xref: /openbmc/linux/arch/s390/kernel/entry.S (revision 239480ab)
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 | _TIF_GUARDED_STORAGE | _TIF_PATCH_PENDING)
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	mvc	__LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next
193	lmg	%r6,%r15,__SF_GPRS(%r15)	# load gprs of next task
194	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
195	bzr	%r14
196	.insn	s,0xb2800000,__LC_LPP		# set program parameter
197	br	%r14
198
199.L__critical_start:
200
201#if IS_ENABLED(CONFIG_KVM)
202/*
203 * sie64a calling convention:
204 * %r2 pointer to sie control block
205 * %r3 guest register save area
206 */
207ENTRY(sie64a)
208	stmg	%r6,%r14,__SF_GPRS(%r15)	# save kernel registers
209	stg	%r2,__SF_EMPTY(%r15)		# save control block pointer
210	stg	%r3,__SF_EMPTY+8(%r15)		# save guest register save area
211	xc	__SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # reason code = 0
212	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU		# load guest fp/vx registers ?
213	jno	.Lsie_load_guest_gprs
214	brasl	%r14,load_fpu_regs		# load guest fp/vx regs
215.Lsie_load_guest_gprs:
216	lmg	%r0,%r13,0(%r3)			# load guest gprs 0-13
217	lg	%r14,__LC_GMAP			# get gmap pointer
218	ltgr	%r14,%r14
219	jz	.Lsie_gmap
220	lctlg	%c1,%c1,__GMAP_ASCE(%r14)	# load primary asce
221.Lsie_gmap:
222	lg	%r14,__SF_EMPTY(%r15)		# get control block pointer
223	oi	__SIE_PROG0C+3(%r14),1		# we are going into SIE now
224	tm	__SIE_PROG20+3(%r14),3		# last exit...
225	jnz	.Lsie_skip
226	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
227	jo	.Lsie_skip			# exit if fp/vx regs changed
228	sie	0(%r14)
229.Lsie_skip:
230	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE
231	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
232.Lsie_done:
233# some program checks are suppressing. C code (e.g. do_protection_exception)
234# will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other
235# instructions between sie64a and .Lsie_done should not cause program
236# interrupts. So lets use a nop (47 00 00 00) as a landing pad.
237# See also .Lcleanup_sie
238.Lrewind_pad:
239	nop	0
240	.globl sie_exit
241sie_exit:
242	lg	%r14,__SF_EMPTY+8(%r15)		# load guest register save area
243	stmg	%r0,%r13,0(%r14)		# save guest gprs 0-13
244	lmg	%r6,%r14,__SF_GPRS(%r15)	# restore kernel registers
245	lg	%r2,__SF_EMPTY+16(%r15)		# return exit reason code
246	br	%r14
247.Lsie_fault:
248	lghi	%r14,-EFAULT
249	stg	%r14,__SF_EMPTY+16(%r15)	# set exit reason code
250	j	sie_exit
251
252	EX_TABLE(.Lrewind_pad,.Lsie_fault)
253	EX_TABLE(sie_exit,.Lsie_fault)
254EXPORT_SYMBOL(sie64a)
255EXPORT_SYMBOL(sie_exit)
256#endif
257
258/*
259 * SVC interrupt handler routine. System calls are synchronous events and
260 * are executed with interrupts enabled.
261 */
262
263ENTRY(system_call)
264	stpt	__LC_SYNC_ENTER_TIMER
265.Lsysc_stmg:
266	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
267	lg	%r12,__LC_CURRENT
268	lghi	%r13,__TASK_thread
269	lghi	%r14,_PIF_SYSCALL
270.Lsysc_per:
271	lg	%r15,__LC_KERNEL_STACK
272	la	%r11,STACK_FRAME_OVERHEAD(%r15)	# pointer to pt_regs
273.Lsysc_vtime:
274	UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
275	stmg	%r0,%r7,__PT_R0(%r11)
276	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
277	mvc	__PT_PSW(16,%r11),__LC_SVC_OLD_PSW
278	mvc	__PT_INT_CODE(4,%r11),__LC_SVC_ILC
279	stg	%r14,__PT_FLAGS(%r11)
280.Lsysc_do_svc:
281	# load address of system call table
282	lg	%r10,__THREAD_sysc_table(%r13,%r12)
283	llgh	%r8,__PT_INT_CODE+2(%r11)
284	slag	%r8,%r8,2			# shift and test for svc 0
285	jnz	.Lsysc_nr_ok
286	# svc 0: system call number in %r1
287	llgfr	%r1,%r1				# clear high word in r1
288	cghi	%r1,NR_syscalls
289	jnl	.Lsysc_nr_ok
290	sth	%r1,__PT_INT_CODE+2(%r11)
291	slag	%r8,%r1,2
292.Lsysc_nr_ok:
293	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
294	stg	%r2,__PT_ORIG_GPR2(%r11)
295	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
296	lgf	%r9,0(%r8,%r10)			# get system call add.
297	TSTMSK	__TI_flags(%r12),_TIF_TRACE
298	jnz	.Lsysc_tracesys
299	basr	%r14,%r9			# call sys_xxxx
300	stg	%r2,__PT_R2(%r11)		# store return value
301
302.Lsysc_return:
303	LOCKDEP_SYS_EXIT
304.Lsysc_tif:
305	TSTMSK	__PT_FLAGS(%r11),_PIF_WORK
306	jnz	.Lsysc_work
307	TSTMSK	__TI_flags(%r12),_TIF_WORK
308	jnz	.Lsysc_work			# check for work
309	TSTMSK	__LC_CPU_FLAGS,_CIF_WORK
310	jnz	.Lsysc_work
311.Lsysc_restore:
312	lg	%r14,__LC_VDSO_PER_CPU
313	lmg	%r0,%r10,__PT_R0(%r11)
314	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
315	stpt	__LC_EXIT_TIMER
316	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
317	lmg	%r11,%r15,__PT_R11(%r11)
318	lpswe	__LC_RETURN_PSW
319.Lsysc_done:
320
321#
322# One of the work bits is on. Find out which one.
