[linux-block.git] / include / asm-s390 / checksum.h

#ifndef _S390_CHECKSUM_H
#define _S390_CHECKSUM_H

/*
 *  include/asm-s390/checksum.h
 *    S390 fast network checksum routines
 *    see also arch/S390/lib/checksum.c
 *
 *  S390 version
 *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Ulrich Hild        (first version)
 *               Martin Schwidefsky (heavily optimized CKSM version)
 *               D.J. Barrow        (third attempt) 
 */

#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
 */
static inline __wsum
csum_partial(const void *buff, int len, __wsum sum)
{
	register unsigned long reg2 asm("2") = (unsigned long) buff;
	register unsigned long reg3 asm("3") = (unsigned long) len;

	asm volatile(
		"0:	cksm	%0,%1\n"	/* do checksum on longs */
		"	jo	0b\n"
		: "+d" (sum), "+d" (reg2), "+d" (reg3) : : "cc", "memory");
	return 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
 *
 * Copy from userspace and compute checksum.  If we catch an exception
 * then zero 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)
{
	int missing;

	missing = copy_from_user(dst, src, len);
	if (missing) {
		memset(dst + len - missing, 0, missing);
		*err_ptr = -EFAULT;
	}
		
	return csum_partial(dst, len, sum);
}


static inline __wsum
csum_partial_copy_nocheck (const void *src, void *dst, int len, __wsum sum)
{
        memcpy(dst,src,len);
	return csum_partial(dst, len, sum);
}

/*
 *      Fold a partial checksum without adding pseudo headers
 */
static inline __sum16 csum_fold(__wsum sum)
{
#ifndef __s390x__
	register_pair rp;

	asm volatile(
		"	slr	%N1,%N1\n"	/* %0 = H L */
		"	lr	%1,%0\n"	/* %0 = H L, %1 = H L 0 0 */
		"	srdl	%1,16\n"	/* %0 = H L, %1 = 0 H L 0 */
		"	alr	%1,%N1\n"	/* %0 = H L, %1 = L H L 0 */
		"	alr	%0,%1\n"	/* %0 = H+L+C L+H */
		"	srl	%0,16\n"	/* %0 = H+L+C */
		: "+&d" (sum), "=d" (rp) : : "cc");
#else /* __s390x__ */
	asm volatile(
		"	sr	3,3\n"		/* %0 = H*65536 + L */
		"	lr	2,%0\n"		/* %0 = H L, 2/3 = H L / 0 0 */
		"	srdl	2,16\n"		/* %0 = H L, 2/3 = 0 H / L 0 */
		"	alr	2,3\n"		/* %0 = H L, 2/3 = L H / L 0 */
		"	alr	%0,2\n"		/* %0 = H+L+C L+H */
		"	srl	%0,16\n"	/* %0 = H+L+C */
		: "+&d" (sum) : : "cc", "2", "3");
#endif /* __s390x__ */
	return (__force __sum16) ~sum;
}

/*
 *	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)
{
	return csum_fold(csum_partial(iph, ihl*4, 0));
}

/*
 * computes the checksum of the TCP/UDP pseudo-header
 * returns a 32-bit checksum
 */
static inline __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
                   unsigned short len, unsigned short proto,
                   __wsum sum)
{
	__u32 csum = (__force __u32)sum;

	csum += (__force __u32)saddr;
	if (csum < (__force __u32)saddr)
		csum++;

	csum += (__force __u32)daddr;
	if (csum < (__force __u32)daddr)
		csum++;

	csum += len + proto;
	if (csum < len + proto)
		csum++;

