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_PER_TRAP 235 jo sysc_singlestep 236 tm __TI_flags+3(%r12),_TIF_SIGPENDING 237 jo sysc_sigpending 238 tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME 239 jo sysc_notify_resume 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 lr %r2,%r11 # pass pointer to pt_regs 263 l %r1,BASED(.Ldo_signal) 264 basr %r14,%r1 # call do_signal 265 tm __TI_flags+3(%r12),_TIF_SYSCALL 266 jno sysc_return 267 lm %r2,%r7,__PT_R2(%r11) # load svc arguments 268 xr %r8,%r8 # svc 0 returns -ENOSYS 269 clc __PT_INT_CODE+2(2,%r11),BASED(.Lnr_syscalls+2) 270 jnl sysc_nr_ok # invalid svc number -> do svc 0 271 lh %r8,__PT_INT_CODE+2(%r11) # load new svc number 272 sla %r8,2 273 j sysc_nr_ok # restart svc 274 275# 276# _TIF_NOTIFY_RESUME is set, call do_notify_resume 277# 278sysc_notify_resume: 279 lr %r2,%r11 # pass pointer to pt_regs 280 l %r1,BASED(.Ldo_notify_resume) 281 la %r14,BASED(sysc_return) 282 br %r1 # call do_notify_resume 283 284# 285# _TIF_PER_TRAP is set, call do_per_trap 286# 287sysc_singlestep: 288 ni __TI_flags+3(%r12),255-_TIF_PER_TRAP 289 lr %r2,%r11 # pass pointer to pt_regs 290 l %r1,BASED(.Ldo_per_trap) 291 la %r14,BASED(sysc_return) 292 br %r1 # call do_per_trap 293 294# 295# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before 296# and after the system call 297# 298sysc_tracesys: 299 l %r1,BASED(.Ltrace_enter) 300 lr %r2,%r11 # pass pointer to pt_regs 301 la %r3,0 302 xr %r0,%r0 303 icm %r0,3,__PT_INT_CODE+2(%r11) 304 st %r0,__PT_R2(%r11) 305 basr %r14,%r1 # call do_syscall_trace_enter 306 cl %r2,BASED(.Lnr_syscalls) 307 jnl sysc_tracenogo 308 lr %r8,%r2 309 sll %r8,2 310 l %r9,0(%r8,%r10) 311sysc_tracego: 312 lm %r3,%r7,__PT_R3(%r11) 313 st %r7,STACK_FRAME_OVERHEAD(%r15) 314 l %r2,__PT_ORIG_GPR2(%r11) 315 basr %r14,%r9 # call sys_xxx 316 st %r2,__PT_R2(%r11) # store return value 317sysc_tracenogo: 318 tm __TI_flags+2(%r12),_TIF_TRACE >> 8 319 jz sysc_return 320 l %r1,BASED(.Ltrace_exit) 321 lr %r2,%r11 # pass pointer to pt_regs 322 la %r14,BASED(sysc_return) 323 br %r1 # call do_syscall_trace_exit 324 325# 326# a new process exits the kernel with ret_from_fork 327# 328ENTRY(ret_from_fork) 329 la %r11,STACK_FRAME_OVERHEAD(%r15) 330 l %r12,__LC_THREAD_INFO 331 l %r13,__LC_SVC_NEW_PSW+4 332 l %r1,BASED(.Lschedule_tail) 333 basr %r14,%r1 # call schedule_tail 334 TRACE_IRQS_ON 335 ssm __LC_SVC_NEW_PSW # reenable interrupts 336 tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ? 337 jne sysc_tracenogo 338 # it's a kernel thread 339 lm %r9,%r10,__PT_R9(%r11) # load gprs 340ENTRY(kernel_thread_starter) 341 la %r2,0(%r10) 342 basr %r14,%r9 343 j sysc_tracenogo 344 345/* 346 * Program check handler routine 347 */ 348 349ENTRY(pgm_check_handler) 350 stpt __LC_SYNC_ENTER_TIMER 351 stm %r8,%r15,__LC_SAVE_AREA_SYNC 352 l %r12,__LC_THREAD_INFO 353 l %r13,__LC_SVC_NEW_PSW+4 354 lm %r8,%r9,__LC_PGM_OLD_PSW 355 tmh %r8,0x0001 # test problem state bit 356 jnz 1f # -> fault in user space 357 tmh %r8,0x4000 # PER bit set in old PSW ? 