arch/s390/kernel/entry.S

   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/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  */
  29 SP_PTREGS    =  STACK_FRAME_OVERHEAD
  30 SP_ARGS      =  STACK_FRAME_OVERHEAD + __PT_ARGS
  31 SP_PSW       =  STACK_FRAME_OVERHEAD + __PT_PSW
  32 SP_R0        =  STACK_FRAME_OVERHEAD + __PT_GPRS
  33 SP_R1        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 4
  34 SP_R2        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 8
  35 SP_R3        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 12
  36 SP_R4        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 16
  37 SP_R5        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 20
  38 SP_R6        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 24
  39 SP_R7        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 28
  40 SP_R8        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 32
  41 SP_R9        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 36
  42 SP_R10       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 40
  43 SP_R11       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 44
  44 SP_R12       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 48
  45 SP_R13       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 52
  46 SP_R14       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 56
  47 SP_R15       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 60
  48 SP_ORIG_R2   =  STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
  49 SP_ILC       =  STACK_FRAME_OVERHEAD + __PT_ILC
  50 SP_TRAP      =  STACK_FRAME_OVERHEAD + __PT_TRAP
  51 SP_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
  57 STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
  58 STACK_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)
  83 0:      al      %r10,\lc_sum
  84         al      %r11,\lc_sum+4
  85         bc      12,BASED(1f)
  86         al      %r10,BASED(.Lc_1)
  87 1:      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)
 113 0:      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)
 117 1:      l       %r15,__LC_ASYNC_STACK
 118         .endif
 119 #ifdef CONFIG_CHECK_STACK
 120         b       BASED(3f)
 121 2:      tml     %r15,STACK_SIZE - CONFIG_STACK_GUARD
 122         bz      BASED(stack_overflow)
 123 3:
 124 #endif
 125 2:
 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
 195 system_call:
 196         STORE_TIMER __LC_SYNC_ENTER_TIMER
 197 sysc_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
 203 sysc_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
 207 sysc_stime:
 208         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
 209 sysc_update:
 210         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
 211 #endif
 212 sysc_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
 221 sysc_nr_ok:
 222         mvc     SP_ARGS(4,%r15),SP_R7(%r15)
 223 sysc_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
 232 sysc_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.)
 237 sysc_leave:
 238         RESTORE_ALL __LC_RETURN_PSW,1
 239
 240 #
 241 # recheck if there is more work to do
 242 #
 243 sysc_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 #
 249 sysc_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 #
 265 sysc_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 #
 273 sysc_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 #
 281 sysc_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 #
 296 sysc_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 #
 307 sysc_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 #
 316 # call trace before and after sys_call
 317 #
 318 sysc_tracesys:
 319         l       %r1,BASED(.Ltrace)
 320         la      %r2,SP_PTREGS(%r15)    # load pt_regs
 321         la      %r3,0
 322         srl     %r7,2
 323         st      %r7,SP_R2(%r15)
 324         basr    %r14,%r1
 325         clc     SP_R2(4,%r15),BASED(.Lnr_syscalls)
 326         bnl     BASED(sysc_tracenogo)
 327         l       %r7,SP_R2(%r15)        # strace might have changed the
 328         sll     %r7,2                  #  system call
 329         l       %r8,sys_call_table-system_call(%r7,%r13)
 330 sysc_tracego:
 331         lm      %r3,%r6,SP_R3(%r15)
 332         l       %r2,SP_ORIG_R2(%r15)
 333         basr    %r14,%r8          # call sys_xxx
 334         st      %r2,SP_R2(%r15)   # store return value
 335 sysc_tracenogo:
 336         tm      __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
 337         bz      BASED(sysc_return)
 338         l       %r1,BASED(.Ltrace)
 339         la      %r2,SP_PTREGS(%r15)    # load pt_regs
 340         la      %r3,1
 341         la      %r14,BASED(sysc_return)
 342         br      %r1
 343
 344 #
 345 # a new process exits the kernel with ret_from_fork
 346 #
 347         .globl  ret_from_fork
 348 ret_from_fork:
 349         l       %r13,__LC_SVC_NEW_PSW+4
 350         l       %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
 351         tm      SP_PSW+1(%r15),0x01     # forking a kernel thread ?