323#
324.Lsysc_work:
325	TSTMSK	__LC_CPU_FLAGS,_CIF_MCCK_PENDING
326	jo	.Lsysc_mcck_pending
327	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
328	jo	.Lsysc_reschedule
329#ifdef CONFIG_UPROBES
330	TSTMSK	__TI_flags(%r12),_TIF_UPROBE
331	jo	.Lsysc_uprobe_notify
332#endif
333	TSTMSK	__TI_flags(%r12),_TIF_GUARDED_STORAGE
334	jo	.Lsysc_guarded_storage
335	TSTMSK	__PT_FLAGS(%r11),_PIF_PER_TRAP
336	jo	.Lsysc_singlestep
337#ifdef CONFIG_LIVEPATCH
338	TSTMSK	__TI_flags(%r12),_TIF_PATCH_PENDING
339	jo	.Lsysc_patch_pending	# handle live patching just before
340					# signals and possible syscall restart
341#endif
342	TSTMSK	__TI_flags(%r12),_TIF_SIGPENDING
343	jo	.Lsysc_sigpending
344	TSTMSK	__TI_flags(%r12),_TIF_NOTIFY_RESUME
345	jo	.Lsysc_notify_resume
346	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
347	jo	.Lsysc_vxrs
348	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
349	jnz	.Lsysc_asce
350	j	.Lsysc_return		# beware of critical section cleanup
351
352#
353# _TIF_NEED_RESCHED is set, call schedule
354#
355.Lsysc_reschedule:
356	larl	%r14,.Lsysc_return
357	jg	schedule
358
359#
360# _CIF_MCCK_PENDING is set, call handler
361#
362.Lsysc_mcck_pending:
363	larl	%r14,.Lsysc_return
364	jg	s390_handle_mcck	# TIF bit will be cleared by handler
365
366#
367# _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
368#
369.Lsysc_asce:
370	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
371	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
372	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_SECONDARY
373	jz	.Lsysc_return
374	larl	%r14,.Lsysc_return
375	jg	set_fs_fixup
376
377#
378# CIF_FPU is set, restore floating-point controls and floating-point registers.
379#
380.Lsysc_vxrs:
381	larl	%r14,.Lsysc_return
382	jg	load_fpu_regs
383
384#
385# _TIF_SIGPENDING is set, call do_signal
386#
387.Lsysc_sigpending:
388	lgr	%r2,%r11		# pass pointer to pt_regs
389	brasl	%r14,do_signal
390	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL
391	jno	.Lsysc_return
392.Lsysc_do_syscall:
393	lghi	%r13,__TASK_thread
394	lmg	%r2,%r7,__PT_R2(%r11)	# load svc arguments
395	lghi	%r1,0			# svc 0 returns -ENOSYS
396	j	.Lsysc_do_svc
397
398#
399# _TIF_NOTIFY_RESUME is set, call do_notify_resume
400#
401.Lsysc_notify_resume:
402	lgr	%r2,%r11		# pass pointer to pt_regs
403	larl	%r14,.Lsysc_return
404	jg	do_notify_resume
405
406#
407# _TIF_UPROBE is set, call uprobe_notify_resume
408#
409#ifdef CONFIG_UPROBES
410.Lsysc_uprobe_notify:
411	lgr	%r2,%r11		# pass pointer to pt_regs
412	larl	%r14,.Lsysc_return
413	jg	uprobe_notify_resume
414#endif
415
416#
417# _TIF_GUARDED_STORAGE is set, call guarded_storage_load
418#
419.Lsysc_guarded_storage:
420	lgr	%r2,%r11		# pass pointer to pt_regs
421	larl	%r14,.Lsysc_return
422	jg	gs_load_bc_cb
423#
424# _TIF_PATCH_PENDING is set, call klp_update_patch_state
425#
426#ifdef CONFIG_LIVEPATCH
427.Lsysc_patch_pending:
428	lg	%r2,__LC_CURRENT	# pass pointer to task struct
429	larl	%r14,.Lsysc_return
430	jg	klp_update_patch_state
431#endif
432
433#
434# _PIF_PER_TRAP is set, call do_per_trap
435#
436.Lsysc_singlestep:
437	ni	__PT_FLAGS+7(%r11),255-_PIF_PER_TRAP
438	lgr	%r2,%r11		# pass pointer to pt_regs
439	larl	%r14,.Lsysc_return
440	jg	do_per_trap
441
442#
443# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
444# and after the system call
445#
446.Lsysc_tracesys:
447	lgr	%r2,%r11		# pass pointer to pt_regs
448	la	%r3,0
449	llgh	%r0,__PT_INT_CODE+2(%r11)
450	stg	%r0,__PT_R2(%r11)
451	brasl	%r14,do_syscall_trace_enter
452	lghi	%r0,NR_syscalls
453	clgr	%r0,%r2
454	jnh	.Lsysc_tracenogo
455	sllg	%r8,%r2,2
456	lgf	%r9,0(%r8,%r10)
457.Lsysc_tracego:
458	lmg	%r3,%r7,__PT_R3(%r11)
459	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
460	lg	%r2,__PT_ORIG_GPR2(%r11)
461	basr	%r14,%r9		# call sys_xxx
462	stg	%r2,__PT_R2(%r11)	# store return value
463.Lsysc_tracenogo:
464	TSTMSK	__TI_flags(%r12),_TIF_TRACE
465	jz	.Lsysc_return
466	lgr	%r2,%r11		# pass pointer to pt_regs
467	larl	%r14,.Lsysc_return
468	jg	do_syscall_trace_exit
469
470#
471# a new process exits the kernel with ret_from_fork
472#
473ENTRY(ret_from_fork)
474	la	%r11,STACK_FRAME_OVERHEAD(%r15)
475	lg	%r12,__LC_CURRENT
476	brasl	%r14,schedule_tail
477	TRACE_IRQS_ON
478	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
479	tm	__PT_PSW+1(%r11),0x01	# forking a kernel thread ?
