1/* 2 * arch/s390/kernel/entry.S 3 * S390 low-level entry points. 4 * 5 * S390 version 6 * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation 7 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 8 * Hartmut Penner (hp@de.ibm.com), 9 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), 10 * Heiko Carstens <heiko.carstens@de.ibm.com> 11 */ 12 13#include <linux/sys.h> 14#include <linux/linkage.h> 15#include <linux/config.h> 16#include <asm/cache.h> 17#include <asm/lowcore.h> 18#include <asm/errno.h> 19#include <asm/ptrace.h> 20#include <asm/thread_info.h> 21#include <asm/offsets.h> 22#include <asm/unistd.h> 23#include <asm/page.h> 24 25/* 26 * Stack layout for the system_call stack entry. 27 * The first few entries are identical to the user_regs_struct. 28 */ 29SP_PTREGS = STACK_FRAME_OVERHEAD 30SP_ARGS = STACK_FRAME_OVERHEAD + __PT_ARGS 31SP_PSW = STACK_FRAME_OVERHEAD + __PT_PSW 32SP_R0 = STACK_FRAME_OVERHEAD + __PT_GPRS 33SP_R1 = STACK_FRAME_OVERHEAD + __PT_GPRS + 4 34SP_R2 = STACK_FRAME_OVERHEAD + __PT_GPRS + 8 35SP_R3 = STACK_FRAME_OVERHEAD + __PT_GPRS + 12 36SP_R4 = STACK_FRAME_OVERHEAD + __PT_GPRS + 16 37SP_R5 = STACK_FRAME_OVERHEAD + __PT_GPRS + 20 38SP_R6 = STACK_FRAME_OVERHEAD + __PT_GPRS + 24 39SP_R7 = STACK_FRAME_OVERHEAD + __PT_GPRS + 28 40SP_R8 = STACK_FRAME_OVERHEAD + __PT_GPRS + 32 41SP_R9 = STACK_FRAME_OVERHEAD + __PT_GPRS + 36 42SP_R10 = STACK_FRAME_OVERHEAD + __PT_GPRS + 40 43SP_R11 = STACK_FRAME_OVERHEAD + __PT_GPRS + 44 44SP_R12 = STACK_FRAME_OVERHEAD + __PT_GPRS + 48 45SP_R13 = STACK_FRAME_OVERHEAD + __PT_GPRS + 52 46SP_R14 = STACK_FRAME_OVERHEAD + __PT_GPRS + 56 47SP_R15 = STACK_FRAME_OVERHEAD + __PT_GPRS + 60 48SP_ORIG_R2 = STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2 49SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC 50SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP 51SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE 52 53_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING | \ 54 _TIF_RESTART_SVC | _TIF_SINGLE_STEP ) 55_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING) 56 57STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER 58STACK_SIZE = 1 << STACK_SHIFT 59 60#define BASED(name) name-system_call(%r13) 61 62/* 63 * Register usage in interrupt handlers: 64 * R9 - pointer to current task structure 65 * R13 - pointer to literal pool 66 * R14 - return register for function calls 67 * R15 - kernel stack pointer 68 */ 69 70 .macro STORE_TIMER lc_offset 71#ifdef CONFIG_VIRT_CPU_ACCOUNTING 72 stpt \lc_offset 73#endif 74 .endm 75 76#ifdef CONFIG_VIRT_CPU_ACCOUNTING 77 .macro UPDATE_VTIME lc_from,lc_to,lc_sum 78 lm %r10,%r11,\lc_from 79 sl %r10,\lc_to 80 sl %r11,\lc_to+4 81 bc 3,BASED(0f) 82 sl %r10,BASED(.Lc_1) 830: al %r10,\lc_sum 84 al %r11,\lc_sum+4 85 bc 12,BASED(1f) 86 al %r10,BASED(.Lc_1) 871: stm %r10,%r11,\lc_sum 88 .endm 89#endif 90 91 .macro SAVE_ALL_BASE savearea 92 stm %r12,%r15,\savearea 93 l %r13,__LC_SVC_NEW_PSW+4 # load &system_call to %r13 94 .endm 95 96 .macro SAVE_ALL psworg,savearea,sync 97 la %r12,\psworg 98 .if \sync 99 tm \psworg+1,0x01 # test problem state bit 100 bz BASED(2f) # skip stack setup save 101 l %r15,__LC_KERNEL_STACK # problem state -> load ksp 102 .else 103 tm \psworg+1,0x01 # test problem state bit 104 bnz BASED(1f) # from user -> load async stack 105 clc \psworg+4(4),BASED(.Lcritical_end) 106 bhe BASED(0f) 107 clc \psworg+4(4),BASED(.Lcritical_start) 108 bl BASED(0f) 109 l %r14,BASED(.Lcleanup_critical) 110 basr %r14,%r14 111 tm 0(%r12),0x01 # retest problem state after cleanup 112 bnz BASED(1f) 1130: l %r14,__LC_ASYNC_STACK # are we already on the async stack ? 