 352         bo      BASED(0f)
 353         st      %r15,SP_R15(%r15)       # store stack pointer for new kthread
 354 0:      l       %r1,BASED(.Lschedtail)
 355         basr    %r14,%r1
 356         stosm   __SF_EMPTY(%r15),0x03     # reenable interrupts
 357         b       BASED(sysc_return)
 358
 359 #
 360 # clone, fork, vfork, exec and sigreturn need glue,
 361 # because they all expect pt_regs as parameter,
 362 # but are called with different parameter.
 363 # return-address is set up above
 364 #
 365 sys_clone_glue:
 366         la      %r2,SP_PTREGS(%r15)    # load pt_regs
 367         l       %r1,BASED(.Lclone)
 368         br      %r1                   # branch to sys_clone
 369
 370 sys_fork_glue:
 371         la      %r2,SP_PTREGS(%r15)    # load pt_regs
 372         l       %r1,BASED(.Lfork)
 373         br      %r1                   # branch to sys_fork
 374
 375 sys_vfork_glue:
 376         la      %r2,SP_PTREGS(%r15)    # load pt_regs
 377         l       %r1,BASED(.Lvfork)
 378         br      %r1                   # branch to sys_vfork
 379
 380 sys_execve_glue:
 381         la      %r2,SP_PTREGS(%r15)   # load pt_regs
 382         l       %r1,BASED(.Lexecve)
 383         lr      %r12,%r14             # save return address
 384         basr    %r14,%r1              # call sys_execve
 385         ltr     %r2,%r2               # check if execve failed
 386         bnz     0(%r12)               # it did fail -> store result in gpr2
 387         b       4(%r12)               # SKIP ST 2,SP_R2(15) after BASR 14,8
 388                                       # in system_call/sysc_tracesys
 389
 390 sys_sigreturn_glue:
 391         la      %r2,SP_PTREGS(%r15)   # load pt_regs as parameter
 392         l       %r1,BASED(.Lsigreturn)
 393         br      %r1                   # branch to sys_sigreturn
 394
 395 sys_rt_sigreturn_glue:
 396         la      %r2,SP_PTREGS(%r15)   # load pt_regs as parameter
 397         l       %r1,BASED(.Lrt_sigreturn)
 398         br      %r1                   # branch to sys_sigreturn
 399
 400 #
 401 # sigsuspend and rt_sigsuspend need pt_regs as an additional
 402 # parameter and they have to skip the store of %r2 into the
 403 # user register %r2 because the return value was set in
 404 # sigsuspend and rt_sigsuspend already and must not be overwritten!
 405 #
 406
 407 sys_sigsuspend_glue:
 408         lr      %r5,%r4               # move mask back
 409         lr      %r4,%r3               # move history1 parameter
 410         lr      %r3,%r2               # move history0 parameter
 411         la      %r2,SP_PTREGS(%r15)   # load pt_regs as first parameter
 412         l       %r1,BASED(.Lsigsuspend)
 413         la      %r14,4(%r14)          # skip store of return value
 414         br      %r1                   # branch to sys_sigsuspend
 415
 416 sys_rt_sigsuspend_glue:
 417         lr      %r4,%r3               # move sigsetsize parameter
 418         lr      %r3,%r2               # move unewset parameter
 419         la      %r2,SP_PTREGS(%r15)   # load pt_regs as first parameter
 420         l       %r1,BASED(.Lrt_sigsuspend)
 421         la      %r14,4(%r14)          # skip store of return value
 422         br      %r1                   # branch to sys_rt_sigsuspend
 423
 424 sys_sigaltstack_glue:
 425         la      %r4,SP_PTREGS(%r15)   # load pt_regs as parameter
 426         l       %r1,BASED(.Lsigaltstack)
 427         br      %r1                   # branch to sys_sigreturn
 428
 429
 430 /*
 431  * Program check handler routine
 432  */
 433
 434         .globl  pgm_check_handler
 435 pgm_check_handler:
 436 /*
 437  * First we need to check for a special case:
 438  * Single stepping an instruction that disables the PER event mask will
 439  * cause a PER event AFTER the mask has been set. Example: SVC or LPSW.