358 jnz 0f # -> enabled, can't be a double fault 359 tm __LC_PGM_ILC+3,0x80 # check for per exception 360 jnz pgm_svcper # -> single stepped svc 3610: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC 362 j 2f 3631: UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER 364 l %r15,__LC_KERNEL_STACK 3652: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 366 la %r11,STACK_FRAME_OVERHEAD(%r15) 367 stm %r0,%r7,__PT_R0(%r11) 368 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC 369 stm %r8,%r9,__PT_PSW(%r11) 370 mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC 371 mvc __PT_INT_PARM_LONG(4,%r11),__LC_TRANS_EXC_CODE 372 tm __LC_PGM_ILC+3,0x80 # check for per exception 373 jz 0f 374 l %r1,__TI_task(%r12) 375 tmh %r8,0x0001 # kernel per event ? 376 jz pgm_kprobe 377 oi __TI_flags+3(%r12),_TIF_PER_TRAP 378 mvc __THREAD_per_address(4,%r1),__LC_PER_ADDRESS 379 mvc __THREAD_per_cause(2,%r1),__LC_PER_CAUSE 380 mvc __THREAD_per_paid(1,%r1),__LC_PER_PAID 3810: REENABLE_IRQS 382 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 383 l %r1,BASED(.Ljump_table) 384 la %r10,0x7f 385 n %r10,__PT_INT_CODE(%r11) 386 je sysc_return 387 sll %r10,2 388 l %r1,0(%r10,%r1) # load address of handler routine 389 lr %r2,%r11 # pass pointer to pt_regs 390 basr %r14,%r1 # branch to interrupt-handler 391 j sysc_return 392 393# 394# PER event in supervisor state, must be kprobes 395# 396pgm_kprobe: 397 REENABLE_IRQS 398 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 399 l %r1,BASED(.Ldo_per_trap) 400 lr %r2,%r11 # pass pointer to pt_regs 401 basr %r14,%r1 # call do_per_trap 402 j sysc_return 403 404# 405# single stepped system call 406# 407pgm_svcper: 408 oi __TI_flags+3(%r12),_TIF_PER_TRAP 409 mvc __LC_RETURN_PSW(4),__LC_SVC_NEW_PSW 410 mvc __LC_RETURN_PSW+4(4),BASED(.Lsysc_per) 411 lpsw __LC_RETURN_PSW # branch to sysc_per and enable irqs 412 413/* 414 * IO interrupt handler routine 415 */ 416 417ENTRY(io_int_handler) 418 stck __LC_INT_CLOCK 419 stpt __LC_ASYNC_ENTER_TIMER 420 stm %r8,%r15,__LC_SAVE_AREA_ASYNC 421 l %r12,__LC_THREAD_INFO 422 l %r13,__LC_SVC_NEW_PSW+4 423 lm %r8,%r9,__LC_IO_OLD_PSW 424 tmh %r8,0x0001 # interrupting from user ? 425 jz io_skip 426 UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER 427io_skip: 428 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT 429 stm %r0,%r7,__PT_R0(%r11) 430 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC 431 stm %r8,%r9,__PT_PSW(%r11) 432 TRACE_IRQS_OFF 433 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 434 l %r1,BASED(.Ldo_IRQ) 435 lr %r2,%r11 # pass pointer to pt_regs 436 basr %r14,%r1 # call do_IRQ 437io_return: 438 LOCKDEP_SYS_EXIT 439 TRACE_IRQS_ON 440io_tif: 441 tm __TI_flags+3(%r12),_TIF_WORK_INT 442 jnz io_work # there is work to do (signals etc.) 443io_restore: 444 mvc __LC_RETURN_PSW(8),__PT_PSW(%r11) 445 stpt __LC_EXIT_TIMER 446 lm %r0,%r15,__PT_R0(%r11) 447 lpsw __LC_RETURN_PSW 448io_done: 449 450# 451# There is work todo, find out in which context we have been interrupted: 452# 1) if we return to user space we can do all _TIF_WORK_INT work 453# 2) if we return to kernel code and preemptive scheduling is enabled check 454# the preemption counter and if it is zero call preempt_schedule_irq 455# Before any work can be done, a switch to the kernel stack is required. 