[mirror_ubuntu-bionic-kernel.git] / arch / metag / include / asm / checksum.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _METAG_CHECKSUM_H
#define _METAG_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(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 __user *src, void *dst,
					int len, __wsum sum, int *csum_err);

#define csum_partial_copy_nocheck(src, dst, len, sum)	\
	csum_partial_copy((src), (dst), (len), (sum))

/*
 * Fold a partial checksum
 */
static inline __sum16 csum_fold(__wsum csum)
{
	u32 sum = (__force u32)csum;
	sum = (sum & 0xffff) + (sum >> 16);
	sum = (sum & 0xffff) + (sum >> 16);
	return (__force __sum16)~sum;
}

/*
 * This is a version of ip_compute_csum() optimized for IP headers,
 * which always checksum on 4 octet boundaries.
 */
extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);

/*
 * 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,
					__u32 len, __u8 proto,
					__wsum sum)
{
	unsigned long len_proto = (proto + len) << 8;
	asm ("ADDS   %0, %0, %1\n"
	     "ADDCS  %0, %0, #1\n"
	     "ADDS   %0, %0, %2\n"
	     "ADDCS  %0, %0, #1\n"
	     "ADDS   %0, %0, %3\n"
	     "ADDCS  %0, %0, #1\n"
	     : "=d" (sum)
	     : "d" (daddr), "d" (saddr), "d" (len_proto),
	       "0" (sum)
	     : "cc");
	return sum;
}

static inline __sum16
csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
		  __u8 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 /* _METAG_CHECKSUM_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
086e9dc0 JH	2	#ifndef _METAG_CHECKSUM_H
	3	#define _METAG_CHECKSUM_H
	4
	5	/*
	6	* computes the checksum of a memory block at buff, length len,
	7	* and adds in "sum" (32-bit)
	8	*
	9	* returns a 32-bit number suitable for feeding into itself
	10	* or csum_tcpudp_magic
	11	*
	12	* this function must be called with even lengths, except
	13	* for the last fragment, which may be odd
	14	*
	15	* it's best to have buff aligned on a 32-bit boundary
	16	*/
	17	extern __wsum csum_partial(const void *buff, int len, __wsum sum);
	18
	19	/*
	20	* the same as csum_partial, but copies from src while it
	21	* checksums
	22	*
	23	* here even more important to align src and dst on a 32-bit (or even
	24	* better 64-bit) boundary
	25	*/
	26	extern __wsum csum_partial_copy(const void src, void dst, int len,
	27	__wsum sum);
	28
	29	/*
	30	* the same as csum_partial_copy, but copies from user space.
	31	*
	32	* here even more important to align src and dst on a 32-bit (or even
	33	* better 64-bit) boundary
	34	*/
	35	extern __wsum csum_partial_copy_from_user(const void __user src, void dst,
	36	int len, __wsum sum, int *csum_err);
	37
	38	#define csum_partial_copy_nocheck(src, dst, len, sum) \
	39	csum_partial_copy((src), (dst), (len), (sum))
	40
	41	/*
	42	* Fold a partial checksum
	43	*/
	44	static inline __sum16 csum_fold(__wsum csum)
	45	{
	46	u32 sum = (__force u32)csum;
	47	sum = (sum & 0xffff) + (sum >> 16);
	48	sum = (sum & 0xffff) + (sum >> 16);
	49	return (__force __sum16)~sum;
	50	}
	51
	52	/*
	53	* This is a version of ip_compute_csum() optimized for IP headers,
	54	* which always checksum on 4 octet boundaries.
	55	*/
	56	extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
	57
	58	/*
	59	* computes the checksum of the TCP/UDP pseudo-header
	60	* returns a 16-bit checksum, already complemented
	61	*/
	62	static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
01cfbad7	63	__u32 len, __u8 proto,
086e9dc0 JH	64	__wsum sum)
	65	{
	66	unsigned long len_proto = (proto + len) << 8;
d903bca9 JH	67	asm ("ADDS %0, %0, %1\n"
d903bca9 JH	68	"ADDCS %0, %0, #1\n"
086e9dc0 JH	69	"ADDS %0, %0, %2\n"
	70	"ADDCS %0, %0, #1\n"
	71	"ADDS %0, %0, %3\n"
	72	"ADDCS %0, %0, #1\n"
	73	: "=d" (sum)
	74	: "d" (daddr), "d" (saddr), "d" (len_proto),
	75	"0" (sum)
	76	: "cc");
	77	return sum;
	78	}
	79
	80	static inline __sum16
01cfbad7 AD	81	csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
01cfbad7 AD	82	__u8 proto, __wsum sum)
086e9dc0 JH	83	{
	84	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
	85	}
	86
	87	/*
	88	* this routine is used for miscellaneous IP-like checksums, mainly
	89	* in icmp.c
	90	*/
	91	extern __sum16 ip_compute_csum(const void *buff, int len);
	92
	93	#endif /* _METAG_CHECKSUM_H */