480	jne	.Lsysc_tracenogo
481	# it's a kernel thread
482	lmg	%r9,%r10,__PT_R9(%r11)	# load gprs
483ENTRY(kernel_thread_starter)
484	la	%r2,0(%r10)
485	basr	%r14,%r9
486	j	.Lsysc_tracenogo
487
488/*
489 * Program check handler routine
490 */
491
492ENTRY(pgm_check_handler)
493	stpt	__LC_SYNC_ENTER_TIMER
494	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
495	lg	%r10,__LC_LAST_BREAK
496	lg	%r12,__LC_CURRENT
497	larl	%r13,cleanup_critical
498	lmg	%r8,%r9,__LC_PGM_OLD_PSW
499	tmhh	%r8,0x0001		# test problem state bit
500	jnz	2f			# -> fault in user space
501#if IS_ENABLED(CONFIG_KVM)
502	# cleanup critical section for sie64a
503	lgr	%r14,%r9
504	slg	%r14,BASED(.Lsie_critical_start)
505	clg	%r14,BASED(.Lsie_critical_length)
506	jhe	0f
507	brasl	%r14,.Lcleanup_sie
508#endif
5090:	tmhh	%r8,0x4000		# PER bit set in old PSW ?
510	jnz	1f			# -> enabled, can't be a double fault
511	tm	__LC_PGM_ILC+3,0x80	# check for per exception
512	jnz	.Lpgm_svcper		# -> single stepped svc
5131:	CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
514	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
515	j	4f
5162:	UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
517	lg	%r15,__LC_KERNEL_STACK
518	lgr	%r14,%r12
519	aghi	%r14,__TASK_thread	# pointer to thread_struct
520	lghi	%r13,__LC_PGM_TDB
521	tm	__LC_PGM_ILC+2,0x02	# check for transaction abort
522	jz	3f
523	mvc	__THREAD_trap_tdb(256,%r14),0(%r13)
5243:	stg	%r10,__THREAD_last_break(%r14)
5254:	la	%r11,STACK_FRAME_OVERHEAD(%r15)
526	stmg	%r0,%r7,__PT_R0(%r11)
527	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
528	stmg	%r8,%r9,__PT_PSW(%r11)
529	mvc	__PT_INT_CODE(4,%r11),__LC_PGM_ILC
530	mvc	__PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE
531	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
532	stg	%r10,__PT_ARGS(%r11)
533	tm	__LC_PGM_ILC+3,0x80	# check for per exception
534	jz	5f
535	tmhh	%r8,0x0001		# kernel per event ?
536	jz	.Lpgm_kprobe
537	oi	__PT_FLAGS+7(%r11),_PIF_PER_TRAP
538	mvc	__THREAD_per_address(8,%r14),__LC_PER_ADDRESS
539	mvc	__THREAD_per_cause(2,%r14),__LC_PER_CODE
540	mvc	__THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
5415:	REENABLE_IRQS
542	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
543	larl	%r1,pgm_check_table
544	llgh	%r10,__PT_INT_CODE+2(%r11)
545	nill	%r10,0x007f
546	sll	%r10,2
547	je	.Lpgm_return
548	lgf	%r1,0(%r10,%r1)		# load address of handler routine
549	lgr	%r2,%r11		# pass pointer to pt_regs
550	basr	%r14,%r1		# branch to interrupt-handler
551.Lpgm_return:
552	LOCKDEP_SYS_EXIT
553	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
554	jno	.Lsysc_restore
555	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL
556	jo	.Lsysc_do_syscall
557	j	.Lsysc_tif
558
559#
560# PER event in supervisor state, must be kprobes
561#
562.Lpgm_kprobe:
563	REENABLE_IRQS
564	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
565	lgr	%r2,%r11		# pass pointer to pt_regs
566	brasl	%r14,do_per_trap
567	j	.Lpgm_return
568
569#
570# single stepped system call
571#
572.Lpgm_svcper:
573	mvc	__LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
574	lghi	%r13,__TASK_thread
575	larl	%r14,.Lsysc_per
576	stg	%r14,__LC_RETURN_PSW+8
577	lghi	%r14,_PIF_SYSCALL | _PIF_PER_TRAP
578	lpswe	__LC_RETURN_PSW		# branch to .Lsysc_per and enable irqs
579
580/*
581 * IO interrupt handler routine
582 */
583ENTRY(io_int_handler)
584	STCK	__LC_INT_CLOCK
585	stpt	__LC_ASYNC_ENTER_TIMER
586	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
587	lg	%r12,__LC_CURRENT
588	larl	%r13,cleanup_critical
589	lmg	%r8,%r9,__LC_IO_OLD_PSW
590	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
591	stmg	%r0,%r7,__PT_R0(%r11)
592	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
593	stmg	%r8,%r9,__PT_PSW(%r11)
594	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
595	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
596	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
597	jo	.Lio_restore
598	TRACE_IRQS_OFF
599	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
600.Lio_loop:
601	lgr	%r2,%r11		# pass pointer to pt_regs
602	lghi	%r3,IO_INTERRUPT
603	tm	__PT_INT_CODE+8(%r11),0x80	# adapter interrupt ?
