xref: /openbmc/linux/arch/s390/kernel/entry.S (revision 68198dca) 
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 *    S390 low-level entry points.
4 *
5 *    Copyright IBM Corp. 1999, 2012
6 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7 *		 Hartmut Penner (hp@de.ibm.com),
8 *		 Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
9 *		 Heiko Carstens <heiko.carstens@de.ibm.com>
10 */
11
12#include <linux/init.h>
13#include <linux/linkage.h>
14#include <asm/processor.h>
15#include <asm/cache.h>
16#include <asm/ctl_reg.h>
17#include <asm/errno.h>
18#include <asm/ptrace.h>
19#include <asm/thread_info.h>
20#include <asm/asm-offsets.h>
21#include <asm/unistd.h>
22#include <asm/page.h>
23#include <asm/sigp.h>
24#include <asm/irq.h>
25#include <asm/vx-insn.h>
26#include <asm/setup.h>
27#include <asm/nmi.h>
28#include <asm/export.h>
29
30__PT_R0      =	__PT_GPRS
31__PT_R1      =	__PT_GPRS + 8
32__PT_R2      =	__PT_GPRS + 16
33__PT_R3      =	__PT_GPRS + 24
34__PT_R4      =	__PT_GPRS + 32
35__PT_R5      =	__PT_GPRS + 40
36__PT_R6      =	__PT_GPRS + 48
37__PT_R7      =	__PT_GPRS + 56
38__PT_R8      =	__PT_GPRS + 64
39__PT_R9      =	__PT_GPRS + 72
40__PT_R10     =	__PT_GPRS + 80
41__PT_R11     =	__PT_GPRS + 88
42__PT_R12     =	__PT_GPRS + 96
43__PT_R13     =	__PT_GPRS + 104
44__PT_R14     =	__PT_GPRS + 112
45__PT_R15     =	__PT_GPRS + 120
46
47STACK_SHIFT = PAGE_SHIFT + THREAD_SIZE_ORDER
48STACK_SIZE  = 1 << STACK_SHIFT
49STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
50
51_TIF_WORK	= (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
52		   _TIF_UPROBE | _TIF_GUARDED_STORAGE | _TIF_PATCH_PENDING)
53_TIF_TRACE	= (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
54		   _TIF_SYSCALL_TRACEPOINT)
55_CIF_WORK	= (_CIF_MCCK_PENDING | _CIF_ASCE_PRIMARY | \
56		   _CIF_ASCE_SECONDARY | _CIF_FPU)
57_PIF_WORK	= (_PIF_PER_TRAP | _PIF_SYSCALL_RESTART)
58
59#define BASED(name) name-cleanup_critical(%r13)
60
61	.macro	TRACE_IRQS_ON
62#ifdef CONFIG_TRACE_IRQFLAGS
63	basr	%r2,%r0
64	brasl	%r14,trace_hardirqs_on_caller
65#endif
66	.endm
67
68	.macro	TRACE_IRQS_OFF
69#ifdef CONFIG_TRACE_IRQFLAGS
70	basr	%r2,%r0
71	brasl	%r14,trace_hardirqs_off_caller
72#endif
73	.endm
74
75	.macro	LOCKDEP_SYS_EXIT
76#ifdef CONFIG_LOCKDEP
77	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
78	jz	.+10
79	brasl	%r14,lockdep_sys_exit
80#endif
81	.endm
82
83	.macro	CHECK_STACK stacksize,savearea
84#ifdef CONFIG_CHECK_STACK
85	tml	%r15,\stacksize - CONFIG_STACK_GUARD
86	lghi	%r14,\savearea
87	jz	stack_overflow
88#endif
89	.endm
90
91	.macro	SWITCH_ASYNC savearea,timer
92	tmhh	%r8,0x0001		# interrupting from user ?
93	jnz	1f
94	lgr	%r14,%r9
95	slg	%r14,BASED(.Lcritical_start)
96	clg	%r14,BASED(.Lcritical_length)
97	jhe	0f
98	lghi	%r11,\savearea		# inside critical section, do cleanup
99	brasl	%r14,cleanup_critical
100	tmhh	%r8,0x0001		# retest problem state after cleanup
101	jnz	1f
1020:	lg	%r14,__LC_ASYNC_STACK	# are we already on the async stack?
103	slgr	%r14,%r15
104	srag	%r14,%r14,STACK_SHIFT
105	jnz	2f
106	CHECK_STACK 1<<STACK_SHIFT,\savearea
107	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
108	j	3f
1091:	UPDATE_VTIME %r14,%r15,\timer
1102:	lg	%r15,__LC_ASYNC_STACK	# load async stack
1113:	la	%r11,STACK_FRAME_OVERHEAD(%r15)
112	.endm
113
114	.macro UPDATE_VTIME w1,w2,enter_timer
115	lg	\w1,__LC_EXIT_TIMER
116	lg	\w2,__LC_LAST_UPDATE_TIMER
117	slg	\w1,\enter_timer
118	slg	\w2,__LC_EXIT_TIMER
119	alg	\w1,__LC_USER_TIMER
120	alg	\w2,__LC_SYSTEM_TIMER
121	stg	\w1,__LC_USER_TIMER
122	stg	\w2,__LC_SYSTEM_TIMER
123	mvc	__LC_LAST_UPDATE_TIMER(8),\enter_timer
124	.endm
125
126	.macro REENABLE_IRQS
127	stg	%r8,__LC_RETURN_PSW
128	ni	__LC_RETURN_PSW,0xbf
129	ssm	__LC_RETURN_PSW
130	.endm
131
132	.macro STCK savearea
133#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
134	.insn	s,0xb27c0000,\savearea		# store clock fast
135#else
136	.insn	s,0xb2050000,\savearea		# store clock
137#endif
138	.endm
139
140	/*
141	 * The TSTMSK macro generates a test-under-mask instruction by
142	 * calculating the memory offset for the specified mask value.
143	 * Mask value can be any constant.  The macro shifts the mask
144	 * value to calculate the memory offset for the test-under-mask
145	 * instruction.
146	 */
147	.macro TSTMSK addr, mask, size=8, bytepos=0
148		.if (\bytepos < \size) && (\mask >> 8)
149			.if (\mask & 0xff)
150				.error "Mask exceeds byte boundary"
151			.endif
152			TSTMSK \addr, "(\mask >> 8)", \size, "(\bytepos + 1)"
153			.exitm
154		.endif
155		.ifeq \mask
156			.error "Mask must not be zero"
157		.endif
158		off = \size - \bytepos - 1
159		tm	off+\addr, \mask
160	.endm
161
162	.section .kprobes.text, "ax"
163.Ldummy:
164	/*
165	 * This nop exists only in order to avoid that __switch_to starts at
166	 * the beginning of the kprobes text section. In that case we would
167	 * have several symbols at the same address. E.g. objdump would take
168	 * an arbitrary symbol name when disassembling this code.
169	 * With the added nop in between the __switch_to symbol is unique
170	 * again.
