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>
		
	
			
		
			
				
	
	
		
			204 lines
		
	
	
	
		
			4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			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);
 |