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1/*
2 * S390 low-level entry points.
3 *
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>
9 */
10
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>
20#include <asm/page.h>
21#include <asm/sigp.h>
22#include <asm/irq.h>
23
24__PT_R0 = __PT_GPRS
25__PT_R1 = __PT_GPRS + 8
26__PT_R2 = __PT_GPRS + 16
27__PT_R3 = __PT_GPRS + 24
28__PT_R4 = __PT_GPRS + 32
29__PT_R5 = __PT_GPRS + 40
30__PT_R6 = __PT_GPRS + 48
31__PT_R7 = __PT_GPRS + 56
32__PT_R8 = __PT_GPRS + 64
33__PT_R9 = __PT_GPRS + 72
34__PT_R10 = __PT_GPRS + 80
35__PT_R11 = __PT_GPRS + 88
36__PT_R12 = __PT_GPRS + 96
37__PT_R13 = __PT_GPRS + 104
38__PT_R14 = __PT_GPRS + 112
39__PT_R15 = __PT_GPRS + 120
40
41STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
42STACK_SIZE = 1 << STACK_SHIFT
43STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
44
45_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
46 _TIF_MCCK_PENDING | _TIF_PER_TRAP | _TIF_ASCE)
47_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
48 _TIF_MCCK_PENDING | _TIF_ASCE)
49_TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
50 _TIF_SYSCALL_TRACEPOINT)
51_TIF_TRANSFER = (_TIF_MCCK_PENDING | _TIF_TLB_WAIT)
52
53#define BASED(name) name-system_call(%r13)
54
55 .macro TRACE_IRQS_ON
56#ifdef CONFIG_TRACE_IRQFLAGS
57 basr %r2,%r0
58 brasl %r14,trace_hardirqs_on_caller
59#endif
60 .endm
61
62 .macro TRACE_IRQS_OFF
63#ifdef CONFIG_TRACE_IRQFLAGS
64 basr %r2,%r0
65 brasl %r14,trace_hardirqs_off_caller
66#endif
67 .endm
68
69 .macro LOCKDEP_SYS_EXIT
70#ifdef CONFIG_LOCKDEP
71 tm __PT_PSW+1(%r11),0x01 # returning to user ?
72 jz .+10
73 brasl %r14,lockdep_sys_exit
74#endif
75 .endm
76
77 .macro LPP newpp
78#if IS_ENABLED(CONFIG_KVM)
79 tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_LPP
80 jz .+8
81 .insn s,0xb2800000,\newpp
82#endif
83 .endm
84
85 .macro HANDLE_SIE_INTERCEPT scratch,reason
86#if IS_ENABLED(CONFIG_KVM)
87 tmhh %r8,0x0001 # interrupting from user ?
88 jnz .+62
89 lgr \scratch,%r9
90 slg \scratch,BASED(.Lsie_critical)
91 clg \scratch,BASED(.Lsie_critical_length)
92 .if \reason==1
93 # Some program interrupts are suppressing (e.g. protection).
94 # We must also check the instruction after SIE in that case.
95 # do_protection_exception will rewind to rewind_pad
96 jh .+42
97 .else
98 jhe .+42
99 .endif
100 lg %r14,__SF_EMPTY(%r15) # get control block pointer
101 LPP __SF_EMPTY+16(%r15) # set host id
102 ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE
103 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
104 larl %r9,sie_exit # skip forward to sie_exit
105 mvi __SF_EMPTY+31(%r15),\reason # set exit reason
106#endif
107 .endm
108
109 .macro CHECK_STACK stacksize,savearea
110#ifdef CONFIG_CHECK_STACK
111 tml %r15,\stacksize - CONFIG_STACK_GUARD
112 lghi %r14,\savearea
113 jz stack_overflow
114#endif
115 .endm
116
117 .macro SWITCH_ASYNC savearea,stack,shift
118 tmhh %r8,0x0001 # interrupting from user ?
119 jnz 1f
120 lgr %r14,%r9
121 slg %r14,BASED(.Lcritical_start)
122 clg %r14,BASED(.Lcritical_length)
123 jhe 0f
124 lghi %r11,\savearea # inside critical section, do cleanup
125 brasl %r14,cleanup_critical
126 tmhh %r8,0x0001 # retest problem state after cleanup
127 jnz 1f
1280: lg %r14,\stack # are we already on the target stack?
