aboutsummaryrefslogtreecommitdiffstats
path: root/arch/cris/arch-v10/lib/old_checksum.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/cris/arch-v10/lib/old_checksum.c')
-rw-r--r--arch/cris/arch-v10/lib/old_checksum.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/lib/old_checksum.c b/arch/cris/arch-v10/lib/old_checksum.c
new file mode 100644
index 000000000000..22a6f0aa9cef
--- /dev/null
+++ b/arch/cris/arch-v10/lib/old_checksum.c
@@ -0,0 +1,85 @@
+/* $Id: old_checksum.c,v 1.3 2003/10/27 08:04:32 starvik 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>
+#include <net/module.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);
+}
+
+EXPORT_SYMBOL(csum_partial);