1/* 2 * arch/s390/kernel/entry64.S 3 * S390 low-level entry points. 4 * 5 * Copyright (C) IBM Corp. 1999,2010 6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 7 * Hartmut Penner (hp@de.ibm.com), 8 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), 9 * Heiko Carstens <heiko.carstens@de.ibm.com> 10 */ 11 12#include <linux/init.h> 13#include <linux/linkage.h> 14#include <asm/cache.h> 15#include <asm/errno.h> 16#include <asm/ptrace.h> 17#include <asm/thread_info.h> 18#include <asm/asm-offsets.h> 19#include <asm/unistd.h> 20#include <asm/page.h> 21 22__PT_R0 = __PT_GPRS 23__PT_R1 = __PT_GPRS + 8 24__PT_R2 = __PT_GPRS + 16 25__PT_R3 = __PT_GPRS + 24 26__PT_R4 = __PT_GPRS + 32 27__PT_R5 = __PT_GPRS + 40 28__PT_R6 = __PT_GPRS + 48 29__PT_R7 = __PT_GPRS + 56 30__PT_R8 = __PT_GPRS + 64 31__PT_R9 = __PT_GPRS + 72 32__PT_R10 = __PT_GPRS + 80 33__PT_R11 = __PT_GPRS + 88 34__PT_R12 = __PT_GPRS + 96 35__PT_R13 = __PT_GPRS + 104 36__PT_R14 = __PT_GPRS + 112 37__PT_R15 = __PT_GPRS + 120 38 39STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER 40STACK_SIZE = 1 << STACK_SHIFT 41 42_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ 43 _TIF_MCCK_PENDING | _TIF_PER_TRAP ) 44_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ 45 _TIF_MCCK_PENDING) 46_TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \ 47 _TIF_SYSCALL_TRACEPOINT) 48_TIF_EXIT_SIE = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING) 49 50#define BASED(name) name-system_call(%r13) 51 52 .macro TRACE_IRQS_ON 53#ifdef CONFIG_TRACE_IRQFLAGS 54 basr %r2,%r0 55 brasl %r14,trace_hardirqs_on_caller 56#endif 57 .endm 58 59 .macro TRACE_IRQS_OFF 60#ifdef CONFIG_TRACE_IRQFLAGS 61 basr %r2,%r0 62 brasl %r14,trace_hardirqs_off_caller 63#endif 64 .endm 65 66 .macro LOCKDEP_SYS_EXIT 67#ifdef CONFIG_LOCKDEP 68 tm __PT_PSW+1(%r11),0x01 # returning to user ? 69 jz .+10 70 brasl %r14,lockdep_sys_exit 71#endif 72 .endm 73 74 .macro SPP newpp 75#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE) 76 tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_SPP 77 jz .+8 78 .insn s,0xb2800000,\newpp 79#endif 80 .endm 81 82 .macro HANDLE_SIE_INTERCEPT scratch 83#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE) 84 tm __TI_flags+6(%r12),_TIF_SIE>>8 85 jz .+42 86 tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_SPP 87 jz .+8 88 .insn s,0xb2800000,BASED(.Lhost_id) # set host id 89 lgr \scratch,%r9 90 slg \scratch,BASED(.Lsie_loop) 91 clg \scratch,BASED(.Lsie_length) 92 jhe .+10 93 lg %r9,BASED(.Lsie_loop) 94#endif 95 .endm 96 97 .macro CHECK_STACK stacksize,savearea 98#ifdef CONFIG_CHECK_STACK 99 tml %r15,\stacksize - CONFIG_STACK_GUARD 100 lghi %r14,\savearea 101 jz stack_overflow 102#endif 103 .endm 104 105 .macro SWITCH_ASYNC savearea,stack,shift 106 tmhh %r8,0x0001 # interrupting from user ? 107 jnz 1f 108 lgr %r14,%r9 109 slg %r14,BASED(.Lcritical_start) 110 clg %r14,BASED(.Lcritical_length) 111 jhe 0f 112 lghi %r11,\savearea # inside critical section, do cleanup 113 brasl %r14,cleanup_critical 114 tmhh %r8,0x0001 # retest problem state after cleanup 115 jnz 1f 1160: lg %r14,\stack # are we already on the target stack? 117 slgr %r14,%r15 118 srag %r14,%r14,\shift 119 jnz 1f 120 CHECK_STACK 1<<\shift,\savearea 121 j 2f 1221: lg %r15,\stack # load target stack 1232: aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 124 la %r11,STACK_FRAME_OVERHEAD(%r15) 125 .endm 126 127 .macro UPDATE_VTIME scratch,enter_timer 128 lg \scratch,__LC_EXIT_TIMER 129 slg \scratch,\enter_timer 130 alg \scratch,__LC_USER_TIMER 131 stg \scratch,__LC_USER_TIMER 132 lg \scratch,__LC_LAST_UPDATE_TIMER 133 slg \scratch,__LC_EXIT_TIMER 134 alg \scratch,__LC_SYSTEM_TIMER 135 stg \scratch,__LC_SYSTEM_TIMER 136 mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer 137 .endm 138 139 .macro LAST_BREAK scratch 140 srag \scratch,%r10,23 141 jz .