arch/mips/include/asm/checksum.h - maze/linux - Git at Google

 /*
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
  * Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle
  * Copyright (C) 1999 Silicon Graphics, Inc.
  * Copyright (C) 2001 Thiemo Seufer.
  * Copyright (C) 2002 Maciej W. Rozycki
  * Copyright (C) 2014 Imagination Technologies Ltd.
  */
 #ifndef _ASM_CHECKSUM_H
 #define _ASM_CHECKSUM_H

 #include <linux/in6.h>

 #include <asm/uaccess.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);

 __wsum __csum_partial_copy_kernel(const void *src, void *dst,
 				  int len, __wsum sum, int *err_ptr);

 __wsum __csum_partial_copy_from_user(const void *src, void *dst,
 				     int len, __wsum sum, int *err_ptr);
 __wsum __csum_partial_copy_to_user(const void *src, void *dst,
 				   int len, __wsum sum, int *err_ptr);
 /*
  * this is a new version of the above that records errors it finds in *errp,
  * but continues and zeros the rest of the buffer.
  */
 static inline
 __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len,
 				   __wsum sum, int *err_ptr)
 {
 	might_fault();
 	if (segment_eq(get_fs(), get_ds()))
 		return __csum_partial_copy_kernel((__force void *)src, dst,
 						  len, sum, err_ptr);
 	else
 		return __csum_partial_copy_from_user((__force void *)src, dst,
 						     len, sum, err_ptr);
 }

 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
 static inline
 __wsum csum_and_copy_from_user(const void __user *src, void *dst,
 			       int len, __wsum sum, int *err_ptr)
 {
 	if (access_ok(VERIFY_READ, src, len))
 		return csum_partial_copy_from_user(src, dst, len, sum,
 						   err_ptr);
 	if (len)
 		*err_ptr = -EFAULT;

 	return sum;
 }

 /*
  * Copy and checksum to user
  */
 #define HAVE_CSUM_COPY_USER
 static inline
 __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
 			     __wsum sum, int *err_ptr)
 {
 	might_fault();
 	if (access_ok(VERIFY_WRITE, dst, len)) {
 		if (segment_eq(get_fs(), get_ds()))
 			return __csum_partial_copy_kernel(src,
 							  (__force void *)dst,
 							  len, sum, err_ptr);
 		else
 			return __csum_partial_copy_to_user(src,
 							   (__force void *)dst,
 							   len, sum, err_ptr);
 	}
 	if (len)
 		*err_ptr = -EFAULT;

 	return (__force __wsum)-1; /* invalid checksum */
 }

 /*
  * the same as csum_partial, but copies from user space (but on MIPS
  * we have just one address space, so this is identical to the above)
  */
 __wsum csum_partial_copy_nocheck(const void *src, void *dst,
 				       int len, __wsum sum);

 /*
  *	Fold a partial checksum without adding pseudo headers
  */
 static inline __sum16 csum_fold(__wsum sum)
 {
 	__asm__(
 	"	.set	push		# csum_fold\n"
 	"	.set	noat		\n"
 	"	sll	$1, %0, 16	\n"
 	"	addu	%0, $1		\n"
 	"	sltu	$1, %0, $1	\n"
 	"	srl	%0, %0, 16	\n"
 	"	addu	%0, $1		\n"
 	"	xori	%0, 0xffff	\n"
 	"	.set	pop"
 	: "=r" (sum)
 	: "0" (sum));

 	return (__force __sum16)sum;
 }

 /*
  *	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.
  */
 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
 {
 	const unsigned int *word = iph;
 	const unsigned int *stop = word + ihl;
 	unsigned int csum;
 	int carry;

 	csum = word[0];
 	csum += word[1];
 	carry = (csum < word[1]);
 	csum += carry;

 	csum += word[2];
 	carry = (csum < word[2]);
 	csum += carry;

