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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * S390 low-level entry points.
4 *
5 * Copyright IBM Corp. 1999, 2012
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7 * Hartmut Penner (hp@de.ibm.com),
8 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
9 */
10
11#include <linux/export.h>
12#include <linux/init.h>
13#include <linux/linkage.h>
14#include <asm/asm-extable.h>
15#include <asm/alternative-asm.h>
16#include <asm/processor.h>
17#include <asm/cache.h>
18#include <asm/dwarf.h>
19#include <asm/errno.h>
20#include <asm/ptrace.h>
21#include <asm/thread_info.h>
22#include <asm/asm-offsets.h>
23#include <asm/unistd.h>
24#include <asm/page.h>
25#include <asm/sigp.h>
26#include <asm/irq.h>
27#include <asm/vx-insn.h>
28#include <asm/setup.h>
29#include <asm/nmi.h>
30#include <asm/nospec-insn.h>
31
32_LPP_OFFSET = __LC_LPP
33
34 .macro STBEAR address
35 ALTERNATIVE "nop", ".insn s,0xb2010000,\address", 193
36 .endm
37
38 .macro LBEAR address
39 ALTERNATIVE "nop", ".insn s,0xb2000000,\address", 193
40 .endm
41
42 .macro LPSWEY address,lpswe
43 ALTERNATIVE "b \lpswe; nopr", ".insn siy,0xeb0000000071,\address,0", 193
44 .endm
45
46 .macro MBEAR reg
47 ALTERNATIVE "brcl 0,0", __stringify(mvc __PT_LAST_BREAK(8,\reg),__LC_LAST_BREAK), 193
48 .endm
49
50 .macro CHECK_STACK savearea
51#ifdef CONFIG_CHECK_STACK
52 tml %r15,THREAD_SIZE - CONFIG_STACK_GUARD
53 lghi %r14,\savearea
54 jz stack_overflow
55#endif
56 .endm
57
58 .macro CHECK_VMAP_STACK savearea,oklabel
59#ifdef CONFIG_VMAP_STACK
60 lgr %r14,%r15
61 nill %r14,0x10000 - THREAD_SIZE
62 oill %r14,STACK_INIT_OFFSET
63 clg %r14,__LC_KERNEL_STACK
64 je \oklabel
65 clg %r14,__LC_ASYNC_STACK
66 je \oklabel
67 clg %r14,__LC_MCCK_STACK
68 je \oklabel
69 clg %r14,__LC_NODAT_STACK
70 je \oklabel
71 clg %r14,__LC_RESTART_STACK
72 je \oklabel
73 lghi %r14,\savearea
74 j stack_overflow
75#else
76 j \oklabel
77#endif
78 .endm
79
80 /*
81 * The TSTMSK macro generates a test-under-mask instruction by
82 * calculating the memory offset for the specified mask value.
83 * Mask value can be any constant. The macro shifts the mask
84 * value to calculate the memory offset for the test-under-mask
85 * instruction.
86 */
87 .macro TSTMSK addr, mask, size=8, bytepos=0
88 .if (\bytepos < \size) && (\mask >> 8)
89 .if (\mask & 0xff)
90 .error "Mask exceeds byte boundary"
91 .endif
92 TSTMSK \addr, "(\mask >> 8)", \size, "(\bytepos + 1)"
93 .exitm
94 .endif
95 .ifeq \mask
96 .error "Mask must not be zero"
97 .endif
98 off = \size - \bytepos - 1
99 tm off+\addr, \mask
100 .endm
101
102 .macro BPOFF
103 ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,12,0", 82
104 .endm
105
106 .macro BPON
107 ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,13,0", 82
108 .endm
109
110 .macro BPENTER tif_ptr,tif_mask
111 ALTERNATIVE "TSTMSK \tif_ptr,\tif_mask; jz .+8; .insn rrf,0xb2e80000,0,0,13,0", \
112 "j .+12; nop; nop", 82
113 .endm
114
115 .macro BPEXIT tif_ptr,tif_mask
116 TSTMSK \tif_ptr,\tif_mask
117 ALTERNATIVE "jz .+8; .insn rrf,0xb2e80000,0,0,12,0", \
118 "jnz .+8; .insn rrf,0xb2e80000,0,0,13,0", 82
119 .endm
120
121#if IS_ENABLED(CONFIG_KVM)
122 /*
123 * The OUTSIDE macro jumps to the provided label in case the value
124 * in the provided register is outside of the provided range. The
125 * macro is useful for checking whether a PSW stored in a register
126 * pair points inside or outside of a block of instructions.
127 * @reg: register to check
128 * @start: start of the range
129 * @end: end of the range
130 * @outside_label: jump here if @reg is outside of [@start..@end)
131 */
132 .macro OUTSIDE reg,start,end,outside_label
133 lgr %r14,\reg
134 larl %r13,\start
135 slgr %r14,%r13
136 clgfrl %r14,.Lrange_size\@
137 jhe \outside_label
138 .section .rodata, "a"
139 .balign 4
140.Lrange_size\@:
141 .long \end - \start
142 .previous
143 .endm
144
145 .macro SIEEXIT
146 lg %r9,__SF_SIE_CONTROL(%r15) # get control block pointer
147 ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE
148 lctlg %c1,%c1,__LC_KERNEL_ASCE # load primary asce
149 larl %r9,sie_exit # skip forward to sie_exit
150 .endm
151#endif
152
153 .macro STACKLEAK_ERASE
154#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
155 brasl %r14,stackleak_erase_on_task_stack
156#endif
157 .endm
158
159 GEN_BR_THUNK %r14
160
161 .section .kprobes.text, "ax"
162.Ldummy:
163 /*
164 * The following nop exists only in order to avoid that the next
165 * symbol starts at the beginning of the kprobes text section.
166 * In that case there would be several symbols at the same address.
167 * E.g. objdump would take an arbitrary symbol when disassembling
168 * the code.
169 * With the added nop in between this cannot happen.
170 */
171 nop 0
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 */
180SYM_FUNC_START(__switch_to)
181 stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
182 lghi %r4,__TASK_stack
183 lghi %r1,__TASK_thread
184 llill %r5,STACK_INIT_OFFSET
185 stg %r15,__THREAD_ksp(%r1,%r2) # store kernel stack of prev
186 lg %r15,0(%r4,%r3) # start of kernel stack of next
187 agr %r15,%r5 # end of kernel stack of next
188 stg %r3,__LC_CURRENT # store task struct of next
189 stg %r15,__LC_KERNEL_STACK # store end of kernel stack
190 lg %r15,__THREAD_ksp(%r1,%r3) # load kernel stack of next
191 aghi %r3,__TASK_pid
192 mvc __LC_CURRENT_PID(4,%r0),0(%r3) # store pid of next
193 lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
194 ALTERNATIVE "nop", "lpp _LPP_OFFSET", 40
195 BR_EX %r14
196SYM_FUNC_END(__switch_to)
197
198#if IS_ENABLED(CONFIG_KVM)
199/*
200 * __sie64a calling convention:
201 * %r2 pointer to sie control block phys
202 * %r3 pointer to sie control block virt
203 * %r4 guest register save area
204 */
205SYM_FUNC_START(__sie64a)
206 stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers
207 lg %r12,__LC_CURRENT
208 stg %r2,__SF_SIE_CONTROL_PHYS(%r15) # save sie block physical..
209 stg %r3,__SF_SIE_CONTROL(%r15) # ...and virtual addresses
210 stg %r4,__SF_SIE_SAVEAREA(%r15) # save guest register save area
211 xc __SF_SIE_REASON(8,%r15),__SF_SIE_REASON(%r15) # reason code = 0
212 mvc __SF_SIE_FLAGS(8,%r15),__TI_flags(%r12) # copy thread flags
213 lmg %r0,%r13,0(%r4) # load guest gprs 0-13
214 lg %r14,__LC_GMAP # get gmap pointer
215 ltgr %r14,%r14
216 jz .Lsie_gmap
217 lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce
218.Lsie_gmap:
219 lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer
220 oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now
221 tm __SIE_PROG20+3(%r14),3 # last exit...
222 jnz .Lsie_skip
223 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
224 jo .Lsie_skip # exit if fp/vx regs changed
225 lg %r14,__SF_SIE_CONTROL_PHYS(%r15) # get sie block phys addr
226 BPEXIT __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST
227.Lsie_entry:
228 sie 0(%r14)
229# Let the next instruction be NOP to avoid triggering a machine check
230# and handling it in a guest as result of the instruction execution.
