Initial import

1 files changed, 1141 insertions, 0 deletions

diff --git a/arch/ia64/kernel/iosapic.c b/arch/ia64/kernel/iosapic.c
new file mode 100644
index 000000000..bc9501e36
--- /dev/null
+++ b/arch/ia64/kernel/iosapic.c
@@ -0,0 +1,1141 @@
+/*
+ * I/O SAPIC support.
+ *
+ * Copyright (C) 1999 Intel Corp.
+ * Copyright (C) 1999 Asit Mallick <asit.k.mallick@intel.com>
+ * Copyright (C) 2000-2002 J.I. Lee <jung-ik.lee@intel.com>
+ * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co.
+ *	David Mosberger-Tang <davidm@hpl.hp.com>
+ * Copyright (C) 1999 VA Linux Systems
+ * Copyright (C) 1999,2000 Walt Drummond <drummond@valinux.com>
+ *
+ * 00/04/19	D. Mosberger	Rewritten to mirror more closely the x86 I/O
+ *				APIC code.  In particular, we now have separate
+ *				handlers for edge and level triggered
+ *				interrupts.
+ * 00/10/27	Asit Mallick, Goutham Rao <goutham.rao@intel.com> IRQ vector
+ *				allocation PCI to vector mapping, shared PCI
+ *				interrupts.
+ * 00/10/27	D. Mosberger	Document things a bit more to make them more
+ *				understandable.  Clean up much of the old
+ *				IOSAPIC cruft.
+ * 01/07/27	J.I. Lee	PCI irq routing, Platform/Legacy interrupts
+ *				and fixes for ACPI S5(SoftOff) support.
+ * 02/01/23	J.I. Lee	iosapic pgm fixes for PCI irq routing from _PRT
+ * 02/01/07     E. Focht        <efocht@ess.nec.de> Redirectable interrupt
+ *				vectors in iosapic_set_affinity(),
+ *				initializations for /proc/irq/#/smp_affinity
+ * 02/04/02	P. Diefenbaugh	Cleaned up ACPI PCI IRQ routing.
+ * 02/04/18	J.I. Lee	bug fix in iosapic_init_pci_irq
+ * 02/04/30	J.I. Lee	bug fix in find_iosapic to fix ACPI PCI IRQ to
+ *				IOSAPIC mapping error
+ * 02/07/29	T. Kochi	Allocate interrupt vectors dynamically
+ * 02/08/04	T. Kochi	Cleaned up terminology (irq, global system
+ *				interrupt, vector, etc.)
+ * 02/09/20	D. Mosberger	Simplified by taking advantage of ACPI's
+ *				pci_irq code.
+ * 03/02/19	B. Helgaas	Make pcat_compat system-wide, not per-IOSAPIC.
+ *				Remove iosapic_address & gsi_base from
+ *				external interfaces.  Rationalize
+ *				__init/__devinit attributes.
+ * 04/12/04 Ashok Raj	<ashok.raj@intel.com> Intel Corporation 2004
+ *				Updated to work with irq migration necessary
+ *				for CPU Hotplug
+ */
+/*
+ * Here is what the interrupt logic between a PCI device and the kernel looks
+ * like:
+ *
+ * (1) A PCI device raises one of the four interrupt pins (INTA, INTB, INTC,
+ *     INTD).  The device is uniquely identified by its bus-, and slot-number
+ *     (the function number does not matter here because all functions share
+ *     the same interrupt lines).
+ *
+ * (2) The motherboard routes the interrupt line to a pin on a IOSAPIC
+ *     controller.  Multiple interrupt lines may have to share the same
+ *     IOSAPIC pin (if they're level triggered and use the same polarity).
+ *     Each interrupt line has a unique Global System Interrupt (GSI) number
+ *     which can be calculated as the sum of the controller's base GSI number
+ *     and the IOSAPIC pin number to which the line connects.
+ *
+ * (3) The IOSAPIC uses an internal routing table entries (RTEs) to map the
+ * IOSAPIC pin into the IA-64 interrupt vector.  This interrupt vector is then
+ * sent to the CPU.
+ *
+ * (4) The kernel recognizes an interrupt as an IRQ.  The IRQ interface is
+ *     used as architecture-independent interrupt handling mechanism in Linux.
+ *     As an IRQ is a number, we have to have
+ *     IA-64 interrupt vector number <-> IRQ number mapping.  On smaller
+ *     systems, we use one-to-one mapping between IA-64 vector and IRQ.  A
+ *     platform can implement platform_irq_to_vector(irq) and
+ *     platform_local_vector_to_irq(vector) APIs to differentiate the mapping.
+ *     Please see also arch/ia64/include/asm/hw_irq.h for those APIs.
+ *
+ * To sum up, there are three levels of mappings involved:
+ *
+ *	PCI pin -> global system interrupt (GSI) -> IA-64 vector <-> IRQ
+ *
+ * Note: The term "IRQ" is loosely used everywhere in Linux kernel to
+ * describe interrupts.  Now we use "IRQ" only for Linux IRQ's.  ISA IRQ
+ * (isa_irq) is the only exception in this source code.
