xref: /openbmc/linux/arch/s390/kernel/entry.S (revision 6c9111bc)
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/alternative-asm.h>
15#include <asm/processor.h>
16#include <asm/cache.h>
17#include <asm/ctl_reg.h>
18#include <asm/dwarf.h>
19#include <asm/errno.h>
20#include <asm/ptrace.h>
21#include <asm/thread_info.h>
22#include <asm/asm-offsets.h>
23#include <asm/unistd.h>
24#include <asm/page.h>
25#include <asm/sigp.h>
26#include <asm/irq.h>
27#include <asm/vx-insn.h>
28#include <asm/setup.h>
29#include <asm/nmi.h>
30#include <asm/export.h>
31#include <asm/nospec-insn.h>
32
33__PT_R0      =	__PT_GPRS
34__PT_R1      =	__PT_GPRS + 8
35__PT_R2      =	__PT_GPRS + 16
36__PT_R3      =	__PT_GPRS + 24
37__PT_R4      =	__PT_GPRS + 32
38__PT_R5      =	__PT_GPRS + 40
39__PT_R6      =	__PT_GPRS + 48
40__PT_R7      =	__PT_GPRS + 56
41__PT_R8      =	__PT_GPRS + 64
42__PT_R9      =	__PT_GPRS + 72
43__PT_R10     =	__PT_GPRS + 80
44__PT_R11     =	__PT_GPRS + 88
45__PT_R12     =	__PT_GPRS + 96
46__PT_R13     =	__PT_GPRS + 104
47__PT_R14     =	__PT_GPRS + 112
48__PT_R15     =	__PT_GPRS + 120
49
50STACK_SHIFT = PAGE_SHIFT + THREAD_SIZE_ORDER
51STACK_SIZE  = 1 << STACK_SHIFT
52STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
53
54_TIF_WORK	= (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
55		   _TIF_UPROBE | _TIF_GUARDED_STORAGE | _TIF_PATCH_PENDING)
56_TIF_TRACE	= (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
57		   _TIF_SYSCALL_TRACEPOINT)
58_CIF_WORK	= (_CIF_ASCE_PRIMARY | _CIF_ASCE_SECONDARY | _CIF_FPU)
59_PIF_WORK	= (_PIF_PER_TRAP | _PIF_SYSCALL_RESTART)
60
61_LPP_OFFSET	= __LC_LPP
62
63	.macro	TRACE_IRQS_ON
64#ifdef CONFIG_TRACE_IRQFLAGS
65	basr	%r2,%r0
66	brasl	%r14,trace_hardirqs_on_caller
67#endif
68	.endm
69
70	.macro	TRACE_IRQS_OFF
71#ifdef CONFIG_TRACE_IRQFLAGS
72	basr	%r2,%r0
73	brasl	%r14,trace_hardirqs_off_caller
74#endif
75	.endm
76
77	.macro	LOCKDEP_SYS_EXIT
78#ifdef CONFIG_LOCKDEP
79	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
80	jz	.+10
81	brasl	%r14,lockdep_sys_exit
82#endif
83	.endm
84
85	.macro	CHECK_STACK savearea
86#ifdef CONFIG_CHECK_STACK
87	tml	%r15,STACK_SIZE - CONFIG_STACK_GUARD
88	lghi	%r14,\savearea
89	jz	stack_overflow
90#endif
91	.endm
92
93	.macro	CHECK_VMAP_STACK savearea,oklabel
94#ifdef CONFIG_VMAP_STACK
95	lgr	%r14,%r15
96	nill	%r14,0x10000 - STACK_SIZE
97	oill	%r14,STACK_INIT
98	clg	%r14,__LC_KERNEL_STACK
99	je	\oklabel
100	clg	%r14,__LC_ASYNC_STACK
101	je	\oklabel
102	clg	%r14,__LC_NODAT_STACK
103	je	\oklabel
104	clg	%r14,__LC_RESTART_STACK
105	je	\oklabel
106	lghi	%r14,\savearea
107	j	stack_overflow
108#else
109	j	\oklabel
110#endif
111	.endm
112
113	.macro	SWITCH_ASYNC savearea,timer
114	tmhh	%r8,0x0001		# interrupting from user ?
115	jnz	2f
116#if IS_ENABLED(CONFIG_KVM)
117	lgr	%r14,%r9
118	larl	%r13,.Lsie_gmap
119	slgr	%r14,%r13
120	lghi	%r13,.Lsie_done - .Lsie_gmap
121	clgr	%r14,%r13
122	jhe	0f
123	lghi	%r11,\savearea		# inside critical section, do cleanup
124	brasl	%r14,.Lcleanup_sie
125#endif
1260:	larl	%r13,.Lpsw_idle_exit
127	cgr	%r13,%r9
128	jne	1f
129
130	mvc	__CLOCK_IDLE_EXIT(8,%r2), __LC_INT_CLOCK
131	mvc	__TIMER_IDLE_EXIT(8,%r2), __LC_ASYNC_ENTER_TIMER
132	# account system time going idle
133	ni	__LC_CPU_FLAGS+7,255-_CIF_ENABLED_WAIT
134
135	lg	%r13,__LC_STEAL_TIMER
136	alg	%r13,__CLOCK_IDLE_ENTER(%r2)
137	slg	%r13,__LC_LAST_UPDATE_CLOCK
138	stg	%r13,__LC_STEAL_TIMER
139
140	mvc	__LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
141
142	lg	%r13,__LC_SYSTEM_TIMER
143	alg	%r13,__LC_LAST_UPDATE_TIMER
144	slg	%r13,__TIMER_IDLE_ENTER(%r2)
145	stg	%r13,__LC_SYSTEM_TIMER
146	mvc	__LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
147
148	nihh	%r8,0xfcfd		# clear wait state and irq bits
1491:	lg	%r14,__LC_ASYNC_STACK	# are we already on the target stack?
