patch-2.2.14 linux/arch/s390/kernel/entry.S

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diff -u --recursive --new-file v2.2.13/linux/arch/s390/kernel/entry.S linux/arch/s390/kernel/entry.S
@@ -0,0 +1,961 @@
+/*
+ *  arch/s390/kernel/entry.S
+ *    S390 low-level entry points.
+ *
+ *  S390 version
+ *    Copyright (C) 1999 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/lowcore.h>
+#include <asm/errno.h>
+#define ASSEMBLY
+#include <asm/smp.h>
+#include <asm/s390-regs-common.h>
+
+
+/*
+ * stack layout for the system_call stack entry
+ * Martin please don't modify these back to hard coded values 
+ * You know how bad I'm at mental arithmetic DJB & it gives 
+ * me grief when I modify the pt_regs
+ */
+SP_PTREGS    =  STACK_FRAME_OVERHEAD 
+SP_PSW       =  SP_PTREGS
+SP_R0        =  (SP_PSW+PSW_MASK_SIZE+PSW_ADDR_SIZE)
+SP_R1        =  (SP_R0+GPR_SIZE)
+SP_R2        =  (SP_R1+GPR_SIZE)
+SP_R3        =  (SP_R2+GPR_SIZE)
+SP_R4        =  (SP_R3+GPR_SIZE)
+SP_R5        =  (SP_R4+GPR_SIZE)
+SP_R6        =  (SP_R5+GPR_SIZE)
+SP_R7        =  (SP_R6+GPR_SIZE)
+SP_R8        =  (SP_R7+GPR_SIZE)
+SP_R9        =  (SP_R8+GPR_SIZE)
+SP_RA        =  (SP_R9+GPR_SIZE)
+SP_RB        =  (SP_RA+GPR_SIZE)
+SP_RC        =  (SP_RB+GPR_SIZE)
+SP_RD        =  (SP_RC+GPR_SIZE)
+SP_RE        =  (SP_RD+GPR_SIZE)
+SP_RF        =  (SP_RE+GPR_SIZE)
+SP_AREGS     =  (SP_RF+GPR_SIZE)
+SP_ORIG_R2   =  (SP_AREGS+(NUM_ACRS*ACR_SIZE))
+SP_TRAP      =  (SP_ORIG_R2+GPR_SIZE)
+#if CONFIG_REMOTE_DEBUG
+SP_CRREGS    =  (SP_TRAP+4)
+/* fpu registers are saved & restored by the gdb stub itself */
+SP_FPC       =  (SP_CRREGS+(NUM_CRS*CR_SIZE))
+SP_FPRS      =  (SP_FPC+FPC_SIZE+FPC_PAD_SIZE)
+SP_SIZE      =  (SP_FPRS+(NUM_FPRS*FPR_SIZE))
+#else
+SP_SIZE      =  (SP_TRAP+4)
+#endif
+/*
+ * these defines are offsets into the thread_struct
+ */
+_TSS_PTREGS  = 0
+_TSS_FPRS    = (_TSS_PTREGS+8)
+_TSS_AR2     = (_TSS_FPRS+136)
+_TSS_AR4     = (_TSS_AR2+4)
+_TSS_KSP     = (_TSS_AR4+4)
+_TSS_USERSEG = (_TSS_KSP+4)
+_TSS_ERROR   = (_TSS_USERSEG+4)
+_TSS_PROT    = (_TSS_ERROR+4)
+_TSS_TRAP    = (_TSS_PROT+4)
+_TSS_MM      = (_TSS_TRAP+4)
+_TSS_PER     = (_TSS_MM+8)
+
+/*
+ * these are offsets into the task-struct.