+ */
+
+#include <linux/acpi.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/string.h>
+#include <linux/bootmem.h>
+
+#include <asm/delay.h>
+#include <asm/hw_irq.h>
+#include <asm/io.h>
+#include <asm/iosapic.h>
+#include <asm/machvec.h>
+#include <asm/processor.h>
+#include <asm/ptrace.h>
+
+#undef DEBUG_INTERRUPT_ROUTING
+
+#ifdef DEBUG_INTERRUPT_ROUTING
+#define DBG(fmt...)	printk(fmt)
+#else
+#define DBG(fmt...)
+#endif
+
+static DEFINE_SPINLOCK(iosapic_lock);
+
+/*
+ * These tables map IA-64 vectors to the IOSAPIC pin that generates this
+ * vector.
+ */
+
+#define NO_REF_RTE	0
+
+static struct iosapic {
+	char __iomem	*addr;		/* base address of IOSAPIC */
+	unsigned int	gsi_base;	/* GSI base */
+	unsigned short	num_rte;	/* # of RTEs on this IOSAPIC */
+	int		rtes_inuse;	/* # of RTEs in use on this IOSAPIC */
+#ifdef CONFIG_NUMA
+	unsigned short	node;		/* numa node association via pxm */
+#endif
+	spinlock_t	lock;		/* lock for indirect reg access */
+} iosapic_lists[NR_IOSAPICS];
+
+struct iosapic_rte_info {
+	struct list_head rte_list;	/* RTEs sharing the same vector */
+	char		rte_index;	/* IOSAPIC RTE index */
+	int		refcnt;		/* reference counter */
+	struct iosapic	*iosapic;
+} ____cacheline_aligned;
+
+static struct iosapic_intr_info {
+	struct list_head rtes;		/* RTEs using this vector (empty =>
+					 * not an IOSAPIC interrupt) */
+	int		count;		/* # of registered RTEs */
+	u32		low32;		/* current value of low word of
+					 * Redirection table entry */
+	unsigned int	dest;		/* destination CPU physical ID */
+	unsigned char	dmode	: 3;	/* delivery mode (see iosapic.h) */
+	unsigned char 	polarity: 1;	/* interrupt polarity
+					 * (see iosapic.h) */
+	unsigned char	trigger	: 1;	/* trigger mode (see iosapic.h) */
+} iosapic_intr_info[NR_IRQS];
+
+static unsigned char pcat_compat;	/* 8259 compatibility flag */
+
+static inline void
+iosapic_write(struct iosapic *iosapic, unsigned int reg, u32 val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&iosapic->lock, flags);
+	__iosapic_write(iosapic->addr, reg, val);
+	spin_unlock_irqrestore(&iosapic->lock, flags);
+}
+
+/*
+ * Find an IOSAPIC associated with a GSI
+ */
+static inline int
+find_iosapic (unsigned int gsi)
+{
+	int i;
+
+	for (i = 0; i < NR_IOSAPICS; i++) {
+		if ((unsigned) (gsi - iosapic_lists[i].gsi_base) <
+		    iosapic_lists[i].num_rte)
+			return i;
+	}
+
+	return -1;
+}
+
+static inline int __gsi_to_irq(unsigned int gsi)
+{
+	int irq;
+	struct iosapic_intr_info *info;
+	struct iosapic_rte_info *rte;
+
+	for (irq = 0; irq < NR_IRQS; irq++) {
+		info = &iosapic_intr_info[irq];
+		list_for_each_entry(rte, &info->rtes, rte_list)
+			if (rte->iosapic->gsi_base + rte->rte_index == gsi)
+				return irq;
+	}
+	return -1;
+}
+
+int
+gsi_to_irq (unsigned int gsi)
+{
+	unsigned long flags;
+	int irq;
+
+	spin_lock_irqsave(&iosapic_lock, flags);
+	irq = __gsi_to_irq(gsi);
+	spin_unlock_irqrestore(&iosapic_lock, flags);
+	return irq;
+}
+
+static struct iosapic_rte_info *find_rte(unsigned int irq, unsigned int gsi)
+{
+	struct iosapic_rte_info *rte;
+
+	list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list)
+		if (rte->iosapic->gsi_base + rte->rte_index == gsi)
+			return rte;
+	return NULL;
+}
+
+static void
+set_rte (unsigned int gsi, unsigned int irq, unsigned int dest, int mask)
+{
+	unsigned long pol, trigger, dmode;
+	u32 low32, high32;
+	int rte_index;
+	char redir;
+	struct iosapic_rte_info *rte;
+	ia64_vector vector = irq_to_vector(irq);
+
+	DBG(KERN_DEBUG"IOSAPIC: routing vector %d to 0x%x\n", vector, dest);
+
+	rte = find_rte(irq, gsi);
+	if (!rte)
+		return;		/* not an IOSAPIC interrupt */
+
+	rte_index = rte->rte_index;
+	pol     = iosapic_intr_info[irq].polarity;
