| /* | 
 |  *  arch/s390/kernel/entry.S | 
 |  *    S390 low-level entry points. | 
 |  * | 
 |  *    Copyright (C) IBM Corp. 1999,2006 | 
 |  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), | 
 |  *		 Hartmut Penner (hp@de.ibm.com), | 
 |  *		 Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), | 
 |  *		 Heiko Carstens <heiko.carstens@de.ibm.com> | 
 |  */ | 
 |  | 
 | #include <linux/sys.h> | 
 | #include <linux/linkage.h> | 
 | #include <linux/init.h> | 
 | #include <asm/cache.h> | 
 | #include <asm/lowcore.h> | 
 | #include <asm/errno.h> | 
 | #include <asm/ptrace.h> | 
 | #include <asm/thread_info.h> | 
 | #include <asm/asm-offsets.h> | 
 | #include <asm/unistd.h> | 
 | #include <asm/page.h> | 
 |  | 
 | /* | 
 |  * Stack layout for the system_call stack entry. | 
 |  * The first few entries are identical to the user_regs_struct. | 
 |  */ | 
 | SP_PTREGS    =	STACK_FRAME_OVERHEAD | 
 | SP_ARGS      =	STACK_FRAME_OVERHEAD + __PT_ARGS | 
 | SP_PSW	     =	STACK_FRAME_OVERHEAD + __PT_PSW | 
 | SP_R0	     =	STACK_FRAME_OVERHEAD + __PT_GPRS | 
 | SP_R1	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 4 | 
 | SP_R2	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 8 | 
 | SP_R3	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 12 | 
 | SP_R4	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 16 | 
 | SP_R5	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 20 | 
 | SP_R6	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 24 | 
 | SP_R7	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 28 | 
 | SP_R8	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 32 | 
 | SP_R9	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 36 | 
 | SP_R10	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 40 | 
 | SP_R11	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 44 | 
 | SP_R12	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 48 | 
 | SP_R13	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 52 | 
 | SP_R14	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 56 | 
 | SP_R15	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 60 | 
 | SP_ORIG_R2   =	STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2 | 
 | SP_ILC	     =	STACK_FRAME_OVERHEAD + __PT_ILC | 
 | SP_TRAP      =	STACK_FRAME_OVERHEAD + __PT_TRAP | 
 | SP_SIZE      =	STACK_FRAME_OVERHEAD + __PT_SIZE | 
 |  | 
 | _TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \ | 
 | 		 _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP ) | 
 | _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \ | 
 | 		 _TIF_MCCK_PENDING) | 
 |  | 
 | STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER | 
 | STACK_SIZE  = 1 << STACK_SHIFT | 
 |  | 
 | #define BASED(name) name-system_call(%r13) | 
 |  | 
 | #ifdef CONFIG_TRACE_IRQFLAGS | 
 | 	.macro	TRACE_IRQS_ON | 
 | 	l	%r1,BASED(.Ltrace_irq_on) | 
 | 	basr	%r14,%r1 | 
 | 	.endm | 
 |  | 
 | 	.macro	TRACE_IRQS_OFF | 
 | 	l	%r1,BASED(.Ltrace_irq_off) | 
 | 	basr	%r14,%r1 | 
 | 	.endm | 
 |  | 
 | 	.macro	TRACE_IRQS_CHECK | 
 | 	tm	SP_PSW(%r15),0x03	# irqs enabled? | 
 | 	jz	0f | 
 | 	l	%r1,BASED(.Ltrace_irq_on) | 
 | 	basr	%r14,%r1 | 
 | 	j	1f | 
 | 0:	l	%r1,BASED(.Ltrace_irq_off) | 
 | 	basr	%r14,%r1 | 
 | 1: | 
 | 	.endm | 
 | #else | 
 | #define TRACE_IRQS_ON | 
 | #define TRACE_IRQS_OFF | 
 | #define TRACE_IRQS_CHECK | 
 | #endif | 
 |  | 
 | #ifdef CONFIG_LOCKDEP | 
 | 	.macro	LOCKDEP_SYS_EXIT | 
 | 	tm	SP_PSW+1(%r15),0x01	# returning to user ? | 
 | 	jz	0f | 
 | 	l	%r1,BASED(.Llockdep_sys_exit) | 
 | 	basr	%r14,%r1 | 
 | 0: | 
 | 	.endm | 
 | #else | 
 | #define LOCKDEP_SYS_EXIT | 
 | #endif | 
 |  | 
 | /* | 
 |  * Register usage in interrupt handlers: | 
 |  *    R9  - pointer to current task structure | 
 |  *    R13 - pointer to literal pool | 
 |  *    R14 - return register for function calls | 
 |  *    R15 - kernel stack pointer | 
 |  */ | 
 |  | 
 | 	.macro	STORE_TIMER lc_offset | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	stpt	\lc_offset | 
 | #endif | 
 | 	.endm | 
 |  | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	.macro	UPDATE_VTIME lc_from,lc_to,lc_sum | 
 | 	lm	%r10,%r11,\lc_from | 
 | 	sl	%r10,\lc_to | 
 | 	sl	%r11,\lc_to+4 | 
 | 	bc	3,BASED(0f) | 
 | 	sl	%r10,BASED(.Lc_1) | 
 | 0:	al	%r10,\lc_sum | 
 | 	al	%r11,\lc_sum+4 | 
 | 	bc	12,BASED(1f) | 
 | 	al	%r10,BASED(.Lc_1) | 
 | 1:	stm	%r10,%r11,\lc_sum | 
 | 	.endm | 
 | #endif | 
 |  | 
 | 	.macro	SAVE_ALL_BASE savearea | 
 | 	stm	%r12,%r15,\savearea | 
 | 	l	%r13,__LC_SVC_NEW_PSW+4	# load &system_call to %r13 | 
 | 	.endm | 
 |  | 
 | 	.macro	SAVE_ALL_SVC psworg,savearea | 
 | 	la	%r12,\psworg | 
 | 	l	%r15,__LC_KERNEL_STACK	# problem state -> load ksp | 
 | 	.endm | 
 |  | 
 | 	.macro	SAVE_ALL_SYNC psworg,savearea | 
 | 	la	%r12,\psworg | 
 | 	tm	\psworg+1,0x01		# test problem state bit | 
 | 	bz	BASED(2f)		# skip stack setup save | 
 | 	l	%r15,__LC_KERNEL_STACK	# problem state -> load ksp | 