231 nopr 7
232.Lsie_leave:
233 BPOFF
234 BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST
235.Lsie_skip:
236 lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer
237 ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE
238 lctlg %c1,%c1,__LC_KERNEL_ASCE # load primary asce
239.Lsie_done:
240# some program checks are suppressing. C code (e.g. do_protection_exception)
241# will rewind the PSW by the ILC, which is often 4 bytes in case of SIE. There
242# are some corner cases (e.g. runtime instrumentation) where ILC is unpredictable.
243# Other instructions between __sie64a and .Lsie_done should not cause program
244# interrupts. So lets use 3 nops as a landing pad for all possible rewinds.
245.Lrewind_pad6:
246 nopr 7
247.Lrewind_pad4:
248 nopr 7
249.Lrewind_pad2:
250 nopr 7
251SYM_INNER_LABEL(sie_exit, SYM_L_GLOBAL)
252 lg %r14,__SF_SIE_SAVEAREA(%r15) # load guest register save area
253 stmg %r0,%r13,0(%r14) # save guest gprs 0-13
254 xgr %r0,%r0 # clear guest registers to
255 xgr %r1,%r1 # prevent speculative use
256 xgr %r3,%r3
257 xgr %r4,%r4
258 xgr %r5,%r5
259 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers
260 lg %r2,__SF_SIE_REASON(%r15) # return exit reason code
261 BR_EX %r14
262.Lsie_fault:
263 lghi %r14,-EFAULT
264 stg %r14,__SF_SIE_REASON(%r15) # set exit reason code
265 j sie_exit
266
267 EX_TABLE(.Lrewind_pad6,.Lsie_fault)
268 EX_TABLE(.Lrewind_pad4,.Lsie_fault)
269 EX_TABLE(.Lrewind_pad2,.Lsie_fault)
270 EX_TABLE(sie_exit,.Lsie_fault)
271SYM_FUNC_END(__sie64a)
272EXPORT_SYMBOL(__sie64a)
273EXPORT_SYMBOL(sie_exit)
274#endif
275
276/*
277 * SVC interrupt handler routine. System calls are synchronous events and
278 * are entered with interrupts disabled.
279 */
280
281SYM_CODE_START(system_call)
282 stpt __LC_SYS_ENTER_TIMER
283 stmg %r8,%r15,__LC_SAVE_AREA_SYNC
284 BPOFF
285 lghi %r14,0
286.Lsysc_per:
287 STBEAR __LC_LAST_BREAK
288 lctlg %c1,%c1,__LC_KERNEL_ASCE
289 lg %r15,__LC_KERNEL_STACK
290 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
291 stmg %r0,%r7,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
292 # clear user controlled register to prevent speculative use
293 xgr %r0,%r0
294 xgr %r1,%r1
295 xgr %r4,%r4
296 xgr %r5,%r5
297 xgr %r6,%r6
298 xgr %r7,%r7
299 xgr %r8,%r8
300 xgr %r9,%r9
301 xgr %r10,%r10
302 xgr %r11,%r11
303 la %r2,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
304 mvc __PT_R8(64,%r2),__LC_SAVE_AREA_SYNC
305 MBEAR %r2
306 lgr %r3,%r14
307 brasl %r14,__do_syscall
308 STACKLEAK_ERASE
309 lctlg %c1,%c1,__LC_USER_ASCE
310 mvc __LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
311 BPON
312 LBEAR STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15)
313 lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
314 stpt __LC_EXIT_TIMER
315 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE
316SYM_CODE_END(system_call)
317
318#
319# a new process exits the kernel with ret_from_fork
320#
321SYM_CODE_START(ret_from_fork)
322 lgr %r3,%r11
323 brasl %r14,__ret_from_fork
324 STACKLEAK_ERASE
325 lctlg %c1,%c1,__LC_USER_ASCE
326 mvc __LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
327 BPON
328 LBEAR STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15)
329 lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
330 stpt __LC_EXIT_TIMER
331 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE
332SYM_CODE_END(ret_from_fork)
333
334/*
335 * Program check handler routine
336 */
337
338SYM_CODE_START(pgm_check_handler)
339 stpt __LC_SYS_ENTER_TIMER
340 BPOFF
341 stmg %r8,%r15,__LC_SAVE_AREA_SYNC
342 lghi %r10,0
343 lmg %r8,%r9,__LC_PGM_OLD_PSW
344 tmhh %r8,0x0001 # coming from user space?
345 jno .Lpgm_skip_asce
346 lctlg %c1,%c1,__LC_KERNEL_ASCE
347 j 3f # -> fault in user space
348.Lpgm_skip_asce:
349#if IS_ENABLED(CONFIG_KVM)
350 # cleanup critical section for program checks in __sie64a
351 OUTSIDE %r9,.Lsie_gmap,.Lsie_done,1f
352 BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST
353 SIEEXIT
354 lghi %r10,_PIF_GUEST_FAULT
355#endif
3561: tmhh %r8,0x4000 # PER bit set in old PSW ?
357 jnz 2f # -> enabled, can't be a double fault
358 tm __LC_PGM_ILC+3,0x80 # check for per exception
359 jnz .Lpgm_svcper # -> single stepped svc
3602: CHECK_STACK __LC_SAVE_AREA_SYNC
361 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
362 # CHECK_VMAP_STACK branches to stack_overflow or 4f
363 CHECK_VMAP_STACK __LC_SAVE_AREA_SYNC,4f
3643: lg %r15,__LC_KERNEL_STACK
3654: la %r11,STACK_FRAME_OVERHEAD(%r15)
366 stg %r10,__PT_FLAGS(%r11)
367 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
368 stmg %r0,%r7,__PT_R0(%r11)
369 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
370 mvc __PT_LAST_BREAK(8,%r11),__LC_PGM_LAST_BREAK
371 stmg %r8,%r9,__PT_PSW(%r11)
372
373 # clear user controlled registers to prevent speculative use
374 xgr %r0,%r0
375 xgr %r1,%r1
376 xgr %r3,%r3
377 xgr %r4,%r4
378 xgr %r5,%r5
379 xgr %r6,%r6
380 xgr %r7,%r7
381 lgr %r2,%r11
382 brasl %r14,__do_pgm_check
383 tmhh %r8,0x0001 # returning to user space?
384 jno .Lpgm_exit_kernel
385 STACKLEAK_ERASE
386 lctlg %c1,%c1,__LC_USER_ASCE
387 BPON
388 stpt __LC_EXIT_TIMER
389.Lpgm_exit_kernel:
390 mvc __LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
391 LBEAR STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15)
392 lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
393 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE
394
395#
396# single stepped system call
397#
398.Lpgm_svcper:
399 mvc __LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
400 larl %r14,.Lsysc_per
401 stg %r14,__LC_RETURN_PSW+8
402 lghi %r14,1
403 LBEAR __LC_PGM_LAST_BREAK
404 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE # branch to .Lsysc_per
405SYM_CODE_END(pgm_check_handler)
406
407/*
408 * Interrupt handler macro used for external and IO interrupts.
409 */
410.macro INT_HANDLER name,lc_old_psw,handler
411SYM_CODE_START(\name)
412 stckf __LC_INT_CLOCK
413 stpt __LC_SYS_ENTER_TIMER
414 STBEAR __LC_LAST_BREAK
415 BPOFF
416 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
417 lmg %r8,%r9,\lc_old_psw
418 tmhh %r8,0x0001 # interrupting from user ?
419 jnz 1f
420#if IS_ENABLED(CONFIG_KVM)
421 OUTSIDE %r9,.Lsie_gmap,.Lsie_done,0f
422 BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST
423 SIEEXIT
424#endif
4250: CHECK_STACK __LC_SAVE_AREA_ASYNC
426 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
427 j 2f
4281: lctlg %c1,%c1,__LC_KERNEL_ASCE
429 lg %r15,__LC_KERNEL_STACK
4302: xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
431 la %r11,STACK_FRAME_OVERHEAD(%r15)
432 stmg %r0,%r7,__PT_R0(%r11)
433 # clear user controlled registers to prevent speculative use
434 xgr %r0,%r0
435 xgr %r1,%r1
436 xgr %r3,%r3
437 xgr %r4,%r4
438 xgr %r5,%r5
439 xgr %r6,%r6
440 xgr %r7,%r7
441 xgr %r10,%r10
442 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
443 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
444 MBEAR %r11
445 stmg %r8,%r9,__PT_PSW(%r11)
446 lgr %r2,%r11 # pass pointer to pt_regs
447 brasl %r14,\handler
448 mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
449 tmhh %r8,0x0001 # returning to user ?