 440  * For a single stepped SVC the program check handler gets control after
 441  * the SVC new PSW has been loaded. But we want to execute the SVC first and
 442  * then handle the PER event. Therefore we update the SVC old PSW to point
 443  * to the pgm_check_handler and branch to the SVC handler after we checked
 444  * if we have to load the kernel stack register.
 445  * For every other possible cause for PER event without the PER mask set
 446  * we just ignore the PER event (FIXME: is there anything we have to do
 447  * for LPSW?).
 448  */
 449         STORE_TIMER __LC_SYNC_ENTER_TIMER
 450         SAVE_ALL_BASE __LC_SAVE_AREA
 451         tm      __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception
 452         bnz     BASED(pgm_per)           # got per exception -> special case
 453         SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1
 454         CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA
 455 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 456         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
 457         bz      BASED(pgm_no_vtime)
 458         UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
 459         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
 460         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
 461 pgm_no_vtime:
 462 #endif
 463         l       %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
 464         l       %r3,__LC_PGM_ILC         # load program interruption code
 465         la      %r8,0x7f
 466         nr      %r8,%r3
 467 pgm_do_call:
 468         l       %r7,BASED(.Ljump_table)
 469         sll     %r8,2
 470         l       %r7,0(%r8,%r7)           # load address of handler routine
 471         la      %r2,SP_PTREGS(%r15)      # address of register-save area
 472         la      %r14,BASED(sysc_return)
 473         br      %r7                      # branch to interrupt-handler
 474
 475 #
 476 # handle per exception
 477 #
 478 pgm_per:
 479         tm      __LC_PGM_OLD_PSW,0x40    # test if per event recording is on
 480         bnz     BASED(pgm_per_std)       # ok, normal per event from user space
 481 # ok its one of the special cases, now we need to find out which one
 482         clc     __LC_PGM_OLD_PSW(8),__LC_SVC_NEW_PSW
 483         be      BASED(pgm_svcper)
 484 # no interesting special case, ignore PER event
 485         lm      %r12,%r15,__LC_SAVE_AREA
 486         lpsw    0x28
 487
 488 #
 489 # Normal per exception
 490 #
 491 pgm_per_std:
 492         SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1
 493         CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA
 494 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 495         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
 496         bz      BASED(pgm_no_vtime2)
 497         UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
 498         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
 499         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
 500 pgm_no_vtime2:
 501 #endif
 502         l       %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
 503         l       %r1,__TI_task(%r9)
 504         mvc     __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
 505         mvc     __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS
 506         mvc     __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
 507         oi      __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
 508         l       %r3,__LC_PGM_ILC         # load program interruption code
 509         la      %r8,0x7f
 510         nr      %r8,%r3                  # clear per-event-bit and ilc
 511         be      BASED(sysc_return)       # only per or per+check ?
 512         b       BASED(pgm_do_call)
 513
 514 #
 515 # it was a single stepped SVC that is causing all the trouble
 516 #
 517 pgm_svcper:
 518         SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
 519         CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
 520 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 521         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
 522         bz      BASED(pgm_no_vtime3)
 523         UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
 524         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
 525         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
 526 pgm_no_vtime3:
 527 #endif
 528         lh      %r7,0x8a                # get svc number from lowcore
 529         l       %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
 530         l       %r1,__TI_task(%r9)
 531         mvc     __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
 532         mvc     __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS
 533         mvc     __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
 534         oi      __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
 535         stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
 536         b       BASED(sysc_do_svc)
 537
 538 /*
 539  * IO interrupt handler routine
 540  */
 541
 542         .globl io_int_handler
 543 io_int_handler:
 544         STORE_TIMER __LC_ASYNC_ENTER_TIMER
 545         stck    __LC_INT_CLOCK
 546         SAVE_ALL_BASE __LC_SAVE_AREA+16
 547         SAVE_ALL __LC_IO_OLD_PSW,__LC_SAVE_AREA+16,0
 548         CREATE_STACK_FRAME __LC_IO_OLD_PSW,__LC_SAVE_AREA+16
 549 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 550         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
 551         bz      BASED(io_no_vtime)
 552         UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
 553         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
 554         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
 555 io_no_vtime:
 556 #endif
 557         l       %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
 558         l       %r1,BASED(.Ldo_IRQ)        # load address of do_IRQ
 559         la      %r2,SP_PTREGS(%r15) # address of register-save area
 560         basr    %r14,%r1          # branch to standard irq handler
 561
 562 io_return:
 563         tm      SP_PSW+1(%r15),0x01    # returning to user ?