+	trigger = iosapic_intr_info[irq].trigger;
+	dmode   = iosapic_intr_info[irq].dmode;
+
+	redir = (dmode == IOSAPIC_LOWEST_PRIORITY) ? 1 : 0;
+
+#ifdef CONFIG_SMP
+	set_irq_affinity_info(irq, (int)(dest & 0xffff), redir);
+#endif
+
+	low32 = ((pol << IOSAPIC_POLARITY_SHIFT) |
+		 (trigger << IOSAPIC_TRIGGER_SHIFT) |
+		 (dmode << IOSAPIC_DELIVERY_SHIFT) |
+		 ((mask ? 1 : 0) << IOSAPIC_MASK_SHIFT) |
+		 vector);
+
+	/* dest contains both id and eid */
+	high32 = (dest << IOSAPIC_DEST_SHIFT);
+
+	iosapic_write(rte->iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
+	iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
+	iosapic_intr_info[irq].low32 = low32;
+	iosapic_intr_info[irq].dest = dest;
+}
+
+static void
+nop (struct irq_data *data)
+{
+	/* do nothing... */
+}
+
+
+#ifdef CONFIG_KEXEC
+void
+kexec_disable_iosapic(void)
+{
+	struct iosapic_intr_info *info;
+	struct iosapic_rte_info *rte;
+	ia64_vector vec;
+	int irq;
+
+	for (irq = 0; irq < NR_IRQS; irq++) {
+		info = &iosapic_intr_info[irq];
+		vec = irq_to_vector(irq);
+		list_for_each_entry(rte, &info->rtes,
+				rte_list) {
+			iosapic_write(rte->iosapic,
+					IOSAPIC_RTE_LOW(rte->rte_index),
+					IOSAPIC_MASK|vec);
+			iosapic_eoi(rte->iosapic->addr, vec);
+		}
+	}
+}
+#endif
+
+static void
+mask_irq (struct irq_data *data)
+{
+	unsigned int irq = data->irq;
+	u32 low32;
+	int rte_index;
+	struct iosapic_rte_info *rte;
+
+	if (!iosapic_intr_info[irq].count)
+		return;			/* not an IOSAPIC interrupt! */
+
+	/* set only the mask bit */
+	low32 = iosapic_intr_info[irq].low32 |= IOSAPIC_MASK;
+	list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
+		rte_index = rte->rte_index;
+		iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
+	}
+}
+
+static void
+unmask_irq (struct irq_data *data)
+{
+	unsigned int irq = data->irq;
+	u32 low32;
+	int rte_index;
+	struct iosapic_rte_info *rte;
+
+	if (!iosapic_intr_info[irq].count)
+		return;			/* not an IOSAPIC interrupt! */
+
+	low32 = iosapic_intr_info[irq].low32 &= ~IOSAPIC_MASK;
+	list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
+		rte_index = rte->rte_index;
+		iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
+	}
+}
+
+
+static int
+iosapic_set_affinity(struct irq_data *data, const struct cpumask *mask,
+		     bool force)
+{
+#ifdef CONFIG_SMP
+	unsigned int irq = data->irq;
+	u32 high32, low32;
+	int cpu, dest, rte_index;
+	int redir = (irq & IA64_IRQ_REDIRECTED) ? 1 : 0;
+	struct iosapic_rte_info *rte;
+	struct iosapic *iosapic;
+
+	irq &= (~IA64_IRQ_REDIRECTED);
+
+	cpu = cpumask_first_and(cpu_online_mask, mask);
+	if (cpu >= nr_cpu_ids)
+		return -1;
+
+	if (irq_prepare_move(irq, cpu))
+		return -1;
+
+	dest = cpu_physical_id(cpu);
+
+	if (!iosapic_intr_info[irq].count)
+		return -1;			/* not an IOSAPIC interrupt */
+
+	set_irq_affinity_info(irq, dest, redir);
+
+	/* dest contains both id and eid */
+	high32 = dest << IOSAPIC_DEST_SHIFT;
+
+	low32 = iosapic_intr_info[irq].low32 & ~(7 << IOSAPIC_DELIVERY_SHIFT);
+	if (redir)
+		/* change delivery mode to lowest priority */
+		low32 |= (IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
+	else
+		/* change delivery mode to fixed */
+		low32 |= (IOSAPIC_FIXED << IOSAPIC_DELIVERY_SHIFT);
+	low32 &= IOSAPIC_VECTOR_MASK;
+	low32 |= irq_to_vector(irq);
+
+	iosapic_intr_info[irq].low32 = low32;
+	iosapic_intr_info[irq].dest = dest;
+	list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
+		iosapic = rte->iosapic;
+		rte_index = rte->rte_index;
+		iosapic_write(iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
+		iosapic_write(iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
+	}
+
+#endif
+	return 0;
+}
+
+/*
+ * Handlers for level-triggered interrupts.
