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1/*
2 * arch/s390/kernel/entry.S
3 * S390 low-level entry points.
4 *
5 * Copyright (C) IBM Corp. 1999,2006
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/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
22/*
23 * Stack layout for the system_call stack entry.
24 * The first few entries are identical to the user_regs_struct.
25 */
26SP_PTREGS = STACK_FRAME_OVERHEAD
27SP_ARGS = STACK_FRAME_OVERHEAD + __PT_ARGS
28SP_PSW = STACK_FRAME_OVERHEAD + __PT_PSW
29SP_R0 = STACK_FRAME_OVERHEAD + __PT_GPRS
30SP_R1 = STACK_FRAME_OVERHEAD + __PT_GPRS + 4
31SP_R2 = STACK_FRAME_OVERHEAD + __PT_GPRS + 8
32SP_R3 = STACK_FRAME_OVERHEAD + __PT_GPRS + 12
33SP_R4 = STACK_FRAME_OVERHEAD + __PT_GPRS + 16
34SP_R5 = STACK_FRAME_OVERHEAD + __PT_GPRS + 20
35SP_R6 = STACK_FRAME_OVERHEAD + __PT_GPRS + 24
36SP_R7 = STACK_FRAME_OVERHEAD + __PT_GPRS + 28
37SP_R8 = STACK_FRAME_OVERHEAD + __PT_GPRS + 32
38SP_R9 = STACK_FRAME_OVERHEAD + __PT_GPRS + 36
39SP_R10 = STACK_FRAME_OVERHEAD + __PT_GPRS + 40
40SP_R11 = STACK_FRAME_OVERHEAD + __PT_GPRS + 44
41SP_R12 = STACK_FRAME_OVERHEAD + __PT_GPRS + 48
42SP_R13 = STACK_FRAME_OVERHEAD + __PT_GPRS + 52
43SP_R14 = STACK_FRAME_OVERHEAD + __PT_GPRS + 56
44SP_R15 = STACK_FRAME_OVERHEAD + __PT_GPRS + 60
45SP_ORIG_R2 = STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
46SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC
47SP_SVCNR = STACK_FRAME_OVERHEAD + __PT_SVCNR
48SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
49
50_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
51 _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_PER_TRAP )
52_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
53 _TIF_MCCK_PENDING)
54_TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
55 _TIF_SECCOMP>>8 | _TIF_SYSCALL_TRACEPOINT>>8)
56
57STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
58STACK_SIZE = 1 << STACK_SHIFT
59
60#define BASED(name) name-system_call(%r13)
61
62#ifdef CONFIG_TRACE_IRQFLAGS
63 .macro TRACE_IRQS_ON
64 basr %r2,%r0
65 l %r1,BASED(.Ltrace_irq_on_caller)
66 basr %r14,%r1
67 .endm
68
69 .macro TRACE_IRQS_OFF
70 basr %r2,%r0
71 l %r1,BASED(.Ltrace_irq_off_caller)
72 basr %r14,%r1
73 .endm
74#else
75#define TRACE_IRQS_ON
76#define TRACE_IRQS_OFF
77#endif
78
79#ifdef CONFIG_LOCKDEP
80 .macro LOCKDEP_SYS_EXIT
81 tm SP_PSW+1(%r15),0x01 # returning to user ?
82 jz 0f
83 l %r1,BASED(.Llockdep_sys_exit)
84 basr %r14,%r1
850:
86 .endm
87#else
88#define LOCKDEP_SYS_EXIT
89#endif
90
91/*
92 * Register usage in interrupt handlers:
93 * R9 - pointer to current task structure
94 * R13 - pointer to literal pool
95 * R14 - return register for function calls
96 * R15 - kernel stack pointer
97 */
98
99 .macro UPDATE_VTIME lc_from,lc_to,lc_sum
100 lm %r10,%r11,\lc_from
101 sl %r10,\lc_to
102 sl %r11,\lc_to+4
103 bc 3,BASED(0f)
104 sl %r10,BASED(.Lc_1)
1050: al %r10,\lc_sum
106 al %r11,\lc_sum+4
107 bc 12,BASED(1f)
108 al %r10,BASED(.Lc_1)
1091: stm %r10,%r11,\lc_sum
110 .endm
111
112 .macro SAVE_ALL_SVC psworg,savearea
113 stm %r12,%r15,\savearea
114 l %r13,__LC_SVC_NEW_PSW+4 # load &system_call to %r13
115 l %r15,__LC_KERNEL_STACK # problem state -> load ksp
116 s %r15,BASED(.Lc_spsize) # make room for registers & psw
117 .endm
118
119 .macro SAVE_ALL_BASE savearea
120 stm %r12,%r15,\savearea
121 l %r13,__LC_SVC_NEW_PSW+4 # load &system_call to %r13
122 .endm
123
124 .macro SAVE_ALL_PGM psworg,savearea
125 tm \psworg+1,0x01 # test problem state bit
126#ifdef CONFIG_CHECK_STACK
127 bnz BASED(1f)
128 tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
129 bnz BASED(2f)
130 la %r12,\psworg
131 b BASED(stack_overflow)
132#else
133 bz BASED(2f)
134#endif
1351: l %r15,__LC_KERNEL_STACK # problem state -> load ksp
1362: s %r15,BASED(.Lc_spsize) # make room for registers & psw
137 .endm
138
139 .macro SAVE_ALL_ASYNC psworg,savearea
140 stm %r12,%r15,\savearea
141 l %r13,__LC_SVC_NEW_PSW+4 # load &system_call to %r13
142 la %r12,\psworg
143 tm \psworg+1,0x01 # test problem state bit
144 bnz BASED(1f) # from user -> load async stack
145 clc \psworg+4(4),BASED(.Lcritical_end)
146 bhe BASED(0f)
147 clc \psworg+4(4),BASED(.Lcritical_start)
148 bl BASED(0f)
149 l %r14,BASED(.Lcleanup_critical)
150 basr %r14,%r14
151 tm 1(%r12),0x01 # retest problem state after cleanup
152 bnz BASED(1f)
1530: l %r14,__LC_ASYNC_STACK # are we already on the async stack ?
154 slr %r14,%r15
155 sra %r14,STACK_SHIFT
156#ifdef CONFIG_CHECK_STACK
157 bnz BASED(1f)
158 tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
159 bnz BASED(2f)
160 b BASED(stack_overflow)
161#else
162 bz BASED(2f)
163#endif
1641: l %r15,__LC_ASYNC_STACK
1652: s %r15,BASED(.Lc_spsize) # make room for registers & psw
166 .endm
167
168 .macro CREATE_STACK_FRAME savearea
169 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
170 st %r2,SP_ORIG_R2(%r15) # store original content of gpr 2
171 mvc SP_R12(16,%r15),\savearea # move %r12-%r15 to stack
172 stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
173 .endm
174
175 .macro RESTORE_ALL psworg,sync
176 mvc \psworg(8),SP_PSW(%r15) # move user PSW to lowcore
177 .if !\sync
178 ni \psworg+1,0xfd # clear wait state bit
179 .endif
180 lm %r0,%r15,SP_R0(%r15) # load gprs 0-15 of user
181 stpt __LC_EXIT_TIMER
182 lpsw \psworg # back to caller
183 .endm
184
185 .macro REENABLE_IRQS
186 mvc __SF_EMPTY(1,%r15),SP_PSW(%r15)
187 ni __SF_EMPTY(%r15),0xbf
188 ssm __SF_EMPTY(%r15)
189 .endm
190
191 .section .kprobes.text, "ax"
192
193/*
194 * Scheduler resume function, called by switch_to
195 * gpr2 = (task_struct *) prev
196 * gpr3 = (task_struct *) next
197 * Returns:
198 * gpr2 = prev
199 */
200ENTRY(__switch_to)
201 basr %r1,0
2020: l %r4,__THREAD_info(%r2) # get thread_info of prev
203 l %r5,__THREAD_info(%r3) # get thread_info of next
204 tm __TI_flags+3(%r4),_TIF_MCCK_PENDING # machine check pending?
205 bz 1f-0b(%r1)
206 ni __TI_flags+3(%r4),255-_TIF_MCCK_PENDING # clear flag in prev
207 oi __TI_flags+3(%r5),_TIF_MCCK_PENDING # set it in next
2081: stm %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
209 st %r15,__THREAD_ksp(%r2) # store kernel stack of prev
210 l %r15,__THREAD_ksp(%r3) # load kernel stack of next
211 lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
212 lm %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
213 st %r3,__LC_CURRENT # store task struct of next
214 mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next
215 st %r5,__LC_THREAD_INFO # store thread info of next
216 ahi %r5,STACK_SIZE # end of kernel stack of next
217 st %r5,__LC_KERNEL_STACK # store end of kernel stack
218 br %r14
219
220__critical_start:
221/*
222 * SVC interrupt handler routine. System calls are synchronous events and
223 * are executed with interrupts enabled.
224 */
225
226ENTRY(system_call)
227 stpt __LC_SYNC_ENTER_TIMER
228sysc_saveall:
229 SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
230 CREATE_STACK_FRAME __LC_SAVE_AREA
231 mvc SP_PSW(8,%r15),__LC_SVC_OLD_PSW
232 mvc SP_ILC(4,%r15),__LC_SVC_ILC
233 l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
234sysc_vtime:
235 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
236sysc_stime:
237 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
238sysc_update:
239 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
240sysc_do_svc:
241 xr %r7,%r7
242 icm %r7,3,SP_SVCNR(%r15) # load svc number and test for svc 0
243 bnz BASED(sysc_nr_ok) # svc number > 0
244 # svc 0: system call number in %r1
245 cl %r1,BASED(.Lnr_syscalls)
246 bnl BASED(sysc_nr_ok)
247 sth %r1,SP_SVCNR(%r15)
248 lr %r7,%r1 # copy svc number to %r7
249sysc_nr_ok:
250 sll %r7,2 # svc number *4
251 l %r10,BASED(.Lsysc_table)
252 tm __TI_flags+2(%r12),_TIF_SYSCALL
253 mvc SP_ARGS(4,%r15),SP_R7(%r15)
254 l %r8,0(%r7,%r10) # get system call addr.
