include/asm-parisc/checksum.h

   1 #ifndef _PARISC_CHECKSUM_H
   2 #define _PARISC_CHECKSUM_H
   3
   4 #include <linux/in6.h>
   5
   6 /*
   7  * computes the checksum of a memory block at buff, length len,
   8  * and adds in "sum" (32-bit)
   9  *
  10  * returns a 32-bit number suitable for feeding into itself
  11  * or csum_tcpudp_magic
  12  *
  13  * this function must be called with even lengths, except
  14  * for the last fragment, which may be odd
  15  *
  16  * it's best to have buff aligned on a 32-bit boundary
  17  */
  18 extern unsigned int csum_partial(const unsigned char *, int, unsigned int);
  19
  20 /*
  21  * The same as csum_partial, but copies from src while it checksums.
  22  *
  23  * Here even more important to align src and dst on a 32-bit (or even
  24  * better 64-bit) boundary
  25  */
  26 extern unsigned int csum_partial_copy_nocheck(const unsigned char *, unsigned char *,
  27                                               int, unsigned int);
  28
  29 /*
  30  * this is a new version of the above that records errors it finds in *errp,
  31  * but continues and zeros the rest of the buffer.
  32  */
  33 extern unsigned int csum_partial_copy_from_user(const unsigned char __user *src,
  34                 unsigned char *dst, int len, unsigned int sum, int *errp);
  35
  36 /*
  37  *      Optimized for IP headers, which always checksum on 4 octet boundaries.
  38  *
  39  *      Written by Randolph Chung <tausq@debian.org>, and then mucked with by
  40  *      LaMont Jones <lamont@debian.org>
  41  */
  42 static inline unsigned short ip_fast_csum(unsigned char * iph,
  43                                           unsigned int ihl) {
  44         unsigned int sum;
  45
  46
  47         __asm__ __volatile__ (
  48 "       ldws,ma         4(%1), %0\n"
  49 "       addib,<=        -4, %2, 2f\n"
  50 "\n"
  51 "       ldws            4(%1), %%r20\n"
  52 "       ldws            8(%1), %%r21\n"
  53 "       add             %0, %%r20, %0\n"
  54 "       ldws,ma         12(%1), %%r19\n"
  55 "       addc            %0, %%r21, %0\n"
  56 "       addc            %0, %%r19, %0\n"
  57 "1:     ldws,ma         4(%1), %%r19\n"
  58 "       addib,<         0, %2, 1b\n"
  59 "       addc            %0, %%r19, %0\n"
  60 "\n"
  61 "       extru           %0, 31, 16, %%r20\n"
  62 "       extru           %0, 15, 16, %%r21\n"
  63 "       addc            %%r20, %%r21, %0\n"
  64 "       extru           %0, 15, 16, %%r21\n"
  65 "       add             %0, %%r21, %0\n"
  66 "       subi            -1, %0, %0\n"
  67 "2:\n"
  68         : "=r" (sum), "=r" (iph), "=r" (ihl)
  69         : "1" (iph), "2" (ihl)
  70         : "r19", "r20", "r21" );
  71
  72         return(sum);
  73 }
  74
  75 /*
  76  *      Fold a partial checksum
  77  */
  78 static inline unsigned int csum_fold(unsigned int sum)
  79 {
  80         /* add the swapped two 16-bit halves of sum,
  81            a possible carry from adding the two 16-bit halves,
  82            will carry from the lower half into the upper half,
  83            giving us the correct sum in the upper half. */
  84         sum += (sum << 16) + (sum >> 16);
  85         return (~sum) >> 16;
  86 }
  87
  88 static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
  89                                                unsigned long daddr,
  90                                                unsigned short len,
  91                                                unsigned short proto,
  92                                                unsigned int sum)
  93 {
  94         __asm__(
  95         "       add  %1, %0, %0\n"
  96         "       addc %2, %0, %0\n"
  97         "       addc %3, %0, %0\n"
  98         "       addc %%r0, %0, %0\n"
  99                 : "=r" (sum)
 100                 : "r" (daddr), "r"(saddr), "r"((proto<<16)+len), "0"(sum));
 101     return sum;
 102 }
 103
 104 /*
 105  * computes the checksum of the TCP/UDP pseudo-header
 106  * returns a 16-bit checksum, already complemented
 107  */
 108 static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
 109                                                    unsigned long daddr,
 110                                                    unsigned short len,
 111                                                    unsigned short proto,
 112                                                    unsigned int sum)
 113 {
 114         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 115 }
 116
 117 /*
 118  * this routine is used for miscellaneous IP-like checksums, mainly
 119  * in icmp.c
 120  */
 121 static inline unsigned short ip_compute_csum(unsigned char * buf, int len) {
 122          return csum_fold (csum_partial(buf, len, 0));
 123 }
 124
 125
 126 #define _HAVE_ARCH_IPV6_CSUM
 127 static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
 128                                                      struct in6_addr *daddr,
 129                                                      __u16 len,
 130                                                      unsigned short proto,
 131                                                      unsigned int sum)
 132 {
 133         __asm__ __volatile__ (
 134
 135 #if BITS_PER_LONG > 32
 136
 137         /*
 138         ** We can execute two loads and two adds per cycle on PA 8000.