 564 #ifdef CONFIG_PREEMPT
 565         bno     BASED(io_preempt)      # no -> check for preemptive scheduling
 566 #else
 567         bno     BASED(io_leave)        # no-> skip resched & signal
 568 #endif
 569         tm      __TI_flags+3(%r9),_TIF_WORK_INT
 570         bnz     BASED(io_work)         # there is work to do (signals etc.)
 571 io_leave:
 572         RESTORE_ALL __LC_RETURN_PSW,0
 573 io_done:
 574
 575 #ifdef CONFIG_PREEMPT
 576 io_preempt:
 577         icm     %r0,15,__TI_precount(%r9)
 578         bnz     BASED(io_leave)
 579         l       %r1,SP_R15(%r15)
 580         s       %r1,BASED(.Lc_spsize)
 581         mvc     SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
 582         xc      __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
 583         lr      %r15,%r1
 584 io_resume_loop:
 585         tm      __TI_flags+3(%r9),_TIF_NEED_RESCHED
 586         bno     BASED(io_leave)
 587         mvc     __TI_precount(4,%r9),BASED(.Lc_pactive)
 588         stosm   __SF_EMPTY(%r15),0x03  # reenable interrupts
 589         l       %r1,BASED(.Lschedule)
 590         basr    %r14,%r1               # call schedule
 591         stnsm   __SF_EMPTY(%r15),0xfc  # disable I/O and ext. interrupts
 592         xc      __TI_precount(4,%r9),__TI_precount(%r9)
 593         b       BASED(io_resume_loop)
 594 #endif
 595
 596 #
 597 # switch to kernel stack, then check the TIF bits
 598 #
 599 io_work:
 600         l       %r1,__LC_KERNEL_STACK
 601         s       %r1,BASED(.Lc_spsize)
 602         mvc     SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
 603         xc      __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
 604         lr      %r15,%r1
 605 #
 606 # One of the work bits is on. Find out which one.
 607 # Checked are: _TIF_SIGPENDING, _TIF_NEED_RESCHED and _TIF_MCCK_PENDING
 608 #
 609 io_work_loop:
 610         tm      __TI_flags+3(%r9),_TIF_MCCK_PENDING
 611         bo      BASED(io_mcck_pending)
 612         tm      __TI_flags+3(%r9),_TIF_NEED_RESCHED
 613         bo      BASED(io_reschedule)
 614         tm      __TI_flags+3(%r9),_TIF_SIGPENDING
 615         bo      BASED(io_sigpending)
 616         b       BASED(io_leave)
 617
 618 #
 619 # _TIF_MCCK_PENDING is set, call handler
 620 #
 621 io_mcck_pending:
 622         l       %r1,BASED(.Ls390_handle_mcck)
 623         la      %r14,BASED(io_work_loop)
 624         br      %r1                    # TIF bit will be cleared by handler
 625
 626 #
 627 # _TIF_NEED_RESCHED is set, call schedule
 628 #
 629 io_reschedule:
 630         l       %r1,BASED(.Lschedule)
 631         stosm   __SF_EMPTY(%r15),0x03  # reenable interrupts
 632         basr    %r14,%r1               # call scheduler
 633         stnsm   __SF_EMPTY(%r15),0xfc  # disable I/O and ext. interrupts
 634         tm      __TI_flags+3(%r9),_TIF_WORK_INT
 635         bz      BASED(io_leave)        # there is no work to do
 636         b       BASED(io_work_loop)
 637
 638 #
 639 # _TIF_SIGPENDING is set, call do_signal
 640 #
 641 io_sigpending:
 642         stosm   __SF_EMPTY(%r15),0x03  # reenable interrupts
 643         la      %r2,SP_PTREGS(%r15)    # load pt_regs
 644         sr      %r3,%r3                # clear *oldset
 645         l       %r1,BASED(.Ldo_signal)
 646         basr    %r14,%r1               # call do_signal
 647         stnsm   __SF_EMPTY(%r15),0xfc  # disable I/O and ext. interrupts
 648         b       BASED(io_leave)        # out of here, do NOT recheck
 649
 650 /*
 651  * External interrupt handler routine
 652  */
 653
 654         .globl  ext_int_handler
 655 ext_int_handler:
 656         STORE_TIMER __LC_ASYNC_ENTER_TIMER
 657         stck    __LC_INT_CLOCK
 658         SAVE_ALL_BASE __LC_SAVE_AREA+16