150	slgr	%r14,%r15
151	srag	%r14,%r14,STACK_SHIFT
152	jnz	3f
153	CHECK_STACK \savearea
154	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
155	j	4f
1562:	UPDATE_VTIME %r14,%r15,\timer
157	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
1583:	lg	%r15,__LC_ASYNC_STACK	# load async stack
1594:	la	%r11,STACK_FRAME_OVERHEAD(%r15)
160	.endm
161
162	.macro UPDATE_VTIME w1,w2,enter_timer
163	lg	\w1,__LC_EXIT_TIMER
164	lg	\w2,__LC_LAST_UPDATE_TIMER
165	slg	\w1,\enter_timer
166	slg	\w2,__LC_EXIT_TIMER
167	alg	\w1,__LC_USER_TIMER
168	alg	\w2,__LC_SYSTEM_TIMER
169	stg	\w1,__LC_USER_TIMER
170	stg	\w2,__LC_SYSTEM_TIMER
171	mvc	__LC_LAST_UPDATE_TIMER(8),\enter_timer
172	.endm
173
174	.macro RESTORE_SM_CLEAR_PER
175	stg	%r8,__LC_RETURN_PSW
176	ni	__LC_RETURN_PSW,0xbf
177	ssm	__LC_RETURN_PSW
178	.endm
179
180	.macro ENABLE_INTS
181	stosm	__SF_EMPTY(%r15),3
182	.endm
183
184	.macro ENABLE_INTS_TRACE
185	TRACE_IRQS_ON
186	ENABLE_INTS
187	.endm
188
189	.macro DISABLE_INTS
190	stnsm	__SF_EMPTY(%r15),0xfc
191	.endm
192
193	.macro DISABLE_INTS_TRACE
194	DISABLE_INTS
195	TRACE_IRQS_OFF
196	.endm
197
198	.macro STCK savearea
199#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
200	.insn	s,0xb27c0000,\savearea		# store clock fast
201#else
202	.insn	s,0xb2050000,\savearea		# store clock
203#endif
204	.endm
205
206	/*
207	 * The TSTMSK macro generates a test-under-mask instruction by
208	 * calculating the memory offset for the specified mask value.
209	 * Mask value can be any constant.  The macro shifts the mask
210	 * value to calculate the memory offset for the test-under-mask
211	 * instruction.
212	 */
213	.macro TSTMSK addr, mask, size=8, bytepos=0
214		.if (\bytepos < \size) && (\mask >> 8)
215			.if (\mask & 0xff)
216				.error "Mask exceeds byte boundary"
217			.endif
218			TSTMSK \addr, "(\mask >> 8)", \size, "(\bytepos + 1)"
219			.exitm
220		.endif
221		.ifeq \mask
222			.error "Mask must not be zero"
223		.endif
224		off = \size - \bytepos - 1
225		tm	off+\addr, \mask
226	.endm
227
228	.macro BPOFF
229	ALTERNATIVE "", ".long 0xb2e8c000", 82
230	.endm
231
232	.macro BPON
233	ALTERNATIVE "", ".long 0xb2e8d000", 82
234	.endm
235
236	.macro BPENTER tif_ptr,tif_mask
237	ALTERNATIVE "TSTMSK \tif_ptr,\tif_mask; jz .+8; .long 0xb2e8d000", \
238		    "", 82
239	.endm
240
241	.macro BPEXIT tif_ptr,tif_mask
242	TSTMSK	\tif_ptr,\tif_mask
243	ALTERNATIVE "jz .+8;  .long 0xb2e8c000", \
244		    "jnz .+8; .long 0xb2e8d000", 82
245	.endm
246
247	GEN_BR_THUNK %r9
248	GEN_BR_THUNK %r14
249	GEN_BR_THUNK %r14,%r11
250
251	.section .kprobes.text, "ax"
252.Ldummy:
253	/*
254	 * This nop exists only in order to avoid that __switch_to starts at
255	 * the beginning of the kprobes text section. In that case we would
256	 * have several symbols at the same address. E.g. objdump would take
257	 * an arbitrary symbol name when disassembling this code.
258	 * With the added nop in between the __switch_to symbol is unique
259	 * again.
260	 */
261	nop	0
262
263ENTRY(__bpon)
264	.globl __bpon
265	BPON
266	BR_EX	%r14
267ENDPROC(__bpon)
268
269/*
270 * Scheduler resume function, called by switch_to
271 *  gpr2 = (task_struct *) prev
272 *  gpr3 = (task_struct *) next
273 * Returns:
274 *  gpr2 = prev
275 */
276ENTRY(__switch_to)
277	stmg	%r6,%r15,__SF_GPRS(%r15)	# store gprs of prev task
278	lghi	%r4,__TASK_stack
279	lghi	%r1,__TASK_thread
280	llill	%r5,STACK_INIT
281	stg	%r15,__THREAD_ksp(%r1,%r2)	# store kernel stack of prev
282	lg	%r15,0(%r4,%r3)			# start of kernel stack of next
283	agr	%r15,%r5			# end of kernel stack of next
284	stg	%r3,__LC_CURRENT		# store task struct of next
285	stg	%r15,__LC_KERNEL_STACK		# store end of kernel stack
286	lg	%r15,__THREAD_ksp(%r1,%r3)	# load kernel stack of next
287	aghi	%r3,__TASK_pid
288	mvc	__LC_CURRENT_PID(4,%r0),0(%r3)	# store pid of next
289	lmg	%r6,%r15,__SF_GPRS(%r15)	# load gprs of next task
290	ALTERNATIVE "", ".insn s,0xb2800000,_LPP_OFFSET", 40
291	BR_EX	%r14
292ENDPROC(__switch_to)
293
294#if IS_ENABLED(CONFIG_KVM)
295/*
296 * sie64a calling convention:
297 * %r2 pointer to sie control block
298 * %r3 guest register save area
299 */
300ENTRY(sie64a)
301	stmg	%r6,%r14,__SF_GPRS(%r15)	# save kernel registers
302	lg	%r12,__LC_CURRENT
303	stg	%r2,__SF_SIE_CONTROL(%r15)	# save control block pointer
304	stg	%r3,__SF_SIE_SAVEAREA(%r15)	# save guest register save area
305	xc	__SF_SIE_REASON(8,%r15),__SF_SIE_REASON(%r15) # reason code = 0
306	mvc	__SF_SIE_FLAGS(8,%r15),__TI_flags(%r12) # copy thread flags
307	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU		# load guest fp/vx registers ?
308	jno	.Lsie_load_guest_gprs
309	brasl	%r14,load_fpu_regs		# load guest fp/vx regs
310.Lsie_load_guest_gprs:
311	lmg	%r0,%r13,0(%r3)			# load guest gprs 0-13
312	lg	%r14,__LC_GMAP			# get gmap pointer
313	ltgr	%r14,%r14
314	jz	.Lsie_gmap
315	lctlg	%c1,%c1,__GMAP_ASCE(%r14)	# load primary asce
316.Lsie_gmap:
317	lg	%r14,__SF_SIE_CONTROL(%r15)	# get control block pointer
318	oi	__SIE_PROG0C+3(%r14),1		# we are going into SIE now
319	tm	__SIE_PROG20+3(%r14),3		# last exit...
320	jnz	.Lsie_skip
321	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
322	jo	.Lsie_skip			# exit if fp/vx regs changed
323	BPEXIT	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
324.Lsie_entry:
325	sie	0(%r14)
326	BPOFF
327	BPENTER	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
328.Lsie_skip:
329	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE
330	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
331.Lsie_done:
332# some program checks are suppressing. C code (e.g. do_protection_exception)
333# will rewind the PSW by the ILC, which is often 4 bytes in case of SIE. There
334# are some corner cases (e.g. runtime instrumentation) where ILC is unpredictable.