 | #ifdef CONFIG_CHECK_STACK | 
 | 	b	BASED(3f) | 
 | 2:	tml	%r15,STACK_SIZE - CONFIG_STACK_GUARD | 
 | 	bz	BASED(stack_overflow) | 
 | 3: | 
 | #endif | 
 | 2: | 
 | 	.endm | 
 |  | 
 | 	.macro	SAVE_ALL_ASYNC psworg,savearea | 
 | 	la	%r12,\psworg | 
 | 	tm	\psworg+1,0x01		# test problem state bit | 
 | 	bnz	BASED(1f)		# from user -> load async stack | 
 | 	clc	\psworg+4(4),BASED(.Lcritical_end) | 
 | 	bhe	BASED(0f) | 
 | 	clc	\psworg+4(4),BASED(.Lcritical_start) | 
 | 	bl	BASED(0f) | 
 | 	l	%r14,BASED(.Lcleanup_critical) | 
 | 	basr	%r14,%r14 | 
 | 	tm	1(%r12),0x01		# retest problem state after cleanup | 
 | 	bnz	BASED(1f) | 
 | 0:	l	%r14,__LC_ASYNC_STACK	# are we already on the async stack ? | 
 | 	slr	%r14,%r15 | 
 | 	sra	%r14,STACK_SHIFT | 
 | 	be	BASED(2f) | 
 | 1:	l	%r15,__LC_ASYNC_STACK | 
 | #ifdef CONFIG_CHECK_STACK | 
 | 	b	BASED(3f) | 
 | 2:	tml	%r15,STACK_SIZE - CONFIG_STACK_GUARD | 
 | 	bz	BASED(stack_overflow) | 
 | 3: | 
 | #endif | 
 | 2: | 
 | 	.endm | 
 |  | 
 | 	.macro	CREATE_STACK_FRAME psworg,savearea | 
 | 	s	%r15,BASED(.Lc_spsize)	# make room for registers & psw | 
 | 	mvc	SP_PSW(8,%r15),0(%r12)	# move user PSW to stack | 
 | 	la	%r12,\psworg | 
 | 	st	%r2,SP_ORIG_R2(%r15)	# store original content of gpr 2 | 
 | 	icm	%r12,12,__LC_SVC_ILC | 
 | 	stm	%r0,%r11,SP_R0(%r15)	# store gprs %r0-%r11 to kernel stack | 
 | 	st	%r12,SP_ILC(%r15) | 
 | 	mvc	SP_R12(16,%r15),\savearea # move %r12-%r15 to stack | 
 | 	la	%r12,0 | 
 | 	st	%r12,__SF_BACKCHAIN(%r15)	# clear back chain | 
 | 	.endm | 
 |  | 
 | 	.macro	RESTORE_ALL psworg,sync | 
 | 	mvc	\psworg(8),SP_PSW(%r15) # move user PSW to lowcore | 
 | 	.if !\sync | 
 | 	ni	\psworg+1,0xfd		# clear wait state bit | 
 | 	.endif | 
 | 	lm	%r0,%r15,SP_R0(%r15)	# load gprs 0-15 of user | 
 | 	STORE_TIMER __LC_EXIT_TIMER | 
 | 	lpsw	\psworg			# back to caller | 
 | 	.endm | 
 |  | 
 | /* | 
 |  * Scheduler resume function, called by switch_to | 
 |  *  gpr2 = (task_struct *) prev | 
 |  *  gpr3 = (task_struct *) next | 
 |  * Returns: | 
 |  *  gpr2 = prev | 
 |  */ | 
 | 	.globl	__switch_to | 
 | __switch_to: | 
 | 	basr	%r1,0 | 
 | __switch_to_base: | 
 | 	tm	__THREAD_per(%r3),0xe8		# new process is using per ? | 
 | 	bz	__switch_to_noper-__switch_to_base(%r1)	# if not we're fine | 
 | 	stctl	%c9,%c11,__SF_EMPTY(%r15)	# We are using per stuff | 
 | 	clc	__THREAD_per(12,%r3),__SF_EMPTY(%r15) | 
 | 	be	__switch_to_noper-__switch_to_base(%r1)	# we got away w/o bashing TLB's | 
 | 	lctl	%c9,%c11,__THREAD_per(%r3)	# Nope we didn't | 
 | __switch_to_noper: | 
 | 	l	%r4,__THREAD_info(%r2)		# get thread_info of prev | 
 | 	tm	__TI_flags+3(%r4),_TIF_MCCK_PENDING # machine check pending? | 
 | 	bz	__switch_to_no_mcck-__switch_to_base(%r1) | 
 | 	ni	__TI_flags+3(%r4),255-_TIF_MCCK_PENDING # clear flag in prev | 
 | 	l	%r4,__THREAD_info(%r3)		# get thread_info of next | 
 | 	oi	__TI_flags+3(%r4),_TIF_MCCK_PENDING # set it in next | 
 | __switch_to_no_mcck: | 
 | 	stm	%r6,%r15,__SF_GPRS(%r15)# store __switch_to registers of prev task | 
 | 	st	%r15,__THREAD_ksp(%r2)	# store kernel stack to prev->tss.ksp | 
 | 	l	%r15,__THREAD_ksp(%r3)	# load kernel stack from next->tss.ksp | 
 | 	lm	%r6,%r15,__SF_GPRS(%r15)# load __switch_to registers of next task | 
 | 	st	%r3,__LC_CURRENT	# __LC_CURRENT = current task struct | 
 | 	lctl	%c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 | 
 | 	l	%r3,__THREAD_info(%r3)	# load thread_info from task struct | 
 | 	st	%r3,__LC_THREAD_INFO | 
 | 	ahi	%r3,STACK_SIZE | 
 | 	st	%r3,__LC_KERNEL_STACK	# __LC_KERNEL_STACK = new kernel stack | 
 | 	br	%r14 | 
 |  | 
 | __critical_start: | 
 | /* | 
 |  * SVC interrupt handler routine. System calls are synchronous events and | 
 |  * are executed with interrupts enabled. | 
 |  */ | 
 |  | 
 | 	.globl	system_call | 
 | system_call: | 
 | 	STORE_TIMER __LC_SYNC_ENTER_TIMER | 
 | sysc_saveall: | 
 | 	SAVE_ALL_BASE __LC_SAVE_AREA | 
 | 	SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA | 
 | 	CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA | 
 | 	lh	%r7,0x8a	  # get svc number from lowcore | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | sysc_vtime: | 
 | 	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER | 
 | sysc_stime: | 
 | 	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER | 
 | sysc_update: | 
 | 	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER | 
 | #endif | 
 | sysc_do_svc: | 
 | 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct | 
 | 	sla	%r7,2			# *4 and test for svc 0 | 
 | 	bnz	BASED(sysc_nr_ok)	# svc number > 0 | 
 | 	# svc 0: system call number in %r1 | 
 | 	cl	%r1,BASED(.Lnr_syscalls) | 
 | 	bnl	BASED(sysc_nr_ok) | 
 | 	lr	%r7,%r1 	  # copy svc number to %r7 | 
 | 	sla	%r7,2		  # *4 | 
 | sysc_nr_ok: | 
 | 	mvc	SP_ARGS(4,%r15),SP_R7(%r15) | 
 | sysc_do_restart: | 
 | 	l	%r8,BASED(.Lsysc_table) | 