171	 */
172	nop	0
173
174/*
175 * Scheduler resume function, called by switch_to
176 *  gpr2 = (task_struct *) prev
177 *  gpr3 = (task_struct *) next
178 * Returns:
179 *  gpr2 = prev
180 */
181ENTRY(__switch_to)
182	stmg	%r6,%r15,__SF_GPRS(%r15)	# store gprs of prev task
183	lghi	%r4,__TASK_stack
184	lghi	%r1,__TASK_thread
185	lg	%r5,0(%r4,%r3)			# start of kernel stack of next
186	stg	%r15,__THREAD_ksp(%r1,%r2)	# store kernel stack of prev
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,%r3)	# load kernel stack of next
192	aghi	%r3,__TASK_pid
193	mvc	__LC_CURRENT_PID(4,%r0),0(%r3)	# store pid of next
194	lmg	%r6,%r15,__SF_GPRS(%r15)	# load gprs of next task
195	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
196	bzr	%r14
197	.insn	s,0xb2800000,__LC_LPP		# set program parameter
198	br	%r14
199
200.L__critical_start:
201
202#if IS_ENABLED(CONFIG_KVM)
203/*
204 * sie64a calling convention:
205 * %r2 pointer to sie control block
206 * %r3 guest register save area
207 */
208ENTRY(sie64a)
209	stmg	%r6,%r14,__SF_GPRS(%r15)	# save kernel registers
210	stg	%r2,__SF_EMPTY(%r15)		# save control block pointer
211	stg	%r3,__SF_EMPTY+8(%r15)		# save guest register save area
212	xc	__SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # reason code = 0
213	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU		# load guest fp/vx registers ?
214	jno	.Lsie_load_guest_gprs
215	brasl	%r14,load_fpu_regs		# load guest fp/vx regs
216.Lsie_load_guest_gprs:
217	lmg	%r0,%r13,0(%r3)			# load guest gprs 0-13
218	lg	%r14,__LC_GMAP			# get gmap pointer
219	ltgr	%r14,%r14
220	jz	.Lsie_gmap
221	lctlg	%c1,%c1,__GMAP_ASCE(%r14)	# load primary asce
222.Lsie_gmap:
223	lg	%r14,__SF_EMPTY(%r15)		# get control block pointer
224	oi	__SIE_PROG0C+3(%r14),1		# we are going into SIE now
225	tm	__SIE_PROG20+3(%r14),3		# last exit...
226	jnz	.Lsie_skip
227	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
228	jo	.Lsie_skip			# exit if fp/vx regs changed
229.Lsie_entry:
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 often 4 bytes in case of SIE. There
237# are some corner cases (e.g. runtime instrumentation) where ILC is unpredictable.
238# Other instructions between sie64a and .Lsie_done should not cause program
239# interrupts. So lets use 3 nops as a landing pad for all possible rewinds.
240# See also .Lcleanup_sie
241.Lrewind_pad6:
242	nopr	7
243.Lrewind_pad4:
244	nopr	7
245.Lrewind_pad2:
246	nopr	7
247	.globl sie_exit
248sie_exit:
249	lg	%r14,__SF_EMPTY+8(%r15)		# load guest register save area
250	stmg	%r0,%r13,0(%r14)		# save guest gprs 0-13
251	lmg	%r6,%r14,__SF_GPRS(%r15)	# restore kernel registers
252	lg	%r2,__SF_EMPTY+16(%r15)		# return exit reason code
253	br	%r14
254.Lsie_fault:
255	lghi	%r14,-EFAULT
256	stg	%r14,__SF_EMPTY+16(%r15)	# set exit reason code
257	j	sie_exit
258
259	EX_TABLE(.Lrewind_pad6,.Lsie_fault)
260	EX_TABLE(.Lrewind_pad4,.Lsie_fault)
261	EX_TABLE(.Lrewind_pad2,.Lsie_fault)
262	EX_TABLE(sie_exit,.Lsie_fault)
263EXPORT_SYMBOL(sie64a)
264EXPORT_SYMBOL(sie_exit)
265#endif
266
267/*
268 * SVC interrupt handler routine. System calls are synchronous events and
269 * are executed with interrupts enabled.
270 */
271
272ENTRY(system_call)
273	stpt	__LC_SYNC_ENTER_TIMER
274.Lsysc_stmg:
275	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
276	lg	%r12,__LC_CURRENT
277	lghi	%r13,__TASK_thread
278	lghi	%r14,_PIF_SYSCALL
279.Lsysc_per:
280	lg	%r15,__LC_KERNEL_STACK
281	la	%r11,STACK_FRAME_OVERHEAD(%r15)	# pointer to pt_regs
282.Lsysc_vtime:
283	UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
284	stmg	%r0,%r7,__PT_R0(%r11)
285	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
286	mvc	__PT_PSW(16,%r11),__LC_SVC_OLD_PSW
287	mvc	__PT_INT_CODE(4,%r11),__LC_SVC_ILC
288	stg	%r14,__PT_FLAGS(%r11)
289.Lsysc_do_svc:
290	# load address of system call table
291	lg	%r10,__THREAD_sysc_table(%r13,%r12)
292	llgh	%r8,__PT_INT_CODE+2(%r11)
293	slag	%r8,%r8,2			# shift and test for svc 0
294	jnz	.Lsysc_nr_ok
295	# svc 0: system call number in %r1
296	llgfr	%r1,%r1				# clear high word in r1
297	cghi	%r1,NR_syscalls
298	jnl	.Lsysc_nr_ok
299	sth	%r1,__PT_INT_CODE+2(%r11)
300	slag	%r8,%r1,2
301.Lsysc_nr_ok:
302	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
303	stg	%r2,__PT_ORIG_GPR2(%r11)
304	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
305	lgf	%r9,0(%r8,%r10)			# get system call add.
306	TSTMSK	__TI_flags(%r12),_TIF_TRACE
307	jnz	.Lsysc_tracesys
308	basr	%r14,%r9			# call sys_xxxx
309	stg	%r2,__PT_R2(%r11)		# store return value
310
311.Lsysc_return:
312	LOCKDEP_SYS_EXIT
313.Lsysc_tif:
314	TSTMSK	__PT_FLAGS(%r11),_PIF_WORK
315	jnz	.Lsysc_work
316	TSTMSK	__TI_flags(%r12),_TIF_WORK
317	jnz	.Lsysc_work			# check for work
318	TSTMSK	__LC_CPU_FLAGS,_CIF_WORK
319	jnz	.Lsysc_work
320.Lsysc_restore:
321	lg	%r14,__LC_VDSO_PER_CPU
322	lmg	%r0,%r10,__PT_R0(%r11)
323	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
324.Lsysc_exit_timer:
325	stpt	__LC_EXIT_TIMER
326	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
327	lmg	%r11,%r15,__PT_R11(%r11)
328	lpswe	__LC_RETURN_PSW
329.Lsysc_done:
330
331#
332# One of the work bits is on. Find out which one.