+ */
+state        =  0
+flags        =  4
+sigpending   =  8
+addr_limit   = 12
+exec_domain  = 20
+need_resched = 24
+
+/* PSW related defines */
+disable      = 0xFC
+enable       = 0x03
+daton        = 0x04
+
+
+#if 0
+/* some code left lying around in case we need a
+ *	printk for debugging purposes
+ */
+  sysc_printk:        .long  printk
+  sysc_msg:	      .string "<2>r15 %X\n"
+	.align 4
+		
+#	basr    %r13,0
+	l       %r0,SP_PSW+4(%r15)
+	sll     %r0,1
+	chi     %r0,0
+	jnz     sysc_dn
+	l       %r9,sysc_printk-sysc_lit(%r13)
+	la      %r2,sysc_msg-sysc_lit(%r13)
+	lr      %r3,%r15
+	basr    %r14,%r9
+sysc_dn:
+#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
+ */
+
+#define SAVE_ALL1(psworg) \
+	st      %r15,__LC_SAVE_AREA   ; \
+        tm      psworg+1,0x01         ; /* test problem state bit */ \
+	jz	0f		      ; /* skip stack setup save */ \
+	l	%r15,__LC_KERNEL_STACK ; /* problem state -> load ksp */ \
+0:	ahi     %r15,-SP_SIZE         ; /* make room for registers & psw */ \
+        srl     %r15,3                ; \
+        sll     %r15,3                ; /* align stack pointer to 8 */ \
+        stm     %r0,%r14,SP_R0(%r15)  ; /* store gprs 0-14 to kernel stack */ \
+        st      %r2,SP_ORIG_R2(%r15)  ; /* store original content of gpr 2 */ \
+        mvc     SP_RF(4,%r15),__LC_SAVE_AREA   ; /* move R15 to stack */ \
+        stam    %a0,%a15,SP_AREGS(%r15) ; /* store access registers to kst. */ \
+        mvc     SP_PSW(8,%r15),psworg ; /* move user PSW to stack */ \
+        xc      0(7,%r15),0(%r15)     ; /* clear back chain & trap ind. */ \
+        mvi     SP_TRAP+3(%r15),psworg ; /* store trap indication in pt_regs */ \
+        slr     %r0,%r0               ; \
+        sar     %a2,%r0               ; /* set ac.reg. 2 to primary space */ \
+        lhi     %r0,1                 ; \
+        sar     %a4,%r0               ; /* set access reg. 4 to home space */
+
+#define RESTORE_ALL1 \
+        mvc     0x50(8,0),SP_PSW(%r15)  ; /* move user PSW to lowcore */ \
+        lam     %a0,%a15,SP_AREGS(%r15) ; /* load the access registers */ \
+        lm      %r0,%r15,SP_R0(%r15)  ; /* load gprs 0-15 of user */ \
+        ni      0x51(0),0xfd          ; /* clear wait state bit */ \
+        lpsw    0x50                    /* back to caller */
+
+#if CONFIG_REMOTE_DEBUG
+#define SAVE_ALL(psworg) \
+	SAVE_ALL1(psworg) \
+	tm      psworg+1,0x01         ; /* test problem state bit */ \
+	jz	0f		      ; /* skip stack setup save */ \
+	stctl    %c0,%c15,SP_CRREGS(%r15) ; /* save control regs for remote debugging */ \
+0:
+
+#define RESTORE_ALL  \
+	tm      SP_PSW+1(%r15),0x01          ; /* test problem state bit */ \
+	jz	0f		             ; /* skip cr restore */ \
+	lctl    %c0,%c15,SP_CRREGS(%r15) ; /* store control regs for remote debugging */ \
+0:	RESTORE_ALL1 
+#else
+	
+#define SAVE_ALL(psworg)  \
+	SAVE_ALL1(psworg)
+
+#define RESTORE_ALL  \
+	RESTORE_ALL1 
+#endif
+	
+#define GET_CURRENT /* load pointer to task_struct to R9 */ \
+        lhi     %r9,-8192             ; \
+        nr      %r9,15
+
+
+/*
+ * Scheduler resume function, called by switch_to
+ *  grp2 = (thread_struct *) prev->tss
+ *  grp3 = (thread_struct *) next->tss
+ * Returns:
+ *  gpr2 = prev
+ */
+        .globl  resume
+resume:
+        l       %r4,_TSS_PTREGS(%r3)
+        tm      SP_PSW-SP_PTREGS(%r4),0x40 # is the new process using per ?
+        jz      RES_DN1                 # if not we're fine
+        stctl   %r9,%r11,24(%r15)       # We are using per stuff
+        clc     _TSS_PER(12,%r3),24(%r15)
+        je      RES_DN1                 # we got away without bashing TLB's
+        lctl    %c9,%c11,_TSS_PER(%r3)  # Nope we didn't
+RES_DN1:
+        stm     %r6,%r15,24(%r15)       # store resume registers of prev task
+	iac     %r1                     # get address space control bits
+        sacf    0
+	st      %r1,4(%r15)
+        st      %r15,_TSS_KSP(%r2) # store kernel stack ptr to prev->tss.ksp
+        lhi     %r0,-8192
+        nr      %r0,%r15
+        l       %r15,_TSS_KSP(%r3) # load kernel stack ptr from next->tss.ksp
+        lhi     %r1,8191
+        or      %r1,%r15
+        ahi     %r1,1
+        st      %r1,__LC_KERNEL_STACK   # __LC_KERNEL_STACK = new kernel stack
+        stam    %a2,%a2,_TSS_AR2(%r2)   # store kernel access reg. 2
+        stam    %a4,%a4,_TSS_AR4(%r2)   # store kernel access reg. 4
+        lam     %a2,%a2,_TSS_AR2(%r3)   # load kernel access reg. 2
+        lam     %a4,%a4,_TSS_AR4(%r3)   # load kernel access reg. 4
+        lctl    %c7,%c7,_TSS_USERSEG(%r3)   # load secondary-space for new task
+        lctl    %c13,%c13,_TSS_USERSEG(%r3) # load home-space for new task
+        lr      %r2,%r0                 # return task_struct of last task
+        l       %r1,4(%r15)
+        sacf    0(%r1)                  # set address space control bits
+        lm      %r6,%r15,24(%r15)       # load resume registers of next task
+        br      %r14
+
+/*
+ * SVC interrupt handler routine. System calls are synchronous events and
+ * are executed with interrupts enabled.
