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/*
* linux/arch/arm/kernel/entry-common.S
*
* Copyright (C) 2000 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/config.h>
#include "entry-header.S"
/*
* We rely on the fact that R0 is at the bottom of the stack (due to
* slow/fast restore user regs).
*/
#if S_R0 != 0
#error "Please fix"
#endif
/*
* Our do_softirq out of line code. See include/asm-arm/softirq.h for
* the calling assembly.
*/
ENTRY(__do_softirq)
stmfd sp!, {r0 - r3, ip, lr}
bl do_softirq
ldmfd sp!, {r0 - r3, ip, pc}
.align 5
/*
* This is the fast syscall return path. We do as little as
* possible here, and this includes saving r0 back into the SVC
* stack.
*/
ret_fast_syscall:
#error ldr r1, [tsk, #TSK_NEED_RESCHED]
#error ldr r2, [tsk, #TSK_SIGPENDING]
teq r1, #0 @ need_resched || sigpending
teqeq r2, #0
bne slow
fast_restore_user_regs
/*
* Ok, we need to do extra processing, enter the slow path.
*/
slow: str r0, [sp, #S_R0+S_OFF]! @ returned r0
b 1f
/*
* "slow" syscall return path. "why" tells us if this was a real syscall.
*/
reschedule:
bl SYMBOL_NAME(schedule)
ENTRY(ret_to_user)
ret_slow_syscall:
#error ldr r1, [tsk, #TSK_NEED_RESCHED]
#error ldr r2, [tsk, #TSK_SIGPENDING]
1: teq r1, #0 @ need_resched => schedule()
bne reschedule
teq r2, #0 @ sigpending => do_signal()
blne __do_signal
restore_user_regs
__do_signal:
mov r0, #0 @ NULL 'oldset'
mov r1, sp @ 'regs'
mov r2, why @ 'syscall'
#error b SYMBOL_NAME(do_signal) @ note the bl above sets lr
/*
* This is how we return from a fork. __switch_to will be calling us
* with r0 pointing at the previous task that was running (ready for
* calling schedule_tail).
*/
ENTRY(ret_from_fork)
bl SYMBOL_NAME(schedule_tail)
get_current_task tsk
ldr ip, [tsk, #TSK_PTRACE] @ check for syscall tracing
mov why, #1
tst ip, #PT_TRACESYS @ are we tracing syscalls?
beq ret_slow_syscall
mov r1, sp
mov r0, #1 @ trace exit [IP = 1]
#error bl SYMBOL_NAME(syscall_trace)
b ret_slow_syscall
#include "calls.S"
/*=============================================================================
* SWI handler
*-----------------------------------------------------------------------------
*/
/* If we're optimising for StrongARM the resulting code won't
run on an ARM7 and we can save a couple of instructions.
--pb */
#ifdef CONFIG_CPU_ARM710
.macro arm710_bug_check, instr, temp
and \temp, \instr, #0x0f000000 @ check for SWI
teq \temp, #0x0f000000
bne .Larm700bug
.endm
.Larm700bug:
ldr r0, [sp, #S_PSR] @ Get calling cpsr
sub lr, lr, #4
str lr, [r8]
msr spsr, r0
ldmia sp, {r0 - lr}^ @ Get calling r0 - lr
mov r0, r0
ldr lr, [sp, #S_PC] @ Get PC
add sp, sp, #S_FRAME_SIZE
movs pc, lr
#else
.macro arm710_bug_check, instr, temp
.endm
#endif
.align 5
ENTRY(vector_swi)
save_user_regs
zero_fp
get_scno
arm710_bug_check scno, ip
#ifdef CONFIG_ALIGNMENT_TRAP
ldr ip, __cr_alignment
ldr ip, [ip]
mcr p15, 0, ip, c1, c0 @ update control register
#endif
enable_irqs ip
str r4, [sp, #-S_OFF]! @ push fifth arg
get_current_task tsk
ldr ip, [tsk, #TSK_PTRACE] @ check for syscall tracing
bic scno, scno, #0xff000000 @ mask off SWI op-code
eor scno, scno, #OS_NUMBER << 20 @ check OS number
adr tbl, sys_call_table @ load syscall table pointer
tst ip, #PT_TRACESYS @ are we tracing syscalls?
