1 files changed, 129 insertions, 0 deletions
diff --git a/arch/x86_64/lib/csum-wrappers.c b/arch/x86_64/lib/csum-wrappers.c
new file mode 100644
index 000000000000..94323f20816e
--- /dev/null
+++ b/arch/x86_64/lib/csum-wrappers.c
@@ -0,0 +1,129 @@
+/* Copyright 2002,2003 Andi Kleen, SuSE Labs.
+ * Subject to the GNU Public License v.2
+ * 
+ * Wrappers of assembly checksum functions for x86-64.
+ */
+
+#include <asm/checksum.h>
+#include <linux/module.h>
+
+/** 
+ * csum_partial_copy_from_user - Copy and checksum from user space. 
+ * @src: source address (user space) 
+ * @dst: destination address
+ * @len: number of bytes to be copied.
+ * @isum: initial sum that is added into the result (32bit unfolded)
+ * @errp: set to -EFAULT for an bad source address.
+ * 
+ * Returns an 32bit unfolded checksum of the buffer.
+ * src and dst are best aligned to 64bits. 
+ */ 
+unsigned int 
+csum_partial_copy_from_user(const unsigned char __user *src, unsigned char *dst,
+			    int len, unsigned int isum, int *errp)
+{ 
+	might_sleep();
+	*errp = 0;
+	if (likely(access_ok(VERIFY_READ,src, len))) { 
+		/* Why 6, not 7? To handle odd addresses aligned we
+		   would need to do considerable complications to fix the
+		   checksum which is defined as an 16bit accumulator. The
+		   fix alignment code is primarily for performance
+		   compatibility with 32bit and that will handle odd
+		   addresses slowly too. */
+		if (unlikely((unsigned long)src & 6)) {			
+			while (((unsigned long)src & 6) && len >= 2) { 
+				__u16 val16;			
+				*errp = __get_user(val16, (__u16 __user *)src); 
+				if (*errp)
+					return isum;
+				*(__u16 *)dst = val16;
+				isum = add32_with_carry(isum, val16); 
+				src += 2; 
+				dst += 2; 
+				len -= 2;
+			}
+		}
+		isum = csum_partial_copy_generic((__force void *)src,dst,len,isum,errp,NULL);
+		if (likely(*errp == 0)) 
+			return isum;
+	} 
+	*errp = -EFAULT;
+	memset(dst,0,len); 
+	return isum;		
+} 
+
+EXPORT_SYMBOL(csum_partial_copy_from_user);
+
+/** 
+ * csum_partial_copy_to_user - Copy and checksum to user space. 
+ * @src: source address
+ * @dst: destination address (user space)
+ * @len: number of bytes to be copied.
+ * @isum: initial sum that is added into the result (32bit unfolded)
+ * @errp: set to -EFAULT for an bad destination address.
+ * 
+ * Returns an 32bit unfolded checksum of the buffer.
+ * src and dst are best aligned to 64bits.
+ */ 
+unsigned int 
+csum_partial_copy_to_user(unsigned const char *src, unsigned char __user *dst,
+			  int len, unsigned int isum, int *errp)
+{ 
+	might_sleep();
+	if (unlikely(!access_ok(VERIFY_WRITE, dst, len))) {
+		*errp = -EFAULT;
+		return 0; 
+	}
+
+	if (unlikely((unsigned long)dst & 6)) {
+		while (((unsigned long)dst & 6) && len >= 2) { 
+			__u16 val16 = *(__u16 *)src;
+			isum = add32_with_carry(isum, val16);
+			*errp = __put_user(val16, (__u16 __user *)dst);
+			if (*errp)
+				return isum;
+			src += 2; 
+			dst += 2; 
+			len -= 2;
+		}
+	}
+
+	*errp = 0;
+	return csum_partial_copy_generic(src, (void __force *)dst,len,isum,NULL,errp); 
+} 
+
+EXPORT_SYMBOL(csum_partial_copy_to_user);
+
+/** 
+ * csum_partial_copy_nocheck - Copy and checksum.
+ * @src: source address
+ * @dst: destination address
+ * @len: number of bytes to be copied.
+ * @isum: initial sum that is added into the result (32bit unfolded)
+ * 
+ * Returns an 32bit unfolded checksum of the buffer.
+ */ 
+unsigned int 
+csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, int len, unsigned int sum)
+{ 
+	return csum_partial_copy_generic(src,dst,len,sum,NULL,NULL);
+} 
+
+unsigned short csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr,
+			       __u32 len, unsigned short proto, unsigned int sum) 
+{
+	__u64 rest, sum64;
+     
+	rest = (__u64)htonl(len) + (__u64)htons(proto) + (__u64)sum;
+	asm("  addq (%[saddr]),%[sum]\n"
+	    "  adcq 8(%[saddr]),%[sum]\n"
+	    "  adcq (%[daddr]),%[sum]\n" 
+	    "  adcq 8(%[daddr]),%[sum]\n"
+	    "  adcq $0,%[sum]\n"
+	    : [sum] "=r" (sum64) 
+	    : "[sum]" (rest),[saddr] "r" (saddr), [daddr] "r" (daddr));
+	return csum_fold(add32_with_carry(sum64 & 0xffffffff, sum64>>32));
+}
+
+EXPORT_SYMBOL(csum_ipv6_magic);