linux/include/asm-i386/paravirt.h

#ifndef __ASM_PARAVIRT_H
#define __ASM_PARAVIRT_H
/* Various instructions on x86 need to be replaced for
 * para-virtualization: those hooks are defined here. */
#include <linux/linkage.h>

#ifdef CONFIG_PARAVIRT
#ifndef __ASSEMBLY__
struct thread_struct;
struct Xgt_desc_struct;
struct tss_struct;
struct paravirt_ops
{
	unsigned int kernel_rpl;
 	int paravirt_enabled;
	const char *name;

	void (*arch_setup)(void);
	char *(*memory_setup)(void);
	void (*init_IRQ)(void);

	void (*banner)(void);

	unsigned long (*get_wallclock)(void);
	int (*set_wallclock)(unsigned long);
	void (*time_init)(void);

	/* All the function pointers here are declared as "fastcall"
	   so that we get a specific register-based calling
	   convention.  This makes it easier to implement inline
	   assembler replacements. */

	void (fastcall *cpuid)(unsigned int *eax, unsigned int *ebx,
		      unsigned int *ecx, unsigned int *edx);

	unsigned long (fastcall *get_debugreg)(int regno);
	void (fastcall *set_debugreg)(int regno, unsigned long value);

	void (fastcall *clts)(void);

	unsigned long (fastcall *read_cr0)(void);
	void (fastcall *write_cr0)(unsigned long);

	unsigned long (fastcall *read_cr2)(void);
	void (fastcall *write_cr2)(unsigned long);

	unsigned long (fastcall *read_cr3)(void);
	void (fastcall *write_cr3)(unsigned long);

	unsigned long (fastcall *read_cr4_safe)(void);
	unsigned long (fastcall *read_cr4)(void);
	void (fastcall *write_cr4)(unsigned long);

	unsigned long (fastcall *save_fl)(void);
	void (fastcall *restore_fl)(unsigned long);
	void (fastcall *irq_disable)(void);
	void (fastcall *irq_enable)(void);
	void (fastcall *safe_halt)(void);
	void (fastcall *halt)(void);
	void (fastcall *wbinvd)(void);

	/* err = 0/-EFAULT.  wrmsr returns 0/-EFAULT. */
	u64 (fastcall *read_msr)(unsigned int msr, int *err);
	int (fastcall *write_msr)(unsigned int msr, u64 val);

	u64 (fastcall *read_tsc)(void);
	u64 (fastcall *read_pmc)(void);

	void (fastcall *load_tr_desc)(void);
	void (fastcall *load_gdt)(const struct Xgt_desc_struct *);
	void (fastcall *load_idt)(const struct Xgt_desc_struct *);
	void (fastcall *store_gdt)(struct Xgt_desc_struct *);
	void (fastcall *store_idt)(struct Xgt_desc_struct *);
	void (fastcall *set_ldt)(const void *desc, unsigned entries);
	unsigned long (fastcall *store_tr)(void);
	void (fastcall *load_tls)(struct thread_struct *t, unsigned int cpu);
	void (fastcall *write_ldt_entry)(void *dt, int entrynum,
					 u32 low, u32 high);
	void (fastcall *write_gdt_entry)(void *dt, int entrynum,
					 u32 low, u32 high);
	void (fastcall *write_idt_entry)(void *dt, int entrynum,
					 u32 low, u32 high);
	void (fastcall *load_esp0)(struct tss_struct *tss,
				   struct thread_struct *thread);

	void (fastcall *set_iopl_mask)(unsigned mask);

	void (fastcall *io_delay)(void);
	void (*const_udelay)(unsigned long loops);

	/* These two are jmp to, not actually called. */
	void (fastcall *irq_enable_sysexit)(void);
	void (fastcall *iret)(void);
};

extern struct paravirt_ops paravirt_ops;

#define paravirt_enabled() (paravirt_ops.paravirt_enabled)

static inline void load_esp0(struct tss_struct *tss,
			     struct thread_struct *thread)
{
	paravirt_ops.load_esp0(tss, thread);
}

#define ARCH_SETUP			paravirt_ops.arch_setup();
static inline unsigned long get_wallclock(void)
{
	return paravirt_ops.get_wallclock();
}

static inline int set_wallclock(unsigned long nowtime)
{
	return paravirt_ops.set_wallclock(nowtime);
}

static inline void do_time_init(void)
{
	return paravirt_ops.time_init();
}

/* The paravirtualized CPUID instruction. */
static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
			   unsigned int *ecx, unsigned int *edx)
{
	paravirt_ops.cpuid(eax, ebx, ecx, edx);
}

/*
 * These special macros can be used to get or set a debugging register
 */
#define get_debugreg(var, reg) var = paravirt_ops.get_debugreg(reg)
#define set_debugreg(val, reg) paravirt_ops.set_debugreg(reg, val)

#define clts() paravirt_ops.clts()

#define read_cr0() paravirt_ops.read_cr0()
#define write_cr0(x) paravirt_ops.write_cr0(x)

#define read_cr2() paravirt_ops.read_cr2()
#define write_cr2(x) paravirt_ops.write_cr2(x)

#define read_cr3() paravirt_ops.read_cr3()
#define write_cr3(x) paravirt_ops.write_cr3(x)

