Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 881 insertions, 0 deletions

diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
new file mode 100644
index 00000000000..51527ab8c8f
--- /dev/null
+++ b/arch/s390/kernel/entry64.S
@@ -0,0 +1,881 @@
+/*
+ *  arch/s390/kernel/entry.S
+ *    S390 low-level entry points.
+ *
+ *  S390 version
+ *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
+ *               Hartmut Penner (hp@de.ibm.com),
+ *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
+ */
+
+#include <linux/sys.h>
+#include <linux/linkage.h>
+#include <linux/config.h>
+#include <asm/cache.h>
+#include <asm/lowcore.h>
+#include <asm/errno.h>
+#include <asm/ptrace.h>
+#include <asm/thread_info.h>
+#include <asm/offsets.h>
+#include <asm/unistd.h>
+#include <asm/page.h>
+
+/*
+ * Stack layout for the system_call stack entry.
+ * The first few entries are identical to the user_regs_struct.
+ */
+SP_PTREGS    =  STACK_FRAME_OVERHEAD
+SP_ARGS      =  STACK_FRAME_OVERHEAD + __PT_ARGS
+SP_PSW       =  STACK_FRAME_OVERHEAD + __PT_PSW
+SP_R0        =  STACK_FRAME_OVERHEAD + __PT_GPRS
+SP_R1        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 8
+SP_R2        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 16
+SP_R3        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 24
+SP_R4        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 32
+SP_R5        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 40
+SP_R6        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 48
+SP_R7        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 56
+SP_R8        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 64
+SP_R9        =  STACK_FRAME_OVERHEAD + __PT_GPRS + 72
+SP_R10       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 80
+SP_R11       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 88
+SP_R12       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 96
+SP_R13       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 104
+SP_R14       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 112
+SP_R15       =  STACK_FRAME_OVERHEAD + __PT_GPRS + 120
+SP_ORIG_R2   =  STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
+SP_ILC       =  STACK_FRAME_OVERHEAD + __PT_ILC
+SP_TRAP      =  STACK_FRAME_OVERHEAD + __PT_TRAP
+SP_SIZE      =  STACK_FRAME_OVERHEAD + __PT_SIZE
+
+STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
+STACK_SIZE  = 1 << STACK_SHIFT
+
+_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
+		 _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
+_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
+
+#define BASED(name) name-system_call(%r13)
+
+	.macro  STORE_TIMER lc_offset
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	stpt	\lc_offset
+#endif
+	.endm
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	.macro  UPDATE_VTIME lc_from,lc_to,lc_sum
+	lg	%r10,\lc_from
+	slg	%r10,\lc_to
+	alg	%r10,\lc_sum
+	stg	%r10,\lc_sum
+	.endm
+#endif
+
+/*
+ * Register usage in interrupt handlers:
+ *    R9  - pointer to current task structure
+ *    R13 - pointer to literal pool
+ *    R14 - return register for function calls
+ *    R15 - kernel stack pointer
+ */
+
+        .macro  SAVE_ALL_BASE savearea
+	stmg	%r12,%r15,\savearea
+	larl	%r13,system_call
+	.endm
+
+        .macro  SAVE_ALL psworg,savearea,sync
+	la	%r12,\psworg
+	.if	\sync
+	tm	\psworg+1,0x01		# test problem state bit
+	jz	2f			# skip stack setup save
+	lg	%r15,__LC_KERNEL_STACK	# problem state -> load ksp
+	.else
+	tm	\psworg+1,0x01		# test problem state bit
+	jnz	1f			# from user -> load kernel stack
+	clc	\psworg+8(8),BASED(.Lcritical_end)
+	jhe	0f
+	clc	\psworg+8(8),BASED(.Lcritical_start)
+	jl	0f
+	brasl	%r14,cleanup_critical
+	tm	0(%r12),0x01		# retest problem state after cleanup
+	jnz	1f
+0:	lg	%r14,__LC_ASYNC_STACK	# are we already on the async. stack ?
