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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/entry-common.S | |
3 | * | |
4 | * Copyright (C) 2000 Russell King | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | #include <linux/config.h> | |
11 | ||
1da177e4 LT |
12 | #include <asm/unistd.h> |
13 | ||
14 | #include "entry-header.S" | |
15 | ||
1da177e4 LT |
16 | |
17 | .align 5 | |
18 | /* | |
19 | * This is the fast syscall return path. We do as little as | |
20 | * possible here, and this includes saving r0 back into the SVC | |
21 | * stack. | |
22 | */ | |
23 | ret_fast_syscall: | |
1ec42c0c | 24 | disable_irq @ disable interrupts |
1da177e4 LT |
25 | ldr r1, [tsk, #TI_FLAGS] |
26 | tst r1, #_TIF_WORK_MASK | |
27 | bne fast_work_pending | |
f4dc9a4c RK |
28 | |
29 | @ fast_restore_user_regs | |
30 | ldr r1, [sp, #S_OFF + S_PSR] @ get calling cpsr | |
31 | ldr lr, [sp, #S_OFF + S_PC]! @ get pc | |
32 | msr spsr_cxsf, r1 @ save in spsr_svc | |
33 | ldmdb sp, {r1 - lr}^ @ get calling r1 - lr | |
34 | mov r0, r0 | |
35 | add sp, sp, #S_FRAME_SIZE - S_PC | |
36 | movs pc, lr @ return & move spsr_svc into cpsr | |
1da177e4 LT |
37 | |
38 | /* | |
39 | * Ok, we need to do extra processing, enter the slow path. | |
40 | */ | |
41 | fast_work_pending: | |
42 | str r0, [sp, #S_R0+S_OFF]! @ returned r0 | |
43 | work_pending: | |
44 | tst r1, #_TIF_NEED_RESCHED | |
45 | bne work_resched | |
46 | tst r1, #_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | |
47 | beq no_work_pending | |
48 | mov r0, sp @ 'regs' | |
49 | mov r2, why @ 'syscall' | |
50 | bl do_notify_resume | |
a6c61e9d | 51 | b ret_slow_syscall @ Check work again |
1da177e4 LT |
52 | |
53 | work_resched: | |
54 | bl schedule | |
55 | /* | |
56 | * "slow" syscall return path. "why" tells us if this was a real syscall. | |
57 | */ | |
58 | ENTRY(ret_to_user) | |
59 | ret_slow_syscall: | |
1ec42c0c | 60 | disable_irq @ disable interrupts |
1da177e4 LT |
61 | ldr r1, [tsk, #TI_FLAGS] |
62 | tst r1, #_TIF_WORK_MASK | |
63 | bne work_pending | |
64 | no_work_pending: | |
f4dc9a4c RK |
65 | @ slow_restore_user_regs |
66 | ldr r1, [sp, #S_PSR] @ get calling cpsr | |
67 | ldr lr, [sp, #S_PC]! @ get pc | |
68 | msr spsr_cxsf, r1 @ save in spsr_svc | |
69 | ldmdb sp, {r0 - lr}^ @ get calling r1 - lr | |
70 | mov r0, r0 | |
71 | add sp, sp, #S_FRAME_SIZE - S_PC | |
72 | movs pc, lr @ return & move spsr_svc into cpsr | |
1da177e4 LT |
73 | |
74 | /* | |
75 | * This is how we return from a fork. | |
76 | */ | |
77 | ENTRY(ret_from_fork) | |
78 | bl schedule_tail | |
79 | get_thread_info tsk | |
80 | ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing | |
81 | mov why, #1 | |
82 | tst r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls? | |
83 | beq ret_slow_syscall | |
84 | mov r1, sp | |
85 | mov r0, #1 @ trace exit [IP = 1] | |
86 | bl syscall_trace | |
87 | b ret_slow_syscall | |
88 | ||
89 | ||
90 | #include "calls.S" | |
91 | ||
92 | /*============================================================================= | |
93 | * SWI handler | |
94 | *----------------------------------------------------------------------------- | |
95 | */ | |
96 | ||
