diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index 534790b..23e8432 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -799,7 +799,6 @@
 #ifdef	CONFIG_X86_IO_APIC
 
 #define MP_ISA_BUS		0
-#define MP_MAX_IOAPIC_PIN	127
 
 extern struct mp_ioapic_routing mp_ioapic_routing[MAX_IO_APICS];
 
@@ -982,9 +981,8 @@
 
 int mp_register_gsi(u32 gsi, int triggering, int polarity)
 {
-	int ioapic = -1;
-	int ioapic_pin = 0;
-	int idx, bit = 0;
+	int ioapic;
+	int ioapic_pin;
 #ifdef CONFIG_X86_32
 #define MAX_GSI_NUM	4096
 #define IRQ_COMPRESSION_START	64
@@ -1024,15 +1022,13 @@
 	 * with redundant pin->gsi mappings (but unique PCI devices);
 	 * we only program the IOAPIC on the first.
 	 */
-	bit = ioapic_pin % 32;
-	idx = (ioapic_pin < 32) ? 0 : (ioapic_pin / 32);
-	if (idx > 3) {
+	if (ioapic_pin > MP_MAX_IOAPIC_PIN) {
 		printk(KERN_ERR "Invalid reference to IOAPIC pin "
 		       "%d-%d\n", mp_ioapic_routing[ioapic].apic_id,
 		       ioapic_pin);
 		return gsi;
 	}
-	if ((1 << bit) & mp_ioapic_routing[ioapic].pin_programmed[idx]) {
+	if (test_bit(ioapic_pin, mp_ioapic_routing[ioapic].pin_programmed)) {
 		Dprintk(KERN_DEBUG "Pin %d-%d already programmed\n",
 			mp_ioapic_routing[ioapic].apic_id, ioapic_pin);
 #ifdef CONFIG_X86_32
@@ -1042,7 +1038,7 @@
 #endif
 	}
 
-	mp_ioapic_routing[ioapic].pin_programmed[idx] |= (1 << bit);
+	set_bit(ioapic_pin, mp_ioapic_routing[ioapic].pin_programmed);
 #ifdef CONFIG_X86_32
 	/*
 	 * For GSI >= 64, use IRQ compression
diff --git a/include/asm-x86/io_apic.h b/include/asm-x86/io_apic.h
index 0c9e17c..d593e14 100644
--- a/include/asm-x86/io_apic.h
+++ b/include/asm-x86/io_apic.h
@@ -1,7 +1,7 @@
 #ifndef __ASM_IO_APIC_H
 #define __ASM_IO_APIC_H
 
-#include <asm/types.h>
+#include <linux/types.h>
 #include <asm/mpspec.h>
 #include <asm/apicdef.h>
 
@@ -110,11 +110,13 @@
  * MP-BIOS irq configuration table structures:
  */
 
+#define MP_MAX_IOAPIC_PIN 127
+
 struct mp_ioapic_routing {
 	int apic_id;
 	int gsi_base;
 	int gsi_end;
-	u32 pin_programmed[4];
+	DECLARE_BITMAP(pin_programmed, MP_MAX_IOAPIC_PIN + 1);
 };
 
 /* I/O APIC entries */