+ */
+
+sysc_lit:
+  sysc_bhmask:        .long  bh_mask
+  sysc_bhactive:      .long  bh_active
+  sysc_do_signal:     .long  do_signal
+  sysc_do_bottom_half:.long  do_bottom_half
+  sysc_schedule:      .long  schedule
+  sysc_trace:         .long  syscall_trace
+#ifdef __SMP__
+  sysc_schedtail:     .long  schedule_tail
+#endif
+  sysc_clone:         .long  sys_clone
+  sysc_fork:          .long  sys_fork
+  sysc_vfork:         .long  sys_vfork
+  sysc_sigreturn:     .long  sys_sigreturn
+  sysc_execve:        .long  sys_execve
+  sysc_sigsuspend:    .long  sys_sigsuspend
+  sysc_rt_sigsuspend: .long  sys_rt_sigsuspend
+
+	.globl  system_call
+system_call:
+        SAVE_ALL(0x20)
+        basr    %r13,0
+        ahi     %r13,sysc_lit-.   # setup base pointer R13 to sysc_lit
+        slr     %r8,%r8           # gpr 8 is call save (-> tracesys)
+        ic      %r8,0x8B          # get svc number from lowcore
+        stosm   24(%r15),0x03     # reenable interrupts
+        GET_CURRENT               # load pointer to task_struct to R9
+        sll     %r8,2
+        l       %r8,sys_call_table-sysc_lit(8,%r13) # get address of system call
+        tm      flags+3(%r9),0x20 # PF_TRACESYS
+        jnz     sysc_tracesys
+        basr    %r14,%r8          # call sys_xxxx
+        st      %r2,SP_R2(%r15)   # store return value (change R2 on stack)
+                                  # ATTENTION: check sys_execve_glue before
+                                  # changing anything here !!
+
+sysc_return:
+        GET_CURRENT               # load pointer to task_struct to R9
+        tm      SP_PSW+1(%r15),0x01 # returning to user ?
+#        tm      SP_PSW+2(%r15),0xc0 # returning to user or kernel thread ?
+        jno     sysc_leave        # no-> skip bottom half, resched & signal
+#
+# check, if bottom-half has to be done
+#
+        l       %r1,sysc_bhmask-sysc_lit(%r13)
+        l       %r0,0(%r1)
+        l       %r1,sysc_bhactive-sysc_lit(%r13)
+        n       %r0,0(%r1)
+        jnz     sysc_handle_bottom_half
+#
+# check, if reschedule is needed
+#
+sysc_return_bh:	
+        icm     %r0,15,need_resched(%r9) # get need_resched from task_struct
+        jnz     sysc_reschedule
+        icm     %r0,15,sigpending(%r9)   # get sigpending from task_struct
+        jnz     sysc_signal_return
+sysc_leave:
+  
+	stnsm   24(%r15),disable  # disable I/O and ext. interrupts
+        RESTORE_ALL
+
+#
+# call do_signal before return
+#
+sysc_signal_return:     
+        la      %r2,SP_PTREGS(%r15) # load pt_regs
+        sr      %r3,%r3           # clear *oldset
+        l       %r1,sysc_do_signal-sysc_lit(%r13)
+	la      %r14,sysc_leave-sysc_lit(%r13)
+        br      %r1               # return point is sysc_leave
+
+#
+# call trace before and after sys_call
+#
+sysc_tracesys:
+        l       %r1,sysc_trace-sysc_lit(%r13)
+	lhi     %r2,-ENOSYS
+	st      %r2,SP_R2(%r15)   # give sysc_trace an -ENOSYS retval
+        basr    %r14,%r1
+	lm      %r3,%r6,SP_R3(%r15)
+	l       %r2,SP_ORIG_R2(%r15)
+        basr    %r14,%r8          # call sys_xxx
+        st      %r2,SP_R2(%r15)   # store return value
+        l       %r1,sysc_trace-sysc_lit(%r13)
+	la      %r14,sysc_return-sysc_lit(%r13)
+        br      %r1               # return point is sysc_return
+
+
+#
+# call do_bottom_half and return from syscall, if interrupt-level
+# is zero
+#
+sysc_handle_bottom_half:        
+        l       %r1,sysc_do_bottom_half-sysc_lit(%r13)
+	la      %r14,sysc_return_bh-sysc_lit(%r13)
+        br      %r1               # call do_bottom_half
+
+#
+# call schedule with sysc_return as return-address
+#
+sysc_reschedule:        
+        l       %r1,sysc_schedule-sysc_lit(%r13)
+	la      %r14,sysc_return-sysc_lit(%r13)
+        br      %r1               # call scheduler, return to sysc_return
+
+#
+# a new process exits the kernel with ret_from_fork
+#
+        .globl  ret_from_fork
+ret_from_fork:  
+        basr    %r13,0
+        ahi     %r13,sysc_lit-.   # setup base pointer R13 to $SYSCDAT
+        GET_CURRENT               # load pointer to task_struct to R9
+        stosm   24(%r15),0x03     # reenable interrupts
+        sr      %r0,%r0           # child returns 0
+        st      %r0,SP_R2(%r15)   # store return value (change R2 on stack)
