5 files changed, 215 insertions, 56 deletions

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index c0e09b33febe..5b262b5d869f 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -7,6 +7,7 @@
  *    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),
+ *               Heiko Carstens <heiko.carstens@de.ibm.com>
  */
 
 #include <linux/sys.h>
@@ -49,9 +50,9 @@ SP_ILC       =  STACK_FRAME_OVERHEAD + __PT_ILC
 SP_TRAP      =  STACK_FRAME_OVERHEAD + __PT_TRAP
 SP_SIZE      =  STACK_FRAME_OVERHEAD + __PT_SIZE
 
-_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
+_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING | \
                  _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
-_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
+_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING)
 
 STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
 STACK_SIZE  = 1 << STACK_SHIFT
@@ -121,7 +122,11 @@ STACK_SIZE  = 1 << STACK_SHIFT
         bz      BASED(stack_overflow)
 3:
 #endif
-2:      s       %r15,BASED(.Lc_spsize)  # make room for registers & psw
+2:
+        .endm
+
+        .macro  CREATE_STACK_FRAME psworg,savearea
+        s       %r15,BASED(.Lc_spsize)  # make room for registers & psw
         mvc     SP_PSW(8,%r15),0(%r12)  # move user PSW to stack
         la      %r12,\psworg
         st      %r2,SP_ORIG_R2(%r15)    # store original content of gpr 2
@@ -161,6 +166,13 @@ __switch_to_base:
         be      __switch_to_noper-__switch_to_base(%r1) # we got away w/o bashing TLB's
         lctl    %c9,%c11,__THREAD_per(%r3)      # Nope we didn't
 __switch_to_noper:
+        l       %r4,__THREAD_info(%r2)          # get thread_info of prev
+        tm      __TI_flags+3(%r4),_TIF_MCCK_PENDING # machine check pending?
+        bz      __switch_to_no_mcck-__switch_to_base(%r1)
+        ni      __TI_flags+3(%r4),255-_TIF_MCCK_PENDING # clear flag in prev
+        l       %r4,__THREAD_info(%r3)          # get thread_info of next
+        oi      __TI_flags+3(%r4),_TIF_MCCK_PENDING # set it in next
+__switch_to_no_mcck:
         stm     %r6,%r15,__SF_GPRS(%r15)# store __switch_to registers of prev task
         st      %r15,__THREAD_ksp(%r2)  # store kernel stack to prev->tss.ksp
         l       %r15,__THREAD_ksp(%r3)  # load kernel stack from next->tss.ksp
@@ -185,6 +197,7 @@ system_call:
 sysc_saveall:
         SAVE_ALL_BASE __LC_SAVE_AREA
         SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
+        CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
         lh      %r7,0x8a          # get svc number from lowcore
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 sysc_vtime:
@@ -234,6 +247,8 @@ sysc_work_loop:
 # One of the work bits is on. Find out which one.
 #
 sysc_work:
+        tm      __TI_flags+3(%r9),_TIF_MCCK_PENDING
+        bo      BASED(sysc_mcck_pending)
         tm      __TI_flags+3(%r9),_TIF_NEED_RESCHED
         bo      BASED(sysc_reschedule)
         tm      __TI_flags+3(%r9),_TIF_SIGPENDING
@@ -253,6 +268,14 @@ sysc_reschedule:
         br      %r1                    # call scheduler
 