129 slgr %r14,%r15
130 srag %r14,%r14,\shift
131 jnz 1f
132 CHECK_STACK 1<<\shift,\savearea
133 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
134 j 2f
1351: lg %r15,\stack # load target stack
1362: la %r11,STACK_FRAME_OVERHEAD(%r15)
137 .endm
138
139 .macro UPDATE_VTIME scratch,enter_timer
140 lg \scratch,__LC_EXIT_TIMER
141 slg \scratch,\enter_timer
142 alg \scratch,__LC_USER_TIMER
143 stg \scratch,__LC_USER_TIMER
144 lg \scratch,__LC_LAST_UPDATE_TIMER
145 slg \scratch,__LC_EXIT_TIMER
146 alg \scratch,__LC_SYSTEM_TIMER
147 stg \scratch,__LC_SYSTEM_TIMER
148 mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer
149 .endm
150
151 .macro LAST_BREAK scratch
152 srag \scratch,%r10,23
153 jz .+10
154 stg %r10,__TI_last_break(%r12)
155 .endm
156
157 .macro REENABLE_IRQS
158 stg %r8,__LC_RETURN_PSW
159 ni __LC_RETURN_PSW,0xbf
160 ssm __LC_RETURN_PSW
161 .endm
162
163 .macro STCK savearea
164#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
165 .insn s,0xb27c0000,\savearea # store clock fast
166#else
167 .insn s,0xb2050000,\savearea # store clock
168#endif
169 .endm
170
171 .section .kprobes.text, "ax"
172
173/*
174 * Scheduler resume function, called by switch_to
175 * gpr2 = (task_struct *) prev
176 * gpr3 = (task_struct *) next
177 * Returns:
178 * gpr2 = prev
179 */
180ENTRY(__switch_to)
181 stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
182 stg %r15,__THREAD_ksp(%r2) # store kernel stack of prev
183 lg %r4,__THREAD_info(%r2) # get thread_info of prev
184 lg %r5,__THREAD_info(%r3) # get thread_info of next
185 lgr %r15,%r5
186 aghi %r15,STACK_INIT # end of kernel stack of next
187 stg %r3,__LC_CURRENT # store task struct of next
188 stg %r5,__LC_THREAD_INFO # store thread info of next
189 stg %r15,__LC_KERNEL_STACK # store end of kernel stack
190 lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
191 mvc __LC_CURRENT_PID+4(4,%r0),__TASK_pid(%r3) # store pid of next
192 lg %r15,__THREAD_ksp(%r3) # load kernel stack of next
193 llill %r6,_TIF_TRANSFER # transfer TIF bits
194 ng %r6,__TI_flags(%r4) # isolate TIF bits
195 jz 0f
196 og %r6,__TI_flags(%r5) # set TIF bits of next
197 stg %r6,__TI_flags(%r5)
198 ni __TI_flags+7(%r4),255-_TIF_TRANSFER # clear TIF bits of prev
1990: lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
200 br %r14
201
202__critical_start:
203/*
204 * SVC interrupt handler routine. System calls are synchronous events and
205 * are executed with interrupts enabled.
206 */
207
208ENTRY(system_call)
209 stpt __LC_SYNC_ENTER_TIMER
210sysc_stmg:
211 stmg %r8,%r15,__LC_SAVE_AREA_SYNC
212 lg %r10,__LC_LAST_BREAK
213 lg %r12,__LC_THREAD_INFO
214sysc_per:
215 lg %r15,__LC_KERNEL_STACK
216 la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
217sysc_vtime:
218 UPDATE_VTIME %r13,__LC_SYNC_ENTER_TIMER
219 LAST_BREAK %r13
220 stmg %r0,%r7,__PT_R0(%r11)
221 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
222 mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW
223 mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC
224sysc_do_svc:
225 oi __TI_flags+7(%r12),_TIF_SYSCALL
226 lg %r10,__TI_sysc_table(%r12) # address of system call table
227 llgh %r8,__PT_INT_CODE+2(%r11)
228 slag %r8,%r8,2 # shift and test for svc 0
229 jnz sysc_nr_ok
230 # svc 0: system call number in %r1
231 llgfr %r1,%r1 # clear high word in r1
232 cghi %r1,NR_syscalls
233 jnl sysc_nr_ok
234 sth %r1,__PT_INT_CODE+2(%r11)
235 slag %r8,%r1,2
236sysc_nr_ok:
237 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
238 stg %r2,__PT_ORIG_GPR2(%r11)
239 stg %r7,STACK_FRAME_OVERHEAD(%r15)
240 lgf %r9,0(%r8,%r10) # get system call add.
241 tm __TI_flags+6(%r12),_TIF_TRACE >> 8
242 jnz sysc_tracesys
243 basr %r14,%r9 # call sys_xxxx
244 stg %r2,__PT_R2(%r11) # store return value
245
246sysc_return:
247 LOCKDEP_SYS_EXIT
248sysc_tif:
249 tm __PT_PSW+1(%r11),0x01 # returning to user ?
250 jno sysc_restore
251 tm __TI_flags+7(%r12),_TIF_WORK_SVC
252 jnz sysc_work # check for work
253 ni __TI_flags+7(%r12),255-_TIF_SYSCALL
254sysc_restore:
255 lg %r14,__LC_VDSO_PER_CPU
256 lmg %r0,%r10,__PT_R0(%r11)
257 mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
258 stpt __LC_EXIT_TIMER
259 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
260 lmg %r11,%r15,__PT_R11(%r11)
261 lpswe __LC_RETURN_PSW
262sysc_done:
263
264#
265# One of the work bits is on. Find out which one.
