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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 * S390 low-level entry points.
3 *
4 * Copyright IBM Corp. 1999, 2012
5 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
6 * Hartmut Penner (hp@de.ibm.com),
7 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
8 * Heiko Carstens <heiko.carstens@de.ibm.com>
9 */
10
11#include <linux/init.h>
12#include <linux/linkage.h>
13#include <asm/processor.h>
14#include <asm/cache.h>
15#include <asm/errno.h>
16#include <asm/ptrace.h>
17#include <asm/thread_info.h>
18#include <asm/asm-offsets.h>
19#include <asm/unistd.h>
20#include <asm/page.h>
21#include <asm/sigp.h>
22#include <asm/irq.h>
23#include <asm/vx-insn.h>
24#include <asm/setup.h>
25#include <asm/nmi.h>
26#include <asm/export.h>
27
28__PT_R0 = __PT_GPRS
29__PT_R1 = __PT_GPRS + 8
30__PT_R2 = __PT_GPRS + 16
31__PT_R3 = __PT_GPRS + 24
32__PT_R4 = __PT_GPRS + 32
33__PT_R5 = __PT_GPRS + 40
34__PT_R6 = __PT_GPRS + 48
35__PT_R7 = __PT_GPRS + 56
36__PT_R8 = __PT_GPRS + 64
37__PT_R9 = __PT_GPRS + 72
38__PT_R10 = __PT_GPRS + 80
39__PT_R11 = __PT_GPRS + 88
40__PT_R12 = __PT_GPRS + 96
41__PT_R13 = __PT_GPRS + 104
42__PT_R14 = __PT_GPRS + 112
43__PT_R15 = __PT_GPRS + 120
44
45STACK_SHIFT = PAGE_SHIFT + THREAD_SIZE_ORDER
46STACK_SIZE = 1 << STACK_SHIFT
47STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
48
49_TIF_WORK = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
50 _TIF_UPROBE)
51_TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
52 _TIF_SYSCALL_TRACEPOINT)
53_CIF_WORK = (_CIF_MCCK_PENDING | _CIF_ASCE | _CIF_FPU)
54_PIF_WORK = (_PIF_PER_TRAP)
55
56#define BASED(name) name-cleanup_critical(%r13)
57
58 .macro TRACE_IRQS_ON
59#ifdef CONFIG_TRACE_IRQFLAGS
60 basr %r2,%r0
61 brasl %r14,trace_hardirqs_on_caller
62#endif
63 .endm
64
65 .macro TRACE_IRQS_OFF
66#ifdef CONFIG_TRACE_IRQFLAGS
67 basr %r2,%r0
68 brasl %r14,trace_hardirqs_off_caller
69#endif
70 .endm
71
72 .macro LOCKDEP_SYS_EXIT
73#ifdef CONFIG_LOCKDEP
74 tm __PT_PSW+1(%r11),0x01 # returning to user ?
75 jz .+10
76 brasl %r14,lockdep_sys_exit
77#endif
78 .endm
79
80 .macro CHECK_STACK stacksize,savearea
81#ifdef CONFIG_CHECK_STACK
82 tml %r15,\stacksize - CONFIG_STACK_GUARD
83 lghi %r14,\savearea
84 jz stack_overflow
85#endif
86 .endm
87
88 .macro SWITCH_ASYNC savearea,timer
89 tmhh %r8,0x0001 # interrupting from user ?
90 jnz 1f
91 lgr %r14,%r9
92 slg %r14,BASED(.Lcritical_start)
93 clg %r14,BASED(.Lcritical_length)
94 jhe 0f
95 lghi %r11,\savearea # inside critical section, do cleanup
96 brasl %r14,cleanup_critical
97 tmhh %r8,0x0001 # retest problem state after cleanup
98 jnz 1f
990: lg %r14,__LC_ASYNC_STACK # are we already on the async stack?
100 slgr %r14,%r15
101 srag %r14,%r14,STACK_SHIFT
102 jnz 2f
103 CHECK_STACK 1<<STACK_SHIFT,\savearea
104 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
105 j 3f
1061: LAST_BREAK %r14
107 UPDATE_VTIME %r14,%r15,\timer
1082: lg %r15,__LC_ASYNC_STACK # load async stack
1093: la %r11,STACK_FRAME_OVERHEAD(%r15)
110 .endm
111
112 .macro UPDATE_VTIME w1,w2,enter_timer
113 lg \w1,__LC_EXIT_TIMER
114 lg \w2,__LC_LAST_UPDATE_TIMER
115 slg \w1,\enter_timer
116 slg \w2,__LC_EXIT_TIMER
117 alg \w1,__LC_USER_TIMER
118 alg \w2,__LC_SYSTEM_TIMER
119 stg \w1,__LC_USER_TIMER
120 stg \w2,__LC_SYSTEM_TIMER
121 mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer
122 .endm
123
124 .macro LAST_BREAK scratch
125 srag \scratch,%r10,23
126#ifdef CONFIG_HAVE_MARCH_Z990_FEATURES
127 jz .+10
128 stg %r10,__TASK_thread+__THREAD_last_break(%r12)
129#else
130 jz .+14
131 lghi \scratch,__TASK_thread
132 stg %r10,__THREAD_last_break(\scratch,%r12)
133#endif
134 .endm
135
136 .macro REENABLE_IRQS
137 stg %r8,__LC_RETURN_PSW
138 ni __LC_RETURN_PSW,0xbf
139 ssm __LC_RETURN_PSW
140 .endm
141
142 .macro STCK savearea
143#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
144 .insn s,0xb27c0000,\savearea # store clock fast
145#else
146 .insn s,0xb2050000,\savearea # store clock
147#endif
148 .endm
149
150 /*
151 * The TSTMSK macro generates a test-under-mask instruction by
152 * calculating the memory offset for the specified mask value.
153 * Mask value can be any constant. The macro shifts the mask
154 * value to calculate the memory offset for the test-under-mask
155 * instruction.
