Commit 6ede31e0 authored by Borislav Petkov's avatar Borislav Petkov Committed by H. Peter Anvin
Browse files

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: default avatarRandy Dunlap <randy.dunlap@oracle.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarBorislav Petkov <petkovbb@gmail.com>
LKML-Reference: <20091216231625.GD27228@liondog.tnic>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 9d260ebc

arch/x86/include/asm/msr.h

+12 −0
Original line number Diff line number Diff line
@@ -27,6 +27,18 @@ struct msr { 
	};

};



struct msr_info {

	u32 msr_no;

	struct msr reg;

	struct msr *msrs;

	int err;

};



struct msr_regs_info {

	u32 *regs;

	int err;

};



static inline unsigned long long native_read_tscp(unsigned int *aux)

{

	unsigned long low, high;

arch/x86/lib/Makefile

+2 −2
Original line number Diff line number Diff line
@@ -14,7 +14,7 @@ $(obj)/inat.o: $(obj)/inat-tables.c 


clean-files := inat-tables.c



obj-$(CONFIG_SMP) := msr.o

obj-$(CONFIG_SMP) += msr-smp.o



lib-y := delay.o

lib-y += thunk_$(BITS).o
@@ -22,7 +22,7 @@ lib-y += usercopy_$(BITS).o getuser.o putuser.o 
lib-y += memcpy_$(BITS).o

lib-y += insn.o inat.o



obj-y += msr-reg.o msr-reg-export.o

obj-y += msr.o msr-reg.o msr-reg-export.o



ifeq ($(CONFIG_X86_32),y)

        obj-y += atomic64_32.o

arch/x86/lib/msr-smp.c

0 → 100644
+204 −0
Original line number Diff line number Diff line 
#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);

arch/x86/lib/msr.c

+0 −213
Original line number Diff line number Diff line 
#include <linux/module.h>

#include <linux/preempt.h>

#include <linux/smp.h>

#include <asm/msr.h>



struct msr_info {

	u32 msr_no;

	struct msr reg;

	struct msr *msrs;

	int err;

};



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);



struct msr *msrs_alloc(void)

{

	struct msr *msrs = NULL;
@@ -137,100 +21,3 @@ void msrs_free(struct msr *msrs) 
	free_percpu(msrs);

}

EXPORT_SYMBOL(msrs_free);
 


/* 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.

 */

struct msr_regs_info {

	u32 *regs;

	int err;

};



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);

CRA Git | Maintained and supported by SUSTech CRA and CCSE