bne __sys_trace
adrsvc al, lr, ret_fast_syscall @ return address
cmp scno, #NR_syscalls @ check upper syscall limit
ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
add r1, sp, #S_OFF
2: mov why, #0 @ no longer a real syscall
cmp scno, #ARMSWI_OFFSET
eor r0, scno, #OS_NUMBER << 20 @ put OS number back
bcs SYMBOL_NAME(arm_syscall)
b SYMBOL_NAME(sys_ni_syscall) @ not private func
/*
* This is the really slow path. We're going to be doing
* context switches, and waiting for our parent to respond.
*/
__sys_trace:
add r1, sp, #S_OFF
mov r0, #0 @ trace entry [IP = 0]
#error bl SYMBOL_NAME(syscall_trace)
adrsvc al, lr, __sys_trace_return @ return address
add r1, sp, #S_R0 + S_OFF @ pointer to regs
cmp scno, #NR_syscalls @ check upper syscall limit
ldmccia r1, {r0 - r3} @ have to reload r0 - r3
ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
b 2b
__sys_trace_return:
str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
mov r1, sp
mov r0, #1 @ trace exit [IP = 1]
#error bl SYMBOL_NAME(syscall_trace)
b ret_slow_syscall
.align 5
#ifdef CONFIG_ALIGNMENT_TRAP
.type __cr_alignment, #object
__cr_alignment:
.word SYMBOL_NAME(cr_alignment)
#endif
.type sys_call_table, #object
ENTRY(sys_call_table)
#include "calls.S"
/*============================================================================
* Special system call wrappers
*/
@ r0 = syscall number
@ r5 = syscall table
.type sys_syscall, #function
SYMBOL_NAME(sys_syscall):
eor scno, r0, #OS_NUMBER << 20
cmp scno, #NR_syscalls @ check range
stmleia sp, {r5, r6} @ shuffle args
movle r0, r1
movle r1, r2
movle r2, r3
movle r3, r4
ldrle pc, [tbl, scno, lsl #2]
b sys_ni_syscall
sys_fork_wrapper:
add r0, sp, #S_OFF
b SYMBOL_NAME(sys_fork)
sys_vfork_wrapper:
add r0, sp, #S_OFF
b SYMBOL_NAME(sys_vfork)
sys_execve_wrapper:
add r3, sp, #S_OFF
b SYMBOL_NAME(sys_execve)
sys_clone_wapper:
add r2, sp, #S_OFF
b SYMBOL_NAME(sys_clone)
sys_sigsuspend_wrapper:
add r3, sp, #S_OFF
b SYMBOL_NAME(sys_sigsuspend)
sys_rt_sigsuspend_wrapper:
add r2, sp, #S_OFF
b SYMBOL_NAME(sys_rt_sigsuspend)
sys_sigreturn_wrapper:
add r0, sp, #S_OFF
b SYMBOL_NAME(sys_sigreturn)
sys_rt_sigreturn_wrapper:
add r0, sp, #S_OFF
b SYMBOL_NAME(sys_rt_sigreturn)
sys_sigaltstack_wrapper:
ldr r2, [sp, #S_OFF + S_SP]
b do_sigaltstack
/*
* Note: off_4k (r5) is always units of 4K. If we can't do the requested
* offset, we return EINVAL.
*/
sys_mmap2:
#if PAGE_SHIFT > 12
tst r5, #PGOFF_MASK
moveq r5, r5, lsr #PAGE_SHIFT - 12
streq r5, [sp, #4]
beq do_mmap2
mov r0, #-EINVAL
RETINSTR(mov,pc, lr)
#else
str r5, [sp, #4]
b do_mmap2
#endif
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