include/asm-sparc64/checksum.h

   1 /* $Id: checksum.h,v 1.19 2002/02/09 19:49:31 davem Exp $ */
   2 #ifndef __SPARC64_CHECKSUM_H
   3 #define __SPARC64_CHECKSUM_H
   4
   5 /*  checksum.h:  IP/UDP/TCP checksum routines on the V9.
   6  *
   7  *  Copyright(C) 1995 Linus Torvalds
   8  *  Copyright(C) 1995 Miguel de Icaza
   9  *  Copyright(C) 1996 David S. Miller
  10  *  Copyright(C) 1996 Eddie C. Dost
  11  *  Copyright(C) 1997 Jakub Jelinek
  12  *
  13  * derived from:
  14  *      Alpha checksum c-code
  15  *      ix86 inline assembly
  16  *      RFC1071 Computing the Internet Checksum
  17  */
  18
  19 #include <linux/in6.h>
  20 #include <asm/uaccess.h>
  21
  22 /* computes the checksum of a memory block at buff, length len,
  23  * and adds in "sum" (32-bit)
  24  *
  25  * returns a 32-bit number suitable for feeding into itself
  26  * or csum_tcpudp_magic
  27  *
  28  * this function must be called with even lengths, except
  29  * for the last fragment, which may be odd
  30  *
  31  * it's best to have buff aligned on a 32-bit boundary
  32  */
  33 extern __wsum csum_partial(const void * buff, int len, __wsum sum);
  34
  35 /* the same as csum_partial, but copies from user space while it
  36  * checksums
  37  *
  38  * here even more important to align src and dst on a 32-bit (or even
  39  * better 64-bit) boundary
  40  */
  41 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
  42                                               int len, __wsum sum);
  43
  44 extern long __csum_partial_copy_from_user(const void __user *src,
  45                                           void *dst, int len,
  46                                           __wsum sum);
  47
  48 static inline __wsum
  49 csum_partial_copy_from_user(const void __user *src,
  50                             void *dst, int len,
  51                             __wsum sum, int *err)
  52 {
  53         long ret = __csum_partial_copy_from_user(src, dst, len, sum);
  54         if (ret < 0)
  55                 *err = -EFAULT;
  56         return (__force __wsum) ret;
  57 }
  58
  59 /*
  60  *      Copy and checksum to user
  61  */
  62 #define HAVE_CSUM_COPY_USER
  63 extern long __csum_partial_copy_to_user(const void *src,
  64                                         void __user *dst, int len,
  65                                           __wsum sum);
  66
  67 static inline __wsum
  68 csum_and_copy_to_user(const void *src,
  69                       void __user *dst, int len,
  70                       __wsum sum, int *err)
  71 {
  72         long ret = __csum_partial_copy_to_user(src, dst, len, sum);
  73         if (ret < 0)
  74                 *err = -EFAULT;
  75         return (__force __wsum) ret;
  76 }
  77
  78 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
  79  * the majority of the time.
  80  */
  81 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  82
  83 /* Fold a partial checksum without adding pseudo headers. */
  84 static inline __sum16 csum_fold(__wsum sum)
  85 {
  86         unsigned int tmp;
  87
  88         __asm__ __volatile__(
  89 "       addcc           %0, %1, %1\n"
  90 "       srl             %1, 16, %1\n"
  91 "       addc            %1, %%g0, %1\n"
  92 "       xnor            %%g0, %1, %0\n"
  93         : "=&r" (sum), "=r" (tmp)
  94         : "0" (sum), "1" ((__force u32)sum<<16)
  95         : "cc");
  96         return (__force __sum16)sum;
  97 }
  98
  99 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 100                                                unsigned int len,
 101                                                unsigned short proto,
 102                                                __wsum sum)
 103 {
 104         __asm__ __volatile__(
 105 "       addcc           %1, %0, %0\n"
 106 "       addccc          %2, %0, %0\n"
 107 "       addccc          %3, %0, %0\n"
 108 "       addc            %0, %%g0, %0\n"
 109         : "=r" (sum), "=r" (saddr)
 110         : "r" (daddr), "r" (proto + len), "0" (sum), "1" (saddr)
 111         : "cc");
 112         return sum;
 113 }
 114
 115 /*
 116  * computes the checksum of the TCP/UDP pseudo-header
 117  * returns a 16-bit checksum, already complemented
 118  */
 119 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 120                                                    unsigned short len,
 121                                                    unsigned short proto,
 122                                                    __wsum sum)
 123 {
 124         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 125 }
 126
 127 #define _HAVE_ARCH_IPV6_CSUM
 128
 129 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 130                                       const struct in6_addr *daddr,
 131                                       __u32 len, unsigned short proto,
 132                                       __wsum sum)
 133 {
 134         __asm__ __volatile__ (
 135 "       addcc           %3, %4, %%g7\n"
 136 "       addccc          %5, %%g7, %%g7\n"
 137 "       lduw            [%2 + 0x0c], %%g2\n"
 138 "       lduw            [%2 + 0x08], %%g3\n"
 139 "       addccc          %%g2, %%g7, %%g7\n"
 140 "       lduw            [%2 + 0x04], %%g2\n"
 141 "       addccc          %%g3, %%g7, %%g7\n"
 142 "       lduw            [%2 + 0x00], %%g3\n"
 143 "       addccc          %%g2, %%g7, %%g7\n"
 144 "       lduw            [%1 + 0x0c], %%g2\n"
 145 "       addccc          %%g3, %%g7, %%g7\n"
 146 "       lduw            [%1 + 0x08], %%g3\n"
 147 "       addccc          %%g2, %%g7, %%g7\n"
 148 "       lduw            [%1 + 0x04], %%g2\n"
 149 "       addccc          %%g3, %%g7, %%g7\n"
 150 "       lduw            [%1 + 0x00], %%g3\n"
 151 "       addccc          %%g2, %%g7, %%g7\n"
 152 "       addccc          %%g3, %%g7, %0\n"
 153 "       addc            0, %0, %0\n"
 154         : "=&r" (sum)
 155         : "r" (saddr), "r" (daddr), "r"(htonl(len)),
 156           "r"(htonl(proto)), "r"(sum)
 157         : "g2", "g3", "g7", "cc");
 158
 159         return csum_fold(sum);
 160 }
 161
 162 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
 163 static inline __sum16 ip_compute_csum(const void *buff, int len)
 164 {
 165         return csum_fold(csum_partial(buff, len, 0));
 166 }
 167
 168 #endif /* !(__SPARC64_CHECKSUM_H) */