i386: simplify smp_call_function_single() call sequence in cpuid

smp_call_function_single() now knows how to call the function on the
current cpu.

[ tglx: arch/x86 adaptation ]

Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/cpuid.c

@@ -43,8 +43,6 @@
 
 static struct class *cpuid_class;
 
-#ifdef CONFIG_SMP
-
 struct cpuid_command {
 	u32 reg;
 	u32 *data;
@@ -62,25 +60,11 @@ static inline void do_cpuid(int cpu, u32 reg, u32 * data)
 {
 	struct cpuid_command cmd;
 
-	preempt_disable();
-	if (cpu == smp_processor_id()) {
-		cpuid(reg, &data[0], &data[1], &data[2], &data[3]);
-	} else {
 	cmd.reg = reg;
 	cmd.data = data;
 
 	smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1, 1);
-	}
-	preempt_enable();
 }
-#else				/* ! CONFIG_SMP */
-
-static inline void do_cpuid(int cpu, u32 reg, u32 * data)
-{
-	cpuid(reg, &data[0], &data[1], &data[2], &data[3]);
-}
-
-#endif				/* ! CONFIG_SMP */
 
 static loff_t cpuid_seek(struct file *file, loff_t offset, int orig)
 {