604	jz	.Lio_call
605	lghi	%r3,THIN_INTERRUPT
606.Lio_call:
607	brasl	%r14,do_IRQ
608	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPAR
609	jz	.Lio_return
610	tpi	0
611	jz	.Lio_return
612	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
613	j	.Lio_loop
614.Lio_return:
615	LOCKDEP_SYS_EXIT
616	TRACE_IRQS_ON
617.Lio_tif:
618	TSTMSK	__TI_flags(%r12),_TIF_WORK
619	jnz	.Lio_work		# there is work to do (signals etc.)
620	TSTMSK	__LC_CPU_FLAGS,_CIF_WORK
621	jnz	.Lio_work
622.Lio_restore:
623	lg	%r14,__LC_VDSO_PER_CPU
624	lmg	%r0,%r10,__PT_R0(%r11)
625	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
626	stpt	__LC_EXIT_TIMER
627	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
628	lmg	%r11,%r15,__PT_R11(%r11)
629	lpswe	__LC_RETURN_PSW
630.Lio_done:
631
632#
633# There is work todo, find out in which context we have been interrupted:
634# 1) if we return to user space we can do all _TIF_WORK work
635# 2) if we return to kernel code and kvm is enabled check if we need to
636#    modify the psw to leave SIE
637# 3) if we return to kernel code and preemptive scheduling is enabled check
638#    the preemption counter and if it is zero call preempt_schedule_irq
639# Before any work can be done, a switch to the kernel stack is required.
640#
641.Lio_work:
642	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
643	jo	.Lio_work_user		# yes -> do resched & signal
644#ifdef CONFIG_PREEMPT
645	# check for preemptive scheduling
646	icm	%r0,15,__LC_PREEMPT_COUNT
647	jnz	.Lio_restore		# preemption is disabled
648	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
649	jno	.Lio_restore
650	# switch to kernel stack
651	lg	%r1,__PT_R15(%r11)
652	aghi	%r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
653	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
654	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
655	la	%r11,STACK_FRAME_OVERHEAD(%r1)
656	lgr	%r15,%r1
657	# TRACE_IRQS_ON already done at .Lio_return, call
658	# TRACE_IRQS_OFF to keep things symmetrical
659	TRACE_IRQS_OFF
660	brasl	%r14,preempt_schedule_irq
661	j	.Lio_return
662#else
663	j	.Lio_restore
664#endif
665
666#
667# Need to do work before returning to userspace, switch to kernel stack
668#
669.Lio_work_user:
670	lg	%r1,__LC_KERNEL_STACK
671	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
672	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
673	la	%r11,STACK_FRAME_OVERHEAD(%r1)
674	lgr	%r15,%r1
675
676#
677# One of the work bits is on. Find out which one.
678#
679.Lio_work_tif:
680	TSTMSK	__LC_CPU_FLAGS,_CIF_MCCK_PENDING
681	jo	.Lio_mcck_pending
682	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
683	jo	.Lio_reschedule
684#ifdef CONFIG_LIVEPATCH
685	TSTMSK	__TI_flags(%r12),_TIF_PATCH_PENDING
686	jo	.Lio_patch_pending
687#endif
688	TSTMSK	__TI_flags(%r12),_TIF_SIGPENDING
689	jo	.Lio_sigpending
690	TSTMSK	__TI_flags(%r12),_TIF_NOTIFY_RESUME
691	jo	.Lio_notify_resume
692	TSTMSK	__TI_flags(%r12),_TIF_GUARDED_STORAGE
693	jo	.Lio_guarded_storage
694	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
695	jo	.Lio_vxrs
696	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
697	jnz	.Lio_asce
698	j	.Lio_return		# beware of critical section cleanup
699
700#
701# _CIF_MCCK_PENDING is set, call handler
702#
703.Lio_mcck_pending:
704	# TRACE_IRQS_ON already done at .Lio_return
705	brasl	%r14,s390_handle_mcck	# TIF bit will be cleared by handler
706	TRACE_IRQS_OFF
707	j	.Lio_return
708
709#
710# _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
711#
712.Lio_asce:
713	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
714	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
715	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_SECONDARY
716	jz	.Lio_return
717	larl	%r14,.Lio_return
718	jg	set_fs_fixup
719
720#
721# CIF_FPU is set, restore floating-point controls and floating-point registers.
722#
723.Lio_vxrs:
724	larl	%r14,.Lio_return
725	jg	load_fpu_regs
726
727#
728# _TIF_GUARDED_STORAGE is set, call guarded_storage_load
729#
730.Lio_guarded_storage:
731	# TRACE_IRQS_ON already done at .Lio_return
732	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
733	lgr	%r2,%r11		# pass pointer to pt_regs
734	brasl	%r14,gs_load_bc_cb
735	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
736	TRACE_IRQS_OFF
737	j	.Lio_return
738
739#
740# _TIF_NEED_RESCHED is set, call schedule
741#
742.Lio_reschedule:
743	# TRACE_IRQS_ON already done at .Lio_return
744	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
745	brasl	%r14,schedule		# call scheduler
746	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
747	TRACE_IRQS_OFF
748	j	.Lio_return
749
750#
751# _TIF_PATCH_PENDING is set, call klp_update_patch_state
752#
753#ifdef CONFIG_LIVEPATCH
754.Lio_patch_pending:
755	lg	%r2,__LC_CURRENT	# pass pointer to task struct
756	larl	%r14,.Lio_return
757	jg	klp_update_patch_state
758#endif
759
760#
761# _TIF_SIGPENDING or is set, call do_signal
762#
763.Lio_sigpending:
764	# TRACE_IRQS_ON already done at .Lio_return
765	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
766	lgr	%r2,%r11		# pass pointer to pt_regs
767	brasl	%r14,do_signal
768	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
769	TRACE_IRQS_OFF
770	j	.Lio_return
771
772#
773# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
774#
775.Lio_notify_resume:
776	# TRACE_IRQS_ON already done at .Lio_return
777	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
778	lgr	%r2,%r11		# pass pointer to pt_regs
779	brasl	%r14,do_notify_resume
780	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
781	TRACE_IRQS_OFF
782	j	.Lio_return
783
784/*
785 * External interrupt handler routine
786 */
787ENTRY(ext_int_handler)
788	STCK	__LC_INT_CLOCK
789	stpt	__LC_ASYNC_ENTER_TIMER
790	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
791	lg	%r12,__LC_CURRENT
792	larl	%r13,cleanup_critical
793	lmg	%r8,%r9,__LC_EXT_OLD_PSW
794	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
795	stmg	%r0,%r7,__PT_R0(%r11)
796	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
797	stmg	%r8,%r9,__PT_PSW(%r11)
798	lghi	%r1,__LC_EXT_PARAMS2
799	mvc	__PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
800	mvc	__PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
801	mvc	__PT_INT_PARM_LONG(8,%r11),0(%r1)
802	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
803	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
804	jo	.Lio_restore
805	TRACE_IRQS_OFF
806	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
807	lgr	%r2,%r11		# pass pointer to pt_regs
808	lghi	%r3,EXT_INTERRUPT
809	brasl	%r14,do_IRQ
810	j	.Lio_return
811
812/*
813 * Load idle PSW. The second "half" of this function is in .Lcleanup_idle.
