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-rw-r--r--arch/v850/lib/checksum.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/arch/v850/lib/checksum.c b/arch/v850/lib/checksum.c
new file mode 100644
index 0000000..d308b72
--- /dev/null
+++ b/arch/v850/lib/checksum.c
@@ -0,0 +1,154 @@
+/*
+ * 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.
+ *
+ * MIPS specific IP/TCP/UDP checksumming routines
+ *
+ * Authors: Ralf Baechle, <ralf@waldorf-gmbh.de>
+ * 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.
+ *
+ * $Id: checksum.c,v 1.1 2002/09/28 14:58:40 gerg Exp $
+ */
+#include <net/checksum.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <asm/byteorder.h>
+#include <asm/string.h>
+#include <asm/uaccess.h>
+
+static inline unsigned short from32to16 (unsigned long sum)
+{
+ unsigned int result;
+ /*
+ %0 %1
+ hsw %1, %0 H L L H
+ add %1, %0 H L H+L+C H+L
+ */
+ asm ("hsw %1, %0; add %1, %0" : "=&r" (result) : "r" (sum));
+ return result >> 16;
+}
+
+static inline unsigned int do_csum(const unsigned char * buff, int len)
+{
+ int odd, count;
+ unsigned int result = 0;
+
+ if (len <= 0)
+ goto out;
+ odd = 1 & (unsigned long) buff;
+ if (odd) {
+ result = be16_to_cpu(*buff);
+ len--;
+ buff++;
+ }
+ count = len >> 1; /* nr of 16-bit words.. */
+ if (count) {
+ if (2 & (unsigned long) buff) {
+ result += *(unsigned short *) buff;
+ count--;
+ len -= 2;
+ buff += 2;
+ }
+ count >>= 1; /* nr of 32-bit words.. */
+ if (count) {
+ unsigned int carry = 0;
+ do {
+ unsigned int w = *(unsigned int *) buff;
+ count--;
+ buff += 4;
+ result += carry;
+ result += w;
+ carry = (w > result);
+ } while (count);
+ result += carry;
+ result = (result & 0xffff) + (result >> 16);
+ }
+ if (len & 2) {
+ result += *(unsigned short *) buff;
+ buff += 2;
+ }
+ }
+ if (len & 1)
+ result += le16_to_cpu(*buff);
+ result = from32to16(result);
+ if (odd)
+ result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
+out:
+ return result;
+}
+
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.
+ */
+unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl)
+{
+ return ~do_csum(iph,ihl*4);
+}
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+unsigned short ip_compute_csum(const unsigned char * buff, int len)
+{
+ return ~do_csum(buff,len);
+}
+
+/*
+ * computes a partial checksum, e.g. for TCP/UDP fragments
+ */
+unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum)
+{
+ unsigned int result = do_csum(buff, len);
+
+ /* add in old sum, and carry.. */
+ result += sum;
+ if(sum > result)
+ result += 1;
+ return result;
+}
+
+EXPORT_SYMBOL(csum_partial);
+
+/*
+ * copy while checksumming, otherwise like csum_partial
+ */
+unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst,
+ int len, unsigned int sum)
+{
+ /*
+ * It's 2:30 am and I don't feel like doing it real ...
+ * This is lots slower than the real thing (tm)
+ */
+ sum = csum_partial(src, len, sum);
+ memcpy(dst, src, len);
+
+ return sum;
+}
+
+/*
+ * Copy from userspace and compute checksum. If we catch an exception
+ * then zero the rest of the buffer.
+ */
+unsigned int csum_partial_copy_from_user (const unsigned char *src, unsigned char *dst,
+ int len, unsigned int sum,
+ int *err_ptr)
+{
+ int missing;
+
+ missing = copy_from_user(dst, src, len);
+ if (missing) {
+ memset(dst + len - missing, 0, missing);
+ *err_ptr = -EFAULT;
+ }
+
+ return csum_partial(dst, len, sum);
+}
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