156 */
157 .macro TSTMSK addr, mask, size=8, bytepos=0
158 .if (\bytepos < \size) && (\mask >> 8)
159 .if (\mask & 0xff)
160 .error "Mask exceeds byte boundary"
161 .endif
162 TSTMSK \addr, "(\mask >> 8)", \size, "(\bytepos + 1)"
163 .exitm
164 .endif
165 .ifeq \mask
166 .error "Mask must not be zero"
167 .endif
168 off = \size - \bytepos - 1
169 tm off+\addr, \mask
170 .endm
171
172 .section .kprobes.text, "ax"
173.Ldummy:
174 /*
175 * This nop exists only in order to avoid that __switch_to starts at
176 * the beginning of the kprobes text section. In that case we would
177 * have several symbols at the same address. E.g. objdump would take
178 * an arbitrary symbol name when disassembling this code.
179 * With the added nop in between the __switch_to symbol is unique
180 * again.
181 */
182 nop 0
183
184/*
185 * Scheduler resume function, called by switch_to
186 * gpr2 = (task_struct *) prev
187 * gpr3 = (task_struct *) next
188 * Returns:
189 * gpr2 = prev
190 */
191ENTRY(__switch_to)
192 stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
193 lgr %r1,%r2
194 aghi %r1,__TASK_thread # thread_struct of prev task
195 lg %r5,__TASK_stack(%r3) # start of kernel stack of next
196 stg %r15,__THREAD_ksp(%r1) # store kernel stack of prev
197 lgr %r1,%r3
198 aghi %r1,__TASK_thread # thread_struct of next task
199 lgr %r15,%r5
200 aghi %r15,STACK_INIT # end of kernel stack of next
201 stg %r3,__LC_CURRENT # store task struct of next
202 stg %r15,__LC_KERNEL_STACK # store end of kernel stack
203 lg %r15,__THREAD_ksp(%r1) # load kernel stack of next
204 /* c4 is used in guest detection: arch/s390/kernel/perf_cpum_sf.c */
205 lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
206 mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next
207 lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
208 TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
209 bzr %r14
210 .insn s,0xb2800000,__LC_LPP # set program parameter
211 br %r14
212
213.L__critical_start:
214
215#if IS_ENABLED(CONFIG_KVM)
216/*
217 * sie64a calling convention:
218 * %r2 pointer to sie control block
219 * %r3 guest register save area
220 */
221ENTRY(sie64a)
222 stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers
223 stg %r2,__SF_EMPTY(%r15) # save control block pointer
224 stg %r3,__SF_EMPTY+8(%r15) # save guest register save area
225 xc __SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # reason code = 0
226 TSTMSK __LC_CPU_FLAGS,_CIF_FPU # load guest fp/vx registers ?
227 jno .Lsie_load_guest_gprs
228 brasl %r14,load_fpu_regs # load guest fp/vx regs
229.Lsie_load_guest_gprs:
230 lmg %r0,%r13,0(%r3) # load guest gprs 0-13
231 lg %r14,__LC_GMAP # get gmap pointer
232 ltgr %r14,%r14
233 jz .Lsie_gmap
234 lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce
235.Lsie_gmap:
236 lg %r14,__SF_EMPTY(%r15) # get control block pointer
237 oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now
238 tm __SIE_PROG20+3(%r14),3 # last exit...
239 jnz .Lsie_skip
240 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
241 jo .Lsie_skip # exit if fp/vx regs changed
242 sie 0(%r14)
243.Lsie_skip:
244 ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE
245 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
246.Lsie_done:
247# some program checks are suppressing. C code (e.g. do_protection_exception)
248# will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other
249# instructions between sie64a and .Lsie_done should not cause program
250# interrupts. So lets use a nop (47 00 00 00) as a landing pad.
251# See also .Lcleanup_sie
252.Lrewind_pad:
253 nop 0
254 .globl sie_exit
255sie_exit:
256 lg %r14,__SF_EMPTY+8(%r15) # load guest register save area
257 stmg %r0,%r13,0(%r14) # save guest gprs 0-13
258 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers
259 lg %r2,__SF_EMPTY+16(%r15) # return exit reason code
260 br %r14
261.Lsie_fault:
262 lghi %r14,-EFAULT
263 stg %r14,__SF_EMPTY+16(%r15) # set exit reason code
264 j sie_exit
265
266 EX_TABLE(.Lrewind_pad,.Lsie_fault)
267 EX_TABLE(sie_exit,.Lsie_fault)
268EXPORT_SYMBOL(sie64a)
269EXPORT_SYMBOL(sie_exit)
270#endif
271
272/*
273 * SVC interrupt handler routine. System calls are synchronous events and
274 * are executed with interrupts enabled.
275 */
276
277ENTRY(system_call)
278 stpt __LC_SYNC_ENTER_TIMER
279.Lsysc_stmg:
280 stmg %r8,%r15,__LC_SAVE_AREA_SYNC
281 lg %r10,__LC_LAST_BREAK
282 lg %r12,__LC_CURRENT
283 lghi %r14,_PIF_SYSCALL
284.Lsysc_per:
285 lg %r15,__LC_KERNEL_STACK
286 la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
287 LAST_BREAK %r13
288.Lsysc_vtime:
289 UPDATE_VTIME %r10,%r13,__LC_SYNC_ENTER_TIMER
290 stmg %r0,%r7,__PT_R0(%r11)
291 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
292 mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW
293 mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC
294 stg %r14,__PT_FLAGS(%r11)
295.Lsysc_do_svc:
296 # load address of system call table
297#ifdef CONFIG_HAVE_MARCH_Z990_FEATURES
298 lg %r10,__TASK_thread+__THREAD_sysc_table(%r12)
299#else
300 lghi %r13,__TASK_thread
301 lg %r10,__THREAD_sysc_table(%r13,%r12)
302#endif
303 llgh %r8,__PT_INT_CODE+2(%r11)
304 slag %r8,%r8,2 # shift and test for svc 0
305 jnz .Lsysc_nr_ok
306 # svc 0: system call number in %r1
307 llgfr %r1,%r1 # clear high word in r1
308 cghi %r1,NR_syscalls
309 jnl .Lsysc_nr_ok
310 sth %r1,__PT_INT_CODE+2(%r11)
311 slag %r8,%r1,2
312.Lsysc_nr_ok:
313 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
314 stg %r2,__PT_ORIG_GPR2(%r11)
315 stg %r7,STACK_FRAME_OVERHEAD(%r15)
316 lgf %r9,0(%r8,%r10) # get system call add.