814 */
815ENTRY(psw_idle)
816	stg	%r3,__SF_EMPTY(%r15)
817	larl	%r1,.Lpsw_idle_lpsw+4
818	stg	%r1,__SF_EMPTY+8(%r15)
819#ifdef CONFIG_SMP
820	larl	%r1,smp_cpu_mtid
821	llgf	%r1,0(%r1)
822	ltgr	%r1,%r1
823	jz	.Lpsw_idle_stcctm
824	.insn	rsy,0xeb0000000017,%r1,5,__SF_EMPTY+16(%r15)
825.Lpsw_idle_stcctm:
826#endif
827	oi	__LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT
828	STCK	__CLOCK_IDLE_ENTER(%r2)
829	stpt	__TIMER_IDLE_ENTER(%r2)
830.Lpsw_idle_lpsw:
831	lpswe	__SF_EMPTY(%r15)
832	br	%r14
833.Lpsw_idle_end:
834
835/*
836 * Store floating-point controls and floating-point or vector register
837 * depending whether the vector facility is available.	A critical section
838 * cleanup assures that the registers are stored even if interrupted for
839 * some other work.  The CIF_FPU flag is set to trigger a lazy restore
840 * of the register contents at return from io or a system call.
841 */
842ENTRY(save_fpu_regs)
843	lg	%r2,__LC_CURRENT
844	aghi	%r2,__TASK_thread
845	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
846	bor	%r14
847	stfpc	__THREAD_FPU_fpc(%r2)
848	lg	%r3,__THREAD_FPU_regs(%r2)
849	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
850	jz	.Lsave_fpu_regs_fp	  # no -> store FP regs
851	VSTM	%v0,%v15,0,%r3		  # vstm 0,15,0(3)
852	VSTM	%v16,%v31,256,%r3	  # vstm 16,31,256(3)
853	j	.Lsave_fpu_regs_done	  # -> set CIF_FPU flag
854.Lsave_fpu_regs_fp:
855	std	0,0(%r3)
856	std	1,8(%r3)
857	std	2,16(%r3)
858	std	3,24(%r3)
859	std	4,32(%r3)
860	std	5,40(%r3)
861	std	6,48(%r3)
862	std	7,56(%r3)
863	std	8,64(%r3)
864	std	9,72(%r3)
865	std	10,80(%r3)
866	std	11,88(%r3)
867	std	12,96(%r3)
868	std	13,104(%r3)
869	std	14,112(%r3)
870	std	15,120(%r3)
871.Lsave_fpu_regs_done:
872	oi	__LC_CPU_FLAGS+7,_CIF_FPU
873	br	%r14
874.Lsave_fpu_regs_end:
875#if IS_ENABLED(CONFIG_KVM)
876EXPORT_SYMBOL(save_fpu_regs)
877#endif
878
879/*
880 * Load floating-point controls and floating-point or vector registers.
881 * A critical section cleanup assures that the register contents are
882 * loaded even if interrupted for some other work.
