xref: /openbmc/linux/arch/s390/kernel/entry.S (revision 29c37341)
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	lg	%r14,__LC_VDSO_PER_CPU
439	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
440	stpt	__LC_EXIT_TIMER
441	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
442	lmg	%r0,%r15,__PT_R0(%r11)
443	b	__LC_RETURN_LPSWE
444
445#
446# One of the work bits is on. Find out which one.
447#
448.Lsysc_work:
449	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
450	jo	.Lsysc_reschedule
451	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL_RESTART
452	jo	.Lsysc_syscall_restart
453#ifdef CONFIG_UPROBES
454	TSTMSK	__TI_flags(%r12),_TIF_UPROBE
455	jo	.Lsysc_uprobe_notify
456#endif
457	TSTMSK	__TI_flags(%r12),_TIF_GUARDED_STORAGE
458	jo	.Lsysc_guarded_storage
459	TSTMSK	__PT_FLAGS(%r11),_PIF_PER_TRAP
460	jo	.Lsysc_singlestep
461#ifdef CONFIG_LIVEPATCH
462	TSTMSK	__TI_flags(%r12),_TIF_PATCH_PENDING
463	jo	.Lsysc_patch_pending	# handle live patching just before
464					# signals and possible syscall restart
465#endif
466	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL_RESTART
467	jo	.Lsysc_syscall_restart
468	TSTMSK	__TI_flags(%r12),_TIF_SIGPENDING
469	jo	.Lsysc_sigpending
470	TSTMSK	__TI_flags(%r12),_TIF_NOTIFY_RESUME
471	jo	.Lsysc_notify_resume
472	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
473	jnz	.Lsysc_asce
474	j	.Lsysc_return
475
476#
477# _TIF_NEED_RESCHED is set, call schedule
478#
479.Lsysc_reschedule:
480	larl	%r14,.Lsysc_return
481	jg	schedule
482
483#
484# _CIF_ASCE_PRIMARY and/or _CIF_ASCE_SECONDARY set, load user space asce
485#
486.Lsysc_asce:
487	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_SECONDARY
488	lctlg	%c7,%c7,__LC_VDSO_ASCE		# load secondary asce
489	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_PRIMARY
490	jz	.Lsysc_return
491#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
492	tm	__LC_STFLE_FAC_LIST+3,0x10	# has MVCOS ?
493	jnz	.Lsysc_set_fs_fixup
494	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
495	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
496	j	.Lsysc_return
497.Lsysc_set_fs_fixup:
498#endif
499	larl	%r14,.Lsysc_return
500	jg	set_fs_fixup
501
502
503#
504# _TIF_SIGPENDING is set, call do_signal
505#
506.Lsysc_sigpending:
507	lgr	%r2,%r11		# pass pointer to pt_regs
508	brasl	%r14,do_signal
509	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL
510	jno	.Lsysc_return
511.Lsysc_do_syscall:
512	lghi	%r13,__TASK_thread
513	lmg	%r2,%r7,__PT_R2(%r11)	# load svc arguments
514	lghi	%r1,0			# svc 0 returns -ENOSYS
515	j	.Lsysc_do_svc
516
517#
518# _TIF_NOTIFY_RESUME is set, call do_notify_resume
519#
520.Lsysc_notify_resume:
521	lgr	%r2,%r11		# pass pointer to pt_regs
522	larl	%r14,.Lsysc_return
523	jg	do_notify_resume
524
525#
526# _TIF_UPROBE is set, call uprobe_notify_resume
527#
528#ifdef CONFIG_UPROBES
529.Lsysc_uprobe_notify:
530	lgr	%r2,%r11		# pass pointer to pt_regs
531	larl	%r14,.Lsysc_return
532	jg	uprobe_notify_resume
533#endif
534
535#
536# _TIF_GUARDED_STORAGE is set, call guarded_storage_load
537#
538.Lsysc_guarded_storage:
539	lgr	%r2,%r11		# pass pointer to pt_regs
540	larl	%r14,.Lsysc_return
541	jg	gs_load_bc_cb
542#
