xref: /linux/arch/s390/kernel/entry.S (revision b889fcf63cb62e7fdb7816565e28f44dbe4a76a5)
1/*
2 *    S390 low-level entry points.
3 *
4 *    Copyright IBM Corp. 1999, 2012
5 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
6 *		 Hartmut Penner (hp@de.ibm.com),
7 *		 Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
8 *		 Heiko Carstens <heiko.carstens@de.ibm.com>
9 */
10
11#include <linux/init.h>
12#include <linux/linkage.h>
13#include <asm/cache.h>
14#include <asm/errno.h>
15#include <asm/ptrace.h>
16#include <asm/thread_info.h>
17#include <asm/asm-offsets.h>
18#include <asm/unistd.h>
19#include <asm/page.h>
20#include <asm/sigp.h>
21
22__PT_R0      =	__PT_GPRS
23__PT_R1      =	__PT_GPRS + 4
24__PT_R2      =	__PT_GPRS + 8
25__PT_R3      =	__PT_GPRS + 12
26__PT_R4      =	__PT_GPRS + 16
27__PT_R5      =	__PT_GPRS + 20
28__PT_R6      =	__PT_GPRS + 24
29__PT_R7      =	__PT_GPRS + 28
30__PT_R8      =	__PT_GPRS + 32
31__PT_R9      =	__PT_GPRS + 36
32__PT_R10     =	__PT_GPRS + 40
33__PT_R11     =	__PT_GPRS + 44
34__PT_R12     =	__PT_GPRS + 48
35__PT_R13     =	__PT_GPRS + 524
36__PT_R14     =	__PT_GPRS + 56
37__PT_R15     =	__PT_GPRS + 60
38
39_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
40		 _TIF_MCCK_PENDING | _TIF_PER_TRAP )
41_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
42		 _TIF_MCCK_PENDING)
43_TIF_TRACE    = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
44		 _TIF_SYSCALL_TRACEPOINT)
45
46STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
47STACK_SIZE  = 1 << STACK_SHIFT
48
49#define BASED(name) name-system_call(%r13)
50
51	.macro	TRACE_IRQS_ON
52#ifdef CONFIG_TRACE_IRQFLAGS
53	basr	%r2,%r0
54	l	%r1,BASED(.Lhardirqs_on)
55	basr	%r14,%r1		# call trace_hardirqs_on_caller
56#endif
57	.endm
58
59	.macro	TRACE_IRQS_OFF
60#ifdef CONFIG_TRACE_IRQFLAGS
61	basr	%r2,%r0
62	l	%r1,BASED(.Lhardirqs_off)
63	basr	%r14,%r1		# call trace_hardirqs_off_caller
64#endif
65	.endm
66
67	.macro	LOCKDEP_SYS_EXIT
68#ifdef CONFIG_LOCKDEP
69	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
70	jz	.+10
71	l	%r1,BASED(.Llockdep_sys_exit)
72	basr	%r14,%r1		# call lockdep_sys_exit
73#endif
74	.endm
75
76	.macro	CHECK_STACK stacksize,savearea
77#ifdef CONFIG_CHECK_STACK
78	tml	%r15,\stacksize - CONFIG_STACK_GUARD
79	la	%r14,\savearea
80	jz	stack_overflow
81#endif
82	.endm
83
84	.macro	SWITCH_ASYNC savearea,stack,shift
85	tmh	%r8,0x0001		# interrupting from user ?
86	jnz	1f
87	lr	%r14,%r9
88	sl	%r14,BASED(.Lcritical_start)
89	cl	%r14,BASED(.Lcritical_length)
90	jhe	0f
91	la	%r11,\savearea		# inside critical section, do cleanup
92	bras	%r14,cleanup_critical
93	tmh	%r8,0x0001		# retest problem state after cleanup
94	jnz	1f
950:	l	%r14,\stack		# are we already on the target stack?