114 slr %r14,%r15 115 sra %r14,STACK_SHIFT 116 be BASED(2f) 1171: l %r15,__LC_ASYNC_STACK 118 .endif 119#ifdef CONFIG_CHECK_STACK 120 b BASED(3f) 1212: tml %r15,STACK_SIZE - CONFIG_STACK_GUARD 122 bz BASED(stack_overflow) 1233: 124#endif 1252: 126 .endm 127 128 .macro CREATE_STACK_FRAME psworg,savearea 129 s %r15,BASED(.Lc_spsize) # make room for registers & psw 130 mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack 131 la %r12,\psworg 132 st %r2,SP_ORIG_R2(%r15) # store original content of gpr 2 133 icm %r12,12,__LC_SVC_ILC 134 stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack 135 st %r12,SP_ILC(%r15) 136 mvc SP_R12(16,%r15),\savearea # move %r12-%r15 to stack 137 la %r12,0 138 st %r12,__SF_BACKCHAIN(%r15) # clear back chain 139 .endm 140 141 .macro RESTORE_ALL sync 142 mvc __LC_RETURN_PSW(8),SP_PSW(%r15) # move user PSW to lowcore 143 .if !\sync 144 ni __LC_RETURN_PSW+1,0xfd # clear wait state bit 145 .endif 146 lm %r0,%r15,SP_R0(%r15) # load gprs 0-15 of user 147 STORE_TIMER __LC_EXIT_TIMER 148 lpsw __LC_RETURN_PSW # back to caller 149 .endm 150 151/* 152 * Scheduler resume function, called by switch_to 153 * gpr2 = (task_struct *) prev 154 * gpr3 = (task_struct *) next 155 * Returns: 156 * gpr2 = prev 157 */ 158 .globl __switch_to 159__switch_to: 160 basr %r1,0 161__switch_to_base: 162 tm __THREAD_per(%r3),0xe8 # new process is using per ? 163 bz __switch_to_noper-__switch_to_base(%r1) # if not we're fine 164 stctl %c9,%c11,__SF_EMPTY(%r15) # We are using per stuff 165 clc __THREAD_per(12,%r3),__SF_EMPTY(%r15) 166 be __switch_to_noper-__switch_to_base(%r1) # we got away w/o bashing TLB's 167 lctl %c9,%c11,__THREAD_per(%r3) # Nope we didn't 168__switch_to_noper: 169 l %r4,__THREAD_info(%r2) # get thread_info of prev 170 tm __TI_flags+3(%r4),_TIF_MCCK_PENDING # machine check pending? 171 bz __switch_to_no_mcck-__switch_to_base(%r1) 172 ni __TI_flags+3(%r4),255-_TIF_MCCK_PENDING # clear flag in prev 173 l %r4,__THREAD_info(%r3) # get thread_info of next 174 oi __TI_flags+3(%r4),_TIF_MCCK_PENDING # set it in next 175__switch_to_no_mcck: 176 stm %r6,%r15,__SF_GPRS(%r15)# store __switch_to registers of prev task 177 st %r15,__THREAD_ksp(%r2) # store kernel stack to prev->tss.ksp 178 l %r15,__THREAD_ksp(%r3) # load kernel stack from next->tss.ksp 179 lm %r6,%r15,__SF_GPRS(%r15)# load __switch_to registers of next task 180 st %r3,__LC_CURRENT # __LC_CURRENT = current task struct 181 lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 182 l %r3,__THREAD_info(%r3) # load thread_info from task struct 183 st %r3,__LC_THREAD_INFO 184 ahi %r3,STACK_SIZE 185 st %r3,__LC_KERNEL_STACK # __LC_KERNEL_STACK = new kernel stack 186 br %r14 187 188__critical_start: 189/* 190 * SVC interrupt handler routine. System calls are synchronous events and 191 * are executed with interrupts enabled. 192 */ 193 194 .globl system_call 195system_call: 196 STORE_TIMER __LC_SYNC_ENTER_TIMER 197sysc_saveall: 198 SAVE_ALL_BASE __LC_SAVE_AREA 199 SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1 200 CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA 201 lh %r7,0x8a # get svc number from lowcore 202#ifdef CONFIG_VIRT_CPU_ACCOUNTING 203sysc_vtime: 204 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 205 bz BASED(sysc_do_svc) 206 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER 207sysc_stime: 208 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 209sysc_update: 210 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 211#endif 212sysc_do_svc: 213 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 214 sla %r7,2 # *4 and test for svc 0 215 bnz BASED(sysc_nr_ok) # svc number > 0 216 # svc 0: system call number in %r1 217 cl %r1,BASED(.Lnr_syscalls) 218 bnl BASED(sysc_nr_ok) 219 lr %r7,%r1 # copy svc number to %r7 220 sla %r7,2 # *4 221sysc_nr_ok: 222 mvc SP_ARGS(4,%r15),SP_R7(%r15) 223sysc_do_restart: 224 tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT) 225 l %r8,sys_call_table-system_call(%r7,%r13) # get system call addr. 226 bnz BASED(sysc_tracesys) 227 basr %r14,%r8 # call sys_xxxx 228 st %r2,SP_R2(%r15) # store return value (change R2 on stack) 229 # ATTENTION: check sys_execve_glue before 230 # changing anything here !! 231 232sysc_return: 233 tm SP_PSW+1(%r15),0x01 # returning to user ? 