+	}
+
+	cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
+	if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE)) {
+		pr_info("UV: CPUID.11 not implemented\n");
+		return;
+	}
+
+	sid_shift = BITS_SHIFT_NEXT_LEVEL(eax);
+	sub_index = 1;
+	do {
+		cpuid_count(0xb, sub_index, &eax, &ebx, &ecx, &edx);
+		if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) {
+			sid_shift = BITS_SHIFT_NEXT_LEVEL(eax);
+			break;
+		}
+		sub_index++;
+	} while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE);
+
+	uv_cpuid.apicid_shift	= 0;
+	uv_cpuid.apicid_mask	= (~(-1 << sid_shift));
+	uv_cpuid.socketid_shift = sid_shift;
+}
+
+static void __init early_get_apic_socketid_shift(void)
+{
+	if (is_uv2_hub() || is_uv3_hub())
+		uvh_apicid.v = uv_early_read_mmr(UVH_APICID);
+
+	set_x2apic_bits();
+
+	pr_info("UV: apicid_shift:%d apicid_mask:0x%x\n", uv_cpuid.apicid_shift, uv_cpuid.apicid_mask);
+	pr_info("UV: socketid_shift:%d pnode_mask:0x%x\n", uv_cpuid.socketid_shift, uv_cpuid.pnode_mask);
+}
+
+static void __init uv_stringify(int len, char *to, char *from)
+{
+	/* Relies on 'to' being NULL chars so result will be NULL terminated */
+	strncpy(to, from, len-1);
+
+	/* Trim trailing spaces */
+	(void)strim(to);
+}
+
+/* Find UV arch type entry in UVsystab */
+static unsigned long __init early_find_archtype(struct uv_systab *st)
+{
+	int i;
+
+	for (i = 0; st->entry[i].type != UV_SYSTAB_TYPE_UNUSED; i++) {
+		unsigned long ptr = st->entry[i].offset;
+
+		if (!ptr)
+			continue;
+		ptr += (unsigned long)st;
+		if (st->entry[i].type == UV_SYSTAB_TYPE_ARCH_TYPE)
+			return ptr;
+	}
+	return 0;
+}
+
+/* Validate UV arch type field in UVsystab */
+static int __init decode_arch_type(unsigned long ptr)
+{
+	struct uv_arch_type_entry *uv_ate = (struct uv_arch_type_entry *)ptr;
+	int n = strlen(uv_ate->archtype);
+
+	if (n > 0 && n < sizeof(uv_ate->archtype)) {
+		pr_info("UV: UVarchtype received from BIOS\n");
+		uv_stringify(sizeof(uv_archtype), uv_archtype, uv_ate->archtype);
+		return 1;
+	}
+	return 0;
+}
+
+/* Determine if UV arch type entry might exist in UVsystab */
+static int __init early_get_arch_type(void)
+{
+	unsigned long uvst_physaddr, uvst_size, ptr;
+	struct uv_systab *st;
+	u32 rev;
+	int ret;
+
+	uvst_physaddr = get_uv_systab_phys(0);
+	if (!uvst_physaddr)
+		return 0;
+
+	st = early_memremap_ro(uvst_physaddr, sizeof(struct uv_systab));
+	if (!st) {
+		pr_err("UV: Cannot access UVsystab, remap failed\n");
+		return 0;
+	}
+
+	rev = st->revision;
+	if (rev < UV_SYSTAB_VERSION_UV5) {
+		early_memunmap(st, sizeof(struct uv_systab));
+		return 0;
+	}
+
+	uvst_size = st->size;
+	early_memunmap(st, sizeof(struct uv_systab));
+	st = early_memremap_ro(uvst_physaddr, uvst_size);
+	if (!st) {
+		pr_err("UV: Cannot access UVarchtype, remap failed\n");
+		return 0;
+	}
+
+	ptr = early_find_archtype(st);
+	if (!ptr) {
+		early_memunmap(st, uvst_size);
+		return 0;
+	}
+
+	ret = decode_arch_type(ptr);
+	early_memunmap(st, uvst_size);
+	return ret;
+}
+
+/* UV system found, check which APIC MODE BIOS already selected */
+static void __init early_set_apic_mode(void)
+{
+	if (x2apic_enabled())
+		uv_system_type = UV_X2APIC;
+	else
+		uv_system_type = UV_LEGACY_APIC;
+}
+
+static int __init uv_set_system_type(char *_oem_id, char *_oem_table_id)
+{
+	/* Save OEM_ID passed from ACPI MADT */
+	uv_stringify(sizeof(oem_id), oem_id, _oem_id);
+
+	/* Check if BIOS sent us a UVarchtype */
+	if (!early_get_arch_type())
+
+		/* If not use OEM ID for UVarchtype */
+		uv_stringify(sizeof(uv_archtype), uv_archtype, oem_id);
+
+	/* Check if not hubbed */
+	if (strncmp(uv_archtype, "SGI", 3) != 0) {
+
+		/* (Not hubbed), check if not hubless */
+		if (strncmp(uv_archtype, "NSGI", 4) != 0)
+
+			/* (Not hubless), not a UV */
+			return 0;
+
+		/* Is UV hubless system */
+		uv_hubless_system = 0x01;
+
+		/* UV5 Hubless */
+		if (strncmp(uv_archtype, "NSGI5", 5) == 0)
+			uv_hubless_system |= 0x20;
+
+		/* UV4 Hubless: CH */
+		else if (strncmp(uv_archtype, "NSGI4", 5) == 0)
+			uv_hubless_system |= 0x10;
+
+		/* UV3 Hubless: UV300/MC990X w/o hub */
+		else
+			uv_hubless_system |= 0x8;
+
+		/* Copy OEM Table ID */
+		uv_stringify(sizeof(oem_table_id), oem_table_id, _oem_table_id);
+
+		pr_info("UV: OEM IDs %s/%s, SystemType %d, HUBLESS ID %x\n",
+			oem_id, oem_table_id, uv_system_type, uv_hubless_system);
+
+		return 0;
+	}
+
+	if (numa_off) {
+		pr_err("UV: NUMA is off, disabling UV support\n");
+		return 0;
+	}
+
+	/* Set hubbed type if true */
+	uv_hub_info->hub_revision =
+		!strncmp(uv_archtype, "SGI5", 4) ? UV5_HUB_REVISION_BASE :
+		!strncmp(uv_archtype, "SGI4", 4) ? UV4_HUB_REVISION_BASE :
+		!strncmp(uv_archtype, "SGI3", 4) ? UV3_HUB_REVISION_BASE :
+		!strcmp(uv_archtype, "SGI2") ? UV2_HUB_REVISION_BASE : 0;
+
+	switch (uv_hub_info->hub_revision) {
+	case UV5_HUB_REVISION_BASE:
+		uv_hubbed_system = 0x21;
+		uv_hub_type_set(UV5);
+		break;
+
+	case UV4_HUB_REVISION_BASE:
+		uv_hubbed_system = 0x11;
+		uv_hub_type_set(UV4);
+		break;
+
+	case UV3_HUB_REVISION_BASE:
+		uv_hubbed_system = 0x9;
+		uv_hub_type_set(UV3);
+		break;
+
+	case UV2_HUB_REVISION_BASE:
+		uv_hubbed_system = 0x5;
+		uv_hub_type_set(UV2);
+		break;
+
+	default:
+		return 0;
+	}
+
+	/* Get UV hub chip part number & revision */
+	early_set_hub_type();
+
+	/* Other UV setup functions */
+	early_set_apic_mode();
+	early_get_pnodeid();
+	early_get_apic_socketid_shift();
