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>
15 #include "entry-header.S"
20 * This is the fast syscall return path. We do as little as
21 * possible here, and this includes saving r0 back into the SVC
25 disable_irq @ disable interrupts
26 ldr r1, [tsk, #TI_FLAGS]
27 tst r1, #_TIF_WORK_MASK
30 /* perform architecture specific actions before user return */
31 arch_ret_to_user r1, lr
33 @ fast_restore_user_regs
34 ldr r1, [sp, #S_OFF + S_PSR] @ get calling cpsr
35 ldr lr, [sp, #S_OFF + S_PC]! @ get pc
36 msr spsr_cxsf, r1 @ save in spsr_svc
37 ldmdb sp, {r1 - lr}^ @ get calling r1 - lr
39 add sp, sp, #S_FRAME_SIZE - S_PC
40 movs pc, lr @ return & move spsr_svc into cpsr
43 * Ok, we need to do extra processing, enter the slow path.
46 str r0, [sp, #S_R0+S_OFF]! @ returned r0
48 tst r1, #_TIF_NEED_RESCHED
50 tst r1, #_TIF_SIGPENDING
53 mov r2, why @ 'syscall'
55 b ret_slow_syscall @ Check work again
60 * "slow" syscall return path. "why" tells us if this was a real syscall.
64 disable_irq @ disable interrupts
65 ldr r1, [tsk, #TI_FLAGS]
66 tst r1, #_TIF_WORK_MASK
69 /* perform architecture specific actions before user return */
70 arch_ret_to_user r1, lr
72 @ slow_restore_user_regs
73 ldr r1, [sp, #S_PSR] @ get calling cpsr
74 ldr lr, [sp, #S_PC]! @ get pc
75 msr spsr_cxsf, r1 @ save in spsr_svc
76 ldmdb sp, {r0 - lr}^ @ get calling r0 - lr
78 add sp, sp, #S_FRAME_SIZE - S_PC
79 movs pc, lr @ return & move spsr_svc into cpsr
83 * This is how we return from a fork.
88 ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing
90 tst r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
93 mov r0, #1 @ trace exit [IP = 1]
96 ENDPROC(ret_from_fork)
99 #define CALL(x) .equ NR_syscalls,NR_syscalls+1
102 #define CALL(x) .long x
104 #ifdef CONFIG_FUNCTION_TRACER
105 #ifdef CONFIG_DYNAMIC_FTRACE
107 stmdb sp!, {r0-r3, lr}
109 sub r0, r0, #MCOUNT_INSN_SIZE
114 ldmia sp!, {r0-r3, pc}
117 stmdb sp!, {r0-r3, lr}
120 sub r0, r0, #MCOUNT_INSN_SIZE
125 ldmia sp!, {r0-r3, pc}
131 ldr r1, [sp, #20] @ lr of instrumented routine
133 sub r0, r0, #MCOUNT_INSN_SIZE
136 ldmia sp!, {r0-r3, ip, lr}
140 stmdb sp!, {r0-r3, lr}
141 ldr r0, =ftrace_trace_function
146 ldmia sp!, {r0-r3, pc}
148 ENTRY(__gnu_mcount_nc)
149 stmdb sp!, {r0-r3, lr}
150 ldr r0, =ftrace_trace_function
155 ldmia sp!, {r0-r3, ip, lr}
161 sub r0, r0, #MCOUNT_INSN_SIZE
164 ldmia sp!, {r0-r3, pc}
166 #endif /* CONFIG_DYNAMIC_FTRACE */
172 #endif /* CONFIG_FUNCTION_TRACER */
174 /*=============================================================================
176 *-----------------------------------------------------------------------------
179 /* If we're optimising for StrongARM the resulting code won't
180 run on an ARM7 and we can save a couple of instructions.
182 #ifdef CONFIG_CPU_ARM710
183 #define A710(code...) code
185 ldmia sp, {r0 - lr}^ @ Get calling r0 - lr
187 add sp, sp, #S_FRAME_SIZE
190 #define A710(code...)
195 sub sp, sp, #S_FRAME_SIZE
196 stmia sp, {r0 - r12} @ Calling r0 - r12
198 stmdb r8, {sp, lr}^ @ Calling sp, lr
199 mrs r8, spsr @ called from non-FIQ mode, so ok.
200 str lr, [sp, #S_PC] @ Save calling PC
201 str r8, [sp, #S_PSR] @ Save CPSR
202 str r0, [sp, #S_OLD_R0] @ Save OLD_R0
206 * Get the system call number.
209 #if defined(CONFIG_OABI_COMPAT)
212 * If we have CONFIG_OABI_COMPAT then we need to look at the swi
213 * value to determine if it is an EABI or an old ABI call.
215 #ifdef CONFIG_ARM_THUMB
217 movne r10, #0 @ no thumb OABI emulation
218 ldreq r10, [lr, #-4] @ get SWI instruction
220 ldr r10, [lr, #-4] @ get SWI instruction
221 A710( and ip, r10, #0x0f000000 @ check for SWI )
222 A710( teq ip, #0x0f000000 )
223 A710( bne .Larm710bug )
226 #elif defined(CONFIG_AEABI)
229 * Pure EABI user space always put syscall number into scno (r7).