255 bnz BASED(sysc_tracesys)
256 basr %r14,%r8 # call sys_xxxx
257 st %r2,SP_R2(%r15) # store return value (change R2 on stack)
258
259sysc_return:
260 LOCKDEP_SYS_EXIT
261sysc_tif:
262 tm __TI_flags+3(%r12),_TIF_WORK_SVC
263 bnz BASED(sysc_work) # there is work to do (signals etc.)
264sysc_restore:
265 RESTORE_ALL __LC_RETURN_PSW,1
266sysc_done:
267
268#
269# There is work to do, but first we need to check if we return to userspace.
270#
271sysc_work:
272 tm SP_PSW+1(%r15),0x01 # returning to user ?
273 bno BASED(sysc_restore)
274
275#
276# One of the work bits is on. Find out which one.
277#
278sysc_work_tif:
279 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
280 bo BASED(sysc_mcck_pending)
281 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
282 bo BASED(sysc_reschedule)
283 tm __TI_flags+3(%r12),_TIF_SIGPENDING
284 bo BASED(sysc_sigpending)
285 tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
286 bo BASED(sysc_notify_resume)
287 tm __TI_flags+3(%r12),_TIF_RESTART_SVC
288 bo BASED(sysc_restart)
289 tm __TI_flags+3(%r12),_TIF_PER_TRAP
290 bo BASED(sysc_singlestep)
291 b BASED(sysc_return) # beware of critical section cleanup
292
293#
294# _TIF_NEED_RESCHED is set, call schedule
295#
296sysc_reschedule:
297 l %r1,BASED(.Lschedule)
298 la %r14,BASED(sysc_return)
299 br %r1 # call scheduler
300
301#
302# _TIF_MCCK_PENDING is set, call handler
303#
304sysc_mcck_pending:
305 l %r1,BASED(.Ls390_handle_mcck)
306 la %r14,BASED(sysc_return)
307 br %r1 # TIF bit will be cleared by handler
308
309#
310# _TIF_SIGPENDING is set, call do_signal
311#
312sysc_sigpending:
313 ni __TI_flags+3(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
314 la %r2,SP_PTREGS(%r15) # load pt_regs
315 l %r1,BASED(.Ldo_signal)
316 basr %r14,%r1 # call do_signal
317 tm __TI_flags+3(%r12),_TIF_RESTART_SVC
318 bo BASED(sysc_restart)
319 tm __TI_flags+3(%r12),_TIF_PER_TRAP
320 bo BASED(sysc_singlestep)
321 b BASED(sysc_return)
322
323#
324# _TIF_NOTIFY_RESUME is set, call do_notify_resume
325#
326sysc_notify_resume:
327 la %r2,SP_PTREGS(%r15) # load pt_regs
328 l %r1,BASED(.Ldo_notify_resume)
329 la %r14,BASED(sysc_return)
330 br %r1 # call do_notify_resume
331
332
333#
334# _TIF_RESTART_SVC is set, set up registers and restart svc
335#
336sysc_restart:
337 ni __TI_flags+3(%r12),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
338 l %r7,SP_R2(%r15) # load new svc number
339 mvc SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument
340 lm %r2,%r6,SP_R2(%r15) # load svc arguments
341 sth %r7,SP_SVCNR(%r15)
342 b BASED(sysc_nr_ok) # restart svc
343
344#
345# _TIF_PER_TRAP is set, call do_per_trap
346#
347sysc_singlestep:
348 ni __TI_flags+3(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
349 xc SP_SVCNR(2,%r15),SP_SVCNR(%r15) # clear svc number
350 la %r2,SP_PTREGS(%r15) # address of register-save area
351 l %r1,BASED(.Lhandle_per) # load adr. of per handler
352 la %r14,BASED(sysc_return) # load adr. of system return
353 br %r1 # branch to do_per_trap
354
355#
356# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
357# and after the system call
358#
359sysc_tracesys:
360 l %r1,BASED(.Ltrace_entry)
361 la %r2,SP_PTREGS(%r15) # load pt_regs
362 la %r3,0
363 xr %r0,%r0
364 icm %r0,3,SP_SVCNR(%r15)
365 st %r0,SP_R2(%r15)
366 basr %r14,%r1
367 cl %r2,BASED(.Lnr_syscalls)
368 bnl BASED(sysc_tracenogo)
369 lr %r7,%r2
370 sll %r7,2 # svc number *4
371 l %r8,0(%r7,%r10)
372sysc_tracego:
373 lm %r3,%r6,SP_R3(%r15)
374 mvc SP_ARGS(4,%r15),SP_R7(%r15)
375 l %r2,SP_ORIG_R2(%r15)
376 basr %r14,%r8 # call sys_xxx
377 st %r2,SP_R2(%r15) # store return value
378sysc_tracenogo:
379 tm __TI_flags+2(%r12),_TIF_SYSCALL
380 bz BASED(sysc_return)
381 l %r1,BASED(.Ltrace_exit)
382 la %r2,SP_PTREGS(%r15) # load pt_regs
383 la %r14,BASED(sysc_return)
384 br %r1
385
386#
387# a new process exits the kernel with ret_from_fork
388#
389ENTRY(ret_from_fork)
390 l %r13,__LC_SVC_NEW_PSW+4
391 l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
392 tm SP_PSW+1(%r15),0x01 # forking a kernel thread ?
393 bo BASED(0f)
394 st %r15,SP_R15(%r15) # store stack pointer for new kthread
3950: l %r1,BASED(.Lschedtail)
396 basr %r14,%r1
397 TRACE_IRQS_ON
398 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
399 b BASED(sysc_tracenogo)
400
401#
402# kernel_execve function needs to deal with pt_regs that is not
403# at the usual place
404#
405ENTRY(kernel_execve)
406 stm %r12,%r15,48(%r15)
407 lr %r14,%r15
408 l %r13,__LC_SVC_NEW_PSW+4
409 s %r15,BASED(.Lc_spsize)
410 st %r14,__SF_BACKCHAIN(%r15)
411 la %r12,SP_PTREGS(%r15)
412 xc 0(__PT_SIZE,%r12),0(%r12)
413 l %r1,BASED(.Ldo_execve)
414 lr %r5,%r12
415 basr %r14,%r1
416 ltr %r2,%r2
417 be BASED(0f)
418 a %r15,BASED(.Lc_spsize)
419 lm %r12,%r15,48(%r15)
420 br %r14
421 # execve succeeded.
4220: stnsm __SF_EMPTY(%r15),0xfc # disable interrupts
423 l %r15,__LC_KERNEL_STACK # load ksp
424 s %r15,BASED(.Lc_spsize) # make room for registers & psw
425 mvc SP_PTREGS(__PT_SIZE,%r15),0(%r12) # copy pt_regs
426 l %r12,__LC_THREAD_INFO
427 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
428 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
429 l %r1,BASED(.Lexecve_tail)
430 basr %r14,%r1
431 b BASED(sysc_return)
432
433/*
434 * Program check handler routine
435 */
436
437ENTRY(pgm_check_handler)
438/*
439 * First we need to check for a special case:
440 * Single stepping an instruction that disables the PER event mask will
441 * cause a PER event AFTER the mask has been set. Example: SVC or LPSW.
442 * For a single stepped SVC the program check handler gets control after
443 * the SVC new PSW has been loaded. But we want to execute the SVC first and
444 * then handle the PER event. Therefore we update the SVC old PSW to point
445 * to the pgm_check_handler and branch to the SVC handler after we checked
446 * if we have to load the kernel stack register.
447 * For every other possible cause for PER event without the PER mask set
448 * we just ignore the PER event (FIXME: is there anything we have to do
449 * for LPSW?).
450 */
451 stpt __LC_SYNC_ENTER_TIMER
452 SAVE_ALL_BASE __LC_SAVE_AREA
453 tm __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception
454 bnz BASED(pgm_per) # got per exception -> special case
455 SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA
456 CREATE_STACK_FRAME __LC_SAVE_AREA
457 xc SP_ILC(4,%r15),SP_ILC(%r15)
458 mvc SP_PSW(8,%r15),__LC_PGM_OLD_PSW
459 l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
460 tm SP_PSW+1(%r15),0x01 # interrupting from user ?
461 bz BASED(pgm_no_vtime)
462 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
463 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
464 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
465pgm_no_vtime:
466 l %r3,__LC_PGM_ILC # load program interruption code
467 l %r4,__LC_TRANS_EXC_CODE
468 REENABLE_IRQS
469 la %r8,0x7f
470 nr %r8,%r3
471 sll %r8,2
472 l %r1,BASED(.Ljump_table)
473 l %r1,0(%r8,%r1) # load address of handler routine
474 la %r2,SP_PTREGS(%r15) # address of register-save area
475 basr %r14,%r1 # branch to interrupt-handler
476pgm_exit:
477 b BASED(sysc_return)
478
479#
480# handle per exception
481#
482pgm_per:
483 tm __LC_PGM_OLD_PSW,0x40 # test if per event recording is on
484 bnz BASED(pgm_per_std) # ok, normal per event from user space
485# ok its one of the special cases, now we need to find out which one
486 clc __LC_PGM_OLD_PSW(8),__LC_SVC_NEW_PSW
487 be BASED(pgm_svcper)
488# no interesting special case, ignore PER event
489 lm %r12,%r15,__LC_SAVE_AREA
490 lpsw 0x28
491
492#
493# Normal per exception
494#
495pgm_per_std:
496 SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA
497 CREATE_STACK_FRAME __LC_SAVE_AREA
498 mvc SP_PSW(8,%r15),__LC_PGM_OLD_PSW
499 l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
500 tm SP_PSW+1(%r15),0x01 # interrupting from user ?
501 bz BASED(pgm_no_vtime2)
502 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
503 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
504 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
505pgm_no_vtime2:
506 l %r1,__TI_task(%r12)
507 tm SP_PSW+1(%r15),0x01 # kernel per event ?
508 bz BASED(kernel_per)
509 mvc __THREAD_per_cause(2,%r1),__LC_PER_CAUSE
510 mvc __THREAD_per_address(4,%r1),__LC_PER_ADDRESS
511 mvc __THREAD_per_paid(1,%r1),__LC_PER_PAID
512 oi __TI_flags+3(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP
513 l %r3,__LC_PGM_ILC # load program interruption code
514 l %r4,__LC_TRANS_EXC_CODE
515 REENABLE_IRQS
516 la %r8,0x7f
517 nr %r8,%r3 # clear per-event-bit and ilc
518 be BASED(pgm_exit2) # only per or per+check ?
