|  | /* | 
|  | *  arch/s390/kernel/entry64.S | 
|  | *    S390 low-level entry points. | 
|  | * | 
|  | *    Copyright (C) IBM Corp. 1999,2010 | 
|  | *    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/linkage.h> | 
|  | #include <linux/init.h> | 
|  | #include <asm/cache.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 + 8 | 
|  | SP_R2	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 16 | 
|  | SP_R3	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 24 | 
|  | SP_R4	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 32 | 
|  | SP_R5	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 40 | 
|  | SP_R6	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 48 | 
|  | SP_R7	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 56 | 
|  | SP_R8	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 64 | 
|  | SP_R9	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 72 | 
|  | SP_R10	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 80 | 
|  | SP_R11	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 88 | 
|  | SP_R12	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 96 | 
|  | SP_R13	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 104 | 
|  | SP_R14	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 112 | 
|  | SP_R15	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 120 | 
|  | SP_ORIG_R2   =	STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2 | 
|  | SP_ILC	     =	STACK_FRAME_OVERHEAD + __PT_ILC | 
|  | SP_SVCNR      =	STACK_FRAME_OVERHEAD + __PT_SVCNR | 
|  | SP_SIZE      =	STACK_FRAME_OVERHEAD + __PT_SIZE | 
|  |  | 
|  | STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER | 
|  | STACK_SIZE  = 1 << STACK_SHIFT | 
|  |  | 
|  | _TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ | 
|  | _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_PER_TRAP ) | 
|  | _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ | 
|  | _TIF_MCCK_PENDING) | 
|  | _TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \ | 
|  | _TIF_SECCOMP>>8 | _TIF_SYSCALL_TRACEPOINT>>8) | 
|  |  | 
|  | #define BASED(name) name-system_call(%r13) | 
|  |  | 
|  | .macro	HANDLE_SIE_INTERCEPT | 
|  | #if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE) | 
|  | lg	%r3,__LC_SIE_HOOK | 
|  | ltgr	%r3,%r3 | 
|  | jz	0f | 
|  | basr	%r14,%r3 | 
|  | 0: | 
|  | #endif | 
|  | .endm | 
|  |  | 
|  | #ifdef CONFIG_TRACE_IRQFLAGS | 
|  | .macro	TRACE_IRQS_ON | 
|  | basr	%r2,%r0 | 
|  | brasl	%r14,trace_hardirqs_on_caller | 
|  | .endm | 
|  |  | 
|  | .macro	TRACE_IRQS_OFF | 
|  | basr	%r2,%r0 | 
|  | brasl	%r14,trace_hardirqs_off_caller | 
|  | .endm | 
|  | #else | 
|  | #define TRACE_IRQS_ON | 
|  | #define TRACE_IRQS_OFF | 
|  | #endif | 
|  |  | 
|  | #ifdef CONFIG_LOCKDEP | 
|  | .macro	LOCKDEP_SYS_EXIT | 
|  | tm	SP_PSW+1(%r15),0x01	# returning to user ? | 
|  | jz	0f | 
|  | brasl	%r14,lockdep_sys_exit | 
|  | 0: | 
|  | .endm | 
|  | #else | 
|  | #define LOCKDEP_SYS_EXIT | 
|  | #endif | 
|  |  | 
|  | .macro	UPDATE_VTIME lc_from,lc_to,lc_sum | 
|  | lg	%r10,\lc_from | 
|  | slg	%r10,\lc_to | 
|  | alg	%r10,\lc_sum | 
|  | stg	%r10,\lc_sum | 
|  | .endm | 
|  |  | 
|  | /* | 
|  | * 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	SAVE_ALL_SVC psworg,savearea | 
|  | stmg	%r11,%r15,\savearea | 
|  | lg	%r15,__LC_KERNEL_STACK	# problem state -> load ksp | 
|  | aghi	%r15,-SP_SIZE		# make room for registers & psw | 
|  | lg	%r11,__LC_LAST_BREAK | 
|  | .endm | 
|  |  | 
|  | .macro	SAVE_ALL_PGM psworg,savearea | 
|  | stmg	%r11,%r15,\savearea | 
|  | tm	\psworg+1,0x01		# test problem state bit | 
|  | #ifdef CONFIG_CHECK_STACK | 
|  | jnz	1f | 
|  | tml	%r15,STACK_SIZE - CONFIG_STACK_GUARD | 
|  | jnz	2f | 
|  | la	%r12,\psworg | 
|  | j	stack_overflow | 
|  | #else | 
|  | jz	2f | 
|  | #endif | 
|  | 1:	lg	%r15,__LC_KERNEL_STACK	# problem state -> load ksp | 
|  | 2:	aghi	%r15,-SP_SIZE		# make room for registers & psw | 
|  | larl	%r13,system_call | 
|  | lg	%r11,__LC_LAST_BREAK | 
|  | .endm | 
|  |  | 
|  | .macro	SAVE_ALL_ASYNC psworg,savearea | 
|  | stmg	%r11,%r15,\savearea | 
|  | larl	%r13,system_call | 
|  | lg	%r11,__LC_LAST_BREAK | 
|  | la	%r12,\psworg | 
|  | tm	\psworg+1,0x01		# test problem state bit | 
|  | jnz	1f			# from user -> load kernel stack | 
|  | clc	\psworg+8(8),BASED(.Lcritical_end) | 
|  | jhe	0f | 
