xref: /openbmc/linux/arch/s390/kernel/entry.S (revision aac5987a)
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/processor.h>
14#include <asm/cache.h>
15#include <asm/errno.h>
16#include <asm/ptrace.h>
17#include <asm/thread_info.h>
18#include <asm/asm-offsets.h>
19#include <asm/unistd.h>
20#include <asm/page.h>
21#include <asm/sigp.h>
22#include <asm/irq.h>
23#include <asm/vx-insn.h>
24#include <asm/setup.h>
25#include <asm/nmi.h>
26#include <asm/export.h>
27
28__PT_R0      =	__PT_GPRS
29__PT_R1      =	__PT_GPRS + 8
30__PT_R2      =	__PT_GPRS + 16
31__PT_R3      =	__PT_GPRS + 24
32__PT_R4      =	__PT_GPRS + 32
33__PT_R5      =	__PT_GPRS + 40
34__PT_R6      =	__PT_GPRS + 48
35__PT_R7      =	__PT_GPRS + 56
36__PT_R8      =	__PT_GPRS + 64
37__PT_R9      =	__PT_GPRS + 72
38__PT_R10     =	__PT_GPRS + 80
39__PT_R11     =	__PT_GPRS + 88
40__PT_R12     =	__PT_GPRS + 96
41__PT_R13     =	__PT_GPRS + 104
42__PT_R14     =	__PT_GPRS + 112
43__PT_R15     =	__PT_GPRS + 120
44
45STACK_SHIFT = PAGE_SHIFT + THREAD_SIZE_ORDER
46STACK_SIZE  = 1 << STACK_SHIFT
47STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
48
49_TIF_WORK	= (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
50		   _TIF_UPROBE)
51_TIF_TRACE	= (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
52		   _TIF_SYSCALL_TRACEPOINT)
53_CIF_WORK	= (_CIF_MCCK_PENDING | _CIF_ASCE_PRIMARY | \
54		   _CIF_ASCE_SECONDARY | _CIF_FPU)
55_PIF_WORK	= (_PIF_PER_TRAP)
56
57#define BASED(name) name-cleanup_critical(%r13)
58
59	.macro	TRACE_IRQS_ON
60#ifdef CONFIG_TRACE_IRQFLAGS
61	basr	%r2,%r0
62	brasl	%r14,trace_hardirqs_on_caller
63#endif
64	.endm
65
66	.macro	TRACE_IRQS_OFF
67#ifdef CONFIG_TRACE_IRQFLAGS
68	basr	%r2,%r0
69	brasl	%r14,trace_hardirqs_off_caller
70#endif
71	.endm
72
73	.macro	LOCKDEP_SYS_EXIT
74#ifdef CONFIG_LOCKDEP
75	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
76	jz	.+10
77	brasl	%r14,lockdep_sys_exit
78#endif
79	.endm
80
81	.macro	CHECK_STACK stacksize,savearea
82#ifdef CONFIG_CHECK_STACK
83	tml	%r15,\stacksize - CONFIG_STACK_GUARD
84	lghi	%r14,\savearea
85	jz	stack_overflow
86#endif
87	.endm
88
89	.macro	SWITCH_ASYNC savearea,timer
90	tmhh	%r8,0x0001		# interrupting from user ?
91	jnz	1f
92	lgr	%r14,%r9
93	slg	%r14,BASED(.Lcritical_start)
94	clg	%r14,BASED(.Lcritical_length)
95	jhe	0f
96	lghi	%r11,\savearea		# inside critical section, do cleanup
97	brasl	%r14,cleanup_critical
98	tmhh	%r8,0x0001		# retest problem state after cleanup
99	jnz	1f
1000:	lg	%r14,__LC_ASYNC_STACK	# are we already on the async stack?
101	slgr	%r14,%r15
102	srag	%r14,%r14,STACK_SHIFT
103	jnz	2f
104	CHECK_STACK 1<<STACK_SHIFT,\savearea
105	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
106	j	3f
1071:	UPDATE_VTIME %r14,%r15,\timer
1082:	lg	%r15,__LC_ASYNC_STACK	# load async stack
1093:	la	%r11,STACK_FRAME_OVERHEAD(%r15)
110	.endm
111
112	.macro UPDATE_VTIME w1,w2,enter_timer
113	lg	\w1,__LC_EXIT_TIMER
114	lg	\w2,__LC_LAST_UPDATE_TIMER
115	slg	\w1,\enter_timer
116	slg	\w2,__LC_EXIT_TIMER
117	alg	\w1,__LC_USER_TIMER
118	alg	\w2,__LC_SYSTEM_TIMER
119	stg	\w1,__LC_USER_TIMER
120	stg	\w2,__LC_SYSTEM_TIMER
121	mvc	__LC_LAST_UPDATE_TIMER(8),\enter_timer
122	.endm
123
124	.macro REENABLE_IRQS
125	stg	%r8,__LC_RETURN_PSW
126	ni	__LC_RETURN_PSW,0xbf
127	ssm	__LC_RETURN_PSW
128	.endm
129
130	.macro STCK savearea
131#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
132	.insn	s,0xb27c0000,\savearea		# store clock fast
133#else
134	.insn	s,0xb2050000,\savearea		# store clock
135#endif
136	.endm
137
138	/*
139	 * The TSTMSK macro generates a test-under-mask instruction by
140	 * calculating the memory offset for the specified mask value.
141	 * Mask value can be any constant.  The macro shifts the mask
142	 * value to calculate the memory offset for the test-under-mask
143	 * instruction.
144	 */
145	.macro TSTMSK addr, mask, size=8, bytepos=0
146		.if (\bytepos < \size) && (\mask >> 8)
147			.if (\mask & 0xff)
148				.error "Mask exceeds byte boundary"
149			.endif
150			TSTMSK \addr, "(\mask >> 8)", \size, "(\bytepos + 1)"
151			.exitm
152		.endif
153		.ifeq \mask
154			.error "Mask must not be zero"
155		.endif
156		off = \size - \bytepos - 1
157		tm	off+\addr, \mask
158	.endm
159
160	.section .kprobes.text, "ax"
161.Ldummy:
162	/*
163	 * This nop exists only in order to avoid that __switch_to starts at
164	 * the beginning of the kprobes text section. In that case we would
165	 * have several symbols at the same address. E.g. objdump would take
166	 * an arbitrary symbol name when disassembling this code.
167	 * With the added nop in between the __switch_to symbol is unique
168	 * again.