317 TSTMSK __TI_flags(%r12),_TIF_TRACE
318 jnz .Lsysc_tracesys
319 basr %r14,%r9 # call sys_xxxx
320 stg %r2,__PT_R2(%r11) # store return value
321
322.Lsysc_return:
323 LOCKDEP_SYS_EXIT
324.Lsysc_tif:
325 TSTMSK __PT_FLAGS(%r11),_PIF_WORK
326 jnz .Lsysc_work
327 TSTMSK __TI_flags(%r12),_TIF_WORK
328 jnz .Lsysc_work # check for work
329 TSTMSK __LC_CPU_FLAGS,_CIF_WORK
330 jnz .Lsysc_work
331.Lsysc_restore:
332 lg %r14,__LC_VDSO_PER_CPU
333 lmg %r0,%r10,__PT_R0(%r11)
334 mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
335 stpt __LC_EXIT_TIMER
336 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
337 lmg %r11,%r15,__PT_R11(%r11)
338 lpswe __LC_RETURN_PSW
339.Lsysc_done:
340
341#
342# One of the work bits is on. Find out which one.
343#
344.Lsysc_work:
345 TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING
346 jo .Lsysc_mcck_pending
347 TSTMSK __TI_flags(%r12),_TIF_NEED_RESCHED
348 jo .Lsysc_reschedule
349#ifdef CONFIG_UPROBES
350 TSTMSK __TI_flags(%r12),_TIF_UPROBE
351 jo .Lsysc_uprobe_notify
352#endif
353 TSTMSK __PT_FLAGS(%r11),_PIF_PER_TRAP
354 jo .Lsysc_singlestep
355 TSTMSK __TI_flags(%r12),_TIF_SIGPENDING
356 jo .Lsysc_sigpending
357 TSTMSK __TI_flags(%r12),_TIF_NOTIFY_RESUME
358 jo .Lsysc_notify_resume
359 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
360 jo .Lsysc_vxrs
361 TSTMSK __LC_CPU_FLAGS,_CIF_ASCE
362 jo .Lsysc_uaccess
363 j .Lsysc_return # beware of critical section cleanup
364
365#
366# _TIF_NEED_RESCHED is set, call schedule
367#
368.Lsysc_reschedule:
369 larl %r14,.Lsysc_return
370 jg schedule
371
372#
373# _CIF_MCCK_PENDING is set, call handler
374#
375.Lsysc_mcck_pending:
376 larl %r14,.Lsysc_return
377 jg s390_handle_mcck # TIF bit will be cleared by handler
378
379#
380# _CIF_ASCE is set, load user space asce
381#
382.Lsysc_uaccess:
383 ni __LC_CPU_FLAGS+7,255-_CIF_ASCE
384 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
385 j .Lsysc_return
386
387#
388# CIF_FPU is set, restore floating-point controls and floating-point registers.
389#
390.Lsysc_vxrs:
391 larl %r14,.Lsysc_return
392 jg load_fpu_regs
393
394#
395# _TIF_SIGPENDING is set, call do_signal
396#
397.Lsysc_sigpending:
398 lgr %r2,%r11 # pass pointer to pt_regs
399 brasl %r14,do_signal
400 TSTMSK __PT_FLAGS(%r11),_PIF_SYSCALL
401 jno .Lsysc_return
402 lmg %r2,%r7,__PT_R2(%r11) # load svc arguments
403 lghi %r8,0 # svc 0 returns -ENOSYS
404 llgh %r1,__PT_INT_CODE+2(%r11) # load new svc number
405 cghi %r1,NR_syscalls
406 jnl .Lsysc_nr_ok # invalid svc number -> do svc 0
407 slag %r8,%r1,2
408 j .Lsysc_nr_ok # restart svc
409
410#
411# _TIF_NOTIFY_RESUME is set, call do_notify_resume
412#
413.Lsysc_notify_resume:
414 lgr %r2,%r11 # pass pointer to pt_regs
415 larl %r14,.Lsysc_return
416 jg do_notify_resume
417
418#
419# _TIF_UPROBE is set, call uprobe_notify_resume
420#
421#ifdef CONFIG_UPROBES
422.Lsysc_uprobe_notify:
423 lgr %r2,%r11 # pass pointer to pt_regs
424 larl %r14,.Lsysc_return
425 jg uprobe_notify_resume
426#endif
427
428#
429# _PIF_PER_TRAP is set, call do_per_trap
430#
431.Lsysc_singlestep:
432 ni __PT_FLAGS+7(%r11),255-_PIF_PER_TRAP
433 lgr %r2,%r11 # pass pointer to pt_regs
434 larl %r14,.Lsysc_return
435 jg do_per_trap
436
437#
438# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
439# and after the system call
440#
441.Lsysc_tracesys:
442 lgr %r2,%r11 # pass pointer to pt_regs
443 la %r3,0
444 llgh %r0,__PT_INT_CODE+2(%r11)
445 stg %r0,__PT_R2(%r11)
446 brasl %r14,do_syscall_trace_enter
447 lghi %r0,NR_syscalls
448 clgr %r0,%r2
449 jnh .Lsysc_tracenogo
450 sllg %r8,%r2,2
451 lgf %r9,0(%r8,%r10)
452.Lsysc_tracego:
453 lmg %r3,%r7,__PT_R3(%r11)
454 stg %r7,STACK_FRAME_OVERHEAD(%r15)
455 lg %r2,__PT_ORIG_GPR2(%r11)
456 basr %r14,%r9 # call sys_xxx
457 stg %r2,__PT_R2(%r11) # store return value
458.Lsysc_tracenogo:
459 TSTMSK __TI_flags(%r12),_TIF_TRACE
460 jz .Lsysc_return
461 lgr %r2,%r11 # pass pointer to pt_regs
462 larl %r14,.Lsysc_return
463 jg do_syscall_trace_exit
464
465#
466# a new process exits the kernel with ret_from_fork
467#
468ENTRY(ret_from_fork)
469 la %r11,STACK_FRAME_OVERHEAD(%r15)
470 lg %r12,__LC_CURRENT
471 brasl %r14,schedule_tail
472 TRACE_IRQS_ON
473 ssm __LC_SVC_NEW_PSW # reenable interrupts
474 tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ?
