1/* 2 * arch/s390/kernel/entry64.S 3 * S390 low-level entry points. 4 * 5 * Copyright (C) IBM Corp. 1999,2012 6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 7 * Hartmut Penner (hp@de.ibm.com), 8 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), 9 * Heiko Carstens <heiko.carstens@de.ibm.com> 10 */ 11 12#include <linux/init.h> 13#include <linux/linkage.h> 14#include <asm/cache.h> 15#include <asm/errno.h> 16#include <asm/ptrace.h> 17#include <asm/thread_info.h> 18#include <asm/asm-offsets.h> 19#include <asm/unistd.h> 20#include <asm/page.h> 21 22__PT_R0 = __PT_GPRS 23__PT_R1 = __PT_GPRS + 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 stpt __LC_EXIT_TIMER 493 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER 494 lmg %r11,%r15,__PT_R11(%r11) 495 lpswe __LC_RETURN_PSW 496io_done: 497 498# 499# There is work todo, find out in which context we have been interrupted: 500# 1) if we return to user space we can do all _TIF_WORK_INT work 501# 2) if we return to kernel code and kvm is enabled check if we need to 502# modify the psw to leave SIE 503# 3) if we return to kernel code and preemptive scheduling is enabled check 504# the preemption counter and if it is zero call preempt_schedule_irq 505# Before any work can be done, a switch to the kernel stack is required. 506# 507io_work: 508 tm __PT_PSW+1(%r11),0x01 # returning to user ? 509 jo io_work_user # yes -> do resched & signal 510#ifdef CONFIG_PREEMPT 511 # check for preemptive scheduling 512 icm %r0,15,__TI_precount(%r12) 513 jnz io_restore # preemption is disabled 514 tm __TI_flags+7(%r12),_TIF_NEED_RESCHED 515 jno io_restore 516 # switch to kernel stack 517 lg %r1,__PT_R15(%r11) 518 aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 519 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 520 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) 521 la %r11,STACK_FRAME_OVERHEAD(%r1) 522 lgr %r15,%r1 523 # TRACE_IRQS_ON already done at io_return, call 524 # TRACE_IRQS_OFF to keep things symmetrical 525 TRACE_IRQS_OFF 526 brasl %r14,preempt_schedule_irq 527 j io_return 528#else 529 j io_restore 530#endif 531 532# 533# Need to do work before returning to userspace, switch to kernel stack 534# 535io_work_user: 536 lg %r1,__LC_KERNEL_STACK 537 aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 538 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 539 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) 540 la %r11,STACK_FRAME_OVERHEAD(%r1) 541 lgr %r15,%r1 542 543# 544# One of the work bits is on. Find out which one. 545# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED 546# and _TIF_MCCK_PENDING 547# 548io_work_tif: 549 tm __TI_flags+7(%r12),_TIF_MCCK_PENDING 550 jo io_mcck_pending 551 tm __TI_flags+7(%r12),_TIF_NEED_RESCHED 552 jo io_reschedule 553 tm __TI_flags+7(%r12),_TIF_SIGPENDING 554 jo io_sigpending 555 tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME 556 jo io_notify_resume 557 j io_return # beware of critical section cleanup 558 559# 560# _TIF_MCCK_PENDING is set, call handler 561# 562io_mcck_pending: 563 # TRACE_IRQS_ON already done at io_return 564 brasl %r14,s390_handle_mcck # TIF bit will be cleared by handler 565 TRACE_IRQS_OFF 566 j io_return 567 568# 569# _TIF_NEED_RESCHED is set, call schedule 570# 571io_reschedule: 572 # TRACE_IRQS_ON already done at io_return 573 ssm __LC_SVC_NEW_PSW # reenable interrupts 574 brasl %r14,schedule # call scheduler 575 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 576 