335# Other instructions between sie64a and .Lsie_done should not cause program
336# interrupts. So lets use 3 nops as a landing pad for all possible rewinds.
337# See also .Lcleanup_sie
338.Lrewind_pad6:
339	nopr	7
340.Lrewind_pad4:
341	nopr	7
342.Lrewind_pad2:
343	nopr	7
344	.globl sie_exit
345sie_exit:
346	lg	%r14,__SF_SIE_SAVEAREA(%r15)	# load guest register save area
347	stmg	%r0,%r13,0(%r14)		# save guest gprs 0-13
348	xgr	%r0,%r0				# clear guest registers to
349	xgr	%r1,%r1				# prevent speculative use
350	xgr	%r2,%r2
351	xgr	%r3,%r3
352	xgr	%r4,%r4
353	xgr	%r5,%r5
354	lmg	%r6,%r14,__SF_GPRS(%r15)	# restore kernel registers
355	lg	%r2,__SF_SIE_REASON(%r15)	# return exit reason code
356	BR_EX	%r14
357.Lsie_fault:
358	lghi	%r14,-EFAULT
359	stg	%r14,__SF_SIE_REASON(%r15)	# set exit reason code
360	j	sie_exit
361
362	EX_TABLE(.Lrewind_pad6,.Lsie_fault)
363	EX_TABLE(.Lrewind_pad4,.Lsie_fault)
364	EX_TABLE(.Lrewind_pad2,.Lsie_fault)
365	EX_TABLE(sie_exit,.Lsie_fault)
366ENDPROC(sie64a)
367EXPORT_SYMBOL(sie64a)
368EXPORT_SYMBOL(sie_exit)
369#endif
370
371/*
372 * SVC interrupt handler routine. System calls are synchronous events and
373 * are entered with interrupts disabled.
374 */
375
376ENTRY(system_call)
377	stpt	__LC_SYNC_ENTER_TIMER
378	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
379	BPOFF
380	lg	%r12,__LC_CURRENT
381	lghi	%r14,_PIF_SYSCALL
382.Lsysc_per:
383	lghi	%r13,__TASK_thread
384	lg	%r15,__LC_KERNEL_STACK
385	la	%r11,STACK_FRAME_OVERHEAD(%r15)	# pointer to pt_regs
386	UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
387	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
388	stmg	%r0,%r7,__PT_R0(%r11)
389	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
390	mvc	__PT_PSW(16,%r11),__LC_SVC_OLD_PSW
391	mvc	__PT_INT_CODE(4,%r11),__LC_SVC_ILC
392	stg	%r14,__PT_FLAGS(%r11)
393	ENABLE_INTS
394.Lsysc_do_svc:
395	# clear user controlled register to prevent speculative use
396	xgr	%r0,%r0
397	# load address of system call table
398	lg	%r10,__THREAD_sysc_table(%r13,%r12)
399	llgh	%r8,__PT_INT_CODE+2(%r11)
400	slag	%r8,%r8,3			# shift and test for svc 0
401	jnz	.Lsysc_nr_ok
402	# svc 0: system call number in %r1
403	llgfr	%r1,%r1				# clear high word in r1
404	sth	%r1,__PT_INT_CODE+2(%r11)
405	cghi	%r1,NR_syscalls
406	jnl	.Lsysc_nr_ok
407	slag	%r8,%r1,3
408.Lsysc_nr_ok:
409	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
410	stg	%r2,__PT_ORIG_GPR2(%r11)
411	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
412	lg	%r9,0(%r8,%r10)			# get system call add.
413	TSTMSK	__TI_flags(%r12),_TIF_TRACE
414	jnz	.Lsysc_tracesys
415	BASR_EX	%r14,%r9			# call sys_xxxx
416	stg	%r2,__PT_R2(%r11)		# store return value
417
418.Lsysc_return:
419#ifdef CONFIG_DEBUG_RSEQ
420	lgr	%r2,%r11
421	brasl	%r14,rseq_syscall
422#endif
423	LOCKDEP_SYS_EXIT
424.Lsysc_tif:
425	TSTMSK	__PT_FLAGS(%r11),_PIF_WORK
426	jnz	.Lsysc_work
427	TSTMSK	__TI_flags(%r12),_TIF_WORK
428	jnz	.Lsysc_work			# check for work
429	TSTMSK	__LC_CPU_FLAGS,(_CIF_WORK-_CIF_FPU)
430	jnz	.Lsysc_work
431	BPEXIT	__TI_flags(%r12),_TIF_ISOLATE_BP
432.Lsysc_restore:
433	DISABLE_INTS
434	TSTMSK	__LC_CPU_FLAGS, _CIF_FPU
435	jz	.Lsysc_skip_fpu
436	brasl	%r14,load_fpu_regs
437.Lsysc_skip_fpu:
438	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
439	stpt	__LC_EXIT_TIMER
440	lmg	%r0,%r15,__PT_R0(%r11)
441	b	__LC_RETURN_LPSWE
442
443#
444# One of the work bits is on. Find out which one.
445#
446.Lsysc_work:
447	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
448	jo	.Lsysc_reschedule
449	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL_RESTART
450	jo	.Lsysc_syscall_restart
451#ifdef CONFIG_UPROBES
452	TSTMSK	__TI_flags(%r12),_TIF_UPROBE
453	jo	.Lsysc_uprobe_notify
454#endif
455	TSTMSK	__TI_flags(%r12),_TIF_GUARDED_STORAGE
456	jo	.Lsysc_guarded_storage
457	TSTMSK	__PT_FLAGS(%r11),_PIF_PER_TRAP
458	jo	.Lsysc_singlestep
459#ifdef CONFIG_LIVEPATCH
460	TSTMSK	__TI_flags(%r12),_TIF_PATCH_PENDING
461	jo	.Lsysc_patch_pending	# handle live patching just before
462					# signals and possible syscall restart
463#endif
464	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL_RESTART
465	jo	.Lsysc_syscall_restart
466	TSTMSK	__TI_flags(%r12),_TIF_SIGPENDING
467	jo	.Lsysc_sigpending
468	TSTMSK	__TI_flags(%r12),_TIF_NOTIFY_RESUME
469	jo	.Lsysc_notify_resume
470	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
471	jnz	.Lsysc_asce
472	j	.Lsysc_return
473
474#
475# _TIF_NEED_RESCHED is set, call schedule
476#
477.Lsysc_reschedule:
478	larl	%r14,.Lsysc_return
479	jg	schedule
480
481#
482# _CIF_ASCE_PRIMARY and/or _CIF_ASCE_SECONDARY set, load user space asce
483#
484.Lsysc_asce:
485	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_SECONDARY
486	lctlg	%c7,%c7,__LC_VDSO_ASCE		# load secondary asce
487	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_PRIMARY
488	jz	.Lsysc_return
489#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
490	tm	__LC_STFLE_FAC_LIST+3,0x10	# has MVCOS ?