+	slgr	%r14,%r15
+	srag	%r14,%r14,STACK_SHIFT
+	jz	2f
+1:	lg	%r15,__LC_ASYNC_STACK	# load async stack
+	.endif
+#ifdef CONFIG_CHECK_STACK
+	j	3f
+2:	tml	%r15,STACK_SIZE - CONFIG_STACK_GUARD
+	jz	stack_overflow
+3:
+#endif
+2:	aghi    %r15,-SP_SIZE		# make room for registers & psw
+	mvc     SP_PSW(16,%r15),0(%r12)	# move user PSW to stack
+	la	%r12,\psworg
+	stg	%r2,SP_ORIG_R2(%r15)	# store original content of gpr 2
+	icm	%r12,12,__LC_SVC_ILC
+	stmg	%r0,%r11,SP_R0(%r15)	# store gprs %r0-%r11 to kernel stack
+	st	%r12,SP_ILC(%r15)
+	mvc	SP_R12(32,%r15),\savearea # move %r12-%r15 to stack
+	la	%r12,0
+	stg	%r12,__SF_BACKCHAIN(%r15)
+        .endm
+
+	.macro	RESTORE_ALL sync
+	mvc	__LC_RETURN_PSW(16),SP_PSW(%r15) # move user PSW to lowcore
+	.if !\sync
+	ni	__LC_RETURN_PSW+1,0xfd	# clear wait state bit
+	.endif
+	lmg	%r0,%r15,SP_R0(%r15)	# load gprs 0-15 of user
+	STORE_TIMER __LC_EXIT_TIMER
+	lpswe	__LC_RETURN_PSW		# back to caller
+	.endm
+
+/*
+ * Scheduler resume function, called by switch_to
+ *  gpr2 = (task_struct *) prev
+ *  gpr3 = (task_struct *) next
+ * Returns:
+ *  gpr2 = prev
+ */
+        .globl  __switch_to
+__switch_to:
+	tm	__THREAD_per+4(%r3),0xe8 # is the new process using per ?
+	jz	__switch_to_noper		# if not we're fine
+        stctg   %c9,%c11,__SF_EMPTY(%r15)# We are using per stuff
+        clc     __THREAD_per(24,%r3),__SF_EMPTY(%r15)
+        je      __switch_to_noper            # we got away without bashing TLB's
+        lctlg   %c9,%c11,__THREAD_per(%r3)	# Nope we didn't
+__switch_to_noper:
+        stmg    %r6,%r15,__SF_GPRS(%r15)# store __switch_to registers of prev task
+	stg	%r15,__THREAD_ksp(%r2)	# store kernel stack to prev->tss.ksp
+	lg	%r15,__THREAD_ksp(%r3)	# load kernel stack from next->tss.ksp
+        lmg     %r6,%r15,__SF_GPRS(%r15)# load __switch_to registers of next task
+	stg	%r3,__LC_CURRENT	# __LC_CURRENT = current task struct
+	lctl	%c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
+	lg	%r3,__THREAD_info(%r3)  # load thread_info from task struct
+	stg	%r3,__LC_THREAD_INFO
+	aghi	%r3,STACK_SIZE
+	stg	%r3,__LC_KERNEL_STACK	# __LC_KERNEL_STACK = new kernel stack
+	br	%r14
+
+__critical_start:
+/*
+ * SVC interrupt handler routine. System calls are synchronous events and
+ * are executed with interrupts enabled.
+ */
+
+	.globl  system_call
+system_call:
+	STORE_TIMER __LC_SYNC_ENTER_TIMER
+sysc_saveall:
+	SAVE_ALL_BASE __LC_SAVE_AREA
+        SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
+	llgh    %r7,__LC_SVC_INT_CODE # get svc number from lowcore
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+sysc_vtime:
+	tm	SP_PSW+1(%r15),0x01	# interrupting from user ?
+	jz	sysc_do_svc
+	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
+sysc_stime:
+	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
+sysc_update:
+	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
+#endif
+sysc_do_svc:
+	lg	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+        slag    %r7,%r7,2         # *4 and test for svc 0
+	jnz	sysc_nr_ok
+	# svc 0: system call number in %r1
+	cl	%r1,BASED(.Lnr_syscalls)
+	jnl	sysc_nr_ok
+	lgfr	%r7,%r1           # clear high word in r1
+	slag    %r7,%r7,2         # svc 0: system call number in %r1
+sysc_nr_ok:
+	mvc	SP_ARGS(8,%r15),SP_R7(%r15)
+sysc_do_restart:
+	larl    %r10,sys_call_table
+#ifdef CONFIG_S390_SUPPORT
+        tm      SP_PSW+3(%r15),0x01  # are we running in 31 bit mode ?
