#ifndef _ASM_IO_H#define _ASM_IO_H/* * This file contains the definitions for the x86 IO instructions * inb/inw/inl/outb/outw/outl and the "string versions" of the same * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing" * versions of the single-IO instructions (inb_p/inw_p/..). * * This file is not meant to be obfuscating: it's just complicated * to (a) handle it all in a way that makes gcc able to optimize it * as well as possible and (b) trying to avoid writing the same thing * over and over again with slight variations and possibly making a * mistake somewhere. *//* * Thanks to James van Artsdalen for a better timing-fix than * the two short jumps: using outb's to a nonexistent port seems * to guarantee better timings even on fast machines. * * On the other hand, I'd like to be sure of a non-existent port: * I feel a bit unsafe about using 0x80 (should be safe, though) * *		Linus */#ifdef SLOW_IO_BY_JUMPING#define __SLOW_DOWN_IO __asm__ __volatile__("jmp 1f\n1:\tjmp 1f\n1:")#else#define __SLOW_DOWN_IO __asm__ __volatile__("outb %al,$0x80")#endif#ifdef REALLY_SLOW_IO#define SLOW_DOWN_IO { __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; }#else#define SLOW_DOWN_IO __SLOW_DOWN_IO#endif/* * Talk about misusing macros.. */#define __OUT1(s,x) \extern inline void __out##s(unsigned x value, unsigned short port) {#define __OUT2(s,s1,s2) \__asm__ __volatile__ ("out" #s " %" s1 "0,%" s2 "1"#define __OUT(s,s1,x) \__OUT1(s,x) __OUT2(s,s1,"w") : : "a" (value), "d" (port)); } \__OUT1(s##c,x) __OUT2(s,s1,"") : : "a" (value), "i" (port)); } \__OUT1(s##_p,x) __OUT2(s,s1,"w") : : "a" (value), "d" (port)); SLOW_DOWN_IO; } \__OUT1(s##c_p,x) __OUT2(s,s1,"") : : "a" (value), "i" (port)); SLOW_DOWN_IO; }#define __IN1(s) \extern inline unsigned int __in##s(unsigned short port) { unsigned int _v;#define __IN2(s,s1,s2) \__asm__ __volatile__ ("in" #s " %" s2 "1,%" s1 "0"#define __IN(s,s1,i...) \__IN1(s) __IN2(s,s1,"w") : "=a" (_v) : "d" (port) ,##i ); return _v; } \__IN1(s##c) __IN2(s,s1,"") : "=a" (_v) : "i" (port) ,##i ); return _v; } \__IN1(s##_p) __IN2(s,s1,"w") : "=a" (_v) : "d" (port) ,##i ); SLOW_DOWN_IO; return _v; } \__IN1(s##c_p) __IN2(s,s1,"") : "=a" (_v) : "i" (port) ,##i ); SLOW_DOWN_IO; return _v; }#define __INS(s) \extern inline void ins##s(unsigned short port, void * addr, unsigned long count) \{ __asm__ __volatile__ ("cld ; rep ; ins" #s \: "=D" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }#define __OUTS(s) \extern inline void outs##s(unsigned short port, const void * addr, unsigned long count) \{ __asm__ __volatile__ ("cld ; rep ; outs" #s \: "=S" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }__IN(b,"b","0" (0))__IN(w,"w","0" (0))__IN(l,"")__OUT(b,"b",char)__OUT(w,"w",short)__OUT(l,,int)__INS(b)__INS(w)__INS(l)__OUTS(b)__OUTS(w)__OUTS(l)/* * Note that due to the way __builtin_constant_p() works, you *  - can't use it inside a inline function (it will never be true) *  - you don't have to worry about side effects within the __builtin.. */#define outb(val,port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__outbc((val),(port)) : \	__outb((val),(port)))#define inb(port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__inbc(port) : \	__inb(port))#define outb_p(val,port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__outbc_p((val),(port)) : \	__outb_p((val),(port)))#define inb_p(port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__inbc_p(port) : \	__inb_p(port))#define outw(val,port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__outwc((val),(port)) : \	__outw((val),(port)))#define inw(port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__inwc(port) : \	__inw(port))#define outw_p(val,port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__outwc_p((val),(port)) : \	__outw_p((val),(port)))#define inw_p(port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__inwc_p(port) : \	__inw_p(port))#define outl(val,port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__outlc((val),(port)) : \	__outl((val),(port)))#define inl(port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__inlc(port) : \	__inl(port))#define outl_p(val,port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__outlc_p((val),(port)) : \	__outl_p((val),(port)))#define inl_p(port) \((__builtin_constant_p((port)) && (port) < 256) ? \	__inlc_p(port) : \	__inl_p(port))#endif