475 jne .Lsysc_tracenogo
476 # it's a kernel thread
477 lmg %r9,%r10,__PT_R9(%r11) # load gprs
478ENTRY(kernel_thread_starter)
479 la %r2,0(%r10)
480 basr %r14,%r9
481 j .Lsysc_tracenogo
482
483/*
484 * Program check handler routine
485 */
486
487ENTRY(pgm_check_handler)
488 stpt __LC_SYNC_ENTER_TIMER
489 stmg %r8,%r15,__LC_SAVE_AREA_SYNC
490 lg %r10,__LC_LAST_BREAK
491 lg %r12,__LC_CURRENT
492 larl %r13,cleanup_critical
493 lmg %r8,%r9,__LC_PGM_OLD_PSW
494 tmhh %r8,0x0001 # test problem state bit
495 jnz 2f # -> fault in user space
496#if IS_ENABLED(CONFIG_KVM)
497 # cleanup critical section for sie64a
498 lgr %r14,%r9
499 slg %r14,BASED(.Lsie_critical_start)
500 clg %r14,BASED(.Lsie_critical_length)
501 jhe 0f
502 brasl %r14,.Lcleanup_sie
503#endif
5040: tmhh %r8,0x4000 # PER bit set in old PSW ?
505 jnz 1f # -> enabled, can't be a double fault
506 tm __LC_PGM_ILC+3,0x80 # check for per exception
507 jnz .Lpgm_svcper # -> single stepped svc
5081: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
509 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
510 j 3f
5112: LAST_BREAK %r14
512 UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
513 lg %r15,__LC_KERNEL_STACK
514 lgr %r14,%r12
515 aghi %r14,__TASK_thread # pointer to thread_struct
516 lghi %r13,__LC_PGM_TDB
517 tm __LC_PGM_ILC+2,0x02 # check for transaction abort
518 jz 3f
519 mvc __THREAD_trap_tdb(256,%r14),0(%r13)
5203: la %r11,STACK_FRAME_OVERHEAD(%r15)
521 stmg %r0,%r7,__PT_R0(%r11)
522 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
523 stmg %r8,%r9,__PT_PSW(%r11)
524 mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC
525 mvc __PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE
526 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
527 stg %r10,__PT_ARGS(%r11)
528 tm __LC_PGM_ILC+3,0x80 # check for per exception
529 jz 4f
530 tmhh %r8,0x0001 # kernel per event ?
531 jz .Lpgm_kprobe
532 oi __PT_FLAGS+7(%r11),_PIF_PER_TRAP
533 mvc __THREAD_per_address(8,%r14),__LC_PER_ADDRESS
534 mvc __THREAD_per_cause(2,%r14),__LC_PER_CODE
535 mvc __THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
5364: REENABLE_IRQS
537 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
538 larl %r1,pgm_check_table
539 llgh %r10,__PT_INT_CODE+2(%r11)
540 nill %r10,0x007f
541 sll %r10,2
542 je .Lpgm_return
543 lgf %r1,0(%r10,%r1) # load address of handler routine
544 lgr %r2,%r11 # pass pointer to pt_regs
545 basr %r14,%r1 # branch to interrupt-handler
546.Lpgm_return:
547 LOCKDEP_SYS_EXIT
548 tm __PT_PSW+1(%r11),0x01 # returning to user ?
549 jno .Lsysc_restore
550 j .Lsysc_tif
551
552#
553# PER event in supervisor state, must be kprobes
554#
555.Lpgm_kprobe:
556 REENABLE_IRQS
557 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
558 lgr %r2,%r11 # pass pointer to pt_regs
559 brasl %r14,do_per_trap
560 j .Lpgm_return
561
562#
563# single stepped system call
564#
565.Lpgm_svcper:
566 mvc __LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
567 larl %r14,.Lsysc_per
568 stg %r14,__LC_RETURN_PSW+8
569 lghi %r14,_PIF_SYSCALL | _PIF_PER_TRAP
570 lpswe __LC_RETURN_PSW # branch to .Lsysc_per and enable irqs
571
572/*
573 * IO interrupt handler routine
574 */
575ENTRY(io_int_handler)
576 STCK __LC_INT_CLOCK
577 stpt __LC_ASYNC_ENTER_TIMER
578 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
579 lg %r10,__LC_LAST_BREAK
580 lg %r12,__LC_CURRENT
581 larl %r13,cleanup_critical
582 lmg %r8,%r9,__LC_IO_OLD_PSW
583 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
584 stmg %r0,%r7,__PT_R0(%r11)
585 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
586 stmg %r8,%r9,__PT_PSW(%r11)
587 mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
588 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
589 TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ
590 jo .Lio_restore
591 TRACE_IRQS_OFF
592 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
593.Lio_loop:
594 lgr %r2,%r11 # pass pointer to pt_regs
595 lghi %r3,IO_INTERRUPT
596 tm __PT_INT_CODE+8(%r11),0x80 # adapter interrupt ?
597 jz .Lio_call
598 lghi %r3,THIN_INTERRUPT
599.Lio_call:
600 brasl %r14,do_IRQ
601 TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPAR
602 jz .Lio_return
603 tpi 0
604 jz .Lio_return
605 mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
606 j .Lio_loop
607.Lio_return:
608 LOCKDEP_SYS_EXIT
609 TRACE_IRQS_ON
610.Lio_tif:
611 TSTMSK __TI_flags(%r12),_TIF_WORK
612 jnz .Lio_work # there is work to do (signals etc.)
613 TSTMSK __LC_CPU_FLAGS,_CIF_WORK
614 jnz .Lio_work
615.Lio_restore:
616 lg %r14,__LC_VDSO_PER_CPU
617 lmg %r0,%r10,__PT_R0(%r11)
618 mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
619 stpt __LC_EXIT_TIMER
620 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
621 lmg %r11,%r15,__PT_R11(%r11)
622 lpswe __LC_RETURN_PSW
623.Lio_done:
624
625#
626# There is work todo, find out in which context we have been interrupted:
627# 1) if we return to user space we can do all _TIF_WORK work
628# 2) if we return to kernel code and kvm is enabled check if we need to
629# modify the psw to leave SIE
630# 3) if we return to kernel code and preemptive scheduling is enabled check
631# the preemption counter and if it is zero call preempt_schedule_irq
632# Before any work can be done, a switch to the kernel stack is required.
633#
634.Lio_work:
635 tm __PT_PSW+1(%r11),0x01 # returning to user ?
