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d2912cb1 | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
75494230 NP |
2 | /* |
3 | * linux/arch/arm/lib/memmove.S | |
4 | * | |
5 | * Author: Nicolas Pitre | |
6 | * Created: Sep 28, 2005 | |
7 | * Copyright: (C) MontaVista Software Inc. | |
75494230 NP |
8 | */ |
9 | ||
10 | #include <linux/linkage.h> | |
11 | #include <asm/assembler.h> | |
207a6cb0 | 12 | #include <asm/unwind.h> |
75494230 | 13 | |
75494230 NP |
14 | .text |
15 | ||
16 | /* | |
17 | * Prototype: void *memmove(void *dest, const void *src, size_t n); | |
18 | * | |
19 | * Note: | |
20 | * | |
21 | * If the memory regions don't overlap, we simply branch to memcpy which is | |
22 | * normally a bit faster. Otherwise the copy is done going downwards. This | |
23 | * is a transposition of the code from copy_template.S but with the copy | |
24 | * occurring in the opposite direction. | |
25 | */ | |
26 | ||
d6d51a96 | 27 | ENTRY(__memmove) |
735e8d93 | 28 | WEAK(memmove) |
207a6cb0 | 29 | UNWIND( .fnstart ) |
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30 | |
31 | subs ip, r0, r1 | |
32 | cmphi r2, ip | |
d6d51a96 | 33 | bls __memcpy |
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34 | |
35 | stmfd sp!, {r0, r4, lr} | |
207a6cb0 LY |
36 | UNWIND( .fnend ) |
37 | ||
38 | UNWIND( .fnstart ) | |
39 | UNWIND( .save {r0, r4, lr} ) @ in first stmfd block | |
75494230 NP |
40 | add r1, r1, r2 |
41 | add r0, r0, r2 | |
42 | subs r2, r2, #4 | |
43 | blt 8f | |
44 | ands ip, r0, #3 | |
45 | PLD( pld [r1, #-4] ) | |
46 | bne 9f | |
47 | ands ip, r1, #3 | |
48 | bne 10f | |
49 | ||
50 | 1: subs r2, r2, #(28) | |
51 | stmfd sp!, {r5 - r8} | |
207a6cb0 LY |
52 | UNWIND( .fnend ) |
53 | ||
54 | UNWIND( .fnstart ) | |
55 | UNWIND( .save {r0, r4, lr} ) | |
56 | UNWIND( .save {r5 - r8} ) @ in second stmfd block | |
75494230 NP |
57 | blt 5f |
58 | ||
2239aff6 | 59 | CALGN( ands ip, r0, #31 ) |
e44fc388 | 60 | CALGN( sbcsne r4, ip, r2 ) @ C is always set here |
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61 | CALGN( bcs 2f ) |
62 | CALGN( adr r4, 6f ) | |
63 | CALGN( subs r2, r2, ip ) @ C is set here | |
4c4925c1 | 64 | CALGN( rsb ip, ip, #32 ) |
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65 | CALGN( add pc, r4, ip ) |
66 | ||
67 | PLD( pld [r1, #-4] ) | |
68 | 2: PLD( subs r2, r2, #96 ) | |
69 | PLD( pld [r1, #-32] ) | |
70 | PLD( blt 4f ) | |
71 | PLD( pld [r1, #-64] ) | |
72 | PLD( pld [r1, #-96] ) | |
73 | ||
74 | 3: PLD( pld [r1, #-128] ) | |
75 | 4: ldmdb r1!, {r3, r4, r5, r6, r7, r8, ip, lr} | |
76 | subs r2, r2, #32 | |
77 | stmdb r0!, {r3, r4, r5, r6, r7, r8, ip, lr} | |
78 | bge 3b | |
79 | PLD( cmn r2, #96 ) | |
80 | PLD( bge 4b ) | |
81 | ||
82 | 5: ands ip, r2, #28 | |
83 | rsb ip, ip, #32 | |
84 | addne pc, pc, ip @ C is always clear here | |
85 | b 7f | |
fd522a8d | 86 | 6: W(nop) |
8b592783 CM |
87 | W(ldr) r3, [r1, #-4]! |
88 | W(ldr) r4, [r1, #-4]! | |
89 | W(ldr) r5, [r1, #-4]! | |
90 | W(ldr) r6, [r1, #-4]! | |
91 | W(ldr) r7, [r1, #-4]! | |
92 | W(ldr) r8, [r1, #-4]! | |
93 | W(ldr) lr, [r1, #-4]! | |
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94 | |
95 | add pc, pc, ip | |
96 | nop | |
fd522a8d | 97 | W(nop) |
8b592783 CM |
98 | W(str) r3, [r0, #-4]! |
99 | W(str) r4, [r0, #-4]! | |
100 | W(str) r5, [r0, #-4]! | |
101 | W(str) r6, [r0, #-4]! | |
102 | W(str) r7, [r0, #-4]! | |
103 | W(str) r8, [r0, #-4]! | |
104 | W(str) lr, [r0, #-4]! | |
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105 | |
106 | CALGN( bcs 2b ) | |
107 | ||
108 | 7: ldmfd sp!, {r5 - r8} | |
207a6cb0 LY |
109 | UNWIND( .fnend ) @ end of second stmfd block |
110 | ||
111 | UNWIND( .fnstart ) | |
112 | UNWIND( .save {r0, r4, lr} ) @ still in first stmfd block | |
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113 | |
