1 files changed, 38 insertions, 21 deletions

diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index d5932226614f..0ed2d300cd46 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -5,7 +5,6 @@
 #include <linux/ioport.h>
 #include <linux/interrupt.h>
 #include <linux/timex.h>
-#include <linux/slab.h>
 #include <linux/random.h>
 #include <linux/kprobes.h>
 #include <linux/init.h>
@@ -84,24 +83,7 @@ static struct irqaction irq2 = {
 };
 
 DEFINE_PER_CPU(vector_irq_t, vector_irq) = {
-        [0 ... IRQ0_VECTOR - 1] = -1,
-        [IRQ0_VECTOR] = 0,
-        [IRQ1_VECTOR] = 1,
-        [IRQ2_VECTOR] = 2,
-        [IRQ3_VECTOR] = 3,
-        [IRQ4_VECTOR] = 4,
-        [IRQ5_VECTOR] = 5,
-        [IRQ6_VECTOR] = 6,
-        [IRQ7_VECTOR] = 7,
-        [IRQ8_VECTOR] = 8,
-        [IRQ9_VECTOR] = 9,
-        [IRQ10_VECTOR] = 10,
-        [IRQ11_VECTOR] = 11,
-        [IRQ12_VECTOR] = 12,
-        [IRQ13_VECTOR] = 13,
-        [IRQ14_VECTOR] = 14,
-        [IRQ15_VECTOR] = 15,
-        [IRQ15_VECTOR + 1 ... NR_VECTORS - 1] = -1
+        [0 ... NR_VECTORS - 1] = -1,
 };
 
 int vector_used_by_percpu_irq(unsigned int vector)
@@ -123,12 +105,12 @@ void __init init_ISA_irqs(void)
 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC)
         init_bsp_APIC();
 #endif
-        init_8259A(0);
+        legacy_pic->init(0);
 
         /*
          * 16 old-style INTA-cycle interrupts:
          */
-        for (i = 0; i < NR_IRQS_LEGACY; i++) {
+        for (i = 0; i < legacy_pic->nr_legacy_irqs; i++) {
                 struct irq_desc *desc = irq_to_desc(i);
 
                 desc->status = IRQ_DISABLED;
@@ -142,9 +124,44 @@ void __init init_ISA_irqs(void)
 
 void __init init_IRQ(void)
 {
+        int i;
+
+        /*
+         * On cpu 0, Assign IRQ0_VECTOR..IRQ15_VECTOR's to IRQ 0..15.
+         * If these IRQ's are handled by legacy interrupt-controllers like PIC,
+         * then this configuration will likely be static after the boot. If
+         * these IRQ's are handled by more mordern controllers like IO-APIC,
+         * then this vector space can be freed and re-used dynamically as the
+         * irq's migrate etc.
+         */
+        for (i = 0; i < legacy_pic->nr_legacy_irqs; i++)
+                per_cpu(vector_irq, 0)[IRQ0_VECTOR + i] = i;
+
         x86_init.irqs.intr_init();
 }
 
+/*
+ * Setup the vector to irq mappings.
+ */
+void setup_vector_irq(int cpu)
+{
+#ifndef CONFIG_X86_IO_APIC
+        int irq;
+
+        /*
+         * On most of the platforms, legacy PIC delivers the interrupts on the
+         * boot cpu. But there are certain platforms where PIC interrupts are
+         * delivered to multiple cpu's. If the legacy IRQ is handled by the
+         * legacy PIC, for the new cpu that is coming online, setup the static
+         * legacy vector to irq mapping:
+         */
+        for (irq = 0; irq < legacy_pic->nr_legacy_irqs; irq++)
+                per_cpu(vector_irq, cpu)[IRQ0_VECTOR + irq] = irq;
+#endif
+
+        __setup_vector_irq(cpu);
+}
+
 static void __init smp_intr_init(void)
 {
 #ifdef CONFIG_SMP