96	slr	%r14,%r15
97	sra	%r14,\shift
98	jnz	1f
99	CHECK_STACK 1<<\shift,\savearea
100	j	2f
1011:	l	%r15,\stack		# load target stack
1022:	ahi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
103	la	%r11,STACK_FRAME_OVERHEAD(%r15)
104	.endm
105
106	.macro	ADD64 high,low,timer
107	al	\high,\timer
108	al	\low,4+\timer
109	brc	12,.+8
110	ahi	\high,1
111	.endm
112
113	.macro	SUB64 high,low,timer
114	sl	\high,\timer
115	sl	\low,4+\timer
116	brc	3,.+8
117	ahi	\high,-1
118	.endm
119
120	.macro	UPDATE_VTIME high,low,enter_timer
121	lm	\high,\low,__LC_EXIT_TIMER
122	SUB64	\high,\low,\enter_timer
123	ADD64	\high,\low,__LC_USER_TIMER
124	stm	\high,\low,__LC_USER_TIMER
125	lm	\high,\low,__LC_LAST_UPDATE_TIMER
126	SUB64	\high,\low,__LC_EXIT_TIMER
127	ADD64	\high,\low,__LC_SYSTEM_TIMER
128	stm	\high,\low,__LC_SYSTEM_TIMER
129	mvc	__LC_LAST_UPDATE_TIMER(8),\enter_timer
130	.endm
131
132	.macro REENABLE_IRQS
133	st	%r8,__LC_RETURN_PSW
134	ni	__LC_RETURN_PSW,0xbf
135	ssm	__LC_RETURN_PSW
136	.endm
137
138	.section .kprobes.text, "ax"
139
140/*
141 * Scheduler resume function, called by switch_to
142 *  gpr2 = (task_struct *) prev
143 *  gpr3 = (task_struct *) next
144 * Returns:
145 *  gpr2 = prev
146 */
147ENTRY(__switch_to)
148	stm	%r6,%r15,__SF_GPRS(%r15)	# store gprs of prev task
149	st	%r15,__THREAD_ksp(%r2)		# store kernel stack of prev
150	l	%r4,__THREAD_info(%r2)		# get thread_info of prev
151	l	%r5,__THREAD_info(%r3)		# get thread_info of next
152	lr	%r15,%r5
153	ahi	%r15,STACK_SIZE			# end of kernel stack of next
154	st	%r3,__LC_CURRENT		# store task struct of next
155	st	%r5,__LC_THREAD_INFO		# store thread info of next
156	st	%r15,__LC_KERNEL_STACK		# store end of kernel stack
157	lctl	%c4,%c4,__TASK_pid(%r3)		# load pid to control reg. 4
158	mvc	__LC_CURRENT_PID(4,%r0),__TASK_pid(%r3)	# store pid of next
159	l	%r15,__THREAD_ksp(%r3)		# load kernel stack of next
160	tm	__TI_flags+3(%r4),_TIF_MCCK_PENDING # machine check pending?
161	jz	0f
162	ni	__TI_flags+3(%r4),255-_TIF_MCCK_PENDING	# clear flag in prev
163	oi	__TI_flags+3(%r5),_TIF_MCCK_PENDING	# set it in next
1640:	lm	%r6,%r15,__SF_GPRS(%r15)	# load gprs of next task
165	br	%r14
166
167__critical_start:
168/*
169 * SVC interrupt handler routine. System calls are synchronous events and
170 * are executed with interrupts enabled.
171 */
172
173ENTRY(system_call)
174	stpt	__LC_SYNC_ENTER_TIMER
175sysc_stm:
176	stm	%r8,%r15,__LC_SAVE_AREA_SYNC
177	l	%r12,__LC_THREAD_INFO
178	l	%r13,__LC_SVC_NEW_PSW+4
179sysc_per:
180	l	%r15,__LC_KERNEL_STACK
181	ahi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
182	la	%r11,STACK_FRAME_OVERHEAD(%r15)	# pointer to pt_regs
183sysc_vtime:
184	UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
185	stm	%r0,%r7,__PT_R0(%r11)
186	mvc	__PT_R8(32,%r11),__LC_SAVE_AREA_SYNC
187	mvc	__PT_PSW(8,%r11),__LC_SVC_OLD_PSW
188	mvc	__PT_INT_CODE(4,%r11),__LC_SVC_ILC
189sysc_do_svc:
190	oi	__TI_flags+3(%r12),_TIF_SYSCALL
191	lh	%r8,__PT_INT_CODE+2(%r11)
192	sla	%r8,2				# shift and test for svc0
193	jnz	sysc_nr_ok
194	# svc 0: system call number in %r1
195	cl	%r1,BASED(.Lnr_syscalls)
196	jnl	sysc_nr_ok
197	sth	%r1,__PT_INT_CODE+2(%r11)
198	lr	%r8,%r1
199	sla	%r8,2
200sysc_nr_ok:
201	l	%r10,BASED(.Lsys_call_table)	# 31 bit system call table
202	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
203	st	%r2,__PT_ORIG_GPR2(%r11)
204	st	%r7,STACK_FRAME_OVERHEAD(%r15)
205	l	%r9,0(%r8,%r10)			# get system call addr.
206	tm	__TI_flags+2(%r12),_TIF_TRACE >> 8
207	jnz	sysc_tracesys
208	basr	%r14,%r9			# call sys_xxxx
209	st	%r2,__PT_R2(%r11)		# store return value
210
211sysc_return:
212	LOCKDEP_SYS_EXIT
213sysc_tif:
214	tm	__PT_PSW+1(%r11),0x01		# returning to user ?
215	jno	sysc_restore
216	tm	__TI_flags+3(%r12),_TIF_WORK_SVC
217	jnz	sysc_work			# check for work
218	ni	__TI_flags+3(%r12),255-_TIF_SYSCALL
219sysc_restore:
220	mvc	__LC_RETURN_PSW(8),__PT_PSW(%r11)
221	stpt	__LC_EXIT_TIMER
222	lm	%r0,%r15,__PT_R0(%r11)
223	lpsw	__LC_RETURN_PSW
224sysc_done:
225
226#
227# One of the work bits is on. Find out which one.