333#
334.Lsysc_work:
335	TSTMSK	__LC_CPU_FLAGS,_CIF_MCCK_PENDING
336	jo	.Lsysc_mcck_pending
337	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
338	jo	.Lsysc_reschedule
339	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL_RESTART
340	jo	.Lsysc_syscall_restart
341#ifdef CONFIG_UPROBES
342	TSTMSK	__TI_flags(%r12),_TIF_UPROBE
343	jo	.Lsysc_uprobe_notify
344#endif
345	TSTMSK	__TI_flags(%r12),_TIF_GUARDED_STORAGE
346	jo	.Lsysc_guarded_storage
347	TSTMSK	__PT_FLAGS(%r11),_PIF_PER_TRAP
348	jo	.Lsysc_singlestep
349#ifdef CONFIG_LIVEPATCH
350	TSTMSK	__TI_flags(%r12),_TIF_PATCH_PENDING
351	jo	.Lsysc_patch_pending	# handle live patching just before
352					# signals and possible syscall restart
353#endif
354	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL_RESTART
355	jo	.Lsysc_syscall_restart
356	TSTMSK	__TI_flags(%r12),_TIF_SIGPENDING
357	jo	.Lsysc_sigpending
358	TSTMSK	__TI_flags(%r12),_TIF_NOTIFY_RESUME
359	jo	.Lsysc_notify_resume
360	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
361	jo	.Lsysc_vxrs
362	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
363	jnz	.Lsysc_asce
364	j	.Lsysc_return		# beware of critical section cleanup
365
366#
367# _TIF_NEED_RESCHED is set, call schedule
368#
369.Lsysc_reschedule:
370	larl	%r14,.Lsysc_return
371	jg	schedule
372
373#
374# _CIF_MCCK_PENDING is set, call handler
375#
376.Lsysc_mcck_pending:
377	larl	%r14,.Lsysc_return
378	jg	s390_handle_mcck	# TIF bit will be cleared by handler
379
380#
381# _CIF_ASCE_PRIMARY and/or _CIF_ASCE_SECONDARY set, load user space asce
382#
383.Lsysc_asce:
384	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_SECONDARY
385	lctlg	%c7,%c7,__LC_VDSO_ASCE		# load secondary asce
386	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_PRIMARY
387	jz	.Lsysc_return
388#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
389	tm	__LC_STFLE_FAC_LIST+3,0x10	# has MVCOS ?
390	jnz	.Lsysc_set_fs_fixup
391	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
392	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
393	j	.Lsysc_return
394.Lsysc_set_fs_fixup:
395#endif
396	larl	%r14,.Lsysc_return
397	jg	set_fs_fixup
398
399#
400# CIF_FPU is set, restore floating-point controls and floating-point registers.
401#
402.Lsysc_vxrs:
403	larl	%r14,.Lsysc_return
404	jg	load_fpu_regs
405
406#
407# _TIF_SIGPENDING is set, call do_signal
408#
409.Lsysc_sigpending:
410	lgr	%r2,%r11		# pass pointer to pt_regs
411	brasl	%r14,do_signal
412	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL
413	jno	.Lsysc_return
414.Lsysc_do_syscall:
415	lghi	%r13,__TASK_thread
416	lmg	%r2,%r7,__PT_R2(%r11)	# load svc arguments
417	lghi	%r1,0			# svc 0 returns -ENOSYS
418	j	.Lsysc_do_svc
419
420#
421# _TIF_NOTIFY_RESUME is set, call do_notify_resume
422#
423.Lsysc_notify_resume:
424	lgr	%r2,%r11		# pass pointer to pt_regs
425	larl	%r14,.Lsysc_return
426	jg	do_notify_resume
427
428#
429# _TIF_UPROBE is set, call uprobe_notify_resume
430#
431#ifdef CONFIG_UPROBES
432.Lsysc_uprobe_notify:
433	lgr	%r2,%r11		# pass pointer to pt_regs
434	larl	%r14,.Lsysc_return
435	jg	uprobe_notify_resume
436#endif
437
438#
439# _TIF_GUARDED_STORAGE is set, call guarded_storage_load
440#
441.Lsysc_guarded_storage:
442	lgr	%r2,%r11		# pass pointer to pt_regs
443	larl	%r14,.Lsysc_return
444	jg	gs_load_bc_cb
445#
446# _TIF_PATCH_PENDING is set, call klp_update_patch_state
447#
448#ifdef CONFIG_LIVEPATCH
449.Lsysc_patch_pending:
450	lg	%r2,__LC_CURRENT	# pass pointer to task struct
451	larl	%r14,.Lsysc_return
452	jg	klp_update_patch_state
453#endif
454
455#
456# _PIF_PER_TRAP is set, call do_per_trap
457#
458.Lsysc_singlestep:
459	ni	__PT_FLAGS+7(%r11),255-_PIF_PER_TRAP
460	lgr	%r2,%r11		# pass pointer to pt_regs
461	larl	%r14,.Lsysc_return
462	jg	do_per_trap
463
464#
465# _PIF_SYSCALL_RESTART is set, repeat the current system call
466#
467.Lsysc_syscall_restart:
468	ni	__PT_FLAGS+7(%r11),255-_PIF_SYSCALL_RESTART
469	lmg	%r1,%r7,__PT_R1(%r11)	# load svc arguments
470	lg	%r2,__PT_ORIG_GPR2(%r11)
471	j	.Lsysc_do_svc
472
473#
474# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
475# and after the system call
476#
477.Lsysc_tracesys:
478	lgr	%r2,%r11		# pass pointer to pt_regs
479	la	%r3,0
480	llgh	%r0,__PT_INT_CODE+2(%r11)
481	stg	%r0,__PT_R2(%r11)
482	brasl	%r14,do_syscall_trace_enter
483	lghi	%r0,NR_syscalls
484	clgr	%r0,%r2
485	jnh	.Lsysc_tracenogo
486	sllg	%r8,%r2,2
487	lgf	%r9,0(%r8,%r10)
488.Lsysc_tracego:
489	lmg	%r3,%r7,__PT_R3(%r11)
490	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
491	lg	%r2,__PT_ORIG_GPR2(%r11)
492	basr	%r14,%r9		# call sys_xxx
493	stg	%r2,__PT_R2(%r11)	# store return value
494.Lsysc_tracenogo:
495	TSTMSK	__TI_flags(%r12),_TIF_TRACE
496	jz	.Lsysc_return
497	lgr	%r2,%r11		# pass pointer to pt_regs
498	larl	%r14,.Lsysc_return
499	jg	do_syscall_trace_exit
500
501#
502# a new process exits the kernel with ret_from_fork
503#
504ENTRY(ret_from_fork)
505	la	%r11,STACK_FRAME_OVERHEAD(%r15)
506	lg	%r12,__LC_CURRENT
507	brasl	%r14,schedule_tail
508	TRACE_IRQS_ON
509	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
510	tm	__PT_PSW+1(%r11),0x01	# forking a kernel thread ?
511	jne	.Lsysc_tracenogo
512	# it's a kernel thread
513	lmg	%r9,%r10,__PT_R9(%r11)	# load gprs
514ENTRY(kernel_thread_starter)
515	la	%r2,0(%r10)
516	basr	%r14,%r9
517	j	.Lsysc_tracenogo
518
519/*
520 * Program check handler routine
521 */
522
523ENTRY(pgm_check_handler)
524	stpt	__LC_SYNC_ENTER_TIMER
525	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
526	lg	%r10,__LC_LAST_BREAK
527	lg	%r12,__LC_CURRENT
528	lghi	%r11,0
529	larl	%r13,cleanup_critical
530	lmg	%r8,%r9,__LC_PGM_OLD_PSW
531	tmhh	%r8,0x0001		# test problem state bit
532	jnz	2f			# -> fault in user space
533#if IS_ENABLED(CONFIG_KVM)
534	# cleanup critical section for program checks in sie64a
535	lgr	%r14,%r9
536	slg	%r14,BASED(.Lsie_critical_start)
537	clg	%r14,BASED(.Lsie_critical_length)
538	jhe	0f
539	lg	%r14,__SF_EMPTY(%r15)		# get control block pointer
540	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE
541	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
542	larl	%r9,sie_exit			# skip forward to sie_exit
543	lghi	%r11,_PIF_GUEST_FAULT
544#endif
5450:	tmhh	%r8,0x4000		# PER bit set in old PSW ?
