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cpufunc.h revision 1.2 
      1 /*
      2  * Functions to provide access to special i386 instructions.
      3  * XXX - bezillions more are defined in locore.s but are not declared anywhere.
      4  *
      5  *	$Id: cpufunc.h,v 1.2 1993/08/02 17:52:24 mycroft Exp $
      6  */
      7 
      8 #include <sys/cdefs.h>
      9 #include <sys/types.h>
     10 
     11 #ifdef	__GNUC__
     12 
     13 static __inline int bdb(void)
     14 {
     15 	extern int bdb_exists;
     16 
     17 	if (!bdb_exists)
     18 		return (0);
     19 	__asm("int $3");
     20 	return (1);
     21 }
     22 
     23 static __inline void
     24 disable_intr(void)
     25 {
     26 	__asm __volatile("cli");
     27 }
     28 
     29 static __inline void
     30 enable_intr(void)
     31 {
     32 	__asm __volatile("sti");
     33 }
     34 
     35 /*
     36  * This roundabout method of returning a u_char helps stop gcc-1.40 from
     37  * generating unnecessary movzbl's.
     38  */
     39 #define	inb(port)	((u_char) u_int_inb(port))
     40 
     41 static __inline u_int
     42 u_int_inb(u_int port)
     43 {
     44 	u_char	data;
     45 	/*
     46 	 * We use %%dx and not %1 here because i/o is done at %dx and not at
     47 	 * %edx, while gcc-2.2.2 generates inferior code (movw instead of movl)
     48 	 * if we tell it to load (u_short) port.
     49 	 */
     50 	__asm __volatile("inb %%dx,%0" : "=a" (data) : "d" (port));
     51 	return data;
     52 }
     53 
     54 static __inline void
     55 outb(u_int port, u_char data)
     56 {
     57 	register u_char	al asm("ax");
     58 
     59 	al = data;		/* help gcc-1.40's register allocator */
     60 	__asm __volatile("outb %0,%%dx" : : "a" (al), "d" (port));
     61 }
     62 
     63 #else /* not __GNUC__ */
     64 
     65 int	bdb		__P((void));
     66 void	disable_intr	__P((void));
     67 void	enable_intr	__P((void));
     68 u_char	inb		__P((u_int port));
     69 void	outb		__P((u_int port, u_int data));	/* XXX - incompat */
     70 
     71 #endif	/* __GNUC__ */
     72 
     73 #define	really_u_int	int	/* XXX */
     74 #define	really_void	int	/* XXX */
     75 
     76 void	load_cr0	__P((u_int cr0));
     77 really_u_int	rcr0	__P((void));
     78 
     79 #ifdef notyet
     80 really_void	setidt	__P((int idx, /*XXX*/caddr_t func, int typ, int dpl));
     81 #endif
     82 
     83 #undef	really_u_int
     84 #undef	really_void
     85