 139         ** But add insn's get serialized waiting for the carry bit.
 140         ** Try to keep 4 registers with "live" values ahead of the ALU.
 141         */
 142
 143 "       ldd,ma          8(%1), %%r19\n" /* get 1st saddr word */
 144 "       ldd,ma          8(%2), %%r20\n" /* get 1st daddr word */
 145 "       add             %8, %3, %3\n"/* add 16-bit proto + len */
 146 "       add             %%r19, %0, %0\n"
 147 "       ldd,ma          8(%1), %%r21\n" /* 2cd saddr */
 148 "       ldd,ma          8(%2), %%r22\n" /* 2cd daddr */
 149 "       add,dc          %%r20, %0, %0\n"
 150 "       add,dc          %%r21, %0, %0\n"
 151 "       add,dc          %%r22, %0, %0\n"
 152 "       add,dc          %3, %0, %0\n"  /* fold in proto+len | carry bit */
 153 "       extrd,u         %0, 31, 32, %%r19\n"    /* copy upper half down */
 154 "       depdi           0, 31, 32, %0\n"        /* clear upper half */
 155 "       add             %%r19, %0, %0\n"        /* fold into 32-bits */
 156 "       addc            0, %0, %0\n"            /* add carry */
 157
 158 #else
 159
 160         /*
 161         ** For PA 1.x, the insn order doesn't matter as much.
 162         ** Insn stream is serialized on the carry bit here too.
 163         ** result from the previous operation (eg r0 + x)
 164         */
 165
 166 "       ldw,ma          4(%1), %%r19\n" /* get 1st saddr word */
 167 "       ldw,ma          4(%2), %%r20\n" /* get 1st daddr word */
 168 "       add             %8, %3, %3\n"   /* add 16-bit proto + len */
 169 "       add             %%r19, %0, %0\n"
 170 "       ldw,ma          4(%1), %%r21\n" /* 2cd saddr */
 171 "       addc            %%r20, %0, %0\n"
 172 "       ldw,ma          4(%2), %%r22\n" /* 2cd daddr */
 173 "       addc            %%r21, %0, %0\n"
 174 "       ldw,ma          4(%1), %%r19\n" /* 3rd saddr */
 175 "       addc            %%r22, %0, %0\n"
 176 "       ldw,ma          4(%2), %%r20\n" /* 3rd daddr */
 177 "       addc            %%r19, %0, %0\n"
 178 "       ldw,ma          4(%1), %%r21\n" /* 4th saddr */
 179 "       addc            %%r20, %0, %0\n"
 180 "       ldw,ma          4(%2), %%r22\n" /* 4th daddr */
 181 "       addc            %%r21, %0, %0\n"
 182 "       addc            %%r22, %0, %0\n"
 183 "       addc            %3, %0, %0\n"   /* fold in proto+len, catch carry */
 184
 185 #endif
 186         : "=r" (sum), "=r" (saddr), "=r" (daddr), "=r" (len)
 187         : "0" (sum), "1" (saddr), "2" (daddr), "3" (len), "r" (proto)
 188         : "r19", "r20", "r21", "r22");
 189         return csum_fold(sum);
 190 }
 191
 192 /*
 193  *      Copy and checksum to user
 194  */
 195 #define HAVE_CSUM_COPY_USER
 196 static __inline__ unsigned int csum_and_copy_to_user (const unsigned char *src,
 197                                                       unsigned char __user *dst,
 198                                                       int len, int sum,
 199                                                       int *err_ptr)
 200 {
 201         /* code stolen from include/asm-mips64 */
 202         sum = csum_partial(src, len, sum);
 203
 204         if (copy_to_user(dst, src, len)) {
 205                 *err_ptr = -EFAULT;
 206                 return -1;
 207         }
 208
 209         return sum;
 210 }
 211
 212 #endif
 213