+#ifdef __SMP__
+        l       %r1,sysc_schedtail-sysc_lit(%r13)
+	la      %r14,sysc_return-sysc_lit(%r13)
+        br      %r1               # call schedule_tail, return to sysc_return
+#else
+        j       sysc_return
+#endif
+
+#
+# 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
+        l       %r1,sysc_clone-sysc_lit(%r13)
+        br      %r1                   # branch to sys_clone
+
+sys_fork_glue:  
+        la      %r2,SP_PTREGS(%r15)    # load pt_regs
+        l       %r1,sysc_fork-sysc_lit(%r13)
+        br      %r1                   # branch to sys_fork
+
+sys_vfork_glue: 
+        la      %r2,SP_PTREGS(%r15)    # load pt_regs
+        l       %r1,sysc_vfork-sysc_lit(%r13)
+        br      %r1                   # branch to sys_vfork
+
+sys_execve_glue:        
+        la      %r2,SP_PTREGS(%r15)    # load pt_regs
+        l       %r1,sysc_execve-sysc_lit(%r13)
+        basr    %r14,%r1              # call sys_execve
+        ltr     %r2,%r2               # check if execve failed
+        jnz     sysc_return-4         # it did fail -> store result in gpr2
+        j       sysc_return           # SKIP ST 2,SP_R2(15) after BASR 14,8
+                                      # in system_call
+
+sys_sigreturn_glue:     
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as parameter
+        l       %r1,sysc_sigreturn-sysc_lit(%r13)
+        br      %r1                   # branch to sys_sigreturn
+
+#
+# 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:    
+        lr      %r5,%r4               # move mask back
+        lr      %r4,%r3               # move history1 parameter
+        lr      %r3,%r2               # move history0 parameter
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as first parameter
+        l       %r1,sysc_sigsuspend-sysc_lit(%r13)
+	la      %r14,sysc_return-sysc_lit(%r13) # skip store of return value
+        br      %r1                   # branch to sys_sigsuspend
+
+sys_rt_sigsuspend_glue: 
+        lr      %r4,%r3               # move sigsetsize parameter
+        lr      %r3,%r2               # move unewset parameter
+        la      %r2,SP_PTREGS(%r15)   # load pt_regs as first parameter
+        l       %r1,sysc_rt_sigsuspend-sysc_lit(%r13)
+	la      %r14,sysc_return-sysc_lit(%r13) # skip store of return value
+        br      %r1                   # branch to sys_rt_sigsuspend
+
+	.globl  sys_call_table	
+sys_call_table:
+        .long  sys_ni_syscall            /* 0 */
+        .long  sys_exit
+        .long  sys_fork_glue
+        .long  sys_read
+        .long  sys_write
+        .long  sys_open                  /* 5 */
+        .long  sys_close
+        .long  sys_waitpid
+        .long  sys_creat
+        .long  sys_link
+        .long  sys_unlink                /* 10 */
+        .long  sys_execve_glue
+        .long  sys_chdir
+        .long  sys_time
+        .long  sys_mknod
+        .long  sys_chmod                /* 15 */
+        .long  sys_lchown
+        .long  sys_ni_syscall           /* old break syscall holder */
+        .long  sys_stat
+        .long  sys_lseek
+        .long  sys_getpid               /* 20 */
+        .long  sys_mount
+        .long  sys_umount
+        .long  sys_setuid
+        .long  sys_getuid
+        .long  sys_stime                /* 25 */
+        .long  sys_ptrace
+        .long  sys_alarm
+        .long  sys_fstat
+        .long  sys_pause
+        .long  sys_utime                /* 30 */
+        .long  sys_ni_syscall           /* old stty syscall holder */
+        .long  sys_ni_syscall           /* old gtty syscall holder */
+        .long  sys_access
+        .long  sys_nice
+        .long  sys_ni_syscall           /* 35 */  /* old ftime syscall holder */
+        .long  sys_sync
+        .long  sys_kill
+        .long  sys_rename
+        .long  sys_mkdir
+        .long  sys_rmdir                /* 40 */
+        .long  sys_dup
+        .long  sys_pipe
+        .long  sys_times
+        .long  sys_ni_syscall           /* old prof syscall holder */
+        .long  sys_brk                  /* 45 */
+        .long  sys_setgid
+        .long  sys_getgid
+        .long  sys_signal
+        .long  sys_geteuid
+        .long  sys_getegid              /* 50 */
