Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 2545 insertions, 0 deletions

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
new file mode 100644
index 0000000..9c1350e
--- /dev/null
+++ b/arch/i386/kernel/io_apic.c
@@ -0,0 +1,2545 @@
+/*
+ *	Intel IO-APIC support for multi-Pentium hosts.
+ *
+ *	Copyright (C) 1997, 1998, 1999, 2000 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
+ */
+
+#include <linux/mm.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/config.h>
+#include <linux/smp_lock.h>
+#include <linux/mc146818rtc.h>
+#include <linux/compiler.h>
+#include <linux/acpi.h>
+
+#include <linux/sysdev.h>
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/desc.h>
+#include <asm/timer.h>
+
+#include <mach_apic.h>
+
+#include "io_ports.h"
+
+int (*ioapic_renumber_irq)(int ioapic, int irq);
+atomic_t irq_mis_count;
+
+static DEFINE_SPINLOCK(ioapic_lock);
+
+/*
+ *	Is the SiS APIC rmw bug present ?
+ *	-1 = don't know, 0 = no, 1 = yes
+ */
+int sis_apic_bug = -1;
+
+/*
+ * # of IRQ routing registers
+ */
+int nr_ioapic_registers[MAX_IO_APICS];
+
+/*
+ * Rough estimation of how many shared IRQs there are, can
+ * be changed anytime.
+ */
+#define MAX_PLUS_SHARED_IRQS NR_IRQS
+#define PIN_MAP_SIZE (MAX_PLUS_SHARED_IRQS + NR_IRQS)
+
+/*
+ * This is performance-critical, we want to do it O(1)
+ *
+ * the indexing order of this array favors 1:1 mappings
+ * between pins and IRQs.
+ */
+
+static struct irq_pin_list {
+	int apic, pin, next;
+} irq_2_pin[PIN_MAP_SIZE];
+
+int vector_irq[NR_VECTORS] = { [0 ... NR_VECTORS - 1] = -1};
+#ifdef CONFIG_PCI_MSI
+#define vector_to_irq(vector) 	\
+	(platform_legacy_irq(vector) ? vector : vector_irq[vector])
+#else
+#define vector_to_irq(vector)	(vector)
+#endif
+
+/*
+ * 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 void add_pin_to_irq(unsigned int irq, int apic, int pin)
+{
+	static int first_free_entry = NR_IRQS;
+	struct irq_pin_list *entry = irq_2_pin + irq;
+
+	while (entry->next)
+		entry = irq_2_pin + entry->next;
+
+	if (entry->pin != -1) {
+		entry->next = first_free_entry;
+		entry = irq_2_pin + entry->next;
+		if (++first_free_entry >= PIN_MAP_SIZE)
+			panic("io_apic.c: whoops");
+	}
+	entry->apic = apic;
+	entry->pin = pin;
+}
+
+/*
+ * Reroute an IRQ to a different pin.
+ */
+static void __init replace_pin_at_irq(unsigned int irq,
+				      int oldapic, int oldpin,
+				      int newapic, int newpin)
+{
+	struct irq_pin_list *entry = irq_2_pin + irq;
+
+	while (1) {
+		if (entry->apic == oldapic && entry->pin == oldpin) {
+			entry->apic = newapic;
+			entry->pin = newpin;
+		}
+		if (!entry->next)
+			break;
+		entry = irq_2_pin + entry->next;
+	}
+}
+
+static void __modify_IO_APIC_irq (unsigned int irq, unsigned long enable, unsigned long disable)
+{
+	struct irq_pin_list *entry = irq_2_pin + irq;
+	unsigned int pin, reg;
+
+	for (;;) {
+		pin = entry->pin;
+		if (pin == -1)
+			break;
+		reg = io_apic_read(entry->apic, 0x10 + pin*2);
+		reg &= ~disable;
+		reg |= enable;
+		io_apic_modify(entry->apic, 0x10 + pin*2, reg);
+		if (!entry->next)
+			break;
+		entry = irq_2_pin + entry->next;
+	}
+}
+
+/* mask = 1 */
+static void __mask_IO_APIC_irq (unsigned int irq)
+{
+	__modify_IO_APIC_irq(irq, 0x00010000, 0);
+}
+
+/* mask = 0 */
+static void __unmask_IO_APIC_irq (unsigned int irq)
+{
+	__modify_IO_APIC_irq(irq, 0, 0x00010000);
+}
+
+/* mask = 1, trigger = 0 */
+static void __mask_and_edge_IO_APIC_irq (unsigned int irq)
+{
+	__modify_IO_APIC_irq(irq, 0x00010000, 0x00008000);
+}
+
+/* mask = 0, trigger = 1 */
+static void __unmask_and_level_IO_APIC_irq (unsigned int irq)
+{
+	__modify_IO_APIC_irq(irq, 0x00008000, 0x00010000);
+}
+
+static void mask_IO_APIC_irq (unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	__mask_IO_APIC_irq(irq);
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+static void unmask_IO_APIC_irq (unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	__unmask_IO_APIC_irq(irq);
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
+{
+	struct IO_APIC_route_entry entry;
+	unsigned long flags;
+	
+	/* Check delivery_mode to be sure we're not clearing an SMI pin */
+	spin_lock_irqsave(&ioapic_lock, flags);
+	*(((int*)&entry) + 0) = io_apic_read(apic, 0x10 + 2 * pin);
+	*(((int*)&entry) + 1) = io_apic_read(apic, 0x11 + 2 * pin);
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+	if (entry.delivery_mode == dest_SMI)
+		return;
+
+	/*
+	 * Disable it in the IO-APIC irq-routing table:
+	 */
+	memset(&entry, 0, sizeof(entry));
+	entry.mask = 1;
+	spin_lock_irqsave(&ioapic_lock, flags);
+	io_apic_write(apic, 0x10 + 2 * pin, *(((int *)&entry) + 0));
+	io_apic_write(apic, 0x11 + 2 * pin, *(((int *)&entry) + 1));
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+static void clear_IO_APIC (void)
+{
+	int apic, pin;
+
+	for (apic = 0; apic < nr_ioapics; apic++)
+		for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
+			clear_IO_APIC_pin(apic, pin);
+}
+
+static void set_ioapic_affinity_irq(unsigned int irq, cpumask_t cpumask)
+{
+	unsigned long flags;
+	int pin;
+	struct irq_pin_list *entry = irq_2_pin + irq;
+	unsigned int apicid_value;
+	
+	apicid_value = cpu_mask_to_apicid(cpumask);
+	/* Prepare to do the io_apic_write */
+	apicid_value = apicid_value << 24;
+	spin_lock_irqsave(&ioapic_lock, flags);
+	for (;;) {
+		pin = entry->pin;
+		if (pin == -1)
+			break;
+		io_apic_write(entry->apic, 0x10 + 1 + pin*2, apicid_value);
+		if (!entry->next)
+			break;
+		entry = irq_2_pin + entry->next;
+	}
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+#if defined(CONFIG_IRQBALANCE)
+# include <asm/processor.h>	/* kernel_thread() */
+# include <linux/kernel_stat.h>	/* kstat */
+# include <linux/slab.h>		/* kmalloc() */
+# include <linux/timer.h>	/* time_after() */
+ 
+# ifdef CONFIG_BALANCED_IRQ_DEBUG
+#  define TDprintk(x...) do { printk("<%ld:%s:%d>: ", jiffies, __FILE__, __LINE__); printk(x); } while (0)
+#  define Dprintk(x...) do { TDprintk(x); } while (0)
+# else
+#  define TDprintk(x...) 
+#  define Dprintk(x...) 