636 jo .Lio_work_user # yes -> do resched & signal
637#ifdef CONFIG_PREEMPT
638 # check for preemptive scheduling
639 icm %r0,15,__LC_PREEMPT_COUNT
640 jnz .Lio_restore # preemption is disabled
641 TSTMSK __TI_flags(%r12),_TIF_NEED_RESCHED
642 jno .Lio_restore
643 # switch to kernel stack
644 lg %r1,__PT_R15(%r11)
645 aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
646 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
647 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
648 la %r11,STACK_FRAME_OVERHEAD(%r1)
649 lgr %r15,%r1
650 # TRACE_IRQS_ON already done at .Lio_return, call
651 # TRACE_IRQS_OFF to keep things symmetrical
652 TRACE_IRQS_OFF
653 brasl %r14,preempt_schedule_irq
654 j .Lio_return
655#else
656 j .Lio_restore
657#endif
658
659#
660# Need to do work before returning to userspace, switch to kernel stack
661#
662.Lio_work_user:
663 lg %r1,__LC_KERNEL_STACK
664 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
665 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
666 la %r11,STACK_FRAME_OVERHEAD(%r1)
667 lgr %r15,%r1
668
669#
670# One of the work bits is on. Find out which one.
671#
672.Lio_work_tif:
673 TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING
674 jo .Lio_mcck_pending
675 TSTMSK __TI_flags(%r12),_TIF_NEED_RESCHED
676 jo .Lio_reschedule
677 TSTMSK __TI_flags(%r12),_TIF_SIGPENDING
678 jo .Lio_sigpending
679 TSTMSK __TI_flags(%r12),_TIF_NOTIFY_RESUME
680 jo .Lio_notify_resume
681 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
682 jo .Lio_vxrs
683 TSTMSK __LC_CPU_FLAGS,_CIF_ASCE
684 jo .Lio_uaccess
685 j .Lio_return # beware of critical section cleanup
686
687#
688# _CIF_MCCK_PENDING is set, call handler
689#
690.Lio_mcck_pending:
691 # TRACE_IRQS_ON already done at .Lio_return
692 brasl %r14,s390_handle_mcck # TIF bit will be cleared by handler
693 TRACE_IRQS_OFF
694 j .Lio_return
695
696#
697# _CIF_ASCE is set, load user space asce
698#
699.Lio_uaccess:
700 ni __LC_CPU_FLAGS+7,255-_CIF_ASCE
701 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
702 j .Lio_return
703
704#
705# CIF_FPU is set, restore floating-point controls and floating-point registers.
706#
707.Lio_vxrs:
708 larl %r14,.Lio_return
709 jg load_fpu_regs
710
711#
712# _TIF_NEED_RESCHED is set, call schedule
713#
714.Lio_reschedule:
715 # TRACE_IRQS_ON already done at .Lio_return
716 ssm __LC_SVC_NEW_PSW # reenable interrupts
717 brasl %r14,schedule # call scheduler
718 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
719 TRACE_IRQS_OFF
720 j .Lio_return
721
722#
723# _TIF_SIGPENDING or is set, call do_signal
724#
725.Lio_sigpending:
726 # TRACE_IRQS_ON already done at .Lio_return
727 ssm __LC_SVC_NEW_PSW # reenable interrupts
728 lgr %r2,%r11 # pass pointer to pt_regs
729 brasl %r14,do_signal
730 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
731 TRACE_IRQS_OFF
732 j .Lio_return
733
734#
735# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
736#
737.Lio_notify_resume:
738 # TRACE_IRQS_ON already done at .Lio_return
739 ssm __LC_SVC_NEW_PSW # reenable interrupts
740 lgr %r2,%r11 # pass pointer to pt_regs
741 brasl %r14,do_notify_resume
742 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
743 TRACE_IRQS_OFF
744 j .Lio_return
745
746/*
747 * External interrupt handler routine
748 */
749ENTRY(ext_int_handler)
750 STCK __LC_INT_CLOCK
751 stpt __LC_ASYNC_ENTER_TIMER
752 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
753 lg %r10,__LC_LAST_BREAK
754 lg %r12,__LC_CURRENT
755 larl %r13,cleanup_critical
756 lmg %r8,%r9,__LC_EXT_OLD_PSW
757 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
758 stmg %r0,%r7,__PT_R0(%r11)
759 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
760 stmg %r8,%r9,__PT_PSW(%r11)
761 lghi %r1,__LC_EXT_PARAMS2
762 mvc __PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
763 mvc __PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
764 mvc __PT_INT_PARM_LONG(8,%r11),0(%r1)
765 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
766 TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ
767 jo .Lio_restore
768 TRACE_IRQS_OFF
769 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
770 lgr %r2,%r11 # pass pointer to pt_regs
771 lghi %r3,EXT_INTERRUPT
772 brasl %r14,do_IRQ
773 j .Lio_return
774
775/*
776 * Load idle PSW. The second "half" of this function is in .Lcleanup_idle.
777 */
778ENTRY(psw_idle)
779 stg %r3,__SF_EMPTY(%r15)
780 larl %r1,.Lpsw_idle_lpsw+4
781 stg %r1,__SF_EMPTY+8(%r15)
782#ifdef CONFIG_SMP
783 larl %r1,smp_cpu_mtid
784 llgf %r1,0(%r1)
785 ltgr %r1,%r1
786 jz .Lpsw_idle_stcctm
787 .insn rsy,0xeb0000000017,%r1,5,__SF_EMPTY+16(%r15)
788.Lpsw_idle_stcctm:
789#endif
790 oi __LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT
791 STCK __CLOCK_IDLE_ENTER(%r2)
792 stpt __TIMER_IDLE_ENTER(%r2)
793.Lpsw_idle_lpsw:
794 lpswe __SF_EMPTY(%r15)
795 br %r14
796.Lpsw_idle_end:
797
798/*
799 * Store floating-point controls and floating-point or vector register
800 * depending whether the vector facility is available. A critical section
801 * cleanup assures that the registers are stored even if interrupted for
802 * some other work. The CIF_FPU flag is set to trigger a lazy restore
803 * of the register contents at return from io or a system call.
