1/* 2 * S390 low-level entry points. 3 * 4 * Copyright IBM Corp. 1999, 2012 5 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 6 * Hartmut Penner (hp@de.ibm.com), 7 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), 8 * Heiko Carstens <heiko.carstens@de.ibm.com> 9 */ 10 11#include <linux/init.h> 12#include <linux/linkage.h> 13#include <asm/cache.h> 14#include <asm/errno.h> 15#include <asm/ptrace.h> 16#include <asm/thread_info.h> 17#include <asm/asm-offsets.h> 18#include <asm/unistd.h> 19#include <asm/page.h> 20#include <asm/sigp.h> 21 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 je 1f 335 l %r1,BASED(.Lschedule_tail) 336 basr %r14,%r1 # call schedule_tail 337 TRACE_IRQS_ON 338 ssm __LC_SVC_NEW_PSW # reenable interrupts 339 j sysc_tracenogo 340 3411: # it's a kernel thread 342 st %r15,__PT_R15(%r11) # store stack pointer for new kthread 343 l %r1,BASED(.Lschedule_tail) 344 basr %r14,%r1 # call schedule_tail 345 TRACE_IRQS_ON 346 ssm __LC_SVC_NEW_PSW # reenable interrupts 347 lm %r9,%r11,__PT_R9(%r11) # load gprs 348ENTRY(kernel_thread_starter) 349 la %r2,0(%r10) 350 basr %r14,%r9 351 la %r2,0 352 br %r11 # do_exit 353 354# 355# kernel_execve function needs to deal with pt_regs that is not 356# at the usual place 357# 358ENTRY(ret_from_kernel_execve) 359 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 360 lr %r15,%r2 361 lr %r11,%r2 362 ahi %r15,-STACK_FRAME_OVERHEAD 363 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 364 l %r12,__LC_THREAD_INFO 365 ssm __LC_SVC_NEW_PSW # reenable interrupts 366 j sysc_return 367 368/* 369 * Program check handler routine 370 */ 371 372ENTRY(pgm_check_handler) 373 stpt __LC_SYNC_ENTER_TIMER 374 stm %r8,%r15,__LC_SAVE_AREA_SYNC 375 l %r12,__LC_THREAD_INFO 376 l %r13,__LC_SVC_NEW_PSW+4 377 lm %r8,%r9,__LC_PGM_OLD_PSW 378 tmh %r8,0x0001 # test problem state bit 379 jnz 1f # -> fault in user space 380 tmh %r8,0x4000 # PER bit set in old PSW ? 381 jnz 0f # -> enabled, can't be a double fault 382 tm __LC_PGM_ILC+3,0x80 # check for per exception 383 jnz pgm_svcper # -> single stepped svc 3840: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC 385 j 2f 3861: UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER 387 l %r15,__LC_KERNEL_STACK 3882: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 389 la %r11,STACK_FRAME_OVERHEAD(%r15) 390 stm %r0,%r7,__PT_R0(%r11) 391 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC 392 stm %r8,%r9,__PT_PSW(%r11) 393 mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC 394 mvc __PT_INT_PARM_LONG(4,%r11),__LC_TRANS_EXC_CODE 395 tm __LC_PGM_ILC+3,0x80 # check for per exception 396 jz 0f 397 l %r1,__TI_task(%r12) 398 tmh %r8,0x0001 # kernel per event ? 399 jz pgm_kprobe 400 oi __TI_flags+3(%r12),_TIF_PER_TRAP 401 mvc __THREAD_per_address(4,%r1),__LC_PER_ADDRESS 402 mvc __THREAD_per_cause(2,%r1),__LC_PER_CAUSE 403 mvc __THREAD_per_paid(1,%r1),__LC_PER_PAID 4040: REENABLE_IRQS 405 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 406 l %r1,BASED(.Ljump_table) 407 la %r10,0x7f 408 n %r10,__PT_INT_CODE(%r11) 409 je sysc_return 410 sll %r10,2 411 l %r1,0(%r10,%r1) # load address of handler routine 412 lr %r2,%r11 # pass pointer to pt_regs 413 basr %r14,%r1 # branch to interrupt-handler 414 j sysc_return 415 416# 417# PER event in supervisor state, must be kprobes 418# 419pgm_kprobe: 420 REENABLE_IRQS 421 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 