+# endif
+
+cpumask_t __cacheline_aligned pending_irq_balance_cpumask[NR_IRQS];
+
+#define IRQBALANCE_CHECK_ARCH -999
+static int irqbalance_disabled = IRQBALANCE_CHECK_ARCH;
+static int physical_balance = 0;
+
+static struct irq_cpu_info {
+	unsigned long * last_irq;
+	unsigned long * irq_delta;
+	unsigned long irq;
+} irq_cpu_data[NR_CPUS];
+
+#define CPU_IRQ(cpu)		(irq_cpu_data[cpu].irq)
+#define LAST_CPU_IRQ(cpu,irq)   (irq_cpu_data[cpu].last_irq[irq])
+#define IRQ_DELTA(cpu,irq) 	(irq_cpu_data[cpu].irq_delta[irq])
+
+#define IDLE_ENOUGH(cpu,now) \
+	(idle_cpu(cpu) && ((now) - per_cpu(irq_stat, (cpu)).idle_timestamp > 1))
+
+#define IRQ_ALLOWED(cpu, allowed_mask)	cpu_isset(cpu, allowed_mask)
+
+#define CPU_TO_PACKAGEINDEX(i) (first_cpu(cpu_sibling_map[i]))
+
+#define MAX_BALANCED_IRQ_INTERVAL	(5*HZ)
+#define MIN_BALANCED_IRQ_INTERVAL	(HZ/2)
+#define BALANCED_IRQ_MORE_DELTA		(HZ/10)
+#define BALANCED_IRQ_LESS_DELTA		(HZ)
+
+static long balanced_irq_interval = MAX_BALANCED_IRQ_INTERVAL;
+
+static unsigned long move(int curr_cpu, cpumask_t allowed_mask,
+			unsigned long now, int direction)
+{
+	int search_idle = 1;
+	int cpu = curr_cpu;
+
+	goto inside;
+
+	do {
+		if (unlikely(cpu == curr_cpu))
+			search_idle = 0;
+inside:
+		if (direction == 1) {
+			cpu++;
+			if (cpu >= NR_CPUS)
+				cpu = 0;
+		} else {
+			cpu--;
+			if (cpu == -1)
+				cpu = NR_CPUS-1;
+		}
+	} while (!cpu_online(cpu) || !IRQ_ALLOWED(cpu,allowed_mask) ||
+			(search_idle && !IDLE_ENOUGH(cpu,now)));
+
+	return cpu;
+}
+
+static inline void balance_irq(int cpu, int irq)
+{
+	unsigned long now = jiffies;
+	cpumask_t allowed_mask;
+	unsigned int new_cpu;
+		
+	if (irqbalance_disabled)
+		return; 
+
+	cpus_and(allowed_mask, cpu_online_map, irq_affinity[irq]);
+	new_cpu = move(cpu, allowed_mask, now, 1);
+	if (cpu != new_cpu) {
+		irq_desc_t *desc = irq_desc + irq;
+		unsigned long flags;
+
+		spin_lock_irqsave(&desc->lock, flags);
+		pending_irq_balance_cpumask[irq] = cpumask_of_cpu(new_cpu);
+		spin_unlock_irqrestore(&desc->lock, flags);
+	}
+}
+
+static inline void rotate_irqs_among_cpus(unsigned long useful_load_threshold)
+{
+	int i, j;
+	Dprintk("Rotating IRQs among CPUs.\n");
+	for (i = 0; i < NR_CPUS; i++) {
+		for (j = 0; cpu_online(i) && (j < NR_IRQS); j++) {
+			if (!irq_desc[j].action)
+				continue;
+			/* Is it a significant load ?  */
+			if (IRQ_DELTA(CPU_TO_PACKAGEINDEX(i),j) <
+						useful_load_threshold)
+				continue;
+			balance_irq(i, j);
+		}
+	}
+	balanced_irq_interval = max((long)MIN_BALANCED_IRQ_INTERVAL,
+		balanced_irq_interval - BALANCED_IRQ_LESS_DELTA);	
+	return;
+}
+
+static void do_irq_balance(void)
+{
+	int i, j;
+	unsigned long max_cpu_irq = 0, min_cpu_irq = (~0);
+	unsigned long move_this_load = 0;
+	int max_loaded = 0, min_loaded = 0;
+	int load;
+	unsigned long useful_load_threshold = balanced_irq_interval + 10;
+	int selected_irq;
+	int tmp_loaded, first_attempt = 1;
+	unsigned long tmp_cpu_irq;
+	unsigned long imbalance = 0;
+	cpumask_t allowed_mask, target_cpu_mask, tmp;
+
+	for (i = 0; i < NR_CPUS; i++) {
+		int package_index;
+		CPU_IRQ(i) = 0;
+		if (!cpu_online(i))
+			continue;
+		package_index = CPU_TO_PACKAGEINDEX(i);
+		for (j = 0; j < NR_IRQS; j++) {
+			unsigned long value_now, delta;
+			/* Is this an active IRQ? */
+			if (!irq_desc[j].action)
+				continue;
+			if ( package_index == i )
+				IRQ_DELTA(package_index,j) = 0;
+			/* Determine the total count per processor per IRQ */
+			value_now = (unsigned long) kstat_cpu(i).irqs[j];
+
+			/* Determine the activity per processor per IRQ */
+			delta = value_now - LAST_CPU_IRQ(i,j);
+
+			/* Update last_cpu_irq[][] for the next time */
+			LAST_CPU_IRQ(i,j) = value_now;
+
+			/* Ignore IRQs whose rate is less than the clock */
+			if (delta < useful_load_threshold)
+				continue;
+			/* update the load for the processor or package total */
+			IRQ_DELTA(package_index,j) += delta;
+
+			/* Keep track of the higher numbered sibling as well */
+			if (i != package_index)
+				CPU_IRQ(i) += delta;
+			/*
+			 * We have sibling A and sibling B in the package
+			 *
+			 * cpu_irq[A] = load for cpu A + load for cpu B
+			 * cpu_irq[B] = load for cpu B
+			 */
+			CPU_IRQ(package_index) += delta;
+		}
+	}
+	/* Find the least loaded processor package */
+	for (i = 0; i < NR_CPUS; i++) {
+		if (!cpu_online(i))
+			continue;
+		if (i != CPU_TO_PACKAGEINDEX(i))
+			continue;
+		if (min_cpu_irq > CPU_IRQ(i)) {
+			min_cpu_irq = CPU_IRQ(i);
+			min_loaded = i;
+		}
+	}
+	max_cpu_irq = ULONG_MAX;
+
+tryanothercpu:
+	/* Look for heaviest loaded processor.
+	 * We may come back to get the next heaviest loaded processor.
+	 * Skip processors with trivial loads.
+	 */
+	tmp_cpu_irq = 0;
+	tmp_loaded = -1;
+	for (i = 0; i < NR_CPUS; i++) {
+		if (!cpu_online(i))
+			continue;
+		if (i != CPU_TO_PACKAGEINDEX(i))
+			continue;
+		if (max_cpu_irq <= CPU_IRQ(i)) 
+			continue;
+		if (tmp_cpu_irq < CPU_IRQ(i)) {
+			tmp_cpu_irq = CPU_IRQ(i);
+			tmp_loaded = i;
+		}
+	}
+
+	if (tmp_loaded == -1) {
+ 	 /* In the case of small number of heavy interrupt sources, 
+	  * loading some of the cpus too much. We use Ingo's original 
+	  * approach to rotate them around.
+	  */
+		if (!first_attempt && imbalance >= useful_load_threshold) {
+			rotate_irqs_among_cpus(useful_load_threshold);
+			return;
+		}
+		goto not_worth_the_effort;
+	}
+	
+	first_attempt = 0;		/* heaviest search */
+	max_cpu_irq = tmp_cpu_irq;	/* load */
+	max_loaded = tmp_loaded;	/* processor */
+	imbalance = (max_cpu_irq - min_cpu_irq) / 2;
+	
+	Dprintk("max_loaded cpu = %d\n", max_loaded);
+	Dprintk("min_loaded cpu = %d\n", min_loaded);
+	Dprintk("max_cpu_irq load = %ld\n", max_cpu_irq);
+	Dprintk("min_cpu_irq load = %ld\n", min_cpu_irq);
+	Dprintk("load imbalance = %lu\n", imbalance);
+
+	/* if imbalance is less than approx 10% of max load, then
+	 * observe diminishing returns action. - quit
+	 */
+	if (imbalance < (max_cpu_irq >> 3)) {
+		Dprintk("Imbalance too trivial\n");
+		goto not_worth_the_effort;
+	}
+
+tryanotherirq:
+	/* if we select an IRQ to move that can't go where we want, then
+	 * see if there is another one to try.
+	 */
+	move_this_load = 0;
+	selected_irq = -1;
+	for (j = 0; j < NR_IRQS; j++) {
+		/* Is this an active IRQ? */
+		if (!irq_desc[j].action)
+			continue;
+		if (imbalance <= IRQ_DELTA(max_loaded,j))
+			continue;
+		/* Try to find the IRQ that is closest to the imbalance
+		 * without going over.
+		 */
+		if (move_this_load < IRQ_DELTA(max_loaded,j)) {
+			move_this_load = IRQ_DELTA(max_loaded,j);
+			selected_irq = j;
+		}
+	}
+	if (selected_irq == -1) {
+		goto tryanothercpu;
+	}
+
+	imbalance = move_this_load;
+	
+	/* For physical_balance case, we accumlated both load
+	 * values in the one of the siblings cpu_irq[],
+	 * to use the same code for physical and logical processors
+	 * as much as possible. 
+	 *
+	 * NOTE: the cpu_irq[] array holds the sum of the load for
+	 * sibling A and sibling B in the slot for the lowest numbered
+	 * sibling (A), _AND_ the load for sibling B in the slot for
+	 * the higher numbered sibling.
+	 *
+	 * We seek the least loaded sibling by making the comparison
+	 * (A+B)/2 vs B
+	 */
+	load = CPU_IRQ(min_loaded) >> 1;
+	for_each_cpu_mask(j, cpu_sibling_map[min_loaded]) {
+		if (load > CPU_IRQ(j)) {
+			/* This won't change cpu_sibling_map[min_loaded] */
+			load = CPU_IRQ(j);
+			min_loaded = j;
+		}
+	}
+
+	cpus_and(allowed_mask, cpu_online_map, irq_affinity[selected_irq]);
+	target_cpu_mask = cpumask_of_cpu(min_loaded);
+	cpus_and(tmp, target_cpu_mask, allowed_mask);
+
+	if (!cpus_empty(tmp)) {
+		irq_desc_t *desc = irq_desc + selected_irq;
+		unsigned long flags;
+
+		Dprintk("irq = %d moved to cpu = %d\n",
+				selected_irq, min_loaded);
+		/* mark for change destination */
+		spin_lock_irqsave(&desc->lock, flags);
+		pending_irq_balance_cpumask[selected_irq] =
+					cpumask_of_cpu(min_loaded);
+		spin_unlock_irqrestore(&desc->lock, flags);
+		/* Since we made a change, come back sooner to 
+		 * check for more variation.
