2 * S390 low-level entry points.
4 * Copyright IBM Corp. 1999, 2012
5 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
6 * Hartmut Penner (hp@de.ibm.com),
7 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
8 * Heiko Carstens <heiko.carstens@de.ibm.com>
11 #include <linux/init.h>
12 #include <linux/linkage.h>
13 #include <asm/processor.h>
14 #include <asm/cache.h>
15 #include <asm/errno.h>
16 #include <asm/ptrace.h>
17 #include <asm/thread_info.h>
18 #include <asm/asm-offsets.h>
19 #include <asm/unistd.h>
23 #include <asm/vx-insn.h>
24 #include <asm/setup.h>
26 #include <asm/export.h>
29 __PT_R1 = __PT_GPRS + 8
30 __PT_R2 = __PT_GPRS + 16
31 __PT_R3 = __PT_GPRS + 24
32 __PT_R4 = __PT_GPRS + 32
33 __PT_R5 = __PT_GPRS + 40
34 __PT_R6 = __PT_GPRS + 48
35 __PT_R7 = __PT_GPRS + 56
36 __PT_R8 = __PT_GPRS + 64
37 __PT_R9 = __PT_GPRS + 72
38 __PT_R10 = __PT_GPRS + 80
39 __PT_R11 = __PT_GPRS + 88
40 __PT_R12 = __PT_GPRS + 96
41 __PT_R13 = __PT_GPRS + 104
42 __PT_R14 = __PT_GPRS + 112
43 __PT_R15 = __PT_GPRS + 120
45 STACK_SHIFT = PAGE_SHIFT + THREAD_SIZE_ORDER
46 STACK_SIZE = 1 << STACK_SHIFT
47 STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
49 _TIF_WORK = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
50 _TIF_UPROBE | _TIF_GUARDED_STORAGE | _TIF_PATCH_PENDING)
51 _TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
52 _TIF_SYSCALL_TRACEPOINT)
53 _CIF_WORK = (_CIF_MCCK_PENDING | _CIF_ASCE_PRIMARY | \
54 _CIF_ASCE_SECONDARY | _CIF_FPU)
55 _PIF_WORK = (_PIF_PER_TRAP)
57 #define BASED(name) name-cleanup_critical(%r13)
60 #ifdef CONFIG_TRACE_IRQFLAGS
62 brasl %r14,trace_hardirqs_on_caller
67 #ifdef CONFIG_TRACE_IRQFLAGS
69 brasl %r14,trace_hardirqs_off_caller
73 .macro LOCKDEP_SYS_EXIT
75 tm __PT_PSW+1(%r11),0x01 # returning to user ?
77 brasl %r14,lockdep_sys_exit
81 .macro CHECK_STACK stacksize,savearea
82 #ifdef CONFIG_CHECK_STACK
83 tml %r15,\stacksize - CONFIG_STACK_GUARD
89 .macro SWITCH_ASYNC savearea,timer
90 tmhh %r8,0x0001 # interrupting from user ?
93 slg %r14,BASED(.Lcritical_start)
94 clg %r14,BASED(.Lcritical_length)
96 lghi %r11,\savearea # inside critical section, do cleanup
97 brasl %r14,cleanup_critical
98 tmhh %r8,0x0001 # retest problem state after cleanup
100 0: lg %r14,__LC_ASYNC_STACK # are we already on the async stack?
102 srag %r14,%r14,STACK_SHIFT
104 CHECK_STACK 1<<STACK_SHIFT,\savearea
105 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
107 1: UPDATE_VTIME %r14,%r15,\timer
108 2: lg %r15,__LC_ASYNC_STACK # load async stack
109 3: la %r11,STACK_FRAME_OVERHEAD(%r15)
112 .macro UPDATE_VTIME w1,w2,enter_timer
113 lg \w1,__LC_EXIT_TIMER
114 lg \w2,__LC_LAST_UPDATE_TIMER
116 slg \w2,__LC_EXIT_TIMER
117 alg \w1,__LC_USER_TIMER
118 alg \w2,__LC_SYSTEM_TIMER
119 stg \w1,__LC_USER_TIMER
120 stg \w2,__LC_SYSTEM_TIMER
121 mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer
125 stg %r8,__LC_RETURN_PSW
126 ni __LC_RETURN_PSW,0xbf
131 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
132 .insn s,0xb27c0000,\savearea # store clock fast
134 .insn s,0xb2050000,\savearea # store clock
139 * The TSTMSK macro generates a test-under-mask instruction by
140 * calculating the memory offset for the specified mask value.
141 * Mask value can be any constant. The macro shifts the mask
142 * value to calculate the memory offset for the test-under-mask
145 .macro TSTMSK addr, mask, size=8, bytepos=0
146 .if (\bytepos < \size) && (\mask >> 8)
148 .error "Mask exceeds byte boundary"
150 TSTMSK \addr, "(\mask >> 8)", \size, "(\bytepos + 1)"
154 .error "Mask must not be zero"
156 off = \size - \bytepos - 1
160 .section .kprobes.text, "ax"
163 * This nop exists only in order to avoid that __switch_to starts at
164 * the beginning of the kprobes text section. In that case we would
165 * have several symbols at the same address. E.g. objdump would take
166 * an arbitrary symbol name when disassembling this code.