TRACE_IRQS_OFF 577 j io_return 578 579# 580# _TIF_SIGPENDING or is set, call do_signal 581# 582io_sigpending: 583 # TRACE_IRQS_ON already done at io_return 584 ssm __LC_SVC_NEW_PSW # reenable interrupts 585 lgr %r2,%r11 # pass pointer to pt_regs 586 brasl %r14,do_signal 587 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 588 TRACE_IRQS_OFF 589 j io_return 590 591# 592# _TIF_NOTIFY_RESUME or is set, call do_notify_resume 593# 594io_notify_resume: 595 # TRACE_IRQS_ON already done at io_return 596 ssm __LC_SVC_NEW_PSW # reenable interrupts 597 lgr %r2,%r11 # pass pointer to pt_regs 598 brasl %r14,do_notify_resume 599 ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts 600 TRACE_IRQS_OFF 601 j io_return 602 603/* 604 * External interrupt handler routine 605 */ 606ENTRY(ext_int_handler) 607 stck __LC_INT_CLOCK 608 stpt __LC_ASYNC_ENTER_TIMER 609 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC 610 lg %r10,__LC_LAST_BREAK 611 lg %r12,__LC_THREAD_INFO 612 larl %r13,system_call 613 lmg %r8,%r9,__LC_EXT_OLD_PSW 614 HANDLE_SIE_INTERCEPT %r14 615 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT 616 tmhh %r8,0x0001 # interrupting from user ? 617 jz ext_skip 618 UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER 619 LAST_BREAK %r14 620ext_skip: 621 stmg %r0,%r7,__PT_R0(%r11) 622 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC 623 stmg %r8,%r9,__PT_PSW(%r11) 624 TRACE_IRQS_OFF 625 lghi %r1,4096 626 lgr %r2,%r11 # pass pointer to pt_regs 627 llgf %r3,__LC_EXT_CPU_ADDR # get cpu address + interruption code 628 llgf %r4,__LC_EXT_PARAMS # get external parameter 629 lg %r5,__LC_EXT_PARAMS2-4096(%r1) # get 64 bit external parameter 630 brasl %r14,do_extint 631 j io_return 632 633/* 634 * Load idle PSW. The second "half" of this function is in cleanup_idle. 635 */ 636ENTRY(psw_idle) 637 stg %r4,__SF_EMPTY(%r15) 638 larl %r1,psw_idle_lpsw+4 639 stg %r1,__SF_EMPTY+8(%r15) 640 larl %r1,.Lvtimer_max 641 stck __IDLE_ENTER(%r2) 642 ltr %r5,%r5 643 stpt __VQ_IDLE_ENTER(%r3) 644 jz psw_idle_lpsw 645 spt 0(%r1) 646psw_idle_lpsw: 647 lpswe __SF_EMPTY(%r15) 648 br %r14 649psw_idle_end: 650 651__critical_end: 652 653/* 654 * Machine check handler routines 655 */ 656ENTRY(mcck_int_handler) 657 stck __LC_MCCK_CLOCK 658 la %r1,4095 # revalidate r1 659 spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # revalidate cpu timer 660 lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs 661 lg %r10,__LC_LAST_BREAK 662 lg %r12,__LC_THREAD_INFO 663 larl %r13,system_call 664 lmg %r8,%r9,__LC_MCK_OLD_PSW 665 HANDLE_SIE_INTERCEPT %r14 666 tm __LC_MCCK_CODE,0x80 # system damage? 667 jo mcck_panic # yes -> rest of mcck code invalid 668 lghi %r14,__LC_CPU_TIMER_SAVE_AREA 669 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 670 tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid? 671 jo 3f 672 la %r14,__LC_SYNC_ENTER_TIMER 673 clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER 674 jl 0f 675 la %r14,__LC_ASYNC_ENTER_TIMER 6760: clc 0(8,%r14),__LC_EXIT_TIMER 677 jl 1f 678 la %r14,__LC_EXIT_TIMER 6791: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER 680 jl 2f 681 la %r14,__LC_LAST_UPDATE_TIMER 6822: spt 0(%r14) 683 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 6843: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid? 685 jno mcck_panic # no -> skip cleanup critical 686 SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_PANIC_STACK,PAGE_SHIFT 687 tm %r8,0x0001 # interrupting from user ? 