aha/arch/x86/lib/msr-on-cpu.c
H. Peter Anvin bdd314616f x86: msr-on-cpu: remove unnecessary level of abstraction
Remove an unnecessary level of abstraction in the msr-on-cpu library.
Although this duplicates some code, the duplicated code is less than
the additional code, and this way should be faster.

Additionally, change the order of the functions to make the regular
structure of this file more obvious.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-08-25 22:45:50 -07:00

97 lines
1.7 KiB
C

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