234 bno BASED(sysc_leave) 235 tm __TI_flags+3(%r9),_TIF_WORK_SVC 236 bnz BASED(sysc_work) # there is work to do (signals etc.) 237sysc_leave: 238 RESTORE_ALL 1 239 240# 241# recheck if there is more work to do 242# 243sysc_work_loop: 244 tm __TI_flags+3(%r9),_TIF_WORK_SVC 245 bz BASED(sysc_leave) # there is no work to do 246# 247# One of the work bits is on. Find out which one. 248# 249sysc_work: 250 tm __TI_flags+3(%r9),_TIF_MCCK_PENDING 251 bo BASED(sysc_mcck_pending) 252 tm __TI_flags+3(%r9),_TIF_NEED_RESCHED 253 bo BASED(sysc_reschedule) 254 tm __TI_flags+3(%r9),_TIF_SIGPENDING 255 bo BASED(sysc_sigpending) 256 tm __TI_flags+3(%r9),_TIF_RESTART_SVC 257 bo BASED(sysc_restart) 258 tm __TI_flags+3(%r9),_TIF_SINGLE_STEP 259 bo BASED(sysc_singlestep) 260 b BASED(sysc_leave) 261 262# 263# _TIF_NEED_RESCHED is set, call schedule 264# 265sysc_reschedule: 266 l %r1,BASED(.Lschedule) 267 la %r14,BASED(sysc_work_loop) 268 br %r1 # call scheduler 269 270# 271# _TIF_MCCK_PENDING is set, call handler 272# 273sysc_mcck_pending: 274 l %r1,BASED(.Ls390_handle_mcck) 275 la %r14,BASED(sysc_work_loop) 276 br %r1 # TIF bit will be cleared by handler 277 278# 279# _TIF_SIGPENDING is set, call do_signal 280# 281sysc_sigpending: 282 ni __TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP 283 la %r2,SP_PTREGS(%r15) # load pt_regs 284 sr %r3,%r3 # clear *oldset 285 l %r1,BASED(.Ldo_signal) 286 basr %r14,%r1 # call do_signal 287 tm __TI_flags+3(%r9),_TIF_RESTART_SVC 288 bo BASED(sysc_restart) 289 tm __TI_flags+3(%r9),_TIF_SINGLE_STEP 290 bo BASED(sysc_singlestep) 291 b BASED(sysc_leave) # out of here, do NOT recheck 292 293# 294# _TIF_RESTART_SVC is set, set up registers and restart svc 295# 296sysc_restart: 297 ni __TI_flags+3(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC 298 l %r7,SP_R2(%r15) # load new svc number 299 sla %r7,2 300 mvc SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument 301 lm %r2,%r6,SP_R2(%r15) # load svc arguments 302 b BASED(sysc_do_restart) # restart svc 303 304# 305# _TIF_SINGLE_STEP is set, call do_single_step 306# 307sysc_singlestep: 308 ni __TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP 309 mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check 310 la %r2,SP_PTREGS(%r15) # address of register-save area 311 l %r1,BASED(.Lhandle_per) # load adr. of per handler 312 la %r14,BASED(sysc_return) # load adr. of system return 313 br %r1 # branch to do_single_step 314 315__critical_end: 316 317# 318# call trace before and after sys_call 319# 320sysc_tracesys: 321 l %r1,BASED(.Ltrace) 322 la %r2,SP_PTREGS(%r15) # load pt_regs 323 la %r3,0 324 srl %r7,2 325 st %r7,SP_R2(%r15) 326 basr %r14,%r1 327 clc SP_R2(4,%r15),BASED(.Lnr_syscalls) 328 bnl BASED(sysc_tracenogo) 329 l %r7,SP_R2(%r15) # strace might have changed the 330 sll %r7,2 # system call 331 l %r8,sys_call_table-system_call(%r7,%r13) 332sysc_tracego: 333 lm %r3,%r6,SP_R3(%r15) 334 l %r2,SP_ORIG_R2(%r15) 335 basr %r14,%r8 # call sys_xxx 336 st %r2,SP_R2(%r15) # store return value 337sysc_tracenogo: 338 tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT) 339 bz BASED(sysc_return) 340 l %r1,BASED(.Ltrace) 341 la %r2,SP_PTREGS(%r15) # load pt_regs 342 la %r3,1 343 la %r14,BASED(sysc_return) 344 br %r1 345 346# 347# a new process exits the kernel with ret_from_fork 348# 349 .globl ret_from_fork 350ret_from_fork: 351 l %r13,__LC_SVC_NEW_PSW+4 352 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 353 tm SP_PSW+1(%r15),0x01 # forking a kernel thread ? 354 bo BASED(0f) 355 st %r15,SP_R15(%r15) # store stack pointer for new kthread 3560: l %r1,BASED(.Lschedtail) 357 basr %r14,%r1 358 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 359 b BASED(sysc_return) 360 361# 362# clone, fork, vfork, exec and sigreturn need glue, 363# because they all expect pt_regs as parameter, 364# but are called with different parameter. 