450 jno 2f
451 STACKLEAK_ERASE
452 lctlg %c1,%c1,__LC_USER_ASCE
453 BPON
454 stpt __LC_EXIT_TIMER
4552: LBEAR __PT_LAST_BREAK(%r11)
456 lmg %r0,%r15,__PT_R0(%r11)
457 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE
458SYM_CODE_END(\name)
459.endm
460
461INT_HANDLER ext_int_handler,__LC_EXT_OLD_PSW,do_ext_irq
462INT_HANDLER io_int_handler,__LC_IO_OLD_PSW,do_io_irq
463
464/*
465 * Load idle PSW.
466 */
467SYM_FUNC_START(psw_idle)
468 stg %r14,(__SF_GPRS+8*8)(%r15)
469 stg %r3,__SF_EMPTY(%r15)
470 larl %r1,psw_idle_exit
471 stg %r1,__SF_EMPTY+8(%r15)
472 larl %r1,smp_cpu_mtid
473 llgf %r1,0(%r1)
474 ltgr %r1,%r1
475 jz .Lpsw_idle_stcctm
476 .insn rsy,0xeb0000000017,%r1,5,__MT_CYCLES_ENTER(%r2)
477.Lpsw_idle_stcctm:
478 oi __LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT
479 BPON
480 stckf __CLOCK_IDLE_ENTER(%r2)
481 stpt __TIMER_IDLE_ENTER(%r2)
482 lpswe __SF_EMPTY(%r15)
483SYM_INNER_LABEL(psw_idle_exit, SYM_L_GLOBAL)
484 BR_EX %r14
485SYM_FUNC_END(psw_idle)
486
487/*
488 * Machine check handler routines
489 */
490SYM_CODE_START(mcck_int_handler)
491 BPOFF
492 la %r1,4095 # validate r1
493 spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # validate cpu timer
494 LBEAR __LC_LAST_BREAK_SAVE_AREA-4095(%r1) # validate bear
495 lmg %r0,%r15,__LC_GPREGS_SAVE_AREA # validate gprs
496 lmg %r8,%r9,__LC_MCK_OLD_PSW
497 TSTMSK __LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE
498 jo .Lmcck_panic # yes -> rest of mcck code invalid
499 TSTMSK __LC_MCCK_CODE,MCCK_CODE_CR_VALID
500 jno .Lmcck_panic # control registers invalid -> panic
501 lctlg %c0,%c15,__LC_CREGS_SAVE_AREA # validate ctl regs
502 ptlb
503 lghi %r14,__LC_CPU_TIMER_SAVE_AREA
504 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
505 TSTMSK __LC_MCCK_CODE,MCCK_CODE_CPU_TIMER_VALID
506 jo 3f
507 la %r14,__LC_SYS_ENTER_TIMER
508 clc 0(8,%r14),__LC_EXIT_TIMER
509 jl 1f
510 la %r14,__LC_EXIT_TIMER
5111: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER
512 jl 2f
513 la %r14,__LC_LAST_UPDATE_TIMER
5142: spt 0(%r14)
515 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
5163: TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_MWP_VALID
517 jno .Lmcck_panic
518 tmhh %r8,0x0001 # interrupting from user ?
519 jnz .Lmcck_user
520 TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID
521 jno .Lmcck_panic
522#if IS_ENABLED(CONFIG_KVM)
523 OUTSIDE %r9,.Lsie_gmap,.Lsie_done,.Lmcck_user
524 OUTSIDE %r9,.Lsie_entry,.Lsie_leave,4f
525 oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST
5264: BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST
527 SIEEXIT
528#endif
529.Lmcck_user:
530 lg %r15,__LC_MCCK_STACK
531 la %r11,STACK_FRAME_OVERHEAD(%r15)
532 stctg %c1,%c1,__PT_CR1(%r11)
533 lctlg %c1,%c1,__LC_KERNEL_ASCE
534 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
535 lghi %r14,__LC_GPREGS_SAVE_AREA+64
536 stmg %r0,%r7,__PT_R0(%r11)
537 # clear user controlled registers to prevent speculative use
538 xgr %r0,%r0
539 xgr %r1,%r1
540 xgr %r3,%r3
541 xgr %r4,%r4
542 xgr %r5,%r5
543 xgr %r6,%r6
544 xgr %r7,%r7
545 xgr %r10,%r10
546 mvc __PT_R8(64,%r11),0(%r14)
547 stmg %r8,%r9,__PT_PSW(%r11)
548 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
549 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
550 lgr %r2,%r11 # pass pointer to pt_regs
551 brasl %r14,s390_do_machine_check
552 lctlg %c1,%c1,__PT_CR1(%r11)
553 lmg %r0,%r10,__PT_R0(%r11)
554 mvc __LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
555 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
556 jno 0f
557 BPON
558 stpt __LC_EXIT_TIMER
5590: ALTERNATIVE "nop", __stringify(lghi %r12,__LC_LAST_BREAK_SAVE_AREA),193
560 LBEAR 0(%r12)
561 lmg %r11,%r15,__PT_R11(%r11)
562 LPSWEY __LC_RETURN_MCCK_PSW,__LC_RETURN_MCCK_LPSWE
563
564.Lmcck_panic:
565 /*
566 * Iterate over all possible CPU addresses in the range 0..0xffff
567 * and stop each CPU using signal processor. Use compare and swap
568 * to allow just one CPU-stopper and prevent concurrent CPUs from
569 * stopping each other while leaving the others running.
570 */
571 lhi %r5,0
572 lhi %r6,1
573 larl %r7,stop_lock
574 cs %r5,%r6,0(%r7) # single CPU-stopper only
575 jnz 4f
576 larl %r7,this_cpu
577 stap 0(%r7) # this CPU address
578 lh %r4,0(%r7)
579 nilh %r4,0
580 lhi %r0,1
581 sll %r0,16 # CPU counter
582 lhi %r3,0 # next CPU address
5830: cr %r3,%r4
584 je 2f
5851: sigp %r1,%r3,SIGP_STOP # stop next CPU
586 brc SIGP_CC_BUSY,1b
5872: ahi %r3,1
588 brct %r0,0b
5893: sigp %r1,%r4,SIGP_STOP # stop this CPU
590 brc SIGP_CC_BUSY,3b
5914: j 4b
592SYM_CODE_END(mcck_int_handler)
593
594SYM_CODE_START(restart_int_handler)
595 ALTERNATIVE "nop", "lpp _LPP_OFFSET", 40
596 stg %r15,__LC_SAVE_AREA_RESTART
597 TSTMSK __LC_RESTART_FLAGS,RESTART_FLAG_CTLREGS,4
598 jz 0f
599 lctlg %c0,%c15,__LC_CREGS_SAVE_AREA
6000: larl %r15,daton_psw
601 lpswe 0(%r15) # turn dat on, keep irqs off
602.Ldaton:
603 lg %r15,__LC_RESTART_STACK
604 xc STACK_FRAME_OVERHEAD(__PT_SIZE,%r15),STACK_FRAME_OVERHEAD(%r15)
605 stmg %r0,%r14,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
606 mvc STACK_FRAME_OVERHEAD+__PT_R15(8,%r15),__LC_SAVE_AREA_RESTART
607 mvc STACK_FRAME_OVERHEAD+__PT_PSW(16,%r15),__LC_RST_OLD_PSW
608 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
609 lg %r1,__LC_RESTART_FN # load fn, parm & source cpu
610 lg %r2,__LC_RESTART_DATA
611 lgf %r3,__LC_RESTART_SOURCE
612 ltgr %r3,%r3 # test source cpu address
613 jm 1f # negative -> skip source stop
6140: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu
615 brc 10,0b # wait for status stored
6161: basr %r14,%r1 # call function
617 stap __SF_EMPTY(%r15) # store cpu address
618 llgh %r3,__SF_EMPTY(%r15)
6192: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu
620 brc 2,2b
6213: j 3b
622SYM_CODE_END(restart_int_handler)
623
624 .section .kprobes.text, "ax"
625
626#if defined(CONFIG_CHECK_STACK) || defined(CONFIG_VMAP_STACK)
627/*
628 * The synchronous or the asynchronous stack overflowed. We are dead.