543# _TIF_PATCH_PENDING is set, call klp_update_patch_state
544#
545#ifdef CONFIG_LIVEPATCH
546.Lsysc_patch_pending:
547	lg	%r2,__LC_CURRENT	# pass pointer to task struct
548	larl	%r14,.Lsysc_return
549	jg	klp_update_patch_state
550#endif
551
552#
553# _PIF_PER_TRAP is set, call do_per_trap
554#
555.Lsysc_singlestep:
556	ni	__PT_FLAGS+7(%r11),255-_PIF_PER_TRAP
557	lgr	%r2,%r11		# pass pointer to pt_regs
558	larl	%r14,.Lsysc_return
559	jg	do_per_trap
560
561#
562# _PIF_SYSCALL_RESTART is set, repeat the current system call
563#
564.Lsysc_syscall_restart:
565	ni	__PT_FLAGS+7(%r11),255-_PIF_SYSCALL_RESTART
566	lmg	%r1,%r7,__PT_R1(%r11)	# load svc arguments
567	lg	%r2,__PT_ORIG_GPR2(%r11)
568	j	.Lsysc_do_svc
569
570#
571# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
572# and after the system call
573#
574.Lsysc_tracesys:
575	lgr	%r2,%r11		# pass pointer to pt_regs
576	la	%r3,0
577	llgh	%r0,__PT_INT_CODE+2(%r11)
578	stg	%r0,__PT_R2(%r11)
579	brasl	%r14,do_syscall_trace_enter
580	lghi	%r0,NR_syscalls
581	clgr	%r0,%r2
582	jnh	.Lsysc_tracenogo
583	sllg	%r8,%r2,3
584	lg	%r9,0(%r8,%r10)
585	lmg	%r3,%r7,__PT_R3(%r11)
586	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
587	lg	%r2,__PT_ORIG_GPR2(%r11)
588	BASR_EX	%r14,%r9		# call sys_xxx
589	stg	%r2,__PT_R2(%r11)	# store return value
590.Lsysc_tracenogo:
591	TSTMSK	__TI_flags(%r12),_TIF_TRACE
592	jz	.Lsysc_return
593	lgr	%r2,%r11		# pass pointer to pt_regs
594	larl	%r14,.Lsysc_return
595	jg	do_syscall_trace_exit
596ENDPROC(system_call)
597
598#
599# a new process exits the kernel with ret_from_fork
600#
601ENTRY(ret_from_fork)
602	la	%r11,STACK_FRAME_OVERHEAD(%r15)
603	lg	%r12,__LC_CURRENT
604	brasl	%r14,schedule_tail
605	tm	__PT_PSW+1(%r11),0x01	# forking a kernel thread ?
606	jne	.Lsysc_tracenogo
607	# it's a kernel thread
608	lmg	%r9,%r10,__PT_R9(%r11)	# load gprs
609	la	%r2,0(%r10)
610	BASR_EX	%r14,%r9
611	j	.Lsysc_tracenogo
612ENDPROC(ret_from_fork)
613
614ENTRY(kernel_thread_starter)
615	la	%r2,0(%r10)
616	BASR_EX	%r14,%r9
617	j	.Lsysc_tracenogo
618ENDPROC(kernel_thread_starter)
619
620/*
621 * Program check handler routine
622 */
623
624ENTRY(pgm_check_handler)
625	stpt	__LC_SYNC_ENTER_TIMER
626	BPOFF
627	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
628	lg	%r10,__LC_LAST_BREAK
629	srag	%r11,%r10,12
630	jnz	0f
631	/* if __LC_LAST_BREAK is < 4096, it contains one of
632	 * the lpswe addresses in lowcore. Set it to 1 (initial state)
633	 * to prevent leaking that address to userspace.
634	 */
635	lghi	%r10,1
6360:	lg	%r12,__LC_CURRENT
637	lghi	%r11,0
638	lmg	%r8,%r9,__LC_PGM_OLD_PSW
639	tmhh	%r8,0x0001		# test problem state bit
640	jnz	3f			# -> fault in user space
641#if IS_ENABLED(CONFIG_KVM)
642	# cleanup critical section for program checks in sie64a
643	lgr	%r14,%r9
644	larl	%r13,.Lsie_gmap
645	slgr	%r14,%r13
646	lghi	%r13,.Lsie_done - .Lsie_gmap
647	clgr	%r14,%r13
648	jhe	1f
649	lg	%r14,__SF_SIE_CONTROL(%r15)	# get control block pointer
650	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE
651	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
652	larl	%r9,sie_exit			# skip forward to sie_exit
653	lghi	%r11,_PIF_GUEST_FAULT
654#endif
6551:	tmhh	%r8,0x4000		# PER bit set in old PSW ?