422 l %r1,BASED(.Ldo_per_trap) 423 lr %r2,%r11 # pass pointer to pt_regs 424 basr %r14,%r1 # call do_per_trap 425 j sysc_return 426 427# 428# single stepped system call 429# 430pgm_svcper: 431 oi __TI_flags+3(%r12),_TIF_PER_TRAP 432 mvc __LC_RETURN_PSW(4),__LC_SVC_NEW_PSW 433 mvc __LC_RETURN_PSW+4(4),BASED(.Lsysc_per) 434 lpsw __LC_RETURN_PSW # branch to sysc_per and enable irqs 435 436/* 437 * IO interrupt handler routine 438 */ 439 440ENTRY(io_int_handler) 441 stck __LC_INT_CLOCK 442 stpt __LC_ASYNC_ENTER_TIMER 443 stm %r8,%r15,__LC_SAVE_AREA_ASYNC 444 l %r12,__LC_THREAD_INFO 445 l %r13,__LC_SVC_NEW_PSW+4 446 lm %r8,%r9,__LC_IO_OLD_PSW 447 tmh %r8,0x0001 # interrupting from user ? 448 jz io_skip 449 UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER 450io_skip: 451 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT 452 stm %r0,%r7,__PT_R0(%r11) 453 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC 454 stm %r8,%r9,__PT_PSW(%r11) 455 TRACE_IRQS_OFF 456 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 457 l %r1,BASED(.Ldo_IRQ) 458 lr %r2,%r11 # pass pointer to pt_regs 459 basr %r14,%r1 # call do_IRQ 460io_return: 461 LOCKDEP_SYS_EXIT 462 TRACE_IRQS_ON 463io_tif: 464 tm __TI_flags+3(%r12),_TIF_WORK_INT 465 jnz io_work # there is work to do (signals etc.) 466io_restore: 467 mvc __LC_RETURN_PSW(8),__PT_PSW(%r11) 468 stpt __LC_EXIT_TIMER 469 lm %r0,%r15,__PT_R0(%r11) 470 lpsw __LC_RETURN_PSW 471io_done: 472 473# 474# There is work todo, find out in which context we have been interrupted: 475# 1) if we return to user space we can do all _TIF_WORK_INT work 476# 2) if we return to kernel code and preemptive scheduling is enabled check 477# the preemption counter and if it is zero call preempt_schedule_irq 478# Before any work can be done, a switch to the kernel stack is required. 479# 480io_work: 481 tm __PT_PSW+1(%r11),0x01 # returning to user ? 482 jo io_work_user # yes -> do resched & signal 483#ifdef CONFIG_PREEMPT 484 # check for preemptive scheduling 485 icm %r0,15,__TI_precount(%r12) 486 jnz io_restore # preemption disabled 487 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED 488 jno io_restore 489 # switch to kernel stack 490 l %r1,__PT_R15(%r11) 491 ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 492 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 493 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) 494 la %r11,STACK_FRAME_OVERHEAD(%r1) 495 lr %r15,%r1 496 # TRACE_IRQS_ON already done at io_return, call 497 # TRACE_IRQS_OFF to keep things symmetrical 498 TRACE_IRQS_OFF 499 l %r1,BASED(.Lpreempt_irq) 500 basr %r14,%r1 # call preempt_schedule_irq 501 j io_return 502#else 503 j io_restore 504#endif 505 506# 507# Need to do work before returning to userspace, switch to kernel stack 508# 509io_work_user: 510 l %r1,__LC_KERNEL_STACK 511 ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 512 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 513 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) 514 la %r11,STACK_FRAME_OVERHEAD(%r1) 515 lr %r15,%r1 516 517# 518# One of the work bits is on. Find out which one. 519# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED 520# and _TIF_MCCK_PENDING 521# 522io_work_tif: 523 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING 524 jo io_mcck_pending 525 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED 526 jo io_reschedule 527 tm __TI_flags+3(%r12),_TIF_SIGPENDING 528 jo io_sigpending 529 tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME 530 jo io_notify_resume 531 j io_return # beware of critical section cleanup 532 533# 534# _TIF_MCCK_PENDING is set, call handler 535# 536io_mcck_pending: 537 # TRACE_IRQS_ON already done at io_return 538 l %r1,BASED(.Lhandle_mcck) 539 basr %r14,%r1 # TIF bit will be cleared by handler 540 TRACE_IRQS_OFF 541 j io_return 542 543# 544# _TIF_NEED_RESCHED is set, call schedule 545# 546io_reschedule: 547 # TRACE_IRQS_ON already done at io_return 548 l %r1,BASED(.Lschedule) 549 ssm __LC_SVC_NEW_PSW # reenable interrupts 550 basr %r14,%r1 # call scheduler 551 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 552 TRACE_IRQS_OFF 553 j io_return 554 555# 556# _TIF_SIGPENDING is set, call do_signal 557# 558io_sigpending: 559 # TRACE_IRQS_ON already done at io_return 560 l %r1,BASED(.Ldo_signal) 561 ssm __LC_SVC_NEW_PSW # reenable interrupts 562 lr %r2,%r11 # pass pointer to pt_regs 563 basr %r14,%r1 # call do_signal 564 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 565 TRACE_IRQS_OFF 566 j io_return 567 568# 569# _TIF_SIGPENDING is set, call do_signal 570# 571io_notify_resume: 572 # TRACE_IRQS_ON already done at io_return 573 l %r1,BASED(.Ldo_notify_resume) 574 ssm __LC_SVC_NEW_PSW # reenable interrupts 575 lr %r2,%r11 # pass pointer to pt_regs 576 basr %r14,%r1 # call do_notify_resume 577 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 578 TRACE_IRQS_OFF 579 j io_return 580 581/* 582 * External interrupt handler routine 583 */ 584 585ENTRY(ext_int_handler) 586 stck __LC_INT_CLOCK 587 stpt __LC_ASYNC_ENTER_TIMER 588 stm %r8,%r15,__LC_SAVE_AREA_ASYNC 589 l %r12,__LC_THREAD_INFO 590 l %r13,__LC_SVC_NEW_PSW+4 591 lm %r8,%r9,__LC_EXT_OLD_PSW 592 tmh %r8,0x0001 # interrupting from user ? 593 jz ext_skip 594 UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER 595ext_skip: 596 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT 597 stm %r0,%r7,__PT_R0(%r11) 598 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC 599 stm %r8,%r9,__PT_PSW(%r11) 600 TRACE_IRQS_OFF 601 lr %r2,%r11 # pass pointer to pt_regs 602 l %r3,__LC_EXT_CPU_ADDR # get cpu address + interruption code 603 l %r4,__LC_EXT_PARAMS # get external parameters 604 l %r1,BASED(.Ldo_extint) 605 basr %r14,%r1 # call do_extint 606 j io_return 607 608/* 609 * Load idle PSW. The second "half" of this function is in cleanup_idle. 610 */ 611ENTRY(psw_idle) 612 st %r3,__SF_EMPTY(%r15) 613 basr %r1,0 614 la %r1,psw_idle_lpsw+4-.(%r1) 615 st %r1,__SF_EMPTY+4(%r15) 616 oi __SF_EMPTY+4(%r15),0x80 617 stck __CLOCK_IDLE_ENTER(%r2) 618 stpt __TIMER_IDLE_ENTER(%r2) 619psw_idle_lpsw: 620 lpsw __SF_EMPTY(%r15) 621 br %r14 622psw_idle_end: 623 624__critical_end: 625 626/* 627 * Machine check handler routines 628 */ 629 630ENTRY(mcck_int_handler) 631 stck __LC_MCCK_CLOCK 632 spt __LC_CPU_TIMER_SAVE_AREA # revalidate cpu timer 633 lm %r0,%r15,__LC_GPREGS_SAVE_AREA # revalidate gprs 634 l %r12,__LC_THREAD_INFO 635 l %r13,__LC_SVC_NEW_PSW+4 636 lm %r8,%r9,__LC_MCK_OLD_PSW 637 tm __LC_MCCK_CODE,0x80 # system damage? 