1#ifdef __KERNEL__
2#ifndef _ASM_M32R_CHECKSUM_H
3#define _ASM_M32R_CHECKSUM_H
4
5/*
6 * include/asm-m32r/checksum.h
7 *
8 * IP/TCP/UDP checksum routines
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License.  See the file "COPYING" in the main directory of this archive
12 * for more details.
13 *
14 * Some code taken from mips and parisc architecture.
15 *
16 *    Copyright (C) 2001, 2002  Hiroyuki Kondo, Hirokazu Takata
17 *    Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
18 */
19
20#include <linux/in6.h>
21
22/*
23 * computes the checksum of a memory block at buff, length len,
24 * and adds in "sum" (32-bit)
25 *
26 * returns a 32-bit number suitable for feeding into itself
27 * or csum_tcpudp_magic
28 *
29 * this function must be called with even lengths, except
30 * for the last fragment, which may be odd
31 *
32 * it's best to have buff aligned on a 32-bit boundary
33 */
34asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);
35
36/*
37 * The same as csum_partial, but copies from src while it checksums.
38 *
39 * Here even more important to align src and dst on a 32-bit (or even
40 * better 64-bit) boundary
41 */
42extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
43                                              int len, __wsum sum);
44
45/*
46 * This is a new version of the above that records errors it finds in *errp,
47 * but continues and zeros thre rest of the buffer.
48 */
49extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
50                                                int len, __wsum sum,
51                                                int *err_ptr);
52
53/*
54 *	Fold a partial checksum
55 */
56
57static inline __sum16 csum_fold(__wsum sum)
58{
59	unsigned long tmpreg;
60	__asm__(
61		"	sll3	%1, %0, #16 \n"
62		"	cmp	%0, %0 \n"
63		"	addx	%0, %1 \n"
64		"	ldi	%1, #0 \n"
65		"	srli	%0, #16 \n"
66		"	addx	%0, %1 \n"
67		"	xor3	%0, %0, #0x0000ffff \n"
68		: "=r" (sum), "=&r" (tmpreg)
69		: "0"  (sum)
70		: "cbit"
71	);
72	return (__force __sum16)sum;
73}
74
75/*
76 * This is a version of ip_compute_csum() optimized for IP headers,
77 * which always checksum on 4 octet boundaries.
78 */
79static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
80{
81	unsigned long tmpreg0, tmpreg1;
82	__wsum sum;
83
84	__asm__ __volatile__(
85		"	ld	%0, @%1+ \n"
86		"	addi	%2, #-4 \n"
87		"#	bgez	%2, 2f \n"
88		"	cmp	%0, %0 \n"
89		"	ld	%3, @%1+ \n"
90		"	ld	%4, @%1+ \n"
91		"	addx	%0, %3 \n"
92		"	ld	%3, @%1+ \n"
93		"	addx	%0, %4 \n"
94		"	addx	%0, %3 \n"
95		"	.fillinsn\n"
96		"1: \n"
97		"	ld	%4, @%1+ \n"
98		"	addi	%2, #-1 \n"
99		"	addx	%0, %4 \n"
100		"	bgtz	%2, 1b \n"
101		"\n"
102		"	ldi	%3, #0 \n"
103		"	addx	%0, %3 \n"
104		"	.fillinsn\n"
105		"2: \n"
106	/* Since the input registers which are loaded with iph and ihl
107	   are modified, we must also specify them as outputs, or gcc
108	   will assume they contain their original values. */
109	: "=&r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmpreg0), "=&r" (tmpreg1)
110	: "1" (iph), "2" (ihl)
111	: "cbit", "memory");
112
113	return csum_fold(sum);
114}
115
116static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
117					       unsigned short len,
118					       unsigned short proto,
119					       __wsum sum)
120{
121#if defined(__LITTLE_ENDIAN)
122	unsigned long len_proto = (proto + len) << 8;
123#else
124	unsigned long len_proto = proto + len;
125#endif
126	unsigned long tmpreg;
127
128	__asm__(
129		"	cmp	%0, %0 \n"
130		"	addx	%0, %2 \n"
131		"	addx	%0, %3 \n"
132		"	addx	%0, %4 \n"
133		"	ldi	%1, #0 \n"
134		"	addx	%0, %1 \n"
135		: "=r" (sum), "=&r" (tmpreg)
136		: "r" (daddr), "r" (saddr), "r" (len_proto), "0" (sum)
137		: "cbit"
138	);
139
140	return sum;
141}
142
143/*
144 * computes the checksum of the TCP/UDP pseudo-header
145 * returns a 16-bit checksum, already complemented
146 */
147static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
148						   unsigned short len,
149						   unsigned short proto,
150						   __wsum sum)
151{
152	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
153}
154
155/*
156 * this routine is used for miscellaneous IP-like checksums, mainly
157 * in icmp.c
158 */
159
160static inline __sum16 ip_compute_csum(const void *buff, int len)
161{
162	return csum_fold (csum_partial(buff, len, 0));
163}
164
165#define _HAVE_ARCH_IPV6_CSUM
166static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
167				      const struct in6_addr *daddr,
168				      __u32 len, unsigned short proto,
169				      __wsum sum)
170{
171	unsigned long tmpreg0, tmpreg1, tmpreg2, tmpreg3;
172	__asm__(
173		"	ld	%1, @(%5) \n"
174		"	ld	%2, @(4,%5) \n"
175		"	ld	%3, @(8,%5) \n"
176		"	ld	%4, @(12,%5) \n"
177		"	add	%0, %1 \n"
178		"	addx	%0, %2 \n"
179		"	addx	%0, %3 \n"
180		"	addx	%0, %4 \n"
181		"	ld	%1, @(%6) \n"
182		"	ld	%2, @(4,%6) \n"
183		"	ld	%3, @(8,%6) \n"
184		"	ld	%4, @(12,%6) \n"
185		"	addx	%0, %1 \n"
186		"	addx	%0, %2 \n"
187		"	addx	%0, %3 \n"
188		"	addx	%0, %4 \n"
189		"	addx	%0, %7 \n"
190		"	addx	%0, %8 \n"
191		"	ldi	%1, #0 \n"
192		"	addx	%0, %1 \n"
193		: "=&r" (sum), "=&r" (tmpreg0), "=&r" (tmpreg1),
194		  "=&r" (tmpreg2), "=&r" (tmpreg3)
195		: "r" (saddr), "r" (daddr),
196		  "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
197		: "cbit"
198	);
199
200	return csum_fold(sum);
201}
202
203#endif /* _ASM_M32R_CHECKSUM_H */
204#endif /* __KERNEL__ */
205