688 jz mcck_skip 689 UPDATE_VTIME %r14,__LC_MCCK_ENTER_TIMER 690 LAST_BREAK %r14 691mcck_skip: 692 lghi %r14,__LC_GPREGS_SAVE_AREA 693 mvc __PT_R0(128,%r11),0(%r14) 694 stmg %r8,%r9,__PT_PSW(%r11) 695 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 696 lgr %r2,%r11 # pass pointer to pt_regs 697 brasl %r14,s390_do_machine_check 698 tm __PT_PSW+1(%r11),0x01 # returning to user ? 699 jno mcck_return 700 lg %r1,__LC_KERNEL_STACK # switch to kernel stack 701 aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 702 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 703 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) 704 la %r11,STACK_FRAME_OVERHEAD(%r1) 705 lgr %r15,%r1 706 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off 707 tm __TI_flags+7(%r12),_TIF_MCCK_PENDING 708 jno mcck_return 709 TRACE_IRQS_OFF 710 brasl %r14,s390_handle_mcck 711 TRACE_IRQS_ON 712mcck_return: 713 lg %r14,__LC_VDSO_PER_CPU 714 lmg %r0,%r10,__PT_R0(%r11) 715 mvc __LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW 716 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ? 717 jno 0f 718 stpt __LC_EXIT_TIMER 719 mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER 7200: lmg %r11,%r15,__PT_R11(%r11) 721 lpswe __LC_RETURN_MCCK_PSW 722 723mcck_panic: 724 lg %r14,__LC_PANIC_STACK 725 slgr %r14,%r15 726 srag %r14,%r14,PAGE_SHIFT 727 jz 0f 728 lg %r15,__LC_PANIC_STACK 7290: aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 730 j mcck_skip 731 732# 733# PSW restart interrupt handler 734# 735ENTRY(restart_int_handler) 736 stg %r15,__LC_SAVE_AREA_RESTART 737 lg %r15,__LC_RESTART_STACK 738 aghi %r15,-__PT_SIZE # create pt_regs on stack 739 xc 0(__PT_SIZE,%r15),0(%r15) 740 stmg %r0,%r14,__PT_R0(%r15) 741 mvc __PT_R15(8,%r15),__LC_SAVE_AREA_RESTART 742 mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw 743 aghi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack 744 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) 745 lmg %r1,%r3,__LC_RESTART_FN # load fn, parm & source cpu 746 ltgr %r3,%r3 # test source cpu address 747 jm 1f # negative -> skip source stop 7480: sigp %r4,%r3,1 # sigp sense to source cpu 749 brc 10,0b # wait for status stored 7501: basr %r14,%r1 # call function 751 stap __SF_EMPTY(%r15) # store cpu address 752 llgh %r3,__SF_EMPTY(%r15) 7532: sigp %r4,%r3,5 # sigp stop to current cpu 754 brc 2,2b 7553: j 3b 756 757 .section .kprobes.text, "ax" 758 759#ifdef CONFIG_CHECK_STACK 760/* 761 * The synchronous or the asynchronous stack overflowed. We are dead. 762 * No need to properly save the registers, we are going to panic anyway. 763 * Setup a pt_regs so that show_trace can provide a good call trace. 764 */ 765stack_overflow: 766 lg %r11,__LC_PANIC_STACK # change to panic stack 767 aghi %r11,-__PT_SIZE # create pt_regs 768 stmg %r0,%r7,__PT_R0(%r11) 769 stmg %r8,%r9,__PT_PSW(%r11) 770 mvc __PT_R8(64,%r11),0(%r14) 771 stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2 772 lgr %r15,%r11 773 aghi %r15,-STACK_FRAME_OVERHEAD 774 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 775 lgr %r2,%r11 # pass pointer to pt_regs 776 jg kernel_stack_overflow 777#endif 778 779 .align 8 780cleanup_table: 781 .quad system_call 782 .quad sysc_do_svc 783 .quad sysc_tif 784 .quad sysc_restore 785 .quad sysc_done 786 .quad io_tif 787 .quad io_restore 788 .quad io_done 789 .quad psw_idle 790 .quad psw_idle_end 791 792cleanup_critical: 793 clg %r9,BASED(cleanup_table) # system_call 794 jl 0f 795 clg %r9,BASED(cleanup_table+8) # sysc_do_svc 796 