 #
+# _TIF_MCCK_PENDING is set, call handler
+#
+sysc_mcck_pending:
+        l       %r1,BASED(.Ls390_handle_mcck)
+        la      %r14,BASED(sysc_work_loop)
+        br      %r1                     # TIF bit will be cleared by handler
+
+#
 # _TIF_SIGPENDING is set, call do_signal
 #
 sysc_sigpending:     
@@ -430,6 +453,7 @@ pgm_check_handler:
         tm      __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception
         bnz     BASED(pgm_per)           # got per exception -> special case
         SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1
+        CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         bz      BASED(pgm_no_vtime)
@@ -468,6 +492,7 @@ pgm_per:
 #
 pgm_per_std:
         SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1
+        CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         bz      BASED(pgm_no_vtime2)
@@ -493,6 +518,7 @@ pgm_no_vtime2:
 #
 pgm_svcper:
         SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
+        CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         bz      BASED(pgm_no_vtime3)
@@ -521,6 +547,7 @@ io_int_handler:
         stck    __LC_INT_CLOCK
         SAVE_ALL_BASE __LC_SAVE_AREA+16
         SAVE_ALL __LC_IO_OLD_PSW,__LC_SAVE_AREA+16,0
+        CREATE_STACK_FRAME __LC_IO_OLD_PSW,__LC_SAVE_AREA+16
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         bz      BASED(io_no_vtime)
@@ -578,9 +605,11 @@ io_work:
         lr      %r15,%r1
 #
 # One of the work bits is on. Find out which one.
-# Checked are: _TIF_SIGPENDING and _TIF_NEED_RESCHED
+# Checked are: _TIF_SIGPENDING, _TIF_NEED_RESCHED and _TIF_MCCK_PENDING
 #
 io_work_loop:
+        tm      __TI_flags+3(%r9),_TIF_MCCK_PENDING
+        bo      BASED(io_mcck_pending)
         tm      __TI_flags+3(%r9),_TIF_NEED_RESCHED
         bo      BASED(io_reschedule)
         tm      __TI_flags+3(%r9),_TIF_SIGPENDING
@@ -588,6 +617,14 @@ io_work_loop:
         b       BASED(io_leave)
 
 #
+# _TIF_MCCK_PENDING is set, call handler
+#
+io_mcck_pending:
+        l       %r1,BASED(.Ls390_handle_mcck)
+        l       %r14,BASED(io_work_loop)
+        br      %r1                    # TIF bit will be cleared by handler
+
+#
 # _TIF_NEED_RESCHED is set, call schedule
 #       
 io_reschedule:        
@@ -621,6 +658,7 @@ ext_int_handler:
         stck    __LC_INT_CLOCK
         SAVE_ALL_BASE __LC_SAVE_AREA+16
         SAVE_ALL __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16,0
+        CREATE_STACK_FRAME __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         bz      BASED(ext_no_vtime)
@@ -642,19 +680,62 @@ ext_no_vtime:
 
         .globl mcck_int_handler
 mcck_int_handler:
-        STORE_TIMER __LC_ASYNC_ENTER_TIMER
+        spt     __LC_CPU_TIMER_SAVE_AREA        # revalidate cpu timer
+        lm      %r0,%r15,__LC_GPREGS_SAVE_AREA  # revalidate gprs
         SAVE_ALL_BASE __LC_SAVE_AREA+32
-        SAVE_ALL __LC_MCK_OLD_PSW,__LC_SAVE_AREA+32,0
+        la      %r12,__LC_MCK_OLD_PSW
+        tm      __LC_MCCK_CODE,0x80     # system damage?
+        bo      BASED(mcck_int_main)    # yes -> rest of mcck code invalid
+        tm      __LC_MCCK_CODE+5,0x02   # stored cpu timer value valid?
+        bo      BASED(0f)
+        spt     __LC_LAST_UPDATE_TIMER  # revalidate cpu timer
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
-        tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
+        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
+        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
+        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_EXIT_TIMER
+0:      tm      __LC_MCCK_CODE+2,0x08   # mwp of old psw valid?
+        bno     BASED(mcck_no_vtime)    # no -> skip cleanup critical
+        tm      __LC_MCK_OLD_PSW+1,0x01 # interrupting from user ?
         bz      BASED(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
+0:
+        tm      __LC_MCCK_CODE+2,0x09   # mwp + ia of old psw valid?
+        bno     BASED(mcck_int_main)    # no -> skip cleanup critical
+        tm      __LC_MCK_OLD_PSW+1,0x01 # test problem state bit
+        bnz     BASED(mcck_int_main)    # from user -> load async stack
+        clc     __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_end)
+        bhe     BASED(mcck_int_main)
+        clc     __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_start)
+        bl      BASED(mcck_int_main)
+        l       %r14,BASED(.Lcleanup_critical)
+        basr    %r14,%r14
+mcck_int_main:
+        l       %r14,__LC_PANIC_STACK   # are we already on the panic stack?
+        slr     %r14,%r15
+        sra     %r14,PAGE_SHIFT
+        be      BASED(0f)
+        l       %r15,__LC_PANIC_STACK   # load panic stack
+0:      CREATE_STACK_FRAME __LC_MCK_OLD_PSW,__LC_SAVE_AREA+32
+        l       %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
+        la      %r2,SP_PTREGS(%r15)     # load pt_regs
         l       %r1,BASED(.Ls390_mcck)
-        basr    %r14,%r1          # call machine check handler
+        basr    %r14,%r1                # call machine check handler
+        tm      SP_PSW+1(%r15),0x01     # returning to user ?
+        bno     BASED(mcck_return)
+        l       %r1,__LC_KERNEL_STACK   # switch to kernel stack
+        s       %r1,BASED(.Lc_spsize)
+        mvc     SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
+        xc      __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
+        lr      %r15,%r1
+        stosm   __SF_EMPTY(%r15),0x04   # turn dat on
+        tm      __TI_flags+3(%r9),_TIF_MCCK_PENDING
+        bno     BASED(mcck_return)
+        l       %r1,BASED(.Ls390_handle_mcck)
+        basr    %r14,%r1                # call machine check handler
 mcck_return:
         RESTORE_ALL 0
 