+		 */
+		balanced_irq_interval = max((long)MIN_BALANCED_IRQ_INTERVAL,
+			balanced_irq_interval - BALANCED_IRQ_LESS_DELTA);	
+		return;
+	}
+	goto tryanotherirq;
+
+not_worth_the_effort:
+	/*
+	 * if we did not find an IRQ to move, then adjust the time interval
+	 * upward
+	 */
+	balanced_irq_interval = min((long)MAX_BALANCED_IRQ_INTERVAL,
+		balanced_irq_interval + BALANCED_IRQ_MORE_DELTA);	
+	Dprintk("IRQ worth rotating not found\n");
+	return;
+}
+
+static int balanced_irq(void *unused)
+{
+	int i;
+	unsigned long prev_balance_time = jiffies;
+	long time_remaining = balanced_irq_interval;
+
+	daemonize("kirqd");
+	
+	/* push everything to CPU 0 to give us a starting point.  */
+	for (i = 0 ; i < NR_IRQS ; i++) {
+		pending_irq_balance_cpumask[i] = cpumask_of_cpu(0);
+	}
+
+	for ( ; ; ) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		time_remaining = schedule_timeout(time_remaining);
+		try_to_freeze(PF_FREEZE);
+		if (time_after(jiffies,
+				prev_balance_time+balanced_irq_interval)) {
+			do_irq_balance();
+			prev_balance_time = jiffies;
+			time_remaining = balanced_irq_interval;
+		}
+	}
+	return 0;
+}
+
+static int __init balanced_irq_init(void)
+{
+	int i;
+	struct cpuinfo_x86 *c;
+	cpumask_t tmp;
+
+	cpus_shift_right(tmp, cpu_online_map, 2);
+        c = &boot_cpu_data;
+	/* When not overwritten by the command line ask subarchitecture. */
+	if (irqbalance_disabled == IRQBALANCE_CHECK_ARCH)
+		irqbalance_disabled = NO_BALANCE_IRQ;
+	if (irqbalance_disabled)
+		return 0;
+	
+	 /* disable irqbalance completely if there is only one processor online */
+	if (num_online_cpus() < 2) {
+		irqbalance_disabled = 1;
+		return 0;
+	}
+	/*
+	 * Enable physical balance only if more than 1 physical processor
+	 * is present
+	 */
+	if (smp_num_siblings > 1 && !cpus_empty(tmp))
+		physical_balance = 1;
+
+	for (i = 0; i < NR_CPUS; i++) {
+		if (!cpu_online(i))
+			continue;
+		irq_cpu_data[i].irq_delta = kmalloc(sizeof(unsigned long) * NR_IRQS, GFP_KERNEL);
+		irq_cpu_data[i].last_irq = kmalloc(sizeof(unsigned long) * NR_IRQS, GFP_KERNEL);
+		if (irq_cpu_data[i].irq_delta == NULL || irq_cpu_data[i].last_irq == NULL) {
+			printk(KERN_ERR "balanced_irq_init: out of memory");
+			goto failed;
+		}
+		memset(irq_cpu_data[i].irq_delta,0,sizeof(unsigned long) * NR_IRQS);
+		memset(irq_cpu_data[i].last_irq,0,sizeof(unsigned long) * NR_IRQS);
+	}
+	
+	printk(KERN_INFO "Starting balanced_irq\n");
+	if (kernel_thread(balanced_irq, NULL, CLONE_KERNEL) >= 0) 
+		return 0;
+	else 
+		printk(KERN_ERR "balanced_irq_init: failed to spawn balanced_irq");
+failed:
+	for (i = 0; i < NR_CPUS; i++) {
+		if(irq_cpu_data[i].irq_delta)
+			kfree(irq_cpu_data[i].irq_delta);
+		if(irq_cpu_data[i].last_irq)
+			kfree(irq_cpu_data[i].last_irq);
+	}
+	return 0;
+}
+
+int __init irqbalance_disable(char *str)
+{
+	irqbalance_disabled = 1;
+	return 0;
+}
+
+__setup("noirqbalance", irqbalance_disable);
+
+static inline void move_irq(int irq)
+{
+	/* note - we hold the desc->lock */
+	if (unlikely(!cpus_empty(pending_irq_balance_cpumask[irq]))) {
+		set_ioapic_affinity_irq(irq, pending_irq_balance_cpumask[irq]);
+		cpus_clear(pending_irq_balance_cpumask[irq]);
+	}
+}
+
+late_initcall(balanced_irq_init);
+
+#else /* !CONFIG_IRQBALANCE */
+static inline void move_irq(int irq) { }
+#endif /* CONFIG_IRQBALANCE */
+
+#ifndef CONFIG_SMP
+void fastcall send_IPI_self(int vector)
+{
+	unsigned int cfg;
+
+	/*
+	 * Wait for idle.
+	 */
+	apic_wait_icr_idle();
+	cfg = APIC_DM_FIXED | APIC_DEST_SELF | vector | APIC_DEST_LOGICAL;
+	/*
+	 * Send the IPI. The write to APIC_ICR fires this off.
+	 */
+	apic_write_around(APIC_ICR, cfg);
+}
+#endif /* !CONFIG_SMP */
+
+
+/*
+ * 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];
+static int pirqs_enabled;
+int skip_ioapic_setup;
+
+static int __init ioapic_setup(char *str)
+{
+	skip_ioapic_setup = 1;
+	return 1;
+}
+
+__setup("noapic", ioapic_setup);
+
+static int __init ioapic_pirq_setup(char *str)
+{
+	int i, max;
+	int ints[MAX_PIRQS+1];
+
+	get_options(str, ARRAY_SIZE(ints), ints);
+
+	for (i = 0; i < MAX_PIRQS; i++)
+		pirq_entries[i] = -1;
+
+	pirqs_enabled = 1;
+	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);
+
+/*
+ * Find the IRQ entry number of a certain pin.
+ */
+static int find_irq_entry(int apic, int pin, int type)
+{
+	int i;
+
+	for (i = 0; i < mp_irq_entries; i++)
+		if (mp_irqs[i].mpc_irqtype == type &&
+		    (mp_irqs[i].mpc_dstapic == mp_ioapics[apic].mpc_apicid ||
+		     mp_irqs[i].mpc_dstapic == MP_APIC_ALL) &&
+		    mp_irqs[i].mpc_dstirq == pin)
+			return i;
+
+	return -1;
+}
+
+/*
+ * Find the pin to which IRQ[irq] (ISA) is connected
+ */
+static int find_isa_irq_pin(int irq, int type)
+{
+	int i;
+
+	for (i = 0; i < mp_irq_entries; i++) {
+		int lbus = mp_irqs[i].mpc_srcbus;
+
+		if ((mp_bus_id_to_type[lbus] == MP_BUS_ISA ||
+		     mp_bus_id_to_type[lbus] == MP_BUS_EISA ||
+		     mp_bus_id_to_type[lbus] == MP_BUS_MCA ||
+		     mp_bus_id_to_type[lbus] == MP_BUS_NEC98
+		    ) &&
+		    (mp_irqs[i].mpc_irqtype == type) &&
+		    (mp_irqs[i].mpc_srcbusirq == irq))
+
+			return mp_irqs[i].mpc_dstirq;
+	}
+	return -1;
+}
+
+/*
+ * Find a specific PCI IRQ entry.
+ * Not an __init, possibly needed by modules
+ */
+static int pin_2_irq(int idx, int apic, int pin);
+
+int IO_APIC_get_PCI_irq_vector(int bus, int slot, int pin)
+{
+	int apic, i, best_guess = -1;
+
+	apic_printk(APIC_DEBUG, "querying PCI -> IRQ mapping bus:%d, "
+		"slot:%d, pin:%d.\n", bus, slot, pin);
+	if (mp_bus_id_to_pci_bus[bus] == -1) {
+		printk(KERN_WARNING "PCI BIOS passed nonexistent PCI bus %d!\n", bus);
+		return -1;
+	}
+	for (i = 0; i < mp_irq_entries; i++) {
+		int lbus = mp_irqs[i].mpc_srcbus;
+
+		for (apic = 0; apic < nr_ioapics; apic++)
+			if (mp_ioapics[apic].mpc_apicid == mp_irqs[i].mpc_dstapic ||
+			    mp_irqs[i].mpc_dstapic == MP_APIC_ALL)
+				break;
+
+		if ((mp_bus_id_to_type[lbus] == MP_BUS_PCI) &&
+		    !mp_irqs[i].mpc_irqtype &&
+		    (bus == lbus) &&
+		    (slot == ((mp_irqs[i].mpc_srcbusirq >> 2) & 0x1f))) {
+			int irq = pin_2_irq(i,apic,mp_irqs[i].mpc_dstirq);
+
+			if (!(apic || IO_APIC_IRQ(irq)))
+				continue;
+
+			if (pin == (mp_irqs[i].mpc_srcbusirq & 3))
+				return irq;
+			/*
+			 * Use the first all-but-pin matching entry as a
+			 * best-guess fuzzy result for broken mptables.