|  | clc	\psworg+8(8),BASED(.Lcritical_start) | 
|  | jl	0f | 
|  | brasl	%r14,cleanup_critical | 
|  | tm	1(%r12),0x01		# retest problem state after cleanup | 
|  | jnz	1f | 
|  | 0:	lg	%r14,__LC_ASYNC_STACK	# are we already on the async. stack ? | 
|  | slgr	%r14,%r15 | 
|  | srag	%r14,%r14,STACK_SHIFT | 
|  | #ifdef CONFIG_CHECK_STACK | 
|  | jnz	1f | 
|  | tml	%r15,STACK_SIZE - CONFIG_STACK_GUARD | 
|  | jnz	2f | 
|  | j	stack_overflow | 
|  | #else | 
|  | jz	2f | 
|  | #endif | 
|  | 1:	lg	%r15,__LC_ASYNC_STACK	# load async stack | 
|  | 2:	aghi	%r15,-SP_SIZE		# make room for registers & psw | 
|  | .endm | 
|  |  | 
|  | .macro	CREATE_STACK_FRAME savearea | 
|  | xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) | 
|  | stg	%r2,SP_ORIG_R2(%r15)	# store original content of gpr 2 | 
|  | mvc	SP_R11(40,%r15),\savearea # move %r11-%r15 to stack | 
|  | stmg	%r0,%r10,SP_R0(%r15)	# store gprs %r0-%r10 to kernel stack | 
|  | .endm | 
|  |  | 
|  | .macro	RESTORE_ALL psworg,sync | 
|  | mvc	\psworg(16),SP_PSW(%r15) # move user PSW to lowcore | 
|  | .if !\sync | 
|  | ni	\psworg+1,0xfd		# clear wait state bit | 
|  | .endif | 
|  | lg	%r14,__LC_VDSO_PER_CPU | 
|  | lmg	%r0,%r13,SP_R0(%r15)	# load gprs 0-13 of user | 
|  | stpt	__LC_EXIT_TIMER | 
|  | mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER | 
|  | lmg	%r14,%r15,SP_R14(%r15)	# load grps 14-15 of user | 
|  | lpswe	\psworg			# back to caller | 
|  | .endm | 
|  |  | 
|  | .macro	LAST_BREAK | 
|  | srag	%r10,%r11,23 | 
|  | jz	0f | 
|  | stg	%r11,__TI_last_break(%r12) | 
|  | 0: | 
|  | .endm | 
|  |  | 
|  | .macro REENABLE_IRQS | 
|  | mvc	__SF_EMPTY(1,%r15),SP_PSW(%r15) | 
|  | ni	__SF_EMPTY(%r15),0xbf | 
|  | ssm	__SF_EMPTY(%r15) | 
|  | .endm | 
|  |  | 
|  | .section .kprobes.text, "ax" | 
|  |  | 
|  | /* | 
|  | * Scheduler resume function, called by switch_to | 
|  | *  gpr2 = (task_struct *) prev | 
|  | *  gpr3 = (task_struct *) next | 
|  | * Returns: | 
|  | *  gpr2 = prev | 
|  | */ | 
|  | .globl	__switch_to | 
|  | __switch_to: | 
|  | lg	%r4,__THREAD_info(%r2)		# get thread_info of prev | 
|  | lg	%r5,__THREAD_info(%r3)		# get thread_info of next | 
|  | tm	__TI_flags+7(%r4),_TIF_MCCK_PENDING # machine check pending? | 
|  | jz	0f | 
|  | ni	__TI_flags+7(%r4),255-_TIF_MCCK_PENDING	# clear flag in prev | 
|  | oi	__TI_flags+7(%r5),_TIF_MCCK_PENDING	# set it in next | 
|  | 0:	stmg	%r6,%r15,__SF_GPRS(%r15)	# store gprs of prev task | 
|  | stg	%r15,__THREAD_ksp(%r2)		# store kernel stack of prev | 
|  | lg	%r15,__THREAD_ksp(%r3)		# load kernel stack of next | 
|  | lctl	%c4,%c4,__TASK_pid(%r3)		# load pid to control reg. 4 | 
|  | lmg	%r6,%r15,__SF_GPRS(%r15)	# load gprs of next task | 
|  | stg	%r3,__LC_CURRENT		# store task struct of next | 
|  | mvc	__LC_CURRENT_PID+4(4,%r0),__TASK_pid(%r3) # store pid of next | 
|  | stg	%r5,__LC_THREAD_INFO		# store thread info of next | 
|  | aghi	%r5,STACK_SIZE			# end of kernel stack of next | 
|  | stg	%r5,__LC_KERNEL_STACK		# store end of 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: | 
|  | stpt	__LC_SYNC_ENTER_TIMER | 
|  | sysc_saveall: | 
|  | SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA | 
|  | CREATE_STACK_FRAME __LC_SAVE_AREA | 
|  | mvc	SP_PSW(16,%r15),__LC_SVC_OLD_PSW | 
|  | mvc	SP_ILC(4,%r15),__LC_SVC_ILC | 
|  | lg	%r12,__LC_THREAD_INFO	# load pointer to thread_info struct | 
|  | 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 | 
|  | LAST_BREAK | 
|  | sysc_do_svc: | 
|  | llgh	%r7,SP_SVCNR(%r15) | 
|  | slag	%r7,%r7,2	# shift and test for svc 0 | 
|  | jnz	sysc_nr_ok | 
|  | # svc 0: system call number in %r1 | 
|  | llgfr	%r1,%r1		# clear high word in r1 | 
|  | cghi	%r1,NR_syscalls | 
|  | jnl	sysc_nr_ok | 
|  | sth	%r1,SP_SVCNR(%r15) | 
|  | slag	%r7,%r1,2	# shift and test for svc 0 | 
|  | sysc_nr_ok: | 
|  | larl	%r10,sys_call_table | 
|  | #ifdef CONFIG_COMPAT | 
|  | tm	__TI_flags+5(%r12),(_TIF_31BIT>>16)  # running in 31 bit mode ? | 
|  | jno	sysc_noemu | 
|  | larl	%r10,sys_call_table_emu  # use 31 bit emulation system calls | 
|  | sysc_noemu: | 
|  | #endif | 
|  | tm	__TI_flags+6(%r12),_TIF_SYSCALL | 
|  | mvc	SP_ARGS(8,%r15),SP_R7(%r15) | 
|  | lgf	%r8,0(%r7,%r10) # load address of system call routine | 
|  | jnz	sysc_tracesys | 
|  | basr	%r14,%r8	# call sys_xxxx | 
|  | stg	%r2,SP_R2(%r15) # store return value (change R2 on stack) | 