167 * With the added nop in between the __switch_to symbol is unique
173 * Scheduler resume function, called by switch_to
174 * gpr2 = (task_struct *) prev
175 * gpr3 = (task_struct *) next
180 stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
182 aghi %r1,__TASK_thread # thread_struct of prev task
183 lg %r5,__TASK_stack(%r3) # start of kernel stack of next
184 stg %r15,__THREAD_ksp(%r1) # store kernel stack of prev
186 aghi %r1,__TASK_thread # thread_struct of next task
188 aghi %r15,STACK_INIT # end of kernel stack of next
189 stg %r3,__LC_CURRENT # store task struct of next
190 stg %r15,__LC_KERNEL_STACK # store end of kernel stack
191 lg %r15,__THREAD_ksp(%r1) # load kernel stack of next
192 mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next
193 lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
194 TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
196 .insn s,0xb2800000,__LC_LPP # set program parameter
201 #if IS_ENABLED(CONFIG_KVM)
203 * sie64a calling convention:
204 * %r2 pointer to sie control block
205 * %r3 guest register save area
208 stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers
209 stg %r2,__SF_EMPTY(%r15) # save control block pointer
210 stg %r3,__SF_EMPTY+8(%r15) # save guest register save area
211 xc __SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # reason code = 0
212 TSTMSK __LC_CPU_FLAGS,_CIF_FPU # load guest fp/vx registers ?
213 jno .Lsie_load_guest_gprs
214 brasl %r14,load_fpu_regs # load guest fp/vx regs
215 .Lsie_load_guest_gprs:
216 lmg %r0,%r13,0(%r3) # load guest gprs 0-13
217 lg %r14,__LC_GMAP # get gmap pointer
220 lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce
222 lg %r14,__SF_EMPTY(%r15) # get control block pointer
223 oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now
224 tm __SIE_PROG20+3(%r14),3 # last exit...
226 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
227 jo .Lsie_skip # exit if fp/vx regs changed
230 ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE
231 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
233 # some program checks are suppressing. C code (e.g. do_protection_exception)
234 # will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other
235 # instructions between sie64a and .Lsie_done should not cause program
236 # interrupts. So lets use a nop (47 00 00 00) as a landing pad.
237 # See also .Lcleanup_sie
242 lg %r14,__SF_EMPTY+8(%r15) # load guest register save area
243 stmg %r0,%r13,0(%r14) # save guest gprs 0-13
244 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers
245 lg %r2,__SF_EMPTY+16(%r15) # return exit reason code
249 stg %r14,__SF_EMPTY+16(%r15) # set exit reason code
252 EX_TABLE(.Lrewind_pad,.Lsie_fault)
253 EX_TABLE(sie_exit,.Lsie_fault)
254 EXPORT_SYMBOL(sie64a)
255 EXPORT_SYMBOL(sie_exit)
259 * SVC interrupt handler routine. System calls are synchronous events and
260 * are executed with interrupts enabled.
264 stpt __LC_SYNC_ENTER_TIMER
266 stmg %r8,%r15,__LC_SAVE_AREA_SYNC
268 lghi %r13,__TASK_thread
269 lghi %r14,_PIF_SYSCALL
271 lg %r15,__LC_KERNEL_STACK
272 la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
274 UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
275 stmg %r0,%r7,__PT_R0(%r11)
276 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
277 mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW
278 mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC
279 stg %r14,__PT_FLAGS(%r11)
281 # load address of system call table
282 lg %r10,__THREAD_sysc_table(%r13,%r12)
283 llgh %r8,__PT_INT_CODE+2(%r11)
284 slag %r8,%r8,2 # shift and test for svc 0
286 # svc 0: system call number in %r1
287 llgfr %r1,%r1 # clear high word in r1
290 sth %r1,__PT_INT_CODE+2(%r11)
293 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
294 stg %r2,__PT_ORIG_GPR2(%r11)
295 stg %r7,STACK_FRAME_OVERHEAD(%r15)
296 lgf %r9,0(%r8,%r10) # get system call add.
297 TSTMSK __TI_flags(%r12),_TIF_TRACE
299 basr %r14,%r9 # call sys_xxxx
300 stg %r2,__PT_R2(%r11) # store return value
305 TSTMSK __PT_FLAGS(%r11),_PIF_WORK
307 TSTMSK __TI_flags(%r12),_TIF_WORK
308 jnz .Lsysc_work # check for work
309 TSTMSK __LC_CPU_FLAGS,_CIF_WORK
312 lg %r14,__LC_VDSO_PER_CPU
313 lmg %r0,%r10,__PT_R0(%r11)
314 mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
316 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
317 lmg %r11,%r15,__PT_R11(%r11)
318 lpswe __LC_RETURN_PSW
322 # One of the work bits is on. Find out which one.
