linux/include/asm-i386/msr.h
H. Peter Anvin b0b73cb41d i386: msr.h: be paranoid about types and parentheses
When implementing things as macros, make sure we use typecasts and
parentheses where needed.  The macros as defined were vulnerable to
surreptitious promotion causing problems.

Avoid macros where practical; e.g. wrmsr() can be an inline instead.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:49:33 -07:00

162 lines
3.8 KiB
C

#ifndef __ASM_MSR_H
#define __ASM_MSR_H
#include <asm/msr-index.h>
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
#include <asm/errno.h>
static inline unsigned long long native_read_msr(unsigned int msr)
{
unsigned long long val;
asm volatile("rdmsr" : "=A" (val) : "c" (msr));
return val;
}
static inline unsigned long long native_read_msr_safe(unsigned int msr,
int *err)
{
unsigned long long val;
asm volatile("2: rdmsr ; xorl %0,%0\n"
"1:\n\t"
".section .fixup,\"ax\"\n\t"
"3: movl %3,%0 ; jmp 1b\n\t"
".previous\n\t"
".section __ex_table,\"a\"\n"
" .align 4\n\t"
" .long 2b,3b\n\t"
".previous"
: "=r" (*err), "=A" (val)
: "c" (msr), "i" (-EFAULT));
return val;
}
static inline void native_write_msr(unsigned int msr, unsigned long long val)
{
asm volatile("wrmsr" : : "c" (msr), "A"(val));
}
static inline int native_write_msr_safe(unsigned int msr,
unsigned long long val)
{
int err;
asm volatile("2: wrmsr ; xorl %0,%0\n"
"1:\n\t"
".section .fixup,\"ax\"\n\t"
"3: movl %4,%0 ; jmp 1b\n\t"
".previous\n\t"
".section __ex_table,\"a\"\n"
" .align 4\n\t"
" .long 2b,3b\n\t"
".previous"
: "=a" (err)
: "c" (msr), "0" ((u32)val), "d" ((u32)(val>>32)),
"i" (-EFAULT));
return err;
}
static inline unsigned long long native_read_tsc(void)
{
unsigned long long val;
asm volatile("rdtsc" : "=A" (val));
return val;
}
static inline unsigned long long native_read_pmc(void)
{
unsigned long long val;
asm volatile("rdpmc" : "=A" (val));
return val;
}
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else
#include <linux/errno.h>
/*
* Access to machine-specific registers (available on 586 and better only)
* Note: the rd* operations modify the parameters directly (without using
* pointer indirection), this allows gcc to optimize better
*/
#define rdmsr(msr,val1,val2) \
do { \
u64 __val = native_read_msr(msr); \
(val1) = (u32)__val; \
(val2) = (u32)(__val >> 32); \
} while(0)
static inline void wrmsr(u32 __msr, u32 __low, u32 __high)
{
native_write_msr(__msr, ((u64)__high << 32) | __low);
}
#define rdmsrl(msr,val) \
((val) = native_read_msr(msr))
#define wrmsrl(msr,val) native_write_msr(msr, val)
/* wrmsr with exception handling */
static inline int wrmsr_safe(u32 __msr, u32 __low, u32 __high)
{
return native_write_msr_safe(__msr, ((u64)__high << 32) | __low);
}
/* rdmsr with exception handling */
#define rdmsr_safe(msr,p1,p2) \
({ \
int __err; \
u64 __val = native_read_msr_safe(msr, &__err); \
(*p1) = (u32)__val; \
(*p2) = (u32)(__val >> 32); \
__err; \
})
#define rdtscl(low) \
((low) = (u32)native_read_tsc())
#define rdtscll(val) \
((val) = native_read_tsc())
#define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
#define rdpmc(counter,low,high) \
do { \
u64 _l = native_read_pmc(); \
(low) = (u32)_l; \
(high) = (u32)(_l >> 32); \
} while(0)
#endif /* !CONFIG_PARAVIRT */
#ifdef CONFIG_SMP
void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
#else /* CONFIG_SMP */
static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
rdmsr(msr_no, *l, *h);
}
static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
wrmsr(msr_no, l, h);
}
static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
return rdmsr_safe(msr_no, l, h);
}
static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
return wrmsr_safe(msr_no, l, h);
}
#endif /* CONFIG_SMP */
#endif
#endif
#endif /* __ASM_MSR_H */