+			 */
+			if (best_guess < 0)
+				best_guess = irq;
+		}
+	}
+	return best_guess;
+}
+
+/*
+ * This function currently is only a helper for the i386 smp boot process where 
+ * we need to reprogram the ioredtbls to cater for the cpus which have come online
+ * so mask in all cases should simply be TARGET_CPUS
+ */
+void __init setup_ioapic_dest(void)
+{
+	int pin, ioapic, irq, irq_entry;
+
+	if (skip_ioapic_setup == 1)
+		return;
+
+	for (ioapic = 0; ioapic < nr_ioapics; ioapic++) {
+		for (pin = 0; pin < nr_ioapic_registers[ioapic]; pin++) {
+			irq_entry = find_irq_entry(ioapic, pin, mp_INT);
+			if (irq_entry == -1)
+				continue;
+			irq = pin_2_irq(irq_entry, ioapic, pin);
+			set_ioapic_affinity_irq(irq, TARGET_CPUS);
+		}
+
+	}
+}
+
+/*
+ * EISA Edge/Level control register, ELCR
+ */
+static int EISA_ELCR(unsigned int irq)
+{
+	if (irq < 16) {
+		unsigned int port = 0x4d0 + (irq >> 3);
+		return (inb(port) >> (irq & 7)) & 1;
+	}
+	apic_printk(APIC_VERBOSE, KERN_INFO
+			"Broken MPtable reports ISA irq %d\n", irq);
+	return 0;
+}
+
+/* EISA interrupts are always polarity zero and can be edge or level
+ * trigger 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 */
+
+#define default_EISA_trigger(idx)	(EISA_ELCR(mp_irqs[idx].mpc_srcbusirq))
+#define default_EISA_polarity(idx)	(0)
+
+/* ISA interrupts are always polarity zero edge triggered,
+ * when listed as conforming in the MP table. */
+
+#define default_ISA_trigger(idx)	(0)
+#define default_ISA_polarity(idx)	(0)
+
+/* PCI interrupts are always polarity one level triggered,
+ * when listed as conforming in the MP table. */
+
+#define default_PCI_trigger(idx)	(1)
+#define default_PCI_polarity(idx)	(1)
+
+/* MCA interrupts are always polarity zero level triggered,
+ * when listed as conforming in the MP table. */
+
+#define default_MCA_trigger(idx)	(1)
+#define default_MCA_polarity(idx)	(0)
+
+/* NEC98 interrupts are always polarity zero edge triggered,
+ * when listed as conforming in the MP table. */
+
+#define default_NEC98_trigger(idx)     (0)
+#define default_NEC98_polarity(idx)    (0)
+
+static int __init MPBIOS_polarity(int idx)
+{
+	int bus = mp_irqs[idx].mpc_srcbus;
+	int polarity;
+
+	/*
+	 * Determine IRQ line polarity (high active or low active):
+	 */
+	switch (mp_irqs[idx].mpc_irqflag & 3)
+	{
+		case 0: /* conforms, ie. bus-type dependent polarity */
+		{
+			switch (mp_bus_id_to_type[bus])
+			{
+				case MP_BUS_ISA: /* ISA pin */
+				{
+					polarity = default_ISA_polarity(idx);
+					break;
+				}
+				case MP_BUS_EISA: /* EISA pin */
+				{
+					polarity = default_EISA_polarity(idx);
+					break;
+				}
+				case MP_BUS_PCI: /* PCI pin */
+				{
+					polarity = default_PCI_polarity(idx);
+					break;
+				}
+				case MP_BUS_MCA: /* MCA pin */
+				{
+					polarity = default_MCA_polarity(idx);
+					break;
+				}
+				case MP_BUS_NEC98: /* NEC 98 pin */
+				{
+					polarity = default_NEC98_polarity(idx);
+					break;
+				}
+				default:
+				{
+					printk(KERN_WARNING "broken BIOS!!\n");
+					polarity = 1;
+					break;
+				}
+			}
+			break;
+		}
+		case 1: /* high active */
+		{
+			polarity = 0;
+			break;
+		}
+		case 2: /* reserved */
+		{
+			printk(KERN_WARNING "broken BIOS!!\n");
+			polarity = 1;
+			break;
+		}
+		case 3: /* low active */
+		{
+			polarity = 1;
+			break;
+		}
+		default: /* invalid */
+		{
+			printk(KERN_WARNING "broken BIOS!!\n");
+			polarity = 1;
+			break;
+		}
+	}
+	return polarity;
+}
+
+static int MPBIOS_trigger(int idx)
+{
+	int bus = mp_irqs[idx].mpc_srcbus;
+	int trigger;
+
+	/*
+	 * Determine IRQ trigger mode (edge or level sensitive):
+	 */
+	switch ((mp_irqs[idx].mpc_irqflag>>2) & 3)
+	{
+		case 0: /* conforms, ie. bus-type dependent */
+		{
+			switch (mp_bus_id_to_type[bus])
+			{
+				case MP_BUS_ISA: /* ISA pin */
+				{
+					trigger = default_ISA_trigger(idx);
+					break;
+				}
+				case MP_BUS_EISA: /* EISA pin */
+				{
+					trigger = default_EISA_trigger(idx);
+					break;
+				}
+				case MP_BUS_PCI: /* PCI pin */
+				{
+					trigger = default_PCI_trigger(idx);
+					break;
+				}
+				case MP_BUS_MCA: /* MCA pin */
+				{
+					trigger = default_MCA_trigger(idx);
+					break;
+				}
+				case MP_BUS_NEC98: /* NEC 98 pin */
+				{
+					trigger = default_NEC98_trigger(idx);
+					break;
+				}
+				default:
+				{
+					printk(KERN_WARNING "broken BIOS!!\n");
+					trigger = 1;
+					break;
+				}
+			}
+			break;
+		}
+		case 1: /* edge */
+		{
+			trigger = 0;
+			break;
+		}
+		case 2: /* reserved */
+		{
+			printk(KERN_WARNING "broken BIOS!!\n");
+			trigger = 1;
+			break;
+		}
+		case 3: /* level */
+		{
+			trigger = 1;
+			break;
+		}
+		default: /* invalid */
+		{
+			printk(KERN_WARNING "broken BIOS!!\n");
+			trigger = 0;
+			break;
+		}
+	}
+	return trigger;
+}
+
+static inline int irq_polarity(int idx)
+{
+	return MPBIOS_polarity(idx);
+}
+
+static inline int irq_trigger(int idx)
+{
+	return MPBIOS_trigger(idx);
+}
+
+static int pin_2_irq(int idx, int apic, int pin)
+{
+	int irq, i;
+	int bus = mp_irqs[idx].mpc_srcbus;
+
+	/*
+	 * Debugging check, we are in big trouble if this message pops up!
+	 */
+	if (mp_irqs[idx].mpc_dstirq != pin)
+		printk(KERN_ERR "broken BIOS or MPTABLE parser, ayiee!!\n");
+
+	switch (mp_bus_id_to_type[bus])
+	{
+		case MP_BUS_ISA: /* ISA pin */
+		case MP_BUS_EISA:
+		case MP_BUS_MCA:
+		case MP_BUS_NEC98:
+		{
+			irq = mp_irqs[idx].mpc_srcbusirq;
+			break;
+		}
+		case MP_BUS_PCI: /* PCI pin */
+		{
+			/*
+			 * PCI IRQs are mapped in order
+			 */
+			i = irq = 0;
+			while (i < apic)
+				irq += nr_ioapic_registers[i++];
+			irq += pin;
+
+			/*
+			 * For MPS mode, so far only needed by ES7000 platform
+			 */
+			if (ioapic_renumber_irq)
+				irq = ioapic_renumber_irq(apic, irq);
+
+			break;
+		}
+		default:
+		{
+			printk(KERN_ERR "unknown bus type %d.\n",bus); 
+			irq = 0;
+			break;
+		}
+	}
+
+	/*
+	 * 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 {
+				irq = pirq_entries[pin-16];
+				apic_printk(APIC_VERBOSE, KERN_DEBUG
+						"using PIRQ%d -> IRQ %d\n",
+						pin-16, irq);
+			}
+		}
+	}
+	return irq;
+}
+
+static inline int IO_APIC_irq_trigger(int irq)
+{
+	int apic, idx, pin;
+
+	for (apic = 0; apic < nr_ioapics; apic++) {
+		for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
+			idx = find_irq_entry(apic,pin,mp_INT);
+			if ((idx != -1) && (irq == pin_2_irq(idx,apic,pin)))
+				return irq_trigger(idx);
+		}
+	}
+	/*
+	 * nonexistent IRQs are edge default
+	 */
+	return 0;
+}
+
+/* irq_vectors is indexed by the sum of all RTEs in all I/O APICs. */
+u8 irq_vector[NR_IRQ_VECTORS] = { FIRST_DEVICE_VECTOR , 0 };
+
+int assign_irq_vector(int irq)
+{
+	static int current_vector = FIRST_DEVICE_VECTOR, offset = 0;
+
+	BUG_ON(irq >= NR_IRQ_VECTORS);
+	if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0)
+		return IO_APIC_VECTOR(irq);
+next:
+	current_vector += 8;
+	if (current_vector == SYSCALL_VECTOR)
+		goto next;
+
+	if (current_vector >= FIRST_SYSTEM_VECTOR) {
+		offset++;
+		if (!(offset%8))
+			return -ENOSPC;
+		current_vector = FIRST_DEVICE_VECTOR + offset;
+	}
+
+	vector_irq[current_vector] = irq;
+	if (irq != AUTO_ASSIGN)
+		IO_APIC_VECTOR(irq) = current_vector;
+
+	return current_vector;
+}
+
+static struct hw_interrupt_type ioapic_level_type;
+static struct hw_interrupt_type ioapic_edge_type;
+
+#define IOAPIC_AUTO	-1
+#define IOAPIC_EDGE	0
+#define IOAPIC_LEVEL	1
+
+static inline void ioapic_register_intr(int irq, int vector, unsigned long trigger)
+{
+	if (use_pci_vector() && !platform_legacy_irq(irq)) {
+		if ((trigger == IOAPIC_AUTO && IO_APIC_irq_trigger(irq)) ||
+				trigger == IOAPIC_LEVEL)
+			irq_desc[vector].handler = &ioapic_level_type;
+		else
+			irq_desc[vector].handler = &ioapic_edge_type;
+		set_intr_gate(vector, interrupt[vector]);
+	} else	{
+		if ((trigger == IOAPIC_AUTO && IO_APIC_irq_trigger(irq)) ||
+				trigger == IOAPIC_LEVEL)
+			irq_desc[irq].handler = &ioapic_level_type;
+		else
+			irq_desc[irq].handler = &ioapic_edge_type;
+		set_intr_gate(vector, interrupt[irq]);
+	}
+}
+
+static void __init setup_IO_APIC_irqs(void)
+{
+	struct IO_APIC_route_entry entry;
+	int apic, pin, idx, irq, first_notcon = 1, vector;
+	unsigned long flags;
+
+	apic_printk(APIC_VERBOSE, KERN_DEBUG "init IO_APIC IRQs\n");
+
+	for (apic = 0; apic < nr_ioapics; apic++) {
+	for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
+
+		/*
+		 * add it to the IO-APIC irq-routing table:
+		 */
+		memset(&entry,0,sizeof(entry));
+
+		entry.delivery_mode = INT_DELIVERY_MODE;
+		entry.dest_mode = INT_DEST_MODE;
+		entry.mask = 0;				/* enable IRQ */
+		entry.dest.logical.logical_dest = 
+					cpu_mask_to_apicid(TARGET_CPUS);
+
+		idx = find_irq_entry(apic,pin,mp_INT);
+		if (idx == -1) {
+			if (first_notcon) {
+				apic_printk(APIC_VERBOSE, KERN_DEBUG
+						" IO-APIC (apicid-pin) %d-%d",
+						mp_ioapics[apic].mpc_apicid,
+						pin);
+				first_notcon = 0;
+			} else
+				apic_printk(APIC_VERBOSE, ", %d-%d",
+					mp_ioapics[apic].mpc_apicid, pin);
+			continue;
+		}
+
+		entry.trigger = irq_trigger(idx);
+		entry.polarity = irq_polarity(idx);
+
+		if (irq_trigger(idx)) {
+			entry.trigger = 1;
+			entry.mask = 1;
+		}
+
+		irq = pin_2_irq(idx, apic, pin);
+		/*
+		 * skip adding the timer int on secondary nodes, which causes
+		 * a small but painful rift in the time-space continuum
+		 */
+		if (multi_timer_check(apic, irq))
+			continue;
+		else
+			add_pin_to_irq(irq, apic, pin);
+
+		if (!apic && !IO_APIC_IRQ(irq))
+			continue;
+
+		if (IO_APIC_IRQ(irq)) {
+			vector = assign_irq_vector(irq);
+			entry.vector = vector;
+			ioapic_register_intr(irq, vector, IOAPIC_AUTO);
+		
+			if (!apic && (irq < 16))
+				disable_8259A_irq(irq);
+		}
+		spin_lock_irqsave(&ioapic_lock, flags);
+		io_apic_write(apic, 0x11+2*pin, *(((int *)&entry)+1));
+		io_apic_write(apic, 0x10+2*pin, *(((int *)&entry)+0));
+		spin_unlock_irqrestore(&ioapic_lock, flags);
+	}
+	}
+
+	if (!first_notcon)
+		apic_printk(APIC_VERBOSE, " not connected.\n");
+}
+
+/*
+ * Set up the 8259A-master output pin:
+ */
+static void __init setup_ExtINT_IRQ0_pin(unsigned int pin, int vector)
+{
+	struct IO_APIC_route_entry entry;
+	unsigned long flags;
+
+	memset(&entry,0,sizeof(entry));
+
+	disable_8259A_irq(0);
+
+	/* mask LVT0 */
+	apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
+
+	/*
+	 * We use logical delivery to get the timer IRQ
+	 * to the first CPU.