169	 */
170	nop	0
171
172/*
173 * Scheduler resume function, called by switch_to
174 *  gpr2 = (task_struct *) prev
175 *  gpr3 = (task_struct *) next
176 * Returns:
177 *  gpr2 = prev
178 */
179ENTRY(__switch_to)
180	stmg	%r6,%r15,__SF_GPRS(%r15)	# store gprs of prev task
181	lgr	%r1,%r2
182	aghi	%r1,__TASK_thread		# thread_struct of prev task
183	lg	%r5,__TASK_stack(%r3)		# start of kernel stack of next
184	stg	%r15,__THREAD_ksp(%r1)		# store kernel stack of prev
185	lgr	%r1,%r3
186	aghi	%r1,__TASK_thread		# thread_struct of next task
187	lgr	%r15,%r5
188	aghi	%r15,STACK_INIT			# end of kernel stack of next
189	stg	%r3,__LC_CURRENT		# store task struct of next
190	stg	%r15,__LC_KERNEL_STACK		# store end of kernel stack
191	lg	%r15,__THREAD_ksp(%r1)		# load kernel stack of next
192	/* c4 is used in guest detection: arch/s390/kernel/perf_cpum_sf.c */
193	lctl	%c4,%c4,__TASK_pid(%r3)		# load pid to control reg. 4
194	mvc	__LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next
195	lmg	%r6,%r15,__SF_GPRS(%r15)	# load gprs of next task
196	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
197	bzr	%r14
198	.insn	s,0xb2800000,__LC_LPP		# set program parameter
199	br	%r14
200
201.L__critical_start:
202
203#if IS_ENABLED(CONFIG_KVM)
204/*
205 * sie64a calling convention:
206 * %r2 pointer to sie control block
207 * %r3 guest register save area
208 */
209ENTRY(sie64a)
210	stmg	%r6,%r14,__SF_GPRS(%r15)	# save kernel registers
211	stg	%r2,__SF_EMPTY(%r15)		# save control block pointer
212	stg	%r3,__SF_EMPTY+8(%r15)		# save guest register save area
213	xc	__SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # reason code = 0
214	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU		# load guest fp/vx registers ?
215	jno	.Lsie_load_guest_gprs
216	brasl	%r14,load_fpu_regs		# load guest fp/vx regs
217.Lsie_load_guest_gprs:
218	lmg	%r0,%r13,0(%r3)			# load guest gprs 0-13
219	lg	%r14,__LC_GMAP			# get gmap pointer
220	ltgr	%r14,%r14
221	jz	.Lsie_gmap
222	lctlg	%c1,%c1,__GMAP_ASCE(%r14)	# load primary asce
223.Lsie_gmap:
224	lg	%r14,__SF_EMPTY(%r15)		# get control block pointer
225	oi	__SIE_PROG0C+3(%r14),1		# we are going into SIE now
226	tm	__SIE_PROG20+3(%r14),3		# last exit...
227	jnz	.Lsie_skip
228	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
229	jo	.Lsie_skip			# exit if fp/vx regs changed
230	sie	0(%r14)
231.Lsie_skip:
232	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE
233	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
234.Lsie_done:
235# some program checks are suppressing. C code (e.g. do_protection_exception)
236# will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other
237# instructions between sie64a and .Lsie_done should not cause program
238# interrupts. So lets use a nop (47 00 00 00) as a landing pad.
239# See also .Lcleanup_sie
240.Lrewind_pad:
241	nop	0
242	.globl sie_exit
243sie_exit:
244	lg	%r14,__SF_EMPTY+8(%r15)		# load guest register save area
245	stmg	%r0,%r13,0(%r14)		# save guest gprs 0-13
246	lmg	%r6,%r14,__SF_GPRS(%r15)	# restore kernel registers
247	lg	%r2,__SF_EMPTY+16(%r15)		# return exit reason code
248	br	%r14
249.Lsie_fault:
250	lghi	%r14,-EFAULT
251	stg	%r14,__SF_EMPTY+16(%r15)	# set exit reason code
252	j	sie_exit
253
254	EX_TABLE(.Lrewind_pad,.Lsie_fault)
255	EX_TABLE(sie_exit,.Lsie_fault)
256EXPORT_SYMBOL(sie64a)
257EXPORT_SYMBOL(sie_exit)
258#endif
259
260/*
261 * SVC interrupt handler routine. System calls are synchronous events and
262 * are executed with interrupts enabled.
263 */
264
265ENTRY(system_call)
266	stpt	__LC_SYNC_ENTER_TIMER
267.Lsysc_stmg:
268	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
269	lg	%r12,__LC_CURRENT
270	lghi	%r13,__TASK_thread
271	lghi	%r14,_PIF_SYSCALL
272.Lsysc_per:
273	lg	%r15,__LC_KERNEL_STACK
274	la	%r11,STACK_FRAME_OVERHEAD(%r15)	# pointer to pt_regs
275.Lsysc_vtime:
276	UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
277	stmg	%r0,%r7,__PT_R0(%r11)
278	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
279	mvc	__PT_PSW(16,%r11),__LC_SVC_OLD_PSW
280	mvc	__PT_INT_CODE(4,%r11),__LC_SVC_ILC
281	stg	%r14,__PT_FLAGS(%r11)
282.Lsysc_do_svc:
283	# load address of system call table
284	lg	%r10,__THREAD_sysc_table(%r13,%r12)
285	llgh	%r8,__PT_INT_CODE+2(%r11)
286	slag	%r8,%r8,2			# shift and test for svc 0
287	jnz	.Lsysc_nr_ok
288	# svc 0: system call number in %r1
289	llgfr	%r1,%r1				# clear high word in r1
290	cghi	%r1,NR_syscalls
291	jnl	.Lsysc_nr_ok
292	sth	%r1,__PT_INT_CODE+2(%r11)
293	slag	%r8,%r1,2
294.Lsysc_nr_ok:
295	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
296	stg	%r2,__PT_ORIG_GPR2(%r11)
297	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
298	lgf	%r9,0(%r8,%r10)			# get system call add.