491	jnz	.Lsysc_set_fs_fixup
492	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
493	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
494	j	.Lsysc_return
495.Lsysc_set_fs_fixup:
496#endif
497	larl	%r14,.Lsysc_return
498	jg	set_fs_fixup
499
500
501#
502# _TIF_SIGPENDING is set, call do_signal
503#
504.Lsysc_sigpending:
505	lgr	%r2,%r11		# pass pointer to pt_regs
506	brasl	%r14,do_signal
507	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL
508	jno	.Lsysc_return
509.Lsysc_do_syscall:
510	lghi	%r13,__TASK_thread
511	lmg	%r2,%r7,__PT_R2(%r11)	# load svc arguments
512	lghi	%r1,0			# svc 0 returns -ENOSYS
513	j	.Lsysc_do_svc
514
515#
516# _TIF_NOTIFY_RESUME is set, call do_notify_resume
517#
518.Lsysc_notify_resume:
519	lgr	%r2,%r11		# pass pointer to pt_regs
520	larl	%r14,.Lsysc_return
521	jg	do_notify_resume
522
523#
524# _TIF_UPROBE is set, call uprobe_notify_resume
525#
526#ifdef CONFIG_UPROBES
527.Lsysc_uprobe_notify:
528	lgr	%r2,%r11		# pass pointer to pt_regs
529	larl	%r14,.Lsysc_return
530	jg	uprobe_notify_resume
531#endif
532
533#
534# _TIF_GUARDED_STORAGE is set, call guarded_storage_load
535#
536.Lsysc_guarded_storage:
537	lgr	%r2,%r11		# pass pointer to pt_regs
538	larl	%r14,.Lsysc_return
539	jg	gs_load_bc_cb
540#
541# _TIF_PATCH_PENDING is set, call klp_update_patch_state
542#
543#ifdef CONFIG_LIVEPATCH
544.Lsysc_patch_pending:
545	lg	%r2,__LC_CURRENT	# pass pointer to task struct
546	larl	%r14,.Lsysc_return
547	jg	klp_update_patch_state
548#endif
549
550#
551# _PIF_PER_TRAP is set, call do_per_trap
552#
553.Lsysc_singlestep:
554	ni	__PT_FLAGS+7(%r11),255-_PIF_PER_TRAP
555	lgr	%r2,%r11		# pass pointer to pt_regs
556	larl	%r14,.Lsysc_return
557	jg	do_per_trap
558
559#
560# _PIF_SYSCALL_RESTART is set, repeat the current system call
561#
562.Lsysc_syscall_restart:
563	ni	__PT_FLAGS+7(%r11),255-_PIF_SYSCALL_RESTART
564	lmg	%r1,%r7,__PT_R1(%r11)	# load svc arguments
565	lg	%r2,__PT_ORIG_GPR2(%r11)
566	j	.Lsysc_do_svc
567
568#
569# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
570# and after the system call
571#
572.Lsysc_tracesys:
573	lgr	%r2,%r11		# pass pointer to pt_regs
574	la	%r3,0
575	llgh	%r0,__PT_INT_CODE+2(%r11)
576	stg	%r0,__PT_R2(%r11)
577	brasl	%r14,do_syscall_trace_enter
578	lghi	%r0,NR_syscalls
579	clgr	%r0,%r2
580	jnh	.Lsysc_tracenogo
581	sllg	%r8,%r2,3
582	lg	%r9,0(%r8,%r10)
583	lmg	%r3,%r7,__PT_R3(%r11)
584	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
585	lg	%r2,__PT_ORIG_GPR2(%r11)
586	BASR_EX	%r14,%r9		# call sys_xxx
587	stg	%r2,__PT_R2(%r11)	# store return value
588.Lsysc_tracenogo:
589	TSTMSK	__TI_flags(%r12),_TIF_TRACE
590	jz	.Lsysc_return
591	lgr	%r2,%r11		# pass pointer to pt_regs
592	larl	%r14,.Lsysc_return
593	jg	do_syscall_trace_exit
594ENDPROC(system_call)
595
596#
597# a new process exits the kernel with ret_from_fork
598#
599ENTRY(ret_from_fork)
600	la	%r11,STACK_FRAME_OVERHEAD(%r15)
601	lg	%r12,__LC_CURRENT
602	brasl	%r14,schedule_tail
603	tm	__PT_PSW+1(%r11),0x01	# forking a kernel thread ?
604	jne	.Lsysc_tracenogo
605	# it's a kernel thread
606	lmg	%r9,%r10,__PT_R9(%r11)	# load gprs
607	la	%r2,0(%r10)
608	BASR_EX	%r14,%r9
609	j	.Lsysc_tracenogo
610ENDPROC(ret_from_fork)
611
612ENTRY(kernel_thread_starter)
613	la	%r2,0(%r10)
614	BASR_EX	%r14,%r9
615	j	.Lsysc_tracenogo
616ENDPROC(kernel_thread_starter)
617
618/*
619 * Program check handler routine
620 */
621
622ENTRY(pgm_check_handler)
623	stpt	__LC_SYNC_ENTER_TIMER
624	BPOFF
625	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
626	lg	%r10,__LC_LAST_BREAK
627	srag	%r11,%r10,12
628	jnz	0f
629	/* if __LC_LAST_BREAK is < 4096, it contains one of
630	 * the lpswe addresses in lowcore. Set it to 1 (initial state)
631	 * to prevent leaking that address to userspace.
632	 */
633	lghi	%r10,1
6340:	lg	%r12,__LC_CURRENT
635	lghi	%r11,0
636	lmg	%r8,%r9,__LC_PGM_OLD_PSW
637	tmhh	%r8,0x0001		# test problem state bit
638	jnz	3f			# -> fault in user space
639#if IS_ENABLED(CONFIG_KVM)
640	# cleanup critical section for program checks in sie64a
641	lgr	%r14,%r9
642	larl	%r13,.Lsie_gmap
643	slgr	%r14,%r13
644	lghi	%r13,.Lsie_done - .Lsie_gmap
645	clgr	%r14,%r13
646	jhe	1f
647	lg	%r14,__SF_SIE_CONTROL(%r15)	# get control block pointer
648	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE
649	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
650	larl	%r9,sie_exit			# skip forward to sie_exit
651	lghi	%r11,_PIF_GUEST_FAULT
652#endif
6531:	tmhh	%r8,0x4000		# PER bit set in old PSW ?