+10 142 stg %r10,__TI_last_break(%r12) 143 .endm 144 145 .macro REENABLE_IRQS 146 stg %r8,__LC_RETURN_PSW 147 ni __LC_RETURN_PSW,0xbf 148 ssm __LC_RETURN_PSW 149 .endm 150 151 .section .kprobes.text, "ax" 152 153/* 154 * Scheduler resume function, called by switch_to 155 * gpr2 = (task_struct *) prev 156 * gpr3 = (task_struct *) next 157 * Returns: 158 * gpr2 = prev 159 */ 160ENTRY(__switch_to) 161 lg %r4,__THREAD_info(%r2) # get thread_info of prev 162 lg %r5,__THREAD_info(%r3) # get thread_info of next 163 tm __TI_flags+7(%r4),_TIF_MCCK_PENDING # machine check pending? 164 jz 0f 165 ni __TI_flags+7(%r4),255-_TIF_MCCK_PENDING # clear flag in prev 166 oi __TI_flags+7(%r5),_TIF_MCCK_PENDING # set it in next 1670: stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task 168 stg %r15,__THREAD_ksp(%r2) # store kernel stack of prev 169 lg %r15,__THREAD_ksp(%r3) # load kernel stack of next 170 lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 171 lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task 172 stg %r3,__LC_CURRENT # store task struct of next 173 mvc __LC_CURRENT_PID+4(4,%r0),__TASK_pid(%r3) # store pid of next 174 stg %r5,__LC_THREAD_INFO # store thread info of next 175 aghi %r5,STACK_SIZE # end of kernel stack of next 176 stg %r5,__LC_KERNEL_STACK # store end of kernel stack 177 br %r14 178 179__critical_start: 180/* 181 * SVC interrupt handler routine. System calls are synchronous events and 182 * are executed with interrupts enabled. 183 */ 184 185ENTRY(system_call) 186 stpt __LC_SYNC_ENTER_TIMER 187sysc_stmg: 188 stmg %r8,%r15,__LC_SAVE_AREA_SYNC 189 lg %r10,__LC_LAST_BREAK 190 lg %r12,__LC_THREAD_INFO 191 larl %r13,system_call 192sysc_per: 193 lg %r15,__LC_KERNEL_STACK 194 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 195 la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs 196sysc_vtime: 197 UPDATE_VTIME %r13,__LC_SYNC_ENTER_TIMER 198 LAST_BREAK %r13 199 stmg %r0,%r7,__PT_R0(%r11) 200 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC 201 mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW 202 mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC 203sysc_do_svc: 204 oi __TI_flags+7(%r12),_TIF_SYSCALL 205 llgh %r8,__PT_INT_CODE+2(%r11) 206 slag %r8,%r8,2 # shift and test for svc 0 207 jnz sysc_nr_ok 208 # svc 0: system call number in %r1 209 llgfr %r1,%r1 # clear high word in r1 210 cghi %r1,NR_syscalls 211 jnl sysc_nr_ok 212 sth %r1,__PT_INT_CODE+2(%r11) 213 slag %r8,%r1,2 214sysc_nr_ok: 215 larl %r10,sys_call_table # 64 bit system call table 216#ifdef CONFIG_COMPAT 217 tm __TI_flags+5(%r12),(_TIF_31BIT>>16) 218 jno sysc_noemu 219 larl %r10,sys_call_table_emu # 31 bit system call table 220sysc_noemu: 221#endif 222 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 223 stg %r2,__PT_ORIG_GPR2(%r11) 224 stg %r7,STACK_FRAME_OVERHEAD(%r15) 225 lgf %r9,0(%r8,%r10) # get system call add. 226 tm __TI_flags+6(%r12),_TIF_TRACE >> 8 227 jnz sysc_tracesys 228 basr %r14,%r9 # call sys_xxxx 229 stg %r2,__PT_R2(%r11) # store return value 230 231sysc_return: 232 LOCKDEP_SYS_EXIT 233sysc_tif: 234 tm __PT_PSW+1(%r11),0x01 # returning to user ? 235 jno sysc_restore 236 tm __TI_flags+7(%r12),_TIF_WORK_SVC 237 jnz sysc_work # check for work 238 ni __TI_flags+7(%r12),255-_TIF_SYSCALL 239sysc_restore: 240 lg %r14,__LC_VDSO_PER_CPU 241 lmg %r0,%r10,__PT_R0(%r11) 242 mvc __LC_RETURN_PSW(16),__PT_PSW(%r11) 243 stpt __LC_EXIT_TIMER 244 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER 245 lmg %r11,%r15,__PT_R11(%r11) 246 lpswe __LC_RETURN_PSW 247sysc_done: 248 249# 250# One of the work bits is on. Find out which one. 251# 252sysc_work: 253 tm __TI_flags+7(%r12),_TIF_MCCK_PENDING 254 jo sysc_mcck_pending 255 tm __TI_flags+7(%r12),_TIF_NEED_RESCHED 256 jo sysc_reschedule 257 tm __TI_flags+7(%r12),_TIF_SIGPENDING 258 jo sysc_sigpending 259 tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME 260 jo