 659         SAVE_ALL __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16,0
 660         CREATE_STACK_FRAME __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16
 661 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 662         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
 663         bz      BASED(ext_no_vtime)
 664         UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
 665         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
 666         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
 667 ext_no_vtime:
 668 #endif
 669         l       %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
 670         la      %r2,SP_PTREGS(%r15)    # address of register-save area
 671         lh      %r3,__LC_EXT_INT_CODE  # get interruption code
 672         l       %r1,BASED(.Ldo_extint)
 673         basr    %r14,%r1
 674         b       BASED(io_return)
 675
 676 __critical_end:
 677
 678 /*
 679  * Machine check handler routines
 680  */
 681
 682         .globl mcck_int_handler
 683 mcck_int_handler:
 684         spt     __LC_CPU_TIMER_SAVE_AREA        # revalidate cpu timer
 685         mvc     __LC_ASYNC_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA
 686         lm      %r0,%r15,__LC_GPREGS_SAVE_AREA  # revalidate gprs
 687         SAVE_ALL_BASE __LC_SAVE_AREA+32
 688         la      %r12,__LC_MCK_OLD_PSW
 689         tm      __LC_MCCK_CODE,0x80     # system damage?
 690         bo      BASED(mcck_int_main)    # yes -> rest of mcck code invalid
 691         tm      __LC_MCCK_CODE+5,0x02   # stored cpu timer value valid?
 692         bo      BASED(0f)
 693         spt     __LC_LAST_UPDATE_TIMER  # revalidate cpu timer
 694 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 695         mvc     __LC_ASYNC_ENTER_TIMER(8),__LC_LAST_UPDATE_TIMER
 696         mvc     __LC_SYNC_ENTER_TIMER(8),__LC_LAST_UPDATE_TIMER
 697         mvc     __LC_EXIT_TIMER(8),__LC_LAST_UPDATE_TIMER
 698 #endif
 699 0:      tm      __LC_MCCK_CODE+2,0x09   # mwp + ia of old psw valid?
 700         bno     BASED(mcck_int_main)    # no -> skip cleanup critical
 701         tm      __LC_MCK_OLD_PSW+1,0x01 # test problem state bit
 702         bnz     BASED(mcck_int_main)    # from user -> load async stack
 703         clc     __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_end)
 704         bhe     BASED(mcck_int_main)
 705         clc     __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_start)
 706         bl      BASED(mcck_int_main)
 707         l       %r14,BASED(.Lcleanup_critical)
 708         basr    %r14,%r14
 709 mcck_int_main:
 710         l       %r14,__LC_PANIC_STACK   # are we already on the panic stack?
 711         slr     %r14,%r15
 712         sra     %r14,PAGE_SHIFT
 713         be      BASED(0f)
 714         l       %r15,__LC_PANIC_STACK   # load panic stack
 715 0:      CREATE_STACK_FRAME __LC_MCK_OLD_PSW,__LC_SAVE_AREA+32
 716 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 717         tm      __LC_MCCK_CODE+2,0x08   # mwp of old psw valid?
 718         bno     BASED(mcck_no_vtime)    # no -> skip cleanup critical
 719         tm      __LC_MCK_OLD_PSW+1,0x01 # interrupting from user ?
 720         bz      BASED(mcck_no_vtime)
 721         UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
 722         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
 723         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
 724 mcck_no_vtime:
 725 #endif
 726         l       %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
 727         la      %r2,SP_PTREGS(%r15)     # load pt_regs
 728         l       %r1,BASED(.Ls390_mcck)
 729         basr    %r14,%r1                # call machine check handler
 730         tm      SP_PSW+1(%r15),0x01     # returning to user ?