228#
229sysc_work:
230	tm	__TI_flags+3(%r12),_TIF_MCCK_PENDING
231	jo	sysc_mcck_pending
232	tm	__TI_flags+3(%r12),_TIF_NEED_RESCHED
233	jo	sysc_reschedule
234	tm	__TI_flags+3(%r12),_TIF_PER_TRAP
235	jo	sysc_singlestep
236	tm	__TI_flags+3(%r12),_TIF_SIGPENDING
237	jo	sysc_sigpending
238	tm	__TI_flags+3(%r12),_TIF_NOTIFY_RESUME
239	jo	sysc_notify_resume
240	j	sysc_return		# beware of critical section cleanup
241
242#
243# _TIF_NEED_RESCHED is set, call schedule
244#
245sysc_reschedule:
246	l	%r1,BASED(.Lschedule)
247	la	%r14,BASED(sysc_return)
248	br	%r1			# call schedule
249
250#
251# _TIF_MCCK_PENDING is set, call handler
252#
253sysc_mcck_pending:
254	l	%r1,BASED(.Lhandle_mcck)
255	la	%r14,BASED(sysc_return)
256	br	%r1			# TIF bit will be cleared by handler
257
258#
259# _TIF_SIGPENDING is set, call do_signal
260#
261sysc_sigpending:
262	lr	%r2,%r11		# pass pointer to pt_regs
263	l	%r1,BASED(.Ldo_signal)
264	basr	%r14,%r1		# call do_signal
265	tm	__TI_flags+3(%r12),_TIF_SYSCALL
266	jno	sysc_return
267	lm	%r2,%r7,__PT_R2(%r11)	# load svc arguments
268	xr	%r8,%r8			# svc 0 returns -ENOSYS
269	clc	__PT_INT_CODE+2(2,%r11),BASED(.Lnr_syscalls+2)
270	jnl	sysc_nr_ok		# invalid svc number -> do svc 0
271	lh	%r8,__PT_INT_CODE+2(%r11)	# load new svc number
272	sla	%r8,2
273	j	sysc_nr_ok		# restart svc
274
275#
276# _TIF_NOTIFY_RESUME is set, call do_notify_resume
277#
278sysc_notify_resume:
279	lr	%r2,%r11		# pass pointer to pt_regs
280	l	%r1,BASED(.Ldo_notify_resume)
281	la	%r14,BASED(sysc_return)
282	br	%r1			# call do_notify_resume
283
284#
285# _TIF_PER_TRAP is set, call do_per_trap
286#
287sysc_singlestep:
288	ni	__TI_flags+3(%r12),255-_TIF_PER_TRAP
289	lr	%r2,%r11		# pass pointer to pt_regs
290	l	%r1,BASED(.Ldo_per_trap)
291	la	%r14,BASED(sysc_return)
292	br	%r1			# call do_per_trap
293
294#
295# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
296# and after the system call
297#
298sysc_tracesys:
299	l	%r1,BASED(.Ltrace_enter)
300	lr	%r2,%r11		# pass pointer to pt_regs
301	la	%r3,0
302	xr	%r0,%r0
303	icm	%r0,3,__PT_INT_CODE+2(%r11)
304	st	%r0,__PT_R2(%r11)
305	basr	%r14,%r1		# call do_syscall_trace_enter
306	cl	%r2,BASED(.Lnr_syscalls)
307	jnl	sysc_tracenogo
308	lr	%r8,%r2
309	sll	%r8,2
310	l	%r9,0(%r8,%r10)
311sysc_tracego:
312	lm	%r3,%r7,__PT_R3(%r11)
313	st	%r7,STACK_FRAME_OVERHEAD(%r15)
314	l	%r2,__PT_ORIG_GPR2(%r11)
315	basr	%r14,%r9		# call sys_xxx
316	st	%r2,__PT_R2(%r11)	# store return value
317sysc_tracenogo:
318	tm	__TI_flags+2(%r12),_TIF_TRACE >> 8
319	jz	sysc_return
320	l	%r1,BASED(.Ltrace_exit)
321	lr	%r2,%r11		# pass pointer to pt_regs
322	la	%r14,BASED(sysc_return)
323	br	%r1			# call do_syscall_trace_exit
324
325#
326# a new process exits the kernel with ret_from_fork
327#
328ENTRY(ret_from_fork)
329	la	%r11,STACK_FRAME_OVERHEAD(%r15)
330	l	%r12,__LC_THREAD_INFO
331	l	%r13,__LC_SVC_NEW_PSW+4
332	l	%r1,BASED(.Lschedule_tail)
333	basr	%r14,%r1		# call schedule_tail
334	TRACE_IRQS_ON
335	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
336	tm	__PT_PSW+1(%r11),0x01	# forking a kernel thread ?
337	jne	sysc_tracenogo
338	# it's a kernel thread
339	lm	%r9,%r10,__PT_R9(%r11)	# load gprs
340ENTRY(kernel_thread_starter)
341	la	%r2,0(%r10)
342	basr	%r14,%r9
343	j	sysc_tracenogo
344
345/*
346 * Program check handler routine
347 */
348
349ENTRY(pgm_check_handler)
350	stpt	__LC_SYNC_ENTER_TIMER
351	stm	%r8,%r15,__LC_SAVE_AREA_SYNC
352	l	%r12,__LC_THREAD_INFO
353	l	%r13,__LC_SVC_NEW_PSW+4
354	lm	%r8,%r9,__LC_PGM_OLD_PSW
355	tmh	%r8,0x0001		# test problem state bit
356	jnz	1f			# -> fault in user space
357	tmh	%r8,0x4000		# PER bit set in old PSW ?
