i386: simplify smp_call_function_single() call sequence in msr-on-cpu

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>
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>

1 files changed, 22 insertions, 40 deletions

diff --git a/arch/x86/lib/msr-on-cpu.c b/arch/x86/lib/msr-on-cpu.c
index 7767962f25d3..57d043fa893e 100644
--- a/arch/x86/lib/msr-on-cpu.c
+++ b/arch/x86/lib/msr-on-cpu.c
@@ -26,27 +26,18 @@ static void __rdmsr_safe_on_cpu(void *info)
 static int _rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h, int safe)
 {
         int err = 0;
-        preempt_disable();
-        if (smp_processor_id() == cpu)
-                if (safe)
-                        err = rdmsr_safe(msr_no, l, h);
-                else
-                        rdmsr(msr_no, *l, *h);
-        else {
-                struct msr_info rv;
-
-                rv.msr_no = msr_no;
-                if (safe) {
-                        smp_call_function_single(cpu, __rdmsr_safe_on_cpu,
-                                                 &rv, 0, 1);
-                        err = rv.err;
-                } else {
-                        smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 0, 1);
-                }
-                *l = rv.l;
-                *h = rv.h;
+        struct msr_info rv;
+
+        rv.msr_no = msr_no;
+        if (safe) {
+                smp_call_function_single(cpu, __rdmsr_safe_on_cpu, &rv, 0, 1);
+                err = rv.err;
+        } else {
+                smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 0, 1);
         }
-        preempt_enable();
+        *l = rv.l;
+        *h = rv.h;
+
         return err;
 }
 
@@ -67,27 +58,18 @@ static void __wrmsr_safe_on_cpu(void *info)
 static int _wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h, int safe)
 {
         int err = 0;
-        preempt_disable();
-        if (smp_processor_id() == cpu)
-                if (safe)
-                        err = wrmsr_safe(msr_no, l, h);
-                else
-                        wrmsr(msr_no, l, h);
-        else {
-                struct msr_info rv;
-
-                rv.msr_no = msr_no;
-                rv.l = l;
-                rv.h = h;
-                if (safe) {
-                        smp_call_function_single(cpu, __wrmsr_safe_on_cpu,
-                                                 &rv, 0, 1);
-                        err = rv.err;
-                } else {
-                        smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 0, 1);
-                }
+        struct msr_info rv;
+
+        rv.msr_no = msr_no;
+        rv.l = l;
+        rv.h = h;
+        if (safe) {
+                smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 0, 1);
+                err = rv.err;
+        } else {
+                smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 0, 1);
         }
-        preempt_enable();
+
         return err;
 }