299	TSTMSK	__TI_flags(%r12),_TIF_TRACE
300	jnz	.Lsysc_tracesys
301	basr	%r14,%r9			# call sys_xxxx
302	stg	%r2,__PT_R2(%r11)		# store return value
303
304.Lsysc_return:
305	LOCKDEP_SYS_EXIT
306.Lsysc_tif:
307	TSTMSK	__PT_FLAGS(%r11),_PIF_WORK
308	jnz	.Lsysc_work
309	TSTMSK	__TI_flags(%r12),_TIF_WORK
310	jnz	.Lsysc_work			# check for work
311	TSTMSK	__LC_CPU_FLAGS,_CIF_WORK
312	jnz	.Lsysc_work
313.Lsysc_restore:
314	lg	%r14,__LC_VDSO_PER_CPU
315	lmg	%r0,%r10,__PT_R0(%r11)
316	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
317	stpt	__LC_EXIT_TIMER
318	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
319	lmg	%r11,%r15,__PT_R11(%r11)
320	lpswe	__LC_RETURN_PSW
321.Lsysc_done:
322
323#
324# One of the work bits is on. Find out which one.
325#
326.Lsysc_work:
327	TSTMSK	__LC_CPU_FLAGS,_CIF_MCCK_PENDING
328	jo	.Lsysc_mcck_pending
329	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
330	jo	.Lsysc_reschedule
331#ifdef CONFIG_UPROBES
332	TSTMSK	__TI_flags(%r12),_TIF_UPROBE
333	jo	.Lsysc_uprobe_notify
334#endif
335	TSTMSK	__PT_FLAGS(%r11),_PIF_PER_TRAP
336	jo	.Lsysc_singlestep
337	TSTMSK	__TI_flags(%r12),_TIF_SIGPENDING
338	jo	.Lsysc_sigpending
339	TSTMSK	__TI_flags(%r12),_TIF_NOTIFY_RESUME
340	jo	.Lsysc_notify_resume
341	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
342	jo	.Lsysc_vxrs
343	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
344	jnz	.Lsysc_asce
345	j	.Lsysc_return		# beware of critical section cleanup
346
347#
348# _TIF_NEED_RESCHED is set, call schedule
349#
350.Lsysc_reschedule:
351	larl	%r14,.Lsysc_return
352	jg	schedule
353
354#
355# _CIF_MCCK_PENDING is set, call handler
356#
357.Lsysc_mcck_pending:
358	larl	%r14,.Lsysc_return
359	jg	s390_handle_mcck	# TIF bit will be cleared by handler
360
361#
362# _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
363#
364.Lsysc_asce:
365	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
366	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
367	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_SECONDARY
368	jz	.Lsysc_return
369	larl	%r14,.Lsysc_return
370	jg	set_fs_fixup
371
372#
373# CIF_FPU is set, restore floating-point controls and floating-point registers.
374#
375.Lsysc_vxrs:
376	larl	%r14,.Lsysc_return
377	jg	load_fpu_regs
378
379#
380# _TIF_SIGPENDING is set, call do_signal
381#
382.Lsysc_sigpending:
383	lgr	%r2,%r11		# pass pointer to pt_regs
384	brasl	%r14,do_signal
385	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL
386	jno	.Lsysc_return
387.Lsysc_do_syscall:
388	lghi	%r13,__TASK_thread
389	lmg	%r2,%r7,__PT_R2(%r11)	# load svc arguments
390	lghi	%r1,0			# svc 0 returns -ENOSYS
391	j	.Lsysc_do_svc
392
393#
394# _TIF_NOTIFY_RESUME is set, call do_notify_resume
395#
396.Lsysc_notify_resume:
397	lgr	%r2,%r11		# pass pointer to pt_regs
398	larl	%r14,.Lsysc_return
399	jg	do_notify_resume
400
401#
402# _TIF_UPROBE is set, call uprobe_notify_resume
403#
404#ifdef CONFIG_UPROBES
405.Lsysc_uprobe_notify:
406	lgr	%r2,%r11		# pass pointer to pt_regs
407	larl	%r14,.Lsysc_return
408	jg	uprobe_notify_resume
409#endif
410
411#
412# _PIF_PER_TRAP is set, call do_per_trap
413#
414.Lsysc_singlestep:
415	ni	__PT_FLAGS+7(%r11),255-_PIF_PER_TRAP
416	lgr	%r2,%r11		# pass pointer to pt_regs
417	larl	%r14,.Lsysc_return
418	jg	do_per_trap
419
420#
421# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
422# and after the system call
423#
424.Lsysc_tracesys:
425	lgr	%r2,%r11		# pass pointer to pt_regs
426	la	%r3,0
427	llgh	%r0,__PT_INT_CODE+2(%r11)
428	stg	%r0,__PT_R2(%r11)
429	brasl	%r14,do_syscall_trace_enter
430	lghi	%r0,NR_syscalls
431	clgr	%r0,%r2
432	jnh	.Lsysc_tracenogo
433	sllg	%r8,%r2,2
434	lgf	%r9,0(%r8,%r10)
435.Lsysc_tracego:
436	lmg	%r3,%r7,__PT_R3(%r11)
437	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
438	lg	%r2,__PT_ORIG_GPR2(%r11)
439	basr	%r14,%r9		# call sys_xxx
440	stg	%r2,__PT_R2(%r11)	# store return value
441.Lsysc_tracenogo:
442	TSTMSK	__TI_flags(%r12),_TIF_TRACE
443	jz	.Lsysc_return
444	lgr	%r2,%r11		# pass pointer to pt_regs
445	larl	%r14,.Lsysc_return
446	jg	do_syscall_trace_exit
447
448#
449# a new process exits the kernel with ret_from_fork
450#
451ENTRY(ret_from_fork)
452	la	%r11,STACK_FRAME_OVERHEAD(%r15)
453	lg	%r12,__LC_CURRENT
454	brasl	%r14,schedule_tail
455	TRACE_IRQS_ON
456	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
457	tm	__PT_PSW+1(%r11),0x01	# forking a kernel thread ?
458	jne	.Lsysc_tracenogo
459	# it's a kernel thread
460	lmg	%r9,%r10,__PT_R9(%r11)	# load gprs
461ENTRY(kernel_thread_starter)
462	la	%r2,0(%r10)
463	basr	%r14,%r9
464	j	.Lsysc_tracenogo
465
466/*
467 * Program check handler routine
468 */
469
470ENTRY(pgm_check_handler)
471	stpt	__LC_SYNC_ENTER_TIMER
472	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
473	lg	%r10,__LC_LAST_BREAK
474	lg	%r12,__LC_CURRENT
475	larl	%r13,cleanup_critical
476	lmg	%r8,%r9,__LC_PGM_OLD_PSW
477	tmhh	%r8,0x0001		# test problem state bit
478	jnz	2f			# -> fault in user space
479#if IS_ENABLED(CONFIG_KVM)
480	# cleanup critical section for sie64a
481	lgr	%r14,%r9
482	slg	%r14,BASED(.Lsie_critical_start)
483	clg	%r14,BASED(.Lsie_critical_length)
484	jhe	0f
485	brasl	%r14,.Lcleanup_sie
486#endif
4870:	tmhh	%r8,0x4000		# PER bit set in old PSW ?