325 TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING
326 jo .Lsysc_mcck_pending
327 TSTMSK __TI_flags(%r12),_TIF_NEED_RESCHED
329 #ifdef CONFIG_UPROBES
330 TSTMSK __TI_flags(%r12),_TIF_UPROBE
331 jo .Lsysc_uprobe_notify
333 TSTMSK __TI_flags(%r12),_TIF_GUARDED_STORAGE
334 jo .Lsysc_guarded_storage
335 TSTMSK __PT_FLAGS(%r11),_PIF_PER_TRAP
337 #ifdef CONFIG_LIVEPATCH
338 TSTMSK __TI_flags(%r12),_TIF_PATCH_PENDING
339 jo .Lsysc_patch_pending # handle live patching just before
340 # signals and possible syscall restart
342 TSTMSK __TI_flags(%r12),_TIF_SIGPENDING
344 TSTMSK __TI_flags(%r12),_TIF_NOTIFY_RESUME
345 jo .Lsysc_notify_resume
346 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
348 TSTMSK __LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
350 j .Lsysc_return # beware of critical section cleanup
353 # _TIF_NEED_RESCHED is set, call schedule
356 larl %r14,.Lsysc_return
360 # _CIF_MCCK_PENDING is set, call handler
363 larl %r14,.Lsysc_return
364 jg s390_handle_mcck # TIF bit will be cleared by handler
367 # _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
370 ni __LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
371 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
372 TSTMSK __LC_CPU_FLAGS,_CIF_ASCE_SECONDARY
374 larl %r14,.Lsysc_return
378 # CIF_FPU is set, restore floating-point controls and floating-point registers.
381 larl %r14,.Lsysc_return
385 # _TIF_SIGPENDING is set, call do_signal
388 lgr %r2,%r11 # pass pointer to pt_regs
390 TSTMSK __PT_FLAGS(%r11),_PIF_SYSCALL
393 lghi %r13,__TASK_thread
394 lmg %r2,%r7,__PT_R2(%r11) # load svc arguments
395 lghi %r1,0 # svc 0 returns -ENOSYS
399 # _TIF_NOTIFY_RESUME is set, call do_notify_resume
401 .Lsysc_notify_resume:
402 lgr %r2,%r11 # pass pointer to pt_regs
403 larl %r14,.Lsysc_return
407 # _TIF_UPROBE is set, call uprobe_notify_resume
409 #ifdef CONFIG_UPROBES
410 .Lsysc_uprobe_notify:
411 lgr %r2,%r11 # pass pointer to pt_regs
412 larl %r14,.Lsysc_return
413 jg uprobe_notify_resume
417 # _TIF_GUARDED_STORAGE is set, call guarded_storage_load
419 .Lsysc_guarded_storage:
420 lgr %r2,%r11 # pass pointer to pt_regs
421 larl %r14,.Lsysc_return
424 # _TIF_PATCH_PENDING is set, call klp_update_patch_state
426 #ifdef CONFIG_LIVEPATCH
427 .Lsysc_patch_pending:
428 lg %r2,__LC_CURRENT # pass pointer to task struct
429 larl %r14,.Lsysc_return
430 jg klp_update_patch_state
434 # _PIF_PER_TRAP is set, call do_per_trap
437 ni __PT_FLAGS+7(%r11),255-_PIF_PER_TRAP
438 lgr %r2,%r11 # pass pointer to pt_regs
439 larl %r14,.Lsysc_return
443 # call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
444 # and after the system call
447 lgr %r2,%r11 # pass pointer to pt_regs
449 llgh %r0,__PT_INT_CODE+2(%r11)
450 stg %r0,__PT_R2(%r11)
451 brasl %r14,do_syscall_trace_enter
458 lmg %r3,%r7,__PT_R3(%r11)
459 stg %r7,STACK_FRAME_OVERHEAD(%r15)
460 lg %r2,__PT_ORIG_GPR2(%r11)
461 basr %r14,%r9 # call sys_xxx
462 stg %r2,__PT_R2(%r11) # store return value
464 TSTMSK __TI_flags(%r12),_TIF_TRACE
466 lgr %r2,%r11 # pass pointer to pt_regs
467 larl %r14,.Lsysc_return
468 jg do_syscall_trace_exit
471 # a new process exits the kernel with ret_from_fork
474 la %r11,STACK_FRAME_OVERHEAD(%r15)
476 brasl %r14,schedule_tail
478 ssm __LC_SVC_NEW_PSW # reenable interrupts
479 tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ?