@@ -742,7 +823,7 @@ cleanup_critical:
         clc     4(4,%r12),BASED(cleanup_table_sysc_work_loop)
         bl      BASED(0f)
         clc     4(4,%r12),BASED(cleanup_table_sysc_work_loop+4)
-        bl      BASED(cleanup_sysc_leave)
+        bl      BASED(cleanup_sysc_return)
 0:
         br      %r14
 
@@ -760,6 +841,7 @@ cleanup_system_call:
         mvc     __LC_SAVE_AREA(16),__LC_SAVE_AREA+16
 0:      st      %r13,__LC_SAVE_AREA+20
         SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
+        CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
         st      %r15,__LC_SAVE_AREA+28
         lh      %r7,0x8a
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
@@ -834,6 +916,8 @@ cleanup_sysc_leave_insn:
  * Symbol constants
  */
 .Ls390_mcck:   .long  s390_do_machine_check
+.Ls390_handle_mcck:
+               .long  s390_handle_mcck
 .Ldo_IRQ:      .long  do_IRQ
 .Ldo_extint:   .long  do_extint
 .Ldo_signal:   .long  do_signal
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 51527ab8c8f9..57ca75d0ad7f 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -7,6 +7,7 @@
  *    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),
+ *               Heiko Carstens <heiko.carstens@de.ibm.com>
  */
 
 #include <linux/sys.h>
@@ -52,9 +53,9 @@ 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_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING | \
                  _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
-_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
+_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING)
 
 #define BASED(name) name-system_call(%r13)
 
@@ -114,7 +115,11 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
         jz      stack_overflow
 3:
 #endif
-2:      aghi    %r15,-SP_SIZE           # make room for registers & psw
+2:
+        .endm
+
+        .macro  CREATE_STACK_FRAME psworg,savearea
+        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
@@ -152,6 +157,13 @@ __switch_to:
         je      __switch_to_noper            # we got away without bashing TLB's
         lctlg   %c9,%c11,__THREAD_per(%r3)      # Nope we didn't
 __switch_to_noper:
+        lg      %r4,__THREAD_info(%r2)              # get thread_info of prev
+        tm      __TI_flags+7(%r4),_TIF_MCCK_PENDING # machine check pending?
+        jz      __switch_to_no_mcck
+        ni      __TI_flags+7(%r4),255-_TIF_MCCK_PENDING # clear flag in prev
+        lg      %r4,__THREAD_info(%r3)              # get thread_info of next
+        oi      __TI_flags+7(%r4),_TIF_MCCK_PENDING # set it in next
+__switch_to_no_mcck:
         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
@@ -176,6 +188,7 @@ system_call:
 sysc_saveall:
         SAVE_ALL_BASE __LC_SAVE_AREA
         SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
+        CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
         llgh    %r7,__LC_SVC_INT_CODE # get svc number from lowcore
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 sysc_vtime:
@@ -232,6 +245,8 @@ sysc_work_loop:
 # One of the work bits is on. Find out which one.
 #
 sysc_work:
+        tm      __TI_flags+7(%r9),_TIF_MCCK_PENDING
+        jo      sysc_mcck_pending
         tm      __TI_flags+7(%r9),_TIF_NEED_RESCHED
         jo      sysc_reschedule
         tm      __TI_flags+7(%r9),_TIF_SIGPENDING
@@ -250,6 +265,13 @@ sysc_reschedule:
         jg      schedule            # return point is sysc_return
 
