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75494230 NP |
1 | /* |
2 | * linux/arch/arm/lib/copy_template.s | |
3 | * | |
4 | * Code template for optimized memory copy functions | |
5 | * | |
6 | * Author: Nicolas Pitre | |
7 | * Created: Sep 28, 2005 | |
8 | * Copyright: MontaVista Software, Inc. | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | */ | |
14 | ||
75494230 NP |
15 | /* |
16 | * Theory of operation | |
17 | * ------------------- | |
18 | * | |
19 | * This file provides the core code for a forward memory copy used in | |
20 | * the implementation of memcopy(), copy_to_user() and copy_from_user(). | |
21 | * | |
22 | * The including file must define the following accessor macros | |
23 | * according to the need of the given function: | |
24 | * | |
25 | * ldr1w ptr reg abort | |
26 | * | |
27 | * This loads one word from 'ptr', stores it in 'reg' and increments | |
28 | * 'ptr' to the next word. The 'abort' argument is used for fixup tables. | |
29 | * | |
30 | * ldr4w ptr reg1 reg2 reg3 reg4 abort | |
31 | * ldr8w ptr, reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort | |
32 | * | |
33 | * This loads four or eight words starting from 'ptr', stores them | |
34 | * in provided registers and increments 'ptr' past those words. | |
35 | * The'abort' argument is used for fixup tables. | |
36 | * | |
37 | * ldr1b ptr reg cond abort | |
38 | * | |
39 | * Similar to ldr1w, but it loads a byte and increments 'ptr' one byte. | |
40 | * It also must apply the condition code if provided, otherwise the | |
41 | * "al" condition is assumed by default. | |
42 | * | |
43 | * str1w ptr reg abort | |
44 | * str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort | |
45 | * str1b ptr reg cond abort | |
46 | * | |
47 | * Same as their ldr* counterparts, but data is stored to 'ptr' location | |
48 | * rather than being loaded. | |
49 | * | |
50 | * enter reg1 reg2 | |
51 | * | |
52 | * Preserve the provided registers on the stack plus any additional | |
53 | * data as needed by the implementation including this code. Called | |
54 | * upon code entry. | |
55 | * | |
56 | * exit reg1 reg2 | |
57 | * | |
58 | * Restore registers with the values previously saved with the | |
59 | * 'preserv' macro. Called upon code termination. | |
8b592783 CM |
60 | * |
61 | * LDR1W_SHIFT | |
62 | * STR1W_SHIFT | |
63 | * | |
64 | * Correction to be applied to the "ip" register when branching into | |
65 | * the ldr1w or str1w instructions (some of these macros may expand to | |
66 | * than one 32bit instruction in Thumb-2) | |
75494230 NP |
67 | */ |
68 | ||
69 | ||
70 | enter r4, lr | |
71 | ||
72 | subs r2, r2, #4 | |
73 | blt 8f | |
74 | ands ip, r0, #3 | |
75 | PLD( pld [r1, #0] ) | |
76 | bne 9f | |
77 | ands ip, r1, #3 | |