481 # it's a kernel thread
482 lmg %r9,%r10,__PT_R9(%r11) # load gprs
483 ENTRY(kernel_thread_starter)
489 * Program check handler routine
492 ENTRY(pgm_check_handler)
493 stpt __LC_SYNC_ENTER_TIMER
494 stmg %r8,%r15,__LC_SAVE_AREA_SYNC
495 lg %r10,__LC_LAST_BREAK
497 larl %r13,cleanup_critical
498 lmg %r8,%r9,__LC_PGM_OLD_PSW
499 tmhh %r8,0x0001 # test problem state bit
500 jnz 2f # -> fault in user space
501 #if IS_ENABLED(CONFIG_KVM)
502 # cleanup critical section for sie64a
504 slg %r14,BASED(.Lsie_critical_start)
505 clg %r14,BASED(.Lsie_critical_length)
507 brasl %r14,.Lcleanup_sie
509 0: tmhh %r8,0x4000 # PER bit set in old PSW ?
510 jnz 1f # -> enabled, can't be a double fault
511 tm __LC_PGM_ILC+3,0x80 # check for per exception
512 jnz .Lpgm_svcper # -> single stepped svc
513 1: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
514 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
516 2: UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
517 lg %r15,__LC_KERNEL_STACK
519 aghi %r14,__TASK_thread # pointer to thread_struct
520 lghi %r13,__LC_PGM_TDB
521 tm __LC_PGM_ILC+2,0x02 # check for transaction abort
523 mvc __THREAD_trap_tdb(256,%r14),0(%r13)
524 3: stg %r10,__THREAD_last_break(%r14)
525 4: la %r11,STACK_FRAME_OVERHEAD(%r15)
526 stmg %r0,%r7,__PT_R0(%r11)
527 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
528 stmg %r8,%r9,__PT_PSW(%r11)
529 mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC
530 mvc __PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE
531 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
532 stg %r10,__PT_ARGS(%r11)
533 tm __LC_PGM_ILC+3,0x80 # check for per exception
535 tmhh %r8,0x0001 # kernel per event ?
537 oi __PT_FLAGS+7(%r11),_PIF_PER_TRAP
538 mvc __THREAD_per_address(8,%r14),__LC_PER_ADDRESS
539 mvc __THREAD_per_cause(2,%r14),__LC_PER_CODE
540 mvc __THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
542 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
543 larl %r1,pgm_check_table
544 llgh %r10,__PT_INT_CODE+2(%r11)
548 lgf %r1,0(%r10,%r1) # load address of handler routine
549 lgr %r2,%r11 # pass pointer to pt_regs
550 basr %r14,%r1 # branch to interrupt-handler
553 tm __PT_PSW+1(%r11),0x01 # returning to user ?
555 TSTMSK __PT_FLAGS(%r11),_PIF_SYSCALL
560 # PER event in supervisor state, must be kprobes
564 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
565 lgr %r2,%r11 # pass pointer to pt_regs
566 brasl %r14,do_per_trap
570 # single stepped system call
573 mvc __LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
574 lghi %r13,__TASK_thread
576 stg %r14,__LC_RETURN_PSW+8
577 lghi %r14,_PIF_SYSCALL | _PIF_PER_TRAP
578 lpswe __LC_RETURN_PSW # branch to .Lsysc_per and enable irqs
581 * IO interrupt handler routine
583 ENTRY(io_int_handler)
585 stpt __LC_ASYNC_ENTER_TIMER
586 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
588 larl %r13,cleanup_critical
589 lmg %r8,%r9,__LC_IO_OLD_PSW
590 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
591 stmg %r0,%r7,__PT_R0(%r11)
592 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
593 stmg %r8,%r9,__PT_PSW(%r11)
594 mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
595 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
596 TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ
599 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
601 lgr %r2,%r11 # pass pointer to pt_regs
602 lghi %r3,IO_INTERRUPT
603 tm __PT_INT_CODE+8(%r11),0x80 # adapter interrupt ?
605 lghi %r3,THIN_INTERRUPT
608 TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPAR
612 mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
618 TSTMSK __TI_flags(%r12),_TIF_WORK
619 jnz .Lio_work # there is work to do (signals etc.)
620 TSTMSK __LC_CPU_FLAGS,_CIF_WORK
623 lg %r14,__LC_VDSO_PER_CPU
624 lmg %r0,%r10,__PT_R0(%r11)
625 mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
627 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
628 lmg %r11,%r15,__PT_R11(%r11)
629 lpswe __LC_RETURN_PSW
633 # There is work todo, find out in which context we have been interrupted:
634 # 1) if we return to user space we can do all _TIF_WORK work
635 # 2) if we return to kernel code and kvm is enabled check if we need to
636 # modify the psw to leave SIE
637 # 3) if we return to kernel code and preemptive scheduling is enabled check
638 # the preemption counter and if it is zero call preempt_schedule_irq
639 # Before any work can be done, a switch to the kernel stack is required.
642 tm __PT_PSW+1(%r11),0x01 # returning to user ?