 731         bno     BASED(mcck_return)
 732         l       %r1,__LC_KERNEL_STACK   # switch to kernel stack
 733         s       %r1,BASED(.Lc_spsize)
 734         mvc     SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
 735         xc      __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
 736         lr      %r15,%r1
 737         stosm   __SF_EMPTY(%r15),0x04   # turn dat on
 738         tm      __TI_flags+3(%r9),_TIF_MCCK_PENDING
 739         bno     BASED(mcck_return)
 740         l       %r1,BASED(.Ls390_handle_mcck)
 741         basr    %r14,%r1                # call machine check handler
 742 mcck_return:
 743         RESTORE_ALL __LC_RETURN_MCCK_PSW,0
 744
 745 #ifdef CONFIG_SMP
 746 /*
 747  * Restart interruption handler, kick starter for additional CPUs
 748  */
 749         .globl restart_int_handler
 750 restart_int_handler:
 751         l       %r15,__LC_SAVE_AREA+60 # load ksp
 752         lctl    %c0,%c15,__LC_CREGS_SAVE_AREA # get new ctl regs
 753         lam     %a0,%a15,__LC_AREGS_SAVE_AREA
 754         lm      %r6,%r15,__SF_GPRS(%r15) # load registers from clone
 755         stosm   __SF_EMPTY(%r15),0x04    # now we can turn dat on
 756         basr    %r14,0
 757         l       %r14,restart_addr-.(%r14)
 758         br      %r14                   # branch to start_secondary
 759 restart_addr:
 760         .long   start_secondary
 761 #else
 762 /*
 763  * If we do not run with SMP enabled, let the new CPU crash ...
 764  */
 765         .globl restart_int_handler
 766 restart_int_handler:
 767         basr    %r1,0
 768 restart_base:
 769         lpsw    restart_crash-restart_base(%r1)
 770         .align 8
 771 restart_crash:
 772         .long  0x000a0000,0x00000000
 773 restart_go:
 774 #endif
 775
 776 #ifdef CONFIG_CHECK_STACK
 777 /*
 778  * The synchronous or the asynchronous stack overflowed. We are dead.
 779  * No need to properly save the registers, we are going to panic anyway.
 780  * Setup a pt_regs so that show_trace can provide a good call trace.
 781  */
 782 stack_overflow:
 783         l       %r15,__LC_PANIC_STACK   # change to panic stack
 784         sl      %r15,BASED(.Lc_spsize)
 785         mvc     SP_PSW(8,%r15),0(%r12)  # move user PSW to stack
 786         stm     %r0,%r11,SP_R0(%r15)    # store gprs %r0-%r11 to kernel stack
 787         la      %r1,__LC_SAVE_AREA
 788         ch      %r12,BASED(.L0x020)     # old psw addr == __LC_SVC_OLD_PSW ?
 789         be      BASED(0f)
 790         ch      %r12,BASED(.L0x028)     # old psw addr == __LC_PGM_OLD_PSW ?
 791         be      BASED(0f)
 792         la      %r1,__LC_SAVE_AREA+16
 793 0:      mvc     SP_R12(16,%r15),0(%r1)  # move %r12-%r15 to stack
 794         xc      __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear back chain
 795         l       %r1,BASED(1f)           # branch to kernel_stack_overflow
 796         la      %r2,SP_PTREGS(%r15)     # load pt_regs
 797         br      %r1
 798 1:      .long  kernel_stack_overflow
 799 #endif
 800
 801 cleanup_table_system_call:
 802         .long   system_call + 0x80000000, sysc_do_svc + 0x80000000
 803 cleanup_table_sysc_return:
 804         .long   sysc_return + 0x80000000, sysc_leave + 0x80000000
 805 cleanup_table_sysc_leave:
 806         .long   sysc_leave + 0x80000000, sysc_work_loop + 0x80000000
 807 cleanup_table_sysc_work_loop:
 808         .long   sysc_work_loop + 0x80000000, sysc_reschedule + 0x80000000
 809 cleanup_table_io_leave:
 810         .long   io_leave + 0x80000000, io_done + 0x80000000
 811 cleanup_table_io_work_loop:
 812         .long   io_work_loop + 0x80000000, io_mcck_pending + 0x80000000
 813
 814 cleanup_critical:
 815         clc     4(4,%r12),BASED(cleanup_table_system_call)
 816         bl      BASED(0f)
 817         clc     4(4,%r12),BASED(cleanup_table_system_call+4)