 	csum += word[3];
 	carry = (csum < word[3]);
 	csum += carry;

 	word += 4;
 	do {
 		csum += *word;
 		carry = (csum < *word);
 		csum += carry;
 		word++;
 	} while (word != stop);

 	return csum_fold(csum);
 }

 static inline __wsum csum_tcpudp_nofold(__be32 saddr,
 	__be32 daddr, unsigned short len, unsigned short proto,
 	__wsum sum)
 {
 	__asm__(
 	"	.set	push		# csum_tcpudp_nofold\n"
 	"	.set	noat		\n"
 #ifdef CONFIG_32BIT
 	"	addu	%0, %2		\n"
 	"	sltu	$1, %0, %2	\n"
 	"	addu	%0, $1		\n"

 	"	addu	%0, %3		\n"
 	"	sltu	$1, %0, %3	\n"
 	"	addu	%0, $1		\n"

 	"	addu	%0, %4		\n"
 	"	sltu	$1, %0, %4	\n"
 	"	addu	%0, $1		\n"
 #endif
 #ifdef CONFIG_64BIT
 	"	daddu	%0, %2		\n"
 	"	daddu	%0, %3		\n"
 	"	daddu	%0, %4		\n"
 	"	dsll32	$1, %0, 0	\n"
 	"	daddu	%0, $1		\n"
 	"	dsra32	%0, %0, 0	\n"
 #endif
 	"	.set	pop"
 	: "=r" (sum)
 	: "0" ((__force unsigned long)daddr),
 	  "r" ((__force unsigned long)saddr),
 #ifdef __MIPSEL__
 	  "r" ((proto + len) << 8),
 #else
 	  "r" (proto + len),
 #endif
 	  "r" ((__force unsigned long)sum));

 	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
 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 					  const struct in6_addr *daddr,
 					  __u32 len, unsigned short proto,
 					  __wsum sum)
 {
 	__asm__(
 	"	.set	push		# csum_ipv6_magic\n"
 	"	.set	noreorder	\n"
 	"	.set	noat		\n"
 	"	addu	%0, %5		# proto (long in network byte order)\n"
 	"	sltu	$1, %0, %5	\n"
 	"	addu	%0, $1		\n"

 	"	addu	%0, %6		# csum\n"
 	"	sltu	$1, %0, %6	\n"
 	"	lw	%1, 0(%2)	# four words source address\n"
 	"	addu	%0, $1		\n"
 	"	addu	%0, %1		\n"
 	"	sltu	$1, %0, %1	\n"

 	"	lw	%1, 4(%2)	\n"
 	"	addu	%0, $1		\n"
 	"	addu	%0, %1		\n"
 	"	sltu	$1, %0, %1	\n"

 	"	lw	%1, 8(%2)	\n"
 	"	addu	%0, $1		\n"
 	"	addu	%0, %1		\n"
 	"	sltu	$1, %0, %1	\n"

 	"	lw	%1, 12(%2)	\n"
 	"	addu	%0, $1		\n"
 	"	addu	%0, %1		\n"
 	"	sltu	$1, %0, %1	\n"

 	"	lw	%1, 0(%3)	\n"
 	"	addu	%0, $1		\n"
 	"	addu	%0, %1		\n"
 	"	sltu	$1, %0, %1	\n"

 	"	lw	%1, 4(%3)	\n"
 	"	addu	%0, $1		\n"
 	"	addu	%0, %1		\n"
 	"	sltu	$1, %0, %1	\n"

 	"	lw	%1, 8(%3)	\n"
 	"	addu	%0, $1		\n"
 	"	addu	%0, %1		\n"
 	"	sltu	$1, %0, %1	\n"

 	"	lw	%1, 12(%3)	\n"
 	"	addu	%0, $1		\n"
 	"	addu	%0, %1		\n"
 	"	sltu	$1, %0, %1	\n"