365# return-address is set up above 366# 367sys_clone_glue: 368 la %r2,SP_PTREGS(%r15) # load pt_regs 369 l %r1,BASED(.Lclone) 370 br %r1 # branch to sys_clone 371 372sys_fork_glue: 373 la %r2,SP_PTREGS(%r15) # load pt_regs 374 l %r1,BASED(.Lfork) 375 br %r1 # branch to sys_fork 376 377sys_vfork_glue: 378 la %r2,SP_PTREGS(%r15) # load pt_regs 379 l %r1,BASED(.Lvfork) 380 br %r1 # branch to sys_vfork 381 382sys_execve_glue: 383 la %r2,SP_PTREGS(%r15) # load pt_regs 384 l %r1,BASED(.Lexecve) 385 lr %r12,%r14 # save return address 386 basr %r14,%r1 # call sys_execve 387 ltr %r2,%r2 # check if execve failed 388 bnz 0(%r12) # it did fail -> store result in gpr2 389 b 4(%r12) # SKIP ST 2,SP_R2(15) after BASR 14,8 390 # in system_call/sysc_tracesys 391 392sys_sigreturn_glue: 393 la %r2,SP_PTREGS(%r15) # load pt_regs as parameter 394 l %r1,BASED(.Lsigreturn) 395 br %r1 # branch to sys_sigreturn 396 397sys_rt_sigreturn_glue: 398 la %r2,SP_PTREGS(%r15) # load pt_regs as parameter 399 l %r1,BASED(.Lrt_sigreturn) 400 br %r1 # branch to sys_sigreturn 401 402# 403# sigsuspend and rt_sigsuspend need pt_regs as an additional 404# parameter and they have to skip the store of %r2 into the 405# user register %r2 because the return value was set in 406# sigsuspend and rt_sigsuspend already and must not be overwritten! 407# 408 409sys_sigsuspend_glue: 410 lr %r5,%r4 # move mask back 411 lr %r4,%r3 # move history1 parameter 412 lr %r3,%r2 # move history0 parameter 413 la %r2,SP_PTREGS(%r15) # load pt_regs as first parameter 414 l %r1,BASED(.Lsigsuspend) 415 la %r14,4(%r14) # skip store of return value 416 br %r1 # branch to sys_sigsuspend 417 418sys_rt_sigsuspend_glue: 419 lr %r4,%r3 # move sigsetsize parameter 420 lr %r3,%r2 # move unewset parameter 421 la %r2,SP_PTREGS(%r15) # load pt_regs as first parameter 422 l %r1,BASED(.Lrt_sigsuspend) 423 la %r14,4(%r14) # skip store of return value 424 br %r1 # branch to sys_rt_sigsuspend 425 426sys_sigaltstack_glue: 427 la %r4,SP_PTREGS(%r15) # load pt_regs as parameter 428 l %r1,BASED(.Lsigaltstack) 429 br %r1 # branch to sys_sigreturn 430 431 432/* 433 * Program check handler routine 434 */ 435 436 .globl pgm_check_handler 437pgm_check_handler: 438/* 439 * First we need to check for a special case: 440 * Single stepping an instruction that disables the PER event mask will 441 * cause a PER event AFTER the mask has been set. Example: SVC or LPSW. 442 * For a single stepped SVC the program check handler gets control after 443 * the SVC new PSW has been loaded. But we want to execute the SVC first and 444 * then handle the PER event. Therefore we update the SVC old PSW to point 445 * to the pgm_check_handler and branch to the SVC handler after we checked 446 * if we have to load the kernel stack register. 447 * For every other possible cause for PER event without the PER mask set 448 * we just ignore the PER event (FIXME: is there anything we have to do 449 * for LPSW?). 450 */ 451 STORE_TIMER __LC_SYNC_ENTER_TIMER 452 SAVE_ALL_BASE __LC_SAVE_AREA 453 tm __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception 454 bnz BASED(pgm_per) # got per exception -> special case 455 SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1 456 CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA 457#ifdef CONFIG_VIRT_CPU_ACCOUNTING 458 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 459 bz BASED(pgm_no_vtime) 460 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER 461 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 462 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 463pgm_no_vtime: 464#endif 465 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 466 l %r3,__LC_PGM_ILC # load program interruption code 467 la %r8,0x7f 468 nr %r8,%r3 469pgm_do_call: 470 l %r7,BASED(.Ljump_table) 471 sll %r8,2 472 l %r7,0(%r8,%r7) # load address of handler routine 473 la %r2,SP_PTREGS(%r15) # address of register-save area 474 la %r14,BASED(sysc_return) 475 br %r7 # branch to interrupt-handler 476 477# 478# handle per exception 479# 480pgm_per: 481 tm __LC_PGM_OLD_PSW,0x40 # test if per event recording is on 482 bnz BASED(pgm_per_std) # ok, normal per event