linux驱动中I/O访问函数inb inw 的实现

inb inw 的实现

#define inb(p)  ({ unsigned int __v = __raw_readb(__io(p)); __v; })

#define inw(p)  ({ unsigned int __v = le16_to_cpu(__raw_readw(__io(p))); __v; })

#define __raw_readb(a)          (*(volatile unsigned char  *)(a))

#define __raw_readw(a)          (*(volatile unsigned short *)(a))

#define outb(v,p)               __raw_writeb(v,__io(p))

#define outw(v,p)               __raw_writew(cpu_to_le16(v),__io(p))

#define __raw_writeb(v,a)       (*(volatile unsigned char  *)(a) = (v))

#define __raw_writew(v,a)       (*(volatile unsigned short *)(a) = (v))