1 files changed, 193 insertions, 0 deletions

diff --git a/include/asm-x86_64/checksum.h b/include/asm-x86_64/checksum.h
new file mode 100644
index 000000000000..d01356f01448
--- /dev/null
+++ b/include/asm-x86_64/checksum.h
@@ -0,0 +1,193 @@
+#ifndef _X86_64_CHECKSUM_H
+#define _X86_64_CHECKSUM_H
+
+/* 
+ * Checksums for x86-64 
+ * Copyright 2002 by Andi Kleen, SuSE Labs 
+ * with some code from asm-i386/checksum.h
+ */ 
+
+#include <linux/compiler.h>
+#include <asm/uaccess.h>
+#include <asm/byteorder.h>
+
+/** 
+ * csum_fold - Fold and invert a 32bit checksum.
+ * sum: 32bit unfolded sum
+ * 
+ * Fold a 32bit running checksum to 16bit and invert it. This is usually
+ * the last step before putting a checksum into a packet.
+ * Make sure not to mix with 64bit checksums.
+ */
+static inline unsigned int csum_fold(unsigned int sum)
+{
+        __asm__(
+                "  addl %1,%0\n"
+                "  adcl $0xffff,%0"
+                : "=r" (sum)
+                : "r" (sum << 16), "0" (sum & 0xffff0000)
+        );
+        return (~sum) >> 16;
+}
+
+/*
+ *      This is a version of ip_compute_csum() optimized for IP headers,
+ *      which always checksum on 4 octet boundaries.
+ *
+ *      By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
+ *      Arnt Gulbrandsen.
+ */
+
+/**
+ * ip_fast_csum - Compute the IPv4 header checksum efficiently.
+ * iph: ipv4 header
+ * ihl: length of header / 4
+ */ 
+static inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) 
+{
+        unsigned int sum;
+
+        asm(    "  movl (%1), %0\n"
+                "  subl $4, %2\n"
+                "  jbe 2f\n"
+                "  addl 4(%1), %0\n"
+                "  adcl 8(%1), %0\n"
+                "  adcl 12(%1), %0\n"
+                "1: adcl 16(%1), %0\n"
+                "  lea 4(%1), %1\n"
+                "  decl %2\n"
+                "  jne  1b\n"
+                "  adcl $0, %0\n"
+                "  movl %0, %2\n"
+                "  shrl $16, %0\n"
+                "  addw %w2, %w0\n"
+                "  adcl $0, %0\n"
+                "  notl %0\n"
+                "2:"
+        /* Since the input registers which are loaded with iph and ipl
+           are modified, we must also specify them as outputs, or gcc
+           will assume they contain their original values. */
+        : "=r" (sum), "=r" (iph), "=r" (ihl)
+        : "1" (iph), "2" (ihl)
+        : "memory");
+        return(sum);
+}
+
+/** 
+ * csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
+ * @saddr: source address
+ * @daddr: destination address
+ * @len: length of packet
+ * @proto: ip protocol of packet
+ * @sum: initial sum to be added in (32bit unfolded) 
+ * 
+ * Returns the pseudo header checksum the input data. Result is 
+ * 32bit unfolded.
+ */
+static inline unsigned long 
+csum_tcpudp_nofold(unsigned saddr, unsigned daddr, unsigned short len,
+                   unsigned short proto, unsigned int sum) 
+{
+        asm("  addl %1, %0\n"
+            "  adcl %2, %0\n"
+            "  adcl %3, %0\n"
+            "  adcl $0, %0\n"
+                : "=r" (sum)
+            : "g" (daddr), "g" (saddr), "g" ((ntohs(len)<<16)+proto*256), "0" (sum));
+    return sum;
+}
+
+
+/** 
+ * csum_tcpup_magic - Compute an IPv4 pseudo header checksum.
+ * @saddr: source address
+ * @daddr: destination address
+ * @len: length of packet
+ * @proto: ip protocol of packet
+ * @sum: initial sum to be added in (32bit unfolded) 
+ * 
+ * Returns the 16bit pseudo header checksum the input data already
+ * complemented and ready to be filled in.
+ */
+static 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));
+}
+
+/** 
+ * csum_partial - Compute an internet checksum.
+ * @buff: buffer to be checksummed
+ * @len: length of buffer.
+ * @sum: initial sum to be added in (32bit unfolded)
+ *
+ * Returns the 32bit unfolded internet checksum of the buffer.
+ * Before filling it in it needs to be csum_fold()'ed.
+ * buff should be aligned to a 64bit boundary if possible.
+ */ 
+extern unsigned int csum_partial(const unsigned char *buff, unsigned len, unsigned int sum);
+
+#define  _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
+#define HAVE_CSUM_COPY_USER 1
+
+
+/* Do not call this directly. Use the wrappers below */
+extern unsigned long csum_partial_copy_generic(const unsigned char *src, const unsigned char *dst,
+                                               unsigned len,
+                                               unsigned sum, 
+                                               int *src_err_ptr, int *dst_err_ptr);
+
+
+extern unsigned int csum_partial_copy_from_user(const unsigned char __user *src, unsigned char *dst,
+                                       int len, unsigned int isum, int *errp);
+extern unsigned int csum_partial_copy_to_user(const unsigned char *src, unsigned char __user *dst,
+                                      int len, unsigned int isum, int *errp);
+extern unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, int len,
+                                              unsigned int sum);
+
+/* Old names. To be removed. */
+#define csum_and_copy_to_user csum_partial_copy_to_user
+#define csum_and_copy_from_user csum_partial_copy_from_user
+
+/** 
+ * ip_compute_csum - Compute an 16bit IP checksum.
+ * @buff: buffer address.
+ * @len: length of buffer.
+ *
+ * Returns the 16bit folded/inverted checksum of the passed buffer.
+ * Ready to fill in.
+ */
+extern unsigned short ip_compute_csum(unsigned char * buff, int len);
+
+/**
+ * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
+ * @saddr: source address
+ * @daddr: destination address
+ * @len: length of packet
+ * @proto: protocol of packet
+ * @sum: initial sum (32bit unfolded) to be added in
+ *
+ * Computes an IPv6 pseudo header checksum. This sum is added the checksum 
+ * into UDP/TCP packets and contains some link layer information.
+ * Returns the unfolded 32bit checksum.
+ */
+
+struct in6_addr;
+
+#define _HAVE_ARCH_IPV6_CSUM 1
+extern unsigned short 
+csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr,
+                __u32 len, unsigned short proto, unsigned int sum);
+
+static inline unsigned add32_with_carry(unsigned a, unsigned b)
+{
+        asm("addl %2,%0\n\t"
+            "adcl $0,%0" 
+            : "=r" (a) 
+            : "0" (a), "r" (b));
+        return a;
+}
+
+#endif
+