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 */
10
11#include <linux/export.h>
12#include <linux/init.h>
13#include <linux/linkage.h>
14#include <asm/asm-extable.h>
15#include <asm/alternative.h>
16#include <asm/processor.h>
17#include <asm/cache.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/fpu-insn.h>
28#include <asm/setup.h>
29#include <asm/nmi.h>
30#include <asm/nospec-insn.h>
31#include <asm/lowcore.h>
32#include <asm/machine.h>
33
34_LPP_OFFSET	= __LC_LPP
35
36	.macro STBEAR address
37	ALTERNATIVE "nop", ".insn s,0xb2010000,\address", ALT_FACILITY(193)
38	.endm
39
40	.macro LBEAR address
41	ALTERNATIVE "nop", ".insn s,0xb2000000,\address", ALT_FACILITY(193)
42	.endm
43
44	.macro LPSWEY address, lpswe
45	ALTERNATIVE_2 "b \lpswe;nopr", \
46		".insn siy,0xeb0000000071,\address,0", ALT_FACILITY(193),		\
47		__stringify(.insn siy,0xeb0000000071,LOWCORE_ALT_ADDRESS+\address,0),	\
48		ALT_FEATURE(MFEATURE_LOWCORE)
49	.endm
50
51	.macro MBEAR reg, lowcore
52	ALTERNATIVE "brcl 0,0", __stringify(mvc __PT_LAST_BREAK(8,\reg),__LC_LAST_BREAK(\lowcore)),\
53		ALT_FACILITY(193)
54	.endm
55
56	.macro	CHECK_VMAP_STACK savearea, lowcore, oklabel
57	lgr	%r14,%r15
58	nill	%r14,0x10000 - THREAD_SIZE
59	oill	%r14,STACK_INIT_OFFSET
60	clg	%r14,__LC_KERNEL_STACK(\lowcore)
61	je	\oklabel
62	clg	%r14,__LC_ASYNC_STACK(\lowcore)
63	je	\oklabel
64	clg	%r14,__LC_MCCK_STACK(\lowcore)
65	je	\oklabel
66	clg	%r14,__LC_NODAT_STACK(\lowcore)
67	je	\oklabel
68	clg	%r14,__LC_RESTART_STACK(\lowcore)
69	je	\oklabel
70	la	%r14,\savearea(\lowcore)
71	j	stack_invalid
72	.endm
73
74	/*
75	 * The TSTMSK macro generates a test-under-mask instruction by
76	 * calculating the memory offset for the specified mask value.
77	 * Mask value can be any constant.  The macro shifts the mask
78	 * value to calculate the memory offset for the test-under-mask
79	 * instruction.
80	 */
81	.macro TSTMSK addr, mask, size=8, bytepos=0
82		.if (\bytepos < \size) && (\mask >> 8)
83			.if (\mask & 0xff)
84				.error "Mask exceeds byte boundary"
85			.endif
86			TSTMSK \addr, "(\mask >> 8)", \size, "(\bytepos + 1)"
87			.exitm
88		.endif
89		.ifeq \mask
90			.error "Mask must not be zero"
91		.endif
92		off = \size - \bytepos - 1
93		tm	off+\addr, \mask
94	.endm
95
96	.macro BPOFF
97	ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,12,0", ALT_SPEC(82)
98	.endm
99
100	.macro BPON
101	ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,13,0", ALT_SPEC(82)
102	.endm
103
104	.macro BPENTER tif_ptr,tif_mask
105	ALTERNATIVE "TSTMSK \tif_ptr,\tif_mask; jz .+8; .insn rrf,0xb2e80000,0,0,13,0", \
106		    "j .+12; nop; nop", ALT_SPEC(82)
107	.endm
108
109	.macro BPEXIT tif_ptr,tif_mask
110	TSTMSK	\tif_ptr,\tif_mask
111	ALTERNATIVE "jz .+8;  .insn rrf,0xb2e80000,0,0,12,0", \
112		    "jnz .+8; .insn rrf,0xb2e80000,0,0,13,0", ALT_SPEC(82)
113	.endm
114
115#if IS_ENABLED(CONFIG_KVM)
116	.macro SIEEXIT sie_control,lowcore
117	lg	%r9,\sie_control			# get control block pointer
118	ni	__SIE_PROG0C+3(%r9),0xfe		# no longer in SIE
119	lctlg	%c1,%c1,__LC_USER_ASCE(\lowcore)	# load primary asce
120	lg	%r9,__LC_CURRENT(\lowcore)
121	mvi	__TI_sie(%r9),0
122	larl	%r9,sie_exit			# skip forward to sie_exit
123	.endm
124#endif
125
126	.macro STACKLEAK_ERASE
127#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
128	brasl	%r14,stackleak_erase_on_task_stack
129#endif
130	.endm
131
132	GEN_BR_THUNK %r14
133
134	.section .kprobes.text, "ax"
135.Ldummy:
136	/*
137	 * The following nop exists only in order to avoid that the next
138	 * symbol starts at the beginning of the kprobes text section.