+        .long  sys_acct
+        .long  sys_ni_syscall           /* old phys syscall holder */
+        .long  sys_ni_syscall           /* old lock syscall holder */
+        .long  sys_ioctl
+        .long  sys_fcntl                /* 55 */
+        .long  sys_ni_syscall           /* old mpx syscall holder */
+        .long  sys_setpgid
+        .long  sys_ni_syscall           /* old ulimit syscall holder */
+        .long  sys_olduname
+        .long  sys_umask                /* 60 */
+        .long  sys_chroot
+        .long  sys_ustat
+        .long  sys_dup2
+        .long  sys_getppid
+        .long  sys_getpgrp              /* 65 */
+        .long  sys_setsid
+        .long  sys_sigaction
+        .long  sys_sgetmask
+        .long  sys_ssetmask
+        .long  sys_setreuid             /* 70 */
+        .long  sys_setregid
+        .long  sys_sigsuspend_glue
+        .long  sys_sigpending
+        .long  sys_sethostname
+        .long  sys_setrlimit            /* 75 */
+        .long  sys_getrlimit
+        .long  sys_getrusage
+        .long  sys_gettimeofday
+        .long  sys_settimeofday
+        .long  sys_getgroups            /* 80 */
+        .long  sys_setgroups
+        .long  old_select
+        .long  sys_symlink
+        .long  sys_lstat
+        .long  sys_readlink             /* 85 */
+        .long  sys_uselib
+        .long  sys_swapon
+        .long  sys_reboot
+        .long  old_readdir
+        .long  old_mmap                 /* 90 */
+        .long  sys_munmap
+        .long  sys_truncate
+        .long  sys_ftruncate
+        .long  sys_fchmod
+        .long  sys_fchown                /* 95 */
+        .long  sys_getpriority
+        .long  sys_setpriority
+        .long  sys_ni_syscall            /* old profil syscall holder */
+        .long  sys_statfs
+        .long  sys_fstatfs               /* 100 */
+        .long  sys_ioperm
+        .long  sys_socketcall
+        .long  sys_syslog
+        .long  sys_setitimer
+        .long  sys_getitimer             /* 105 */
+        .long  sys_newstat
+        .long  sys_newlstat
+        .long  sys_newfstat
+        .long  sys_uname
+        .long  sys_ni_syscall            /* 110 */ /* iopl for i386 */
+        .long  sys_vhangup
+        .long  sys_idle
+        .long  sys_ni_syscall            /* vm86old for i386 */
+        .long  sys_wait4
+        .long  sys_swapoff               /* 115 */
+        .long  sys_sysinfo
+        .long  sys_ipc
+        .long  sys_fsync
+        .long  sys_sigreturn_glue
+        .long  sys_clone_glue            /* 120 */
+        .long  sys_setdomainname
+        .long  sys_newuname
+        .long  sys_ni_syscall            /* modify_ldt for i386 */
+        .long  sys_adjtimex
+        .long  sys_mprotect              /* 125 */
+        .long  sys_sigprocmask
+        .long  sys_create_module
+        .long  sys_init_module
+        .long  sys_delete_module
+        .long  sys_get_kernel_syms       /* 130 */
+        .long  sys_quotactl
+        .long  sys_getpgid
+        .long  sys_fchdir
+        .long  sys_bdflush
+        .long  sys_sysfs                 /* 135 */
+        .long  sys_personality
+        .long  sys_ni_syscall            /* for afs_syscall */
+        .long  sys_setfsuid
+        .long  sys_setfsgid
+        .long  sys_llseek                /* 140 */
+        .long  sys_getdents
+        .long  sys_select
+        .long  sys_flock
+        .long  sys_msync
+        .long  sys_readv                 /* 145 */
+        .long  sys_writev
+        .long  sys_getsid
+        .long  sys_fdatasync
+        .long  sys_sysctl
+        .long  sys_mlock                 /* 150 */
+        .long  sys_munlock
+        .long  sys_mlockall
+        .long  sys_munlockall
+        .long  sys_sched_setparam
+        .long  sys_sched_getparam        /* 155 */
+        .long  sys_sched_setscheduler
+        .long  sys_sched_getscheduler
+        .long  sys_sched_yield
+        .long  sys_sched_get_priority_max
+        .long  sys_sched_get_priority_min  /* 160 */
+        .long  sys_sched_rr_get_interval
+        .long  sys_nanosleep
+        .long  sys_mremap
+        .long  sys_setresuid
+        .long  sys_getresuid             /* 165 */