+	x86_platform.is_untracked_pat_range = uv_is_untracked_pat_range;
+	x86_platform.nmi_init = uv_nmi_init;
+	uv_tsc_check_sync();
+
+	return 1;
+}
+
+/* Called early to probe for the correct APIC driver */
+static int __init uv_acpi_madt_oem_check(char *_oem_id, char *_oem_table_id)
+{
+	/* Set up early hub info fields for Node 0 */
+	uv_cpu_info->p_uv_hub_info = &uv_hub_info_node0;
+
+	/* If not UV, return. */
+	if (uv_set_system_type(_oem_id, _oem_table_id) == 0)
+		return 0;
+
+	/* Save for display of the OEM Table ID */
+	uv_stringify(sizeof(oem_table_id), oem_table_id, _oem_table_id);
+
+	pr_info("UV: OEM IDs %s/%s, System/UVType %d/0x%x, HUB RevID %d\n",
+		oem_id, oem_table_id, uv_system_type, is_uv(UV_ANY),
+		uv_min_hub_revision_id);
+
+	return 0;
+}
+
+enum uv_system_type get_uv_system_type(void)
+{
+	return uv_system_type;
+}
+
+int uv_get_hubless_system(void)
+{
+	return uv_hubless_system;
+}
+EXPORT_SYMBOL_GPL(uv_get_hubless_system);
+
+ssize_t uv_get_archtype(char *buf, int len)
+{
+	return scnprintf(buf, len, "%s/%s", uv_archtype, oem_table_id);
+}
+EXPORT_SYMBOL_GPL(uv_get_archtype);
+
+int is_uv_system(void)
+{
+	return uv_system_type != UV_NONE;
+}
+EXPORT_SYMBOL_GPL(is_uv_system);
+
+int is_uv_hubbed(int uvtype)
+{
+	return (uv_hubbed_system & uvtype);
+}
+EXPORT_SYMBOL_GPL(is_uv_hubbed);
+
+static int is_uv_hubless(int uvtype)
+{
+	return (uv_hubless_system & uvtype);
+}
+
+void **__uv_hub_info_list;
+EXPORT_SYMBOL_GPL(__uv_hub_info_list);
+
+DEFINE_PER_CPU(struct uv_cpu_info_s, __uv_cpu_info);
+EXPORT_PER_CPU_SYMBOL_GPL(__uv_cpu_info);
+
+short uv_possible_blades;
+EXPORT_SYMBOL_GPL(uv_possible_blades);
+
+unsigned long sn_rtc_cycles_per_second;
+EXPORT_SYMBOL(sn_rtc_cycles_per_second);
+
+/* The following values are used for the per node hub info struct */
+static __initdata unsigned short		*_node_to_pnode;
+static __initdata unsigned short		_min_socket, _max_socket;
+static __initdata unsigned short		_min_pnode, _max_pnode, _gr_table_len;
+static __initdata struct uv_gam_range_entry	*uv_gre_table;
+static __initdata struct uv_gam_parameters	*uv_gp_table;
+static __initdata unsigned short		*_socket_to_node;
+static __initdata unsigned short		*_socket_to_pnode;
+static __initdata unsigned short		*_pnode_to_socket;
+
+static __initdata struct uv_gam_range_s		*_gr_table;
+
+#define	SOCK_EMPTY	((unsigned short)~0)
+
+/* Default UV memory block size is 2GB */
+static unsigned long mem_block_size __initdata = (2UL << 30);
+
+/* Kernel parameter to specify UV mem block size */
+static int __init parse_mem_block_size(char *ptr)
+{
+	unsigned long size = memparse(ptr, NULL);
+
+	/* Size will be rounded down by set_block_size() below */
+	mem_block_size = size;
+	return 0;
+}
+early_param("uv_memblksize", parse_mem_block_size);
+
+static __init int adj_blksize(u32 lgre)
+{
+	unsigned long base = (unsigned long)lgre << UV_GAM_RANGE_SHFT;
+	unsigned long size;
+
+	for (size = mem_block_size; size > MIN_MEMORY_BLOCK_SIZE; size >>= 1)
+		if (IS_ALIGNED(base, size))
+			break;
+
+	if (size >= mem_block_size)
+		return 0;
+
+	mem_block_size = size;
+	return 1;
+}
+
+static __init void set_block_size(void)
+{
+	unsigned int order = ffs(mem_block_size);
+
+	if (order) {
+		/* adjust for ffs return of 1..64 */
+		set_memory_block_size_order(order - 1);
+		pr_info("UV: mem_block_size set to 0x%lx\n", mem_block_size);
+	} else {
+		/* bad or zero value, default to 1UL << 31 (2GB) */
+		pr_err("UV: mem_block_size error with 0x%lx\n", mem_block_size);
+		set_memory_block_size_order(31);
+	}
+}
+
+/* Build GAM range lookup table: */
+static __init void build_uv_gr_table(void)
+{
+	struct uv_gam_range_entry *gre = uv_gre_table;
+	struct uv_gam_range_s *grt;
+	unsigned long last_limit = 0, ram_limit = 0;
+	int bytes, i, sid, lsid = -1, indx = 0, lindx = -1;
+
+	if (!gre)
+		return;
+
+	bytes = _gr_table_len * sizeof(struct uv_gam_range_s);
+	grt = kzalloc(bytes, GFP_KERNEL);
+	BUG_ON(!grt);
+	_gr_table = grt;
+
+	for (; gre->type != UV_GAM_RANGE_TYPE_UNUSED; gre++) {
+		if (gre->type == UV_GAM_RANGE_TYPE_HOLE) {
+			if (!ram_limit) {
+				/* Mark hole between RAM/non-RAM: */
+				ram_limit = last_limit;
+				last_limit = gre->limit;
+				lsid++;
+				continue;
+			}
+			last_limit = gre->limit;
+			pr_info("UV: extra hole in GAM RE table @%d\n", (int)(gre - uv_gre_table));
+			continue;
+		}
+		if (_max_socket < gre->sockid) {
+			pr_err("UV: GAM table sockid(%d) too large(>%d) @%d\n", gre->sockid, _max_socket, (int)(gre - uv_gre_table));
+			continue;
+		}
+		sid = gre->sockid - _min_socket;
+		if (lsid < sid) {
+			/* New range: */
+			grt = &_gr_table[indx];
+			grt->base = lindx;
+			grt->nasid = gre->nasid;
+			grt->limit = last_limit = gre->limit;
+			lsid = sid;
+			lindx = indx++;
+			continue;
+		}
+		/* Update range: */
+		if (lsid == sid && !ram_limit) {
+			/* .. if contiguous: */
+			if (grt->limit == last_limit) {
+				grt->limit = last_limit = gre->limit;
+				continue;
+			}
+		}
+		/* Non-contiguous RAM range: */
+		if (!ram_limit) {
+			grt++;
+			grt->base = lindx;
+			grt->nasid = gre->nasid;
+			grt->limit = last_limit = gre->limit;
+			continue;
+		}
+		/* Non-contiguous/non-RAM: */
+		grt++;
+		/* base is this entry */
+		grt->base = grt - _gr_table;
+		grt->nasid = gre->nasid;
+		grt->limit = last_limit = gre->limit;
+		lsid++;
+	}
+
+	/* Shorten table if possible */
+	grt++;