|  |  | 
|  | sysc_return: | 
|  | LOCKDEP_SYS_EXIT | 
|  | sysc_tif: | 
|  | tm	__TI_flags+7(%r12),_TIF_WORK_SVC | 
|  | jnz	sysc_work	# there is work to do (signals etc.) | 
|  | sysc_restore: | 
|  | RESTORE_ALL __LC_RETURN_PSW,1 | 
|  | sysc_done: | 
|  |  | 
|  | # | 
|  | # There is work to do, but first we need to check if we return to userspace. | 
|  | # | 
|  | sysc_work: | 
|  | tm	SP_PSW+1(%r15),0x01	# returning to user ? | 
|  | jno	sysc_restore | 
|  |  | 
|  | # | 
|  | # One of the work bits is on. Find out which one. | 
|  | # | 
|  | sysc_work_tif: | 
|  | tm	__TI_flags+7(%r12),_TIF_MCCK_PENDING | 
|  | jo	sysc_mcck_pending | 
|  | tm	__TI_flags+7(%r12),_TIF_NEED_RESCHED | 
|  | jo	sysc_reschedule | 
|  | tm	__TI_flags+7(%r12),_TIF_SIGPENDING | 
|  | jo	sysc_sigpending | 
|  | tm	__TI_flags+7(%r12),_TIF_NOTIFY_RESUME | 
|  | jo	sysc_notify_resume | 
|  | tm	__TI_flags+7(%r12),_TIF_RESTART_SVC | 
|  | jo	sysc_restart | 
|  | tm	__TI_flags+7(%r12),_TIF_PER_TRAP | 
|  | jo	sysc_singlestep | 
|  | j	sysc_return		# beware of critical section cleanup | 
|  |  | 
|  | # | 
|  | # _TIF_NEED_RESCHED is set, call schedule | 
|  | # | 
|  | sysc_reschedule: | 
|  | larl	%r14,sysc_return | 
|  | jg	schedule		# return point is sysc_return | 
|  |  | 
|  | # | 
|  | # _TIF_MCCK_PENDING is set, call handler | 
|  | # | 
|  | sysc_mcck_pending: | 
|  | larl	%r14,sysc_return | 
|  | jg	s390_handle_mcck	# TIF bit will be cleared by handler | 
|  |  | 
|  | # | 
|  | # _TIF_SIGPENDING is set, call do_signal | 
|  | # | 
|  | sysc_sigpending: | 
|  | ni	__TI_flags+7(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP | 
|  | la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
|  | brasl	%r14,do_signal		# call do_signal | 
|  | tm	__TI_flags+7(%r12),_TIF_RESTART_SVC | 
|  | jo	sysc_restart | 
|  | tm	__TI_flags+7(%r12),_TIF_PER_TRAP | 
|  | jo	sysc_singlestep | 
|  | j	sysc_return | 
|  |  | 
|  | # | 
|  | # _TIF_NOTIFY_RESUME is set, call do_notify_resume | 
|  | # | 
|  | sysc_notify_resume: | 
|  | la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
|  | larl	%r14,sysc_return | 
|  | jg	do_notify_resume	# call do_notify_resume | 
|  |  | 
|  | # | 
|  | # _TIF_RESTART_SVC is set, set up registers and restart svc | 
|  | # | 
|  | sysc_restart: | 
|  | ni	__TI_flags+7(%r12),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC | 
|  | lg	%r7,SP_R2(%r15)		# load new svc number | 
|  | mvc	SP_R2(8,%r15),SP_ORIG_R2(%r15) # restore first argument | 
|  | lmg	%r2,%r6,SP_R2(%r15)	# load svc arguments | 
|  | sth	%r7,SP_SVCNR(%r15) | 
|  | slag	%r7,%r7,2 | 
|  | j	sysc_nr_ok		# restart svc | 
|  |  | 
|  | # | 
|  | # _TIF_PER_TRAP is set, call do_per_trap | 
|  | # | 
|  | sysc_singlestep: | 
|  | ni	__TI_flags+7(%r12),255-_TIF_PER_TRAP	# clear TIF_PER_TRAP | 
|  | xc	SP_SVCNR(2,%r15),SP_SVCNR(%r15)		# clear svc number | 
|  | la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
|  | larl	%r14,sysc_return	# load adr. of system return | 
|  | jg	do_per_trap | 
|  |  | 
|  | # | 
|  | # call tracehook_report_syscall_entry/tracehook_report_syscall_exit before | 
|  | # and after the system call | 
|  | # | 
|  | sysc_tracesys: | 
|  | la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
|  | la	%r3,0 | 
|  | llgh	%r0,SP_SVCNR(%r15) | 
|  | stg	%r0,SP_R2(%r15) | 
|  | brasl	%r14,do_syscall_trace_enter | 
|  | lghi	%r0,NR_syscalls | 
|  | clgr	%r0,%r2 | 
|  | jnh	sysc_tracenogo | 
|  | sllg	%r7,%r2,2		# svc number *4 | 
|  | lgf	%r8,0(%r7,%r10) | 
|  | sysc_tracego: | 
|  | lmg	%r3,%r6,SP_R3(%r15) | 
|  | mvc	SP_ARGS(8,%r15),SP_R7(%r15) | 
|  | lg	%r2,SP_ORIG_R2(%r15) | 
|  | basr	%r14,%r8		# call sys_xxx | 
|  | stg	%r2,SP_R2(%r15)		# store return value | 
|  | sysc_tracenogo: | 
|  | tm	__TI_flags+6(%r12),_TIF_SYSCALL | 
|  | jz	sysc_return | 
|  | la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
|  | larl	%r14,sysc_return	# return point is sysc_return | 
|  | jg	do_syscall_trace_exit | 
|  |  | 
|  | # | 
|  | # a new process exits the kernel with ret_from_fork | 
|  | # | 
|  | .globl	ret_from_fork | 
|  | ret_from_fork: | 
|  | lg	%r13,__LC_SVC_NEW_PSW+8 | 
|  | lg	%r12,__LC_THREAD_INFO	# load pointer to thread_info struct | 
|  | tm	SP_PSW+1(%r15),0x01	# forking a kernel thread ? | 
|  | jo	0f | 
|  | stg	%r15,SP_R15(%r15)	# store stack pointer for new kthread | 