 	"	addu	%0, $1		# Add final carry\n"
 	"	.set	pop"
 	: "=r" (sum), "=r" (proto)
 	: "r" (saddr), "r" (daddr),
 	  "0" (htonl(len)), "1" (htonl(proto)), "r" (sum));

 	return csum_fold(sum);
 }

 #endif /* _ASM_CHECKSUM_H */
	/*
	* This file is subject to the terms and conditions of the GNU General Public
	* License. See the file "COPYING" in the main directory of this archive
	* for more details.
	*
	* Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle
	* Copyright (C) 1999 Silicon Graphics, Inc.
	* Copyright (C) 2001 Thiemo Seufer.
	* Copyright (C) 2002 Maciej W. Rozycki
	* Copyright (C) 2014 Imagination Technologies Ltd.
	*/
	#ifndef _ASM_CHECKSUM_H
	#define _ASM_CHECKSUM_H

	#include <linux/in6.h>

	#include <asm/uaccess.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);

	__wsum __csum_partial_copy_kernel(const void src, void dst,
	int len, __wsum sum, int *err_ptr);

	__wsum __csum_partial_copy_from_user(const void src, void dst,
	int len, __wsum sum, int *err_ptr);
	__wsum __csum_partial_copy_to_user(const void src, void dst,
	int len, __wsum sum, int *err_ptr);
	/*
	* this is a new version of the above that records errors it finds in *errp,
	* but continues and zeros the rest of the buffer.
	*/
	static inline
	__wsum csum_partial_copy_from_user(const void __user src, void dst, int len,
	__wsum sum, int *err_ptr)
	{
	might_fault();
	if (segment_eq(get_fs(), get_ds()))
	return __csum_partial_copy_kernel((__force void *)src, dst,
	len, sum, err_ptr);
	else
	return __csum_partial_copy_from_user((__force void *)src, dst,
	len, sum, err_ptr);
	}

	#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
	static inline
	__wsum csum_and_copy_from_user(const void __user src, void dst,
	int len, __wsum sum, int *err_ptr)
	{
	if (access_ok(VERIFY_READ, src, len))
	return csum_partial_copy_from_user(src, dst, len, sum,
	err_ptr);
	if (len)
	*err_ptr = -EFAULT;

	return sum;
	}

	/*
	* Copy and checksum to user
	*/
	#define HAVE_CSUM_COPY_USER
	static inline
	__wsum csum_and_copy_to_user(const void src, void __user dst, int len,
	__wsum sum, int *err_ptr)
	{
	might_fault();
	if (access_ok(VERIFY_WRITE, dst, len)) {
	if (segment_eq(get_fs(), get_ds()))
	return __csum_partial_copy_kernel(src,
	(__force void *)dst,
	len, sum, err_ptr);
	else
	return __csum_partial_copy_to_user(src,
	(__force void *)dst,
	len, sum, err_ptr);
	}
	if (len)
	*err_ptr = -EFAULT;

	return (__force __wsum)-1; /* invalid checksum */
	}

	/*
	* the same as csum_partial, but copies from user space (but on MIPS
	* we have just one address space, so this is identical to the above)
	*/
	__wsum csum_partial_copy_nocheck(const void src, void dst,
	int len, __wsum sum);

	/*
	* Fold a partial checksum without adding pseudo headers
	*/
	static inline __sum16 csum_fold(__wsum sum)
	{
	__asm__(
	" .set push # csum_fold\n"
	" .set noat \n"
	" sll $1, %0, 16 \n"
	" addu %0, $1 \n"
	" sltu $1, %0, $1 \n"
	" srl %0, %0, 16 \n"
	" addu %0, $1 \n"
	" xori %0, 0xffff \n"
	" .set pop"
	: "=r" (sum)
	: "0" (sum));

	return (__force __sum16)sum;
	}

	/*
	* 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.
	*/
	static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
	{
	const unsigned int *word = iph;
	const unsigned int *stop = word + ihl;
	unsigned int csum;
	int carry;

