[mirror_ubuntu-zesty-kernel.git] / arch / ia64 / lib / checksum.c

/*
 * Network checksum routines
 *
 * Copyright (C) 1999, 2003 Hewlett-Packard Co
 *	Stephane Eranian <eranian@hpl.hp.com>
 *
 * Most of the code coming from arch/alpha/lib/checksum.c
 *
 * This file contains network checksum routines that are better done
 * in an architecture-specific manner due to speed..
 */

#include <linux/module.h>
#include <linux/string.h>

#include <asm/byteorder.h>

static inline unsigned short
from64to16 (unsigned long x)
{
	/* add up 32-bit words for 33 bits */
	x = (x & 0xffffffff) + (x >> 32);
	/* add up 16-bit and 17-bit words for 17+c bits */
	x = (x & 0xffff) + (x >> 16);
	/* add up 16-bit and 2-bit for 16+c bit */
	x = (x & 0xffff) + (x >> 16);
	/* add up carry.. */
	x = (x & 0xffff) + (x >> 16);
	return x;
}

/*
 * computes the checksum of the TCP/UDP pseudo-header
 * returns a 16-bit checksum, already complemented.
 */
__sum16
csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
		  __u8 proto, __wsum sum)
{
	return (__force __sum16)~from64to16(
		(__force u64)saddr + (__force u64)daddr +
		(__force u64)sum + ((len + proto) << 8));
}

EXPORT_SYMBOL(csum_tcpudp_magic);

__wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
		   __u8 proto, __wsum sum)
{
	unsigned long result;

	result = (__force u64)saddr + (__force u64)daddr +
		 (__force u64)sum + ((len + proto) << 8);

	/* Fold down to 32-bits so we don't lose in the typedef-less network stack.  */
	/* 64 to 33 */
	result = (result & 0xffffffff) + (result >> 32);
	/* 33 to 32 */
	result = (result & 0xffffffff) + (result >> 32);
	return (__force __wsum)result;
}
EXPORT_SYMBOL(csum_tcpudp_nofold);

extern unsigned long do_csum (const unsigned char *, long);

/*
 * 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)
{
	u64 result = do_csum(buff, len);

	/* add in old sum, and carry.. */
	result += (__force u32)sum;
	/* 32+c bits -> 32 bits */
	result = (result & 0xffffffff) + (result >> 32);
	return (__force __wsum)result;
}

EXPORT_SYMBOL(csum_partial);

/*
 * this routine is used for miscellaneous IP-like checksums, mainly
 * in icmp.c
 */
__sum16 ip_compute_csum (const void *buff, int len)
{
	return (__force __sum16)~do_csum(buff,len);
}

EXPORT_SYMBOL(ip_compute_csum);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Network checksum routines
	3	*
	4	* Copyright (C) 1999, 2003 Hewlett-Packard Co
	5	* Stephane Eranian <eranian@hpl.hp.com>
	6	*
	7	* Most of the code coming from arch/alpha/lib/checksum.c
	8	*
	9	* This file contains network checksum routines that are better done
	10	* in an architecture-specific manner due to speed..
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/string.h>
	15
	16	#include <asm/byteorder.h>
	17
	18	static inline unsigned short
	19	from64to16 (unsigned long x)
	20	{
	21	/* add up 32-bit words for 33 bits */
	22	x = (x & 0xffffffff) + (x >> 32);
	23	/* add up 16-bit and 17-bit words for 17+c bits */
	24	x = (x & 0xffff) + (x >> 16);
	25	/* add up 16-bit and 2-bit for 16+c bit */
	26	x = (x & 0xffff) + (x >> 16);
	27	/* add up carry.. */
	28	x = (x & 0xffff) + (x >> 16);
	29	return x;
	30	}
	31
	32	/*
	33	* computes the checksum of the TCP/UDP pseudo-header
	34	* returns a 16-bit checksum, already complemented.
	35	*/
32252996	36	__sum16
01cfbad7 AD	37	csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
01cfbad7 AD	38	__u8 proto, __wsum sum)
1da177e4	39	{
32252996 AV	40	return (__force __sum16)~from64to16(
	41	(__force u64)saddr + (__force u64)daddr +
	42	(__force u64)sum + ((len + proto) << 8));
1da177e4 LT	43	}
	44
	45	EXPORT_SYMBOL(csum_tcpudp_magic);
	46
32252996	47	__wsum
01cfbad7 AD	48	csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
01cfbad7 AD	49	__u8 proto, __wsum sum)
1da177e4 LT	50	{
	51	unsigned long result;
	52
32252996 AV	53	result = (__force u64)saddr + (__force u64)daddr +
32252996 AV	54	(__force u64)sum + ((len + proto) << 8);
1da177e4 LT	55
	56	/* Fold down to 32-bits so we don't lose in the typedef-less network stack. */
	57	/* 64 to 33 */
	58	result = (result & 0xffffffff) + (result >> 32);
	59	/* 33 to 32 */
	60	result = (result & 0xffffffff) + (result >> 32);
32252996	61	return (__force __wsum)result;
1da177e4	62	}
547c178b	63	EXPORT_SYMBOL(csum_tcpudp_nofold);
1da177e4 LT	64
	65	extern unsigned long do_csum (const unsigned char *, long);
	66
	67	/*
	68	* computes the checksum of a memory block at buff, length len,
	69	* and adds in "sum" (32-bit)
	70	*
	71	* returns a 32-bit number suitable for feeding into itself
	72	* or csum_tcpudp_magic
	73	*
	74	* this function must be called with even lengths, except
	75	* for the last fragment, which may be odd
	76	*
	77	* it's best to have buff aligned on a 32-bit boundary
	78	*/
32252996	79	__wsum csum_partial(const void *buff, int len, __wsum sum)
1da177e4	80	{
32252996	81	u64 result = do_csum(buff, len);
1da177e4 LT	82
1da177e4 LT	83	/* add in old sum, and carry.. */
32252996	84	result += (__force u32)sum;
1da177e4 LT	85	/* 32+c bits -> 32 bits */
1da177e4 LT	86	result = (result & 0xffffffff) + (result >> 32);
32252996	87	return (__force __wsum)result;
1da177e4 LT	88	}
	89
	90	EXPORT_SYMBOL(csum_partial);
	91
	92	/*
	93	* this routine is used for miscellaneous IP-like checksums, mainly
	94	* in icmp.c
	95	*/
32252996	96	__sum16 ip_compute_csum (const void *buff, int len)
1da177e4	97	{
32252996	98	return (__force __sum16)~do_csum(buff,len);
1da177e4 LT	99	}
	100
	101	EXPORT_SYMBOL(ip_compute_csum);