From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001
From: root <root@artemis.panaceas.org>
Date: Fri, 25 Dec 2015 04:40:36 +0000
Subject: initial_commit

---
 arch/arm/include/asm/checksum.h | 139 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 139 insertions(+)
 create mode 100644 arch/arm/include/asm/checksum.h

(limited to 'arch/arm/include/asm/checksum.h')

diff --git a/arch/arm/include/asm/checksum.h b/arch/arm/include/asm/checksum.h
new file mode 100644
index 00000000..6dcc1643
--- /dev/null
+++ b/arch/arm/include/asm/checksum.h
@@ -0,0 +1,139 @@
+/*
+ *  arch/arm/include/asm/checksum.h
+ *
+ * IP checksum routines
+ *
+ * Copyright (C) Original authors of ../asm-i386/checksum.h
+ * Copyright (C) 1996-1999 Russell King
+ */
+#ifndef __ASM_ARM_CHECKSUM_H
+#define __ASM_ARM_CHECKSUM_H
+
+#include <linux/in6.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
+ */
+__wsum csum_partial(const void *buff, int len, __wsum sum);
+
+/*
+ * the same as csum_partial, but copies from src while it
+ * checksums, and handles user-space pointer exceptions correctly, when needed.
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+
+__wsum
+csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
+
+__wsum
+csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr);
+
+/*
+ * 	Fold a partial checksum without adding pseudo headers
+ */
+static inline __sum16 csum_fold(__wsum sum)
+{
+	__asm__(
+	"add	%0, %1, %1, ror #16	@ csum_fold"
+	: "=r" (sum)
+	: "r" (sum)
+	: "cc");
+	return (__force __sum16)(~(__force u32)sum >> 16);
+}
+
+/*
+ *	This is a version of ip_compute_csum() optimized for IP headers,
+ *	which always checksum on 4 octet boundaries.
+ */
+static inline __sum16
+ip_fast_csum(const void *iph, unsigned int ihl)
+{
+	unsigned int tmp1;
+	__wsum sum;
+
+	__asm__ __volatile__(
+	"ldr	%0, [%1], #4		@ ip_fast_csum		\n\
+	ldr	%3, [%1], #4					\n\
+	sub	%2, %2, #5					\n\
+	adds	%0, %0, %3					\n\
+	ldr	%3, [%1], #4					\n\
+	adcs	%0, %0, %3					\n\
+	ldr	%3, [%1], #4					\n\
+1:	adcs	%0, %0, %3					\n\
+	ldr	%3, [%1], #4					\n\
+	tst	%2, #15			@ do this carefully	\n\
+	subne	%2, %2, #1		@ without destroying	\n\
+	bne	1b			@ the carry flag	\n\
+	adcs	%0, %0, %3					\n\
+	adc	%0, %0, #0"
+	: "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (tmp1)
+	: "1" (iph), "2" (ihl)
+	: "cc", "memory");
+	return csum_fold(sum);
+}
+
+static inline __wsum
+csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
+		   unsigned short proto, __wsum sum)
+{
+	__asm__(
+	"adds	%0, %1, %2		@ csum_tcpudp_nofold	\n\
+	adcs	%0, %0, %3					\n"
+#ifdef __ARMEB__
+	"adcs	%0, %0, %4					\n"
+#else
+	"adcs	%0, %0, %4, lsl #8				\n"
+#endif
+	"adcs	%0, %0, %5					\n\
+	adc	%0, %0, #0"
+	: "=&r"(sum)
+	: "r" (sum), "r" (daddr), "r" (saddr), "r" (len), "Ir" (htons(proto))
+	: "cc");
+	return sum;
+}	
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+static inline __sum16
+csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
+		  unsigned short proto, __wsum sum)
+{
+	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
+}
+
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+static inline __sum16
+ip_compute_csum(const void *buff, int len)
+{
+	return csum_fold(csum_partial(buff, len, 0));
+}
+
+#define _HAVE_ARCH_IPV6_CSUM
+extern __wsum
+__csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __be32 len,
+		__be32 proto, __wsum sum);
+
+static inline __sum16
+csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __u32 len,
+		unsigned short proto, __wsum sum)
+{
+	return csum_fold(__csum_ipv6_magic(saddr, daddr, htonl(len),
+					   htonl(proto), sum));
+}
+#endif
-- 
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