643 jo .Lio_work_user # yes -> do resched & signal
644 #ifdef CONFIG_PREEMPT
645 # check for preemptive scheduling
646 icm %r0,15,__LC_PREEMPT_COUNT
647 jnz .Lio_restore # preemption is disabled
648 TSTMSK __TI_flags(%r12),_TIF_NEED_RESCHED
650 # switch to kernel stack
651 lg %r1,__PT_R15(%r11)
652 aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
653 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
654 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
655 la %r11,STACK_FRAME_OVERHEAD(%r1)
657 # TRACE_IRQS_ON already done at .Lio_return, call
658 # TRACE_IRQS_OFF to keep things symmetrical
660 brasl %r14,preempt_schedule_irq
667 # Need to do work before returning to userspace, switch to kernel stack
670 lg %r1,__LC_KERNEL_STACK
671 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
672 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
673 la %r11,STACK_FRAME_OVERHEAD(%r1)
677 # One of the work bits is on. Find out which one.
680 TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING
682 TSTMSK __TI_flags(%r12),_TIF_NEED_RESCHED
684 #ifdef CONFIG_LIVEPATCH
685 TSTMSK __TI_flags(%r12),_TIF_PATCH_PENDING
686 jo .Lio_patch_pending
688 TSTMSK __TI_flags(%r12),_TIF_SIGPENDING
690 TSTMSK __TI_flags(%r12),_TIF_NOTIFY_RESUME
691 jo .Lio_notify_resume
692 TSTMSK __TI_flags(%r12),_TIF_GUARDED_STORAGE
693 jo .Lio_guarded_storage
694 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
696 TSTMSK __LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
698 j .Lio_return # beware of critical section cleanup
701 # _CIF_MCCK_PENDING is set, call handler
704 # TRACE_IRQS_ON already done at .Lio_return
705 brasl %r14,s390_handle_mcck # TIF bit will be cleared by handler
710 # _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
713 ni __LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
714 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
715 TSTMSK __LC_CPU_FLAGS,_CIF_ASCE_SECONDARY
717 larl %r14,.Lio_return
721 # CIF_FPU is set, restore floating-point controls and floating-point registers.
724 larl %r14,.Lio_return
728 # _TIF_GUARDED_STORAGE is set, call guarded_storage_load
730 .Lio_guarded_storage:
731 # TRACE_IRQS_ON already done at .Lio_return
732 ssm __LC_SVC_NEW_PSW # reenable interrupts
733 lgr %r2,%r11 # pass pointer to pt_regs
734 brasl %r14,gs_load_bc_cb
735 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
740 # _TIF_NEED_RESCHED is set, call schedule
743 # TRACE_IRQS_ON already done at .Lio_return
744 ssm __LC_SVC_NEW_PSW # reenable interrupts
745 brasl %r14,schedule # call scheduler
746 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
751 # _TIF_PATCH_PENDING is set, call klp_update_patch_state
753 #ifdef CONFIG_LIVEPATCH
755 lg %r2,__LC_CURRENT # pass pointer to task struct
756 larl %r14,.Lio_return
757 jg klp_update_patch_state
761 # _TIF_SIGPENDING or is set, call do_signal
764 # TRACE_IRQS_ON already done at .Lio_return
765 ssm __LC_SVC_NEW_PSW # reenable interrupts
766 lgr %r2,%r11 # pass pointer to pt_regs
768 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
773 # _TIF_NOTIFY_RESUME or is set, call do_notify_resume
776 # TRACE_IRQS_ON already done at .Lio_return
777 ssm __LC_SVC_NEW_PSW # reenable interrupts
778 lgr %r2,%r11 # pass pointer to pt_regs
779 brasl %r14,do_notify_resume
780 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
785 * External interrupt handler routine
787 ENTRY(ext_int_handler)
789 stpt __LC_ASYNC_ENTER_TIMER
790 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
792 larl %r13,cleanup_critical
793 lmg %r8,%r9,__LC_EXT_OLD_PSW
794 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
795 stmg %r0,%r7,__PT_R0(%r11)
796 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
797 stmg %r8,%r9,__PT_PSW(%r11)
798 lghi %r1,__LC_EXT_PARAMS2
799 mvc __PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
800 mvc __PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
801 mvc __PT_INT_PARM_LONG(8,%r11),0(%r1)
802 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
803 TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ
806 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
807 lgr %r2,%r11 # pass pointer to pt_regs
808 lghi %r3,EXT_INTERRUPT
813 * Load idle PSW. The second "half" of this function is in .Lcleanup_idle.
816 stg %r3,__SF_EMPTY(%r15)
817 larl %r1,.Lpsw_idle_lpsw+4
818 stg %r1,__SF_EMPTY+8(%r15)
820 larl %r1,smp_cpu_mtid
824 .insn rsy,0xeb0000000017,%r1,5,__SF_EMPTY+16(%r15)
827 oi __LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT
828 STCK __CLOCK_IDLE_ENTER(%r2)
829 stpt __TIMER_IDLE_ENTER(%r2)
831 lpswe __SF_EMPTY(%r15)
836 * Store floating-point controls and floating-point or vector register
837 * depending whether the vector facility is available. A critical section
838 * cleanup assures that the registers are stored even if interrupted for
839 * some other work. The CIF_FPU flag is set to trigger a lazy restore
840 * of the register contents at return from io or a system call.