654	jnz	2f			# -> enabled, can't be a double fault
655	tm	__LC_PGM_ILC+3,0x80	# check for per exception
656	jnz	.Lpgm_svcper		# -> single stepped svc
6572:	CHECK_STACK __LC_SAVE_AREA_SYNC
658	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
659	# CHECK_VMAP_STACK branches to stack_overflow or 5f
660	CHECK_VMAP_STACK __LC_SAVE_AREA_SYNC,5f
6613:	UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
662	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
663	lg	%r15,__LC_KERNEL_STACK
664	lgr	%r14,%r12
665	aghi	%r14,__TASK_thread	# pointer to thread_struct
666	lghi	%r13,__LC_PGM_TDB
667	tm	__LC_PGM_ILC+2,0x02	# check for transaction abort
668	jz	4f
669	mvc	__THREAD_trap_tdb(256,%r14),0(%r13)
6704:	stg	%r10,__THREAD_last_break(%r14)
6715:	lgr	%r13,%r11
672	la	%r11,STACK_FRAME_OVERHEAD(%r15)
673	stmg	%r0,%r7,__PT_R0(%r11)
674	# clear user controlled registers to prevent speculative use
675	xgr	%r0,%r0
676	xgr	%r1,%r1
677	xgr	%r2,%r2
678	xgr	%r3,%r3
679	xgr	%r4,%r4
680	xgr	%r5,%r5
681	xgr	%r6,%r6
682	xgr	%r7,%r7
683	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
684	stmg	%r8,%r9,__PT_PSW(%r11)
685	mvc	__PT_INT_CODE(4,%r11),__LC_PGM_ILC
686	mvc	__PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE
687	stg	%r13,__PT_FLAGS(%r11)
688	stg	%r10,__PT_ARGS(%r11)
689	tm	__LC_PGM_ILC+3,0x80	# check for per exception
690	jz	6f
691	tmhh	%r8,0x0001		# kernel per event ?
692	jz	.Lpgm_kprobe
693	oi	__PT_FLAGS+7(%r11),_PIF_PER_TRAP
694	mvc	__THREAD_per_address(8,%r14),__LC_PER_ADDRESS
695	mvc	__THREAD_per_cause(2,%r14),__LC_PER_CODE
696	mvc	__THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
6976:	RESTORE_SM_CLEAR_PER
698	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
699	larl	%r1,pgm_check_table
700	llgh	%r10,__PT_INT_CODE+2(%r11)
701	nill	%r10,0x007f
702	sll	%r10,3
703	je	.Lpgm_return
704	lg	%r9,0(%r10,%r1)		# load address of handler routine
705	lgr	%r2,%r11		# pass pointer to pt_regs
706	BASR_EX	%r14,%r9		# branch to interrupt-handler
707.Lpgm_return:
708	LOCKDEP_SYS_EXIT
709	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
710	jno	.Lsysc_restore
711	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL
712	jo	.Lsysc_do_syscall
713	j	.Lsysc_tif
714
715#
716# PER event in supervisor state, must be kprobes
717#
718.Lpgm_kprobe:
719	RESTORE_SM_CLEAR_PER
720	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
721	lgr	%r2,%r11		# pass pointer to pt_regs
722	brasl	%r14,do_per_trap
723	j	.Lpgm_return
724
725#
726# single stepped system call
727#
728.Lpgm_svcper:
729	mvc	__LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
730	larl	%r14,.Lsysc_per
731	stg	%r14,__LC_RETURN_PSW+8
732	lghi	%r14,_PIF_SYSCALL | _PIF_PER_TRAP
733	lpswe	__LC_RETURN_PSW		# branch to .Lsysc_per
734ENDPROC(pgm_check_handler)
735
736/*
737 * IO interrupt handler routine
738 */
739ENTRY(io_int_handler)
740	STCK	__LC_INT_CLOCK
741	stpt	__LC_ASYNC_ENTER_TIMER
742	BPOFF
743	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
744	lg	%r12,__LC_CURRENT
745	lmg	%r8,%r9,__LC_IO_OLD_PSW
746	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
747	stmg	%r0,%r7,__PT_R0(%r11)
748	# clear user controlled registers to prevent speculative use
749	xgr	%r0,%r0
750	xgr	%r1,%r1
751	xgr	%r2,%r2
752	xgr	%r3,%r3
753	xgr	%r4,%r4
754	xgr	%r5,%r5
755	xgr	%r6,%r6
756	xgr	%r7,%r7
757	xgr	%r10,%r10
758	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
759	stmg	%r8,%r9,__PT_PSW(%r11)
760	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
761	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
762	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
763	jo	.Lio_restore
764#if IS_ENABLED(CONFIG_TRACE_IRQFLAGS)
765	tmhh	%r8,0x300
766	jz	1f
767	TRACE_IRQS_OFF
7681:
769#endif
770	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
771.Lio_loop:
772	lgr	%r2,%r11		# pass pointer to pt_regs
773	lghi	%r3,IO_INTERRUPT
774	tm	__PT_INT_CODE+8(%r11),0x80	# adapter interrupt ?
775	jz	.Lio_call
776	lghi	%r3,THIN_INTERRUPT
777.Lio_call:
778	brasl	%r14,do_IRQ
779	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPAR
780	jz	.Lio_return
781	tpi	0
782	jz	.Lio_return
783	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
784	j	.Lio_loop
785.Lio_return:
786	LOCKDEP_SYS_EXIT
787	TSTMSK	__TI_flags(%r12),_TIF_WORK
788	jnz	.Lio_work		# there is work to do (signals etc.)
789	TSTMSK	__LC_CPU_FLAGS,_CIF_WORK
790	jnz	.Lio_work
791.Lio_restore:
792#if IS_ENABLED(CONFIG_TRACE_IRQFLAGS)
793	tm	__PT_PSW(%r11),3
794	jno	0f
795	TRACE_IRQS_ON
7960:
797#endif
798	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
799	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
800	jno	.Lio_exit_kernel
801	BPEXIT	__TI_flags(%r12),_TIF_ISOLATE_BP
802	stpt	__LC_EXIT_TIMER
803.Lio_exit_kernel:
804	lmg	%r0,%r15,__PT_R0(%r11)
805	b	__LC_RETURN_LPSWE
806.Lio_done:
807
808#
809# There is work todo, find out in which context we have been interrupted:
810# 1) if we return to user space we can do all _TIF_WORK work
811# 2) if we return to kernel code and kvm is enabled check if we need to
812#    modify the psw to leave SIE
813# 3) if we return to kernel code and preemptive scheduling is enabled check
814#    the preemption counter and if it is zero call preempt_schedule_irq
815# Before any work can be done, a switch to the kernel stack is required.