456# 457io_work: 458 tm __PT_PSW+1(%r11),0x01 # returning to user ? 459 jo io_work_user # yes -> do resched & signal 460#ifdef CONFIG_PREEMPT 461 # check for preemptive scheduling 462 icm %r0,15,__TI_precount(%r12) 463 jnz io_restore # preemption disabled 464 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED 465 jno io_restore 466 # switch to kernel stack 467 l %r1,__PT_R15(%r11) 468 ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 469 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 470 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) 471 la %r11,STACK_FRAME_OVERHEAD(%r1) 472 lr %r15,%r1 473 # TRACE_IRQS_ON already done at io_return, call 474 # TRACE_IRQS_OFF to keep things symmetrical 475 TRACE_IRQS_OFF 476 l %r1,BASED(.Lpreempt_irq) 477 basr %r14,%r1 # call preempt_schedule_irq 478 j io_return 479#else 480 j io_restore 481#endif 482 483# 484# Need to do work before returning to userspace, switch to kernel stack 485# 486io_work_user: 487 l %r1,__LC_KERNEL_STACK 488 ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 489 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 490 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) 491 la %r11,STACK_FRAME_OVERHEAD(%r1) 492 lr %r15,%r1 493 494# 495# One of the work bits is on. Find out which one. 496# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED 497# and _TIF_MCCK_PENDING 498# 499io_work_tif: 500 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING 501 jo io_mcck_pending 502 tm __TI_flags+3(%r12),_TIF_NEED_RESCHED 503 jo io_reschedule 504 tm __TI_flags+3(%r12),_TIF_SIGPENDING 505 jo io_sigpending 506 tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME 507 jo io_notify_resume 508 j io_return # beware of critical section cleanup 509 510# 511# _TIF_MCCK_PENDING is set, call handler 512# 513io_mcck_pending: 514 # TRACE_IRQS_ON already done at io_return 515 l %r1,BASED(.Lhandle_mcck) 516 basr %r14,%r1 # TIF bit will be cleared by handler 517 TRACE_IRQS_OFF 518 j io_return 519 520# 521# _TIF_NEED_RESCHED is set, call schedule 522# 523io_reschedule: 524 # TRACE_IRQS_ON already done at io_return 525 l %r1,BASED(.Lschedule) 526 ssm __LC_SVC_NEW_PSW # reenable interrupts 527 basr %r14,%r1 # call scheduler 528 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 529 TRACE_IRQS_OFF 530 j io_return 531 532# 533# _TIF_SIGPENDING is set, call do_signal 534# 535io_sigpending: 536 # TRACE_IRQS_ON already done at io_return 537 l %r1,BASED(.Ldo_signal) 538 ssm __LC_SVC_NEW_PSW # reenable interrupts 539 lr %r2,%r11 # pass pointer to pt_regs 540 basr %r14,%r1 # call do_signal 541 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 542 TRACE_IRQS_OFF 543 j io_return 544 545# 546# _TIF_SIGPENDING is set, call do_signal 547# 548io_notify_resume: 549 # TRACE_IRQS_ON already done at io_return 550 l %r1,BASED(.Ldo_notify_resume) 551 ssm __LC_SVC_NEW_PSW # reenable interrupts 