+        jo      sysc_noemu
+	larl    %r10,sys_call_table_emu  # use 31 bit emulation system calls
+sysc_noemu:
+#endif
+	tm	__TI_flags+7(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
+        lgf     %r8,0(%r7,%r10)   # load address of system call routine
+        jnz     sysc_tracesys
+        basr    %r14,%r8          # call sys_xxxx
+        stg     %r2,SP_R2(%r15)   # store return value (change R2 on stack)
+                                  # ATTENTION: check sys_execve_glue before
+                                  # changing anything here !!
+
+sysc_return:
+        tm      SP_PSW+1(%r15),0x01    # returning to user ?
+        jno     sysc_leave
+	tm	__TI_flags+7(%r9),_TIF_WORK_SVC
+	jnz	sysc_work         # there is work to do (signals etc.)
+sysc_leave:
+        RESTORE_ALL 1
+
+#
+# recheck if there is more work to do
+#
+sysc_work_loop:
+	tm	__TI_flags+7(%r9),_TIF_WORK_SVC
+	jz	sysc_leave        # there is no work to do
+#
+# One of the work bits is on. Find out which one.
+#
+sysc_work:
+	tm	__TI_flags+7(%r9),_TIF_NEED_RESCHED
+	jo	sysc_reschedule
+	tm	__TI_flags+7(%r9),_TIF_SIGPENDING
+	jo	sysc_sigpending
+	tm	__TI_flags+7(%r9),_TIF_RESTART_SVC
+	jo	sysc_restart
+	tm	__TI_flags+7(%r9),_TIF_SINGLE_STEP
+	jo	sysc_singlestep
+	j	sysc_leave
+
+#
+# _TIF_NEED_RESCHED is set, call schedule
+#	
+sysc_reschedule:        
+	larl    %r14,sysc_work_loop
+        jg      schedule            # return point is sysc_return
+
+#
+# _TIF_SIGPENDING is set, call do_signal
+#
+sysc_sigpending:     
+	ni	__TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
+        la      %r2,SP_PTREGS(%r15) # load pt_regs
+        sgr     %r3,%r3           # clear *oldset
+	brasl	%r14,do_signal    # call do_signal
+	tm	__TI_flags+7(%r9),_TIF_RESTART_SVC
+	jo	sysc_restart
+	tm	__TI_flags+7(%r9),_TIF_SINGLE_STEP
+	jo	sysc_singlestep
+	j	sysc_leave        # out of here, do NOT recheck
+
+#
+# _TIF_RESTART_SVC is set, set up registers and restart svc
+#
+sysc_restart:
+	ni	__TI_flags+7(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
+	lg	%r7,SP_R2(%r15)        # load new svc number
+        slag    %r7,%r7,2              # *4
+	mvc	SP_R2(8,%r15),SP_ORIG_R2(%r15) # restore first argument
+	lmg	%r2,%r6,SP_R2(%r15)    # load svc arguments
+	j	sysc_do_restart        # restart svc
+
+#
+# _TIF_SINGLE_STEP is set, call do_single_step
+#
+sysc_singlestep:
+	ni	__TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
+	lhi	%r0,__LC_PGM_OLD_PSW
+	sth	%r0,SP_TRAP(%r15)	# set trap indication to pgm check
+	la	%r2,SP_PTREGS(%r15)	# address of register-save area
+	larl	%r14,sysc_return	# load adr. of system return
+	jg	do_single_step		# branch to do_sigtrap
+
+
+__critical_end:
+
+#
+# call syscall_trace before and after system call
+# special linkage: %r12 contains the return address for trace_svc
+#
+sysc_tracesys:
+	la	%r2,SP_PTREGS(%r15)    # load pt_regs
+	la	%r3,0
+	srl	%r7,2
+	stg     %r7,SP_R2(%r15)
+        brasl   %r14,syscall_trace
+	lghi	%r0,NR_syscalls
+	clg	%r0,SP_R2(%r15)
+	jnh	sysc_tracenogo
+	lg	%r7,SP_R2(%r15)   # strace might have changed the
+	sll     %r7,2             #  system call
+	lgf	%r8,0(%r7,%r10)
+sysc_tracego:
+	lmg     %r3,%r6,SP_R3(%r15)
+	lg      %r2,SP_ORIG_R2(%r15)
+        basr    %r14,%r8            # call sys_xxx
+        stg     %r2,SP_R2(%r15)     # store return value
+sysc_tracenogo:
+	tm	__TI_flags+7(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
+        jz      sysc_return
+	la	%r2,SP_PTREGS(%r15)    # load pt_regs
+	la	%r3,1
+	larl	%r14,sysc_return    # return point is sysc_return
+	jg	syscall_trace
+
+#
+# a new process exits the kernel with ret_from_fork
+#
+        .globl  ret_from_fork
+ret_from_fork:
+	lg	%r13,__LC_SVC_NEW_PSW+8
+	lg	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+	tm	SP_PSW+1(%r15),0x01	# forking a kernel thread ?