jl cleanup_system_call 797 clg %r9,BASED(cleanup_table+16) # sysc_tif 798 jl 0f 799 clg %r9,BASED(cleanup_table+24) # sysc_restore 800 jl cleanup_sysc_tif 801 clg %r9,BASED(cleanup_table+32) # sysc_done 802 jl cleanup_sysc_restore 803 clg %r9,BASED(cleanup_table+40) # io_tif 804 jl 0f 805 clg %r9,BASED(cleanup_table+48) # io_restore 806 jl cleanup_io_tif 807 clg %r9,BASED(cleanup_table+56) # io_done 808 jl cleanup_io_restore 809 clg %r9,BASED(cleanup_table+64) # psw_idle 810 jl 0f 811 clg %r9,BASED(cleanup_table+72) # psw_idle_end 812 jl cleanup_idle 8130: br %r14 814 815 816cleanup_system_call: 817 # check if stpt has been executed 818 clg %r9,BASED(cleanup_system_call_insn) 819 jh 0f 820 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER 821 cghi %r11,__LC_SAVE_AREA_ASYNC 822 je 0f 823 mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER 8240: # check if stmg has been executed 825 clg %r9,BASED(cleanup_system_call_insn+8) 826 jh 0f 827 mvc __LC_SAVE_AREA_SYNC(64),0(%r11) 8280: # check if base register setup + TIF bit load has been done 829 clg %r9,BASED(cleanup_system_call_insn+16) 830 jhe 0f 831 # set up saved registers r10 and r12 832 stg %r10,16(%r11) # r10 last break 833 stg %r12,32(%r11) # r12 thread-info pointer 8340: # check if the user time update has been done 835 clg %r9,BASED(cleanup_system_call_insn+24) 836 jh 0f 837 lg %r15,__LC_EXIT_TIMER 838 slg %r15,__LC_SYNC_ENTER_TIMER 839 alg %r15,__LC_USER_TIMER 840 stg %r15,__LC_USER_TIMER 8410: # check if the system time update has been done 842 clg %r9,BASED(cleanup_system_call_insn+32) 843 jh 0f 844 lg %r15,__LC_LAST_UPDATE_TIMER 845 slg %r15,__LC_EXIT_TIMER 846 alg %r15,__LC_SYSTEM_TIMER 847 stg %r15,__LC_SYSTEM_TIMER 8480: # update accounting time stamp 849 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 850 # do LAST_BREAK 851 lg %r9,16(%r11) 852 srag %r9,%r9,23 853 jz 0f 854 mvc __TI_last_break(8,%r12),16(%r11) 8550: # set up saved register r11 856 lg %r15,__LC_KERNEL_STACK 857 aghi %r15,-__PT_SIZE 858 stg %r15,24(%r11) # r11 pt_regs pointer 859 # fill pt_regs 860 mvc __PT_R8(64,%r15),__LC_SAVE_AREA_SYNC 861 stmg %r0,%r7,__PT_R0(%r15) 862 mvc __PT_PSW(16,%r15),__LC_SVC_OLD_PSW 863 mvc __PT_INT_CODE(4,%r15),__LC_SVC_ILC 864 # setup saved register r15 865 aghi %r15,-STACK_FRAME_OVERHEAD 866 stg %r15,56(%r11) # r15 stack pointer 867 # set new psw address and exit 868 larl %r9,sysc_do_svc 869 br %r14 870cleanup_system_call_insn: 871 .quad system_call 872 .quad sysc_stmg 873 .quad sysc_per 874 .quad sysc_vtime+18 875 .quad sysc_vtime+42 876 877cleanup_sysc_tif: 878 larl %r9,sysc_tif 879 br %r14 880 881cleanup_sysc_restore: 882 clg %r9,BASED(cleanup_sysc_restore_insn) 883 je 0f 884 lg %r9,24(%r11) # get saved pointer to pt_regs 885 mvc __LC_RETURN_PSW(16),__PT_PSW(%r9) 886 mvc 0(64,%r11),__PT_R8(%r9) 887 lmg %r0,%r7,__PT_R0(%r9) 8880: lmg %r8,%r9,__LC_RETURN_PSW 889 br %r14 890cleanup_sysc_restore_insn: 891 .quad sysc_done - 4 892 893cleanup_io_tif: 894 larl %r9,io_tif 895 br %r14 896 897cleanup_io_restore: 898 clg %r9,BASED(cleanup_io_restore_insn) 899 je 0f 900 lg %r9,24(%r11) # get saved r11 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_io_restore_insn: 907 .quad io_done - 4 908 909cleanup_idle: 910 # copy interrupt clock & cpu timer 911 mvc __IDLE_EXIT(8,%r2),__LC_INT_CLOCK 912 mvc __VQ_IDLE_EXIT(8,%r3),__LC_ASYNC_ENTER_TIMER 913 cghi %r11,__LC_SAVE_AREA_ASYNC 914 je 0f 915 mvc __IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK 916 mvc __VQ_IDLE_EXIT(8,%r3),__LC_MCCK_ENTER_TIMER 9170: # check if stck & stpt have been executed 918 clg %r9,BASED(cleanup_idle_insn) 919 jhe 1f 920 mvc __IDLE_ENTER(8,%r2),__IDLE_EXIT(%r2) 921 mvc __VQ_IDLE_ENTER(8,%r3),__VQ_IDLE_EXIT(%r3) 922 j 2f 9231: # check if the cpu timer has been reprogrammed 924 ltr %r5,%r5 925 jz 2f 926 spt __VQ_IDLE_ENTER(%r3) 9272: # account system time going idle 928 lg %r9,__LC_STEAL_TIMER 929 alg %r9,__IDLE_ENTER(%r2) 930 slg %r9,__LC_LAST_UPDATE_CLOCK 931 stg %r9,__LC_STEAL_TIMER 932 mvc __LC_LAST_UPDATE_CLOCK(8),__IDLE_EXIT(%r2) 933 lg %r9,__LC_SYSTEM_TIMER 934 alg %r9,__LC_LAST_UPDATE_TIMER 935 slg %r9,__VQ_IDLE_ENTER(%r3) 936 stg %r9,__LC_SYSTEM_TIMER 937 mvc __LC_LAST_UPDATE_TIMER(8),__VQ_IDLE_EXIT(%r3) 938 # prepare return psw 939 nihh %r8,0xfffd # clear wait state bit 940 lg %r9,48(%r11) # return from psw_idle 941 br %r14 942cleanup_idle_insn: 943 .quad psw_idle_lpsw 944 945/* 946 * Integer constants 947 */ 948 .align 8 949.Lcritical_start: 950 .quad __critical_start 951.Lcritical_length: 952 .quad __critical_end - __critical_start 953.Lvtimer_max: 954 .quad 0x7fffffffffffffff 955 956 957#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE) 958/* 959 * sie64a calling convention: 960 * %r2 pointer to sie control block 961 * %r3 guest register save area 962 */ 963ENTRY(sie64a) 964 stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers 965 stg %r2,__SF_EMPTY(%r15) # save control block pointer 966 stg %r3,__SF_EMPTY+8(%r15) # save guest register save area 967 xc __SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # host id == 0 968 lmg %r0,%r13,0(%r3) # load guest gprs 0-13 969 lg %r14,__LC_THREAD_INFO # pointer thread_info struct 970 oi __TI_flags+6(%r14),_TIF_SIE>>8 971sie_loop: 972 lg %r14,__LC_THREAD_INFO # pointer thread_info struct 973 tm __TI_flags+7(%r14),_TIF_EXIT_SIE 974 jnz sie_exit 975 lg %r14,__LC_GMAP # get gmap pointer 976 ltgr %r14,%r14 977 jz sie_gmap 978 lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce 979sie_gmap: 980 lg %r14,__SF_EMPTY(%r15) # get control block pointer 981 SPP __SF_EMPTY(%r15) # set guest id 982 sie 0(%r14) 983sie_done: 984 SPP __SF_EMPTY+16(%r15) # set host id 985 lg %r14,__LC_THREAD_INFO # pointer thread_info struct 986sie_exit: 987 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce 988 ni __TI_flags+6(%r14),255-(_TIF_SIE>>8) 989 lg %r14,__SF_EMPTY+8(%r15) # load guest register save area 990 stmg %r0,%r13,0(%r14) # save guest gprs 0-13 991 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers 992 lghi %r2,0 993 br %r14 994sie_fault: 995 lctlg %c1,%c1,__LC_USER_ASCE # load primary asce 996 lg %r14,__LC_THREAD_INFO # pointer thread_info struct 997 ni __TI_flags+6(%r14),255-(_TIF_SIE>>8) 998 lg %r14,__SF_EMPTY+8(%r15) # load guest register save area 999 stmg %r0,%r13,0(%r14) # save guest gprs 0-13 1000 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers 1001 lghi %r2,-EFAULT 1002 br %r14 1003 1004 .align 8 1005.Lsie_loop: 1006 .quad sie_loop 1007.Lsie_length: 1008 .quad sie_done - sie_loop 1009.Lhost_id: 1010 .quad 0 1011 1012 .section __ex_table,"a" 1013 .quad sie_loop,sie_fault 1014 .previous 1015#endif 1016 1017 .section .rodata, "a" 1018#define SYSCALL(esa,esame,emu) .long esame 1019 .globl sys_call_table 1020sys_call_table: 1021#include "syscalls.S" 1022#undef SYSCALL 1023 1024#ifdef CONFIG_COMPAT 1025 1026#define SYSCALL(esa,esame,emu) .long emu 1027sys_call_table_emu: 1028#include "syscalls.S" 1029#undef SYSCALL 1030#endif 1031