release/src-rt-6.x.4708/linux/linux-2.6.36/arch/sparc/include/asm/checksum_32.h

   1 #ifndef __SPARC_CHECKSUM_H
   2 #define __SPARC_CHECKSUM_H
   3
   4 /*  checksum.h:  IP/UDP/TCP checksum routines on the Sparc.
   5  *
   6  *  Copyright(C) 1995 Linus Torvalds
   7  *  Copyright(C) 1995 Miguel de Icaza
   8  *  Copyright(C) 1996 David S. Miller
   9  *  Copyright(C) 1996 Eddie C. Dost
  10  *  Copyright(C) 1997 Jakub Jelinek
  11  *
  12  * derived from:
  13  *      Alpha checksum c-code
  14  *      ix86 inline assembly
  15  *      RFC1071 Computing the Internet Checksum
  16  */
  17
  18 #include <linux/in6.h>
  19 #include <asm/uaccess.h>
  20
  21 /* computes the checksum of a memory block at buff, length len,
  22  * and adds in "sum" (32-bit)
  23  *
  24  * returns a 32-bit number suitable for feeding into itself
  25  * or csum_tcpudp_magic
  26  *
  27  * this function must be called with even lengths, except
  28  * for the last fragment, which may be odd
  29  *
  30  * it's best to have buff aligned on a 32-bit boundary
  31  */
  32 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
  33
  34 /* the same as csum_partial, but copies from fs:src while it
  35  * checksums
  36  *
  37  * here even more important to align src and dst on a 32-bit (or even
  38  * better 64-bit) boundary
  39  */
  40
  41 extern unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);
  42
  43 static inline __wsum
  44 csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
  45 {
  46         register unsigned int ret asm("o0") = (unsigned int)src;
  47         register char *d asm("o1") = dst;
  48         register int l asm("g1") = len;
  49
  50         __asm__ __volatile__ (
  51                 "call __csum_partial_copy_sparc_generic\n\t"
  52                 " mov %6, %%g7\n"
  53         : "=&r" (ret), "=&r" (d), "=&r" (l)
  54         : "0" (ret), "1" (d), "2" (l), "r" (sum)
  55         : "o2", "o3", "o4", "o5", "o7",
  56           "g2", "g3", "g4", "g5", "g7",
  57           "memory", "cc");
  58         return (__force __wsum)ret;
  59 }
  60
  61 static inline __wsum
  62 csum_partial_copy_from_user(const void __user *src, void *dst, int len,
  63                             __wsum sum, int *err)
  64   {
  65         register unsigned long ret asm("o0") = (unsigned long)src;
  66         register char *d asm("o1") = dst;
  67         register int l asm("g1") = len;
  68         register __wsum s asm("g7") = sum;
  69
  70         __asm__ __volatile__ (
  71         ".section __ex_table,#alloc\n\t"
  72         ".align 4\n\t"
  73         ".word 1f,2\n\t"
  74         ".previous\n"
  75         "1:\n\t"
  76         "call __csum_partial_copy_sparc_generic\n\t"
  77         " st %8, [%%sp + 64]\n"
  78         : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
  79         : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
  80         : "o2", "o3", "o4", "o5", "o7", "g2", "g3", "g4", "g5",
  81           "cc", "memory");
  82         return (__force __wsum)ret;
  83 }
  84
  85 static inline __wsum
  86 csum_partial_copy_to_user(const void *src, void __user *dst, int len,
  87                           __wsum sum, int *err)
  88 {
  89         if (!access_ok (VERIFY_WRITE, dst, len)) {
  90                 *err = -EFAULT;
  91                 return sum;
  92         } else {
  93                 register unsigned long ret asm("o0") = (unsigned long)src;
  94                 register char __user *d asm("o1") = dst;
  95                 register int l asm("g1") = len;
  96                 register __wsum s asm("g7") = sum;
  97
  98                 __asm__ __volatile__ (
  99                 ".section __ex_table,#alloc\n\t"
 100                 ".align 4\n\t"
 101                 ".word 1f,1\n\t"
 102                 ".previous\n"
 103                 "1:\n\t"
 104                 "call __csum_partial_copy_sparc_generic\n\t"
 105                 " st %8, [%%sp + 64]\n"
 106                 : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
 107                 : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
 108                 : "o2", "o3", "o4", "o5", "o7",
 109                   "g2", "g3", "g4", "g5",
 110                   "cc", "memory");
 111                 return (__force __wsum)ret;
 112         }
 113 }
 114
 115 #define HAVE_CSUM_COPY_USER
 116 #define csum_and_copy_to_user csum_partial_copy_to_user
 117
 118 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
 119  * the majority of the time.
 120  */
 121 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
 122 {
 123         __sum16 sum;
 124
 125         /* Note: We must read %2 before we touch %0 for the first time,
 126          *       because GCC can legitimately use the same register for
 127          *       both operands.