+	i = grt - _gr_table;
+	if (i < _gr_table_len) {
+		void *ret;
+
+		bytes = i * sizeof(struct uv_gam_range_s);
+		ret = krealloc(_gr_table, bytes, GFP_KERNEL);
+		if (ret) {
+			_gr_table = ret;
+			_gr_table_len = i;
+		}
+	}
+
+	/* Display resultant GAM range table: */
+	for (i = 0, grt = _gr_table; i < _gr_table_len; i++, grt++) {
+		unsigned long start, end;
+		int gb = grt->base;
+
+		start = gb < 0 ?  0 : (unsigned long)_gr_table[gb].limit << UV_GAM_RANGE_SHFT;
+		end = (unsigned long)grt->limit << UV_GAM_RANGE_SHFT;
+
+		pr_info("UV: GAM Range %2d %04x 0x%013lx-0x%013lx (%d)\n", i, grt->nasid, start, end, gb);
+	}
+}
+
+static int uv_wakeup_secondary(int phys_apicid, unsigned long start_rip)
+{
+	unsigned long val;
+	int pnode;
+
+	pnode = uv_apicid_to_pnode(phys_apicid);
+
+	val = (1UL << UVH_IPI_INT_SEND_SHFT) |
+	    (phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) |
+	    ((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) |
+	    APIC_DM_INIT;
+
+	uv_write_global_mmr64(pnode, UVH_IPI_INT, val);
+
+	val = (1UL << UVH_IPI_INT_SEND_SHFT) |
+	    (phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) |
+	    ((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) |
+	    APIC_DM_STARTUP;
+
+	uv_write_global_mmr64(pnode, UVH_IPI_INT, val);
+
+	return 0;
+}
+
+static void uv_send_IPI_one(int cpu, int vector)
+{
+	unsigned long apicid = per_cpu(x86_cpu_to_apicid, cpu);
+	int pnode = uv_apicid_to_pnode(apicid);
+	unsigned long dmode, val;
+
+	if (vector == NMI_VECTOR)
+		dmode = APIC_DELIVERY_MODE_NMI;
+	else
+		dmode = APIC_DELIVERY_MODE_FIXED;
+
+	val = (1UL << UVH_IPI_INT_SEND_SHFT) |
+		(apicid << UVH_IPI_INT_APIC_ID_SHFT) |
+		(dmode << UVH_IPI_INT_DELIVERY_MODE_SHFT) |
+		(vector << UVH_IPI_INT_VECTOR_SHFT);
+
+	uv_write_global_mmr64(pnode, UVH_IPI_INT, val);
+}
+
+static void uv_send_IPI_mask(const struct cpumask *mask, int vector)
+{
+	unsigned int cpu;
+
+	for_each_cpu(cpu, mask)
+		uv_send_IPI_one(cpu, vector);
+}
+
+static void uv_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
+{
+	unsigned int this_cpu = smp_processor_id();
+	unsigned int cpu;
+
+	for_each_cpu(cpu, mask) {
+		if (cpu != this_cpu)
+			uv_send_IPI_one(cpu, vector);
+	}
+}
+
+static void uv_send_IPI_allbutself(int vector)
+{
+	unsigned int this_cpu = smp_processor_id();
+	unsigned int cpu;
+
+	for_each_online_cpu(cpu) {
+		if (cpu != this_cpu)
+			uv_send_IPI_one(cpu, vector);
+	}
+}
+
+static void uv_send_IPI_all(int vector)
+{
+	uv_send_IPI_mask(cpu_online_mask, vector);
+}
+
+static int uv_apic_id_valid(u32 apicid)
+{
+	return 1;
+}
+
+static int uv_apic_id_registered(void)
+{
+	return 1;
+}
+
+static void uv_init_apic_ldr(void)
+{
+}
+
+static u32 apic_uv_calc_apicid(unsigned int cpu)
+{
+	return apic_default_calc_apicid(cpu);
+}
+
+static unsigned int x2apic_get_apic_id(unsigned long id)
+{
+	return id;
+}
+
+static u32 set_apic_id(unsigned int id)
+{
+	return id;
+}
+
+static unsigned int uv_read_apic_id(void)
+{
+	return x2apic_get_apic_id(apic_read(APIC_ID));
+}
+
+static int uv_phys_pkg_id(int initial_apicid, int index_msb)
+{
+	return uv_read_apic_id() >> index_msb;
+}
+
+static void uv_send_IPI_self(int vector)
+{
+	apic_write(APIC_SELF_IPI, vector);
+}
+
+static int uv_probe(void)
+{
+	return apic == &apic_x2apic_uv_x;
+}
+
+static struct apic apic_x2apic_uv_x __ro_after_init = {
+
+	.name				= "UV large system",
+	.probe				= uv_probe,
+	.acpi_madt_oem_check		= uv_acpi_madt_oem_check,
+	.apic_id_valid			= uv_apic_id_valid,
+	.apic_id_registered		= uv_apic_id_registered,
+
+	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
+	.dest_mode_logical		= false,
+
+	.disable_esr			= 0,
+
+	.check_apicid_used		= NULL,
+	.init_apic_ldr			= uv_init_apic_ldr,
+	.ioapic_phys_id_map		= NULL,
+	.setup_apic_routing		= NULL,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= NULL,
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+	.phys_pkg_id			= uv_phys_pkg_id,
+
+	.get_apic_id			= x2apic_get_apic_id,
+	.set_apic_id			= set_apic_id,
+
+	.calc_dest_apicid		= apic_uv_calc_apicid,
+
+	.send_IPI			= uv_send_IPI_one,
+	.send_IPI_mask			= uv_send_IPI_mask,
+	.send_IPI_mask_allbutself	= uv_send_IPI_mask_allbutself,
+	.send_IPI_allbutself		= uv_send_IPI_allbutself,
+	.send_IPI_all			= uv_send_IPI_all,
+	.send_IPI_self			= uv_send_IPI_self,
+
+	.wakeup_secondary_cpu		= uv_wakeup_secondary,
+	.inquire_remote_apic		= NULL,
+
+	.read				= native_apic_msr_read,
+	.write				= native_apic_msr_write,
+	.eoi_write			= native_apic_msr_eoi_write,
+	.icr_read			= native_x2apic_icr_read,
+	.icr_write			= native_x2apic_icr_write,
+	.wait_icr_idle			= native_x2apic_wait_icr_idle,
+	.safe_wait_icr_idle		= native_safe_x2apic_wait_icr_idle,
+};
+
+#define	UVH_RH_GAM_ALIAS210_REDIRECT_CONFIG_LENGTH	3
+#define DEST_SHIFT UVXH_RH_GAM_ALIAS_0_REDIRECT_CONFIG_DEST_BASE_SHFT
+
+static __init void get_lowmem_redirect(unsigned long *base, unsigned long *size)
+{
+	union uvh_rh_gam_alias_2_overlay_config_u alias;
+	union uvh_rh_gam_alias_2_redirect_config_u redirect;
+	unsigned long m_redirect;
+	unsigned long m_overlay;
+	int i;
+
+	for (i = 0; i < UVH_RH_GAM_ALIAS210_REDIRECT_CONFIG_LENGTH; i++) {
+		switch (i) {
+		case 0:
+			m_redirect = UVH_RH_GAM_ALIAS_0_REDIRECT_CONFIG;
+			m_overlay  = UVH_RH_GAM_ALIAS_0_OVERLAY_CONFIG;
+			break;
+		case 1:
+			m_redirect = UVH_RH_GAM_ALIAS_1_REDIRECT_CONFIG;
+			m_overlay  = UVH_RH_GAM_ALIAS_1_OVERLAY_CONFIG;
