x86, apic: Introduce the NOOP apic driver
Introduce NOOP APIC driver. We should use it in case if apic was
disabled due to hardware of software/firmware problems (including
user requested to disable it case).
The driver is attempting to catch any inappropriate apic operation
call with warning issue.
Also it is possible to use some apic operation like IPI calls,
read/write without checking for apic presence which should make
callers code easier.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: yinghai@kernel.org
Cc: macro@linux-mips.org
LKML-Reference: <20091013201022.534682104@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 474d80d..08a5f42 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -488,6 +488,8 @@
extern void default_setup_apic_routing(void);
+extern struct apic apic_noop;
+
#ifdef CONFIG_X86_32
extern struct apic apic_default;