from user space 483# ok its one of the special cases, now we need to find out which one 484 clc __LC_PGM_OLD_PSW(8),__LC_SVC_NEW_PSW 485 be BASED(pgm_svcper) 486# no interesting special case, ignore PER event 487 lm %r12,%r15,__LC_SAVE_AREA 488 lpsw 0x28 489 490# 491# Normal per exception 492# 493pgm_per_std: 494 SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1 495 CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA 496#ifdef CONFIG_VIRT_CPU_ACCOUNTING 497 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 498 bz BASED(pgm_no_vtime2) 499 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER 500 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 501 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 502pgm_no_vtime2: 503#endif 504 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 505 l %r1,__TI_task(%r9) 506 mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID 507 mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS 508 mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID 509 oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP 510 l %r3,__LC_PGM_ILC # load program interruption code 511 la %r8,0x7f 512 nr %r8,%r3 # clear per-event-bit and ilc 513 be BASED(sysc_return) # only per or per+check ? 514 b BASED(pgm_do_call) 515 516# 517# it was a single stepped SVC that is causing all the trouble 518# 519pgm_svcper: 520 SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1 521 CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA 522#ifdef CONFIG_VIRT_CPU_ACCOUNTING 523 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 524 bz BASED(pgm_no_vtime3) 525 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER 526 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 527 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 528pgm_no_vtime3: 529#endif 530 lh %r7,0x8a # get svc number from lowcore 531 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 532 l %r1,__TI_task(%r9) 533 mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID 534 mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS 535 mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID 536 oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP 537 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 538 b BASED(sysc_do_svc) 539 540/* 541 * IO interrupt handler routine 542 */ 543 544 .globl io_int_handler 545io_int_handler: 546 STORE_TIMER __LC_ASYNC_ENTER_TIMER 547 stck __LC_INT_CLOCK 548 SAVE_ALL_BASE __LC_SAVE_AREA+16 549 SAVE_ALL __LC_IO_OLD_PSW,__LC_SAVE_AREA+16,0 550 CREATE_STACK_FRAME __LC_IO_OLD_PSW,__LC_SAVE_AREA+16 551#ifdef CONFIG_VIRT_CPU_ACCOUNTING 552 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 553 bz BASED(io_no_vtime) 554 UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER 555 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 556 mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER 557io_no_vtime: 558#endif 559 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 560 l %r1,BASED(.Ldo_IRQ) # load address of do_IRQ 561 la %r2,SP_PTREGS(%r15) # address of register-save area 562 basr %r14,%r1 # branch to standard irq handler 563 564io_return: 565 tm SP_PSW+1(%r15),0x01 # returning to user ? 566#ifdef CONFIG_PREEMPT 567 bno BASED(io_preempt) # no -> check for preemptive scheduling 568#else 569 bno BASED(io_leave) # no-> skip resched & signal 570#endif 571 tm __TI_flags+3(%r9),_TIF_WORK_INT 572 bnz BASED(io_work) # there is work to do (signals etc.) 573io_leave: 574 RESTORE_ALL 0 575 576#ifdef CONFIG_PREEMPT 577io_preempt: 578 icm %r0,15,__TI_precount(%r9) 579 bnz BASED(io_leave) 580 l %r1,SP_R15(%r15) 581 s %r1,BASED(.Lc_spsize) 582 mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) 583 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain 584 lr %r15,%r1 585io_resume_loop: 586 tm __TI_flags+3(%r9),_TIF_NEED_RESCHED 587 bno BASED(io_leave) 588 mvc __TI_precount(4,%r9),BASED(.Lc_pactive) 589 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 590 l %r1,BASED(.Lschedule) 