546	jnz	1f			# -> enabled, can't be a double fault
547	tm	__LC_PGM_ILC+3,0x80	# check for per exception
548	jnz	.Lpgm_svcper		# -> single stepped svc
5491:	CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
550	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
551	j	4f
5522:	UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
553	lg	%r15,__LC_KERNEL_STACK
554	lgr	%r14,%r12
555	aghi	%r14,__TASK_thread	# pointer to thread_struct
556	lghi	%r13,__LC_PGM_TDB
557	tm	__LC_PGM_ILC+2,0x02	# check for transaction abort
558	jz	3f
559	mvc	__THREAD_trap_tdb(256,%r14),0(%r13)
5603:	stg	%r10,__THREAD_last_break(%r14)
5614:	lgr	%r13,%r11
562	la	%r11,STACK_FRAME_OVERHEAD(%r15)
563	stmg	%r0,%r7,__PT_R0(%r11)
564	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
565	stmg	%r8,%r9,__PT_PSW(%r11)
566	mvc	__PT_INT_CODE(4,%r11),__LC_PGM_ILC
567	mvc	__PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE
568	stg	%r13,__PT_FLAGS(%r11)
569	stg	%r10,__PT_ARGS(%r11)
570	tm	__LC_PGM_ILC+3,0x80	# check for per exception
571	jz	5f
572	tmhh	%r8,0x0001		# kernel per event ?
573	jz	.Lpgm_kprobe
574	oi	__PT_FLAGS+7(%r11),_PIF_PER_TRAP
575	mvc	__THREAD_per_address(8,%r14),__LC_PER_ADDRESS
576	mvc	__THREAD_per_cause(2,%r14),__LC_PER_CODE
577	mvc	__THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
5785:	REENABLE_IRQS
579	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
580	larl	%r1,pgm_check_table
581	llgh	%r10,__PT_INT_CODE+2(%r11)
582	nill	%r10,0x007f
583	sll	%r10,2
584	je	.Lpgm_return
585	lgf	%r1,0(%r10,%r1)		# load address of handler routine
586	lgr	%r2,%r11		# pass pointer to pt_regs
587	basr	%r14,%r1		# branch to interrupt-handler
588.Lpgm_return:
589	LOCKDEP_SYS_EXIT
590	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
591	jno	.Lsysc_restore
592	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL
593	jo	.Lsysc_do_syscall
594	j	.Lsysc_tif
595
596#
597# PER event in supervisor state, must be kprobes
598#
599.Lpgm_kprobe:
600	REENABLE_IRQS
601	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
602	lgr	%r2,%r11		# pass pointer to pt_regs
603	brasl	%r14,do_per_trap
604	j	.Lpgm_return
605
606#
607# single stepped system call
608#
609.Lpgm_svcper:
610	mvc	__LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
611	lghi	%r13,__TASK_thread
612	larl	%r14,.Lsysc_per
613	stg	%r14,__LC_RETURN_PSW+8
614	lghi	%r14,_PIF_SYSCALL | _PIF_PER_TRAP
615	lpswe	__LC_RETURN_PSW		# branch to .Lsysc_per and enable irqs
616
617/*
618 * IO interrupt handler routine
619 */
620ENTRY(io_int_handler)
621	STCK	__LC_INT_CLOCK
622	stpt	__LC_ASYNC_ENTER_TIMER
623	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
624	lg	%r12,__LC_CURRENT
625	larl	%r13,cleanup_critical
626	lmg	%r8,%r9,__LC_IO_OLD_PSW
627	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
628	stmg	%r0,%r7,__PT_R0(%r11)
629	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
630	stmg	%r8,%r9,__PT_PSW(%r11)
631	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
632	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
633	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
634	jo	.Lio_restore
635	TRACE_IRQS_OFF
636	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
637.Lio_loop:
638	lgr	%r2,%r11		# pass pointer to pt_regs
639	lghi	%r3,IO_INTERRUPT
640	tm	__PT_INT_CODE+8(%r11),0x80	# adapter interrupt ?
641	jz	.Lio_call
642	lghi	%r3,THIN_INTERRUPT
643.Lio_call:
644	brasl	%r14,do_IRQ
645	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPAR
646	jz	.Lio_return
647	tpi	0
648	jz	.Lio_return
649	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
650	j	.Lio_loop
651.Lio_return:
652	LOCKDEP_SYS_EXIT
653	TRACE_IRQS_ON
654.Lio_tif:
655	TSTMSK	__TI_flags(%r12),_TIF_WORK
656	jnz	.Lio_work		# there is work to do (signals etc.)
657	TSTMSK	__LC_CPU_FLAGS,_CIF_WORK
658	jnz	.Lio_work
659.Lio_restore:
660	lg	%r14,__LC_VDSO_PER_CPU
661	lmg	%r0,%r10,__PT_R0(%r11)
662	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
663.Lio_exit_timer:
664	stpt	__LC_EXIT_TIMER
665	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
666	lmg	%r11,%r15,__PT_R11(%r11)
667	lpswe	__LC_RETURN_PSW
668.Lio_done:
669
670#
671# There is work todo, find out in which context we have been interrupted:
672# 1) if we return to user space we can do all _TIF_WORK work
673# 2) if we return to kernel code and kvm is enabled check if we need to
674#    modify the psw to leave SIE
675# 3) if we return to kernel code and preemptive scheduling is enabled check
676#    the preemption counter and if it is zero call preempt_schedule_irq
677# Before any work can be done, a switch to the kernel stack is required.
678#
679.Lio_work:
680	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
681	jo	.Lio_work_user		# yes -> do resched & signal
682#ifdef CONFIG_PREEMPT
683	# check for preemptive scheduling
684	icm	%r0,15,__LC_PREEMPT_COUNT
685	jnz	.Lio_restore		# preemption is disabled
686	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
687	jno	.Lio_restore
688	# switch to kernel stack
689	lg	%r1,__PT_R15(%r11)
690	aghi	%r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
691	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
692	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
693	la	%r11,STACK_FRAME_OVERHEAD(%r1)
694	lgr	%r15,%r1
695	# TRACE_IRQS_ON already done at .Lio_return, call
696	# TRACE_IRQS_OFF to keep things symmetrical
697	TRACE_IRQS_OFF
698	brasl	%r14,preempt_schedule_irq
699	j	.Lio_return
700#else
701	j	.Lio_restore
702#endif
703
704#
705# Need to do work before returning to userspace, switch to kernel stack
706#
707.Lio_work_user:
708	lg	%r1,__LC_KERNEL_STACK
709	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
710	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
711	la	%r11,STACK_FRAME_OVERHEAD(%r1)
712	lgr	%r15,%r1
713
714#
715# One of the work bits is on. Find out which one.