804 */
805ENTRY(save_fpu_regs)
806 lg %r2,__LC_CURRENT
807 aghi %r2,__TASK_thread
808 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
809 bor %r14
810 stfpc __THREAD_FPU_fpc(%r2)
811 lg %r3,__THREAD_FPU_regs(%r2)
812 TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_VX
813 jz .Lsave_fpu_regs_fp # no -> store FP regs
814 VSTM %v0,%v15,0,%r3 # vstm 0,15,0(3)
815 VSTM %v16,%v31,256,%r3 # vstm 16,31,256(3)
816 j .Lsave_fpu_regs_done # -> set CIF_FPU flag
817.Lsave_fpu_regs_fp:
818 std 0,0(%r3)
819 std 1,8(%r3)
820 std 2,16(%r3)
821 std 3,24(%r3)
822 std 4,32(%r3)
823 std 5,40(%r3)
824 std 6,48(%r3)
825 std 7,56(%r3)
826 std 8,64(%r3)
827 std 9,72(%r3)
828 std 10,80(%r3)
829 std 11,88(%r3)
830 std 12,96(%r3)
831 std 13,104(%r3)
832 std 14,112(%r3)
833 std 15,120(%r3)
834.Lsave_fpu_regs_done:
835 oi __LC_CPU_FLAGS+7,_CIF_FPU
836 br %r14
837.Lsave_fpu_regs_end:
838#if IS_ENABLED(CONFIG_KVM)
839EXPORT_SYMBOL(save_fpu_regs)
840#endif
841
842/*
843 * Load floating-point controls and floating-point or vector registers.
844 * A critical section cleanup assures that the register contents are
845 * loaded even if interrupted for some other work.
846 *
847 * There are special calling conventions to fit into sysc and io return work:
848 * %r15: <kernel stack>
849 * The function requires:
850 * %r4
851 */
852load_fpu_regs:
853 lg %r4,__LC_CURRENT
854 aghi %r4,__TASK_thread
855 TSTMSK __LC_CPU_FLAGS,_CIF_FPU
856 bnor %r14
857 lfpc __THREAD_FPU_fpc(%r4)
858 TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_VX
859 lg %r4,__THREAD_FPU_regs(%r4) # %r4 <- reg save area
860 jz .Lload_fpu_regs_fp # -> no VX, load FP regs
861 VLM %v0,%v15,0,%r4
862 VLM %v16,%v31,256,%r4
863 j .Lload_fpu_regs_done
864.Lload_fpu_regs_fp:
865 ld 0,0(%r4)
866 ld 1,8(%r4)
867 ld 2,16(%r4)
868 ld 3,24(%r4)
869 ld 4,32(%r4)
870 ld 5,40(%r4)
871 ld 6,48(%r4)
872 ld 7,56(%r4)
873 ld 8,64(%r4)
874 ld 9,72(%r4)
875 ld 10,80(%r4)
876 ld 11,88(%r4)
877 ld 12,96(%r4)
878 ld 13,104(%r4)
879 ld 14,112(%r4)
880 ld 15,120(%r4)
881.Lload_fpu_regs_done:
882 ni __LC_CPU_FLAGS+7,255-_CIF_FPU
883 br %r14
884.Lload_fpu_regs_end:
885
886.L__critical_end:
887
888/*
889 * Machine check handler routines
890 */
891ENTRY(mcck_int_handler)
892 STCK __LC_MCCK_CLOCK
893 la %r1,4095 # revalidate r1
894 spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # revalidate cpu timer
895 lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
896 lg %r10,__LC_LAST_BREAK
897 lg %r12,__LC_CURRENT
898 larl %r13,cleanup_critical
899 lmg %r8,%r9,__LC_MCK_OLD_PSW
900 TSTMSK __LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE
901 jo .Lmcck_panic # yes -> rest of mcck code invalid
902 lghi %r14,__LC_CPU_TIMER_SAVE_AREA
903 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
904 TSTMSK __LC_MCCK_CODE,MCCK_CODE_CPU_TIMER_VALID
905 jo 3f
906 la %r14,__LC_SYNC_ENTER_TIMER
907 clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER
908 jl 0f
909 la %r14,__LC_ASYNC_ENTER_TIMER
9100: clc 0(8,%r14),__LC_EXIT_TIMER
911 jl 1f
912 la %r14,__LC_EXIT_TIMER
9131: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER
914 jl 2f
915 la %r14,__LC_LAST_UPDATE_TIMER
9162: spt 0(%r14)
917 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
9183: TSTMSK __LC_MCCK_CODE,(MCCK_CODE_PSW_MWP_VALID|MCCK_CODE_PSW_IA_VALID)
919 jno .Lmcck_panic # no -> skip cleanup critical
920 SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER
921.Lmcck_skip:
922 lghi %r14,__LC_GPREGS_SAVE_AREA+64
923 stmg %r0,%r7,__PT_R0(%r11)
924 mvc __PT_R8(64,%r11),0(%r14)
925 stmg %r8,%r9,__PT_PSW(%r11)
926 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
927 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
928 lgr %r2,%r11 # pass pointer to pt_regs
929 brasl %r14,s390_do_machine_check
930 tm __PT_PSW+1(%r11),0x01 # returning to user ?
931 jno .Lmcck_return
932 lg %r1,__LC_KERNEL_STACK # switch to kernel stack
933 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
934 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
935 la %r11,STACK_FRAME_OVERHEAD(%r1)
936 lgr %r15,%r1
937 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off
938 TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING
939 jno .Lmcck_return
940 TRACE_IRQS_OFF
941 brasl %r14,s390_handle_mcck
942 TRACE_IRQS_ON
943.Lmcck_return:
944 lg %r14,__LC_VDSO_PER_CPU
945 lmg %r0,%r10,__PT_R0(%r11)
946 mvc __LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
947 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
948 jno 0f
949 stpt __LC_EXIT_TIMER
950 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
9510: lmg %r11,%r15,__PT_R11(%r11)
952 lpswe __LC_RETURN_MCCK_PSW
953
954.Lmcck_panic:
955 lg %r15,__LC_PANIC_STACK
956 la %r11,STACK_FRAME_OVERHEAD(%r15)
957 j .Lmcck_skip
958
959#
960# PSW restart interrupt handler
961#
962ENTRY(restart_int_handler)
963 TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
964 jz 0f
965 .insn s,0xb2800000,__LC_LPP
9660: stg %r15,__LC_SAVE_AREA_RESTART
967 lg %r15,__LC_RESTART_STACK
968 aghi %r15,-__PT_SIZE # create pt_regs on stack
969 xc 0(__PT_SIZE,%r15),0(%r15)
970 stmg %r0,%r14,__PT_R0(%r15)
971 mvc __PT_R15(8,%r15),__LC_SAVE_AREA_RESTART
972 mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw
973 aghi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack
974 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
975 lg %r1,__LC_RESTART_FN # load fn, parm & source cpu
976 lg %r2,__LC_RESTART_DATA
977 lg %r3,__LC_RESTART_SOURCE
978 ltgr %r3,%r3 # test source cpu address
979 jm 1f # negative -> skip source stop
9800: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu
981 brc 10,0b # wait for status stored
9821: basr %r14,%r1 # call function
983 stap __SF_EMPTY(%r15) # store cpu address
984 llgh %r3,__SF_EMPTY(%r15)
9852: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu
986 brc 2,2b
9873: j 3b
988
989 .section .kprobes.text, "ax"
990
991#ifdef CONFIG_CHECK_STACK
992/*
993 * The synchronous or the asynchronous stack overflowed. We are dead.