266#
267sysc_work:
268 tm __TI_flags+7(%r12),_TIF_MCCK_PENDING
269 jo sysc_mcck_pending
270 tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
271 jo sysc_reschedule
272 tm __TI_flags+7(%r12),_TIF_PER_TRAP
273 jo sysc_singlestep
274 tm __TI_flags+7(%r12),_TIF_SIGPENDING
275 jo sysc_sigpending
276 tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
277 jo sysc_notify_resume
278 tm __TI_flags+7(%r12),_TIF_ASCE
279 jo sysc_uaccess
280 j sysc_return # beware of critical section cleanup
281
282#
283# _TIF_NEED_RESCHED is set, call schedule
284#
285sysc_reschedule:
286 larl %r14,sysc_return
287 jg schedule
288
289#
290# _TIF_MCCK_PENDING is set, call handler
291#
292sysc_mcck_pending:
293 larl %r14,sysc_return
294 jg s390_handle_mcck # TIF bit will be cleared by handler
295
296#
297# _TIF_ASCE is set, load user space asce
298#
299sysc_uaccess:
300 ni __TI_flags+7(%r12),255-_TIF_ASCE
301 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
302 j sysc_return
303
304#
305# _TIF_SIGPENDING is set, call do_signal
306#
307sysc_sigpending:
308 lgr %r2,%r11 # pass pointer to pt_regs
309 brasl %r14,do_signal
310 tm __TI_flags+7(%r12),_TIF_SYSCALL
311 jno sysc_return
312 lmg %r2,%r7,__PT_R2(%r11) # load svc arguments
313 lg %r10,__TI_sysc_table(%r12) # address of system call table
314 lghi %r8,0 # svc 0 returns -ENOSYS
315 llgh %r1,__PT_INT_CODE+2(%r11) # load new svc number
316 cghi %r1,NR_syscalls
317 jnl sysc_nr_ok # invalid svc number -> do svc 0
318 slag %r8,%r1,2
319 j sysc_nr_ok # restart svc
320
321#
322# _TIF_NOTIFY_RESUME is set, call do_notify_resume
323#
324sysc_notify_resume:
325 lgr %r2,%r11 # pass pointer to pt_regs
326 larl %r14,sysc_return
327 jg do_notify_resume
328
329#
330# _TIF_PER_TRAP is set, call do_per_trap
331#
332sysc_singlestep:
333 ni __TI_flags+7(%r12),255-_TIF_PER_TRAP
334 lgr %r2,%r11 # pass pointer to pt_regs
335 larl %r14,sysc_return
336 jg do_per_trap
337
338#
339# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
340# and after the system call
341#
342sysc_tracesys:
343 lgr %r2,%r11 # pass pointer to pt_regs
344 la %r3,0
345 llgh %r0,__PT_INT_CODE+2(%r11)
346 stg %r0,__PT_R2(%r11)
347 brasl %r14,do_syscall_trace_enter
348 lghi %r0,NR_syscalls
349 clgr %r0,%r2
350 jnh sysc_tracenogo
351 sllg %r8,%r2,2
352 lgf %r9,0(%r8,%r10)
353sysc_tracego:
354 lmg %r3,%r7,__PT_R3(%r11)
355 stg %r7,STACK_FRAME_OVERHEAD(%r15)
356 lg %r2,__PT_ORIG_GPR2(%r11)
357 basr %r14,%r9 # call sys_xxx
358 stg %r2,__PT_R2(%r11) # store return value
359sysc_tracenogo:
360 tm __TI_flags+6(%r12),_TIF_TRACE >> 8
361 jz sysc_return
362 lgr %r2,%r11 # pass pointer to pt_regs
363 larl %r14,sysc_return
364 jg do_syscall_trace_exit
365
366#
367# a new process exits the kernel with ret_from_fork
368#
369ENTRY(ret_from_fork)
370 la %r11,STACK_FRAME_OVERHEAD(%r15)
371 lg %r12,__LC_THREAD_INFO
372 brasl %r14,schedule_tail
373 TRACE_IRQS_ON
374 ssm __LC_SVC_NEW_PSW # reenable interrupts
375 tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ?
376 jne sysc_tracenogo
377 # it's a kernel thread
378 lmg %r9,%r10,__PT_R9(%r11) # load gprs
379ENTRY(kernel_thread_starter)
380 la %r2,0(%r10)
381 basr %r14,%r9
382 j sysc_tracenogo
383
384/*
385 * Program check handler routine
386 */
387
388ENTRY(pgm_check_handler)
389 stpt __LC_SYNC_ENTER_TIMER
390 stmg %r8,%r15,__LC_SAVE_AREA_SYNC
391 lg %r10,__LC_LAST_BREAK
392 lg %r12,__LC_THREAD_INFO
393 larl %r13,system_call
394 lmg %r8,%r9,__LC_PGM_OLD_PSW
395 HANDLE_SIE_INTERCEPT %r14,1
396 tmhh %r8,0x0001 # test problem state bit
397 jnz 1f # -> fault in user space
398 tmhh %r8,0x4000 # PER bit set in old PSW ?
