1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _PARISC_CHECKSUM_H 3 #define _PARISC_CHECKSUM_H 4 5 #include <linux/in6.h> 6 7 /* 8 * computes the checksum of a memory block at buff, length len, 9 * and adds in "sum" (32-bit) 10 * 11 * returns a 32-bit number suitable for feeding into itself 12 * or csum_tcpudp_magic 13 * 14 * this function must be called with even lengths, except 15 * for the last fragment, which may be odd 16 * 17 * it's best to have buff aligned on a 32-bit boundary 18 */ 19 extern __wsum csum_partial(const void *, int, __wsum); 20 21 /* 22 * Optimized for IP headers, which always checksum on 4 octet boundaries. 23 * 24 * Written by Randolph Chung <tausq@debian.org>, and then mucked with by 25 * LaMont Jones <lamont@debian.org> 26 */ 27 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 28 { 29 unsigned int sum; 30 unsigned long t0, t1, t2; 31 32 __asm__ __volatile__ ( 33 " ldws,ma 4(%1), %0\n" 34 " addib,<= -4, %2, 2f\n" 35 "\n" 36 " ldws 4(%1), %4\n" 37 " ldws 8(%1), %5\n" 38 " add %0, %4, %0\n" 39 " ldws,ma 12(%1), %3\n" 40 " addc %0, %5, %0\n" 41 " addc %0, %3, %0\n" 42 "1: ldws,ma 4(%1), %3\n" 43 " addib,> -1, %2, 1b\n" 44 " addc %0, %3, %0\n" 45 "\n" 46 " extru %0, 31, 16, %4\n" 47 " extru %0, 15, 16, %5\n" 48 " addc %4, %5, %0\n" 49 " extru %0, 15, 16, %5\n" 50 " add %0, %5, %0\n" 51 " subi -1, %0, %0\n" 52 "2:\n" 53 : "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (t0), "=r" (t1), "=r" (t2) 54 : "1" (iph), "2" (ihl) 55 : "memory"); 56 57 return (__force __sum16)sum; 58 } 59 60 /* 61 * Fold a partial checksum 62 */ 63 static inline __sum16 csum_fold(__wsum csum) 64 { 65 u32 sum = (__force u32)csum; 66 /* add the swapped two 16-bit halves of sum, 67 a possible carry from adding the two 16-bit halves, 68 will carry from the lower half into the upper half, 69 giving us the correct sum in the upper half. */ 70 sum += (sum << 16) + (sum >> 16); 71 return (__force __sum16)(~sum >> 16); 72 } 73 74 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 75 __u32 len, __u8 proto, 76 __wsum sum) 77 { 78 __asm__( 79 " add %1, %0, %0\n" 80 " addc %2, %0, %0\n" 81 " addc %3, %0, %0\n" 82 " addc %%r0, %0, %0\n" 83 : "=r" (sum) 84 : "r" (daddr), "r"(saddr), "r"(proto+len), "0"(sum)); 85 return sum; 86 } 87 88 /* 89 * computes the checksum of the TCP/UDP pseudo-header 90 * returns a 16-bit checksum, already complemented 91 */ 92 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 93 __u32 len, __u8 proto, 94 __wsum sum) 95 { 96 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); 97 } 98 99 /* 100 * this routine is used for miscellaneous IP-like checksums, mainly 101 * in icmp.c 102 */ 103 static inline __sum16 ip_compute_csum(const void *buf, int len) 104 { 105 return csum_fold (csum_partial(buf, len, 0)); 106 } 107 108 109 #define _HAVE_ARCH_IPV6_CSUM 110 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 111 const struct in6_addr *daddr, 112 __u32 len, __u8 proto, 113 __wsum sum) 114 { 115 unsigned long t0, t1, t2, t3; 116 117 len += proto; /* add 16-bit proto + len */ 118 119 __asm__ __volatile__ ( 120 121 #if BITS_PER_LONG > 32 122 123 /* 124 ** We can execute two loads and two adds per cycle on PA 8000. 125 ** But add insn's get serialized waiting for the carry bit. 126 ** Try to keep 4 registers with "live" values ahead of the ALU. 127 */ 128 129 " depdi 0, 31, 32, %0\n"/* clear upper half of incoming checksum */ 130 " ldd,ma 8(%1), %4\n" /* get 1st saddr word */ 131 " ldd,ma 8(%2), %5\n" /* get 1st daddr word */ 132 " add %4, %0, %0\n" 133 " ldd,ma 8(%1), %6\n" /* 2nd saddr */ 134 " ldd,ma 8(%2), %7\n" /* 2nd daddr */ 135 " add,dc %5, %0, %0\n" 136 " add,dc %6, %0, %0\n" 137 " add,dc %7, %0, %0\n" 138 " add,dc %3, %0, %0\n" /* fold in proto+len | carry bit */ 139 " extrd,u %0, 31, 32, %4\n"/* copy upper half down */ 140 " depdi 0, 31, 32, %0\n"/* clear upper half */ 141 " add,dc %4, %0, %0\n" /* fold into 32-bits, plus carry */ 142 " addc 0, %0, %0\n" /* add final carry */ 143 144 #else 145 146 /* 147 ** For PA 1.x, the insn order doesn't matter as much. 148 ** Insn stream is serialized on the carry bit here too. 149 ** result from the previous operation (eg r0 + x) 150 */ 151 " ldw,ma 4(%1), %4\n" /* get 1st saddr word */ 152 " ldw,ma 4(%2), %5\n" /* get 1st daddr word */ 153 " add %4, %0, %0\n" 154 " ldw,ma 4(%1), %6\n" /* 2nd saddr */ 155 " addc %5, %0, %0\n" 156 " ldw,ma 4(%2), %7\n" /* 2nd daddr */ 157 " addc %6, %0, %0\n" 158 " ldw,ma 4(%1), %4\n" /* 3rd saddr */ 159 " addc %7, %0, %0\n" 160 " ldw,ma 4(%2), %5\n" /* 3rd daddr */ 161 " addc %4, %0, %0\n" 162 " ldw,ma 4(%1), %6\n" /* 4th saddr */ 163 " addc %5, %0, %0\n" 164 " ldw,ma 4(%2), %7\n" /* 4th daddr */ 165 " addc %6, %0, %0\n" 166 " addc %7, %0, %0\n" 167 " addc %3, %0, %0\n" /* fold in proto+len */ 168 " addc 0, %0, %0\n" /* add carry */ 169 170 #endif 171 : "=r" (sum), "=r" (saddr), "=r" (daddr), "=r" (len), 172 "=r" (t0), "=r" (t1), "=r" (t2), "=r" (t3) 173 : "0" (sum), "1" (saddr), "2" (daddr), "3" (len) 174 : "memory"); 175 return csum_fold(sum); 176 } 177 178 #endif 179 180