816#
817.Lio_work:
818	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
819	jo	.Lio_work_user		# yes -> do resched & signal
820#ifdef CONFIG_PREEMPTION
821	# check for preemptive scheduling
822	icm	%r0,15,__LC_PREEMPT_COUNT
823	jnz	.Lio_restore		# preemption is disabled
824	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
825	jno	.Lio_restore
826	# switch to kernel stack
827	lg	%r1,__PT_R15(%r11)
828	aghi	%r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
829	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
830	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
831	la	%r11,STACK_FRAME_OVERHEAD(%r1)
832	lgr	%r15,%r1
833	brasl	%r14,preempt_schedule_irq
834	j	.Lio_return
835#else
836	j	.Lio_restore
837#endif
838
839#
840# Need to do work before returning to userspace, switch to kernel stack
841#
842.Lio_work_user:
843	lg	%r1,__LC_KERNEL_STACK
844	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
845	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
846	la	%r11,STACK_FRAME_OVERHEAD(%r1)
847	lgr	%r15,%r1
848
849#
850# One of the work bits is on. Find out which one.
851#
852	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
853	jo	.Lio_reschedule
854#ifdef CONFIG_LIVEPATCH
855	TSTMSK	__TI_flags(%r12),_TIF_PATCH_PENDING
856	jo	.Lio_patch_pending
857#endif
858	TSTMSK	__TI_flags(%r12),_TIF_SIGPENDING
859	jo	.Lio_sigpending
860	TSTMSK	__TI_flags(%r12),_TIF_NOTIFY_RESUME
861	jo	.Lio_notify_resume
862	TSTMSK	__TI_flags(%r12),_TIF_GUARDED_STORAGE
863	jo	.Lio_guarded_storage
864	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
865	jo	.Lio_vxrs
866	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
867	jnz	.Lio_asce
868	j	.Lio_return
869
870#
871# _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
872#
873.Lio_asce:
874	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_SECONDARY
875	lctlg	%c7,%c7,__LC_VDSO_ASCE		# load secondary asce
876	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_PRIMARY
877	jz	.Lio_return
878#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
879	tm	__LC_STFLE_FAC_LIST+3,0x10	# has MVCOS ?
880	jnz	.Lio_set_fs_fixup
881	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
882	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
883	j	.Lio_return
884.Lio_set_fs_fixup:
885#endif
886	larl	%r14,.Lio_return
887	jg	set_fs_fixup
888
889#
890# CIF_FPU is set, restore floating-point controls and floating-point registers.
891#
892.Lio_vxrs:
893	larl	%r14,.Lio_return
894	jg	load_fpu_regs
895
896#
897# _TIF_GUARDED_STORAGE is set, call guarded_storage_load
898#
899.Lio_guarded_storage:
900	ENABLE_INTS_TRACE
901	lgr	%r2,%r11		# pass pointer to pt_regs
902	brasl	%r14,gs_load_bc_cb
903	DISABLE_INTS_TRACE
904	j	.Lio_return
905
906#
907# _TIF_NEED_RESCHED is set, call schedule
908#
909.Lio_reschedule:
910	ENABLE_INTS_TRACE
911	brasl	%r14,schedule		# call scheduler
912	DISABLE_INTS_TRACE
913	j	.Lio_return
914
915#
916# _TIF_PATCH_PENDING is set, call klp_update_patch_state
917#
918#ifdef CONFIG_LIVEPATCH
919.Lio_patch_pending:
920	lg	%r2,__LC_CURRENT	# pass pointer to task struct
921	larl	%r14,.Lio_return
922	jg	klp_update_patch_state
923#endif
924
925#
926# _TIF_SIGPENDING or is set, call do_signal
927#
928.Lio_sigpending:
929	ENABLE_INTS_TRACE
930	lgr	%r2,%r11		# pass pointer to pt_regs
931	brasl	%r14,do_signal
932	DISABLE_INTS_TRACE
933	j	.Lio_return
934
935#
936# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
937#
938.Lio_notify_resume:
939	ENABLE_INTS_TRACE
940	lgr	%r2,%r11		# pass pointer to pt_regs
941	brasl	%r14,do_notify_resume
942	DISABLE_INTS_TRACE
943	j	.Lio_return
944ENDPROC(io_int_handler)
945
946/*
947 * External interrupt handler routine
948 */
949ENTRY(ext_int_handler)
950	STCK	__LC_INT_CLOCK
951	stpt	__LC_ASYNC_ENTER_TIMER
952	BPOFF
953	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
954	lg	%r12,__LC_CURRENT
955	lmg	%r8,%r9,__LC_EXT_OLD_PSW
956	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
957	stmg	%r0,%r7,__PT_R0(%r11)
958	# clear user controlled registers to prevent speculative use
959	xgr	%r0,%r0
960	xgr	%r1,%r1
961	xgr	%r2,%r2
962	xgr	%r3,%r3
963	xgr	%r4,%r4
964	xgr	%r5,%r5
965	xgr	%r6,%r6
966	xgr	%r7,%r7
967	xgr	%r10,%r10
968	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
969	stmg	%r8,%r9,__PT_PSW(%r11)
970	lghi	%r1,__LC_EXT_PARAMS2
971	mvc	__PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
972	mvc	__PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
973	mvc	__PT_INT_PARM_LONG(8,%r11),0(%r1)
974	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
975	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
976	jo	.Lio_restore
977#if IS_ENABLED(CONFIG_TRACE_IRQFLAGS)
978	tmhh	%r8,0x300
979	jz	1f
980	TRACE_IRQS_OFF
9811:
982#endif
983	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
984	lgr	%r2,%r11		# pass pointer to pt_regs
985	lghi	%r3,EXT_INTERRUPT
986	brasl	%r14,do_IRQ
987	j	.Lio_return
988ENDPROC(ext_int_handler)
989
990/*
991 * Load idle PSW.
992 */
993ENTRY(psw_idle)
994	stg	%r3,__SF_EMPTY(%r15)
995	larl	%r1,.Lpsw_idle_exit
996	stg	%r1,__SF_EMPTY+8(%r15)
997	larl	%r1,smp_cpu_mtid
998	llgf	%r1,0(%r1)
999	ltgr	%r1,%r1
1000	jz	.Lpsw_idle_stcctm
1001	.insn	rsy,0xeb0000000017,%r1,5,__SF_EMPTY+16(%r15)
1002.Lpsw_idle_stcctm:
1003	oi	__LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT
1004	BPON
1005	STCK	__CLOCK_IDLE_ENTER(%r2)
1006	stpt	__TIMER_IDLE_ENTER(%r2)
1007	lpswe	__SF_EMPTY(%r15)
1008.Lpsw_idle_exit:
1009	BR_EX	%r14
1010ENDPROC(psw_idle)
1011
1012/*
1013 * Store floating-point controls and floating-point or vector register
1014 * depending whether the vector facility is available.	A critical section
1015 * cleanup assures that the registers are stored even if interrupted for
1016 * some other work.  The CIF_FPU flag is set to trigger a lazy restore
1017 * of the register contents at return from io or a system call.