552 lr %r2,%r11 # pass pointer to pt_regs 553 basr %r14,%r1 # call do_notify_resume 554 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 555 TRACE_IRQS_OFF 556 j io_return 557 558/* 559 * External interrupt handler routine 560 */ 561 562ENTRY(ext_int_handler) 563 stck __LC_INT_CLOCK 564 stpt __LC_ASYNC_ENTER_TIMER 565 stm %r8,%r15,__LC_SAVE_AREA_ASYNC 566 l %r12,__LC_THREAD_INFO 567 l %r13,__LC_SVC_NEW_PSW+4 568 lm %r8,%r9,__LC_EXT_OLD_PSW 569 tmh %r8,0x0001 # interrupting from user ? 570 jz ext_skip 571 UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER 572ext_skip: 573 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT 574 stm %r0,%r7,__PT_R0(%r11) 575 mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC 576 stm %r8,%r9,__PT_PSW(%r11) 577 TRACE_IRQS_OFF 578 lr %r2,%r11 # pass pointer to pt_regs 579 l %r3,__LC_EXT_CPU_ADDR # get cpu address + interruption code 580 l %r4,__LC_EXT_PARAMS # get external parameters 581 l %r1,BASED(.Ldo_extint) 582 basr %r14,%r1 # call do_extint 583 j io_return 584 585/* 586 * Load idle PSW. The second "half" of this function is in cleanup_idle. 587 */ 588ENTRY(psw_idle) 589 st %r3,__SF_EMPTY(%r15) 590 basr %r1,0 591 la %r1,psw_idle_lpsw+4-.(%r1) 592 st %r1,__SF_EMPTY+4(%r15) 593 oi __SF_EMPTY+4(%r15),0x80 594 stck __CLOCK_IDLE_ENTER(%r2) 595 stpt __TIMER_IDLE_ENTER(%r2) 596psw_idle_lpsw: 597 lpsw __SF_EMPTY(%r15) 598 br %r14 599psw_idle_end: 600 601__critical_end: 602 603/* 604 * Machine check handler routines 605 */ 606 607ENTRY(mcck_int_handler) 608 stck __LC_MCCK_CLOCK 609 spt __LC_CPU_TIMER_SAVE_AREA # revalidate cpu timer 610 lm %r0,%r15,__LC_GPREGS_SAVE_AREA # revalidate gprs 611 l %r12,__LC_THREAD_INFO 612 l %r13,__LC_SVC_NEW_PSW+4 613 lm %r8,%r9,__LC_MCK_OLD_PSW 614 tm __LC_MCCK_CODE,0x80 # system damage? 615 jo mcck_panic # yes -> rest of mcck code invalid 616 la %r14,__LC_CPU_TIMER_SAVE_AREA 617 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 618 tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid? 619 jo 3f 620 la %r14,__LC_SYNC_ENTER_TIMER 621 clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER 622 jl 0f 623 la %r14,__LC_ASYNC_ENTER_TIMER 6240: clc 0(8,%r14),__LC_EXIT_TIMER 625 jl 1f 626 la %r14,__LC_EXIT_TIMER 6271: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER 628 jl 2f 629 la %r14,__LC_LAST_UPDATE_TIMER 6302: spt 0(%r14) 631 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 6323: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid? 633 jno mcck_panic # no -> skip cleanup critical 634 tm %r8,0x0001 # interrupting from user ? 635 jz mcck_skip 636 UPDATE_VTIME %r14,%r15,__LC_MCCK_ENTER_TIMER 637mcck_skip: 638 SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+32,__LC_PANIC_STACK,PAGE_SHIFT 639 mvc __PT_R0(64,%r11),__LC_GPREGS_SAVE_AREA 640 stm %r8,%r9,__PT_PSW(%r11) 641 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 642 l %r1,BASED(.Ldo_machine_check) 643 lr %r2,%r11 # pass pointer to pt_regs 644 basr %r14,%r1 # call s390_do_machine_check 645 tm __PT_PSW+1(%r11),0x01 # returning to user ? 