139	 * In that case there would be several symbols at the same address.
140	 * E.g. objdump would take an arbitrary symbol when disassembling
141	 * the code.
142	 * With the added nop in between this cannot happen.
143	 */
144	nop	0
145
146/*
147 * Scheduler resume function, called by __switch_to
148 *  gpr2 = (task_struct *)prev
149 *  gpr3 = (task_struct *)next
150 * Returns:
151 *  gpr2 = prev
152 */
153SYM_FUNC_START(__switch_to_asm)
154	stmg	%r6,%r15,__SF_GPRS(%r15)	# store gprs of prev task
155	lghi	%r4,__TASK_stack
156	lghi	%r1,__TASK_thread
157	llill	%r5,STACK_INIT_OFFSET
158	stg	%r15,__THREAD_ksp(%r1,%r2)	# store kernel stack of prev
159	lg	%r15,0(%r4,%r3)			# start of kernel stack of next
160	agr	%r15,%r5			# end of kernel stack of next
161	GET_LC	%r13
162	stg	%r3,__LC_CURRENT(%r13)		# store task struct of next
163	stg	%r15,__LC_KERNEL_STACK(%r13)	# store end of kernel stack
164	lg	%r15,__THREAD_ksp(%r1,%r3)	# load kernel stack of next
165	aghi	%r3,__TASK_pid
166	mvc	__LC_CURRENT_PID(4,%r13),0(%r3)	# store pid of next
167	ALTERNATIVE "nop", "lpp _LPP_OFFSET(%r13)", ALT_FACILITY(40)
168	lmg	%r6,%r15,__SF_GPRS(%r15)	# load gprs of next task
169	BR_EX	%r14
170SYM_FUNC_END(__switch_to_asm)
171
172#if IS_ENABLED(CONFIG_KVM)
173/*
174 * __sie64a calling convention:
175 * %r2 pointer to sie control block phys
176 * %r3 pointer to sie control block virt
177 * %r4 guest register save area
178 * %r5 guest asce
179 */
180SYM_FUNC_START(__sie64a)
181	stmg	%r6,%r14,__SF_GPRS(%r15)	# save kernel registers
182	GET_LC	%r13
183	lg	%r14,__LC_CURRENT(%r13)
184	stg	%r2,__SF_SIE_CONTROL_PHYS(%r15)	# save sie block physical..
185	stg	%r3,__SF_SIE_CONTROL(%r15)	# ...and virtual addresses
186	stg	%r4,__SF_SIE_SAVEAREA(%r15)	# save guest register save area
187	stg	%r5,__SF_SIE_GUEST_ASCE(%r15)	# save guest asce
188	xc	__SF_SIE_REASON(8,%r15),__SF_SIE_REASON(%r15) # reason code = 0
189	mvc	__SF_SIE_FLAGS(8,%r15),__TI_flags(%r14) # copy thread flags
190	lmg	%r0,%r13,0(%r4)			# load guest gprs 0-13
191	mvi	__TI_sie(%r14),1
192	lctlg	%c1,%c1,__SF_SIE_GUEST_ASCE(%r15) # load primary asce
193	lg	%r14,__SF_SIE_CONTROL(%r15)	# get control block pointer
194	oi	__SIE_PROG0C+3(%r14),1		# we are going into SIE now
195	tm	__SIE_PROG20+3(%r14),3		# last exit...
