include/asm-m32r/checksum.h

   1 #ifdef __KERNEL__
   2 #ifndef _ASM_M32R_CHECKSUM_H
   3 #define _ASM_M32R_CHECKSUM_H
   4
   5 /*
   6  * include/asm-m32r/checksum.h
   7  *
   8  * IP/TCP/UDP checksum routines
   9  *
  10  * This file is subject to the terms and conditions of the GNU General Public
  11  * License.  See the file "COPYING" in the main directory of this archive
  12  * for more details.
  13  *
  14  * Some code taken from mips and parisc architecture.
  15  *
  16  *    Copyright (C) 2001, 2002  Hiroyuki Kondo, Hirokazu Takata
  17  *    Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
  18  */
  19
  20 #include <linux/in6.h>
  21
  22 /*
  23  * computes the checksum of a memory block at buff, length len,
  24  * and adds in "sum" (32-bit)
  25  *
  26  * returns a 32-bit number suitable for feeding into itself
  27  * or csum_tcpudp_magic
  28  *
  29  * this function must be called with even lengths, except
  30  * for the last fragment, which may be odd
  31  *
  32  * it's best to have buff aligned on a 32-bit boundary
  33  */
  34 asmlinkage unsigned int csum_partial(const unsigned char *buff,
  35                                      int len, unsigned int sum);
  36
  37 /*
  38  * The same as csum_partial, but copies from src while it checksums.
  39  *
  40  * Here even more important to align src and dst on a 32-bit (or even
  41  * better 64-bit) boundary
  42  */
  43 extern unsigned int csum_partial_copy_nocheck(const unsigned char *src,
  44                                               unsigned char *dst,
  45                                               int len, unsigned int sum);
  46
  47 /*
  48  * This is a new version of the above that records errors it finds in *errp,
  49  * but continues and zeros thre rest of the buffer.
  50  */
  51 extern unsigned int csum_partial_copy_from_user(const unsigned char __user *src,
  52                                                 unsigned char *dst,
  53                                                 int len, unsigned int sum,
  54                                                 int *err_ptr);
  55
  56 /*
  57  *      Fold a partial checksum
  58  */
  59
  60 static inline unsigned int csum_fold(unsigned int sum)
  61 {
  62         unsigned long tmpreg;
  63         __asm__(
  64                 "       sll3    %1, %0, #16 \n"
  65                 "       cmp     %0, %0 \n"
  66                 "       addx    %0, %1 \n"
  67                 "       ldi     %1, #0 \n"
  68                 "       srli    %0, #16 \n"
  69                 "       addx    %0, %1 \n"
  70                 "       xor3    %0, %0, #0x0000ffff \n"
  71                 : "=r" (sum), "=&r" (tmpreg)
  72                 : "0"  (sum)
  73                 : "cbit"
  74         );
  75         return sum;
  76 }
  77
  78 /*
  79  * This is a version of ip_compute_csum() optimized for IP headers,
  80  * which always checksum on 4 octet boundaries.
