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| author | Borislav Petkov <petkovbb@googlemail.com> | 2009-08-31 09:50:09 +0200 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-08-31 15:14:26 -0700 |
| commit | 132ec92f3f70fe365c1f4b8d46e66cf8a2a16880 (patch) | |
| tree | f8e3f3ab5541f583030b0bcd5f3f81ca338f77a2 /arch/x86/include/asm/msr.h | |
| parent | 366d19e181be873c70f4aafca3931d77d781ccd7 (diff) | |
| download | linux-0-day-132ec92f3f70fe365c1f4b8d46e66cf8a2a16880.tar.gz linux-0-day-132ec92f3f70fe365c1f4b8d46e66cf8a2a16880.tar.xz | |
x86, msr: Add rd/wrmsr interfaces with preset registers
native_{rdmsr,wrmsr}_safe_regs are two new interfaces which allow
presetting of a subset of eight x86 GPRs before executing the rd/wrmsr
instructions. This is needed at least on AMD K8 for accessing an erratum
workaround MSR.
Originally based on an idea by H. Peter Anvin.
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
LKML-Reference: <1251705011-18636-1-git-send-email-petkovbb@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/include/asm/msr.h')
| -rw-r--r-- | arch/x86/include/asm/msr.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index 48ad9d29484a0..184d4a113961a 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -113,6 +113,9 @@ notrace static inline int native_write_msr_safe(unsigned int msr, extern unsigned long long native_read_tsc(void); +extern int native_rdmsr_safe_regs(u32 *regs); +extern int native_wrmsr_safe_regs(u32 *regs); + static __always_inline unsigned long long __native_read_tsc(void) { DECLARE_ARGS(val, low, high); @@ -189,6 +192,16 @@ static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p) return err; } +static inline int rdmsr_safe_regs(u32 *regs) +{ + return native_rdmsr_safe_regs(regs); +} + +static inline int wrmsr_safe_regs(u32 *regs) +{ + return native_wrmsr_safe_regs(regs); +} + #define rdtscl(low) \ ((low) = (u32)__native_read_tsc()) |