--- zzzz-none-000/linux-2.6.19.2/include/asm-i386/io_apic.h	2007-01-10 19:10:37.000000000 +0000
+++ davinci-8020-5505/linux-2.6.19.2/include/asm-i386/io_apic.h	2007-01-11 07:38:19.000000000 +0000
@@ -12,6 +12,10 @@
 
 #ifdef CONFIG_X86_IO_APIC
 
+#define IO_APIC_BASE(idx) \
+		((volatile int *)(__fix_to_virt(FIX_IO_APIC_BASE_0 + idx) \
+		+ (mp_ioapics[idx].mpc_apicaddr & ~PAGE_MASK)))
+
 /*
  * The structure of the IO-APIC:
  */
@@ -115,8 +119,31 @@
 /* non-0 if default (table-less) MP configuration */
 extern int mpc_default_type;
 
-/* Older SiS APIC requires we rewrite the index register */
+static inline unsigned int io_apic_read(unsigned int apic, unsigned int reg)
+{
+	*IO_APIC_BASE(apic) = reg;
+	return *(IO_APIC_BASE(apic)+4);
+}
+
+static inline void io_apic_write(unsigned int apic, unsigned int reg, unsigned int value)
+{
+	*IO_APIC_BASE(apic) = reg;
+	*(IO_APIC_BASE(apic)+4) = value;
+}
+
+/*
+ * Re-write a value: to be used for read-modify-write
+ * cycles where the read already set up the index register.
+ *
+ * Older SiS APIC requires we rewrite the index regiser
+ */
 extern int sis_apic_bug;
+static inline void io_apic_modify(unsigned int apic, unsigned int reg, unsigned int value)
+{
+	if (sis_apic_bug)
+		*IO_APIC_BASE(apic) = reg;
+	*(IO_APIC_BASE(apic)+4) = value;
+}
 
 /* 1 if "noapic" boot option passed */
 extern int skip_ioapic_setup;