linux/arch/x86/lib/msr-smp.c
Borislav Petkov 6ede31e030 x86, msr: msrs_alloc/free for CONFIG_SMP=n
Randy Dunlap reported the following build error:

"When CONFIG_SMP=n, CONFIG_X86_MSR=m:

ERROR: "msrs_free" [drivers/edac/amd64_edac_mod.ko] undefined!
ERROR: "msrs_alloc" [drivers/edac/amd64_edac_mod.ko] undefined!"

This is due to the fact that <arch/x86/lib/msr.c> is conditioned on
CONFIG_SMP and in the UP case we have only the stubs in the header.
Fork off SMP functionality into a new file (msr-smp.c) and build
msrs_{alloc,free} unconditionally.

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
LKML-Reference: <20091216231625.GD27228@liondog.tnic>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-16 15:36:32 -08:00

204 lines
4 KiB
C

#include <linux/module.h>
#include <linux/preempt.h>
#include <linux/smp.h>
#include <asm/msr.h>
static void __rdmsr_on_cpu(void *info)
{
struct msr_info *rv = info;
struct msr *reg;
int this_cpu = raw_smp_processor_id();
if (rv->msrs)
reg = per_cpu_ptr(rv->msrs, this_cpu);
else
reg = &rv->reg;
rdmsr(rv->msr_no, reg->l, reg->h);
}
static void __wrmsr_on_cpu(void *info)
{
struct msr_info *rv = info;
struct msr *reg;
int this_cpu = raw_smp_processor_id();
if (rv->msrs)
reg = per_cpu_ptr(rv->msrs, this_cpu);
else
reg = &rv->reg;
wrmsr(rv->msr_no, reg->l, reg->h);
}
int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
int err;
struct msr_info rv;
memset(&rv, 0, sizeof(rv));
rv.msr_no = msr_no;
err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
*l = rv.reg.l;
*h = rv.reg.h;
return err;
}
EXPORT_SYMBOL(rdmsr_on_cpu);
int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
int err;
struct msr_info rv;
memset(&rv, 0, sizeof(rv));
rv.msr_no = msr_no;
rv.reg.l = l;
rv.reg.h = h;
err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
return err;
}
EXPORT_SYMBOL(wrmsr_on_cpu);
static void __rwmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
struct msr *msrs,
void (*msr_func) (void *info))
{
struct msr_info rv;
int this_cpu;
memset(&rv, 0, sizeof(rv));
rv.msrs = msrs;
rv.msr_no = msr_no;
this_cpu = get_cpu();
if (cpumask_test_cpu(this_cpu, mask))
msr_func(&rv);
smp_call_function_many(mask, msr_func, &rv, 1);
put_cpu();
}
/* rdmsr on a bunch of CPUs
*
* @mask: which CPUs
* @msr_no: which MSR
* @msrs: array of MSR values
*
*/
void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
{
__rwmsr_on_cpus(mask, msr_no, msrs, __rdmsr_on_cpu);
}
EXPORT_SYMBOL(rdmsr_on_cpus);
/*
* wrmsr on a bunch of CPUs
*
* @mask: which CPUs
* @msr_no: which MSR
* @msrs: array of MSR values
*
*/
void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
{
__rwmsr_on_cpus(mask, msr_no, msrs, __wrmsr_on_cpu);
}
EXPORT_SYMBOL(wrmsr_on_cpus);
/* 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->reg.l, &rv->reg.h);
}
static void __wrmsr_safe_on_cpu(void *info)
{
struct msr_info *rv = info;
rv->err = wrmsr_safe(rv->msr_no, rv->reg.l, rv->reg.h);
}
int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
int err;
struct msr_info rv;
memset(&rv, 0, sizeof(rv));
rv.msr_no = msr_no;
err = smp_call_function_single(cpu, __rdmsr_safe_on_cpu, &rv, 1);
*l = rv.reg.l;
*h = rv.reg.h;
return err ? err : rv.err;
}
EXPORT_SYMBOL(rdmsr_safe_on_cpu);
int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
int err;
struct msr_info rv;
memset(&rv, 0, sizeof(rv));
rv.msr_no = msr_no;
rv.reg.l = l;
rv.reg.h = h;
err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
return err ? err : rv.err;
}
EXPORT_SYMBOL(wrmsr_safe_on_cpu);
/*
* These variants are significantly slower, but allows control over
* the entire 32-bit GPR set.
*/
static void __rdmsr_safe_regs_on_cpu(void *info)
{
struct msr_regs_info *rv = info;
rv->err = rdmsr_safe_regs(rv->regs);
}
static void __wrmsr_safe_regs_on_cpu(void *info)
{
struct msr_regs_info *rv = info;
rv->err = wrmsr_safe_regs(rv->regs);
}
int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs)
{
int err;
struct msr_regs_info rv;
rv.regs = regs;
rv.err = -EIO;
err = smp_call_function_single(cpu, __rdmsr_safe_regs_on_cpu, &rv, 1);
return err ? err : rv.err;
}
EXPORT_SYMBOL(rdmsr_safe_regs_on_cpu);
int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs)
{
int err;
struct msr_regs_info rv;
rv.regs = regs;
rv.err = -EIO;
err = smp_call_function_single(cpu, __wrmsr_safe_regs_on_cpu, &rv, 1);
return err ? err : rv.err;
}
EXPORT_SYMBOL(wrmsr_safe_regs_on_cpu);