358	jnz	0f			# -> enabled, can't be a double fault
359	tm	__LC_PGM_ILC+3,0x80	# check for per exception
360	jnz	pgm_svcper		# -> single stepped svc
3610:	CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
362	j	2f
3631:	UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
364	l	%r15,__LC_KERNEL_STACK
3652:	ahi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
366	la	%r11,STACK_FRAME_OVERHEAD(%r15)
367	stm	%r0,%r7,__PT_R0(%r11)
368	mvc	__PT_R8(32,%r11),__LC_SAVE_AREA_SYNC
369	stm	%r8,%r9,__PT_PSW(%r11)
370	mvc	__PT_INT_CODE(4,%r11),__LC_PGM_ILC
371	mvc	__PT_INT_PARM_LONG(4,%r11),__LC_TRANS_EXC_CODE
372	tm	__LC_PGM_ILC+3,0x80	# check for per exception
373	jz	0f
374	l	%r1,__TI_task(%r12)
375	tmh	%r8,0x0001		# kernel per event ?
376	jz	pgm_kprobe
377	oi	__TI_flags+3(%r12),_TIF_PER_TRAP
378	mvc	__THREAD_per_address(4,%r1),__LC_PER_ADDRESS
379	mvc	__THREAD_per_cause(2,%r1),__LC_PER_CAUSE
380	mvc	__THREAD_per_paid(1,%r1),__LC_PER_PAID
3810:	REENABLE_IRQS
382	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
383	l	%r1,BASED(.Ljump_table)
384	la	%r10,0x7f
385	n	%r10,__PT_INT_CODE(%r11)
386	je	sysc_return
387	sll	%r10,2
388	l	%r1,0(%r10,%r1)		# load address of handler routine
389	lr	%r2,%r11		# pass pointer to pt_regs
390	basr	%r14,%r1		# branch to interrupt-handler
391	j	sysc_return
392
393#
394# PER event in supervisor state, must be kprobes
395#
396pgm_kprobe:
397	REENABLE_IRQS
398	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
399	l	%r1,BASED(.Ldo_per_trap)
400	lr	%r2,%r11		# pass pointer to pt_regs
401	basr	%r14,%r1		# call do_per_trap
402	j	sysc_return
403
404#
405# single stepped system call
406#
407pgm_svcper:
408	oi	__TI_flags+3(%r12),_TIF_PER_TRAP
409	mvc	__LC_RETURN_PSW(4),__LC_SVC_NEW_PSW
410	mvc	__LC_RETURN_PSW+4(4),BASED(.Lsysc_per)
411	lpsw	__LC_RETURN_PSW		# branch to sysc_per and enable irqs
412
413/*
414 * IO interrupt handler routine
415 */
416
417ENTRY(io_int_handler)
418	stck	__LC_INT_CLOCK
419	stpt	__LC_ASYNC_ENTER_TIMER
420	stm	%r8,%r15,__LC_SAVE_AREA_ASYNC
421	l	%r12,__LC_THREAD_INFO
422	l	%r13,__LC_SVC_NEW_PSW+4
423	lm	%r8,%r9,__LC_IO_OLD_PSW
424	tmh	%r8,0x0001		# interrupting from user ?
425	jz	io_skip
426	UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER
427io_skip:
428	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
429	stm	%r0,%r7,__PT_R0(%r11)
430	mvc	__PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC
431	stm	%r8,%r9,__PT_PSW(%r11)
432	TRACE_IRQS_OFF
433	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
434	l	%r1,BASED(.Ldo_IRQ)
435	lr	%r2,%r11		# pass pointer to pt_regs
436	basr	%r14,%r1		# call do_IRQ
437io_return:
438	LOCKDEP_SYS_EXIT
439	TRACE_IRQS_ON
440io_tif:
441	tm	__TI_flags+3(%r12),_TIF_WORK_INT
442	jnz	io_work			# there is work to do (signals etc.)
443io_restore:
444	mvc	__LC_RETURN_PSW(8),__PT_PSW(%r11)
445	stpt	__LC_EXIT_TIMER
446	lm	%r0,%r15,__PT_R0(%r11)
447	lpsw	__LC_RETURN_PSW
448io_done:
449
450#
451# There is work todo, find out in which context we have been interrupted:
452# 1) if we return to user space we can do all _TIF_WORK_INT work
453# 2) if we return to kernel code and preemptive scheduling is enabled check
454#    the preemption counter and if it is zero call preempt_schedule_irq
455# Before any work can be done, a switch to the kernel stack is required.