|  | 0:	brasl	%r14,schedule_tail | 
|  | TRACE_IRQS_ON | 
|  | stosm	24(%r15),0x03		# reenable interrupts | 
|  | j	sysc_tracenogo | 
|  |  | 
|  | # | 
|  | # kernel_execve function needs to deal with pt_regs that is not | 
|  | # at the usual place | 
|  | # | 
|  | .globl	kernel_execve | 
|  | kernel_execve: | 
|  | stmg	%r12,%r15,96(%r15) | 
|  | lgr	%r14,%r15 | 
|  | aghi	%r15,-SP_SIZE | 
|  | stg	%r14,__SF_BACKCHAIN(%r15) | 
|  | la	%r12,SP_PTREGS(%r15) | 
|  | xc	0(__PT_SIZE,%r12),0(%r12) | 
|  | lgr	%r5,%r12 | 
|  | brasl	%r14,do_execve | 
|  | ltgfr	%r2,%r2 | 
|  | je	0f | 
|  | aghi	%r15,SP_SIZE | 
|  | lmg	%r12,%r15,96(%r15) | 
|  | br	%r14 | 
|  | # execve succeeded. | 
|  | 0:	stnsm	__SF_EMPTY(%r15),0xfc	# disable interrupts | 
|  | lg	%r15,__LC_KERNEL_STACK	# load ksp | 
|  | aghi	%r15,-SP_SIZE		# make room for registers & psw | 
|  | lg	%r13,__LC_SVC_NEW_PSW+8 | 
|  | mvc	SP_PTREGS(__PT_SIZE,%r15),0(%r12)	# copy pt_regs | 
|  | lg	%r12,__LC_THREAD_INFO | 
|  | xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) | 
|  | stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts | 
|  | brasl	%r14,execve_tail | 
|  | j	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?). | 
|  | */ | 
|  | stpt	__LC_SYNC_ENTER_TIMER | 
|  | tm	__LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception | 
|  | jnz	pgm_per 		 # got per exception -> special case | 
|  | SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA | 
|  | CREATE_STACK_FRAME __LC_SAVE_AREA | 
|  | xc	SP_ILC(4,%r15),SP_ILC(%r15) | 
|  | mvc	SP_PSW(16,%r15),__LC_PGM_OLD_PSW | 
|  | lg	%r12,__LC_THREAD_INFO	# load pointer to thread_info struct | 
|  | tm	SP_PSW+1(%r15),0x01	# interrupting from user ? | 
|  | jz	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 | 
|  | LAST_BREAK | 
|  | pgm_no_vtime: | 
|  | HANDLE_SIE_INTERCEPT | 
|  | stg	%r11,SP_ARGS(%r15) | 
|  | lgf	%r3,__LC_PGM_ILC	# load program interruption code | 
|  | lg	%r4,__LC_TRANS_EXC_CODE | 
|  | REENABLE_IRQS | 
|  | lghi	%r8,0x7f | 
|  | ngr	%r8,%r3 | 
|  | sll	%r8,3 | 
|  | larl	%r1,pgm_check_table | 
|  | lg	%r1,0(%r8,%r1)		# load address of handler routine | 
|  | la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
|  | basr	%r14,%r1		# branch to interrupt-handler | 
|  | pgm_exit: | 
|  | j	sysc_return | 
|  |  | 
|  | # | 
|  | # handle per exception | 
|  | # | 
|  | pgm_per: | 
|  | tm	__LC_PGM_OLD_PSW,0x40	# test if per event recording is on | 
|  | jnz	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(16),__LC_SVC_NEW_PSW | 
|  | je	pgm_svcper | 
|  | # no interesting special case, ignore PER event | 
|  | lpswe	__LC_PGM_OLD_PSW | 
|  |  | 
|  | # | 
|  | # Normal per exception | 
|  | # | 
|  | pgm_per_std: | 
|  | SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA | 
|  | CREATE_STACK_FRAME __LC_SAVE_AREA | 
|  | mvc	SP_PSW(16,%r15),__LC_PGM_OLD_PSW | 
|  | lg	%r12,__LC_THREAD_INFO	# load pointer to thread_info struct | 
|  | tm	SP_PSW+1(%r15),0x01	# interrupting from user ? | 
|  | jz	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 | 
|  | LAST_BREAK | 
|  | pgm_no_vtime2: | 
|  | HANDLE_SIE_INTERCEPT | 
|  | lg	%r1,__TI_task(%r12) | 
|  | tm	SP_PSW+1(%r15),0x01	# kernel per event ? | 
|  | jz	kernel_per | 
|  | mvc	__THREAD_per_cause(2,%r1),__LC_PER_CAUSE | 
|  | mvc	__THREAD_per_address(8,%r1),__LC_PER_ADDRESS | 
|  | mvc	__THREAD_per_paid(1,%r1),__LC_PER_PAID | 
|  | oi	__TI_flags+7(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP | 
|  | lgf	%r3,__LC_PGM_ILC	# load program interruption code | 
|  | lg	%r4,__LC_TRANS_EXC_CODE | 
|  | REENABLE_IRQS | 
|  | lghi	%r8,0x7f | 
|  | ngr	%r8,%r3			# clear per-event-bit and ilc | 
|  | je	pgm_exit2 | 
|  | sll	%r8,3 | 
|  | larl	%r1,pgm_check_table | 
|  | lg	%r1,0(%r8,%r1)		# load address of handler routine | 
|  | la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
|  | basr	%r14,%r1		# branch to interrupt-handler | 
|  | pgm_exit2: | 
|  | j	sysc_return | 
|  |  | 
|  | # | 
|  | # it was a single stepped SVC that is causing all the trouble | 
|  | # | 
|  | pgm_svcper: | 
|  | SAVE_ALL_PGM __LC_SVC_OLD_PSW,__LC_SAVE_AREA | 
|  | CREATE_STACK_FRAME __LC_SAVE_AREA | 
|  | mvc	SP_PSW(16,%r15),__LC_SVC_OLD_PSW | 
|  | mvc	SP_ILC(4,%r15),__LC_SVC_ILC | 
|  | lg	%r12,__LC_THREAD_INFO	# load pointer to thread_info struct | 
|  | 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 | 
