1/* 2 * arch/s390/kernel/entry.S 3 * S390 low-level entry points. 4 * 5 * Copyright (C) IBM Corp. 1999,2006 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/sys.h> 13#include <linux/linkage.h> 14#include <linux/config.h> 15#include <asm/cache.h> 16#include <asm/lowcore.h> 17#include <asm/errno.h> 18#include <asm/ptrace.h> 19#include <asm/thread_info.h> 20#include <asm/asm-offsets.h> 21#include <asm/unistd.h> 22#include <asm/page.h> 23 24/* 25 * Stack layout for the system_call stack entry. 26 * The first few entries are identical to the user_regs_struct. 27 */ 28SP_PTREGS = STACK_FRAME_OVERHEAD 29SP_ARGS = STACK_FRAME_OVERHEAD + __PT_ARGS 30SP_PSW = STACK_FRAME_OVERHEAD + __PT_PSW 31SP_R0 = STACK_FRAME_OVERHEAD + __PT_GPRS 32SP_R1 = STACK_FRAME_OVERHEAD + __PT_GPRS + 4 33SP_R2 = STACK_FRAME_OVERHEAD + __PT_GPRS + 8 34SP_R3 = STACK_FRAME_OVERHEAD + __PT_GPRS + 12 35SP_R4 = STACK_FRAME_OVERHEAD + __PT_GPRS + 16 36SP_R5 = STACK_FRAME_OVERHEAD + __PT_GPRS + 20 37SP_R6 = STACK_FRAME_OVERHEAD + __PT_GPRS + 24 38SP_R7 = STACK_FRAME_OVERHEAD + __PT_GPRS + 28 39SP_R8 = STACK_FRAME_OVERHEAD + __PT_GPRS + 32 40SP_R9 = STACK_FRAME_OVERHEAD + __PT_GPRS + 36 41SP_R10 = STACK_FRAME_OVERHEAD + __PT_GPRS + 40 42SP_R11 = STACK_FRAME_OVERHEAD + __PT_GPRS + 44 43SP_R12 = STACK_FRAME_OVERHEAD + __PT_GPRS + 48 44SP_R13 = STACK_FRAME_OVERHEAD + __PT_GPRS + 52 45SP_R14 = STACK_FRAME_OVERHEAD + __PT_GPRS + 56 46SP_R15 = STACK_FRAME_OVERHEAD + __PT_GPRS + 60 47SP_ORIG_R2 = STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2 48SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC 49SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP 50SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE 51 52_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NEED_RESCHED | \ 53 _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP ) 54_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NEED_RESCHED | \ 55 _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 1(%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 psworg,sync 142 mvc \psworg(8),SP_PSW(%r15) # move user PSW to lowcore 143 .if !\sync 144 ni \psworg+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 \psworg # 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 __LC_RETURN_PSW,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 | _TIF_RESTORE_SIGMASK) 255 bnz 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 or _TIF_RESTORE_SIGMASK 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 l %r1,BASED(.Ldo_signal) 285 basr %r14,%r1 # call do_signal 286 tm __TI_flags+3(%r9),_TIF_RESTART_SVC 287 bo BASED(sysc_restart) 288 tm __TI_flags+3(%r9),_TIF_SINGLE_STEP 289 bo BASED(sysc_singlestep) 290 b BASED(sysc_work_loop) 291 292# 293# _TIF_RESTART_SVC is set, set up registers and restart svc 294# 295sysc_restart: 296 ni __TI_flags+3(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC 297 l %r7,SP_R2(%r15) # load new svc number 298 sla %r7,2 299 mvc SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument 300 lm %r2,%r6,SP_R2(%r15) # load svc arguments 301 b BASED(sysc_do_restart) # restart svc 302 303# 304# _TIF_SINGLE_STEP is set, call do_single_step 305# 306sysc_singlestep: 307 ni __TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP 308 mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check 309 la %r2,SP_PTREGS(%r15) # address of register-save area 310 l %r1,BASED(.Lhandle_per) # load adr. of per handler 311 la %r14,BASED(sysc_return) # load adr. of system return 312 br %r1 # branch