	return (__force __wsum)csum;
}

/*
 * 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));
}

#endif /* _S390_CHECKSUM_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _S390_CHECKSUM_H
	2	#define _S390_CHECKSUM_H
	3
	4	/*
	5	* include/asm-s390/checksum.h
	6	* S390 fast network checksum routines
	7	* see also arch/S390/lib/checksum.c
	8	*
	9	* S390 version
	10	* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
	11	* Author(s): Ulrich Hild (first version)
	12	* Martin Schwidefsky (heavily optimized CKSM version)
	13	* D.J. Barrow (third attempt)
	14	*/
	15
	16	#include <asm/uaccess.h>
	17
	18	/*
	19	* computes the checksum of a memory block at buff, length len,
	20	* and adds in "sum" (32-bit)
	21	*
	22	* returns a 32-bit number suitable for feeding into itself
	23	* or csum_tcpudp_magic
	24	*
	25	* this function must be called with even lengths, except
	26	* for the last fragment, which may be odd
	27	*
	28	* it's best to have buff aligned on a 32-bit boundary
	29	*/
f994aae1 AV	30	static inline __wsum
f994aae1 AV	31	csum_partial(const void *buff, int len, __wsum sum)
1da177e4	32	{
94c12cc7 MS	33	register unsigned long reg2 asm("2") = (unsigned long) buff;
94c12cc7 MS	34	register unsigned long reg3 asm("3") = (unsigned long) len;
1da177e4	35
94c12cc7 MS	36	asm volatile(
	37	"0: cksm %0,%1\n" /* do checksum on longs */
	38	" jo 0b\n"
	39	: "+d" (sum), "+d" (reg2), "+d" (reg3) : : "cc", "memory");
1da177e4 LT	40	return sum;
	41	}
	42
	43	/*
	44	* the same as csum_partial_copy, but copies from user space.
	45	*
	46	* here even more important to align src and dst on a 32-bit (or even
	47	* better 64-bit) boundary
	48	*
	49	* Copy from userspace and compute checksum. If we catch an exception
	50	* then zero the rest of the buffer.
	51	*/
f994aae1 AV	52	static inline __wsum
	53	csum_partial_copy_from_user(const void __user src, void dst,
	54	int len, __wsum sum,
1da177e4 LT	55	int *err_ptr)
	56	{
	57	int missing;
	58
	59	missing = copy_from_user(dst, src, len);
	60	if (missing) {
	61	memset(dst + len - missing, 0, missing);
	62	*err_ptr = -EFAULT;
	63	}
	64
	65	return csum_partial(dst, len, sum);
	66	}
	67
	68
f994aae1 AV	69	static inline __wsum
f994aae1 AV	70	csum_partial_copy_nocheck (const void src, void dst, int len, __wsum sum)
1da177e4 LT	71	{
1da177e4 LT	72	memcpy(dst,src,len);
94c12cc7	73	return csum_partial(dst, len, sum);
1da177e4 LT	74	}
	75
	76	/*
	77	* Fold a partial checksum without adding pseudo headers
	78	*/
f994aae1	79	static inline __sum16 csum_fold(__wsum sum)
1da177e4 LT	80	{
	81	#ifndef __s390x__
	82	register_pair rp;
	83
94c12cc7 MS	84	asm volatile(
	85	" slr %N1,%N1\n" /* %0 = H L */
	86	" lr %1,%0\n" /* %0 = H L, %1 = H L 0 0 */
	87	" srdl %1,16\n" /* %0 = H L, %1 = 0 H L 0 */
	88	" alr %1,%N1\n" /* %0 = H L, %1 = L H L 0 */
	89	" alr %0,%1\n" /* %0 = H+L+C L+H */
	90	" srl %0,16\n" /* %0 = H+L+C */
	91	: "+&d" (sum), "=d" (rp) : : "cc");
1da177e4	92	#else /* __s390x__ */
94c12cc7 MS	93	asm volatile(
	94	" sr 3,3\n" /* %0 = H65536 + L /
	95	" lr 2,%0\n" /* %0 = H L, 2/3 = H L / 0 0 */
	96	" srdl 2,16\n" /* %0 = H L, 2/3 = 0 H / L 0 */
	97	" alr 2,3\n" /* %0 = H L, 2/3 = L H / L 0 */
	98	" alr %0,2\n" /* %0 = H+L+C L+H */
	99	" srl %0,16\n" /* %0 = H+L+C */
1da177e4 LT	100	: "+&d" (sum) : : "cc", "2", "3");
1da177e4 LT	101	#endif /* __s390x__ */
f994aae1	102	return (__force __sum16) ~sum;
1da177e4 LT	103	}
	104
	105	/*
	106	* This is a version of ip_compute_csum() optimized for IP headers,
	107	* which always checksum on 4 octet boundaries.
	108	*
	109	*/
f994aae1	110	static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
1da177e4	111	{
94c12cc7	112	return csum_fold(csum_partial(iph, ihl*4, 0));
1da177e4 LT	113	}
	114
	115	/*
	116	* computes the checksum of the TCP/UDP pseudo-header
	117	* returns a 32-bit checksum
	118	*/
f994aae1 AV	119	static inline __wsum
f994aae1 AV	120	csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
1da177e4	121	unsigned short len, unsigned short proto,
f994aae1	122	__wsum sum)
1da177e4	123	{
afbc1e99 HC	124	__u32 csum = (__force __u32)sum;
	125
	126	csum += (__force __u32)saddr;
	127	if (csum < (__force __u32)saddr)
	128	csum++;
	129
	130	csum += (__force __u32)daddr;
	131	if (csum < (__force __u32)daddr)
	132	csum++;
	133
	134	csum += len + proto;
	135	if (csum < len + proto)
	136	csum++;
	137
	138	return (__force __wsum)csum;
1da177e4 LT	139	}
	140
	141	/*
	142	* computes the checksum of the TCP/UDP pseudo-header
	143	* returns a 16-bit checksum, already complemented
	144	*/
	145
f994aae1 AV	146	static inline __sum16
f994aae1 AV	147	csum_tcpudp_magic(__be32 saddr, __be32 daddr,
1da177e4	148	unsigned short len, unsigned short proto,
f994aae1	149	__wsum sum)
1da177e4 LT	150	{
	151	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
	152	}
	153
	154	/*
	155	* this routine is used for miscellaneous IP-like checksums, mainly
	156	* in icmp.c
	157	*/
	158
f994aae1	159	static inline __sum16 ip_compute_csum(const void *buff, int len)
1da177e4 LT	160	{
	161	return csum_fold(csum_partial(buff, len, 0));
	162	}
	163
	164	#endif /* _S390_CHECKSUM_H */
	165
	166