+        .long  sys_ni_syscall            /* for vm86 */
+        .long  sys_query_module
+        .long  sys_poll
+        .long  sys_nfsservctl
+        .long  sys_setresgid             /* 170 */
+        .long  sys_getresgid
+        .long  sys_prctl
+        .long  sys_rt_sigreturn
+        .long  sys_rt_sigaction
+        .long  sys_rt_sigprocmask        /* 175 */
+        .long  sys_rt_sigpending
+        .long  sys_rt_sigtimedwait
+        .long  sys_rt_sigqueueinfo
+        .long  sys_rt_sigsuspend_glue
+        .long  sys_pread                 /* 180 */
+        .long  sys_pwrite
+        .long  sys_chown
+        .long  sys_getcwd
+        .long  sys_capget
+        .long  sys_capset                /* 185 */
+        .long  sys_sigaltstack
+        .long  sys_sendfile
+        .long  sys_ni_syscall            /* streams1 */
+        .long  sys_ni_syscall            /* streams2 */
+        .long  sys_vfork_glue            /* 190 */
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall            /* 195 */
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall     /* 205 */
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall    /* 215 */
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall    /* 225 */
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall    /* 235 */
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall    /* 245 */
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_ni_syscall
+        .long  sys_msgcp         /* 255 */
+
+/*
+ * Program check handler routine
+ */
+
+pgm_lit:
+  pgm_handle_per:  .long  handle_per_exception
+  pgm_jump_table:  .long  pgm_check_table
+  pgm_sysc_ret:    .long  sysc_return
+  pgm_sysc_lit:    .long  sysc_lit
+  pgm_do_signal:   .long  do_signal
+
+        .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?).
+ */
+        tm      __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception
+        jz      pgm_sv                   # skip if not
+        tm      __LC_PGM_OLD_PSW,0x40    # test if per event recording is on
+        jnz     pgm_sv                   # skip if it is
+# ok its one of the special cases, now we need to find out which one
+        clc     __LC_PGM_OLD_PSW(8),__LC_SVC_NEW_PSW
+        je      pgm_svcper
+# no interesting special case, ignore PER event
+        lpsw    0x28
+# it was a single stepped SVC that is causing all the trouble
+pgm_svcper:
+        st      %r15,__LC_SAVE_AREA
+        l       %r15,__LC_PGM_NEW_PSW+4  # prepare return psw
+        ahi     %r15,pgm_svcret-pgm_check_handler
+        st      %r15,__LC_PGM_OLD_PSW+4  # use pgm old psw as temp storage
+        tm      __LC_SVC_OLD_PSW,0x01    # test problem state of svc old psw
+        jz      .+8
+        l       %r15,__LC_KERNEL_STACK   # load ksp
+        ahi     %r15,-16
+        srl     %r15,3                   # align stack pointer to 8
+        sll     %r15,3
+        mvc     0(4,%r15),__LC_SAVE_AREA # save user r15
+        mvc     4(4,%r15),__LC_PGM_ILC   # save program check information
+        mvc     8(8,%r15),__LC_SVC_OLD_PSW # save return point
+        mvc     __LC_SVC_OLD_PSW(8),__LC_PGM_OLD_PSW # move prepared return pt.
+        j       system_call              # now do the svc
+pgm_svcret:
+        mvc     __LC_PGM_OLD_PSW(8),8(%r15) # return point is svc return point
+        mvc     __LC_PGM_ILC(4),4(%r15)  # restore program check info
+        l       %r15,0(%r15)             # restore user r15
+pgm_sv:
+        SAVE_ALL(0x28)
+        basr    %r13,0
+        ahi     %r13,pgm_lit-.    # setup base pointer R13 to $PGMDAT
+        lh      %r7,__LC_PGM_ILC  # load instruction length
+        lh      %r8,__LC_PGM_INT_CODE  # N.B. saved int code used later KEEP it
+        stosm   24(%r15),0x03     # reenable interrupts
+        lr      %r3,%r8
+        lhi     %r0,0x7f
+        nr      %r3,%r0           # clear per-event-bit
+        je      pgm_dn            # none of Martins exceptions occured bypass
+        l       %r9,pgm_jump_table-pgm_lit(%r13)
+        sll     %r3,2
+        l       %r9,0(%r3,%r9)    # load address of handler routine
+        la      %r2,SP_PTREGS(%r15) # address of register-save area
+        srl     %r3,2
+        chi     %r3,0x4           # protection-exception ?