78 | bne 10f | |
79 | ||
80 | 1: subs r2, r2, #(28) | |
81 | stmfd sp!, {r5 - r8} | |
82 | blt 5f | |
83 | ||
2239aff6 | 84 | CALGN( ands ip, r0, #31 ) |
75494230 NP |
85 | CALGN( rsb r3, ip, #32 ) |
86 | CALGN( sbcnes r4, r3, r2 ) @ C is always set here | |
87 | CALGN( bcs 2f ) | |
88 | CALGN( adr r4, 6f ) | |
89 | CALGN( subs r2, r2, r3 ) @ C gets set | |
90 | CALGN( add pc, r4, ip ) | |
91 | ||
92 | PLD( pld [r1, #0] ) | |
93 | 2: PLD( subs r2, r2, #96 ) | |
94 | PLD( pld [r1, #28] ) | |
95 | PLD( blt 4f ) | |
96 | PLD( pld [r1, #60] ) | |
97 | PLD( pld [r1, #92] ) | |
98 | ||
99 | 3: PLD( pld [r1, #124] ) | |
100 | 4: ldr8w r1, r3, r4, r5, r6, r7, r8, ip, lr, abort=20f | |
101 | subs r2, r2, #32 | |
102 | str8w r0, r3, r4, r5, r6, r7, r8, ip, lr, abort=20f | |
103 | bge 3b | |
104 | PLD( cmn r2, #96 ) | |
105 | PLD( bge 4b ) | |
106 | ||
107 | 5: ands ip, r2, #28 | |
108 | rsb ip, ip, #32 | |
8b592783 CM |
109 | #if LDR1W_SHIFT > 0 |
110 | lsl ip, ip, #LDR1W_SHIFT | |
111 | #endif | |
75494230 NP |
112 | addne pc, pc, ip @ C is always clear here |
113 | b 7f | |
8b592783 CM |
114 | 6: |
115 | .rept (1 << LDR1W_SHIFT) | |
116 | W(nop) | |
117 | .endr | |
75494230 NP |
118 | ldr1w r1, r3, abort=20f |
119 | ldr1w r1, r4, abort=20f | |
120 | ldr1w r1, r5, abort=20f | |
121 | ldr1w r1, r6, abort=20f | |
122 | ldr1w r1, r7, abort=20f | |
123 | ldr1w r1, r8, abort=20f | |
124 | ldr1w r1, lr, abort=20f | |
125 | ||
8b592783 CM |
126 | #if LDR1W_SHIFT < STR1W_SHIFT |
127 | lsl ip, ip, #STR1W_SHIFT - LDR1W_SHIFT | |
128 | #elif LDR1W_SHIFT > STR1W_SHIFT | |
129 | lsr ip, ip, #LDR1W_SHIFT - STR1W_SHIFT | |
130 | #endif | |
75494230 NP |
131 | add pc, pc, ip |
132 | nop | |
8b592783 CM |
133 | .rept (1 << STR1W_SHIFT) |
134 | W(nop) | |
135 | .endr | |
75494230 NP |
136 | str1w r0, r3, abort=20f |
137 | str1w r0, r4, abort=20f | |
138 | str1w r0, r5, abort=20f | |
139 | str1w r0, r6, abort=20f | |
140 | str1w r0, r7, abort=20f | |
141 | str1w r0, r8, abort=20f | |
142 | str1w r0, lr, abort=20f | |
143 | ||
144 | CALGN( bcs 2b ) | |
145 | ||
146 | 7: ldmfd sp!, {r5 - r8} | |
147 | ||
148 | 8: movs r2, r2, lsl #31 | |
149 | ldr1b r1, r3, ne, abort=21f | |
150 | ldr1b r1, r4, cs, abort=21f | |
151 | ldr1b r1, ip, cs, abort=21f | |
152 | str1b r0, r3, ne, abort=21f | |
153 | str1b r0, r4, cs, abort=21f | |
154 | str1b r0, ip, cs, abort=21f | |
155 | ||
156 | exit r4, pc | |
157 | ||
158 | 9: rsb ip, ip, #4 | |
159 | cmp ip, #2 | |
160 | ldr1b r1, r3, gt, abort=21f | |
161 | ldr1b r1, r4, ge, abort=21f | |
162 | ldr1b r1, lr, abort=21f | |
163 | str1b r0, r3, gt, abort=21f | |
164 | str1b r0, r4, ge, abort=21f | |
165 | subs r2, r2, ip | |
166 | str1b r0, lr, abort=21f | |
167 | blt 8b | |
168 | ands ip, r1, #3 | |
