xenocara/xserver/hw/xfree86/os-support/misc/SlowBcopy.c
2007-11-24 17:55:21 +00:00

128 lines
2.6 KiB
C

/*******************************************************************************
for Alpha Linux
*******************************************************************************/
/*
* Create a dependency that should be immune from the effect of register
* renaming as is commonly seen in superscalar processors. This should
* insert a minimum of 100-ns delays between reads/writes at clock rates
* up to 100 MHz---GGL
*
* Slowbcopy(char *src, char *dst, int count)
*
*/
#ifdef HAVE_XORG_CONFIG_H
#include <xorg-config.h>
#endif
#include <X11/X.h>
#include "xf86.h"
#include "xf86Priv.h"
#include "xf86_OSlib.h"
#include "compiler.h"
static int really_slow_bcopy;
_X_EXPORT void
xf86SetReallySlowBcopy(void)
{
really_slow_bcopy = 1;
}
#if defined(__i386__) || defined(__x86_64__)
static void xf86_really_slow_bcopy(unsigned char *src, unsigned char *dst, int len)
{
while(len--)
{
*dst++ = *src++;
outb(0x80, 0x00);
}
}
#endif
/* The outb() isn't needed on my machine, but who knows ... -- ost */
_X_EXPORT void
xf86SlowBcopy(unsigned char *src, unsigned char *dst, int len)
{
#if defined(__i386__) || defined(__x86_64__)
if (really_slow_bcopy) {
xf86_really_slow_bcopy(src, dst, len);
return;
}
#endif
while(len--)
*dst++ = *src++;
}
#ifdef __alpha__
/*
* The Jensen lacks dense memory, thus we have to address the bus via
* the sparse addressing scheme. Time critical code uses routines from
* BUSmemcpy.c
*
* Martin Ostermann (ost@comnets.rwth-aachen.de) - Apr.-Sep. 1996
*/
#ifdef linux
unsigned long _bus_base(void);
#ifdef TEST_JENSEN_CODE /* define to test the Sparse addressing on a non-Jensen */
#define SPARSE (5)
#else
#define SPARSE (7)
#endif
#define isJensen() (!_bus_base())
#else
#define isJensen() 0
#define SPARSE 0
#endif
_X_EXPORT void
xf86SlowBCopyFromBus(unsigned char *src, unsigned char *dst, int count)
{
if (isJensen())
{
unsigned long addr;
long result;
addr = (unsigned long) src;
while( count ){
result = *(volatile int *) addr;
result >>= ((addr>>SPARSE) & 3) * 8;
*dst++ = (unsigned char) (0xffUL & result);
addr += 1<<SPARSE;
count--;
outb(0x80, 0x00);
}
}
else
xf86SlowBcopy(src,dst,count);
}
_X_EXPORT void
xf86SlowBCopyToBus(unsigned char *src, unsigned char *dst, int count)
{
if (isJensen())
{
unsigned long addr;
addr = (unsigned long) dst;
while(count) {
*(volatile unsigned int *) addr = (unsigned short)(*src) * 0x01010101;
src++;
addr += 1<<SPARSE;
count--;
outb(0x80, 0x00);
}
}
else
xf86SlowBcopy(src,dst,count);
}
#endif