97 | /* If we're optimising for StrongARM the resulting code won't | |
98 | run on an ARM7 and we can save a couple of instructions. | |
99 | --pb */ | |
100 | #ifdef CONFIG_CPU_ARM710 | |
3f2829a3 NP |
101 | #define A710(code...) code |
102 | .Larm710bug: | |
1da177e4 LT |
103 | ldmia sp, {r0 - lr}^ @ Get calling r0 - lr |
104 | mov r0, r0 | |
1da177e4 | 105 | add sp, sp, #S_FRAME_SIZE |
60ac133a | 106 | subs pc, lr, #4 |
1da177e4 | 107 | #else |
3f2829a3 | 108 | #define A710(code...) |
1da177e4 LT |
109 | #endif |
110 | ||
111 | .align 5 | |
112 | ENTRY(vector_swi) | |
f4dc9a4c RK |
113 | sub sp, sp, #S_FRAME_SIZE |
114 | stmia sp, {r0 - r12} @ Calling r0 - r12 | |
115 | add r8, sp, #S_PC | |
116 | stmdb r8, {sp, lr}^ @ Calling sp, lr | |
117 | mrs r8, spsr @ called from non-FIQ mode, so ok. | |
118 | str lr, [sp, #S_PC] @ Save calling PC | |
119 | str r8, [sp, #S_PSR] @ Save CPSR | |
120 | str r0, [sp, #S_OLD_R0] @ Save OLD_R0 | |
1da177e4 | 121 | zero_fp |
e0f9f4a6 RK |
122 | |
123 | /* | |
124 | * Get the system call number. | |
125 | */ | |
3f2829a3 | 126 | |
dd35afc2 | 127 | #if defined(CONFIG_OABI_COMPAT) |
3f2829a3 | 128 | |
dd35afc2 NP |
129 | /* |
130 | * If we have CONFIG_OABI_COMPAT then we need to look at the swi | |
131 | * value to determine if it is an EABI or an old ABI call. | |
132 | */ | |
133 | #ifdef CONFIG_ARM_THUMB | |
134 | tst r8, #PSR_T_BIT | |
135 | movne r10, #0 @ no thumb OABI emulation | |
136 | ldreq r10, [lr, #-4] @ get SWI instruction | |
137 | #else | |
138 | ldr r10, [lr, #-4] @ get SWI instruction | |
139 | A710( and ip, r10, #0x0f000000 @ check for SWI ) | |
140 | A710( teq ip, #0x0f000000 ) | |
141 | A710( bne .Larm710bug ) | |
142 | #endif | |
143 | ||
144 | #elif defined(CONFIG_AEABI) | |
145 | ||
146 | /* | |
147 | * Pure EABI user space always put syscall number into scno (r7). | |
148 | */ | |
3f2829a3 NP |
149 | A710( ldr ip, [lr, #-4] @ get SWI instruction ) |
150 | A710( and ip, ip, #0x0f000000 @ check for SWI ) | |
151 | A710( teq ip, #0x0f000000 ) | |
152 | A710( bne .Larm710bug ) | |
dd35afc2 | 153 | |
3f2829a3 | 154 | #elif defined(CONFIG_ARM_THUMB) |
dd35afc2 NP |
155 | |
156 | /* Legacy ABI only, possibly thumb mode. */ | |
e0f9f4a6 RK |
157 | tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs |
158 | addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in | |
159 | ldreq scno, [lr, #-4] | |
dd35afc2 | 160 | |
e0f9f4a6 | 161 | #else |
dd35afc2 NP |
162 | |
163 | /* Legacy ABI only. */ | |
e0f9f4a6 | 164 | ldr scno, [lr, #-4] @ get SWI instruction |
3f2829a3 NP |
165 | A710( and ip, scno, #0x0f000000 @ check for SWI ) |
166 | A710( teq ip, #0x0f000000 ) | |
167 | A710( bne .Larm710bug ) | |
dd35afc2 | 168 | |
e0f9f4a6 | 169 | #endif |
1da177e4 LT |
170 | |
171 | #ifdef CONFIG_ALIGNMENT_TRAP | |
172 | ldr ip, __cr_alignment | |
173 | ldr ip, [ip] | |
174 | mcr p15, 0, ip, c1, c0 @ update control register | |
175 | #endif | |
1ec42c0c | 176 | enable_irq |
1da177e4 | 177 | |
1da177e4 | 178 | get_thread_info tsk |
dd35afc2 | 179 | adr tbl, sys_call_table @ load syscall table pointer |
1da177e4 | 180 | ldr ip, [tsk, #TI_FLAGS] @ check for syscall tracing |
dd35afc2 NP |
181 | |
182 | #if defined(CONFIG_OABI_COMPAT) | |
