1 #ifndef _ASM_X86_CHECKSUM_64_H 2 #define _ASM_X86_CHECKSUM_64_H 3 4 /* 5 * Checksums for x86-64 6 * Copyright 2002 by Andi Kleen, SuSE Labs 7 * with some code from asm-x86/checksum.h 8 */ 9 10 #include <linux/compiler.h> 11 #include <asm/uaccess.h> 12 #include <asm/byteorder.h> 13 14 /** 15 * csum_fold - Fold and invert a 32bit checksum. 16 * sum: 32bit unfolded sum 17 * 18 * Fold a 32bit running checksum to 16bit and invert it. This is usually 19 * the last step before putting a checksum into a packet. 20 * Make sure not to mix with 64bit checksums. 21 */ 22 static inline __sum16 csum_fold(__wsum sum) 23 { 24 asm(" addl %1,%0\n" 25 " adcl $0xffff,%0" 26 : "=r" (sum) 27 : "r" ((__force u32)sum << 16), 28 "0" ((__force u32)sum & 0xffff0000)); 29 return (__force __sum16)(~(__force u32)sum >> 16); 30 } 31 32 /* 33 * This is a version of ip_compute_csum() optimized for IP headers, 34 * which always checksum on 4 octet boundaries. 35 * 36 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by 37 * Arnt Gulbrandsen. 38 */ 39 40 /** 41 * ip_fast_csum - Compute the IPv4 header checksum efficiently. 42 * iph: ipv4 header 43 * ihl: length of header / 4 44 */ 45 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 46 { 47 unsigned int sum; 48 49 asm(" movl (%1), %0\n" 50 " subl $4, %2\n" 51 " jbe 2f\n" 52 " addl 4(%1), %0\n" 53 " adcl 8(%1), %0\n" 54 " adcl 12(%1), %0\n" 55 "1: adcl 16(%1), %0\n" 56 " lea 4(%1), %1\n" 57 " decl %2\n" 58 " jne 1b\n" 59 " adcl $0, %0\n" 60 " movl %0, %2\n" 61 " shrl $16, %0\n" 62 " addw %w2, %w0\n" 63 " adcl $0, %0\n" 64 " notl %0\n" 65 "2:" 66 /* Since the input registers which are loaded with iph and ihl 67 are modified, we must also specify them as outputs, or gcc 68 will assume they contain their original values. */ 69 : "=r" (sum), "=r" (iph), "=r" (ihl) 70 : "1" (iph), "2" (ihl) 71 : "memory"); 72 return (__force __sum16)sum; 73 } 74 75 /** 76 * csum_tcpup_nofold - Compute an IPv4 pseudo header checksum. 77 * @saddr: source address 78 * @daddr: destination address 79 * @len: length of packet 80 * @proto: ip protocol of packet 81 * @sum: initial sum to be added in (32bit unfolded) 82 * 83 * Returns the pseudo header checksum the input data. Result is 84 * 32bit unfolded. 85 */ 86 static inline __wsum 87 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len, 88 unsigned short proto, __wsum sum) 89 { 90 asm(" addl %1, %0\n" 91 " adcl %2, %0\n" 92 " adcl %3, %0\n" 93 " adcl $0, %0\n" 94 : "=r" (sum) 95 : "g" (daddr), "g" (saddr), 96 "g" ((len + proto)<<8), "0" (sum)); 97 return sum; 98 } 99 100 101 /** 102 * csum_tcpup_magic - Compute an IPv4 pseudo header checksum. 103 * @saddr: source address 104 * @daddr: destination address 105 * @len: length of packet 106 * @proto: ip protocol of packet 107 * @sum: initial sum to be added in (32bit unfolded) 108 * 109 * Returns the 16bit pseudo header checksum the input data already 110 * complemented and ready to be filled in. 111 */ 112 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 113 unsigned short len, 114 unsigned short proto, __wsum sum) 115 { 116 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 117 } 118 119 /** 120 * csum_partial - Compute an internet checksum. 121 * @buff: buffer to be checksummed 122 * @len: length of buffer. 123 * @sum: initial sum to be added in (32bit unfolded) 124 * 125 * Returns the 32bit unfolded internet checksum of the buffer. 126 * Before filling it in it needs to be csum_fold()'ed. 127 * buff should be aligned to a 64bit boundary if possible. 128 */ 129 extern __wsum csum_partial(const void *buff, int len, __wsum sum); 130 131 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1 132 #define HAVE_CSUM_COPY_USER 1 133 134 135 /* Do not call this directly. Use the wrappers below */ 136 extern __visible __wsum csum_partial_copy_generic(const void *src, const void *dst, 137 int len, __wsum sum, 138 int *src_err_ptr, int *dst_err_ptr); 139 140 141 extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst, 142 int len, __wsum isum, int *errp); 143 extern __wsum csum_partial_copy_to_user(const void *src, void __user *dst, 144 int len, __wsum isum, int *errp); 145 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, 146 int len, __wsum sum); 147 148 /* Old names. To be removed. */ 149 #define csum_and_copy_to_user csum_partial_copy_to_user 150 #define csum_and_copy_from_user csum_partial_copy_from_user 151 152 /** 153 * ip_compute_csum - Compute an 16bit IP checksum. 154 * @buff: buffer address. 155 * @len: length of buffer. 156 * 157 * Returns the 16bit folded/inverted checksum of the passed buffer. 158 * Ready to fill in. 159 */ 160 extern __sum16 ip_compute_csum(const void *buff, int len); 161 162 /** 163 * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header. 164 * @saddr: source address 165 * @daddr: destination address 166 * @len: length of packet 167 * @proto: protocol of packet 168 * @sum: initial sum (32bit unfolded) to be added in 169 * 170 * Computes an IPv6 pseudo header checksum. This sum is added the checksum 171 * into UDP/TCP packets and contains some link layer information. 172 * Returns the unfolded 32bit checksum. 173 */ 174 175 struct in6_addr; 176 177 #define _HAVE_ARCH_IPV6_CSUM 1 178 extern __sum16 179 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, 180 __u32 len, unsigned short proto, __wsum sum); 181 182 static inline unsigned add32_with_carry(unsigned a, unsigned b) 183 { 184 asm("addl %2,%0\n\t" 185 "adcl $0,%0" 186 : "=r" (a) 187 : "0" (a), "rm" (b)); 188 return a; 189 } 190 191 #define HAVE_ARCH_CSUM_ADD 192 static inline __wsum csum_add(__wsum csum, __wsum addend) 193 { 194 return (__force __wsum)add32_with_carry((__force unsigned)csum, 195 (__force unsigned)addend); 196 } 197 198 #endif /* _ASM_X86_CHECKSUM_64_H */ 199