patch-2.1.16 linux/include/asm-sparc64/checksum.h

• Lines: 167
• Date: Fri Dec 13 11:37:41 1996
• Orig file: v2.1.15/linux/include/asm-sparc64/checksum.h
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.15/linux/include/asm-sparc64/checksum.h linux/include/asm-sparc64/checksum.h
@@ -0,0 +1,166 @@
+/* $Id: checksum.h,v 1.3 1996/12/12 15:39:13 davem Exp $ */
+#ifndef __SPARC64_CHECKSUM_H
+#define __SPARC64_CHECKSUM_H
+
+/*  checksum.h:  IP/UDP/TCP checksum routines on the V9.
+ *
+ *  Copyright(C) 1995 Linus Torvalds
+ *  Copyright(C) 1995 Miguel de Icaza
+ *  Copyright(C) 1996 David S. Miller
+ *  Copyright(C) 1996 Eddie C. Dost
+ *
+ * derived from:
+ *	Alpha checksum c-code
+ *      ix86 inline assembly
+ *      RFC1071 Computing the Internet Checksum
+ */
+
+/* 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(unsigned char * buff, int len, unsigned int sum);
+
+/* the same as csum_partial, but copies from user space while it
+ * checksums
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+extern unsigned int csum_partial_copy(char *src, char *dst, int len, int sum);
+
+#define csum_partial_copy_fromuser(s, d, l, w)  \
+                       csum_partial_copy((char *) (s), (d), (l), (w))
+
+/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
+ * the majority of the time.
+ */
+extern __inline__ unsigned short ip_fast_csum(__const__ unsigned char *iph,
+					      unsigned int ihl)
+{
+	unsigned short sum;
+
+	/* Note: We must read %2 before we touch %0 for the first time,
+	 *       because GCC can legitimately use the same register for
+	 *       both operands.
+	 */
+	__asm__ __volatile__("
+	sub		%2, 4, %%g4
+	lduw		[%1 + 0x00], %0
+	lduw		[%1 + 0x04], %%g2
+	lduw		[%1 + 0x08], %%g3
+	addcc		%%g2, %0, %0
+	addccc		%%g3, %0, %0
+	lduw		[%1 + 0x0c], %%g2
+	lduw		[%1 + 0x10], %%g3
+	addccc		%%g2, %0, %0
+	addc		%0, %%g0, %0
+1:
+	addcc		%%g3, %0, %0
+	add		%1, 4, %1
+	addccc		%0, %%g0, %0
+	subcc		%%g4, 1, %%g4
+	be,a,pt		%%icc, 2f
+	 sll		%0, 16, %%g2
+	ba,pt		1b
+	 lduw		[%1 + 0x10], %%g3
+2:
+	addcc		%0, %%g2, %%g2
+	srl		%%g2, 16, %0
+	addc		%0, %%g0, %0
+	xnor		%%g0, %0, %0
+"	: "=r" (sum), "=&r" (iph)
+	: "r" (ihl), "1" (iph)
+	: "g2", "g3", "g4");
+	return sum;
+}
+
+/* computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+extern __inline__ unsigned short csum_tcpudp_magic(unsigned long saddr,
+						   unsigned long daddr,
+						   unsigned int len,
+						   unsigned short proto,
+						   unsigned int sum)
+{
+	__asm__ __volatile__("
+	addcc		%1, %0, %0
+	addccc		%2, %0, %0
+	addccc		%3, %0, %0
+	addc		%0, %%g0, %0
+	sll		%0, 16, %1
+	addcc		%1, %0, %0
+	srl		%0, 16, %0
+	addc		%0, %%g0, %0
+	xnor		%%g0, %0, %0
+"	: "=r" (sum), "=r" (saddr)
+	: "r" (daddr), "r" ((proto<<16)+len), "0" (sum), "1" (saddr));
+	return sum;
+}
+
+/* Fold a partial checksum without adding pseudo headers. */
+extern __inline__ unsigned int csum_fold(unsigned int sum)
+{
+	unsigned int tmp;
+
+	__asm__ __volatile__("
+	addcc		%0, %1, %1
+	srl		%1, 16, %1
+	addc		%1, %%g0, %1
+	xnor		%%g0, %1, %0
+"	: "=&r" (sum), "=r" (tmp)
+	: "0" (sum), "1" (sum<<16));
+	return sum;
+}
+
+#define _HAVE_ARCH_IPV6_CSUM
+
+static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
+						     struct in6_addr *daddr,
+						     __u16 len,
+						     unsigned short proto,
+						     unsigned int sum) 
+{
+	__asm__ __volatile__ ("
+	addcc		%3, %4, %%g4
+	addccc		%5, %%g4, %%g4
+	lduw		[%2 + 0x0c], %%g2
+	lduw		[%2 + 0x08], %%g3
+	addccc		%%g2, %%g4, %%g4
+	lduw		[%2 + 0x04], %%g2
+	addccc		%%g3, %%g4, %%g4
+	lduw		[%2 + 0x00], %%g3
+	addccc		%%g2, %%g4, %%g4
+	lduw		[%1 + 0x0c], %%g2
+	addccc		%%g3, %%g4, %%g4
+	lduw		[%1 + 0x08], %%g3
+	addccc		%%g2, %%g4, %%g4
+	lduw		[%1 + 0x04], %%g2
+	addccc		%%g3, %%g4, %%g4
+	lduw		[%1 + 0x00], %%g3
+	addccc		%%g2, %%g4, %%g4
+	addccc		%%g3, %%g4, %0
+	addc		0, %0, %0
+"	: "=&r" (sum)
+	: "r" (saddr), "r" (daddr), "r"(htonl((__u32) (len))),
+	  "r"(htonl(proto)), "r"(sum)
+	: "g2", "g3", "g4");
+
+	return csum_fold(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 /* !(__SPARC64_CHECKSUM_H) */