196	jnz	.Lsie_skip
197	lg	%r14,__SF_SIE_CONTROL_PHYS(%r15)	# get sie block phys addr
198	BPEXIT	__SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST
199.Lsie_entry:
200	sie	0(%r14)
201# Let the next instruction be NOP to avoid triggering a machine check
202# and handling it in a guest as result of the instruction execution.
203	nopr	7
204.Lsie_leave:
205	BPOFF
206	BPENTER	__SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST
207.Lsie_skip:
208	lg	%r14,__SF_SIE_CONTROL(%r15)	# get control block pointer
209	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE
210	GET_LC	%r14
211	lctlg	%c1,%c1,__LC_USER_ASCE(%r14)	# load primary asce
212	lg	%r14,__LC_CURRENT(%r14)
213	mvi	__TI_sie(%r14),0
214SYM_INNER_LABEL(sie_exit, SYM_L_GLOBAL)
215	lg	%r14,__SF_SIE_SAVEAREA(%r15)	# load guest register save area
216	stmg	%r0,%r13,0(%r14)		# save guest gprs 0-13
217	xgr	%r0,%r0				# clear guest registers to
218	xgr	%r1,%r1				# prevent speculative use
219	xgr	%r3,%r3
220	xgr	%r4,%r4
221	xgr	%r5,%r5
222	lmg	%r6,%r14,__SF_GPRS(%r15)	# restore kernel registers
223	lg	%r2,__SF_SIE_REASON(%r15)	# return exit reason code
224	BR_EX	%r14
225SYM_FUNC_END(__sie64a)
226EXPORT_SYMBOL(__sie64a)
227EXPORT_SYMBOL(sie_exit)
228#endif
229
230/*
231 * SVC interrupt handler routine. System calls are synchronous events and
232 * are entered with interrupts disabled.
233 */
234
235SYM_CODE_START(system_call)
236	STMG_LC	%r8,%r15,__LC_SAVE_AREA
237	GET_LC	%r13
238	stpt	__LC_SYS_ENTER_TIMER(%r13)
239	BPOFF
240	lghi	%r14,0
241.Lsysc_per:
242	STBEAR	__LC_LAST_BREAK(%r13)
243	lg	%r15,__LC_KERNEL_STACK(%r13)
244	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
245	stmg	%r0,%r7,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
246	# clear user controlled register to prevent speculative use
247	xgr	%r0,%r0
248	xgr	%r1,%r1
249	xgr	%r4,%r4
250	xgr	%r5,%r5
251	xgr	%r6,%r6
252	xgr	%r7,%r7
253	xgr	%r8,%r8
254	xgr	%r9,%r9
255	xgr	%r10,%r10
256	xgr	%r11,%r11
257	la	%r2,STACK_FRAME_OVERHEAD(%r15)	# pointer to pt_regs
258	mvc	__PT_R8(64,%r2),__LC_SAVE_AREA(%r13)
259	MBEAR	%r2,%r13
260	lgr	%r3,%r14
261	brasl	%r14,__do_syscall
262	STACKLEAK_ERASE
263	mvc	__LC_RETURN_PSW(16,%r13),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
264	BPON
265	LBEAR	STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15)
266	stpt	__LC_EXIT_TIMER(%r13)
267	lmg	%r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
268	LPSWEY	__LC_RETURN_PSW,__LC_RETURN_LPSWE
269SYM_CODE_END(system_call)
270
271#
272# a new process exits the kernel with ret_from_fork
273#
274SYM_CODE_START(ret_from_fork)
275	lgr	%r3,%r11
276	brasl	%r14,__ret_from_fork
277	STACKLEAK_ERASE
278	GET_LC	%r13
279	mvc	__LC_RETURN_PSW(16,%r13),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
280	BPON
281	LBEAR	STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15)
282	stpt	__LC_EXIT_TIMER(%r13)
283	lmg	%r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
284	LPSWEY	__LC_RETURN_PSW,__LC_RETURN_LPSWE
285SYM_CODE_END(ret_from_fork)
286
287/*
288 * Program check handler routine
289 */
290
291SYM_CODE_START(pgm_check_handler)
292	STMG_LC	%r8,%r15,__LC_SAVE_AREA
293	GET_LC	%r13
294	stpt	__LC_SYS_ENTER_TIMER(%r13)
295	BPOFF
296	lmg	%r8,%r9,__LC_PGM_OLD_PSW(%r13)
297	xgr	%r10,%r10
298	tmhh	%r8,0x0001		# coming from user space?
