[PATCH] Fix written but not read warnings for x2apic.h

From: Andi Kleen
Date: Tue Oct 26 2010 - 10:02:26 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

A current linus master build with x2apic and a gcc 4.6 snapshot is very noisy,
because of a lot of

arch/x86/include/asm/apic.h:184:11: warning: variable 'msr2' set but not used [-Wunused-but-set-variable]
In file included from /home/lsrc/git/linux-2.6/arch/x86/include/asm/smp.h:13:0,
from /home/lsrc/git/linux-2.6/arch/x86/include/asm/mmzone_64.h:12,
from /home/lsrc/git/linux-2.6/arch/x86/include/asm/mmzone.h:4,
from /home/lsrc/git/linux-2.6/include/linux/mmzone.h:784,
from /home/lsrc/git/linux-2.6/include/linux/gfp.h:4,
from /home/lsrc/git/linux-2.6/include/linux/mm.h:8,
from /home/lsrc/git/linux-2.6/mm/page_io.c:13:
/home/lsrc/git/linux-2.6/arch/x86/include/asm/apic.h: In function 'native_apic_msr_read':
/home/lsrc/git/linux-2.6/arch/x86/include/asm/apic.h:144:11: warning: variable 'high' set but not used [-Wunused-but-set-variable]
/home/lsrc/git/linux-2.6/arch/x86/include/asm/apic.h: In function 'x2apic_enabled':
/home/lsrc/git/linux-2.6/arch/x86/include/asm/apic.h:184:11: warning: variable 'msr2' set but not used [-Wunused-but-set-variable]

in the x2apic code. Use rdmsrl to avoid this warning. This actually
avoids some code because rdmsr is just a wrapper around rdmsrl.

Cc: Suresh.b.siddha@xxxxxxxxx
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/apic.h | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 286de34..9c4e06b 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -141,12 +141,12 @@ 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);
+ rdmsrl(APIC_BASE_MSR + (reg >> 4), low);
return low;
}

@@ -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;
+ int 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

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