+	jo	0f
+	stg	%r15,SP_R15(%r15)	# store stack pointer for new kthread
+0:	brasl   %r14,schedule_tail
+        stosm   24(%r15),0x03     # reenable interrupts
+	j	sysc_return
+
+#
+# clone, fork, vfork, exec and sigreturn need glue,
+# because they all expect pt_regs as parameter,
+# but are called with different parameter.
+# return-address is set up above
+#
+sys_clone_glue: 
+        la      %r2,SP_PTREGS(%r15)    # load pt_regs
+        jg      sys_clone              # branch to sys_clone
+
+#ifdef CONFIG_S390_SUPPORT
+sys32_clone_glue: 
+        la      %r2,SP_PTREGS(%r15)    # load pt_regs
+        jg      sys32_clone            # branch to sys32_clone
+#endif
+
+sys_fork_glue:  
+        la      %r2,SP_PTREGS(%r15)    # load pt_regs
+        jg      sys_fork               # branch to sys_fork
+
+sys_vfork_glue: 
+        la      %r2,SP_PTREGS(%r15)    # load pt_regs
+        jg      sys_vfork              # branch to sys_vfork
+
+sys_execve_glue:        
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs
+	lgr     %r12,%r14             # save return address
+        brasl   %r14,sys_execve       # call sys_execve
+        ltgr    %r2,%r2               # check if execve failed
+        bnz     0(%r12)               # it did fail -> store result in gpr2
+        b       6(%r12)               # SKIP STG 2,SP_R2(15) in
+                                      # system_call/sysc_tracesys
+#ifdef CONFIG_S390_SUPPORT
+sys32_execve_glue:        
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs
+	lgr     %r12,%r14             # save return address
+        brasl   %r14,sys32_execve     # call sys32_execve
+        ltgr    %r2,%r2               # check if execve failed
+        bnz     0(%r12)               # it did fail -> store result in gpr2
+        b       6(%r12)               # SKIP STG 2,SP_R2(15) in
+                                      # system_call/sysc_tracesys
+#endif
+
+sys_sigreturn_glue:     
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as parameter
+        jg      sys_sigreturn         # branch to sys_sigreturn
+
+#ifdef CONFIG_S390_SUPPORT
+sys32_sigreturn_glue:     
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as parameter
+        jg      sys32_sigreturn       # branch to sys32_sigreturn
+#endif
+
+sys_rt_sigreturn_glue:     
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as parameter
+        jg      sys_rt_sigreturn      # branch to sys_sigreturn
+
+#ifdef CONFIG_S390_SUPPORT
+sys32_rt_sigreturn_glue:     
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as parameter
+        jg      sys32_rt_sigreturn    # branch to sys32_sigreturn
+#endif
+
+#
+# sigsuspend and rt_sigsuspend need pt_regs as an additional
+# parameter and they have to skip the store of %r2 into the
+# user register %r2 because the return value was set in 
+# sigsuspend and rt_sigsuspend already and must not be overwritten!