sysc_notify_resume 261 tm __TI_flags+7(%r12),_TIF_PER_TRAP 262 jo sysc_singlestep 263 j sysc_return # beware of critical section cleanup 264 265# 266# _TIF_NEED_RESCHED is set, call schedule 267# 268sysc_reschedule: 269 larl %r14,sysc_return 270 jg schedule 271 272# 273# _TIF_MCCK_PENDING is set, call handler 274# 275sysc_mcck_pending: 276 larl %r14,sysc_return 277 jg s390_handle_mcck # TIF bit will be cleared by handler 278 279# 280# _TIF_SIGPENDING is set, call do_signal 281# 282sysc_sigpending: 283 ni __TI_flags+7(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP 284 lgr %r2,%r11 # pass pointer to pt_regs 285 brasl %r14,do_signal 286 tm __TI_flags+7(%r12),_TIF_SYSCALL 287 jno sysc_return 288 lmg %r2,%r7,__PT_R2(%r11) # load svc arguments 289 lghi %r8,0 # svc 0 returns -ENOSYS 290 lh %r1,__PT_INT_CODE+2(%r11) # load new svc number 291 cghi %r1,NR_syscalls 292 jnl sysc_nr_ok # invalid svc number -> do svc 0 293 slag %r8,%r1,2 294 j sysc_nr_ok # restart svc 295 296# 297# _TIF_NOTIFY_RESUME is set, call do_notify_resume 298# 299sysc_notify_resume: 300 lgr %r2,%r11 # pass pointer to pt_regs 301 larl %r14,sysc_return 302 jg do_notify_resume 303 304# 305# _TIF_PER_TRAP is set, call do_per_trap 306# 307sysc_singlestep: 308 ni __TI_flags+7(%r12),255-(_TIF_SYSCALL | _TIF_PER_TRAP) 309 lgr %r2,%r11 # pass pointer to pt_regs 310 larl %r14,sysc_return 311 jg do_per_trap 312 313# 314# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before 315# and after the system call 316# 317sysc_tracesys: 318 lgr %r2,%r11 # pass pointer to pt_regs 319 la %r3,0 320 llgh %r0,__PT_INT_CODE+2(%r11) 321 stg %r0,__PT_R2(%r11) 322 brasl %r14,do_syscall_trace_enter 323 lghi %r0,NR_syscalls 324 clgr %r0,%r2 325 jnh sysc_tracenogo 326 sllg %r8,%r2,2 327 lgf %r9,0(%r8,%r10) 328sysc_tracego: 329 lmg %r3,%r7,__PT_R3(%r11) 330 stg %r7,STACK_FRAME_OVERHEAD(%r15) 331 lg %r2,__PT_ORIG_GPR2(%r11) 332 basr %r14,%r9 # call sys_xxx 333 stg %r2,__PT_R2(%r11) # store return value 334sysc_tracenogo: 335 tm __TI_flags+6(%r12),_TIF_TRACE >> 8 336 jz sysc_return 337 lgr %r2,%r11 # pass pointer to pt_regs 338 larl %r14,sysc_return 339 jg do_syscall_trace_exit 340 341# 342# a new process exits the kernel with ret_from_fork 343# 344ENTRY(ret_from_fork) 345 la %r11,STACK_FRAME_OVERHEAD(%r15) 346 lg %r12,__LC_THREAD_INFO 347 tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ? 348 jo 0f 349 stg %r15,__PT_R15(%r11) # store stack pointer for new kthread 3500: brasl %r14,schedule_tail 351 TRACE_IRQS_ON 352 ssm __LC_SVC_NEW_PSW # reenable interrupts 353 j sysc_tracenogo 354 355# 356# kernel_execve function needs to deal with pt_regs that is not 357# at the usual place 358# 359ENTRY(kernel_execve) 360 stmg %r12,%r15,96(%r15) 361 lgr %r14,%r15 362 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 363 stg %r14,__SF_BACKCHAIN(%r15) 364 la %r12,STACK_FRAME_OVERHEAD(%r15) 365 xc 0(__PT_SIZE,%r12),0(%r12) 366 lgr %r5,%r12 367 brasl %r14,do_execve 368 ltgfr %r2,%r2 369 je 0f 370 aghi %r15,(STACK_FRAME_OVERHEAD + __PT_SIZE) 371 lmg %r12,%r15,96(%r15) 372 br %r14 373 # execve succeeded. 3740: ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 375 lg %r15,__LC_KERNEL_STACK # load ksp 376 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 377 la %r11,STACK_FRAME_OVERHEAD(%r15) 378 mvc 0(__PT_SIZE,%r11),0(%r12) # copy pt_regs 379 lg %r12,__LC_THREAD_INFO 380 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 381 ssm __LC_SVC_NEW_PSW # reenable interrupts 382 brasl %r14,execve_tail 383 j sysc_return 384 385/* 386 * Program check handler routine 387 */ 388 389ENTRY(pgm_check_handler) 390 stpt __LC_SYNC_ENTER_TIMER 391 stmg %r8,%r15,__LC_SAVE_AREA_SYNC 392 lg %r10,__LC_LAST_BREAK 393 lg %r12,__LC_THREAD_INFO 394 larl %r13,system_call 395 lmg %r8,%r9,__LC_PGM_OLD_PSW 396 HANDLE_SIE_INTERCEPT %r14 397 tmhh %r8,0x0001 # test problem state bit 398 jnz 1f # -> fault in user space 399 tmhh %r8,0x4000 # PER bit set in old PSW ? 