994 * No need to properly save the registers, we are going to panic anyway.
995 * Setup a pt_regs so that show_trace can provide a good call trace.
996 */
997stack_overflow:
998 lg %r15,__LC_PANIC_STACK # change to panic stack
999 la %r11,STACK_FRAME_OVERHEAD(%r15)
1000 stmg %r0,%r7,__PT_R0(%r11)
1001 stmg %r8,%r9,__PT_PSW(%r11)
1002 mvc __PT_R8(64,%r11),0(%r14)
1003 stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
1004 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
1005 lgr %r2,%r11 # pass pointer to pt_regs
1006 jg kernel_stack_overflow
1007#endif
1008
1009cleanup_critical:
1010#if IS_ENABLED(CONFIG_KVM)
1011 clg %r9,BASED(.Lcleanup_table_sie) # .Lsie_gmap
1012 jl 0f
1013 clg %r9,BASED(.Lcleanup_table_sie+8)# .Lsie_done
1014 jl .Lcleanup_sie
1015#endif
1016 clg %r9,BASED(.Lcleanup_table) # system_call
1017 jl 0f
1018 clg %r9,BASED(.Lcleanup_table+8) # .Lsysc_do_svc
1019 jl .Lcleanup_system_call
1020 clg %r9,BASED(.Lcleanup_table+16) # .Lsysc_tif
1021 jl 0f
1022 clg %r9,BASED(.Lcleanup_table+24) # .Lsysc_restore
1023 jl .Lcleanup_sysc_tif
1024 clg %r9,BASED(.Lcleanup_table+32) # .Lsysc_done
1025 jl .Lcleanup_sysc_restore
1026 clg %r9,BASED(.Lcleanup_table+40) # .Lio_tif
1027 jl 0f
1028 clg %r9,BASED(.Lcleanup_table+48) # .Lio_restore
1029 jl .Lcleanup_io_tif
1030 clg %r9,BASED(.Lcleanup_table+56) # .Lio_done
1031 jl .Lcleanup_io_restore
1032 clg %r9,BASED(.Lcleanup_table+64) # psw_idle
1033 jl 0f
1034 clg %r9,BASED(.Lcleanup_table+72) # .Lpsw_idle_end
1035 jl .Lcleanup_idle
1036 clg %r9,BASED(.Lcleanup_table+80) # save_fpu_regs
1037 jl 0f
1038 clg %r9,BASED(.Lcleanup_table+88) # .Lsave_fpu_regs_end
1039 jl .Lcleanup_save_fpu_regs
1040 clg %r9,BASED(.Lcleanup_table+96) # load_fpu_regs
1041 jl 0f
1042 clg %r9,BASED(.Lcleanup_table+104) # .Lload_fpu_regs_end
1043 jl .Lcleanup_load_fpu_regs
10440: br %r14
1045
1046 .align 8
1047.Lcleanup_table:
1048 .quad system_call
1049 .quad .Lsysc_do_svc
1050 .quad .Lsysc_tif
1051 .quad .Lsysc_restore
1052 .quad .Lsysc_done
1053 .quad .Lio_tif
1054 .quad .Lio_restore
1055 .quad .Lio_done
1056 .quad psw_idle
1057 .quad .Lpsw_idle_end
1058 .quad save_fpu_regs
1059 .quad .Lsave_fpu_regs_end
1060 .quad load_fpu_regs
1061 .quad .Lload_fpu_regs_end
1062
1063#if IS_ENABLED(CONFIG_KVM)
1064.Lcleanup_table_sie:
1065 .quad .Lsie_gmap
1066 .quad .Lsie_done
1067
1068.Lcleanup_sie:
1069 lg %r9,__SF_EMPTY(%r15) # get control block pointer
1070 ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE
1071 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
1072 larl %r9,sie_exit # skip forward to sie_exit
1073 br %r14
1074#endif
1075
1076.Lcleanup_system_call:
1077 # check if stpt has been executed
1078 clg %r9,BASED(.Lcleanup_system_call_insn)
1079 jh 0f
1080 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
1081 cghi %r11,__LC_SAVE_AREA_ASYNC
1082 je 0f
1083 mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
10840: # check if stmg has been executed
1085 clg %r9,BASED(.Lcleanup_system_call_insn+8)
1086 jh 0f
1087 mvc __LC_SAVE_AREA_SYNC(64),0(%r11)
10880: # check if base register setup + TIF bit load has been done
1089 clg %r9,BASED(.Lcleanup_system_call_insn+16)
1090 jhe 0f
1091 # set up saved registers r10 and r12
1092 stg %r10,16(%r11) # r10 last break
1093 stg %r12,32(%r11) # r12 task struct pointer
10940: # check if the user time update has been done
1095 clg %r9,BASED(.Lcleanup_system_call_insn+24)
1096 jh 0f
1097 lg %r15,__LC_EXIT_TIMER
1098 slg %r15,__LC_SYNC_ENTER_TIMER
1099 alg %r15,__LC_USER_TIMER
1100 stg %r15,__LC_USER_TIMER
11010: # check if the system time update has been done
1102 clg %r9,BASED(.Lcleanup_system_call_insn+32)
1103 jh 0f
1104 lg %r15,__LC_LAST_UPDATE_TIMER
1105 slg %r15,__LC_EXIT_TIMER
1106 alg %r15,__LC_SYSTEM_TIMER
1107 stg %r15,__LC_SYSTEM_TIMER
11080: # update accounting time stamp
1109 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
1110 # do LAST_BREAK
1111 lg %r9,16(%r11)
1112 srag %r9,%r9,23
1113 jz 0f
1114 lgr %r9,%r12
1115 aghi %r9,__TASK_thread
1116 mvc __THREAD_last_break(8,%r9),16(%r11)
11170: # set up saved register r11
