1 files changed, 102 insertions, 0 deletions
diff --git a/arch/tile/lib/checksum.c b/arch/tile/lib/checksum.c
new file mode 100644
index 00000000000..e4bab5bd3f3
--- /dev/null
+++ b/arch/tile/lib/checksum.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   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, version 2.
+ *
+ *   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, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ * Support code for the main lib/checksum.c.
+ */
+
+#include <net/checksum.h>
+#include <linux/module.h>
+
+static inline unsigned int longto16(unsigned long x)
+{
+	unsigned long ret;
+#ifdef __tilegx__
+	ret = __insn_v2sadu(x, 0);
+	ret = __insn_v2sadu(ret, 0);
+#else
+	ret = __insn_sadh_u(x, 0);
+	ret = __insn_sadh_u(ret, 0);
+#endif
+	return ret;
+}
+
+__wsum do_csum(const unsigned char *buff, int len)
+{
+	int odd, count;
+	unsigned long result = 0;
+
+	if (len <= 0)
+		goto out;
+	odd = 1 & (unsigned long) buff;
+	if (odd) {
+		result = (*buff << 8);
+		len--;
+		buff++;
+	}
+	count = len >> 1;		/* nr of 16-bit words.. */
+	if (count) {
+		if (2 & (unsigned long) buff) {
+			result += *(const unsigned short *)buff;
+			count--;
+			len -= 2;
+			buff += 2;
+		}
+		count >>= 1;		/* nr of 32-bit words.. */
+		if (count) {
+#ifdef __tilegx__
+			if (4 & (unsigned long) buff) {
+				unsigned int w = *(const unsigned int *)buff;
+				result = __insn_v2sadau(result, w, 0);
+				count--;
+				len -= 4;
+				buff += 4;
+			}
+			count >>= 1;		/* nr of 64-bit words.. */
+#endif
+
+			/*
+			 * This algorithm could wrap around for very
+			 * large buffers, but those should be impossible.
+			 */
+			BUG_ON(count >= 65530);
+
+			while (count) {
+				unsigned long w = *(const unsigned long *)buff;
+				count--;
+				buff += sizeof(w);
+#ifdef __tilegx__
+				result = __insn_v2sadau(result, w, 0);
+#else
+				result = __insn_sadah_u(result, w, 0);
+#endif
+			}
+#ifdef __tilegx__
+			if (len & 4) {
+				unsigned int w = *(const unsigned int *)buff;
+				result = __insn_v2sadau(result, w, 0);
+				buff += 4;
+			}
+#endif
+		}
+		if (len & 2) {
+			result += *(const unsigned short *) buff;
+			buff += 2;
+		}
+	}
+	if (len & 1)
+		result += *buff;
+	result = longto16(result);
+	if (odd)
+		result = swab16(result);
+out:
+	return result;
+}