LXR linux/arch/sparc/include/asm/checksum

   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. */
  51static 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
  66static 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 */
  85static 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
  94static 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 */
 127static 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
 133static 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) */
 145