656	jnz	2f			# -> enabled, can't be a double fault
657	tm	__LC_PGM_ILC+3,0x80	# check for per exception
658	jnz	.Lpgm_svcper		# -> single stepped svc
6592:	CHECK_STACK __LC_SAVE_AREA_SYNC
660	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
661	# CHECK_VMAP_STACK branches to stack_overflow or 5f
662	CHECK_VMAP_STACK __LC_SAVE_AREA_SYNC,5f
6633:	UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
664	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
665	lg	%r15,__LC_KERNEL_STACK
666	lgr	%r14,%r12
667	aghi	%r14,__TASK_thread	# pointer to thread_struct
668	lghi	%r13,__LC_PGM_TDB
669	tm	__LC_PGM_ILC+2,0x02	# check for transaction abort
670	jz	4f
671	mvc	__THREAD_trap_tdb(256,%r14),0(%r13)
6724:	stg	%r10,__THREAD_last_break(%r14)
6735:	lgr	%r13,%r11
674	la	%r11,STACK_FRAME_OVERHEAD(%r15)
675	stmg	%r0,%r7,__PT_R0(%r11)
676	# clear user controlled registers to prevent speculative use
677	xgr	%r0,%r0
678	xgr	%r1,%r1
679	xgr	%r2,%r2
680	xgr	%r3,%r3
681	xgr	%r4,%r4
682	xgr	%r5,%r5
683	xgr	%r6,%r6
684	xgr	%r7,%r7
685	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
686	stmg	%r8,%r9,__PT_PSW(%r11)
687	mvc	__PT_INT_CODE(4,%r11),__LC_PGM_ILC
688	mvc	__PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE
689	stg	%r13,__PT_FLAGS(%r11)
690	stg	%r10,__PT_ARGS(%r11)
691	tm	__LC_PGM_ILC+3,0x80	# check for per exception
692	jz	6f
693	tmhh	%r8,0x0001		# kernel per event ?
694	jz	.Lpgm_kprobe
695	oi	__PT_FLAGS+7(%r11),_PIF_PER_TRAP
696	mvc	__THREAD_per_address(8,%r14),__LC_PER_ADDRESS
697	mvc	__THREAD_per_cause(2,%r14),__LC_PER_CODE
698	mvc	__THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
6996:	RESTORE_SM_CLEAR_PER
700	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
701	larl	%r1,pgm_check_table
702	llgh	%r10,__PT_INT_CODE+2(%r11)
703	nill	%r10,0x007f
704	sll	%r10,3
705	je	.Lpgm_return
706	lg	%r9,0(%r10,%r1)		# load address of handler routine
707	lgr	%r2,%r11		# pass pointer to pt_regs
708	BASR_EX	%r14,%r9		# branch to interrupt-handler
709.Lpgm_return:
710	LOCKDEP_SYS_EXIT
711	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
712	jno	.Lsysc_restore
713	TSTMSK	__PT_FLAGS(%r11),_PIF_SYSCALL
714	jo	.Lsysc_do_syscall
715	j	.Lsysc_tif
716
717#
718# PER event in supervisor state, must be kprobes
719#
720.Lpgm_kprobe:
721	RESTORE_SM_CLEAR_PER
722	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
723	lgr	%r2,%r11		# pass pointer to pt_regs
724	brasl	%r14,do_per_trap
725	j	.Lpgm_return
726
727#
728# single stepped system call
729#
730.Lpgm_svcper:
731	mvc	__LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
732	larl	%r14,.Lsysc_per
733	stg	%r14,__LC_RETURN_PSW+8
734	lghi	%r14,_PIF_SYSCALL | _PIF_PER_TRAP
735	lpswe	__LC_RETURN_PSW		# branch to .Lsysc_per
736ENDPROC(pgm_check_handler)
737
738/*
739 * IO interrupt handler routine
740 */
741ENTRY(io_int_handler)
742	STCK	__LC_INT_CLOCK
743	stpt	__LC_ASYNC_ENTER_TIMER
744	BPOFF
745	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
746	lg	%r12,__LC_CURRENT
747	lmg	%r8,%r9,__LC_IO_OLD_PSW
748	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
749	stmg	%r0,%r7,__PT_R0(%r11)
750	# clear user controlled registers to prevent speculative use
751	xgr	%r0,%r0
752	xgr	%r1,%r1
753	xgr	%r2,%r2
754	xgr	%r3,%r3
755	xgr	%r4,%r4
756	xgr	%r5,%r5
757	xgr	%r6,%r6
758	xgr	%r7,%r7
759	xgr	%r10,%r10
760	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
761	stmg	%r8,%r9,__PT_PSW(%r11)
762	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
763	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
764	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
765	jo	.Lio_restore
766#if IS_ENABLED(CONFIG_TRACE_IRQFLAGS)
767	tmhh	%r8,0x300
768	jz	1f
769	TRACE_IRQS_OFF
7701:
771#endif
772	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
773.Lio_loop:
774	lgr	%r2,%r11		# pass pointer to pt_regs
775	lghi	%r3,IO_INTERRUPT
776	tm	__PT_INT_CODE+8(%r11),0x80	# adapter interrupt ?