+#
+
+sys_sigsuspend_glue:    
+        lgr     %r5,%r4               # move mask back
+        lgr     %r4,%r3               # move history1 parameter
+        lgr     %r3,%r2               # move history0 parameter
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as first parameter
+	la      %r14,6(%r14)          # skip store of return value
+        jg      sys_sigsuspend        # branch to sys_sigsuspend
+
+#ifdef CONFIG_S390_SUPPORT
+sys32_sigsuspend_glue:    
+	llgfr	%r4,%r4               # unsigned long			
+        lgr     %r5,%r4               # move mask back
+	lgfr	%r3,%r3               # int			
+        lgr     %r4,%r3               # move history1 parameter
+	lgfr	%r2,%r2               # int			
+        lgr     %r3,%r2               # move history0 parameter
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as first parameter
+	la      %r14,6(%r14)          # skip store of return value
+        jg      sys32_sigsuspend      # branch to sys32_sigsuspend
+#endif
+
+sys_rt_sigsuspend_glue: 
+        lgr     %r4,%r3               # move sigsetsize parameter
+        lgr     %r3,%r2               # move unewset parameter
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as first parameter
+	la      %r14,6(%r14)          # skip store of return value
+        jg      sys_rt_sigsuspend     # branch to sys_rt_sigsuspend
+
+#ifdef CONFIG_S390_SUPPORT
+sys32_rt_sigsuspend_glue: 
+	llgfr	%r3,%r3               # size_t			
+        lgr     %r4,%r3               # move sigsetsize parameter
+	llgtr	%r2,%r2               # sigset_emu31_t *
+        lgr     %r3,%r2               # move unewset parameter
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as first parameter
+	la      %r14,6(%r14)          # skip store of return value
+        jg      sys32_rt_sigsuspend   # branch to sys32_rt_sigsuspend
+#endif
+
+sys_sigaltstack_glue:
+        la      %r4,SP_PTREGS(%r15)   # load pt_regs as parameter
+        jg      sys_sigaltstack       # branch to sys_sigreturn
+
+#ifdef CONFIG_S390_SUPPORT
+sys32_sigaltstack_glue:
+        la      %r4,SP_PTREGS(%r15)   # load pt_regs as parameter
+        jg      sys32_sigaltstack_wrapper # branch to sys_sigreturn
+#endif
+
+/*
+ * Program check handler routine
+ */
+
+        .globl  pgm_check_handler
+pgm_check_handler:
+/*
+ * First we need to check for a special case:
+ * Single stepping an instruction that disables the PER event mask will
+ * cause a PER event AFTER the mask has been set. Example: SVC or LPSW.
+ * For a single stepped SVC the program check handler gets control after
+ * the SVC new PSW has been loaded. But we want to execute the SVC first and
+ * then handle the PER event. Therefore we update the SVC old PSW to point
+ * to the pgm_check_handler and branch to the SVC handler after we checked
+ * if we have to load the kernel stack register.
+ * For every other possible cause for PER event without the PER mask set
+ * we just ignore the PER event (FIXME: is there anything we have to do
+ * for LPSW?).
+ */
+	STORE_TIMER __LC_SYNC_ENTER_TIMER
+	SAVE_ALL_BASE __LC_SAVE_AREA
+        tm      __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception
+        jnz     pgm_per                  # got per exception -> special case
+	SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	tm	SP_PSW+1(%r15),0x01	# interrupting from user ?
+	jz	pgm_no_vtime
+	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
+	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
+	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
+pgm_no_vtime:
+#endif
+	lg	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+	lgf     %r3,__LC_PGM_ILC	 # load program interruption code
+	lghi	%r8,0x7f
+	ngr	%r8,%r3
+pgm_do_call:
+        sll     %r8,3
+        larl    %r1,pgm_check_table
+        lg      %r1,0(%r8,%r1)		 # load address of handler routine
+        la      %r2,SP_PTREGS(%r15)	 # address of register-save area
+	larl	%r14,sysc_return
+        br      %r1			 # branch to interrupt-handler
+
+#
+# handle per exception
+#
+pgm_per:
+        tm      __LC_PGM_OLD_PSW,0x40    # test if per event recording is on
+        jnz     pgm_per_std              # ok, normal per event from user space
+# ok its one of the special cases, now we need to find out which one
+        clc     __LC_PGM_OLD_PSW(16),__LC_SVC_NEW_PSW
+        je      pgm_svcper
+# no interesting special case, ignore PER event
+	lmg	%r12,%r15,__LC_SAVE_AREA
+	lpswe   __LC_PGM_OLD_PSW
+
+#
+# Normal per exception
+#
+pgm_per_std:
+	SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	tm	SP_PSW+1(%r15),0x01	# interrupting from user ?
+	jz	pgm_no_vtime2
+	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
+	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
+	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
+pgm_no_vtime2:
+#endif
+	lg	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+	lg	%r1,__TI_task(%r9)
+	mvc	__THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
+	mvc	__THREAD_per+__PER_address(8,%r1),__LC_PER_ADDRESS
+	mvc	__THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
+	oi	__TI_flags+7(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+	lgf     %r3,__LC_PGM_ILC	 # load program interruption code
+	lghi	%r8,0x7f
+	ngr	%r8,%r3			 # clear per-event-bit and ilc
+	je	sysc_return
+	j	pgm_do_call
+
+#
+# it was a single stepped SVC that is causing all the trouble
+#
+pgm_svcper:
+	SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	tm	SP_PSW+1(%r15),0x01	# interrupting from user ?