#define read_cr4() paravirt_ops.read_cr4()
#define read_cr4_safe(x) paravirt_ops.read_cr4_safe()
#define write_cr4(x) paravirt_ops.write_cr4(x)

static inline unsigned long __raw_local_save_flags(void)
{
	return paravirt_ops.save_fl();
}

static inline void raw_local_irq_restore(unsigned long flags)
{
	return paravirt_ops.restore_fl(flags);
}

static inline void raw_local_irq_disable(void)
{
	paravirt_ops.irq_disable();
}

static inline void raw_local_irq_enable(void)
{
	paravirt_ops.irq_enable();
}

static inline unsigned long __raw_local_irq_save(void)
{
	unsigned long flags = paravirt_ops.save_fl();

	paravirt_ops.irq_disable();

	return flags;
}

static inline void raw_safe_halt(void)
{
	paravirt_ops.safe_halt();
}

static inline void halt(void)
{
	paravirt_ops.safe_halt();
}
#define wbinvd() paravirt_ops.wbinvd()

#define get_kernel_rpl()  (paravirt_ops.kernel_rpl)

#define rdmsr(msr,val1,val2) do {				\
	int _err;						\
	u64 _l = paravirt_ops.read_msr(msr,&_err);		\
	val1 = (u32)_l;						\
	val2 = _l >> 32;					\
} while(0)

#define wrmsr(msr,val1,val2) do {				\
	u64 _l = ((u64)(val2) << 32) | (val1);			\
	paravirt_ops.write_msr((msr), _l);			\
} while(0)

#define rdmsrl(msr,val) do {					\
	int _err;						\
	val = paravirt_ops.read_msr((msr),&_err);		\
} while(0)

#define wrmsrl(msr,val) (paravirt_ops.write_msr((msr),(val)))
#define wrmsr_safe(msr,a,b) ({					\
	u64 _l = ((u64)(b) << 32) | (a);			\
	paravirt_ops.write_msr((msr),_l);			\
})

/* rdmsr with exception handling */
#define rdmsr_safe(msr,a,b) ({					\
	int _err;						\
	u64 _l = paravirt_ops.read_msr(msr,&_err);		\
	(*a) = (u32)_l;						\
	(*b) = _l >> 32;					\
	_err; })

#define rdtsc(low,high) do {					\
	u64 _l = paravirt_ops.read_tsc();			\
	low = (u32)_l;						\
	high = _l >> 32;					\
} while(0)

#define rdtscl(low) do {					\
	u64 _l = paravirt_ops.read_tsc();			\
	low = (int)_l;						\
} while(0)

#define rdtscll(val) (val = paravirt_ops.read_tsc())

#define write_tsc(val1,val2) wrmsr(0x10, val1, val2)

#define rdpmc(counter,low,high) do {				\
	u64 _l = paravirt_ops.read_pmc();			\
	low = (u32)_l;						\
	high = _l >> 32;					\
} while(0)

#define load_TR_desc() (paravirt_ops.load_tr_desc())
#define load_gdt(dtr) (paravirt_ops.load_gdt(dtr))
#define load_idt(dtr) (paravirt_ops.load_idt(dtr))
#define set_ldt(addr, entries) (paravirt_ops.set_ldt((addr), (entries)))
#define store_gdt(dtr) (paravirt_ops.store_gdt(dtr))
#define store_idt(dtr) (paravirt_ops.store_idt(dtr))
#define store_tr(tr) ((tr) = paravirt_ops.store_tr())
#define load_TLS(t,cpu) (paravirt_ops.load_tls((t),(cpu)))
#define write_ldt_entry(dt, entry, low, high)				\
	(paravirt_ops.write_ldt_entry((dt), (entry), (low), (high)))
#define write_gdt_entry(dt, entry, low, high)				\
	(paravirt_ops.write_gdt_entry((dt), (entry), (low), (high)))
#define write_idt_entry(dt, entry, low, high)				\
	(paravirt_ops.write_idt_entry((dt), (entry), (low), (high)))
#define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask))

/* The paravirtualized I/O functions */
static inline void slow_down_io(void) {
	paravirt_ops.io_delay();
#ifdef REALLY_SLOW_IO
	paravirt_ops.io_delay();
	paravirt_ops.io_delay();
	paravirt_ops.io_delay();
#endif
}

#define CLI_STRING	"pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_disable; popl %edx; popl %ecx; popl %eax"
#define STI_STRING	"pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_enable; popl %edx; popl %ecx; popl %eax"
#else  /* __ASSEMBLY__ */

#define INTERRUPT_RETURN	jmp *%cs:paravirt_ops+PARAVIRT_iret
#define DISABLE_INTERRUPTS	pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_disable; popl %edx; popl %ecx; popl %eax
#define ENABLE_INTERRUPTS	pushl %eax; pushl %ecx; pushl %edx; call *%cs:paravirt_ops+PARAVIRT_irq_enable; popl %edx; popl %ecx; popl %eax
#define ENABLE_INTERRUPTS_SYSEXIT	jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit
#define GET_CR0_INTO_EAX	call *paravirt_ops+PARAVIRT_read_cr0
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_PARAVIRT */
#endif	/* __ASM_PARAVIRT_H */