591 basr %r14,%r1 # call schedule 592 stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts 593 xc __TI_precount(4,%r9),__TI_precount(%r9) 594 b BASED(io_resume_loop) 595#endif 596 597# 598# switch to kernel stack, then check the TIF bits 599# 600io_work: 601 l %r1,__LC_KERNEL_STACK 602 s %r1,BASED(.Lc_spsize) 603 mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) 604 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain 605 lr %r15,%r1 606# 607# One of the work bits is on. Find out which one. 608# Checked are: _TIF_SIGPENDING, _TIF_NEED_RESCHED and _TIF_MCCK_PENDING 609# 610io_work_loop: 611 tm __TI_flags+3(%r9),_TIF_MCCK_PENDING 612 bo BASED(io_mcck_pending) 613 tm __TI_flags+3(%r9),_TIF_NEED_RESCHED 614 bo BASED(io_reschedule) 615 tm __TI_flags+3(%r9),_TIF_SIGPENDING 616 bo BASED(io_sigpending) 617 b BASED(io_leave) 618 619# 620# _TIF_MCCK_PENDING is set, call handler 621# 622io_mcck_pending: 623 l %r1,BASED(.Ls390_handle_mcck) 624 l %r14,BASED(io_work_loop) 625 br %r1 # TIF bit will be cleared by handler 626 627# 628# _TIF_NEED_RESCHED is set, call schedule 629# 630io_reschedule: 631 l %r1,BASED(.Lschedule) 632 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 633 basr %r14,%r1 # call scheduler 634 stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts 635 tm __TI_flags+3(%r9),_TIF_WORK_INT 636 bz BASED(io_leave) # there is no work to do 637 b BASED(io_work_loop) 638 639# 640# _TIF_SIGPENDING is set, call do_signal 641# 642io_sigpending: 643 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 644 la %r2,SP_PTREGS(%r15) # load pt_regs 645 sr %r3,%r3 # clear *oldset 646 l %r1,BASED(.Ldo_signal) 647 basr %r14,%r1 # call do_signal 648 stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts 649 b BASED(io_leave) # out of here, do NOT recheck 650 651/* 652 * External interrupt handler routine 653 */ 654 655 .globl ext_int_handler 656ext_int_handler: 657 STORE_TIMER __LC_ASYNC_ENTER_TIMER 658 stck __LC_INT_CLOCK 659 SAVE_ALL_BASE __LC_SAVE_AREA+16 660 SAVE_ALL __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16,0 661 CREATE_STACK_FRAME __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16 662#ifdef CONFIG_VIRT_CPU_ACCOUNTING 663 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 664 bz BASED(ext_no_vtime) 665 UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER 666 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 667 mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER 668ext_no_vtime: 669#endif 670 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 671 la %r2,SP_PTREGS(%r15) # address of register-save area 672 lh %r3,__LC_EXT_INT_CODE # get interruption code 673 l %r1,BASED(.Ldo_extint) 674 basr %r14,%r1 675 b BASED(io_return) 676 677/* 678 * Machine check handler routines 679 */ 680 681 .globl mcck_int_handler 682mcck_int_handler: 683 spt __LC_CPU_TIMER_SAVE_AREA # revalidate cpu timer 684 lm %r0,%r15,__LC_GPREGS_SAVE_AREA # revalidate gprs 685 SAVE_ALL_BASE __LC_SAVE_AREA+32 686 la %r12,__LC_MCK_OLD_PSW 687 tm __LC_MCCK_CODE,0x80 # system damage? 688 bo BASED(mcck_int_main) # yes -> rest of mcck code invalid 689 tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid? 690 bo BASED(0f) 691 spt __LC_LAST_UPDATE_TIMER # revalidate cpu timer 692#ifdef CONFIG_VIRT_CPU_ACCOUNTING 693 mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER 694 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 695 mvc __LC_LAST_UPDATE_TIMER(8),__LC_EXIT_TIMER 6960: tm __LC_MCCK_CODE+2,0x08 # mwp of old psw valid? 697 bno BASED(mcck_no_vtime) # no -> skip cleanup critical 698 tm __LC_MCK_OLD_PSW+1,0x01 # interrupting from user ? 