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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 | #ifndef _S390_CHECKSUM_H
#define _S390_CHECKSUM_H
/*
* include/asm-s390/checksum.h
* S390 fast network checksum routines
* see also arch/S390/lib/checksum.c
*
* S390 version
* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Ulrich Hild (first version)
* Martin Schwidefsky (heavily optimized CKSM version)
* D.J. Barrow (third attempt)
*/
#include <asm/uaccess.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
*/
static inline unsigned int
csum_partial(const unsigned char * buff, int len, unsigned int sum)
{
/*
* Experiments with ethernet and slip connections show that buf
* is aligned on either a 2-byte or 4-byte boundary.
*/
#ifndef __s390x__
register_pair rp;
rp.subreg.even = (unsigned long) buff;
rp.subreg.odd = (unsigned long) len;
__asm__ __volatile__ (
"0: cksm %0,%1\n" /* do checksum on longs */
" jo 0b\n"
: "+&d" (sum), "+&a" (rp) : : "cc", "memory" );
#else /* __s390x__ */
__asm__ __volatile__ (
" lgr 2,%1\n" /* address in gpr 2 */
" lgfr 3,%2\n" /* length in gpr 3 */
"0: cksm %0,2\n" /* do checksum on longs */
" jo 0b\n"
: "+&d" (sum)
: "d" (buff), "d" (len)
: "cc", "memory", "2", "3" );
#endif /* __s390x__ */
return sum;
}
/*
* csum_partial as an inline function
*/
static inline unsigned int
csum_partial_inline(const unsigned char * buff, int len, unsigned int sum)
{
#ifndef __s390x__
register_pair rp;
rp.subreg.even = (unsigned long) buff;
rp.subreg.odd = (unsigned long) len;
__asm__ __volatile__ (
"0: cksm %0,%1\n" /* do checksum on longs */
" jo 0b\n"
: "+&d" (sum), "+&a" (rp) : : "cc", "memory" );
#else /* __s390x__ */
__asm__ __volatile__ (
" lgr 2,%1\n" /* address in gpr 2 */
" lgfr 3,%2\n" /* length in gpr 3 */
"0: cksm %0,2\n" /* do checksum on longs */
" jo 0b\n"
: "+&d" (sum)
: "d" (buff), "d" (len)
: "cc", "memory", "2", "3" );
#endif /* __s390x__ */
return sum;
}
/*
* the same as csum_partial_copy, but copies from user space.
*
* here even more important to align src and dst on a 32-bit (or even
* better 64-bit) boundary
*
* Copy from userspace and compute checksum. If we catch an exception
* then zero the rest of the buffer.
*/
static inline unsigned int
csum_partial_copy_from_user(const char __user *src, char *dst,
int len, unsigned int sum,
int *err_ptr)
{
int missing;
missing = copy_from_user(dst, src, len);
if (missing) {
memset(dst + len - missing, 0, missing);
*err_ptr = -EFAULT;
}
return csum_partial(dst, len, sum);
}
static inline unsigned int
csum_partial_copy_nocheck (const char *src, char *dst, int len, unsigned int sum)
{
memcpy(dst,src,len);
return csum_partial_inline(dst, len, sum);
}
/*
* Fold a partial checksum without adding pseudo headers
*/
static inline unsigned short
csum_fold(unsigned int sum)
{
#ifndef __s390x__
register_pair rp;
__asm__ __volatile__ (
" slr %N1,%N1\n" /* %0 = H L */
" lr %1,%0\n" /* %0 = H L, %1 = H L 0 0 */
" srdl %1,16\n" /* %0 = H L, %1 = 0 H L 0 */
