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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>
#define PT_TRACESYS 0x00000002
@ OS version number used in SWIs
@ RISC OS is 0
@ RISC iX is 8
@
#define OS_NUMBER 9
/*============================================================================
* All exits to user mode from the kernel go through this code.
*/
#define S_OFF 8
.macro get_softirq, rd
#ifdef CONFIG_SMP
#error SMP not supported
#else
ldr \rd, __irq_stat
#endif
.endm
.globl ret_from_sys_call
.align 5
fast_syscall_return:
str r0, [sp, #S_R0 + S_OFF] @ returned r0
slow_syscall_return:
add sp, sp, #S_OFF
ret_from_sys_call: @ external entry
get_softirq r0
get_current_task r5
ldmia r0, {r0, r1} @ softirq_active, softirq_mask
mov r4, #1 @ flag this as being syscall return
tst r0, r1
blne SYMBOL_NAME(do_softirq)
ret_with_reschedule: @ external entry (r5 must be set) (__irq_usr)
ldr r0, [r5, #TSK_NEED_RESCHED]
ldr r1, [r5, #TSK_SIGPENDING]
teq r0, #0
bne ret_reschedule
teq r1, #0 @ check for signals
blne ret_signal
ret_from_all: restore_user_regs @ internal
ret_signal: mov r1, sp @ internal
mov r2, r4
b SYMBOL_NAME(do_signal) @ note the bl above sets lr
ret_reschedule: adrsvc al, lr, ret_with_reschedule @ internal
b SYMBOL_NAME(schedule)
.globl ret_from_exception
ret_from_exception: @ external entry
get_softirq r0
get_current_task r5
ldmia r0, {r0, r1} @ softirq_active, softirq_mask
mov r4, #0
tst r0, r1
ldr r6, [sp, #S_PSR]
blne SYMBOL_NAME(do_softirq)
tst r6, #3 @ returning to user mode?
beq ret_with_reschedule
b ret_from_all
#include "calls.S"
/*=============================================================================
* SWI handler
*-----------------------------------------------------------------------------
*/
/*
* Create some aliases for some registers. These should allow
* us to have in theory up to 7 arguments to a function.
*/
scno .req r9 @ syscall number
tbl .req r8 @ syscall table pointer
tip .req r7 @ temporary IP
.align 5
vector_swi: save_user_regs
mask_pc lr, lr
zero_fp
ldr scno, [lr, #-4] @ get SWI instruction
arm700_bug_check scno, ip
#ifdef CONFIG_ALIGNMENT_TRAP
ldr ip, .LCswi
ldr ip, [ip]
mcr p15, 0, ip, c1, c0
#endif
enable_irqs ip
str r4, [sp, #-S_OFF]! @ push fifth arg
adrsvc al, lr, fast_syscall_return
bic scno, scno, #0xff000000 @ mask off SWI op-code
eor scno, scno, #OS_NUMBER<<20 @ check OS number
cmp scno, #NR_syscalls @ check upper syscall limit
bcs 2f
get_current_task ip
ldr ip, [ip, #TSK_PTRACE] @ check for syscall tracing
adr tbl, SYMBOL_NAME(sys_call_table)
tst ip, #PT_TRACESYS
ldreq pc, [tbl, scno, lsl #2] @ call sys routine
ldr tip, [sp, #S_IP + S_OFF] @ save old IP
mov ip, #0
str ip, [sp, #S_IP + S_OFF] @ trace entry [IP = 0]
bl SYMBOL_NAME(syscall_trace)
str tip, [sp, #S_IP + S_OFF]
add ip, sp, #S_OFF
ldmia ip, {r0 - r3} @ have to reload r0 - r3
mov lr, pc
ldr pc, [tbl, scno, lsl #2] @ call sys routine
str r0, [sp, #S_R0 + S_OFF] @ returned r0
mov ip, #1
str ip, [sp, #S_IP + S_OFF] @ trace exit [IP = 1]
bl SYMBOL_NAME(syscall_trace)
str tip, [sp, #S_IP + S_OFF]
b slow_syscall_return
2: add r1, sp, #S_OFF
tst scno, #0x00f00000 @ is it a Unix SWI?
bne 3f
subs r0, scno, #(KSWI_SYS_BASE - KSWI_BASE)
bcs SYMBOL_NAME(arm_syscall)
b SYMBOL_NAME(sys_ni_syscall) @ not private func
3: eor r0, scno, #OS_NUMBER <<20 @ Put OS number back
adrsvc al, lr, slow_syscall_return
b SYMBOL_NAME(deferred)
.align 5
.type __irq_stat, #object
__irq_stat:
.word SYMBOL_NAME(irq_stat)
.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
add ip, sp, #S_OFF
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
.data
ENTRY(fp_enter)
.word fpe_not_present
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