 | 	tm	__TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT) | 
 | 	l	%r8,0(%r7,%r8)	  # get system call addr. | 
 | 	bnz	BASED(sysc_tracesys) | 
 | 	basr	%r14,%r8	  # call sys_xxxx | 
 | 	st	%r2,SP_R2(%r15)   # store return value (change R2 on stack) | 
 |  | 
 | sysc_return: | 
 | 	tm	__TI_flags+3(%r9),_TIF_WORK_SVC | 
 | 	bnz	BASED(sysc_work)  # there is work to do (signals etc.) | 
 | sysc_restore: | 
 | #ifdef CONFIG_TRACE_IRQFLAGS | 
 | 	la	%r1,BASED(sysc_restore_trace_psw) | 
 | 	lpsw	0(%r1) | 
 | sysc_restore_trace: | 
 | 	TRACE_IRQS_CHECK | 
 | 	LOCKDEP_SYS_EXIT | 
 | #endif | 
 | sysc_leave: | 
 | 	RESTORE_ALL __LC_RETURN_PSW,1 | 
 | sysc_done: | 
 |  | 
 | #ifdef CONFIG_TRACE_IRQFLAGS | 
 | 	.align	8 | 
 | 	.globl	sysc_restore_trace_psw | 
 | sysc_restore_trace_psw: | 
 | 	.long	0, sysc_restore_trace + 0x80000000 | 
 | #endif | 
 |  | 
 | # | 
 | # recheck if there is more work to do | 
 | # | 
 | sysc_work_loop: | 
 | 	tm	__TI_flags+3(%r9),_TIF_WORK_SVC | 
 | 	bz	BASED(sysc_restore)	# there is no work to do | 
 | # | 
 | # One of the work bits is on. Find out which one. | 
 | # | 
 | sysc_work: | 
 | 	tm	SP_PSW+1(%r15),0x01	# returning to user ? | 
 | 	bno	BASED(sysc_restore) | 
 | 	tm	__TI_flags+3(%r9),_TIF_MCCK_PENDING | 
 | 	bo	BASED(sysc_mcck_pending) | 
 | 	tm	__TI_flags+3(%r9),_TIF_NEED_RESCHED | 
 | 	bo	BASED(sysc_reschedule) | 
 | 	tm	__TI_flags+3(%r9),_TIF_SIGPENDING | 
 | 	bnz	BASED(sysc_sigpending) | 
 | 	tm	__TI_flags+3(%r9),_TIF_RESTART_SVC | 
 | 	bo	BASED(sysc_restart) | 
 | 	tm	__TI_flags+3(%r9),_TIF_SINGLE_STEP | 
 | 	bo	BASED(sysc_singlestep) | 
 | 	b	BASED(sysc_restore) | 
 | sysc_work_done: | 
 |  | 
 | # | 
 | # _TIF_NEED_RESCHED is set, call schedule | 
 | # | 
 | sysc_reschedule: | 
 | 	l	%r1,BASED(.Lschedule) | 
 | 	la	%r14,BASED(sysc_work_loop) | 
 | 	br	%r1			# call scheduler | 
 |  | 
 | # | 
 | # _TIF_MCCK_PENDING is set, call handler | 
 | # | 
 | sysc_mcck_pending: | 
 | 	l	%r1,BASED(.Ls390_handle_mcck) | 
 | 	la	%r14,BASED(sysc_work_loop) | 
 | 	br	%r1			# TIF bit will be cleared by handler | 
 |  | 
 | # | 
 | # _TIF_SIGPENDING is set, call do_signal | 
 | # | 
 | sysc_sigpending: | 
 | 	ni	__TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP | 
 | 	la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
 | 	l	%r1,BASED(.Ldo_signal) | 
 | 	basr	%r14,%r1		# call do_signal | 
 | 	tm	__TI_flags+3(%r9),_TIF_RESTART_SVC | 
 | 	bo	BASED(sysc_restart) | 
 | 	tm	__TI_flags+3(%r9),_TIF_SINGLE_STEP | 
 | 	bo	BASED(sysc_singlestep) | 
 | 	b	BASED(sysc_work_loop) | 
 |  | 
 | # | 
 | # _TIF_RESTART_SVC is set, set up registers and restart svc | 
 | # | 
 | sysc_restart: | 
 | 	ni	__TI_flags+3(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC | 
 | 	l	%r7,SP_R2(%r15) 	# load new svc number | 
 | 	sla	%r7,2 | 
 | 	mvc	SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument | 
 | 	lm	%r2,%r6,SP_R2(%r15)	# load svc arguments | 
 | 	b	BASED(sysc_do_restart)	# restart svc | 
 |  | 
 | # | 
 | # _TIF_SINGLE_STEP is set, call do_single_step | 
 | # | 
 | sysc_singlestep: | 
 | 	ni	__TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP | 
 | 	mvi	SP_TRAP+1(%r15),0x28	# set trap indication to pgm check | 
 | 	la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
 | 	l	%r1,BASED(.Lhandle_per)	# load adr. of per handler | 
 | 	la	%r14,BASED(sysc_return)	# load adr. of system return | 
 | 	br	%r1			# branch to do_single_step | 
 |  | 
 | # | 
 | # call trace before and after sys_call | 
 | # | 
 | sysc_tracesys: | 
 | 	l	%r1,BASED(.Ltrace) | 
 | 	la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
 | 	la	%r3,0 | 
 | 	srl	%r7,2 | 
 | 	st	%r7,SP_R2(%r15) | 
 | 	basr	%r14,%r1 | 
 | 	clc	SP_R2(4,%r15),BASED(.Lnr_syscalls) | 
 | 	bnl	BASED(sysc_tracenogo) | 
 | 	l	%r8,BASED(.Lsysc_table) | 
 | 	l	%r7,SP_R2(%r15) 	# strace might have changed the | 
 | 	sll	%r7,2			#  system call | 
 | 	l	%r8,0(%r7,%r8) | 
 | sysc_tracego: | 
 | 	lm	%r3,%r6,SP_R3(%r15) | 
 | 	l	%r2,SP_ORIG_R2(%r15) | 
 | 	basr	%r14,%r8		# call sys_xxx | 
 | 	st	%r2,SP_R2(%r15)		# store return value | 
 | sysc_tracenogo: | 
 | 	tm	__TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT) | 
 | 	bz	BASED(sysc_return) | 
 | 	l	%r1,BASED(.Ltrace) | 
 | 	la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
 | 	la	%r3,1 | 
 | 	la	%r14,BASED(sysc_return) | 
 | 	br	%r1 | 
 |  | 
 | # | 
 | # a new process exits the kernel with ret_from_fork | 
 | # | 
 | 	.globl	ret_from_fork | 
 | ret_from_fork: | 
 | 	l	%r13,__LC_SVC_NEW_PSW+4 | 
 | 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct | 
 | 	tm	SP_PSW+1(%r15),0x01	# forking a kernel thread ? | 
 | 	bo	BASED(0f) | 
 | 	st	%r15,SP_R15(%r15)	# store stack pointer for new kthread | 
 | 0:	l	%r1,BASED(.Lschedtail) | 
 | 	basr	%r14,%r1 | 
 | 	TRACE_IRQS_ON | 
 | 	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts | 
 | 	b	BASED(sysc_return) | 
 |  | 
 | # | 