|  | LAST_BREAK | 
|  | lg	%r8,__TI_task(%r12) | 
|  | mvc	__THREAD_per_cause(2,%r8),__LC_PER_CAUSE | 
|  | mvc	__THREAD_per_address(8,%r8),__LC_PER_ADDRESS | 
|  | mvc	__THREAD_per_paid(1,%r8),__LC_PER_PAID | 
|  | oi	__TI_flags+7(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP | 
|  | stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts | 
|  | lmg	%r2,%r6,SP_R2(%r15)	# load svc arguments | 
|  | j	sysc_do_svc | 
|  |  | 
|  | # | 
|  | # per was called from kernel, must be kprobes | 
|  | # | 
|  | kernel_per: | 
|  | REENABLE_IRQS | 
|  | xc	SP_SVCNR(2,%r15),SP_SVCNR(%r15)	# clear svc number | 
|  | la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
|  | brasl	%r14,do_per_trap | 
|  | j	pgm_exit | 
|  |  | 
|  | /* | 
|  | * IO interrupt handler routine | 
|  | */ | 
|  | .globl io_int_handler | 
|  | io_int_handler: | 
|  | stck	__LC_INT_CLOCK | 
|  | stpt	__LC_ASYNC_ENTER_TIMER | 
|  | SAVE_ALL_ASYNC __LC_IO_OLD_PSW,__LC_SAVE_AREA+40 | 
|  | CREATE_STACK_FRAME __LC_SAVE_AREA+40 | 
|  | mvc	SP_PSW(16,%r15),0(%r12)	# move user PSW to stack | 
|  | lg	%r12,__LC_THREAD_INFO	# load pointer to thread_info struct | 
|  | tm	SP_PSW+1(%r15),0x01	# interrupting from user ? | 
|  | jz	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 | 
|  | LAST_BREAK | 
|  | io_no_vtime: | 
|  | HANDLE_SIE_INTERCEPT | 
|  | TRACE_IRQS_OFF | 
|  | la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
|  | brasl	%r14,do_IRQ		# call standard irq handler | 
|  | io_return: | 
|  | LOCKDEP_SYS_EXIT | 
|  | TRACE_IRQS_ON | 
|  | io_tif: | 
|  | tm	__TI_flags+7(%r12),_TIF_WORK_INT | 
|  | jnz	io_work 		# there is work to do (signals etc.) | 
|  | io_restore: | 
|  | RESTORE_ALL __LC_RETURN_PSW,0 | 
|  | io_done: | 
|  |  | 
|  | # | 
|  | # There is work todo, find out in which context we have been interrupted: | 
|  | # 1) if we return to user space we can do all _TIF_WORK_INT work | 
|  | # 2) if we return to kernel code and kvm is enabled check if we need to | 
|  | #    modify the psw to leave SIE | 
|  | # 3) if we return to kernel code and preemptive scheduling is enabled check | 
|  | #    the preemption counter and if it is zero call preempt_schedule_irq | 
|  | # Before any work can be done, a switch to the kernel stack is required. | 
|  | # | 
|  | io_work: | 
|  | tm	SP_PSW+1(%r15),0x01	# returning to user ? | 
|  | jo	io_work_user		# yes -> do resched & signal | 
|  | #ifdef CONFIG_PREEMPT | 
|  | # check for preemptive scheduling | 
|  | icm	%r0,15,__TI_precount(%r12) | 
|  | jnz	io_restore		# preemption is disabled | 
|  | tm	__TI_flags+7(%r12),_TIF_NEED_RESCHED | 
|  | jno	io_restore | 
|  | # switch to kernel stack | 
|  | lg	%r1,SP_R15(%r15) | 
|  | aghi	%r1,-SP_SIZE | 
|  | mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) | 
|  | xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain | 
|  | lgr	%r15,%r1 | 
|  | # TRACE_IRQS_ON already done at io_return, call | 
|  | # TRACE_IRQS_OFF to keep things symmetrical | 
|  | TRACE_IRQS_OFF | 
|  | brasl	%r14,preempt_schedule_irq | 
|  | j	io_return | 
|  | #else | 
|  | j	io_restore | 
|  | #endif | 
|  |  | 
|  | # | 
|  | # Need to do work before returning to userspace, switch to kernel stack | 
|  | # | 
|  | io_work_user: | 
|  | lg	%r1,__LC_KERNEL_STACK | 
|  | aghi	%r1,-SP_SIZE | 
|  | mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) | 
|  | xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain | 
|  | lgr	%r15,%r1 | 
|  |  | 
|  | # | 
|  | # One of the work bits is on. Find out which one. | 
|  | # Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED | 
|  | #	       and _TIF_MCCK_PENDING | 
|  | # | 
|  | io_work_tif: | 
|  | tm	__TI_flags+7(%r12),_TIF_MCCK_PENDING | 
|  | jo	io_mcck_pending | 
|  | tm	__TI_flags+7(%r12),_TIF_NEED_RESCHED | 
|  | jo	io_reschedule | 
|  | tm	__TI_flags+7(%r12),_TIF_SIGPENDING | 
|  | jo	io_sigpending | 
|  | tm	__TI_flags+7(%r12),_TIF_NOTIFY_RESUME | 
|  | jo	io_notify_resume | 
|  | j	io_return		# beware of critical section cleanup | 
|  |  | 
|  | # | 
|  | # _TIF_MCCK_PENDING is set, call handler | 
|  | # | 
|  | io_mcck_pending: | 
|  | # TRACE_IRQS_ON already done at io_return | 
|  | brasl	%r14,s390_handle_mcck	# TIF bit will be cleared by handler | 
|  | TRACE_IRQS_OFF | 
|  | j	io_return | 
|  |  | 
|  | # | 
|  | # _TIF_NEED_RESCHED is set, call schedule | 
