ppcIOLib.h

/*
        these routines _MUST_ be declared as they are because we want to
        inline them. 

*/

#ifndef _PPC_IO_LIB_H
#define _PPC_IO_LIB_H

#ifdef __cplusplus
extern "C" {
#endif


/*
        eieio ensures that all the instructions preceeding it will finish
        before new ones are started.
        It effectively flushes the PPC's pipeline
*/
extern __inline void eieio(void)
{
        __asm__ volatile ("eieio ") ;

        return ;
}


/*
        w32 writes a 32bit quantity "data" to the address in
        "addr" followed by the sync primitive (eieio) thus
        ensuring that the write finishes before any other operation
        after it
*/
extern __inline void w32(volatile unsigned int *addr, unsigned int data)
{
        *addr = data ;
        eieio() ;
        return ;
}

/*
        see above
*/
extern __inline void w16(volatile unsigned short *addr, unsigned short data)
{
        *addr = data ;
        eieio() ;
        return ;
}

/*
        see above
*/
extern __inline void w8(volatile unsigned char *addr, unsigned char data)
{
        *addr = data ;
        eieio() ;
        return ;
}


/*
        routines returns the byte-swapped 32bit integer at address "addr".
        Used for endian conversion
*/      
extern __inline unsigned int rs32(volatile unsigned int *addr)
{
        unsigned int tmp ;

        __asm__ volatile ("lwbrx %0,0,%1 " : "=rI" (tmp) : "rI" (addr)) ;


        return tmp ;
}

/*
        see above except for 16bit datum
*/
extern __inline unsigned short rs16(volatile unsigned short *addr)
{
        unsigned int tmp ;

        __asm__ volatile ("lhbrx %0,0,%1 " : "=rI" (tmp) : "rI" (addr)) ;


        return (unsigned short)tmp ;
}


/*
        writes the data byte-spawed to address addr followed by the
        syncing primitive (eieio)
        Used for endian conversion
*/
extern __inline void ws32(volatile unsigned int *addr, unsigned int data)
{
        __asm__ volatile ("stwbrx %0,0,%1; eieio " : : "r" (data) , "rI" (addr)) ;

        return ;
}

/*
        writes the data byte-spawed to address addr WIHTOUT eieio
        Used for endian conversion
*/
extern __inline void ws32_no_eieio(volatile unsigned int *addr, unsigned int data)
{
        __asm__ volatile ("stwbrx %0,0,%1 " : : "r" (data) , "rI" (addr)) ;

        return ;
}

/*
        see above except for 16bit data
*/
extern __inline void ws16(volatile unsigned short *addr, unsigned short data)
{
        __asm__ volatile ("sthbrx %0,0,%1 \n eieio " : : "r" (data) , "rI" (addr)) ;

        return ;
}



#ifdef __cplusplus
}
#endif

#endif