299	jo	3f			# -> fault in user space
300#if IS_ENABLED(CONFIG_KVM)
301	lg	%r11,__LC_CURRENT(%r13)
302	tm	__TI_sie(%r11),0xff
303	jz	1f
304	BPENTER	__SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST
305	SIEEXIT __SF_SIE_CONTROL(%r15),%r13
306	lghi	%r10,_PIF_GUEST_FAULT
307#endif
3081:	tmhh	%r8,0x4000		# PER bit set in old PSW ?
309	jnz	2f			# -> enabled, can't be a double fault
310	tm	__LC_PGM_ILC+3(%r13),0x80	# check for per exception
311	jnz	.Lpgm_svcper		# -> single stepped svc
3122:	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
313	# CHECK_VMAP_STACK branches to stack_invalid or 4f
314	CHECK_VMAP_STACK __LC_SAVE_AREA,%r13,4f
3153:	lg	%r15,__LC_KERNEL_STACK(%r13)
3164:	la	%r11,STACK_FRAME_OVERHEAD(%r15)
317	stg	%r10,__PT_FLAGS(%r11)
318	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
319	stmg	%r0,%r7,__PT_R0(%r11)
320	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA(%r13)
321	mvc	__PT_LAST_BREAK(8,%r11),__LC_PGM_LAST_BREAK(%r13)
322	stmg	%r8,%r9,__PT_PSW(%r11)
323	# clear user controlled registers to prevent speculative use
324	xgr	%r0,%r0
325	xgr	%r1,%r1
326	xgr	%r3,%r3
327	xgr	%r4,%r4
328	xgr	%r5,%r5
329	xgr	%r6,%r6
330	xgr	%r7,%r7
331	xgr	%r12,%r12
332	lgr	%r2,%r11
333	brasl	%r14,__do_pgm_check
334	tmhh	%r8,0x0001		# returning to user space?
335	jno	.Lpgm_exit_kernel
336	STACKLEAK_ERASE
337	BPON
338	stpt	__LC_EXIT_TIMER(%r13)
339.Lpgm_exit_kernel:
340	mvc	__LC_RETURN_PSW(16,%r13),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
341	LBEAR	STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15)
342	lmg	%r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
343	LPSWEY	__LC_RETURN_PSW,__LC_RETURN_LPSWE
344
345#
346# single stepped system call
347#
348.Lpgm_svcper:
349	mvc	__LC_RETURN_PSW(8,%r13),__LC_SVC_NEW_PSW(%r13)
350	larl	%r14,.Lsysc_per
351	stg	%r14,__LC_RETURN_PSW+8(%r13)
352	lghi	%r14,1
353	LBEAR	__LC_PGM_LAST_BREAK(%r13)
354	LPSWEY	__LC_RETURN_PSW,__LC_RETURN_LPSWE # branch to .Lsysc_per
355SYM_CODE_END(pgm_check_handler)
356
357/*
358 * Interrupt handler macro used for external and IO interrupts.
359 */
360.macro INT_HANDLER name,lc_old_psw,handler
361SYM_CODE_START(\name)
362	STMG_LC	%r8,%r15,__LC_SAVE_AREA
363	GET_LC	%r13
364	stckf	__LC_INT_CLOCK(%r13)
365	stpt	__LC_SYS_ENTER_TIMER(%r13)
366	STBEAR	__LC_LAST_BREAK(%r13)
367	BPOFF
368	lmg	%r8,%r9,\lc_old_psw(%r13)
369	tmhh	%r8,0x0001			# interrupting from user ?