716#
717.Lio_work_tif:
718	TSTMSK	__LC_CPU_FLAGS,_CIF_MCCK_PENDING
719	jo	.Lio_mcck_pending
720	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
721	jo	.Lio_reschedule
722#ifdef CONFIG_LIVEPATCH
723	TSTMSK	__TI_flags(%r12),_TIF_PATCH_PENDING
724	jo	.Lio_patch_pending
725#endif
726	TSTMSK	__TI_flags(%r12),_TIF_SIGPENDING
727	jo	.Lio_sigpending
728	TSTMSK	__TI_flags(%r12),_TIF_NOTIFY_RESUME
729	jo	.Lio_notify_resume
730	TSTMSK	__TI_flags(%r12),_TIF_GUARDED_STORAGE
731	jo	.Lio_guarded_storage
732	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
733	jo	.Lio_vxrs
734	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
735	jnz	.Lio_asce
736	j	.Lio_return		# beware of critical section cleanup
737
738#
739# _CIF_MCCK_PENDING is set, call handler
740#
741.Lio_mcck_pending:
742	# TRACE_IRQS_ON already done at .Lio_return
743	brasl	%r14,s390_handle_mcck	# TIF bit will be cleared by handler
744	TRACE_IRQS_OFF
745	j	.Lio_return
746
747#
748# _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
749#
750.Lio_asce:
751	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_SECONDARY
752	lctlg	%c7,%c7,__LC_VDSO_ASCE		# load secondary asce
753	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_PRIMARY
754	jz	.Lio_return
755#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
756	tm	__LC_STFLE_FAC_LIST+3,0x10	# has MVCOS ?
757	jnz	.Lio_set_fs_fixup
758	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
759	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
760	j	.Lio_return
761.Lio_set_fs_fixup:
762#endif
763	larl	%r14,.Lio_return
764	jg	set_fs_fixup
765
766#
767# CIF_FPU is set, restore floating-point controls and floating-point registers.
768#
769.Lio_vxrs:
770	larl	%r14,.Lio_return
771	jg	load_fpu_regs
772
773#
774# _TIF_GUARDED_STORAGE is set, call guarded_storage_load
775#
776.Lio_guarded_storage:
777	# TRACE_IRQS_ON already done at .Lio_return
778	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
779	lgr	%r2,%r11		# pass pointer to pt_regs
780	brasl	%r14,gs_load_bc_cb
781	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
782	TRACE_IRQS_OFF
783	j	.Lio_return
784
785#
786# _TIF_NEED_RESCHED is set, call schedule
787#
788.Lio_reschedule:
789	# TRACE_IRQS_ON already done at .Lio_return
790	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
791	brasl	%r14,schedule		# call scheduler
792	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
793	TRACE_IRQS_OFF
794	j	.Lio_return
795
796#
797# _TIF_PATCH_PENDING is set, call klp_update_patch_state
798#
799#ifdef CONFIG_LIVEPATCH
800.Lio_patch_pending:
801	lg	%r2,__LC_CURRENT	# pass pointer to task struct
802	larl	%r14,.Lio_return
803	jg	klp_update_patch_state
804#endif
805
806#
807# _TIF_SIGPENDING or is set, call do_signal
808#
809.Lio_sigpending:
810	# TRACE_IRQS_ON already done at .Lio_return
811	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
812	lgr	%r2,%r11		# pass pointer to pt_regs
813	brasl	%r14,do_signal
814	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
815	TRACE_IRQS_OFF
816	j	.Lio_return
817
818#
819# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
820#
821.Lio_notify_resume:
822	# TRACE_IRQS_ON already done at .Lio_return
823	ssm	__LC_SVC_NEW_PSW	# reenable interrupts
824	lgr	%r2,%r11		# pass pointer to pt_regs
825	brasl	%r14,do_notify_resume
826	ssm	__LC_PGM_NEW_PSW	# disable I/O and ext. interrupts
827	TRACE_IRQS_OFF
828	j	.Lio_return
829
830/*
831 * External interrupt handler routine
832 */
833ENTRY(ext_int_handler)
834	STCK	__LC_INT_CLOCK
835	stpt	__LC_ASYNC_ENTER_TIMER
836	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
837	lg	%r12,__LC_CURRENT
838	larl	%r13,cleanup_critical
839	lmg	%r8,%r9,__LC_EXT_OLD_PSW
840	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
841	stmg	%r0,%r7,__PT_R0(%r11)
842	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
843	stmg	%r8,%r9,__PT_PSW(%r11)
844	lghi	%r1,__LC_EXT_PARAMS2
845	mvc	__PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
846	mvc	__PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
847	mvc	__PT_INT_PARM_LONG(8,%r11),0(%r1)
848	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
849	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
850	jo	.Lio_restore
851	TRACE_IRQS_OFF
852	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
853	lgr	%r2,%r11		# pass pointer to pt_regs
854	lghi	%r3,EXT_INTERRUPT
855	brasl	%r14,do_IRQ
856	j	.Lio_return
857
858/*
859 * Load idle PSW. The second "half" of this function is in .Lcleanup_idle.
860 */
861ENTRY(psw_idle)
862	stg	%r3,__SF_EMPTY(%r15)
863	larl	%r1,.Lpsw_idle_lpsw+4
864	stg	%r1,__SF_EMPTY+8(%r15)
865#ifdef CONFIG_SMP
866	larl	%r1,smp_cpu_mtid
867	llgf	%r1,0(%r1)
868	ltgr	%r1,%r1
869	jz	.Lpsw_idle_stcctm
870	.insn	rsy,0xeb0000000017,%r1,5,__SF_EMPTY+16(%r15)
871.Lpsw_idle_stcctm:
872#endif
873	oi	__LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT
874	STCK	__CLOCK_IDLE_ENTER(%r2)
875	stpt	__TIMER_IDLE_ENTER(%r2)
876.Lpsw_idle_lpsw:
877	lpswe	__SF_EMPTY(%r15)
878	br	%r14
879.Lpsw_idle_end:
880
881/*
882 * Store floating-point controls and floating-point or vector register
883 * depending whether the vector facility is available.	A critical section
884 * cleanup assures that the registers are stored even if interrupted for
885 * some other work.  The CIF_FPU flag is set to trigger a lazy restore
886 * of the register contents at return from io or a system call.
887 */
888ENTRY(save_fpu_regs)
889	lg	%r2,__LC_CURRENT
890	aghi	%r2,__TASK_thread
891	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
892	bor	%r14
893	stfpc	__THREAD_FPU_fpc(%r2)
894	lg	%r3,__THREAD_FPU_regs(%r2)
895	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
896	jz	.Lsave_fpu_regs_fp	  # no -> store FP regs
897	VSTM	%v0,%v15,0,%r3		  # vstm 0,15,0(3)
898	VSTM	%v16,%v31,256,%r3	  # vstm 16,31,256(3)
899	j	.Lsave_fpu_regs_done	  # -> set CIF_FPU flag
900.Lsave_fpu_regs_fp:
901	std	0,0(%r3)
902	std	1,8(%r3)
903	std	2,16(%r3)
904	std	3,24(%r3)
905	std	4,32(%r3)
906	std	5,40(%r3)
907	std	6,48(%r3)
908	std	7,56(%r3)
909	std	8,64(%r3)
910	std	9,72(%r3)
911	std	10,80(%r3)
912	std	11,88(%r3)
913	std	12,96(%r3)
914	std	13,104(%r3)
915	std	14,112(%r3)
916	std	15,120(%r3)
917.Lsave_fpu_regs_done:
918	oi	__LC_CPU_FLAGS+7,_CIF_FPU
919	br	%r14
920.Lsave_fpu_regs_end:
921EXPORT_SYMBOL(save_fpu_regs)
922
923/*
924 * Load floating-point controls and floating-point or vector registers.