  81  */
  82 static inline unsigned short ip_fast_csum(unsigned char * iph,
  83                                           unsigned int ihl) {
  84         unsigned long sum, tmpreg0, tmpreg1;
  85
  86         __asm__ __volatile__(
  87                 "       ld      %0, @%1+ \n"
  88                 "       addi    %2, #-4 \n"
  89                 "#      bgez    %2, 2f \n"
  90                 "       cmp     %0, %0 \n"
  91                 "       ld      %3, @%1+ \n"
  92                 "       ld      %4, @%1+ \n"
  93                 "       addx    %0, %3 \n"
  94                 "       ld      %3, @%1+ \n"
  95                 "       addx    %0, %4 \n"
  96                 "       addx    %0, %3 \n"
  97                 "       .fillinsn\n"
  98                 "1: \n"
  99                 "       ld      %4, @%1+ \n"
 100                 "       addi    %2, #-1 \n"
 101                 "       addx    %0, %4 \n"
 102                 "       bgtz    %2, 1b \n"
 103                 "\n"
 104                 "       ldi     %3, #0 \n"
 105                 "       addx    %0, %3 \n"
 106                 "       .fillinsn\n"
 107                 "2: \n"
 108         /* Since the input registers which are loaded with iph and ihl
 109            are modified, we must also specify them as outputs, or gcc
 110            will assume they contain their original values. */
 111         : "=&r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmpreg0), "=&r" (tmpreg1)
 112         : "1" (iph), "2" (ihl)
 113         : "cbit", "memory");
 114
 115         return csum_fold(sum);
 116 }
 117
 118 static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
 119                                                unsigned long daddr,
 120                                                unsigned short len,
 121                                                unsigned short proto,
 122                                                unsigned int sum)
 123 {
 124 #if defined(__LITTLE_ENDIAN)
 125         unsigned long len_proto = (ntohs(len)<<16)+proto*256;
 126 #else
 127         unsigned long len_proto = (proto<<16)+len;
 128 #endif
 129         unsigned long tmpreg;
 130
 131         __asm__(
 132                 "       cmp     %0, %0 \n"
 133                 "       addx    %0, %2 \n"
 134                 "       addx    %0, %3 \n"
 135                 "       addx    %0, %4 \n"
 136                 "       ldi     %1, #0 \n"
 137                 "       addx    %0, %1 \n"
 138                 : "=r" (sum), "=&r" (tmpreg)
 139                 : "r" (daddr), "r" (saddr), "r" (len_proto), "0" (sum)
 140                 : "cbit"
 141         );
 142
 143         return sum;
 144 }
 145
 146 /*
 147  * computes the checksum of the TCP/UDP pseudo-header
 148  * returns a 16-bit checksum, already complemented
 149  */
 150 static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
 151                                                    unsigned long daddr,
 152                                                    unsigned short len,
 153                                                    unsigned short proto,
 154                                                    unsigned int sum)
 155 {
 156         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 157 }
 158
 159 /*
 160  * this routine is used for miscellaneous IP-like checksums, mainly
 161  * in icmp.c
 162  */
 163
 164 static inline unsigned short ip_compute_csum(unsigned char * buff, int len) {
 165         return csum_fold (csum_partial(buff, len, 0));
 166 }
 167
 168 #define _HAVE_ARCH_IPV6_CSUM
 169 static inline unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
 170                                                  struct in6_addr *daddr,
 171                                                  __u16 len,
 172                                                  unsigned short proto,
 173                                                  unsigned int sum)
 174 {
 175         unsigned long tmpreg0, tmpreg1, tmpreg2, tmpreg3;
 176         __asm__(
 177                 "       ld      %1, @(%5) \n"
 178                 "       ld      %2, @(4,%5) \n"
 179                 "       ld      %3, @(8,%5) \n"
 180                 "       ld      %4, @(12,%5) \n"
 181                 "       add     %0, %1 \n"
 182                 "       addx    %0, %2 \n"
 183                 "       addx    %0, %3 \n"
 184                 "       addx    %0, %4 \n"
 185                 "       ld      %1, @(%6) \n"
 186                 "       ld      %2, @(4,%6) \n"
 187                 "       ld      %3, @(8,%6) \n"
 188                 "       ld      %4, @(12,%6) \n"
 189                 "       addx    %0, %1 \n"
 190                 "       addx    %0, %2 \n"
 191                 "       addx    %0, %3 \n"
 192                 "       addx    %0, %4 \n"
 193                 "       addx    %0, %7 \n"
 194                 "       addx    %0, %8 \n"
 195                 "       ldi     %1, #0 \n"
 196                 "       addx    %0, %1 \n"
 197                 : "=&r" (sum), "=&r" (tmpreg0), "=&r" (tmpreg1),
 198                   "=&r" (tmpreg2), "=&r" (tmpreg3)
 199                 : "r" (saddr), "r" (daddr),
 200                   "r" (htonl((__u32) (len))), "r" (htonl(proto)), "0" (sum)
 201                 : "cbit"
 202         );
 203
 204         return csum_fold(sum);
 205 }
 206
 207 #endif /* _ASM_M32R_CHECKSUM_H */
 208 #endif /* __KERNEL__ */