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xserver/hw/xfree86/os-support/misc/SlowBcopy.c

117 lines
2.4 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;
void
xf86SetReallySlowBcopy(void)
{
really_slow_bcopy = 1;
}
#if defined(__i386__) || defined(__amd64__)
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 */
void
xf86SlowBcopy(unsigned char *src, unsigned char *dst, int len)
{
#if defined(__i386__) || defined(__amd64__)
if (really_slow_bcopy) {
xf86_really_slow_bcopy(src, dst, len);
return;
}
#endif
while (len--)
*dst++ = *src++;
}
#ifdef __alpha__
#ifdef __linux__
unsigned long _bus_base(void);
#define useSparse() (!_bus_base())
#define SPARSE (7)
#else
#define useSparse() 0
#define SPARSE 0
#endif
void
xf86SlowBCopyFromBus(unsigned char *src, unsigned char *dst, int count)
{
if (useSparse()) {
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);
}
void
xf86SlowBCopyToBus(unsigned char *src, unsigned char *dst, int count)
{
if (useSparse()) {
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