777	jz	.Lio_call
778	lghi	%r3,THIN_INTERRUPT
779.Lio_call:
780	brasl	%r14,do_IRQ
781	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPAR
782	jz	.Lio_return
783	tpi	0
784	jz	.Lio_return
785	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
786	j	.Lio_loop
787.Lio_return:
788	LOCKDEP_SYS_EXIT
789	TSTMSK	__TI_flags(%r12),_TIF_WORK
790	jnz	.Lio_work		# there is work to do (signals etc.)
791	TSTMSK	__LC_CPU_FLAGS,_CIF_WORK
792	jnz	.Lio_work
793.Lio_restore:
794#if IS_ENABLED(CONFIG_TRACE_IRQFLAGS)
795	tm	__PT_PSW(%r11),3
796	jno	0f
797	TRACE_IRQS_ON
7980:
799#endif
800	lg	%r14,__LC_VDSO_PER_CPU
801	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
802	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
803	jno	.Lio_exit_kernel
804	BPEXIT	__TI_flags(%r12),_TIF_ISOLATE_BP
805	stpt	__LC_EXIT_TIMER
806	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
807.Lio_exit_kernel:
808	lmg	%r0,%r15,__PT_R0(%r11)
809	b	__LC_RETURN_LPSWE
810.Lio_done:
811
812#
813# There is work todo, find out in which context we have been interrupted:
814# 1) if we return to user space we can do all _TIF_WORK work
815# 2) if we return to kernel code and kvm is enabled check if we need to
816#    modify the psw to leave SIE
817# 3) if we return to kernel code and preemptive scheduling is enabled check
818#    the preemption counter and if it is zero call preempt_schedule_irq
819# Before any work can be done, a switch to the kernel stack is required.
820#
821.Lio_work:
822	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
823	jo	.Lio_work_user		# yes -> do resched & signal
824#ifdef CONFIG_PREEMPTION
825	# check for preemptive scheduling
826	icm	%r0,15,__LC_PREEMPT_COUNT
827	jnz	.Lio_restore		# preemption is disabled
828	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
829	jno	.Lio_restore
830	# switch to kernel stack
831	lg	%r1,__PT_R15(%r11)
832	aghi	%r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
833	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
834	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
835	la	%r11,STACK_FRAME_OVERHEAD(%r1)
836	lgr	%r15,%r1
837	brasl	%r14,preempt_schedule_irq
838	j	.Lio_return
839#else
840	j	.Lio_restore
841#endif
842
843#
844# Need to do work before returning to userspace, switch to kernel stack
845#
846.Lio_work_user:
847	lg	%r1,__LC_KERNEL_STACK
848	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
849	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
850	la	%r11,STACK_FRAME_OVERHEAD(%r1)
851	lgr	%r15,%r1
852
853#
854# One of the work bits is on. Find out which one.
855#
856	TSTMSK	__TI_flags(%r12),_TIF_NEED_RESCHED
857	jo	.Lio_reschedule
858#ifdef CONFIG_LIVEPATCH
859	TSTMSK	__TI_flags(%r12),_TIF_PATCH_PENDING
860	jo	.Lio_patch_pending
861#endif
862	TSTMSK	__TI_flags(%r12),_TIF_SIGPENDING
863	jo	.Lio_sigpending
864	TSTMSK	__TI_flags(%r12),_TIF_NOTIFY_RESUME
865	jo	.Lio_notify_resume
866	TSTMSK	__TI_flags(%r12),_TIF_GUARDED_STORAGE
867	jo	.Lio_guarded_storage
868	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
869	jo	.Lio_vxrs
870	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
871	jnz	.Lio_asce
872	j	.Lio_return
873
874#
875# _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
876#
877.Lio_asce:
878	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_SECONDARY
879	lctlg	%c7,%c7,__LC_VDSO_ASCE		# load secondary asce
880	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_PRIMARY
881	jz	.Lio_return
882#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
883	tm	__LC_STFLE_FAC_LIST+3,0x10	# has MVCOS ?
884	jnz	.Lio_set_fs_fixup
885	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
886	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
887	j	.Lio_return
888.Lio_set_fs_fixup:
889#endif
890	larl	%r14,.Lio_return
891	jg	set_fs_fixup
892
893#
894# CIF_FPU is set, restore floating-point controls and floating-point registers.