844 aghi %r2,__TASK_thread
845 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
847 stfpc __THREAD_FPU_fpc(%r2)
848 lg %r3,__THREAD_FPU_regs(%r2)
849 TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_VX
850 jz .Lsave_fpu_regs_fp # no -> store FP regs
851 VSTM %v0,%v15,0,%r3 # vstm 0,15,0(3)
852 VSTM %v16,%v31,256,%r3 # vstm 16,31,256(3)
853 j .Lsave_fpu_regs_done # -> set CIF_FPU flag
871 .Lsave_fpu_regs_done:
872 oi __LC_CPU_FLAGS+7,_CIF_FPU
875 #if IS_ENABLED(CONFIG_KVM)
876 EXPORT_SYMBOL(save_fpu_regs)
880 * Load floating-point controls and floating-point or vector registers.
881 * A critical section cleanup assures that the register contents are
882 * loaded even if interrupted for some other work.
884 * There are special calling conventions to fit into sysc and io return work:
885 * %r15: <kernel stack>
886 * The function requires:
891 aghi %r4,__TASK_thread
892 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
894 lfpc __THREAD_FPU_fpc(%r4)
895 TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_VX
896 lg %r4,__THREAD_FPU_regs(%r4) # %r4 <- reg save area
897 jz .Lload_fpu_regs_fp # -> no VX, load FP regs
899 VLM %v16,%v31,256,%r4
900 j .Lload_fpu_regs_done
918 .Lload_fpu_regs_done:
919 ni __LC_CPU_FLAGS+7,255-_CIF_FPU
926 * Machine check handler routines
928 ENTRY(mcck_int_handler)
930 la %r1,4095 # revalidate r1
931 spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # revalidate cpu timer
932 lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
934 larl %r13,cleanup_critical
935 lmg %r8,%r9,__LC_MCK_OLD_PSW
936 TSTMSK __LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE
937 jo .Lmcck_panic # yes -> rest of mcck code invalid
938 lghi %r14,__LC_CPU_TIMER_SAVE_AREA
939 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
940 TSTMSK __LC_MCCK_CODE,MCCK_CODE_CPU_TIMER_VALID
942 la %r14,__LC_SYNC_ENTER_TIMER
943 clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER
945 la %r14,__LC_ASYNC_ENTER_TIMER
946 0: clc 0(8,%r14),__LC_EXIT_TIMER
948 la %r14,__LC_EXIT_TIMER
949 1: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER
951 la %r14,__LC_LAST_UPDATE_TIMER
953 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
954 3: TSTMSK __LC_MCCK_CODE,(MCCK_CODE_PSW_MWP_VALID|MCCK_CODE_PSW_IA_VALID)
955 jno .Lmcck_panic # no -> skip cleanup critical
956 SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER
958 lghi %r14,__LC_GPREGS_SAVE_AREA+64
959 stmg %r0,%r7,__PT_R0(%r11)
960 mvc __PT_R8(64,%r11),0(%r14)
961 stmg %r8,%r9,__PT_PSW(%r11)
962 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
963 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
964 lgr %r2,%r11 # pass pointer to pt_regs
965 brasl %r14,s390_do_machine_check
966 tm __PT_PSW+1(%r11),0x01 # returning to user ?
968 lg %r1,__LC_KERNEL_STACK # switch to kernel stack
969 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
970 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
971 la %r11,STACK_FRAME_OVERHEAD(%r1)
973 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off
974 TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING
977 brasl %r14,s390_handle_mcck
980 lg %r14,__LC_VDSO_PER_CPU
981 lmg %r0,%r10,__PT_R0(%r11)
982 mvc __LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
983 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
986 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
987 0: lmg %r11,%r15,__PT_R11(%r11)
988 lpswe __LC_RETURN_MCCK_PSW
991 lg %r15,__LC_PANIC_STACK
992 la %r11,STACK_FRAME_OVERHEAD(%r15)
996 # PSW restart interrupt handler
998 ENTRY(restart_int_handler)
999 TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
1001 .insn s,0xb2800000,__LC_LPP
1002 0: stg %r15,__LC_SAVE_AREA_RESTART
1003 lg %r15,__LC_RESTART_STACK
1004 aghi %r15,-__PT_SIZE # create pt_regs on stack
1005 xc 0(__PT_SIZE,%r15),0(%r15)
1006 stmg %r0,%r14,__PT_R0(%r15)
1007 mvc __PT_R15(8,%r15),__LC_SAVE_AREA_RESTART
1008 mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw
1009 aghi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack
1010 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
1011 lg %r1,__LC_RESTART_FN # load fn, parm & source cpu
1012 lg %r2,__LC_RESTART_DATA
1013 lg %r3,__LC_RESTART_SOURCE
1014 ltgr %r3,%r3 # test source cpu address
1015 jm 1f # negative -> skip source stop
1016 0: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu
1017 brc 10,0b # wait for status stored
1018 1: basr %r14,%r1 # call function
1019 stap __SF_EMPTY(%r15) # store cpu address
1020 llgh %r3,__SF_EMPTY(%r15)
1021 2: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu
1025 .section .kprobes.text, "ax"
1027 #ifdef CONFIG_CHECK_STACK
1029 * The synchronous or the asynchronous stack overflowed. We are dead.
