x86: Add dummy functions for compiling without IOAPIC

This patch adds IOAPIC dummy functions for compilation
with local APIC, but without IOAPIC.

The local variable ioapic_entries in enable_IR_x2apic()
does not need initialization anymore, since the dummy
returns NULL.
Signed-off-by: NHenrik Kretzschmar <henne@nachtwindheim.de>
LKML-Reference: <1298385487-4708-4-git-send-email-henne@nachtwindheim.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/include/asm/io_apic.h

@@ -190,6 +190,24 @@ static inline int mp_find_ioapic(u32 gsi) { return 0; }
 struct io_apic_irq_attr;
 static inline int io_apic_set_pci_routing(struct device *dev, int irq,
 		 struct io_apic_irq_attr *irq_attr) { return 0; }
+
+static inline struct IO_APIC_route_entry **alloc_ioapic_entries(void)
+{
+	return NULL;
+}
+
+static inline void free_ioapic_entries(struct IO_APIC_route_entry **ent) { }
+static inline int save_IO_APIC_setup(struct IO_APIC_route_entry **ent)
+{
+	return -ENOMEM;
+}
+
+static inline void mask_IO_APIC_setup(struct IO_APIC_route_entry **ent) { }
+static inline int restore_IO_APIC_setup(struct IO_APIC_route_entry **ent)
+{
+	return -ENOMEM;
+}
+
 static inline void mp_save_irq(struct mpc_intsrc *m) { };
 static inline void disable_ioapic_support(void) { }
 #endif

arch/x86/kernel/apic/apic.c

@@ -1449,7 +1449,7 @@ int __init enable_IR(void)
 void __init enable_IR_x2apic(void)
 {
 	unsigned long flags;
-	struct IO_APIC_route_entry **ioapic_entries = NULL;
+	struct IO_APIC_route_entry **ioapic_entries;
 	int ret, x2apic_enabled = 0;
 	int dmar_table_init_ret;