" alr %1,%N1\n" /* %0 = H L, %1 = L H L 0 */
" alr %0,%1\n" /* %0 = H+L+C L+H */
" srl %0,16\n" /* %0 = H+L+C */
: "+&d" (sum), "=d" (rp) : : "cc" );
#else /* __s390x__ */
__asm__ __volatile__ (
" sr 3,3\n" /* %0 = H*65536 + L */
" lr 2,%0\n" /* %0 = H L, R2/R3 = H L / 0 0 */
" srdl 2,16\n" /* %0 = H L, R2/R3 = 0 H / L 0 */
" alr 2,3\n" /* %0 = H L, R2/R3 = L H / L 0 */
" alr %0,2\n" /* %0 = H+L+C L+H */
" srl %0,16\n" /* %0 = H+L+C */
: "+&d" (sum) : : "cc", "2", "3");
#endif /* __s390x__ */
return ((unsigned short) ~sum);
}
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*
*/
static inline unsigned short
ip_fast_csum(unsigned char *iph, unsigned int ihl)
{
unsigned long sum;
#ifndef __s390x__
register_pair rp;
rp.subreg.even = (unsigned long) iph;
rp.subreg.odd = (unsigned long) ihl*4;
__asm__ __volatile__ (
" sr %0,%0\n" /* set sum to zero */
"0: cksm %0,%1\n" /* do checksum on longs */
" jo 0b\n"
: "=&d" (sum), "+&a" (rp) : : "cc", "memory" );
#else /* __s390x__ */
__asm__ __volatile__ (
" slgr %0,%0\n" /* set sum to zero */
" lgr 2,%1\n" /* address in gpr 2 */
" lgfr 3,%2\n" /* length in gpr 3 */
"0: cksm %0,2\n" /* do checksum on ints */
" jo 0b\n"
: "=&d" (sum)
: "d" (iph), "d" (ihl*4)
: "cc", "memory", "2", "3" );
#endif /* __s390x__ */
return csum_fold(sum);
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 32-bit checksum
*/
static inline unsigned int
csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr,
unsigned short len, unsigned short proto,
unsigned int sum)
{
#ifndef __s390x__
__asm__ __volatile__ (
" alr %0,%1\n" /* sum += saddr */
" brc 12,0f\n"
" ahi %0,1\n" /* add carry */
"0:"
: "+&d" (sum) : "d" (saddr) : "cc" );
__asm__ __volatile__ (
" alr %0,%1\n" /* sum += daddr */
" brc 12,1f\n"
" ahi %0,1\n" /* add carry */
"1:"
: "+&d" (sum) : "d" (daddr) : "cc" );
__asm__ __volatile__ (
" alr %0,%1\n" /* sum += (len<<16) + (proto<<8) */
" brc 12,2f\n"
" ahi %0,1\n" /* add carry */
"2:"
: "+&d" (sum)
: "d" (((unsigned int) len<<16) + (unsigned int) proto)
: "cc" );
#else /* __s390x__ */
__asm__ __volatile__ (
" lgfr %0,%0\n"
" algr %0,%1\n" /* sum += saddr */
" brc 12,0f\n"
" aghi %0,1\n" /* add carry */
"0: algr %0,%2\n" /* sum += daddr */
" brc 12,1f\n"
" aghi %0,1\n" /* add carry */
"1: algfr %0,%3\n" /* sum += (len<<16) + proto */
" brc 12,2f\n"
" aghi %0,1\n" /* add carry */
"2: srlg 0,%0,32\n"
" alr %0,0\n" /* fold to 32 bits */
" brc 12,3f\n"
" ahi %0,1\n" /* add carry */
"3: llgfr %0,%0"
: "+&d" (sum)
: "d" (saddr), "d" (daddr),
"d" (((unsigned int) len<<16) + (unsigned int) proto)
: "cc", "0" );
#endif /* __s390x__ */
return sum;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline unsigned short int
csum_tcpudp_magic(unsigned long saddr, unsigned long daddr,
unsigned short len, unsigned short proto,
unsigned int 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 unsigned short
ip_compute_csum(unsigned char * buff, int len)
{
return csum_fold(csum_partial(buff, len, 0));
}
#endif /* _S390_CHECKSUM_H */
|