aboutsummaryrefslogtreecommitdiff
path: root/xorg-server/hw/xfree86/os-support/misc/SlowBcopy.c
diff options
context:
space:
mode:
Diffstat (limited to 'xorg-server/hw/xfree86/os-support/misc/SlowBcopy.c')
-rw-r--r--xorg-server/hw/xfree86/os-support/misc/SlowBcopy.c127
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