 #
+# _TIF_MCCK_PENDING is set, call handler
+#
+sysc_mcck_pending:
+        larl    %r14,sysc_work_loop
+        jg      s390_handle_mcck    # TIF bit will be cleared by handler
+
+#
 # _TIF_SIGPENDING is set, call do_signal
 #
 sysc_sigpending:     
@@ -474,6 +496,7 @@ pgm_check_handler:
         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
+        CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         jz      pgm_no_vtime
@@ -512,6 +535,7 @@ pgm_per:
 #
 pgm_per_std:
         SAVE_ALL __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1
+        CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         jz      pgm_no_vtime2
@@ -537,6 +561,7 @@ pgm_no_vtime2:
 #
 pgm_svcper:
         SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
+        CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         jz      pgm_no_vtime3
@@ -564,6 +589,7 @@ io_int_handler:
         stck    __LC_INT_CLOCK
         SAVE_ALL_BASE __LC_SAVE_AREA+32
         SAVE_ALL __LC_IO_OLD_PSW,__LC_SAVE_AREA+32,0
+        CREATE_STACK_FRAME __LC_IO_OLD_PSW,__LC_SAVE_AREA+32
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         jz      io_no_vtime
@@ -621,9 +647,11 @@ io_work:
         lgr     %r15,%r1
 #
 # One of the work bits is on. Find out which one.
-# Checked are: _TIF_SIGPENDING and _TIF_NEED_RESCHED
+# Checked are: _TIF_SIGPENDING, _TIF_NEED_RESCHED and _TIF_MCCK_PENDING
 #
 io_work_loop:
+        tm      __TI_flags+7(%r9),_TIF_MCCK_PENDING
+        jo      io_mcck_pending
         tm      __TI_flags+7(%r9),_TIF_NEED_RESCHED
         jo      io_reschedule
         tm      __TI_flags+7(%r9),_TIF_SIGPENDING
@@ -631,6 +659,13 @@ io_work_loop:
         j       io_leave
 
