Merge branch 'for-linus/samsung4' of git://git.fluff.org/bjdooks/linux
[linux-2.6-block.git] / arch / arm / kernel / entry-common.S
CommitLineData
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
1da177e4 11#include <asm/unistd.h>
395a59d0 12#include <asm/ftrace.h>
a09e64fb 13#include <mach/entry-macro.S>
c4c5716e 14#include <asm/unwind.h>
1da177e4
LT
15
16#include "entry-header.S"
17
1da177e4
LT
18
19 .align 5
20/*
21 * This is the fast syscall return path. We do as little as
22 * possible here, and this includes saving r0 back into the SVC
23 * stack.
24 */
25ret_fast_syscall:
c4c5716e
CM
26 UNWIND(.fnstart )
27 UNWIND(.cantunwind )
1ec42c0c 28 disable_irq @ disable interrupts
1da177e4
LT
29 ldr r1, [tsk, #TI_FLAGS]
30 tst r1, #_TIF_WORK_MASK
31 bne fast_work_pending
f4dc9a4c 32
f80dff9d
DW
33 /* perform architecture specific actions before user return */
34 arch_ret_to_user r1, lr
35
b86040a5 36 restore_user_regs fast = 1, offset = S_OFF
c4c5716e 37 UNWIND(.fnend )
1da177e4
LT
38
39/*
40 * Ok, we need to do extra processing, enter the slow path.
41 */
42fast_work_pending:
43 str r0, [sp, #S_R0+S_OFF]! @ returned r0
44work_pending:
45 tst r1, #_TIF_NEED_RESCHED
46 bne work_resched
d0420c83 47 tst r1, #_TIF_SIGPENDING|_TIF_NOTIFY_RESUME
1da177e4
LT
48 beq no_work_pending
49 mov r0, sp @ 'regs'
50 mov r2, why @ 'syscall'
51 bl do_notify_resume
a6c61e9d 52 b ret_slow_syscall @ Check work again
1da177e4
LT
53
54work_resched:
55 bl schedule
56/*
57 * "slow" syscall return path. "why" tells us if this was a real syscall.
58 */
59ENTRY(ret_to_user)
60ret_slow_syscall:
1ec42c0c 61 disable_irq @ disable interrupts
1da177e4
LT
62 ldr r1, [tsk, #TI_FLAGS]
63 tst r1, #_TIF_WORK_MASK
64 bne work_pending
65no_work_pending:
f80dff9d
DW
66 /* perform architecture specific actions before user return */
67 arch_ret_to_user r1, lr
68
b86040a5 69 restore_user_regs fast = 0, offset = 0
93ed3970 70ENDPROC(ret_to_user)
1da177e4
LT
71
72/*
73 * This is how we return from a fork.
74 */
75ENTRY(ret_from_fork)
76 bl schedule_tail
77 get_thread_info tsk
78 ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing
79 mov why, #1
80 tst r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
81 beq ret_slow_syscall
82 mov r1, sp
83 mov r0, #1 @ trace exit [IP = 1]
84 bl syscall_trace
85 b ret_slow_syscall
93ed3970 86ENDPROC(ret_from_fork)
1da177e4 87
fa1b4f91
AV
88 .equ NR_syscalls,0
89#define CALL(x) .equ NR_syscalls,NR_syscalls+1
1da177e4 90#include "calls.S"
fa1b4f91
AV
91#undef CALL
92#define CALL(x) .long x
1da177e4 93
606576ce 94#ifdef CONFIG_FUNCTION_TRACER
014c257c
AS
95#ifdef CONFIG_DYNAMIC_FTRACE
96ENTRY(mcount)
97 stmdb sp!, {r0-r3, lr}
98 mov r0, lr
395a59d0 99 sub r0, r0, #MCOUNT_INSN_SIZE
014c257c
AS
100
101 .globl mcount_call
102mcount_call:
103 bl ftrace_stub
d4cc510c 104 ldr lr, [fp, #-4] @ restore lr
014c257c
AS
105 ldmia sp!, {r0-r3, pc}
106
107ENTRY(ftrace_caller)
108 stmdb sp!, {r0-r3, lr}
109 ldr r1, [fp, #-4]
110 mov r0, lr
395a59d0 111 sub r0, r0, #MCOUNT_INSN_SIZE
014c257c
AS
112
113 .globl ftrace_call
114ftrace_call:
115 bl ftrace_stub
d4cc510c 116 ldr lr, [fp, #-4] @ restore lr
014c257c
AS