+        jne     pgm_go            # if not,
+        l       %r5,SP_PSW+4(15)  # load psw addr
+        sr      %r5,%r7           # substract ilc from psw
+        st      %r5,SP_PSW+4(15)  # store corrected psw addr
+pgm_go: basr    %r14,%r9          # branch to interrupt-handler
+pgm_dn: lhi     %r0,0x80
+        nr      %r8,%r0           # check for per exception
+        je      pgm_return
+        la      %r2,SP_PTREGS(15) # address of register-save area
+        l       %r9,pgm_handle_per-pgm_lit(%r13) # load adr. of per handler
+        l       %r14,pgm_sysc_ret-pgm_lit(%r13)  # load adr. of system return
+        l       %r13,pgm_sysc_lit-pgm_lit(%r13)
+        br      %r9               # branch to handle_per_exception
+#
+# the backend code is the same as for sys-call
+#
+pgm_return:
+        l       %r14,pgm_sysc_ret-pgm_lit(%r13)
+        l       %r13,pgm_sysc_lit-pgm_lit(%r13)
+        br      %r14
+
+default_trap_handler:
+        .globl  default_trap_handler
+        lpsw    112
+
+/*
+ * IO interrupt handler routine
+ */
+
+io_lit:
+  io_do_IRQ:        .long do_IRQ
+  io_schedule:	    .long schedule
+  io_do_signal:     .long do_signal
+  io_bhmask:        .long  bh_mask
+  io_bhactive:      .long  bh_active
+  io_do_bottom_half:.long  do_bottom_half
+
+        .globl io_int_handler
+io_int_handler:
+        SAVE_ALL(0x38)
+        basr    %r13,0
+        ahi     %r13,io_lit-.     # setup base pointer R13 to $IODAT
+        la      %r2,SP_PTREGS(%r15) # address of register-save area
+        sr      %r3,%r3
+        icm     %r3,%r3,__LC_SUBCHANNEL_NR # load subchannel nr & extend to int
+        l       %r4,__LC_IO_INT_PARM       # load interuption parm
+        l       %r9,io_do_IRQ-io_lit(%r13) # load address of do_IRQ
+        basr    %r14,%r9          # branch to standard irq handler
+
+io_return:
+        GET_CURRENT               # load pointer to task_struct to R9
+        tm      SP_PSW+1(%r15),0x01 # returning to user ?
+#        tm      SP_PSW+2(%r15),0x80 # returning to user or kernel thread ?
+        jz      io_leave          # no-> skip resched & signal
+        stosm   24(%r15),0x03     # reenable interrupts
+#
+# check, if bottom-half has to be done
+#
+        l       %r1,io_bhmask-io_lit(%r13)
+        l       %r0,0(%r1)
+        l       %r1,io_bhactive-io_lit(%r13)
+        n       %r0,0(%r1)
+        jnz     io_handle_bottom_half
+io_return_bh:	
+#
+# check, if reschedule is needed
+#
+        icm     %r0,15,need_resched(%r9) # get need_resched from task_struct
+        jnz     io_reschedule
+        icm     %r0,15,sigpending(%r9)   # get sigpending from task_struct
+        jnz     io_signal_return
+io_leave:
+        stnsm   24(%r15),disable  # disable I/O and ext. interrupts
+        RESTORE_ALL
+
+#
+# call do_bottom_half and return from syscall, if interrupt-level
+# is zero
+#
+io_handle_bottom_half:        
+        l       %r1,io_do_bottom_half-io_lit(%r13)
+	la      %r14,io_return_bh-io_lit(%r13)
+        br      %r1               # call do_bottom_half
+
+#
+# call schedule with io_return as return-address
+#
+io_reschedule:        
+        l       %r1,io_schedule-io_lit(%r13)
+	la      %r14,io_return-io_lit(%r13)
+        br      %r1               # call scheduler, return to io_return
+
+#
+# call do_signal before return
+#
+io_signal_return:     
+        la      %r2,SP_PTREGS(%r15) # load pt_regs
+        sr      %r3,%r3           # clear *oldset
+        l       %r1,io_do_signal-io_lit(%r13)
+	la      %r14,io_leave-io_lit(%r13)
+        br      %r1               # return point is io_leave
+
+/*
+ * External interrupt handler routine
+ */
+
+ext_lit:
+  ext_timer_int:     .long  do_timer_interrupt
+#ifdef __SMP__
+  ext_call_int:      .long  do_ext_call_interrupt
