Commit | Line | Data |
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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 | */ | |
1da177e4 | 10 | |
6ebbf2ce | 11 | #include <asm/assembler.h> |
1da177e4 | 12 | #include <asm/unistd.h> |
395a59d0 | 13 | #include <asm/ftrace.h> |
c4c5716e | 14 | #include <asm/unwind.h> |
1da177e4 | 15 | |
13a5045d RH |
16 | #ifdef CONFIG_NEED_RET_TO_USER |
17 | #include <mach/entry-macro.S> | |
18 | #else | |
19 | .macro arch_ret_to_user, tmp1, tmp2 | |
20 | .endm | |
21 | #endif | |
22 | ||
1da177e4 LT |
23 | #include "entry-header.S" |
24 | ||
1da177e4 LT |
25 | |
26 | .align 5 | |
27 | /* | |
28 | * This is the fast syscall return path. We do as little as | |
29 | * possible here, and this includes saving r0 back into the SVC | |
30 | * stack. | |
31 | */ | |
32 | ret_fast_syscall: | |
c4c5716e CM |
33 | UNWIND(.fnstart ) |
34 | UNWIND(.cantunwind ) | |
1ec42c0c | 35 | disable_irq @ disable interrupts |
1b979372 RK |
36 | ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing |
37 | tst r1, #_TIF_SYSCALL_WORK | |
38 | bne __sys_trace_return | |
1da177e4 LT |
39 | tst r1, #_TIF_WORK_MASK |
40 | bne fast_work_pending | |
d13e5edd | 41 | asm_trace_hardirqs_on |
f4dc9a4c | 42 | |
f80dff9d DW |
43 | /* perform architecture specific actions before user return */ |
44 | arch_ret_to_user r1, lr | |
b0088480 | 45 | ct_user_enter |
f80dff9d | 46 | |
b86040a5 | 47 | restore_user_regs fast = 1, offset = S_OFF |
c4c5716e | 48 | UNWIND(.fnend ) |
1da177e4 LT |
49 | |
50 | /* | |
51 | * Ok, we need to do extra processing, enter the slow path. | |
52 | */ | |
53 | fast_work_pending: | |
54 | str r0, [sp, #S_R0+S_OFF]! @ returned r0 | |
55 | work_pending: | |
1da177e4 LT |
56 | mov r0, sp @ 'regs' |
57 | mov r2, why @ 'syscall' | |
0a267fa6 | 58 | bl do_work_pending |
66285217 | 59 | cmp r0, #0 |
81783786 | 60 | beq no_work_pending |
66285217 | 61 | movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE) |
81783786 AV |
62 | ldmia sp, {r0 - r6} @ have to reload r0 - r6 |
63 | b local_restart @ ... and off we go | |
e83dd377 | 64 | ENDPROC(ret_fast_syscall) |
81783786 | 65 | |
1da177e4 LT |
66 | /* |
67 | * "slow" syscall return path. "why" tells us if this was a real syscall. | |
68 | */ | |
69 | ENTRY(ret_to_user) | |
70 | ret_slow_syscall: | |
1ec42c0c | 71 | disable_irq @ disable interrupts |
9fc2552a | 72 | ENTRY(ret_to_user_from_irq) |
1da177e4 LT |
73 | ldr r1, [tsk, #TI_FLAGS] |
74 | tst r1, #_TIF_WORK_MASK | |
75 | bne work_pending | |
76 | no_work_pending: | |
d13e5edd | 77 | asm_trace_hardirqs_on |
651e9499 | 78 | |
f80dff9d DW |
79 | /* perform architecture specific actions before user return */ |
80 | arch_ret_to_user r1, lr | |
b0088480 | 81 | ct_user_enter save = 0 |
f80dff9d | 82 | |
b86040a5 | 83 | restore_user_regs fast = 0, offset = 0 |
9fc2552a | 84 | ENDPROC(ret_to_user_from_irq) |
93ed3970 | 85 | ENDPROC(ret_to_user) |
1da177e4 LT |
86 | |
87 | /* | |
88 | * This is how we return from a fork. | |
89 | */ | |
90 | ENTRY(ret_from_fork) | |
91 | bl schedule_tail | |
9fff2fa0 AV |
92 | cmp r5, #0 |
93 | movne r0, r4 | |
14327c66 | 94 | badrne lr, 1f |
6ebbf2ce | 95 | retne r5 |
68687c84 | 96 | 1: get_thread_info tsk |
1da177e4 | 97 | b ret_slow_syscall |
93ed3970 | 98 | ENDPROC(ret_from_fork) |
1da177e4 | 99 | |
fa1b4f91 AV |
100 | .equ NR_syscalls,0 |
101 | #define CALL(x) .equ NR_syscalls,NR_syscalls+1 | |
1da177e4 | 102 | #include "calls.S" |
1f66e06f WF |
103 | |
104 | /* | |
