[linux-2.6-block.git] / include / asm-v850 / checksum.h

/*
 * include/asm-v850/checksum.h -- Checksum ops
 *
 *  Copyright (C) 2001,2005  NEC Corporation
 *  Copyright (C) 2001,2005  Miles Bader <miles@gnu.org>
 *
 * 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.
 *
 * Written by Miles Bader <miles@gnu.org>
 */

#ifndef __V850_CHECKSUM_H__
#define __V850_CHECKSUM_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
 */
extern __wsum csum_partial(const void *buff, int len, __wsum sum);

/*
 * the same as csum_partial, but copies from src while it
 * checksums
 *
 * here even more important to align src and dst on a 32-bit (or even
 * better 64-bit) boundary
 */
extern __wsum csum_partial_copy_nocheck(const void *src,
				   void *dst, int len, __wsum sum);


/*
 * the same as csum_partial_copy, but copies from user space.
 *
 * here even more important to align src and dst on a 32-bit (or even
 * better 64-bit) boundary
 */
extern __wsum csum_partial_copy_from_user (const void *src,
					     void *dst,
					     int len, __wsum sum,
					     int *csum_err);

__sum16 ip_fast_csum(const void *iph, unsigned int ihl);

/*
 *	Fold a partial checksum
 */
static inline __sum16 csum_fold (__wsum sum)
{
	unsigned int result;
	/*
			        %0		%1
	      hsw %1, %0	H     L		L     H
	      add %1, %0	H     L		H+L+C H+L
	*/
	asm ("hsw %1, %0; add %1, %0" : "=&r" (result) : "r" (sum));
	return (__force __sum16)(~result >> 16);
}


/*
 * computes the checksum of the TCP/UDP pseudo-header
 * returns a 16-bit checksum, already complemented
 */
static inline __wsum
csum_tcpudp_nofold (__be32 saddr, __be32 daddr,
		    unsigned short len,
		    unsigned short proto, __wsum sum)
{
	int __carry;
	__asm__ ("add %2, %0;"
		 "setf c, %1;"
		 "add %1, %0;"
		 "add %3, %0;"
		 "setf c, %1;"
		 "add %1, %0;"
		 "add %4, %0;"
		 "setf c, %1;"
		 "add %1, %0"
		 : "=&r" (sum), "=&r" (__carry)
		 : "r" (daddr), "r" (saddr),
		 "r" ((len + proto) << 8),
		 "0" (sum));
	return sum;
}

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
 */
extern __sum16 ip_compute_csum(const void *buff, int len);


#endif /* __V850_CHECKSUM_H__ */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* include/asm-v850/checksum.h -- Checksum ops
	3	*
623cdf4a MB	4	* Copyright (C) 2001,2005 NEC Corporation
623cdf4a MB	5	* Copyright (C) 2001,2005 Miles Bader <miles@gnu.org>
1da177e4 LT	6	*
	7	* This file is subject to the terms and conditions of the GNU General
	8	* Public License. See the file COPYING in the main directory of this
	9	* archive for more details.
	10	*
	11	* Written by Miles Bader <miles@gnu.org>
	12	*/
	13
	14	#ifndef __V850_CHECKSUM_H__
	15	#define __V850_CHECKSUM_H__
	16
	17	/*
	18	* computes the checksum of a memory block at buff, length len,
	19	* and adds in "sum" (32-bit)
	20	*
	21	* returns a 32-bit number suitable for feeding into itself
	22	* or csum_tcpudp_magic
	23	*
	24	* this function must be called with even lengths, except
	25	* for the last fragment, which may be odd
	26	*
	27	* it's best to have buff aligned on a 32-bit boundary
	28	*/
9d3d4195	29	extern __wsum csum_partial(const void *buff, int len, __wsum sum);
1da177e4 LT	30
	31	/*
	32	* the same as csum_partial, but copies from src while it
	33	* checksums
	34	*
	35	* here even more important to align src and dst on a 32-bit (or even
	36	* better 64-bit) boundary
	37	*/
9d3d4195 AV	38	extern __wsum csum_partial_copy_nocheck(const void *src,
9d3d4195 AV	39	void *dst, int len, __wsum sum);
1da177e4 LT	40
	41
	42	/*
	43	* the same as csum_partial_copy, but copies from user space.
	44	*
	45	* here even more important to align src and dst on a 32-bit (or even
	46	* better 64-bit) boundary
	47	*/
9d3d4195 AV	48	extern __wsum csum_partial_copy_from_user (const void *src,
	49	void *dst,
	50	int len, __wsum sum,
1da177e4 LT	51	int *csum_err);
1da177e4 LT	52
9d3d4195	53	__sum16 ip_fast_csum(const void *iph, unsigned int ihl);
1da177e4 LT	54
	55	/*
	56	* Fold a partial checksum
	57	*/
9d3d4195	58	static inline __sum16 csum_fold (__wsum sum)
1da177e4 LT	59	{
	60	unsigned int result;
	61	/*
	62	%0 %1
	63	hsw %1, %0 H L L H
	64	add %1, %0 H L H+L+C H+L
	65	*/
	66	asm ("hsw %1, %0; add %1, %0" : "=&r" (result) : "r" (sum));
9d3d4195	67	return (__force __sum16)(~result >> 16);
1da177e4 LT	68	}
	69
	70
	71	/*
	72	* computes the checksum of the TCP/UDP pseudo-header
	73	* returns a 16-bit checksum, already complemented
	74	*/
9d3d4195 AV	75	static inline __wsum
9d3d4195 AV	76	csum_tcpudp_nofold (__be32 saddr, __be32 daddr,
1da177e4	77	unsigned short len,
9d3d4195	78	unsigned short proto, __wsum sum)
1da177e4 LT	79	{
	80	int __carry;
	81	__asm__ ("add %2, %0;"
	82	"setf c, %1;"
	83	"add %1, %0;"
	84	"add %3, %0;"
	85	"setf c, %1;"
	86	"add %1, %0;"
	87	"add %4, %0;"
	88	"setf c, %1;"
	89	"add %1, %0"
	90	: "=&r" (sum), "=&r" (__carry)
	91	: "r" (daddr), "r" (saddr),
9d3d4195	92	"r" ((len + proto) << 8),
1da177e4 LT	93	"0" (sum));
	94	return sum;
	95	}
	96
9d3d4195 AV	97	static inline __sum16
9d3d4195 AV	98	csum_tcpudp_magic (__be32 saddr, __be32 daddr,
1da177e4	99	unsigned short len,
9d3d4195	100	unsigned short proto, __wsum sum)
1da177e4 LT	101	{
	102	return csum_fold (csum_tcpudp_nofold (saddr, daddr, len, proto, sum));
	103	}
	104
	105	/*
	106	* this routine is used for miscellaneous IP-like checksums, mainly
	107	* in icmp.c
	108	*/
9d3d4195	109	extern __sum16 ip_compute_csum(const void *buff, int len);
1da177e4 LT	110
	111
	112	#endif /* __V850_CHECKSUM_H__ */