925 * A critical section cleanup assures that the register contents are
926 * loaded even if interrupted for some other work.
927 *
928 * There are special calling conventions to fit into sysc and io return work:
929 *	%r15:	<kernel stack>
930 * The function requires:
931 *	%r4
932 */
933load_fpu_regs:
934	lg	%r4,__LC_CURRENT
935	aghi	%r4,__TASK_thread
936	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
937	bnor	%r14
938	lfpc	__THREAD_FPU_fpc(%r4)
939	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
940	lg	%r4,__THREAD_FPU_regs(%r4)	# %r4 <- reg save area
941	jz	.Lload_fpu_regs_fp		# -> no VX, load FP regs
942	VLM	%v0,%v15,0,%r4
943	VLM	%v16,%v31,256,%r4
944	j	.Lload_fpu_regs_done
945.Lload_fpu_regs_fp:
946	ld	0,0(%r4)
947	ld	1,8(%r4)
948	ld	2,16(%r4)
949	ld	3,24(%r4)
950	ld	4,32(%r4)
951	ld	5,40(%r4)
952	ld	6,48(%r4)
953	ld	7,56(%r4)
954	ld	8,64(%r4)
955	ld	9,72(%r4)
956	ld	10,80(%r4)
957	ld	11,88(%r4)
958	ld	12,96(%r4)
959	ld	13,104(%r4)
960	ld	14,112(%r4)
961	ld	15,120(%r4)
962.Lload_fpu_regs_done:
963	ni	__LC_CPU_FLAGS+7,255-_CIF_FPU
964	br	%r14
965.Lload_fpu_regs_end:
966
967.L__critical_end:
968
969/*
970 * Machine check handler routines
971 */
972ENTRY(mcck_int_handler)
973	STCK	__LC_MCCK_CLOCK
974	la	%r1,4095		# validate r1
975	spt	__LC_CPU_TIMER_SAVE_AREA-4095(%r1)	# validate cpu timer
976	sckc	__LC_CLOCK_COMPARATOR			# validate comparator
977	lam	%a0,%a15,__LC_AREGS_SAVE_AREA-4095(%r1) # validate acrs
978	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# validate gprs
979	lg	%r12,__LC_CURRENT
980	larl	%r13,cleanup_critical
981	lmg	%r8,%r9,__LC_MCK_OLD_PSW
982	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE
983	jo	.Lmcck_panic		# yes -> rest of mcck code invalid
984	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_CR_VALID
985	jno	.Lmcck_panic		# control registers invalid -> panic
986	la	%r14,4095
987	lctlg	%c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r14) # validate ctl regs
988	ptlb
989	lg	%r11,__LC_MCESAD-4095(%r14) # extended machine check save area
990	nill	%r11,0xfc00		# MCESA_ORIGIN_MASK
991	TSTMSK	__LC_CREGS_SAVE_AREA+16-4095(%r14),CR2_GUARDED_STORAGE
992	jno	0f
993	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_GS_VALID
994	jno	0f
995	.insn	 rxy,0xe3000000004d,0,__MCESA_GS_SAVE_AREA(%r11) # LGSC
9960:	l	%r14,__LC_FP_CREG_SAVE_AREA-4095(%r14)
997	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_FC_VALID
998	jo	0f
999	sr	%r14,%r14
10000:	sfpc	%r14
1001	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
1002	jo	0f
1003	lghi	%r14,__LC_FPREGS_SAVE_AREA
1004	ld	%f0,0(%r14)
1005	ld	%f1,8(%r14)
1006	ld	%f2,16(%r14)
1007	ld	%f3,24(%r14)
1008	ld	%f4,32(%r14)
1009	ld	%f5,40(%r14)
1010	ld	%f6,48(%r14)
1011	ld	%f7,56(%r14)
1012	ld	%f8,64(%r14)
1013	ld	%f9,72(%r14)
1014	ld	%f10,80(%r14)
1015	ld	%f11,88(%r14)
1016	ld	%f12,96(%r14)
1017	ld	%f13,104(%r14)
1018	ld	%f14,112(%r14)
1019	ld	%f15,120(%r14)
1020	j	1f
10210:	VLM	%v0,%v15,0,%r11
1022	VLM	%v16,%v31,256,%r11
10231:	lghi	%r14,__LC_CPU_TIMER_SAVE_AREA
1024	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
1025	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_CPU_TIMER_VALID
1026	jo	3f
1027	la	%r14,__LC_SYNC_ENTER_TIMER
1028	clc	0(8,%r14),__LC_ASYNC_ENTER_TIMER
1029	jl	0f
1030	la	%r14,__LC_ASYNC_ENTER_TIMER
10310:	clc	0(8,%r14),__LC_EXIT_TIMER
1032	jl	1f
1033	la	%r14,__LC_EXIT_TIMER
10341:	clc	0(8,%r14),__LC_LAST_UPDATE_TIMER
1035	jl	2f
1036	la	%r14,__LC_LAST_UPDATE_TIMER
10372:	spt	0(%r14)
1038	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
10393:	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_PSW_MWP_VALID
1040	jno	.Lmcck_panic
1041	tmhh	%r8,0x0001		# interrupting from user ?
1042	jnz	4f
1043	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID
1044	jno	.Lmcck_panic
10454:	SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER
1046.Lmcck_skip:
1047	lghi	%r14,__LC_GPREGS_SAVE_AREA+64
1048	stmg	%r0,%r7,__PT_R0(%r11)
1049	mvc	__PT_R8(64,%r11),0(%r14)
1050	stmg	%r8,%r9,__PT_PSW(%r11)
1051	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
1052	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
1053	lgr	%r2,%r11		# pass pointer to pt_regs
1054	brasl	%r14,s390_do_machine_check
1055	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
1056	jno	.Lmcck_return
1057	lg	%r1,__LC_KERNEL_STACK	# switch to kernel stack
1058	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
1059	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
1060	la	%r11,STACK_FRAME_OVERHEAD(%r1)
1061	lgr	%r15,%r1
1062	ssm	__LC_PGM_NEW_PSW	# turn dat on, keep irqs off
1063	TSTMSK	__LC_CPU_FLAGS,_CIF_MCCK_PENDING
1064	jno	.Lmcck_return
1065	TRACE_IRQS_OFF
1066	brasl	%r14,s390_handle_mcck
1067	TRACE_IRQS_ON
1068.Lmcck_return:
1069	lg	%r14,__LC_VDSO_PER_CPU
1070	lmg	%r0,%r10,__PT_R0(%r11)
1071	mvc	__LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
1072	tm	__LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
1073	jno	0f
1074	stpt	__LC_EXIT_TIMER
1075	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
10760:	lmg	%r11,%r15,__PT_R11(%r11)
1077	lpswe	__LC_RETURN_MCCK_PSW
1078
1079.Lmcck_panic:
1080	lg	%r15,__LC_PANIC_STACK
1081	la	%r11,STACK_FRAME_OVERHEAD(%r15)
1082	j	.Lmcck_skip
1083
1084#
1085# PSW restart interrupt handler
1086#
1087ENTRY(restart_int_handler)
1088	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
1089	jz	0f
1090	.insn	s,0xb2800000,__LC_LPP
10910:	stg	%r15,__LC_SAVE_AREA_RESTART
1092	lg	%r15,__LC_RESTART_STACK
1093	aghi	%r15,-__PT_SIZE			# create pt_regs on stack
1094	xc	0(__PT_SIZE,%r15),0(%r15)
1095	stmg	%r0,%r14,__PT_R0(%r15)
1096	mvc	__PT_R15(8,%r15),__LC_SAVE_AREA_RESTART
1097	mvc	__PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw
1098	aghi	%r15,-STACK_FRAME_OVERHEAD	# create stack frame on stack
1099	xc	0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
1100	lg	%r1,__LC_RESTART_FN		# load fn, parm & source cpu
1101	lg	%r2,__LC_RESTART_DATA
1102	lg	%r3,__LC_RESTART_SOURCE
1103	ltgr	%r3,%r3				# test source cpu address
1104	jm	1f				# negative -> skip source stop
11050:	sigp	%r4,%r3,SIGP_SENSE		# sigp sense to source cpu
1106	brc	10,0b				# wait for status stored
11071:	basr	%r14,%r1			# call function
1108	stap	__SF_EMPTY(%r15)		# store cpu address
1109	llgh	%r3,__SF_EMPTY(%r15)
11102:	sigp	%r4,%r3,SIGP_STOP		# sigp stop to current cpu
1111	brc	2,2b
11123:	j	3b
1113
1114	.section .kprobes.text, "ax"
1115
1116#ifdef CONFIG_CHECK_STACK
1117/*
1118 * The synchronous or the asynchronous stack overflowed. We are dead.