456#
457io_work:
458	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
459	jo	io_work_user		# yes -> do resched & signal
460#ifdef CONFIG_PREEMPT
461	# check for preemptive scheduling
462	icm	%r0,15,__TI_precount(%r12)
463	jnz	io_restore		# preemption disabled
464	tm	__TI_flags+3(%r12),_TIF_NEED_RESCHED
465	jno	io_restore
466	# switch to kernel stack
467	l	%r1,__PT_R15(%r11)
468	ahi	%r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
469	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
470	xc	__SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
471	la	%r11,STACK_FRAME_OVERHEAD(%r1)
472	lr	%r15,%r1
473	# TRACE_IRQS_ON already done at io_return, call
474	# TRACE_IRQS_OFF to keep things symmetrical
475	TRACE_IRQS_OFF
476	l	%r1,BASED(.Lpreempt_irq)
477	basr	%r14,%r1		# call preempt_schedule_irq
478	j	io_return
479#else
480	j	io_restore
481#endif
482
483#
484# Need to do work before returning to userspace, switch to kernel stack
485#
486io_work_user:
487	l	%r1,__LC_KERNEL_STACK
488	ahi	%r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
489	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
490	xc	__SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
491	la	%r11,STACK_FRAME_OVERHEAD(%r1)
492	lr	%r15,%r1
493
494#
495# One of the work bits is on. Find out which one.
496# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED
497#		and _TIF_MCCK_PENDING
498#
499io_work_tif:
500	tm	__TI_flags+3(%r12),_TIF_MCCK_PENDING
501	jo	io_mcck_pending
502	tm	__TI_flags+3(%r12),_TIF_NEED_RESCHED
503	jo	io_reschedule
504	tm	__TI_flags+3(%r12),_TIF_SIGPENDING
505	jo	io_sigpending
506	tm	__TI_flags+3(%r12),_TIF_NOTIFY_RESUME
507	jo	io_notify_resume
508	j	io_return		# beware of critical section cleanup
509
510#
511# _TIF_MCCK_PENDING is set, call handler
512#
513io_mcck_pending:
514	# TRACE_IRQS_ON already done at io_return
515	l	%r1,BASED(.Lhandle_mcck)
516	basr	%r14,%r1		# TIF bit will be cleared by handler
517	TRACE_IRQS_OFF
518	j	io_return
519
520#
521# _TIF_NEED_RESCHED is set, call schedule
522#
523io_reschedule:
524	# TRACE_IRQS_ON already done at io_return
525	l	%r1,BASED(.Lschedule)
526	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
527	basr	%r14,%r1		# call scheduler
528	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
529	TRACE_IRQS_OFF
530	j	io_return
531
532#
533# _TIF_SIGPENDING is set, call do_signal
534#
535io_sigpending:
536	# TRACE_IRQS_ON already done at io_return
537	l	%r1,BASED(.Ldo_signal)
538	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
539	lr	%r2,%r11		# pass pointer to pt_regs
540	basr	%r14,%r1		# call do_signal
541	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
542	TRACE_IRQS_OFF
543	j	io_return
544
545#
546# _TIF_SIGPENDING is set, call do_signal
547#
548io_notify_resume:
549	# TRACE_IRQS_ON already done at io_return
550	l	%r1,BASED(.Ldo_notify_resume)
551	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
552	lr	%r2,%r11		# pass pointer to pt_regs
553	basr	%r14,%r1		# call do_notify_resume
554	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
555	TRACE_IRQS_OFF
556	j	io_return
557
558/*
559 * External interrupt handler routine
560 */
561
562ENTRY(ext_int_handler)
563	stck	__LC_INT_CLOCK
564	stpt	__LC_ASYNC_ENTER_TIMER
565	stm	%r8,%r15,__LC_SAVE_AREA_ASYNC
566	l	%r12,__LC_THREAD_INFO
567	l	%r13,__LC_SVC_NEW_PSW+4
568	lm	%r8,%r9,__LC_EXT_OLD_PSW
569	tmh	%r8,0x0001		# interrupting from user ?
570	jz	ext_skip
571	UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER
572ext_skip:
573	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
574	stm	%r0,%r7,__PT_R0(%r11)
575	mvc	__PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC
576	stm	%r8,%r9,__PT_PSW(%r11)
577	TRACE_IRQS_OFF
578	lr	%r2,%r11		# pass pointer to pt_regs
579	l	%r3,__LC_EXT_CPU_ADDR	# get cpu address + interruption code
580	l	%r4,__LC_EXT_PARAMS	# get external parameters
581	l	%r1,BASED(.Ldo_extint)
582	basr	%r14,%r1		# call do_extint
583	j	io_return
584
585/*
586 * Load idle PSW. The second "half" of this function is in cleanup_idle.
587 */
588ENTRY(psw_idle)
589	st	%r3,__SF_EMPTY(%r15)
590	basr	%r1,0
591	la	%r1,psw_idle_lpsw+4-.(%r1)
592	st	%r1,__SF_EMPTY+4(%r15)
593	oi	__SF_EMPTY+4(%r15),0x80
594	stck	__CLOCK_IDLE_ENTER(%r2)
595	stpt	__TIMER_IDLE_ENTER(%r2)
596psw_idle_lpsw:
597	lpsw	__SF_EMPTY(%r15)
598	br	%r14
599psw_idle_end:
600
601__critical_end:
602
603/*
604 * Machine check handler routines
605 */
606
607ENTRY(mcck_int_handler)
608	stck	__LC_MCCK_CLOCK
609	spt	__LC_CPU_TIMER_SAVE_AREA	# revalidate cpu timer
610	lm	%r0,%r15,__LC_GPREGS_SAVE_AREA	# revalidate gprs
611	l	%r12,__LC_THREAD_INFO
612	l	%r13,__LC_SVC_NEW_PSW+4
613	lm	%r8,%r9,__LC_MCK_OLD_PSW
614	tm	__LC_MCCK_CODE,0x80	# system damage?
