[PATCH] [5/7] Readd rdmsrl_safe

From: Andi Kleen
Date: Tue Mar 11 2008 - 22:54:48 EST



RDMSR for 64bit values with exception handling.

Makes it easier to deal with 64bit valued MSRs. The old 64bit code
base had that too as checking_rdmsrl(), but it got dropped somehow.

Needed for followup patch.

Signed-off-by: Andi Kleen <ak@xxxxxxx>

---
include/asm-x86/msr.h | 3 +++
include/asm-x86/paravirt.h | 4 ++++
2 files changed, 7 insertions(+)

Index: linux/include/asm-x86/msr.h
===================================================================
--- linux.orig/include/asm-x86/msr.h
+++ linux/include/asm-x86/msr.h
@@ -150,6 +150,9 @@ static inline int wrmsr_safe(unsigned ms
__err; \
})

+#define rdmsrl_safe(msr,p) \
+ ({ int __err; *(p) = native_read_msr_safe(msr, &__err); __err; })
+
#define rdtscl(low) \
((low) = (u32)native_read_tsc())

Index: linux/include/asm-x86/paravirt.h
===================================================================
--- linux.orig/include/asm-x86/paravirt.h
+++ linux/include/asm-x86/paravirt.h
@@ -687,6 +687,10 @@ static inline int paravirt_write_msr(uns
(*b) = _l >> 32; \
_err; })

+#define rdmsrl_safe(msr, p) ({ \
+ int _err; \
+ *(p) = paravirt_read_msr(msr, &_err); \
+ _err; })

static inline u64 paravirt_read_tsc(void)
{
--
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