+ */
+
+static unsigned int
+iosapic_startup_level_irq (struct irq_data *data)
+{
+	unmask_irq(data);
+	return 0;
+}
+
+static void
+iosapic_unmask_level_irq (struct irq_data *data)
+{
+	unsigned int irq = data->irq;
+	ia64_vector vec = irq_to_vector(irq);
+	struct iosapic_rte_info *rte;
+	int do_unmask_irq = 0;
+
+	irq_complete_move(irq);
+	if (unlikely(irqd_is_setaffinity_pending(data))) {
+		do_unmask_irq = 1;
+		mask_irq(data);
+	} else
+		unmask_irq(data);
+
+	list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list)
+		iosapic_eoi(rte->iosapic->addr, vec);
+
+	if (unlikely(do_unmask_irq)) {
+		irq_move_masked_irq(data);
+		unmask_irq(data);
+	}
+}
+
+#define iosapic_shutdown_level_irq	mask_irq
+#define iosapic_enable_level_irq	unmask_irq
+#define iosapic_disable_level_irq	mask_irq
+#define iosapic_ack_level_irq		nop
+
+static struct irq_chip irq_type_iosapic_level = {
+	.name =			"IO-SAPIC-level",
+	.irq_startup =		iosapic_startup_level_irq,
+	.irq_shutdown =		iosapic_shutdown_level_irq,
+	.irq_enable =		iosapic_enable_level_irq,
+	.irq_disable =		iosapic_disable_level_irq,
+	.irq_ack =		iosapic_ack_level_irq,
+	.irq_mask =		mask_irq,
+	.irq_unmask =		iosapic_unmask_level_irq,
+	.irq_set_affinity =	iosapic_set_affinity
+};
+
+/*
+ * Handlers for edge-triggered interrupts.
+ */
+
+static unsigned int
+iosapic_startup_edge_irq (struct irq_data *data)
+{
+	unmask_irq(data);
+	/*
+	 * IOSAPIC simply drops interrupts pended while the
+	 * corresponding pin was masked, so we can't know if an
+	 * interrupt is pending already.  Let's hope not...
+	 */
+	return 0;
+}
+
+static void
+iosapic_ack_edge_irq (struct irq_data *data)
+{
+	irq_complete_move(data->irq);
+	irq_move_irq(data);
+}
+
+#define iosapic_enable_edge_irq		unmask_irq
+#define iosapic_disable_edge_irq	nop
+
+static struct irq_chip irq_type_iosapic_edge = {
+	.name =			"IO-SAPIC-edge",
+	.irq_startup =		iosapic_startup_edge_irq,
+	.irq_shutdown =		iosapic_disable_edge_irq,
+	.irq_enable =		iosapic_enable_edge_irq,
+	.irq_disable =		iosapic_disable_edge_irq,
+	.irq_ack =		iosapic_ack_edge_irq,
+	.irq_mask =		mask_irq,
+	.irq_unmask =		unmask_irq,
+	.irq_set_affinity =	iosapic_set_affinity
+};
+
+static unsigned int
+iosapic_version (char __iomem *addr)
+{
+	/*
+	 * IOSAPIC Version Register return 32 bit structure like:
+	 * {
+	 *	unsigned int version   : 8;
+	 *	unsigned int reserved1 : 8;
+	 *	unsigned int max_redir : 8;
+	 *	unsigned int reserved2 : 8;
+	 * }
+	 */
+	return __iosapic_read(addr, IOSAPIC_VERSION);
+}
+
+static int iosapic_find_sharable_irq(unsigned long trigger, unsigned long pol)
+{
+	int i, irq = -ENOSPC, min_count = -1;
+	struct iosapic_intr_info *info;
+
+	/*
+	 * shared vectors for edge-triggered interrupts are not
+	 * supported yet
+	 */
+	if (trigger == IOSAPIC_EDGE)
+		return -EINVAL;
+
+	for (i = 0; i < NR_IRQS; i++) {
+		info = &iosapic_intr_info[i];
+		if (info->trigger == trigger && info->polarity == pol &&
+		    (info->dmode == IOSAPIC_FIXED ||
+		     info->dmode == IOSAPIC_LOWEST_PRIORITY) &&
+		    can_request_irq(i, IRQF_SHARED)) {
+			if (min_count == -1 || info->count < min_count) {
+				irq = i;
+				min_count = info->count;
+			}
+		}
+	}
+	return irq;
+}
+
+/*
+ * if the given vector is already owned by other,
+ *  assign a new vector for the other and make the vector available
+ */
+static void __init
+iosapic_reassign_vector (int irq)
+{
+	int new_irq;
+
+	if (iosapic_intr_info[irq].count) {
+		new_irq = create_irq();
+		if (new_irq < 0)
+			panic("%s: out of interrupt vectors!\n", __func__);
+		printk(KERN_INFO "Reassigning vector %d to %d\n",
+		       irq_to_vector(irq), irq_to_vector(new_irq));
+		memcpy(&iosapic_intr_info[new_irq], &iosapic_intr_info[irq],
+		       sizeof(struct iosapic_intr_info));
+		INIT_LIST_HEAD(&iosapic_intr_info[new_irq].rtes);
+		list_move(iosapic_intr_info[irq].rtes.next,
+			  &iosapic_intr_info[new_irq].rtes);
+		memset(&iosapic_intr_info[irq], 0,
+		       sizeof(struct iosapic_intr_info));
+		iosapic_intr_info[irq].low32 = IOSAPIC_MASK;