399 jnz 0f # -> enabled, can't be a double fault
400 tm __LC_PGM_ILC+3,0x80 # check for per exception
401 jnz pgm_svcper # -> single stepped svc
4020: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
403 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
404 j 2f
4051: UPDATE_VTIME %r14,__LC_SYNC_ENTER_TIMER
406 LAST_BREAK %r14
407 lg %r15,__LC_KERNEL_STACK
408 lg %r14,__TI_task(%r12)
409 lghi %r13,__LC_PGM_TDB
410 tm __LC_PGM_ILC+2,0x02 # check for transaction abort
411 jz 2f
412 mvc __THREAD_trap_tdb(256,%r14),0(%r13)
4132: la %r11,STACK_FRAME_OVERHEAD(%r15)
414 stmg %r0,%r7,__PT_R0(%r11)
415 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
416 stmg %r8,%r9,__PT_PSW(%r11)
417 mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC
418 mvc __PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE
419 stg %r10,__PT_ARGS(%r11)
420 tm __LC_PGM_ILC+3,0x80 # check for per exception
421 jz 0f
422 tmhh %r8,0x0001 # kernel per event ?
423 jz pgm_kprobe
424 oi __TI_flags+7(%r12),_TIF_PER_TRAP
425 mvc __THREAD_per_address(8,%r14),__LC_PER_ADDRESS
426 mvc __THREAD_per_cause(2,%r14),__LC_PER_CAUSE
427 mvc __THREAD_per_paid(1,%r14),__LC_PER_PAID
4280: REENABLE_IRQS
429 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
430 larl %r1,pgm_check_table
431 llgh %r10,__PT_INT_CODE+2(%r11)
432 nill %r10,0x007f
433 sll %r10,2
434 je sysc_return
435 lgf %r1,0(%r10,%r1) # load address of handler routine
436 lgr %r2,%r11 # pass pointer to pt_regs
437 basr %r14,%r1 # branch to interrupt-handler
438 j sysc_return
439
440#
441# PER event in supervisor state, must be kprobes
442#
443pgm_kprobe:
444 REENABLE_IRQS
445 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
446 lgr %r2,%r11 # pass pointer to pt_regs
447 brasl %r14,do_per_trap
448 j sysc_return
449
450#
451# single stepped system call
452#
453pgm_svcper:
454 oi __TI_flags+7(%r12),_TIF_PER_TRAP
455 mvc __LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
456 larl %r14,sysc_per
457 stg %r14,__LC_RETURN_PSW+8
458 lpswe __LC_RETURN_PSW # branch to sysc_per and enable irqs
459
460/*
461 * IO interrupt handler routine
462 */
463ENTRY(io_int_handler)
464 STCK __LC_INT_CLOCK
465 stpt __LC_ASYNC_ENTER_TIMER
466 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
467 lg %r10,__LC_LAST_BREAK
468 lg %r12,__LC_THREAD_INFO
469 larl %r13,system_call
470 lmg %r8,%r9,__LC_IO_OLD_PSW
471 HANDLE_SIE_INTERCEPT %r14,2
472 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
473 tmhh %r8,0x0001 # interrupting from user?
474 jz io_skip
475 UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER
476 LAST_BREAK %r14
477io_skip:
478 stmg %r0,%r7,__PT_R0(%r11)
479 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
480 stmg %r8,%r9,__PT_PSW(%r11)
481 mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
482 TRACE_IRQS_OFF
483 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
484io_loop:
485 lgr %r2,%r11 # pass pointer to pt_regs
486 lghi %r3,IO_INTERRUPT
487 tm __PT_INT_CODE+8(%r11),0x80 # adapter interrupt ?
488 jz io_call
489 lghi %r3,THIN_INTERRUPT
490io_call:
491 brasl %r14,do_IRQ
492 tm __LC_MACHINE_FLAGS+6,0x10 # MACHINE_FLAG_LPAR
493 jz io_return
494 tpi 0
495 jz io_return
496 mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
497 j io_loop
498io_return:
499 LOCKDEP_SYS_EXIT
500 TRACE_IRQS_ON
501io_tif:
502 tm __TI_flags+7(%r12),_TIF_WORK_INT
503 jnz io_work # there is work to do (signals etc.)
504io_restore:
505 lg %r14,__LC_VDSO_PER_CPU
506 lmg %r0,%r10,__PT_R0(%r11)
507 mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
508 stpt __LC_EXIT_TIMER
509 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
510 lmg %r11,%r15,__PT_R11(%r11)
511 lpswe __LC_RETURN_PSW
512io_done:
513
514#
515# There is work todo, find out in which context we have been interrupted:
516# 1) if we return to user space we can do all _TIF_WORK_INT work
517# 2) if we return to kernel code and kvm is enabled check if we need to
518# modify the psw to leave SIE
519# 3) if we return to kernel code and preemptive scheduling is enabled check
520# the preemption counter and if it is zero call preempt_schedule_irq
521# Before any work can be done, a switch to the kernel stack is required.