+	jz	pgm_no_vtime3
+	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
+	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
+	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
+pgm_no_vtime3:
+#endif
+	llgh    %r7,__LC_SVC_INT_CODE	# get svc number from lowcore
+	lg	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+	lg	%r1,__TI_task(%r9)
+	mvc	__THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
+	mvc	__THREAD_per+__PER_address(8,%r1),__LC_PER_ADDRESS
+	mvc	__THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
+	oi	__TI_flags+7(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts
+	j	sysc_do_svc
+
+/*
+ * IO interrupt handler routine
+ */
+        .globl io_int_handler
+io_int_handler:
+	STORE_TIMER __LC_ASYNC_ENTER_TIMER
+	stck	__LC_INT_CLOCK
+	SAVE_ALL_BASE __LC_SAVE_AREA+32
+        SAVE_ALL __LC_IO_OLD_PSW,__LC_SAVE_AREA+32,0
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	tm	SP_PSW+1(%r15),0x01	# interrupting from user ?
+	jz	io_no_vtime
+	UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
+	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
+	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
+io_no_vtime:
+#endif
+	lg	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+        la      %r2,SP_PTREGS(%r15)    # address of register-save area
+	brasl   %r14,do_IRQ            # call standard irq handler
+
+io_return:
+        tm      SP_PSW+1(%r15),0x01    # returning to user ?
+#ifdef CONFIG_PREEMPT
+	jno     io_preempt             # no -> check for preemptive scheduling
+#else
+        jno     io_leave               # no-> skip resched & signal
+#endif
+	tm	__TI_flags+7(%r9),_TIF_WORK_INT
+	jnz	io_work                # there is work to do (signals etc.)
+io_leave:
+        RESTORE_ALL 0
+
+#ifdef CONFIG_PREEMPT
+io_preempt:
+	icm	%r0,15,__TI_precount(%r9)	
+	jnz     io_leave
+	# switch to kernel stack
+	lg	%r1,SP_R15(%r15)
+	aghi	%r1,-SP_SIZE
+	mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
+        xc      __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain
+	lgr	%r15,%r1
+io_resume_loop:
+	tm	__TI_flags+7(%r9),_TIF_NEED_RESCHED
+	jno	io_leave
+	larl    %r1,.Lc_pactive
+	mvc     __TI_precount(4,%r9),0(%r1)
+        stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
+	brasl   %r14,schedule          # call schedule
+        stnsm   __SF_EMPTY(%r15),0xfc   # disable I/O and ext. interrupts
+	xc      __TI_precount(4,%r9),__TI_precount(%r9)
+	j	io_resume_loop
+#endif
+
+#
+# switch to kernel stack, then check TIF bits
+#
+io_work:
+	lg	%r1,__LC_KERNEL_STACK
+	aghi	%r1,-SP_SIZE
+	mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
+        xc      __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain
+	lgr	%r15,%r1
+#
+# One of the work bits is on. Find out which one.
+# Checked are: _TIF_SIGPENDING and _TIF_NEED_RESCHED
+#
+io_work_loop:
+	tm	__TI_flags+7(%r9),_TIF_NEED_RESCHED
+	jo	io_reschedule
+	tm	__TI_flags+7(%r9),_TIF_SIGPENDING
+	jo	io_sigpending
+	j	io_leave
+
+#
+# _TIF_NEED_RESCHED is set, call schedule
+#	
+io_reschedule:        
+	stosm   __SF_EMPTY(%r15),0x03	# reenable interrupts
+	brasl   %r14,schedule		# call scheduler
+	stnsm   __SF_EMPTY(%r15),0xfc	# disable I/O and ext. interrupts
+	tm	__TI_flags+7(%r9),_TIF_WORK_INT
+	jz	io_leave		# there is no work to do
+	j	io_work_loop
+
+#
+# _TIF_SIGPENDING is set, call do_signal
+#
+io_sigpending:     
+	stosm   __SF_EMPTY(%r15),0x03	# reenable interrupts
+	la      %r2,SP_PTREGS(%r15)	# load pt_regs
+	slgr    %r3,%r3			# clear *oldset
+	brasl	%r14,do_signal		# call do_signal
+	stnsm   __SF_EMPTY(%r15),0xfc	# disable I/O and ext. interrupts
+	j	sysc_leave		# out of here, do NOT recheck
+
+/*
+ * External interrupt handler routine
+ */
+        .globl  ext_int_handler
+ext_int_handler:
+	STORE_TIMER __LC_ASYNC_ENTER_TIMER
+	stck	__LC_INT_CLOCK
+	SAVE_ALL_BASE __LC_SAVE_AREA+32
+        SAVE_ALL __LC_EXT_OLD_PSW,__LC_SAVE_AREA+32,0
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	tm	SP_PSW+1(%r15),0x01	# interrupting from user ?
