x86: Use kick_all_cpus_sync()

Use kick_all_cpus_sync() and remove cpu_idle_wait().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120507175652.190382227@linutronix.de
Cc: x86@kernel.org

arch/x86/Kconfig

@@ -161,9 +161,6 @@ config RWSEM_GENERIC_SPINLOCK
 config RWSEM_XCHGADD_ALGORITHM
 	def_bool X86_XADD
 
-config ARCH_HAS_CPU_IDLE_WAIT
-	def_bool y
-
 config GENERIC_CALIBRATE_DELAY
 	def_bool y
 

arch/x86/include/asm/processor.h

@@ -974,8 +974,6 @@ extern bool cpu_has_amd_erratum(const int *);
 #define cpu_has_amd_erratum(x)	(false)
 #endif /* CONFIG_CPU_SUP_AMD */
 
-void cpu_idle_wait(void);
-
 extern unsigned long arch_align_stack(unsigned long sp);
 extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
 

arch/x86/kernel/apm_32.c

@@ -2401,7 +2401,7 @@ static void __exit apm_exit(void)
 		 * (pm_idle), Wait for all processors to update cached/local
 		 * copies of pm_idle before proceeding.
 		 */
-		cpu_idle_wait();
+		kick_all_cpus_sync();
 	}
 	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
 	    && (apm_info.connection_version > 0x0100)) {

arch/x86/kernel/process.c

@@ -525,26 +525,6 @@ void stop_this_cpu(void *dummy)
 	}
 }
 
-static void do_nothing(void *unused)
-{
-}
-
-/*
- * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
- * pm_idle and update to new pm_idle value. Required while changing pm_idle
- * handler on SMP systems.
- *
- * Caller must have changed pm_idle to the new value before the call. Old
- * pm_idle value will not be used by any CPU after the return of this function.
- */
-void cpu_idle_wait(void)
-{
-	smp_mb();
-	/* kick all the CPUs so that they exit out of pm_idle */
-	smp_call_function(do_nothing, NULL, 1);
-}
-EXPORT_SYMBOL_GPL(cpu_idle_wait);
-
 /* Default MONITOR/MWAIT with no hints, used for default C1 state */
 static void mwait_idle(void)
 {