+	 */
+	entry.dest_mode = INT_DEST_MODE;
+	entry.mask = 0;					/* unmask IRQ now */
+	entry.dest.logical.logical_dest = cpu_mask_to_apicid(TARGET_CPUS);
+	entry.delivery_mode = INT_DELIVERY_MODE;
+	entry.polarity = 0;
+	entry.trigger = 0;
+	entry.vector = vector;
+
+	/*
+	 * The timer IRQ doesn't have to know that behind the
+	 * scene we have a 8259A-master in AEOI mode ...
+	 */
+	irq_desc[0].handler = &ioapic_edge_type;
+
+	/*
+	 * Add it to the IO-APIC irq-routing table:
+	 */
+	spin_lock_irqsave(&ioapic_lock, flags);
+	io_apic_write(0, 0x11+2*pin, *(((int *)&entry)+1));
+	io_apic_write(0, 0x10+2*pin, *(((int *)&entry)+0));
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	enable_8259A_irq(0);
+}
+
+static inline void UNEXPECTED_IO_APIC(void)
+{
+}
+
+void __init print_IO_APIC(void)
+{
+	int apic, i;
+	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;
+
+	if (apic_verbosity == APIC_QUIET)
+		return;
+
+ 	printk(KERN_DEBUG "number of MP IRQ sources: %d.\n", mp_irq_entries);
+	for (i = 0; i < nr_ioapics; i++)
+		printk(KERN_DEBUG "number of IO-APIC #%d registers: %d.\n",
+		       mp_ioapics[i].mpc_apicid, nr_ioapic_registers[i]);
+
+	/*
+	 * 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 (apic = 0; apic < nr_ioapics; apic++) {
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	reg_00.raw = io_apic_read(apic, 0);
+	reg_01.raw = io_apic_read(apic, 1);
+	if (reg_01.bits.version >= 0x10)
+		reg_02.raw = io_apic_read(apic, 2);
+	if (reg_01.bits.version >= 0x20)
+		reg_03.raw = io_apic_read(apic, 3);
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	printk(KERN_DEBUG "IO APIC #%d......\n", mp_ioapics[apic].mpc_apicid);
+	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);
+	if (reg_00.bits.ID >= get_physical_broadcast())
+		UNEXPECTED_IO_APIC();
+	if (reg_00.bits.__reserved_1 || reg_00.bits.__reserved_2)
+		UNEXPECTED_IO_APIC();
+
+	printk(KERN_DEBUG ".... register #01: %08X\n", reg_01.raw);
+	printk(KERN_DEBUG ".......     : max redirection entries: %04X\n", reg_01.bits.entries);
+	if (	(reg_01.bits.entries != 0x0f) && /* older (Neptune) boards */
+		(reg_01.bits.entries != 0x17) && /* typical ISA+PCI boards */
+		(reg_01.bits.entries != 0x1b) && /* Compaq Proliant boards */
+		(reg_01.bits.entries != 0x1f) && /* dual Xeon boards */
+		(reg_01.bits.entries != 0x22) && /* bigger Xeon boards */
+		(reg_01.bits.entries != 0x2E) &&
+		(reg_01.bits.entries != 0x3F)
+	)
+		UNEXPECTED_IO_APIC();
+
+	printk(KERN_DEBUG ".......     : PRQ implemented: %X\n", reg_01.bits.PRQ);
+	printk(KERN_DEBUG ".......     : IO APIC version: %04X\n", reg_01.bits.version);
+	if (	(reg_01.bits.version != 0x01) && /* 82489DX IO-APICs */
+		(reg_01.bits.version != 0x10) && /* oldest IO-APICs */
+		(reg_01.bits.version != 0x11) && /* Pentium/Pro IO-APICs */
+		(reg_01.bits.version != 0x13) && /* Xeon IO-APICs */
+		(reg_01.bits.version != 0x20)    /* Intel P64H (82806 AA) */
+	)
+		UNEXPECTED_IO_APIC();
+	if (reg_01.bits.__reserved_1 || reg_01.bits.__reserved_2)
+		UNEXPECTED_IO_APIC();
+
+	/*
+	 * 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);
+		if (reg_02.bits.__reserved_1 || reg_02.bits.__reserved_2)
+			UNEXPECTED_IO_APIC();
+	}
+
+	/*
+	 * 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);
+		if (reg_03.bits.__reserved_1)
+			UNEXPECTED_IO_APIC();
+	}
+
+	printk(KERN_DEBUG ".... IRQ redirection table:\n");
+
+	printk(KERN_DEBUG " NR Log Phy Mask Trig IRR Pol"
+			  " Stat Dest Deli Vect:   \n");
+
+	for (i = 0; i <= reg_01.bits.entries; i++) {
+		struct IO_APIC_route_entry entry;
+
+		spin_lock_irqsave(&ioapic_lock, flags);
+		*(((int *)&entry)+0) = io_apic_read(apic, 0x10+i*2);
+		*(((int *)&entry)+1) = io_apic_read(apic, 0x11+i*2);
+		spin_unlock_irqrestore(&ioapic_lock, flags);
+
+		printk(KERN_DEBUG " %02x %03X %02X  ",
+			i,
+			entry.dest.logical.logical_dest,
+			entry.dest.physical.physical_dest
+		);
+
+		printk("%1d    %1d    %1d   %1d   %1d    %1d    %1d    %02X\n",
+			entry.mask,
+			entry.trigger,
+			entry.irr,
+			entry.polarity,
+			entry.delivery_status,
+			entry.dest_mode,
+			entry.delivery_mode,
+			entry.vector
+		);
+	}
+	}
+	if (use_pci_vector())
+		printk(KERN_INFO "Using vector-based indexing\n");
+	printk(KERN_DEBUG "IRQ to pin mappings:\n");
+	for (i = 0; i < NR_IRQS; i++) {
+		struct irq_pin_list *entry = irq_2_pin + i;
+		if (entry->pin < 0)
+			continue;
+ 		if (use_pci_vector() && !platform_legacy_irq(i))
+			printk(KERN_DEBUG "IRQ%d ", IO_APIC_VECTOR(i));
+		else
+			printk(KERN_DEBUG "IRQ%d ", i);
+		for (;;) {
+			printk("-> %d:%d", entry->apic, entry->pin);
+			if (!entry->next)
+				break;
+			entry = irq_2_pin + entry->next;
+		}
+		printk("\n");
+	}
+
+	printk(KERN_INFO ".................................... done.\n");
+
+	return;
+}
+
+#if 0
+
+static void print_APIC_bitfield (int base)
+{
+	unsigned int v;
+	int i, j;
+
+	if (apic_verbosity == APIC_QUIET)
+		return;
+
+	printk(KERN_DEBUG "0123456789abcdef0123456789abcdef\n" KERN_DEBUG);
+	for (i = 0; i < 8; i++) {
+		v = apic_read(base + i*0x10);
+		for (j = 0; j < 32; j++) {
+			if (v & (1<<j))
+				printk("1");
+			else
+				printk("0");
+		}
+		printk("\n");
+	}
+}
+
+void /*__init*/ print_local_APIC(void * dummy)
+{
+	unsigned int v, ver, maxlvt;
+
+	if (apic_verbosity == APIC_QUIET)
+		return;
+
+	printk("\n" KERN_DEBUG "printing local APIC contents on CPU#%d/%d:\n",
+		smp_processor_id(), hard_smp_processor_id());
+	v = apic_read(APIC_ID);
+	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v, GET_APIC_ID(v));
+	v = apic_read(APIC_LVR);
+	printk(KERN_INFO "... APIC VERSION: %08x\n", v);
+	ver = GET_APIC_VERSION(v);
+	maxlvt = get_maxlvt();
+
+	v = apic_read(APIC_TASKPRI);
+	printk(KERN_DEBUG "... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);
+
+	if (APIC_INTEGRATED(ver)) {			/* !82489DX */
+		v = apic_read(APIC_ARBPRI);
+		printk(KERN_DEBUG "... APIC ARBPRI: %08x (%02x)\n", v,
+			v & APIC_ARBPRI_MASK);
+		v = apic_read(APIC_PROCPRI);
+		printk(KERN_DEBUG "... APIC PROCPRI: %08x\n", v);
+	}
+
+	v = apic_read(APIC_EOI);
+	printk(KERN_DEBUG "... APIC EOI: %08x\n", v);
+	v = apic_read(APIC_RRR);
+	printk(KERN_DEBUG "... APIC RRR: %08x\n", v);
+	v = apic_read(APIC_LDR);
+	printk(KERN_DEBUG "... APIC LDR: %08x\n", v);
+	v = apic_read(APIC_DFR);
+	printk(KERN_DEBUG "... APIC DFR: %08x\n", v);
+	v = apic_read(APIC_SPIV);
+	printk(KERN_DEBUG "... APIC SPIV: %08x\n", v);
+
+	printk(KERN_DEBUG "... APIC ISR field:\n");
+	print_APIC_bitfield(APIC_ISR);
+	printk(KERN_DEBUG "... APIC TMR field:\n");
+	print_APIC_bitfield(APIC_TMR);
+	printk(KERN_DEBUG "... APIC IRR field:\n");
+	print_APIC_bitfield(APIC_IRR);
+
+	if (APIC_INTEGRATED(ver)) {		/* !82489DX */
+		if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
+			apic_write(APIC_ESR, 0);
+		v = apic_read(APIC_ESR);
+		printk(KERN_DEBUG "... APIC ESR: %08x\n", v);
+	}
+
+	v = apic_read(APIC_ICR);
+	printk(KERN_DEBUG "... APIC ICR: %08x\n", v);
+	v = apic_read(APIC_ICR2);