400 jnz 0f # -> enabled, can't be a double fault 401 tm __LC_PGM_ILC+3,0x80 # check for per exception 402 jnz pgm_svcper # -> single stepped svc 4030: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC 404 j 2f 4051: UPDATE_VTIME %r14,__LC_SYNC_ENTER_TIMER 406 LAST_BREAK %r14 407 lg %r15,__LC_KERNEL_STACK 4082: aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 409 la %r11,STACK_FRAME_OVERHEAD(%r15) 410 stmg %r0,%r7,__PT_R0(%r11) 411 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC 412 stmg %r8,%r9,__PT_PSW(%r11) 413 mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC 414 mvc __PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE 415 stg %r10,__PT_ARGS(%r11) 416 tm __LC_PGM_ILC+3,0x80 # check for per exception 417 jz 0f 418 lg %r1,__TI_task(%r12) 419 tmhh %r8,0x0001 # kernel per event ? 420 jz pgm_kprobe 421 oi __TI_flags+7(%r12),_TIF_PER_TRAP 422 mvc __THREAD_per_address(8,%r1),__LC_PER_ADDRESS 423 mvc __THREAD_per_cause(2,%r1),__LC_PER_CAUSE 424 mvc __THREAD_per_paid(1,%r1),__LC_PER_PAID 4250: REENABLE_IRQS 426 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 427 larl %r1,pgm_check_table 428 llgh %r10,__PT_INT_CODE+2(%r11) 429 nill %r10,0x007f 430 sll %r10,3 431 je sysc_return 432 lg %r1,0(%r10,%r1) # load address of handler routine 433 lgr %r2,%r11 # pass pointer to pt_regs 434 basr %r14,%r1 # branch to interrupt-handler 435 j sysc_return 436 437# 438# PER event in supervisor state, must be kprobes 439# 440pgm_kprobe: 441 REENABLE_IRQS 442 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 443 lgr %r2,%r11 # pass pointer to pt_regs 444 brasl %r14,do_per_trap 445 j sysc_return 446 447# 448# single stepped system call 449# 450pgm_svcper: 451 oi __TI_flags+7(%r12),_TIF_PER_TRAP 452 mvc __LC_RETURN_PSW(8),__LC_SVC_NEW_PSW 453 larl %r14,sysc_per 454 stg %r14,__LC_RETURN_PSW+8 455 lpswe __LC_RETURN_PSW # branch to sysc_per and enable irqs 456 457/* 458 * IO interrupt handler routine 459 */ 460ENTRY(io_int_handler) 461 stck __LC_INT_CLOCK 462 stpt __LC_ASYNC_ENTER_TIMER 463 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC 464 lg %r10,__LC_LAST_BREAK 465 lg %r12,__LC_THREAD_INFO 466 larl %r13,system_call 467 lmg %r8,%r9,__LC_IO_OLD_PSW 468 HANDLE_SIE_INTERCEPT %r14 469 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT 470 tmhh %r8,0x0001 # interrupting from user? 471 jz io_skip 472 UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER 473 LAST_BREAK %r14 474io_skip: 475 stmg %r0,%r7,__PT_R0(%r11) 476 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC 477 stmg %r8,%r9,__PT_PSW(%r11) 478 TRACE_IRQS_OFF 479 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 480 lgr %r2,%r11 # pass pointer to pt_regs 481 brasl %r14,do_IRQ 482io_return: 483 LOCKDEP_SYS_EXIT 484 TRACE_IRQS_ON 485io_tif: 486 tm __TI_flags+7(%r12),_TIF_WORK_INT 487 jnz io_work # there is work to do (signals etc.) 488io_restore: 489 lg %r14,__LC_VDSO_PER_CPU 490 lmg %r0,%r10,__PT_R0(%r11) 491 mvc __LC_RETURN_PSW(16),__PT_PSW(%r11) 492 ni __LC_RETURN_PSW+1,0xfd # clear wait state bit 493 stpt __LC_EXIT_TIMER 494 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER 495 lmg %r11,%r15,__PT_R11(%r11) 496 lpswe __LC_RETURN_PSW 497io_done: 498 499# 500# There is work todo, find out in which context we have been interrupted: 501# 1) if we return to user space we can do all _TIF_WORK_INT work 502# 2) if we return to kernel code and kvm is enabled check if we need to 503# modify the psw to leave SIE 504# 3) if we return to kernel code and preemptive scheduling is enabled check 505# the preemption counter and if it is zero call preempt_schedule_irq 506# Before any work can be done, a switch to the kernel stack is required. 507# 508io_work: 509 tm __PT_PSW+1(%r11),0x01 # returning to user ? 