370	jnz	1f
371#if IS_ENABLED(CONFIG_KVM)
372	lg	%r10,__LC_CURRENT(%r13)
373	tm	__TI_sie(%r10),0xff
374	jz	0f
375	BPENTER	__SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST
376	SIEEXIT __SF_SIE_CONTROL(%r15),%r13
377#endif
3780:	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
379	j	2f
3801:	lg	%r15,__LC_KERNEL_STACK(%r13)
3812:	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
382	la	%r11,STACK_FRAME_OVERHEAD(%r15)
383	stmg	%r0,%r7,__PT_R0(%r11)
384	# clear user controlled registers to prevent speculative use
385	xgr	%r0,%r0
386	xgr	%r1,%r1
387	xgr	%r3,%r3
388	xgr	%r4,%r4
389	xgr	%r5,%r5
390	xgr	%r6,%r6
391	xgr	%r7,%r7
392	xgr	%r10,%r10
393	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
394	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA(%r13)
395	MBEAR	%r11,%r13
396	stmg	%r8,%r9,__PT_PSW(%r11)
397	lgr	%r2,%r11		# pass pointer to pt_regs
398	brasl	%r14,\handler
399	mvc	__LC_RETURN_PSW(16,%r13),__PT_PSW(%r11)
400	tmhh	%r8,0x0001		# returning to user ?
401	jno	2f
402	STACKLEAK_ERASE
403	BPON
404	stpt	__LC_EXIT_TIMER(%r13)
4052:	LBEAR	__PT_LAST_BREAK(%r11)
406	lmg	%r0,%r15,__PT_R0(%r11)
407	LPSWEY	__LC_RETURN_PSW,__LC_RETURN_LPSWE
408SYM_CODE_END(\name)
409.endm
410
411	.section .irqentry.text, "ax"
412
413INT_HANDLER ext_int_handler,__LC_EXT_OLD_PSW,do_ext_irq
414INT_HANDLER io_int_handler,__LC_IO_OLD_PSW,do_io_irq
415
416	.section .kprobes.text, "ax"
417
418/*
419 * Machine check handler routines
420 */
421SYM_CODE_START(mcck_int_handler)
422	BPOFF
423	GET_LC	%r13
424	lmg	%r8,%r9,__LC_MCK_OLD_PSW(%r13)
425	TSTMSK	__LC_MCCK_CODE(%r13),MCCK_CODE_SYSTEM_DAMAGE
426	jo	.Lmcck_panic		# yes -> rest of mcck code invalid
427	TSTMSK	__LC_MCCK_CODE(%r13),MCCK_CODE_CR_VALID
428	jno	.Lmcck_panic		# control registers invalid -> panic
429	ptlb
430	lay	%r14,__LC_CPU_TIMER_SAVE_AREA(%r13)
431	mvc	__LC_MCCK_ENTER_TIMER(8,%r13),0(%r14)
432	TSTMSK	__LC_MCCK_CODE(%r13),MCCK_CODE_CPU_TIMER_VALID
433	jo	3f
434	la	%r14,__LC_SYS_ENTER_TIMER(%r13)
435	clc	0(8,%r14),__LC_EXIT_TIMER(%r13)
436	jl	1f
437	la	%r14,__LC_EXIT_TIMER(%r13)
4381:	clc	0(8,%r14),__LC_LAST_UPDATE_TIMER(%r13)
439	jl	2f
440	la	%r14,__LC_LAST_UPDATE_TIMER(%r13)
4412:	spt	0(%r14)
442	mvc	__LC_MCCK_ENTER_TIMER(8,%r13),0(%r14)
4433:	TSTMSK	__LC_MCCK_CODE(%r13),MCCK_CODE_PSW_MWP_VALID
444	jno	.Lmcck_panic
445	tmhh	%r8,0x0001		# interrupting from user ?
446	jnz	.Lmcck_user
447	TSTMSK	__LC_MCCK_CODE(%r13),MCCK_CODE_PSW_IA_VALID
448	jno	.Lmcck_panic
449#if IS_ENABLED(CONFIG_KVM)
450	lg	%r10,__LC_CURRENT(%r13)
451	tm	__TI_sie(%r10),0xff
452	jz	.Lmcck_user
453	# Need to compare the address instead of __TI_SIE flag.
454	# Otherwise there would be a race between setting the flag
455	# and entering SIE (or leaving and clearing the flag). This
456	# would cause machine checks targeted at the guest to be
457	# handled by the host.