+	jz	ext_no_vtime
+	UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
+	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
+	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
+ext_no_vtime:
+#endif
+	lg	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+	la	%r2,SP_PTREGS(%r15)    # address of register-save area
+	llgh	%r3,__LC_EXT_INT_CODE  # get interruption code
+	brasl   %r14,do_extint
+	j	io_return
+
+/*
+ * Machine check handler routines
+ */
+        .globl mcck_int_handler
+mcck_int_handler:
+	STORE_TIMER __LC_ASYNC_ENTER_TIMER
+	SAVE_ALL_BASE __LC_SAVE_AREA+64
+        SAVE_ALL __LC_MCK_OLD_PSW,__LC_SAVE_AREA+64,0
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	tm	SP_PSW+1(%r15),0x01	# interrupting from user ?
+	jz	mcck_no_vtime
+	UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
+	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
+	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
+mcck_no_vtime:
+#endif
+	brasl   %r14,s390_do_machine_check
+mcck_return:
+        RESTORE_ALL 0
+
+#ifdef CONFIG_SMP
+/*
+ * Restart interruption handler, kick starter for additional CPUs
+ */
+        .globl restart_int_handler
+restart_int_handler:
+        lg      %r15,__LC_SAVE_AREA+120 # load ksp
+        lghi    %r10,__LC_CREGS_SAVE_AREA
+        lctlg   %c0,%c15,0(%r10) # get new ctl regs
+        lghi    %r10,__LC_AREGS_SAVE_AREA
+        lam     %a0,%a15,0(%r10)
+        lmg     %r6,%r15,__SF_GPRS(%r15) # load registers from clone
+        stosm   __SF_EMPTY(%r15),0x04    # now we can turn dat on
+	jg      start_secondary
+#else
+/*
+ * If we do not run with SMP enabled, let the new CPU crash ...
+ */
+        .globl restart_int_handler
+restart_int_handler:
+        basr    %r1,0
+restart_base:
+        lpswe   restart_crash-restart_base(%r1)
+        .align 8
+restart_crash:
+        .long  0x000a0000,0x00000000,0x00000000,0x00000000
+restart_go:
+#endif
+
+#ifdef CONFIG_CHECK_STACK
+/*
+ * The synchronous or the asynchronous stack overflowed. We are dead.
+ * No need to properly save the registers, we are going to panic anyway.
+ * Setup a pt_regs so that show_trace can provide a good call trace.