+			break;
+		case 2:
+			m_redirect = UVH_RH_GAM_ALIAS_2_REDIRECT_CONFIG;
+			m_overlay  = UVH_RH_GAM_ALIAS_2_OVERLAY_CONFIG;
+			break;
+		}
+		alias.v = uv_read_local_mmr(m_overlay);
+		if (alias.s.enable && alias.s.base == 0) {
+			*size = (1UL << alias.s.m_alias);
+			redirect.v = uv_read_local_mmr(m_redirect);
+			*base = (unsigned long)redirect.s.dest_base << DEST_SHIFT;
+			return;
+		}
+	}
+	*base = *size = 0;
+}
+
+enum map_type {map_wb, map_uc};
+static const char * const mt[] = { "WB", "UC" };
+
+static __init void map_high(char *id, unsigned long base, int pshift, int bshift, int max_pnode, enum map_type map_type)
+{
+	unsigned long bytes, paddr;
+
+	paddr = base << pshift;
+	bytes = (1UL << bshift) * (max_pnode + 1);
+	if (!paddr) {
+		pr_info("UV: Map %s_HI base address NULL\n", id);
+		return;
+	}
+	if (map_type == map_uc)
+		init_extra_mapping_uc(paddr, bytes);
+	else
+		init_extra_mapping_wb(paddr, bytes);
+
+	pr_info("UV: Map %s_HI 0x%lx - 0x%lx %s (%d segments)\n",
+		id, paddr, paddr + bytes, mt[map_type], max_pnode + 1);
+}
+
+static __init void map_gru_high(int max_pnode)
+{
+	union uvh_rh_gam_gru_overlay_config_u gru;
+	unsigned long mask, base;
+	int shift;
+
+	if (UVH_RH_GAM_GRU_OVERLAY_CONFIG) {
+		gru.v = uv_read_local_mmr(UVH_RH_GAM_GRU_OVERLAY_CONFIG);
+		shift = UVH_RH_GAM_GRU_OVERLAY_CONFIG_BASE_SHFT;
+		mask = UVH_RH_GAM_GRU_OVERLAY_CONFIG_BASE_MASK;
+	} else if (UVH_RH10_GAM_GRU_OVERLAY_CONFIG) {
+		gru.v = uv_read_local_mmr(UVH_RH10_GAM_GRU_OVERLAY_CONFIG);
+		shift = UVH_RH10_GAM_GRU_OVERLAY_CONFIG_BASE_SHFT;
+		mask = UVH_RH10_GAM_GRU_OVERLAY_CONFIG_BASE_MASK;
+	} else {
+		pr_err("UV: GRU unavailable (no MMR)\n");
+		return;
+	}
+
+	if (!gru.s.enable) {
+		pr_info("UV: GRU disabled (by BIOS)\n");
+		return;
+	}
+
+	base = (gru.v & mask) >> shift;
+	map_high("GRU", base, shift, shift, max_pnode, map_wb);
+	gru_start_paddr = ((u64)base << shift);
+	gru_end_paddr = gru_start_paddr + (1UL << shift) * (max_pnode + 1);
+}
+
+static __init void map_mmr_high(int max_pnode)
+{
+	unsigned long base;
+	int shift;
+	bool enable;
+
+	if (UVH_RH10_GAM_MMR_OVERLAY_CONFIG) {
+		union uvh_rh10_gam_mmr_overlay_config_u mmr;
+
+		mmr.v = uv_read_local_mmr(UVH_RH10_GAM_MMR_OVERLAY_CONFIG);
+		enable = mmr.s.enable;
+		base = mmr.s.base;
+		shift = UVH_RH10_GAM_MMR_OVERLAY_CONFIG_BASE_SHFT;
+	} else if (UVH_RH_GAM_MMR_OVERLAY_CONFIG) {
+		union uvh_rh_gam_mmr_overlay_config_u mmr;
+
+		mmr.v = uv_read_local_mmr(UVH_RH_GAM_MMR_OVERLAY_CONFIG);
+		enable = mmr.s.enable;
+		base = mmr.s.base;
+		shift = UVH_RH_GAM_MMR_OVERLAY_CONFIG_BASE_SHFT;
+	} else {
+		pr_err("UV:%s:RH_GAM_MMR_OVERLAY_CONFIG MMR undefined?\n",
+			__func__);
+		return;
+	}
+
+	if (enable)
+		map_high("MMR", base, shift, shift, max_pnode, map_uc);
+	else
+		pr_info("UV: MMR disabled\n");
+}
+
+/* Arch specific ENUM cases */
+enum mmioh_arch {
+	UV2_MMIOH = -1,
+	UVY_MMIOH0, UVY_MMIOH1,
+	UVX_MMIOH0, UVX_MMIOH1,
+};
+
+/* Calculate and Map MMIOH Regions */
+static void __init calc_mmioh_map(enum mmioh_arch index,
+	int min_pnode, int max_pnode,
+	int shift, unsigned long base, int m_io, int n_io)
+{
+	unsigned long mmr, nasid_mask;
+	int nasid, min_nasid, max_nasid, lnasid, mapped;
+	int i, fi, li, n, max_io;
+	char id[8];
+
+	/* One (UV2) mapping */
+	if (index == UV2_MMIOH) {
+		strncpy(id, "MMIOH", sizeof(id));
+		max_io = max_pnode;
+		mapped = 0;
+		goto map_exit;
+	}
+
+	/* small and large MMIOH mappings */
+	switch (index) {
+	case UVY_MMIOH0:
+		mmr = UVH_RH10_GAM_MMIOH_REDIRECT_CONFIG0;
+		nasid_mask = UVH_RH10_GAM_MMIOH_OVERLAY_CONFIG0_BASE_MASK;
+		n = UVH_RH10_GAM_MMIOH_REDIRECT_CONFIG0_DEPTH;
+		min_nasid = min_pnode;
+		max_nasid = max_pnode;
+		mapped = 1;
+		break;
+	case UVY_MMIOH1:
+		mmr = UVH_RH10_GAM_MMIOH_REDIRECT_CONFIG1;
+		nasid_mask = UVH_RH10_GAM_MMIOH_OVERLAY_CONFIG1_BASE_MASK;
+		n = UVH_RH10_GAM_MMIOH_REDIRECT_CONFIG1_DEPTH;
+		min_nasid = min_pnode;
+		max_nasid = max_pnode;
+		mapped = 1;
+		break;
+	case UVX_MMIOH0:
+		mmr = UVH_RH_GAM_MMIOH_REDIRECT_CONFIG0;
+		nasid_mask = UVH_RH_GAM_MMIOH_OVERLAY_CONFIG0_BASE_MASK;
+		n = UVH_RH_GAM_MMIOH_REDIRECT_CONFIG0_DEPTH;
+		min_nasid = min_pnode * 2;
+		max_nasid = max_pnode * 2;
+		mapped = 1;
+		break;
+	case UVX_MMIOH1:
+		mmr = UVH_RH_GAM_MMIOH_REDIRECT_CONFIG1;
+		nasid_mask = UVH_RH_GAM_MMIOH_OVERLAY_CONFIG1_BASE_MASK;
+		n = UVH_RH_GAM_MMIOH_REDIRECT_CONFIG1_DEPTH;
+		min_nasid = min_pnode * 2;
+		max_nasid = max_pnode * 2;
+		mapped = 1;
+		break;
+	default:
+		pr_err("UV:%s:Invalid mapping type:%d\n", __func__, index);
+		return;
+	}
+
+	/* enum values chosen so (index mod 2) is MMIOH 0/1 (low/high) */
+	snprintf(id, sizeof(id), "MMIOH%d", index%2);
+
+	max_io = lnasid = fi = li = -1;
+	for (i = 0; i < n; i++) {
+		unsigned long m_redirect = mmr + i * 8;
+		unsigned long redirect = uv_read_local_mmr(m_redirect);
+
+		nasid = redirect & nasid_mask;
+		if (i == 0)
+			pr_info("UV: %s redirect base 0x%lx(@0x%lx) 0x%04x\n",
+				id, redirect, m_redirect, nasid);
+
+		/* Invalid NASID check */
+		if (nasid < min_nasid || max_nasid < nasid) {
+			pr_err("UV:%s:Invalid NASID:%x (range:%x..%x)\n",
+				__func__, index, min_nasid, max_nasid);
+			nasid = -1;
+		}
+
+		if (nasid == lnasid) {
+			li = i;
+			/* Last entry check: */
+			if (i != n-1)
+				continue;
+		}
+
+		/* Check if we have a cached (or last) redirect to print: */