to do_single_step 313 314# 315# call trace before and after sys_call 316# 317sysc_tracesys: 318 l %r1,BASED(.Ltrace) 319 la %r2,SP_PTREGS(%r15) # load pt_regs 320 la %r3,0 321 srl %r7,2 322 st %r7,SP_R2(%r15) 323 basr %r14,%r1 324 clc SP_R2(4,%r15),BASED(.Lnr_syscalls) 325 bnl BASED(sysc_tracenogo) 326 l %r7,SP_R2(%r15) # strace might have changed the 327 sll %r7,2 # system call 328 l %r8,sys_call_table-system_call(%r7,%r13) 329sysc_tracego: 330 lm %r3,%r6,SP_R3(%r15) 331 l %r2,SP_ORIG_R2(%r15) 332 basr %r14,%r8 # call sys_xxx 333 st %r2,SP_R2(%r15) # store return value 334sysc_tracenogo: 335 tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT) 336 bz BASED(sysc_return) 337 l %r1,BASED(.Ltrace) 338 la %r2,SP_PTREGS(%r15) # load pt_regs 339 la %r3,1 340 la %r14,BASED(sysc_return) 341 br %r1 342 343# 344# a new process exits the kernel with ret_from_fork 345# 346 .globl ret_from_fork 347ret_from_fork: 348 l %r13,__LC_SVC_NEW_PSW+4 349 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 350 tm SP_PSW+1(%r15),0x01 # forking a kernel thread ? 351 bo BASED(0f) 352 st %r15,SP_R15(%r15) # store stack pointer for new kthread 3530: l %r1,BASED(.Lschedtail) 354 basr %r14,%r1 355 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 356 b BASED(sysc_return) 357 358# 359# clone, fork, vfork, exec and sigreturn need glue, 360# because they all expect pt_regs as parameter, 361# but are called with different parameter. 362# return-address is set up above 363# 364sys_clone_glue: 365 la %r2,SP_PTREGS(%r15) # load pt_regs 366 l %r1,BASED(.Lclone) 367 br %r1 # branch to sys_clone 368 369sys_fork_glue: 370 la %r2,SP_PTREGS(%r15) # load pt_regs 371 l %r1,BASED(.Lfork) 372 br %r1 # branch to sys_fork 373 374sys_vfork_glue: 375 la %r2,SP_PTREGS(%r15) # load pt_regs 376 l %r1,BASED(.Lvfork) 377 br %r1 # branch to sys_vfork 378 379sys_execve_glue: 380 la %r2,SP_PTREGS(%r15) # load pt_regs 381 l %r1,BASED(.Lexecve) 382 lr %r12,%r14 # save return address 383 basr %r14,%r1 # call sys_execve 384 ltr %r2,%r2 # check if execve failed 385 bnz 0(%r12) # it did fail -> store result in gpr2 386 b 4(%r12) # SKIP ST 2,SP_R2(15) after BASR 14,8 387 # in system_call/sysc_tracesys 388 389sys_sigreturn_glue: 390 la %r2,SP_PTREGS(%r15) # load pt_regs as parameter 391 l %r1,BASED(.Lsigreturn) 392 br %r1 # branch to sys_sigreturn 393 394sys_rt_sigreturn_glue: 395 la %r2,SP_PTREGS(%r15) # load pt_regs as parameter 396 l %r1,BASED(.Lrt_sigreturn) 397 br %r1 # branch to sys_sigreturn 398 399sys_sigaltstack_glue: 400 la %r4,SP_PTREGS(%r15) # load pt_regs as parameter 401 l %r1,BASED(.Lsigaltstack) 402 br %r1 # branch to sys_sigreturn 403 404 405/* 406 * Program check handler routine 407 */ 408 409 .globl pgm_check_handler 410pgm_check_handler: 411/* 412 * First we need to check for a special case: 413 * Single stepping an instruction that disables the PER event mask will 414 * cause a PER event AFTER the mask has been set. Example: SVC or LPSW. 415 * For a single stepped SVC the program check handler gets control after 416 * the SVC new PSW has been loaded. But we want to execute the SVC first and 417 * then handle the PER event. Therefore we update the SVC old PSW to point 418 * to the pgm_check_handler and branch to the SVC handler after we checked 419 * if we have to load the kernel stack register. 420 * For every other possible cause for PER event without the PER mask set 421 * we just ignore the PER event (FIXME: is there anything we have to do 422 * for LPSW?). 