|  | # | 
|  | io_reschedule: | 
|  | # TRACE_IRQS_ON already done at io_return | 
|  | stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts | 
|  | brasl	%r14,schedule		# call scheduler | 
|  | stnsm	__SF_EMPTY(%r15),0xfc	# disable I/O and ext. interrupts | 
|  | TRACE_IRQS_OFF | 
|  | j	io_return | 
|  |  | 
|  | # | 
|  | # _TIF_SIGPENDING or is set, call do_signal | 
|  | # | 
|  | io_sigpending: | 
|  | # TRACE_IRQS_ON already done at io_return | 
|  | stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts | 
|  | la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
|  | brasl	%r14,do_signal		# call do_signal | 
|  | stnsm	__SF_EMPTY(%r15),0xfc	# disable I/O and ext. interrupts | 
|  | TRACE_IRQS_OFF | 
|  | j	io_return | 
|  |  | 
|  | # | 
|  | # _TIF_NOTIFY_RESUME or is set, call do_notify_resume | 
|  | # | 
|  | io_notify_resume: | 
|  | # TRACE_IRQS_ON already done at io_return | 
|  | stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts | 
|  | la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
|  | brasl	%r14,do_notify_resume	# call do_notify_resume | 
|  | stnsm	__SF_EMPTY(%r15),0xfc	# disable I/O and ext. interrupts | 
|  | TRACE_IRQS_OFF | 
|  | j	io_return | 
|  |  | 
|  | /* | 
|  | * External interrupt handler routine | 
|  | */ | 
|  | .globl	ext_int_handler | 
|  | ext_int_handler: | 
|  | stck	__LC_INT_CLOCK | 
|  | stpt	__LC_ASYNC_ENTER_TIMER | 
|  | SAVE_ALL_ASYNC __LC_EXT_OLD_PSW,__LC_SAVE_AREA+40 | 
|  | CREATE_STACK_FRAME __LC_SAVE_AREA+40 | 
|  | mvc	SP_PSW(16,%r15),0(%r12)	# move user PSW to stack | 
|  | lg	%r12,__LC_THREAD_INFO	# load pointer to thread_info struct | 
|  | tm	SP_PSW+1(%r15),0x01	# interrupting from user ? | 
|  | jz	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 | 
|  | LAST_BREAK | 
|  | ext_no_vtime: | 
|  | HANDLE_SIE_INTERCEPT | 
|  | TRACE_IRQS_OFF | 
|  | lghi	%r1,4096 | 
|  | la	%r2,SP_PTREGS(%r15)	# address of register-save area | 
|  | llgf	%r3,__LC_CPU_ADDRESS	# get cpu address + interruption code | 
|  | llgf	%r4,__LC_EXT_PARAMS	# get external parameter | 
|  | lg	%r5,__LC_EXT_PARAMS2-4096(%r1)	# get 64 bit external parameter | 
|  | brasl	%r14,do_extint | 
|  | j	io_return | 
|  |  | 
|  | __critical_end: | 
|  |  | 
|  | /* | 
|  | * Machine check handler routines | 
|  | */ | 
|  | .globl mcck_int_handler | 
|  | mcck_int_handler: | 
|  | stck	__LC_MCCK_CLOCK | 
|  | la	%r1,4095		# revalidate r1 | 
|  | spt	__LC_CPU_TIMER_SAVE_AREA-4095(%r1)	# revalidate cpu timer | 
|  | lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs | 
|  | stmg	%r11,%r15,__LC_SAVE_AREA+80 | 
|  | larl	%r13,system_call | 
|  | lg	%r11,__LC_LAST_BREAK | 
|  | la	%r12,__LC_MCK_OLD_PSW | 
|  | tm	__LC_MCCK_CODE,0x80	# system damage? | 
|  | jo	mcck_int_main		# yes -> rest of mcck code invalid | 
|  | la	%r14,4095 | 
|  | mvc	__LC_MCCK_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA-4095(%r14) | 
|  | tm	__LC_MCCK_CODE+5,0x02	# stored cpu timer value valid? | 
|  | jo	1f | 
|  | la	%r14,__LC_SYNC_ENTER_TIMER | 
|  | clc	0(8,%r14),__LC_ASYNC_ENTER_TIMER | 
|  | jl	0f | 
|  | la	%r14,__LC_ASYNC_ENTER_TIMER | 
|  | 0:	clc	0(8,%r14),__LC_EXIT_TIMER | 
|  | jl	0f | 
|  | la	%r14,__LC_EXIT_TIMER | 
|  | 0:	clc	0(8,%r14),__LC_LAST_UPDATE_TIMER | 
|  | jl	0f | 
|  | la	%r14,__LC_LAST_UPDATE_TIMER | 
|  | 0:	spt	0(%r14) | 
|  | mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14) | 
|  | 1:	tm	__LC_MCCK_CODE+2,0x09	# mwp + ia of old psw valid? | 
|  | jno	mcck_int_main		# no -> skip cleanup critical | 
|  | tm	__LC_MCK_OLD_PSW+1,0x01 # test problem state bit | 
|  | jnz	mcck_int_main		# from user -> load kernel stack | 
|  | clc	__LC_MCK_OLD_PSW+8(8),BASED(.Lcritical_end) | 
|  | jhe	mcck_int_main | 
|  | clc	__LC_MCK_OLD_PSW+8(8),BASED(.Lcritical_start) | 
|  | jl	mcck_int_main | 
|  | brasl	%r14,cleanup_critical | 
|  | mcck_int_main: | 
|  | lg	%r14,__LC_PANIC_STACK	# are we already on the panic stack? | 
|  | slgr	%r14,%r15 | 
|  | srag	%r14,%r14,PAGE_SHIFT | 
|  | jz	0f | 
|  | lg	%r15,__LC_PANIC_STACK	# load panic stack | 
|  | 0:	aghi	%r15,-SP_SIZE		# make room for registers & psw | 
|  | CREATE_STACK_FRAME __LC_SAVE_AREA+80 | 
|  | mvc	SP_PSW(16,%r15),0(%r12) | 
|  | lg	%r12,__LC_THREAD_INFO	# load pointer to thread_info struct | 
|  | tm	__LC_MCCK_CODE+2,0x08	# mwp of old psw valid? | 
