x86/MSR: Carve out bare minimum accessors
Add __rdmsr() and __wrmsr() which *only* read and write an MSR with
exception handling. Those are going to be used in early code, like the
microcode loader, which cannot stomach tracing code piggybacking on the
MSR operation.
While at it, get rid of __native_write_msr_notrace().
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-3-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 0c5fbc6..eff8e36 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -195,7 +195,7 @@ static inline void native_apic_msr_write(u32 reg, u32 v)
static inline void native_apic_msr_eoi_write(u32 reg, u32 v)
{
- wrmsr_notrace(APIC_BASE_MSR + (APIC_EOI >> 4), APIC_EOI_ACK, 0);
+ __wrmsr(APIC_BASE_MSR + (APIC_EOI >> 4), APIC_EOI_ACK, 0);
}
static inline u32 native_apic_msr_read(u32 reg)