+		if (lnasid != -1 || (i == n-1 && nasid != -1))  {
+			unsigned long addr1, addr2;
+			int f, l;
+
+			if (lnasid == -1) {
+				f = l = i;
+				lnasid = nasid;
+			} else {
+				f = fi;
+				l = li;
+			}
+			addr1 = (base << shift) + f * (1ULL << m_io);
+			addr2 = (base << shift) + (l + 1) * (1ULL << m_io);
+			pr_info("UV: %s[%03d..%03d] NASID 0x%04x ADDR 0x%016lx - 0x%016lx\n",
+				id, fi, li, lnasid, addr1, addr2);
+			if (max_io < l)
+				max_io = l;
+		}
+		fi = li = i;
+		lnasid = nasid;
+	}
+
+map_exit:
+	pr_info("UV: %s base:0x%lx shift:%d m_io:%d max_io:%d max_pnode:0x%x\n",
+		id, base, shift, m_io, max_io, max_pnode);
+
+	if (max_io >= 0 && !mapped)
+		map_high(id, base, shift, m_io, max_io, map_uc);
+}
+
+static __init void map_mmioh_high(int min_pnode, int max_pnode)
+{
+	/* UVY flavor */
+	if (UVH_RH10_GAM_MMIOH_OVERLAY_CONFIG0) {
+		union uvh_rh10_gam_mmioh_overlay_config0_u mmioh0;
+		union uvh_rh10_gam_mmioh_overlay_config1_u mmioh1;
+
+		mmioh0.v = uv_read_local_mmr(UVH_RH10_GAM_MMIOH_OVERLAY_CONFIG0);
+		if (unlikely(mmioh0.s.enable == 0))
+			pr_info("UV: MMIOH0 disabled\n");
+		else
+			calc_mmioh_map(UVY_MMIOH0, min_pnode, max_pnode,
+				UVH_RH10_GAM_MMIOH_OVERLAY_CONFIG0_BASE_SHFT,
+				mmioh0.s.base, mmioh0.s.m_io, mmioh0.s.n_io);
+
+		mmioh1.v = uv_read_local_mmr(UVH_RH10_GAM_MMIOH_OVERLAY_CONFIG1);
+		if (unlikely(mmioh1.s.enable == 0))
+			pr_info("UV: MMIOH1 disabled\n");
+		else
+			calc_mmioh_map(UVY_MMIOH1, min_pnode, max_pnode,
+				UVH_RH10_GAM_MMIOH_OVERLAY_CONFIG1_BASE_SHFT,
+				mmioh1.s.base, mmioh1.s.m_io, mmioh1.s.n_io);
+		return;
+	}
+	/* UVX flavor */
+	if (UVH_RH_GAM_MMIOH_OVERLAY_CONFIG0) {
+		union uvh_rh_gam_mmioh_overlay_config0_u mmioh0;
+		union uvh_rh_gam_mmioh_overlay_config1_u mmioh1;
+
+		mmioh0.v = uv_read_local_mmr(UVH_RH_GAM_MMIOH_OVERLAY_CONFIG0);
+		if (unlikely(mmioh0.s.enable == 0))
+			pr_info("UV: MMIOH0 disabled\n");
+		else {
+			unsigned long base = uvxy_field(mmioh0, base, 0);
+			int m_io = uvxy_field(mmioh0, m_io, 0);
+			int n_io = uvxy_field(mmioh0, n_io, 0);
+
+			calc_mmioh_map(UVX_MMIOH0, min_pnode, max_pnode,
+				UVH_RH_GAM_MMIOH_OVERLAY_CONFIG0_BASE_SHFT,
+				base, m_io, n_io);
+		}
+
+		mmioh1.v = uv_read_local_mmr(UVH_RH_GAM_MMIOH_OVERLAY_CONFIG1);
+		if (unlikely(mmioh1.s.enable == 0))
+			pr_info("UV: MMIOH1 disabled\n");
+		else {
+			unsigned long base = uvxy_field(mmioh1, base, 0);
+			int m_io = uvxy_field(mmioh1, m_io, 0);
+			int n_io = uvxy_field(mmioh1, n_io, 0);
+
+			calc_mmioh_map(UVX_MMIOH1, min_pnode, max_pnode,
+				UVH_RH_GAM_MMIOH_OVERLAY_CONFIG1_BASE_SHFT,
+				base, m_io, n_io);
+		}
+		return;
+	}
+
+	/* UV2 flavor */
+	if (UVH_RH_GAM_MMIOH_OVERLAY_CONFIG) {
+		union uvh_rh_gam_mmioh_overlay_config_u mmioh;
+
+		mmioh.v	= uv_read_local_mmr(UVH_RH_GAM_MMIOH_OVERLAY_CONFIG);
+		if (unlikely(mmioh.s2.enable == 0))
+			pr_info("UV: MMIOH disabled\n");
+		else
+			calc_mmioh_map(UV2_MMIOH, min_pnode, max_pnode,
+				UV2H_RH_GAM_MMIOH_OVERLAY_CONFIG_BASE_SHFT,
+				mmioh.s2.base, mmioh.s2.m_io, mmioh.s2.n_io);
+		return;
+	}
+}
+
+static __init void map_low_mmrs(void)
+{
+	if (UV_GLOBAL_MMR32_BASE)
+		init_extra_mapping_uc(UV_GLOBAL_MMR32_BASE, UV_GLOBAL_MMR32_SIZE);
+
+	if (UV_LOCAL_MMR_BASE)
+		init_extra_mapping_uc(UV_LOCAL_MMR_BASE, UV_LOCAL_MMR_SIZE);
+}
+
+static __init void uv_rtc_init(void)
+{
+	long status;
+	u64 ticks_per_sec;
+
+	status = uv_bios_freq_base(BIOS_FREQ_BASE_REALTIME_CLOCK, &ticks_per_sec);
+
+	if (status != BIOS_STATUS_SUCCESS || ticks_per_sec < 100000) {
+		pr_warn("UV: unable to determine platform RTC clock frequency, guessing.\n");
+
+		/* BIOS gives wrong value for clock frequency, so guess: */
+		sn_rtc_cycles_per_second = 1000000000000UL / 30000UL;
+	} else {
+		sn_rtc_cycles_per_second = ticks_per_sec;
+	}
+}
+
+/* Direct Legacy VGA I/O traffic to designated IOH */
+static int uv_set_vga_state(struct pci_dev *pdev, bool decode, unsigned int command_bits, u32 flags)
+{
+	int domain, bus, rc;
+
+	if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
+		return 0;
+
+	if ((command_bits & PCI_COMMAND_IO) == 0)
+		return 0;
+
+	domain = pci_domain_nr(pdev->bus);
+	bus = pdev->bus->number;
+
+	rc = uv_bios_set_legacy_vga_target(decode, domain, bus);
+
+	return rc;
+}
+
+/*
+ * Called on each CPU to initialize the per_cpu UV data area.
+ * FIXME: hotplug not supported yet
+ */
+void uv_cpu_init(void)
+{
+	/* CPU 0 initialization will be done via uv_system_init. */
+	if (smp_processor_id() == 0)
+		return;
+
+	uv_hub_info->nr_online_cpus++;
+}
+
+struct mn {
+	unsigned char	m_val;
+	unsigned char	n_val;
+	unsigned char	m_shift;
+	unsigned char	n_lshift;
+};
+
+/* Initialize caller's MN struct and fill in values */
+static void get_mn(struct mn *mnp)
+{
+	memset(mnp, 0, sizeof(*mnp));
+	mnp->n_val	= uv_cpuid.n_skt;
+	if (is_uv(UV4|UVY)) {
+		mnp->m_val	= 0;
+		mnp->n_lshift	= 0;
+	} else if (is_uv3_hub()) {
+		union uvyh_gr0_gam_gr_config_u m_gr_config;
+
+		mnp->m_val	= uv_cpuid.m_skt;
+		m_gr_config.v	= uv_read_local_mmr(UVH_GR0_GAM_GR_CONFIG);
+		mnp->n_lshift	= m_gr_config.s3.m_skt;
+	} else if (is_uv2_hub()) {
+		mnp->m_val	= uv_cpuid.m_skt;
+		mnp->n_lshift	= mnp->m_val == 40 ? 40 : 39;
+	}
+	mnp->m_shift = mnp->m_val ? 64 - mnp->m_val : 0;
+}
+
+static void __init uv_init_hub_info(struct uv_hub_info_s *hi)
+{
+	struct mn mn;
+
+	get_mn(&mn);
+	hi->gpa_mask = mn.m_val ?