+#endif
+#ifdef CONFIG_HWC
+  ext_hwc_int:      .long  do_hwc_interrupt
+#endif
+#ifdef CONFIG_MDISK
+  ext_mdisk_int:     .long  do_mdisk_interrupt
+#endif
+#ifdef CONFIG_IUCV
+  ext_iucv_int:      .long  do_iucv_interrupt
+#endif
+  ext_io_lit:	     .long  io_lit
+  ext_io_return:     .long  io_return
+
+        .globl  ext_int_handler
+ext_int_handler:
+        SAVE_ALL(0x18)
+        basr    %r13,0
+        ahi     %r13,ext_lit-.    # setup base pointer R13 to $EXTDAT
+        la      %r2,SP_PTREGS(%r15)    # address of register-save area
+        lh      %r3,__LC_EXT_INT_CODE  # error code
+#ifdef __SMP__
+	chi     %r3,0x1202        # EXTERNAL_CALL
+	jne     ext_no_extcall
+	l       %r9,ext_call_int-ext_lit(%r13) # load ext_call_interrupt
+	l       %r14,ext_io_return-ext_lit(%r13)
+        l       %r13,ext_io_lit-ext_lit(%r13)
+	br      %r9               # branch to ext call handler
+ext_no_extcall:
+#endif
+        chi     %r3,0x1004        # CPU_TIMER
+        jne     ext_no_timer
+        l       %r9,ext_timer_int-ext_lit(%r13) # load timer_interrupt
+	l       %r14,ext_io_return-ext_lit(%r13)
+        l       %r13,ext_io_lit-ext_lit(%r13)
+	br      %r9               # branch to ext call handler
+ext_no_timer:   
+#ifdef CONFIG_HWC
+        chi     %r3,0x2401        # HWC interrupt
+        jne     ext_no_hwc
+        l       %r9,ext_hwc_int-ext_lit(%r13) # load addr. of hwc routine
+	l       %r14,ext_io_return-ext_lit(%r13)
+        l       %r13,ext_io_lit-ext_lit(%r13)
+	br      %r9               # branch to ext call handler
+ext_no_hwc:    
+#endif
+#ifdef CONFIG_MDISK
+        chi     %r3,0x2603        # diag 250 (VM) interrupt
+        jne     ext_no_mdisk
+        l       %r9,ext_mdisk_int-ext_lit(%r13)
+	l       %r14,ext_io_return-ext_lit(%r13)
+        l       %r13,ext_io_lit-ext_lit(%r13)
+	br      %r9               # branch to ext call handler
+ext_no_mdisk:   
+#endif
+#ifdef CONFIG_IUCV
+        chi     %r3,0x4000        # diag 250 (VM) interrupt
+        jne     ext_no_iucv
+        l       %r9,ext_iucv_int-ext_lit(%r13)
+	l       %r14,ext_io_return-ext_lit(%r13)
+        l       %r13,ext_io_lit-ext_lit(%r13)
+	br      %r9               # branch to ext call handler
+ext_no_iucv:    
+#endif
+
+	l       %r14,ext_io_return-ext_lit(%r13)
+        l       %r13,ext_io_lit-ext_lit(%r13)
+	br      %r14              # use backend code of io_int_handler
+
+/*
+ * Machine check handler routines
+ */
+mcck_lit:
+  mcck_crw_pending: .long  do_crw_pending
+
+
+        .globl mcck_int_handler
+mcck_int_handler:
+        SAVE_ALL(0x30)
+        basr    %r13,0
+        ahi     %r13,mcck_lit-.   # setup base pointer R13 to $MCCKDAT
+	tm      __LC_MCCK_CODE+1,0x40
+	jno     mcck_no_crw
+	l       %r1,mcck_crw_pending-mcck_lit(%r13)
+	basr    %r14,%r1	  # call do_crw_pending
+mcck_no_crw:
+mcck_return:
+        RESTORE_ALL
+
+#ifdef __SMP__
+/*
+ * Restart interruption handler, kick starter for additional CPUs
+ */
+        .globl restart_int_handler
+restart_int_handler:
+        l       %r15,__LC_KERNEL_STACK # load ksp
+        lctl    %c0,%c15,__LC_CREGS_SAVE_AREA # get new ctl regs
+        lam     %a0,%a15,__LC_AREGS_SAVE_AREA
+        stosm   0(%r15),daton          # now we can turn dat on
+        lm      %r6,%r15,24(%r15)      # load registers from clone
+        bras    %r14,restart_go
+        .long   start_secondary
+restart_go:
+        l       %r14,0(%r14)
+        br      %r14                   # branch to 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:
+        lpsw    restart_crash-restart_base(%r1)
+        .align 8
+restart_crash:
+        .long  0x000a0000,0x00000000
+restart_go:
+#endif
+

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)