2 * linux/arch/arm/kernel/entry-common.S
4 * Copyright (C) 2000 Russell King
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.
11 #include <asm/unistd.h>
12 #include <asm/ftrace.h>
13 #include <mach/entry-macro.S>
14 #include <asm/unwind.h>
16 #include "entry-header.S"
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
28 disable_irq @ disable interrupts
29 ldr r1, [tsk, #TI_FLAGS]
30 tst r1, #_TIF_WORK_MASK
33 /* perform architecture specific actions before user return */
34 arch_ret_to_user r1, lr
36 @ fast_restore_user_regs
37 ldr r1, [sp, #S_OFF + S_PSR] @ get calling cpsr
38 ldr lr, [sp, #S_OFF + S_PC]! @ get pc
39 msr spsr_cxsf, r1 @ save in spsr_svc
40 ldmdb sp, {r1 - lr}^ @ get calling r1 - lr
42 add sp, sp, #S_FRAME_SIZE - S_PC
43 movs pc, lr @ return & move spsr_svc into cpsr
47 * Ok, we need to do extra processing, enter the slow path.
50 str r0, [sp, #S_R0+S_OFF]! @ returned r0
52 tst r1, #_TIF_NEED_RESCHED
54 tst r1, #_TIF_SIGPENDING
57 mov r2, why @ 'syscall'
59 b ret_slow_syscall @ Check work again
64 * "slow" syscall return path. "why" tells us if this was a real syscall.
68 disable_irq @ disable interrupts
69 ldr r1, [tsk, #TI_FLAGS]
70 tst r1, #_TIF_WORK_MASK
73 /* perform architecture specific actions before user return */
74 arch_ret_to_user r1, lr
76 @ slow_restore_user_regs
77 ldr r1, [sp, #S_PSR] @ get calling cpsr
78 ldr lr, [sp, #S_PC]! @ get pc
79 msr spsr_cxsf, r1 @ save in spsr_svc
80 ldmdb sp, {r0 - lr}^ @ get calling r0 - lr
82 add sp, sp, #S_FRAME_SIZE - S_PC
83 movs pc, lr @ return & move spsr_svc into cpsr
87 * This is how we return from a fork.
92 ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing
94 tst r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
97 mov r0, #1 @ trace exit [IP = 1]
100 ENDPROC(ret_from_fork)
103 #define CALL(x) .equ NR_syscalls,NR_syscalls+1
106 #define CALL(x) .long x
108 #ifdef CONFIG_FUNCTION_TRACER
109 #ifdef CONFIG_DYNAMIC_FTRACE
111 stmdb sp!, {r0-r3, lr}
113 sub r0, r0, #MCOUNT_INSN_SIZE
118 ldr lr, [fp, #-4] @ restore lr
119 ldmia sp!, {r0-r3, pc}
122 stmdb sp!, {r0-r3, lr}
125 sub r0, r0, #MCOUNT_INSN_SIZE
130 ldr lr, [fp, #-4] @ restore lr
131 ldmia sp!, {r0-r3, pc}
135 ENTRY(__gnu_mcount_nc)
136 stmdb sp!, {r0-r3, lr}
137 ldr r0, =ftrace_trace_function
142 ldmia sp!, {r0-r3, ip, lr}
146 ldr r1, [sp, #20] @ lr of instrumented routine
148 sub r0, r0, #MCOUNT_INSN_SIZE
151 ldmia sp!, {r0-r3, ip, lr}
155 stmdb sp!, {r0-r3, lr}
156 ldr r0, =ftrace_trace_function
161 ldr lr, [fp, #-4] @ restore lr
162 ldmia sp!, {r0-r3, pc}
165 ldr r1, [fp, #-4] @ lr of instrumented routine
167 sub r0, r0, #MCOUNT_INSN_SIZE
170 mov lr, r1 @ restore lr
171 ldmia sp!, {r0-r3, pc}
173 #endif /* CONFIG_DYNAMIC_FTRACE */
179 #endif /* CONFIG_FUNCTION_TRACER */
181 /*=============================================================================
183 *-----------------------------------------------------------------------------
186 /* If we're optimising for StrongARM the resulting code won't
187 run on an ARM7 and we can save a couple of instructions.
189 #ifdef CONFIG_CPU_ARM710
190 #define A710(code...) code
192 ldmia sp, {r0 - lr}^ @ Get calling r0 - lr
194 add sp, sp, #S_FRAME_SIZE
197 #define A710(code...)
202 sub sp, sp, #S_FRAME_SIZE
203 stmia sp, {r0 - r12} @ Calling r0 - r12
205 stmdb r8, {sp, lr}^ @ Calling sp, lr
206 mrs r8, spsr @ called from non-FIQ mode, so ok.
207 str lr, [sp, #S_PC] @ Save calling PC
208 str r8, [sp, #S_PSR] @ Save CPSR
209 str r0, [sp, #S_OLD_R0] @ Save OLD_R0
213 * Get the system call number.
216 #if defined(CONFIG_OABI_COMPAT)
219 * If we have CONFIG_OABI_COMPAT then we need to look at the swi
220 * value to determine if it is an EABI or an old ABI call.
222 #ifdef CONFIG_ARM_THUMB
224 movne r10, #0 @ no thumb OABI emulation
225 ldreq r10, [lr, #-4] @ get SWI instruction
227 ldr r10, [lr, #-4] @ get SWI instruction
228 A710( and ip, r10, #0x0f000000 @ check for SWI )
229 A710( teq ip, #0x0f000000 )
230 A710( bne .Larm710bug )
232 #ifdef CONFIG_CPU_ENDIAN_BE8
233 rev r10, r10 @ little endian instruction
236 #elif defined(CONFIG_AEABI)
239 * Pure EABI user space always put syscall number into scno (r7).