519 sll %r8,2
520 l %r1,BASED(.Ljump_table)
521 l %r1,0(%r8,%r1) # load address of handler routine
522 la %r2,SP_PTREGS(%r15) # address of register-save area
523 basr %r14,%r1 # branch to interrupt-handler
524pgm_exit2:
525 b BASED(sysc_return)
526
527#
528# it was a single stepped SVC that is causing all the trouble
529#
530pgm_svcper:
531 SAVE_ALL_PGM __LC_SVC_OLD_PSW,__LC_SAVE_AREA
532 CREATE_STACK_FRAME __LC_SAVE_AREA
533 mvc SP_PSW(8,%r15),__LC_SVC_OLD_PSW
534 mvc SP_ILC(4,%r15),__LC_SVC_ILC
535 l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
536 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
537 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
538 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
539 l %r8,__TI_task(%r12)
540 mvc __THREAD_per_cause(2,%r8),__LC_PER_CAUSE
541 mvc __THREAD_per_address(4,%r8),__LC_PER_ADDRESS
542 mvc __THREAD_per_paid(1,%r8),__LC_PER_PAID
543 oi __TI_flags+3(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP
544 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
545 lm %r2,%r6,SP_R2(%r15) # load svc arguments
546 b BASED(sysc_do_svc)
547
548#
549# per was called from kernel, must be kprobes
550#
551kernel_per:
552 REENABLE_IRQS
553 xc SP_SVCNR(2,%r15),SP_SVCNR(%r15)
554 la %r2,SP_PTREGS(%r15) # address of register-save area
555 l %r1,BASED(.Lhandle_per) # load adr. of per handler
556 basr %r14,%r1 # branch to do_single_step
557 b BASED(pgm_exit)
558
559/*
560 * IO interrupt handler routine
561 */
562
563ENTRY(io_int_handler)
564 stck __LC_INT_CLOCK
565 stpt __LC_ASYNC_ENTER_TIMER
566 SAVE_ALL_ASYNC __LC_IO_OLD_PSW,__LC_SAVE_AREA+16
567 CREATE_STACK_FRAME __LC_SAVE_AREA+16
568 mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
569 l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
570 tm SP_PSW+1(%r15),0x01 # interrupting from user ?
571 bz BASED(io_no_vtime)
572 UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
573 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
574 mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
575io_no_vtime:
576 TRACE_IRQS_OFF
577 l %r1,BASED(.Ldo_IRQ) # load address of do_IRQ
578 la %r2,SP_PTREGS(%r15) # address of register-save area
579 basr %r14,%r1 # branch to standard irq handler
580io_return:
581 LOCKDEP_SYS_EXIT
582 TRACE_IRQS_ON
583io_tif:
584 tm __TI_flags+3(%r12),_TIF_WORK_INT
585 bnz BASED(io_work) # there is work to do (signals etc.)
586io_restore:
587 RESTORE_ALL __LC_RETURN_PSW,0
588io_done:
589
590#
591# There is work todo, find out in which context we have been interrupted:
592# 1) if we return to user space we can do all _TIF_WORK_INT work
593# 2) if we return to kernel code and preemptive scheduling is enabled check
594# the preemption counter and if it is zero call preempt_schedule_irq
595# Before any work can be done, a switch to the kernel stack is required.
596#
597io_work:
598 tm SP_PSW+1(%r15),0x01 # returning to user ?
599 bo BASED(io_work_user) # yes -> do resched & signal
600#ifdef CONFIG_PREEMPT
601 # check for preemptive scheduling
602 icm %r0,15,__TI_precount(%r12)
603 bnz BASED(io_restore) # preemption disabled
604 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
605 bno BASED(io_restore)
606 # switch to kernel stack
607 l %r1,SP_R15(%r15)
608 s %r1,BASED(.Lc_spsize)
609 mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
610 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
611 lr %r15,%r1
612 # TRACE_IRQS_ON already done at io_return, call
613 # TRACE_IRQS_OFF to keep things symmetrical
614 TRACE_IRQS_OFF
615 l %r1,BASED(.Lpreempt_schedule_irq)
616 basr %r14,%r1 # call preempt_schedule_irq
617 b BASED(io_return)
618#else
619 b BASED(io_restore)
620#endif
621
622#
623# Need to do work before returning to userspace, switch to kernel stack
624#
625io_work_user:
626 l %r1,__LC_KERNEL_STACK
627 s %r1,BASED(.Lc_spsize)
628 mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
629 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
630 lr %r15,%r1
631
632#
633# One of the work bits is on. Find out which one.
634# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED
635# and _TIF_MCCK_PENDING
636#
637io_work_tif:
638 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
639 bo BASED(io_mcck_pending)
640 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
641 bo BASED(io_reschedule)
642 tm __TI_flags+3(%r12),_TIF_SIGPENDING
643 bo BASED(io_sigpending)
644 tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
645 bo BASED(io_notify_resume)
646 b BASED(io_return) # beware of critical section cleanup
647
648#
649# _TIF_MCCK_PENDING is set, call handler
650#
651io_mcck_pending:
652 # TRACE_IRQS_ON already done at io_return
653 l %r1,BASED(.Ls390_handle_mcck)
654 basr %r14,%r1 # TIF bit will be cleared by handler
655 TRACE_IRQS_OFF
656 b BASED(io_return)
657
658#
659# _TIF_NEED_RESCHED is set, call schedule
660#
661io_reschedule:
662 # TRACE_IRQS_ON already done at io_return
663 l %r1,BASED(.Lschedule)
664 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
665 basr %r14,%r1 # call scheduler
666 stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
667 TRACE_IRQS_OFF
668 b BASED(io_return)
669
670#
671# _TIF_SIGPENDING is set, call do_signal
672#
673io_sigpending:
674 # TRACE_IRQS_ON already done at io_return
675 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
676 la %r2,SP_PTREGS(%r15) # load pt_regs
677 l %r1,BASED(.Ldo_signal)
678 basr %r14,%r1 # call do_signal
679 stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
680 TRACE_IRQS_OFF
681 b BASED(io_return)
682
683#
684# _TIF_SIGPENDING is set, call do_signal
685#
686io_notify_resume:
687 # TRACE_IRQS_ON already done at io_return
688 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
689 la %r2,SP_PTREGS(%r15) # load pt_regs
690 l %r1,BASED(.Ldo_notify_resume)
691 basr %r14,%r1 # call do_signal
692 stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
693 TRACE_IRQS_OFF
694 b BASED(io_return)
695
696/*
697 * External interrupt handler routine
698 */
699
700ENTRY(ext_int_handler)
701 stck __LC_INT_CLOCK
702 stpt __LC_ASYNC_ENTER_TIMER
703 SAVE_ALL_ASYNC __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16
704 CREATE_STACK_FRAME __LC_SAVE_AREA+16
705 mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
706 l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
707 tm SP_PSW+1(%r15),0x01 # interrupting from user ?
708 bz BASED(ext_no_vtime)
709 UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
710 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
711 mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
712ext_no_vtime:
713 TRACE_IRQS_OFF
714 la %r2,SP_PTREGS(%r15) # address of register-save area
715 l %r3,__LC_CPU_ADDRESS # get cpu address + interruption code
716 l %r4,__LC_EXT_PARAMS # get external parameters
717 l %r1,BASED(.Ldo_extint)
718 basr %r14,%r1
719 b BASED(io_return)
720
721__critical_end:
722
723/*
724 * Machine check handler routines
725 */
726
727ENTRY(mcck_int_handler)
728 stck __LC_MCCK_CLOCK
729 spt __LC_CPU_TIMER_SAVE_AREA # revalidate cpu timer
730 lm %r0,%r15,__LC_GPREGS_SAVE_AREA # revalidate gprs
731 SAVE_ALL_BASE __LC_SAVE_AREA+32
732 la %r12,__LC_MCK_OLD_PSW
733 tm __LC_MCCK_CODE,0x80 # system damage?
734 bo BASED(mcck_int_main) # yes -> rest of mcck code invalid
735 mvc __LC_MCCK_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA
736 tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid?
737 bo BASED(1f)
738 la %r14,__LC_SYNC_ENTER_TIMER
739 clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER
740 bl BASED(0f)
741 la %r14,__LC_ASYNC_ENTER_TIMER
7420: clc 0(8,%r14),__LC_EXIT_TIMER
743 bl BASED(0f)
744 la %r14,__LC_EXIT_TIMER
7450: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER
746 bl BASED(0f)
747 la %r14,__LC_LAST_UPDATE_TIMER
7480: spt 0(%r14)
749 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
7501: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid?
751 bno BASED(mcck_int_main) # no -> skip cleanup critical
752 tm __LC_MCK_OLD_PSW+1,0x01 # test problem state bit
753 bnz BASED(mcck_int_main) # from user -> load async stack
754 clc __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_end)
755 bhe BASED(mcck_int_main)
756 clc __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_start)
757 bl BASED(mcck_int_main)
758 l %r14,BASED(.Lcleanup_critical)
759 basr %r14,%r14
760mcck_int_main:
761 l %r14,__LC_PANIC_STACK # are we already on the panic stack?
762 slr %r14,%r15
763 sra %r14,PAGE_SHIFT
764 be BASED(0f)
765 l %r15,__LC_PANIC_STACK # load panic stack
7660: s %r15,BASED(.Lc_spsize) # make room for registers & psw
767 CREATE_STACK_FRAME __LC_SAVE_AREA+32
768 mvc SP_PSW(8,%r15),0(%r12)
769 l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
770 tm __LC_MCCK_CODE+2,0x08 # mwp of old psw valid?
771 bno BASED(mcck_no_vtime) # no -> skip cleanup critical
772 tm SP_PSW+1(%r15),0x01 # interrupting from user ?
773 bz BASED(mcck_no_vtime)
774 UPDATE_VTIME __LC_EXIT_TIMER,__LC_MCCK_ENTER_TIMER,__LC_USER_TIMER
775 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
776 mvc __LC_LAST_UPDATE_TIMER(8),__LC_MCCK_ENTER_TIMER
777mcck_no_vtime:
778 la %r2,SP_PTREGS(%r15) # load pt_regs
779 l %r1,BASED(.Ls390_mcck)
780 basr %r14,%r1 # call machine check handler
781 tm SP_PSW+1(%r15),0x01 # returning to user ?