+		INIT_LIST_HEAD(&iosapic_intr_info[irq].rtes);
+	}
+}
+
+static inline int irq_is_shared (int irq)
+{
+	return (iosapic_intr_info[irq].count > 1);
+}
+
+struct irq_chip*
+ia64_native_iosapic_get_irq_chip(unsigned long trigger)
+{
+	if (trigger == IOSAPIC_EDGE)
+		return &irq_type_iosapic_edge;
+	else
+		return &irq_type_iosapic_level;
+}
+
+static int
+register_intr (unsigned int gsi, int irq, unsigned char delivery,
+	       unsigned long polarity, unsigned long trigger)
+{
+	struct irq_chip *chip, *irq_type;
+	int index;
+	struct iosapic_rte_info *rte;
+
+	index = find_iosapic(gsi);
+	if (index < 0) {
+		printk(KERN_WARNING "%s: No IOSAPIC for GSI %u\n",
+		       __func__, gsi);
+		return -ENODEV;
+	}
+
+	rte = find_rte(irq, gsi);
+	if (!rte) {
+		rte = kzalloc(sizeof (*rte), GFP_ATOMIC);
+		if (!rte) {
+			printk(KERN_WARNING "%s: cannot allocate memory\n",
+			       __func__);
+			return -ENOMEM;
+		}
+
+		rte->iosapic	= &iosapic_lists[index];
+		rte->rte_index	= gsi - rte->iosapic->gsi_base;
+		rte->refcnt++;
+		list_add_tail(&rte->rte_list, &iosapic_intr_info[irq].rtes);
+		iosapic_intr_info[irq].count++;
+		iosapic_lists[index].rtes_inuse++;
+	}
+	else if (rte->refcnt == NO_REF_RTE) {
+		struct iosapic_intr_info *info = &iosapic_intr_info[irq];
+		if (info->count > 0 &&
+		    (info->trigger != trigger || info->polarity != polarity)){
+			printk (KERN_WARNING
+				"%s: cannot override the interrupt\n",
+				__func__);
+			return -EINVAL;
+		}
+		rte->refcnt++;
+		iosapic_intr_info[irq].count++;
+		iosapic_lists[index].rtes_inuse++;
+	}
+
+	iosapic_intr_info[irq].polarity = polarity;
+	iosapic_intr_info[irq].dmode    = delivery;
+	iosapic_intr_info[irq].trigger  = trigger;
+
+	irq_type = iosapic_get_irq_chip(trigger);
+
+	chip = irq_get_chip(irq);
+	if (irq_type != NULL && chip != irq_type) {
+		if (chip != &no_irq_chip)
+			printk(KERN_WARNING
+			       "%s: changing vector %d from %s to %s\n",
+			       __func__, irq_to_vector(irq),
+			       chip->name, irq_type->name);
+		chip = irq_type;
+	}
+	__irq_set_chip_handler_name_locked(irq, chip, trigger == IOSAPIC_EDGE ?
+					   handle_edge_irq : handle_level_irq,
+					   NULL);
+	return 0;
+}
+
+static unsigned int
+get_target_cpu (unsigned int gsi, int irq)
+{
+#ifdef CONFIG_SMP
+	static int cpu = -1;
+	extern int cpe_vector;
+	cpumask_t domain = irq_to_domain(irq);
+
+	/*
+	 * In case of vector shared by multiple RTEs, all RTEs that
+	 * share the vector need to use the same destination CPU.
+	 */
+	if (iosapic_intr_info[irq].count)
+		return iosapic_intr_info[irq].dest;
+
+	/*
+	 * If the platform supports redirection via XTP, let it
+	 * distribute interrupts.
+	 */
+	if (smp_int_redirect & SMP_IRQ_REDIRECTION)
+		return cpu_physical_id(smp_processor_id());
+
+	/*
+	 * Some interrupts (ACPI SCI, for instance) are registered
+	 * before the BSP is marked as online.
+	 */
+	if (!cpu_online(smp_processor_id()))
+		return cpu_physical_id(smp_processor_id());
+
+#ifdef CONFIG_ACPI
+	if (cpe_vector > 0 && irq_to_vector(irq) == IA64_CPEP_VECTOR)
+		return get_cpei_target_cpu();
+#endif
+
+#ifdef CONFIG_NUMA
+	{
+		int num_cpus, cpu_index, iosapic_index, numa_cpu, i = 0;
+		const struct cpumask *cpu_mask;
+
+		iosapic_index = find_iosapic(gsi);
+		if (iosapic_index < 0 ||
+		    iosapic_lists[iosapic_index].node == MAX_NUMNODES)
+			goto skip_numa_setup;
+
+		cpu_mask = cpumask_of_node(iosapic_lists[iosapic_index].node);
+		num_cpus = 0;
+		for_each_cpu_and(numa_cpu, cpu_mask, &domain) {
+			if (cpu_online(numa_cpu))
+				num_cpus++;
+		}
+
+		if (!num_cpus)
+			goto skip_numa_setup;
+
+		/* Use irq assignment to distribute across cpus in node */
+		cpu_index = irq % num_cpus;
+
+		for_each_cpu_and(numa_cpu, cpu_mask, &domain)
+			if (cpu_online(numa_cpu) && i++ >= cpu_index)
+				break;
+
+		if (numa_cpu < nr_cpu_ids)
+			return cpu_physical_id(numa_cpu);
+	}
+skip_numa_setup:
+#endif
+	/*
+	 * Otherwise, round-robin interrupt vectors across all the
+	 * processors.  (It'd be nice if we could be smarter in the
+	 * case of NUMA.)