 128          */
 129         __asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
 130                              "ld\t[%1 + 0x00], %0\n\t"
 131                              "ld\t[%1 + 0x04], %%g2\n\t"
 132                              "ld\t[%1 + 0x08], %%g3\n\t"
 133                              "addcc\t%%g2, %0, %0\n\t"
 134                              "addxcc\t%%g3, %0, %0\n\t"
 135                              "ld\t[%1 + 0x0c], %%g2\n\t"
 136                              "ld\t[%1 + 0x10], %%g3\n\t"
 137                              "addxcc\t%%g2, %0, %0\n\t"
 138                              "addx\t%0, %%g0, %0\n"
 139                              "1:\taddcc\t%%g3, %0, %0\n\t"
 140                              "add\t%1, 4, %1\n\t"
 141                              "addxcc\t%0, %%g0, %0\n\t"
 142                              "subcc\t%%g4, 1, %%g4\n\t"
 143                              "be,a\t2f\n\t"
 144                              "sll\t%0, 16, %%g2\n\t"
 145                              "b\t1b\n\t"
 146                              "ld\t[%1 + 0x10], %%g3\n"
 147                              "2:\taddcc\t%0, %%g2, %%g2\n\t"
 148                              "srl\t%%g2, 16, %0\n\t"
 149                              "addx\t%0, %%g0, %0\n\t"
 150                              "xnor\t%%g0, %0, %0"
 151                              : "=r" (sum), "=&r" (iph)
 152                              : "r" (ihl), "1" (iph)
 153                              : "g2", "g3", "g4", "cc", "memory");
 154         return sum;
 155 }
 156
 157 /* Fold a partial checksum without adding pseudo headers. */
 158 static inline __sum16 csum_fold(__wsum sum)
 159 {
 160         unsigned int tmp;
 161
 162         __asm__ __volatile__("addcc\t%0, %1, %1\n\t"
 163                              "srl\t%1, 16, %1\n\t"
 164                              "addx\t%1, %%g0, %1\n\t"
 165                              "xnor\t%%g0, %1, %0"
 166                              : "=&r" (sum), "=r" (tmp)
 167                              : "0" (sum), "1" ((__force u32)sum<<16)
 168                              : "cc");
 169         return (__force __sum16)sum;
 170 }
 171
 172 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 173                                                unsigned short len,
 174                                                unsigned short proto,
 175                                                __wsum sum)
 176 {
 177         __asm__ __volatile__("addcc\t%1, %0, %0\n\t"
 178                              "addxcc\t%2, %0, %0\n\t"
 179                              "addxcc\t%3, %0, %0\n\t"
 180                              "addx\t%0, %%g0, %0\n\t"
 181                              : "=r" (sum), "=r" (saddr)
 182                              : "r" (daddr), "r" (proto + len), "0" (sum),
 183                                "1" (saddr)
 184                              : "cc");
 185         return sum;
 186 }
 187
 188 /*
 189  * computes the checksum of the TCP/UDP pseudo-header
 190  * returns a 16-bit checksum, already complemented
 191  */
 192 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 193                                                    unsigned short len,
 194                                                    unsigned short proto,
 195                                                    __wsum sum)
 196 {
 197         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 198 }
 199
 200 #define _HAVE_ARCH_IPV6_CSUM
 201
 202 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 203                                       const struct in6_addr *daddr,
 204                                       __u32 len, unsigned short proto,
 205                                       __wsum sum)
 206 {
 207         __asm__ __volatile__ (
 208                 "addcc  %3, %4, %%g4\n\t"
 209                 "addxcc %5, %%g4, %%g4\n\t"
 210                 "ld     [%2 + 0x0c], %%g2\n\t"
 211                 "ld     [%2 + 0x08], %%g3\n\t"
 212                 "addxcc %%g2, %%g4, %%g4\n\t"
 213                 "ld     [%2 + 0x04], %%g2\n\t"
 214                 "addxcc %%g3, %%g4, %%g4\n\t"
 215                 "ld     [%2 + 0x00], %%g3\n\t"
 216                 "addxcc %%g2, %%g4, %%g4\n\t"
 217                 "ld     [%1 + 0x0c], %%g2\n\t"
 218                 "addxcc %%g3, %%g4, %%g4\n\t"
 219                 "ld     [%1 + 0x08], %%g3\n\t"
 220                 "addxcc %%g2, %%g4, %%g4\n\t"
 221                 "ld     [%1 + 0x04], %%g2\n\t"
 222                 "addxcc %%g3, %%g4, %%g4\n\t"
 223                 "ld     [%1 + 0x00], %%g3\n\t"
 224                 "addxcc %%g2, %%g4, %%g4\n\t"
 225                 "addxcc %%g3, %%g4, %0\n\t"
 226                 "addx   0, %0, %0\n"
 227                 : "=&r" (sum)
 228                 : "r" (saddr), "r" (daddr),
 229                   "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
 230                 : "g2", "g3", "g4", "cc");
 231
 232         return csum_fold(sum);
 233 }
 234
 235 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
 236 static inline __sum16 ip_compute_csum(const void *buff, int len)
 237 {
 238         return csum_fold(csum_partial(buff, len, 0));
 239 }
 240
 241 #endif /* !(__SPARC_CHECKSUM_H) */