linux/include/asm-x86_64/msr.h
Rudolf Marek 4e9baad8f5 i386: Add safe variants of rdmsr_on_cpu and wrmsr_on_cpu
Add safe (exception handled) variants of rdmsr_on_cpu and wrmsr_on_cpu.
You should use these when the target MSR may not actually exist, as
doing so could trigger an exception which the regular functions do not
handle. The safe variants are slower, though.

The upcoming coretemp hardware monitoring driver will need this.

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Cc: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-08 17:22:01 +02:00

187 lines
4.9 KiB
C

#ifndef X86_64_MSR_H
#define X86_64_MSR_H 1
#include <asm/msr-index.h>
#ifndef __ASSEMBLY__
#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) \
__asm__ __volatile__("rdmsr" \
: "=a" (val1), "=d" (val2) \
: "c" (msr))
#define rdmsrl(msr,val) do { unsigned long a__,b__; \
__asm__ __volatile__("rdmsr" \
: "=a" (a__), "=d" (b__) \
: "c" (msr)); \
val = a__ | (b__<<32); \
} while(0)
#define wrmsr(msr,val1,val2) \
__asm__ __volatile__("wrmsr" \
: /* no outputs */ \
: "c" (msr), "a" (val1), "d" (val2))
#define wrmsrl(msr,val) wrmsr(msr,(__u32)((__u64)(val)),((__u64)(val))>>32)
/* wrmsr with exception handling */
#define wrmsr_safe(msr,a,b) ({ int ret__; \
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 8\n\t" \
" .quad 2b,3b\n\t" \
".previous" \
: "=a" (ret__) \
: "c" (msr), "0" (a), "d" (b), "i" (-EFAULT)); \
ret__; })
#define checking_wrmsrl(msr,val) wrmsr_safe(msr,(u32)(val),(u32)((val)>>32))
#define rdmsr_safe(msr,a,b) \
({ int ret__; \
asm volatile ("1: rdmsr\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: movl %4,%0\n" \
" jmp 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 8\n" \
" .quad 1b,3b\n" \
".previous":"=&bDS" (ret__), "=a"(*(a)), "=d"(*(b))\
:"c"(msr), "i"(-EIO), "0"(0)); \
ret__; })
#define rdtsc(low,high) \
__asm__ __volatile__("rdtsc" : "=a" (low), "=d" (high))
#define rdtscl(low) \
__asm__ __volatile__ ("rdtsc" : "=a" (low) : : "edx")
#define rdtscp(low,high,aux) \
asm volatile (".byte 0x0f,0x01,0xf9" : "=a" (low), "=d" (high), "=c" (aux))
#define rdtscll(val) do { \
unsigned int __a,__d; \
asm volatile("rdtsc" : "=a" (__a), "=d" (__d)); \
(val) = ((unsigned long)__a) | (((unsigned long)__d)<<32); \
} while(0)
#define rdtscpll(val, aux) do { \
unsigned long __a, __d; \
asm volatile (".byte 0x0f,0x01,0xf9" : "=a" (__a), "=d" (__d), "=c" (aux)); \
(val) = (__d << 32) | __a; \
} while (0)
#define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
#define write_rdtscp_aux(val) wrmsr(0xc0000103, val, 0)
#define rdpmc(counter,low,high) \
__asm__ __volatile__("rdpmc" \
: "=a" (low), "=d" (high) \
: "c" (counter))
static inline void cpuid(int op, unsigned int *eax, unsigned int *ebx,
unsigned int *ecx, unsigned int *edx)
{
__asm__("cpuid"
: "=a" (*eax),
"=b" (*ebx),
"=c" (*ecx),
"=d" (*edx)
: "0" (op));
}
/* Some CPUID calls want 'count' to be placed in ecx */
static inline void cpuid_count(int op, int count, int *eax, int *ebx, int *ecx,
int *edx)
{
__asm__("cpuid"
: "=a" (*eax),
"=b" (*ebx),
"=c" (*ecx),
"=d" (*edx)
: "0" (op), "c" (count));
}
/*
* CPUID functions returning a single datum
*/
static inline unsigned int cpuid_eax(unsigned int op)
{
unsigned int eax;
__asm__("cpuid"
: "=a" (eax)
: "0" (op)
: "bx", "cx", "dx");
return eax;
}
static inline unsigned int cpuid_ebx(unsigned int op)
{
unsigned int eax, ebx;
__asm__("cpuid"
: "=a" (eax), "=b" (ebx)
: "0" (op)
: "cx", "dx" );
return ebx;
}
static inline unsigned int cpuid_ecx(unsigned int op)
{
unsigned int eax, ecx;
__asm__("cpuid"
: "=a" (eax), "=c" (ecx)
: "0" (op)
: "bx", "dx" );
return ecx;
}
static inline unsigned int cpuid_edx(unsigned int op)
{
unsigned int eax, edx;
__asm__("cpuid"
: "=a" (eax), "=d" (edx)
: "0" (op)
: "bx", "cx");
return edx;
}
#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 /* __ASSEMBLY__ */
#endif /* X86_64_MSR_H */