423 */ 424 STORE_TIMER __LC_SYNC_ENTER_TIMER 425 SAVE_ALL_BASE __LC_SAVE_AREA 426 tm __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception 427 bnz BASED(pgm_per) # got per exception -> special case 428 SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1 429 CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA 430#ifdef CONFIG_VIRT_CPU_ACCOUNTING 431 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 432 bz BASED(pgm_no_vtime) 433 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER 434 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 435 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 436pgm_no_vtime: 437#endif 438 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 439 l %r3,__LC_PGM_ILC # load program interruption code 440 la %r8,0x7f 441 nr %r8,%r3 442pgm_do_call: 443 l %r7,BASED(.Ljump_table) 444 sll %r8,2 445 l %r7,0(%r8,%r7) # load address of handler routine 446 la %r2,SP_PTREGS(%r15) # address of register-save area 447 la %r14,BASED(sysc_return) 448 br %r7 # branch to interrupt-handler 449 450# 451# handle per exception 452# 453pgm_per: 454 tm __LC_PGM_OLD_PSW,0x40 # test if per event recording is on 455 bnz BASED(pgm_per_std) # ok, normal per event from user space 456# ok its one of the special cases, now we need to find out which one 457 clc __LC_PGM_OLD_PSW(8),__LC_SVC_NEW_PSW 458 be BASED(pgm_svcper) 459# no interesting special case, ignore PER event 460 lm %r12,%r15,__LC_SAVE_AREA 461 lpsw 0x28 462 463# 464# Normal per exception 465# 466pgm_per_std: 467 SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1 468 CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA 469#ifdef CONFIG_VIRT_CPU_ACCOUNTING 470 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 471 bz BASED(pgm_no_vtime2) 472 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER 473 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 474 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 475pgm_no_vtime2: 476#endif 477 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 478 l %r1,__TI_task(%r9) 479 mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID 480 mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS 481 mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID 482 oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP 483 l %r3,__LC_PGM_ILC # load program interruption code 484 la %r8,0x7f 485 nr %r8,%r3 # clear per-event-bit and ilc 486 be BASED(sysc_return) # only per or per+check ? 487 b BASED(pgm_do_call) 488 489# 490# it was a single stepped SVC that is causing all the trouble 491# 492pgm_svcper: 493 SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1 494 CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA 495#ifdef CONFIG_VIRT_CPU_ACCOUNTING 496 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 497 bz BASED(pgm_no_vtime3) 498 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER 499 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 500 mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER 501pgm_no_vtime3: 502#endif 503 lh %r7,0x8a # get svc number from lowcore 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 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 511 b BASED(sysc_do_svc) 512 513/* 514 * IO interrupt handler routine 515 */ 516 517 .globl io_int_handler 518io_int_handler: 519 STORE_TIMER __LC_ASYNC_ENTER_TIMER 520 stck __LC_INT_CLOCK 521 SAVE_ALL_BASE __LC_SAVE_AREA+16 522 SAVE_ALL __LC_IO_OLD_PSW,__LC_SAVE_AREA+16,0 523 CREATE_STACK_FRAME __LC_IO_OLD_PSW,__LC_SAVE_AREA+16 524#ifdef