241 A710( ldr ip, [lr, #-4] @ get SWI instruction )
242 A710( and ip, ip, #0x0f000000 @ check for SWI )
243 A710( teq ip, #0x0f000000 )
244 A710( bne .Larm710bug )
246 #elif defined(CONFIG_ARM_THUMB)
248 /* Legacy ABI only, possibly thumb mode. */
249 tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs
250 addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
251 ldreq scno, [lr, #-4]
255 /* Legacy ABI only. */
256 ldr scno, [lr, #-4] @ get SWI instruction
257 A710( and ip, scno, #0x0f000000 @ check for SWI )
258 A710( teq ip, #0x0f000000 )
259 A710( bne .Larm710bug )
263 #ifdef CONFIG_ALIGNMENT_TRAP
264 ldr ip, __cr_alignment
266 mcr p15, 0, ip, c1, c0 @ update control register
271 adr tbl, sys_call_table @ load syscall table pointer
272 ldr ip, [tsk, #TI_FLAGS] @ check for syscall tracing
274 #if defined(CONFIG_OABI_COMPAT)
276 * If the swi argument is zero, this is an EABI call and we do nothing.
278 * If this is an old ABI call, get the syscall number into scno and
279 * get the old ABI syscall table address.
281 bics r10, r10, #0xff000000
282 eorne scno, r10, #__NR_OABI_SYSCALL_BASE
283 ldrne tbl, =sys_oabi_call_table
284 #elif !defined(CONFIG_AEABI)
285 bic scno, scno, #0xff000000 @ mask off SWI op-code
286 eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
289 stmdb sp!, {r4, r5} @ push fifth and sixth args
290 tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
293 cmp scno, #NR_syscalls @ check upper syscall limit
294 adr lr, ret_fast_syscall @ return address
295 ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
298 2: mov why, #0 @ no longer a real syscall
299 cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
300 eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
302 b sys_ni_syscall @ not private func
306 * This is the really slow path. We're going to be doing
307 * context switches, and waiting for our parent to respond.
312 mov r0, #0 @ trace entry [IP = 0]
315 adr lr, __sys_trace_return @ return address
316 mov scno, r0 @ syscall number (possibly new)
317 add r1, sp, #S_R0 + S_OFF @ pointer to regs
318 cmp scno, #NR_syscalls @ check upper syscall limit
319 ldmccia r1, {r0 - r3} @ have to reload r0 - r3
320 ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
324 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
327 mov r0, #1 @ trace exit [IP = 1]
332 #ifdef CONFIG_ALIGNMENT_TRAP
333 .type __cr_alignment, #object
340 * This is the syscall table declaration for native ABI syscalls.
341 * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
343 #define ABI(native, compat) native
345 #define OBSOLETE(syscall) sys_ni_syscall
347 #define OBSOLETE(syscall) syscall
350 .type sys_call_table, #object
351 ENTRY(sys_call_table)
356 /*============================================================================
357 * Special system call wrappers
359 @ r0 = syscall number
362 bic scno, r0, #__NR_OABI_SYSCALL_BASE
363 cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
364 cmpne scno, #NR_syscalls @ check range
365 stmloia sp, {r5, r6} @ shuffle args
370 ldrlo pc, [tbl, scno, lsl #2]
377 ENDPROC(sys_fork_wrapper)
382 ENDPROC(sys_vfork_wrapper)
387 ENDPROC(sys_execve_wrapper)
393 ENDPROC(sys_clone_wrapper)
395 sys_sigsuspend_wrapper:
398 ENDPROC(sys_sigsuspend_wrapper)
400 sys_rt_sigsuspend_wrapper:
403 ENDPROC(sys_rt_sigsuspend_wrapper)
405 sys_sigreturn_wrapper:
408 ENDPROC(sys_sigreturn_wrapper)
410 sys_rt_sigreturn_wrapper:
413 ENDPROC(sys_rt_sigreturn_wrapper)
415 sys_sigaltstack_wrapper:
416 ldr r2, [sp, #S_OFF + S_SP]
418 ENDPROC(sys_sigaltstack_wrapper)
420 sys_statfs64_wrapper:
424 ENDPROC(sys_statfs64_wrapper)
426 sys_fstatfs64_wrapper:
430 ENDPROC(sys_fstatfs64_wrapper)
433 * Note: off_4k (r5) is always units of 4K. If we can't do the requested
434 * offset, we return EINVAL.
439 moveq r5, r5, lsr #PAGE_SHIFT - 12
451 mrc p15, 0, r0, cr6, cr0, 2
455 ENDPROC(pabort_noifar)
457 #ifdef CONFIG_OABI_COMPAT
460 * These are syscalls with argument register differences
466 ENDPROC(sys_oabi_pread64)
471 ENDPROC(sys_oabi_pwrite64)
477 ENDPROC(sys_oabi_truncate64)
479 sys_oabi_ftruncate64:
483 ENDPROC(sys_oabi_ftruncate64)
490 ENDPROC(sys_oabi_readahead)
493 * Let's declare a second syscall table for old ABI binaries
494 * using the compatibility syscall entries.
496 #define ABI(native, compat) compat
497 #define OBSOLETE(syscall) syscall
499 .type sys_oabi_call_table, #object
500 ENTRY(sys_oabi_call_table)