| 1 | /* |
| 2 | * arch/ubicom32/include/asm/checksum.h |
| 3 | * Checksum utilities for Ubicom32 architecture. |
| 4 | * |
| 5 | * (C) Copyright 2009, Ubicom, Inc. |
| 6 | * |
| 7 | * This file is part of the Ubicom32 Linux Kernel Port. |
| 8 | * |
| 9 | * The Ubicom32 Linux Kernel Port is free software: you can redistribute |
| 10 | * it and/or modify it under the terms of the GNU General Public License |
| 11 | * as published by the Free Software Foundation, either version 2 of the |
| 12 | * License, or (at your option) any later version. |
| 13 | * |
| 14 | * The Ubicom32 Linux Kernel Port is distributed in the hope that it |
| 15 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| 16 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| 17 | * the GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License |
| 20 | * along with the Ubicom32 Linux Kernel Port. If not, |
| 21 | * see <http://www.gnu.org/licenses/>. |
| 22 | * |
| 23 | * Ubicom32 implementation derived from (with many thanks): |
| 24 | * arch/m68knommu |
| 25 | * arch/blackfin |
| 26 | * arch/parisc |
| 27 | */ |
| 28 | #ifndef _ASM_UBICOM32_CHECKSUM_H |
| 29 | #define _ASM_UBICOM32_CHECKSUM_H |
| 30 | |
| 31 | #include <linux/in6.h> |
| 32 | |
| 33 | /* |
| 34 | * computes the checksum of a memory block at buff, length len, |
| 35 | * and adds in "sum" (32-bit) |
| 36 | * |
| 37 | * returns a 32-bit number suitable for feeding into itself |
| 38 | * or csum_tcpudp_magic |
| 39 | * |
| 40 | * this function must be called with even lengths, except |
| 41 | * for the last fragment, which may be odd |
| 42 | * |
| 43 | * it's best to have buff aligned on a 32-bit boundary |
| 44 | */ |
| 45 | __wsum csum_partial(const void *buff, int len, __wsum sum); |
| 46 | |
| 47 | /* |
| 48 | * the same as csum_partial, but copies from src while it |
| 49 | * checksums |
| 50 | * |
| 51 | * here even more important to align src and dst on a 32-bit (or even |
| 52 | * better 64-bit) boundary |
| 53 | */ |
| 54 | |
| 55 | __wsum csum_partial_copy_nocheck(const void *src, void *dst, |
| 56 | int len, __wsum sum); |
| 57 | |
| 58 | |
| 59 | /* |
| 60 | * the same as csum_partial_copy, but copies from user space. |
| 61 | * |
| 62 | * here even more important to align src and dst on a 32-bit (or even |
| 63 | * better 64-bit) boundary |
| 64 | */ |
| 65 | |
| 66 | extern __wsum csum_partial_copy_from_user(const void __user *src, |
| 67 | void *dst, int len, __wsum sum, int *csum_err); |
| 68 | |
| 69 | __sum16 ip_fast_csum(const void *iph, unsigned int ihl); |
| 70 | |
| 71 | /* |
| 72 | * Fold a partial checksum |
| 73 | */ |
| 74 | |
| 75 | static inline __sum16 csum_fold(__wsum sum) |
| 76 | { |
| 77 | asm volatile ( |
| 78 | " lsr.4 d15, %0, #16 \n\t" |
| 79 | " bfextu %0, %0, #16 \n\t" |
| 80 | " add.4 %0, d15, %0 \n\t" |
| 81 | " lsr.4 d15, %0, #16 \n\t" |
| 82 | " bfextu %0, %0, #16 \n\t" |
| 83 | " add.4 %0, d15, %0 \n\t" |
| 84 | : "=&d" (sum) |
| 85 | : "0"(sum) |
| 86 | : "d15" |
| 87 | ); |
| 88 | return (__force __sum16)~sum; |
| 89 | } |
| 90 | |
| 91 | |
| 92 | /* |
| 93 | * computes the checksum of the TCP/UDP pseudo-header |
| 94 | * returns a 16-bit checksum, already complemented |
| 95 | */ |
| 96 | |
| 97 | static inline __wsum |
| 98 | csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len, |
| 99 | unsigned short proto, __wsum sum) |
| 100 | { |
| 101 | asm volatile ( |
| 102 | " add.4 %0, %2, %0 \n\t" |
| 103 | " addc %0, %3, %0 \n\t" |
| 104 | " addc %0, %4, %0 \n\t" |
| 105 | " addc %0, %5, %0 \n\t" |
| 106 | " addc %0, #0, %0 \n\t" |
| 107 | : "=&d" (sum) |
| 108 | : "0"(sum), "r" (saddr), "r" (daddr), "r" (len), "r"(proto) |
| 109 | ); |
| 110 | return sum; |
| 111 | } |
| 112 | |
| 113 | static inline __sum16 |
| 114 | csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len, |
| 115 | unsigned short proto, __wsum sum) |
| 116 | { |
| 117 | return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); |
| 118 | } |
| 119 | |
| 120 | /* |
| 121 | * this routine is used for miscellaneous IP-like checksums, mainly |
| 122 | * in icmp.c |
| 123 | */ |
| 124 | extern __sum16 ip_compute_csum(const void *buff, int len); |
| 125 | |
| 126 | #define _HAVE_ARCH_IPV6_CSUM |
| 127 | |
| 128 | static __inline__ __sum16 |
| 129 | csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, |
| 130 | __u32 len, unsigned short proto, __wsum sum) |
| 131 | { |
| 132 | asm volatile ( |
| 133 | " add.4 %0, 0(%2), %0 \n\t" |
| 134 | " addc %0, 4(%2), %0 \n\t" |
| 135 | " addc %0, 8(%2), %0 \n\t" |
| 136 | " addc %0, 12(%2), %0 \n\t" |
| 137 | " addc %0, 0(%3), %0 \n\t" |
| 138 | " addc %0, 4(%3), %0 \n\t" |
| 139 | " addc %0, 8(%3), %0 \n\t" |
| 140 | " addc %0, 12(%3), %0 \n\t" |
| 141 | " addc %0, %4, %0 \n\t" |
| 142 | " addc %0, #0, %0 \n\t" |
| 143 | : "=&d" (sum) |
| 144 | : "0" (sum), "a" (saddr), "a" (daddr), "d" (len + proto) |
| 145 | ); |
| 146 | return csum_fold(sum); |
| 147 | } |
| 148 | |
| 149 | #endif /* _ASM_UBICOM32_CHECKSUM_H */ |
| 150 | |