 | # kernel_execve function needs to deal with pt_regs that is not | 
 | # at the usual place | 
 | # | 
 | 	.globl	kernel_execve | 
 | kernel_execve: | 
 | 	stm	%r12,%r15,48(%r15) | 
 | 	lr	%r14,%r15 | 
 | 	l	%r13,__LC_SVC_NEW_PSW+4 | 
 | 	s	%r15,BASED(.Lc_spsize) | 
 | 	st	%r14,__SF_BACKCHAIN(%r15) | 
 | 	la	%r12,SP_PTREGS(%r15) | 
 | 	xc	0(__PT_SIZE,%r12),0(%r12) | 
 | 	l	%r1,BASED(.Ldo_execve) | 
 | 	lr	%r5,%r12 | 
 | 	basr	%r14,%r1 | 
 | 	ltr	%r2,%r2 | 
 | 	be	BASED(0f) | 
 | 	a	%r15,BASED(.Lc_spsize) | 
 | 	lm	%r12,%r15,48(%r15) | 
 | 	br	%r14 | 
 | 	# execve succeeded. | 
 | 0:	stnsm	__SF_EMPTY(%r15),0xfc	# disable interrupts | 
 | 	l	%r15,__LC_KERNEL_STACK	# load ksp | 
 | 	s	%r15,BASED(.Lc_spsize)	# make room for registers & psw | 
 | 	l	%r9,__LC_THREAD_INFO | 
 | 	mvc	SP_PTREGS(__PT_SIZE,%r15),0(%r12)	# copy pt_regs | 
 | 	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) | 
 | 	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts | 
 | 	l	%r1,BASED(.Lexecve_tail) | 
 | 	basr	%r14,%r1 | 
 | 	b	BASED(sysc_return) | 
 |  | 
 | /* | 
 |  * Program check handler routine | 
 |  */ | 
 |  | 
 | 	.globl	pgm_check_handler | 
 | pgm_check_handler: | 
 | /* | 
 |  * First we need to check for a special case: | 
 |  * Single stepping an instruction that disables the PER event mask will | 
 |  * cause a PER event AFTER the mask has been set. Example: SVC or LPSW. | 
 |  * For a single stepped SVC the program check handler gets control after | 
 |  * the SVC new PSW has been loaded. But we want to execute the SVC first and | 
 |  * then handle the PER event. Therefore we update the SVC old PSW to point | 
 |  * to the pgm_check_handler and branch to the SVC handler after we checked | 
 |  * if we have to load the kernel stack register. | 
 |  * For every other possible cause for PER event without the PER mask set | 
 |  * we just ignore the PER event (FIXME: is there anything we have to do | 
 |  * for LPSW?). | 
 |  */ | 
 | 	STORE_TIMER __LC_SYNC_ENTER_TIMER | 
 | 	SAVE_ALL_BASE __LC_SAVE_AREA | 
 | 	tm	__LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception | 
 | 	bnz	BASED(pgm_per)		# got per exception -> special case | 
 | 	SAVE_ALL_SYNC __LC_PGM_OLD_PSW,__LC_SAVE_AREA | 
 | 	CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	tm	SP_PSW+1(%r15),0x01	# interrupting from user ? | 
 | 	bz	BASED(pgm_no_vtime) | 
 | 	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER | 
 | 	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER | 
 | 	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER | 
 | pgm_no_vtime: | 
 | #endif | 
 | 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct | 
 | 	TRACE_IRQS_OFF | 
 | 	l	%r3,__LC_PGM_ILC	# load program interruption code | 
 | 	la	%r8,0x7f | 
 | 	nr	%r8,%r3 | 
 | pgm_do_call: | 
 | 	l	%r7,BASED(.Ljump_table) | 
 | 	sll	%r8,2 | 
 | 	l	%r7,0(%r8,%r7)		# load address of handler routine | 
 | 	la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
 | 	la	%r14,BASED(sysc_return) | 
 | 	br	%r7			# branch to interrupt-handler | 
 |  | 
 | # | 
 | # handle per exception | 
 | # | 
 | pgm_per: | 
 | 	tm	__LC_PGM_OLD_PSW,0x40	# test if per event recording is on | 
 | 	bnz	BASED(pgm_per_std)	# ok, normal per event from user space | 
 | # ok its one of the special cases, now we need to find out which one | 
 | 	clc	__LC_PGM_OLD_PSW(8),__LC_SVC_NEW_PSW | 
 | 	be	BASED(pgm_svcper) | 
 | # no interesting special case, ignore PER event | 
 | 	lm	%r12,%r15,__LC_SAVE_AREA | 
 | 	lpsw	0x28 | 
 |  | 
 | # | 
 | # Normal per exception | 
 | # | 
 | pgm_per_std: | 
 | 	SAVE_ALL_SYNC __LC_PGM_OLD_PSW,__LC_SAVE_AREA | 
 | 	CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	tm	SP_PSW+1(%r15),0x01	# interrupting from user ? | 
 | 	bz	BASED(pgm_no_vtime2) | 
 | 	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER | 
 | 	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER | 
 | 	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER | 
 | pgm_no_vtime2: | 
 | #endif | 
 | 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct | 
 | 	TRACE_IRQS_OFF | 
 | 	l	%r1,__TI_task(%r9) | 
 | 	mvc	__THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID | 
 | 	mvc	__THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS | 
 | 	mvc	__THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID | 
 | 	oi	__TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP | 
 | 	tm	SP_PSW+1(%r15),0x01	# kernel per event ? | 
 | 	bz	BASED(kernel_per) | 
 | 	l	%r3,__LC_PGM_ILC	# load program interruption code | 
 | 	la	%r8,0x7f | 
 | 	nr	%r8,%r3 		# clear per-event-bit and ilc | 
 | 	be	BASED(sysc_return)	# only per or per+check ? | 
 | 	b	BASED(pgm_do_call) | 
 |  | 
 | # | 
 | # it was a single stepped SVC that is causing all the trouble | 
 | # | 
 | pgm_svcper: | 
 | 	SAVE_ALL_SYNC __LC_SVC_OLD_PSW,__LC_SAVE_AREA | 
 | 	CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER | 