+ */
+stack_overflow:
+	lg	%r15,__LC_PANIC_STACK	# change to panic stack
+	aghi	%r1,-SP_SIZE
+	mvc	SP_PSW(16,%r15),0(%r12)	# move user PSW to stack
+	stmg	%r0,%r11,SP_R0(%r15)	# store gprs %r0-%r11 to kernel stack
+	la	%r1,__LC_SAVE_AREA
+	chi	%r12,__LC_SVC_OLD_PSW
+	je	0f
+	chi	%r12,__LC_PGM_OLD_PSW
+	je	0f
+	la	%r1,__LC_SAVE_AREA+16
+0:	mvc	SP_R12(32,%r15),0(%r1)  # move %r12-%r15 to stack
+        xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) # clear back chain
+        la      %r2,SP_PTREGS(%r15)	# load pt_regs
+	jg	kernel_stack_overflow
+#endif
+
+cleanup_table_system_call:
+	.quad	system_call, sysc_do_svc
+cleanup_table_sysc_return:
+	.quad	sysc_return, sysc_leave
+cleanup_table_sysc_leave:
+	.quad	sysc_leave, sysc_work_loop
+cleanup_table_sysc_work_loop:
+	.quad	sysc_work_loop, sysc_reschedule
+
+cleanup_critical:
+	clc	8(8,%r12),BASED(cleanup_table_system_call)
+	jl	0f
+	clc	8(8,%r12),BASED(cleanup_table_system_call+8)
+	jl	cleanup_system_call
+0:
+	clc	8(8,%r12),BASED(cleanup_table_sysc_return)
+	jl	0f
+	clc	8(8,%r12),BASED(cleanup_table_sysc_return+8)
+	jl	cleanup_sysc_return
+0:
+	clc	8(8,%r12),BASED(cleanup_table_sysc_leave)
+	jl	0f
+	clc	8(8,%r12),BASED(cleanup_table_sysc_leave+8)
+	jl	cleanup_sysc_leave
+0:
+	clc	8(8,%r12),BASED(cleanup_table_sysc_work_loop)
+	jl	0f
+	clc	8(8,%r12),BASED(cleanup_table_sysc_work_loop+8)
+	jl	cleanup_sysc_leave
+0:
+	br	%r14
+
+cleanup_system_call:
+	mvc	__LC_RETURN_PSW(16),0(%r12)
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+8)
+	jh	0f
+	mvc	__LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
+0:	clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+16)
+	jhe	cleanup_vtime
+#endif
+	clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn)
+	jh	0f
+	mvc	__LC_SAVE_AREA(32),__LC_SAVE_AREA+32
+0:	stg	%r13,__LC_SAVE_AREA+40
+	SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
+	stg	%r15,__LC_SAVE_AREA+56
+	llgh	%r7,__LC_SVC_INT_CODE
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+cleanup_vtime:
+	clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+24)
+	jhe	cleanup_stime
+	tm	SP_PSW+1(%r15),0x01	# interrupting from user ?
+	jz	cleanup_novtime
+	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
+cleanup_stime:
+	clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+32)
+	jh	cleanup_update
+	UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
+cleanup_update:
+	mvc	__LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
+cleanup_novtime:
+#endif
+	mvc	__LC_RETURN_PSW+8(8),BASED(cleanup_table_system_call+8)
+	la	%r12,__LC_RETURN_PSW
+	br	%r14
+cleanup_system_call_insn:
+	.quad	sysc_saveall
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	.quad   system_call
+	.quad   sysc_vtime
+	.quad   sysc_stime
+	.quad   sysc_update
+#endif
+
+cleanup_sysc_return:
+	mvc	__LC_RETURN_PSW(8),0(%r12)
+	mvc	__LC_RETURN_PSW+8(8),BASED(cleanup_table_sysc_return)
+	la	%r12,__LC_RETURN_PSW
+	br	%r14
+
+cleanup_sysc_leave:
+	clc	8(8,%r12),BASED(cleanup_sysc_leave_insn)
+	je	0f
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	mvc	__LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
+	clc	8(8,%r12),BASED(cleanup_sysc_leave_insn+8)
+	je	0f
+#endif
+	mvc	__LC_RETURN_PSW(16),SP_PSW(%r15)
+	mvc	__LC_SAVE_AREA+32(32),SP_R12(%r15)
+	lmg	%r0,%r11,SP_R0(%r15)
+	lg	%r15,SP_R15(%r15)
+0:	la	%r12,__LC_RETURN_PSW
+	br	%r14
+cleanup_sysc_leave_insn:
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	.quad	sysc_leave + 16
+#endif
+	.quad	sysc_leave + 12
+
+/*
+ * Integer constants
+ */
+               .align 4
+.Lconst:
+.Lc_pactive:   .long  PREEMPT_ACTIVE
+.Lnr_syscalls: .long  NR_syscalls
+.L0x0130:      .short 0x130
+.L0x0140:      .short 0x140
+.L0x0150:      .short 0x150
+.L0x0160:      .short 0x160
+.L0x0170:      .short 0x170
+.Lcritical_start:
+               .quad  __critical_start
+.Lcritical_end:
+               .quad  __critical_end
+
+#define SYSCALL(esa,esame,emu)	.long esame
+	.globl  sys_call_table
+sys_call_table:
+#include "syscalls.S"
+#undef SYSCALL
+
+#ifdef CONFIG_S390_SUPPORT
+
+#define SYSCALL(esa,esame,emu)	.long emu
+	.globl  sys_call_table_emu
+sys_call_table_emu:
+#include "syscalls.S"
+#undef SYSCALL
+#endif