895#
896.Lio_vxrs:
897	larl	%r14,.Lio_return
898	jg	load_fpu_regs
899
900#
901# _TIF_GUARDED_STORAGE is set, call guarded_storage_load
902#
903.Lio_guarded_storage:
904	ENABLE_INTS_TRACE
905	lgr	%r2,%r11		# pass pointer to pt_regs
906	brasl	%r14,gs_load_bc_cb
907	DISABLE_INTS_TRACE
908	j	.Lio_return
909
910#
911# _TIF_NEED_RESCHED is set, call schedule
912#
913.Lio_reschedule:
914	ENABLE_INTS_TRACE
915	brasl	%r14,schedule		# call scheduler
916	DISABLE_INTS_TRACE
917	j	.Lio_return
918
919#
920# _TIF_PATCH_PENDING is set, call klp_update_patch_state
921#
922#ifdef CONFIG_LIVEPATCH
923.Lio_patch_pending:
924	lg	%r2,__LC_CURRENT	# pass pointer to task struct
925	larl	%r14,.Lio_return
926	jg	klp_update_patch_state
927#endif
928
929#
930# _TIF_SIGPENDING or is set, call do_signal
931#
932.Lio_sigpending:
933	ENABLE_INTS_TRACE
934	lgr	%r2,%r11		# pass pointer to pt_regs
935	brasl	%r14,do_signal
936	DISABLE_INTS_TRACE
937	j	.Lio_return
938
939#
940# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
941#
942.Lio_notify_resume:
943	ENABLE_INTS_TRACE
944	lgr	%r2,%r11		# pass pointer to pt_regs
945	brasl	%r14,do_notify_resume
946	DISABLE_INTS_TRACE
947	j	.Lio_return
948ENDPROC(io_int_handler)
949
950/*
951 * External interrupt handler routine
952 */
953ENTRY(ext_int_handler)
954	STCK	__LC_INT_CLOCK
955	stpt	__LC_ASYNC_ENTER_TIMER
956	BPOFF
957	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
958	lg	%r12,__LC_CURRENT
959	lmg	%r8,%r9,__LC_EXT_OLD_PSW
960	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
961	stmg	%r0,%r7,__PT_R0(%r11)
962	# clear user controlled registers to prevent speculative use
963	xgr	%r0,%r0
964	xgr	%r1,%r1
965	xgr	%r2,%r2
966	xgr	%r3,%r3
967	xgr	%r4,%r4
968	xgr	%r5,%r5
969	xgr	%r6,%r6
970	xgr	%r7,%r7
971	xgr	%r10,%r10
972	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
973	stmg	%r8,%r9,__PT_PSW(%r11)
974	lghi	%r1,__LC_EXT_PARAMS2
975	mvc	__PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
976	mvc	__PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
977	mvc	__PT_INT_PARM_LONG(8,%r11),0(%r1)
978	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
979	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
980	jo	.Lio_restore
981#if IS_ENABLED(CONFIG_TRACE_IRQFLAGS)
982	tmhh	%r8,0x300
983	jz	1f
984	TRACE_IRQS_OFF
9851:
986#endif
987	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
988	lgr	%r2,%r11		# pass pointer to pt_regs
989	lghi	%r3,EXT_INTERRUPT
990	brasl	%r14,do_IRQ
991	j	.Lio_return
992ENDPROC(ext_int_handler)
993
994/*
995 * Load idle PSW.
996 */
997ENTRY(psw_idle)
998	stg	%r3,__SF_EMPTY(%r15)
999	larl	%r1,.Lpsw_idle_exit
1000	stg	%r1,__SF_EMPTY+8(%r15)
1001	larl	%r1,smp_cpu_mtid
1002	llgf	%r1,0(%r1)
1003	ltgr	%r1,%r1
1004	jz	.Lpsw_idle_stcctm
1005	.insn	rsy,0xeb0000000017,%r1,5,__SF_EMPTY+16(%r15)
1006.Lpsw_idle_stcctm:
1007	oi	__LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT
1008	BPON
1009	STCK	__CLOCK_IDLE_ENTER(%r2)
1010	stpt	__TIMER_IDLE_ENTER(%r2)
1011	lpswe	__SF_EMPTY(%r15)
1012.Lpsw_idle_exit:
1013	BR_EX	%r14
1014ENDPROC(psw_idle)
1015
1016/*
1017 * Store floating-point controls and floating-point or vector register
1018 * depending whether the vector facility is available.	A critical section
1019 * cleanup assures that the registers are stored even if interrupted for
1020 * some other work.  The CIF_FPU flag is set to trigger a lazy restore
1021 * of the register contents at return from io or a system call.
