Blame view

kernel/linux-rt-4.4.41/arch/x86/lib/csum-copy_64.S 3.66 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
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
  /*
   * Copyright 2002, 2003 Andi Kleen, SuSE Labs.
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file COPYING in the main directory of this archive
   * for more details. No warranty for anything given at all.
   */
  #include <linux/linkage.h>
  #include <asm/errno.h>
  #include <asm/asm.h>
  
  /*
   * Checksum copy with exception handling.
   * On exceptions src_err_ptr or dst_err_ptr is set to -EFAULT and the
   * destination is zeroed.
   *
   * Input
   * rdi  source
   * rsi  destination
   * edx  len (32bit)
   * ecx  sum (32bit)
   * r8   src_err_ptr (int)
   * r9   dst_err_ptr (int)
   *
   * Output
   * eax  64bit sum. undefined in case of exception.
   *
   * Wrappers need to take care of valid exception sum and zeroing.
   * They also should align source or destination to 8 bytes.
   */
  
  	.macro source
  10:
  	_ASM_EXTABLE(10b, .Lbad_source)
  	.endm
  
  	.macro dest
  20:
  	_ASM_EXTABLE(20b, .Lbad_dest)
  	.endm
  
  	.macro ignore L=.Lignore
  30:
  	_ASM_EXTABLE(30b, \L)
  	.endm
  
  
  ENTRY(csum_partial_copy_generic)
  	cmpl	$3*64, %edx
  	jle	.Lignore
  
  .Lignore:
  	subq  $7*8, %rsp
  	movq  %rbx, 2*8(%rsp)
  	movq  %r12, 3*8(%rsp)
  	movq  %r14, 4*8(%rsp)
  	movq  %r13, 5*8(%rsp)
  	movq  %rbp, 6*8(%rsp)
  
  	movq  %r8, (%rsp)
  	movq  %r9, 1*8(%rsp)
  
  	movl  %ecx, %eax
  	movl  %edx, %ecx
  
  	xorl  %r9d, %r9d
  	movq  %rcx, %r12
  
  	shrq  $6, %r12
  	jz	.Lhandle_tail       /* < 64 */
  
  	clc
  
  	/* main loop. clear in 64 byte blocks */
  	/* r9: zero, r8: temp2, rbx: temp1, rax: sum, rcx: saved length */
  	/* r11:	temp3, rdx: temp4, r12 loopcnt */
  	/* r10:	temp5, rbp: temp6, r14 temp7, r13 temp8 */
  	.p2align 4
  .Lloop:
  	source
  	movq  (%rdi), %rbx
  	source
  	movq  8(%rdi), %r8
  	source
  	movq  16(%rdi), %r11
  	source
  	movq  24(%rdi), %rdx
  
  	source
  	movq  32(%rdi), %r10
  	source
  	movq  40(%rdi), %rbp
  	source
  	movq  48(%rdi), %r14
  	source
  	movq  56(%rdi), %r13
  
  	ignore 2f
  	prefetcht0 5*64(%rdi)
  2:
  	adcq  %rbx, %rax
  	adcq  %r8, %rax
  	adcq  %r11, %rax
  	adcq  %rdx, %rax
  	adcq  %r10, %rax
  	adcq  %rbp, %rax
  	adcq  %r14, %rax
  	adcq  %r13, %rax
  
  	decl %r12d
  
  	dest
  	movq %rbx, (%rsi)
  	dest
  	movq %r8, 8(%rsi)
  	dest
  	movq %r11, 16(%rsi)
  	dest
  	movq %rdx, 24(%rsi)
  
  	dest
  	movq %r10, 32(%rsi)
  	dest
  	movq %rbp, 40(%rsi)
  	dest
  	movq %r14, 48(%rsi)
  	dest
  	movq %r13, 56(%rsi)
  
  3:
  
  	leaq 64(%rdi), %rdi
  	leaq 64(%rsi), %rsi
  
  	jnz	.Lloop
  
  	adcq  %r9, %rax
  
  	/* do last up to 56 bytes */
  .Lhandle_tail:
  	/* ecx:	count */
  	movl %ecx, %r10d
  	andl $63, %ecx
  	shrl $3, %ecx
  	jz	.Lfold
  	clc
  	.p2align 4
  .Lloop_8:
  	source
  	movq (%rdi), %rbx
  	adcq %rbx, %rax
  	decl %ecx
  	dest
  	movq %rbx, (%rsi)
  	leaq 8(%rsi), %rsi /* preserve carry */
  	leaq 8(%rdi), %rdi
  	jnz	.Lloop_8
  	adcq %r9, %rax	/* add in carry */
  
  .Lfold:
  	/* reduce checksum to 32bits */
  	movl %eax, %ebx
  	shrq $32, %rax
  	addl %ebx, %eax
  	adcl %r9d, %eax
  
  	/* do last up to 6 bytes */
  .Lhandle_7:
  	movl %r10d, %ecx
  	andl $7, %ecx
  	shrl $1, %ecx
  	jz   .Lhandle_1
  	movl $2, %edx
  	xorl %ebx, %ebx
  	clc
  	.p2align 4
  .Lloop_1:
  	source
  	movw (%rdi), %bx
  	adcl %ebx, %eax
  	decl %ecx
  	dest
  	movw %bx, (%rsi)
  	leaq 2(%rdi), %rdi
  	leaq 2(%rsi), %rsi
  	jnz .Lloop_1
  	adcl %r9d, %eax	/* add in carry */
  
  	/* handle last odd byte */
  .Lhandle_1:
  	testb $1, %r10b
  	jz    .Lende
  	xorl  %ebx, %ebx
  	source
  	movb (%rdi), %bl
  	dest
  	movb %bl, (%rsi)
  	addl %ebx, %eax
  	adcl %r9d, %eax		/* carry */
  
  .Lende:
  	movq 2*8(%rsp), %rbx
  	movq 3*8(%rsp), %r12
  	movq 4*8(%rsp), %r14
  	movq 5*8(%rsp), %r13
  	movq 6*8(%rsp), %rbp
  	addq $7*8, %rsp
  	ret
  
  	/* Exception handlers. Very simple, zeroing is done in the wrappers */
  .Lbad_source:
  	movq (%rsp), %rax
  	testq %rax, %rax
  	jz   .Lende
  	movl $-EFAULT, (%rax)
  	jmp  .Lende
  
  .Lbad_dest:
  	movq 8(%rsp), %rax
  	testq %rax, %rax
  	jz   .Lende
  	movl $-EFAULT, (%rax)
  	jmp .Lende
  ENDPROC(csum_partial_copy_generic)