629 * No need to properly save the registers, we are going to panic anyway.
630 * Setup a pt_regs so that show_trace can provide a good call trace.
631 */
632SYM_CODE_START(stack_overflow)
633 lg %r15,__LC_NODAT_STACK # change to panic stack
634 la %r11,STACK_FRAME_OVERHEAD(%r15)
635 stmg %r0,%r7,__PT_R0(%r11)
636 stmg %r8,%r9,__PT_PSW(%r11)
637 mvc __PT_R8(64,%r11),0(%r14)
638 stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
639 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
640 lgr %r2,%r11 # pass pointer to pt_regs
641 jg kernel_stack_overflow
642SYM_CODE_END(stack_overflow)
643#endif
644
645 .section .data, "aw"
646 .balign 4
647SYM_DATA_LOCAL(stop_lock, .long 0)
648SYM_DATA_LOCAL(this_cpu, .short 0)
649 .balign 8
650SYM_DATA_START_LOCAL(daton_psw)
651 .quad PSW_KERNEL_BITS
652 .quad .Ldaton
653SYM_DATA_END(daton_psw)
654
655 .section .rodata, "a"
656#define SYSCALL(esame,emu) .quad __s390x_ ## esame
657SYM_DATA_START(sys_call_table)
658#include "asm/syscall_table.h"
659SYM_DATA_END(sys_call_table)
660#undef SYSCALL
661
662#ifdef CONFIG_COMPAT
663
664#define SYSCALL(esame,emu) .quad __s390_ ## emu
665SYM_DATA_START(sys_call_table_emu)
666#include "asm/syscall_table.h"
667SYM_DATA_END(sys_call_table_emu)
668#undef SYSCALL
669#endif
1/*
2 * arch/s390/kernel/entry.S
3 * S390 low-level entry points.
4 *
5 * Copyright (C) IBM Corp. 1999,2012
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7 * Hartmut Penner (hp@de.ibm.com),
8 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
9 * Heiko Carstens <heiko.carstens@de.ibm.com>
10 */
11
12#include <linux/init.h>
13#include <linux/linkage.h>
14#include <asm/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__PT_R0 = __PT_GPRS
23__PT_R1 = __PT_GPRS + 4
24__PT_R2 = __PT_GPRS + 8
25__PT_R3 = __PT_GPRS + 12
26__PT_R4 = __PT_GPRS + 16
27__PT_R5 = __PT_GPRS + 20
28__PT_R6 = __PT_GPRS + 24
29__PT_R7 = __PT_GPRS + 28
30__PT_R8 = __PT_GPRS + 32
31__PT_R9 = __PT_GPRS + 36
32__PT_R10 = __PT_GPRS + 40
33__PT_R11 = __PT_GPRS + 44
34__PT_R12 = __PT_GPRS + 48
35__PT_R13 = __PT_GPRS + 524
36__PT_R14 = __PT_GPRS + 56
37__PT_R15 = __PT_GPRS + 60
38
39_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
40 _TIF_MCCK_PENDING | _TIF_PER_TRAP )
41_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
42 _TIF_MCCK_PENDING)
43_TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
44 _TIF_SYSCALL_TRACEPOINT)
45
46STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
47STACK_SIZE = 1 << STACK_SHIFT
48
49#define BASED(name) name-system_call(%r13)
50
51 .macro TRACE_IRQS_ON
52#ifdef CONFIG_TRACE_IRQFLAGS
53 basr %r2,%r0
54 l %r1,BASED(.Lhardirqs_on)
55 basr %r14,%r1 # call trace_hardirqs_on_caller
56#endif
57 .endm
58
59 .macro TRACE_IRQS_OFF
60#ifdef CONFIG_TRACE_IRQFLAGS
61 basr %r2,%r0
62 l %r1,BASED(.Lhardirqs_off)
63 basr %r14,%r1 # call trace_hardirqs_off_caller
64#endif
65 .endm
66
67 .macro LOCKDEP_SYS_EXIT
68#ifdef CONFIG_LOCKDEP
69 tm __PT_PSW+1(%r11),0x01 # returning to user ?
70 jz .+10
71 l %r1,BASED(.Llockdep_sys_exit)
72 basr %r14,%r1 # call lockdep_sys_exit
73#endif
74 .endm
75
76 .macro CHECK_STACK stacksize,savearea
77#ifdef CONFIG_CHECK_STACK
78 tml %r15,\stacksize - CONFIG_STACK_GUARD
79 la %r14,\savearea
80 jz stack_overflow
81#endif
82 .endm
83
84 .macro SWITCH_ASYNC savearea,stack,shift
85 tmh %r8,0x0001 # interrupting from user ?
86 jnz 1f
87 lr %r14,%r9
88 sl %r14,BASED(.Lcritical_start)
89 cl %r14,BASED(.Lcritical_length)
90 jhe 0f
91 la %r11,\savearea # inside critical section, do cleanup
92 bras %r14,cleanup_critical
93 tmh %r8,0x0001 # retest problem state after cleanup
94 jnz 1f
950: l %r14,\stack # are we already on the target stack?
96 slr %r14,%r15
97 sra %r14,\shift
98 jnz 1f
99 CHECK_STACK 1<<\shift,\savearea
100 j 2f
1011: l %r15,\stack # load target stack
1022: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
103 la %r11,STACK_FRAME_OVERHEAD(%r15)
104 .endm
105
106 .macro ADD64 high,low,timer
107 al \high,\timer
108 al \low,4+\timer
109 brc 12,.+8
110 ahi \high,1
111 .endm
112
113 .macro SUB64 high,low,timer
114 sl \high,\timer
115 sl \low,4+\timer
116 brc 3,.+8
117 ahi \high,-1
118 .endm
119
120 .macro UPDATE_VTIME high,low,enter_timer
121 lm \high,\low,__LC_EXIT_TIMER
122 SUB64 \high,\low,\enter_timer
123 ADD64 \high,\low,__LC_USER_TIMER
124 stm \high,\low,__LC_USER_TIMER
125 lm \high,\low,__LC_LAST_UPDATE_TIMER
126 SUB64 \high,\low,__LC_EXIT_TIMER
127 ADD64 \high,\low,__LC_SYSTEM_TIMER
128 stm \high,\low,__LC_SYSTEM_TIMER
129 mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer
130 .endm
131
132 .macro REENABLE_IRQS
133 st %r8,__LC_RETURN_PSW
134 ni __LC_RETURN_PSW,0xbf
135 ssm __LC_RETURN_PSW
136 .endm
137
138 .section .kprobes.text, "ax"
139
140/*
141 * Scheduler resume function, called by switch_to
142 * gpr2 = (task_struct *) prev
143 * gpr3 = (task_struct *) next
144 * Returns:
145 * gpr2 = prev
146 */
147ENTRY(__switch_to)
148 stm %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
149 st %r15,__THREAD_ksp(%r2) # store kernel stack of prev
150 l %r4,__THREAD_info(%r2) # get thread_info of prev
151 l %r5,__THREAD_info(%r3) # get thread_info of next
152 lr %r15,%r5
153 ahi %r15,STACK_SIZE # end of kernel stack of next
154 st %r3,__LC_CURRENT # store task struct of next
155 st %r5,__LC_THREAD_INFO # store thread info of next
156 st %r15,__LC_KERNEL_STACK # store end of kernel stack
157 lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
158 mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next
159 l %r15,__THREAD_ksp(%r3) # load kernel stack of next
160 tm __TI_flags+3(%r4),_TIF_MCCK_PENDING # machine check pending?
161 jz 0f
162 ni __TI_flags+3(%r4),255-_TIF_MCCK_PENDING # clear flag in prev
163 oi __TI_flags+3(%r5),_TIF_MCCK_PENDING # set it in next
1640: lm %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
165 br %r14
166
167__critical_start:
168/*
169 * SVC interrupt handler routine. System calls are synchronous events and
170 * are executed with interrupts enabled.