699 bz BASED(mcck_no_vtime) 700 UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER 701 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 702 mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER 703mcck_no_vtime: 704#endif 7050: 706 tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid? 707 bno BASED(mcck_int_main) # no -> skip cleanup critical 708 tm __LC_MCK_OLD_PSW+1,0x01 # test problem state bit 709 bnz BASED(mcck_int_main) # from user -> load async stack 710 clc __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_end) 711 bhe BASED(mcck_int_main) 712 clc __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_start) 713 bl BASED(mcck_int_main) 714 l %r14,BASED(.Lcleanup_critical) 715 basr %r14,%r14 716mcck_int_main: 717 l %r14,__LC_PANIC_STACK # are we already on the panic stack? 718 slr %r14,%r15 719 sra %r14,PAGE_SHIFT 720 be BASED(0f) 721 l %r15,__LC_PANIC_STACK # load panic stack 7220: CREATE_STACK_FRAME __LC_MCK_OLD_PSW,__LC_SAVE_AREA+32 723 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 724 la %r2,SP_PTREGS(%r15) # load pt_regs 725 l %r1,BASED(.Ls390_mcck) 726 basr %r14,%r1 # call machine check handler 727 tm SP_PSW+1(%r15),0x01 # returning to user ? 728 bno BASED(mcck_return) 729 l %r1,__LC_KERNEL_STACK # switch to kernel stack 730 s %r1,BASED(.Lc_spsize) 731 mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) 732 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain 733 lr %r15,%r1 734 stosm __SF_EMPTY(%r15),0x04 # turn dat on 735 tm __TI_flags+3(%r9),_TIF_MCCK_PENDING 736 bno BASED(mcck_return) 737 l %r1,BASED(.Ls390_handle_mcck) 738 basr %r14,%r1 # call machine check handler 739mcck_return: 740 RESTORE_ALL 0 741 742#ifdef CONFIG_SMP 743/* 744 * Restart interruption handler, kick starter for additional CPUs 745 */ 746 .globl restart_int_handler 747restart_int_handler: 748 l %r15,__LC_SAVE_AREA+60 # load ksp 749 lctl %c0,%c15,__LC_CREGS_SAVE_AREA # get new ctl regs 750 lam %a0,%a15,__LC_AREGS_SAVE_AREA 751 lm %r6,%r15,__SF_GPRS(%r15) # load registers from clone 752 stosm __SF_EMPTY(%r15),0x04 # now we can turn dat on 753 basr %r14,0 754 l %r14,restart_addr-.(%r14) 755 br %r14 # branch to start_secondary 756restart_addr: 757 .long start_secondary 758#else 759/* 760 * If we do not run with SMP enabled, let the new CPU crash ... 761 */ 762 .globl restart_int_handler 763restart_int_handler: 764 basr %r1,0 765restart_base: 766 lpsw restart_crash-restart_base(%r1) 767 .align 8 768restart_crash: 769 .long 0x000a0000,0x00000000 770restart_go: 771#endif 772 773#ifdef CONFIG_CHECK_STACK 774/* 775 * The synchronous or the asynchronous stack overflowed. We are dead. 776 * No need to properly save the registers, we are going to panic anyway. 777 * Setup a pt_regs so that show_trace can provide a good call trace. 778 */ 779stack_overflow: 780 l %r15,__LC_PANIC_STACK # change to panic stack 781 sl %r15,BASED(.Lc_spsize) 782 mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack 783 stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack 784 la %r1,__LC_SAVE_AREA 785 ch %r12,BASED(.L0x020) # old psw addr == __LC_SVC_OLD_PSW ? 786 be BASED(0f) 787 ch %r12,BASED(.L0x028) # old psw addr == __LC_PGM_OLD_PSW ? 788 be BASED(0f) 789 la %r1,__LC_SAVE_AREA+16 7900: mvc SP_R12(16,%r15),0(%r1) # move %r12-%r15 to stack 791 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear back chain 792 l %r1,BASED(1f) # branch to kernel_stack_overflow 793 la %r2,SP_PTREGS(%r15) # load pt_regs 794 br %r1 7951: .long kernel_stack_overflow 796#endif 797 798cleanup_table_system_call: 799 .long system_call + 0x80000000, sysc_do_svc + 0x80000000 800cleanup_table_sysc_return: 801 .long sysc_return + 0x80000000, sysc_leave + 0x80000000 802cleanup_table_sysc_leave: 803 .long sysc_leave + 0x80000000, sysc_work_loop + 0x80000000 804cleanup_table_sysc_work_loop: 805 .long sysc_work_loop + 0x80000000, sysc_reschedule + 0x80000000 806 807cleanup_critical: 808 clc 4(4,%r12),BASED(cleanup_table_system_call) 809 bl BASED(0f) 810 clc 4(4,%r12),BASED(cleanup_table_system_call+4) 811 bl BASED(cleanup_system_call) 8120: 813 clc 4(4,%r12),BASED(cleanup_table_sysc_return) 814 bl BASED(0f) 815 clc 4(4,%r12),BASED(cleanup_table_sysc_return+4) 816 bl BASED(cleanup_sysc_return) 8170: 818 clc 4(4,%r12),BASED(cleanup_table_sysc_leave) 819 bl BASED(0f) 820 clc 