freebsd-src/sys/i386/include/cpufunc.h
1993-06-12 14:58:17 +00:00

83 lines
1.6 KiB
C

/*
* Functions to provide access to special i386 instructions.
* XXX - bezillions more are defined in locore.s but are not declared anywhere.
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#ifdef __GNUC__
static __inline int bdb(void)
{
extern int bdb_exists;
if (!bdb_exists)
return (0);
__asm("int $3");
return (1);
}
static __inline void
disable_intr(void)
{
__asm __volatile("cli");
}
static __inline void
enable_intr(void)
{
__asm __volatile("sti");
}
/*
* This roundabout method of returning a u_char helps stop gcc-1.40 from
* generating unnecessary movzbl's.
*/
#define inb(port) ((u_char) u_int_inb(port))
static __inline u_int
u_int_inb(u_int port)
{
u_char data;
/*
* We use %%dx and not %1 here because i/o is done at %dx and not at
* %edx, while gcc-2.2.2 generates inferior code (movw instead of movl)
* if we tell it to load (u_short) port.
*/
__asm __volatile("inb %%dx,%0" : "=a" (data) : "d" (port));
return data;
}
static __inline void
outb(u_int port, u_char data)
{
register u_char al asm("ax");
al = data; /* help gcc-1.40's register allocator */
__asm __volatile("outb %0,%%dx" : : "a" (al), "d" (port));
}
#else /* not __GNUC__ */
int bdb __P((void));
void disable_intr __P((void));
void enable_intr __P((void));
u_char inb __P((u_int port));
void outb __P((u_int port, u_int data)); /* XXX - incompat */
#endif /* __GNUC__ */
#define really_u_int int /* XXX */
#define really_void int /* XXX */
void load_cr0 __P((u_int cr0));
really_u_int rcr0 __P((void));
#ifdef notyet
really_void setidt __P((int idx, /*XXX*/caddr_t func, int typ, int dpl));
#endif
#undef really_u_int
#undef really_void