458	larl	%r14,.Lsie_entry
459	clgrjl	%r9,%r14, 4f
460	larl	%r14,.Lsie_leave
461	clgrjhe	%r9,%r14, 4f
462	lg	%r10,__LC_PCPU(%r13)
463	oi	__PCPU_FLAGS+7(%r10), _CIF_MCCK_GUEST
4644:	BPENTER	__SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST
465	SIEEXIT __SF_SIE_CONTROL(%r15),%r13
466#endif
467.Lmcck_user:
468	lg	%r15,__LC_MCCK_STACK(%r13)
469	la	%r11,STACK_FRAME_OVERHEAD(%r15)
470	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
471	lay	%r14,__LC_GPREGS_SAVE_AREA(%r13)
472	mvc	__PT_R0(128,%r11),0(%r14)
473	# clear user controlled registers to prevent speculative use
474	xgr	%r0,%r0
475	xgr	%r1,%r1
476	xgr	%r3,%r3
477	xgr	%r4,%r4
478	xgr	%r5,%r5
479	xgr	%r6,%r6
480	xgr	%r7,%r7
481	xgr	%r10,%r10
482	stmg	%r8,%r9,__PT_PSW(%r11)
483	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
484	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
485	lgr	%r2,%r11		# pass pointer to pt_regs
486	brasl	%r14,s390_do_machine_check
487	lmg	%r0,%r10,__PT_R0(%r11)
488	mvc	__LC_RETURN_MCCK_PSW(16,%r13),__PT_PSW(%r11) # move return PSW
489	tm	__LC_RETURN_MCCK_PSW+1(%r13),0x01 # returning to user ?
490	jno	0f
491	BPON
492	stpt	__LC_EXIT_TIMER(%r13)
4930:	ALTERNATIVE "brcl 0,0", __stringify(lay %r12,__LC_LAST_BREAK_SAVE_AREA(%r13)),\
494		ALT_FACILITY(193)
495	LBEAR	0(%r12)
496	lmg	%r11,%r15,__PT_R11(%r11)
497	LPSWEY	__LC_RETURN_MCCK_PSW,__LC_RETURN_MCCK_LPSWE
498
499.Lmcck_panic:
500	/*
501	 * Iterate over all possible CPU addresses in the range 0..0xffff
502	 * and stop each CPU using signal processor. Use compare and swap
503	 * to allow just one CPU-stopper and prevent concurrent CPUs from
504	 * stopping each other while leaving the others running.
505	 */
506	lhi	%r5,0
507	lhi	%r6,1
508	larl	%r7,stop_lock
509	cs	%r5,%r6,0(%r7)		# single CPU-stopper only
510	jnz	4f
511	larl	%r7,this_cpu
512	stap	0(%r7)			# this CPU address
513	lh	%r4,0(%r7)
514	nilh	%r4,0
515	lhi	%r0,1
516	sll	%r0,16			# CPU counter
517	lhi	%r3,0			# next CPU address
5180:	cr	%r3,%r4
519	je	2f
5201:	sigp	%r1,%r3,SIGP_STOP	# stop next CPU
521	brc	SIGP_CC_BUSY,1b
5222:	ahi	%r3,1
523	brct	%r0,0b
5243:	sigp	%r1,%r4,SIGP_STOP	# stop this CPU
525	brc	SIGP_CC_BUSY,3b
5264:	j	4b
527SYM_CODE_END(mcck_int_handler)
528
529SYM_CODE_START(restart_int_handler)
530	ALTERNATIVE "nop", "lpp _LPP_OFFSET", ALT_FACILITY(40)
531	stg	%r15,__LC_SAVE_AREA_RESTART
532	TSTMSK	__LC_RESTART_FLAGS,RESTART_FLAG_CTLREGS,4
533	jz	0f
534	lctlg	%c0,%c15,__LC_CREGS_SAVE_AREA
5350:	larl	%r15,daton_psw
536	lpswe	0(%r15)				# turn dat on, keep irqs off
537.Ldaton:
538	GET_LC	%r15
539	lg	%r15,__LC_RESTART_STACK(%r15)
540	xc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r15),STACK_FRAME_OVERHEAD(%r15)
541	stmg	%r0,%r14,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
542	GET_LC	%r13
543	mvc	STACK_FRAME_OVERHEAD+__PT_R15(8,%r15),__LC_SAVE_AREA_RESTART(%r13)
