x86/platform: Introduce APIC post-initialization callback

Some subarchitectures (such as vSMP) need to slightly adjust the
underlying APIC structure. Add an APIC post-initialization callback
to 'struct x86_platform_ops' for this purpose and use it for
adjusting the APIC structure on vSMP systems.

Signed-off-by: Ido Yariv <ido@wizery.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
Link: http://lkml.kernel.org/r/1338675095-27260-1-git-send-email-ido@wizery.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/x86_init.h

@@ -164,6 +164,7 @@ struct x86_cpuinit_ops {
  * @i8042_detect		pre-detect if i8042 controller exists
  * @save_sched_clock_state:	save state for sched_clock() on suspend
  * @restore_sched_clock_state:	restore state for sched_clock() on resume
+ * @apic_post_init:		adjust apic if neeeded
  */
 struct x86_platform_ops {
 	unsigned long (*calibrate_tsc)(void);
@@ -177,6 +178,7 @@ struct x86_platform_ops {
 	int (*i8042_detect)(void);
 	void (*save_sched_clock_state)(void);
 	void (*restore_sched_clock_state)(void);
+	void (*apic_post_init)(void);
 };
 
 struct pci_dev;

arch/x86/kernel/apic/probe_32.c

@@ -208,6 +208,9 @@ void __init default_setup_apic_routing(void)
 
 	if (apic->setup_apic_routing)
 		apic->setup_apic_routing();
+
+	if (x86_platform.apic_post_init)
+		x86_platform.apic_post_init();
 }
 
 void __init generic_apic_probe(void)

arch/x86/kernel/apic/probe_64.c

@@ -23,11 +23,6 @@
 #include <asm/ipi.h>
 #include <asm/setup.h>
 
-static int apicid_phys_pkg_id(int initial_apic_id, int index_msb)
-{
-	return hard_smp_processor_id() >> index_msb;
-}
-
 /*
  * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
  */
@@ -48,10 +43,8 @@ void __init default_setup_apic_routing(void)
 		}
 	}
 
-	if (is_vsmp_box()) {
-		/* need to update phys_pkg_id */
-		apic->phys_pkg_id = apicid_phys_pkg_id;
-	}
+	if (x86_platform.apic_post_init)
+		x86_platform.apic_post_init();
 }
 
 /* Same for both flat and physical. */

arch/x86/kernel/vsmp_64.c

@@ -187,12 +187,25 @@ static void __init vsmp_cap_cpus(void)
 #endif
 }
 
+static int apicid_phys_pkg_id(int initial_apic_id, int index_msb)
+{
+	return hard_smp_processor_id() >> index_msb;
+}
+
+static void vsmp_apic_post_init(void)
+{
+	/* need to update phys_pkg_id */
+	apic->phys_pkg_id = apicid_phys_pkg_id;
+}
+
 void __init vsmp_init(void)
 {
 	detect_vsmp_box();
 	if (!is_vsmp_box())
 		return;
 
+	x86_platform.apic_post_init = vsmp_apic_post_init;
+
 	vsmp_cap_cpus();
 
 	set_vsmp_pv_ops();