arch/sparc/include/asm/checksum_64.h

   1 #ifndef __SPARC64_CHECKSUM_H
   2 #define __SPARC64_CHECKSUM_H
   3
   4 /*  checksum.h:  IP/UDP/TCP checksum routines on the V9.
   5  *
   6  *  Copyright(C) 1995 Linus Torvalds
   7  *  Copyright(C) 1995 Miguel de Icaza
   8  *  Copyright(C) 1996 David S. Miller
   9  *  Copyright(C) 1996 Eddie C. Dost
  10  *  Copyright(C) 1997 Jakub Jelinek
  11  *
  12  * derived from:
  13  *      Alpha checksum c-code
  14  *      ix86 inline assembly
  15  *      RFC1071 Computing the Internet Checksum
  16  */
  17
  18 #include <linux/in6.h>
  19 #include <linux/uaccess.h>
  20
  21 /* computes the checksum of a memory block at buff, length len,
  22  * and adds in "sum" (32-bit)
  23  *
  24  * returns a 32-bit number suitable for feeding into itself
  25  * or csum_tcpudp_magic
  26  *
  27  * this function must be called with even lengths, except
  28  * for the last fragment, which may be odd
  29  *
  30  * it's best to have buff aligned on a 32-bit boundary
  31  */
  32 __wsum csum_partial(const void * buff, int len, __wsum sum);
  33
  34 /* the same as csum_partial, but copies from user space while it
  35  * checksums
  36  *
  37  * here even more important to align src and dst on a 32-bit (or even
  38  * better 64-bit) boundary
  39  */
  40 __wsum csum_partial_copy_nocheck(const void *src, void *dst,
  41                                  int len, __wsum sum);
  42
  43 long __csum_partial_copy_from_user(const void __user *src,
  44                                    void *dst, int len,
  45                                    __wsum sum);
  46
  47 static inline __wsum
  48 csum_partial_copy_from_user(const void __user *src,
  49                             void *dst, int len,
  50                             __wsum sum, int *err)
  51 {
  52         long ret = __csum_partial_copy_from_user(src, dst, len, sum);
  53         if (ret < 0)
  54                 *err = -EFAULT;
  55         return (__force __wsum) ret;
  56 }
  57
  58 /*
  59  *      Copy and checksum to user
  60  */
  61 #define HAVE_CSUM_COPY_USER
  62 long __csum_partial_copy_to_user(const void *src,
  63                                  void __user *dst, int len,
  64                                  __wsum sum);
  65
  66 static inline __wsum
  67 csum_and_copy_to_user(const void *src,
  68                       void __user *dst, int len,
  69                       __wsum sum, int *err)
  70 {
  71         long ret = __csum_partial_copy_to_user(src, dst, len, sum);
  72         if (ret < 0)
  73                 *err = -EFAULT;
  74         return (__force __wsum) ret;
  75 }
  76
  77 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
  78  * the majority of the time.
  79  */
  80 __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  81
  82 /* Fold a partial checksum without adding pseudo headers. */
  83 static inline __sum16 csum_fold(__wsum sum)
  84 {
  85         unsigned int tmp;
  86
  87         __asm__ __volatile__(
  88 "       addcc           %0, %1, %1\n"
  89 "       srl             %1, 16, %1\n"
  90 "       addc            %1, %%g0, %1\n"
  91 "       xnor            %%g0, %1, %0\n"
  92         : "=&r" (sum), "=r" (tmp)
  93         : "0" (sum), "1" ((__force u32)sum<<16)
  94         : "cc");
  95         return (__force __sum16)sum;
  96 }
  97
  98 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
  99                                         __u32 len, __u8 proto,
 100                                         __wsum sum)
 101 {
 102         __asm__ __volatile__(
 103 "       addcc           %1, %0, %0\n"
 104 "       addccc          %2, %0, %0\n"
 105 "       addccc          %3, %0, %0\n"
 106 "       addc            %0, %%g0, %0\n"
 107         : "=r" (sum), "=r" (saddr)
 108         : "r" (daddr), "r" (proto + len), "0" (sum), "1" (saddr)
 109         : "cc");
 110         return sum;
 111 }
 112
 113 /*
 114  * computes the checksum of the TCP/UDP pseudo-header
 115  * returns a 16-bit checksum, already complemented
 116  */
 117 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 118                                         __u32 len, __u8 proto,
 119                                         __wsum sum)
 120 {
 121         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 122 }
 123
 124 #define _HAVE_ARCH_IPV6_CSUM
 125
 126 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 127                                       const struct in6_addr *daddr,
 128                                       __u32 len, __u8 proto, __wsum sum)
 129 {
 130         __asm__ __volatile__ (
 131 "       addcc           %3, %4, %%g7\n"
 132 "       addccc          %5, %%g7, %%g7\n"
 133 "       lduw            [%2 + 0x0c], %%g2\n"
 134 "       lduw            [%2 + 0x08], %%g3\n"
 135 "       addccc          %%g2, %%g7, %%g7\n"
 136 "       lduw            [%2 + 0x04], %%g2\n"
 137 "       addccc          %%g3, %%g7, %%g7\n"
 138 "       lduw            [%2 + 0x00], %%g3\n"
 139 "       addccc          %%g2, %%g7, %%g7\n"
 140 "       lduw            [%1 + 0x0c], %%g2\n"
 141 "       addccc          %%g3, %%g7, %%g7\n"
 142 "       lduw            [%1 + 0x08], %%g3\n"
 143 "       addccc          %%g2, %%g7, %%g7\n"
 144 "       lduw            [%1 + 0x04], %%g2\n"
 145 "       addccc          %%g3, %%g7, %%g7\n"
 146 "       lduw            [%1 + 0x00], %%g3\n"
 147 "       addccc          %%g2, %%g7, %%g7\n"
 148 "       addccc          %%g3, %%g7, %0\n"
 149 "       addc            0, %0, %0\n"
 150         : "=&r" (sum)
 151         : "r" (saddr), "r" (daddr), "r"(htonl(len)),
 152           "r"(htonl(proto)), "r"(sum)
 153         : "g2", "g3", "g7", "cc");
 154
 155         return csum_fold(sum);
 156 }
 157
 158 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
 159 static inline __sum16 ip_compute_csum(const void *buff, int len)
 160 {
 161         return csum_fold(csum_partial(buff, len, 0));
 162 }
 163
 164 #define HAVE_ARCH_CSUM_ADD
 165 static inline __wsum csum_add(__wsum csum, __wsum addend)
 166 {
 167         __asm__ __volatile__(
 168                 "addcc   %0, %1, %0\n"
 169                 "addx    %0, %%g0, %0"
 170                 : "=r" (csum)
 171                 : "r" (addend), "0" (csum));
 172
 173         return csum;
 174 }
 175
 176 #endif /* !(__SPARC64_CHECKSUM_H) */