1022 */
1023ENTRY(save_fpu_regs)
1024	stnsm	__SF_EMPTY(%r15),0xfc
1025	lg	%r2,__LC_CURRENT
1026	aghi	%r2,__TASK_thread
1027	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
1028	jo	.Lsave_fpu_regs_exit
1029	stfpc	__THREAD_FPU_fpc(%r2)
1030	lg	%r3,__THREAD_FPU_regs(%r2)
1031	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
1032	jz	.Lsave_fpu_regs_fp	  # no -> store FP regs
1033	VSTM	%v0,%v15,0,%r3		  # vstm 0,15,0(3)
1034	VSTM	%v16,%v31,256,%r3	  # vstm 16,31,256(3)
1035	j	.Lsave_fpu_regs_done	  # -> set CIF_FPU flag
1036.Lsave_fpu_regs_fp:
1037	std	0,0(%r3)
1038	std	1,8(%r3)
1039	std	2,16(%r3)
1040	std	3,24(%r3)
1041	std	4,32(%r3)
1042	std	5,40(%r3)
1043	std	6,48(%r3)
1044	std	7,56(%r3)
1045	std	8,64(%r3)
1046	std	9,72(%r3)
1047	std	10,80(%r3)
1048	std	11,88(%r3)
1049	std	12,96(%r3)
1050	std	13,104(%r3)
1051	std	14,112(%r3)
1052	std	15,120(%r3)
1053.Lsave_fpu_regs_done:
1054	oi	__LC_CPU_FLAGS+7,_CIF_FPU
1055.Lsave_fpu_regs_exit:
1056	ssm	__SF_EMPTY(%r15)
1057	BR_EX	%r14
1058.Lsave_fpu_regs_end:
1059ENDPROC(save_fpu_regs)
1060EXPORT_SYMBOL(save_fpu_regs)
1061
1062/*
1063 * Load floating-point controls and floating-point or vector registers.
1064 * A critical section cleanup assures that the register contents are
1065 * loaded even if interrupted for some other work.
1066 *
1067 * There are special calling conventions to fit into sysc and io return work:
1068 *	%r15:	<kernel stack>
1069 * The function requires:
1070 *	%r4
1071 */
1072load_fpu_regs:
1073	lg	%r4,__LC_CURRENT
1074	aghi	%r4,__TASK_thread
1075	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
1076	jno	.Lload_fpu_regs_exit
1077	lfpc	__THREAD_FPU_fpc(%r4)
1078	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
1079	lg	%r4,__THREAD_FPU_regs(%r4)	# %r4 <- reg save area
1080	jz	.Lload_fpu_regs_fp		# -> no VX, load FP regs
1081	VLM	%v0,%v15,0,%r4
1082	VLM	%v16,%v31,256,%r4
1083	j	.Lload_fpu_regs_done
1084.Lload_fpu_regs_fp:
1085	ld	0,0(%r4)
1086	ld	1,8(%r4)
1087	ld	2,16(%r4)
1088	ld	3,24(%r4)
1089	ld	4,32(%r4)
1090	ld	5,40(%r4)
1091	ld	6,48(%r4)
1092	ld	7,56(%r4)
1093	ld	8,64(%r4)
1094	ld	9,72(%r4)
1095	ld	10,80(%r4)
1096	ld	11,88(%r4)
1097	ld	12,96(%r4)
1098	ld	13,104(%r4)
1099	ld	14,112(%r4)
1100	ld	15,120(%r4)
1101.Lload_fpu_regs_done:
1102	ni	__LC_CPU_FLAGS+7,255-_CIF_FPU
1103.Lload_fpu_regs_exit:
1104	BR_EX	%r14
1105.Lload_fpu_regs_end:
1106ENDPROC(load_fpu_regs)
1107
1108/*
1109 * Machine check handler routines
1110 */
1111ENTRY(mcck_int_handler)
1112	STCK	__LC_MCCK_CLOCK
1113	BPOFF
1114	la	%r1,4095		# validate r1
1115	spt	__LC_CPU_TIMER_SAVE_AREA-4095(%r1)	# validate cpu timer
1116	sckc	__LC_CLOCK_COMPARATOR			# validate comparator
1117	lam	%a0,%a15,__LC_AREGS_SAVE_AREA-4095(%r1) # validate acrs
1118	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# validate gprs
1119	lg	%r12,__LC_CURRENT
1120	lmg	%r8,%r9,__LC_MCK_OLD_PSW
1121	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE
1122	jo	.Lmcck_panic		# yes -> rest of mcck code invalid
1123	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_CR_VALID
1124	jno	.Lmcck_panic		# control registers invalid -> panic
1125	la	%r14,4095
1126	lctlg	%c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r14) # validate ctl regs