646 jno mcck_return 647 l %r1,__LC_KERNEL_STACK # switch to kernel stack 648 ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 649 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 650 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) 651 la %r11,STACK_FRAME_OVERHEAD(%r15) 652 lr %r15,%r1 653 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off 654 tm __TI_flags+3(%r12),_TIF_MCCK_PENDING 655 jno mcck_return 656 TRACE_IRQS_OFF 657 l %r1,BASED(.Lhandle_mcck) 658 basr %r14,%r1 # call s390_handle_mcck 659 TRACE_IRQS_ON 660mcck_return: 661 mvc __LC_RETURN_MCCK_PSW(8),__PT_PSW(%r11) # move return PSW 662 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ? 663 jno 0f 664 lm %r0,%r15,__PT_R0(%r11) 665 stpt __LC_EXIT_TIMER 666 lpsw __LC_RETURN_MCCK_PSW 6670: lm %r0,%r15,__PT_R0(%r11) 668 lpsw __LC_RETURN_MCCK_PSW 669 670mcck_panic: 671 l %r14,__LC_PANIC_STACK 672 slr %r14,%r15 673 sra %r14,PAGE_SHIFT 674 jz 0f 675 l %r15,__LC_PANIC_STACK 6760: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 677 j mcck_skip 678 679# 680# PSW restart interrupt handler 681# 682ENTRY(restart_int_handler) 683 st %r15,__LC_SAVE_AREA_RESTART 684 l %r15,__LC_RESTART_STACK 685 ahi %r15,-__PT_SIZE # create pt_regs on stack 686 xc 0(__PT_SIZE,%r15),0(%r15) 687 stm %r0,%r14,__PT_R0(%r15) 688 mvc __PT_R15(4,%r15),__LC_SAVE_AREA_RESTART 689 mvc __PT_PSW(8,%r15),__LC_RST_OLD_PSW # store restart old psw 690 ahi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack 691 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) 692 l %r1,__LC_RESTART_FN # load fn, parm & source cpu 693 l %r2,__LC_RESTART_DATA 694 l %r3,__LC_RESTART_SOURCE 695 ltr %r3,%r3 # test source cpu address 696 jm 1f # negative -> skip source stop 6970: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu 698 brc 10,0b # wait for status stored 6991: basr %r14,%r1 # call function 700 stap __SF_EMPTY(%r15) # store cpu address 701 lh %r3,__SF_EMPTY(%r15) 7022: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu 703 brc 2,2b 7043: j 3b 705 706 .section .kprobes.text, "ax" 707 708#ifdef CONFIG_CHECK_STACK 709/* 710 * The synchronous or the asynchronous stack overflowed. We are dead. 711 * No need to properly save the registers, we are going to panic anyway. 712 * Setup a pt_regs so that show_trace can provide a good call trace. 713 */ 714stack_overflow: 715 l %r15,__LC_PANIC_STACK # change to panic stack 716 ahi %r15,-__PT_SIZE # create pt_regs 717 stm %r0,%r7,__PT_R0(%r15) 718 stm %r8,%r9,__PT_PSW(%r15) 719 mvc __PT_R8(32,%r11),0(%r14) 720 lr %r15,%r11 721 ahi %r15,-STACK_FRAME_OVERHEAD 722 l %r1,BASED(1f) 723 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) 724 lr %r2,%r11 # pass pointer to pt_regs 725 br %r1 # branch to kernel_stack_overflow 7261: .long kernel_stack_overflow 727#endif 728 729cleanup_table: 730 .long system_call + 0x80000000 731 .long sysc_do_svc + 0x80000000 732 .long sysc_tif + 0x80000000 733 .long sysc_restore + 0x80000000 734 .long sysc_done + 0x80000000 735 .long io_tif + 0x80000000 736 .long io_restore + 0x80000000 737 .long io_done + 0x80000000 738 .long psw_idle + 0x80000000 