init: Get rid of x86isms

The UP local API support can be set up from an early initcall. No need
for horrible hackery in the init code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20150115211703.827943883@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

4 files changed, 18 insertions, 13 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ba397bde7948..ffcc3ca5862a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -855,6 +855,10 @@ config SCHED_MC
 
 source "kernel/Kconfig.preempt"
 
+config UP_LATE_INIT
+       def_bool y
+       depends on X86_UP_APIC
+
 config X86_UP_APIC
         bool "Local APIC support on uniprocessors"
         depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index c681e9ba9e47..19f1bc714ee6 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2267,6 +2267,13 @@ int __init APIC_init_uniprocessor(void)
         return 0;
 }
 
+#ifdef CONFIG_UP_LATE_INIT
+void __init up_late_init(void)
+{
+        APIC_init_uniprocessor();
+}
+#endif
+
 /*
  * Power management
  */
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 93dff5fff524..be91db2a7017 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -151,6 +151,13 @@ smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 static inline void kick_all_cpus_sync(void) {  }
 static inline void wake_up_all_idle_cpus(void) {  }
 
+#ifdef CONFIG_UP_LATE_INIT
+extern void __init up_late_init(void);
+static inline void smp_init(void) { up_late_init(); }
+#else
+static inline void smp_init(void) { }
+#endif
+
 #endif /* !SMP */
 
 /*
diff --git a/init/main.c b/init/main.c
index 61b993767db5..179ada15d08a 100644
--- a/init/main.c
+++ b/init/main.c
@@ -87,10 +87,6 @@
 #include <asm/sections.h>
 #include <asm/cacheflush.h>
 
-#ifdef CONFIG_X86_LOCAL_APIC
-#include <asm/smp.h>
-#endif
-
 static int kernel_init(void *);
 
 extern void init_IRQ(void);
@@ -351,15 +347,6 @@ __setup("rdinit=", rdinit_setup);
 
 #ifndef CONFIG_SMP
 static const unsigned int setup_max_cpus = NR_CPUS;
-#ifdef CONFIG_X86_LOCAL_APIC
-static void __init smp_init(void)
-{
-        APIC_init_uniprocessor();
-}
-#else
-#define smp_init()      do { } while (0)
-#endif
-
 static inline void setup_nr_cpu_ids(void) { }
 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 #endif