1030 * No need to properly save the registers, we are going to panic anyway.
1031 * Setup a pt_regs so that show_trace can provide a good call trace.
1034 lg %r15,__LC_PANIC_STACK # change to panic stack
1035 la %r11,STACK_FRAME_OVERHEAD(%r15)
1036 stmg %r0,%r7,__PT_R0(%r11)
1037 stmg %r8,%r9,__PT_PSW(%r11)
1038 mvc __PT_R8(64,%r11),0(%r14)
1039 stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
1040 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
1041 lgr %r2,%r11 # pass pointer to pt_regs
1042 jg kernel_stack_overflow
1046 #if IS_ENABLED(CONFIG_KVM)
1047 clg %r9,BASED(.Lcleanup_table_sie) # .Lsie_gmap
1049 clg %r9,BASED(.Lcleanup_table_sie+8)# .Lsie_done
1052 clg %r9,BASED(.Lcleanup_table) # system_call
1054 clg %r9,BASED(.Lcleanup_table+8) # .Lsysc_do_svc
1055 jl .Lcleanup_system_call
1056 clg %r9,BASED(.Lcleanup_table+16) # .Lsysc_tif
1058 clg %r9,BASED(.Lcleanup_table+24) # .Lsysc_restore
1059 jl .Lcleanup_sysc_tif
1060 clg %r9,BASED(.Lcleanup_table+32) # .Lsysc_done
1061 jl .Lcleanup_sysc_restore
1062 clg %r9,BASED(.Lcleanup_table+40) # .Lio_tif
1064 clg %r9,BASED(.Lcleanup_table+48) # .Lio_restore
1066 clg %r9,BASED(.Lcleanup_table+56) # .Lio_done
1067 jl .Lcleanup_io_restore
1068 clg %r9,BASED(.Lcleanup_table+64) # psw_idle
1070 clg %r9,BASED(.Lcleanup_table+72) # .Lpsw_idle_end
1072 clg %r9,BASED(.Lcleanup_table+80) # save_fpu_regs
1074 clg %r9,BASED(.Lcleanup_table+88) # .Lsave_fpu_regs_end
1075 jl .Lcleanup_save_fpu_regs
1076 clg %r9,BASED(.Lcleanup_table+96) # load_fpu_regs
1078 clg %r9,BASED(.Lcleanup_table+104) # .Lload_fpu_regs_end
1079 jl .Lcleanup_load_fpu_regs
1087 .quad .Lsysc_restore
1093 .quad .Lpsw_idle_end
1095 .quad .Lsave_fpu_regs_end
1097 .quad .Lload_fpu_regs_end
1099 #if IS_ENABLED(CONFIG_KVM)
1100 .Lcleanup_table_sie:
1105 lg %r9,__SF_EMPTY(%r15) # get control block pointer
1106 ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE
1107 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
1108 larl %r9,sie_exit # skip forward to sie_exit
1112 .Lcleanup_system_call:
1113 # check if stpt has been executed
1114 clg %r9,BASED(.Lcleanup_system_call_insn)
1116 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
1117 cghi %r11,__LC_SAVE_AREA_ASYNC
1119 mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
1120 0: # check if stmg has been executed
1121 clg %r9,BASED(.Lcleanup_system_call_insn+8)
1123 mvc __LC_SAVE_AREA_SYNC(64),0(%r11)
1124 0: # check if base register setup + TIF bit load has been done
1125 clg %r9,BASED(.Lcleanup_system_call_insn+16)
1127 # set up saved register r12 task struct pointer
1129 # set up saved register r13 __TASK_thread offset
1130 mvc 40(8,%r11),BASED(.Lcleanup_system_call_const)
1131 0: # check if the user time update has been done
1132 clg %r9,BASED(.Lcleanup_system_call_insn+24)
1134 lg %r15,__LC_EXIT_TIMER
1135 slg %r15,__LC_SYNC_ENTER_TIMER
1136 alg %r15,__LC_USER_TIMER
1137 stg %r15,__LC_USER_TIMER
1138 0: # check if the system time update has been done
1139 clg %r9,BASED(.Lcleanup_system_call_insn+32)
1141 lg %r15,__LC_LAST_UPDATE_TIMER
1142 slg %r15,__LC_EXIT_TIMER
1143 alg %r15,__LC_SYSTEM_TIMER
1144 stg %r15,__LC_SYSTEM_TIMER
1145 0: # update accounting time stamp
1146 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