+		(1UL << (mn.m_val + mn.n_val)) - 1 :
+		(1UL << uv_cpuid.gpa_shift) - 1;
+
+	hi->m_val		= mn.m_val;
+	hi->n_val		= mn.n_val;
+	hi->m_shift		= mn.m_shift;
+	hi->n_lshift		= mn.n_lshift ? mn.n_lshift : 0;
+	hi->hub_revision	= uv_hub_info->hub_revision;
+	hi->hub_type		= uv_hub_info->hub_type;
+	hi->pnode_mask		= uv_cpuid.pnode_mask;
+	hi->nasid_shift		= uv_cpuid.nasid_shift;
+	hi->min_pnode		= _min_pnode;
+	hi->min_socket		= _min_socket;
+	hi->pnode_to_socket	= _pnode_to_socket;
+	hi->socket_to_node	= _socket_to_node;
+	hi->socket_to_pnode	= _socket_to_pnode;
+	hi->gr_table_len	= _gr_table_len;
+	hi->gr_table		= _gr_table;
+
+	uv_cpuid.gnode_shift	= max_t(unsigned int, uv_cpuid.gnode_shift, mn.n_val);
+	hi->gnode_extra		= (uv_node_id & ~((1 << uv_cpuid.gnode_shift) - 1)) >> 1;
+	if (mn.m_val)
+		hi->gnode_upper	= (u64)hi->gnode_extra << mn.m_val;
+
+	if (uv_gp_table) {
+		hi->global_mmr_base	= uv_gp_table->mmr_base;
+		hi->global_mmr_shift	= uv_gp_table->mmr_shift;
+		hi->global_gru_base	= uv_gp_table->gru_base;
+		hi->global_gru_shift	= uv_gp_table->gru_shift;
+		hi->gpa_shift		= uv_gp_table->gpa_shift;
+		hi->gpa_mask		= (1UL << hi->gpa_shift) - 1;
+	} else {
+		hi->global_mmr_base	=
+			uv_read_local_mmr(UVH_RH_GAM_MMR_OVERLAY_CONFIG) &
+			~UV_MMR_ENABLE;
+		hi->global_mmr_shift	= _UV_GLOBAL_MMR64_PNODE_SHIFT;
+	}
+
+	get_lowmem_redirect(&hi->lowmem_remap_base, &hi->lowmem_remap_top);
+
+	hi->apic_pnode_shift = uv_cpuid.socketid_shift;
+
+	/* Show system specific info: */
+	pr_info("UV: N:%d M:%d m_shift:%d n_lshift:%d\n", hi->n_val, hi->m_val, hi->m_shift, hi->n_lshift);
+	pr_info("UV: gpa_mask/shift:0x%lx/%d pnode_mask:0x%x apic_pns:%d\n", hi->gpa_mask, hi->gpa_shift, hi->pnode_mask, hi->apic_pnode_shift);
+	pr_info("UV: mmr_base/shift:0x%lx/%ld\n", hi->global_mmr_base, hi->global_mmr_shift);
+	if (hi->global_gru_base)
+		pr_info("UV: gru_base/shift:0x%lx/%ld\n",
+			hi->global_gru_base, hi->global_gru_shift);
+
+	pr_info("UV: gnode_upper:0x%lx gnode_extra:0x%x\n", hi->gnode_upper, hi->gnode_extra);
+}
+
+static void __init decode_gam_params(unsigned long ptr)
+{
+	uv_gp_table = (struct uv_gam_parameters *)ptr;
+
+	pr_info("UV: GAM Params...\n");
+	pr_info("UV: mmr_base/shift:0x%llx/%d gru_base/shift:0x%llx/%d gpa_shift:%d\n",
+		uv_gp_table->mmr_base, uv_gp_table->mmr_shift,
+		uv_gp_table->gru_base, uv_gp_table->gru_shift,
+		uv_gp_table->gpa_shift);
+}
+
+static void __init decode_gam_rng_tbl(unsigned long ptr)
+{
+	struct uv_gam_range_entry *gre = (struct uv_gam_range_entry *)ptr;
+	unsigned long lgre = 0, gend = 0;
+	int index = 0;
+	int sock_min = 999999, pnode_min = 99999;
+	int sock_max = -1, pnode_max = -1;
+
+	uv_gre_table = gre;
+	for (; gre->type != UV_GAM_RANGE_TYPE_UNUSED; gre++) {
+		unsigned long size = ((unsigned long)(gre->limit - lgre)
+					<< UV_GAM_RANGE_SHFT);
+		int order = 0;
+		char suffix[] = " KMGTPE";
+		int flag = ' ';
+
+		while (size > 9999 && order < sizeof(suffix)) {
+			size /= 1024;
+			order++;
+		}
+
+		/* adjust max block size to current range start */
+		if (gre->type == 1 || gre->type == 2)
+			if (adj_blksize(lgre))
+				flag = '*';
+
+		if (!index) {
+			pr_info("UV: GAM Range Table...\n");
+			pr_info("UV:  # %20s %14s %6s %4s %5s %3s %2s\n", "Range", "", "Size", "Type", "NASID", "SID", "PN");
+		}
+		pr_info("UV: %2d: 0x%014lx-0x%014lx%c %5lu%c %3d   %04x  %02x %02x\n",
+			index++,
+			(unsigned long)lgre << UV_GAM_RANGE_SHFT,
+			(unsigned long)gre->limit << UV_GAM_RANGE_SHFT,
+			flag, size, suffix[order],
+			gre->type, gre->nasid, gre->sockid, gre->pnode);
+
+		if (gre->type == UV_GAM_RANGE_TYPE_HOLE)
+			gend = (unsigned long)gre->limit << UV_GAM_RANGE_SHFT;
+
+		/* update to next range start */
+		lgre = gre->limit;
+		if (sock_min > gre->sockid)
+			sock_min = gre->sockid;
+		if (sock_max < gre->sockid)
+			sock_max = gre->sockid;
+		if (pnode_min > gre->pnode)
+			pnode_min = gre->pnode;
+		if (pnode_max < gre->pnode)
+			pnode_max = gre->pnode;
+	}
+	_min_socket	= sock_min;
+	_max_socket	= sock_max;
+	_min_pnode	= pnode_min;
+	_max_pnode	= pnode_max;
+	_gr_table_len	= index;
+
+	pr_info("UV: GRT: %d entries, sockets(min:%x,max:%x), pnodes(min:%x,max:%x), gap_end(%d)\n",
+	  index, _min_socket, _max_socket, _min_pnode, _max_pnode, fls64(gend));
+}
+
+/* Walk through UVsystab decoding the fields */
+static int __init decode_uv_systab(void)
+{
+	struct uv_systab *st;
+	int i;
+
+	/* Get mapped UVsystab pointer */
+	st = uv_systab;
+
+	/* If UVsystab is version 1, there is no extended UVsystab */
+	if (st && st->revision == UV_SYSTAB_VERSION_1)
+		return 0;
+
+	if ((!st) || (st->revision < UV_SYSTAB_VERSION_UV4_LATEST)) {
+		int rev = st ? st->revision : 0;
+
+		pr_err("UV: BIOS UVsystab mismatch, (%x < %x)\n",
+			rev, UV_SYSTAB_VERSION_UV4_LATEST);
+		pr_err("UV: Does not support UV, switch to non-UV x86_64\n");
+		uv_system_type = UV_NONE;
+
+		return -EINVAL;
+	}
+
+	for (i = 0; st->entry[i].type != UV_SYSTAB_TYPE_UNUSED; i++) {
+		unsigned long ptr = st->entry[i].offset;
+
+		if (!ptr)
+			continue;
+
+		/* point to payload */
+		ptr += (unsigned long)st;
+
+		switch (st->entry[i].type) {