1127	ptlb
1128	lg	%r11,__LC_MCESAD-4095(%r14) # extended machine check save area
1129	nill	%r11,0xfc00		# MCESA_ORIGIN_MASK
1130	TSTMSK	__LC_CREGS_SAVE_AREA+16-4095(%r14),CR2_GUARDED_STORAGE
1131	jno	0f
1132	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_GS_VALID
1133	jno	0f
1134	.insn	 rxy,0xe3000000004d,0,__MCESA_GS_SAVE_AREA(%r11) # LGSC
11350:	l	%r14,__LC_FP_CREG_SAVE_AREA-4095(%r14)
1136	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_FC_VALID
1137	jo	0f
1138	sr	%r14,%r14
11390:	sfpc	%r14
1140	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_VX
1141	jo	0f
1142	lghi	%r14,__LC_FPREGS_SAVE_AREA
1143	ld	%f0,0(%r14)
1144	ld	%f1,8(%r14)
1145	ld	%f2,16(%r14)
1146	ld	%f3,24(%r14)
1147	ld	%f4,32(%r14)
1148	ld	%f5,40(%r14)
1149	ld	%f6,48(%r14)
1150	ld	%f7,56(%r14)
1151	ld	%f8,64(%r14)
1152	ld	%f9,72(%r14)
1153	ld	%f10,80(%r14)
1154	ld	%f11,88(%r14)
1155	ld	%f12,96(%r14)
1156	ld	%f13,104(%r14)
1157	ld	%f14,112(%r14)
1158	ld	%f15,120(%r14)
1159	j	1f
11600:	VLM	%v0,%v15,0,%r11
1161	VLM	%v16,%v31,256,%r11
11621:	lghi	%r14,__LC_CPU_TIMER_SAVE_AREA
1163	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
1164	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_CPU_TIMER_VALID
1165	jo	3f
1166	la	%r14,__LC_SYNC_ENTER_TIMER
1167	clc	0(8,%r14),__LC_ASYNC_ENTER_TIMER
1168	jl	0f
1169	la	%r14,__LC_ASYNC_ENTER_TIMER
11700:	clc	0(8,%r14),__LC_EXIT_TIMER
1171	jl	1f
1172	la	%r14,__LC_EXIT_TIMER
11731:	clc	0(8,%r14),__LC_LAST_UPDATE_TIMER
1174	jl	2f
1175	la	%r14,__LC_LAST_UPDATE_TIMER
11762:	spt	0(%r14)
1177	mvc	__LC_MCCK_ENTER_TIMER(8),0(%r14)
11783:	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_PSW_MWP_VALID
1179	jno	.Lmcck_panic
1180	tmhh	%r8,0x0001		# interrupting from user ?
1181	jnz	4f
1182	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID
1183	jno	.Lmcck_panic
11844:	ssm	__LC_PGM_NEW_PSW	# turn dat on, keep irqs off
1185	SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER
1186.Lmcck_skip:
1187	lghi	%r14,__LC_GPREGS_SAVE_AREA+64
1188	stmg	%r0,%r7,__PT_R0(%r11)
1189	# clear user controlled registers to prevent speculative use
1190	xgr	%r0,%r0
1191	xgr	%r1,%r1
1192	xgr	%r2,%r2
1193	xgr	%r3,%r3
1194	xgr	%r4,%r4
1195	xgr	%r5,%r5
1196	xgr	%r6,%r6
1197	xgr	%r7,%r7
1198	xgr	%r10,%r10
1199	mvc	__PT_R8(64,%r11),0(%r14)
1200	stmg	%r8,%r9,__PT_PSW(%r11)
1201	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
1202	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
1203	lgr	%r2,%r11		# pass pointer to pt_regs
1204	brasl	%r14,s390_do_machine_check
1205	cghi	%r2,0
1206	je	.Lmcck_return
1207	lg	%r1,__LC_KERNEL_STACK	# switch to kernel stack
1208	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
1209	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
1210	la	%r11,STACK_FRAME_OVERHEAD(%r1)
1211	lgr	%r15,%r1
1212	TRACE_IRQS_OFF
1213	brasl	%r14,s390_handle_mcck
1214	TRACE_IRQS_ON
1215.Lmcck_return:
1216	lg	%r14,__LC_VDSO_PER_CPU
1217	lmg	%r0,%r10,__PT_R0(%r11)
1218	mvc	__LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
1219	tm	__LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
1220	jno	0f
1221	BPEXIT	__TI_flags(%r12),_TIF_ISOLATE_BP
1222	stpt	__LC_EXIT_TIMER