+	 */
+	do {
+		if (++cpu >= nr_cpu_ids)
+			cpu = 0;
+	} while (!cpu_online(cpu) || !cpumask_test_cpu(cpu, &domain));
+
+	return cpu_physical_id(cpu);
+#else  /* CONFIG_SMP */
+	return cpu_physical_id(smp_processor_id());
+#endif
+}
+
+static inline unsigned char choose_dmode(void)
+{
+#ifdef CONFIG_SMP
+	if (smp_int_redirect & SMP_IRQ_REDIRECTION)
+		return IOSAPIC_LOWEST_PRIORITY;
+#endif
+	return IOSAPIC_FIXED;
+}
+
+/*
+ * ACPI can describe IOSAPIC interrupts via static tables and namespace
+ * methods.  This provides an interface to register those interrupts and
+ * program the IOSAPIC RTE.
+ */
+int
+iosapic_register_intr (unsigned int gsi,
+		       unsigned long polarity, unsigned long trigger)
+{
+	int irq, mask = 1, err;
+	unsigned int dest;
+	unsigned long flags;
+	struct iosapic_rte_info *rte;
+	u32 low32;
+	unsigned char dmode;
+	struct irq_desc *desc;
+
+	/*
+	 * If this GSI has already been registered (i.e., it's a
+	 * shared interrupt, or we lost a race to register it),
+	 * don't touch the RTE.
+	 */
+	spin_lock_irqsave(&iosapic_lock, flags);
+	irq = __gsi_to_irq(gsi);
+	if (irq > 0) {
+		rte = find_rte(irq, gsi);
+		if(iosapic_intr_info[irq].count == 0) {
+			assign_irq_vector(irq);
+			irq_init_desc(irq);
+		} else if (rte->refcnt != NO_REF_RTE) {
+			rte->refcnt++;
+			goto unlock_iosapic_lock;
+		}
+	} else
+		irq = create_irq();
+
+	/* If vector is running out, we try to find a sharable vector */
+	if (irq < 0) {
+		irq = iosapic_find_sharable_irq(trigger, polarity);
+		if (irq < 0)
+			goto unlock_iosapic_lock;
+	}
+
+	desc = irq_to_desc(irq);
+	raw_spin_lock(&desc->lock);
+	dest = get_target_cpu(gsi, irq);
+	dmode = choose_dmode();
+	err = register_intr(gsi, irq, dmode, polarity, trigger);
+	if (err < 0) {
+		raw_spin_unlock(&desc->lock);
+		irq = err;
+		goto unlock_iosapic_lock;
+	}
+
+	/*
+	 * If the vector is shared and already unmasked for other
+	 * interrupt sources, don't mask it.
+	 */
+	low32 = iosapic_intr_info[irq].low32;
+	if (irq_is_shared(irq) && !(low32 & IOSAPIC_MASK))
+		mask = 0;
+	set_rte(gsi, irq, dest, mask);
+
+	printk(KERN_INFO "GSI %u (%s, %s) -> CPU %d (0x%04x) vector %d\n",
+	       gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
+	       (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
+	       cpu_logical_id(dest), dest, irq_to_vector(irq));
+
+	raw_spin_unlock(&desc->lock);
+ unlock_iosapic_lock:
+	spin_unlock_irqrestore(&iosapic_lock, flags);
+	return irq;
+}
+
+void
+iosapic_unregister_intr (unsigned int gsi)
+{
+	unsigned long flags;
+	int irq, index;
+	u32 low32;
+	unsigned long trigger, polarity;
+	unsigned int dest;
+	struct iosapic_rte_info *rte;
+
+	/*
+	 * If the irq associated with the gsi is not found,
+	 * iosapic_unregister_intr() is unbalanced. We need to check
+	 * this again after getting locks.
+	 */
+	irq = gsi_to_irq(gsi);
+	if (irq < 0) {
+		printk(KERN_ERR "iosapic_unregister_intr(%u) unbalanced\n",
+		       gsi);
+		WARN_ON(1);
+		return;
+	}
+
+	spin_lock_irqsave(&iosapic_lock, flags);
+	if ((rte = find_rte(irq, gsi)) == NULL) {
+		printk(KERN_ERR "iosapic_unregister_intr(%u) unbalanced\n",
+		       gsi);
+		WARN_ON(1);
+		goto out;
+	}
+
+	if (--rte->refcnt > 0)
+		goto out;
+
+	rte->refcnt = NO_REF_RTE;
+
+	/* Mask the interrupt */
+	low32 = iosapic_intr_info[irq].low32 | IOSAPIC_MASK;
+	iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte->rte_index), low32);
+
+	iosapic_intr_info[irq].count--;
+	index = find_iosapic(gsi);
+	iosapic_lists[index].rtes_inuse--;
+	WARN_ON(iosapic_lists[index].rtes_inuse < 0);
+
+	trigger  = iosapic_intr_info[irq].trigger;
+	polarity = iosapic_intr_info[irq].polarity;
+	dest     = iosapic_intr_info[irq].dest;
+	printk(KERN_INFO
+	       "GSI %u (%s, %s) -> CPU %d (0x%04x) vector %d unregistered\n",
+	       gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
+	       (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
+	       cpu_logical_id(dest), dest, irq_to_vector(irq));
+
+	if (iosapic_intr_info[irq].count == 0) {
+#ifdef CONFIG_SMP
+		/* Clear affinity */
+		cpumask_setall(irq_get_irq_data(irq)->affinity);
+#endif
+		/* Clear the interrupt information */
+		iosapic_intr_info[irq].dest = 0;
+		iosapic_intr_info[irq].dmode = 0;
+		iosapic_intr_info[irq].polarity = 0;
+		iosapic_intr_info[irq].trigger = 0;
+		iosapic_intr_info[irq].low32 |= IOSAPIC_MASK;
+
+		/* Destroy and reserve IRQ */
+		destroy_and_reserve_irq(irq);
+	}
+ out:
+	spin_unlock_irqrestore(&iosapic_lock, flags);
+}
+
+/*
+ * ACPI calls this when it finds an entry for a platform interrupt.