638 jo mcck_panic # yes -> rest of mcck code invalid 639 la %r14,__LC_CPU_TIMER_SAVE_AREA 640 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 641 tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid? 642 jo 3f 643 la %r14,__LC_SYNC_ENTER_TIMER 644 clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER 645 jl 0f 646 la %r14,__LC_ASYNC_ENTER_TIMER 6470: clc 0(8,%r14),__LC_EXIT_TIMER 648 jl 1f 649 la %r14,__LC_EXIT_TIMER 6501: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER 651 jl 2f 652 la %r14,__LC_LAST_UPDATE_TIMER 6532: spt 0(%r14) 654 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 6553: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid? 656 jno mcck_panic # no -> skip cleanup critical 657 tm %r8,0x0001 # interrupting from user ? 658 jz mcck_skip 659 UPDATE_VTIME %r14,%r15,__LC_MCCK_ENTER_TIMER 660mcck_skip: 661 SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+32,__LC_PANIC_STACK,PAGE_SHIFT 662 mvc __PT_R0(64,%r11),__LC_GPREGS_SAVE_AREA 663 stm %r8,%r9,__PT_PSW(%r11) 664 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 665 l %r1,BASED(.Ldo_machine_check) 666 lr %r2,%r11 # pass pointer to pt_regs 667 basr %r14,%r1 # call s390_do_machine_check 668 tm __PT_PSW+1(%r11),0x01 # returning to user ? 669 jno mcck_return 670 l %r1,__LC_KERNEL_STACK # switch to kernel stack 671 ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 672 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 673 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) 674 la %r11,STACK_FRAME_OVERHEAD(%r15) 675 lr %r15,%r1 676 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off 677 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING 678 jno mcck_return 679 TRACE_IRQS_OFF 680 l %r1,BASED(.Lhandle_mcck) 681 basr %r14,%r1 # call s390_handle_mcck 682 TRACE_IRQS_ON 683mcck_return: 684 mvc __LC_RETURN_MCCK_PSW(8),__PT_PSW(%r11) # move return PSW 685 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ? 686 jno 0f 687 lm %r0,%r15,__PT_R0(%r11) 688 stpt __LC_EXIT_TIMER 689 lpsw __LC_RETURN_MCCK_PSW 6900: lm %r0,%r15,__PT_R0(%r11) 691 lpsw __LC_RETURN_MCCK_PSW 692 693mcck_panic: 694 l %r14,__LC_PANIC_STACK 695 slr %r14,%r15 696 sra %r14,PAGE_SHIFT 697 jz 0f 698 l %r15,__LC_PANIC_STACK 6990: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 700 j mcck_skip 701 702# 703# PSW restart interrupt handler 704# 705ENTRY(restart_int_handler) 706 st %r15,__LC_SAVE_AREA_RESTART 707 l %r15,__LC_RESTART_STACK 708 ahi %r15,-__PT_SIZE # create pt_regs on stack 709 xc 0(__PT_SIZE,%r15),0(%r15) 710 stm %r0,%r14,__PT_R0(%r15) 711 mvc __PT_R15(4,%r15),__LC_SAVE_AREA_RESTART 712 mvc __PT_PSW(8,%r15),__LC_RST_OLD_PSW # store restart old psw 713 ahi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack 714 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) 715 l %r1,__LC_RESTART_FN # load fn, parm & source cpu 716 l %r2,__LC_RESTART_DATA 717 l %r3,__LC_RESTART_SOURCE 718 ltr %r3,%r3 # test source cpu address 719 jm 1f # negative -> skip source stop 7200: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu 721 brc 10,0b # wait for status stored 7221: basr %r14,%r1 # call function 723 stap __SF_EMPTY(%r15) # store cpu address 724 lh %r3,__SF_EMPTY(%r15) 7252: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu 726 brc 2,2b 7273: j 3b 728 729 .section .kprobes.text, "ax" 730 731#ifdef CONFIG_CHECK_STACK 732/* 733 * The synchronous or the asynchronous stack overflowed. We are dead. 734 * No need to properly save the registers, we are going to panic anyway. 735 * Setup a pt_regs so that show_trace can provide a good call trace. 