Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 | /*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_AVR32_CHECKSUM_H
#define __ASM_AVR32_CHECKSUM_H
/*
* computes the checksum of a memory block at buff, length len,
* and adds in "sum" (32-bit)
*
* returns a 32-bit number suitable for feeding into itself
* or csum_tcpudp_magic
*
* this function must be called with even lengths, except
* for the last fragment, which may be odd
*
* it's best to have buff aligned on a 32-bit boundary
*/
__wsum csum_partial(const void *buff, int len, __wsum sum);
/*
* the same as csum_partial, but copies from src while it
* checksums, and handles user-space pointer exceptions correctly, when needed.
*
* here even more important to align src and dst on a 32-bit (or even
* better 64-bit) boundary
*/
__wsum csum_partial_copy_generic(const void *src, void *dst, int len,
__wsum sum, int *src_err_ptr,
int *dst_err_ptr);
/*
* Note: when you get a NULL pointer exception here this means someone
* passed in an incorrect kernel address to one of these functions.
*
* If you use these functions directly please don't forget the
* access_ok().
*/
static inline
__wsum csum_partial_copy_nocheck(const void *src, void *dst,
int len, __wsum sum)
{
return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
}
static inline
__wsum csum_partial_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *err_ptr)
{
return csum_partial_copy_generic((const void __force *)src, dst, len,
sum, err_ptr, NULL);
}
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*/
static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
unsigned int sum, tmp;
__asm__ __volatile__(
" ld.w %0, %1++\n"
" ld.w %3, %1++\n"
" sub %2, 4\n"
" add %0, %3\n"
" ld.w %3, %1++\n"
" adc %0, %0, %3\n"
" ld.w %3, %1++\n"
" adc %0, %0, %3\n"
" acr %0\n"
"1: ld.w %3, %1++\n"
" add %0, %3\n"
" acr %0\n"
" sub %2, 1\n"
" brne 1b\n"
" lsl %3, %0, 16\n"
" andl %0, 0\n"
" mov %2, 0xffff\n"
" add %0, %3\n"
" adc %0, %0, %2\n"
" com %0\n"
" lsr %0, 16\n"
: "=r"(sum), "=r"(iph), "=r"(ihl), "=r"(tmp)
: "1"(iph), "2"(ihl)
: "memory", "cc");
return (__force __sum16)sum;
}
/*
* Fold a partial checksum
*/
static inline __sum16 csum_fold(__wsum sum)
{
unsigned int tmp;
asm(" bfextu %1, %0, 0, 16\n"
" lsr %0, 16\n"
" add %0, %1\n"
" bfextu %1, %0, 16, 16\n"
" add %0, %1"
: "=&r"(sum), "=&r"(tmp)
: "0"(sum));
return (__force __sum16)~sum;
}
static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
unsigned short len,
unsigned short proto,
__wsum sum)
{
asm(" add %0, %1\n"
" adc %0, %0, %2\n"
" adc %0, %0, %3\n"
" acr %0"
: "=r"(sum)
: "r"(daddr), "r"(saddr), "r"(len + proto),
"0"(sum)
: "cc");
return sum;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
unsigned short len,
unsigned short proto,
__wsum sum)
{
return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
}
/*
* this routine is used for miscellaneous IP-like checksums, mainly
* in icmp.c
*/
static inline __sum16 ip_compute_csum(const void *buff, int len)
{
return csum_fold(csum_partial(buff, len, 0));
}
#endif /* __ASM_AVR32_CHECKSUM_H */
|