+	printk(KERN_DEBUG "... APIC ICR2: %08x\n", v);
+
+	v = apic_read(APIC_LVTT);
+	printk(KERN_DEBUG "... APIC LVTT: %08x\n", v);
+
+	if (maxlvt > 3) {                       /* PC is LVT#4. */
+		v = apic_read(APIC_LVTPC);
+		printk(KERN_DEBUG "... APIC LVTPC: %08x\n", v);
+	}
+	v = apic_read(APIC_LVT0);
+	printk(KERN_DEBUG "... APIC LVT0: %08x\n", v);
+	v = apic_read(APIC_LVT1);
+	printk(KERN_DEBUG "... APIC LVT1: %08x\n", v);
+
+	if (maxlvt > 2) {			/* ERR is LVT#3. */
+		v = apic_read(APIC_LVTERR);
+		printk(KERN_DEBUG "... APIC LVTERR: %08x\n", v);
+	}
+
+	v = apic_read(APIC_TMICT);
+	printk(KERN_DEBUG "... APIC TMICT: %08x\n", v);
+	v = apic_read(APIC_TMCCT);
+	printk(KERN_DEBUG "... APIC TMCCT: %08x\n", v);
+	v = apic_read(APIC_TDCR);
+	printk(KERN_DEBUG "... APIC TDCR: %08x\n", v);
+	printk("\n");
+}
+
+void print_all_local_APICs (void)
+{
+	on_each_cpu(print_local_APIC, NULL, 1, 1);
+}
+
+void /*__init*/ print_PIC(void)
+{
+	extern spinlock_t i8259A_lock;
+	unsigned int v;
+	unsigned long flags;
+
+	if (apic_verbosity == APIC_QUIET)
+		return;
+
+	printk(KERN_DEBUG "\nprinting PIC contents\n");
+
+	spin_lock_irqsave(&i8259A_lock, flags);
+
+	v = inb(0xa1) << 8 | inb(0x21);
+	printk(KERN_DEBUG "... PIC  IMR: %04x\n", v);
+
+	v = inb(0xa0) << 8 | inb(0x20);
+	printk(KERN_DEBUG "... PIC  IRR: %04x\n", v);
+
+	outb(0x0b,0xa0);
+	outb(0x0b,0x20);
+	v = inb(0xa0) << 8 | inb(0x20);
+	outb(0x0a,0xa0);
+	outb(0x0a,0x20);
+
+	spin_unlock_irqrestore(&i8259A_lock, flags);
+
+	printk(KERN_DEBUG "... PIC  ISR: %04x\n", v);
+
+	v = inb(0x4d1) << 8 | inb(0x4d0);
+	printk(KERN_DEBUG "... PIC ELCR: %04x\n", v);
+}
+
+#endif  /*  0  */
+
+static void __init enable_IO_APIC(void)
+{
+	union IO_APIC_reg_01 reg_01;
+	int i;
+	unsigned long flags;
+
+	for (i = 0; i < PIN_MAP_SIZE; i++) {
+		irq_2_pin[i].pin = -1;
+		irq_2_pin[i].next = 0;
+	}
+	if (!pirqs_enabled)
+		for (i = 0; i < MAX_PIRQS; i++)
+			pirq_entries[i] = -1;
+
+	/*
+	 * The number of IO-APIC IRQ registers (== #pins):
+	 */
+	for (i = 0; i < nr_ioapics; i++) {
+		spin_lock_irqsave(&ioapic_lock, flags);
+		reg_01.raw = io_apic_read(i, 1);
+		spin_unlock_irqrestore(&ioapic_lock, flags);
+		nr_ioapic_registers[i] = reg_01.bits.entries+1;
+	}
+
+	/*
+	 * Do not trust the IO-APIC being empty at bootup
+	 */
+	clear_IO_APIC();
+}
+
+/*
+ * Not an __init, needed by the reboot code
+ */
+void disable_IO_APIC(void)
+{
+	/*
+	 * Clear the IO-APIC before rebooting:
+	 */
+	clear_IO_APIC();
+
+	disconnect_bsp_APIC();
+}
+
+/*
+ * 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
+ */
+
+#ifndef CONFIG_X86_NUMAQ
+static void __init setup_ioapic_ids_from_mpc(void)
+{
+	union IO_APIC_reg_00 reg_00;
+	physid_mask_t phys_id_present_map;
+	int apic;
+	int i;
+	unsigned char old_id;
+	unsigned long flags;
+
+	/*
+	 * This is broken; anything with a real cpu count has to
+	 * circumvent this idiocy regardless.
+	 */
+	phys_id_present_map = ioapic_phys_id_map(phys_cpu_present_map);
+
+	/*
+	 * Set the IOAPIC ID to the value stored in the MPC table.
+	 */
+	for (apic = 0; apic < nr_ioapics; apic++) {
+
+		/* Read the register 0 value */
+		spin_lock_irqsave(&ioapic_lock, flags);
+		reg_00.raw = io_apic_read(apic, 0);
+		spin_unlock_irqrestore(&ioapic_lock, flags);
+		
+		old_id = mp_ioapics[apic].mpc_apicid;
+
+		if (mp_ioapics[apic].mpc_apicid >= get_physical_broadcast()) {
+			printk(KERN_ERR "BIOS bug, IO-APIC#%d ID is %d in the MPC table!...\n",
+				apic, mp_ioapics[apic].mpc_apicid);
+			printk(KERN_ERR "... fixing up to %d. (tell your hw vendor)\n",
+				reg_00.bits.ID);
+			mp_ioapics[apic].mpc_apicid = reg_00.bits.ID;
+		}
+
+		/* Don't check I/O APIC IDs for some xAPIC systems.  They have
+		 * no meaning without the serial APIC bus. */
+		if (NO_IOAPIC_CHECK)
+			continue;
+		/*
+		 * 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 (check_apicid_used(phys_id_present_map,
+					mp_ioapics[apic].mpc_apicid)) {
+			printk(KERN_ERR "BIOS bug, IO-APIC#%d ID %d is already used!...\n",
+				apic, mp_ioapics[apic].mpc_apicid);
+			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);
+			mp_ioapics[apic].mpc_apicid = i;
+		} else {
+			physid_mask_t tmp;
+			tmp = apicid_to_cpu_present(mp_ioapics[apic].mpc_apicid);
+			apic_printk(APIC_VERBOSE, "Setting %d in the "
+					"phys_id_present_map\n",
+					mp_ioapics[apic].mpc_apicid);
+			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 != mp_ioapics[apic].mpc_apicid)
+			for (i = 0; i < mp_irq_entries; i++)
+				if (mp_irqs[i].mpc_dstapic == old_id)
+					mp_irqs[i].mpc_dstapic
+						= mp_ioapics[apic].mpc_apicid;
+
+		/*
+		 * Read the right value from the MPC table and
+		 * write it into the ID register.
+	 	 */
+		apic_printk(APIC_VERBOSE, KERN_INFO
+			"...changing IO-APIC physical APIC ID to %d ...",
+			mp_ioapics[apic].mpc_apicid);
+
+		reg_00.bits.ID = mp_ioapics[apic].mpc_apicid;
+		spin_lock_irqsave(&ioapic_lock, flags);
+		io_apic_write(apic, 0, reg_00.raw);
+		spin_unlock_irqrestore(&ioapic_lock, flags);
+
+		/*
+		 * Sanity check
+		 */
+		spin_lock_irqsave(&ioapic_lock, flags);
+		reg_00.raw = io_apic_read(apic, 0);
+		spin_unlock_irqrestore(&ioapic_lock, flags);
+		if (reg_00.bits.ID != mp_ioapics[apic].mpc_apicid)
+			printk("could not set ID!\n");
+		else
+			apic_printk(APIC_VERBOSE, " ok.\n");
+	}
+}
+#else
+static void __init setup_ioapic_ids_from_mpc(void) { }
+#endif
+
+/*
+ * 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;
+
+	local_irq_enable();
+	/* Let ten ticks pass... */
+	mdelay((10 * 1000) / HZ);
+
+	/*
+	 * 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.
+	 */
+	if (jiffies - t1 > 4)
+		return 1;
+
+	return 0;
+}
+
+/*
+ * 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_edge_ioapic_irq(unsigned int irq)
+{
+	int was_pending = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	if (irq < 16) {
+		disable_8259A_irq(irq);
+		if (i8259A_irq_pending(irq))
+			was_pending = 1;
+	}
+	__unmask_IO_APIC_irq(irq);
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return was_pending;
+}
+
+/*
+ * Once we have recorded IRQ_PENDING already, we can mask the
+ * interrupt for real. This prevents IRQ storms from unhandled
+ * devices.
+ */
+static void ack_edge_ioapic_irq(unsigned int irq)
+{
+	move_irq(irq);
+	if ((irq_desc[irq].status & (IRQ_PENDING | IRQ_DISABLED))
+					== (IRQ_PENDING | IRQ_DISABLED))
+		mask_IO_APIC_irq(irq);
+	ack_APIC_irq();
+}
+
+/*
+ * Level triggered interrupts can just be masked,
+ * and shutting down and starting up the interrupt
+ * is the same as enabling and disabling them -- except
+ * with a startup need to return a "was pending" value.
+ *
+ * Level triggered interrupts are special because we
+ * do not touch any IO-APIC register while handling
+ * them. We ack the APIC in the end-IRQ handler, not
+ * in the start-IRQ-handler. Protection against reentrance
+ * from the same interrupt is still provided, both by the
+ * generic IRQ layer and by the fact that an unacked local
+ * APIC does not accept IRQs.
