include/asm-frv/checksum.h

   1 /* checksum.h: FRV checksumming
   2  *
   3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #ifndef _ASM_CHECKSUM_H
  13 #define _ASM_CHECKSUM_H
  14
  15 #include <linux/in6.h>
  16
  17 /*
  18  * computes the checksum of a memory block at buff, length len,
  19  * and adds in "sum" (32-bit)
  20  *
  21  * returns a 32-bit number suitable for feeding into itself
  22  * or csum_tcpudp_magic
  23  *
  24  * this function must be called with even lengths, except
  25  * for the last fragment, which may be odd
  26  *
  27  * it's best to have buff aligned on a 32-bit boundary
  28  */
  29 unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
  30
  31 /*
  32  * the same as csum_partial, but copies from src while it
  33  * checksums
  34  *
  35  * here even more important to align src and dst on a 32-bit (or even
  36  * better 64-bit) boundary
  37  */
  38 unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum);
  39
  40 /*
  41  * the same as csum_partial_copy, but copies from user space.
  42  *
  43  * here even more important to align src and dst on a 32-bit (or even
  44  * better 64-bit) boundary
  45  */
  46 extern unsigned int csum_partial_copy_from_user(const char __user *src, char *dst,
  47                                                 int len, int sum, int *csum_err);
  48
  49 #define csum_partial_copy_nocheck(src, dst, len, sum)   \
  50         csum_partial_copy((src), (dst), (len), (sum))
  51
  52 /*
  53  *      This is a version of ip_compute_csum() optimized for IP headers,
  54  *      which always checksum on 4 octet boundaries.
  55  *
  56  */
  57 static inline
  58 unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl)
  59 {
  60         unsigned int tmp, inc, sum = 0;
  61
  62         asm("   addcc           gr0,gr0,gr0,icc0\n" /* clear icc0.C */
  63             "   subi            %1,#4,%1        \n"
  64             "0:                                 \n"
  65             "   ldu.p           @(%1,%3),%4     \n"
  66             "   subicc          %2,#1,%2,icc1   \n"
  67             "   addxcc.p        %4,%0,%0,icc0   \n"
  68             "   bhi             icc1,#2,0b      \n"
  69
  70             /* fold the 33-bit result into 16-bits */
  71             "   addxcc          gr0,%0,%0,icc0  \n"
  72             "   srli            %0,#16,%1       \n"
  73             "   sethi           #0,%0           \n"
  74             "   add             %1,%0,%0        \n"
  75             "   srli            %0,#16,%1       \n"
  76             "   add             %1,%0,%0        \n"
  77
  78             : "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (inc), "=&r"(tmp)
  79             : "0" (sum), "1" (iph), "2" (ihl), "3" (4),
  80             "m"(*(volatile struct { int _[100]; } *)iph)
  81             : "icc0", "icc1"
  82             );
  83
  84         return ~sum;
  85 }
  86
  87 /*
  88  *      Fold a partial checksum
  89  */
  90 static inline unsigned int csum_fold(unsigned int sum)
  91 {
  92         unsigned int tmp;
  93
  94         asm("   srli            %0,#16,%1       \n"
  95             "   sethi           #0,%0           \n"
  96             "   add             %1,%0,%0        \n"
  97             "   srli            %0,#16,%1       \n"
  98             "   add             %1,%0,%0        \n"
  99             : "=r"(sum), "=&r"(tmp)
 100             : "0"(sum)
 101             );
 102
 103         return ~sum;
 104 }
 105
 106 /*
 107  * computes the checksum of the TCP/UDP pseudo-header
 108  * returns a 16-bit checksum, already complemented
 109  */
 110 static inline unsigned int
 111 csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
 112                   unsigned short proto, unsigned int sum)
 113 {
 114         asm("   addcc           %1,%0,%0,icc0   \n"
 115             "   addxcc          %2,%0,%0,icc0   \n"
 116             "   addxcc          %3,%0,%0,icc0   \n"
 117             "   addxcc          gr0,%0,%0,icc0  \n"
 118             : "=r" (sum)
 119             : "r" (daddr), "r" (saddr), "r" (len + proto), "0"(sum)
 120             : "icc0"
 121             );
 122         return sum;
 123 }
 124
 125 static inline unsigned short int
 126 csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
 127                   unsigned short proto, unsigned int sum)
 128 {
 129         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 130 }
 131
 132 /*
 133  * this routine is used for miscellaneous IP-like checksums, mainly
 134  * in icmp.c
 135  */
 136 extern unsigned short ip_compute_csum(const unsigned char * buff, int len);
 137
 138 #define _HAVE_ARCH_IPV6_CSUM
 139 static inline unsigned short int
 140 csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr,
 141                 __u32 len, unsigned short proto, unsigned int sum)
 142 {
 143         unsigned long tmp, tmp2;
 144
 145         asm("   addcc           %2,%0,%0,icc0   \n"
 146
 147             /* add up the source addr */
 148             "   ldi             @(%3,0),%1      \n"
 149             "   addxcc          %1,%0,%0,icc0   \n"
 150             "   ldi             @(%3,4),%2      \n"
 151             "   addxcc          %2,%0,%0,icc0   \n"
 152             "   ldi             @(%3,8),%1      \n"
 153             "   addxcc          %1,%0,%0,icc0   \n"
 154             "   ldi             @(%3,12),%2     \n"
 155             "   addxcc          %2,%0,%0,icc0   \n"
 156
 157             /* add up the dest addr */
 158             "   ldi             @(%4,0),%1      \n"
 159             "   addxcc          %1,%0,%0,icc0   \n"
 160             "   ldi             @(%4,4),%2      \n"
 161             "   addxcc          %2,%0,%0,icc0   \n"
 162             "   ldi             @(%4,8),%1      \n"
 163             "   addxcc          %1,%0,%0,icc0   \n"
 164             "   ldi             @(%4,12),%2     \n"
 165             "   addxcc          %2,%0,%0,icc0   \n"
 166
 167             /* fold the 33-bit result into 16-bits */
 168             "   addxcc          gr0,%0,%0,icc0  \n"
 169             "   srli            %0,#16,%1       \n"
 170             "   sethi           #0,%0           \n"
 171             "   add             %1,%0,%0        \n"
 172             "   srli            %0,#16,%1       \n"
 173             "   add             %1,%0,%0        \n"
 174
 175             : "=r" (sum), "=&r" (tmp), "=r" (tmp2)
 176             : "r" (saddr), "r" (daddr), "0" (sum), "2" (len + proto)
 177             : "icc0"
 178             );
 179
 180         return ~sum;
 181 }
 182
 183 #endif /* _ASM_CHECKSUM_H */