4(4,%r12),BASED(cleanup_table_sysc_leave+4) 821 bl BASED(cleanup_sysc_leave) 8220: 823 clc 4(4,%r12),BASED(cleanup_table_sysc_work_loop) 824 bl BASED(0f) 825 clc 4(4,%r12),BASED(cleanup_table_sysc_work_loop+4) 826 bl BASED(cleanup_sysc_return) 8270: 828 br %r14 829 830cleanup_system_call: 831 mvc __LC_RETURN_PSW(8),0(%r12) 832#ifdef CONFIG_VIRT_CPU_ACCOUNTING 833 clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+4) 834 bh BASED(0f) 835 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER 8360: clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+8) 837 bhe BASED(cleanup_vtime) 838#endif 839 clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn) 840 bh BASED(0f) 841 mvc __LC_SAVE_AREA(16),__LC_SAVE_AREA+16 8420: st %r13,__LC_SAVE_AREA+20 843 SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1 844 CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA 845 st %r15,__LC_SAVE_AREA+28 846 lh %r7,0x8a 847#ifdef CONFIG_VIRT_CPU_ACCOUNTING 848cleanup_vtime: 849 clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+12) 850 bhe BASED(cleanup_stime) 851 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 852 bz BASED(cleanup_novtime) 853 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER 854cleanup_stime: 855 clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+16) 856 bh BASED(cleanup_update) 857 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 858cleanup_update: 859 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 860cleanup_novtime: 861#endif 862 mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_system_call+4) 863 la %r12,__LC_RETURN_PSW 864 br %r14 865cleanup_system_call_insn: 866 .long sysc_saveall + 0x80000000 867#ifdef CONFIG_VIRT_CPU_ACCOUNTING 868 .long system_call + 0x80000000 869 .long sysc_vtime + 0x80000000 870 .long sysc_stime + 0x80000000 871 .long sysc_update + 0x80000000 872#endif 873 874cleanup_sysc_return: 875 mvc __LC_RETURN_PSW(4),0(%r12) 876 mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_sysc_return) 877 la %r12,__LC_RETURN_PSW 878 br %r14 879 880cleanup_sysc_leave: 881 clc 4(4,%r12),BASED(cleanup_sysc_leave_insn) 882 be BASED(0f) 883#ifdef CONFIG_VIRT_CPU_ACCOUNTING 884 mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER 885 clc 4(4,%r12),BASED(cleanup_sysc_leave_insn+4) 886 be BASED(0f) 887#endif 888 mvc __LC_RETURN_PSW(8),SP_PSW(%r15) 889 mvc __LC_SAVE_AREA+16(16),SP_R12(%r15) 890 lm %r0,%r11,SP_R0(%r15) 891 l %r15,SP_R15(%r15) 8920: la %r12,__LC_RETURN_PSW 893 br %r14 894cleanup_sysc_leave_insn: 895#ifdef CONFIG_VIRT_CPU_ACCOUNTING 896 .long sysc_leave + 14 + 0x80000000 897#endif 898 .long sysc_leave + 10 + 0x80000000 899 900/* 901 * Integer constants 902 */ 903 .align 4 904.Lc_spsize: .long SP_SIZE 905.Lc_overhead: .long STACK_FRAME_OVERHEAD 906.Lc_pactive: .long PREEMPT_ACTIVE 907.Lnr_syscalls: .long NR_syscalls 908.L0x018: .short 0x018 909.L0x020: .short 0x020 910.L0x028: .short 0x028 911.L0x030: .short 0x030 912.L0x038: .short 0x038 913.Lc_1: .long 1 914 915/* 916 * Symbol constants 917 */ 918.Ls390_mcck: .long s390_do_machine_check 919.Ls390_handle_mcck: 920 .long s390_handle_mcck 921.Ldo_IRQ: .long do_IRQ 922.Ldo_extint: .long do_extint 923.Ldo_signal: .long do_signal 924.Lhandle_per: .long do_single_step 925.Ljump_table: .long pgm_check_table 926.Lschedule: .long schedule 927.Lclone: .long sys_clone 928.Lexecve: .long sys_execve 929.Lfork: .long sys_fork 930.Lrt_sigreturn:.long sys_rt_sigreturn 931.Lrt_sigsuspend: 932 .long sys_rt_sigsuspend 933.Lsigreturn: .long sys_sigreturn 934.Lsigsuspend: .long sys_sigsuspend 935.Lsigaltstack: .long sys_sigaltstack 936.Ltrace: .long syscall_trace 937.Lvfork: .long sys_vfork 938.Lschedtail: .long schedule_tail 939 940.Lcritical_start: 941 .long __critical_start + 0x80000000 942.Lcritical_end: 943 .long __critical_end + 0x80000000 944.Lcleanup_critical: 945 .long cleanup_critical 946 947#define SYSCALL(esa,esame,emu) .long esa 948 .globl sys_call_table 949sys_call_table: 950#include "syscalls.S" 951#undef SYSCALL 952 953