+		case UV_SYSTAB_TYPE_GAM_PARAMS:
+			decode_gam_params(ptr);
+			break;
+
+		case UV_SYSTAB_TYPE_GAM_RNG_TBL:
+			decode_gam_rng_tbl(ptr);
+			break;
+
+		case UV_SYSTAB_TYPE_ARCH_TYPE:
+			/* already processed in early startup */
+			break;
+
+		default:
+			pr_err("UV:%s:Unrecognized UV_SYSTAB_TYPE:%d, skipped\n",
+				__func__, st->entry[i].type);
+			break;
+		}
+	}
+	return 0;
+}
+
+/* Set up physical blade translations from UVH_NODE_PRESENT_TABLE */
+static __init void boot_init_possible_blades(struct uv_hub_info_s *hub_info)
+{
+	unsigned long np;
+	int i, uv_pb = 0;
+
+	if (UVH_NODE_PRESENT_TABLE) {
+		pr_info("UV: NODE_PRESENT_DEPTH = %d\n",
+			UVH_NODE_PRESENT_TABLE_DEPTH);
+		for (i = 0; i < UVH_NODE_PRESENT_TABLE_DEPTH; i++) {
+			np = uv_read_local_mmr(UVH_NODE_PRESENT_TABLE + i * 8);
+			pr_info("UV: NODE_PRESENT(%d) = 0x%016lx\n", i, np);
+			uv_pb += hweight64(np);
+		}
+	}
+	if (UVH_NODE_PRESENT_0) {
+		np = uv_read_local_mmr(UVH_NODE_PRESENT_0);
+		pr_info("UV: NODE_PRESENT_0 = 0x%016lx\n", np);
+		uv_pb += hweight64(np);
+	}
+	if (UVH_NODE_PRESENT_1) {
+		np = uv_read_local_mmr(UVH_NODE_PRESENT_1);
+		pr_info("UV: NODE_PRESENT_1 = 0x%016lx\n", np);
+		uv_pb += hweight64(np);
+	}
+	if (uv_possible_blades != uv_pb)
+		uv_possible_blades = uv_pb;
+
+	pr_info("UV: number nodes/possible blades %d\n", uv_pb);
+}
+
+static void __init build_socket_tables(void)
+{
+	struct uv_gam_range_entry *gre = uv_gre_table;
+	int num, nump;
+	int cpu, i, lnid;
+	int minsock = _min_socket;
+	int maxsock = _max_socket;
+	int minpnode = _min_pnode;
+	int maxpnode = _max_pnode;
+	size_t bytes;
+
+	if (!gre) {
+		if (is_uv2_hub() || is_uv3_hub()) {
+			pr_info("UV: No UVsystab socket table, ignoring\n");
+			return;
+		}
+		pr_err("UV: Error: UVsystab address translations not available!\n");
+		BUG();
+	}
+
+	/* Build socket id -> node id, pnode */
+	num = maxsock - minsock + 1;
+	bytes = num * sizeof(_socket_to_node[0]);
+	_socket_to_node = kmalloc(bytes, GFP_KERNEL);
+	_socket_to_pnode = kmalloc(bytes, GFP_KERNEL);
+
+	nump = maxpnode - minpnode + 1;
+	bytes = nump * sizeof(_pnode_to_socket[0]);
+	_pnode_to_socket = kmalloc(bytes, GFP_KERNEL);
+	BUG_ON(!_socket_to_node || !_socket_to_pnode || !_pnode_to_socket);
+
+	for (i = 0; i < num; i++)
+		_socket_to_node[i] = _socket_to_pnode[i] = SOCK_EMPTY;
+
+	for (i = 0; i < nump; i++)
+		_pnode_to_socket[i] = SOCK_EMPTY;
+
+	/* Fill in pnode/node/addr conversion list values: */
+	pr_info("UV: GAM Building socket/pnode conversion tables\n");
+	for (; gre->type != UV_GAM_RANGE_TYPE_UNUSED; gre++) {
+		if (gre->type == UV_GAM_RANGE_TYPE_HOLE)
+			continue;
+		i = gre->sockid - minsock;
+		/* Duplicate: */
+		if (_socket_to_pnode[i] != SOCK_EMPTY)
+			continue;
+		_socket_to_pnode[i] = gre->pnode;
+
+		i = gre->pnode - minpnode;
+		_pnode_to_socket[i] = gre->sockid;
+
+		pr_info("UV: sid:%02x type:%d nasid:%04x pn:%02x pn2s:%2x\n",
+			gre->sockid, gre->type, gre->nasid,
+			_socket_to_pnode[gre->sockid - minsock],
+			_pnode_to_socket[gre->pnode - minpnode]);
+	}
+
+	/* Set socket -> node values: */
+	lnid = NUMA_NO_NODE;
+	for_each_present_cpu(cpu) {
+		int nid = cpu_to_node(cpu);
+		int apicid, sockid;
+
+		if (lnid == nid)
+			continue;
+		lnid = nid;
+		apicid = per_cpu(x86_cpu_to_apicid, cpu);
+		sockid = apicid >> uv_cpuid.socketid_shift;
+		_socket_to_node[sockid - minsock] = nid;
+		pr_info("UV: sid:%02x: apicid:%04x node:%2d\n",
+			sockid, apicid, nid);
+	}
+
+	/* Set up physical blade to pnode translation from GAM Range Table: */
+	bytes = num_possible_nodes() * sizeof(_node_to_pnode[0]);
+	_node_to_pnode = kmalloc(bytes, GFP_KERNEL);
+	BUG_ON(!_node_to_pnode);
+
+	for (lnid = 0; lnid < num_possible_nodes(); lnid++) {
+		unsigned short sockid;
+
+		for (sockid = minsock; sockid <= maxsock; sockid++) {
+			if (lnid == _socket_to_node[sockid - minsock]) {
+				_node_to_pnode[lnid] = _socket_to_pnode[sockid - minsock];
+				break;
+			}
+		}
+		if (sockid > maxsock) {
+			pr_err("UV: socket for node %d not found!\n", lnid);
+			BUG();
+		}
+	}
+
+	/*
+	 * If socket id == pnode or socket id == node for all nodes,
+	 *   system runs faster by removing corresponding conversion table.
+	 */
+	pr_info("UV: Checking socket->node/pnode for identity maps\n");
+	if (minsock == 0) {
+		for (i = 0; i < num; i++)
+			if (_socket_to_node[i] == SOCK_EMPTY || i != _socket_to_node[i])
+				break;
+		if (i >= num) {
+			kfree(_socket_to_node);
+			_socket_to_node = NULL;
+			pr_info("UV: 1:1 socket_to_node table removed\n");
+		}
+	}
+	if (minsock == minpnode) {
+		for (i = 0; i < num; i++)
+			if (_socket_to_pnode[i] != SOCK_EMPTY &&
+				_socket_to_pnode[i] != i + minpnode)
+				break;
+		if (i >= num) {
+			kfree(_socket_to_pnode);
+			_socket_to_pnode = NULL;
+			pr_info("UV: 1:1 socket_to_pnode table removed\n");
+		}
+	}
+}
+
+/* Check which reboot to use */
+static void check_efi_reboot(void)
+{
+	/* If EFI reboot not available, use ACPI reboot */
+	if (!efi_enabled(EFI_BOOT))
+		reboot_type = BOOT_ACPI;
+}
+
+/*
+ * User proc fs file handling now deprecated.
+ * Recommend using /sys/firmware/sgi_uv/... instead.