522#
523io_work:
524 tm __PT_PSW+1(%r11),0x01 # returning to user ?
525 jo io_work_user # yes -> do resched & signal
526#ifdef CONFIG_PREEMPT
527 # check for preemptive scheduling
528 icm %r0,15,__TI_precount(%r12)
529 jnz io_restore # preemption is disabled
530 tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
531 jno io_restore
532 # switch to kernel stack
533 lg %r1,__PT_R15(%r11)
534 aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
535 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
536 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
537 la %r11,STACK_FRAME_OVERHEAD(%r1)
538 lgr %r15,%r1
539 # TRACE_IRQS_ON already done at io_return, call
540 # TRACE_IRQS_OFF to keep things symmetrical
541 TRACE_IRQS_OFF
542 brasl %r14,preempt_schedule_irq
543 j io_return
544#else
545 j io_restore
546#endif
547
548#
549# Need to do work before returning to userspace, switch to kernel stack
550#
551io_work_user:
552 lg %r1,__LC_KERNEL_STACK
553 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
554 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
555 la %r11,STACK_FRAME_OVERHEAD(%r1)
556 lgr %r15,%r1
557
558#
559# One of the work bits is on. Find out which one.
560# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED
561# and _TIF_MCCK_PENDING
562#
563io_work_tif:
564 tm __TI_flags+7(%r12),_TIF_MCCK_PENDING
565 jo io_mcck_pending
566 tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
567 jo io_reschedule
568 tm __TI_flags+7(%r12),_TIF_SIGPENDING
569 jo io_sigpending
570 tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
571 jo io_notify_resume
572 tm __TI_flags+7(%r12),_TIF_ASCE
573 jo io_uaccess
574 j io_return # beware of critical section cleanup
575
576#
577# _TIF_MCCK_PENDING is set, call handler
578#
579io_mcck_pending:
580 # TRACE_IRQS_ON already done at io_return
581 brasl %r14,s390_handle_mcck # TIF bit will be cleared by handler
582 TRACE_IRQS_OFF
583 j io_return
584
585#
586# _TIF_ASCE is set, load user space asce
587#
588io_uaccess:
589 ni __TI_flags+7(%r12),255-_TIF_ASCE
590 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
591 j io_return
592
593#
594# _TIF_NEED_RESCHED is set, call schedule
595#
596io_reschedule:
597 # TRACE_IRQS_ON already done at io_return
598 ssm __LC_SVC_NEW_PSW # reenable interrupts
599 brasl %r14,schedule # call scheduler
600 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
601 TRACE_IRQS_OFF
602 j io_return
603
604#
605# _TIF_SIGPENDING or is set, call do_signal
606#
607io_sigpending:
608 # TRACE_IRQS_ON already done at io_return
609 ssm __LC_SVC_NEW_PSW # reenable interrupts
610 lgr %r2,%r11 # pass pointer to pt_regs
611 brasl %r14,do_signal
612 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
613 TRACE_IRQS_OFF
614 j io_return
615
616#
617# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
618#
619io_notify_resume:
620 # TRACE_IRQS_ON already done at io_return
621 ssm __LC_SVC_NEW_PSW # reenable interrupts
622 lgr %r2,%r11 # pass pointer to pt_regs
623 brasl %r14,do_notify_resume
624 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
625 TRACE_IRQS_OFF
626 j io_return
627
628/*
629 * External interrupt handler routine
630 */
631ENTRY(ext_int_handler)
632 STCK __LC_INT_CLOCK
633 stpt __LC_ASYNC_ENTER_TIMER
634 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
635 lg %r10,__LC_LAST_BREAK
636 lg %r12,__LC_THREAD_INFO
637 larl %r13,system_call
638 lmg %r8,%r9,__LC_EXT_OLD_PSW
639 HANDLE_SIE_INTERCEPT %r14,3
640 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
641 tmhh %r8,0x0001 # interrupting from user ?
642 jz ext_skip
643 UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER
644 LAST_BREAK %r14
645ext_skip:
646 stmg %r0,%r7,__PT_R0(%r11)
647 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
648 stmg %r8,%r9,__PT_PSW(%r11)
649 lghi %r1,__LC_EXT_PARAMS2
650 mvc __PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
651 mvc __PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
652 mvc __PT_INT_PARM_LONG(8,%r11),0(%r1)
653 TRACE_IRQS_OFF
654 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
655 lgr %r2,%r11 # pass pointer to pt_regs
656 lghi %r3,EXT_INTERRUPT
657 brasl %r14,do_IRQ
658 j io_return
659
660/*
661 * Load idle PSW. The second "half" of this function is in cleanup_idle.