117 ldmia sp!, {r0-r3, pc}
118
119#else
120
181f817e
UKK
121ENTRY(__gnu_mcount_nc)
122 stmdb sp!, {r0-r3, lr}
123 ldr r0, =ftrace_trace_function
124 ldr r2, [r0]
125 adr r0, ftrace_stub
126 cmp r0, r2
127 bne gnu_trace
128 ldmia sp!, {r0-r3, ip, lr}
6176d394 129 mov pc, ip
181f817e
UKK
130
131gnu_trace:
132 ldr r1, [sp, #20] @ lr of instrumented routine
133 mov r0, lr
134 sub r0, r0, #MCOUNT_INSN_SIZE
135 mov lr, pc
136 mov pc, r2
137 ldmia sp!, {r0-r3, ip, lr}
6176d394 138 mov pc, ip
181f817e 139
014c257c
AS
140ENTRY(mcount)
141 stmdb sp!, {r0-r3, lr}
142 ldr r0, =ftrace_trace_function
143 ldr r2, [r0]
144 adr r0, ftrace_stub
145 cmp r0, r2
146 bne trace
d4cc510c 147 ldr lr, [fp, #-4] @ restore lr
014c257c
AS
148 ldmia sp!, {r0-r3, pc}
149
150trace:
b3c960b2 151 ldr r1, [fp, #-4] @ lr of instrumented routine
014c257c 152 mov r0, lr
395a59d0 153 sub r0, r0, #MCOUNT_INSN_SIZE
014c257c
AS
154 mov lr, pc
155 mov pc, r2
3ef7143d 156 ldr lr, [fp, #-4] @ restore lr
014c257c
AS
157 ldmia sp!, {r0-r3, pc}
158
159#endif /* CONFIG_DYNAMIC_FTRACE */
160
161 .globl ftrace_stub
162ftrace_stub:
163 mov pc, lr
164
606576ce 165#endif /* CONFIG_FUNCTION_TRACER */
014c257c 166
1da177e4
LT
167/*=============================================================================
168 * SWI handler
169 *-----------------------------------------------------------------------------
170 */
171
172 /* If we're optimising for StrongARM the resulting code won't
173 run on an ARM7 and we can save a couple of instructions.
174 --pb */
175#ifdef CONFIG_CPU_ARM710
3f2829a3
NP
176#define A710(code...) code
177.Larm710bug:
1da177e4
LT
178 ldmia sp, {r0 - lr}^ @ Get calling r0 - lr
179 mov r0, r0
1da177e4 180 add sp, sp, #S_FRAME_SIZE
60ac133a 181 subs pc, lr, #4
1da177e4 182#else
3f2829a3 183#define A710(code...)
1da177e4
LT
184#endif
185
186 .align 5
187ENTRY(vector_swi)
f4dc9a4c
RK
188 sub sp, sp, #S_FRAME_SIZE
189 stmia sp, {r0 - r12} @ Calling r0 - r12
b86040a5
CM
190 ARM( add r8, sp, #S_PC )
191 ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr
192 THUMB( mov r8, sp )
193 THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr
f4dc9a4c
RK
194 mrs r8, spsr @ called from non-FIQ mode, so ok.
195 str lr, [sp, #S_PC] @ Save calling PC
196 str r8, [sp, #S_PSR] @ Save CPSR
197 str r0, [sp, #S_OLD_R0] @ Save OLD_R0
1da177e4 198 zero_fp
e0f9f4a6
RK
199
200 /*
201 * Get the system call number.
202 */
3f2829a3 203
dd35afc2 204#if defined(CONFIG_OABI_COMPAT)
3f2829a3 205
dd35afc2
NP
206 /*
207 * If we have CONFIG_OABI_COMPAT then we need to look at the swi
208 * value to determine if it is an EABI or an old ABI call.
209 */
210#ifdef CONFIG_ARM_THUMB
211 tst r8, #PSR_T_BIT
212 movne r10, #0 @ no thumb OABI emulation
213 ldreq r10, [lr, #-4] @ get SWI instruction
214#else
215 ldr r10, [lr, #-4] @ get SWI instruction
216 A710( and ip, r10, #0x0f000000 @ check for SWI )
217 A710( teq ip, #0x0f000000 )
218 A710( bne .Larm710bug )
219#endif
26584853
CM
220#ifdef CONFIG_CPU_ENDIAN_BE8
221 rev r10, r10 @ little endian instruction
222#endif
dd35afc2
NP
223
224#elif defined(CONFIG_AEABI)
225
226 /*
227 * Pure EABI user space always put syscall number into scno (r7).