 818         bl      BASED(cleanup_system_call)
 819 0:
 820         clc     4(4,%r12),BASED(cleanup_table_sysc_return)
 821         bl      BASED(0f)
 822         clc     4(4,%r12),BASED(cleanup_table_sysc_return+4)
 823         bl      BASED(cleanup_sysc_return)
 824 0:
 825         clc     4(4,%r12),BASED(cleanup_table_sysc_leave)
 826         bl      BASED(0f)
 827         clc     4(4,%r12),BASED(cleanup_table_sysc_leave+4)
 828         bl      BASED(cleanup_sysc_leave)
 829 0:
 830         clc     4(4,%r12),BASED(cleanup_table_sysc_work_loop)
 831         bl      BASED(0f)
 832         clc     4(4,%r12),BASED(cleanup_table_sysc_work_loop+4)
 833         bl      BASED(cleanup_sysc_return)
 834 0:
 835         clc     4(4,%r12),BASED(cleanup_table_io_leave)
 836         bl      BASED(0f)
 837         clc     4(4,%r12),BASED(cleanup_table_io_leave+4)
 838         bl      BASED(cleanup_io_leave)
 839 0:
 840         clc     4(4,%r12),BASED(cleanup_table_io_work_loop)
 841         bl      BASED(0f)
 842         clc     4(4,%r12),BASED(cleanup_table_io_work_loop+4)
 843         bl      BASED(cleanup_io_return)
 844 0:
 845         br      %r14
 846
 847 cleanup_system_call:
 848         mvc     __LC_RETURN_PSW(8),0(%r12)
 849         c       %r12,BASED(.Lmck_old_psw)
 850         be      BASED(0f)
 851         la      %r12,__LC_SAVE_AREA+16
 852         b       BASED(1f)
 853 0:      la      %r12,__LC_SAVE_AREA+32
 854 1:
 855 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 856         clc     __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+4)
 857         bh      BASED(0f)
 858         mvc     __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
 859 0:      clc     __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+8)
 860         bhe     BASED(cleanup_vtime)
 861 #endif
 862         clc     __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn)
 863         bh      BASED(0f)
 864         mvc     __LC_SAVE_AREA(16),0(%r12)
 865 0:      st      %r13,4(%r12)
 866         st      %r12,__LC_SAVE_AREA+48  # argh
 867         SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
 868         CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
 869         l       %r12,__LC_SAVE_AREA+48  # argh
 870         st      %r15,12(%r12)
 871         lh      %r7,0x8a
 872 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 873 cleanup_vtime:
 874         clc     __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+12)
 875         bhe     BASED(cleanup_stime)
 876         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
 877         bz      BASED(cleanup_novtime)
 878         UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
 879 cleanup_stime:
 880         clc     __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+16)
 881         bh      BASED(cleanup_update)
 882         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
 883 cleanup_update:
 884         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
 885 cleanup_novtime:
 886 #endif
 887         mvc     __LC_RETURN_PSW+4(4),BASED(cleanup_table_system_call+4)
 888         la      %r12,__LC_RETURN_PSW
 889         br      %r14
 890 cleanup_system_call_insn:
 891         .long   sysc_saveall + 0x80000000
 892 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 893         .long   system_call + 0x80000000
 894         .long   sysc_vtime + 0x80000000
 895         .long   sysc_stime + 0x80000000
 896         .long   sysc_update + 0x80000000
 897 #endif
 898
 899 cleanup_sysc_return:
 900         mvc     __LC_RETURN_PSW(4),0(%r12)
 901         mvc     __LC_RETURN_PSW+4(4),BASED(cleanup_table_sysc_return)
 902         la      %r12,__LC_RETURN_PSW
 903         br      %r14
 904
 905 cleanup_sysc_leave:
 906         clc     4(4,%r12),BASED(cleanup_sysc_leave_insn)