662 */
663ENTRY(psw_idle)
664 stg %r3,__SF_EMPTY(%r15)
665 larl %r1,psw_idle_lpsw+4
666 stg %r1,__SF_EMPTY+8(%r15)
667 STCK __CLOCK_IDLE_ENTER(%r2)
668 stpt __TIMER_IDLE_ENTER(%r2)
669psw_idle_lpsw:
670 lpswe __SF_EMPTY(%r15)
671 br %r14
672psw_idle_end:
673
674__critical_end:
675
676/*
677 * Machine check handler routines
678 */
679ENTRY(mcck_int_handler)
680 STCK __LC_MCCK_CLOCK
681 la %r1,4095 # revalidate r1
682 spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # revalidate cpu timer
683 lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
684 lg %r10,__LC_LAST_BREAK
685 lg %r12,__LC_THREAD_INFO
686 larl %r13,system_call
687 lmg %r8,%r9,__LC_MCK_OLD_PSW
688 HANDLE_SIE_INTERCEPT %r14,4
689 tm __LC_MCCK_CODE,0x80 # system damage?
690 jo mcck_panic # yes -> rest of mcck code invalid
691 lghi %r14,__LC_CPU_TIMER_SAVE_AREA
692 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
693 tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid?
694 jo 3f
695 la %r14,__LC_SYNC_ENTER_TIMER
696 clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER
697 jl 0f
698 la %r14,__LC_ASYNC_ENTER_TIMER
6990: clc 0(8,%r14),__LC_EXIT_TIMER
700 jl 1f
701 la %r14,__LC_EXIT_TIMER
7021: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER
703 jl 2f
704 la %r14,__LC_LAST_UPDATE_TIMER
7052: spt 0(%r14)
706 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
7073: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid?
708 jno mcck_panic # no -> skip cleanup critical
709 SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_PANIC_STACK,PAGE_SHIFT
710 tm %r8,0x0001 # interrupting from user ?
711 jz mcck_skip
712 UPDATE_VTIME %r14,__LC_MCCK_ENTER_TIMER
713 LAST_BREAK %r14
714mcck_skip:
715 lghi %r14,__LC_GPREGS_SAVE_AREA+64
716 stmg %r0,%r7,__PT_R0(%r11)
717 mvc __PT_R8(64,%r11),0(%r14)
718 stmg %r8,%r9,__PT_PSW(%r11)
719 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
720 lgr %r2,%r11 # pass pointer to pt_regs
721 brasl %r14,s390_do_machine_check
722 tm __PT_PSW+1(%r11),0x01 # returning to user ?
723 jno mcck_return
724 lg %r1,__LC_KERNEL_STACK # switch to kernel stack
725 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
726 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
727 la %r11,STACK_FRAME_OVERHEAD(%r1)
728 lgr %r15,%r1
729 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off
730 tm __TI_flags+7(%r12),_TIF_MCCK_PENDING
731 jno mcck_return
732 TRACE_IRQS_OFF
733 brasl %r14,s390_handle_mcck
734 TRACE_IRQS_ON
735mcck_return:
736 lg %r14,__LC_VDSO_PER_CPU
737 lmg %r0,%r10,__PT_R0(%r11)
738 mvc __LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
739 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
740 jno 0f
741 stpt __LC_EXIT_TIMER
742 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
7430: lmg %r11,%r15,__PT_R11(%r11)
744 lpswe __LC_RETURN_MCCK_PSW
745
746mcck_panic:
747 lg %r14,__LC_PANIC_STACK
748 slgr %r14,%r15
749 srag %r14,%r14,PAGE_SHIFT
750 jz 0f
751 lg %r15,__LC_PANIC_STACK
7520: aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
753 j mcck_skip
754
755#
756# PSW restart interrupt handler
757#
758ENTRY(restart_int_handler)
759 stg %r15,__LC_SAVE_AREA_RESTART
760 lg %r15,__LC_RESTART_STACK
761 aghi %r15,-__PT_SIZE # create pt_regs on stack
762 xc 0(__PT_SIZE,%r15),0(%r15)
763 stmg %r0,%r14,__PT_R0(%r15)
764 mvc __PT_R15(8,%r15),__LC_SAVE_AREA_RESTART
765 mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw
766 aghi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack
767 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
768 lg %r1,__LC_RESTART_FN # load fn, parm & source cpu
769 lg %r2,__LC_RESTART_DATA
770 lg %r3,__LC_RESTART_SOURCE
771 ltgr %r3,%r3 # test source cpu address
772 jm 1f # negative -> skip source stop
7730: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu
774 brc 10,0b # wait for status stored
7751: basr %r14,%r1 # call function
776 stap __SF_EMPTY(%r15) # store cpu address
777 llgh %r3,__SF_EMPTY(%r15)
7782: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu
779 brc 2,2b
7803: j 3b
781
782 .section .kprobes.text, "ax"
783
784#ifdef CONFIG_CHECK_STACK
785/*
786 * The synchronous or the asynchronous stack overflowed. We are dead.
787 * No need to properly save the registers, we are going to panic anyway.
788 * Setup a pt_regs so that show_trace can provide a good call trace.