105 | * Ensure that the system call table is equal to __NR_syscalls, | |
106 | * which is the value the rest of the system sees | |
107 | */ | |
108 | .ifne NR_syscalls - __NR_syscalls | |
109 | .error "__NR_syscalls is not equal to the size of the syscall table" | |
110 | .endif | |
111 | ||
fa1b4f91 AV |
112 | #undef CALL |
113 | #define CALL(x) .long x | |
1da177e4 LT |
114 | |
115 | /*============================================================================= | |
116 | * SWI handler | |
117 | *----------------------------------------------------------------------------- | |
118 | */ | |
119 | ||
1da177e4 LT |
120 | .align 5 |
121 | ENTRY(vector_swi) | |
19c4d593 UKK |
122 | #ifdef CONFIG_CPU_V7M |
123 | v7m_exception_entry | |
124 | #else | |
f4dc9a4c RK |
125 | sub sp, sp, #S_FRAME_SIZE |
126 | stmia sp, {r0 - r12} @ Calling r0 - r12 | |
b86040a5 CM |
127 | ARM( add r8, sp, #S_PC ) |
128 | ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr | |
129 | THUMB( mov r8, sp ) | |
130 | THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr | |
f4dc9a4c RK |
131 | mrs r8, spsr @ called from non-FIQ mode, so ok. |
132 | str lr, [sp, #S_PC] @ Save calling PC | |
133 | str r8, [sp, #S_PSR] @ Save CPSR | |
134 | str r0, [sp, #S_OLD_R0] @ Save OLD_R0 | |
19c4d593 | 135 | #endif |
1da177e4 | 136 | zero_fp |
195b58ad | 137 | alignment_trap r10, ip, __cr_alignment |
1aa2b3b7 WD |
138 | enable_irq |
139 | ct_user_exit | |
140 | get_thread_info tsk | |
141 | ||
e0f9f4a6 RK |
142 | /* |
143 | * Get the system call number. | |
144 | */ | |
3f2829a3 | 145 | |
dd35afc2 | 146 | #if defined(CONFIG_OABI_COMPAT) |
3f2829a3 | 147 | |
dd35afc2 NP |
148 | /* |
149 | * If we have CONFIG_OABI_COMPAT then we need to look at the swi | |
150 | * value to determine if it is an EABI or an old ABI call. | |
151 | */ | |
152 | #ifdef CONFIG_ARM_THUMB | |
153 | tst r8, #PSR_T_BIT | |
154 | movne r10, #0 @ no thumb OABI emulation | |
1aa2b3b7 | 155 | USER( ldreq r10, [lr, #-4] ) @ get SWI instruction |
dd35afc2 | 156 | #else |
1aa2b3b7 | 157 | USER( ldr r10, [lr, #-4] ) @ get SWI instruction |
dd35afc2 | 158 | #endif |
457c2403 | 159 | ARM_BE8(rev r10, r10) @ little endian instruction |
dd35afc2 NP |
160 | |
161 | #elif defined(CONFIG_AEABI) | |
162 | ||
163 | /* | |
164 | * Pure EABI user space always put syscall number into scno (r7). | |
165 | */ | |
3f2829a3 | 166 | #elif defined(CONFIG_ARM_THUMB) |
dd35afc2 | 167 | /* Legacy ABI only, possibly thumb mode. */ |
e0f9f4a6 RK |
168 | tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs |
169 | addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in | |
1aa2b3b7 | 170 | USER( ldreq scno, [lr, #-4] ) |
dd35afc2 | 171 | |
e0f9f4a6 | 172 | #else |
dd35afc2 | 173 | /* Legacy ABI only. */ |
1aa2b3b7 | 174 | USER( ldr scno, [lr, #-4] ) @ get SWI instruction |
e0f9f4a6 | 175 | #endif |
1da177e4 | 176 | |
dd35afc2 | 177 | adr tbl, sys_call_table @ load syscall table pointer |
dd35afc2 NP |
178 | |
179 | #if defined(CONFIG_OABI_COMPAT) | |
180 | /* | |
181 | * If the swi argument is zero, this is an EABI call and we do nothing. | |
182 | * | |
183 | * If this is an old ABI call, get the syscall number into scno and | |
184 | * get the old ABI syscall table address. | |
185 | */ | |
186 | bics r10, r10, #0xff000000 | |
187 | eorne scno, r10, #__NR_OABI_SYSCALL_BASE | |
188 | ldrne tbl, =sys_oabi_call_table | |
189 | #elif !defined(CONFIG_AEABI) | |
1da177e4 | 190 | bic scno, scno, #0xff000000 @ mask off SWI op-code |
