patch-1.3.94 linux/include/asm-m68k/checksum.h

• Lines: 176
• Date: Sat Apr 6 12:42:22 1996
• Orig file: v1.3.93/linux/include/asm-m68k/checksum.h
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.93/linux/include/asm-m68k/checksum.h linux/include/asm-m68k/checksum.h
@@ -0,0 +1,175 @@
+#ifndef _M68K_CHECKSUM_H
+#define _M68K_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_copy, 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(const char *src, char *dst, int len, int sum);
+
+
+/*
+ * the same as csum_partial_copy, but copies from user space.
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+
+unsigned int csum_partial_copy_fromuser(const char *src, char *dst, int len, int sum);
+
+
+/*
+ *	This is a version of ip_compute_csum() optimized for IP headers,
+ *	which always checksum on 4 octet boundaries.
+ *
+ */
+static inline unsigned short
+ip_fast_csum(unsigned char *iph, unsigned int ihl)
+{
+	unsigned int sum = 0;
+
+	__asm__ ("subqw #1,%2\n"
+		 "1:\t"
+		 "movel %1@+,%/d0\n\t"
+		 "addxl %/d0,%0\n\t"
+		 "dbra  %2,1b\n\t"
+		 "movel %0,%/d0\n\t"
+		 "swap  %/d0\n\t"
+		 "addxw %/d0,%0\n\t"
+		 "clrw  %/d0\n\t"
+		 "addxw %/d0,%0\n\t"
+		 : "=d" (sum), "=a" (iph), "=d" (ihl)
+		 : "0" (sum), "1" (iph), "2" (ihl)
+		 : "d0");
+	return ~sum;
+}
+
+
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+
+static inline unsigned short int
+csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
+		  unsigned short proto, unsigned int sum)
+{
+	__asm__ ("addl  %1,%0\n\t"
+		 "addxl %4,%0\n\t"
+		 "addxl %5,%0\n\t"
+		 "movl  %0,%1\n\t"
+		 "swap  %1\n\t"
+		 "addxw %1,%0\n\t"
+		 "clrw  %1\n\t"
+		 "addxw %1,%0\n\t"
+		 : "=&d" (sum), "=&d" (saddr)
+		 : "0" (daddr), "1" (saddr), "d" (len + proto),
+		   "d"(sum));
+	return ~sum;
+}
+
+/*
+ *	Fold a partial checksum without adding pseudo headers
+ */
+
+static inline unsigned int csum_fold(unsigned int sum)
+{
+	unsigned int tmp = sum;
+	__asm__("swap %1\n\t"
+		"addw %1, %0\n\t"
+		"clrw %1\n\t"
+		"addxw %1, %0"
+		: "=&d" (sum), "=&d" (tmp)
+		: "0" (sum), "1" (sum));
+	return ~sum;
+}
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+
+#if 1
+static inline unsigned short
+ip_compute_csum(unsigned char * buff, int len)
+{
+	unsigned int sum;
+	unsigned int scratch;
+
+	__asm__("movel %0,%1\n\t"
+		"swap  %1\n\t"
+		"addw  %1,%0\n\t"
+		"clrw  %1\n\t"
+		"addxw %1,%0\n\t"
+		: "=d" (sum), "=d" (scratch)
+		: "0" (csum_partial(buff, len, 0)));
+	return ~sum;
+}
+#else
+static inline unsigned short
+ip_compute_csum(unsigned char * buff, int len)
+{
+	unsigned long sum = 0;
+
+  /* Do the first multiple of 4 bytes and convert to 16 bits. */
+  if (len > 3)
+    {
+      int dummy;
+      __asm__ ("subql #1,%2\n\t"
+	       "1:\t"
+	       "movel %1@+,%/d0\n\t"
+	       "addxl %/d0,%0\n\t"
+	       "dbra %2,1b\n\t"
+	       "movel %0,%/d0\n\t"
+	       "swap %/d0\n\t"
+	       "addxw %/d0,%0\n\t"
+	       "clrw %/d0\n\t"
+	       "addxw %/d0,%0"
+	       : "=d" (sum), "=a" (buff), "=d" (dummy)
+	       : "0" (sum), "1" (buff), "2" (len >> 2)
+	       : "d0");
+    }
+  if (len & 2)
+    {
+      __asm__ ("addw %1@+,%0\n\t"
+	       "addxw %2,%0"
+	       : "=d" (sum), "=a" (buff)
+	       : "d" (0), "0" (sum), "1" (buff));
+    }
+  if (len & 1)
+    {
+      __asm__ ("movew %1@,%/d0\n\t"
+	       "clrb %/d0\n\t"
+	       "addw %/d0,%0\n\t"
+	       "clrw %/d0\n\t"
+	       "addxw %/d0,%0"
+	       : "=d" (sum)
+	       : "a" (buff), "0" (sum)
+	       : "d0");
+    }
+
+	sum =~sum;
+	return(sum & 0xffff);
+}
+#endif
+
+#endif /* _M68K_CHECKSUM_H */