228 */
3f2829a3
NP
229 A710( ldr ip, [lr, #-4] @ get SWI instruction )
230 A710( and ip, ip, #0x0f000000 @ check for SWI )
231 A710( teq ip, #0x0f000000 )
232 A710( bne .Larm710bug )
dd35afc2 233
3f2829a3 234#elif defined(CONFIG_ARM_THUMB)
dd35afc2
NP
235
236 /* Legacy ABI only, possibly thumb mode. */
e0f9f4a6
RK
237 tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs
238 addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
239 ldreq scno, [lr, #-4]
dd35afc2 240
e0f9f4a6 241#else
dd35afc2
NP
242
243 /* Legacy ABI only. */
e0f9f4a6 244 ldr scno, [lr, #-4] @ get SWI instruction
3f2829a3
NP
245 A710( and ip, scno, #0x0f000000 @ check for SWI )
246 A710( teq ip, #0x0f000000 )
247 A710( bne .Larm710bug )
dd35afc2 248
e0f9f4a6 249#endif
1da177e4
LT
250
251#ifdef CONFIG_ALIGNMENT_TRAP
252 ldr ip, __cr_alignment
253 ldr ip, [ip]
254 mcr p15, 0, ip, c1, c0 @ update control register
255#endif
1ec42c0c 256 enable_irq
1da177e4 257
1da177e4 258 get_thread_info tsk
dd35afc2 259 adr tbl, sys_call_table @ load syscall table pointer
1da177e4 260 ldr ip, [tsk, #TI_FLAGS] @ check for syscall tracing
dd35afc2
NP
261
262#if defined(CONFIG_OABI_COMPAT)
263 /*
264 * If the swi argument is zero, this is an EABI call and we do nothing.
265 *
266 * If this is an old ABI call, get the syscall number into scno and
267 * get the old ABI syscall table address.
268 */
269 bics r10, r10, #0xff000000
270 eorne scno, r10, #__NR_OABI_SYSCALL_BASE
271 ldrne tbl, =sys_oabi_call_table
272#elif !defined(CONFIG_AEABI)
1da177e4 273 bic scno, scno, #0xff000000 @ mask off SWI op-code
e0f9f4a6 274 eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
3f2829a3 275#endif
dd35afc2 276
3f2829a3 277 stmdb sp!, {r4, r5} @ push fifth and sixth args
1da177e4
LT
278 tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
279 bne __sys_trace
280
1da177e4 281 cmp scno, #NR_syscalls @ check upper syscall limit
b86040a5 282 adr lr, BSYM(ret_fast_syscall) @ return address
1da177e4
LT
283 ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
284
285 add r1, sp, #S_OFF
2862: mov why, #0 @ no longer a real syscall
e0f9f4a6
RK
287 cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
288 eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
1da177e4
LT
289 bcs arm_syscall
290 b sys_ni_syscall @ not private func
93ed3970 291ENDPROC(vector_swi)
1da177e4
LT
292
293 /*
294 * This is the really slow path. We're going to be doing
295 * context switches, and waiting for our parent to respond.
296 */
297__sys_trace:
3f471126 298 mov r2, scno
1da177e4
LT
299 add r1, sp, #S_OFF
300 mov r0, #0 @ trace entry [IP = 0]
301 bl syscall_trace
302
b86040a5 303 adr lr, BSYM(__sys_trace_return) @ return address
3f471126 304 mov scno, r0 @ syscall number (possibly new)
1da177e4
LT
305 add r1, sp, #S_R0 + S_OFF @ pointer to regs
306 cmp scno, #NR_syscalls @ check upper syscall limit
307 ldmccia r1, {r0 - r3} @ have to reload r0 - r3
308 ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
309 b 2b
310
311__sys_trace_return:
312 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
3f471126 313 mov r2, scno
1da177e4
LT
314 mov r1, sp
315 mov r0, #1 @ trace exit [IP = 1]
316 bl syscall_trace
317 b ret_slow_syscall
318
319 .align 5
320#ifdef CONFIG_ALIGNMENT_TRAP
321 .type __cr_alignment, #object
322__cr_alignment:
323 .word cr_alignment
dd35afc2
NP
324#endif
325 .ltorg
326
327/*
328 * This is the syscall table declaration for native ABI syscalls.