183 | /* | |
184 | * If the swi argument is zero, this is an EABI call and we do nothing. | |
185 | * | |
186 | * If this is an old ABI call, get the syscall number into scno and | |
187 | * get the old ABI syscall table address. | |
188 | */ | |
189 | bics r10, r10, #0xff000000 | |
190 | eorne scno, r10, #__NR_OABI_SYSCALL_BASE | |
191 | ldrne tbl, =sys_oabi_call_table | |
192 | #elif !defined(CONFIG_AEABI) | |
1da177e4 | 193 | bic scno, scno, #0xff000000 @ mask off SWI op-code |
e0f9f4a6 | 194 | eor scno, scno, #__NR_SYSCALL_BASE @ check OS number |
3f2829a3 | 195 | #endif |
dd35afc2 | 196 | |
3f2829a3 | 197 | stmdb sp!, {r4, r5} @ push fifth and sixth args |
1da177e4 LT |
198 | tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls? |
199 | bne __sys_trace | |
200 | ||
1da177e4 | 201 | cmp scno, #NR_syscalls @ check upper syscall limit |
3f2829a3 | 202 | adr lr, ret_fast_syscall @ return address |
1da177e4 LT |
203 | ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine |
204 | ||
205 | add r1, sp, #S_OFF | |
206 | 2: mov why, #0 @ no longer a real syscall | |
e0f9f4a6 RK |
207 | cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE) |
208 | eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back | |
1da177e4 LT |
209 | bcs arm_syscall |
210 | b sys_ni_syscall @ not private func | |
211 | ||
212 | /* | |
213 | * This is the really slow path. We're going to be doing | |
214 | * context switches, and waiting for our parent to respond. | |
215 | */ | |
216 | __sys_trace: | |
217 | add r1, sp, #S_OFF | |
218 | mov r0, #0 @ trace entry [IP = 0] | |
219 | bl syscall_trace | |
220 | ||
221 | adr lr, __sys_trace_return @ return address | |
222 | add r1, sp, #S_R0 + S_OFF @ pointer to regs | |
223 | cmp scno, #NR_syscalls @ check upper syscall limit | |
224 | ldmccia r1, {r0 - r3} @ have to reload r0 - r3 | |
225 | ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine | |
226 | b 2b | |
227 | ||
228 | __sys_trace_return: | |
229 | str r0, [sp, #S_R0 + S_OFF]! @ save returned r0 | |
230 | mov r1, sp | |
231 | mov r0, #1 @ trace exit [IP = 1] | |
232 | bl syscall_trace | |
233 | b ret_slow_syscall | |
234 | ||
235 | .align 5 | |
236 | #ifdef CONFIG_ALIGNMENT_TRAP | |
237 | .type __cr_alignment, #object | |
238 | __cr_alignment: | |
239 | .word cr_alignment | |
dd35afc2 NP |
240 | #endif |
241 | .ltorg | |
242 | ||
243 | /* | |
244 | * This is the syscall table declaration for native ABI syscalls. | |
245 | * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall. | |
246 | */ | |
247 | #define ABI(native, compat) native | |
248 | #ifdef CONFIG_AEABI | |
249 | #define OBSOLETE(syscall) sys_ni_syscall | |
250 | #else | |
251 | #define OBSOLETE(syscall) syscall | |
1da177e4 LT |
252 | #endif |
253 | ||
254 | .type sys_call_table, #object | |
255 | ENTRY(sys_call_table) | |
256 | #include "calls.S" | |
dd35afc2 NP |
257 | #undef ABI |
258 | #undef OBSOLETE | |
1da177e4 LT |
259 | |
260 | /*============================================================================ | |
261 | * Special system call wrappers | |
262 | */ | |
263 | @ r0 = syscall number | |
567bd980 | 264 | @ r8 = syscall table |
1da177e4 LT |
265 | .type sys_syscall, #function |