488	jnz	1f			# -> enabled, can't be a double fault
489	tm	__LC_PGM_ILC+3,0x80	# check for per exception
490	jnz	.Lpgm_svcper		# -> single stepped svc
4911:	CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
492	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
493	j	3f
4942:	UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
495	lg	%r15,__LC_KERNEL_STACK
496	lgr	%r14,%r12
497	aghi	%r14,__TASK_thread	# pointer to thread_struct
498	lghi	%r13,__LC_PGM_TDB
499	tm	__LC_PGM_ILC+2,0x02	# check for transaction abort
500	jz	3f
501	mvc	__THREAD_trap_tdb(256,%r14),0(%r13)
5023:	la	%r11,STACK_FRAME_OVERHEAD(%r15)
503	stg	%r10,__THREAD_last_break(%r14)
504	stmg	%r0,%r7,__PT_R0(%r11)
505	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
506	stmg	%r8,%r9,__PT_PSW(%r11)
507	mvc	__PT_INT_CODE(4,%r11),__LC_PGM_ILC
508	mvc	__PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE
509	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
510	stg	%r10,__PT_ARGS(%r11)
511	tm	__LC_PGM_ILC+3,0x80	# check for per exception
512	jz	4f
513	tmhh	%r8,0x0001		# kernel per event ?
514	jz	.Lpgm_kprobe
515	oi	__PT_FLAGS+7(%r11),_PIF_PER_TRAP
516	mvc	__THREAD_per_address(8,%r14),__LC_PER_ADDRESS
517	mvc	__THREAD_per_cause(2,%r14),__LC_PER_CODE
518	mvc	__THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
5194:	REENABLE_IRQS
520	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
521	larl	%r1,pgm_check_table
522	llgh	%r10,__PT_INT_CODE+2(%r11)
523	nill	%r10,0x007f
524	sll	%r10,2
525	je	.Lpgm_return
526	lgf	%r1,0(%r10,%r1)		# load address of handler routine
527	lgr	%r2,%r11		# pass pointer to pt_regs
528	basr	%r14,%r1		# branch to interrupt-handler
529.Lpgm_return:
530	LOCKDEP_SYS_EXIT
531	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
532	jno	.Lsysc_restore
533	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL
534	jo	.Lsysc_do_syscall
535	j	.Lsysc_tif
536
537#
538# PER event in supervisor state, must be kprobes
539#
540.Lpgm_kprobe:
541	REENABLE_IRQS
542	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
543	lgr	%r2,%r11		# pass pointer to pt_regs
544	brasl	%r14,do_per_trap
545	j	.Lpgm_return
546
547#
548# single stepped system call
549#
550.Lpgm_svcper:
551	mvc	__LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
552	lghi	%r13,__TASK_thread
553	larl	%r14,.Lsysc_per
554	stg	%r14,__LC_RETURN_PSW+8
555	lghi	%r14,_PIF_SYSCALL | _PIF_PER_TRAP
556	lpswe	__LC_RETURN_PSW		# branch to .Lsysc_per and enable irqs
557
558/*
559 * IO interrupt handler routine
560 */
561ENTRY(io_int_handler)
562	STCK	__LC_INT_CLOCK
563	stpt	__LC_ASYNC_ENTER_TIMER
564	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
565	lg	%r12,__LC_CURRENT
566	larl	%r13,cleanup_critical
567	lmg	%r8,%r9,__LC_IO_OLD_PSW
568	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
569	stmg	%r0,%r7,__PT_R0(%r11)
570	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
571	stmg	%r8,%r9,__PT_PSW(%r11)
572	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
573	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
574	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
575	jo	.Lio_restore
576	TRACE_IRQS_OFF
577	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
578.Lio_loop:
579	lgr	%r2,%r11		# pass pointer to pt_regs
580	lghi	%r3,IO_INTERRUPT
581	tm	__PT_INT_CODE+8(%r11),0x80	# adapter interrupt ?
582	jz	.Lio_call
583	lghi	%r3,THIN_INTERRUPT
584.Lio_call:
585	brasl	%r14,do_IRQ
586	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPAR
587	jz	.Lio_return
588	tpi	0
589	jz	.Lio_return
590	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
591	j	.Lio_loop
592.Lio_return:
593	LOCKDEP_SYS_EXIT
594	TRACE_IRQS_ON
595.Lio_tif:
596	TSTMSK	__TI_flags(%r12),_TIF_WORK
597	jnz	.Lio_work		# there is work to do (signals etc.)
598	TSTMSK	__LC_CPU_FLAGS,_CIF_WORK
599	jnz	.Lio_work
600.Lio_restore:
601	lg	%r14,__LC_VDSO_PER_CPU
602	lmg	%r0,%r10,__PT_R0(%r11)
603	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
604	stpt	__LC_EXIT_TIMER
605	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
606	lmg	%r11,%r15,__PT_R11(%r11)
607	lpswe	__LC_RETURN_PSW
608.Lio_done:
609
610#
611# There is work todo, find out in which context we have been interrupted:
612# 1) if we return to user space we can do all _TIF_WORK work
613# 2) if we return to kernel code and kvm is enabled check if we need to
614#    modify the psw to leave SIE
615# 3) if we return to kernel code and preemptive scheduling is enabled check
616#    the preemption counter and if it is zero call preempt_schedule_irq
617# Before any work can be done, a switch to the kernel stack is required.
