arch/m32r/include/asm/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 __wsum csum_partial(const void *buff, int len, __wsum sum);
  35
  36 /*
  37  * The same as csum_partial, but copies from src while it checksums.
  38  *
  39  * Here even more important to align src and dst on a 32-bit (or even
  40  * better 64-bit) boundary
  41  */
  42 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
  43                                               int len, __wsum sum);
  44
  45 /*
  46  * This is a new version of the above that records errors it finds in *errp,
  47  * but continues and zeros thre rest of the buffer.
  48  */
  49 extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
  50                                                 int len, __wsum sum,
  51                                                 int *err_ptr);
  52
  53 /*
  54  *      Fold a partial checksum
  55  */
  56
  57 static inline __sum16 csum_fold(__wsum sum)
  58 {
  59         unsigned long tmpreg;
  60         __asm__(
  61                 "       sll3    %1, %0, #16 \n"
  62                 "       cmp     %0, %0 \n"
  63                 "       addx    %0, %1 \n"
  64                 "       ldi     %1, #0 \n"
  65                 "       srli    %0, #16 \n"
  66                 "       addx    %0, %1 \n"
  67                 "       xor3    %0, %0, #0x0000ffff \n"
  68                 : "=r" (sum), "=&r" (tmpreg)
  69                 : "0"  (sum)
  70                 : "cbit"
  71         );
  72         return (__force __sum16)sum;
  73 }
  74
  75 /*
  76  * This is a version of ip_compute_csum() optimized for IP headers,
  77  * which always checksum on 4 octet boundaries.
  78  */
  79 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
  80 {
  81         unsigned long tmpreg0, tmpreg1;
  82         __wsum sum;
  83
  84         __asm__ __volatile__(
  85                 "       ld      %0, @%1+ \n"
  86                 "       addi    %2, #-4 \n"
  87                 "#      bgez    %2, 2f \n"
  88                 "       cmp     %0, %0 \n"
  89                 "       ld      %3, @%1+ \n"
  90                 "       ld      %4, @%1+ \n"
  91                 "       addx    %0, %3 \n"
  92                 "       ld      %3, @%1+ \n"
  93                 "       addx    %0, %4 \n"
  94                 "       addx    %0, %3 \n"
  95                 "       .fillinsn\n"
  96                 "1: \n"
  97                 "       ld      %4, @%1+ \n"
  98                 "       addi    %2, #-1 \n"
  99                 "       addx    %0, %4 \n"
 100                 "       bgtz    %2, 1b \n"
 101                 "\n"
 102                 "       ldi     %3, #0 \n"
 103                 "       addx    %0, %3 \n"
 104                 "       .fillinsn\n"
 105                 "2: \n"
 106         /* Since the input registers which are loaded with iph and ihl
 107            are modified, we must also specify them as outputs, or gcc
 108            will assume they contain their original values. */
 109         : "=&r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmpreg0), "=&r" (tmpreg1)
 110         : "1" (iph), "2" (ihl)
 111         : "cbit", "memory");
 112
 113         return csum_fold(sum);
 114 }
 115
 116 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 117                                                unsigned short len,
 118                                                unsigned short proto,
 119                                                __wsum sum)
 120 {
 121 #if defined(__LITTLE_ENDIAN)
 122         unsigned long len_proto = (proto + len) << 8;
 123 #else
 124         unsigned long len_proto = proto + len;
 125 #endif
 126         unsigned long tmpreg;
 127
 128         __asm__(
 129                 "       cmp     %0, %0 \n"
 130                 "       addx    %0, %2 \n"
 131                 "       addx    %0, %3 \n"
 132                 "       addx    %0, %4 \n"
 133                 "       ldi     %1, #0 \n"
 134                 "       addx    %0, %1 \n"
 135                 : "=r" (sum), "=&r" (tmpreg)
 136                 : "r" (daddr), "r" (saddr), "r" (len_proto), "0" (sum)
 137                 : "cbit"
 138         );
 139
 140         return sum;
 141 }
 142
 143 /*
 144  * computes the checksum of the TCP/UDP pseudo-header
 145  * returns a 16-bit checksum, already complemented
 146  */
 147 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 148                                                    unsigned short len,
 149                                                    unsigned short proto,
 150                                                    __wsum sum)
 151 {
 152         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 153 }
 154
 155 /*
 156  * this routine is used for miscellaneous IP-like checksums, mainly
 157  * in icmp.c
 158  */
 159
 160 static inline __sum16 ip_compute_csum(const void *buff, int len)
 161 {
 162         return csum_fold (csum_partial(buff, len, 0));
 163 }
 164
 165 #define _HAVE_ARCH_IPV6_CSUM
 166 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 167                                       const struct in6_addr *daddr,
 168                                       __u32 len, unsigned short proto,
 169                                       __wsum sum)
 170 {
 171         unsigned long tmpreg0, tmpreg1, tmpreg2, tmpreg3;
 172         __asm__(
 173                 "       ld      %1, @(%5) \n"
 174                 "       ld      %2, @(4,%5) \n"
 175                 "       ld      %3, @(8,%5) \n"
 176                 "       ld      %4, @(12,%5) \n"
 177                 "       add     %0, %1 \n"
 178                 "       addx    %0, %2 \n"
 179                 "       addx    %0, %3 \n"
 180                 "       addx    %0, %4 \n"
 181                 "       ld      %1, @(%6) \n"
 182                 "       ld      %2, @(4,%6) \n"
 183                 "       ld      %3, @(8,%6) \n"
 184                 "       ld      %4, @(12,%6) \n"
 185                 "       addx    %0, %1 \n"
 186                 "       addx    %0, %2 \n"
 187                 "       addx    %0, %3 \n"
 188                 "       addx    %0, %4 \n"
 189                 "       addx    %0, %7 \n"
 190                 "       addx    %0, %8 \n"
 191                 "       ldi     %1, #0 \n"
 192                 "       addx    %0, %1 \n"
 193                 : "=&r" (sum), "=&r" (tmpreg0), "=&r" (tmpreg1),
 194                   "=&r" (tmpreg2), "=&r" (tmpreg3)
 195                 : "r" (saddr), "r" (daddr),
 196                   "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
 197                 : "cbit"
 198         );
 199
 200         return csum_fold(sum);
 201 }
 202
 203 #endif /* _ASM_M32R_CHECKSUM_H */
 204 #endif /* __KERNEL__ */