266 | sys_syscall: | |
dd35afc2 | 267 | eor scno, r0, #__NR_OABI_SYSCALL_BASE |
1da177e4 LT |
268 | cmp scno, #__NR_syscall - __NR_SYSCALL_BASE |
269 | cmpne scno, #NR_syscalls @ check range | |
270 | stmloia sp, {r5, r6} @ shuffle args | |
271 | movlo r0, r1 | |
272 | movlo r1, r2 | |
273 | movlo r2, r3 | |
274 | movlo r3, r4 | |
275 | ldrlo pc, [tbl, scno, lsl #2] | |
276 | b sys_ni_syscall | |
277 | ||
278 | sys_fork_wrapper: | |
279 | add r0, sp, #S_OFF | |
280 | b sys_fork | |
281 | ||
282 | sys_vfork_wrapper: | |
283 | add r0, sp, #S_OFF | |
284 | b sys_vfork | |
285 | ||
286 | sys_execve_wrapper: | |
287 | add r3, sp, #S_OFF | |
288 | b sys_execve | |
289 | ||
290 | sys_clone_wrapper: | |
291 | add ip, sp, #S_OFF | |
292 | str ip, [sp, #4] | |
293 | b sys_clone | |
294 | ||
295 | sys_sigsuspend_wrapper: | |
296 | add r3, sp, #S_OFF | |
297 | b sys_sigsuspend | |
298 | ||
299 | sys_rt_sigsuspend_wrapper: | |
300 | add r2, sp, #S_OFF | |
301 | b sys_rt_sigsuspend | |
302 | ||
303 | sys_sigreturn_wrapper: | |
304 | add r0, sp, #S_OFF | |
305 | b sys_sigreturn | |
306 | ||
307 | sys_rt_sigreturn_wrapper: | |
308 | add r0, sp, #S_OFF | |
309 | b sys_rt_sigreturn | |
310 | ||
311 | sys_sigaltstack_wrapper: | |
312 | ldr r2, [sp, #S_OFF + S_SP] | |
313 | b do_sigaltstack | |
314 | ||
713c4815 NP |
315 | sys_statfs64_wrapper: |
316 | teq r1, #88 | |
317 | moveq r1, #84 | |
318 | b sys_statfs64 | |
319 | ||
320 | sys_fstatfs64_wrapper: | |
321 | teq r1, #88 | |
322 | moveq r1, #84 | |
323 | b sys_fstatfs64 | |
324 | ||
1da177e4 LT |
325 | /* |
326 | * Note: off_4k (r5) is always units of 4K. If we can't do the requested | |
327 | * offset, we return EINVAL. | |
328 | */ | |
329 | sys_mmap2: | |
330 | #if PAGE_SHIFT > 12 | |
331 | tst r5, #PGOFF_MASK | |
332 | moveq r5, r5, lsr #PAGE_SHIFT - 12 | |
333 | streq r5, [sp, #4] | |
334 | beq do_mmap2 | |
335 | mov r0, #-EINVAL | |
336 | RETINSTR(mov,pc, lr) | |
337 | #else | |
338 | str r5, [sp, #4] | |
339 | b do_mmap2 | |
340 | #endif | |
687ad019 NP |
341 | |
342 | #ifdef CONFIG_OABI_COMPAT | |
dd35afc2 | 343 | |
687ad019 NP |
344 | /* |
345 | * These are syscalls with argument register differences | |
346 | */ | |
347 | ||
348 | sys_oabi_pread64: | |
349 | stmia sp, {r3, r4} | |
350 | b sys_pread64 | |
351 | ||
352 | sys_oabi_pwrite64: | |
353 | stmia sp, {r3, r4} | |
354 | b sys_pwrite64 | |
355 | ||
356 | sys_oabi_truncate64: | |
357 | mov r3, r2 | |
358 | mov r2, r1 | |
359 | b sys_truncate64 | |
360 | ||
361 | sys_oabi_ftruncate64: | |
362 | mov r3, r2 | |
363 | mov r2, r1 | |
364 | b sys_ftruncate64 | |
365 | ||
366 | sys_oabi_readahead: | |
367 | str r3, [sp] | |
368 | mov r3, r2 | |
369 | mov r2, r1 | |
370 | b sys_readahead | |
371 | ||
dd35afc2 NP |
372 | /* |
373 | * Let's declare a second syscall table for old ABI binaries | |
374 | * using the compatibility syscall entries. | |
375 | */ | |
376 | #define ABI(native, compat) compat | |
377 | #define OBSOLETE(syscall) syscall | |
378 | ||
379 | .type sys_oabi_call_table, #object | |
380 | ENTRY(sys_oabi_call_table) | |
381 | #include "calls.S" | |
382 | #undef ABI | |
383 | #undef OBSOLETE | |
384 | ||
687ad019 NP |
385 | #endif |
386 |