789 */
790stack_overflow:
791 lg %r15,__LC_PANIC_STACK # change to panic stack
792 la %r11,STACK_FRAME_OVERHEAD(%r15)
793 stmg %r0,%r7,__PT_R0(%r11)
794 stmg %r8,%r9,__PT_PSW(%r11)
795 mvc __PT_R8(64,%r11),0(%r14)
796 stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
797 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
798 lgr %r2,%r11 # pass pointer to pt_regs
799 jg kernel_stack_overflow
800#endif
801
802 .align 8
803cleanup_table:
804 .quad system_call
805 .quad sysc_do_svc
806 .quad sysc_tif
807 .quad sysc_restore
808 .quad sysc_done
809 .quad io_tif
810 .quad io_restore
811 .quad io_done
812 .quad psw_idle
813 .quad psw_idle_end
814
815cleanup_critical:
816 clg %r9,BASED(cleanup_table) # system_call
817 jl 0f
818 clg %r9,BASED(cleanup_table+8) # sysc_do_svc
819 jl cleanup_system_call
820 clg %r9,BASED(cleanup_table+16) # sysc_tif
821 jl 0f
822 clg %r9,BASED(cleanup_table+24) # sysc_restore
823 jl cleanup_sysc_tif
824 clg %r9,BASED(cleanup_table+32) # sysc_done
825 jl cleanup_sysc_restore
826 clg %r9,BASED(cleanup_table+40) # io_tif
827 jl 0f
828 clg %r9,BASED(cleanup_table+48) # io_restore
829 jl cleanup_io_tif
830 clg %r9,BASED(cleanup_table+56) # io_done
831 jl cleanup_io_restore
832 clg %r9,BASED(cleanup_table+64) # psw_idle
833 jl 0f
834 clg %r9,BASED(cleanup_table+72) # psw_idle_end
835 jl cleanup_idle
8360: br %r14
837
838
839cleanup_system_call:
840 # check if stpt has been executed
841 clg %r9,BASED(cleanup_system_call_insn)
842 jh 0f
843 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
844 cghi %r11,__LC_SAVE_AREA_ASYNC
845 je 0f
846 mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
8470: # check if stmg has been executed
848 clg %r9,BASED(cleanup_system_call_insn+8)
849 jh 0f
850 mvc __LC_SAVE_AREA_SYNC(64),0(%r11)
8510: # check if base register setup + TIF bit load has been done
852 clg %r9,BASED(cleanup_system_call_insn+16)
853 jhe 0f
854 # set up saved registers r10 and r12
855 stg %r10,16(%r11) # r10 last break
856 stg %r12,32(%r11) # r12 thread-info pointer
8570: # check if the user time update has been done
858 clg %r9,BASED(cleanup_system_call_insn+24)
859 jh 0f
860 lg %r15,__LC_EXIT_TIMER
861 slg %r15,__LC_SYNC_ENTER_TIMER
862 alg %r15,__LC_USER_TIMER
863 stg %r15,__LC_USER_TIMER
8640: # check if the system time update has been done
865 clg %r9,BASED(cleanup_system_call_insn+32)
866 jh 0f
867 lg %r15,__LC_LAST_UPDATE_TIMER
868 slg %r15,__LC_EXIT_TIMER
869 alg %r15,__LC_SYSTEM_TIMER
870 stg %r15,__LC_SYSTEM_TIMER
8710: # update accounting time stamp
872 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
873 # do LAST_BREAK
874 lg %r9,16(%r11)
875 srag %r9,%r9,23
876 jz 0f
877 mvc __TI_last_break(8,%r12),16(%r11)
8780: # set up saved register r11
879 lg %r15,__LC_KERNEL_STACK
880 la %r9,STACK_FRAME_OVERHEAD(%r15)
881 stg %r9,24(%r11) # r11 pt_regs pointer
882 # fill pt_regs
883 mvc __PT_R8(64,%r9),__LC_SAVE_AREA_SYNC
884 stmg %r0,%r7,__PT_R0(%r9)
885 mvc __PT_PSW(16,%r9),__LC_SVC_OLD_PSW
886 mvc __PT_INT_CODE(4,%r9),__LC_SVC_ILC
887 # setup saved register r15
888 stg %r15,56(%r11) # r15 stack pointer
889 # set new psw address and exit
890 larl %r9,sysc_do_svc
891 br %r14
892cleanup_system_call_insn:
893 .quad system_call
894 .quad sysc_stmg
895 .quad sysc_per
896 .quad sysc_vtime+18
897 .quad sysc_vtime+42
898
899cleanup_sysc_tif:
900 larl %r9,sysc_tif
901 br %r14
902
903cleanup_sysc_restore:
904 clg %r9,BASED(cleanup_sysc_restore_insn)
905 je 0f
906 lg %r9,24(%r11) # get saved pointer to pt_regs
907 mvc __LC_RETURN_PSW(16),__PT_PSW(%r9)
908 mvc 0(64,%r11),__PT_R8(%r9)
909 lmg %r0,%r7,__PT_R0(%r9)
9100: lmg %r8,%r9,__LC_RETURN_PSW
911 br %r14
912cleanup_sysc_restore_insn:
913 .quad sysc_done - 4
914
915cleanup_io_tif:
916 larl %r9,io_tif
917 br %r14
918
919cleanup_io_restore:
920 clg %r9,BASED(cleanup_io_restore_insn)
921 je 0f
922 lg %r9,24(%r11) # get saved r11 pointer to pt_regs