+ */
+int __init
+iosapic_register_platform_intr (u32 int_type, unsigned int gsi,
+				int iosapic_vector, u16 eid, u16 id,
+				unsigned long polarity, unsigned long trigger)
+{
+	static const char * const name[] = {"unknown", "PMI", "INIT", "CPEI"};
+	unsigned char delivery;
+	int irq, vector, mask = 0;
+	unsigned int dest = ((id << 8) | eid) & 0xffff;
+
+	switch (int_type) {
+	      case ACPI_INTERRUPT_PMI:
+		irq = vector = iosapic_vector;
+		bind_irq_vector(irq, vector, CPU_MASK_ALL);
+		/*
+		 * since PMI vector is alloc'd by FW(ACPI) not by kernel,
+		 * we need to make sure the vector is available
+		 */
+		iosapic_reassign_vector(irq);
+		delivery = IOSAPIC_PMI;
+		break;
+	      case ACPI_INTERRUPT_INIT:
+		irq = create_irq();
+		if (irq < 0)
+			panic("%s: out of interrupt vectors!\n", __func__);
+		vector = irq_to_vector(irq);
+		delivery = IOSAPIC_INIT;
+		break;
+	      case ACPI_INTERRUPT_CPEI:
+		irq = vector = IA64_CPE_VECTOR;
+		BUG_ON(bind_irq_vector(irq, vector, CPU_MASK_ALL));
+		delivery = IOSAPIC_FIXED;
+		mask = 1;
+		break;
+	      default:
+		printk(KERN_ERR "%s: invalid int type 0x%x\n", __func__,
+		       int_type);
+		return -1;
+	}
+
+	register_intr(gsi, irq, delivery, polarity, trigger);
+
+	printk(KERN_INFO
+	       "PLATFORM int %s (0x%x): GSI %u (%s, %s) -> CPU %d (0x%04x)"
+	       " vector %d\n",
+	       int_type < ARRAY_SIZE(name) ? name[int_type] : "unknown",
+	       int_type, gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
+	       (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
+	       cpu_logical_id(dest), dest, vector);
+
+	set_rte(gsi, irq, dest, mask);
+	return vector;
+}
+
+/*
+ * ACPI calls this when it finds an entry for a legacy ISA IRQ override.
+ */
+void iosapic_override_isa_irq(unsigned int isa_irq, unsigned int gsi,
+			      unsigned long polarity, unsigned long trigger)
+{
+	int vector, irq;
+	unsigned int dest = cpu_physical_id(smp_processor_id());
+	unsigned char dmode;
+
+	irq = vector = isa_irq_to_vector(isa_irq);
+	BUG_ON(bind_irq_vector(irq, vector, CPU_MASK_ALL));
+	dmode = choose_dmode();
+	register_intr(gsi, irq, dmode, polarity, trigger);
+
+	DBG("ISA: IRQ %u -> GSI %u (%s,%s) -> CPU %d (0x%04x) vector %d\n",
+	    isa_irq, gsi, trigger == IOSAPIC_EDGE ? "edge" : "level",
+	    polarity == IOSAPIC_POL_HIGH ? "high" : "low",
+	    cpu_logical_id(dest), dest, vector);
+
+	set_rte(gsi, irq, dest, 1);
+}
+
+void __init
+ia64_native_iosapic_pcat_compat_init(void)
+{
+	if (pcat_compat) {
+		/*
+		 * Disable the compatibility mode interrupts (8259 style),
+		 * needs IN/OUT support enabled.