510 jo io_work_user # yes -> do resched & signal 511#ifdef CONFIG_PREEMPT 512 # check for preemptive scheduling 513 icm %r0,15,__TI_precount(%r12) 514 jnz io_restore # preemption is disabled 515 tm __TI_flags+7(%r12),_TIF_NEED_RESCHED 516 jno io_restore 517 # switch to kernel stack 518 lg %r1,__PT_R15(%r11) 519 aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 520 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 521 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) 522 la %r11,STACK_FRAME_OVERHEAD(%r1) 523 lgr %r15,%r1 524 # TRACE_IRQS_ON already done at io_return, call 525 # TRACE_IRQS_OFF to keep things symmetrical 526 TRACE_IRQS_OFF 527 brasl %r14,preempt_schedule_irq 528 j io_return 529#else 530 j io_restore 531#endif 532 533# 534# Need to do work before returning to userspace, switch to kernel stack 535# 536io_work_user: 537 lg %r1,__LC_KERNEL_STACK 538 aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 539 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 540 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) 541 la %r11,STACK_FRAME_OVERHEAD(%r1) 542 lgr %r15,%r1 543 544# 545# One of the work bits is on. Find out which one. 546# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED 547# and _TIF_MCCK_PENDING 548# 549io_work_tif: 550 tm __TI_flags+7(%r12),_TIF_MCCK_PENDING 551 jo io_mcck_pending 552 tm __TI_flags+7(%r12),_TIF_NEED_RESCHED 553 jo io_reschedule 554 tm __TI_flags+7(%r12),_TIF_SIGPENDING 555 jo io_sigpending 556 tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME 557 jo io_notify_resume 558 j io_return # beware of critical section cleanup 559 560# 561# _TIF_MCCK_PENDING is set, call handler 562# 563io_mcck_pending: 564 # TRACE_IRQS_ON already done at io_return 565 brasl %r14,s390_handle_mcck # TIF bit will be cleared by handler 566 TRACE_IRQS_OFF 567 j io_return 568 569# 570# _TIF_NEED_RESCHED is set, call schedule 571# 572io_reschedule: 573 # TRACE_IRQS_ON already done at io_return 574 ssm __LC_SVC_NEW_PSW # reenable interrupts 575 brasl %r14,schedule # call scheduler 576 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 577 TRACE_IRQS_OFF 578 j io_return 579 580# 581# _TIF_SIGPENDING or is set, call do_signal 582# 583io_sigpending: 584 # TRACE_IRQS_ON already done at io_return 585 ssm __LC_SVC_NEW_PSW # reenable interrupts 586 lgr %r2,%r11 # pass pointer to pt_regs 587 brasl %r14,do_signal 588 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 589 TRACE_IRQS_OFF 590 j io_return 591 592# 593# _TIF_NOTIFY_RESUME or is set, call do_notify_resume 594# 595io_notify_resume: 596 # TRACE_IRQS_ON already done at io_return 597 ssm __LC_SVC_NEW_PSW # reenable interrupts 598 lgr %r2,%r11 # pass pointer to pt_regs 599 brasl %r14,do_notify_resume 600 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 601 TRACE_IRQS_OFF 602 j io_return 603 604/* 605 * External interrupt handler routine 606 */ 607ENTRY(ext_int_handler) 608 stck __LC_INT_CLOCK 609 stpt __LC_ASYNC_ENTER_TIMER 610 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC 611 lg %r10,__LC_LAST_BREAK 612 lg %r12,__LC_THREAD_INFO 613 larl %r13,system_call 614 lmg %r8,%r9,__LC_EXT_OLD_PSW 615 HANDLE_SIE_INTERCEPT %r14 616 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT 617 tmhh %r8,0x0001 # interrupting from user ? 618 jz ext_skip 619 UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER 620 LAST_BREAK %r14 621ext_skip: 622 stmg %r0,%r7,__PT_R0(%r11) 623 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC 624 stmg %r8,%r9,__PT_PSW(%r11) 625 TRACE_IRQS_OFF 626 lghi %r1,4096 627 lgr %r2,%r11 # pass pointer to pt_regs 628 llgf %r3,__LC_CPU_ADDRESS # get cpu address + interruption code 629 llgf %r4,__LC_EXT_PARAMS # get external parameter 630 lg %r5,__LC_EXT_PARAMS2-4096(%r1) # get 64 bit external parameter 631 brasl %r14,do_extint 632 j io_return 633 634__critical_end: 635 636/* 637 * Machine check handler routines 638 */ 639ENTRY(mcck_int_handler) 640 stck __LC_MCCK_CLOCK 641 la %r1,4095 # revalidate r1 642 spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # revalidate cpu timer 643 lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs 644 lg %r10,__LC_LAST_BREAK 645 lg %r12,__LC_THREAD_INFO 646 larl %r13,system_call 647 lmg %r8,%r9,__LC_MCK_OLD_PSW 648 HANDLE_SIE_INTERCEPT %r14 649 tm __LC_MCCK_CODE,0x80 # system damage? 