782 bno BASED(mcck_return)
783 l %r1,__LC_KERNEL_STACK # switch to kernel stack
784 s %r1,BASED(.Lc_spsize)
785 mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
786 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
787 lr %r15,%r1
788 stosm __SF_EMPTY(%r15),0x04 # turn dat on
789 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
790 bno BASED(mcck_return)
791 TRACE_IRQS_OFF
792 l %r1,BASED(.Ls390_handle_mcck)
793 basr %r14,%r1 # call machine check handler
794 TRACE_IRQS_ON
795mcck_return:
796 mvc __LC_RETURN_MCCK_PSW(8),SP_PSW(%r15) # move return PSW
797 ni __LC_RETURN_MCCK_PSW+1,0xfd # clear wait state bit
798 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
799 bno BASED(0f)
800 lm %r0,%r15,SP_R0(%r15) # load gprs 0-15
801 stpt __LC_EXIT_TIMER
802 lpsw __LC_RETURN_MCCK_PSW # back to caller
8030: lm %r0,%r15,SP_R0(%r15) # load gprs 0-15
804 lpsw __LC_RETURN_MCCK_PSW # back to caller
805
806 RESTORE_ALL __LC_RETURN_MCCK_PSW,0
807
808/*
809 * Restart interruption handler, kick starter for additional CPUs
810 */
811#ifdef CONFIG_SMP
812 __CPUINIT
813ENTRY(restart_int_handler)
814 basr %r1,0
815restart_base:
816 spt restart_vtime-restart_base(%r1)
817 stck __LC_LAST_UPDATE_CLOCK
818 mvc __LC_LAST_UPDATE_TIMER(8),restart_vtime-restart_base(%r1)
819 mvc __LC_EXIT_TIMER(8),restart_vtime-restart_base(%r1)
820 l %r15,__LC_SAVE_AREA+60 # load ksp
821 lctl %c0,%c15,__LC_CREGS_SAVE_AREA # get new ctl regs
822 lam %a0,%a15,__LC_AREGS_SAVE_AREA
823 lm %r6,%r15,__SF_GPRS(%r15) # load registers from clone
824 l %r1,__LC_THREAD_INFO
825 mvc __LC_USER_TIMER(8),__TI_user_timer(%r1)
826 mvc __LC_SYSTEM_TIMER(8),__TI_system_timer(%r1)
827 xc __LC_STEAL_TIMER(8),__LC_STEAL_TIMER
828 stosm __SF_EMPTY(%r15),0x04 # now we can turn dat on
829 basr %r14,0
830 l %r14,restart_addr-.(%r14)
831 basr %r14,%r14 # branch to start_secondary
832restart_addr:
833 .long start_secondary
834 .align 8
835restart_vtime:
836 .long 0x7fffffff,0xffffffff
837 .previous
838#else
839/*
840 * If we do not run with SMP enabled, let the new CPU crash ...
841 */
842ENTRY(restart_int_handler)
843 basr %r1,0
844restart_base:
845 lpsw restart_crash-restart_base(%r1)
846 .align 8
847restart_crash:
848 .long 0x000a0000,0x00000000
849restart_go:
850#endif
851
852#
853# PSW restart interrupt handler
854#
855ENTRY(psw_restart_int_handler)
856 st %r15,__LC_SAVE_AREA_64(%r0) # save r15
857 basr %r15,0
8580: l %r15,.Lrestart_stack-0b(%r15) # load restart stack
859 l %r15,0(%r15)
860 ahi %r15,-SP_SIZE # make room for pt_regs
861 stm %r0,%r14,SP_R0(%r15) # store gprs %r0-%r14 to stack
862 mvc SP_R15(4,%r15),__LC_SAVE_AREA_64(%r0)# store saved %r15 to stack
863 mvc SP_PSW(8,%r15),__LC_RST_OLD_PSW(%r0) # store restart old psw
864 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # set backchain to 0
865 basr %r14,0
8661: l %r14,.Ldo_restart-1b(%r14)
867 basr %r14,%r14
868
869 basr %r14,0 # load disabled wait PSW if
8702: lpsw restart_psw_crash-2b(%r14) # do_restart returns
871 .align 4
872.Ldo_restart:
873 .long do_restart
874.Lrestart_stack:
875 .long restart_stack
876 .align 8
877restart_psw_crash:
878 .long 0x000a0000,0x00000000 + restart_psw_crash
879
880 .section .kprobes.text, "ax"
881
882#ifdef CONFIG_CHECK_STACK
883/*
884 * The synchronous or the asynchronous stack overflowed. We are dead.
885 * No need to properly save the registers, we are going to panic anyway.
886 * Setup a pt_regs so that show_trace can provide a good call trace.
887 */
888stack_overflow:
889 l %r15,__LC_PANIC_STACK # change to panic stack
890 sl %r15,BASED(.Lc_spsize)
891 mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
892 stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
893 la %r1,__LC_SAVE_AREA
894 ch %r12,BASED(.L0x020) # old psw addr == __LC_SVC_OLD_PSW ?
895 be BASED(0f)
896 ch %r12,BASED(.L0x028) # old psw addr == __LC_PGM_OLD_PSW ?
897 be BASED(0f)
898 la %r1,__LC_SAVE_AREA+16
8990: mvc SP_R12(16,%r15),0(%r1) # move %r12-%r15 to stack
900 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear back chain
901 l %r1,BASED(1f) # branch to kernel_stack_overflow
902 la %r2,SP_PTREGS(%r15) # load pt_regs
903 br %r1
9041: .long kernel_stack_overflow
905#endif
906
907cleanup_table_system_call:
908 .long system_call + 0x80000000, sysc_do_svc + 0x80000000
909cleanup_table_sysc_tif:
910 .long sysc_tif + 0x80000000, sysc_restore + 0x80000000
911cleanup_table_sysc_restore:
912 .long sysc_restore + 0x80000000, sysc_done + 0x80000000
913cleanup_table_io_tif:
914 .long io_tif + 0x80000000, io_restore + 0x80000000
915cleanup_table_io_restore:
916 .long io_restore + 0x80000000, io_done + 0x80000000
917
918cleanup_critical:
919 clc 4(4,%r12),BASED(cleanup_table_system_call)
920 bl BASED(0f)
921 clc 4(4,%r12),BASED(cleanup_table_system_call+4)
922 bl BASED(cleanup_system_call)
9230:
924 clc 4(4,%r12),BASED(cleanup_table_sysc_tif)
925 bl BASED(0f)
926 clc 4(4,%r12),BASED(cleanup_table_sysc_tif+4)
927 bl BASED(cleanup_sysc_tif)
9280:
929 clc 4(4,%r12),BASED(cleanup_table_sysc_restore)
930 bl BASED(0f)
931 clc 4(4,%r12),BASED(cleanup_table_sysc_restore+4)
932 bl BASED(cleanup_sysc_restore)
9330:
934 clc 4(4,%r12),BASED(cleanup_table_io_tif)
935 bl BASED(0f)
936 clc 4(4,%r12),BASED(cleanup_table_io_tif+4)
937 bl BASED(cleanup_io_tif)
9380:
939 clc 4(4,%r12),BASED(cleanup_table_io_restore)
940 bl BASED(0f)
941 clc 4(4,%r12),BASED(cleanup_table_io_restore+4)
942 bl BASED(cleanup_io_restore)
9430:
944 br %r14
945
946cleanup_system_call:
947 mvc __LC_RETURN_PSW(8),0(%r12)
948 clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+4)
949 bh BASED(0f)
950 mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
951 c %r12,BASED(.Lmck_old_psw)
952 be BASED(0f)
953 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
9540: c %r12,BASED(.Lmck_old_psw)
955 la %r12,__LC_SAVE_AREA+32
956 be BASED(0f)
957 la %r12,__LC_SAVE_AREA+16
9580: clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+8)
959 bhe BASED(cleanup_vtime)
960 clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn)
961 bh BASED(0f)
962 mvc __LC_SAVE_AREA(16),0(%r12)
9630: st %r13,4(%r12)
964 l %r15,__LC_KERNEL_STACK # problem state -> load ksp
965 s %r15,BASED(.Lc_spsize) # make room for registers & psw
966 st %r15,12(%r12)
967 CREATE_STACK_FRAME __LC_SAVE_AREA
968 mvc SP_PSW(8,%r15),__LC_SVC_OLD_PSW
969 mvc SP_ILC(4,%r15),__LC_SVC_ILC
970 mvc 0(4,%r12),__LC_THREAD_INFO
971cleanup_vtime:
972 clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+12)
973 bhe BASED(cleanup_stime)
974 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
975cleanup_stime:
976 clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+16)
977 bh BASED(cleanup_update)
978 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
979cleanup_update:
980 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
981 mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_system_call+4)
982 la %r12,__LC_RETURN_PSW
983 br %r14
984cleanup_system_call_insn:
985 .long sysc_saveall + 0x80000000
986 .long system_call + 0x80000000
987 .long sysc_vtime + 0x80000000
988 .long sysc_stime + 0x80000000
989 .long sysc_update + 0x80000000
990
991cleanup_sysc_tif:
992 mvc __LC_RETURN_PSW(4),0(%r12)
993 mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_sysc_tif)
994 la %r12,__LC_RETURN_PSW
995 br %r14
996
997cleanup_sysc_restore:
998 clc 4(4,%r12),BASED(cleanup_sysc_restore_insn)
999 be BASED(2f)
1000 mvc __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
1001 c %r12,BASED(.Lmck_old_psw)
1002 be BASED(0f)
1003 mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