169 | beq 1b | |
170 | ||
171 | 10: bic r1, r1, #3 | |
172 | cmp ip, #2 | |
173 | ldr1w r1, lr, abort=21f | |
174 | beq 17f | |
175 | bgt 18f | |
176 | ||
177 | ||
178 | .macro forward_copy_shift pull push | |
179 | ||
180 | subs r2, r2, #28 | |
181 | blt 14f | |
182 | ||
2239aff6 | 183 | CALGN( ands ip, r0, #31 ) |
75494230 NP |
184 | CALGN( rsb ip, ip, #32 ) |
185 | CALGN( sbcnes r4, ip, r2 ) @ C is always set here | |
186 | CALGN( subcc r2, r2, ip ) | |
187 | CALGN( bcc 15f ) | |
188 | ||
189 | 11: stmfd sp!, {r5 - r9} | |
190 | ||
191 | PLD( pld [r1, #0] ) | |
192 | PLD( subs r2, r2, #96 ) | |
193 | PLD( pld [r1, #28] ) | |
194 | PLD( blt 13f ) | |
195 | PLD( pld [r1, #60] ) | |
196 | PLD( pld [r1, #92] ) | |
197 | ||
198 | 12: PLD( pld [r1, #124] ) | |
199 | 13: ldr4w r1, r4, r5, r6, r7, abort=19f | |
200 | mov r3, lr, pull #\pull | |
201 | subs r2, r2, #32 | |
202 | ldr4w r1, r8, r9, ip, lr, abort=19f | |
203 | orr r3, r3, r4, push #\push | |
204 | mov r4, r4, pull #\pull | |
205 | orr r4, r4, r5, push #\push | |
206 | mov r5, r5, pull #\pull | |
207 | orr r5, r5, r6, push #\push | |
208 | mov r6, r6, pull #\pull | |
209 | orr r6, r6, r7, push #\push | |
210 | mov r7, r7, pull #\pull | |
211 | orr r7, r7, r8, push #\push | |
212 | mov r8, r8, pull #\pull | |
213 | orr r8, r8, r9, push #\push | |
214 | mov r9, r9, pull #\pull | |
215 | orr r9, r9, ip, push #\push | |
216 | mov ip, ip, pull #\pull | |
217 | orr ip, ip, lr, push #\push | |
218 | str8w r0, r3, r4, r5, r6, r7, r8, r9, ip, , abort=19f | |
219 | bge 12b | |
220 | PLD( cmn r2, #96 ) | |
221 | PLD( bge 13b ) | |
222 | ||
223 | ldmfd sp!, {r5 - r9} | |
224 | ||
225 | 14: ands ip, r2, #28 | |
226 | beq 16f | |
227 | ||
228 | 15: mov r3, lr, pull #\pull | |
229 | ldr1w r1, lr, abort=21f | |
230 | subs ip, ip, #4 | |
231 | orr r3, r3, lr, push #\push | |
232 | str1w r0, r3, abort=21f | |
233 | bgt 15b | |
234 | CALGN( cmp r2, #0 ) | |
235 | CALGN( bge 11b ) | |
236 | ||
237 | 16: sub r1, r1, #(\push / 8) | |
238 | b 8b | |
239 | ||
240 | .endm | |
241 | ||
242 | ||
243 | forward_copy_shift pull=8 push=24 | |
244 | ||
245 | 17: forward_copy_shift pull=16 push=16 | |
246 | ||
247 | 18: forward_copy_shift pull=24 push=8 | |
248 | ||
249 | ||
250 | /* | |
7f927fcc | 251 | * Abort preamble and completion macros. |
75494230 NP |
252 | * If a fixup handler is required then those macros must surround it. |
253 | * It is assumed that the fixup code will handle the private part of | |
254 | * the exit macro. | |
255 | */ | |
256 | ||
257 | .macro copy_abort_preamble | |
258 | 19: ldmfd sp!, {r5 - r9} | |
259 | b 21f | |
260 | 20: ldmfd sp!, {r5 - r8} | |
261 | 21: | |
262 | .endm | |
263 | ||
264 | .macro copy_abort_end | |
265 | ldmfd sp!, {r4, pc} | |
266 | .endm | |
267 |