923 mvc __LC_RETURN_PSW(16),__PT_PSW(%r9)
924 mvc 0(64,%r11),__PT_R8(%r9)
925 lmg %r0,%r7,__PT_R0(%r9)
9260: lmg %r8,%r9,__LC_RETURN_PSW
927 br %r14
928cleanup_io_restore_insn:
929 .quad io_done - 4
930
931cleanup_idle:
932 # copy interrupt clock & cpu timer
933 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK
934 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER
935 cghi %r11,__LC_SAVE_AREA_ASYNC
936 je 0f
937 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK
938 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER
9390: # check if stck & stpt have been executed
940 clg %r9,BASED(cleanup_idle_insn)
941 jhe 1f
942 mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
943 mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r2)
9441: # account system time going idle
945 lg %r9,__LC_STEAL_TIMER
946 alg %r9,__CLOCK_IDLE_ENTER(%r2)
947 slg %r9,__LC_LAST_UPDATE_CLOCK
948 stg %r9,__LC_STEAL_TIMER
949 mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
950 lg %r9,__LC_SYSTEM_TIMER
951 alg %r9,__LC_LAST_UPDATE_TIMER
952 slg %r9,__TIMER_IDLE_ENTER(%r2)
953 stg %r9,__LC_SYSTEM_TIMER
954 mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
955 # prepare return psw
956 nihh %r8,0xfcfd # clear irq & wait state bits
957 lg %r9,48(%r11) # return from psw_idle
958 br %r14
959cleanup_idle_insn:
960 .quad psw_idle_lpsw
961
962/*
963 * Integer constants
964 */
965 .align 8
966.Lcritical_start:
967 .quad __critical_start
968.Lcritical_length:
969 .quad __critical_end - __critical_start
970
971
972#if IS_ENABLED(CONFIG_KVM)
973/*
974 * sie64a calling convention:
975 * %r2 pointer to sie control block
976 * %r3 guest register save area
977 */
978ENTRY(sie64a)
979 stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers
980 stg %r2,__SF_EMPTY(%r15) # save control block pointer
981 stg %r3,__SF_EMPTY+8(%r15) # save guest register save area
982 xc __SF_EMPTY+16(16,%r15),__SF_EMPTY+16(%r15) # host id & reason
983 lmg %r0,%r13,0(%r3) # load guest gprs 0-13
984 lg %r14,__LC_GMAP # get gmap pointer
985 ltgr %r14,%r14
986 jz sie_gmap
987 lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce
988sie_gmap:
989 lg %r14,__SF_EMPTY(%r15) # get control block pointer
990 oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now
991 tm __SIE_PROG20+3(%r14),1 # last exit...
992 jnz sie_done
993 LPP __SF_EMPTY(%r15) # set guest id
994 sie 0(%r14)
995sie_done:
996 LPP __SF_EMPTY+16(%r15) # set host id
997 ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE
998 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
999# some program checks are suppressing. C code (e.g. do_protection_exception)
1000# will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other
1001# instructions between sie64a and sie_done should not cause program
1002# interrupts. So lets use a nop (47 00 00 00) as a landing pad.
1003# See also HANDLE_SIE_INTERCEPT
1004rewind_pad:
1005 nop 0
1006 .globl sie_exit
1007sie_exit:
1008 lg %r14,__SF_EMPTY+8(%r15) # load guest register save area
1009 stmg %r0,%r13,0(%r14) # save guest gprs 0-13
1010 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers
1011 lg %r2,__SF_EMPTY+24(%r15) # return exit reason code
1012 br %r14
1013sie_fault:
1014 lghi %r14,-EFAULT
1015 stg %r14,__SF_EMPTY+24(%r15) # set exit reason code
1016 j sie_exit
1017
1018 .align 8
1019.Lsie_critical:
1020 .quad sie_gmap
1021.Lsie_critical_length:
1022 .quad sie_done - sie_gmap
1023
1024 EX_TABLE(rewind_pad,sie_fault)
1025 EX_TABLE(sie_exit,sie_fault)
1026#endif
1027
1028 .section .rodata, "a"
1029#define SYSCALL(esa,esame,emu) .long esame
1030 .globl sys_call_table
1031sys_call_table:
1032#include "syscalls.S"
1033#undef SYSCALL
1034
1035#ifdef CONFIG_COMPAT
1036
1037#define SYSCALL(esa,esame,emu) .long emu
1038 .globl sys_call_table_emu
1039sys_call_table_emu:
1040#include "syscalls.S"
1041#undef SYSCALL
1042#endif