include/asm-sparc/checksum.h

   1 /* $Id: checksum.h,v 1.29 1999/03/21 05:22:07 davem Exp $ */
   2 #ifndef __SPARC_CHECKSUM_H
   3 #define __SPARC_CHECKSUM_H
   4
   5 /*  checksum.h:  IP/UDP/TCP checksum routines on the Sparc.
   6  *
   7  *  Copyright(C) 1995 Linus Torvalds
   8  *  Copyright(C) 1995 Miguel de Icaza
   9  *  Copyright(C) 1996 David S. Miller
  10  *  Copyright(C) 1996 Eddie C. Dost
  11  *  Copyright(C) 1997 Jakub Jelinek
  12  *
  13  * derived from:
  14  *      Alpha checksum c-code
  15  *      ix86 inline assembly
  16  *      RFC1071 Computing the Internet Checksum
  17  */
  18
  19 #include <asm/uaccess.h>
  20 #include <asm/cprefix.h>
  21
  22 /* computes the checksum of a memory block at buff, length len,
  23  * and adds in "sum" (32-bit)
  24  *
  25  * returns a 32-bit number suitable for feeding into itself
  26  * or csum_tcpudp_magic
  27  *
  28  * this function must be called with even lengths, except
  29  * for the last fragment, which may be odd
  30  *
  31  * it's best to have buff aligned on a 32-bit boundary
  32  */
  33 extern unsigned int csum_partial(unsigned char * buff, int len, unsigned int sum);
  34
  35 /* the same as csum_partial, but copies from fs:src while it
  36  * checksums
  37  *
  38  * here even more important to align src and dst on a 32-bit (or even
  39  * better 64-bit) boundary
  40  */
  41
  42 /* FIXME: Remove these two macros ASAP */
  43 #define csum_partial_copy(src, dst, len, sum) \
  44                        csum_partial_copy_nocheck(src,dst,len,sum)
  45 #define csum_partial_copy_fromuser(s, d, l, w)  \
  46                          csum_partial_copy((char *) (s), (d), (l), (w))
  47
  48 extern unsigned int __csum_partial_copy_sparc_generic (const char *, char *);
  49
  50 extern __inline__ unsigned int
  51 csum_partial_copy_nocheck (const char *src, char *dst, int len,
  52                            unsigned int sum)
  53 {
  54         register unsigned int ret asm("o0") = (unsigned int)src;
  55         register char *d asm("o1") = dst;
  56         register int l asm("g1") = len;
  57
  58         __asm__ __volatile__ ("
  59                 call " C_LABEL_STR(__csum_partial_copy_sparc_generic) "
  60                  mov %4, %%g7
  61         " : "=r" (ret) : "0" (ret), "r" (d), "r" (l), "r" (sum) :
  62         "o1", "o2", "o3", "o4", "o5", "o7", "g1", "g2", "g3", "g4", "g5", "g7");
  63         return ret;
  64 }
  65
  66 extern __inline__ unsigned int
  67 csum_partial_copy_from_user(const char *src, char *dst, int len,
  68                             unsigned int sum, int *err)
  69   {
  70         if (!access_ok (VERIFY_READ, src, len)) {
  71                 *err = -EFAULT;
  72                 memset (dst, 0, len);
  73                 return sum;
  74         } else {
  75                 register unsigned int ret asm("o0") = (unsigned int)src;
  76                 register char *d asm("o1") = dst;
  77                 register int l asm("g1") = len;
  78                 register unsigned int s asm("g7") = sum;
  79
  80                 __asm__ __volatile__ ("
  81                 .section __ex_table,#alloc
  82                 .align 4
  83                 .word 1f,2
  84                 .previous
  85 1:
  86                 call " C_LABEL_STR(__csum_partial_copy_sparc_generic) "
  87                  st %5, [%%sp + 64]
  88                 " : "=r" (ret) : "0" (ret), "r" (d), "r" (l), "r" (s), "r" (err) :
  89                 "o1", "o2", "o3", "o4", "o5", "o7", "g1", "g2", "g3", "g4", "g5", "g7");
  90                 return ret;
  91         }
  92   }
  93
  94 extern __inline__ unsigned int
  95 csum_partial_copy_to_user(const char *src, char *dst, int len,
  96                           unsigned int sum, int *err)
  97 {
  98         if (!access_ok (VERIFY_WRITE, dst, len)) {
  99                 *err = -EFAULT;
 100                 return sum;
 101         } else {
 102                 register unsigned int ret asm("o0") = (unsigned int)src;
 103                 register char *d asm("o1") = dst;
 104                 register int l asm("g1") = len;
 105                 register unsigned int s asm("g7") = sum;
 106
 107                 __asm__ __volatile__ ("
 108                 .section __ex_table,#alloc
 109                 .align 4
 110                 .word 1f,1
 111                 .previous
 112 1:
 113                 call " C_LABEL_STR(__csum_partial_copy_sparc_generic) "
 114                  st %5, [%%sp + 64]
 115                 " : "=r" (ret) : "0" (ret), "r" (d), "r" (l), "r" (s), "r" (err) :
 116                 "o1", "o2", "o3", "o4", "o5", "o7", "g1", "g2", "g3", "g4", "g5", "g7");
 117                 return ret;
 118         }
 119 }
 120
 121 #define HAVE_CSUM_COPY_USER
 122 #define csum_and_copy_to_user csum_partial_copy_to_user
 123
 124 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
 125  * the majority of the time.