+ */
+static int __maybe_unused proc_hubbed_show(struct seq_file *file, void *data)
+{
+	pr_notice_once("%s: using deprecated /proc/sgi_uv/hubbed, use /sys/firmware/sgi_uv/hub_type\n",
+		       current->comm);
+	seq_printf(file, "0x%x\n", uv_hubbed_system);
+	return 0;
+}
+
+static int __maybe_unused proc_hubless_show(struct seq_file *file, void *data)
+{
+	pr_notice_once("%s: using deprecated /proc/sgi_uv/hubless, use /sys/firmware/sgi_uv/hubless\n",
+		       current->comm);
+	seq_printf(file, "0x%x\n", uv_hubless_system);
+	return 0;
+}
+
+static int __maybe_unused proc_archtype_show(struct seq_file *file, void *data)
+{
+	pr_notice_once("%s: using deprecated /proc/sgi_uv/archtype, use /sys/firmware/sgi_uv/archtype\n",
+		       current->comm);
+	seq_printf(file, "%s/%s\n", uv_archtype, oem_table_id);
+	return 0;
+}
+
+static __init void uv_setup_proc_files(int hubless)
+{
+	struct proc_dir_entry *pde;
+
+	pde = proc_mkdir(UV_PROC_NODE, NULL);
+	proc_create_single("archtype", 0, pde, proc_archtype_show);
+	if (hubless)
+		proc_create_single("hubless", 0, pde, proc_hubless_show);
+	else
+		proc_create_single("hubbed", 0, pde, proc_hubbed_show);
+}
+
+/* Initialize UV hubless systems */
+static __init int uv_system_init_hubless(void)
+{
+	int rc;
+
+	/* Setup PCH NMI handler */
+	uv_nmi_setup_hubless();
+
+	/* Init kernel/BIOS interface */
+	rc = uv_bios_init();
+	if (rc < 0)
+		return rc;
+
+	/* Process UVsystab */
+	rc = decode_uv_systab();
+	if (rc < 0)
+		return rc;
+
+	/* Set section block size for current node memory */
+	set_block_size();
+
+	/* Create user access node */
+	if (rc >= 0)
+		uv_setup_proc_files(1);
+
+	check_efi_reboot();
+
+	return rc;
+}
+
+static void __init uv_system_init_hub(void)
+{
+	struct uv_hub_info_s hub_info = {0};
+	int bytes, cpu, nodeid;
+	unsigned short min_pnode = 9999, max_pnode = 0;
+	char *hub = is_uv5_hub() ? "UV500" :
+		    is_uv4_hub() ? "UV400" :
+		    is_uv3_hub() ? "UV300" :
+		    is_uv2_hub() ? "UV2000/3000" : NULL;
+
+	if (!hub) {
+		pr_err("UV: Unknown/unsupported UV hub\n");
+		return;
+	}
+	pr_info("UV: Found %s hub\n", hub);
+
+	map_low_mmrs();
+
+	/* Get uv_systab for decoding, setup UV BIOS calls */
+	uv_bios_init();
+
+	/* If there's an UVsystab problem then abort UV init: */
+	if (decode_uv_systab() < 0) {
+		pr_err("UV: Mangled UVsystab format\n");
+		return;
+	}
+
+	build_socket_tables();
+	build_uv_gr_table();
+	set_block_size();
+	uv_init_hub_info(&hub_info);
+	uv_possible_blades = num_possible_nodes();
+	if (!_node_to_pnode)
+		boot_init_possible_blades(&hub_info);
+
+	/* uv_num_possible_blades() is really the hub count: */
+	pr_info("UV: Found %d hubs, %d nodes, %d CPUs\n", uv_num_possible_blades(), num_possible_nodes(), num_possible_cpus());
+
+	uv_bios_get_sn_info(0, &uv_type, &sn_partition_id, &sn_coherency_id, &sn_region_size, &system_serial_number);
+	hub_info.coherency_domain_number = sn_coherency_id;
+	uv_rtc_init();
+
+	bytes = sizeof(void *) * uv_num_possible_blades();
+	__uv_hub_info_list = kzalloc(bytes, GFP_KERNEL);
+	BUG_ON(!__uv_hub_info_list);
+
+	bytes = sizeof(struct uv_hub_info_s);
+	for_each_node(nodeid) {
+		struct uv_hub_info_s *new_hub;
+
+		if (__uv_hub_info_list[nodeid]) {
+			pr_err("UV: Node %d UV HUB already initialized!?\n", nodeid);
+			BUG();
+		}
+
+		/* Allocate new per hub info list */
+		new_hub = (nodeid == 0) ?  &uv_hub_info_node0 : kzalloc_node(bytes, GFP_KERNEL, nodeid);
+		BUG_ON(!new_hub);
+		__uv_hub_info_list[nodeid] = new_hub;
+		new_hub = uv_hub_info_list(nodeid);
+		BUG_ON(!new_hub);
+		*new_hub = hub_info;
+
+		/* Use information from GAM table if available: */
+		if (_node_to_pnode)
+			new_hub->pnode = _node_to_pnode[nodeid];
+		else /* Or fill in during CPU loop: */
+			new_hub->pnode = 0xffff;
+
+		new_hub->numa_blade_id = uv_node_to_blade_id(nodeid);
+		new_hub->memory_nid = NUMA_NO_NODE;
+		new_hub->nr_possible_cpus = 0;
+		new_hub->nr_online_cpus = 0;
+	}
+
+	/* Initialize per CPU info: */
+	for_each_possible_cpu(cpu) {
+		int apicid = per_cpu(x86_cpu_to_apicid, cpu);
+		int numa_node_id;
+		unsigned short pnode;
+
+		nodeid = cpu_to_node(cpu);
+		numa_node_id = numa_cpu_node(cpu);
+		pnode = uv_apicid_to_pnode(apicid);
+
+		uv_cpu_info_per(cpu)->p_uv_hub_info = uv_hub_info_list(nodeid);
+		uv_cpu_info_per(cpu)->blade_cpu_id = uv_cpu_hub_info(cpu)->nr_possible_cpus++;
+		if (uv_cpu_hub_info(cpu)->memory_nid == NUMA_NO_NODE)
+			uv_cpu_hub_info(cpu)->memory_nid = cpu_to_node(cpu);
+
+		/* Init memoryless node: */
+		if (nodeid != numa_node_id &&
+		    uv_hub_info_list(numa_node_id)->pnode == 0xffff)
+			uv_hub_info_list(numa_node_id)->pnode = pnode;
+		else if (uv_cpu_hub_info(cpu)->pnode == 0xffff)
+			uv_cpu_hub_info(cpu)->pnode = pnode;
+	}
+
+	for_each_node(nodeid) {
+		unsigned short pnode = uv_hub_info_list(nodeid)->pnode;
+
+		/* Add pnode info for pre-GAM list nodes without CPUs: */
+		if (pnode == 0xffff) {
+			unsigned long paddr;
+
+			paddr = node_start_pfn(nodeid) << PAGE_SHIFT;
+			pnode = uv_gpa_to_pnode(uv_soc_phys_ram_to_gpa(paddr));
+			uv_hub_info_list(nodeid)->pnode = pnode;
+		}
+		min_pnode = min(pnode, min_pnode);
+		max_pnode = max(pnode, max_pnode);
+		pr_info("UV: UVHUB node:%2d pn:%02x nrcpus:%d\n",
+			nodeid,
+			uv_hub_info_list(nodeid)->pnode,
+			uv_hub_info_list(nodeid)->nr_possible_cpus);
+	}
+
+	pr_info("UV: min_pnode:%02x max_pnode:%02x\n", min_pnode, max_pnode);
+	map_gru_high(max_pnode);
+	map_mmr_high(max_pnode);
+	map_mmioh_high(min_pnode, max_pnode);
+
+	uv_nmi_setup();
+	uv_cpu_init();
+	uv_setup_proc_files(0);
+
+	/* Register Legacy VGA I/O redirection handler: */
+	pci_register_set_vga_state(uv_set_vga_state);
+
+	check_efi_reboot();
+}
+
+/*
+ * There is a different code path needed to initialize a UV system that does
+ * not have a "UV HUB" (referred to as "hubless").
+ */
+void __init uv_system_init(void)
+{
+	if (likely(!is_uv_system() && !is_uv_hubless(1)))
+		return;
+
+	if (is_uv_system())
+		uv_system_init_hub();
+	else
+		uv_system_init_hubless();
+}
+
+apic_driver(apic_x2apic_uv_x);