+ */
+static unsigned int startup_level_ioapic_irq (unsigned int irq)
+{
+	unmask_IO_APIC_irq(irq);
+
+	return 0; /* don't check for pending */
+}
+
+static void end_level_ioapic_irq (unsigned int irq)
+{
+	unsigned long v;
+	int i;
+
+	move_irq(irq);
+/*
+ * 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
+ */
+	i = IO_APIC_VECTOR(irq);
+
+	v = apic_read(APIC_TMR + ((i & ~0x1f) >> 1));
+
+	ack_APIC_irq();
+
+	if (!(v & (1 << (i & 0x1f)))) {
+		atomic_inc(&irq_mis_count);
+		spin_lock(&ioapic_lock);
+		__mask_and_edge_IO_APIC_irq(irq);
+		__unmask_and_level_IO_APIC_irq(irq);
+		spin_unlock(&ioapic_lock);
+	}
+}
+
+#ifdef CONFIG_PCI_MSI
+static unsigned int startup_edge_ioapic_vector(unsigned int vector)
+{
+	int irq = vector_to_irq(vector);
+
+	return startup_edge_ioapic_irq(irq);
+}
+
+static void ack_edge_ioapic_vector(unsigned int vector)
+{
+	int irq = vector_to_irq(vector);
+
+	ack_edge_ioapic_irq(irq);
+}
+
+static unsigned int startup_level_ioapic_vector (unsigned int vector)
+{
+	int irq = vector_to_irq(vector);
+
+	return startup_level_ioapic_irq (irq);
+}
+
+static void end_level_ioapic_vector (unsigned int vector)
+{
+	int irq = vector_to_irq(vector);
+
+	end_level_ioapic_irq(irq);
+}
+
+static void mask_IO_APIC_vector (unsigned int vector)
+{
+	int irq = vector_to_irq(vector);
+
+	mask_IO_APIC_irq(irq);
+}
+
+static void unmask_IO_APIC_vector (unsigned int vector)
+{
+	int irq = vector_to_irq(vector);
+
+	unmask_IO_APIC_irq(irq);
+}
+
+static void set_ioapic_affinity_vector (unsigned int vector,
+					cpumask_t cpu_mask)
+{
+	int irq = vector_to_irq(vector);
+
+	set_ioapic_affinity_irq(irq, cpu_mask);
+}
+#endif
+
+/*
+ * Level and edge triggered IO-APIC interrupts need different handling,
+ * so we use two separate IRQ descriptors. Edge triggered IRQs can be
+ * handled with the level-triggered descriptor, but that one has slightly
+ * more overhead. Level-triggered interrupts cannot be handled with the
+ * edge-triggered handler, without risking IRQ storms and other ugly
+ * races.
+ */
+static struct hw_interrupt_type ioapic_edge_type = {
+	.typename 	= "IO-APIC-edge",
+	.startup 	= startup_edge_ioapic,
+	.shutdown 	= shutdown_edge_ioapic,
+	.enable 	= enable_edge_ioapic,
+	.disable 	= disable_edge_ioapic,
+	.ack 		= ack_edge_ioapic,
+	.end 		= end_edge_ioapic,
+	.set_affinity 	= set_ioapic_affinity,
+};
+
+static struct hw_interrupt_type ioapic_level_type = {
+	.typename 	= "IO-APIC-level",
+	.startup 	= startup_level_ioapic,
+	.shutdown 	= shutdown_level_ioapic,
+	.enable 	= enable_level_ioapic,
+	.disable 	= disable_level_ioapic,
+	.ack 		= mask_and_ack_level_ioapic,
+	.end 		= end_level_ioapic,
+	.set_affinity 	= set_ioapic_affinity,
+};
+
+static inline void init_IO_APIC_traps(void)
+{
+	int irq;
+
+	/*
+	 * NOTE! The local APIC isn't very good at handling
+	 * multiple interrupts at the same interrupt level.
+	 * As the interrupt level is determined by taking the
+	 * vector number and shifting that right by 4, we
+	 * want to spread these out a bit so that they don't
+	 * all fall in the same interrupt level.
+	 *
+	 * Also, we've got to be careful not to trash gate
+	 * 0x80, because int 0x80 is hm, kind of importantish. ;)
+	 */
+	for (irq = 0; irq < NR_IRQS ; irq++) {
+		int tmp = irq;
+		if (use_pci_vector()) {
+			if (!platform_legacy_irq(tmp))
+				if ((tmp = vector_to_irq(tmp)) == -1)
+					continue;
+		}
+		if (IO_APIC_IRQ(tmp) && !IO_APIC_VECTOR(tmp)) {
+			/*
+			 * Hmm.. We don't have an entry for this,
+			 * so default to an old-fashioned 8259
+			 * interrupt if we can..
+			 */
+			if (irq < 16)
+				make_8259A_irq(irq);
+			else
+				/* Strange. Oh, well.. */
+				irq_desc[irq].handler = &no_irq_type;
+		}
+	}
+}
+
+static void enable_lapic_irq (unsigned int irq)
+{
+	unsigned long v;
+
+	v = apic_read(APIC_LVT0);
+	apic_write_around(APIC_LVT0, v & ~APIC_LVT_MASKED);
+}
+
+static void disable_lapic_irq (unsigned int irq)
+{
+	unsigned long v;
+
+	v = apic_read(APIC_LVT0);
+	apic_write_around(APIC_LVT0, v | APIC_LVT_MASKED);
+}
+
+static void ack_lapic_irq (unsigned int irq)
+{
+	ack_APIC_irq();
+}
+
+static void end_lapic_irq (unsigned int i) { /* nothing */ }
+
+static struct hw_interrupt_type lapic_irq_type = {
+	.typename 	= "local-APIC-edge",
+	.startup 	= NULL, /* startup_irq() not used for IRQ0 */
+	.shutdown 	= NULL, /* shutdown_irq() not used for IRQ0 */
+	.enable 	= enable_lapic_irq,
+	.disable 	= disable_lapic_irq,
+	.ack 		= ack_lapic_irq,
+	.end 		= end_lapic_irq
+};
+
+static void setup_nmi (void)
+{
+	/*
+ 	 * Dirty trick to enable the NMI watchdog ...
+	 * We put the 8259A master into AEOI mode and
+	 * unmask on all local APICs LVT0 as NMI.
+	 *
+	 * The idea to use the 8259A in AEOI mode ('8259A Virtual Wire')
+	 * is from Maciej W. Rozycki - so we do not have to EOI from
+	 * the NMI handler or the timer interrupt.
+	 */ 
+	apic_printk(APIC_VERBOSE, KERN_INFO "activating NMI Watchdog ...");
+
+	on_each_cpu(enable_NMI_through_LVT0, NULL, 1, 1);
+
+	apic_printk(APIC_VERBOSE, " done.\n");
+}
+
+/*
+ * 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 unlock_ExtINT_logic(void)
+{
+	int pin, i;
+	struct IO_APIC_route_entry entry0, entry1;
+	unsigned char save_control, save_freq_select;
+	unsigned long flags;
+
+	pin = find_isa_irq_pin(8, mp_INT);
+	if (pin == -1)
+		return;
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	*(((int *)&entry0) + 1) = io_apic_read(0, 0x11 + 2 * pin);
+	*(((int *)&entry0) + 0) = io_apic_read(0, 0x10 + 2 * pin);
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+	clear_IO_APIC_pin(0, pin);
+
+	memset(&entry1, 0, sizeof(entry1));
+
+	entry1.dest_mode = 0;			/* physical delivery */
+	entry1.mask = 0;			/* unmask IRQ now */
+	entry1.dest.physical.physical_dest = hard_smp_processor_id();
+	entry1.delivery_mode = dest_ExtINT;
+	entry1.polarity = entry0.polarity;
+	entry1.trigger = 0;
+	entry1.vector = 0;
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	io_apic_write(0, 0x11 + 2 * pin, *(((int *)&entry1) + 1));
+	io_apic_write(0, 0x10 + 2 * pin, *(((int *)&entry1) + 0));
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	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(0, pin);
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	io_apic_write(0, 0x11 + 2 * pin, *(((int *)&entry0) + 1));
+	io_apic_write(0, 0x10 + 2 * pin, *(((int *)&entry0) + 0));
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+/*
+ * 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.
+ */
+static inline void check_timer(void)
+{
+	int pin1, pin2;
+	int vector;
+
+	/*
+	 * get/set the timer IRQ vector:
+	 */
+	disable_8259A_irq(0);
+	vector = assign_irq_vector(0);
+	set_intr_gate(vector, interrupt[0]);
+
+	/*
+	 * Subtle, code in do_timer_interrupt() expects an AEOI
+	 * mode for the 8259A whenever interrupts are routed
+	 * through I/O APICs.  Also IRQ0 has to be enabled in
+	 * the 8259A which implies the virtual wire has to be
+	 * disabled in the local APIC.
+	 */
+	apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
+	init_8259A(1);
+	timer_ack = 1;
+	enable_8259A_irq(0);
+
+	pin1 = find_isa_irq_pin(0, mp_INT);
+	pin2 = find_isa_irq_pin(0, mp_ExtINT);
+
+	printk(KERN_INFO "..TIMER: vector=0x%02X pin1=%d pin2=%d\n", vector, pin1, pin2);
+
+	if (pin1 != -1) {
+		/*
+		 * Ok, does IRQ0 through the IOAPIC work?
+		 */
+		unmask_IO_APIC_irq(0);
+		if (timer_irq_works()) {
+			if (nmi_watchdog == NMI_IO_APIC) {
+				disable_8259A_irq(0);
+				setup_nmi();
+				enable_8259A_irq(0);
+				check_nmi_watchdog();
+			}
+			return;
+		}
+		clear_IO_APIC_pin(0, pin1);
+		printk(KERN_ERR "..MP-BIOS bug: 8254 timer not connected to IO-APIC\n");
+	}
+
+	printk(KERN_INFO "...trying to set up timer (IRQ0) through the 8259A ... ");
+	if (pin2 != -1) {
+		printk("\n..... (found pin %d) ...", pin2);
+		/*
+		 * legacy devices should be connected to IO APIC #0
+		 */
+		setup_ExtINT_IRQ0_pin(pin2, vector);
+		if (timer_irq_works()) {
+			printk("works.\n");
+			if (pin1 != -1)
+				replace_pin_at_irq(0, 0, pin1, 0, pin2);
+			else
+				add_pin_to_irq(0, 0, pin2);
+			if (nmi_watchdog == NMI_IO_APIC) {
+				setup_nmi();
+				check_nmi_watchdog();
+			}
+			return;
+		}
+		/*
+		 * Cleanup, just in case ...