329 * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
330 */
331#define ABI(native, compat) native
332#ifdef CONFIG_AEABI
333#define OBSOLETE(syscall) sys_ni_syscall
334#else
335#define OBSOLETE(syscall) syscall
1da177e4
LT
336#endif
337
338 .type sys_call_table, #object
339ENTRY(sys_call_table)
340#include "calls.S"
dd35afc2
NP
341#undef ABI
342#undef OBSOLETE
1da177e4
LT
343
344/*============================================================================
345 * Special system call wrappers
346 */
347@ r0 = syscall number
567bd980 348@ r8 = syscall table
1da177e4 349sys_syscall:
5247593c 350 bic scno, r0, #__NR_OABI_SYSCALL_BASE
1da177e4
LT
351 cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
352 cmpne scno, #NR_syscalls @ check range
353 stmloia sp, {r5, r6} @ shuffle args
354 movlo r0, r1
355 movlo r1, r2
356 movlo r2, r3
357 movlo r3, r4
358 ldrlo pc, [tbl, scno, lsl #2]
359 b sys_ni_syscall
93ed3970 360ENDPROC(sys_syscall)
1da177e4
LT
361
362sys_fork_wrapper:
363 add r0, sp, #S_OFF
364 b sys_fork
93ed3970 365ENDPROC(sys_fork_wrapper)
1da177e4
LT
366
367sys_vfork_wrapper:
368 add r0, sp, #S_OFF
369 b sys_vfork
93ed3970 370ENDPROC(sys_vfork_wrapper)
1da177e4
LT
371
372sys_execve_wrapper:
373 add r3, sp, #S_OFF
374 b sys_execve
93ed3970 375ENDPROC(sys_execve_wrapper)
1da177e4
LT
376
377sys_clone_wrapper:
378 add ip, sp, #S_OFF
379 str ip, [sp, #4]
380 b sys_clone
93ed3970 381ENDPROC(sys_clone_wrapper)
1da177e4 382
1da177e4
LT
383sys_sigreturn_wrapper:
384 add r0, sp, #S_OFF
385 b sys_sigreturn
93ed3970 386ENDPROC(sys_sigreturn_wrapper)
1da177e4
LT
387
388sys_rt_sigreturn_wrapper:
389 add r0, sp, #S_OFF
390 b sys_rt_sigreturn
93ed3970 391ENDPROC(sys_rt_sigreturn_wrapper)
1da177e4
LT
392
393sys_sigaltstack_wrapper:
394 ldr r2, [sp, #S_OFF + S_SP]
395 b do_sigaltstack
93ed3970 396ENDPROC(sys_sigaltstack_wrapper)
1da177e4 397
713c4815
NP
398sys_statfs64_wrapper:
399 teq r1, #88
400 moveq r1, #84
401 b sys_statfs64
93ed3970 402ENDPROC(sys_statfs64_wrapper)
713c4815
NP
403
404sys_fstatfs64_wrapper:
405 teq r1, #88
406 moveq r1, #84
407 b sys_fstatfs64
93ed3970 408ENDPROC(sys_fstatfs64_wrapper)
713c4815 409
1da177e4
LT
410/*
411 * Note: off_4k (r5) is always units of 4K. If we can't do the requested
412 * offset, we return EINVAL.
413 */
414sys_mmap2:
415#if PAGE_SHIFT > 12
416 tst r5, #PGOFF_MASK
417 moveq r5, r5, lsr #PAGE_SHIFT - 12
418 streq r5, [sp, #4]
f8b72560 419 beq sys_mmap_pgoff
1da177e4 420 mov r0, #-EINVAL
7999d8d7 421 mov pc, lr
1da177e4
LT
422#else
423 str r5, [sp, #4]
f8b72560 424 b sys_mmap_pgoff
1da177e4 425#endif
93ed3970 426ENDPROC(sys_mmap2)
687ad019
NP
427
428#ifdef CONFIG_OABI_COMPAT
dd35afc2 429
687ad019
NP
430/*
431 * These are syscalls with argument register differences
432 */
433
434sys_oabi_pread64:
435 stmia sp, {r3, r4}
436 b sys_pread64
93ed3970 437ENDPROC(sys_oabi_pread64)
687ad019
NP
438
439sys_oabi_pwrite64:
440 stmia sp, {r3, r4}
441 b sys_pwrite64
93ed3970 442ENDPROC(sys_oabi_pwrite64)
687ad019
NP
443
444sys_oabi_truncate64:
445 mov r3, r2
446 mov r2, r1
447 b sys_truncate64
93ed3970 448ENDPROC(sys_oabi_truncate64)
687ad019
NP
449
450sys_oabi_ftruncate64:
451 mov r3, r2
452 mov r2, r1
453 b sys_ftruncate64
93ed3970 454ENDPROC(sys_oabi_ftruncate64)
687ad019
NP
455
456sys_oabi_readahead:
457 str r3, [sp]
458 mov r3, r2
459 mov r2, r1
460 b sys_readahead
93ed3970 461ENDPROC(sys_oabi_readahead)
687ad019 462
dd35afc2
NP
463/*
464 * Let's declare a second syscall table for old ABI binaries
465 * using the compatibility syscall entries.
466 */
467#define ABI(native, compat) compat
468#define OBSOLETE(syscall) syscall
469
470 .type sys_oabi_call_table, #object
471ENTRY(sys_oabi_call_table)
472#include "calls.S"
473#undef ABI
474#undef OBSOLETE
475
687ad019
NP
476#endif
477