LXR linux/arch/x86/um/asm/checksum

   1/*
   2 * Licensed under the GPL
   3 */
   4
   5#ifndef __UM_SYSDEP_CHECKSUM_H
   6#define __UM_SYSDEP_CHECKSUM_H
   7
   8static inline __sum16 ip_compute_csum(const void *buff, int len)
   9{
  10    return csum_fold (csum_partial(buff, len, 0));
  11}
  12
  13#define _HAVE_ARCH_IPV6_CSUM
  14static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
  15                                          const struct in6_addr *daddr,
  16                                          __u32 len, __u8 proto,
  17                                          __wsum sum)
  18{
  19        __asm__(
  20                "addl 0(%1), %0         ;\n"
  21                "adcl 4(%1), %0         ;\n"
  22                "adcl 8(%1), %0         ;\n"
  23                "adcl 12(%1), %0        ;\n"
  24                "adcl 0(%2), %0         ;\n"
  25                "adcl 4(%2), %0         ;\n"
  26                "adcl 8(%2), %0         ;\n"
  27                "adcl 12(%2), %0        ;\n"
  28                "adcl %3, %0            ;\n"
  29                "adcl %4, %0            ;\n"
  30                "adcl $0, %0            ;\n"
  31                : "=&r" (sum)
  32                : "r" (saddr), "r" (daddr),
  33                  "r"(htonl(len)), "r"(htonl(proto)), "0"(sum));
  34
  35        return csum_fold(sum);
  36}
  37
  38/*
  39 *      Copy and checksum to user
  40 */
  41#define HAVE_CSUM_COPY_USER
  42static __inline__ __wsum csum_and_copy_to_user(const void *src,
  43                                                     void __user *dst,
  44                                                     int len, __wsum sum, int *err_ptr)
  45{
  46        if (access_ok(VERIFY_WRITE, dst, len)) {
  47                if (copy_to_user(dst, src, len)) {
  48                        *err_ptr = -EFAULT;
  49                        return (__force __wsum)-1;
  50                }
  51
  52                return csum_partial(src, len, sum);
  53        }
  54
  55        if (len)
  56                *err_ptr = -EFAULT;
  57
  58        return (__force __wsum)-1; /* invalid checksum */
  59}
  60
  61#endif
  62