|  | jno	mcck_no_vtime		# no -> no timer update | 
|  | tm	SP_PSW+1(%r15),0x01	# interrupting from user ? | 
|  | jz	mcck_no_vtime | 
|  | UPDATE_VTIME __LC_EXIT_TIMER,__LC_MCCK_ENTER_TIMER,__LC_USER_TIMER | 
|  | UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER | 
|  | mvc	__LC_LAST_UPDATE_TIMER(8),__LC_MCCK_ENTER_TIMER | 
|  | LAST_BREAK | 
|  | mcck_no_vtime: | 
|  | la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
|  | brasl	%r14,s390_do_machine_check | 
|  | tm	SP_PSW+1(%r15),0x01	# returning to user ? | 
|  | jno	mcck_return | 
|  | lg	%r1,__LC_KERNEL_STACK	# switch to kernel stack | 
|  | aghi	%r1,-SP_SIZE | 
|  | mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) | 
|  | xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain | 
|  | lgr	%r15,%r1 | 
|  | stosm	__SF_EMPTY(%r15),0x04	# turn dat on | 
|  | tm	__TI_flags+7(%r12),_TIF_MCCK_PENDING | 
|  | jno	mcck_return | 
|  | HANDLE_SIE_INTERCEPT | 
|  | TRACE_IRQS_OFF | 
|  | brasl	%r14,s390_handle_mcck | 
|  | TRACE_IRQS_ON | 
|  | mcck_return: | 
|  | mvc	__LC_RETURN_MCCK_PSW(16),SP_PSW(%r15) # move return PSW | 
|  | ni	__LC_RETURN_MCCK_PSW+1,0xfd # clear wait state bit | 
|  | lmg	%r0,%r15,SP_R0(%r15)	# load gprs 0-15 | 
|  | tm	__LC_RETURN_MCCK_PSW+1,0x01 # returning to user ? | 
|  | jno	0f | 
|  | stpt	__LC_EXIT_TIMER | 
|  | 0:	lpswe	__LC_RETURN_MCCK_PSW	# back to caller | 
|  | mcck_done: | 
|  |  | 
|  | /* | 
|  | * Restart interruption handler, kick starter for additional CPUs | 
|  | */ | 
|  | #ifdef CONFIG_SMP | 
|  | __CPUINIT | 
|  | .globl restart_int_handler | 
|  | restart_int_handler: | 
|  | basr	%r1,0 | 
|  | restart_base: | 
|  | spt	restart_vtime-restart_base(%r1) | 
|  | stck	__LC_LAST_UPDATE_CLOCK | 
|  | mvc	__LC_LAST_UPDATE_TIMER(8),restart_vtime-restart_base(%r1) | 
|  | mvc	__LC_EXIT_TIMER(8),restart_vtime-restart_base(%r1) | 
|  | lg	%r15,__LC_SAVE_AREA+120 # load ksp | 
|  | lghi	%r10,__LC_CREGS_SAVE_AREA | 
|  | lctlg	%c0,%c15,0(%r10) # get new ctl regs | 
|  | lghi	%r10,__LC_AREGS_SAVE_AREA | 
|  | lam	%a0,%a15,0(%r10) | 
|  | lmg	%r6,%r15,__SF_GPRS(%r15) # load registers from clone | 
|  | lg	%r1,__LC_THREAD_INFO | 
|  | mvc	__LC_USER_TIMER(8),__TI_user_timer(%r1) | 
|  | mvc	__LC_SYSTEM_TIMER(8),__TI_system_timer(%r1) | 
|  | xc	__LC_STEAL_TIMER(8),__LC_STEAL_TIMER | 
|  | stosm	__SF_EMPTY(%r15),0x04	# now we can turn dat on | 
|  | brasl	%r14,start_secondary | 
|  | .align	8 | 
|  | restart_vtime: | 
|  | .long	0x7fffffff,0xffffffff | 
|  | .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: | 
|  | lpswe	restart_crash-restart_base(%r1) | 
|  | .align 8 | 
|  | restart_crash: | 
|  | .long  0x000a0000,0x00000000,0x00000000,0x00000000 | 
|  | restart_go: | 
|  | #endif | 
|  |  | 
|  | .section .kprobes.text, "ax" | 
|  |  | 
|  | #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: | 
|  | lg	%r15,__LC_PANIC_STACK	# change to panic stack | 
|  | aghi	%r15,-SP_SIZE | 
|  | mvc	SP_PSW(16,%r15),0(%r12)	# move user PSW to stack | 
|  | stmg	%r0,%r10,SP_R0(%r15)	# store gprs %r0-%r10 to kernel stack | 
|  | la	%r1,__LC_SAVE_AREA | 
|  | chi	%r12,__LC_SVC_OLD_PSW | 
|  | je	0f | 
|  | chi	%r12,__LC_PGM_OLD_PSW | 
|  | je	0f | 
|  | la	%r1,__LC_SAVE_AREA+40 | 
|  | 0:	mvc	SP_R11(40,%r15),0(%r1)	# move %r11-%r15 to stack | 
|  | mvc	SP_ARGS(8,%r15),__LC_LAST_BREAK | 
|  | xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) # clear back chain | 
|  | la	%r2,SP_PTREGS(%r15)	# load pt_regs | 
|  | jg	kernel_stack_overflow | 
|  | #endif | 
|  |  | 
|  | cleanup_table_system_call: | 
|  | .quad	system_call, sysc_do_svc | 
|  | cleanup_table_sysc_tif: | 
|  | .quad	sysc_tif, sysc_restore | 
|  | cleanup_table_sysc_restore: | 
|  | .quad	sysc_restore, sysc_done | 
|  | cleanup_table_io_tif: | 
|  | .quad	io_tif, io_restore | 
|  | cleanup_table_io_restore: | 
|  | .quad	io_restore, io_done | 
|  |  | 
|  | cleanup_critical: | 
|  | clc	8(8,%r12),BASED(cleanup_table_system_call) | 
|  | jl	0f | 
|  | clc	8(8,%r12),BASED(cleanup_table_system_call+8) | 
|  | jl	cleanup_system_call | 
|  | 0: | 
|  | clc	8(8,%r12),BASED(cleanup_table_sysc_tif) | 
|  | jl	0f | 
|  | clc	8(8,%r12),BASED(cleanup_table_sysc_tif+8) | 
|  | jl	cleanup_sysc_tif | 
|  | 0: | 
|  | clc	8(8,%r12),BASED(cleanup_table_sysc_restore) | 
|  | jl	0f | 
|  | clc	8(8,%r12),BASED(cleanup_table_sysc_restore+8) | 
|  | jl	cleanup_sysc_restore | 