171 */
172
173ENTRY(system_call)
174 stpt __LC_SYNC_ENTER_TIMER
175sysc_stm:
176 stm %r8,%r15,__LC_SAVE_AREA_SYNC
177 l %r12,__LC_THREAD_INFO
178 l %r13,__LC_SVC_NEW_PSW+4
179sysc_per:
180 l %r15,__LC_KERNEL_STACK
181 ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
182 la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
183sysc_vtime:
184 UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
185 stm %r0,%r7,__PT_R0(%r11)
186 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC
187 mvc __PT_PSW(8,%r11),__LC_SVC_OLD_PSW
188 mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC
189sysc_do_svc:
190 oi __TI_flags+3(%r12),_TIF_SYSCALL
191 lh %r8,__PT_INT_CODE+2(%r11)
192 sla %r8,2 # shift and test for svc0
193 jnz sysc_nr_ok
194 # svc 0: system call number in %r1
195 cl %r1,BASED(.Lnr_syscalls)
196 jnl sysc_nr_ok
197 sth %r1,__PT_INT_CODE+2(%r11)
198 lr %r8,%r1
199 sla %r8,2
200sysc_nr_ok:
201 l %r10,BASED(.Lsys_call_table) # 31 bit system call table
202 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
203 st %r2,__PT_ORIG_GPR2(%r11)
204 st %r7,STACK_FRAME_OVERHEAD(%r15)
205 l %r9,0(%r8,%r10) # get system call addr.
206 tm __TI_flags+2(%r12),_TIF_TRACE >> 8
207 jnz sysc_tracesys
208 basr %r14,%r9 # call sys_xxxx
209 st %r2,__PT_R2(%r11) # store return value
210
211sysc_return:
212 LOCKDEP_SYS_EXIT
213sysc_tif:
214 tm __PT_PSW+1(%r11),0x01 # returning to user ?
215 jno sysc_restore
216 tm __TI_flags+3(%r12),_TIF_WORK_SVC
217 jnz sysc_work # check for work
218 ni __TI_flags+3(%r12),255-_TIF_SYSCALL
219sysc_restore:
220 mvc __LC_RETURN_PSW(8),__PT_PSW(%r11)
221 stpt __LC_EXIT_TIMER
222 lm %r0,%r15,__PT_R0(%r11)
223 lpsw __LC_RETURN_PSW
224sysc_done:
225
226#
227# One of the work bits is on. Find out which one.
228#
229sysc_work:
230 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
231 jo sysc_mcck_pending
232 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
233 jo sysc_reschedule
234 tm __TI_flags+3(%r12),_TIF_SIGPENDING
235 jo sysc_sigpending
236 tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
237 jo sysc_notify_resume
238 tm __TI_flags+3(%r12),_TIF_PER_TRAP
239 jo sysc_singlestep
240 j sysc_return # beware of critical section cleanup
241
242#
243# _TIF_NEED_RESCHED is set, call schedule
244#
245sysc_reschedule:
246 l %r1,BASED(.Lschedule)
247 la %r14,BASED(sysc_return)
248 br %r1 # call schedule
249
250#
251# _TIF_MCCK_PENDING is set, call handler
252#
253sysc_mcck_pending:
254 l %r1,BASED(.Lhandle_mcck)
255 la %r14,BASED(sysc_return)
256 br %r1 # TIF bit will be cleared by handler
257
258#
259# _TIF_SIGPENDING is set, call do_signal
260#
261sysc_sigpending:
262 ni __TI_flags+3(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
263 lr %r2,%r11 # pass pointer to pt_regs
264 l %r1,BASED(.Ldo_signal)
265 basr %r14,%r1 # call do_signal
266 tm __TI_flags+3(%r12),_TIF_SYSCALL
267 jno sysc_return
268 lm %r2,%r7,__PT_R2(%r11) # load svc arguments
269 xr %r8,%r8 # svc 0 returns -ENOSYS
270 clc __PT_INT_CODE+2(2,%r11),BASED(.Lnr_syscalls+2)
271 jnl sysc_nr_ok # invalid svc number -> do svc 0
272 lh %r8,__PT_INT_CODE+2(%r11) # load new svc number
273 sla %r8,2
274 j sysc_nr_ok # restart svc
275
276#
277# _TIF_NOTIFY_RESUME is set, call do_notify_resume
278#
279sysc_notify_resume:
280 lr %r2,%r11 # pass pointer to pt_regs
281 l %r1,BASED(.Ldo_notify_resume)
282 la %r14,BASED(sysc_return)
283 br %r1 # call do_notify_resume
284
285#
286# _TIF_PER_TRAP is set, call do_per_trap
287#
288sysc_singlestep:
289 ni __TI_flags+3(%r12),255-(_TIF_SYSCALL | _TIF_PER_TRAP)
290 lr %r2,%r11 # pass pointer to pt_regs
291 l %r1,BASED(.Ldo_per_trap)
292 la %r14,BASED(sysc_return)
293 br %r1 # call do_per_trap
294
295#
296# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
297# and after the system call
298#
299sysc_tracesys:
300 l %r1,BASED(.Ltrace_enter)
301 lr %r2,%r11 # pass pointer to pt_regs
302 la %r3,0
303 xr %r0,%r0
304 icm %r0,3,__PT_INT_CODE+2(%r11)
305 st %r0,__PT_R2(%r11)
306 basr %r14,%r1 # call do_syscall_trace_enter
307 cl %r2,BASED(.Lnr_syscalls)
308 jnl sysc_tracenogo
309 lr %r8,%r2
310 sll %r8,2
311 l %r9,0(%r8,%r10)
312sysc_tracego:
313 lm %r3,%r7,__PT_R3(%r11)
314 st %r7,STACK_FRAME_OVERHEAD(%r15)
315 l %r2,__PT_ORIG_GPR2(%r11)
316 basr %r14,%r9 # call sys_xxx
317 st %r2,__PT_R2(%r11) # store return value
318sysc_tracenogo:
319 tm __TI_flags+2(%r12),_TIF_TRACE >> 8
320 jz sysc_return
321 l %r1,BASED(.Ltrace_exit)
322 lr %r2,%r11 # pass pointer to pt_regs
323 la %r14,BASED(sysc_return)
324 br %r1 # call do_syscall_trace_exit
325
326#
327# a new process exits the kernel with ret_from_fork
328#
329ENTRY(ret_from_fork)
330 la %r11,STACK_FRAME_OVERHEAD(%r15)
331 l %r12,__LC_THREAD_INFO
332 l %r13,__LC_SVC_NEW_PSW+4
333 tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ?
334 jo 0f
335 st %r15,__PT_R15(%r11) # store stack pointer for new kthread
3360: l %r1,BASED(.Lschedule_tail)
337 basr %r14,%r1 # call schedule_tail
338 TRACE_IRQS_ON
339 ssm __LC_SVC_NEW_PSW # reenable interrupts
340 j sysc_tracenogo
341
342#
343# kernel_execve function needs to deal with pt_regs that is not
344# at the usual place
345#
346ENTRY(kernel_execve)
347 stm %r12,%r15,48(%r15)
348 lr %r14,%r15
349 l %r13,__LC_SVC_NEW_PSW+4
350 ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
351 st %r14,__SF_BACKCHAIN(%r15)
352 la %r12,STACK_FRAME_OVERHEAD(%r15)
353 xc 0(__PT_SIZE,%r12),0(%r12)
354 l %r1,BASED(.Ldo_execve)
355 lr %r5,%r12
356 basr %r14,%r1 # call do_execve
357 ltr %r2,%r2
358 je 0f
359 ahi %r15,(STACK_FRAME_OVERHEAD + __PT_SIZE)
360 lm %r12,%r15,48(%r15)
361 br %r14
362 # execve succeeded.
3630: ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
364 l %r15,__LC_KERNEL_STACK # load ksp
365 ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
366 la %r11,STACK_FRAME_OVERHEAD(%r15)
367 mvc 0(__PT_SIZE,%r11),0(%r12) # copy pt_regs
368 l %r12,__LC_THREAD_INFO
369 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
370 ssm __LC_SVC_NEW_PSW # reenable interrupts
371 l %r1,BASED(.Lexecve_tail)
372 basr %r14,%r1 # call execve_tail
373 j sysc_return
374
375/*
376 * Program check handler routine
377 */
378
379ENTRY(pgm_check_handler)
380 stpt __LC_SYNC_ENTER_TIMER
381 stm %r8,%r15,__LC_SAVE_AREA_SYNC
382 l %r12,__LC_THREAD_INFO
383 l %r13,__LC_SVC_NEW_PSW+4
384 lm %r8,%r9,__LC_PGM_OLD_PSW
385 tmh %r8,0x0001 # test problem state bit
386 jnz 1f # -> fault in user space
387 tmh %r8,0x4000 # PER bit set in old PSW ?