1119 * No need to properly save the registers, we are going to panic anyway.
1120 * Setup a pt_regs so that show_trace can provide a good call trace.
1121 */
1122stack_overflow:
1123	lg	%r15,__LC_PANIC_STACK	# change to panic stack
1124	la	%r11,STACK_FRAME_OVERHEAD(%r15)
1125	stmg	%r0,%r7,__PT_R0(%r11)
1126	stmg	%r8,%r9,__PT_PSW(%r11)
1127	mvc	__PT_R8(64,%r11),0(%r14)
1128	stg	%r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
1129	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
1130	lgr	%r2,%r11		# pass pointer to pt_regs
1131	jg	kernel_stack_overflow
1132#endif
1133
1134cleanup_critical:
1135#if IS_ENABLED(CONFIG_KVM)
1136	clg	%r9,BASED(.Lcleanup_table_sie)	# .Lsie_gmap
1137	jl	0f
1138	clg	%r9,BASED(.Lcleanup_table_sie+8)# .Lsie_done
1139	jl	.Lcleanup_sie
1140#endif
1141	clg	%r9,BASED(.Lcleanup_table)	# system_call
1142	jl	0f
1143	clg	%r9,BASED(.Lcleanup_table+8)	# .Lsysc_do_svc
1144	jl	.Lcleanup_system_call
1145	clg	%r9,BASED(.Lcleanup_table+16)	# .Lsysc_tif
1146	jl	0f
1147	clg	%r9,BASED(.Lcleanup_table+24)	# .Lsysc_restore
1148	jl	.Lcleanup_sysc_tif
1149	clg	%r9,BASED(.Lcleanup_table+32)	# .Lsysc_done
1150	jl	.Lcleanup_sysc_restore
1151	clg	%r9,BASED(.Lcleanup_table+40)	# .Lio_tif
1152	jl	0f
1153	clg	%r9,BASED(.Lcleanup_table+48)	# .Lio_restore
1154	jl	.Lcleanup_io_tif
1155	clg	%r9,BASED(.Lcleanup_table+56)	# .Lio_done
1156	jl	.Lcleanup_io_restore
1157	clg	%r9,BASED(.Lcleanup_table+64)	# psw_idle
1158	jl	0f
1159	clg	%r9,BASED(.Lcleanup_table+72)	# .Lpsw_idle_end
1160	jl	.Lcleanup_idle
1161	clg	%r9,BASED(.Lcleanup_table+80)	# save_fpu_regs
1162	jl	0f
1163	clg	%r9,BASED(.Lcleanup_table+88)	# .Lsave_fpu_regs_end
1164	jl	.Lcleanup_save_fpu_regs
1165	clg	%r9,BASED(.Lcleanup_table+96)	# load_fpu_regs
1166	jl	0f
1167	clg	%r9,BASED(.Lcleanup_table+104)	# .Lload_fpu_regs_end
1168	jl	.Lcleanup_load_fpu_regs
11690:	br	%r14
1170
1171	.align	8
1172.Lcleanup_table:
1173	.quad	system_call
1174	.quad	.Lsysc_do_svc
1175	.quad	.Lsysc_tif
1176	.quad	.Lsysc_restore
1177	.quad	.Lsysc_done
1178	.quad	.Lio_tif
1179	.quad	.Lio_restore
1180	.quad	.Lio_done
1181	.quad	psw_idle
1182	.quad	.Lpsw_idle_end
1183	.quad	save_fpu_regs
1184	.quad	.Lsave_fpu_regs_end
1185	.quad	load_fpu_regs
1186	.quad	.Lload_fpu_regs_end
1187
1188#if IS_ENABLED(CONFIG_KVM)
1189.Lcleanup_table_sie:
1190	.quad	.Lsie_gmap
1191	.quad	.Lsie_done
1192
1193.Lcleanup_sie:
1194	cghi    %r11,__LC_SAVE_AREA_ASYNC 	#Is this in normal interrupt?
