kernel_optimize_test/arch/i386/lib/msr-on-cpu.c
Adrian Bunk b44755cfaa {rd,wr}msr_on_cpu SMP=n optimization
Let's save a few bytes in the CONFIG_SMP=n case.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2007-02-20 14:29:37 -05:00

59 lines
1.0 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;
};
static void __rdmsr_on_cpu(void *info)
{
struct msr_info *rv = info;
rdmsr(rv->msr_no, rv->l, rv->h);
}
void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
preempt_disable();
if (smp_processor_id() == cpu)
rdmsr(msr_no, *l, *h);
else {
struct msr_info rv;
rv.msr_no = msr_no;
smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 0, 1);
*l = rv.l;
*h = rv.h;
}
preempt_enable();
}
static void __wrmsr_on_cpu(void *info)
{
struct msr_info *rv = info;
wrmsr(rv->msr_no, rv->l, rv->h);
}
void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
preempt_disable();
if (smp_processor_id() == cpu)
wrmsr(msr_no, l, h);
else {
struct msr_info rv;
rv.msr_no = msr_no;
rv.l = l;
rv.h = h;
smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 0, 1);
}
preempt_enable();
}
EXPORT_SYMBOL(rdmsr_on_cpu);
EXPORT_SYMBOL(wrmsr_on_cpu);