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_sparc64(const char *src, char *dst, int len, unsigned int sum);
  42
  43 static inline unsigned int
  44 csum_partial_copy_nocheck (const char *src, char *dst, int len,
  45                            unsigned int sum)
  46 {
  47         int ret;
  48         unsigned char cur_ds = get_thread_current_ds();
  49         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "i" (ASI_P));
  50         ret = csum_partial_copy_sparc64(src, dst, len, sum);
  51         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" (cur_ds));
  52         return ret;
  53 }
  54
  55 static inline unsigned int
  56 csum_partial_copy_from_user(const char __user *src, char *dst, int len,
  57                             unsigned int sum, int *err)
  58 {
  59         __asm__ __volatile__ ("stx      %0, [%%sp + 0x7ff + 128]"
  60                               : : "r" (err));
  61         return csum_partial_copy_sparc64((__force const char *) src,
  62                                          dst, len, sum);
  63 }
  64
  65 /*
  66  *      Copy and checksum to user
  67  */
  68 #define HAVE_CSUM_COPY_USER
  69 extern unsigned int csum_partial_copy_user_sparc64(const char *src, char __user *dst, int len, unsigned int sum);
  70
  71 static inline unsigned int
  72 csum_and_copy_to_user(const char *src, char __user *dst, int len,
  73                       unsigned int sum, int *err)
  74 {
  75         __asm__ __volatile__ ("stx      %0, [%%sp + 0x7ff + 128]"
  76                               : : "r" (err));
  77         return csum_partial_copy_user_sparc64(src, dst, len, sum);
  78 }
  79
  80 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
  81  * the majority of the time.
  82  */
  83 extern unsigned short ip_fast_csum(__const__ unsigned char *iph,
  84                                    unsigned int ihl);
  85
  86 /* Fold a partial checksum without adding pseudo headers. */
  87 static inline unsigned short csum_fold(unsigned int sum)
  88 {
  89         unsigned int tmp;
  90
  91         __asm__ __volatile__(
  92 "       addcc           %0, %1, %1\n"
  93 "       srl             %1, 16, %1\n"
  94 "       addc            %1, %%g0, %1\n"
  95 "       xnor            %%g0, %1, %0\n"
  96         : "=&r" (sum), "=r" (tmp)
  97         : "0" (sum), "1" (sum<<16)
  98         : "cc");
  99         return (sum & 0xffff);
 100 }
 101
 102 static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
 103                                                unsigned long daddr,
 104                                                unsigned int len,
 105                                                unsigned short proto,
 106                                                unsigned int sum)
 107 {
 108         __asm__ __volatile__(
 109 "       addcc           %1, %0, %0\n"
 110 "       addccc          %2, %0, %0\n"
 111 "       addccc          %3, %0, %0\n"
 112 "       addc            %0, %%g0, %0\n"
 113         : "=r" (sum), "=r" (saddr)
 114         : "r" (daddr), "r" ((proto<<16)+len), "0" (sum), "1" (saddr)
 115         : "cc");
 116         return sum;
 117 }
 118
 119 /*
 120  * computes the checksum of the TCP/UDP pseudo-header
 121  * returns a 16-bit checksum, already complemented
 122  */
 123 static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
 124                                                    unsigned long daddr,
 125                                                    unsigned short len,
 126                                                    unsigned short proto,
 127                                                    unsigned int sum)
 128 {
 129         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 130 }
 131
 132 #define _HAVE_ARCH_IPV6_CSUM
 133
 134 static inline unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
 135                                                  struct in6_addr *daddr,
 136                                                  __u32 len,
 137                                                  unsigned short proto,
 138                                                  unsigned int sum)
 139 {
 140         __asm__ __volatile__ (
 141 "       addcc           %3, %4, %%g7\n"
 142 "       addccc          %5, %%g7, %%g7\n"
 143 "       lduw            [%2 + 0x0c], %%g2\n"
 144 "       lduw            [%2 + 0x08], %%g3\n"
 145 "       addccc          %%g2, %%g7, %%g7\n"
 146 "       lduw            [%2 + 0x04], %%g2\n"
 147 "       addccc          %%g3, %%g7, %%g7\n"
 148 "       lduw            [%2 + 0x00], %%g3\n"
 149 "       addccc          %%g2, %%g7, %%g7\n"
 150 "       lduw            [%1 + 0x0c], %%g2\n"
 151 "       addccc          %%g3, %%g7, %%g7\n"
 152 "       lduw            [%1 + 0x08], %%g3\n"
 153 "       addccc          %%g2, %%g7, %%g7\n"
 154 "       lduw            [%1 + 0x04], %%g2\n"
 155 "       addccc          %%g3, %%g7, %%g7\n"
 156 "       lduw            [%1 + 0x00], %%g3\n"
 157 "       addccc          %%g2, %%g7, %%g7\n"
 158 "       addccc          %%g3, %%g7, %0\n"
 159 "       addc            0, %0, %0\n"
 160         : "=&r" (sum)
 161         : "r" (saddr), "r" (daddr), "r"(htonl(len)),
 162           "r"(htonl(proto)), "r"(sum)
 163         : "g2", "g3", "g7", "cc");
 164
 165         return csum_fold(sum);
 166 }
 167
 168 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
 169 static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
 170 {
 171         return csum_fold(csum_partial(buff, len, 0));
 172 }
 173
 174 #endif /* !(__SPARC64_CHECKSUM_H) */