1195	je      1f
1196	slg     %r9,BASED(.Lsie_crit_mcck_start)
1197	clg     %r9,BASED(.Lsie_crit_mcck_length)
1198	jh      1f
1199	oi      __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST
12001:	lg	%r9,__SF_EMPTY(%r15)		# get control block pointer
1201	ni	__SIE_PROG0C+3(%r9),0xfe	# no longer in SIE
1202	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
1203	larl	%r9,sie_exit			# skip forward to sie_exit
1204	br	%r14
1205#endif
1206
1207.Lcleanup_system_call:
1208	# check if stpt has been executed
1209	clg	%r9,BASED(.Lcleanup_system_call_insn)
1210	jh	0f
1211	mvc	__LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
1212	cghi	%r11,__LC_SAVE_AREA_ASYNC
1213	je	0f
1214	mvc	__LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
12150:	# check if stmg has been executed
1216	clg	%r9,BASED(.Lcleanup_system_call_insn+8)
1217	jh	0f
1218	mvc	__LC_SAVE_AREA_SYNC(64),0(%r11)
12190:	# check if base register setup + TIF bit load has been done
1220	clg	%r9,BASED(.Lcleanup_system_call_insn+16)
1221	jhe	0f
1222	# set up saved register r12 task struct pointer
1223	stg	%r12,32(%r11)
1224	# set up saved register r13 __TASK_thread offset
1225	mvc	40(8,%r11),BASED(.Lcleanup_system_call_const)
12260:	# check if the user time update has been done
1227	clg	%r9,BASED(.Lcleanup_system_call_insn+24)
1228	jh	0f
1229	lg	%r15,__LC_EXIT_TIMER
1230	slg	%r15,__LC_SYNC_ENTER_TIMER
1231	alg	%r15,__LC_USER_TIMER
1232	stg	%r15,__LC_USER_TIMER
12330:	# check if the system time update has been done
1234	clg	%r9,BASED(.Lcleanup_system_call_insn+32)
1235	jh	0f
1236	lg	%r15,__LC_LAST_UPDATE_TIMER
1237	slg	%r15,__LC_EXIT_TIMER
1238	alg	%r15,__LC_SYSTEM_TIMER
1239	stg	%r15,__LC_SYSTEM_TIMER
12400:	# update accounting time stamp
1241	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
1242	# set up saved register r11
1243	lg	%r15,__LC_KERNEL_STACK
1244	la	%r9,STACK_FRAME_OVERHEAD(%r15)
1245	stg	%r9,24(%r11)		# r11 pt_regs pointer
1246	# fill pt_regs
1247	mvc	__PT_R8(64,%r9),__LC_SAVE_AREA_SYNC
1248	stmg	%r0,%r7,__PT_R0(%r9)
1249	mvc	__PT_PSW(16,%r9),__LC_SVC_OLD_PSW
1250	mvc	__PT_INT_CODE(4,%r9),__LC_SVC_ILC
1251	xc	__PT_FLAGS(8,%r9),__PT_FLAGS(%r9)
1252	mvi	__PT_FLAGS+7(%r9),_PIF_SYSCALL
1253	# setup saved register r15
1254	stg	%r15,56(%r11)		# r15 stack pointer
1255	# set new psw address and exit
1256	larl	%r9,.Lsysc_do_svc
1257	br	%r14
1258.Lcleanup_system_call_insn:
1259	.quad	system_call
1260	.quad	.Lsysc_stmg
1261	.quad	.Lsysc_per
1262	.quad	.Lsysc_vtime+36
1263	.quad	.Lsysc_vtime+42
1264.Lcleanup_system_call_const:
1265	.quad	__TASK_thread
1266
1267.Lcleanup_sysc_tif:
1268	larl	%r9,.Lsysc_tif
1269	br	%r14
1270
1271.Lcleanup_sysc_restore:
1272	# check if stpt has been executed
1273	clg	%r9,BASED(.Lcleanup_sysc_restore_insn)
1274	jh	0f
1275	mvc	__LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
1276	cghi	%r11,__LC_SAVE_AREA_ASYNC
1277	je	0f
1278	mvc	__LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
12790:	clg	%r9,BASED(.Lcleanup_sysc_restore_insn+8)
1280	je	1f
1281	lg	%r9,24(%r11)		# get saved pointer to pt_regs
1282	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r9)
1283	mvc	0(64,%r11),__PT_R8(%r9)
1284	lmg	%r0,%r7,__PT_R0(%r9)
12851:	lmg	%r8,%r9,__LC_RETURN_PSW
1286	br	%r14
1287.Lcleanup_sysc_restore_insn:
1288	.quad	.Lsysc_exit_timer
1289	.quad	.Lsysc_done - 4
1290
1291.Lcleanup_io_tif:
1292	larl	%r9,.Lio_tif
1293	br	%r14
1294
1295.Lcleanup_io_restore:
1296	# check if stpt has been executed
1297	clg	%r9,BASED(.Lcleanup_io_restore_insn)
1298	jh	0f
1299	mvc	__LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
13000:	clg	%r9,BASED(.Lcleanup_io_restore_insn+8)
1301	je	1f
1302	lg	%r9,24(%r11)		# get saved r11 pointer to pt_regs
1303	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r9)
1304	mvc	0(64,%r11),__PT_R8(%r9)
1305	lmg	%r0,%r7,__PT_R0(%r9)
13061:	lmg	%r8,%r9,__LC_RETURN_PSW
1307	br	%r14
1308.Lcleanup_io_restore_insn:
1309	.quad	.Lio_exit_timer
1310	.quad	.Lio_done - 4
1311
1312.Lcleanup_idle:
1313	ni	__LC_CPU_FLAGS+7,255-_CIF_ENABLED_WAIT
1314	# copy interrupt clock & cpu timer
1315	mvc	__CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK
1316	mvc	__TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER
1317	cghi	%r11,__LC_SAVE_AREA_ASYNC
1318	je	0f
1319	mvc	__CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK
1320	mvc	__TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER
13210:	# check if stck & stpt have been executed
1322	clg	%r9,BASED(.Lcleanup_idle_insn)
1323	jhe	1f
1324	mvc	__CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
1325	mvc	__TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r2)
13261:	# calculate idle cycles
1327#ifdef CONFIG_SMP
1328	clg	%r9,BASED(.Lcleanup_idle_insn)
1329	jl	3f
1330	larl	%r1,smp_cpu_mtid
1331	llgf	%r1,0(%r1)
1332	ltgr	%r1,%r1
1333	jz	3f
1334	.insn	rsy,0xeb0000000017,%r1,5,__SF_EMPTY+80(%r15)
1335	larl	%r3,mt_cycles
1336	ag	%r3,__LC_PERCPU_OFFSET
1337	la	%r4,__SF_EMPTY+16(%r15)
13382:	lg	%r0,0(%r3)
1339	slg	%r0,0(%r4)
1340	alg	%r0,64(%r4)
1341	stg	%r0,0(%r3)
1342	la	%r3,8(%r3)
1343	la	%r4,8(%r4)
1344	brct	%r1,2b
1345#endif
13463:	# account system time going idle
1347	lg	%r9,__LC_STEAL_TIMER
1348	alg	%r9,__CLOCK_IDLE_ENTER(%r2)
1349	slg	%r9,__LC_LAST_UPDATE_CLOCK
1350	stg	%r9,__LC_STEAL_TIMER
1351	mvc	__LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
1352	lg	%r9,__LC_SYSTEM_TIMER
1353	alg	%r9,__LC_LAST_UPDATE_TIMER
1354	slg	%r9,__TIMER_IDLE_ENTER(%r2)
1355	stg	%r9,__LC_SYSTEM_TIMER
1356	mvc	__LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
1357	# prepare return psw
1358	nihh	%r8,0xfcfd		# clear irq & wait state bits
1359	lg	%r9,48(%r11)		# return from psw_idle
1360	br	%r14
1361.Lcleanup_idle_insn:
1362	.quad	.Lpsw_idle_lpsw
1363
1364.Lcleanup_save_fpu_regs:
1365	larl	%r9,save_fpu_regs
1366	br	%r14
1367
1368.Lcleanup_load_fpu_regs:
1369	larl	%r9,load_fpu_regs
1370	br	%r14
1371
1372/*
1373 * Integer constants
1374 */
1375	.align	8
1376.Lcritical_start:
1377	.quad	.L__critical_start
1378.Lcritical_length:
1379	.quad	.L__critical_end - .L__critical_start
1380#if IS_ENABLED(CONFIG_KVM)
1381.Lsie_critical_start:
1382	.quad	.Lsie_gmap
1383.Lsie_critical_length:
1384	.quad	.Lsie_done - .Lsie_gmap
1385.Lsie_crit_mcck_start:
1386	.quad   .Lsie_entry
1387.Lsie_crit_mcck_length:
1388	.quad   .Lsie_skip - .Lsie_entry
1389#endif
1390
1391	.section .rodata, "a"
1392#define SYSCALL(esame,emu)	.long esame
1393	.globl	sys_call_table
1394sys_call_table:
1395#include "syscalls.S"
1396#undef SYSCALL
1397
1398#ifdef CONFIG_COMPAT
1399
1400#define SYSCALL(esame,emu)	.long emu
1401	.globl	sys_call_table_emu
1402sys_call_table_emu:
1403#include "syscalls.S"
1404#undef SYSCALL
1405#endif
1406