arch/sparc/include/asm/checksum_64.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   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 <linux/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 __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 __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
  42 __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len);
  43 __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len);
  44
  45 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
  46  * the majority of the time.
  47  */
  48 __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  49
  50 /* Fold a partial checksum without adding pseudo headers. */
  51 static inline __sum16 csum_fold(__wsum sum)
  52 {
  53         unsigned int tmp;
  54
  55         __asm__ __volatile__(
  56 "       addcc           %0, %1, %1\n"
  57 "       srl             %1, 16, %1\n"
  58 "       addc            %1, %%g0, %1\n"
  59 "       xnor            %%g0, %1, %0\n"
  60         : "=&r" (sum), "=r" (tmp)
  61         : "0" (sum), "1" ((__force u32)sum<<16)
  62         : "cc");
  63         return (__force __sum16)sum;
  64 }
  65
  66 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
  67                                         __u32 len, __u8 proto,
  68                                         __wsum sum)
  69 {
  70         __asm__ __volatile__(
  71 "       addcc           %1, %0, %0\n"
  72 "       addccc          %2, %0, %0\n"
  73 "       addccc          %3, %0, %0\n"
  74 "       addc            %0, %%g0, %0\n"
  75         : "=r" (sum), "=r" (saddr)
  76         : "r" (daddr), "r" (proto + len), "0" (sum), "1" (saddr)
  77         : "cc");
  78         return sum;
  79 }
  80
  81 /*
  82  * computes the checksum of the TCP/UDP pseudo-header
  83  * returns a 16-bit checksum, already complemented
  84  */
  85 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
  86                                         __u32 len, __u8 proto,
  87                                         __wsum sum)
  88 {
  89         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
  90 }
  91
  92 #define _HAVE_ARCH_IPV6_CSUM
  93
  94 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
  95                                       const struct in6_addr *daddr,
  96                                       __u32 len, __u8 proto, __wsum sum)
  97 {
  98         __asm__ __volatile__ (
  99 "       addcc           %3, %4, %%g7\n"
 100 "       addccc          %5, %%g7, %%g7\n"
 101 "       lduw            [%2 + 0x0c], %%g2\n"
 102 "       lduw            [%2 + 0x08], %%g3\n"
 103 "       addccc          %%g2, %%g7, %%g7\n"
 104 "       lduw            [%2 + 0x04], %%g2\n"
 105 "       addccc          %%g3, %%g7, %%g7\n"
 106 "       lduw            [%2 + 0x00], %%g3\n"
 107 "       addccc          %%g2, %%g7, %%g7\n"
 108 "       lduw            [%1 + 0x0c], %%g2\n"
 109 "       addccc          %%g3, %%g7, %%g7\n"
 110 "       lduw            [%1 + 0x08], %%g3\n"
 111 "       addccc          %%g2, %%g7, %%g7\n"
 112 "       lduw            [%1 + 0x04], %%g2\n"
 113 "       addccc          %%g3, %%g7, %%g7\n"
 114 "       lduw            [%1 + 0x00], %%g3\n"
 115 "       addccc          %%g2, %%g7, %%g7\n"
 116 "       addccc          %%g3, %%g7, %0\n"
 117 "       addc            0, %0, %0\n"
 118         : "=&r" (sum)
 119         : "r" (saddr), "r" (daddr), "r"(htonl(len)),
 120           "r"(htonl(proto)), "r"(sum)
 121         : "g2", "g3", "g7", "cc");
 122
 123         return csum_fold(sum);
 124 }
 125
 126 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
 127 static inline __sum16 ip_compute_csum(const void *buff, int len)
 128 {
 129         return csum_fold(csum_partial(buff, len, 0));
 130 }
 131
 132 #define HAVE_ARCH_CSUM_ADD
 133 static inline __wsum csum_add(__wsum csum, __wsum addend)
 134 {
 135         __asm__ __volatile__(
 136                 "addcc   %0, %1, %0\n"
 137                 "addx    %0, %%g0, %0"
 138                 : "=r" (csum)
 139                 : "r" (addend), "0" (csum));
 140
 141         return csum;
 142 }
 143
 144 #endif /* !(__SPARC64_CHECKSUM_H) */