	csum = word[0];
	csum += word[1];
	carry = (csum < word[1]);
	csum += carry;

	csum += word[2];
	carry = (csum < word[2]);
	csum += carry;

	csum += word[3];
	carry = (csum < word[3]);
	csum += carry;

	word += 4;
	do {
	csum += *word;
	carry = (csum < *word);
	csum += carry;
	word++;
	} while (word != stop);

	return csum_fold(csum);
	}

	static inline __wsum csum_tcpudp_nofold(__be32 saddr,
	__be32 daddr, unsigned short len, unsigned short proto,
	__wsum sum)
	{
	__asm__(
	" .set push # csum_tcpudp_nofold\n"
	" .set noat \n"
	#ifdef CONFIG_32BIT
	" addu %0, %2 \n"
	" sltu $1, %0, %2 \n"
	" addu %0, $1 \n"

	" addu %0, %3 \n"
	" sltu $1, %0, %3 \n"
	" addu %0, $1 \n"

	" addu %0, %4 \n"
	" sltu $1, %0, %4 \n"
	" addu %0, $1 \n"
	#endif
	#ifdef CONFIG_64BIT
	" daddu %0, %2 \n"
	" daddu %0, %3 \n"
	" daddu %0, %4 \n"
	" dsll32 $1, %0, 0 \n"
	" daddu %0, $1 \n"
	" dsra32 %0, %0, 0 \n"
	#endif
	" .set pop"
	: "=r" (sum)
	: "0" ((__force unsigned long)daddr),
	"r" ((__force unsigned long)saddr),
	#ifdef __MIPSEL__
	"r" ((proto + len) << 8),
	#else
	"r" (proto + len),
	#endif
	"r" ((__force unsigned long)sum));

	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
	static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
	const struct in6_addr *daddr,
	__u32 len, unsigned short proto,
	__wsum sum)
	{
	__asm__(
	" .set push # csum_ipv6_magic\n"
	" .set noreorder \n"
	" .set noat \n"
	" addu %0, %5 # proto (long in network byte order)\n"
	" sltu $1, %0, %5 \n"
	" addu %0, $1 \n"

	" addu %0, %6 # csum\n"
	" sltu $1, %0, %6 \n"
	" lw %1, 0(%2) # four words source address\n"
	" addu %0, $1 \n"
	" addu %0, %1 \n"
	" sltu $1, %0, %1 \n"

	" lw %1, 4(%2) \n"
	" addu %0, $1 \n"
	" addu %0, %1 \n"
	" sltu $1, %0, %1 \n"

	" lw %1, 8(%2) \n"
	" addu %0, $1 \n"
	" addu %0, %1 \n"
	" sltu $1, %0, %1 \n"

	" lw %1, 12(%2) \n"
	" addu %0, $1 \n"
	" addu %0, %1 \n"
	" sltu $1, %0, %1 \n"

	" lw %1, 0(%3) \n"
	" addu %0, $1 \n"
	" addu %0, %1 \n"
	" sltu $1, %0, %1 \n"

	" lw %1, 4(%3) \n"
	" addu %0, $1 \n"
	" addu %0, %1 \n"
	" sltu $1, %0, %1 \n"

	" lw %1, 8(%3) \n"
	" addu %0, $1 \n"
	" addu %0, %1 \n"
	" sltu $1, %0, %1 \n"

	" lw %1, 12(%3) \n"
	" addu %0, $1 \n"
	" addu %0, %1 \n"
	" sltu $1, %0, %1 \n"

	" addu %0, $1 # Add final carry\n"
	" .set pop"
	: "=r" (sum), "=r" (proto)
	: "r" (saddr), "r" (daddr),
	"0" (htonl(len)), "1" (htonl(proto)), "r" (sum));

	return csum_fold(sum);
	}

	#endif /* _ASM_CHECKSUM_H */