739 .long psw_idle_end + 0x80000000 740 741cleanup_critical: 742 cl %r9,BASED(cleanup_table) # system_call 743 jl 0f 744 cl %r9,BASED(cleanup_table+4) # sysc_do_svc 745 jl cleanup_system_call 746 cl %r9,BASED(cleanup_table+8) # sysc_tif 747 jl 0f 748 cl %r9,BASED(cleanup_table+12) # sysc_restore 749 jl cleanup_sysc_tif 750 cl %r9,BASED(cleanup_table+16) # sysc_done 751 jl cleanup_sysc_restore 752 cl %r9,BASED(cleanup_table+20) # io_tif 753 jl 0f 754 cl %r9,BASED(cleanup_table+24) # io_restore 755 jl cleanup_io_tif 756 cl %r9,BASED(cleanup_table+28) # io_done 757 jl cleanup_io_restore 758 cl %r9,BASED(cleanup_table+32) # psw_idle 759 jl 0f 760 cl %r9,BASED(cleanup_table+36) # psw_idle_end 761 jl cleanup_idle 7620: br %r14 763 764cleanup_system_call: 765 # check if stpt has been executed 766 cl %r9,BASED(cleanup_system_call_insn) 767 jh 0f 768 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER 769 chi %r11,__LC_SAVE_AREA_ASYNC 770 je 0f 771 mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER 7720: # check if stm has been executed 773 cl %r9,BASED(cleanup_system_call_insn+4) 774 jh 0f 775 mvc __LC_SAVE_AREA_SYNC(32),0(%r11) 7760: # set up saved registers r12, and r13 777 st %r12,16(%r11) # r12 thread-info pointer 778 st %r13,20(%r11) # r13 literal-pool pointer 779 # check if the user time calculation has been done 780 cl %r9,BASED(cleanup_system_call_insn+8) 781 jh 0f 782 l %r10,__LC_EXIT_TIMER 783 l %r15,__LC_EXIT_TIMER+4 784 SUB64 %r10,%r15,__LC_SYNC_ENTER_TIMER 785 ADD64 %r10,%r15,__LC_USER_TIMER 786 st %r10,__LC_USER_TIMER 787 st %r15,__LC_USER_TIMER+4 7880: # check if the system time calculation has been done 789 cl %r9,BASED(cleanup_system_call_insn+12) 790 jh 0f 791 l %r10,__LC_LAST_UPDATE_TIMER 792 l %r15,__LC_LAST_UPDATE_TIMER+4 793 SUB64 %r10,%r15,__LC_EXIT_TIMER 794 ADD64 %r10,%r15,__LC_SYSTEM_TIMER 795 st %r10,__LC_SYSTEM_TIMER 796 st %r15,__LC_SYSTEM_TIMER+4 7970: # update accounting time stamp 798 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 799 # set up saved register 11 800 l %r15,__LC_KERNEL_STACK 801 ahi %r15,-__PT_SIZE 802 st %r15,12(%r11) # r11 pt_regs pointer 803 # fill pt_regs 804 mvc __PT_R8(32,%r15),__LC_SAVE_AREA_SYNC 805 stm %r0,%r7,__PT_R0(%r15) 806 mvc __PT_PSW(8,%r15),__LC_SVC_OLD_PSW 807 mvc __PT_INT_CODE(4,%r15),__LC_SVC_ILC 808 # setup saved register 15 809 ahi %r15,-STACK_FRAME_OVERHEAD 810 st %r15,28(%r11) # r15 stack pointer 811 # set new psw address and exit 812 l %r9,BASED(cleanup_table+4) # sysc_do_svc + 0x80000000 813 br %r14 814cleanup_system_call_insn: 815 .long system_call + 0x80000000 816 .long sysc_stm + 0x80000000 817 .long sysc_vtime + 0x80000000 + 36 818 .long sysc_vtime + 0x80000000 + 76 819 820cleanup_sysc_tif: 821 l %r9,BASED(cleanup_table+8) # sysc_tif + 0x80000000 822 br %r14 823 824cleanup_sysc_restore: 825 cl %r9,BASED(cleanup_sysc_restore_insn) 826 jhe 0f 827 l %r9,12(%r11) # get saved pointer to pt_regs 828 mvc __LC_RETURN_PSW(8),__PT_PSW(%r9) 829 mvc 0(32,%r11),__PT_R8(%r9) 830 lm %r0,%r7,__PT_R0(%r9) 8310: lm %r8,%r9,__LC_RETURN_PSW 832 br %r14 