1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_SH_CHECKSUM_H
3 #define __ASM_SH_CHECKSUM_H
6 * Copyright (C) 1999 by Kaz Kojima & Niibe Yutaka
12 * computes the checksum of a memory block at buff, length len,
13 * and adds in "sum" (32-bit)
15 * returns a 32-bit number suitable for feeding into itself
16 * or csum_tcpudp_magic
18 * this function must be called with even lengths, except
19 * for the last fragment, which may be odd
21 * it's best to have buff aligned on a 32-bit boundary
23 asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);
26 * the same as csum_partial, but copies from src while it
27 * checksums, and handles user-space pointer exceptions correctly, when needed.
29 * here even more important to align src and dst on a 32-bit (or even
30 * better 64-bit) boundary
33 asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst,
35 int *src_err_ptr, int *dst_err_ptr);
38 * Note: when you get a NULL pointer exception here this means someone
39 * passed in an incorrect kernel address to one of these functions.
41 * If you use these functions directly please don't forget the
45 __wsum csum_partial_copy_nocheck(const void *src, void *dst,
48 return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
52 __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
53 int len, __wsum sum, int *err_ptr)
55 return csum_partial_copy_generic((__force const void *)src, dst,
56 len, sum, err_ptr, NULL);
60 * Fold a partial checksum
63 static inline __sum16 csum_fold(__wsum sum)
66 __asm__("swap.w %0, %1\n\t"
73 : "=r" (sum), "=&r" (__dummy)
76 return (__force __sum16)sum;
80 * This is a version of ip_compute_csum() optimized for IP headers,
81 * which always checksum on 4 octet boundaries.
83 * i386 version by Jorge Cwik <jorge@laser.satlink.net>, adapted
84 * for linux by * Arnt Gulbrandsen.
86 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
88 unsigned int sum, __dummy0, __dummy1;
103 "addc %2, %0" /* Here %2 is 0, add carry-bit */
104 /* Since the input registers which are loaded with iph and ihl
105 are modified, we must also specify them as outputs, or gcc
106 will assume they contain their original values. */
107 : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (__dummy0), "=&z" (__dummy1)
108 : "1" (iph), "2" (ihl)
111 return csum_fold(sum);
114 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
115 __u32 len, __u8 proto,
118 #ifdef __LITTLE_ENDIAN__
119 unsigned long len_proto = (proto + len) << 8;
121 unsigned long len_proto = proto + len;
129 : "=r" (sum), "=r" (len_proto)
130 : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)
137 * computes the checksum of the TCP/UDP pseudo-header
138 * returns a 16-bit checksum, already complemented
140 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
141 __u32 len, __u8 proto,
144 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
148 * this routine is used for miscellaneous IP-like checksums, mainly
151 static inline __sum16 ip_compute_csum(const void *buff, int len)
153 return csum_fold(csum_partial(buff, len, 0));
156 #define _HAVE_ARCH_IPV6_CSUM
157 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
158 const struct in6_addr *daddr,
159 __u32 len, __u8 proto, __wsum sum)
161 unsigned int __dummy;
163 "mov.l @(0,%2), %1\n\t"
165 "mov.l @(4,%2), %1\n\t"
167 "mov.l @(8,%2), %1\n\t"
169 "mov.l @(12,%2), %1\n\t"
171 "mov.l @(0,%3), %1\n\t"
173 "mov.l @(4,%3), %1\n\t"
175 "mov.l @(8,%3), %1\n\t"
177 "mov.l @(12,%3), %1\n\t"
183 : "=r" (sum), "=&r" (__dummy)
184 : "r" (saddr), "r" (daddr),
185 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
188 return csum_fold(sum);
192 * Copy and checksum to user
194 #define HAVE_CSUM_COPY_USER
195 static inline __wsum csum_and_copy_to_user(const void *src,
200 if (access_ok(dst, len))
201 return csum_partial_copy_generic((__force const void *)src,
202 dst, len, sum, NULL, err_ptr);
207 return (__force __wsum)-1; /* invalid checksum */
209 #endif /* __ASM_SH_CHECKSUM_H */