CONFIG_VIRT_CPU_ACCOUNTING 525 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 526 bz BASED(io_no_vtime) 527 UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER 528 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 529 mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER 530io_no_vtime: 531#endif 532 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 533 l %r1,BASED(.Ldo_IRQ) # load address of do_IRQ 534 la %r2,SP_PTREGS(%r15) # address of register-save area 535 basr %r14,%r1 # branch to standard irq handler 536 537io_return: 538 tm SP_PSW+1(%r15),0x01 # returning to user ? 539#ifdef CONFIG_PREEMPT 540 bno BASED(io_preempt) # no -> check for preemptive scheduling 541#else 542 bno BASED(io_leave) # no-> skip resched & signal 543#endif 544 tm __TI_flags+3(%r9),_TIF_WORK_INT 545 bnz BASED(io_work) # there is work to do (signals etc.) 546io_leave: 547 RESTORE_ALL __LC_RETURN_PSW,0 548io_done: 549 550#ifdef CONFIG_PREEMPT 551io_preempt: 552 icm %r0,15,__TI_precount(%r9) 553 bnz BASED(io_leave) 554 l %r1,SP_R15(%r15) 555 s %r1,BASED(.Lc_spsize) 556 mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) 557 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain 558 lr %r15,%r1 559io_resume_loop: 560 tm __TI_flags+3(%r9),_TIF_NEED_RESCHED 561 bno BASED(io_leave) 562 mvc __TI_precount(4,%r9),BASED(.Lc_pactive) 563 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 564 l %r1,BASED(.Lschedule) 565 basr %r14,%r1 # call schedule 566 stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts 567 xc __TI_precount(4,%r9),__TI_precount(%r9) 568 b BASED(io_resume_loop) 569#endif 570 571# 572# switch to kernel stack, then check the TIF bits 573# 574io_work: 575 l %r1,__LC_KERNEL_STACK 576 s %r1,BASED(.Lc_spsize) 577 mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) 578 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain 579 lr %r15,%r1 580# 581# One of the work bits is on. Find out which one. 582# Checked are: _TIF_SIGPENDING, _TIF_RESTORE_SIGMASK, _TIF_NEED_RESCHED 583# and _TIF_MCCK_PENDING 584# 585io_work_loop: 586 tm __TI_flags+3(%r9),_TIF_MCCK_PENDING 587 bo BASED(io_mcck_pending) 588 tm __TI_flags+3(%r9),_TIF_NEED_RESCHED 589 bo BASED(io_reschedule) 590 tm __TI_flags+3(%r9),(_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK) 591 bnz BASED(io_sigpending) 592 b BASED(io_leave) 593 594# 595# _TIF_MCCK_PENDING is set, call handler 596# 597io_mcck_pending: 598 l %r1,BASED(.Ls390_handle_mcck) 599 la %r14,BASED(io_work_loop) 600 br %r1 # TIF bit will be cleared by handler 601 602# 603# _TIF_NEED_RESCHED is set, call schedule 604# 605io_reschedule: 606 l %r1,BASED(.Lschedule) 607 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 608 basr %r14,%r1 # call scheduler 609 stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts 610 tm __TI_flags+3(%r9),_TIF_WORK_INT 611 bz BASED(io_leave) # there is no work to do 612 b BASED(io_work_loop) 613 614# 615# _TIF_SIGPENDING or _TIF_RESTORE_SIGMASK is set, call do_signal 616# 617io_sigpending: 618 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 619 la %r2,SP_PTREGS(%r15) # load pt_regs 620 l %r1,BASED(.Ldo_signal) 621 basr %r14,%r1 # call do_signal 622 stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts 623 b BASED(io_work_loop) 624 625/* 626 * External interrupt handler routine 627 */ 628 629 .globl ext_int_handler 630ext_int_handler: 631 STORE_TIMER __LC_ASYNC_ENTER_TIMER 632 stck __LC_INT_CLOCK 633 SAVE_ALL_BASE __LC_SAVE_AREA+16 634 SAVE_ALL __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16,0 635 CREATE_STACK_FRAME __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16 636#ifdef CONFIG_VIRT_CPU_ACCOUNTING 637 tm SP_PSW+1(%r15),0x01 # interrupting from user ? 