+		 */
+		clear_IO_APIC_pin(0, pin2);
+	}
+	printk(" failed.\n");
+
+	if (nmi_watchdog == NMI_IO_APIC) {
+		printk(KERN_WARNING "timer doesn't work through the IO-APIC - disabling NMI Watchdog!\n");
+		nmi_watchdog = 0;
+	}
+
+	printk(KERN_INFO "...trying to set up timer as Virtual Wire IRQ...");
+
+	disable_8259A_irq(0);
+	irq_desc[0].handler = &lapic_irq_type;
+	apic_write_around(APIC_LVT0, APIC_DM_FIXED | vector);	/* Fixed mode */
+	enable_8259A_irq(0);
+
+	if (timer_irq_works()) {
+		printk(" works.\n");
+		return;
+	}
+	apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | vector);
+	printk(" failed.\n");
+
+	printk(KERN_INFO "...trying to set up timer as ExtINT IRQ...");
+
+	timer_ack = 0;
+	init_8259A(0);
+	make_8259A_irq(0);
+	apic_write_around(APIC_LVT0, APIC_DM_EXTINT);
+
+	unlock_ExtINT_logic();
+
+	if (timer_irq_works()) {
+		printk(" works.\n");
+		return;
+	}
+	printk(" failed :(.\n");
+	panic("IO-APIC + timer doesn't work!  Boot with apic=debug and send a "
+		"report.  Then try booting with the 'noapic' option");
+}
+
+/*
+ *
+ * IRQ's that are handled by the PIC in the MPS IOAPIC case.
+ * - IRQ2 is the cascade IRQ, and cannot be a io-apic IRQ.
+ *   Linux doesn't really care, as it's not actually used
+ *   for any interrupt handling anyway.
+ */
+#define PIC_IRQS	(1 << PIC_CASCADE_IR)
+
+void __init setup_IO_APIC(void)
+{
+	enable_IO_APIC();
+
+	if (acpi_ioapic)
+		io_apic_irqs = ~0;	/* all IRQs go through IOAPIC */
+	else
+		io_apic_irqs = ~PIC_IRQS;
+
+	printk("ENABLING IO-APIC IRQs\n");
+
+	/*
+	 * Set up IO-APIC IRQ routing.
+	 */
+	if (!acpi_ioapic)
+		setup_ioapic_ids_from_mpc();
+	sync_Arb_IDs();
+	setup_IO_APIC_irqs();
+	init_IO_APIC_traps();
+	check_timer();
+	if (!acpi_ioapic)
+		print_IO_APIC();
+}
+
+/*
+ *	Called after all the initialization is done. If we didnt find any
+ *	APIC bugs then we can allow the modify fast path
+ */
+ 
+static int __init io_apic_bug_finalize(void)
+{
+	if(sis_apic_bug == -1)
+		sis_apic_bug = 0;
+	return 0;
+}
+
+late_initcall(io_apic_bug_finalize);
+
+struct sysfs_ioapic_data {
+	struct sys_device dev;
+	struct IO_APIC_route_entry entry[0];
+};
+static struct sysfs_ioapic_data * mp_ioapic_data[MAX_IO_APICS];
+
+static int ioapic_suspend(struct sys_device *dev, u32 state)
+{
+	struct IO_APIC_route_entry *entry;
+	struct sysfs_ioapic_data *data;
+	unsigned long flags;
+	int i;
+	
+	data = container_of(dev, struct sysfs_ioapic_data, dev);
+	entry = data->entry;
+	spin_lock_irqsave(&ioapic_lock, flags);
+	for (i = 0; i < nr_ioapic_registers[dev->id]; i ++, entry ++ ) {
+		*(((int *)entry) + 1) = io_apic_read(dev->id, 0x11 + 2 * i);
+		*(((int *)entry) + 0) = io_apic_read(dev->id, 0x10 + 2 * i);
+	}
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return 0;
+}
+
+static int ioapic_resume(struct sys_device *dev)
+{
+	struct IO_APIC_route_entry *entry;
+	struct sysfs_ioapic_data *data;
+	unsigned long flags;
+	union IO_APIC_reg_00 reg_00;
+	int i;
+	
+	data = container_of(dev, struct sysfs_ioapic_data, dev);
+	entry = data->entry;
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	reg_00.raw = io_apic_read(dev->id, 0);
+	if (reg_00.bits.ID != mp_ioapics[dev->id].mpc_apicid) {
+		reg_00.bits.ID = mp_ioapics[dev->id].mpc_apicid;
+		io_apic_write(dev->id, 0, reg_00.raw);
+	}
+	for (i = 0; i < nr_ioapic_registers[dev->id]; i ++, entry ++ ) {
+		io_apic_write(dev->id, 0x11+2*i, *(((int *)entry)+1));
+		io_apic_write(dev->id, 0x10+2*i, *(((int *)entry)+0));
+	}
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return 0;
+}
+
+static struct sysdev_class ioapic_sysdev_class = {
+	set_kset_name("ioapic"),
+	.suspend = ioapic_suspend,
+	.resume = ioapic_resume,
+};
+
+static int __init ioapic_init_sysfs(void)
+{
+	struct sys_device * dev;
+	int i, size, error = 0;
+
+	error = sysdev_class_register(&ioapic_sysdev_class);
+	if (error)
+		return error;
+
+	for (i = 0; i < nr_ioapics; i++ ) {
+		size = sizeof(struct sys_device) + nr_ioapic_registers[i] 
+			* sizeof(struct IO_APIC_route_entry);
+		mp_ioapic_data[i] = kmalloc(size, GFP_KERNEL);
+		if (!mp_ioapic_data[i]) {
+			printk(KERN_ERR "Can't suspend/resume IOAPIC %d\n", i);
+			continue;
+		}
+		memset(mp_ioapic_data[i], 0, size);
+		dev = &mp_ioapic_data[i]->dev;
+		dev->id = i; 
+		dev->cls = &ioapic_sysdev_class;
+		error = sysdev_register(dev);
+		if (error) {
+			kfree(mp_ioapic_data[i]);
+			mp_ioapic_data[i] = NULL;
+			printk(KERN_ERR "Can't suspend/resume IOAPIC %d\n", i);
+			continue;
+		}
+	}
+
+	return 0;
+}
+
+device_initcall(ioapic_init_sysfs);
+
+/* --------------------------------------------------------------------------
+                          ACPI-based IOAPIC Configuration
+   -------------------------------------------------------------------------- */
+
+#ifdef CONFIG_ACPI_BOOT
+
+int __init 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_id_map = ioapic_phys_id_map(phys_cpu_present_map);
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	reg_00.raw = io_apic_read(ioapic, 0);
+	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 (check_apicid_used(apic_id_map, apic_id)) {
+
+		for (i = 0; i < get_physical_broadcast(); i++) {
+			if (!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;
+	} 
+
+	tmp = apicid_to_cpu_present(apic_id);
+	physids_or(apic_id_map, apic_id_map, tmp);
+
+	if (reg_00.bits.ID != apic_id) {
+		reg_00.bits.ID = apic_id;
+
+		spin_lock_irqsave(&ioapic_lock, flags);
+		io_apic_write(ioapic, 0, reg_00.raw);
+		reg_00.raw = io_apic_read(ioapic, 0);
+		spin_unlock_irqrestore(&ioapic_lock, flags);
+
+		/* Sanity check */
+		if (reg_00.bits.ID != apic_id)
+			panic("IOAPIC[%d]: Unable change apic_id!\n", ioapic);
+	}
+
+	apic_printk(APIC_VERBOSE, KERN_INFO
+			"IOAPIC[%d]: Assigned apic_id %d\n", ioapic, apic_id);
+
+	return apic_id;
+}
+
+
+int __init io_apic_get_version (int ioapic)
+{
+	union IO_APIC_reg_01	reg_01;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	reg_01.raw = io_apic_read(ioapic, 1);
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return reg_01.bits.version;
+}
+
+
+int __init io_apic_get_redir_entries (int ioapic)
+{
+	union IO_APIC_reg_01	reg_01;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	reg_01.raw = io_apic_read(ioapic, 1);
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return reg_01.bits.entries;
+}
+
+
+int io_apic_set_pci_routing (int ioapic, int pin, int irq, int edge_level, int active_high_low)
+{
+	struct IO_APIC_route_entry entry;
+	unsigned long flags;
+
+	if (!IO_APIC_IRQ(irq)) {
+		printk(KERN_ERR "IOAPIC[%d]: Invalid reference to IRQ 0\n",
+			ioapic);
+		return -EINVAL;
+	}
+
+	/*
+	 * Generate a PCI IRQ routing entry and program the IOAPIC accordingly.
+	 * Note that we mask (disable) IRQs now -- these get enabled when the
+	 * corresponding device driver registers for this IRQ.
+	 */
+
+	memset(&entry,0,sizeof(entry));
+
+	entry.delivery_mode = INT_DELIVERY_MODE;
+	entry.dest_mode = INT_DEST_MODE;
+	entry.dest.logical.logical_dest = cpu_mask_to_apicid(TARGET_CPUS);
+	entry.trigger = edge_level;
+	entry.polarity = active_high_low;
+	entry.mask  = 1;
+
+	/*
+	 * IRQs < 16 are already in the irq_2_pin[] map
+	 */
+	if (irq >= 16)
+		add_pin_to_irq(irq, ioapic, pin);
+
+	entry.vector = assign_irq_vector(irq);
+
+	apic_printk(APIC_DEBUG, KERN_DEBUG "IOAPIC[%d]: Set PCI routing entry "
+		"(%d-%d -> 0x%x -> IRQ %d Mode:%i Active:%i)\n", ioapic,
+		mp_ioapics[ioapic].mpc_apicid, pin, entry.vector, irq,
+		edge_level, active_high_low);
+
+	ioapic_register_intr(irq, entry.vector, edge_level);
+
+	if (!ioapic && (irq < 16))
+		disable_8259A_irq(irq);
+
+	spin_lock_irqsave(&ioapic_lock, flags);
+	io_apic_write(ioapic, 0x11+2*pin, *(((int *)&entry)+1));
+	io_apic_write(ioapic, 0x10+2*pin, *(((int *)&entry)+0));
+	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return 0;
+}
+
+#endif /*CONFIG_ACPI_BOOT*/