650 jo mcck_panic # yes -> rest of mcck code invalid 651 lghi %r14,__LC_CPU_TIMER_SAVE_AREA 652 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 653 tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid? 654 jo 3f 655 la %r14,__LC_SYNC_ENTER_TIMER 656 clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER 657 jl 0f 658 la %r14,__LC_ASYNC_ENTER_TIMER 6590: clc 0(8,%r14),__LC_EXIT_TIMER 660 jl 1f 661 la %r14,__LC_EXIT_TIMER 6621: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER 663 jl 2f 664 la %r14,__LC_LAST_UPDATE_TIMER 6652: spt 0(%r14) 666 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 6673: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid? 668 jno mcck_panic # no -> skip cleanup critical 669 SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_PANIC_STACK,PAGE_SHIFT 670 tm %r8,0x0001 # interrupting from user ? 671 jz mcck_skip 672 UPDATE_VTIME %r14,__LC_MCCK_ENTER_TIMER 673 LAST_BREAK %r14 674mcck_skip: 675 lghi %r14,__LC_GPREGS_SAVE_AREA 676 mvc __PT_R0(128,%r11),0(%r14) 677 stmg %r8,%r9,__PT_PSW(%r11) 678 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 679 lgr %r2,%r11 # pass pointer to pt_regs 680 brasl %r14,s390_do_machine_check 681 tm __PT_PSW+1(%r11),0x01 # returning to user ? 682 jno mcck_return 683 lg %r1,__LC_KERNEL_STACK # switch to kernel stack 684 aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 685 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 686 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) 687 la %r11,STACK_FRAME_OVERHEAD(%r1) 688 lgr %r15,%r1 689 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off 690 tm __TI_flags+7(%r12),_TIF_MCCK_PENDING 691 jno mcck_return 692 TRACE_IRQS_OFF 693 brasl %r14,s390_handle_mcck 694 TRACE_IRQS_ON 695mcck_return: 696 lg %r14,__LC_VDSO_PER_CPU 697 lmg %r0,%r10,__PT_R0(%r11) 698 mvc __LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW 699 ni __LC_RETURN_MCCK_PSW+1,0xfd # clear wait state bit 700 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ? 701 jno 0f 702 stpt __LC_EXIT_TIMER 703 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER 7040: lmg %r11,%r15,__PT_R11(%r11) 705 lpswe __LC_RETURN_MCCK_PSW 706 707mcck_panic: 708 lg %r14,__LC_PANIC_STACK 709 slgr %r14,%r15 710 srag %r14,%r14,PAGE_SHIFT 711 jz 0f 712 lg %r15,__LC_PANIC_STACK 7130: aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 714 j mcck_skip 715 716/* 717 * Restart interruption handler, kick starter for additional CPUs 718 */ 719#ifdef CONFIG_SMP 720 __CPUINIT 721ENTRY(restart_int_handler) 722 basr %r1,0 723restart_base: 724 spt restart_vtime-restart_base(%r1) 725 stck __LC_LAST_UPDATE_CLOCK 726 mvc __LC_LAST_UPDATE_TIMER(8),restart_vtime-restart_base(%r1) 727 mvc __LC_EXIT_TIMER(8),restart_vtime-restart_base(%r1) 728 lghi %r10,__LC_GPREGS_SAVE_AREA 729 lg %r15,120(%r10) # load ksp 730 lghi %r10,__LC_CREGS_SAVE_AREA 731 lctlg %c0,%c15,0(%r10) # get new ctl regs 732 lghi %r10,__LC_AREGS_SAVE_AREA 733 lam %a0,%a15,0(%r10) 734 lmg %r6,%r15,__SF_GPRS(%r15)# load registers from clone 735 lg %r1,__LC_THREAD_INFO 736 mvc __LC_USER_TIMER(8),__TI_user_timer(%r1) 737 mvc __LC_SYSTEM_TIMER(8),__TI_system_timer(%r1) 738 xc __LC_STEAL_TIMER(8),__LC_STEAL_TIMER 739 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off 740 brasl %r14,start_secondary 741 .align 8 742restart_vtime: 743 .long 0x7fffffff,0xffffffff 744 .previous 745#else 746/* 747 * If we do not run with SMP enabled, let the new CPU crash ... 