 | 	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER | 
 | 	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER | 
 | #endif | 
 | 	lh	%r7,0x8a		# get svc number from lowcore | 
 | 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct | 
 | 	TRACE_IRQS_OFF | 
 | 	l	%r1,__TI_task(%r9) | 
 | 	mvc	__THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID | 
 | 	mvc	__THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS | 
 | 	mvc	__THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID | 
 | 	oi	__TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP | 
 | 	TRACE_IRQS_ON | 
 | 	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts | 
 | 	b	BASED(sysc_do_svc) | 
 |  | 
 | # | 
 | # per was called from kernel, must be kprobes | 
 | # | 
 | kernel_per: | 
 | 	mvi	SP_TRAP+1(%r15),0x28	# set trap indication to pgm check | 
 | 	la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
 | 	l	%r1,BASED(.Lhandle_per)	# load adr. of per handler | 
 | 	la	%r14,BASED(sysc_restore)# load adr. of system return | 
 | 	br	%r1			# branch to do_single_step | 
 |  | 
 | /* | 
 |  * IO interrupt handler routine | 
 |  */ | 
 |  | 
 | 	.globl io_int_handler | 
 | io_int_handler: | 
 | 	STORE_TIMER __LC_ASYNC_ENTER_TIMER | 
 | 	stck	__LC_INT_CLOCK | 
 | 	SAVE_ALL_BASE __LC_SAVE_AREA+16 | 
 | 	SAVE_ALL_ASYNC __LC_IO_OLD_PSW,__LC_SAVE_AREA+16 | 
 | 	CREATE_STACK_FRAME __LC_IO_OLD_PSW,__LC_SAVE_AREA+16 | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	tm	SP_PSW+1(%r15),0x01	# interrupting from user ? | 
 | 	bz	BASED(io_no_vtime) | 
 | 	UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER | 
 | 	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER | 
 | 	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER | 
 | io_no_vtime: | 
 | #endif | 
 | 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct | 
 | 	TRACE_IRQS_OFF | 
 | 	l	%r1,BASED(.Ldo_IRQ)	# load address of do_IRQ | 
 | 	la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
 | 	basr	%r14,%r1		# branch to standard irq handler | 
 | io_return: | 
 | 	tm	__TI_flags+3(%r9),_TIF_WORK_INT | 
 | 	bnz	BASED(io_work)		# there is work to do (signals etc.) | 
 | io_restore: | 
 | #ifdef CONFIG_TRACE_IRQFLAGS | 
 | 	la	%r1,BASED(io_restore_trace_psw) | 
 | 	lpsw	0(%r1) | 
 | io_restore_trace: | 
 | 	TRACE_IRQS_CHECK | 
 | 	LOCKDEP_SYS_EXIT | 
 | #endif | 
 | io_leave: | 
 | 	RESTORE_ALL __LC_RETURN_PSW,0 | 
 | io_done: | 
 |  | 
 | #ifdef CONFIG_TRACE_IRQFLAGS | 
 | 	.align	8 | 
 | 	.globl	io_restore_trace_psw | 
 | io_restore_trace_psw: | 
 | 	.long	0, io_restore_trace + 0x80000000 | 
 | #endif | 
 |  | 
 | # | 
 | # switch to kernel stack, then check the TIF bits | 
 | # | 
 | io_work: | 
 | 	tm	SP_PSW+1(%r15),0x01	# returning to user ? | 
 | #ifndef CONFIG_PREEMPT | 
 | 	bno	BASED(io_restore)	# no-> skip resched & signal | 
 | #else | 
 | 	bnz	BASED(io_work_user)	# no -> check for preemptive scheduling | 
 | 	# check for preemptive scheduling | 
 | 	icm	%r0,15,__TI_precount(%r9) | 
 | 	bnz	BASED(io_restore)	# preemption disabled | 
 | 	l	%r1,SP_R15(%r15) | 
 | 	s	%r1,BASED(.Lc_spsize) | 
 | 	mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) | 
 | 	xc	__SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain | 
 | 	lr	%r15,%r1 | 
 | io_resume_loop: | 
 | 	tm	__TI_flags+3(%r9),_TIF_NEED_RESCHED | 
 | 	bno	BASED(io_restore) | 
 | 	l	%r1,BASED(.Lpreempt_schedule_irq) | 
 | 	la	%r14,BASED(io_resume_loop) | 
 | 	br	%r1			# call schedule | 
 | #endif | 
 |  | 
 | io_work_user: | 
 | 	l	%r1,__LC_KERNEL_STACK | 
 | 	s	%r1,BASED(.Lc_spsize) | 
 | 	mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) | 
 | 	xc	__SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain | 
 | 	lr	%r15,%r1 | 
 | # | 
 | # One of the work bits is on. Find out which one. | 
 | # Checked are: _TIF_SIGPENDING, _TIF_NEED_RESCHED | 
 | #		and _TIF_MCCK_PENDING | 
 | # | 
 | io_work_loop: | 
 | 	tm	__TI_flags+3(%r9),_TIF_MCCK_PENDING | 
 | 	bo	BASED(io_mcck_pending) | 
 | 	tm	__TI_flags+3(%r9),_TIF_NEED_RESCHED | 
 | 	bo	BASED(io_reschedule) | 
 | 	tm	__TI_flags+3(%r9),_TIF_SIGPENDING | 
 | 	bnz	BASED(io_sigpending) | 
 | 	b	BASED(io_restore) | 
 | io_work_done: | 
 |  | 
 | # | 
 | # _TIF_MCCK_PENDING is set, call handler | 
 | # | 
 | io_mcck_pending: | 
 | 	l	%r1,BASED(.Ls390_handle_mcck) | 
 | 	basr	%r14,%r1		# TIF bit will be cleared by handler | 
 | 	b	BASED(io_work_loop) | 
 |  | 
 | # | 
 | # _TIF_NEED_RESCHED is set, call schedule | 
 | # | 
 | io_reschedule: | 
 | 	TRACE_IRQS_ON | 
 | 	l	%r1,BASED(.Lschedule) | 
 | 	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts | 
 | 	basr	%r14,%r1		# call scheduler | 
 | 	stnsm	__SF_EMPTY(%r15),0xfc	# disable I/O and ext. interrupts | 
 | 	TRACE_IRQS_OFF | 
 | 	tm	__TI_flags+3(%r9),_TIF_WORK_INT | 
 | 	bz	BASED(io_restore)	# there is no work to do | 
 | 	b	BASED(io_work_loop) | 
 |  | 
 | # | 