+		 */
+		printk(KERN_INFO
+		       "%s: Disabling PC-AT compatible 8259 interrupts\n",
+		       __func__);
+		outb(0xff, 0xA1);
+		outb(0xff, 0x21);
+	}
+}
+
+void __init
+iosapic_system_init (int system_pcat_compat)
+{
+	int irq;
+
+	for (irq = 0; irq < NR_IRQS; ++irq) {
+		iosapic_intr_info[irq].low32 = IOSAPIC_MASK;
+		/* mark as unused */
+		INIT_LIST_HEAD(&iosapic_intr_info[irq].rtes);
+
+		iosapic_intr_info[irq].count = 0;
+	}
+
+	pcat_compat = system_pcat_compat;
+	if (pcat_compat)
+		iosapic_pcat_compat_init();
+}
+
+static inline int
+iosapic_alloc (void)
+{
+	int index;
+
+	for (index = 0; index < NR_IOSAPICS; index++)
+		if (!iosapic_lists[index].addr)
+			return index;
+
+	printk(KERN_WARNING "%s: failed to allocate iosapic\n", __func__);
+	return -1;
+}
+
+static inline void
+iosapic_free (int index)
+{
+	memset(&iosapic_lists[index], 0, sizeof(iosapic_lists[0]));
+}
+
+static inline int
+iosapic_check_gsi_range (unsigned int gsi_base, unsigned int ver)
+{
+	int index;
+	unsigned int gsi_end, base, end;
+
+	/* check gsi range */
+	gsi_end = gsi_base + ((ver >> 16) & 0xff);
+	for (index = 0; index < NR_IOSAPICS; index++) {
+		if (!iosapic_lists[index].addr)
+			continue;
+
+		base = iosapic_lists[index].gsi_base;
+		end  = base + iosapic_lists[index].num_rte - 1;
+
+		if (gsi_end < base || end < gsi_base)
+			continue; /* OK */
+
+		return -EBUSY;
+	}
+	return 0;
+}
+
+static int
+iosapic_delete_rte(unsigned int irq, unsigned int gsi)
+{
+	struct iosapic_rte_info *rte, *temp;
+
+	list_for_each_entry_safe(rte, temp, &iosapic_intr_info[irq].rtes,
+								rte_list) {
+		if (rte->iosapic->gsi_base + rte->rte_index == gsi) {
+			if (rte->refcnt)
+				return -EBUSY;
+
+			list_del(&rte->rte_list);
+			kfree(rte);
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+int iosapic_init(unsigned long phys_addr, unsigned int gsi_base)
+{
+	int num_rte, err, index;
+	unsigned int isa_irq, ver;
+	char __iomem *addr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&iosapic_lock, flags);
+	index = find_iosapic(gsi_base);
+	if (index >= 0) {
+		spin_unlock_irqrestore(&iosapic_lock, flags);
+		return -EBUSY;
+	}
+
+	addr = ioremap(phys_addr, 0);
+	if (addr == NULL) {
+		spin_unlock_irqrestore(&iosapic_lock, flags);
+		return -ENOMEM;
+	}
+	ver = iosapic_version(addr);
+	if ((err = iosapic_check_gsi_range(gsi_base, ver))) {
+		iounmap(addr);
+		spin_unlock_irqrestore(&iosapic_lock, flags);
+		return err;
+	}
+
+	/*
+	 * The MAX_REDIR register holds the highest input pin number
+	 * (starting from 0).  We add 1 so that we can use it for
+	 * number of pins (= RTEs)
+	 */
+	num_rte = ((ver >> 16) & 0xff) + 1;
+
+	index = iosapic_alloc();
+	iosapic_lists[index].addr = addr;
+	iosapic_lists[index].gsi_base = gsi_base;
+	iosapic_lists[index].num_rte = num_rte;
+#ifdef CONFIG_NUMA
+	iosapic_lists[index].node = MAX_NUMNODES;
+#endif
+	spin_lock_init(&iosapic_lists[index].lock);
+	spin_unlock_irqrestore(&iosapic_lock, flags);
+
+	if ((gsi_base == 0) && pcat_compat) {
+		/*
+		 * Map the legacy ISA devices into the IOSAPIC data.  Some of
+		 * these may get reprogrammed later on with data from the ACPI
+		 * Interrupt Source Override table.
+		 */
+		for (isa_irq = 0; isa_irq < 16; ++isa_irq)
+			iosapic_override_isa_irq(isa_irq, isa_irq,
+						 IOSAPIC_POL_HIGH,
+						 IOSAPIC_EDGE);
+	}
+	return 0;
+}
+
+int iosapic_remove(unsigned int gsi_base)
+{
+	int i, irq, index, err = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&iosapic_lock, flags);
+	index = find_iosapic(gsi_base);
+	if (index < 0) {
+		printk(KERN_WARNING "%s: No IOSAPIC for GSI base %u\n",
+		       __func__, gsi_base);
+		goto out;
+	}
+
+	if (iosapic_lists[index].rtes_inuse) {
+		err = -EBUSY;
+		printk(KERN_WARNING "%s: IOSAPIC for GSI base %u is busy\n",
+		       __func__, gsi_base);
+		goto out;
+	}
+
+	for (i = gsi_base; i < gsi_base + iosapic_lists[index].num_rte; i++) {
+		irq = __gsi_to_irq(i);
+		if (irq < 0)
+			continue;
+
+		err = iosapic_delete_rte(irq, i);
+		if (err)
+			goto out;
+	}
+
+	iounmap(iosapic_lists[index].addr);
+	iosapic_free(index);
+ out:
+	spin_unlock_irqrestore(&iosapic_lock, flags);
+	return err;
+}
+
+#ifdef CONFIG_NUMA
+void map_iosapic_to_node(unsigned int gsi_base, int node)
+{
+	int index;
+
+	index = find_iosapic(gsi_base);
+	if (index < 0) {
+		printk(KERN_WARNING "%s: No IOSAPIC for GSI %u\n",
+		       __func__, gsi_base);
+		return;
+	}
+	iosapic_lists[index].node = node;
+	return;
+}
+#endif