388 jnz 0f # -> enabled, can't be a double fault
389 tm __LC_PGM_ILC+3,0x80 # check for per exception
390 jnz pgm_svcper # -> single stepped svc
3910: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
392 j 2f
3931: UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
394 l %r15,__LC_KERNEL_STACK
3952: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
396 la %r11,STACK_FRAME_OVERHEAD(%r15)
397 stm %r0,%r7,__PT_R0(%r11)
398 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC
399 stm %r8,%r9,__PT_PSW(%r11)
400 mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC
401 mvc __PT_INT_PARM_LONG(4,%r11),__LC_TRANS_EXC_CODE
402 tm __LC_PGM_ILC+3,0x80 # check for per exception
403 jz 0f
404 l %r1,__TI_task(%r12)
405 tmh %r8,0x0001 # kernel per event ?
406 jz pgm_kprobe
407 oi __TI_flags+3(%r12),_TIF_PER_TRAP
408 mvc __THREAD_per_address(4,%r1),__LC_PER_ADDRESS
409 mvc __THREAD_per_cause(2,%r1),__LC_PER_CAUSE
410 mvc __THREAD_per_paid(1,%r1),__LC_PER_PAID
4110: REENABLE_IRQS
412 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
413 l %r1,BASED(.Ljump_table)
414 la %r10,0x7f
415 n %r10,__PT_INT_CODE(%r11)
416 je sysc_return
417 sll %r10,2
418 l %r1,0(%r10,%r1) # load address of handler routine
419 lr %r2,%r11 # pass pointer to pt_regs
420 basr %r14,%r1 # branch to interrupt-handler
421 j sysc_return
422
423#
424# PER event in supervisor state, must be kprobes
425#
426pgm_kprobe:
427 REENABLE_IRQS
428 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
429 l %r1,BASED(.Ldo_per_trap)
430 lr %r2,%r11 # pass pointer to pt_regs
431 basr %r14,%r1 # call do_per_trap
432 j sysc_return
433
434#
435# single stepped system call
436#
437pgm_svcper:
438 oi __TI_flags+3(%r12),_TIF_PER_TRAP
439 mvc __LC_RETURN_PSW(4),__LC_SVC_NEW_PSW
440 mvc __LC_RETURN_PSW+4(4),BASED(.Lsysc_per)
441 lpsw __LC_RETURN_PSW # branch to sysc_per and enable irqs
442
443/*
444 * IO interrupt handler routine
445 */
446
447ENTRY(io_int_handler)
448 stck __LC_INT_CLOCK
449 stpt __LC_ASYNC_ENTER_TIMER
450 stm %r8,%r15,__LC_SAVE_AREA_ASYNC
451 l %r12,__LC_THREAD_INFO
452 l %r13,__LC_SVC_NEW_PSW+4
453 lm %r8,%r9,__LC_IO_OLD_PSW
454 tmh %r8,0x0001 # interrupting from user ?
455 jz io_skip
456 UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER
457io_skip:
458 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
459 stm %r0,%r7,__PT_R0(%r11)
460 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC
461 stm %r8,%r9,__PT_PSW(%r11)
462 TRACE_IRQS_OFF
463 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
464 l %r1,BASED(.Ldo_IRQ)
465 lr %r2,%r11 # pass pointer to pt_regs
466 basr %r14,%r1 # call do_IRQ
467io_return:
468 LOCKDEP_SYS_EXIT
469 TRACE_IRQS_ON
470io_tif:
471 tm __TI_flags+3(%r12),_TIF_WORK_INT
472 jnz io_work # there is work to do (signals etc.)
473io_restore:
474 mvc __LC_RETURN_PSW(8),__PT_PSW(%r11)
475 stpt __LC_EXIT_TIMER
476 lm %r0,%r15,__PT_R0(%r11)
477 lpsw __LC_RETURN_PSW
478io_done:
479
480#
481# There is work todo, find out in which context we have been interrupted:
482# 1) if we return to user space we can do all _TIF_WORK_INT work
483# 2) if we return to kernel code and preemptive scheduling is enabled check
484# the preemption counter and if it is zero call preempt_schedule_irq
485# Before any work can be done, a switch to the kernel stack is required.
486#
487io_work:
488 tm __PT_PSW+1(%r11),0x01 # returning to user ?
489 jo io_work_user # yes -> do resched & signal
490#ifdef CONFIG_PREEMPT
491 # check for preemptive scheduling
492 icm %r0,15,__TI_precount(%r12)
493 jnz io_restore # preemption disabled
494 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
495 jno io_restore
496 # switch to kernel stack
497 l %r1,__PT_R15(%r11)
498 ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
499 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
500 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
501 la %r11,STACK_FRAME_OVERHEAD(%r1)
502 lr %r15,%r1
503 # TRACE_IRQS_ON already done at io_return, call
504 # TRACE_IRQS_OFF to keep things symmetrical
505 TRACE_IRQS_OFF
506 l %r1,BASED(.Lpreempt_irq)
507 basr %r14,%r1 # call preempt_schedule_irq
508 j io_return
509#else
510 j io_restore
511#endif
512
513#
514# Need to do work before returning to userspace, switch to kernel stack
515#
516io_work_user:
517 l %r1,__LC_KERNEL_STACK
518 ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
519 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
520 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
521 la %r11,STACK_FRAME_OVERHEAD(%r1)
522 lr %r15,%r1
523
524#
525# One of the work bits is on. Find out which one.
526# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED
527# and _TIF_MCCK_PENDING
528#
529io_work_tif:
530 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
531 jo io_mcck_pending
532 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
533 jo io_reschedule
534 tm __TI_flags+3(%r12),_TIF_SIGPENDING
535 jo io_sigpending
536 tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
537 jo io_notify_resume
538 j io_return # beware of critical section cleanup
539
540#
541# _TIF_MCCK_PENDING is set, call handler
542#
543io_mcck_pending:
544 # TRACE_IRQS_ON already done at io_return
545 l %r1,BASED(.Lhandle_mcck)
546 basr %r14,%r1 # TIF bit will be cleared by handler
547 TRACE_IRQS_OFF
548 j io_return
549
550#
551# _TIF_NEED_RESCHED is set, call schedule
552#
553io_reschedule:
554 # TRACE_IRQS_ON already done at io_return
555 l %r1,BASED(.Lschedule)
556 ssm __LC_SVC_NEW_PSW # reenable interrupts
557 basr %r14,%r1 # call scheduler
558 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
559 TRACE_IRQS_OFF
560 j io_return
561
562#
563# _TIF_SIGPENDING is set, call do_signal
564#
565io_sigpending:
566 # TRACE_IRQS_ON already done at io_return
567 l %r1,BASED(.Ldo_signal)
568 ssm __LC_SVC_NEW_PSW # reenable interrupts
569 lr %r2,%r11 # pass pointer to pt_regs
570 basr %r14,%r1 # call do_signal
571 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
572 TRACE_IRQS_OFF
573 j io_return
574
575#
576# _TIF_SIGPENDING is set, call do_signal
577#
578io_notify_resume:
579 # TRACE_IRQS_ON already done at io_return
580 l %r1,BASED(.Ldo_notify_resume)
581 ssm __LC_SVC_NEW_PSW # reenable interrupts
582 lr %r2,%r11 # pass pointer to pt_regs
583 basr %r14,%r1 # call do_notify_resume
584 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
585 TRACE_IRQS_OFF
586 j io_return
587
588/*
589 * External interrupt handler routine
590 */
591
592ENTRY(ext_int_handler)
593 stck __LC_INT_CLOCK
594 stpt __LC_ASYNC_ENTER_TIMER
595 stm %r8,%r15,__LC_SAVE_AREA_ASYNC
596 l %r12,__LC_THREAD_INFO
597 l %r13,__LC_SVC_NEW_PSW+4
598 lm %r8,%r9,__LC_EXT_OLD_PSW
599 tmh %r8,0x0001 # interrupting from user ?
