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#include <linux/config.h>
/*============================================================================
* All exits to user mode from the kernel go through this code.
*/
#define S_OFF 8
#define SYSCALL_REGS r4, r5
/*
* Define to favour ARM8, ARM9 and StrongARM cpus. This says that it is
* cheaper to use two LDR instructions than a two-register LDM, if the
* latter would entail calculating an address specially.
*/
#if defined(CONFIG_CPU_SA110)
#define HARVARD_CACHE
#endif
.macro get_softirq, rd
#ifdef __SMP__
#error SMP not supported
#else
ldr \rd, __softirq_state
#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
ldmia r0, {r0, r1}
mov r4, #1 @ flag this as being syscall return
tst r0, r1
blne SYMBOL_NAME(do_softirq)
ret_with_reschedule: @ external entry (__irq_usr)
get_current_task r5
ldr r0, [r5, #TSK_NEED_RESCHED]
ldr r1, [r5, #TSK_SIGPENDING]
teq r0, #0
bne ret_reschedule
teq r1, #0 @ check for signals
bne ret_signal
ret_from_all: restore_user_regs @ internal
ret_signal: mov r1, sp @ internal
adrsvc al, lr, ret_from_all
mov r2, r4
b SYMBOL_NAME(do_signal)
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
ldmia r0, {r0, r1}
mov r4, #0
tst r0, r1
blne SYMBOL_NAME(do_softirq)
ldr r0, [sp, #S_PSR]
tst r0, #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
mov fp, #0
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
stmdb sp!, {SYSCALL_REGS} @ new style: (r0 = arg1, r4 = arg5, r5 = arg6)
@ Note that we dont have to handle
@ sys_syscalls arg7 here
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_FLAGS] @ check for syscall tracing
adr tbl, SYMBOL_NAME(sys_call_table)
tst ip, #PF_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
__softirq_state:
.word SYMBOL_NAME(softirq_state)
ENTRY(sys_call_table)
#include "calls.S"
/*============================================================================
* Special system call wrappers
*/
@ r0 = syscall number
@ r5 = syscall table
SYMBOL_NAME(sys_syscall):
eor scno, r0, #OS_NUMBER << 20
cmp scno, #NR_syscalls @ check range
add ip, sp, #S_OFF
ldmleib ip, {r0 - r3, SYSCALL_REGS} @ get our args
stmleia sp, {SYSCALL_REGS} @ Put our arg on the stack
ldrle pc, [tbl, scno, lsl #2]
mov r0, #-ENOSYS
RETINSTR(mov,pc,lr)
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
.data
ENTRY(fp_enter)
.word fpe_not_present
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