e0f9f4a6 | 191 | eor scno, scno, #__NR_SYSCALL_BASE @ check OS number |
3f2829a3 | 192 | #endif |
dd35afc2 | 193 | |
81783786 | 194 | local_restart: |
70c70d97 | 195 | ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing |
3f2829a3 | 196 | stmdb sp!, {r4, r5} @ push fifth and sixth args |
70c70d97 | 197 | |
29ef73b7 | 198 | tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls? |
1da177e4 LT |
199 | bne __sys_trace |
200 | ||
1da177e4 | 201 | cmp scno, #NR_syscalls @ check upper syscall limit |
14327c66 | 202 | badr 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 | |
d95bc250 | 206 | 2: cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE) |
e0f9f4a6 | 207 | eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back |
377747c4 | 208 | bcs arm_syscall |
d95bc250 | 209 | mov why, #0 @ no longer a real syscall |
1da177e4 | 210 | b sys_ni_syscall @ not private func |
1aa2b3b7 WD |
211 | |
212 | #if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI) | |
213 | /* | |
214 | * We failed to handle a fault trying to access the page | |
215 | * containing the swi instruction, but we're not really in a | |
216 | * position to return -EFAULT. Instead, return back to the | |
217 | * instruction and re-enter the user fault handling path trying | |
218 | * to page it in. This will likely result in sending SEGV to the | |
219 | * current task. | |
220 | */ | |
221 | 9001: | |
222 | sub lr, lr, #4 | |
223 | str lr, [sp, #S_PC] | |
224 | b ret_fast_syscall | |
225 | #endif | |
93ed3970 | 226 | ENDPROC(vector_swi) |
1da177e4 LT |
227 | |
228 | /* | |
229 | * This is the really slow path. We're going to be doing | |
230 | * context switches, and waiting for our parent to respond. | |
231 | */ | |
232 | __sys_trace: | |
ad722541 WD |
233 | mov r1, scno |
234 | add r0, sp, #S_OFF | |
235 | bl syscall_trace_enter | |
1da177e4 | 236 | |
14327c66 | 237 | badr lr, __sys_trace_return @ return address |
3f471126 | 238 | mov scno, r0 @ syscall number (possibly new) |
1da177e4 LT |
239 | add r1, sp, #S_R0 + S_OFF @ pointer to regs |
240 | cmp scno, #NR_syscalls @ check upper syscall limit | |
c7aa00db WD |
241 | ldmccia r1, {r0 - r6} @ have to reload r0 - r6 |
242 | stmccia sp, {r4, r5} @ and update the stack args | |
1da177e4 | 243 | ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine |
ad75b514 KC |
244 | cmp scno, #-1 @ skip the syscall? |
245 | bne 2b | |
246 | add sp, sp, #S_OFF @ restore stack | |
247 | b ret_slow_syscall | |
1da177e4 LT |
248 | |
249 | __sys_trace_return: | |
250 | str r0, [sp, #S_R0 + S_OFF]! @ save returned r0 | |
ad722541 WD |
251 | mov r0, sp |
252 | bl syscall_trace_exit | |
1da177e4 LT |
253 | b ret_slow_syscall |
254 | ||
255 | .align 5 | |
256 | #ifdef CONFIG_ALIGNMENT_TRAP | |
257 | .type __cr_alignment, #object | |
258 | __cr_alignment: | |
259 | .word cr_alignment | |
dd35afc2 NP |
260 | #endif |
261 | .ltorg | |
262 | ||
263 | /* | |
264 | * This is the syscall table declaration for native ABI syscalls. | |
265 | * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall. | |
266 | */ | |
267 | #define ABI(native, compat) native | |
268 | #ifdef CONFIG_AEABI | |
269 | #define OBSOLETE(syscall) sys_ni_syscall | |
270 | #else | |
271 | #define OBSOLETE(syscall) syscall | |
1da177e4 LT |
272 | #endif |
273 | ||
274 | .type sys_call_table, #object | |
275 | ENTRY(sys_call_table) | |
276 | #include "calls.S" | |
dd35afc2 NP |
277 | #undef ABI |
278 | #undef OBSOLETE | |
1da177e4 LT |
279 | |
280 | /*============================================================================ | |