748 */ 749ENTRY(restart_int_handler) 750 basr %r1,0 751restart_base: 752 lpswe restart_crash-restart_base(%r1) 753 .align 8 754restart_crash: 755 .long 0x000a0000,0x00000000,0x00000000,0x00000000 756restart_go: 757#endif 758 759# 760# PSW restart interrupt handler 761# 762ENTRY(psw_restart_int_handler) 763 stg %r15,__LC_SAVE_AREA_RESTART 764 larl %r15,restart_stack # load restart stack 765 lg %r15,0(%r15) 766 aghi %r15,-__PT_SIZE # create pt_regs on stack 767 stmg %r0,%r14,__PT_R0(%r15) 768 mvc __PT_R15(8,%r15),__LC_SAVE_AREA_RESTART 769 mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw 770 aghi %r15,-STACK_FRAME_OVERHEAD 771 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 772 brasl %r14,do_restart 773 larl %r14,restart_psw_crash # load disabled wait PSW if 774 lpswe 0(%r14) # do_restart returns 775 .align 8 776restart_psw_crash: 777 .quad 0x0002000080000000,0x0000000000000000 + restart_psw_crash 778 779 .section .kprobes.text, "ax" 780 781#ifdef CONFIG_CHECK_STACK 782/* 783 * The synchronous or the asynchronous stack overflowed. We are dead. 784 * No need to properly save the registers, we are going to panic anyway. 785 * Setup a pt_regs so that show_trace can provide a good call trace. 786 */ 787stack_overflow: 788 lg %r11,__LC_PANIC_STACK # change to panic stack 789 aghi %r11,-__PT_SIZE # create pt_regs 790 stmg %r0,%r7,__PT_R0(%r11) 791 stmg %r8,%r9,__PT_PSW(%r11) 792 mvc __PT_R8(64,%r11),0(%r14) 793 stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2 794 lgr %r15,%r11 795 aghi %r15,-STACK_FRAME_OVERHEAD 796 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 797 lgr %r2,%r11 # pass pointer to pt_regs 798 jg kernel_stack_overflow 799#endif 800 801 .align 8 802cleanup_table: 803 .quad system_call 804 .quad sysc_do_svc 805 .quad sysc_tif 806 .quad sysc_restore 807 .quad sysc_done 808 .quad io_tif 809 .quad io_restore 810 .quad io_done 811 812cleanup_critical: 813 clg %r9,BASED(cleanup_table) # system_call 814 jl 0f 815 clg %r9,BASED(cleanup_table+8) # sysc_do_svc 816 jl cleanup_system_call 817 clg %r9,BASED(cleanup_table+16) # sysc_tif 818 jl 0f 819 clg %r9,BASED(cleanup_table+24) # sysc_restore 820 jl cleanup_sysc_tif 821 clg %r9,BASED(cleanup_table+32) # sysc_done 822 jl cleanup_sysc_restore 823 clg %r9,BASED(cleanup_table+40) # io_tif 824 jl 0f 825 clg %r9,BASED(cleanup_table+48) # io_restore 826 jl cleanup_io_tif 827 clg %r9,BASED(cleanup_table+56) # io_done 828 jl cleanup_io_restore 8290: br %r14 830 831 832cleanup_system_call: 833 # check if stpt has been executed 834 clg %r9,BASED(cleanup_system_call_insn) 835 jh 0f 836 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER 837 cghi %r11,__LC_SAVE_AREA_ASYNC 838 je 0f 839 mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER 8400: # check if stmg has been executed 841 clg %r9,BASED(cleanup_system_call_insn+8) 842 jh 0f 843 mvc __LC_SAVE_AREA_SYNC(64),0(%r11) 8440: # check if base register setup + TIF bit load has been done 845 clg %r9,BASED(cleanup_system_call_insn+16) 846 jhe 0f 847 # set up saved registers r10 and r12 848 stg %r10,16(%r11) # r10 last break 849 stg %r12,32(%r11) # r12 thread-info pointer 8500: # check if the user time update has been done 851 clg %r9,BASED(cleanup_system_call_insn+24) 852 jh 0f 853 lg %r15,__LC_EXIT_TIMER 854 slg %r15,__LC_SYNC_ENTER_TIMER 855 alg %r15,__LC_USER_TIMER 856 stg %r15,__LC_USER_TIMER 8570: # check if the system time update has been done 858 clg %r9,BASED(cleanup_system_call_insn+32) 859 jh 0f 860 lg %r15,__LC_LAST_UPDATE_TIMER 861 slg %r15,__LC_EXIT_TIMER 862 alg %r15,__LC_SYSTEM_TIMER 863 stg %r15,__LC_SYSTEM_TIMER 8640: # update accounting time stamp 865 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 866 # do LAST_BREAK 867 lg %r9,16(%r11) 868 srag %r9,%r9,23 869 jz 0f 870 mvc __TI_last_break(8,%r12),16(%r11) 8710: # set up saved register r11 872 lg %r15,__LC_KERNEL_STACK 873 aghi %r15,-__PT_SIZE 874 stg %r15,24(%r11) # r11 