736 */ 737stack_overflow: 738 l %r15,__LC_PANIC_STACK # change to panic stack 739 ahi %r15,-__PT_SIZE # create pt_regs 740 stm %r0,%r7,__PT_R0(%r15) 741 stm %r8,%r9,__PT_PSW(%r15) 742 mvc __PT_R8(32,%r11),0(%r14) 743 lr %r15,%r11 744 ahi %r15,-STACK_FRAME_OVERHEAD 745 l %r1,BASED(1f) 746 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 747 lr %r2,%r11 # pass pointer to pt_regs 748 br %r1 # branch to kernel_stack_overflow 7491: .long kernel_stack_overflow 750#endif 751 752cleanup_table: 753 .long system_call + 0x80000000 754 .long sysc_do_svc + 0x80000000 755 .long sysc_tif + 0x80000000 756 .long sysc_restore + 0x80000000 757 .long sysc_done + 0x80000000 758 .long io_tif + 0x80000000 759 .long io_restore + 0x80000000 760 .long io_done + 0x80000000 761 .long psw_idle + 0x80000000 762 .long psw_idle_end + 0x80000000 763 764cleanup_critical: 765 cl %r9,BASED(cleanup_table) # system_call 766 jl 0f 767 cl %r9,BASED(cleanup_table+4) # sysc_do_svc 768 jl cleanup_system_call 769 cl %r9,BASED(cleanup_table+8) # sysc_tif 770 jl 0f 771 cl %r9,BASED(cleanup_table+12) # sysc_restore 772 jl cleanup_sysc_tif 773 cl %r9,BASED(cleanup_table+16) # sysc_done 774 jl cleanup_sysc_restore 775 cl %r9,BASED(cleanup_table+20) # io_tif 776 jl 0f 777 cl %r9,BASED(cleanup_table+24) # io_restore 778 jl cleanup_io_tif 779 cl %r9,BASED(cleanup_table+28) # io_done 780 jl cleanup_io_restore 781 cl %r9,BASED(cleanup_table+32) # psw_idle 782 jl 0f 783 cl %r9,BASED(cleanup_table+36) # psw_idle_end 784 jl cleanup_idle 7850: br %r14 786 787cleanup_system_call: 788 # check if stpt has been executed 789 cl %r9,BASED(cleanup_system_call_insn) 790 jh 0f 791 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER 792 chi %r11,__LC_SAVE_AREA_ASYNC 793 je 0f 794 mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER 7950: # check if stm has been executed 796 cl %r9,BASED(cleanup_system_call_insn+4) 797 jh 0f 798 mvc __LC_SAVE_AREA_SYNC(32),0(%r11) 7990: # set up saved registers r12, and r13 800 st %r12,16(%r11) # r12 thread-info pointer 801 st %r13,20(%r11) # r13 literal-pool pointer 802 # check if the user time calculation has been done 803 cl %r9,BASED(cleanup_system_call_insn+8) 804 jh 0f 805 l %r10,__LC_EXIT_TIMER 806 l %r15,__LC_EXIT_TIMER+4 807 SUB64 %r10,%r15,__LC_SYNC_ENTER_TIMER 808 ADD64 %r10,%r15,__LC_USER_TIMER 809 st %r10,__LC_USER_TIMER 810 st %r15,__LC_USER_TIMER+4 8110: # check if the system time calculation has been done 812 cl %r9,BASED(cleanup_system_call_insn+12) 813 jh 0f 814 l %r10,__LC_LAST_UPDATE_TIMER 815 l %r15,__LC_LAST_UPDATE_TIMER+4 816 SUB64 %r10,%r15,__LC_EXIT_TIMER 817 ADD64 %r10,%r15,__LC_SYSTEM_TIMER 818 st %r10,__LC_SYSTEM_TIMER 819 st %r15,__LC_SYSTEM_TIMER+4 8200: # update accounting time stamp 821 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 822 # set up saved register 11 823 l %r15,__LC_KERNEL_STACK 824 ahi %r15,-__PT_SIZE 825 st %r15,12(%r11) # r11 pt_regs pointer 826 # fill pt_regs 827 mvc __PT_R8(32,%r15),__LC_SAVE_AREA_SYNC 828 stm %r0,%r7,__PT_R0(%r15) 829 mvc __PT_PSW(8,%r15),__LC_SVC_OLD_PSW 830 mvc __PT_INT_CODE(4,%r15),__LC_SVC_ILC 831 # setup saved register 15 832 ahi %r15,-STACK_FRAME_OVERHEAD 833 st %r15,28(%r11) # r15 stack pointer 834 # set new psw address and exit 835 l %r9,BASED(cleanup_table+4) # sysc_do_svc + 0x80000000 836 br %r14 837cleanup_system_call_insn: 838 .long system_call + 0x80000000 839 .long sysc_stm + 0x80000000 840 .long sysc_vtime + 0x80000000 + 36 841 .long sysc_vtime + 0x80000000 + 76 842 843cleanup_sysc_tif: 844 l %r9,BASED(cleanup_table+8) # sysc_tif + 0x80000000 845 br %r14 846 847cleanup_sysc_restore: 848 cl %r9,BASED(cleanup_sysc_restore_insn) 849 jhe 0f 850 l %r9,12(%r11) # get saved pointer to pt_regs 851 mvc __LC_RETURN_PSW(8),__PT_PSW(%r9) 852 mvc 0(32,%r11),__PT_R8(%r9) 853 lm %r0,%r7,__PT_R0(%r9) 8540: lm %r8,%r9,__LC_RETURN_PSW 855 br %r14 856cleanup_sysc_restore_insn: 857 .long sysc_done - 4 + 0x80000000 858 859cleanup_io_tif: 860 l %r9,BASED(cleanup_table+20) # io_tif + 0x80000000 861 br %r14 862 863cleanup_io_restore: 864 cl %r9,BASED(cleanup_io_restore_insn) 865 jhe 0f 866 l %r9,12(%r11) # get saved r11 pointer to pt_regs 867 mvc __LC_RETURN_PSW(8),__PT_PSW(%r9) 868 mvc 0(32,%r11),__PT_R8(%r9) 869 lm %r0,%r7,__PT_R0(%r9) 8700: lm %r8,%r9,__LC_RETURN_PSW 871 br %r14 872cleanup_io_restore_insn: 873 .long io_done - 4 + 0x80000000 874 875cleanup_idle: 876 # copy interrupt clock & cpu timer 877 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK 878 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER 879 chi %r11,__LC_SAVE_AREA_ASYNC 880 je 0f 881 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK 882 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER 8830: # check if stck has been executed 884 cl %r9,BASED(cleanup_idle_insn) 885 jhe 1f 886 mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2) 887 mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r3) 8881: # account system time going idle 889 lm %r9,%r10,__LC_STEAL_TIMER 890 ADD64 %r9,%r10,__CLOCK_IDLE_ENTER(%r2) 891 SUB64 %r9,%r10,__LC_LAST_UPDATE_CLOCK 892 stm %r9,%r10,__LC_STEAL_TIMER 893 mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2) 894 lm %r9,%r10,__LC_SYSTEM_TIMER 895 ADD64 %r9,%r10,__LC_LAST_UPDATE_TIMER 896 SUB64 %r9,%r10,__TIMER_IDLE_ENTER(%r2) 897 stm %r9,%r10,__LC_SYSTEM_TIMER 898 mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2) 899 # prepare return psw 900 n %r8,BASED(cleanup_idle_wait) # clear wait state bit 901 l %r9,24(%r11) # return from psw_idle 902 br %r14 903cleanup_idle_insn: 904 .long psw_idle_lpsw + 0x80000000 905cleanup_idle_wait: 906 .long 0xfffdffff 907 908/* 909 * Integer constants 910 */ 911 .align 4 912.Lnr_syscalls: 913 .long NR_syscalls 914.Lvtimer_max: 915 .quad 0x7fffffffffffffff 916 917/* 918 * Symbol constants 919 */ 920.Ldo_machine_check: .long s390_do_machine_check 921.Lhandle_mcck: .long s390_handle_mcck 922.Ldo_IRQ: .long do_IRQ 923.Ldo_extint: .long do_extint 924.Ldo_signal: .long do_signal 925.Ldo_notify_resume: .long do_notify_resume 926.Ldo_per_trap: .long do_per_trap 927.Ljump_table: .long pgm_check_table 928.Lschedule: .long schedule 929#ifdef CONFIG_PREEMPT 930.Lpreempt_irq: .long preempt_schedule_irq 931#endif 932.Ltrace_enter: .long do_syscall_trace_enter 933.Ltrace_exit: .long do_syscall_trace_exit 934.Lschedule_tail: .long schedule_tail 935.Lsys_call_table: .long sys_call_table 936.Lsysc_per: .long sysc_per + 0x80000000 937#ifdef CONFIG_TRACE_IRQFLAGS 938.Lhardirqs_on: .long trace_hardirqs_on_caller 939.Lhardirqs_off: .long trace_hardirqs_off_caller 940#endif 941#ifdef CONFIG_LOCKDEP 942.Llockdep_sys_exit: .long lockdep_sys_exit 943#endif 944.Lcritical_start: .long __critical_start + 0x80000000 945.Lcritical_length: .long __critical_end - __critical_start 946 947 .section .rodata, "a" 948#define SYSCALL(esa,esame,emu) .long esa 949 .globl sys_call_table 950sys_call_table: 951#include "syscalls.S" 952#undef SYSCALL 953