618#
619.Lio_work:
620	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
621	jo	.Lio_work_user		# yes -> do resched & signal
622#ifdef CONFIG_PREEMPT
623	# check for preemptive scheduling
624	icm	%r0,15,__LC_PREEMPT_COUNT
625	jnz	.Lio_restore		# preemption is disabled
626	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
627	jno	.Lio_restore
628	# switch to kernel stack
629	lg	%r1,__PT_R15(%r11)
630	aghi	%r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
631	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
632	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
633	la	%r11,STACK_FRAME_OVERHEAD(%r1)
634	lgr	%r15,%r1
635	# TRACE_IRQS_ON already done at .Lio_return, call
636	# TRACE_IRQS_OFF to keep things symmetrical
637	TRACE_IRQS_OFF
638	brasl	%r14,preempt_schedule_irq
639	j	.Lio_return
640#else
641	j	.Lio_restore
642#endif
643
644#
645# Need to do work before returning to userspace, switch to kernel stack
646#
647.Lio_work_user:
648	lg	%r1,__LC_KERNEL_STACK
649	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
650	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
651	la	%r11,STACK_FRAME_OVERHEAD(%r1)
652	lgr	%r15,%r1
653
654#
655# One of the work bits is on. Find out which one.
656#
657.Lio_work_tif:
658	TSTMSK	__LC_CPU_FLAGS,_CIF_MCCK_PENDING
659	jo	.Lio_mcck_pending
660	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
661	jo	.Lio_reschedule
662	TSTMSK	__TI_flags(%r12),_TIF_SIGPENDING
663	jo	.Lio_sigpending
664	TSTMSK	__TI_flags(%r12),_TIF_NOTIFY_RESUME
665	jo	.Lio_notify_resume
666	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
667	jo	.Lio_vxrs
668	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
669	jnz	.Lio_asce
670	j	.Lio_return		# beware of critical section cleanup
671
672#
673# _CIF_MCCK_PENDING is set, call handler
674#
675.Lio_mcck_pending:
676	# TRACE_IRQS_ON already done at .Lio_return
677	brasl	%r14,s390_handle_mcck	# TIF bit will be cleared by handler
678	TRACE_IRQS_OFF
679	j	.Lio_return
680
681#
682# _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
683#
684.Lio_asce:
685	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
686	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
687	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_SECONDARY
688	jz	.Lio_return
689	larl	%r14,.Lio_return
690	jg	set_fs_fixup
691
692#
693# CIF_FPU is set, restore floating-point controls and floating-point registers.
694#
695.Lio_vxrs:
696	larl	%r14,.Lio_return
697	jg	load_fpu_regs
698
699#
700# _TIF_NEED_RESCHED is set, call schedule
701#
702.Lio_reschedule:
703	# TRACE_IRQS_ON already done at .Lio_return
704	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
705	brasl	%r14,schedule		# call scheduler
706	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
707	TRACE_IRQS_OFF
708	j	.Lio_return
709
710#
711# _TIF_SIGPENDING or is set, call do_signal
712#
713.Lio_sigpending:
714	# TRACE_IRQS_ON already done at .Lio_return
715	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
716	lgr	%r2,%r11		# pass pointer to pt_regs
717	brasl	%r14,do_signal
718	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
719	TRACE_IRQS_OFF
720	j	.Lio_return
721
722#
723# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
724#
725.Lio_notify_resume:
726	# TRACE_IRQS_ON already done at .Lio_return
727	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
728	lgr	%r2,%r11		# pass pointer to pt_regs
729	brasl	%r14,do_notify_resume
730	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
731	TRACE_IRQS_OFF
732	j	.Lio_return
733
734/*
735 * External interrupt handler routine
736 */
737ENTRY(ext_int_handler)
738	STCK	__LC_INT_CLOCK
739	stpt	__LC_ASYNC_ENTER_TIMER
740	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
741	lg	%r12,__LC_CURRENT
742	larl	%r13,cleanup_critical
743	lmg	%r8,%r9,__LC_EXT_OLD_PSW
744	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
745	stmg	%r0,%r7,__PT_R0(%r11)
746	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
747	stmg	%r8,%r9,__PT_PSW(%r11)
748	lghi	%r1,__LC_EXT_PARAMS2
749	mvc	__PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
750	mvc	__PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
751	mvc	__PT_INT_PARM_LONG(8,%r11),0(%r1)
752	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
753	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
754	jo	.Lio_restore
755	TRACE_IRQS_OFF
756	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
757	lgr	%r2,%r11		# pass pointer to pt_regs
758	lghi	%r3,EXT_INTERRUPT
759	brasl	%r14,do_IRQ
760	j	.Lio_return
761
762/*
763 * Load idle PSW. The second "half" of this function is in .Lcleanup_idle.
764 */
765ENTRY(psw_idle)
766	stg	%r3,__SF_EMPTY(%r15)
767	larl	%r1,.Lpsw_idle_lpsw+4
768	stg	%r1,__SF_EMPTY+8(%r15)
769#ifdef CONFIG_SMP
770	larl	%r1,smp_cpu_mtid
771	llgf	%r1,0(%r1)
772	ltgr	%r1,%r1
773	jz	.Lpsw_idle_stcctm
774	.insn	rsy,0xeb0000000017,%r1,5,__SF_EMPTY+16(%r15)
775.Lpsw_idle_stcctm:
776#endif
777	oi	__LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT
778	STCK	__CLOCK_IDLE_ENTER(%r2)
779	stpt	__TIMER_IDLE_ENTER(%r2)
780.Lpsw_idle_lpsw:
781	lpswe	__SF_EMPTY(%r15)
782	br	%r14
783.Lpsw_idle_end:
784
785/*
786 * Store floating-point controls and floating-point or vector register
787 * depending whether the vector facility is available.	A critical section
788 * cleanup assures that the registers are stored even if interrupted for
789 * some other work.  The CIF_FPU flag is set to trigger a lazy restore
790 * of the register contents at return from io or a system call.
791 */
792ENTRY(save_fpu_regs)
793	lg	%r2,__LC_CURRENT
794	aghi	%r2,__TASK_thread
795	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
796	bor	%r14
797	stfpc	__THREAD_FPU_fpc(%r2)
798	lg	%r3,__THREAD_FPU_regs(%r2)
799	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
800	jz	.Lsave_fpu_regs_fp	  # no -> store FP regs
801	VSTM	%v0,%v15,0,%r3		  # vstm 0,15,0(3)
802	VSTM	%v16,%v31,256,%r3	  # vstm 16,31,256(3)
803	j	.Lsave_fpu_regs_done	  # -> set CIF_FPU flag
804.Lsave_fpu_regs_fp:
805	std	0,0(%r3)
806	std	1,8(%r3)
807	std	2,16(%r3)
808	std	3,24(%r3)
809	std	4,32(%r3)
810	std	5,40(%r3)
811	std	6,48(%r3)
812	std	7,56(%r3)
813	std	8,64(%r3)
814	std	9,72(%r3)
815	std	10,80(%r3)
816	std	11,88(%r3)
817	std	12,96(%r3)
818	std	13,104(%r3)
819	std	14,112(%r3)
820	std	15,120(%r3)
821.Lsave_fpu_regs_done:
822	oi	__LC_CPU_FLAGS+7,_CIF_FPU
823	br	%r14
824.Lsave_fpu_regs_end:
825#if IS_ENABLED(CONFIG_KVM)
826EXPORT_SYMBOL(save_fpu_regs)
827#endif
828
829/*
830 * Load floating-point controls and floating-point or vector registers.