pt_regs pointer 875 # fill pt_regs 876 mvc __PT_R8(64,%r15),__LC_SAVE_AREA_SYNC 877 stmg %r0,%r7,__PT_R0(%r15) 878 mvc __PT_PSW(16,%r15),__LC_SVC_OLD_PSW 879 mvc __PT_INT_CODE(4,%r15),__LC_SVC_ILC 880 # setup saved register r15 881 aghi %r15,-STACK_FRAME_OVERHEAD 882 stg %r15,56(%r11) # r15 stack pointer 883 # set new psw address and exit 884 larl %r9,sysc_do_svc 885 br %r14 886cleanup_system_call_insn: 887 .quad system_call 888 .quad sysc_stmg 889 .quad sysc_per 890 .quad sysc_vtime+18 891 .quad sysc_vtime+42 892 893cleanup_sysc_tif: 894 larl %r9,sysc_tif 895 br %r14 896 897cleanup_sysc_restore: 898 clg %r9,BASED(cleanup_sysc_restore_insn) 899 je 0f 900 lg %r9,24(%r11) # get saved pointer to pt_regs 901 mvc __LC_RETURN_PSW(16),__PT_PSW(%r9) 902 mvc 0(64,%r11),__PT_R8(%r9) 903 lmg %r0,%r7,__PT_R0(%r9) 9040: lmg %r8,%r9,__LC_RETURN_PSW 905 br %r14 906cleanup_sysc_restore_insn: 907 .quad sysc_done - 4 908 909cleanup_io_tif: 910 larl %r9,io_tif 911 br %r14 912 913cleanup_io_restore: 914 clg %r9,BASED(cleanup_io_restore_insn) 915 je 0f 916 lg %r9,24(%r11) # get saved r11 pointer to pt_regs 917 mvc __LC_RETURN_PSW(16),__PT_PSW(%r9) 918 ni __LC_RETURN_PSW+1,0xfd # clear wait state bit 919 mvc 0(64,%r11),__PT_R8(%r9) 920 lmg %r0,%r7,__PT_R0(%r9) 9210: lmg %r8,%r9,__LC_RETURN_PSW 922 br %r14 923cleanup_io_restore_insn: 924 .quad io_done - 4 925 926/* 927 * Integer constants 928 */ 929 .align 8 930.Lcritical_start: 931 .quad __critical_start 932.Lcritical_length: 933 .quad __critical_end - __critical_start 934 935 936#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE) 937/* 938 * sie64a calling convention: 939 * %r2 pointer to sie control block 940 * %r3 guest register save area 941 */ 942ENTRY(sie64a) 943 stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers 944 stg %r2,__SF_EMPTY(%r15) # save control block pointer 945 stg %r3,__SF_EMPTY+8(%r15) # save guest register save area 946 xc __SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # host id == 0 947 lmg %r0,%r13,0(%r3) # load guest gprs 0-13 948 lg %r14,__LC_THREAD_INFO # pointer thread_info struct 949 oi __TI_flags+6(%r14),_TIF_SIE>>8 950sie_loop: 951 lg %r14,__LC_THREAD_INFO # pointer thread_info struct 952 tm __TI_flags+7(%r14),_TIF_EXIT_SIE 953 jnz sie_exit 954 lg %r14,__LC_GMAP # get gmap pointer 955 ltgr %r14,%r14 956 jz sie_gmap 957 lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce 958sie_gmap: 959 lg %r14,__SF_EMPTY(%r15) # get control block pointer 960 SPP __SF_EMPTY(%r15) # set guest id 961 sie 0(%r14) 962sie_done: 963 SPP __SF_EMPTY+16(%r15) # set host id 964 lg %r14,__LC_THREAD_INFO # pointer thread_info struct 965sie_exit: 966 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce 967 ni __TI_flags+6(%r14),255-(_TIF_SIE>>8) 968 lg %r14,__SF_EMPTY+8(%r15) # load guest register save area 969 stmg %r0,%r13,0(%r14) # save guest gprs 0-13 970 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers 971 lghi %r2,0 972 br %r14 973sie_fault: 974 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce 975 lg %r14,__LC_THREAD_INFO # pointer thread_info struct 976 ni __TI_flags+6(%r14),255-(_TIF_SIE>>8) 977 lg %r14,__SF_EMPTY+8(%r15) # load guest register save area 978 stmg %r0,%r13,0(%r14) # save guest gprs 0-13 979 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers 980 lghi %r2,-EFAULT 981 br %r14 982 983 .align 8 984.Lsie_loop: 985 .quad sie_loop 986.Lsie_length: 987 .quad sie_done - sie_loop 988.Lhost_id: 989 .quad 0 990 991 .section __ex_table,"a" 992 .quad sie_loop,sie_fault 993 .previous 994#endif 995 996 .section .rodata, "a" 997#define SYSCALL(esa,esame,emu) .long esame 998 .globl sys_call_table 999sys_call_table: 1000#include "syscalls.S" 1001#undef SYSCALL 1002 1003#ifdef CONFIG_COMPAT 1004 1005#define SYSCALL(esa,esame,emu) .long emu 1006sys_call_table_emu: 1007#include "syscalls.S" 1008#undef SYSCALL 1009#endif 1010