638 bz BASED(ext_no_vtime) 639 UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER 640 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 641 mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER 642ext_no_vtime: 643#endif 644 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 645 la %r2,SP_PTREGS(%r15) # address of register-save area 646 lh %r3,__LC_EXT_INT_CODE # get interruption code 647 l %r1,BASED(.Ldo_extint) 648 basr %r14,%r1 649 b BASED(io_return) 650 651__critical_end: 652 653/* 654 * Machine check handler routines 655 */ 656 657 .globl mcck_int_handler 658mcck_int_handler: 659 spt __LC_CPU_TIMER_SAVE_AREA # revalidate cpu timer 660 mvc __LC_ASYNC_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA 661 lm %r0,%r15,__LC_GPREGS_SAVE_AREA # revalidate gprs 662 SAVE_ALL_BASE __LC_SAVE_AREA+32 663 la %r12,__LC_MCK_OLD_PSW 664 tm __LC_MCCK_CODE,0x80 # system damage? 665 bo BASED(mcck_int_main) # yes -> rest of mcck code invalid 666 tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid? 667 bo BASED(0f) 668 spt __LC_LAST_UPDATE_TIMER # revalidate cpu timer 669#ifdef CONFIG_VIRT_CPU_ACCOUNTING 670 mvc __LC_ASYNC_ENTER_TIMER(8),__LC_LAST_UPDATE_TIMER 671 mvc __LC_SYNC_ENTER_TIMER(8),__LC_LAST_UPDATE_TIMER 672 mvc __LC_EXIT_TIMER(8),__LC_LAST_UPDATE_TIMER 673#endif 6740: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid? 675 bno BASED(mcck_int_main) # no -> skip cleanup critical 676 tm __LC_MCK_OLD_PSW+1,0x01 # test problem state bit 677 bnz BASED(mcck_int_main) # from user -> load async stack 678 clc __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_end) 679 bhe BASED(mcck_int_main) 680 clc __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_start) 681 bl BASED(mcck_int_main) 682 l %r14,BASED(.Lcleanup_critical) 683 basr %r14,%r14 684mcck_int_main: 685 l %r14,__LC_PANIC_STACK # are we already on the panic stack? 686 slr %r14,%r15 687 sra %r14,PAGE_SHIFT 688 be BASED(0f) 689 l %r15,__LC_PANIC_STACK # load panic stack 6900: CREATE_STACK_FRAME __LC_MCK_OLD_PSW,__LC_SAVE_AREA+32 691#ifdef CONFIG_VIRT_CPU_ACCOUNTING 692 tm __LC_MCCK_CODE+2,0x08 # mwp of old psw valid? 693 bno BASED(mcck_no_vtime) # no -> skip cleanup critical 694 tm __LC_MCK_OLD_PSW+1,0x01 # interrupting from user ? 695 bz BASED(mcck_no_vtime) 696 UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER 697 UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER 698 mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER 699mcck_no_vtime: 700#endif 701 l %r9,__LC_THREAD_INFO # load pointer to thread_info struct 702 la %r2,SP_PTREGS(%r15) # load pt_regs 703 l %r1,BASED(.Ls390_mcck) 704 basr %r14,%r1 # call machine check handler 705 tm SP_PSW+1(%r15),0x01 # returning to user ? 706 bno BASED(mcck_return) 707 l %r1,__LC_KERNEL_STACK # switch to kernel stack 708 s %r1,BASED(.Lc_spsize) 709 mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15) 710 xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain 711 lr %r15,%r1 712 stosm __SF_EMPTY(%r15),0x04 # turn dat on 713 tm __TI_flags+3(%r9),_TIF_MCCK_PENDING 714 bno BASED(mcck_return) 715 l %r1,BASED(.Ls390_handle_mcck) 716 basr %r14,%r1 # call machine check handler 717mcck_return: 718 RESTORE_ALL __LC_RETURN_MCCK_PSW,0 719 720#ifdef CONFIG_SMP 721/* 722 * Restart interruption handler, kick starter for additional CPUs 723 */ 724 .globl restart_int_handler 725restart_int_handler: 726 l %r15,__LC_SAVE_AREA+60 # load ksp 727 lctl %c0,%c15,__LC_CREGS_SAVE_AREA # get new ctl regs 728 lam %a0,%a15,__LC_AREGS_SAVE_AREA 729 lm %r6,%r15,__SF_GPRS(%r15) # load registers from clone 730 stosm __SF_EMPTY(%r15),0x04 # now we can turn dat on 731 basr %r14,0 732 l %r14,restart_addr-.