|  | 0: | 
|  | clc	8(8,%r12),BASED(cleanup_table_io_tif) | 
|  | jl	0f | 
|  | clc	8(8,%r12),BASED(cleanup_table_io_tif+8) | 
|  | jl	cleanup_io_tif | 
|  | 0: | 
|  | clc	8(8,%r12),BASED(cleanup_table_io_restore) | 
|  | jl	0f | 
|  | clc	8(8,%r12),BASED(cleanup_table_io_restore+8) | 
|  | jl	cleanup_io_restore | 
|  | 0: | 
|  | br	%r14 | 
|  |  | 
|  | cleanup_system_call: | 
|  | mvc	__LC_RETURN_PSW(16),0(%r12) | 
|  | clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+8) | 
|  | jh	0f | 
|  | mvc	__LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER | 
|  | cghi	%r12,__LC_MCK_OLD_PSW | 
|  | je	0f | 
|  | mvc	__LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER | 
|  | 0:	cghi	%r12,__LC_MCK_OLD_PSW | 
|  | la	%r12,__LC_SAVE_AREA+80 | 
|  | je	0f | 
|  | la	%r12,__LC_SAVE_AREA+40 | 
|  | 0:	clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+16) | 
|  | jhe	cleanup_vtime | 
|  | clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn) | 
|  | jh	0f | 
|  | mvc	__LC_SAVE_AREA(40),0(%r12) | 
|  | 0:	lg	%r15,__LC_KERNEL_STACK	# problem state -> load ksp | 
|  | aghi	%r15,-SP_SIZE		# make room for registers & psw | 
|  | stg	%r15,32(%r12) | 
|  | stg	%r11,0(%r12) | 
|  | CREATE_STACK_FRAME __LC_SAVE_AREA | 
|  | mvc	SP_PSW(16,%r15),__LC_SVC_OLD_PSW | 
|  | mvc	SP_ILC(4,%r15),__LC_SVC_ILC | 
|  | mvc	8(8,%r12),__LC_THREAD_INFO | 
|  | cleanup_vtime: | 
|  | clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+24) | 
|  | jhe	cleanup_stime | 
|  | UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER | 
|  | cleanup_stime: | 
|  | clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+32) | 
|  | jh	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 | 
|  | srag	%r12,%r11,23 | 
|  | lg	%r12,__LC_THREAD_INFO | 
|  | jz	0f | 
|  | stg	%r11,__TI_last_break(%r12) | 
|  | 0:	mvc	__LC_RETURN_PSW+8(8),BASED(cleanup_table_system_call+8) | 
|  | la	%r12,__LC_RETURN_PSW | 
|  | br	%r14 | 
|  | cleanup_system_call_insn: | 
|  | .quad	sysc_saveall | 
|  | .quad	system_call | 
|  | .quad	sysc_vtime | 
|  | .quad	sysc_stime | 
|  | .quad	sysc_update | 
|  |  | 
|  | cleanup_sysc_tif: | 
|  | mvc	__LC_RETURN_PSW(8),0(%r12) | 
|  | mvc	__LC_RETURN_PSW+8(8),BASED(cleanup_table_sysc_tif) | 
|  | la	%r12,__LC_RETURN_PSW | 
|  | br	%r14 | 
|  |  | 
|  | cleanup_sysc_restore: | 
|  | clc	8(8,%r12),BASED(cleanup_sysc_restore_insn) | 
|  | je	2f | 
|  | clc	8(8,%r12),BASED(cleanup_sysc_restore_insn+8) | 
|  | jhe	0f | 
|  | mvc	__LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER | 
|  | cghi	%r12,__LC_MCK_OLD_PSW | 
|  | je	0f | 
|  | mvc	__LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER | 
|  | 0:	mvc	__LC_RETURN_PSW(16),SP_PSW(%r15) | 
|  | cghi	%r12,__LC_MCK_OLD_PSW | 
|  | la	%r12,__LC_SAVE_AREA+80 | 
|  | je	1f | 
|  | la	%r12,__LC_SAVE_AREA+40 | 
|  | 1:	mvc	0(40,%r12),SP_R11(%r15) | 
|  | lmg	%r0,%r10,SP_R0(%r15) | 
|  | lg	%r15,SP_R15(%r15) | 
|  | 2:	la	%r12,__LC_RETURN_PSW | 
|  | br	%r14 | 
|  | cleanup_sysc_restore_insn: | 
|  | .quad	sysc_done - 4 | 
|  | .quad	sysc_done - 16 | 
|  |  | 
|  | cleanup_io_tif: | 
|  | mvc	__LC_RETURN_PSW(8),0(%r12) | 
|  | mvc	__LC_RETURN_PSW+8(8),BASED(cleanup_table_io_tif) | 
|  | la	%r12,__LC_RETURN_PSW | 
|  | br	%r14 | 
|  |  | 
|  | cleanup_io_restore: | 
|  | clc	8(8,%r12),BASED(cleanup_io_restore_insn) | 
|  | je	1f | 
|  | clc	8(8,%r12),BASED(cleanup_io_restore_insn+8) | 
|  | jhe	0f | 
|  | mvc	__LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER | 
|  | 0:	mvc	__LC_RETURN_PSW(16),SP_PSW(%r15) | 
|  | mvc	__LC_SAVE_AREA+80(40),SP_R11(%r15) | 
|  | lmg	%r0,%r10,SP_R0(%r15) | 
|  | lg	%r15,SP_R15(%r15) | 
|  | 1:	la	%r12,__LC_RETURN_PSW | 
|  | br	%r14 | 
|  | cleanup_io_restore_insn: | 
|  | .quad	io_done - 4 | 
|  | .quad	io_done - 16 | 
|  |  | 
|  | /* | 
|  | * Integer constants | 
|  | */ | 
|  | .align	4 | 
|  | .Lcritical_start: | 
|  | .quad	__critical_start | 
|  | .Lcritical_end: | 
|  | .quad	__critical_end | 
|  |  | 
|  | .section .rodata, "a" | 
|  | #define SYSCALL(esa,esame,emu)	.long esame | 
|  | .globl	sys_call_table | 
|  | sys_call_table: | 
|  | #include "syscalls.S" | 
|  | #undef SYSCALL | 
|  |  | 
|  | #ifdef CONFIG_COMPAT | 
|  |  | 
|  | #define SYSCALL(esa,esame,emu)	.long emu | 
|  | sys_call_table_emu: | 
|  | #include "syscalls.S" | 
|  | #undef SYSCALL | 
|  | #endif |