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Diffstat (limited to 'arch/x86/kernel/irqinit.c')
-rw-r--r--arch/x86/kernel/irqinit.c35
1 files changed, 17 insertions, 18 deletions
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index d5932226614f..fce55d532631 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -84,24 +84,7 @@ 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)
@@ -116,6 +99,9 @@ int vector_used_by_percpu_irq(unsigned int vector)
return 0;
}
+/* Number of legacy interrupts */
+int nr_legacy_irqs __read_mostly = NR_IRQS_LEGACY;
+
void __init init_ISA_irqs(void)
{
int i;
@@ -142,6 +128,19 @@ 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 < nr_legacy_irqs; i++)
+ per_cpu(vector_irq, 0)[IRQ0_VECTOR + i] = i;
+
x86_init.irqs.intr_init();
}