#include <linux/module.h>
#include <linux/preempt.h>
#include <linux/smp.h>
#include <asm/msr.h>
struct msr_info {
u32 msr_no;
u32 l, h;
int err;
};
static void __rdmsr_on_cpu(void *info)
{
struct msr_info *rv = info;
rdmsr(rv->msr_no, rv->l, rv->h);
}
static void __rdmsr_safe_on_cpu(void *info)
rv->err = rdmsr_safe(rv->msr_no, &rv->l, &rv->h);
static int _rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h, int safe)
int err = 0;
struct msr_info rv;
rv.msr_no = msr_no;
if (safe) {
err = smp_call_function_single(cpu, __rdmsr_safe_on_cpu,
&rv, 1);
err = err ? err : rv.err;
} else {
err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
*l = rv.l;
*h = rv.h;
return err;
static void __wrmsr_on_cpu(void *info)
wrmsr(rv->msr_no, rv->l, rv->h);
static void __wrmsr_safe_on_cpu(void *info)
rv->err = wrmsr_safe(rv->msr_no, rv->l, rv->h);
static int _wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h, int safe)
rv.l = l;
rv.h = h;
err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu,
err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
return _wrmsr_on_cpu(cpu, msr_no, l, h, 0);
int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
return _rdmsr_on_cpu(cpu, msr_no, l, h, 0);
/* These "safe" variants are slower and should be used when the target MSR
may not actually exist. */
int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
return _wrmsr_on_cpu(cpu, msr_no, l, h, 1);
int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
return _rdmsr_on_cpu(cpu, msr_no, l, h, 1);
EXPORT_SYMBOL(rdmsr_on_cpu);
EXPORT_SYMBOL(wrmsr_on_cpu);
EXPORT_SYMBOL(rdmsr_safe_on_cpu);
EXPORT_SYMBOL(wrmsr_safe_on_cpu);