831 * A critical section cleanup assures that the register contents are
832 * loaded even if interrupted for some other work.
833 *
834 * There are special calling conventions to fit into sysc and io return work:
835 *	%r15:	<kernel stack>
836 * The function requires:
837 *	%r4
838 */
839load_fpu_regs:
840	lg	%r4,__LC_CURRENT
841	aghi	%r4,__TASK_thread
842	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
843	bnor	%r14
844	lfpc	__THREAD_FPU_fpc(%r4)
845	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
846	lg	%r4,__THREAD_FPU_regs(%r4)	# %r4 <- reg save area
847	jz	.Lload_fpu_regs_fp		# -> no VX, load FP regs
848	VLM	%v0,%v15,0,%r4
849	VLM	%v16,%v31,256,%r4
850	j	.Lload_fpu_regs_done
851.Lload_fpu_regs_fp:
852	ld	0,0(%r4)
853	ld	1,8(%r4)
854	ld	2,16(%r4)
855	ld	3,24(%r4)
856	ld	4,32(%r4)
857	ld	5,40(%r4)
858	ld	6,48(%r4)
859	ld	7,56(%r4)
860	ld	8,64(%r4)
861	ld	9,72(%r4)
862	ld	10,80(%r4)
863	ld	11,88(%r4)
864	ld	12,96(%r4)
865	ld	13,104(%r4)
866	ld	14,112(%r4)
867	ld	15,120(%r4)
868.Lload_fpu_regs_done:
869	ni	__LC_CPU_FLAGS+7,255-_CIF_FPU
870	br	%r14
871.Lload_fpu_regs_end:
872
873.L__critical_end:
874
875/*
876 * Machine check handler routines
877 */
878ENTRY(mcck_int_handler)
879	STCK	__LC_MCCK_CLOCK
880	la	%r1,4095		# revalidate r1
881	spt	__LC_CPU_TIMER_SAVE_AREA-4095(%r1)	# revalidate cpu timer
882	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
883	lg	%r12,__LC_CURRENT
884	larl	%r13,cleanup_critical
885	lmg	%r8,%r9,__LC_MCK_OLD_PSW
886	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE
887	jo	.Lmcck_panic		# yes -> rest of mcck code invalid
888	lghi	%r14,__LC_CPU_TIMER_SAVE_AREA
889	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
890	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_CPU_TIMER_VALID
891	jo	3f
892	la	%r14,__LC_SYNC_ENTER_TIMER
893	clc	0(8,%r14),__LC_ASYNC_ENTER_TIMER
894	jl	0f
895	la	%r14,__LC_ASYNC_ENTER_TIMER
8960:	clc	0(8,%r14),__LC_EXIT_TIMER
897	jl	1f
898	la	%r14,__LC_EXIT_TIMER
8991:	clc	0(8,%r14),__LC_LAST_UPDATE_TIMER
900	jl	2f
901	la	%r14,__LC_LAST_UPDATE_TIMER
9022:	spt	0(%r14)
903	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
9043:	TSTMSK	__LC_MCCK_CODE,(MCCK_CODE_PSW_MWP_VALID|MCCK_CODE_PSW_IA_VALID)
905	jno	.Lmcck_panic		# no -> skip cleanup critical
906	SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER
907.Lmcck_skip:
908	lghi	%r14,__LC_GPREGS_SAVE_AREA+64
909	stmg	%r0,%r7,__PT_R0(%r11)
910	mvc	__PT_R8(64,%r11),0(%r14)
911	stmg	%r8,%r9,__PT_PSW(%r11)
912	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
913	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
914	lgr	%r2,%r11		# pass pointer to pt_regs
915	brasl	%r14,s390_do_machine_check
916	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
917	jno	.Lmcck_return
918	lg	%r1,__LC_KERNEL_STACK	# switch to kernel stack
919	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
920	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
921	la	%r11,STACK_FRAME_OVERHEAD(%r1)
922	lgr	%r15,%r1
923	ssm	__LC_PGM_NEW_PSW	# turn dat on, keep irqs off
924	TSTMSK	__LC_CPU_FLAGS,_CIF_MCCK_PENDING
925	jno	.Lmcck_return
926	TRACE_IRQS_OFF
927	brasl	%r14,s390_handle_mcck
928	TRACE_IRQS_ON
929.Lmcck_return:
930	lg	%r14,__LC_VDSO_PER_CPU
931	lmg	%r0,%r10,__PT_R0(%r11)
932	mvc	__LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
933	tm	__LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
934	jno	0f
935	stpt	__LC_EXIT_TIMER
936	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
9370:	lmg	%r11,%r15,__PT_R11(%r11)
938	lpswe	__LC_RETURN_MCCK_PSW
939
940.Lmcck_panic:
941	lg	%r15,__LC_PANIC_STACK
942	la	%r11,STACK_FRAME_OVERHEAD(%r15)
943	j	.Lmcck_skip
944
945#
946# PSW restart interrupt handler
947#
948ENTRY(restart_int_handler)
949	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
950	jz	0f
951	.insn	s,0xb2800000,__LC_LPP
9520:	stg	%r15,__LC_SAVE_AREA_RESTART
953	lg	%r15,__LC_RESTART_STACK
954	aghi	%r15,-__PT_SIZE			# create pt_regs on stack
955	xc	0(__PT_SIZE,%r15),0(%r15)
956	stmg	%r0,%r14,__PT_R0(%r15)
957	mvc	__PT_R15(8,%r15),__LC_SAVE_AREA_RESTART
958	mvc	__PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw
959	aghi	%r15,-STACK_FRAME_OVERHEAD	# create stack frame on stack
960	xc	0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
961	lg	%r1,__LC_RESTART_FN		# load fn, parm & source cpu
962	lg	%r2,__LC_RESTART_DATA
963	lg	%r3,__LC_RESTART_SOURCE
964	ltgr	%r3,%r3				# test source cpu address
965	jm	1f				# negative -> skip source stop
9660:	sigp	%r4,%r3,SIGP_SENSE		# sigp sense to source cpu
967	brc	10,0b				# wait for status stored
9681:	basr	%r14,%r1			# call function
969	stap	__SF_EMPTY(%r15)		# store cpu address
970	llgh	%r3,__SF_EMPTY(%r15)
9712:	sigp	%r4,%r3,SIGP_STOP		# sigp stop to current cpu
972	brc	2,2b
9733:	j	3b
974
975	.section .kprobes.text, "ax"
976
977#ifdef CONFIG_CHECK_STACK
978/*
979 * The synchronous or the asynchronous stack overflowed. We are dead.