1018 */
1019ENTRY(save_fpu_regs)
1020	stnsm	__SF_EMPTY(%r15),0xfc
1021	lg	%r2,__LC_CURRENT
1022	aghi	%r2,__TASK_thread
1023	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
1024	jo	.Lsave_fpu_regs_exit
1025	stfpc	__THREAD_FPU_fpc(%r2)
1026	lg	%r3,__THREAD_FPU_regs(%r2)
1027	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
1028	jz	.Lsave_fpu_regs_fp	  # no -> store FP regs
1029	VSTM	%v0,%v15,0,%r3		  # vstm 0,15,0(3)
1030	VSTM	%v16,%v31,256,%r3	  # vstm 16,31,256(3)
1031	j	.Lsave_fpu_regs_done	  # -> set CIF_FPU flag
1032.Lsave_fpu_regs_fp:
1033	std	0,0(%r3)
1034	std	1,8(%r3)
1035	std	2,16(%r3)
1036	std	3,24(%r3)
1037	std	4,32(%r3)
1038	std	5,40(%r3)
1039	std	6,48(%r3)
1040	std	7,56(%r3)
1041	std	8,64(%r3)
1042	std	9,72(%r3)
1043	std	10,80(%r3)
1044	std	11,88(%r3)
1045	std	12,96(%r3)
1046	std	13,104(%r3)
1047	std	14,112(%r3)
1048	std	15,120(%r3)
1049.Lsave_fpu_regs_done:
1050	oi	__LC_CPU_FLAGS+7,_CIF_FPU
1051.Lsave_fpu_regs_exit:
1052	ssm	__SF_EMPTY(%r15)
1053	BR_EX	%r14
1054.Lsave_fpu_regs_end:
1055ENDPROC(save_fpu_regs)
1056EXPORT_SYMBOL(save_fpu_regs)
1057
1058/*
1059 * Load floating-point controls and floating-point or vector registers.
1060 * A critical section cleanup assures that the register contents are
1061 * loaded even if interrupted for some other work.
1062 *
1063 * There are special calling conventions to fit into sysc and io return work:
1064 *	%r15:	<kernel stack>
1065 * The function requires:
1066 *	%r4
1067 */
1068load_fpu_regs:
1069	lg	%r4,__LC_CURRENT
1070	aghi	%r4,__TASK_thread
1071	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
1072	jno	.Lload_fpu_regs_exit
1073	lfpc	__THREAD_FPU_fpc(%r4)
1074	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
1075	lg	%r4,__THREAD_FPU_regs(%r4)	# %r4 <- reg save area
1076	jz	.Lload_fpu_regs_fp		# -> no VX, load FP regs
1077	VLM	%v0,%v15,0,%r4
1078	VLM	%v16,%v31,256,%r4
1079	j	.Lload_fpu_regs_done
1080.Lload_fpu_regs_fp:
1081	ld	0,0(%r4)
1082	ld	1,8(%r4)
1083	ld	2,16(%r4)
1084	ld	3,24(%r4)
1085	ld	4,32(%r4)
1086	ld	5,40(%r4)
1087	ld	6,48(%r4)
1088	ld	7,56(%r4)
1089	ld	8,64(%r4)
1090	ld	9,72(%r4)
1091	ld	10,80(%r4)
1092	ld	11,88(%r4)
1093	ld	12,96(%r4)
1094	ld	13,104(%r4)
1095	ld	14,112(%r4)
1096	ld	15,120(%r4)
1097.Lload_fpu_regs_done:
1098	ni	__LC_CPU_FLAGS+7,255-_CIF_FPU
1099.Lload_fpu_regs_exit:
1100	BR_EX	%r14
1101.Lload_fpu_regs_end:
1102ENDPROC(load_fpu_regs)
1103
1104/*
1105 * Machine check handler routines
1106 */
1107ENTRY(mcck_int_handler)
1108	STCK	__LC_MCCK_CLOCK
1109	BPOFF
1110	la	%r1,4095		# validate r1
1111	spt	__LC_CPU_TIMER_SAVE_AREA-4095(%r1)	# validate cpu timer
1112	sckc	__LC_CLOCK_COMPARATOR			# validate comparator
1113	lam	%a0,%a15,__LC_AREGS_SAVE_AREA-4095(%r1) # validate acrs
1114	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# validate gprs
1115	lg	%r12,__LC_CURRENT
1116	lmg	%r8,%r9,__LC_MCK_OLD_PSW
1117	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE
1118	jo	.Lmcck_panic		# yes -> rest of mcck code invalid
1119	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_CR_VALID
1120	jno	.Lmcck_panic		# control registers invalid -> panic
1121	la	%r14,4095
1122	lctlg	%c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r14) # validate ctl regs
1123	ptlb
1124	lg	%r11,__LC_MCESAD-4095(%r14) # extended machine check save area
1125	nill	%r11,0xfc00		# MCESA_ORIGIN_MASK
1126	TSTMSK	__LC_CREGS_SAVE_AREA+16-4095(%r14),CR2_GUARDED_STORAGE
1127	jno	0f
1128	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_GS_VALID
1129	jno	0f
1130	.insn	 rxy,0xe3000000004d,0,__MCESA_GS_SAVE_AREA(%r11) # LGSC
11310:	l	%r14,__LC_FP_CREG_SAVE_AREA-4095(%r14)
1132	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_FC_VALID
1133	jo	0f
1134	sr	%r14,%r14
11350:	sfpc	%r14
1136	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
1137	jo	0f
1138	lghi	%r14,__LC_FPREGS_SAVE_AREA
1139	ld	%f0,0(%r14)
1140	ld	%f1,8(%r14)
1141	ld	%f2,16(%r14)
1142	ld	%f3,24(%r14)
1143	ld	%f4,32(%r14)
1144	ld	%f5,40(%r14)
1145	ld	%f6,48(%r14)
1146	ld	%f7,56(%r14)
1147	ld	%f8,64(%r14)
1148	ld	%f9,72(%r14)
1149	ld	%f10,80(%r14)
1150	ld	%f11,88(%r14)
1151	ld	%f12,96(%r14)
1152	ld	%f13,104(%r14)
1153	ld	%f14,112(%r14)
1154	ld	%f15,120(%r14)
1155	j	1f
11560:	VLM	%v0,%v15,0,%r11
1157	VLM	%v16,%v31,256,%r11
11581:	lghi	%r14,__LC_CPU_TIMER_SAVE_AREA
1159	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
1160	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_CPU_TIMER_VALID
1161	jo	3f
1162	la	%r14,__LC_SYNC_ENTER_TIMER
1163	clc	0(8,%r14),__LC_ASYNC_ENTER_TIMER
1164	jl	0f
1165	la	%r14,__LC_ASYNC_ENTER_TIMER
11660:	clc	0(8,%r14),__LC_EXIT_TIMER
1167	jl	1f
1168	la	%r14,__LC_EXIT_TIMER
11691:	clc	0(8,%r14),__LC_LAST_UPDATE_TIMER
1170	jl	2f
1171	la	%r14,__LC_LAST_UPDATE_TIMER
11722:	spt	0(%r14)
1173	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
11743:	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_PSW_MWP_VALID
1175	jno	.Lmcck_panic
1176	tmhh	%r8,0x0001		# interrupting from user ?
