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