231 A710( ldr ip, [lr, #-4] @ get SWI instruction )
232 A710( and ip, ip, #0x0f000000 @ check for SWI )
233 A710( teq ip, #0x0f000000 )
234 A710( bne .Larm710bug )
236 #elif defined(CONFIG_ARM_THUMB)
238 /* Legacy ABI only, possibly thumb mode. */
239 tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs
240 addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
241 ldreq scno, [lr, #-4]
245 /* Legacy ABI only. */
246 ldr scno, [lr, #-4] @ get SWI instruction
247 A710( and ip, scno, #0x0f000000 @ check for SWI )
248 A710( teq ip, #0x0f000000 )
249 A710( bne .Larm710bug )
253 #ifdef CONFIG_ALIGNMENT_TRAP
254 ldr ip, __cr_alignment
256 mcr p15, 0, ip, c1, c0 @ update control register
261 adr tbl, sys_call_table @ load syscall table pointer
262 ldr ip, [tsk, #TI_FLAGS] @ check for syscall tracing
264 #if defined(CONFIG_OABI_COMPAT)
266 * If the swi argument is zero, this is an EABI call and we do nothing.
268 * If this is an old ABI call, get the syscall number into scno and
269 * get the old ABI syscall table address.
271 bics r10, r10, #0xff000000
272 eorne scno, r10, #__NR_OABI_SYSCALL_BASE
273 ldrne tbl, =sys_oabi_call_table
274 #elif !defined(CONFIG_AEABI)
275 bic scno, scno, #0xff000000 @ mask off SWI op-code
276 eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
279 stmdb sp!, {r4, r5} @ push fifth and sixth args
280 tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
283 cmp scno, #NR_syscalls @ check upper syscall limit
284 adr lr, ret_fast_syscall @ return address
285 ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
288 2: mov why, #0 @ no longer a real syscall
289 cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
290 eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
292 b sys_ni_syscall @ not private func
296 * This is the really slow path. We're going to be doing
297 * context switches, and waiting for our parent to respond.
302 mov r0, #0 @ trace entry [IP = 0]
305 adr lr, __sys_trace_return @ return address
306 mov scno, r0 @ syscall number (possibly new)
307 add r1, sp, #S_R0 + S_OFF @ pointer to regs
308 cmp scno, #NR_syscalls @ check upper syscall limit
309 ldmccia r1, {r0 - r3} @ have to reload r0 - r3
310 ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
314 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
317 mov r0, #1 @ trace exit [IP = 1]
322 #ifdef CONFIG_ALIGNMENT_TRAP
323 .type __cr_alignment, #object
330 * This is the syscall table declaration for native ABI syscalls.
331 * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
333 #define ABI(native, compat) native
335 #define OBSOLETE(syscall) sys_ni_syscall
337 #define OBSOLETE(syscall) syscall
340 .type sys_call_table, #object
341 ENTRY(sys_call_table)
346 /*============================================================================
347 * Special system call wrappers
349 @ r0 = syscall number
352 bic scno, r0, #__NR_OABI_SYSCALL_BASE
353 cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
354 cmpne scno, #NR_syscalls @ check range
355 stmloia sp, {r5, r6} @ shuffle args
360 ldrlo pc, [tbl, scno, lsl #2]
367 ENDPROC(sys_fork_wrapper)
372 ENDPROC(sys_vfork_wrapper)
377 ENDPROC(sys_execve_wrapper)
383 ENDPROC(sys_clone_wrapper)
385 sys_sigsuspend_wrapper:
388 ENDPROC(sys_sigsuspend_wrapper)
390 sys_rt_sigsuspend_wrapper:
393 ENDPROC(sys_rt_sigsuspend_wrapper)
395 sys_sigreturn_wrapper:
398 ENDPROC(sys_sigreturn_wrapper)
400 sys_rt_sigreturn_wrapper:
403 ENDPROC(sys_rt_sigreturn_wrapper)
405 sys_sigaltstack_wrapper:
406 ldr r2, [sp, #S_OFF + S_SP]
408 ENDPROC(sys_sigaltstack_wrapper)
410 sys_statfs64_wrapper:
414 ENDPROC(sys_statfs64_wrapper)
416 sys_fstatfs64_wrapper:
420 ENDPROC(sys_fstatfs64_wrapper)
423 * Note: off_4k (r5) is always units of 4K. If we can't do the requested
424 * offset, we return EINVAL.
429 moveq r5, r5, lsr #PAGE_SHIFT - 12
441 mrc p15, 0, r0, cr6, cr0, 2
445 ENDPROC(pabort_noifar)
447 #ifdef CONFIG_OABI_COMPAT
450 * These are syscalls with argument register differences
456 ENDPROC(sys_oabi_pread64)
461 ENDPROC(sys_oabi_pwrite64)
467 ENDPROC(sys_oabi_truncate64)
469 sys_oabi_ftruncate64:
473 ENDPROC(sys_oabi_ftruncate64)
480 ENDPROC(sys_oabi_readahead)
483 * Let's declare a second syscall table for old ABI binaries
484 * using the compatibility syscall entries.
486 #define ABI(native, compat) compat
487 #define OBSOLETE(syscall) syscall
489 .type sys_oabi_call_table, #object
490 ENTRY(sys_oabi_call_table)