600 jz ext_skip
601 UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER
602ext_skip:
603 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
604 stm %r0,%r7,__PT_R0(%r11)
605 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC
606 stm %r8,%r9,__PT_PSW(%r11)
607 TRACE_IRQS_OFF
608 lr %r2,%r11 # pass pointer to pt_regs
609 l %r3,__LC_EXT_CPU_ADDR # get cpu address + interruption code
610 l %r4,__LC_EXT_PARAMS # get external parameters
611 l %r1,BASED(.Ldo_extint)
612 basr %r14,%r1 # call do_extint
613 j io_return
614
615/*
616 * Load idle PSW. The second "half" of this function is in cleanup_idle.
617 */
618ENTRY(psw_idle)
619 st %r4,__SF_EMPTY(%r15)
620 basr %r1,0
621 la %r1,psw_idle_lpsw+4-.(%r1)
622 st %r1,__SF_EMPTY+4(%r15)
623 oi __SF_EMPTY+4(%r15),0x80
624 la %r1,.Lvtimer_max-psw_idle_lpsw-4(%r1)
625 stck __IDLE_ENTER(%r2)
626 ltr %r5,%r5
627 stpt __VQ_IDLE_ENTER(%r3)
628 jz psw_idle_lpsw
629 spt 0(%r1)
630psw_idle_lpsw:
631 lpsw __SF_EMPTY(%r15)
632 br %r14
633psw_idle_end:
634
635__critical_end:
636
637/*
638 * Machine check handler routines
639 */
640
641ENTRY(mcck_int_handler)
642 stck __LC_MCCK_CLOCK
643 spt __LC_CPU_TIMER_SAVE_AREA # revalidate cpu timer
644 lm %r0,%r15,__LC_GPREGS_SAVE_AREA # revalidate gprs
645 l %r12,__LC_THREAD_INFO
646 l %r13,__LC_SVC_NEW_PSW+4
647 lm %r8,%r9,__LC_MCK_OLD_PSW
648 tm __LC_MCCK_CODE,0x80 # system damage?
649 jo mcck_panic # yes -> rest of mcck code invalid
650 la %r14,__LC_CPU_TIMER_SAVE_AREA
651 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
652 tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid?
653 jo 3f
654 la %r14,__LC_SYNC_ENTER_TIMER
655 clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER
656 jl 0f
657 la %r14,__LC_ASYNC_ENTER_TIMER
6580: clc 0(8,%r14),__LC_EXIT_TIMER
659 jl 1f
660 la %r14,__LC_EXIT_TIMER
6611: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER
662 jl 2f
663 la %r14,__LC_LAST_UPDATE_TIMER
6642: spt 0(%r14)
665 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
6663: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid?
667 jno mcck_panic # no -> skip cleanup critical
668 tm %r8,0x0001 # interrupting from user ?
669 jz mcck_skip
670 UPDATE_VTIME %r14,%r15,__LC_MCCK_ENTER_TIMER
671mcck_skip:
672 SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+32,__LC_PANIC_STACK,PAGE_SHIFT
673 mvc __PT_R0(64,%r11),__LC_GPREGS_SAVE_AREA
674 stm %r8,%r9,__PT_PSW(%r11)
675 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
676 l %r1,BASED(.Ldo_machine_check)
677 lr %r2,%r11 # pass pointer to pt_regs
678 basr %r14,%r1 # call s390_do_machine_check
679 tm __PT_PSW+1(%r11),0x01 # returning to user ?
680 jno mcck_return
681 l %r1,__LC_KERNEL_STACK # switch to kernel stack
682 ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
683 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
684 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
685 la %r11,STACK_FRAME_OVERHEAD(%r15)
686 lr %r15,%r1
687 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off
688 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
689 jno mcck_return
690 TRACE_IRQS_OFF
691 l %r1,BASED(.Lhandle_mcck)
692 basr %r14,%r1 # call s390_handle_mcck
693 TRACE_IRQS_ON
694mcck_return:
695 mvc __LC_RETURN_MCCK_PSW(8),__PT_PSW(%r11) # move return PSW
696 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
697 jno 0f
698 lm %r0,%r15,__PT_R0(%r11)
699 stpt __LC_EXIT_TIMER
700 lpsw __LC_RETURN_MCCK_PSW
7010: lm %r0,%r15,__PT_R0(%r11)
702 lpsw __LC_RETURN_MCCK_PSW
703
704mcck_panic:
705 l %r14,__LC_PANIC_STACK
706 slr %r14,%r15
707 sra %r14,PAGE_SHIFT
708 jz 0f
709 l %r15,__LC_PANIC_STACK
7100: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
711 j mcck_skip
712
713#
714# PSW restart interrupt handler
715#
716ENTRY(restart_int_handler)
717 st %r15,__LC_SAVE_AREA_RESTART
718 l %r15,__LC_RESTART_STACK
719 ahi %r15,-__PT_SIZE # create pt_regs on stack
720 xc 0(__PT_SIZE,%r15),0(%r15)
721 stm %r0,%r14,__PT_R0(%r15)
722 mvc __PT_R15(4,%r15),__LC_SAVE_AREA_RESTART
723 mvc __PT_PSW(8,%r15),__LC_RST_OLD_PSW # store restart old psw
724 ahi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack
725 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
726 lm %r1,%r3,__LC_RESTART_FN # load fn, parm & source cpu
727 ltr %r3,%r3 # test source cpu address
728 jm 1f # negative -> skip source stop
7290: sigp %r4,%r3,1 # sigp sense to source cpu
730 brc 10,0b # wait for status stored
7311: basr %r14,%r1 # call function
732 stap __SF_EMPTY(%r15) # store cpu address
733 lh %r3,__SF_EMPTY(%r15)
7342: sigp %r4,%r3,5 # sigp stop to current cpu
735 brc 2,2b
7363: j 3b
737
738 .section .kprobes.text, "ax"
739
740#ifdef CONFIG_CHECK_STACK
741/*
742 * The synchronous or the asynchronous stack overflowed. We are dead.
743 * No need to properly save the registers, we are going to panic anyway.
744 * Setup a pt_regs so that show_trace can provide a good call trace.
