[PATCH] i386: move apic init in init_IRQs

All kinds of ugliness exists because we don't initialize
the apics during init_IRQs.
- We calibrate jiffies in non apic mode even when we are using apics.
- We have to have special code to initialize the apics when non-smp.
- The legacy i8259 must exist and be setup correctly, even
  when we won't use it past initialization.
- The kexec on panic code must restore the state of the io_apics.
- init/main.c needs a special case for !smp smp_init on x86

In addition to pure code movement I needed a couple
of non-obvious changes:
- Move setup_boot_APIC_clock into APIC_late_time_init for
  simplicity.
- Use cpu_khz to generate a better approximation of loops_per_jiffies
  so I can verify the timer interrupt is working.
- Call setup_apic_nmi_watchdog again after cpu_khz is initialized on
  the boot cpu.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-i386/apic.h

@@ -118,7 +118,8 @@ extern void release_lapic_nmi(void);
 extern void disable_timer_nmi_watchdog(void);
 extern void enable_timer_nmi_watchdog(void);
 extern void nmi_watchdog_tick (struct pt_regs * regs);
-extern int APIC_init_uniprocessor (void);
+extern int APIC_init(void);
+extern void APIC_late_time_init(void);
 extern void disable_APIC_timer(void);
 extern void enable_APIC_timer(void);
 

include/asm-i386/hw_irq.h

@@ -55,6 +55,7 @@ void init_8259A(int aeoi);
 void FASTCALL(send_IPI_self(int vector));
 void init_VISWS_APIC_irqs(void);
 void setup_IO_APIC(void);
+void IO_APIC_late_time_init(void);
 void disable_IO_APIC(void);
 void print_IO_APIC(void);
 int IO_APIC_get_PCI_irq_vector(int bus, int slot, int fn);

include/asm-i386/mach-default/smpboot_hooks.h

@@ -1,11 +1,6 @@
 /* two abstractions specific to kernel/smpboot.c, mainly to cater to visws
  * which needs to alter them. */
 
-static inline void smpboot_clear_io_apic_irqs(void)
-{
-	io_apic_irqs = 0;
-}
-
 static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
 {
 	CMOS_WRITE(0xa, 0xf);
@@ -32,13 +27,3 @@ static inline void smpboot_restore_warm_reset_vector(void)
 
 	*((volatile long *) phys_to_virt(0x467)) = 0;
 }
-
-static inline void smpboot_setup_io_apic(void)
-{
-	/*
-	 * Here we can be sure that there is an IO-APIC in the system. Let's
-	 * go and set it up:
-	 */
-	if (!skip_ioapic_setup && nr_ioapics)
-		setup_IO_APIC();
-}

include/asm-i386/mach-visws/smpboot_hooks.h

@@ -11,14 +11,7 @@ static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
 
 /* for visws do nothing for any of these */
 
-static inline void smpboot_clear_io_apic_irqs(void)
-{
-}
-
 static inline void smpboot_restore_warm_reset_vector(void)
 {
 }
 
-static inline void smpboot_setup_io_apic(void)
-{
-}