arch/parisc/include/asm/checksum.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _PARISC_CHECKSUM_H
   3 #define _PARISC_CHECKSUM_H
   4
   5 #include <linux/in6.h>
   6
   7 /*
   8  * computes the checksum of a memory block at buff, length len,
   9  * and adds in "sum" (32-bit)
  10  *
  11  * returns a 32-bit number suitable for feeding into itself
  12  * or csum_tcpudp_magic
  13  *
  14  * this function must be called with even lengths, except
  15  * for the last fragment, which may be odd
  16  *
  17  * it's best to have buff aligned on a 32-bit boundary
  18  */
  19 extern __wsum csum_partial(const void *, int, __wsum);
  20
  21 /*
  22  * The same as csum_partial, but copies from src while it checksums.
  23  *
  24  * Here even more important to align src and dst on a 32-bit (or even
  25  * better 64-bit) boundary
  26  */
  27 extern __wsum csum_partial_copy_nocheck(const void *, void *, int, __wsum);
  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 __wsum csum_partial_copy_from_user(const void __user *src,
  34                 void *dst, int len, __wsum 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 __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
  43 {
  44         unsigned int sum;
  45         unsigned long t0, t1, t2;
  46
  47         __asm__ __volatile__ (
  48 "       ldws,ma         4(%1), %0\n"
  49 "       addib,<=        -4, %2, 2f\n"
  50 "\n"
  51 "       ldws            4(%1), %4\n"
  52 "       ldws            8(%1), %5\n"
  53 "       add             %0, %4, %0\n"
  54 "       ldws,ma         12(%1), %3\n"
  55 "       addc            %0, %5, %0\n"
  56 "       addc            %0, %3, %0\n"
  57 "1:     ldws,ma         4(%1), %3\n"
  58 "       addib,<         0, %2, 1b\n"
  59 "       addc            %0, %3, %0\n"
  60 "\n"
  61 "       extru           %0, 31, 16, %4\n"
  62 "       extru           %0, 15, 16, %5\n"
  63 "       addc            %4, %5, %0\n"
  64 "       extru           %0, 15, 16, %5\n"
  65 "       add             %0, %5, %0\n"
  66 "       subi            -1, %0, %0\n"
  67 "2:\n"
  68         : "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (t0), "=r" (t1), "=r" (t2)
  69         : "1" (iph), "2" (ihl)
  70         : "memory");
  71
  72         return (__force __sum16)sum;
  73 }
  74
  75 /*
  76  *      Fold a partial checksum
  77  */
  78 static inline __sum16 csum_fold(__wsum csum)
  79 {
  80         u32 sum = (__force u32)csum;
  81         /* add the swapped two 16-bit halves of sum,
  82            a possible carry from adding the two 16-bit halves,
  83            will carry from the lower half into the upper half,
  84            giving us the correct sum in the upper half. */
  85         sum += (sum << 16) + (sum >> 16);
  86         return (__force __sum16)(~sum >> 16);
  87 }
  88
  89 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
  90                                         __u32 len, __u8 proto,
  91                                         __wsum sum)
  92 {
  93         __asm__(
  94         "       add  %1, %0, %0\n"
  95         "       addc %2, %0, %0\n"
  96         "       addc %3, %0, %0\n"
  97         "       addc %%r0, %0, %0\n"
  98                 : "=r" (sum)
  99                 : "r" (daddr), "r"(saddr), "r"(proto+len), "0"(sum));
 100         return sum;
 101 }
 102
 103 /*
 104  * computes the checksum of the TCP/UDP pseudo-header
 105  * returns a 16-bit checksum, already complemented
 106  */
 107 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 108                                         __u32 len, __u8 proto,
 109                                         __wsum sum)
 110 {
 111         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 112 }
 113
 114 /*
 115  * this routine is used for miscellaneous IP-like checksums, mainly
 116  * in icmp.c
 117  */
 118 static inline __sum16 ip_compute_csum(const void *buf, int len)
 119 {
 120          return csum_fold (csum_partial(buf, len, 0));
 121 }
 122
 123
 124 #define _HAVE_ARCH_IPV6_CSUM
 125 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 126                                           const struct in6_addr *daddr,
 127                                           __u32 len, __u8 proto,
 128                                           __wsum sum)
 129 {
 130         unsigned long t0, t1, t2, t3;
 131
 132         len += proto;   /* add 16-bit proto + len */
 133
 134         __asm__ __volatile__ (
 135
 136 #if BITS_PER_LONG > 32
 137
 138         /*
 139         ** We can execute two loads and two adds per cycle on PA 8000.
 140         ** But add insn's get serialized waiting for the carry bit.
 141         ** Try to keep 4 registers with "live" values ahead of the ALU.
 142         */
 143
 144 "       ldd,ma          8(%1), %4\n"    /* get 1st saddr word */
 145 "       ldd,ma          8(%2), %5\n"    /* get 1st daddr word */
 146 "       add             %4, %0, %0\n"
 147 "       ldd,ma          8(%1), %6\n"    /* 2nd saddr */
 148 "       ldd,ma          8(%2), %7\n"    /* 2nd daddr */
 149 "       add,dc          %5, %0, %0\n"
 150 "       add,dc          %6, %0, %0\n"
 151 "       add,dc          %7, %0, %0\n"
 152 "       add,dc          %3, %0, %0\n"  /* fold in proto+len | carry bit */
 153 "       extrd,u         %0, 31, 32, %4\n"/* copy upper half down */
 154 "       depdi           0, 31, 32, %0\n"/* clear upper half */
 155 "       add             %4, %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 "       ldw,ma          4(%1), %4\n"    /* get 1st saddr word */
 166 "       ldw,ma          4(%2), %5\n"    /* get 1st daddr word */
 167 "       add             %4, %0, %0\n"
 168 "       ldw,ma          4(%1), %6\n"    /* 2nd saddr */
 169 "       addc            %5, %0, %0\n"
 170 "       ldw,ma          4(%2), %7\n"    /* 2nd daddr */
 171 "       addc            %6, %0, %0\n"
 172 "       ldw,ma          4(%1), %4\n"    /* 3rd saddr */
 173 "       addc            %7, %0, %0\n"
 174 "       ldw,ma          4(%2), %5\n"    /* 3rd daddr */
 175 "       addc            %4, %0, %0\n"
 176 "       ldw,ma          4(%1), %6\n"    /* 4th saddr */
 177 "       addc            %5, %0, %0\n"
 178 "       ldw,ma          4(%2), %7\n"    /* 4th daddr */
 179 "       addc            %6, %0, %0\n"
 180 "       addc            %7, %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           "=r" (t0), "=r" (t1), "=r" (t2), "=r" (t3)
 186         : "0" (sum), "1" (saddr), "2" (daddr), "3" (len)
 187         : "memory");
 188         return csum_fold(sum);
 189 }
 190
 191 /*
 192  *      Copy and checksum to user
 193  */
 194 #define HAVE_CSUM_COPY_USER
 195 static __inline__ __wsum csum_and_copy_to_user(const void *src,
 196                                                       void __user *dst,
 197                                                       int len, __wsum sum,
 198                                                       int *err_ptr)
 199 {
 200         /* code stolen from include/asm-mips64 */
 201         sum = csum_partial(src, len, sum);
 202
 203         if (copy_to_user(dst, src, len)) {
 204                 *err_ptr = -EFAULT;
 205                 return (__force __wsum)-1;
 206         }
 207
 208         return sum;
 209 }
 210
 211 #endif
 212