include/asm-sparc/checksum.h

   1 /* $Id: checksum.h,v 1.33 2002/02/01 22:01:05 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 <linux/in6.h>
  20 #include <asm/uaccess.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(const 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 extern unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);
  43
  44 static inline unsigned int
  45 csum_partial_copy_nocheck (const unsigned char *src, unsigned char *dst, int len,
  46                            unsigned int sum)
  47 {
  48         register unsigned int ret asm("o0") = (unsigned int)src;
  49         register char *d asm("o1") = dst;
  50         register int l asm("g1") = len;
  51
  52         __asm__ __volatile__ (
  53                 "call __csum_partial_copy_sparc_generic\n\t"
  54                 " mov %6, %%g7\n"
  55         : "=&r" (ret), "=&r" (d), "=&r" (l)
  56         : "0" (ret), "1" (d), "2" (l), "r" (sum)
  57         : "o2", "o3", "o4", "o5", "o7",
  58           "g2", "g3", "g4", "g5", "g7",
  59           "memory", "cc");
  60         return ret;
  61 }
  62
  63 static inline unsigned int
  64 csum_partial_copy_from_user(const unsigned char __user *src, unsigned char *dst, int len,
  65                             unsigned int sum, int *err)
  66   {
  67         if (!access_ok (VERIFY_READ, src, len)) {
  68                 *err = -EFAULT;
  69                 memset (dst, 0, len);
  70                 return sum;
  71         } else {
  72                 register unsigned long ret asm("o0") = (unsigned long)src;
  73                 register char *d asm("o1") = dst;
  74                 register int l asm("g1") = len;
  75                 register unsigned int s asm("g7") = sum;
  76
  77                 __asm__ __volatile__ (
  78                 ".section __ex_table,#alloc\n\t"
  79                 ".align 4\n\t"
  80                 ".word 1f,2\n\t"
  81                 ".previous\n"
  82                 "1:\n\t"
  83                 "call __csum_partial_copy_sparc_generic\n\t"
  84                 " st %8, [%%sp + 64]\n"
  85                 : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
  86                 : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
  87                 : "o2", "o3", "o4", "o5", "o7", "g2", "g3", "g4", "g5",
  88                   "cc", "memory");
  89                 return ret;
  90         }
  91   }
  92
  93 static inline unsigned int
  94 csum_partial_copy_to_user(const unsigned char *src, unsigned char __user *dst, int len,
  95                           unsigned int sum, int *err)
  96 {
  97         if (!access_ok (VERIFY_WRITE, dst, len)) {
  98                 *err = -EFAULT;
  99                 return sum;
 100         } else {
 101                 register unsigned long ret asm("o0") = (unsigned long)src;
 102                 register char __user *d asm("o1") = dst;
 103                 register int l asm("g1") = len;
 104                 register unsigned int s asm("g7") = sum;
 105
 106                 __asm__ __volatile__ (
 107                 ".section __ex_table,#alloc\n\t"
 108                 ".align 4\n\t"
 109                 ".word 1f,1\n\t"
 110                 ".previous\n"
 111                 "1:\n\t"
 112                 "call __csum_partial_copy_sparc_generic\n\t"
 113                 " st %8, [%%sp + 64]\n"
 114                 : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
 115                 : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
 116                 : "o2", "o3", "o4", "o5", "o7",
 117                   "g2", "g3", "g4", "g5",
 118                   "cc", "memory");
 119                 return ret;
 120         }
 121 }
 122
 123 #define HAVE_CSUM_COPY_USER
 124 #define csum_and_copy_to_user csum_partial_copy_to_user
 125
 126 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
 127  * the majority of the time.
 128  */
 129 static inline unsigned short ip_fast_csum(const unsigned char *iph,
 130                                           unsigned int ihl)
 131 {
 132         unsigned short sum;
 133
 134         /* Note: We must read %2 before we touch %0 for the first time,
 135          *       because GCC can legitimately use the same register for
 136          *       both operands.