980 * No need to properly save the registers, we are going to panic anyway.
981 * Setup a pt_regs so that show_trace can provide a good call trace.
982 */
983stack_overflow:
984	lg	%r15,__LC_PANIC_STACK	# change to panic stack
985	la	%r11,STACK_FRAME_OVERHEAD(%r15)
986	stmg	%r0,%r7,__PT_R0(%r11)
987	stmg	%r8,%r9,__PT_PSW(%r11)
988	mvc	__PT_R8(64,%r11),0(%r14)
989	stg	%r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
990	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
991	lgr	%r2,%r11		# pass pointer to pt_regs
992	jg	kernel_stack_overflow
993#endif
994
995cleanup_critical:
996#if IS_ENABLED(CONFIG_KVM)
997	clg	%r9,BASED(.Lcleanup_table_sie)	# .Lsie_gmap
998	jl	0f
999	clg	%r9,BASED(.Lcleanup_table_sie+8)# .Lsie_done
1000	jl	.Lcleanup_sie
1001#endif
1002	clg	%r9,BASED(.Lcleanup_table)	# system_call
1003	jl	0f
1004	clg	%r9,BASED(.Lcleanup_table+8)	# .Lsysc_do_svc
1005	jl	.Lcleanup_system_call
1006	clg	%r9,BASED(.Lcleanup_table+16)	# .Lsysc_tif
1007	jl	0f
1008	clg	%r9,BASED(.Lcleanup_table+24)	# .Lsysc_restore
1009	jl	.Lcleanup_sysc_tif
1010	clg	%r9,BASED(.Lcleanup_table+32)	# .Lsysc_done
1011	jl	.Lcleanup_sysc_restore
1012	clg	%r9,BASED(.Lcleanup_table+40)	# .Lio_tif
1013	jl	0f
1014	clg	%r9,BASED(.Lcleanup_table+48)	# .Lio_restore
1015	jl	.Lcleanup_io_tif
1016	clg	%r9,BASED(.Lcleanup_table+56)	# .Lio_done
1017	jl	.Lcleanup_io_restore
1018	clg	%r9,BASED(.Lcleanup_table+64)	# psw_idle
1019	jl	0f
1020	clg	%r9,BASED(.Lcleanup_table+72)	# .Lpsw_idle_end
1021	jl	.Lcleanup_idle
1022	clg	%r9,BASED(.Lcleanup_table+80)	# save_fpu_regs
1023	jl	0f
1024	clg	%r9,BASED(.Lcleanup_table+88)	# .Lsave_fpu_regs_end
1025	jl	.Lcleanup_save_fpu_regs
1026	clg	%r9,BASED(.Lcleanup_table+96)	# load_fpu_regs
1027	jl	0f
1028	clg	%r9,BASED(.Lcleanup_table+104)	# .Lload_fpu_regs_end
1029	jl	.Lcleanup_load_fpu_regs
10300:	br	%r14
1031
1032	.align	8
1033.Lcleanup_table:
1034	.quad	system_call
1035	.quad	.Lsysc_do_svc
1036	.quad	.Lsysc_tif
1037	.quad	.Lsysc_restore
1038	.quad	.Lsysc_done
1039	.quad	.Lio_tif
1040	.quad	.Lio_restore
1041	.quad	.Lio_done
1042	.quad	psw_idle
1043	.quad	.Lpsw_idle_end
1044	.quad	save_fpu_regs
1045	.quad	.Lsave_fpu_regs_end
1046	.quad	load_fpu_regs
1047	.quad	.Lload_fpu_regs_end
1048
1049#if IS_ENABLED(CONFIG_KVM)
1050.Lcleanup_table_sie:
1051	.quad	.Lsie_gmap
1052	.quad	.Lsie_done
1053
1054.Lcleanup_sie:
1055	lg	%r9,__SF_EMPTY(%r15)		# get control block pointer
1056	ni	__SIE_PROG0C+3(%r9),0xfe	# no longer in SIE
1057	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
1058	larl	%r9,sie_exit			# skip forward to sie_exit
1059	br	%r14
1060#endif
1061
1062.Lcleanup_system_call:
1063	# check if stpt has been executed
1064	clg	%r9,BASED(.Lcleanup_system_call_insn)
1065	jh	0f
1066	mvc	__LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
1067	cghi	%r11,__LC_SAVE_AREA_ASYNC
1068	je	0f
1069	mvc	__LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
10700:	# check if stmg has been executed
1071	clg	%r9,BASED(.Lcleanup_system_call_insn+8)
1072	jh	0f
1073	mvc	__LC_SAVE_AREA_SYNC(64),0(%r11)
10740:	# check if base register setup + TIF bit load has been done
1075	clg	%r9,BASED(.Lcleanup_system_call_insn+16)
1076	jhe	0f
1077	# set up saved register r12 task struct pointer
1078	stg	%r12,32(%r11)
1079	# set up saved register r13 __TASK_thread offset
1080	mvc	40(8,%r11),BASED(.Lcleanup_system_call_const)
10810:	# check if the user time update has been done
1082	clg	%r9,BASED(.Lcleanup_system_call_insn+24)
1083	jh	0f
1084	lg	%r15,__LC_EXIT_TIMER
1085	slg	%r15,__LC_SYNC_ENTER_TIMER
1086	alg	%r15,__LC_USER_TIMER
1087	stg	%r15,__LC_USER_TIMER
10880:	# check if the system time update has been done
1089	clg	%r9,BASED(.Lcleanup_system_call_insn+32)
1090	jh	0f
1091	lg	%r15,__LC_LAST_UPDATE_TIMER
1092	slg	%r15,__LC_EXIT_TIMER
1093	alg	%r15,__LC_SYSTEM_TIMER
1094	stg	%r15,__LC_SYSTEM_TIMER
10950:	# update accounting time stamp
1096	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
1097	# set up saved register r11
1098	lg	%r15,__LC_KERNEL_STACK
1099	la	%r9,STACK_FRAME_OVERHEAD(%r15)
1100	stg	%r9,24(%r11)		# r11 pt_regs pointer
1101	# fill pt_regs