883 *
884 * There are special calling conventions to fit into sysc and io return work:
885 *	%r15:	<kernel stack>
886 * The function requires:
887 *	%r4
888 */
889load_fpu_regs:
890	lg	%r4,__LC_CURRENT
891	aghi	%r4,__TASK_thread
892	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
893	bnor	%r14
894	lfpc	__THREAD_FPU_fpc(%r4)
895	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
896	lg	%r4,__THREAD_FPU_regs(%r4)	# %r4 <- reg save area
897	jz	.Lload_fpu_regs_fp		# -> no VX, load FP regs
898	VLM	%v0,%v15,0,%r4
899	VLM	%v16,%v31,256,%r4
900	j	.Lload_fpu_regs_done
901.Lload_fpu_regs_fp:
902	ld	0,0(%r4)
903	ld	1,8(%r4)
904	ld	2,16(%r4)
905	ld	3,24(%r4)
906	ld	4,32(%r4)
907	ld	5,40(%r4)
908	ld	6,48(%r4)
909	ld	7,56(%r4)
910	ld	8,64(%r4)
911	ld	9,72(%r4)
912	ld	10,80(%r4)
913	ld	11,88(%r4)
914	ld	12,96(%r4)
915	ld	13,104(%r4)
916	ld	14,112(%r4)
917	ld	15,120(%r4)
918.Lload_fpu_regs_done:
919	ni	__LC_CPU_FLAGS+7,255-_CIF_FPU
920	br	%r14
921.Lload_fpu_regs_end:
922
923.L__critical_end:
924
925/*
926 * Machine check handler routines
927 */
928ENTRY(mcck_int_handler)
929	STCK	__LC_MCCK_CLOCK
930	la	%r1,4095		# revalidate r1
931	spt	__LC_CPU_TIMER_SAVE_AREA-4095(%r1)	# revalidate cpu timer
932	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
933	lg	%r12,__LC_CURRENT
934	larl	%r13,cleanup_critical
935	lmg	%r8,%r9,__LC_MCK_OLD_PSW
936	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE
937	jo	.Lmcck_panic		# yes -> rest of mcck code invalid
938	lghi	%r14,__LC_CPU_TIMER_SAVE_AREA
939	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
940	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_CPU_TIMER_VALID
941	jo	3f
942	la	%r14,__LC_SYNC_ENTER_TIMER
943	clc	0(8,%r14),__LC_ASYNC_ENTER_TIMER
944	jl	0f
945	la	%r14,__LC_ASYNC_ENTER_TIMER
9460:	clc	0(8,%r14),__LC_EXIT_TIMER
947	jl	1f
948	la	%r14,__LC_EXIT_TIMER
9491:	clc	0(8,%r14),__LC_LAST_UPDATE_TIMER
950	jl	2f
951	la	%r14,__LC_LAST_UPDATE_TIMER
9522:	spt	0(%r14)
953	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
9543:	TSTMSK	__LC_MCCK_CODE,(MCCK_CODE_PSW_MWP_VALID|MCCK_CODE_PSW_IA_VALID)
955	jno	.Lmcck_panic		# no -> skip cleanup critical
956	SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER
957.Lmcck_skip:
958	lghi	%r14,__LC_GPREGS_SAVE_AREA+64
959	stmg	%r0,%r7,__PT_R0(%r11)
960	mvc	__PT_R8(64,%r11),0(%r14)
961	stmg	%r8,%r9,__PT_PSW(%r11)
962	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
963	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
964	lgr	%r2,%r11		# pass pointer to pt_regs
965	brasl	%r14,s390_do_machine_check
966	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
967	jno	.Lmcck_return
968	lg	%r1,__LC_KERNEL_STACK	# switch to kernel stack
969	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
970	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
971	la	%r11,STACK_FRAME_OVERHEAD(%r1)
972	lgr	%r15,%r1
973	ssm	__LC_PGM_NEW_PSW	# turn dat on, keep irqs off
974	TSTMSK	__LC_CPU_FLAGS,_CIF_MCCK_PENDING
975	jno	.Lmcck_return
976	TRACE_IRQS_OFF
977	brasl	%r14,s390_handle_mcck
978	TRACE_IRQS_ON
979.Lmcck_return:
980	lg	%r14,__LC_VDSO_PER_CPU
981	lmg	%r0,%r10,__PT_R0(%r11)
982	mvc	__LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
983	tm	__LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
984	jno	0f
985	stpt	__LC_EXIT_TIMER
986	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
9870:	lmg	%r11,%r15,__PT_R11(%r11)
988	lpswe	__LC_RETURN_MCCK_PSW
989
990.Lmcck_panic:
991	lg	%r15,__LC_PANIC_STACK
992	la	%r11,STACK_FRAME_OVERHEAD(%r15)
993	j	.Lmcck_skip
994
995#
996# PSW restart interrupt handler
997#
998ENTRY(restart_int_handler)
999	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
1000	jz	0f
1001	.insn	s,0xb2800000,__LC_LPP
10020:	stg	%r15,__LC_SAVE_AREA_RESTART
1003	lg	%r15,__LC_RESTART_STACK
1004	aghi	%r15,-__PT_SIZE			# create pt_regs on stack
1005	xc	0(__PT_SIZE,%r15),0(%r15)
1006	stmg	%r0,%r14,__PT_R0(%r15)
1007	mvc	__PT_R15(8,%r15),__LC_SAVE_AREA_RESTART
1008	mvc	__PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw
1009	aghi	%r15,-STACK_FRAME_OVERHEAD	# create stack frame on stack
1010	xc	0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
1011	lg	%r1,__LC_RESTART_FN		# load fn, parm & source cpu
1012	lg	%r2,__LC_RESTART_DATA
1013	lg	%r3,__LC_RESTART_SOURCE
1014	ltgr	%r3,%r3				# test source cpu address
1015	jm	1f				# negative -> skip source stop
10160:	sigp	%r4,%r3,SIGP_SENSE		# sigp sense to source cpu
1017	brc	10,0b				# wait for status stored
10181:	basr	%r14,%r1			# call function
1019	stap	__SF_EMPTY(%r15)		# store cpu address
1020	llgh	%r3,__SF_EMPTY(%r15)
10212:	sigp	%r4,%r3,SIGP_STOP		# sigp stop to current cpu
1022	brc	2,2b
10233:	j	3b
1024
1025	.section .kprobes.text, "ax"
1026
1027#ifdef CONFIG_CHECK_STACK
1028/*
1029 * The synchronous or the asynchronous stack overflowed. We are dead.
1030 * No need to properly save the registers, we are going to panic anyway.
1031 * Setup a pt_regs so that show_trace can provide a good call trace.