1223	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
12240:	lmg	%r11,%r15,__PT_R11(%r11)
1225	b	__LC_RETURN_MCCK_LPSWE
1226
1227.Lmcck_panic:
1228	lg	%r15,__LC_NODAT_STACK
1229	la	%r11,STACK_FRAME_OVERHEAD(%r15)
1230	j	.Lmcck_skip
1231ENDPROC(mcck_int_handler)
1232
1233#
1234# PSW restart interrupt handler
1235#
1236ENTRY(restart_int_handler)
1237	ALTERNATIVE "", ".insn s,0xb2800000,_LPP_OFFSET", 40
1238	stg	%r15,__LC_SAVE_AREA_RESTART
1239	lg	%r15,__LC_RESTART_STACK
1240	xc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r15),STACK_FRAME_OVERHEAD(%r15)
1241	stmg	%r0,%r14,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
1242	mvc	STACK_FRAME_OVERHEAD+__PT_R15(8,%r15),__LC_SAVE_AREA_RESTART
1243	mvc	STACK_FRAME_OVERHEAD+__PT_PSW(16,%r15),__LC_RST_OLD_PSW
1244	xc	0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
1245	lg	%r1,__LC_RESTART_FN		# load fn, parm & source cpu
1246	lg	%r2,__LC_RESTART_DATA
1247	lg	%r3,__LC_RESTART_SOURCE
1248	ltgr	%r3,%r3				# test source cpu address
1249	jm	1f				# negative -> skip source stop
12500:	sigp	%r4,%r3,SIGP_SENSE		# sigp sense to source cpu
1251	brc	10,0b				# wait for status stored
12521:	basr	%r14,%r1			# call function
1253	stap	__SF_EMPTY(%r15)		# store cpu address
1254	llgh	%r3,__SF_EMPTY(%r15)
12552:	sigp	%r4,%r3,SIGP_STOP		# sigp stop to current cpu
1256	brc	2,2b
12573:	j	3b
1258ENDPROC(restart_int_handler)
1259
1260	.section .kprobes.text, "ax"
1261
1262#if defined(CONFIG_CHECK_STACK) || defined(CONFIG_VMAP_STACK)
1263/*
1264 * The synchronous or the asynchronous stack overflowed. We are dead.
1265 * No need to properly save the registers, we are going to panic anyway.
1266 * Setup a pt_regs so that show_trace can provide a good call trace.
1267 */
1268ENTRY(stack_overflow)
1269	lg	%r15,__LC_NODAT_STACK	# change to panic stack
1270	la	%r11,STACK_FRAME_OVERHEAD(%r15)
1271	stmg	%r0,%r7,__PT_R0(%r11)
1272	stmg	%r8,%r9,__PT_PSW(%r11)
1273	mvc	__PT_R8(64,%r11),0(%r14)
1274	stg	%r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
1275	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
1276	lgr	%r2,%r11		# pass pointer to pt_regs
1277	jg	kernel_stack_overflow
1278ENDPROC(stack_overflow)
1279#endif
1280
1281#if IS_ENABLED(CONFIG_KVM)
1282.Lcleanup_sie:
1283	cghi	%r11,__LC_SAVE_AREA_ASYNC	#Is this in normal interrupt?
1284	je	1f
1285	larl	%r13,.Lsie_entry
1286	slgr	%r9,%r13
1287	larl	%r13,.Lsie_skip
1288	clgr	%r9,%r13
1289	jh	1f
1290	oi	__LC_CPU_FLAGS+7, _CIF_MCCK_GUEST
12911:	BPENTER	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
1292	lg	%r9,__SF_SIE_CONTROL(%r15)	# get control block pointer
1293	ni	__SIE_PROG0C+3(%r9),0xfe	# no longer in SIE
1294	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
1295	larl	%r9,sie_exit			# skip forward to sie_exit
1296	BR_EX	%r14,%r11
1297
1298#endif
1299	.section .rodata, "a"
1300#define SYSCALL(esame,emu)	.quad __s390x_ ## esame
1301	.globl	sys_call_table
1302sys_call_table:
1303#include "asm/syscall_table.h"
1304#undef SYSCALL
1305
1306#ifdef CONFIG_COMPAT
1307
1308#define SYSCALL(esame,emu)	.quad __s390_ ## emu
1309	.globl	sys_call_table_emu
1310sys_call_table_emu:
1311#include "asm/syscall_table.h"
1312#undef SYSCALL
1313#endif
1314