615	jo	mcck_panic		# yes -> rest of mcck code invalid
616	la	%r14,__LC_CPU_TIMER_SAVE_AREA
617	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
618	tm	__LC_MCCK_CODE+5,0x02	# stored cpu timer value valid?
619	jo	3f
620	la	%r14,__LC_SYNC_ENTER_TIMER
621	clc	0(8,%r14),__LC_ASYNC_ENTER_TIMER
622	jl	0f
623	la	%r14,__LC_ASYNC_ENTER_TIMER
6240:	clc	0(8,%r14),__LC_EXIT_TIMER
625	jl	1f
626	la	%r14,__LC_EXIT_TIMER
6271:	clc	0(8,%r14),__LC_LAST_UPDATE_TIMER
628	jl	2f
629	la	%r14,__LC_LAST_UPDATE_TIMER
6302:	spt	0(%r14)
631	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
6323:	tm	__LC_MCCK_CODE+2,0x09	# mwp + ia of old psw valid?
633	jno	mcck_panic		# no -> skip cleanup critical
634	tm	%r8,0x0001		# interrupting from user ?
635	jz	mcck_skip
636	UPDATE_VTIME %r14,%r15,__LC_MCCK_ENTER_TIMER
637mcck_skip:
638	SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+32,__LC_PANIC_STACK,PAGE_SHIFT
639	mvc	__PT_R0(64,%r11),__LC_GPREGS_SAVE_AREA
640	stm	%r8,%r9,__PT_PSW(%r11)
641	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
642	l	%r1,BASED(.Ldo_machine_check)
643	lr	%r2,%r11		# pass pointer to pt_regs
644	basr	%r14,%r1		# call s390_do_machine_check
645	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
646	jno	mcck_return
647	l	%r1,__LC_KERNEL_STACK	# switch to kernel stack
648	ahi	%r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
649	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
650	xc	__SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
651	la	%r11,STACK_FRAME_OVERHEAD(%r15)
652	lr	%r15,%r1
653	ssm	__LC_PGM_NEW_PSW	# turn dat on, keep irqs off
654	tm	__TI_flags+3(%r12),_TIF_MCCK_PENDING
655	jno	mcck_return
656	TRACE_IRQS_OFF
657	l	%r1,BASED(.Lhandle_mcck)
658	basr	%r14,%r1		# call s390_handle_mcck
659	TRACE_IRQS_ON
660mcck_return:
661	mvc	__LC_RETURN_MCCK_PSW(8),__PT_PSW(%r11) # move return PSW
662	tm	__LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
663	jno	0f
664	lm	%r0,%r15,__PT_R0(%r11)
665	stpt	__LC_EXIT_TIMER
666	lpsw	__LC_RETURN_MCCK_PSW
6670:	lm	%r0,%r15,__PT_R0(%r11)
668	lpsw	__LC_RETURN_MCCK_PSW
669
670mcck_panic:
671	l	%r14,__LC_PANIC_STACK
672	slr	%r14,%r15
673	sra	%r14,PAGE_SHIFT
674	jz	0f
675	l	%r15,__LC_PANIC_STACK
6760:	ahi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
677	j	mcck_skip
678
679#
680# PSW restart interrupt handler
681#
682ENTRY(restart_int_handler)
683	st	%r15,__LC_SAVE_AREA_RESTART
684	l	%r15,__LC_RESTART_STACK
685	ahi	%r15,-__PT_SIZE			# create pt_regs on stack
686	xc	0(__PT_SIZE,%r15),0(%r15)
687	stm	%r0,%r14,__PT_R0(%r15)
688	mvc	__PT_R15(4,%r15),__LC_SAVE_AREA_RESTART
689	mvc	__PT_PSW(8,%r15),__LC_RST_OLD_PSW # store restart old psw
690	ahi	%r15,-STACK_FRAME_OVERHEAD	# create stack frame on stack
691	xc	0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
692	l	%r1,__LC_RESTART_FN		# load fn, parm & source cpu
693	l	%r2,__LC_RESTART_DATA
694	l	%r3,__LC_RESTART_SOURCE
695	ltr	%r3,%r3				# test source cpu address
696	jm	1f				# negative -> skip source stop
6970:	sigp	%r4,%r3,SIGP_SENSE		# sigp sense to source cpu
698	brc	10,0b				# wait for status stored
6991:	basr	%r14,%r1			# call function
700	stap	__SF_EMPTY(%r15)		# store cpu address
701	lh	%r3,__SF_EMPTY(%r15)
7022:	sigp	%r4,%r3,SIGP_STOP		# sigp stop to current cpu
703	brc	2,2b
7043:	j	3b
705
706	.section .kprobes.text, "ax"
707
708#ifdef CONFIG_CHECK_STACK
709/*
710 * The synchronous or the asynchronous stack overflowed. We are dead.