 | # _TIF_SIGPENDING is set, call do_signal | 
 | # | 
 | io_sigpending: | 
 | 	TRACE_IRQS_ON | 
 | 	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts | 
 | 	la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
 | 	l	%r1,BASED(.Ldo_signal) | 
 | 	basr	%r14,%r1		# call do_signal | 
 | 	stnsm	__SF_EMPTY(%r15),0xfc	# disable I/O and ext. interrupts | 
 | 	TRACE_IRQS_OFF | 
 | 	b	BASED(io_work_loop) | 
 |  | 
 | /* | 
 |  * External interrupt handler routine | 
 |  */ | 
 |  | 
 | 	.globl	ext_int_handler | 
 | ext_int_handler: | 
 | 	STORE_TIMER __LC_ASYNC_ENTER_TIMER | 
 | 	stck	__LC_INT_CLOCK | 
 | 	SAVE_ALL_BASE __LC_SAVE_AREA+16 | 
 | 	SAVE_ALL_ASYNC __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16 | 
 | 	CREATE_STACK_FRAME __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16 | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	tm	SP_PSW+1(%r15),0x01	# interrupting from user ? | 
 | 	bz	BASED(ext_no_vtime) | 
 | 	UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER | 
 | 	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER | 
 | 	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER | 
 | ext_no_vtime: | 
 | #endif | 
 | 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct | 
 | 	TRACE_IRQS_OFF | 
 | 	la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
 | 	lh	%r3,__LC_EXT_INT_CODE	# get interruption code | 
 | 	l	%r1,BASED(.Ldo_extint) | 
 | 	basr	%r14,%r1 | 
 | 	b	BASED(io_return) | 
 |  | 
 | __critical_end: | 
 |  | 
 | /* | 
 |  * Machine check handler routines | 
 |  */ | 
 |  | 
 | 	.globl mcck_int_handler | 
 | mcck_int_handler: | 
 | 	spt	__LC_CPU_TIMER_SAVE_AREA	# revalidate cpu timer | 
 | 	lm	%r0,%r15,__LC_GPREGS_SAVE_AREA	# revalidate gprs | 
 | 	SAVE_ALL_BASE __LC_SAVE_AREA+32 | 
 | 	la	%r12,__LC_MCK_OLD_PSW | 
 | 	tm	__LC_MCCK_CODE,0x80	# system damage? | 
 | 	bo	BASED(mcck_int_main)	# yes -> rest of mcck code invalid | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	mvc	__LC_SAVE_AREA+52(8),__LC_ASYNC_ENTER_TIMER | 
 | 	mvc	__LC_ASYNC_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA | 
 | 	tm	__LC_MCCK_CODE+5,0x02	# stored cpu timer value valid? | 
 | 	bo	BASED(1f) | 
 | 	la	%r14,__LC_SYNC_ENTER_TIMER | 
 | 	clc	0(8,%r14),__LC_ASYNC_ENTER_TIMER | 
 | 	bl	BASED(0f) | 
 | 	la	%r14,__LC_ASYNC_ENTER_TIMER | 
 | 0:	clc	0(8,%r14),__LC_EXIT_TIMER | 
 | 	bl	BASED(0f) | 
 | 	la	%r14,__LC_EXIT_TIMER | 
 | 0:	clc	0(8,%r14),__LC_LAST_UPDATE_TIMER | 
 | 	bl	BASED(0f) | 
 | 	la	%r14,__LC_LAST_UPDATE_TIMER | 
 | 0:	spt	0(%r14) | 
 | 	mvc	__LC_ASYNC_ENTER_TIMER(8),0(%r14) | 
 | 1: | 
 | #endif | 
 | 	tm	__LC_MCCK_CODE+2,0x09	# mwp + ia of old psw valid? | 
 | 	bno	BASED(mcck_int_main)	# no -> skip cleanup critical | 
 | 	tm	__LC_MCK_OLD_PSW+1,0x01	# test problem state bit | 
 | 	bnz	BASED(mcck_int_main)	# from user -> load async stack | 
 | 	clc	__LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_end) | 
 | 	bhe	BASED(mcck_int_main) | 
 | 	clc	__LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_start) | 
 | 	bl	BASED(mcck_int_main) | 
 | 	l	%r14,BASED(.Lcleanup_critical) | 
 | 	basr	%r14,%r14 | 
 | mcck_int_main: | 
 | 	l	%r14,__LC_PANIC_STACK	# are we already on the panic stack? | 
 | 	slr	%r14,%r15 | 
 | 	sra	%r14,PAGE_SHIFT | 
 | 	be	BASED(0f) | 
 | 	l	%r15,__LC_PANIC_STACK	# load panic stack | 
 | 0:	CREATE_STACK_FRAME __LC_MCK_OLD_PSW,__LC_SAVE_AREA+32 | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	tm	__LC_MCCK_CODE+2,0x08	# mwp of old psw valid? | 
 | 	bno	BASED(mcck_no_vtime)	# no -> skip cleanup critical | 
 | 	tm	SP_PSW+1(%r15),0x01	# interrupting from user ? | 
 | 	bz	BASED(mcck_no_vtime) | 
 | 	UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER | 
 | 	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER | 
 | 	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER | 
 | mcck_no_vtime: | 
 | #endif | 
 | 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct | 
 | 	la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
 | 	l	%r1,BASED(.Ls390_mcck) | 
 | 	basr	%r14,%r1		# call machine check handler | 
 | 	tm	SP_PSW+1(%r15),0x01	# returning to user ? | 
 | 	bno	BASED(mcck_return) | 
 | 	l	%r1,__LC_KERNEL_STACK	# switch to kernel stack | 
 | 	s	%r1,BASED(.Lc_spsize) | 
 | 	mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) | 
 | 	xc	__SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain | 
 | 	lr	%r15,%r1 | 
 | 	stosm	__SF_EMPTY(%r15),0x04	# turn dat on | 
 | 	tm	__TI_flags+3(%r9),_TIF_MCCK_PENDING | 
 | 	bno	BASED(mcck_return) | 
 | 	TRACE_IRQS_OFF | 
 | 	l	%r1,BASED(.Ls390_handle_mcck) | 
 | 	basr	%r14,%r1		# call machine check handler | 
 | 	TRACE_IRQS_ON | 
 | mcck_return: | 
 | 	mvc	__LC_RETURN_MCCK_PSW(8),SP_PSW(%r15) # move return PSW | 
 | 	ni	__LC_RETURN_MCCK_PSW+1,0xfd # clear wait state bit | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	mvc	__LC_ASYNC_ENTER_TIMER(8),__LC_SAVE_AREA+52 | 