745 */
746stack_overflow:
747 l %r15,__LC_PANIC_STACK # change to panic stack
748 ahi %r15,-__PT_SIZE # create pt_regs
749 stm %r0,%r7,__PT_R0(%r15)
750 stm %r8,%r9,__PT_PSW(%r15)
751 mvc __PT_R8(32,%r11),0(%r14)
752 lr %r15,%r11
753 ahi %r15,-STACK_FRAME_OVERHEAD
754 l %r1,BASED(1f)
755 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
756 lr %r2,%r11 # pass pointer to pt_regs
757 br %r1 # branch to kernel_stack_overflow
7581: .long kernel_stack_overflow
759#endif
760
761cleanup_table:
762 .long system_call + 0x80000000
763 .long sysc_do_svc + 0x80000000
764 .long sysc_tif + 0x80000000
765 .long sysc_restore + 0x80000000
766 .long sysc_done + 0x80000000
767 .long io_tif + 0x80000000
768 .long io_restore + 0x80000000
769 .long io_done + 0x80000000
770 .long psw_idle + 0x80000000
771 .long psw_idle_end + 0x80000000
772
773cleanup_critical:
774 cl %r9,BASED(cleanup_table) # system_call
775 jl 0f
776 cl %r9,BASED(cleanup_table+4) # sysc_do_svc
777 jl cleanup_system_call
778 cl %r9,BASED(cleanup_table+8) # sysc_tif
779 jl 0f
780 cl %r9,BASED(cleanup_table+12) # sysc_restore
781 jl cleanup_sysc_tif
782 cl %r9,BASED(cleanup_table+16) # sysc_done
783 jl cleanup_sysc_restore
784 cl %r9,BASED(cleanup_table+20) # io_tif
785 jl 0f
786 cl %r9,BASED(cleanup_table+24) # io_restore
787 jl cleanup_io_tif
788 cl %r9,BASED(cleanup_table+28) # io_done
789 jl cleanup_io_restore
790 cl %r9,BASED(cleanup_table+32) # psw_idle
791 jl 0f
792 cl %r9,BASED(cleanup_table+36) # psw_idle_end
793 jl cleanup_idle
7940: br %r14
795
796cleanup_system_call:
797 # check if stpt has been executed
798 cl %r9,BASED(cleanup_system_call_insn)
799 jh 0f
800 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
801 chi %r11,__LC_SAVE_AREA_ASYNC
802 je 0f
803 mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
8040: # check if stm has been executed
805 cl %r9,BASED(cleanup_system_call_insn+4)
806 jh 0f
807 mvc __LC_SAVE_AREA_SYNC(32),0(%r11)
8080: # set up saved registers r12, and r13
809 st %r12,16(%r11) # r12 thread-info pointer
810 st %r13,20(%r11) # r13 literal-pool pointer
811 # check if the user time calculation has been done
812 cl %r9,BASED(cleanup_system_call_insn+8)
813 jh 0f
814 l %r10,__LC_EXIT_TIMER
815 l %r15,__LC_EXIT_TIMER+4
816 SUB64 %r10,%r15,__LC_SYNC_ENTER_TIMER
817 ADD64 %r10,%r15,__LC_USER_TIMER
818 st %r10,__LC_USER_TIMER
819 st %r15,__LC_USER_TIMER+4
8200: # check if the system time calculation has been done
821 cl %r9,BASED(cleanup_system_call_insn+12)
822 jh 0f
823 l %r10,__LC_LAST_UPDATE_TIMER
824 l %r15,__LC_LAST_UPDATE_TIMER+4
825 SUB64 %r10,%r15,__LC_EXIT_TIMER
826 ADD64 %r10,%r15,__LC_SYSTEM_TIMER
827 st %r10,__LC_SYSTEM_TIMER
828 st %r15,__LC_SYSTEM_TIMER+4
8290: # update accounting time stamp
830 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
831 # set up saved register 11
832 l %r15,__LC_KERNEL_STACK
833 ahi %r15,-__PT_SIZE
834 st %r15,12(%r11) # r11 pt_regs pointer
835 # fill pt_regs
836 mvc __PT_R8(32,%r15),__LC_SAVE_AREA_SYNC
837 stm %r0,%r7,__PT_R0(%r15)
838 mvc __PT_PSW(8,%r15),__LC_SVC_OLD_PSW
839 mvc __PT_INT_CODE(4,%r15),__LC_SVC_ILC
840 # setup saved register 15
841 ahi %r15,-STACK_FRAME_OVERHEAD
842 st %r15,28(%r11) # r15 stack pointer
843 # set new psw address and exit
844 l %r9,BASED(cleanup_table+4) # sysc_do_svc + 0x80000000
845 br %r14
846cleanup_system_call_insn:
847 .long system_call + 0x80000000
848 .long sysc_stm + 0x80000000
849 .long sysc_vtime + 0x80000000 + 36
850 .long sysc_vtime + 0x80000000 + 76
851
852cleanup_sysc_tif:
853 l %r9,BASED(cleanup_table+8) # sysc_tif + 0x80000000
854 br %r14
855
856cleanup_sysc_restore:
857 cl %r9,BASED(cleanup_sysc_restore_insn)
858 jhe 0f
859 l %r9,12(%r11) # get saved pointer to pt_regs
860 mvc __LC_RETURN_PSW(8),__PT_PSW(%r9)
861 mvc 0(32,%r11),__PT_R8(%r9)
862 lm %r0,%r7,__PT_R0(%r9)
8630: lm %r8,%r9,__LC_RETURN_PSW
864 br %r14
865cleanup_sysc_restore_insn:
866 .long sysc_done - 4 + 0x80000000
867
868cleanup_io_tif:
869 l %r9,BASED(cleanup_table+20) # io_tif + 0x80000000
870 br %r14
871
872cleanup_io_restore:
873 cl %r9,BASED(cleanup_io_restore_insn)
874 jhe 0f
875 l %r9,12(%r11) # get saved r11 pointer to pt_regs
876 mvc __LC_RETURN_PSW(8),__PT_PSW(%r9)
877 mvc 0(32,%r11),__PT_R8(%r9)
878 lm %r0,%r7,__PT_R0(%r9)
8790: lm %r8,%r9,__LC_RETURN_PSW
880 br %r14
881cleanup_io_restore_insn:
882 .long io_done - 4 + 0x80000000
883
884cleanup_idle:
885 # copy interrupt clock & cpu timer
886 mvc __IDLE_EXIT(8,%r2),__LC_INT_CLOCK
887 mvc __VQ_IDLE_EXIT(8,%r3),__LC_ASYNC_ENTER_TIMER
888 chi %r11,__LC_SAVE_AREA_ASYNC
889 je 0f
890 mvc __IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK
891 mvc __VQ_IDLE_EXIT(8,%r3),__LC_MCCK_ENTER_TIMER
8920: # check if stck has been executed
893 cl %r9,BASED(cleanup_idle_insn)
894 jhe 1f
895 mvc __IDLE_ENTER(8,%r2),__IDLE_EXIT(%r2)
896 mvc __VQ_IDLE_ENTER(8,%r3),__VQ_IDLE_EXIT(%r3)
897 j 2f
8981: # check if the cpu timer has been reprogrammed
899 ltr %r5,%r5
900 jz 2f
901 spt __VQ_IDLE_ENTER(%r3)
9022: # account system time going idle
903 lm %r9,%r10,__LC_STEAL_TIMER
904 ADD64 %r9,%r10,__IDLE_ENTER(%r2)
905 SUB64 %r9,%r10,__LC_LAST_UPDATE_CLOCK
906 stm %r9,%r10,__LC_STEAL_TIMER
907 mvc __LC_LAST_UPDATE_CLOCK(8),__IDLE_EXIT(%r2)
908 lm %r9,%r10,__LC_SYSTEM_TIMER
909 ADD64 %r9,%r10,__LC_LAST_UPDATE_TIMER
910 SUB64 %r9,%r10,__VQ_IDLE_ENTER(%r3)
911 stm %r9,%r10,__LC_SYSTEM_TIMER
912 mvc __LC_LAST_UPDATE_TIMER(8),__VQ_IDLE_EXIT(%r3)
913 # prepare return psw
914 n %r8,BASED(cleanup_idle_wait) # clear wait state bit
915 l %r9,24(%r11) # return from psw_idle
916 br %r14
917cleanup_idle_insn:
918 .long psw_idle_lpsw + 0x80000000
919cleanup_idle_wait:
920 .long 0xfffdffff
921
922/*
923 * Integer constants
924 */
925 .align 4
926.Lnr_syscalls:
927 .long NR_syscalls
928.Lvtimer_max:
929 .quad 0x7fffffffffffffff
930
931/*
932 * Symbol constants
933 */
934.Ldo_machine_check: .long s390_do_machine_check
935.Lhandle_mcck: .long s390_handle_mcck
936.Ldo_IRQ: .long do_IRQ
937.Ldo_extint: .long do_extint
938.Ldo_signal: .long do_signal
939.Ldo_notify_resume: .long do_notify_resume
940.Ldo_per_trap: .long do_per_trap
941.Ldo_execve: .long do_execve
942.Lexecve_tail: .long execve_tail
943.Ljump_table: .long pgm_check_table
944.Lschedule: .long schedule
945#ifdef CONFIG_PREEMPT
946.Lpreempt_irq: .long preempt_schedule_irq
947#endif
948.Ltrace_enter: .long do_syscall_trace_enter
949.Ltrace_exit: .long do_syscall_trace_exit
950.Lschedule_tail: .long schedule_tail
951.Lsys_call_table: .long sys_call_table
952.Lsysc_per: .long sysc_per + 0x80000000
953#ifdef CONFIG_TRACE_IRQFLAGS
954.Lhardirqs_on: .long trace_hardirqs_on_caller
955.Lhardirqs_off: .long trace_hardirqs_off_caller
956#endif
957#ifdef CONFIG_LOCKDEP
958.Llockdep_sys_exit: .long lockdep_sys_exit
959#endif
960.Lcritical_start: .long __critical_start + 0x80000000
961.Lcritical_length: .long __critical_end - __critical_start
962
963 .section .rodata, "a"
964#define SYSCALL(esa,esame,emu) .long esa
965 .globl sys_call_table
966sys_call_table:
967#include "syscalls.S"
968#undef SYSCALL