1032 */
1033stack_overflow:
1034	lg	%r15,__LC_PANIC_STACK	# change to panic stack
1035	la	%r11,STACK_FRAME_OVERHEAD(%r15)
1036	stmg	%r0,%r7,__PT_R0(%r11)
1037	stmg	%r8,%r9,__PT_PSW(%r11)
1038	mvc	__PT_R8(64,%r11),0(%r14)
1039	stg	%r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
1040	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
1041	lgr	%r2,%r11		# pass pointer to pt_regs
1042	jg	kernel_stack_overflow
1043#endif
1044
1045cleanup_critical:
1046#if IS_ENABLED(CONFIG_KVM)
1047	clg	%r9,BASED(.Lcleanup_table_sie)	# .Lsie_gmap
1048	jl	0f
1049	clg	%r9,BASED(.Lcleanup_table_sie+8)# .Lsie_done
1050	jl	.Lcleanup_sie
1051#endif
1052	clg	%r9,BASED(.Lcleanup_table)	# system_call
1053	jl	0f
1054	clg	%r9,BASED(.Lcleanup_table+8)	# .Lsysc_do_svc
1055	jl	.Lcleanup_system_call
1056	clg	%r9,BASED(.Lcleanup_table+16)	# .Lsysc_tif
1057	jl	0f
1058	clg	%r9,BASED(.Lcleanup_table+24)	# .Lsysc_restore
1059	jl	.Lcleanup_sysc_tif
1060	clg	%r9,BASED(.Lcleanup_table+32)	# .Lsysc_done
1061	jl	.Lcleanup_sysc_restore
1062	clg	%r9,BASED(.Lcleanup_table+40)	# .Lio_tif
1063	jl	0f
1064	clg	%r9,BASED(.Lcleanup_table+48)	# .Lio_restore
1065	jl	.Lcleanup_io_tif
1066	clg	%r9,BASED(.Lcleanup_table+56)	# .Lio_done
1067	jl	.Lcleanup_io_restore
1068	clg	%r9,BASED(.Lcleanup_table+64)	# psw_idle
1069	jl	0f
1070	clg	%r9,BASED(.Lcleanup_table+72)	# .Lpsw_idle_end
1071	jl	.Lcleanup_idle
1072	clg	%r9,BASED(.Lcleanup_table+80)	# save_fpu_regs
1073	jl	0f
1074	clg	%r9,BASED(.Lcleanup_table+88)	# .Lsave_fpu_regs_end
1075	jl	.Lcleanup_save_fpu_regs
1076	clg	%r9,BASED(.Lcleanup_table+96)	# load_fpu_regs
1077	jl	0f
1078	clg	%r9,BASED(.Lcleanup_table+104)	# .Lload_fpu_regs_end
1079	jl	.Lcleanup_load_fpu_regs
10800:	br	%r14
1081
1082	.align	8
1083.Lcleanup_table:
1084	.quad	system_call
1085	.quad	.Lsysc_do_svc
1086	.quad	.Lsysc_tif
1087	.quad	.Lsysc_restore
1088	.quad	.Lsysc_done
1089	.quad	.Lio_tif
1090	.quad	.Lio_restore
1091	.quad	.Lio_done
1092	.quad	psw_idle
1093	.quad	.Lpsw_idle_end
1094	.quad	save_fpu_regs
1095	.quad	.Lsave_fpu_regs_end
1096	.quad	load_fpu_regs
1097	.quad	.Lload_fpu_regs_end
1098
1099#if IS_ENABLED(CONFIG_KVM)
1100.Lcleanup_table_sie:
1101	.quad	.Lsie_gmap
1102	.quad	.Lsie_done
1103
1104.Lcleanup_sie:
1105	lg	%r9,__SF_EMPTY(%r15)		# get control block pointer
1106	ni	__SIE_PROG0C+3(%r9),0xfe	# no longer in SIE
1107	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
1108	larl	%r9,sie_exit			# skip forward to sie_exit
1109	br	%r14
1110#endif
1111
1112.Lcleanup_system_call:
1113	# check if stpt has been executed
1114	clg	%r9,BASED(.Lcleanup_system_call_insn)
1115	jh	0f
1116	mvc	__LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
1117	cghi	%r11,__LC_SAVE_AREA_ASYNC
1118	je	0f
1119	mvc	__LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
11200:	# check if stmg has been executed
1121	clg	%r9,BASED(.Lcleanup_system_call_insn+8)
1122	jh	0f
1123	mvc	__LC_SAVE_AREA_SYNC(64),0(%r11)
11240:	# check if base register setup + TIF bit load has been done
1125	clg	%r9,BASED(.Lcleanup_system_call_insn+16)
1126	jhe	0f
1127	# set up saved register r12 task struct pointer
1128	stg	%r12,32(%r11)
1129	# set up saved register r13 __TASK_thread offset
1130	mvc	40(8,%r11),BASED(.Lcleanup_system_call_const)
11310:	# check if the user time update has been done
1132	clg	%r9,BASED(.Lcleanup_system_call_insn+24)
1133	jh	0f
1134	lg	%r15,__LC_EXIT_TIMER
1135	slg	%r15,__LC_SYNC_ENTER_TIMER
1136	alg	%r15,__LC_USER_TIMER
1137	stg	%r15,__LC_USER_TIMER
11380:	# check if the system time update has been done
1139	clg	%r9,BASED(.Lcleanup_system_call_insn+32)
1140	jh	0f
1141	lg	%r15,__LC_LAST_UPDATE_TIMER
1142	slg	%r15,__LC_EXIT_TIMER
1143	alg	%r15,__LC_SYSTEM_TIMER
1144	stg	%r15,__LC_SYSTEM_TIMER
11450:	# update accounting time stamp
1146	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
1147	# set up saved register r11
1148	lg	%r15,__LC_KERNEL_STACK
1149	la	%r9,STACK_FRAME_OVERHEAD(%r15)
1150	stg	%r9,24(%r11)		# r11 pt_regs pointer
1151	# fill pt_regs
1152	mvc	__PT_R8(64,%r9),__LC_SAVE_AREA_SYNC
