summaryrefslogtreecommitdiffstats
path: root/arch/x86_64/lib/csum-copy_64.S
blob: f0dba36578ea0765827efc68f9448dd38f12e6f0 (plain)
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
/*
 * 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/dwarf2.h>
#include <asm/errno.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:
	.section __ex_table,"a"
	.align 8
	.quad 10b,.Lbad_source
	.previous
	.endm
		
	.macro dest
20:
	.section __ex_table,"a"
	.align 8
	.quad 20b,.Lbad_dest
	.previous
	.endm
			
	.macro ignore L=.Lignore
30:
	.section __ex_table,"a"
	.align 8
	.quad 30b,\L
	.previous
	.endm
	
				
ENTRY(csum_partial_copy_generic)
	CFI_STARTPROC
	cmpl	 $3*64,%edx
	jle	 .Lignore

.Lignore:		
	subq  $7*8,%rsp
	CFI_ADJUST_CFA_OFFSET 7*8
	movq  %rbx,2*8(%rsp)
	CFI_REL_OFFSET rbx, 2*8
	movq  %r12,3*8(%rsp)
	CFI_REL_OFFSET r12, 3*8
	movq  %r14,4*8(%rsp)
	CFI_REL_OFFSET r14, 4*8
	movq  %r13,5*8(%rsp)
	CFI_REL_OFFSET r13, 5*8
	movq  %rbp,6*8(%rsp)
	CFI_REL_OFFSET rbp, 6*8

	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 upto 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 upto 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:
	testl $1,%r10d
	jz    .Lende
	xorl  %ebx,%ebx
	source
	movb (%rdi),%bl
	dest
	movb %bl,(%rsi)
	addl %ebx,%eax
	adcl %r9d,%eax		/* carry */
			
	CFI_REMEMBER_STATE
.Lende:
	movq 2*8(%rsp),%rbx
	CFI_RESTORE rbx
	movq 3*8(%rsp),%r12
	CFI_RESTORE r12
	movq 4*8(%rsp),%r14
	CFI_RESTORE r14
	movq 5*8(%rsp),%r13
	CFI_RESTORE r13
	movq 6*8(%rsp),%rbp
	CFI_RESTORE rbp
	addq $7*8,%rsp
	CFI_ADJUST_CFA_OFFSET -7*8
	ret
	CFI_RESTORE_STATE

	/* 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
	CFI_ENDPROC
ENDPROC(csum_partial_copy_generic)