From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@ppc970.osdl.org>
Date: Sat, 16 Apr 2005 15:20:36 -0700
Subject: Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
---
 include/asm-cris/checksum.h | 87 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 include/asm-cris/checksum.h

(limited to 'include/asm-cris/checksum.h')

diff --git a/include/asm-cris/checksum.h b/include/asm-cris/checksum.h
new file mode 100644
index 000000000000..15ca8aec5c63
--- /dev/null
+++ b/include/asm-cris/checksum.h
@@ -0,0 +1,87 @@
+/* TODO: csum_tcpudp_magic could be speeded up, and csum_fold as well */
+
+#ifndef _CRIS_CHECKSUM_H
+#define _CRIS_CHECKSUM_H
+
+#include <asm/arch/checksum.h>
+
+/*
+ * 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);
+
+/*
+ * the same as csum_partial, but copies from src while it
+ * checksums
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+
+unsigned int csum_partial_copy_nocheck(const char *src, char *dst,
+				       int len, unsigned int sum);
+
+/*
+ *	Fold a partial checksum into a word
+ */
+
+extern inline unsigned int csum_fold(unsigned int sum)
+{
+	/* the while loop is unnecessary really, it's always enough with two
+	   iterations */
+	
+	while(sum >> 16)
+		sum = (sum & 0xffff) + (sum >> 16); /* add in end-around carry */
+	
+	return ~sum;
+}
+
+extern unsigned int csum_partial_copy_from_user(const char *src, char *dst,
+						int len, unsigned int sum, 
+						int *errptr);
+
+/*
+ *	This is a version of ip_compute_csum() optimized for IP headers,
+ *	which always checksum on 4 octet boundaries.
+ *
+ */
+
+extern inline unsigned short ip_fast_csum(unsigned char * iph,
+					  unsigned int ihl)
+{
+	return csum_fold(csum_partial(iph, ihl * 4, 0));
+}
+ 
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+
+extern inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
+						   unsigned long daddr,
+						   unsigned short len,
+						   unsigned short proto,
+						   unsigned int sum)
+{
+	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
+}
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+
+extern inline unsigned short ip_compute_csum(unsigned char * buff, int len) {
+	return csum_fold (csum_partial(buff, len, 0));
+}
+
+#endif
-- 
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