From: Andi Kleen <ak@linux.intel.com>

Fix

linux-2.6/arch/x86/include/asm/apic.h: In function 'native_apic_msr_read':
linux-2.6/arch/x86/include/asm/apic.h:144:11: warning: variable 'high' set but not used [-Wunused-but-set-variable]
linux-2.6/arch/x86/include/asm/apic.h: In function 'x2apic_enabled':
linux-2.6/arch/x86/include/asm/apic.h:184:11: warning: variable 'msr2' set but not used [-Wunused-but-set-variable]

which happen with a gcc 4.6 build

Since this is in a frequently included header these warnings are printed
very frequently and make a gcc 4.6 build very noisy.

v2: Add cast and change types based on review feedback.

Cc: x86@kernel.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 arch/x86/include/asm/apic.h |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 286de34..e5472de 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -141,13 +141,13 @@ static inline void native_apic_msr_write(u32 reg, u32 v)
 
 static inline u32 native_apic_msr_read(u32 reg)
 {
-	u32 low, high;
+	u32 low;
 
 	if (reg == APIC_DFR)
 		return -1;
 
-	rdmsr(APIC_BASE_MSR + (reg >> 4), low, high);
-	return low;
+	rdmsrl(APIC_BASE_MSR + (reg >> 4), low);
+	return (u32)low;
 }
 
 static inline void native_x2apic_wait_icr_idle(void)
@@ -181,12 +181,12 @@ extern void enable_x2apic(void);
 extern void x2apic_icr_write(u32 low, u32 id);
 static inline int x2apic_enabled(void)
 {
-	int msr, msr2;
+	u32 msr;
 
 	if (!cpu_has_x2apic)
 		return 0;
 
-	rdmsr(MSR_IA32_APICBASE, msr, msr2);
+	rdmsrl(MSR_IA32_APICBASE, msr);
 	if (msr & X2APIC_ENABLE)
 		return 1;
 	return 0;
-- 
1.7.1

--

[ message continues ]

What's the point of casting u32 to u32 ?

Thanks,

	tglx
--

[ message continues ]

One of the earlier reviewers thought adding an explicit cast would make
the truncation in the code clearer.  I didn't full agree either, but 
still did the change.

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.
--

[ message continues ]

Well, Andi I proposed to define variable as u64 and convert it back to u32 at procedure
exit point. That would be clean, and I still think so ;) Though I'm fine with
either way (I just thought about ones who will be reading this code in future,
and since most the rdmsrl callers already use u64 and unsigned long, this would
be consistent as well).

  Cyrill
--

[ message continues ]

I didn't use u64 because that would use more code on i386

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.
--

[ message continues ]

Fair enough. Thanks Andi.

  Cyrill
--

[ message continues ]