1147 # set up saved register r11
1148 lg %r15,__LC_KERNEL_STACK
1149 la %r9,STACK_FRAME_OVERHEAD(%r15)
1150 stg %r9,24(%r11) # r11 pt_regs pointer
1152 mvc __PT_R8(64,%r9),__LC_SAVE_AREA_SYNC
1153 stmg %r0,%r7,__PT_R0(%r9)
1154 mvc __PT_PSW(16,%r9),__LC_SVC_OLD_PSW
1155 mvc __PT_INT_CODE(4,%r9),__LC_SVC_ILC
1156 xc __PT_FLAGS(8,%r9),__PT_FLAGS(%r9)
1157 mvi __PT_FLAGS+7(%r9),_PIF_SYSCALL
1158 # setup saved register r15
1159 stg %r15,56(%r11) # r15 stack pointer
1160 # set new psw address and exit
1161 larl %r9,.Lsysc_do_svc
1163 .Lcleanup_system_call_insn:
1167 .quad .Lsysc_vtime+36
1168 .quad .Lsysc_vtime+42
1169 .Lcleanup_system_call_const:
1176 .Lcleanup_sysc_restore:
1177 clg %r9,BASED(.Lcleanup_sysc_restore_insn)
1179 lg %r9,24(%r11) # get saved pointer to pt_regs
1180 mvc __LC_RETURN_PSW(16),__PT_PSW(%r9)
1181 mvc 0(64,%r11),__PT_R8(%r9)
1182 lmg %r0,%r7,__PT_R0(%r9)
1183 0: lmg %r8,%r9,__LC_RETURN_PSW
1185 .Lcleanup_sysc_restore_insn:
1186 .quad .Lsysc_done - 4
1192 .Lcleanup_io_restore:
1193 clg %r9,BASED(.Lcleanup_io_restore_insn)
1195 lg %r9,24(%r11) # get saved r11 pointer to pt_regs
1196 mvc __LC_RETURN_PSW(16),__PT_PSW(%r9)
1197 mvc 0(64,%r11),__PT_R8(%r9)
1198 lmg %r0,%r7,__PT_R0(%r9)
1199 0: lmg %r8,%r9,__LC_RETURN_PSW
1201 .Lcleanup_io_restore_insn:
1205 ni __LC_CPU_FLAGS+7,255-_CIF_ENABLED_WAIT
1206 # copy interrupt clock & cpu timer
1207 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK
1208 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER
1209 cghi %r11,__LC_SAVE_AREA_ASYNC
1211 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK
1212 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER
1213 0: # check if stck & stpt have been executed
1214 clg %r9,BASED(.Lcleanup_idle_insn)
1216 mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
1217 mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r2)
1218 1: # calculate idle cycles
1220 clg %r9,BASED(.Lcleanup_idle_insn)
1222 larl %r1,smp_cpu_mtid
1226 .insn rsy,0xeb0000000017,%r1,5,__SF_EMPTY+80(%r15)
1228 ag %r3,__LC_PERCPU_OFFSET
1229 la %r4,__SF_EMPTY+16(%r15)
1238 3: # account system time going idle
1239 lg %r9,__LC_STEAL_TIMER
1240 alg %r9,__CLOCK_IDLE_ENTER(%r2)
1241 slg %r9,__LC_LAST_UPDATE_CLOCK
1242 stg %r9,__LC_STEAL_TIMER
1243 mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
1244 lg %r9,__LC_SYSTEM_TIMER
1245 alg %r9,__LC_LAST_UPDATE_TIMER
1246 slg %r9,__TIMER_IDLE_ENTER(%r2)
1247 stg %r9,__LC_SYSTEM_TIMER
1248 mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
1249 # prepare return psw
1250 nihh %r8,0xfcfd # clear irq & wait state bits
1251 lg %r9,48(%r11) # return from psw_idle
1253 .Lcleanup_idle_insn:
1254 .quad .Lpsw_idle_lpsw
1256 .Lcleanup_save_fpu_regs:
1257 larl %r9,save_fpu_regs
1260 .Lcleanup_load_fpu_regs:
1261 larl %r9,load_fpu_regs
1269 .quad .L__critical_start
1271 .quad .L__critical_end - .L__critical_start
1272 #if IS_ENABLED(CONFIG_KVM)
1273 .Lsie_critical_start:
1275 .Lsie_critical_length:
1276 .quad .Lsie_done - .Lsie_gmap
1279 .section .rodata, "a"
1280 #define SYSCALL(esame,emu) .long esame
1281 .globl sys_call_table
1283 #include "syscalls.S"
1286 #ifdef CONFIG_COMPAT
1288 #define SYSCALL(esame,emu) .long emu
1289 .globl sys_call_table_emu
1291 #include "syscalls.S"