1 files changed, 98 insertions, 0 deletions
diff --git a/arch/ia64/lib/csum_partial_copy.c b/arch/ia64/lib/csum_partial_copy.c
new file mode 100644
index 000000000..917e3138b
--- /dev/null
+++ b/arch/ia64/lib/csum_partial_copy.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Network Checksum & Copy routine
+ *
+ * Copyright (C) 1999, 2003-2004 Hewlett-Packard Co
+ *	Stephane Eranian <eranian@hpl.hp.com>
+ *
+ * Most of the code has been imported from Linux/Alpha
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/string.h>
+
+#include <net/checksum.h>
+
+/*
+ * XXX Fixme: those 2 inlines are meant for debugging and will go away
+ */
+static inline unsigned
+short from64to16(unsigned long x)
+{
+	/* add up 32-bit words for 33 bits */
+	x = (x & 0xffffffff) + (x >> 32);
+	/* add up 16-bit and 17-bit words for 17+c bits */
+	x = (x & 0xffff) + (x >> 16);
+	/* add up 16-bit and 2-bit for 16+c bit */
+	x = (x & 0xffff) + (x >> 16);
+	/* add up carry.. */
+	x = (x & 0xffff) + (x >> 16);
+	return x;
+}
+
+static inline
+unsigned long do_csum_c(const unsigned char * buff, int len, unsigned int psum)
+{
+	int odd, count;
+	unsigned long result = (unsigned long)psum;
+
+	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 += *(unsigned short *) buff;
+			count--;
+			len -= 2;
+			buff += 2;
+		}
+		count >>= 1;		/* nr of 32-bit words.. */
+		if (count) {
+			if (4 & (unsigned long) buff) {
+				result += *(unsigned int *) buff;
+				count--;
+				len -= 4;
+				buff += 4;
+			}
+			count >>= 1;	/* nr of 64-bit words.. */
+			if (count) {
+				unsigned long carry = 0;
+				do {
+					unsigned long w = *(unsigned long *) buff;
+					count--;
+					buff += 8;
+					result += carry;
+					result += w;
+					carry = (w > result);
+				} while (count);
+				result += carry;
+				result = (result & 0xffffffff) + (result >> 32);
+			}
+			if (len & 4) {
+				result += *(unsigned int *) buff;
+				buff += 4;
+			}
+		}
+		if (len & 2) {
+			result += *(unsigned short *) buff;
+			buff += 2;
+		}
+	}
+	if (len & 1)
+		result += *buff;
+
+	result = from64to16(result);
+
+	if (odd)
+		result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
+
+out:
+	return result;
+}