114 | 8: movs r2, r2, lsl #31 | |
e44fc388 SA |
115 | ldrbne r3, [r1, #-1]! |
116 | ldrbcs r4, [r1, #-1]! | |
117 | ldrbcs ip, [r1, #-1] | |
118 | strbne r3, [r0, #-1]! | |
119 | strbcs r4, [r0, #-1]! | |
120 | strbcs ip, [r0, #-1] | |
75494230 NP |
121 | ldmfd sp!, {r0, r4, pc} |
122 | ||
123 | 9: cmp ip, #2 | |
e44fc388 SA |
124 | ldrbgt r3, [r1, #-1]! |
125 | ldrbge r4, [r1, #-1]! | |
75494230 | 126 | ldrb lr, [r1, #-1]! |
e44fc388 SA |
127 | strbgt r3, [r0, #-1]! |
128 | strbge r4, [r0, #-1]! | |
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129 | subs r2, r2, ip |
130 | strb lr, [r0, #-1]! | |
131 | blt 8b | |
132 | ands ip, r1, #3 | |
133 | beq 1b | |
134 | ||
135 | 10: bic r1, r1, #3 | |
136 | cmp ip, #2 | |
137 | ldr r3, [r1, #0] | |
138 | beq 17f | |
139 | blt 18f | |
207a6cb0 | 140 | UNWIND( .fnend ) |
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141 | |
142 | ||
143 | .macro backward_copy_shift push pull | |
144 | ||
207a6cb0 LY |
145 | UNWIND( .fnstart ) |
146 | UNWIND( .save {r0, r4, lr} ) @ still in first stmfd block | |
75494230 NP |
147 | subs r2, r2, #28 |
148 | blt 14f | |
149 | ||
2239aff6 | 150 | CALGN( ands ip, r0, #31 ) |
e44fc388 | 151 | CALGN( sbcsne r4, ip, r2 ) @ C is always set here |
75494230 NP |
152 | CALGN( subcc r2, r2, ip ) |
153 | CALGN( bcc 15f ) | |
154 | ||
155 | 11: stmfd sp!, {r5 - r9} | |
207a6cb0 LY |
156 | UNWIND( .fnend ) |
157 | ||
158 | UNWIND( .fnstart ) | |
159 | UNWIND( .save {r0, r4, lr} ) | |
160 | UNWIND( .save {r5 - r9} ) @ in new second stmfd block | |
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161 | |
162 | PLD( pld [r1, #-4] ) | |
163 | PLD( subs r2, r2, #96 ) | |
164 | PLD( pld [r1, #-32] ) | |
165 | PLD( blt 13f ) | |
166 | PLD( pld [r1, #-64] ) | |
167 | PLD( pld [r1, #-96] ) | |
168 | ||
169 | 12: PLD( pld [r1, #-128] ) | |
170 | 13: ldmdb r1!, {r7, r8, r9, ip} | |
d98b90ea | 171 | mov lr, r3, lspush #\push |
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172 | subs r2, r2, #32 |
173 | ldmdb r1!, {r3, r4, r5, r6} | |
d98b90ea VK |
174 | orr lr, lr, ip, lspull #\pull |
175 | mov ip, ip, lspush #\push | |
176 | orr ip, ip, r9, lspull #\pull | |
177 | mov r9, r9, lspush #\push | |
178 | orr r9, r9, r8, lspull #\pull | |
179 | mov r8, r8, lspush #\push | |
180 | orr r8, r8, r7, lspull #\pull | |
181 | mov r7, r7, lspush #\push | |
182 | orr r7, r7, r6, lspull #\pull | |
183 | mov r6, r6, lspush #\push | |
184 | orr r6, r6, r5, lspull #\pull | |
185 | mov r5, r5, lspush #\push | |
186 | orr r5, r5, r4, lspull #\pull | |
187 | mov r4, r4, lspush #\push | |
188 | orr r4, r4, r3, lspull #\pull | |
75494230 NP |
189 | stmdb r0!, {r4 - r9, ip, lr} |
190 | bge 12b | |
191 | PLD( cmn r2, #96 ) | |
192 | PLD( bge 13b ) | |
193 | ||
194 | ldmfd sp!, {r5 - r9} | |
207a6cb0 LY |
195 | UNWIND( .fnend ) @ end of the second stmfd block |
196 | ||
197 | UNWIND( .fnstart ) | |
198 | UNWIND( .save {r0, r4, lr} ) @ still in first stmfd block | |
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199 | |
200 | 14: ands ip, r2, #28 | |
201 | beq 16f | |
202 | ||
d98b90ea | 203 | 15: mov lr, r3, lspush #\push |
75494230 NP |
204 | ldr r3, [r1, #-4]! |
205 | subs ip, ip, #4 | |
d98b90ea | 206 | orr lr, lr, r3, lspull #\pull |
75494230 NP |
207 | str lr, [r0, #-4]! |
208 | bgt 15b | |
209 | CALGN( cmp r2, #0 ) | |
210 | CALGN( bge 11b ) | |
211 | ||
212 | 16: add r1, r1, #(\pull / 8) | |
213 | b 8b | |
207a6cb0 | 214 | UNWIND( .fnend ) |
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215 | |
216 | .endm | |
217 | ||
218 | ||
219 | backward_copy_shift push=8 pull=24 | |
220 | ||
221 | 17: backward_copy_shift push=16 pull=16 | |
222 | ||
223 | 18: backward_copy_shift push=24 pull=8 | |
224 | ||
93ed3970 | 225 | ENDPROC(memmove) |
d6d51a96 | 226 | ENDPROC(__memmove) |