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Commit 8b956bf1 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86, msr: Create _on_cpu helpers for {rw,wr}msr_safe_regs() 



Create _on_cpu helpers for {rw,wr}msr_safe_regs() analogously with the
other MSR functions.  This will be necessary to add support for these
to the MSR driver.

Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <petkovbb@gmail.com>
parent 0cc0213e

arch/x86/include/asm/msr.h

+14 −4
Original line number Diff line number Diff line
@@ -97,8 +97,8 @@ notrace static inline int native_write_msr_safe(unsigned int msr, 


extern unsigned long long native_read_tsc(void);



extern int native_rdmsr_safe_regs(u32 *regs);

extern int native_wrmsr_safe_regs(u32 *regs);

extern int native_rdmsr_safe_regs(u32 regs[8]);

extern int native_wrmsr_safe_regs(u32 regs[8]);



static __always_inline unsigned long long __native_read_tsc(void)

{
@@ -196,12 +196,12 @@ static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val) 
	return native_wrmsr_safe_regs(gprs);

}



static inline int rdmsr_safe_regs(u32 *regs)

static inline int rdmsr_safe_regs(u32 regs[8])

{

	return native_rdmsr_safe_regs(regs);

}



static inline int wrmsr_safe_regs(u32 *regs)

static inline int wrmsr_safe_regs(u32 regs[8])

{

	return native_wrmsr_safe_regs(regs);

}
@@ -245,6 +245,8 @@ void rdmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs); 
void wrmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs);

int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);

int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);

int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);

int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);

#else  /*  CONFIG_SMP  */

static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)

{
@@ -275,6 +277,14 @@ static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) 
{

	return wrmsr_safe(msr_no, l, h);

}

static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])

{

	return rdmsr_safe_regs(regs);

}

static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])

{

	return wrmsr_safe_regs(regs);

}

#endif  /* CONFIG_SMP */

#endif /* __ASSEMBLY__ */

#endif /* __KERNEL__ */

arch/x86/lib/msr.c

+49 −0
Original line number Diff line number Diff line
@@ -175,3 +175,52 @@ int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) 
	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);