711 * No need to properly save the registers, we are going to panic anyway.
712 * Setup a pt_regs so that show_trace can provide a good call trace.
713 */
714stack_overflow:
715	l	%r15,__LC_PANIC_STACK	# change to panic stack
716	ahi	%r15,-__PT_SIZE		# create pt_regs
717	stm	%r0,%r7,__PT_R0(%r15)
718	stm	%r8,%r9,__PT_PSW(%r15)
719	mvc	__PT_R8(32,%r11),0(%r14)
720	lr	%r15,%r11
721	ahi	%r15,-STACK_FRAME_OVERHEAD
722	l	%r1,BASED(1f)
723	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
724	lr	%r2,%r11		# pass pointer to pt_regs
725	br	%r1			# branch to kernel_stack_overflow
7261:	.long	kernel_stack_overflow
727#endif
728
729cleanup_table:
730	.long	system_call + 0x80000000
731	.long	sysc_do_svc + 0x80000000
732	.long	sysc_tif + 0x80000000
733	.long	sysc_restore + 0x80000000
734	.long	sysc_done + 0x80000000
735	.long	io_tif + 0x80000000
736	.long	io_restore + 0x80000000
737	.long	io_done + 0x80000000
738	.long	psw_idle + 0x80000000
739	.long	psw_idle_end + 0x80000000
740
741cleanup_critical:
742	cl	%r9,BASED(cleanup_table)	# system_call
743	jl	0f
744	cl	%r9,BASED(cleanup_table+4)	# sysc_do_svc
745	jl	cleanup_system_call
746	cl	%r9,BASED(cleanup_table+8)	# sysc_tif
747	jl	0f
748	cl	%r9,BASED(cleanup_table+12)	# sysc_restore
749	jl	cleanup_sysc_tif
750	cl	%r9,BASED(cleanup_table+16)	# sysc_done
751	jl	cleanup_sysc_restore
752	cl	%r9,BASED(cleanup_table+20)	# io_tif
753	jl	0f
754	cl	%r9,BASED(cleanup_table+24)	# io_restore
755	jl	cleanup_io_tif
756	cl	%r9,BASED(cleanup_table+28)	# io_done
757	jl	cleanup_io_restore
758	cl	%r9,BASED(cleanup_table+32)	# psw_idle
759	jl	0f
760	cl	%r9,BASED(cleanup_table+36)	# psw_idle_end
761	jl	cleanup_idle
7620:	br	%r14
763
764cleanup_system_call:
765	# check if stpt has been executed
766	cl	%r9,BASED(cleanup_system_call_insn)
767	jh	0f
768	mvc	__LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
769	chi	%r11,__LC_SAVE_AREA_ASYNC
770	je	0f
771	mvc	__LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
7720:	# check if stm has been executed
773	cl	%r9,BASED(cleanup_system_call_insn+4)
774	jh	0f
775	mvc	__LC_SAVE_AREA_SYNC(32),0(%r11)
7760:	# set up saved registers r12, and r13
777	st	%r12,16(%r11)		# r12 thread-info pointer
778	st	%r13,20(%r11)		# r13 literal-pool pointer
779	# check if the user time calculation has been done
780	cl	%r9,BASED(cleanup_system_call_insn+8)
781	jh	0f
782	l	%r10,__LC_EXIT_TIMER
783	l	%r15,__LC_EXIT_TIMER+4
784	SUB64	%r10,%r15,__LC_SYNC_ENTER_TIMER
785	ADD64	%r10,%r15,__LC_USER_TIMER
786	st	%r10,__LC_USER_TIMER
787	st	%r15,__LC_USER_TIMER+4
7880:	# check if the system time calculation has been done
789	cl	%r9,BASED(cleanup_system_call_insn+12)
790	jh	0f
791	l	%r10,__LC_LAST_UPDATE_TIMER
792	l	%r15,__LC_LAST_UPDATE_TIMER+4
793	SUB64	%r10,%r15,__LC_EXIT_TIMER
794	ADD64	%r10,%r15,__LC_SYSTEM_TIMER
795	st	%r10,__LC_SYSTEM_TIMER
796	st	%r15,__LC_SYSTEM_TIMER+4
7970:	# update accounting time stamp
798	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
799	# set up saved register 11
800	l	%r15,__LC_KERNEL_STACK
801	ahi	%r15,-__PT_SIZE
802	st	%r15,12(%r11)		# r11 pt_regs pointer
803	# fill pt_regs
804	mvc	__PT_R8(32,%r15),__LC_SAVE_AREA_SYNC
805	stm	%r0,%r7,__PT_R0(%r15)
806	mvc	__PT_PSW(8,%r15),__LC_SVC_OLD_PSW
807	mvc	__PT_INT_CODE(4,%r15),__LC_SVC_ILC
808	# setup saved register 15
809	ahi	%r15,-STACK_FRAME_OVERHEAD
810	st	%r15,28(%r11)		# r15 stack pointer
811	# set new psw address and exit
812	l	%r9,BASED(cleanup_table+4)	# sysc_do_svc + 0x80000000
813	br	%r14
814cleanup_system_call_insn:
815	.long	system_call + 0x80000000
816	.long	sysc_stm + 0x80000000