544	mvc	STACK_FRAME_OVERHEAD+__PT_PSW(16,%r15),__LC_RST_OLD_PSW(%r13)
545	xc	0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
546	lg	%r1,__LC_RESTART_FN(%r13)	# load fn, parm & source cpu
547	lg	%r2,__LC_RESTART_DATA(%r13)
548	lgf	%r3,__LC_RESTART_SOURCE(%r13)
549	ltgr	%r3,%r3				# test source cpu address
550	jm	1f				# negative -> skip source stop
5510:	sigp	%r4,%r3,SIGP_SENSE		# sigp sense to source cpu
552	brc	10,0b				# wait for status stored
5531:	basr	%r14,%r1			# call function
554	stap	__SF_EMPTY(%r15)		# store cpu address
555	llgh	%r3,__SF_EMPTY(%r15)
5562:	sigp	%r4,%r3,SIGP_STOP		# sigp stop to current cpu
557	brc	2,2b
5583:	j	3b
559SYM_CODE_END(restart_int_handler)
560
561	__INIT
562SYM_CODE_START(early_pgm_check_handler)
563	STMG_LC %r8,%r15,__LC_SAVE_AREA
564	GET_LC	%r13
565	aghi	%r15,-(STACK_FRAME_OVERHEAD+__PT_SIZE)
566	la	%r11,STACK_FRAME_OVERHEAD(%r15)
567	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
568	stmg	%r0,%r7,__PT_R0(%r11)
569	mvc	__PT_PSW(16,%r11),__LC_PGM_OLD_PSW(%r13)
570	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA(%r13)
571	lgr	%r2,%r11
572	brasl	%r14,__do_early_pgm_check
573	mvc	__LC_RETURN_PSW(16,%r13),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
574	lmg	%r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
575	LPSWEY	__LC_RETURN_PSW,__LC_RETURN_LPSWE
576SYM_CODE_END(early_pgm_check_handler)
577	__FINIT
578
579	.section .kprobes.text, "ax"
580
581/*
582 * The synchronous or the asynchronous stack pointer is invalid. We are dead.
583 * No need to properly save the registers, we are going to panic anyway.
584 * Setup a pt_regs so that show_trace can provide a good call trace.
585 */
586SYM_CODE_START(stack_invalid)
587	GET_LC	%r15
588	lg	%r15,__LC_NODAT_STACK(%r15) # change to panic stack
589	la	%r11,STACK_FRAME_OVERHEAD(%r15)
590	stmg	%r0,%r7,__PT_R0(%r11)
591	stmg	%r8,%r9,__PT_PSW(%r11)
592	mvc	__PT_R8(64,%r11),0(%r14)
593	GET_LC	%r2
594	mvc	__PT_ORIG_GPR2(8,%r11),__LC_PGM_LAST_BREAK(%r2)
595	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
596	lgr	%r2,%r11		# pass pointer to pt_regs
597	jg	kernel_stack_invalid
598SYM_CODE_END(stack_invalid)
599
600	.section .data, "aw"
601	.balign	4
602SYM_DATA_LOCAL(stop_lock,	.long 0)
603SYM_DATA_LOCAL(this_cpu,	.short 0)
604	.balign	8
605SYM_DATA_START_LOCAL(daton_psw)
606	.quad	PSW_KERNEL_BITS
607	.quad	.Ldaton
608SYM_DATA_END(daton_psw)
609
610	.section .rodata, "a"
611	.balign	8
612#define SYSCALL(esame,emu)	.quad __s390x_ ## esame
613SYM_DATA_START(sys_call_table)
614#include <asm/syscall_table.h>
615SYM_DATA_END(sys_call_table)
616#undef SYSCALL
617
618#ifdef CONFIG_COMPAT
619
620#define SYSCALL(esame,emu)	.quad __s390_ ## emu
621SYM_DATA_START(sys_call_table_emu)
622#include <asm/syscall_table.h>
623SYM_DATA_END(sys_call_table_emu)
624#undef SYSCALL
625#endif
626