1 files changed, 70 insertions, 0 deletions
diff --git a/arch/nios2/include/asm/checksum.h b/arch/nios2/include/asm/checksum.h
new file mode 100644
index 000000000..69004e07a
--- /dev/null
+++ b/arch/nios2/include/asm/checksum.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2004 Microtronix Datacom Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef _ASM_NIOS_CHECKSUM_H
+#define _ASM_NIOS_CHECKSUM_H
+
+/* Take these from lib/checksum.c */
+extern __wsum csum_partial(const void *buff, int len, __wsum sum);
+extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
+extern __sum16 ip_compute_csum(const void *buff, int len);
+
+/*
+ * Fold a partial checksum
+ */
+static inline __sum16 csum_fold(__wsum sum)
+{
+	__asm__ __volatile__(
+		"add	%0, %1, %0\n"
+		"cmpltu	r8, %0, %1\n"
+		"srli	%0, %0, 16\n"
+		"add	%0, %0, r8\n"
+		"nor	%0, %0, %0\n"
+		: "=r" (sum)
+		: "r" (sum << 16), "0" (sum)
+		: "r8");
+	return (__force __sum16) sum;
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+#define csum_tcpudp_nofold csum_tcpudp_nofold
+static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
+					__u32 len, __u8 proto,
+					__wsum sum)
+{
+	__asm__ __volatile__(
+		"add	%0, %1, %0\n"
+		"cmpltu	r8, %0, %1\n"
+		"add	%0, %0, r8\n"	/* add carry */
+		"add	%0, %2, %0\n"
+		"cmpltu	r8, %0, %2\n"
+		"add	%0, %0, r8\n"	/* add carry */
+		"add	%0, %3, %0\n"
+		"cmpltu	r8, %0, %3\n"
+		"add	%0, %0, r8\n"	/* add carry */
+		: "=r" (sum), "=r" (saddr)
+		: "r" (daddr), "r" ((len + proto) << 8),
+		  "0" (sum),
+		  "1" (saddr)
+		: "r8");
+
+	return sum;
+}
+
+static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
+					__u32 len, __u8 proto,
+					__wsum sum)
+{
+	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
+}
+
+#endif /* _ASM_NIOS_CHECKSUM_H */