1 #ifndef _ASM_POWERPC_CHECKSUM_H 2 #define _ASM_POWERPC_CHECKSUM_H 3 #ifdef __KERNEL__ 4 5 /* 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 /* 13 * This is a version of ip_compute_csum() optimized for IP headers, 14 * which always checksum on 4 octet boundaries. ihl is the number 15 * of 32-bit words and is always >= 5. 16 */ 17 #ifdef CONFIG_GENERIC_CSUM 18 #include <asm-generic/checksum.h> 19 #else 20 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl); 21 22 /* 23 * computes the checksum of the TCP/UDP pseudo-header 24 * returns a 16-bit checksum, already complemented 25 */ 26 extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 27 unsigned short len, 28 unsigned short proto, 29 __wsum sum); 30 31 /* 32 * computes the checksum of a memory block at buff, length len, 33 * and adds in "sum" (32-bit) 34 * 35 * returns a 32-bit number suitable for feeding into itself 36 * or csum_tcpudp_magic 37 * 38 * this function must be called with even lengths, except 39 * for the last fragment, which may be odd 40 * 41 * it's best to have buff aligned on a 32-bit boundary 42 */ 43 extern __wsum csum_partial(const void *buff, int len, __wsum sum); 44 45 /* 46 * Computes the checksum of a memory block at src, length len, 47 * and adds in "sum" (32-bit), while copying the block to dst. 48 * If an access exception occurs on src or dst, it stores -EFAULT 49 * to *src_err or *dst_err respectively (if that pointer is not 50 * NULL), and, for an error on src, zeroes the rest of dst. 51 * 52 * Like csum_partial, this must be called with even lengths, 53 * except for the last fragment. 54 */ 55 extern __wsum csum_partial_copy_generic(const void *src, void *dst, 56 int len, __wsum sum, 57 int *src_err, int *dst_err); 58 59 #ifdef __powerpc64__ 60 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 61 extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, 62 int len, __wsum sum, int *err_ptr); 63 #define HAVE_CSUM_COPY_USER 64 extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, 65 int len, __wsum sum, int *err_ptr); 66 #else 67 /* 68 * the same as csum_partial, but copies from src to dst while it 69 * checksums. 70 */ 71 #define csum_partial_copy_from_user(src, dst, len, sum, errp) \ 72 csum_partial_copy_generic((__force const void *)(src), (dst), (len), (sum), (errp), NULL) 73 #endif 74 75 #define csum_partial_copy_nocheck(src, dst, len, sum) \ 76 csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL) 77 78 79 /* 80 * turns a 32-bit partial checksum (e.g. from csum_partial) into a 81 * 1's complement 16-bit checksum. 82 */ 83 static inline __sum16 csum_fold(__wsum sum) 84 { 85 unsigned int tmp; 86 87 /* swap the two 16-bit halves of sum */ 88 __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum)); 89 /* if there is a carry from adding the two 16-bit halves, 90 it will carry from the lower half into the upper half, 91 giving us the correct sum in the upper half. */ 92 return (__force __sum16)(~((__force u32)sum + tmp) >> 16); 93 } 94 95 /* 96 * this routine is used for miscellaneous IP-like checksums, mainly 97 * in icmp.c 98 */ 99 static inline __sum16 ip_compute_csum(const void *buff, int len) 100 { 101 return csum_fold(csum_partial(buff, len, 0)); 102 } 103 104 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 105 unsigned short len, 106 unsigned short proto, 107 __wsum sum) 108 { 109 #ifdef __powerpc64__ 110 unsigned long s = (__force u32)sum; 111 112 s += (__force u32)saddr; 113 s += (__force u32)daddr; 114 s += proto + len; 115 s += (s >> 32); 116 return (__force __wsum) s; 117 #else 118 __asm__("\n\ 119 addc %0,%0,%1 \n\ 120 adde %0,%0,%2 \n\ 121 adde %0,%0,%3 \n\ 122 addze %0,%0 \n\ 123 " 124 : "=r" (sum) 125 : "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum)); 126 return sum; 127 #endif 128 } 129 130 #endif 131 #endif /* __KERNEL__ */ 132 #endif 133