1153	stmg	%r0,%r7,__PT_R0(%r9)
1154	mvc	__PT_PSW(16,%r9),__LC_SVC_OLD_PSW
1155	mvc	__PT_INT_CODE(4,%r9),__LC_SVC_ILC
1156	xc	__PT_FLAGS(8,%r9),__PT_FLAGS(%r9)
1157	mvi	__PT_FLAGS+7(%r9),_PIF_SYSCALL
1158	# setup saved register r15
1159	stg	%r15,56(%r11)		# r15 stack pointer
1160	# set new psw address and exit
1161	larl	%r9,.Lsysc_do_svc
1162	br	%r14
1163.Lcleanup_system_call_insn:
1164	.quad	system_call
1165	.quad	.Lsysc_stmg
1166	.quad	.Lsysc_per
1167	.quad	.Lsysc_vtime+36
1168	.quad	.Lsysc_vtime+42
1169.Lcleanup_system_call_const:
1170	.quad	__TASK_thread
1171
1172.Lcleanup_sysc_tif:
1173	larl	%r9,.Lsysc_tif
1174	br	%r14
1175
1176.Lcleanup_sysc_restore:
1177	clg	%r9,BASED(.Lcleanup_sysc_restore_insn)
1178	je	0f
1179	lg	%r9,24(%r11)		# get saved pointer to pt_regs
1180	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r9)
1181	mvc	0(64,%r11),__PT_R8(%r9)
1182	lmg	%r0,%r7,__PT_R0(%r9)
11830:	lmg	%r8,%r9,__LC_RETURN_PSW
1184	br	%r14
1185.Lcleanup_sysc_restore_insn:
1186	.quad	.Lsysc_done - 4
1187
1188.Lcleanup_io_tif:
1189	larl	%r9,.Lio_tif
1190	br	%r14
1191
1192.Lcleanup_io_restore:
1193	clg	%r9,BASED(.Lcleanup_io_restore_insn)
1194	je	0f
1195	lg	%r9,24(%r11)		# get saved r11 pointer to pt_regs
1196	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r9)
1197	mvc	0(64,%r11),__PT_R8(%r9)
1198	lmg	%r0,%r7,__PT_R0(%r9)
11990:	lmg	%r8,%r9,__LC_RETURN_PSW
1200	br	%r14
1201.Lcleanup_io_restore_insn:
1202	.quad	.Lio_done - 4
1203
1204.Lcleanup_idle:
1205	ni	__LC_CPU_FLAGS+7,255-_CIF_ENABLED_WAIT
1206	# copy interrupt clock & cpu timer
1207	mvc	__CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK
1208	mvc	__TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER
1209	cghi	%r11,__LC_SAVE_AREA_ASYNC
1210	je	0f
1211	mvc	__CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK
1212	mvc	__TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER
12130:	# check if stck & stpt have been executed
1214	clg	%r9,BASED(.Lcleanup_idle_insn)
1215	jhe	1f
1216	mvc	__CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
1217	mvc	__TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r2)
12181:	# calculate idle cycles
1219#ifdef CONFIG_SMP
1220	clg	%r9,BASED(.Lcleanup_idle_insn)
1221	jl	3f
1222	larl	%r1,smp_cpu_mtid
1223	llgf	%r1,0(%r1)
1224	ltgr	%r1,%r1
1225	jz	3f
1226	.insn	rsy,0xeb0000000017,%r1,5,__SF_EMPTY+80(%r15)
1227	larl	%r3,mt_cycles
1228	ag	%r3,__LC_PERCPU_OFFSET
1229	la	%r4,__SF_EMPTY+16(%r15)
12302:	lg	%r0,0(%r3)
1231	slg	%r0,0(%r4)
1232	alg	%r0,64(%r4)
1233	stg	%r0,0(%r3)
1234	la	%r3,8(%r3)
1235	la	%r4,8(%r4)
1236	brct	%r1,2b
1237#endif
12383:	# account system time going idle
1239	lg	%r9,__LC_STEAL_TIMER
1240	alg	%r9,__CLOCK_IDLE_ENTER(%r2)
1241	slg	%r9,__LC_LAST_UPDATE_CLOCK
1242	stg	%r9,__LC_STEAL_TIMER
1243	mvc	__LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
1244	lg	%r9,__LC_SYSTEM_TIMER
1245	alg	%r9,__LC_LAST_UPDATE_TIMER
1246	slg	%r9,__TIMER_IDLE_ENTER(%r2)
1247	stg	%r9,__LC_SYSTEM_TIMER
1248	mvc	__LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
1249	# prepare return psw
1250	nihh	%r8,0xfcfd		# clear irq & wait state bits
1251	lg	%r9,48(%r11)		# return from psw_idle
1252	br	%r14
1253.Lcleanup_idle_insn:
1254	.quad	.Lpsw_idle_lpsw
1255
1256.Lcleanup_save_fpu_regs:
1257	larl	%r9,save_fpu_regs
1258	br	%r14
1259
1260.Lcleanup_load_fpu_regs:
1261	larl	%r9,load_fpu_regs
1262	br	%r14
1263
1264/*
1265 * Integer constants
1266 */
1267	.align	8
1268.Lcritical_start:
1269	.quad	.L__critical_start
1270.Lcritical_length:
1271	.quad	.L__critical_end - .L__critical_start
1272#if IS_ENABLED(CONFIG_KVM)
1273.Lsie_critical_start:
1274	.quad	.Lsie_gmap
1275.Lsie_critical_length:
1276	.quad	.Lsie_done - .Lsie_gmap
1277#endif
1278
1279	.section .rodata, "a"
1280#define SYSCALL(esame,emu)	.long esame
1281	.globl	sys_call_table
1282sys_call_table:
1283#include "syscalls.S"
1284#undef SYSCALL
1285
1286#ifdef CONFIG_COMPAT
1287
1288#define SYSCALL(esame,emu)	.long emu
1289	.globl	sys_call_table_emu
1290sys_call_table_emu:
1291#include "syscalls.S"
1292#undef SYSCALL
1293#endif
1294