patch-2.4.19 linux-2.4.19/include/asm-ppc64/checksum.h

• Lines: 116
• Date: Fri Aug 2 17:39:45 2002
• Orig file: linux-2.4.18/include/asm-ppc64/checksum.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/include/asm-ppc64/checksum.h linux-2.4.19/include/asm-ppc64/checksum.h
@@ -0,0 +1,115 @@
+#ifndef _PPC64_CHECKSUM_H
+#define _PPC64_CHECKSUM_H
+
+/*
+ * 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 is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.  ihl is the number
+ * of 32-bit words and is always >= 5.
+ */
+extern unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl);
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+extern unsigned short csum_tcpudp_magic(unsigned long saddr,
+					unsigned long daddr,
+					unsigned short len,
+					unsigned short proto,
+					unsigned int sum);
+
+/*
+ * 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
+ */
+extern unsigned int csum_partial(const unsigned char * buff, int len,
+				 unsigned int sum);
+
+/*
+ * the same as csum_partial, but copies from src to dst while it
+ * checksums
+ */
+unsigned int csum_partial_copy(const char *src, char *dst, 
+			       int len, unsigned int sum);
+
+extern unsigned int csum_partial_copy_generic(const char *src, char *dst,
+					      int len, unsigned int sum,
+					      int *src_err, int *dst_err);
+/*
+ * the same as csum_partial, but copies from user space.
+ */
+
+unsigned int csum_partial_copy_fromuser(const char *src, 
+					char *dst, 
+					int len, 
+					unsigned int sum,
+					int *src_err);
+
+unsigned int csum_partial_copy_nocheck(const char *src, 
+				       char *dst, 
+				       int len, 
+				       unsigned int sum);
+
+/*
+ * turns a 32-bit partial checksum (e.g. from csum_partial) into a
+ * 1's complement 16-bit checksum.
+ */
+static inline unsigned int csum_fold(unsigned int sum)
+{
+	unsigned int tmp;
+
+	/* swap the two 16-bit halves of sum */
+	__asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum));
+	/* if there is a carry from adding the two 16-bit halves,
+	   it will carry from the lower half into the upper half,
+	   giving us the correct sum in the upper half. */
+	sum = ~(sum + tmp) >> 16;
+	return sum;
+}
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
+{
+	return csum_fold(csum_partial(buff, len, 0));
+}
+
+#define csum_partial_copy_from_user(src, dst, len, sum, errp)   \
+        csum_partial_copy_generic((src), (dst), (len), (sum), (errp), 0)
+
+#define csum_partial_copy_nocheck(src, dst, len, sum)   \
+        csum_partial_copy_generic((src), (dst), (len), (sum), 0, 0)
+
+static inline u32 csum_tcpudp_nofold(u32 saddr,
+                                     u32 daddr,
+                                     unsigned short len,
+                                     unsigned short proto,
+                                     unsigned int sum)
+{
+	unsigned long s = sum;
+
+	s += saddr;
+	s += daddr;
+	s += (proto << 16) + len;
+	s += (s >> 32);
+	return (u32) s;
+}
+
+#endif