833cleanup_sysc_restore_insn: 834 .long sysc_done - 4 + 0x80000000 835 836cleanup_io_tif: 837 l %r9,BASED(cleanup_table+20) # io_tif + 0x80000000 838 br %r14 839 840cleanup_io_restore: 841 cl %r9,BASED(cleanup_io_restore_insn) 842 jhe 0f 843 l %r9,12(%r11) # get saved r11 pointer to pt_regs 844 mvc __LC_RETURN_PSW(8),__PT_PSW(%r9) 845 mvc 0(32,%r11),__PT_R8(%r9) 846 lm %r0,%r7,__PT_R0(%r9) 8470: lm %r8,%r9,__LC_RETURN_PSW 848 br %r14 849cleanup_io_restore_insn: 850 .long io_done - 4 + 0x80000000 851 852cleanup_idle: 853 # copy interrupt clock & cpu timer 854 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK 855 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER 856 chi %r11,__LC_SAVE_AREA_ASYNC 857 je 0f 858 mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK 859 mvc __TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER 8600: # check if stck has been executed 861 cl %r9,BASED(cleanup_idle_insn) 862 jhe 1f 863 mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2) 864 mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r3) 8651: # account system time going idle 866 lm %r9,%r10,__LC_STEAL_TIMER 867 ADD64 %r9,%r10,__CLOCK_IDLE_ENTER(%r2) 868 SUB64 %r9,%r10,__LC_LAST_UPDATE_CLOCK 869 stm %r9,%r10,__LC_STEAL_TIMER 870 mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2) 871 lm %r9,%r10,__LC_SYSTEM_TIMER 872 ADD64 %r9,%r10,__LC_LAST_UPDATE_TIMER 873 SUB64 %r9,%r10,__TIMER_IDLE_ENTER(%r2) 874 stm %r9,%r10,__LC_SYSTEM_TIMER 875 mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2) 876 # prepare return psw 877 n %r8,BASED(cleanup_idle_wait) # clear wait state bit 878 l %r9,24(%r11) # return from psw_idle 879 br %r14 880cleanup_idle_insn: 881 .long psw_idle_lpsw + 0x80000000 882cleanup_idle_wait: 883 .long 0xfffdffff 884 885/* 886 * Integer constants 887 */ 888 .align 4 889.Lnr_syscalls: 890 .long NR_syscalls 891.Lvtimer_max: 892 .quad 0x7fffffffffffffff 893 894/* 895 * Symbol constants 896 */ 897.Ldo_machine_check: .long s390_do_machine_check 898.Lhandle_mcck: .long s390_handle_mcck 899.Ldo_IRQ: .long do_IRQ 900.Ldo_extint: .long do_extint 901.Ldo_signal: .long do_signal 902.Ldo_notify_resume: .long do_notify_resume 903.Ldo_per_trap: .long do_per_trap 904.Ljump_table: .long pgm_check_table 905.Lschedule: .long schedule 906#ifdef CONFIG_PREEMPT 907.Lpreempt_irq: .long preempt_schedule_irq 908#endif 909.Ltrace_enter: .long do_syscall_trace_enter 910.Ltrace_exit: .long do_syscall_trace_exit 911.Lschedule_tail: .long schedule_tail 912.Lsys_call_table: .long sys_call_table 913.Lsysc_per: .long sysc_per + 0x80000000 914#ifdef CONFIG_TRACE_IRQFLAGS 915.Lhardirqs_on: .long trace_hardirqs_on_caller 916.Lhardirqs_off: .long trace_hardirqs_off_caller 917#endif 918#ifdef CONFIG_LOCKDEP 919.Llockdep_sys_exit: .long lockdep_sys_exit 920#endif 921.Lcritical_start: .long __critical_start + 0x80000000 922.Lcritical_length: .long __critical_end - __critical_start 923 924 .section .rodata, "a" 925#define SYSCALL(esa,esame,emu) .long esa 926 .globl sys_call_table 927sys_call_table: 928#include "syscalls.S" 929#undef SYSCALL 930