patch-2.4.2 linux/arch/cris/lib/old_checksum.c

• Lines: 128
• Date: Thu Feb 8 16:32:44 2001
• Orig file: v2.4.1/linux/arch/cris/lib/old_checksum.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.1/linux/arch/cris/lib/old_checksum.c linux/arch/cris/lib/old_checksum.c
@@ -0,0 +1,127 @@
+/* $Id: old_checksum.c,v 1.1 2000/07/10 16:25:21 bjornw Exp $
+ *
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		IP/TCP/UDP checksumming routines
+ *
+ * Authors:	Jorge Cwik, <jorge@laser.satlink.net>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Tom May, <ftom@netcom.com>
+ *		Lots of code moved from tcp.c and ip.c; see those files
+ *		for more names.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <net/checksum.h>
+
+#undef PROFILE_CHECKSUM
+
+#ifdef PROFILE_CHECKSUM
+/* these are just for profiling the checksum code with an oscillioscope.. uh */
+#if 0
+#define BITOFF *((unsigned char *)0xb0000030) = 0xff
+#define BITON *((unsigned char *)0xb0000030) = 0x0
+#endif
+#include <asm/io.h>
+#define CBITON LED_ACTIVE_SET(1)
+#define CBITOFF LED_ACTIVE_SET(0)
+#define BITOFF
+#define BITON
+#else
+#define BITOFF
+#define BITON
+#define CBITOFF
+#define CBITON
+#endif
+
+/*
+ * computes a partial checksum, e.g. for TCP/UDP fragments
+ */
+
+#include <asm/delay.h>
+
+unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum)
+{
+  /*
+   * Experiments with ethernet and slip connections show that buff
+   * is aligned on either a 2-byte or 4-byte boundary.
+   */
+  const unsigned char *endMarker = buff + len;
+  const unsigned char *marker = endMarker - (len % 16);
+#if 0
+  if((int)buff & 0x3)
+    printk("unaligned buff %p\n", buff);
+  __delay(900); /* extra delay of 90 us to test performance hit */
+#endif
+  BITON;
+  while (buff < marker) {
+    sum += *((unsigned short *)buff)++;
+    sum += *((unsigned short *)buff)++;
+    sum += *((unsigned short *)buff)++;
+    sum += *((unsigned short *)buff)++;
+    sum += *((unsigned short *)buff)++;
+    sum += *((unsigned short *)buff)++;
+    sum += *((unsigned short *)buff)++;
+    sum += *((unsigned short *)buff)++;
+  }
+  marker = endMarker - (len % 2);
+  while(buff < marker) {
+    sum += *((unsigned short *)buff)++;
+  }
+  if(endMarker - buff > 0) {
+    sum += *buff;                 /* add extra byte seperately */
+  }
+  BITOFF;
+  return(sum);
+}
+
+#if 0
+
+/*
+ * copy while checksumming, otherwise like csum_partial
+ */
+
+unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst, 
+				  int len, unsigned int sum)
+{
+  const unsigned char *endMarker;
+  const unsigned char *marker;
+  printk("csum_partial_copy len %d.\n", len);
+#if 0
+  if((int)src & 0x3)
+    printk("unaligned src %p\n", src);
+  if((int)dst & 0x3)
+    printk("unaligned dst %p\n", dst);
+  __delay(1800); /* extra delay of 90 us to test performance hit */
+#endif
+  endMarker = src + len;
+  marker = endMarker - (len % 16);
+  CBITON;
+  while(src < marker) {
+    sum += (*((unsigned short *)dst)++ = *((unsigned short *)src)++);
+    sum += (*((unsigned short *)dst)++ = *((unsigned short *)src)++);
+    sum += (*((unsigned short *)dst)++ = *((unsigned short *)src)++);
+    sum += (*((unsigned short *)dst)++ = *((unsigned short *)src)++);
+    sum += (*((unsigned short *)dst)++ = *((unsigned short *)src)++);
+    sum += (*((unsigned short *)dst)++ = *((unsigned short *)src)++);
+    sum += (*((unsigned short *)dst)++ = *((unsigned short *)src)++);
+    sum += (*((unsigned short *)dst)++ = *((unsigned short *)src)++);
+  }
+  marker = endMarker - (len % 2);
+  while(src < marker) {
+    sum += (*((unsigned short *)dst)++ = *((unsigned short *)src)++);
+  }
+  if(endMarker - src > 0) {
+    sum += (*dst = *src);                 /* add extra byte seperately */
+  }
+  CBITOFF;
+  return(sum);
+}
+
+#endif