1 files changed, 140 insertions, 0 deletions
diff --git a/arch/blackfin/lib/checksum.c b/arch/blackfin/lib/checksum.c
new file mode 100644
index 00000000000..42768e0c80c
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+++ b/arch/blackfin/lib/checksum.c
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+/*
+ * File:         arch/blackfin/lib/checksum.c
+ * Based on:     none - original work
+ * Author:
+ *
+ * Created:
+ * Description:  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.
+ *
+ * Modified:
+ *               Copyright 2004-2006 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <net/checksum.h>
+#include <asm/checksum.h>
+
+#ifdef CONFIG_IP_CHECKSUM_L1
+static unsigned short do_csum(const unsigned char *buff, int len)__attribute__((l1_text));
+#endif
+
+static unsigned short do_csum(const unsigned char *buff, int len)
+{
+	register unsigned long sum = 0;
+	int swappem = 0;
+
+	if (1 & (unsigned long)buff) {
+		sum = *buff << 8;
+		buff++;
+		len--;
+		++swappem;
+	}
+
+	while (len > 1) {
+		sum += *(unsigned short *)buff;
+		buff += 2;
+		len -= 2;
+	}
+
+	if (len > 0)
+		sum += *buff;
+
+	/*  Fold 32-bit sum to 16 bits */
+	while (sum >> 16)
+		sum = (sum & 0xffff) + (sum >> 16);
+
+	if (swappem)
+		sum = ((sum & 0xff00) >> 8) + ((sum & 0x00ff) << 8);
+
+	return sum;
+
+}
+
+/*
+ *	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);
+}
+
+/*
+ * computes the checksum of a memory block at buff, length len,
+ * and adds in "sum" (32-bit)
+ *
+ * returns a 32-bit number suitable for feeding into itself
+ * or csum_tcpudp_magic
+ *
+ * this function must be called with even lengths, except
+ * for the last fragment, which may be odd
+ *
+ * it's best to have buff aligned on a 32-bit boundary
+ */
+unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum)
+{
+	/*
+	 * Just in case we get nasty checksum data...
+	 * Like 0xffff6ec3 in the case of our IPv6 multicast header.
+	 * We fold to begin with, as well as at the end.
+	 */
+	sum = (sum & 0xffff) + (sum >> 16);
+
+	sum += do_csum(buff, len);
+
+	sum = (sum & 0xffff) + (sum >> 16);
+
+	return sum;
+}
+
+/*
+ * 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);
+}
+
+/*
+ * copy from fs while checksumming, otherwise like csum_partial
+ */
+
+unsigned int
+csum_partial_copy_from_user(const unsigned char *src, unsigned char *dst,
+			    int len, int sum, int *csum_err)
+{
+	if (csum_err)
+		*csum_err = 0;
+	memcpy(dst, src, len);
+	return csum_partial(dst, len, sum);
+}
+
+/*
+ * copy from ds while checksumming, otherwise like csum_partial
+ */
+
+unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst,
+			       int len, int sum)
+{
+	memcpy(dst, src, len);
+	return csum_partial(dst, len, sum);
+}