1118 lg %r15,__LC_KERNEL_STACK
1119 la %r9,STACK_FRAME_OVERHEAD(%r15)
1120 stg %r9,24(%r11) # r11 pt_regs pointer
1121 # fill pt_regs
1122 mvc __PT_R8(64,%r9),__LC_SAVE_AREA_SYNC
1123 stmg %r0,%r7,__PT_R0(%r9)
1124 mvc __PT_PSW(16,%r9),__LC_SVC_OLD_PSW
1125 mvc __PT_INT_CODE(4,%r9),__LC_SVC_ILC
1126 xc __PT_FLAGS(8,%r9),__PT_FLAGS(%r9)
1127 mvi __PT_FLAGS+7(%r9),_PIF_SYSCALL
1128 # setup saved register r15
1129 stg %r15,56(%r11) # r15 stack pointer
1130 # set new psw address and exit
1131 larl %r9,.Lsysc_do_svc
1132 br %r14
1133.Lcleanup_system_call_insn:
1134 .quad system_call
1135 .quad .Lsysc_stmg
1136 .quad .Lsysc_per
1137 .quad .Lsysc_vtime+36
1138 .quad .Lsysc_vtime+42
1139
1140.Lcleanup_sysc_tif:
1141 larl %r9,.Lsysc_tif
1142 br %r14
1143
1144.Lcleanup_sysc_restore:
1145 clg %r9,BASED(.Lcleanup_sysc_restore_insn)
1146 je 0f
1147 lg %r9,24(%r11) # get saved pointer to pt_regs
1148 mvc __LC_RETURN_PSW(16),__PT_PSW(%r9)
1149 mvc 0(64,%r11),__PT_R8(%r9)
1150 lmg %r0,%r7,__PT_R0(%r9)
11510: lmg %r8,%r9,__LC_RETURN_PSW
1152 br %r14
1153.Lcleanup_sysc_restore_insn:
1154 .quad .Lsysc_done - 4
1155
1156.Lcleanup_io_tif:
1157 larl %r9,.Lio_tif
1158 br %r14
1159
1160.Lcleanup_io_restore:
1161 clg %r9,BASED(.Lcleanup_io_restore_insn)
1162 je 0f
1163 lg %r9,24(%r11) # get saved r11 pointer to pt_regs
1164 mvc __LC_RETURN_PSW(16),__PT_PSW(%r9)
1165 mvc 0(64,%r11),__PT_R8(%r9)
1166 lmg %r0,%r7,__PT_R0(%r9)
11670: lmg %r8,%r9,__LC_RETURN_PSW
1168 br %r14
1169.Lcleanup_io_restore_insn:
1170 .quad .Lio_done - 4
1171
1172.Lcleanup_idle:
1173 ni __LC_CPU_FLAGS+7,255-_CIF_ENABLED_WAIT
1174 # copy interrupt clock & cpu timer
1175 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK
1176 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER
1177 cghi %r11,__LC_SAVE_AREA_ASYNC
1178 je 0f
1179 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK
1180 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER
11810: # check if stck & stpt have been executed
1182 clg %r9,BASED(.Lcleanup_idle_insn)
1183 jhe 1f
1184 mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
1185 mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r2)
11861: # calculate idle cycles
1187#ifdef CONFIG_SMP
1188 clg %r9,BASED(.Lcleanup_idle_insn)
1189 jl 3f
1190 larl %r1,smp_cpu_mtid
1191 llgf %r1,0(%r1)
1192 ltgr %r1,%r1
1193 jz 3f
1194 .insn rsy,0xeb0000000017,%r1,5,__SF_EMPTY+80(%r15)
1195 larl %r3,mt_cycles
1196 ag %r3,__LC_PERCPU_OFFSET
1197 la %r4,__SF_EMPTY+16(%r15)
11982: lg %r0,0(%r3)
1199 slg %r0,0(%r4)
1200 alg %r0,64(%r4)
1201 stg %r0,0(%r3)
1202 la %r3,8(%r3)
1203 la %r4,8(%r4)
1204 brct %r1,2b
1205#endif
12063: # account system time going idle
1207 lg %r9,__LC_STEAL_TIMER
1208 alg %r9,__CLOCK_IDLE_ENTER(%r2)
1209 slg %r9,__LC_LAST_UPDATE_CLOCK
1210 stg %r9,__LC_STEAL_TIMER
1211 mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
1212 lg %r9,__LC_SYSTEM_TIMER
1213 alg %r9,__LC_LAST_UPDATE_TIMER
1214 slg %r9,__TIMER_IDLE_ENTER(%r2)
1215 stg %r9,__LC_SYSTEM_TIMER
1216 mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
1217 # prepare return psw
1218 nihh %r8,0xfcfd # clear irq & wait state bits
1219 lg %r9,48(%r11) # return from psw_idle
1220 br %r14
1221.Lcleanup_idle_insn:
1222 .quad .Lpsw_idle_lpsw
1223
1224.Lcleanup_save_fpu_regs:
1225 larl %r9,save_fpu_regs
1226 br %r14
1227
1228.Lcleanup_load_fpu_regs:
1229 larl %r9,load_fpu_regs
1230 br %r14
1231
1232/*
1233 * Integer constants
1234 */
1235 .align 8
1236.Lcritical_start:
1237 .quad .L__critical_start
1238.Lcritical_length:
1239 .quad .L__critical_end - .L__critical_start
1240#if IS_ENABLED(CONFIG_KVM)
1241.Lsie_critical_start:
1242 .quad .Lsie_gmap
1243.Lsie_critical_length:
1244 .quad .Lsie_done - .Lsie_gmap
1245#endif
1246
1247 .section .rodata, "a"
1248#define SYSCALL(esame,emu) .long esame
1249 .globl sys_call_table
1250sys_call_table:
1251#include "syscalls.S"
1252#undef SYSCALL
1253
1254#ifdef CONFIG_COMPAT
1255
1256#define SYSCALL(esame,emu) .long emu
1257 .globl sys_call_table_emu
1258sys_call_table_emu:
1259#include "syscalls.S"
1260#undef SYSCALL
1261#endif