10040: clc 4(4,%r12),BASED(cleanup_sysc_restore_insn+4)
1005 be BASED(2f)
1006 mvc __LC_RETURN_PSW(8),SP_PSW(%r15)
1007 c %r12,BASED(.Lmck_old_psw)
1008 la %r12,__LC_SAVE_AREA+32
1009 be BASED(1f)
1010 la %r12,__LC_SAVE_AREA+16
10111: mvc 0(16,%r12),SP_R12(%r15)
1012 lm %r0,%r11,SP_R0(%r15)
1013 l %r15,SP_R15(%r15)
10142: la %r12,__LC_RETURN_PSW
1015 br %r14
1016cleanup_sysc_restore_insn:
1017 .long sysc_done - 4 + 0x80000000
1018 .long sysc_done - 8 + 0x80000000
1019
1020cleanup_io_tif:
1021 mvc __LC_RETURN_PSW(4),0(%r12)
1022 mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_io_tif)
1023 la %r12,__LC_RETURN_PSW
1024 br %r14
1025
1026cleanup_io_restore:
1027 clc 4(4,%r12),BASED(cleanup_io_restore_insn)
1028 be BASED(1f)
1029 mvc __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
1030 clc 4(4,%r12),BASED(cleanup_io_restore_insn+4)
1031 be BASED(1f)
1032 mvc __LC_RETURN_PSW(8),SP_PSW(%r15)
1033 mvc __LC_SAVE_AREA+32(16),SP_R12(%r15)
1034 lm %r0,%r11,SP_R0(%r15)
1035 l %r15,SP_R15(%r15)
10361: la %r12,__LC_RETURN_PSW
1037 br %r14
1038cleanup_io_restore_insn:
1039 .long io_done - 4 + 0x80000000
1040 .long io_done - 8 + 0x80000000
1041
1042/*
1043 * Integer constants
1044 */
1045 .align 4
1046.Lc_spsize: .long SP_SIZE
1047.Lc_overhead: .long STACK_FRAME_OVERHEAD
1048.Lnr_syscalls: .long NR_syscalls
1049.L0x018: .short 0x018
1050.L0x020: .short 0x020
1051.L0x028: .short 0x028
1052.L0x030: .short 0x030
1053.L0x038: .short 0x038
1054.Lc_1: .long 1
1055
1056/*
1057 * Symbol constants
1058 */
1059.Ls390_mcck: .long s390_do_machine_check
1060.Ls390_handle_mcck:
1061 .long s390_handle_mcck
1062.Lmck_old_psw: .long __LC_MCK_OLD_PSW
1063.Ldo_IRQ: .long do_IRQ
1064.Ldo_extint: .long do_extint
1065.Ldo_signal: .long do_signal
1066.Ldo_notify_resume:
1067 .long do_notify_resume
1068.Lhandle_per: .long do_per_trap
1069.Ldo_execve: .long do_execve
1070.Lexecve_tail: .long execve_tail
1071.Ljump_table: .long pgm_check_table
1072.Lschedule: .long schedule
1073#ifdef CONFIG_PREEMPT
1074.Lpreempt_schedule_irq:
1075 .long preempt_schedule_irq
1076#endif
1077.Ltrace_entry: .long do_syscall_trace_enter
1078.Ltrace_exit: .long do_syscall_trace_exit
1079.Lschedtail: .long schedule_tail
1080.Lsysc_table: .long sys_call_table
1081#ifdef CONFIG_TRACE_IRQFLAGS
1082.Ltrace_irq_on_caller:
1083 .long trace_hardirqs_on_caller
1084.Ltrace_irq_off_caller:
1085 .long trace_hardirqs_off_caller
1086#endif
1087#ifdef CONFIG_LOCKDEP
1088.Llockdep_sys_exit:
1089 .long lockdep_sys_exit
1090#endif
1091.Lcritical_start:
1092 .long __critical_start + 0x80000000
1093.Lcritical_end:
1094 .long __critical_end + 0x80000000
1095.Lcleanup_critical:
1096 .long cleanup_critical
1097
1098 .section .rodata, "a"
1099#define SYSCALL(esa,esame,emu) .long esa
1100 .globl sys_call_table
1101sys_call_table:
1102#include "syscalls.S"
1103#undef SYSCALL
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/cache.h>
14#include <asm/errno.h>
15#include <asm/ptrace.h>
16#include <asm/thread_info.h>
17#include <asm/asm-offsets.h>
18#include <asm/unistd.h>
19#include <asm/page.h>
20#include <asm/sigp.h>
21#include <asm/irq.h>
22
23__PT_R0 = __PT_GPRS
24__PT_R1 = __PT_GPRS + 4
25__PT_R2 = __PT_GPRS + 8
26__PT_R3 = __PT_GPRS + 12
27__PT_R4 = __PT_GPRS + 16
28__PT_R5 = __PT_GPRS + 20
29__PT_R6 = __PT_GPRS + 24
30__PT_R7 = __PT_GPRS + 28
31__PT_R8 = __PT_GPRS + 32
32__PT_R9 = __PT_GPRS + 36
33__PT_R10 = __PT_GPRS + 40
34__PT_R11 = __PT_GPRS + 44
35__PT_R12 = __PT_GPRS + 48
36__PT_R13 = __PT_GPRS + 524
37__PT_R14 = __PT_GPRS + 56
38__PT_R15 = __PT_GPRS + 60
39
40_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
41 _TIF_MCCK_PENDING | _TIF_PER_TRAP | _TIF_ASCE)
42_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
43 _TIF_MCCK_PENDING | _TIF_ASCE)
44_TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
45 _TIF_SYSCALL_TRACEPOINT)
46_TIF_TRANSFER = (_TIF_MCCK_PENDING | _TIF_TLB_WAIT)
47
48STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
49STACK_SIZE = 1 << STACK_SHIFT
50STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
51
52#define BASED(name) name-system_call(%r13)
53
54 .macro TRACE_IRQS_ON
55#ifdef CONFIG_TRACE_IRQFLAGS
56 basr %r2,%r0
57 l %r1,BASED(.Lhardirqs_on)
58 basr %r14,%r1 # call trace_hardirqs_on_caller
59#endif
60 .endm
61
62 .macro TRACE_IRQS_OFF
63#ifdef CONFIG_TRACE_IRQFLAGS
64 basr %r2,%r0
65 l %r1,BASED(.Lhardirqs_off)
66 basr %r14,%r1 # call trace_hardirqs_off_caller
67#endif
68 .endm
69
70 .macro LOCKDEP_SYS_EXIT
71#ifdef CONFIG_LOCKDEP
72 tm __PT_PSW+1(%r11),0x01 # returning to user ?
73 jz .+10
74 l %r1,BASED(.Llockdep_sys_exit)
75 basr %r14,%r1 # call lockdep_sys_exit
76#endif
77 .endm
78
79 .macro CHECK_STACK stacksize,savearea
80#ifdef CONFIG_CHECK_STACK
81 tml %r15,\stacksize - CONFIG_STACK_GUARD
82 la %r14,\savearea
83 jz stack_overflow
84#endif
85 .endm
86
87 .macro SWITCH_ASYNC savearea,stack,shift
88 tmh %r8,0x0001 # interrupting from user ?
89 jnz 1f
90 lr %r14,%r9
91 sl %r14,BASED(.Lcritical_start)
92 cl %r14,BASED(.Lcritical_length)
93 jhe 0f
94 la %r11,\savearea # inside critical section, do cleanup
95 bras %r14,cleanup_critical
96 tmh %r8,0x0001 # retest problem state after cleanup
97 jnz 1f
980: l %r14,\stack # are we already on the target stack?
99 slr %r14,%r15
100 sra %r14,\shift
101 jnz 1f
102 CHECK_STACK 1<<\shift,\savearea
103 ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
104 j 2f
1051: l %r15,\stack # load target stack
1062: la %r11,STACK_FRAME_OVERHEAD(%r15)
107 .endm
108
109 .macro ADD64 high,low,timer
110 al \high,\timer
111 al \low,4+\timer
112 brc 12,.+8
113 ahi \high,1
114 .endm
115
116 .macro SUB64 high,low,timer
117 sl \high,\timer
118 sl \low,4+\timer
119 brc 3,.+8
120 ahi \high,-1
121 .endm
122
123 .macro UPDATE_VTIME high,low,enter_timer
124 lm \high,\low,__LC_EXIT_TIMER
125 SUB64 \high,\low,\enter_timer
126 ADD64 \high,\low,__LC_USER_TIMER
127 stm \high,\low,__LC_USER_TIMER
128 lm \high,\low,__LC_LAST_UPDATE_TIMER
129 SUB64 \high,\low,__LC_EXIT_TIMER
130 ADD64 \high,\low,__LC_SYSTEM_TIMER
131 stm \high,\low,__LC_SYSTEM_TIMER
132 mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer
133 .endm
134
135 .macro REENABLE_IRQS
136 st %r8,__LC_RETURN_PSW
137 ni __LC_RETURN_PSW,0xbf
138 ssm __LC_RETURN_PSW
139 .endm
140
141 .section .kprobes.text, "ax"
142
143/*
144 * Scheduler resume function, called by switch_to
145 * gpr2 = (task_struct *) prev
146 * gpr3 = (task_struct *) next
147 * Returns:
148 * gpr2 = prev
149 */
150ENTRY(__switch_to)
151 stm %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
152 st %r15,__THREAD_ksp(%r2) # store kernel stack of prev
153 l %r4,__THREAD_info(%r2) # get thread_info of prev
154 l %r5,__THREAD_info(%r3) # get thread_info of next
155 lr %r15,%r5
156 ahi %r15,STACK_INIT # end of kernel stack of next
157 st %r3,__LC_CURRENT # store task struct of next
158 st %r5,__LC_THREAD_INFO # store thread info of next
159 st %r15,__LC_KERNEL_STACK # store end of kernel stack
160 lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
161 mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next
162 l %r15,__THREAD_ksp(%r3) # load kernel stack of next
163 lhi %r6,_TIF_TRANSFER # transfer TIF bits
164 n %r6,__TI_flags(%r4) # isolate TIF bits
165 jz 0f
166 o %r6,__TI_flags(%r5) # set TIF bits of next
167 st %r6,__TI_flags(%r5)
168 ni __TI_flags+3(%r4),255-_TIF_TRANSFER # clear TIF bits of prev
1690: lm %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
170 br %r14
171
172__critical_start:
173/*
174 * SVC interrupt handler routine. System calls are synchronous events and
175 * are executed with interrupts enabled.