 137          */
 138         __asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
 139                              "ld\t[%1 + 0x00], %0\n\t"
 140                              "ld\t[%1 + 0x04], %%g2\n\t"
 141                              "ld\t[%1 + 0x08], %%g3\n\t"
 142                              "addcc\t%%g2, %0, %0\n\t"
 143                              "addxcc\t%%g3, %0, %0\n\t"
 144                              "ld\t[%1 + 0x0c], %%g2\n\t"
 145                              "ld\t[%1 + 0x10], %%g3\n\t"
 146                              "addxcc\t%%g2, %0, %0\n\t"
 147                              "addx\t%0, %%g0, %0\n"
 148                              "1:\taddcc\t%%g3, %0, %0\n\t"
 149                              "add\t%1, 4, %1\n\t"
 150                              "addxcc\t%0, %%g0, %0\n\t"
 151                              "subcc\t%%g4, 1, %%g4\n\t"
 152                              "be,a\t2f\n\t"
 153                              "sll\t%0, 16, %%g2\n\t"
 154                              "b\t1b\n\t"
 155                              "ld\t[%1 + 0x10], %%g3\n"
 156                              "2:\taddcc\t%0, %%g2, %%g2\n\t"
 157                              "srl\t%%g2, 16, %0\n\t"
 158                              "addx\t%0, %%g0, %0\n\t"
 159                              "xnor\t%%g0, %0, %0"
 160                              : "=r" (sum), "=&r" (iph)
 161                              : "r" (ihl), "1" (iph)
 162                              : "g2", "g3", "g4", "cc");
 163         return sum;
 164 }
 165
 166 /* Fold a partial checksum without adding pseudo headers. */
 167 static inline unsigned int csum_fold(unsigned int sum)
 168 {
 169         unsigned int tmp;
 170
 171         __asm__ __volatile__("addcc\t%0, %1, %1\n\t"
 172                              "srl\t%1, 16, %1\n\t"
 173                              "addx\t%1, %%g0, %1\n\t"
 174                              "xnor\t%%g0, %1, %0"
 175                              : "=&r" (sum), "=r" (tmp)
 176                              : "0" (sum), "1" (sum<<16)
 177                              : "cc");
 178         return sum;
 179 }
 180
 181 static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
 182                                                unsigned long daddr,
 183                                                unsigned int len,
 184                                                unsigned short proto,
 185                                                unsigned int sum)
 186 {
 187         __asm__ __volatile__("addcc\t%1, %0, %0\n\t"
 188                              "addxcc\t%2, %0, %0\n\t"
 189                              "addxcc\t%3, %0, %0\n\t"
 190                              "addx\t%0, %%g0, %0\n\t"
 191                              : "=r" (sum), "=r" (saddr)
 192                              : "r" (daddr), "r" ((proto<<16)+len), "0" (sum),
 193                                "1" (saddr)
 194                              : "cc");
 195         return sum;
 196 }
 197
 198 /*
 199  * computes the checksum of the TCP/UDP pseudo-header
 200  * returns a 16-bit checksum, already complemented
 201  */
 202 static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
 203                                                    unsigned long daddr,
 204                                                    unsigned short len,
 205                                                    unsigned short proto,
 206                                                    unsigned int sum)
 207 {
 208         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 209 }
 210
 211 #define _HAVE_ARCH_IPV6_CSUM
 212
 213 static inline unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
 214                                                  struct in6_addr *daddr,
 215                                                  __u32 len,
 216                                                  unsigned short proto,
 217                                                  unsigned int sum)
 218 {
 219         __asm__ __volatile__ (
 220                 "addcc  %3, %4, %%g4\n\t"
 221                 "addxcc %5, %%g4, %%g4\n\t"
 222                 "ld     [%2 + 0x0c], %%g2\n\t"
 223                 "ld     [%2 + 0x08], %%g3\n\t"
 224                 "addxcc %%g2, %%g4, %%g4\n\t"
 225                 "ld     [%2 + 0x04], %%g2\n\t"
 226                 "addxcc %%g3, %%g4, %%g4\n\t"
 227                 "ld     [%2 + 0x00], %%g3\n\t"
 228                 "addxcc %%g2, %%g4, %%g4\n\t"
 229                 "ld     [%1 + 0x0c], %%g2\n\t"
 230                 "addxcc %%g3, %%g4, %%g4\n\t"
 231                 "ld     [%1 + 0x08], %%g3\n\t"
 232                 "addxcc %%g2, %%g4, %%g4\n\t"
 233                 "ld     [%1 + 0x04], %%g2\n\t"
 234                 "addxcc %%g3, %%g4, %%g4\n\t"
 235                 "ld     [%1 + 0x00], %%g3\n\t"
 236                 "addxcc %%g2, %%g4, %%g4\n\t"
 237                 "addxcc %%g3, %%g4, %0\n\t"
 238                 "addx   0, %0, %0\n"
 239                 : "=&r" (sum)
 240                 : "r" (saddr), "r" (daddr),
 241                   "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
 242                 : "g2", "g3", "g4", "cc");
 243
 244         return csum_fold(sum);
 245 }
 246
 247 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
 248 static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
 249 {
 250         return csum_fold(csum_partial(buff, len, 0));
 251 }
 252
 253 #endif /* !(__SPARC_CHECKSUM_H) */