 | 	tm	__LC_RETURN_MCCK_PSW+1,0x01 # returning to user ? | 
 | 	bno	BASED(0f) | 
 | 	lm	%r0,%r15,SP_R0(%r15)	# load gprs 0-15 | 
 | 	stpt	__LC_EXIT_TIMER | 
 | 	lpsw	__LC_RETURN_MCCK_PSW	# back to caller | 
 | 0: | 
 | #endif | 
 | 	lm	%r0,%r15,SP_R0(%r15)	# load gprs 0-15 | 
 | 	lpsw	__LC_RETURN_MCCK_PSW	# back to caller | 
 |  | 
 | 	RESTORE_ALL __LC_RETURN_MCCK_PSW,0 | 
 |  | 
 | /* | 
 |  * Restart interruption handler, kick starter for additional CPUs | 
 |  */ | 
 | #ifdef CONFIG_SMP | 
 | 	__CPUINIT | 
 | 	.globl restart_int_handler | 
 | restart_int_handler: | 
 | 	l	%r15,__LC_SAVE_AREA+60	# load ksp | 
 | 	lctl	%c0,%c15,__LC_CREGS_SAVE_AREA # get new ctl regs | 
 | 	lam	%a0,%a15,__LC_AREGS_SAVE_AREA | 
 | 	lm	%r6,%r15,__SF_GPRS(%r15) # load registers from clone | 
 | 	stosm	__SF_EMPTY(%r15),0x04	# now we can turn dat on | 
 | 	basr	%r14,0 | 
 | 	l	%r14,restart_addr-.(%r14) | 
 | 	br	%r14			# branch to start_secondary | 
 | restart_addr: | 
 | 	.long	start_secondary | 
 | 	.previous | 
 | #else | 
 | /* | 
 |  * If we do not run with SMP enabled, let the new CPU crash ... | 
 |  */ | 
 | 	.globl restart_int_handler | 
 | restart_int_handler: | 
 | 	basr	%r1,0 | 
 | restart_base: | 
 | 	lpsw	restart_crash-restart_base(%r1) | 
 | 	.align	8 | 
 | restart_crash: | 
 | 	.long	0x000a0000,0x00000000 | 
 | restart_go: | 
 | #endif | 
 |  | 
 | #ifdef CONFIG_CHECK_STACK | 
 | /* | 
 |  * The synchronous or the asynchronous stack overflowed. We are dead. | 
 |  * No need to properly save the registers, we are going to panic anyway. | 
 |  * Setup a pt_regs so that show_trace can provide a good call trace. | 
 |  */ | 
 | stack_overflow: | 
 | 	l	%r15,__LC_PANIC_STACK	# change to panic stack | 
 | 	sl	%r15,BASED(.Lc_spsize) | 
 | 	mvc	SP_PSW(8,%r15),0(%r12)	# move user PSW to stack | 
 | 	stm	%r0,%r11,SP_R0(%r15)	# store gprs %r0-%r11 to kernel stack | 
 | 	la	%r1,__LC_SAVE_AREA | 
 | 	ch	%r12,BASED(.L0x020)	# old psw addr == __LC_SVC_OLD_PSW ? | 
 | 	be	BASED(0f) | 
 | 	ch	%r12,BASED(.L0x028)	# old psw addr == __LC_PGM_OLD_PSW ? | 
 | 	be	BASED(0f) | 
 | 	la	%r1,__LC_SAVE_AREA+16 | 
 | 0:	mvc	SP_R12(16,%r15),0(%r1)	# move %r12-%r15 to stack | 
 | 	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear back chain | 
 | 	l	%r1,BASED(1f)		# branch to kernel_stack_overflow | 
 | 	la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
 | 	br	%r1 | 
 | 1:	.long	kernel_stack_overflow | 
 | #endif | 
 |  | 
 | cleanup_table_system_call: | 
 | 	.long	system_call + 0x80000000, sysc_do_svc + 0x80000000 | 
 | cleanup_table_sysc_return: | 
 | 	.long	sysc_return + 0x80000000, sysc_leave + 0x80000000 | 
 | cleanup_table_sysc_leave: | 
 | 	.long	sysc_leave + 0x80000000, sysc_done + 0x80000000 | 
 | cleanup_table_sysc_work_loop: | 
 | 	.long	sysc_work_loop + 0x80000000, sysc_work_done + 0x80000000 | 
 | cleanup_table_io_return: | 
 | 	.long	io_return + 0x80000000, io_leave + 0x80000000 | 
 | cleanup_table_io_leave: | 
 | 	.long	io_leave + 0x80000000, io_done + 0x80000000 | 
 | cleanup_table_io_work_loop: | 
 | 	.long	io_work_loop + 0x80000000, io_work_done + 0x80000000 | 
 |  | 
 | cleanup_critical: | 
 | 	clc	4(4,%r12),BASED(cleanup_table_system_call) | 
 | 	bl	BASED(0f) | 
 | 	clc	4(4,%r12),BASED(cleanup_table_system_call+4) | 
 | 	bl	BASED(cleanup_system_call) | 
 | 0: | 
 | 	clc	4(4,%r12),BASED(cleanup_table_sysc_return) | 
 | 	bl	BASED(0f) | 
 | 	clc	4(4,%r12),BASED(cleanup_table_sysc_return+4) | 
 | 	bl	BASED(cleanup_sysc_return) | 
 | 0: | 
 | 	clc	4(4,%r12),BASED(cleanup_table_sysc_leave) | 
 | 	bl	BASED(0f) | 
 | 	clc	4(4,%r12),BASED(cleanup_table_sysc_leave+4) | 
 | 	bl	BASED(cleanup_sysc_leave) | 
 | 0: | 
 | 	clc	4(4,%r12),BASED(cleanup_table_sysc_work_loop) | 
 | 	bl	BASED(0f) | 
 | 	clc	4(4,%r12),BASED(cleanup_table_sysc_work_loop+4) | 
 | 	bl	BASED(cleanup_sysc_return) | 
 | 0: | 
 | 	clc	4(4,%r12),BASED(cleanup_table_io_return) | 
 | 	bl	BASED(0f) | 
 | 	clc	4(4,%r12),BASED(cleanup_table_io_return+4) | 
 | 	bl	BASED(cleanup_io_return) | 
 | 0: | 
 | 	clc	4(4,%r12),BASED(cleanup_table_io_leave) | 
 | 	bl	BASED(0f) | 
 | 	clc	4(4,%r12),BASED(cleanup_table_io_leave+4) | 
 | 	bl	BASED(cleanup_io_leave) | 
 | 0: | 
 | 	clc	4(4,%r12),BASED(cleanup_table_io_work_loop) | 
 | 	bl	BASED(0f) | 
 | 	clc	4(4,%r12),BASED(cleanup_table_io_work_loop+4) | 
 | 	bl	BASED(cleanup_io_return) | 
 | 0: | 
 | 	br	%r14 | 
 |  | 
 | cleanup_system_call: | 
 | 	mvc	__LC_RETURN_PSW(8),0(%r12) | 
 | 	c	%r12,BASED(.Lmck_old_psw) | 
 | 	be	BASED(0f) | 
 | 	la	%r12,__LC_SAVE_AREA+16 | 
 | 	b	BASED(1f) | 
 | 0:	la	%r12,__LC_SAVE_AREA+32 | 
 | 1: | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	clc	__LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+4) | 
 | 	bh	BASED(0f) | 
 | 	mvc	__LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER | 
 | 0:	clc	__LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+8) | 
 | 	bhe	BASED(cleanup_vtime) | 