1102	mvc	__PT_R8(64,%r9),__LC_SAVE_AREA_SYNC
1103	stmg	%r0,%r7,__PT_R0(%r9)
1104	mvc	__PT_PSW(16,%r9),__LC_SVC_OLD_PSW
1105	mvc	__PT_INT_CODE(4,%r9),__LC_SVC_ILC
1106	xc	__PT_FLAGS(8,%r9),__PT_FLAGS(%r9)
1107	mvi	__PT_FLAGS+7(%r9),_PIF_SYSCALL
1108	# setup saved register r15
1109	stg	%r15,56(%r11)		# r15 stack pointer
1110	# set new psw address and exit
1111	larl	%r9,.Lsysc_do_svc
1112	br	%r14
1113.Lcleanup_system_call_insn:
1114	.quad	system_call
1115	.quad	.Lsysc_stmg
1116	.quad	.Lsysc_per
1117	.quad	.Lsysc_vtime+36
1118	.quad	.Lsysc_vtime+42
1119.Lcleanup_system_call_const:
1120	.quad	__TASK_thread
1121
1122.Lcleanup_sysc_tif:
1123	larl	%r9,.Lsysc_tif
1124	br	%r14
1125
1126.Lcleanup_sysc_restore:
1127	clg	%r9,BASED(.Lcleanup_sysc_restore_insn)
1128	je	0f
1129	lg	%r9,24(%r11)		# get saved pointer to pt_regs
1130	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r9)
1131	mvc	0(64,%r11),__PT_R8(%r9)
1132	lmg	%r0,%r7,__PT_R0(%r9)
11330:	lmg	%r8,%r9,__LC_RETURN_PSW
1134	br	%r14
1135.Lcleanup_sysc_restore_insn:
1136	.quad	.Lsysc_done - 4
1137
1138.Lcleanup_io_tif:
1139	larl	%r9,.Lio_tif
1140	br	%r14
1141
1142.Lcleanup_io_restore:
1143	clg	%r9,BASED(.Lcleanup_io_restore_insn)
1144	je	0f
1145	lg	%r9,24(%r11)		# get saved r11 pointer to pt_regs
1146	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r9)
1147	mvc	0(64,%r11),__PT_R8(%r9)
1148	lmg	%r0,%r7,__PT_R0(%r9)
11490:	lmg	%r8,%r9,__LC_RETURN_PSW
1150	br	%r14
1151.Lcleanup_io_restore_insn:
1152	.quad	.Lio_done - 4
1153
1154.Lcleanup_idle:
1155	ni	__LC_CPU_FLAGS+7,255-_CIF_ENABLED_WAIT
1156	# copy interrupt clock & cpu timer
1157	mvc	__CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK
1158	mvc	__TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER
1159	cghi	%r11,__LC_SAVE_AREA_ASYNC
1160	je	0f
1161	mvc	__CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK
1162	mvc	__TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER
11630:	# check if stck & stpt have been executed
1164	clg	%r9,BASED(.Lcleanup_idle_insn)
1165	jhe	1f
1166	mvc	__CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
1167	mvc	__TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r2)
11681:	# calculate idle cycles
1169#ifdef CONFIG_SMP
1170	clg	%r9,BASED(.Lcleanup_idle_insn)
1171	jl	3f
1172	larl	%r1,smp_cpu_mtid
1173	llgf	%r1,0(%r1)
1174	ltgr	%r1,%r1
1175	jz	3f
1176	.insn	rsy,0xeb0000000017,%r1,5,__SF_EMPTY+80(%r15)
1177	larl	%r3,mt_cycles
1178	ag	%r3,__LC_PERCPU_OFFSET
1179	la	%r4,__SF_EMPTY+16(%r15)
11802:	lg	%r0,0(%r3)
1181	slg	%r0,0(%r4)
1182	alg	%r0,64(%r4)
1183	stg	%r0,0(%r3)
1184	la	%r3,8(%r3)
1185	la	%r4,8(%r4)
1186	brct	%r1,2b
1187#endif
11883:	# account system time going idle
1189	lg	%r9,__LC_STEAL_TIMER
1190	alg	%r9,__CLOCK_IDLE_ENTER(%r2)
1191	slg	%r9,__LC_LAST_UPDATE_CLOCK
1192	stg	%r9,__LC_STEAL_TIMER
1193	mvc	__LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
1194	lg	%r9,__LC_SYSTEM_TIMER
1195	alg	%r9,__LC_LAST_UPDATE_TIMER
1196	slg	%r9,__TIMER_IDLE_ENTER(%r2)
1197	stg	%r9,__LC_SYSTEM_TIMER
1198	mvc	__LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
1199	# prepare return psw
1200	nihh	%r8,0xfcfd		# clear irq & wait state bits
1201	lg	%r9,48(%r11)		# return from psw_idle
1202	br	%r14
1203.Lcleanup_idle_insn:
1204	.quad	.Lpsw_idle_lpsw
1205
1206.Lcleanup_save_fpu_regs:
1207	larl	%r9,save_fpu_regs
1208	br	%r14
1209
1210.Lcleanup_load_fpu_regs:
1211	larl	%r9,load_fpu_regs
1212	br	%r14
1213
1214/*
1215 * Integer constants
1216 */
1217	.align	8
1218.Lcritical_start:
1219	.quad	.L__critical_start
1220.Lcritical_length:
1221	.quad	.L__critical_end - .L__critical_start
1222#if IS_ENABLED(CONFIG_KVM)
1223.Lsie_critical_start:
1224	.quad	.Lsie_gmap
1225.Lsie_critical_length:
1226	.quad	.Lsie_done - .Lsie_gmap
1227#endif
1228
1229	.section .rodata, "a"
1230#define SYSCALL(esame,emu)	.long esame
1231	.globl	sys_call_table
1232sys_call_table:
1233#include "syscalls.S"
1234#undef SYSCALL
1235
1236#ifdef CONFIG_COMPAT
1237
1238#define SYSCALL(esame,emu)	.long emu
1239	.globl	sys_call_table_emu
1240sys_call_table_emu:
1241#include "syscalls.S"
1242#undef SYSCALL
1243#endif
1244