281 | * Special system call wrappers | |
282 | */ | |
283 | @ r0 = syscall number | |
567bd980 | 284 | @ r8 = syscall table |
1da177e4 | 285 | sys_syscall: |
5247593c | 286 | bic scno, r0, #__NR_OABI_SYSCALL_BASE |
1da177e4 LT |
287 | cmp scno, #__NR_syscall - __NR_SYSCALL_BASE |
288 | cmpne scno, #NR_syscalls @ check range | |
289 | stmloia sp, {r5, r6} @ shuffle args | |
290 | movlo r0, r1 | |
291 | movlo r1, r2 | |
292 | movlo r2, r3 | |
293 | movlo r3, r4 | |
294 | ldrlo pc, [tbl, scno, lsl #2] | |
295 | b sys_ni_syscall | |
93ed3970 | 296 | ENDPROC(sys_syscall) |
1da177e4 | 297 | |
1da177e4 LT |
298 | sys_sigreturn_wrapper: |
299 | add r0, sp, #S_OFF | |
653d48b2 | 300 | mov why, #0 @ prevent syscall restart handling |
1da177e4 | 301 | b sys_sigreturn |
93ed3970 | 302 | ENDPROC(sys_sigreturn_wrapper) |
1da177e4 LT |
303 | |
304 | sys_rt_sigreturn_wrapper: | |
305 | add r0, sp, #S_OFF | |
653d48b2 | 306 | mov why, #0 @ prevent syscall restart handling |
1da177e4 | 307 | b sys_rt_sigreturn |
93ed3970 | 308 | ENDPROC(sys_rt_sigreturn_wrapper) |
1da177e4 | 309 | |
713c4815 NP |
310 | sys_statfs64_wrapper: |
311 | teq r1, #88 | |
312 | moveq r1, #84 | |
313 | b sys_statfs64 | |
93ed3970 | 314 | ENDPROC(sys_statfs64_wrapper) |
713c4815 NP |
315 | |
316 | sys_fstatfs64_wrapper: | |
317 | teq r1, #88 | |
318 | moveq r1, #84 | |
319 | b sys_fstatfs64 | |
93ed3970 | 320 | ENDPROC(sys_fstatfs64_wrapper) |
713c4815 | 321 | |
1da177e4 LT |
322 | /* |
323 | * Note: off_4k (r5) is always units of 4K. If we can't do the requested | |
324 | * offset, we return EINVAL. | |
325 | */ | |
326 | sys_mmap2: | |
327 | #if PAGE_SHIFT > 12 | |
328 | tst r5, #PGOFF_MASK | |
329 | moveq r5, r5, lsr #PAGE_SHIFT - 12 | |
330 | streq r5, [sp, #4] | |
f8b72560 | 331 | beq sys_mmap_pgoff |
1da177e4 | 332 | mov r0, #-EINVAL |
6ebbf2ce | 333 | ret lr |
1da177e4 LT |
334 | #else |
335 | str r5, [sp, #4] | |
f8b72560 | 336 | b sys_mmap_pgoff |
1da177e4 | 337 | #endif |
93ed3970 | 338 | ENDPROC(sys_mmap2) |
687ad019 NP |
339 | |
340 | #ifdef CONFIG_OABI_COMPAT | |
dd35afc2 | 341 | |
687ad019 NP |
342 | /* |
343 | * These are syscalls with argument register differences | |
344 | */ | |
345 | ||
346 | sys_oabi_pread64: | |
347 | stmia sp, {r3, r4} | |
348 | b sys_pread64 | |
93ed3970 | 349 | ENDPROC(sys_oabi_pread64) |
687ad019 NP |
350 | |
351 | sys_oabi_pwrite64: | |
352 | stmia sp, {r3, r4} | |
353 | b sys_pwrite64 | |
93ed3970 | 354 | ENDPROC(sys_oabi_pwrite64) |
687ad019 NP |
355 | |
356 | sys_oabi_truncate64: | |
357 | mov r3, r2 | |
358 | mov r2, r1 | |
359 | b sys_truncate64 | |
93ed3970 | 360 | ENDPROC(sys_oabi_truncate64) |
687ad019 NP |
361 | |
362 | sys_oabi_ftruncate64: | |
363 | mov r3, r2 | |
364 | mov r2, r1 | |
365 | b sys_ftruncate64 | |
93ed3970 | 366 | ENDPROC(sys_oabi_ftruncate64) |
687ad019 NP |
367 | |
368 | sys_oabi_readahead: | |
369 | str r3, [sp] | |
370 | mov r3, r2 | |
371 | mov r2, r1 | |
372 | b sys_readahead | |
93ed3970 | 373 | ENDPROC(sys_oabi_readahead) |
687ad019 | 374 | |
dd35afc2 NP |
375 | /* |
376 | * Let's declare a second syscall table for old ABI binaries | |
377 | * using the compatibility syscall entries. | |
378 | */ | |
379 | #define ABI(native, compat) compat | |
380 | #define OBSOLETE(syscall) syscall | |
381 | ||
382 | .type sys_oabi_call_table, #object | |
383 | ENTRY(sys_oabi_call_table) | |
384 | #include "calls.S" | |
385 | #undef ABI | |
386 | #undef OBSOLETE | |
387 | ||
687ad019 NP |
388 | #endif |
389 |