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 unsigned int csum_partial(const unsigned char * buff, int len, unsigned int 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 unsigned int csum_partial_copy_nocheck(const unsigned char *src,
  42                                               unsigned char *dst,
  43                                               int len, unsigned int sum);
  44
  45 extern long __csum_partial_copy_from_user(const unsigned char __user *src,
  46                                           unsigned char *dst, int len,
  47                                           unsigned int sum);
  48
  49 static inline unsigned int
  50 csum_partial_copy_from_user(const unsigned char __user *src,
  51                             unsigned char *dst, int len,
  52                             unsigned int sum, int *err)
  53 {
  54         long ret = __csum_partial_copy_from_user(src, dst, len, sum);
  55         if (ret < 0)
  56                 *err = -EFAULT;
  57         return (unsigned int) ret;
  58 }
  59
  60 /*
  61  *      Copy and checksum to user
  62  */
  63 #define HAVE_CSUM_COPY_USER
  64 extern long __csum_partial_copy_to_user(const unsigned char *src,
  65                                         unsigned char __user *dst, int len,
  66                                           unsigned int sum);
  67
  68 static inline unsigned int
  69 csum_and_copy_to_user(const unsigned char *src,
  70                       unsigned char __user *dst, int len,
  71                       unsigned int sum, int *err)
  72 {
  73         long ret = __csum_partial_copy_to_user(src, dst, len, sum);
  74         if (ret < 0)
  75                 *err = -EFAULT;
  76         return (unsigned int) ret;
  77 }
  78
  79 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
  80  * the majority of the time.
  81  */
  82 extern unsigned short ip_fast_csum(__const__ unsigned char *iph,
  83                                    unsigned int ihl);
  84
  85 /* Fold a partial checksum without adding pseudo headers. */
  86 static inline unsigned short csum_fold(unsigned int sum)
  87 {
  88         unsigned int tmp;
  89
  90         __asm__ __volatile__(
  91 "       addcc           %0, %1, %1\n"
  92 "       srl             %1, 16, %1\n"
  93 "       addc            %1, %%g0, %1\n"
  94 "       xnor            %%g0, %1, %0\n"
  95         : "=&r" (sum), "=r" (tmp)
  96         : "0" (sum), "1" (sum<<16)
  97         : "cc");
  98         return (sum & 0xffff);
  99 }
 100
 101 static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
 102                                                unsigned long daddr,
 103                                                unsigned int len,
 104                                                unsigned short proto,
 105                                                unsigned int sum)
 106 {
 107         __asm__ __volatile__(
 108 "       addcc           %1, %0, %0\n"
 109 "       addccc          %2, %0, %0\n"
 110 "       addccc          %3, %0, %0\n"
 111 "       addc            %0, %%g0, %0\n"
 112         : "=r" (sum), "=r" (saddr)
 113         : "r" (daddr), "r" ((proto<<16)+len), "0" (sum), "1" (saddr)
 114         : "cc");
 115         return sum;
 116 }
 117
 118 /*
 119  * computes the checksum of the TCP/UDP pseudo-header
 120  * returns a 16-bit checksum, already complemented
 121  */
 122 static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
 123                                                    unsigned long daddr,
 124                                                    unsigned short len,
 125                                                    unsigned short proto,
 126                                                    unsigned int sum)
 127 {
 128         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 129 }
 130
 131 #define _HAVE_ARCH_IPV6_CSUM
 132
 133 static inline unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
 134                                                  struct in6_addr *daddr,
 135                                                  __u32 len,
 136                                                  unsigned short proto,
 137                                                  unsigned int sum)
 138 {
 139         __asm__ __volatile__ (
 140 "       addcc           %3, %4, %%g7\n"
 141 "       addccc          %5, %%g7, %%g7\n"
 142 "       lduw            [%2 + 0x0c], %%g2\n"
 143 "       lduw            [%2 + 0x08], %%g3\n"
 144 "       addccc          %%g2, %%g7, %%g7\n"
 145 "       lduw            [%2 + 0x04], %%g2\n"
 146 "       addccc          %%g3, %%g7, %%g7\n"
 147 "       lduw            [%2 + 0x00], %%g3\n"
 148 "       addccc          %%g2, %%g7, %%g7\n"
 149 "       lduw            [%1 + 0x0c], %%g2\n"
 150 "       addccc          %%g3, %%g7, %%g7\n"
 151 "       lduw            [%1 + 0x08], %%g3\n"
 152 "       addccc          %%g2, %%g7, %%g7\n"
 153 "       lduw            [%1 + 0x04], %%g2\n"
 154 "       addccc          %%g3, %%g7, %%g7\n"
 155 "       lduw            [%1 + 0x00], %%g3\n"
 156 "       addccc          %%g2, %%g7, %%g7\n"
 157 "       addccc          %%g3, %%g7, %0\n"
 158 "       addc            0, %0, %0\n"
 159         : "=&r" (sum)
 160         : "r" (saddr), "r" (daddr), "r"(htonl(len)),
 161           "r"(htonl(proto)), "r"(sum)
 162         : "g2", "g3", "g7", "cc");
 163
 164         return csum_fold(sum);
 165 }
 166
 167 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
 168 static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
 169 {
 170         return csum_fold(csum_partial(buff, len, 0));
 171 }
 172
 173 #endif /* !(__SPARC64_CHECKSUM_H) */