176 */
177
178ENTRY(system_call)
179 stpt __LC_SYNC_ENTER_TIMER
180sysc_stm:
181 stm %r8,%r15,__LC_SAVE_AREA_SYNC
182 l %r12,__LC_THREAD_INFO
183 l %r13,__LC_SVC_NEW_PSW+4
184sysc_per:
185 l %r15,__LC_KERNEL_STACK
186 la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
187sysc_vtime:
188 UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
189 stm %r0,%r7,__PT_R0(%r11)
190 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC
191 mvc __PT_PSW(8,%r11),__LC_SVC_OLD_PSW
192 mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC
193sysc_do_svc:
194 oi __TI_flags+3(%r12),_TIF_SYSCALL
195 l %r10,__TI_sysc_table(%r12) # 31 bit system call table
196 lh %r8,__PT_INT_CODE+2(%r11)
197 sla %r8,2 # shift and test for svc0
198 jnz sysc_nr_ok
199 # svc 0: system call number in %r1
200 cl %r1,BASED(.Lnr_syscalls)
201 jnl sysc_nr_ok
202 sth %r1,__PT_INT_CODE+2(%r11)
203 lr %r8,%r1
204 sla %r8,2
205sysc_nr_ok:
206 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
207 st %r2,__PT_ORIG_GPR2(%r11)
208 st %r7,STACK_FRAME_OVERHEAD(%r15)
209 l %r9,0(%r8,%r10) # get system call addr.
210 tm __TI_flags+2(%r12),_TIF_TRACE >> 8
211 jnz sysc_tracesys
212 basr %r14,%r9 # call sys_xxxx
213 st %r2,__PT_R2(%r11) # store return value
214
215sysc_return:
216 LOCKDEP_SYS_EXIT
217sysc_tif:
218 tm __PT_PSW+1(%r11),0x01 # returning to user ?
219 jno sysc_restore
220 tm __TI_flags+3(%r12),_TIF_WORK_SVC
221 jnz sysc_work # check for work
222 ni __TI_flags+3(%r12),255-_TIF_SYSCALL
223sysc_restore:
224 mvc __LC_RETURN_PSW(8),__PT_PSW(%r11)
225 stpt __LC_EXIT_TIMER
226 lm %r0,%r15,__PT_R0(%r11)
227 lpsw __LC_RETURN_PSW
228sysc_done:
229
230#
231# One of the work bits is on. Find out which one.
232#
233sysc_work:
234 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
235 jo sysc_mcck_pending
236 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
237 jo sysc_reschedule
238 tm __TI_flags+3(%r12),_TIF_PER_TRAP
239 jo sysc_singlestep
240 tm __TI_flags+3(%r12),_TIF_SIGPENDING
241 jo sysc_sigpending
242 tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
243 jo sysc_notify_resume
244 tm __TI_flags+3(%r12),_TIF_ASCE
245 jo sysc_uaccess
246 j sysc_return # beware of critical section cleanup
247
248#
249# _TIF_NEED_RESCHED is set, call schedule
250#
251sysc_reschedule:
252 l %r1,BASED(.Lschedule)
253 la %r14,BASED(sysc_return)
254 br %r1 # call schedule
255
256#
257# _TIF_MCCK_PENDING is set, call handler
258#
259sysc_mcck_pending:
260 l %r1,BASED(.Lhandle_mcck)
261 la %r14,BASED(sysc_return)
262 br %r1 # TIF bit will be cleared by handler
263
264#
265# _TIF_ASCE is set, load user space asce
266#
267sysc_uaccess:
268 ni __TI_flags+3(%r12),255-_TIF_ASCE
269 lctl %c1,%c1,__LC_USER_ASCE # load primary asce
270 j sysc_return
271
272#
273# _TIF_SIGPENDING is set, call do_signal
274#
275sysc_sigpending:
276 lr %r2,%r11 # pass pointer to pt_regs
277 l %r1,BASED(.Ldo_signal)
278 basr %r14,%r1 # call do_signal
279 tm __TI_flags+3(%r12),_TIF_SYSCALL
280 jno sysc_return
281 lm %r2,%r7,__PT_R2(%r11) # load svc arguments
282 l %r10,__TI_sysc_table(%r12) # 31 bit system call table
283 xr %r8,%r8 # svc 0 returns -ENOSYS
284 clc __PT_INT_CODE+2(2,%r11),BASED(.Lnr_syscalls+2)
285 jnl sysc_nr_ok # invalid svc number -> do svc 0
286 lh %r8,__PT_INT_CODE+2(%r11) # load new svc number
287 sla %r8,2
288 j sysc_nr_ok # restart svc
289
290#
291# _TIF_NOTIFY_RESUME is set, call do_notify_resume
292#
293sysc_notify_resume:
294 lr %r2,%r11 # pass pointer to pt_regs
295 l %r1,BASED(.Ldo_notify_resume)
296 la %r14,BASED(sysc_return)
297 br %r1 # call do_notify_resume
298
299#
300# _TIF_PER_TRAP is set, call do_per_trap
301#
302sysc_singlestep:
303 ni __TI_flags+3(%r12),255-_TIF_PER_TRAP
304 lr %r2,%r11 # pass pointer to pt_regs
305 l %r1,BASED(.Ldo_per_trap)
306 la %r14,BASED(sysc_return)
307 br %r1 # call do_per_trap
308
309#
310# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
311# and after the system call
312#
313sysc_tracesys:
314 l %r1,BASED(.Ltrace_enter)
315 lr %r2,%r11 # pass pointer to pt_regs
316 la %r3,0
317 xr %r0,%r0
318 icm %r0,3,__PT_INT_CODE+2(%r11)
319 st %r0,__PT_R2(%r11)
320 basr %r14,%r1 # call do_syscall_trace_enter
321 cl %r2,BASED(.Lnr_syscalls)
322 jnl sysc_tracenogo
323 lr %r8,%r2
324 sll %r8,2
325 l %r9,0(%r8,%r10)
326sysc_tracego:
327 lm %r3,%r7,__PT_R3(%r11)
328 st %r7,STACK_FRAME_OVERHEAD(%r15)
329 l %r2,__PT_ORIG_GPR2(%r11)
330 basr %r14,%r9 # call sys_xxx
331 st %r2,__PT_R2(%r11) # store return value
332sysc_tracenogo:
333 tm __TI_flags+2(%r12),_TIF_TRACE >> 8
334 jz sysc_return
335 l %r1,BASED(.Ltrace_exit)
336 lr %r2,%r11 # pass pointer to pt_regs
337 la %r14,BASED(sysc_return)
338 br %r1 # call do_syscall_trace_exit
339
340#
341# a new process exits the kernel with ret_from_fork
342#
343ENTRY(ret_from_fork)
344 la %r11,STACK_FRAME_OVERHEAD(%r15)
345 l %r12,__LC_THREAD_INFO
346 l %r13,__LC_SVC_NEW_PSW+4
347 l %r1,BASED(.Lschedule_tail)
348 basr %r14,%r1 # call schedule_tail
349 TRACE_IRQS_ON
350 ssm __LC_SVC_NEW_PSW # reenable interrupts
351 tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ?
352 jne sysc_tracenogo
353 # it's a kernel thread
354 lm %r9,%r10,__PT_R9(%r11) # load gprs
355ENTRY(kernel_thread_starter)
356 la %r2,0(%r10)
357 basr %r14,%r9
358 j sysc_tracenogo
359
360/*
361 * Program check handler routine
362 */
363
364ENTRY(pgm_check_handler)
365 stpt __LC_SYNC_ENTER_TIMER
366 stm %r8,%r15,__LC_SAVE_AREA_SYNC
367 l %r12,__LC_THREAD_INFO
368 l %r13,__LC_SVC_NEW_PSW+4
369 lm %r8,%r9,__LC_PGM_OLD_PSW
370 tmh %r8,0x0001 # test problem state bit
371 jnz 1f # -> fault in user space
372 tmh %r8,0x4000 # PER bit set in old PSW ?
373 jnz 0f # -> enabled, can't be a double fault
374 tm __LC_PGM_ILC+3,0x80 # check for per exception
375 jnz pgm_svcper # -> single stepped svc
3760: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
377 ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
378 j 2f
3791: UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
380 l %r15,__LC_KERNEL_STACK
3812: la %r11,STACK_FRAME_OVERHEAD(%r15)
382 stm %r0,%r7,__PT_R0(%r11)
383 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC
384 stm %r8,%r9,__PT_PSW(%r11)
385 mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC
386 mvc __PT_INT_PARM_LONG(4,%r11),__LC_TRANS_EXC_CODE
387 tm __LC_PGM_ILC+3,0x80 # check for per exception
388 jz 0f
389 l %r1,__TI_task(%r12)
390 tmh %r8,0x0001 # kernel per event ?
391 jz pgm_kprobe
392 oi __TI_flags+3(%r12),_TIF_PER_TRAP
393 mvc __THREAD_per_address(4,%r1),__LC_PER_ADDRESS
394 mvc __THREAD_per_cause(2,%r1),__LC_PER_CAUSE
395 mvc __THREAD_per_paid(1,%r1),__LC_PER_PAID
3960: REENABLE_IRQS
397 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
398 l %r1,BASED(.Ljump_table)
399 la %r10,0x7f
400 n %r10,__PT_INT_CODE(%r11)
401 je sysc_return
402 sll %r10,2
403 l %r1,0(%r10,%r1) # load address of handler routine
404 lr %r2,%r11 # pass pointer to pt_regs
405 basr %r14,%r1 # branch to interrupt-handler
406 j sysc_return
407
408#
409# PER event in supervisor state, must be kprobes
410#
411pgm_kprobe:
412 REENABLE_IRQS
413 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
414 l %r1,BASED(.Ldo_per_trap)
415 lr %r2,%r11 # pass pointer to pt_regs
416 basr %r14,%r1 # call do_per_trap
417 j sysc_return
418
419#
420# single stepped system call
421#
422pgm_svcper:
423 oi __TI_flags+3(%r12),_TIF_PER_TRAP
424 mvc __LC_RETURN_PSW(4),__LC_SVC_NEW_PSW
425 mvc __LC_RETURN_PSW+4(4),BASED(.Lsysc_per)
426 lpsw __LC_RETURN_PSW # branch to sysc_per and enable irqs
427
428/*
429 * IO interrupt handler routine
430 */
431
432ENTRY(io_int_handler)
433 stck __LC_INT_CLOCK
434 stpt __LC_ASYNC_ENTER_TIMER
435 stm %r8,%r15,__LC_SAVE_AREA_ASYNC
436 l %r12,__LC_THREAD_INFO
437 l %r13,__LC_SVC_NEW_PSW+4
438 lm %r8,%r9,__LC_IO_OLD_PSW
439 tmh %r8,0x0001 # interrupting from user ?
