linux/arch/x86/include/asm/msr.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_MSR_H
#define _ASM_X86_MSR_H

#include "msr-index.h"

#ifndef __ASSEMBLY__

#include <asm/asm.h>
#include <asm/errno.h>
#include <asm/cpumask.h>
#include <uapi/asm/msr.h>
#include <asm/shared/msr.h>

#include <linux/percpu.h>

struct msr_info {};

struct msr_regs_info {};

struct saved_msr {};

struct saved_msrs {};

/*
 * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A"
 * constraint has different meanings. For i386, "A" means exactly
 * edx:eax, while for x86_64 it doesn't mean rdx:rax or edx:eax. Instead,
 * it means rax *or* rdx.
 */
#ifdef CONFIG_X86_64
/* Using 64-bit values saves one instruction clearing the high half of low */
#define DECLARE_ARGS(val, low, high)
#define EAX_EDX_VAL(val, low, high)
#define EAX_EDX_RET(val, low, high)
#else
#define DECLARE_ARGS
#define EAX_EDX_VAL
#define EAX_EDX_RET
#endif

/*
 * Be very careful with includes. This header is prone to include loops.
 */
#include <asm/atomic.h>
#include <linux/tracepoint-defs.h>

#ifdef CONFIG_TRACEPOINTS
DECLARE_TRACEPOINT();
DECLARE_TRACEPOINT();
DECLARE_TRACEPOINT();
extern void do_trace_write_msr(unsigned int msr, u64 val, int failed);
extern void do_trace_read_msr(unsigned int msr, u64 val, int failed);
extern void do_trace_rdpmc(unsigned int msr, u64 val, int failed);
#else
static inline void do_trace_write_msr(unsigned int msr, u64 val, int failed) {}
static inline void do_trace_read_msr(unsigned int msr, u64 val, int failed) {}
static inline void do_trace_rdpmc(unsigned int msr, u64 val, int failed) {}
#endif

/*
 * __rdmsr() and __wrmsr() are the two primitives which are the bare minimum MSR
 * accessors and should not have any tracing or other functionality piggybacking
 * on them - those are *purely* for accessing MSRs and nothing more. So don't even
 * think of extending them - you will be slapped with a stinking trout or a frozen
 * shark will reach you, wherever you are! You've been warned.
 */
static __always_inline unsigned long long __rdmsr(unsigned int msr)
{}

static __always_inline void __wrmsr(unsigned int msr, u32 low, u32 high)
{}

/*
 * WRMSRNS behaves exactly like WRMSR with the only difference being
 * that it is not a serializing instruction by default.
 */
static __always_inline void __wrmsrns(u32 msr, u32 low, u32 high)
{}

#define native_rdmsr(msr, val1, val2)

#define native_wrmsr(msr, low, high)

#define native_wrmsrl(msr, val)

static inline unsigned long long native_read_msr(unsigned int msr)
{}

static inline unsigned long long native_read_msr_safe(unsigned int msr,
						      int *err)
{}

/* Can be uninlined because referenced by paravirt */
static inline void notrace
native_write_msr(unsigned int msr, u32 low, u32 high)
{}

/* Can be uninlined because referenced by paravirt */
static inline int notrace
native_write_msr_safe(unsigned int msr, u32 low, u32 high)
{}

extern int rdmsr_safe_regs(u32 regs[8]);
extern int wrmsr_safe_regs(u32 regs[8]);

/**
 * rdtsc() - returns the current TSC without ordering constraints
 *
 * rdtsc() returns the result of RDTSC as a 64-bit integer.  The
 * only ordering constraint it supplies is the ordering implied by
 * "asm volatile": it will put the RDTSC in the place you expect.  The
 * CPU can and will speculatively execute that RDTSC, though, so the
 * results can be non-monotonic if compared on different CPUs.
 */
static __always_inline unsigned long long rdtsc(void)
{}

/**
 * rdtsc_ordered() - read the current TSC in program order
 *
 * rdtsc_ordered() returns the result of RDTSC as a 64-bit integer.
 * It is ordered like a load to a global in-memory counter.  It should
 * be impossible to observe non-monotonic rdtsc_unordered() behavior
 * across multiple CPUs as long as the TSC is synced.
 */
static __always_inline unsigned long long rdtsc_ordered(void)
{}

static inline unsigned long long native_read_pmc(int counter)
{}

#ifdef CONFIG_PARAVIRT_XXL
#include <asm/paravirt.h>
#else
#include <linux/errno.h>
/*
 * Access to machine-specific registers (available on 586 and better only)
 * Note: the rd* operations modify the parameters directly (without using
 * pointer indirection), this allows gcc to optimize better
 */

#define rdmsr

static inline void wrmsr(unsigned int msr, u32 low, u32 high)
{
	native_write_msr(msr, low, high);
}

#define rdmsrl

static inline void wrmsrl(unsigned int msr, u64 val)
{
	native_write_msr(msr, (u32)(val & 0xffffffffULL), (u32)(val >> 32));
}

/* wrmsr with exception handling */
static inline int wrmsr_safe(unsigned int msr, u32 low, u32 high)
{
	return native_write_msr_safe(msr, low, high);
}

/* rdmsr with exception handling */
#define rdmsr_safe

static inline int rdmsrl_safe(unsigned int msr, unsigned long long *p)
{
	int err;

	*p = native_read_msr_safe(msr, &err);
	return err;
}

#define rdpmc

#define rdpmcl

#endif	/* !CONFIG_PARAVIRT_XXL */

static __always_inline void wrmsrns(u32 msr, u64 val)
{}

/*
 * 64-bit version of wrmsr_safe():
 */
static inline int wrmsrl_safe(u32 msr, u64 val)
{}

struct msr __percpu *msrs_alloc(void);
void msrs_free(struct msr __percpu *msrs);
int msr_set_bit(u32 msr, u8 bit);
int msr_clear_bit(u32 msr, u8 bit);

#ifdef CONFIG_SMP
int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q);
void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr __percpu *msrs);
void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr __percpu *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 rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q);
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)
{
	rdmsr(msr_no, *l, *h);
	return 0;
}
static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
	wrmsr(msr_no, l, h);
	return 0;
}
static inline int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
{
	rdmsrl(msr_no, *q);
	return 0;
}
static inline int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
{
	wrmsrl(msr_no, q);
	return 0;
}
static inline void rdmsr_on_cpus(const struct cpumask *m, u32 msr_no,
				struct msr __percpu *msrs)
{
	rdmsr_on_cpu(0, msr_no, raw_cpu_ptr(&msrs->l), raw_cpu_ptr(&msrs->h));
}
static inline void wrmsr_on_cpus(const struct cpumask *m, u32 msr_no,
				struct msr __percpu *msrs)
{
	wrmsr_on_cpu(0, msr_no, raw_cpu_read(msrs->l), raw_cpu_read(msrs->h));
}
static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
				    u32 *l, u32 *h)
{
	return rdmsr_safe(msr_no, l, h);
}
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 rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
{
	return rdmsrl_safe(msr_no, q);
}
static inline int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
{
	return wrmsrl_safe(msr_no, q);
}
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 /* _ASM_X86_MSR_H */