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 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 */ 34 extern __wsum csum_partial(const void *buff, int len, __wsum sum); 35 36 /* 37 * Computes the checksum of a memory block at src, length len, 38 * and adds in "sum" (32-bit), while copying the block to dst. 39 * If an access exception occurs on src or dst, it stores -EFAULT 40 * to *src_err or *dst_err respectively (if that pointer is not 41 * NULL), and, for an error on src, zeroes the rest of dst. 42 * 43 * Like csum_partial, this must be called with even lengths, 44 * except for the last fragment. 45 */ 46 extern __wsum csum_partial_copy_generic(const void *src, void *dst, 47 int len, __wsum sum, 48 int *src_err, int *dst_err); 49 50 #ifdef __powerpc64__ 51 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 52 extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, 53 int len, __wsum sum, int *err_ptr); 54 #define HAVE_CSUM_COPY_USER 55 extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, 56 int len, __wsum sum, int *err_ptr); 57 #else 58 /* 59 * the same as csum_partial, but copies from src to dst while it 60 * checksums. 61 */ 62 #define csum_partial_copy_from_user(src, dst, len, sum, errp) \ 63 csum_partial_copy_generic((__force const void *)(src), (dst), (len), (sum), (errp), NULL) 64 #endif 65 66 #define csum_partial_copy_nocheck(src, dst, len, sum) \ 67 csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL) 68 69 70 /* 71 * turns a 32-bit partial checksum (e.g. from csum_partial) into a 72 * 1's complement 16-bit checksum. 73 */ 74 static inline __sum16 csum_fold(__wsum sum) 75 { 76 unsigned int tmp; 77 78 /* swap the two 16-bit halves of sum */ 79 __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum)); 80 /* if there is a carry from adding the two 16-bit halves, 81 it will carry from the lower half into the upper half, 82 giving us the correct sum in the upper half. */ 83 return (__force __sum16)(~((__force u32)sum + tmp) >> 16); 84 } 85 86 /* 87 * this routine is used for miscellaneous IP-like checksums, mainly 88 * in icmp.c 89 */ 90 static inline __sum16 ip_compute_csum(const void *buff, int len) 91 { 92 return csum_fold(csum_partial(buff, len, 0)); 93 } 94 95 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 96 unsigned short len, 97 unsigned short proto, 98 __wsum sum) 99 { 100 #ifdef __powerpc64__ 101 unsigned long s = (__force u32)sum; 102 103 s += (__force u32)saddr; 104 s += (__force u32)daddr; 105 s += proto + len; 106 s += (s >> 32); 107 return (__force __wsum) s; 108 #else 109 __asm__("\n\ 110 addc %0,%0,%1 \n\ 111 adde %0,%0,%2 \n\ 112 adde %0,%0,%3 \n\ 113 addze %0,%0 \n\ 114 " 115 : "=r" (sum) 116 : "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum)); 117 return sum; 118 #endif 119 } 120 121 /* 122 * computes the checksum of the TCP/UDP pseudo-header 123 * returns a 16-bit checksum, already complemented 124 */ 125 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 126 unsigned short len, 127 unsigned short proto, 128 __wsum sum) 129 { 130 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 131 } 132 133 #define HAVE_ARCH_CSUM_ADD 134 static inline __wsum csum_add(__wsum csum, __wsum addend) 135 { 136 #ifdef __powerpc64__ 137 u64 res = (__force u64)csum; 138 139 res += (__force u64)addend; 140 return (__force __wsum)((u32)res + (res >> 32)); 141 #else 142 asm("addc %0,%0,%1;" 143 "addze %0,%0;" 144 : "+r" (csum) : "r" (addend)); 145 return csum; 146 #endif 147 } 148 149 #endif 150 #endif /* __KERNEL__ */ 151 #endif 152