440 jz io_skip
441 UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER
442io_skip:
443 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
444 stm %r0,%r7,__PT_R0(%r11)
445 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC
446 stm %r8,%r9,__PT_PSW(%r11)
447 mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
448 TRACE_IRQS_OFF
449 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
450io_loop:
451 l %r1,BASED(.Ldo_IRQ)
452 lr %r2,%r11 # pass pointer to pt_regs
453 lhi %r3,IO_INTERRUPT
454 tm __PT_INT_CODE+8(%r11),0x80 # adapter interrupt ?
455 jz io_call
456 lhi %r3,THIN_INTERRUPT
457io_call:
458 basr %r14,%r1 # call do_IRQ
459 tm __LC_MACHINE_FLAGS+2,0x10 # MACHINE_FLAG_LPAR
460 jz io_return
461 tpi 0
462 jz io_return
463 mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
464 j io_loop
465io_return:
466 LOCKDEP_SYS_EXIT
467 TRACE_IRQS_ON
468io_tif:
469 tm __TI_flags+3(%r12),_TIF_WORK_INT
470 jnz io_work # there is work to do (signals etc.)
471io_restore:
472 mvc __LC_RETURN_PSW(8),__PT_PSW(%r11)
473 stpt __LC_EXIT_TIMER
474 lm %r0,%r15,__PT_R0(%r11)
475 lpsw __LC_RETURN_PSW
476io_done:
477
478#
479# There is work todo, find out in which context we have been interrupted:
480# 1) if we return to user space we can do all _TIF_WORK_INT work
481# 2) if we return to kernel code and preemptive scheduling is enabled check
482# the preemption counter and if it is zero call preempt_schedule_irq
483# Before any work can be done, a switch to the kernel stack is required.
484#
485io_work:
486 tm __PT_PSW+1(%r11),0x01 # returning to user ?
487 jo io_work_user # yes -> do resched & signal
488#ifdef CONFIG_PREEMPT
489 # check for preemptive scheduling
490 icm %r0,15,__TI_precount(%r12)
491 jnz io_restore # preemption disabled
492 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
493 jno io_restore
494 # switch to kernel stack
495 l %r1,__PT_R15(%r11)
496 ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
497 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
498 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
499 la %r11,STACK_FRAME_OVERHEAD(%r1)
500 lr %r15,%r1
501 # TRACE_IRQS_ON already done at io_return, call
502 # TRACE_IRQS_OFF to keep things symmetrical
503 TRACE_IRQS_OFF
504 l %r1,BASED(.Lpreempt_irq)
505 basr %r14,%r1 # call preempt_schedule_irq
506 j io_return
507#else
508 j io_restore
509#endif
510
511#
512# Need to do work before returning to userspace, switch to kernel stack
513#
514io_work_user:
515 l %r1,__LC_KERNEL_STACK
516 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
517 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
518 la %r11,STACK_FRAME_OVERHEAD(%r1)
519 lr %r15,%r1
520
521#
522# One of the work bits is on. Find out which one.
523# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED
524# and _TIF_MCCK_PENDING
525#
526io_work_tif:
527 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
528 jo io_mcck_pending
529 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
530 jo io_reschedule
531 tm __TI_flags+3(%r12),_TIF_SIGPENDING
532 jo io_sigpending
533 tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
534 jo io_notify_resume
535 tm __TI_flags+3(%r12),_TIF_ASCE
536 jo io_uaccess
537 j io_return # beware of critical section cleanup
538
539#
540# _TIF_MCCK_PENDING is set, call handler
541#
542io_mcck_pending:
543 # TRACE_IRQS_ON already done at io_return
544 l %r1,BASED(.Lhandle_mcck)
545 basr %r14,%r1 # TIF bit will be cleared by handler
546 TRACE_IRQS_OFF
547 j io_return
548
549#
550# _TIF_ASCE is set, load user space asce
551#
552io_uaccess:
553 ni __TI_flags+3(%r12),255-_TIF_ASCE
554 lctl %c1,%c1,__LC_USER_ASCE # load primary asce
555 j io_return
556
557#
558# _TIF_NEED_RESCHED is set, call schedule
559#
560io_reschedule:
561 # TRACE_IRQS_ON already done at io_return
562 l %r1,BASED(.Lschedule)
563 ssm __LC_SVC_NEW_PSW # reenable interrupts
564 basr %r14,%r1 # call scheduler
565 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
566 TRACE_IRQS_OFF
567 j io_return
568
569#
570# _TIF_SIGPENDING is set, call do_signal
571#
572io_sigpending:
573 # TRACE_IRQS_ON already done at io_return
574 l %r1,BASED(.Ldo_signal)
575 ssm __LC_SVC_NEW_PSW # reenable interrupts
576 lr %r2,%r11 # pass pointer to pt_regs
577 basr %r14,%r1 # call do_signal
578 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
579 TRACE_IRQS_OFF
580 j io_return
581
582#
583# _TIF_SIGPENDING is set, call do_signal
584#
585io_notify_resume:
586 # TRACE_IRQS_ON already done at io_return
587 l %r1,BASED(.Ldo_notify_resume)
588 ssm __LC_SVC_NEW_PSW # reenable interrupts
589 lr %r2,%r11 # pass pointer to pt_regs
590 basr %r14,%r1 # call do_notify_resume
591 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
592 TRACE_IRQS_OFF
593 j io_return
594
595/*
596 * External interrupt handler routine
597 */
598
599ENTRY(ext_int_handler)
600 stck __LC_INT_CLOCK
601 stpt __LC_ASYNC_ENTER_TIMER
602 stm %r8,%r15,__LC_SAVE_AREA_ASYNC
603 l %r12,__LC_THREAD_INFO
604 l %r13,__LC_SVC_NEW_PSW+4
605 lm %r8,%r9,__LC_EXT_OLD_PSW
606 tmh %r8,0x0001 # interrupting from user ?
607 jz ext_skip
608 UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER
609ext_skip:
610 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
611 stm %r0,%r7,__PT_R0(%r11)
612 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC
613 stm %r8,%r9,__PT_PSW(%r11)
614 mvc __PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
615 mvc __PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
616 TRACE_IRQS_OFF
617 l %r1,BASED(.Ldo_IRQ)
618 lr %r2,%r11 # pass pointer to pt_regs
619 lhi %r3,EXT_INTERRUPT
620 basr %r14,%r1 # call do_IRQ
621 j io_return
622
623/*
624 * Load idle PSW. The second "half" of this function is in cleanup_idle.
625 */
626ENTRY(psw_idle)
627 st %r3,__SF_EMPTY(%r15)
628 basr %r1,0
629 la %r1,psw_idle_lpsw+4-.(%r1)
630 st %r1,__SF_EMPTY+4(%r15)
631 oi __SF_EMPTY+4(%r15),0x80
632 stck __CLOCK_IDLE_ENTER(%r2)
633 stpt __TIMER_IDLE_ENTER(%r2)
634psw_idle_lpsw:
635 lpsw __SF_EMPTY(%r15)
636 br %r14
637psw_idle_end:
638
639__critical_end:
640
641/*
642 * Machine check handler routines
643 */
644
645ENTRY(mcck_int_handler)
646 stck __LC_MCCK_CLOCK
647 spt __LC_CPU_TIMER_SAVE_AREA # revalidate cpu timer
648 lm %r0,%r15,__LC_GPREGS_SAVE_AREA # revalidate gprs
649 l %r12,__LC_THREAD_INFO
650 l %r13,__LC_SVC_NEW_PSW+4
651 lm %r8,%r9,__LC_MCK_OLD_PSW
652 tm __LC_MCCK_CODE,0x80 # system damage?
653 jo mcck_panic # yes -> rest of mcck code invalid
654 la %r14,__LC_CPU_TIMER_SAVE_AREA
655 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
656 tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid?
657 jo 3f
658 la %r14,__LC_SYNC_ENTER_TIMER
659 clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER
660 jl 0f
661 la %r14,__LC_ASYNC_ENTER_TIMER
6620: clc 0(8,%r14),__LC_EXIT_TIMER
663 jl 1f
664 la %r14,__LC_EXIT_TIMER
6651: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER
666 jl 2f
667 la %r14,__LC_LAST_UPDATE_TIMER
6682: spt 0(%r14)
669 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
6703: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid?
671 jno mcck_panic # no -> skip cleanup critical
672 tm %r8,0x0001 # interrupting from user ?
673 jz mcck_skip
674 UPDATE_VTIME %r14,%r15,__LC_MCCK_ENTER_TIMER
675mcck_skip:
676 SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+32,__LC_PANIC_STACK,PAGE_SHIFT
677 stm %r0,%r7,__PT_R0(%r11)
678 mvc __PT_R8(32,%r11),__LC_GPREGS_SAVE_AREA+32
679 stm %r8,%r9,__PT_PSW(%r11)
680 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
681 l %r1,BASED(.Ldo_machine_check)
682 lr %r2,%r11 # pass pointer to pt_regs
683 basr %r14,%r1 # call s390_do_machine_check
684 tm __PT_PSW+1(%r11),0x01 # returning to user ?
685 jno mcck_return
686 l %r1,__LC_KERNEL_STACK # switch to kernel stack
687 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
688 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
689 la %r11,STACK_FRAME_OVERHEAD(%r15)
690 lr %r15,%r1
691 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off
692 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
693 jno mcck_return
694 TRACE_IRQS_OFF
695 l %r1,BASED(.Lhandle_mcck)
696 basr %r14,%r1 # call s390_handle_mcck
697 TRACE_IRQS_ON
698mcck_return:
699 mvc __LC_RETURN_MCCK_PSW(8),__PT_PSW(%r11) # move return PSW
700 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
701 jno 0f
702 lm %r0,%r15,__PT_R0(%r11)
703 stpt __LC_EXIT_TIMER
704 lpsw __LC_RETURN_MCCK_PSW
7050: lm %r0,%r15,__PT_R0(%r11)
706 lpsw __LC_RETURN_MCCK_PSW
707
708mcck_panic:
709 l %r14,__LC_PANIC_STACK
710 slr %r14,%r15
711 sra %r14,PAGE_SHIFT
712 jz 0f
713 l %r15,__LC_PANIC_STACK
714 j mcck_skip
7150: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
716 j mcck_skip
717
718#
719# PSW restart interrupt handler
720#
721ENTRY(restart_int_handler)
722 st %r15,__LC_SAVE_AREA_RESTART
723 l %r15,__LC_RESTART_STACK
724 ahi %r15,-__PT_SIZE # create pt_regs on stack
725 xc 0(__PT_SIZE,%r15),0(%r15)
726 stm %r0,%r14,__PT_R0(%r15)
727 mvc __PT_R15(4,%r15),__LC_SAVE_AREA_RESTART
728 mvc __PT_PSW(8,%r15),__LC_RST_OLD_PSW # store restart old psw
729 ahi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack
730 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
731 l %r1,__LC_RESTART_FN # load fn, parm & source cpu
732 l %r2,__LC_RESTART_DATA
733 l %r3,__LC_RESTART_SOURCE
734 ltr %r3,%r3 # test source cpu address
735 jm 1f # negative -> skip source stop
7360: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu
737 brc 10,0b # wait for status stored
7381: basr %r14,%r1 # call function
739 stap __SF_EMPTY(%r15) # store cpu address
740 lh %r3,__SF_EMPTY(%r15)
7412: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu
742 brc 2,2b
7433: j 3b
744
745 .section .kprobes.text, "ax"
746
747#ifdef CONFIG_CHECK_STACK
748/*
749 * The synchronous or the asynchronous stack overflowed. We are dead.
