arch/s390/kernel/entry.S

   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  */
  28 SP_PTREGS    =  STACK_FRAME_OVERHEAD
  29 SP_ARGS      =  STACK_FRAME_OVERHEAD + __PT_ARGS
  30 SP_PSW       =  STACK_FRAME_OVERHEAD + __PT_PSW
  31 SP_R0        =  STACK_FRAME_OVERHEAD + __PT_GPRS
  32 SP_R1        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 4
  33 SP_R2        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 8
  34 SP_R3        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 12
  35 SP_R4        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 16
  36 SP_R5        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 20
  37 SP_R6        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 24
  38 SP_R7        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 28
  39 SP_R8        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 32
  40 SP_R9        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 36
  41 SP_R10       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 40
  42 SP_R11       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 44
  43 SP_R12       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 48
  44 SP_R13       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 52
  45 SP_R14       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 56
  46 SP_R15       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 60
  47 SP_ORIG_R2   =  STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
  48 SP_ILC       =  STACK_FRAME_OVERHEAD + __PT_ILC
  49 SP_TRAP      =  STACK_FRAME_OVERHEAD + __PT_TRAP
  50 SP_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
  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 | _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 #
 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 or _TIF_RESTORE_SIGMASK 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         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 #
 295 sysc_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 #
 306 sysc_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 #
 317 sysc_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)
 329 sysc_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
 334 sysc_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
 347 ret_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
 353 0:      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 #
 364 sys_clone_glue:
 365         la      %r2,SP_PTREGS(%r15)    # load pt_regs
 366         l       %r1,BASED(.Lclone)
 367         br      %r1                   # branch to sys_clone
 368
 369 sys_fork_glue:
 370         la      %r2,SP_PTREGS(%r15)    # load pt_regs
 371         l       %r1,BASED(.Lfork)
 372         br      %r1                   # branch to sys_fork
 373
 374 sys_vfork_glue:
 375         la      %r2,SP_PTREGS(%r15)    # load pt_regs
 376         l       %r1,BASED(.Lvfork)
 377         br      %r1                   # branch to sys_vfork
 378
 379 sys_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
 389 sys_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
 394 sys_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
 399 sys_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
 410 pgm_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
 436 pgm_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
 442 pgm_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 #
 453 pgm_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 #
 466 pgm_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
 475 pgm_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 #
 492 pgm_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
 501 pgm_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
 518 io_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
 530 io_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
 537 io_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.)
 546 io_leave:
 547         RESTORE_ALL __LC_RETURN_PSW,0
 548 io_done:
 549
 550 #ifdef CONFIG_PREEMPT
 551 io_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
 559 io_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 #
 574 io_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 #
 585 io_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 #
 597 io_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 #
 605 io_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 #
 617 io_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
 630 ext_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
 642 ext_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
 658 mcck_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
 674 0:      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
 684 mcck_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
 690 0:      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
 699 mcck_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
 717 mcck_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
 725 restart_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
 734 restart_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
 741 restart_int_handler:
 742         basr    %r1,0
 743 restart_base:
 744         lpsw    restart_crash-restart_base(%r1)
 745         .align 8
 746 restart_crash:
 747         .long  0x000a0000,0x00000000
 748 restart_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  */
 757 stack_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
 768 0:      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
 773 1:      .long  kernel_stack_overflow
 774 #endif
 775
 776 cleanup_table_system_call:
 777         .long   system_call + 0x80000000, sysc_do_svc + 0x80000000
 778 cleanup_table_sysc_return:
 779         .long   sysc_return + 0x80000000, sysc_leave + 0x80000000
 780 cleanup_table_sysc_leave:
 781         .long   sysc_leave + 0x80000000, sysc_work_loop + 0x80000000
 782 cleanup_table_sysc_work_loop:
 783         .long   sysc_work_loop + 0x80000000, sysc_reschedule + 0x80000000
 784 cleanup_table_io_leave:
 785         .long   io_leave + 0x80000000, io_done + 0x80000000
 786 cleanup_table_io_work_loop:
 787         .long   io_work_loop + 0x80000000, io_mcck_pending + 0x80000000
 788
 789 cleanup_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)
 794 0:
 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)
 799 0:
 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)
 804 0:
 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)
 809 0:
 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)
 814 0:
 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)
 819 0:
 820         br      %r14
 821
 822 cleanup_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)
 828 0:      la      %r12,__LC_SAVE_AREA+32
 829 1:
 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
 834 0:      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)
 840 0:      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
 848 cleanup_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
 854 cleanup_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
 858 cleanup_update:
 859         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
 860 cleanup_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
 865 cleanup_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
 874 cleanup_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
 880 cleanup_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)
 893 0:      mvc     __LC_SAVE_AREA+16(16),SP_R12(%r15)
 894 1:      lm      %r0,%r11,SP_R0(%r15)
 895         l       %r15,SP_R15(%r15)
 896 2:      la      %r12,__LC_RETURN_PSW
 897         br      %r14
 898 cleanup_sysc_leave_insn:
 899 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 900         .long   sysc_leave + 14 + 0x80000000
 901 #endif
 902         .long   sysc_leave + 10 + 0x80000000
 903
 904 cleanup_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
 910 cleanup_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)
 923 0:      mvc     __LC_SAVE_AREA+16(16),SP_R12(%r15)
 924 1:      lm      %r0,%r11,SP_R0(%r15)
 925         l       %r15,SP_R15(%r15)
 926 2:      la      %r12,__LC_RETURN_PSW
 927         br      %r14
 928 cleanup_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
 984 sys_call_table:
 985 #include "syscalls.S"
 986 #undef SYSCALL
 987