 907         be      BASED(2f)
 908 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 909         mvc     __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
 910         clc     4(4,%r12),BASED(cleanup_sysc_leave_insn+4)
 911         be      BASED(2f)
 912 #endif
 913         mvc     __LC_RETURN_PSW(8),SP_PSW(%r15)
 914         c       %r12,BASED(.Lmck_old_psw)
 915         bne     BASED(0f)
 916         mvc     __LC_SAVE_AREA+32(16),SP_R12(%r15)
 917         b       BASED(1f)
 918 0:      mvc     __LC_SAVE_AREA+16(16),SP_R12(%r15)
 919 1:      lm      %r0,%r11,SP_R0(%r15)
 920         l       %r15,SP_R15(%r15)
 921 2:      la      %r12,__LC_RETURN_PSW
 922         br      %r14
 923 cleanup_sysc_leave_insn:
 924 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 925         .long   sysc_leave + 14 + 0x80000000
 926 #endif
 927         .long   sysc_leave + 10 + 0x80000000
 928
 929 cleanup_io_return:
 930         mvc     __LC_RETURN_PSW(4),0(%r12)
 931         mvc     __LC_RETURN_PSW+4(4),BASED(cleanup_table_io_work_loop)
 932         la      %r12,__LC_RETURN_PSW
 933         br      %r14
 934
 935 cleanup_io_leave:
 936         clc     4(4,%r12),BASED(cleanup_io_leave_insn)
 937         be      BASED(2f)
 938 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 939         mvc     __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
 940         clc     4(4,%r12),BASED(cleanup_io_leave_insn+4)
 941         be      BASED(2f)
 942 #endif
 943         mvc     __LC_RETURN_PSW(8),SP_PSW(%r15)
 944         c       %r12,BASED(.Lmck_old_psw)
 945         bne     BASED(0f)
 946         mvc     __LC_SAVE_AREA+32(16),SP_R12(%r15)
 947         b       BASED(1f)
 948 0:      mvc     __LC_SAVE_AREA+16(16),SP_R12(%r15)
 949 1:      lm      %r0,%r11,SP_R0(%r15)
 950         l       %r15,SP_R15(%r15)
 951 2:      la      %r12,__LC_RETURN_PSW
 952         br      %r14
 953 cleanup_io_leave_insn:
 954 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 955         .long   io_leave + 18 + 0x80000000
 956 #endif
 957         .long   io_leave + 14 + 0x80000000
 958
 959 /*
 960  * Integer constants
 961  */
 962                .align 4
 963 .Lc_spsize:    .long  SP_SIZE
 964 .Lc_overhead:  .long  STACK_FRAME_OVERHEAD
 965 .Lc_pactive:   .long  PREEMPT_ACTIVE
 966 .Lnr_syscalls: .long  NR_syscalls
 967 .L0x018:       .short 0x018
 968 .L0x020:       .short 0x020
 969 .L0x028:       .short 0x028
 970 .L0x030:       .short 0x030
 971 .L0x038:       .short 0x038
 972 .Lc_1:         .long  1
 973
 974 /*
 975  * Symbol constants
 976  */
 977 .Ls390_mcck:   .long  s390_do_machine_check
 978 .Ls390_handle_mcck:
 979                .long  s390_handle_mcck
 980 .Lmck_old_psw: .long  __LC_MCK_OLD_PSW
 981 .Ldo_IRQ:      .long  do_IRQ
 982 .Ldo_extint:   .long  do_extint
 983 .Ldo_signal:   .long  do_signal
 984 .Lhandle_per:  .long  do_single_step
 985 .Ljump_table:  .long  pgm_check_table
 986 .Lschedule:    .long  schedule
 987 .Lclone:       .long  sys_clone
 988 .Lexecve:      .long  sys_execve
 989 .Lfork:        .long  sys_fork
 990 .Lrt_sigreturn:.long  sys_rt_sigreturn
 991 .Lrt_sigsuspend:
 992                .long  sys_rt_sigsuspend
 993 .Lsigreturn:   .long  sys_sigreturn
 994 .Lsigsuspend:  .long  sys_sigsuspend
 995 .Lsigaltstack: .long  sys_sigaltstack
 996 .Ltrace:       .long  syscall_trace
 997 .Lvfork:       .long  sys_vfork
 998 .Lschedtail:   .long  schedule_tail
 999
1000 .Lcritical_start:
1001                .long  __critical_start + 0x80000000
1002 .Lcritical_end:
1003                .long  __critical_end + 0x80000000
1004 .Lcleanup_critical:
1005                .long  cleanup_critical
1006
1007 #define SYSCALL(esa,esame,emu)  .long esa
1008         .globl  sys_call_table
1009 sys_call_table:
1010 #include "syscalls.S"
1011 #undef SYSCALL
1012