750 * No need to properly save the registers, we are going to panic anyway.
751 * Setup a pt_regs so that show_trace can provide a good call trace.
752 */
753stack_overflow:
754 l %r15,__LC_PANIC_STACK # change to panic stack
755 la %r11,STACK_FRAME_OVERHEAD(%r15)
756 stm %r0,%r7,__PT_R0(%r11)
757 stm %r8,%r9,__PT_PSW(%r11)
758 mvc __PT_R8(32,%r11),0(%r14)
759 l %r1,BASED(1f)
760 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
761 lr %r2,%r11 # pass pointer to pt_regs
762 br %r1 # branch to kernel_stack_overflow
7631: .long kernel_stack_overflow
764#endif
765
766cleanup_table:
767 .long system_call + 0x80000000
768 .long sysc_do_svc + 0x80000000
769 .long sysc_tif + 0x80000000
770 .long sysc_restore + 0x80000000
771 .long sysc_done + 0x80000000
772 .long io_tif + 0x80000000
773 .long io_restore + 0x80000000
774 .long io_done + 0x80000000
775 .long psw_idle + 0x80000000
776 .long psw_idle_end + 0x80000000
777
778cleanup_critical:
779 cl %r9,BASED(cleanup_table) # system_call
780 jl 0f
781 cl %r9,BASED(cleanup_table+4) # sysc_do_svc
782 jl cleanup_system_call
783 cl %r9,BASED(cleanup_table+8) # sysc_tif
784 jl 0f
785 cl %r9,BASED(cleanup_table+12) # sysc_restore
786 jl cleanup_sysc_tif
787 cl %r9,BASED(cleanup_table+16) # sysc_done
788 jl cleanup_sysc_restore
789 cl %r9,BASED(cleanup_table+20) # io_tif
790 jl 0f
791 cl %r9,BASED(cleanup_table+24) # io_restore
792 jl cleanup_io_tif
793 cl %r9,BASED(cleanup_table+28) # io_done
794 jl cleanup_io_restore
795 cl %r9,BASED(cleanup_table+32) # psw_idle
796 jl 0f
797 cl %r9,BASED(cleanup_table+36) # psw_idle_end
798 jl cleanup_idle
7990: br %r14
800
801cleanup_system_call:
802 # check if stpt has been executed
803 cl %r9,BASED(cleanup_system_call_insn)
804 jh 0f
805 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
806 chi %r11,__LC_SAVE_AREA_ASYNC
807 je 0f
808 mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
8090: # check if stm has been executed
810 cl %r9,BASED(cleanup_system_call_insn+4)
811 jh 0f
812 mvc __LC_SAVE_AREA_SYNC(32),0(%r11)
8130: # set up saved registers r12, and r13
814 st %r12,16(%r11) # r12 thread-info pointer
815 st %r13,20(%r11) # r13 literal-pool pointer
816 # check if the user time calculation has been done
817 cl %r9,BASED(cleanup_system_call_insn+8)
818 jh 0f
819 l %r10,__LC_EXIT_TIMER
820 l %r15,__LC_EXIT_TIMER+4
821 SUB64 %r10,%r15,__LC_SYNC_ENTER_TIMER
822 ADD64 %r10,%r15,__LC_USER_TIMER
823 st %r10,__LC_USER_TIMER
824 st %r15,__LC_USER_TIMER+4
8250: # check if the system time calculation has been done
826 cl %r9,BASED(cleanup_system_call_insn+12)
827 jh 0f
828 l %r10,__LC_LAST_UPDATE_TIMER
829 l %r15,__LC_LAST_UPDATE_TIMER+4
830 SUB64 %r10,%r15,__LC_EXIT_TIMER
831 ADD64 %r10,%r15,__LC_SYSTEM_TIMER
832 st %r10,__LC_SYSTEM_TIMER
833 st %r15,__LC_SYSTEM_TIMER+4
8340: # update accounting time stamp
835 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
836 # set up saved register 11
837 l %r15,__LC_KERNEL_STACK
838 la %r9,STACK_FRAME_OVERHEAD(%r15)
839 st %r9,12(%r11) # r11 pt_regs pointer
840 # fill pt_regs
841 mvc __PT_R8(32,%r9),__LC_SAVE_AREA_SYNC
842 stm %r0,%r7,__PT_R0(%r9)
843 mvc __PT_PSW(8,%r9),__LC_SVC_OLD_PSW
844 mvc __PT_INT_CODE(4,%r9),__LC_SVC_ILC
845 # setup saved register 15
846 st %r15,28(%r11) # r15 stack pointer
847 # set new psw address and exit
848 l %r9,BASED(cleanup_table+4) # sysc_do_svc + 0x80000000
849 br %r14
850cleanup_system_call_insn:
851 .long system_call + 0x80000000
852 .long sysc_stm + 0x80000000
853 .long sysc_vtime + 0x80000000 + 36
854 .long sysc_vtime + 0x80000000 + 76
855
856cleanup_sysc_tif:
857 l %r9,BASED(cleanup_table+8) # sysc_tif + 0x80000000
858 br %r14
859
860cleanup_sysc_restore:
861 cl %r9,BASED(cleanup_sysc_restore_insn)
862 jhe 0f
863 l %r9,12(%r11) # get saved pointer to pt_regs
864 mvc __LC_RETURN_PSW(8),__PT_PSW(%r9)
865 mvc 0(32,%r11),__PT_R8(%r9)
866 lm %r0,%r7,__PT_R0(%r9)
8670: lm %r8,%r9,__LC_RETURN_PSW
868 br %r14
869cleanup_sysc_restore_insn:
870 .long sysc_done - 4 + 0x80000000
871
872cleanup_io_tif:
873 l %r9,BASED(cleanup_table+20) # io_tif + 0x80000000
874 br %r14
875
876cleanup_io_restore:
877 cl %r9,BASED(cleanup_io_restore_insn)
878 jhe 0f
879 l %r9,12(%r11) # get saved r11 pointer to pt_regs
880 mvc __LC_RETURN_PSW(8),__PT_PSW(%r9)
881 mvc 0(32,%r11),__PT_R8(%r9)
882 lm %r0,%r7,__PT_R0(%r9)
8830: lm %r8,%r9,__LC_RETURN_PSW
884 br %r14
885cleanup_io_restore_insn:
886 .long io_done - 4 + 0x80000000
887
888cleanup_idle:
889 # copy interrupt clock & cpu timer
890 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK
891 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER
892 chi %r11,__LC_SAVE_AREA_ASYNC
893 je 0f
894 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK
895 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER
8960: # check if stck has been executed
897 cl %r9,BASED(cleanup_idle_insn)
898 jhe 1f
899 mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
900 mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r3)
9011: # account system time going idle
902 lm %r9,%r10,__LC_STEAL_TIMER
903 ADD64 %r9,%r10,__CLOCK_IDLE_ENTER(%r2)
904 SUB64 %r9,%r10,__LC_LAST_UPDATE_CLOCK
905 stm %r9,%r10,__LC_STEAL_TIMER
906 mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
907 lm %r9,%r10,__LC_SYSTEM_TIMER
908 ADD64 %r9,%r10,__LC_LAST_UPDATE_TIMER
909 SUB64 %r9,%r10,__TIMER_IDLE_ENTER(%r2)
910 stm %r9,%r10,__LC_SYSTEM_TIMER
911 mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
912 # prepare return psw
913 n %r8,BASED(cleanup_idle_wait) # clear irq & wait state bits
914 l %r9,24(%r11) # return from psw_idle
915 br %r14
916cleanup_idle_insn:
917 .long psw_idle_lpsw + 0x80000000
918cleanup_idle_wait:
919 .long 0xfcfdffff
920
921/*
922 * Integer constants
923 */
924 .align 4
925.Lnr_syscalls:
926 .long NR_syscalls
927.Lvtimer_max:
928 .quad 0x7fffffffffffffff
929
930/*
931 * Symbol constants
932 */
933.Ldo_machine_check: .long s390_do_machine_check
934.Lhandle_mcck: .long s390_handle_mcck
935.Ldo_IRQ: .long do_IRQ
936.Ldo_signal: .long do_signal
937.Ldo_notify_resume: .long do_notify_resume
938.Ldo_per_trap: .long do_per_trap
939.Ljump_table: .long pgm_check_table
940.Lschedule: .long schedule
941#ifdef CONFIG_PREEMPT
942.Lpreempt_irq: .long preempt_schedule_irq
943#endif
944.Ltrace_enter: .long do_syscall_trace_enter
945.Ltrace_exit: .long do_syscall_trace_exit
946.Lschedule_tail: .long schedule_tail
947.Lsysc_per: .long sysc_per + 0x80000000
948#ifdef CONFIG_TRACE_IRQFLAGS
949.Lhardirqs_on: .long trace_hardirqs_on_caller
950.Lhardirqs_off: .long trace_hardirqs_off_caller
951#endif
952#ifdef CONFIG_LOCKDEP
953.Llockdep_sys_exit: .long lockdep_sys_exit
954#endif
955.Lcritical_start: .long __critical_start + 0x80000000
956.Lcritical_length: .long __critical_end - __critical_start
957
958 .section .rodata, "a"
959#define SYSCALL(esa,esame,emu) .long esa
960 .globl sys_call_table
961sys_call_table:
962#include "syscalls.S"
963#undef SYSCALL