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
  46         __asm__ __volatile__ (
  47 "       ldws,ma         4(%1), %0\n"
  48 "       addib,<=        -4, %2, 2f\n"
  49 "\n"
  50 "       ldws            4(%1), %%r20\n"
  51 "       ldws            8(%1), %%r21\n"
  52 "       add             %0, %%r20, %0\n"
  53 "       ldws,ma         12(%1), %%r19\n"
  54 "       addc            %0, %%r21, %0\n"
  55 "       addc            %0, %%r19, %0\n"
  56 "1:     ldws,ma         4(%1), %%r19\n"
  57 "       addib,<         0, %2, 1b\n"
  58 "       addc            %0, %%r19, %0\n"
  59 "\n"
  60 "       extru           %0, 31, 16, %%r20\n"
  61 "       extru           %0, 15, 16, %%r21\n"
  62 "       addc            %%r20, %%r21, %0\n"
  63 "       extru           %0, 15, 16, %%r21\n"
  64 "       add             %0, %%r21, %0\n"
  65 "       subi            -1, %0, %0\n"
  66 "2:\n"
  67         : "=r" (sum), "=r" (iph), "=r" (ihl)
  68         : "1" (iph), "2" (ihl)
  69         : "r19", "r20", "r21", "memory");
  70
  71         return (__force __sum16)sum;
  72 }
  73
  74 /*
  75  *      Fold a partial checksum
  76  */
  77 static inline __sum16 csum_fold(__wsum csum)
  78 {
  79         u32 sum = (__force u32)csum;
  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 (__force __sum16)(~sum >> 16);
  86 }
  87
  88 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
  89                                         __u32 len, __u8 proto,
  90                                         __wsum 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+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 __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 107                                         __u32 len, __u8 proto,
 108                                         __wsum sum)
 109 {
 110         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 111 }
 112
 113 /*
 114  * this routine is used for miscellaneous IP-like checksums, mainly
 115  * in icmp.c
 116  */
 117 static inline __sum16 ip_compute_csum(const void *buf, int len)
 118 {
 119          return csum_fold (csum_partial(buf, len, 0));
 120 }
 121
 122
 123 #define _HAVE_ARCH_IPV6_CSUM
 124 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 125                                           const struct in6_addr *daddr,
 126                                           __u32 len, __u8 proto,
 127                                           __wsum sum)
 128 {
 129         __asm__ __volatile__ (
 130
 131 #if BITS_PER_LONG > 32
 132
 133         /*
 134         ** We can execute two loads and two adds per cycle on PA 8000.
 135         ** But add insn's get serialized waiting for the carry bit.
 136         ** Try to keep 4 registers with "live" values ahead of the ALU.
 137         */
 138
 139 "       ldd,ma          8(%1), %%r19\n" /* get 1st saddr word */
 140 "       ldd,ma          8(%2), %%r20\n" /* get 1st daddr word */
 141 "       add             %8, %3, %3\n"/* add 16-bit proto + len */
 142 "       add             %%r19, %0, %0\n"
 143 "       ldd,ma          8(%1), %%r21\n" /* 2cd saddr */
 144 "       ldd,ma          8(%2), %%r22\n" /* 2cd daddr */
 145 "       add,dc          %%r20, %0, %0\n"
 146 "       add,dc          %%r21, %0, %0\n"
 147 "       add,dc          %%r22, %0, %0\n"
 148 "       add,dc          %3, %0, %0\n"  /* fold in proto+len | carry bit */
 149 "       extrd,u         %0, 31, 32, %%r19\n"    /* copy upper half down */
 150 "       depdi           0, 31, 32, %0\n"        /* clear upper half */
 151 "       add             %%r19, %0, %0\n"        /* fold into 32-bits */
 152 "       addc            0, %0, %0\n"            /* add carry */
 153
 154 #else
 155
 156         /*
 157         ** For PA 1.x, the insn order doesn't matter as much.
 158         ** Insn stream is serialized on the carry bit here too.
 159         ** result from the previous operation (eg r0 + x)
 160         */
 161
 162 "       ldw,ma          4(%1), %%r19\n" /* get 1st saddr word */
 163 "       ldw,ma          4(%2), %%r20\n" /* get 1st daddr word */
 164 "       add             %8, %3, %3\n"   /* add 16-bit proto + len */
 165 "       add             %%r19, %0, %0\n"
 166 "       ldw,ma          4(%1), %%r21\n" /* 2cd saddr */
 167 "       addc            %%r20, %0, %0\n"
 168 "       ldw,ma          4(%2), %%r22\n" /* 2cd daddr */
 169 "       addc            %%r21, %0, %0\n"
 170 "       ldw,ma          4(%1), %%r19\n" /* 3rd saddr */
 171 "       addc            %%r22, %0, %0\n"
 172 "       ldw,ma          4(%2), %%r20\n" /* 3rd daddr */
 173 "       addc            %%r19, %0, %0\n"
 174 "       ldw,ma          4(%1), %%r21\n" /* 4th saddr */
 175 "       addc            %%r20, %0, %0\n"
 176 "       ldw,ma          4(%2), %%r22\n" /* 4th daddr */
 177 "       addc            %%r21, %0, %0\n"
 178 "       addc            %%r22, %0, %0\n"
 179 "       addc            %3, %0, %0\n"   /* fold in proto+len, catch carry */
 180
 181 #endif
 182         : "=r" (sum), "=r" (saddr), "=r" (daddr), "=r" (len)
 183         : "0" (sum), "1" (saddr), "2" (daddr), "3" (len), "r" (proto)
 184         : "r19", "r20", "r21", "r22", "memory");
 185         return csum_fold(sum);
 186 }
 187
 188 /*
 189  *      Copy and checksum to user
 190  */
 191 #define HAVE_CSUM_COPY_USER
 192 static __inline__ __wsum csum_and_copy_to_user(const void *src,
 193                                                       void __user *dst,
 194                                                       int len, __wsum sum,
 195                                                       int *err_ptr)
 196 {
 197         /* code stolen from include/asm-mips64 */
 198         sum = csum_partial(src, len, sum);
 199
 200         if (copy_to_user(dst, src, len)) {
 201                 *err_ptr = -EFAULT;
 202                 return (__force __wsum)-1;
 203         }
 204
 205         return sum;
 206 }
 207
 208 #endif
 209