1177	jnz	4f
1178	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID
1179	jno	.Lmcck_panic
11804:	ssm	__LC_PGM_NEW_PSW	# turn dat on, keep irqs off
1181	SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER
1182.Lmcck_skip:
1183	lghi	%r14,__LC_GPREGS_SAVE_AREA+64
1184	stmg	%r0,%r7,__PT_R0(%r11)
1185	# clear user controlled registers to prevent speculative use
1186	xgr	%r0,%r0
1187	xgr	%r1,%r1
1188	xgr	%r2,%r2
1189	xgr	%r3,%r3
1190	xgr	%r4,%r4
1191	xgr	%r5,%r5
1192	xgr	%r6,%r6
1193	xgr	%r7,%r7
1194	xgr	%r10,%r10
1195	mvc	__PT_R8(64,%r11),0(%r14)
1196	stmg	%r8,%r9,__PT_PSW(%r11)
1197	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
1198	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
1199	lgr	%r2,%r11		# pass pointer to pt_regs
1200	brasl	%r14,s390_do_machine_check
1201	cghi	%r2,0
1202	je	.Lmcck_return
1203	lg	%r1,__LC_KERNEL_STACK	# switch to kernel stack
1204	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
1205	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
1206	la	%r11,STACK_FRAME_OVERHEAD(%r1)
1207	lgr	%r15,%r1
1208	TRACE_IRQS_OFF
1209	brasl	%r14,s390_handle_mcck
1210	TRACE_IRQS_ON
1211.Lmcck_return:
1212	lmg	%r0,%r10,__PT_R0(%r11)
1213	mvc	__LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
1214	tm	__LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
1215	jno	0f
1216	BPEXIT	__TI_flags(%r12),_TIF_ISOLATE_BP
1217	stpt	__LC_EXIT_TIMER
12180:	lmg	%r11,%r15,__PT_R11(%r11)
1219	b	__LC_RETURN_MCCK_LPSWE
1220
1221.Lmcck_panic:
1222	lg	%r15,__LC_NODAT_STACK
1223	la	%r11,STACK_FRAME_OVERHEAD(%r15)
1224	j	.Lmcck_skip
1225ENDPROC(mcck_int_handler)
1226
1227#
1228# PSW restart interrupt handler
1229#
1230ENTRY(restart_int_handler)
1231	ALTERNATIVE "", ".insn s,0xb2800000,_LPP_OFFSET", 40
1232	stg	%r15,__LC_SAVE_AREA_RESTART
1233	lg	%r15,__LC_RESTART_STACK
1234	xc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r15),STACK_FRAME_OVERHEAD(%r15)
1235	stmg	%r0,%r14,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
1236	mvc	STACK_FRAME_OVERHEAD+__PT_R15(8,%r15),__LC_SAVE_AREA_RESTART
1237	mvc	STACK_FRAME_OVERHEAD+__PT_PSW(16,%r15),__LC_RST_OLD_PSW
1238	xc	0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
1239	lg	%r1,__LC_RESTART_FN		# load fn, parm & source cpu
1240	lg	%r2,__LC_RESTART_DATA
1241	lg	%r3,__LC_RESTART_SOURCE
1242	ltgr	%r3,%r3				# test source cpu address
1243	jm	1f				# negative -> skip source stop
12440:	sigp	%r4,%r3,SIGP_SENSE		# sigp sense to source cpu
1245	brc	10,0b				# wait for status stored
12461:	basr	%r14,%r1			# call function
1247	stap	__SF_EMPTY(%r15)		# store cpu address
1248	llgh	%r3,__SF_EMPTY(%r15)
12492:	sigp	%r4,%r3,SIGP_STOP		# sigp stop to current cpu
1250	brc	2,2b
12513:	j	3b
1252ENDPROC(restart_int_handler)
1253
1254	.section .kprobes.text, "ax"
1255
1256#if defined(CONFIG_CHECK_STACK) || defined(CONFIG_VMAP_STACK)
1257/*
1258 * The synchronous or the asynchronous stack overflowed. We are dead.
1259 * No need to properly save the registers, we are going to panic anyway.
1260 * Setup a pt_regs so that show_trace can provide a good call trace.
1261 */
1262ENTRY(stack_overflow)
1263	lg	%r15,__LC_NODAT_STACK	# change to panic stack
1264	la	%r11,STACK_FRAME_OVERHEAD(%r15)
1265	stmg	%r0,%r7,__PT_R0(%r11)
1266	stmg	%r8,%r9,__PT_PSW(%r11)
1267	mvc	__PT_R8(64,%r11),0(%r14)
1268	stg	%r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
1269	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
1270	lgr	%r2,%r11		# pass pointer to pt_regs
1271	jg	kernel_stack_overflow
1272ENDPROC(stack_overflow)
1273#endif
1274
1275#if IS_ENABLED(CONFIG_KVM)
1276.Lcleanup_sie:
1277	cghi	%r11,__LC_SAVE_AREA_ASYNC	#Is this in normal interrupt?
1278	je	1f
1279	larl	%r13,.Lsie_entry
1280	slgr	%r9,%r13
1281	larl	%r13,.Lsie_skip
1282	clgr	%r9,%r13
1283	jh	1f
1284	oi	__LC_CPU_FLAGS+7, _CIF_MCCK_GUEST
12851:	BPENTER	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
1286	lg	%r9,__SF_SIE_CONTROL(%r15)	# get control block pointer
1287	ni	__SIE_PROG0C+3(%r9),0xfe	# no longer in SIE
1288	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
1289	larl	%r9,sie_exit			# skip forward to sie_exit
1290	BR_EX	%r14,%r11
1291
1292#endif
1293	.section .rodata, "a"
1294#define SYSCALL(esame,emu)	.quad __s390x_ ## esame
1295	.globl	sys_call_table
1296sys_call_table:
1297#include "asm/syscall_table.h"
1298#undef SYSCALL
1299
1300#ifdef CONFIG_COMPAT
1301
1302#define SYSCALL(esame,emu)	.quad __s390_ ## emu
1303	.globl	sys_call_table_emu
1304sys_call_table_emu:
1305#include "asm/syscall_table.h"
1306#undef SYSCALL
1307#endif
1308