 126  */
 127 extern __inline__ unsigned short ip_fast_csum(__const__ unsigned char *iph,
 128                                               unsigned int ihl)
 129 {
 130         unsigned short sum;
 131
 132         /* Note: We must read %2 before we touch %0 for the first time,
 133          *       because GCC can legitimately use the same register for
 134          *       both operands.
 135          */
 136         __asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
 137                              "ld\t[%1 + 0x00], %0\n\t"
 138                              "ld\t[%1 + 0x04], %%g2\n\t"
 139                              "ld\t[%1 + 0x08], %%g3\n\t"
 140                              "addcc\t%%g2, %0, %0\n\t"
 141                              "addxcc\t%%g3, %0, %0\n\t"
 142                              "ld\t[%1 + 0x0c], %%g2\n\t"
 143                              "ld\t[%1 + 0x10], %%g3\n\t"
 144                              "addxcc\t%%g2, %0, %0\n\t"
 145                              "addx\t%0, %%g0, %0\n"
 146                              "1:\taddcc\t%%g3, %0, %0\n\t"
 147                              "add\t%1, 4, %1\n\t"
 148                              "addxcc\t%0, %%g0, %0\n\t"
 149                              "subcc\t%%g4, 1, %%g4\n\t"
 150                              "be,a\t2f\n\t"
 151                              "sll\t%0, 16, %%g2\n\t"
 152                              "b\t1b\n\t"
 153                              "ld\t[%1 + 0x10], %%g3\n"
 154                              "2:\taddcc\t%0, %%g2, %%g2\n\t"
 155                              "srl\t%%g2, 16, %0\n\t"
 156                              "addx\t%0, %%g0, %0\n\t"
 157                              "xnor\t%%g0, %0, %0"
 158                              : "=r" (sum), "=&r" (iph)
 159                              : "r" (ihl), "1" (iph)
 160                              : "g2", "g3", "g4", "cc");
 161         return sum;
 162 }
 163
 164 /* Fold a partial checksum without adding pseudo headers. */
 165 extern __inline__ unsigned int csum_fold(unsigned int sum)
 166 {
 167         unsigned int tmp;
 168
 169         __asm__ __volatile__("addcc\t%0, %1, %1\n\t"
 170                              "srl\t%1, 16, %1\n\t"
 171                              "addx\t%1, %%g0, %1\n\t"
 172                              "xnor\t%%g0, %1, %0"
 173                              : "=&r" (sum), "=r" (tmp)
 174                              : "0" (sum), "1" (sum<<16)
 175                              : "cc");
 176         return sum;
 177 }
 178
 179 extern __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr,
 180                                                    unsigned long daddr,
 181                                                    unsigned int len,
 182                                                    unsigned short proto,
 183                                                    unsigned int sum)
 184 {
 185         __asm__ __volatile__("addcc\t%1, %0, %0\n\t"
 186                              "addxcc\t%2, %0, %0\n\t"
 187                              "addxcc\t%3, %0, %0\n\t"
 188                              "addx\t%0, %%g0, %0\n\t"
 189                              : "=r" (sum), "=r" (saddr)
 190                              : "r" (daddr), "r" ((proto<<16)+len), "0" (sum),
 191                                "1" (saddr)
 192                              : "cc");
 193         return sum;
 194 }
 195
 196 /*
 197  * computes the checksum of the TCP/UDP pseudo-header
 198  * returns a 16-bit checksum, already complemented
 199  */
 200 static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
 201                                                    unsigned long daddr,
 202                                                    unsigned short len,
 203                                                    unsigned short proto,
 204                                                    unsigned int sum)
 205 {
 206         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 207 }
 208
 209 #define _HAVE_ARCH_IPV6_CSUM
 210
 211 static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
 212                                                      struct in6_addr *daddr,
 213                                                      __u16 len,
 214                                                      unsigned short proto,
 215                                                      unsigned int sum)
 216 {
 217         __asm__ __volatile__ ("
 218                 addcc   %3, %4, %%g4
 219                 addxcc  %5, %%g4, %%g4
 220                 ld      [%2 + 0x0c], %%g2
 221                 ld      [%2 + 0x08], %%g3
 222                 addxcc  %%g2, %%g4, %%g4
 223                 ld      [%2 + 0x04], %%g2
 224                 addxcc  %%g3, %%g4, %%g4
 225                 ld      [%2 + 0x00], %%g3
 226                 addxcc  %%g2, %%g4, %%g4
 227                 ld      [%1 + 0x0c], %%g2
 228                 addxcc  %%g3, %%g4, %%g4
 229                 ld      [%1 + 0x08], %%g3
 230                 addxcc  %%g2, %%g4, %%g4
 231                 ld      [%1 + 0x04], %%g2
 232                 addxcc  %%g3, %%g4, %%g4
 233                 ld      [%1 + 0x00], %%g3
 234                 addxcc  %%g2, %%g4, %%g4
 235                 addxcc  %%g3, %%g4, %0
 236                 addx    0, %0, %0
 237                 "
 238                 : "=&r" (sum)
 239                 : "r" (saddr), "r" (daddr),
 240                   "r"(htonl((__u32) (len))), "r"(htonl(proto)), "r"(sum)
 241                 : "g2", "g3", "g4", "cc");
 242
 243         return csum_fold(sum);
 244 }
 245
 246 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
 247 extern __inline__ unsigned short ip_compute_csum(unsigned char * buff, int len)
 248 {
 249         return csum_fold(csum_partial(buff, len, 0));
 250 }
 251
 252 #endif /* !(__SPARC_CHECKSUM_H) */