1 files changed, 127 insertions, 0 deletions
diff --git a/xorg-server/hw/xfree86/os-support/misc/SlowBcopy.c b/xorg-server/hw/xfree86/os-support/misc/SlowBcopy.c
new file mode 100644
index 000000000..5cd716823
--- /dev/null
+++ b/xorg-server/hw/xfree86/os-support/misc/SlowBcopy.c
@@ -0,0 +1,127 @@
+/*******************************************************************************
+  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