(%r14) 733 br %r14 # branch to start_secondary 734restart_addr: 735 .long start_secondary 736#else 737/* 738 * If we do not run with SMP enabled, let the new CPU crash ... 739 */ 740 .globl restart_int_handler 741restart_int_handler: 742 basr %r1,0 743restart_base: 744 lpsw restart_crash-restart_base(%r1) 745 .align 8 746restart_crash: 747 .long 0x000a0000,0x00000000 748restart_go: 749#endif 750 751#ifdef CONFIG_CHECK_STACK 752/* 753 * The synchronous or the asynchronous stack overflowed. We are dead. 754 * No need to properly save the registers, we are going to panic anyway. 755 * Setup a pt_regs so that show_trace can provide a good call trace. 756 */ 757stack_overflow: 758 l %r15,__LC_PANIC_STACK # change to panic stack 759 sl %r15,BASED(.Lc_spsize) 760 mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack 761 stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack 762 la %r1,__LC_SAVE_AREA 763 ch %r12,BASED(.L0x020) # old psw addr == __LC_SVC_OLD_PSW ? 764 be BASED(0f) 765 ch %r12,BASED(.L0x028) # old psw addr == __LC_PGM_OLD_PSW ? 766 be BASED(0f) 767 la %r1,__LC_SAVE_AREA+16 7680: mvc SP_R12(16,%r15),0(%r1) # move %r12-%r15 to stack 769 xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear back chain 770 l %r1,BASED(1f) # branch to kernel_stack_overflow 771 la %r2,SP_PTREGS(%r15) # load pt_regs 772 br %r1 7731: .long kernel_stack_overflow 774#endif 775 776cleanup_table_system_call: 777 .long system_call + 0x80000000, sysc_do_svc + 0x80000000 778cleanup_table_sysc_return: 779 .long sysc_return + 0x80000000, sysc_leave + 0x80000000 780cleanup_table_sysc_leave: 781 .long sysc_leave + 0x80000000, sysc_work_loop + 0x80000000 782cleanup_table_sysc_work_loop: 783 .long sysc_work_loop + 0x80000000, sysc_reschedule + 0x80000000 784cleanup_table_io_leave: 785 .long io_leave + 0x80000000, io_done + 0x80000000 786cleanup_table_io_work_loop: 787 .long io_work_loop + 0x80000000, io_mcck_pending + 0x80000000 788 789cleanup_critical: 790 clc 4(4,%r12),BASED(cleanup_table_system_call) 791 bl BASED(0f) 792 clc 4(4,%r12),BASED(cleanup_table_system_call+4) 793 bl BASED(cleanup_system_call) 7940: 795 clc 4(4,%r12),BASED(cleanup_table_sysc_return) 796 bl BASED(0f) 797 clc 4(4,%r12),BASED(cleanup_table_sysc_return+4) 798 bl BASED(cleanup_sysc_return) 7990: 800 clc 4(4,%r12),BASED(cleanup_table_sysc_leave) 801 bl BASED(0f) 802 clc 4(4,%r12),BASED(cleanup_table_sysc_leave+4) 803 bl BASED(cleanup_sysc_leave) 8040: 805 clc 4(4,%r12),BASED(cleanup_table_sysc_work_loop) 806 bl BASED(0f) 807 clc 4(4,%r12),BASED(cleanup_table_sysc_work_loop+4) 808 bl BASED(cleanup_sysc_return) 8090: 810 clc 4(4,%r12),BASED(cleanup_table_io_leave) 811 bl BASED(0f) 812 clc 4(4,%r12),BASED(cleanup_table_io_leave+4) 813 bl BASED(cleanup_io_leave) 8140: 815 clc 4(4,%r12),BASED(cleanup_table_io_work_loop) 816 bl BASED(0f) 817 clc 4(4,%r12),BASED(cleanup_table_io_work_loop+4) 818 bl BASED(cleanup_io_return) 8190: 820 br %r14 821 822cleanup_system_call: 823 mvc __LC_RETURN_PSW(8),0(%r12) 824 c %r12,BASED(.Lmck_old_psw) 825 be BASED(0f) 826 la %r12,__LC_SAVE_AREA+16 827 b BASED(1f) 8280: la %r12,__LC_SAVE_AREA+32 8291: 830#ifdef CONFIG_VIRT_CPU_ACCOUNTING 831 clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+4) 832 bh BASED(0f) 833 mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER 8340: clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+8) 835 bhe BASED(cleanup_vtime) 836#endif 837 clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn) 838 bh BASED(0f) 839 mvc __LC_SAVE_AREA(16),0(%r12) 8400: st %r13,4(%r12) 841 st %r12,__LC_SAVE_AREA+48 # argh 842 SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1 843 CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA 844 l %r12,__LC_SAVE_AREA+48 # argh 845 st %r15,12(%r12) 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(2f) 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(2f) 887#endif 888 mvc __LC_RETURN_PSW(8),SP_PSW(%r15) 889 c %r12,BASED(.Lmck_old_psw) 890 bne BASED(0f) 891 mvc __LC_SAVE_AREA+32(16),SP_R12(%r15) 892 b BASED(1f) 8930: mvc __LC_SAVE_AREA+16(16),SP_R12(%r15) 8941: lm %r0,%r11,SP_R0(%r15) 895 l %r15,SP_R15(%r15) 8962: la %r12,__LC_RETURN_PSW 897 br %r14 898cleanup_sysc_leave_insn: 899#ifdef CONFIG_VIRT_CPU_ACCOUNTING 900 .long sysc_leave + 14 + 0x80000000 901#endif 902 .long sysc_leave + 10 + 0x80000000 903 904cleanup_io_return: 905 mvc __LC_RETURN_PSW(4),0(%r12) 906 mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_io_work_loop) 907 la %r12,__LC_RETURN_PSW 908 br %r14 909 910cleanup_io_leave: 911 clc 4(4,%r12),BASED(cleanup_io_leave_insn) 912 be BASED(2f) 913#ifdef CONFIG_VIRT_CPU_ACCOUNTING 914 mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER 915 clc 4(4,%r12),BASED(cleanup_io_leave_insn+4) 916 be BASED(2f) 917#endif 918 mvc __LC_RETURN_PSW(8),SP_PSW(%r15) 919 c %r12,BASED(.Lmck_old_psw) 920 bne BASED(0f) 921 mvc __LC_SAVE_AREA+32(16),SP_R12(%r15) 922 b BASED(1f) 9230: mvc __LC_SAVE_AREA+16(16),SP_R12(%r15) 9241: lm %r0,%r11,SP_R0(%r15) 925 l %r15,SP_R15(%r15) 9262: la %r12,__LC_RETURN_PSW 927 br %r14 928cleanup_io_leave_insn: 929#ifdef CONFIG_VIRT_CPU_ACCOUNTING 930 .long io_leave + 18 + 0x80000000 931#endif 932 .long io_leave + 14 + 0x80000000 933 934/* 935 * Integer constants 936 */ 937 .align 4 938.Lc_spsize: .long SP_SIZE 939.Lc_overhead: .long STACK_FRAME_OVERHEAD 940.Lc_pactive: .long PREEMPT_ACTIVE 941.Lnr_syscalls: .long NR_syscalls 942.L0x018: .short 0x018 943.L0x020: .short 0x020 944.L0x028: .short 0x028 945.L0x030: .short 0x030 946.L0x038: .short 0x038 947.Lc_1: .long 1 948 949/* 950 * Symbol constants 951 */ 952.Ls390_mcck: .long s390_do_machine_check 953.Ls390_handle_mcck: 954 .long s390_handle_mcck 955.Lmck_old_psw: .long __LC_MCK_OLD_PSW 956.Ldo_IRQ: .long do_IRQ 957.Ldo_extint: .long do_extint 958.Ldo_signal: .long do_signal 959.Lhandle_per: .long do_single_step 960.Ljump_table: .long pgm_check_table 961.Lschedule: .long schedule 962.Lclone: .long sys_clone 963.Lexecve: .long sys_execve 964.Lfork: .long sys_fork 965.Lrt_sigreturn:.long sys_rt_sigreturn 966.Lrt_sigsuspend: 967 .long sys_rt_sigsuspend 968.Lsigreturn: .long sys_sigreturn 969.Lsigsuspend: .long sys_sigsuspend 970.Lsigaltstack: .long sys_sigaltstack 971.Ltrace: .long syscall_trace 972.Lvfork: .long sys_vfork 973.Lschedtail: .long schedule_tail 974 975.Lcritical_start: 976 .long __critical_start + 0x80000000 977.Lcritical_end: 978 .long __critical_end + 0x80000000 979.Lcleanup_critical: 980 .long cleanup_critical 981 982#define SYSCALL(esa,esame,emu) .long esa 983 .globl sys_call_table 984sys_call_table: 985#include "syscalls.S" 986#undef SYSCALL 987 988