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                                         __u32 len, __u8 proto,
 118                                         __wsum sum)
 119 {
 120 #if defined(__LITTLE_ENDIAN)
 121         unsigned long len_proto = (proto + len) << 8;
 122 #else
 123         unsigned long len_proto = proto + len;
 124 #endif
 125         unsigned long tmpreg;
 126
 127         __asm__(
 128                 "       cmp     %0, %0 \n"
 129                 "       addx    %0, %2 \n"
 130                 "       addx    %0, %3 \n"
 131                 "       addx    %0, %4 \n"
 132                 "       ldi     %1, #0 \n"
 133                 "       addx    %0, %1 \n"
 134                 : "=r" (sum), "=&r" (tmpreg)
 135                 : "r" (daddr), "r" (saddr), "r" (len_proto), "0" (sum)
 136                 : "cbit"
 137         );
 138
 139         return sum;
 140 }
 141
 142 /*
 143  * computes the checksum of the TCP/UDP pseudo-header
 144  * returns a 16-bit checksum, already complemented
 145  */
 146 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 147                                         __u32 len, __u8 proto,
 148                                         __wsum sum)
 149 {
 150         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 151 }
 152
 153 /*
 154  * this routine is used for miscellaneous IP-like checksums, mainly
 155  * in icmp.c
 156  */
 157
 158 static inline __sum16 ip_compute_csum(const void *buff, int len)
 159 {
 160         return csum_fold (csum_partial(buff, len, 0));
 161 }
 162
 163 #define _HAVE_ARCH_IPV6_CSUM
 164 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 165                                       const struct in6_addr *daddr,
 166                                       __u32 len, unsigned short proto,
 167                                       __wsum sum)
 168 {
 169         unsigned long tmpreg0, tmpreg1, tmpreg2, tmpreg3;
 170         __asm__(
 171                 "       ld      %1, @(%5) \n"
 172                 "       ld      %2, @(4,%5) \n"
 173                 "       ld      %3, @(8,%5) \n"
 174                 "       ld      %4, @(12,%5) \n"
 175                 "       add     %0, %1 \n"
 176                 "       addx    %0, %2 \n"
 177                 "       addx    %0, %3 \n"
 178                 "       addx    %0, %4 \n"
 179                 "       ld      %1, @(%6) \n"
 180                 "       ld      %2, @(4,%6) \n"
 181                 "       ld      %3, @(8,%6) \n"
 182                 "       ld      %4, @(12,%6) \n"
 183                 "       addx    %0, %1 \n"
 184                 "       addx    %0, %2 \n"
 185                 "       addx    %0, %3 \n"
 186                 "       addx    %0, %4 \n"
 187                 "       addx    %0, %7 \n"
 188                 "       addx    %0, %8 \n"
 189                 "       ldi     %1, #0 \n"
 190                 "       addx    %0, %1 \n"
 191                 : "=&r" (sum), "=&r" (tmpreg0), "=&r" (tmpreg1),
 192                   "=&r" (tmpreg2), "=&r" (tmpreg3)
 193                 : "r" (saddr), "r" (daddr),
 194                   "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
 195                 : "cbit"
 196         );
 197
 198         return csum_fold(sum);
 199 }
 200
 201 #endif /* _ASM_M32R_CHECKSUM_H */
 202 #endif /* __KERNEL__ */