817	.long	sysc_vtime + 0x80000000 + 36
818	.long	sysc_vtime + 0x80000000 + 76
819
820cleanup_sysc_tif:
821	l	%r9,BASED(cleanup_table+8)	# sysc_tif + 0x80000000
822	br	%r14
823
824cleanup_sysc_restore:
825	cl	%r9,BASED(cleanup_sysc_restore_insn)
826	jhe	0f
827	l	%r9,12(%r11)		# get saved pointer to pt_regs
828	mvc	__LC_RETURN_PSW(8),__PT_PSW(%r9)
829	mvc	0(32,%r11),__PT_R8(%r9)
830	lm	%r0,%r7,__PT_R0(%r9)
8310:	lm	%r8,%r9,__LC_RETURN_PSW
832	br	%r14
833cleanup_sysc_restore_insn:
834	.long	sysc_done - 4 + 0x80000000
835
836cleanup_io_tif:
837	l	%r9,BASED(cleanup_table+20)	# io_tif + 0x80000000
838	br	%r14
839
840cleanup_io_restore:
841	cl	%r9,BASED(cleanup_io_restore_insn)
842	jhe	0f
843	l	%r9,12(%r11)		# get saved r11 pointer to pt_regs
844	mvc	__LC_RETURN_PSW(8),__PT_PSW(%r9)
845	mvc	0(32,%r11),__PT_R8(%r9)
846	lm	%r0,%r7,__PT_R0(%r9)
8470:	lm	%r8,%r9,__LC_RETURN_PSW
848	br	%r14
849cleanup_io_restore_insn:
850	.long	io_done - 4 + 0x80000000
851
852cleanup_idle:
853	# copy interrupt clock & cpu timer
854	mvc	__CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK
855	mvc	__TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER
856	chi	%r11,__LC_SAVE_AREA_ASYNC
857	je	0f
858	mvc	__CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK
859	mvc	__TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER
8600:	# check if stck has been executed
861	cl	%r9,BASED(cleanup_idle_insn)
862	jhe	1f
863	mvc	__CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
864	mvc	__TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r3)
8651:	# account system time going idle
866	lm	%r9,%r10,__LC_STEAL_TIMER
867	ADD64	%r9,%r10,__CLOCK_IDLE_ENTER(%r2)
868	SUB64	%r9,%r10,__LC_LAST_UPDATE_CLOCK
869	stm	%r9,%r10,__LC_STEAL_TIMER
870	mvc	__LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
871	lm	%r9,%r10,__LC_SYSTEM_TIMER
872	ADD64	%r9,%r10,__LC_LAST_UPDATE_TIMER
873	SUB64	%r9,%r10,__TIMER_IDLE_ENTER(%r2)
874	stm	%r9,%r10,__LC_SYSTEM_TIMER
875	mvc	__LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
876	# prepare return psw
877	n	%r8,BASED(cleanup_idle_wait)	# clear wait state bit
878	l	%r9,24(%r11)			# return from psw_idle
879	br	%r14
880cleanup_idle_insn:
881	.long	psw_idle_lpsw + 0x80000000
882cleanup_idle_wait:
883	.long	0xfffdffff
884
885/*
886 * Integer constants
887 */
888	.align	4
889.Lnr_syscalls:
890	.long	NR_syscalls
891.Lvtimer_max:
892	.quad	0x7fffffffffffffff
893
894/*
895 * Symbol constants
896 */
897.Ldo_machine_check:	.long	s390_do_machine_check
898.Lhandle_mcck:		.long	s390_handle_mcck
899.Ldo_IRQ:		.long	do_IRQ
900.Ldo_extint:		.long	do_extint
901.Ldo_signal:		.long	do_signal
902.Ldo_notify_resume:	.long	do_notify_resume
903.Ldo_per_trap:		.long	do_per_trap
904.Ljump_table:		.long	pgm_check_table
905.Lschedule:		.long	schedule
906#ifdef CONFIG_PREEMPT
907.Lpreempt_irq:		.long	preempt_schedule_irq
908#endif
909.Ltrace_enter:		.long	do_syscall_trace_enter
910.Ltrace_exit:		.long	do_syscall_trace_exit
911.Lschedule_tail:	.long	schedule_tail
912.Lsys_call_table:	.long	sys_call_table
913.Lsysc_per:		.long	sysc_per + 0x80000000
914#ifdef CONFIG_TRACE_IRQFLAGS
915.Lhardirqs_on:		.long	trace_hardirqs_on_caller
916.Lhardirqs_off:		.long	trace_hardirqs_off_caller
917#endif
918#ifdef CONFIG_LOCKDEP
919.Llockdep_sys_exit:	.long	lockdep_sys_exit
920#endif
921.Lcritical_start:	.long	__critical_start + 0x80000000
922.Lcritical_length:	.long	__critical_end - __critical_start
923
924		.section .rodata, "a"
925#define SYSCALL(esa,esame,emu)	.long esa
926	.globl	sys_call_table
927sys_call_table:
928#include "syscalls.S"
929#undef SYSCALL
930