io_hw_swap.h

来自「Linux Kernel 2.6.9 for OMAP1710」· C头文件 代码 · 共 114 行

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#ifndef _M68K_IO_HW_SWAP_H#define _M68K_IO_HW_SWAP_H/* * swap functions are sometimes needed to interface little-endian hardware */static inline unsigned short _swapw(volatile unsigned short v){    return ((v << 8) | (v >> 8));}static inline unsigned int _swapl(volatile unsigned long v){    return ((v << 24) | ((v & 0xff00) << 8) | ((v & 0xff0000) >> 8) | (v >> 24));}/* * readX/writeX() are used to access memory mapped devices. On some * architectures the memory mapped IO stuff needs to be accessed * differently. On the m68k architecture, we just read/write the * memory location directly. *//* ++roman: The assignments to temp. vars avoid that gcc sometimes generates * two accesses to memory, which may be undesireable for some devices. */#define readb(addr) \    ({ unsigned char __v = (*(volatile unsigned char *) (addr)); __v; })#define readw(addr) \    ({ unsigned short __v = (*(volatile unsigned short *) (addr)); __v; })#define readl(addr) \    ({ unsigned int __v = (*(volatile unsigned int *) (addr)); __v; })#define writeb(b,addr) ((*(volatile unsigned char *) (addr)) = (b))#define writew(b,addr) ((*(volatile unsigned short *) (addr)) = (b))#define writel(b,addr) ((*(volatile unsigned int *) (addr)) = (b))/* There is no difference between I/O and memory on 68k, these are the same */#define inb(addr) \    ({ unsigned char __v = (*(volatile unsigned char *) (addr)); __v; })#define inw(addr) \    ({ unsigned short __v = (*(volatile unsigned short *) (addr)); \       _swapw(__v); })#define inl(addr) \    ({ unsigned int __v = (*(volatile unsigned int *) (addr)); _swapl(__v); })#define outb(b,addr) ((*(volatile unsigned char *) (addr)) = (b))#define outw(b,addr) ((*(volatile unsigned short *) (addr)) = (_swapw(b)))#define outl(b,addr) ((*(volatile unsigned int *) (addr)) = (_swapl(b)))/* FIXME: these need to be optimized.  Watch out for byte swapping, they * are used mostly for Intel devices... */#define outsw(addr,buf,len) \    ({ unsigned short * __p = (unsigned short *)(buf); \       unsigned short * __e = (unsigned short *)(__p) + (len); \       while (__p < __e) { \	  *(volatile unsigned short *)(addr) = *__p++;\       } \     })#define insw(addr,buf,len) \    ({ unsigned short * __p = (unsigned short *)(buf); \       unsigned short * __e = (unsigned short *)(__p) + (len); \       while (__p < __e) { \          *(__p++) = *(volatile unsigned short *)(addr); \       } \     })static inline unsigned char get_user_byte_io(const char * addr){	register unsigned char _v;	__asm__ __volatile__ ("moveb %1,%0":"=dm" (_v):"m" (*addr));	return _v;}#define inb_p(addr) get_user_byte_io((char *)(addr))static inline void put_user_byte_io(char val,char *addr){	__asm__ __volatile__ ("moveb %0,%1"			      : /* no outputs */			      :"idm" (val),"m" (*addr)			      : "memory");}#define outb_p(x,addr) put_user_byte_io((x),(char *)(addr))/* * Change virtual addresses to physical addresses and vv. * These are trivial on the 1:1 Linux/i386 mapping (but if we ever * make the kernel segment mapped at 0, we need to do translation * on the i386 as well) */extern unsigned long mm_vtop(unsigned long addr);extern unsigned long mm_ptov(unsigned long addr);extern inline unsigned long virt_to_phys(volatile void * address){	return (unsigned long) mm_vtop((unsigned long)address);}extern inline void * phys_to_virt(unsigned long address){	return (void *) mm_ptov(address);}/* * IO bus memory addresses are also 1:1 with the physical address */#define virt_to_bus virt_to_phys#define bus_to_virt phys_to_virt#endif /* _M68K_IO_HW_SWAP_H */

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