 | #endif | 
 | 	clc	__LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn) | 
 | 	bh	BASED(0f) | 
 | 	mvc	__LC_SAVE_AREA(16),0(%r12) | 
 | 0:	st	%r13,4(%r12) | 
 | 	st	%r12,__LC_SAVE_AREA+48	# argh | 
 | 	SAVE_ALL_SYNC __LC_SVC_OLD_PSW,__LC_SAVE_AREA | 
 | 	CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA | 
 | 	l	%r12,__LC_SAVE_AREA+48	# argh | 
 | 	st	%r15,12(%r12) | 
 | 	lh	%r7,0x8a | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | cleanup_vtime: | 
 | 	clc	__LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+12) | 
 | 	bhe	BASED(cleanup_stime) | 
 | 	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER | 
 | cleanup_stime: | 
 | 	clc	__LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+16) | 
 | 	bh	BASED(cleanup_update) | 
 | 	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER | 
 | cleanup_update: | 
 | 	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER | 
 | #endif | 
 | 	mvc	__LC_RETURN_PSW+4(4),BASED(cleanup_table_system_call+4) | 
 | 	la	%r12,__LC_RETURN_PSW | 
 | 	br	%r14 | 
 | cleanup_system_call_insn: | 
 | 	.long	sysc_saveall + 0x80000000 | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	.long	system_call + 0x80000000 | 
 | 	.long	sysc_vtime + 0x80000000 | 
 | 	.long	sysc_stime + 0x80000000 | 
 | 	.long	sysc_update + 0x80000000 | 
 | #endif | 
 |  | 
 | cleanup_sysc_return: | 
 | 	mvc	__LC_RETURN_PSW(4),0(%r12) | 
 | 	mvc	__LC_RETURN_PSW+4(4),BASED(cleanup_table_sysc_return) | 
 | 	la	%r12,__LC_RETURN_PSW | 
 | 	br	%r14 | 
 |  | 
 | cleanup_sysc_leave: | 
 | 	clc	4(4,%r12),BASED(cleanup_sysc_leave_insn) | 
 | 	be	BASED(2f) | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	mvc	__LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER | 
 | 	clc	4(4,%r12),BASED(cleanup_sysc_leave_insn+4) | 
 | 	be	BASED(2f) | 
 | #endif | 
 | 	mvc	__LC_RETURN_PSW(8),SP_PSW(%r15) | 
 | 	c	%r12,BASED(.Lmck_old_psw) | 
 | 	bne	BASED(0f) | 
 | 	mvc	__LC_SAVE_AREA+32(16),SP_R12(%r15) | 
 | 	b	BASED(1f) | 
 | 0:	mvc	__LC_SAVE_AREA+16(16),SP_R12(%r15) | 
 | 1:	lm	%r0,%r11,SP_R0(%r15) | 
 | 	l	%r15,SP_R15(%r15) | 
 | 2:	la	%r12,__LC_RETURN_PSW | 
 | 	br	%r14 | 
 | cleanup_sysc_leave_insn: | 
 | 	.long	sysc_done - 4 + 0x80000000 | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	.long	sysc_done - 8 + 0x80000000 | 
 | #endif | 
 |  | 
 | cleanup_io_return: | 
 | 	mvc	__LC_RETURN_PSW(4),0(%r12) | 
 | 	mvc	__LC_RETURN_PSW+4(4),BASED(cleanup_table_io_work_loop) | 
 | 	la	%r12,__LC_RETURN_PSW | 
 | 	br	%r14 | 
 |  | 
 | cleanup_io_leave: | 
 | 	clc	4(4,%r12),BASED(cleanup_io_leave_insn) | 
 | 	be	BASED(2f) | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	mvc	__LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER | 
 | 	clc	4(4,%r12),BASED(cleanup_io_leave_insn+4) | 
 | 	be	BASED(2f) | 
 | #endif | 
 | 	mvc	__LC_RETURN_PSW(8),SP_PSW(%r15) | 
 | 	c	%r12,BASED(.Lmck_old_psw) | 
 | 	bne	BASED(0f) | 
 | 	mvc	__LC_SAVE_AREA+32(16),SP_R12(%r15) | 
 | 	b	BASED(1f) | 
 | 0:	mvc	__LC_SAVE_AREA+16(16),SP_R12(%r15) | 
 | 1:	lm	%r0,%r11,SP_R0(%r15) | 
 | 	l	%r15,SP_R15(%r15) | 
 | 2:	la	%r12,__LC_RETURN_PSW | 
 | 	br	%r14 | 
 | cleanup_io_leave_insn: | 
 | 	.long	io_done - 4 + 0x80000000 | 
 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | 
 | 	.long	io_done - 8 + 0x80000000 | 
 | #endif | 
 |  | 
 | /* | 
 |  * Integer constants | 
 |  */ | 
 | 		.align	4 | 
 | .Lc_spsize:	.long	SP_SIZE | 
 | .Lc_overhead:	.long	STACK_FRAME_OVERHEAD | 
 | .Lnr_syscalls:	.long	NR_syscalls | 
 | .L0x018:	.short	0x018 | 
 | .L0x020:	.short	0x020 | 
 | .L0x028:	.short	0x028 | 
 | .L0x030:	.short	0x030 | 
 | .L0x038:	.short	0x038 | 
 | .Lc_1:		.long	1 | 
 |  | 
 | /* | 
 |  * Symbol constants | 
 |  */ | 
 | .Ls390_mcck:	.long	s390_do_machine_check | 
 | .Ls390_handle_mcck: | 
 | 		.long	s390_handle_mcck | 
 | .Lmck_old_psw:	.long	__LC_MCK_OLD_PSW | 
 | .Ldo_IRQ:	.long	do_IRQ | 
 | .Ldo_extint:	.long	do_extint | 
 | .Ldo_signal:	.long	do_signal | 
 | .Lhandle_per:	.long	do_single_step | 
 | .Ldo_execve:	.long	do_execve | 
 | .Lexecve_tail:	.long	execve_tail | 
 | .Ljump_table:	.long	pgm_check_table | 
 | .Lschedule:	.long	schedule | 
 | #ifdef CONFIG_PREEMPT | 
 | .Lpreempt_schedule_irq: | 
 | 		.long	preempt_schedule_irq | 
 | #endif | 
 | .Ltrace:	.long	syscall_trace | 
 | .Lschedtail:	.long	schedule_tail | 
 | .Lsysc_table:	.long	sys_call_table | 
 | #ifdef CONFIG_TRACE_IRQFLAGS | 
 | .Ltrace_irq_on: .long	trace_hardirqs_on | 
 | .Ltrace_irq_off: | 
 | 		.long	trace_hardirqs_off | 
 | .Llockdep_sys_exit: | 
 | 		.long	lockdep_sys_exit | 
 | #endif | 
 | .Lcritical_start: | 
 | 		.long	__critical_start + 0x80000000 | 
 | .Lcritical_end: | 
 | 		.long	__critical_end + 0x80000000 | 
 | .Lcleanup_critical: | 
 | 		.long	cleanup_critical | 
 |  | 
 | 		.section .rodata, "a" | 
 | #define SYSCALL(esa,esame,emu)	.long esa | 
 | sys_call_table: | 
 | #include "syscalls.S" | 
 | #undef SYSCALL |