Blame view

kernel/linux-rt-4.4.41/arch/arc/include/asm/checksum.h 2.47 KB
5113f6f70   김현기   kernel add
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
  /*
   * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   *
   * 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.
   *
   * Joern Rennecke  <joern.rennecke@embecosm.com>: Jan 2012
   *  -Insn Scheduling improvements to csum core routines.
   *      = csum_fold( ) largely derived from ARM version.
   *      = ip_fast_cum( ) to have module scheduling
   *  -gcc 4.4.x broke networking. Alias analysis needed to be primed.
   *   worked around by adding memory clobber to ip_fast_csum( )
   *
   * vineetg: May 2010
   *  -Rewrote ip_fast_cscum( ) and csum_fold( ) with fast inline asm
   */
  
  #ifndef _ASM_ARC_CHECKSUM_H
  #define _ASM_ARC_CHECKSUM_H
  
  /*
   *	Fold a partial checksum
   *
   *  The 2 swords comprising the 32bit sum are added, any carry to 16th bit
   *  added back and final sword result inverted.
   */
  static inline __sum16 csum_fold(__wsum s)
  {
  	unsigned r = s << 16 | s >> 16;	/* ror */
  	s = ~s;
  	s -= r;
  	return s >> 16;
  }
  
  /*
   *	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)
  {
  	const void *ptr = iph;
  	unsigned int tmp, tmp2, sum;
  
  	__asm__(
  	"	ld.ab  %0, [%3, 4]		
  "
  	"	ld.ab  %2, [%3, 4]		
  "
  	"	sub    %1, %4, 2		
  "
  	"	lsr.f  lp_count, %1, 1		
  "
  	"	bcc    0f			
  "
  	"	add.f  %0, %0, %2		
  "
  	"	ld.ab  %2, [%3, 4]		
  "
  	"0:	lp     1f			
  "
  	"	ld.ab  %1, [%3, 4]		
  "
  	"	adc.f  %0, %0, %2		
  "
  	"	ld.ab  %2, [%3, 4]		
  "
  	"	adc.f  %0, %0, %1		
  "
  	"1:	adc.f  %0, %0, %2		
  "
  	"	add.cs %0,%0,1			
  "
  	: "=&r"(sum), "=r"(tmp), "=&r"(tmp2), "+&r" (ptr)
  	: "r"(ihl)
  	: "cc", "lp_count", "memory");
  
  	return csum_fold(sum);
  }
  
  /*
   * TCP pseudo Header is 12 bytes:
   * SA [4], DA [4], zeroes [1], Proto[1], TCP Seg(hdr+data) Len [2]
   */
  static inline __wsum
  csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
  		   unsigned short proto, __wsum sum)
  {
  	__asm__ __volatile__(
  	"	add.f %0, %0, %1	
  "
  	"	adc.f %0, %0, %2	
  "
  	"	adc.f %0, %0, %3	
  "
  	"	adc.f %0, %0, %4	
  "
  	"	adc   %0, %0, 0		
  "
  	: "+&r"(sum)
  	: "r"(saddr), "r"(daddr),
  #ifdef CONFIG_CPU_BIG_ENDIAN
  	  "r"(len),
  #else
  	  "r"(len << 8),
  #endif
  	  "r"(htons(proto))
  	: "cc");
  
  	return sum;
  }
  
  #define csum_fold csum_fold
  #define ip_fast_csum ip_fast_csum
  #define csum_tcpudp_nofold csum_tcpudp_nofold
  
  #include <asm-generic/checksum.h>
  
  #endif /* _ASM_ARC_CHECKSUM_H */