[12/15] x86 ioapic: Optimize pin_2_irq

Commit Message

Eric W. Biederman March 30, 2010, 8:07 a.m. UTC

None

Patch

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index c505fe0..764c74c 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1018,7 +1018,7 @@  static inline int irq_trigger(int idx)
 int (*ioapic_renumber_irq)(int ioapic, int irq);
 static int pin_2_irq(int idx, int apic, int pin)
 {
-	int irq, i;
+	int irq;
 	int bus = mp_irqs[idx].srcbus;
 
 	/*
@@ -1030,18 +1030,13 @@  static int pin_2_irq(int idx, int apic, int pin)
 	if (test_bit(bus, mp_bus_not_pci)) {
 		irq = mp_irqs[idx].srcbusirq;
 	} else {
-		/*
-		 * PCI IRQs are mapped in order
-		 */
-		i = irq = 0;
-		while (i < apic)
-			irq += nr_ioapic_registers[i++];
-		irq += pin;
+		u32 gsi = mp_gsi_routing[apic].gsi_base + pin;
 		/*
                  * For MPS mode, so far only needed by ES7000 platform
                  */
 		if (ioapic_renumber_irq)
-			irq = ioapic_renumber_irq(apic, irq);
+			gsi = ioapic_renumber_irq(apic, gsi);
+		irq = gsi;
 	}
 
 #ifdef CONFIG_X86_32