 #
+# _TIF_MCCK_PENDING is set, call handler
+#
+io_mcck_pending:
+        larl    %r14,io_work_loop
+        jg      s390_handle_mcck        # TIF bit will be cleared by handler
+
+#
 # _TIF_NEED_RESCHED is set, call schedule
 #       
 io_reschedule:        
@@ -661,6 +696,7 @@ ext_int_handler:
         stck    __LC_INT_CLOCK
         SAVE_ALL_BASE __LC_SAVE_AREA+32
         SAVE_ALL __LC_EXT_OLD_PSW,__LC_SAVE_AREA+32,0
+        CREATE_STACK_FRAME __LC_EXT_OLD_PSW,__LC_SAVE_AREA+32
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         jz      ext_no_vtime
@@ -680,18 +716,60 @@ ext_no_vtime:
  */
         .globl mcck_int_handler
 mcck_int_handler:
-        STORE_TIMER __LC_ASYNC_ENTER_TIMER
+        la      %r1,4095                # revalidate r1
+        spt     __LC_CPU_TIMER_SAVE_AREA-4095(%r1)      # revalidate cpu timer
+        lmg     %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
         SAVE_ALL_BASE __LC_SAVE_AREA+64
-        SAVE_ALL __LC_MCK_OLD_PSW,__LC_SAVE_AREA+64,0
+        la      %r12,__LC_MCK_OLD_PSW
+        tm      __LC_MCCK_CODE,0x80     # system damage?
+        jo      mcck_int_main           # yes -> rest of mcck code invalid
+        tm      __LC_MCCK_CODE+5,0x02   # stored cpu timer value valid?
+        jo      0f
+        spt     __LC_LAST_UPDATE_TIMER
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
-        tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
+        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
+        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
+        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_EXIT_TIMER
+0:      tm      __LC_MCCK_CODE+2,0x08   # mwp of old psw valid?
+        jno     mcck_no_vtime           # no -> no timer update
+        tm      __LC_MCK_OLD_PSW+1,0x01 # 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
+0:
+        tm      __LC_MCCK_CODE+2,0x09   # mwp + ia of old psw valid?
+        jno     mcck_int_main           # no -> skip cleanup critical
+        tm      __LC_MCK_OLD_PSW+1,0x01 # test problem state bit
+        jnz     mcck_int_main           # from user -> load kernel stack
+        clc     __LC_MCK_OLD_PSW+8(8),BASED(.Lcritical_end)
+        jhe     mcck_int_main
+        clc     __LC_MCK_OLD_PSW+8(8),BASED(.Lcritical_start)
+        jl      mcck_int_main
+        brasl   %r14,cleanup_critical
+mcck_int_main:
+        lg      %r14,__LC_PANIC_STACK   # are we already on the panic stack?
+        slgr    %r14,%r15
+        srag    %r14,%r14,PAGE_SHIFT
+        jz      0f
+        lg      %r15,__LC_PANIC_STACK   # load panic stack
+0:      CREATE_STACK_FRAME __LC_MCK_OLD_PSW,__LC_SAVE_AREA+64
+        lg      %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
+        la      %r2,SP_PTREGS(%r15)     # load pt_regs
+        brasl   %r14,s390_do_machine_check
+        tm      SP_PSW+1(%r15),0x01     # returning to user ?
+        jno     mcck_return
+        lg      %r1,__LC_KERNEL_STACK   # switch to 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
+        stosm   __SF_EMPTY(%r15),0x04   # turn dat on
+        tm      __TI_flags+7(%r9),_TIF_MCCK_PENDING
+        jno     mcck_return
+        brasl   %r14,s390_handle_mcck
 mcck_return:
         RESTORE_ALL 0
 
@@ -775,7 +853,7 @@ cleanup_critical:
         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
+        jl      cleanup_sysc_return
 0:
         br      %r14
 
@@ -793,6 +871,7 @@ cleanup_system_call:
         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
+        CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
         stg     %r15,__LC_SAVE_AREA+56
         llgh    %r7,__LC_SVC_INT_CODE
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 7aea25d6e300..9f3dff6c0b72 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -91,13 +91,12 @@ void do_monitor_call(struct pt_regs *regs, long interruption_code)
                             (void *)(long) smp_processor_id());
 }
 
+extern void s390_handle_mcck(void);
 /*
  * The idle loop on a S390...
  */
 void default_idle(void)
 {
-        psw_t wait_psw;
-        unsigned long reg;
         int cpu, rc;
 
         local_irq_disable();
@@ -125,38 +124,17 @@ void default_idle(void)
                 cpu_die();
 #endif
 
-        /* 
-         * Wait for external, I/O or machine check interrupt and
-         * switch off machine check bit after the wait has ended.
-         */
-        wait_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK | PSW_MASK_WAIT |
-                PSW_MASK_IO | PSW_MASK_EXT;
-#ifndef CONFIG_ARCH_S390X
-        asm volatile (
-                "    basr %0,0\n"
-                "0:  la   %0,1f-0b(%0)\n"
-                "    st   %0,4(%1)\n"
-                "    oi   4(%1),0x80\n"
-                "    lpsw 0(%1)\n"
-                "1:  la   %0,2f-1b(%0)\n"
-                "    st   %0,4(%1)\n"
-                "    oi   4(%1),0x80\n"
-                "    ni   1(%1),0xf9\n"
-                "    lpsw 0(%1)\n"
-                "2:"
-                : "=&a" (reg) : "a" (&wait_psw) : "memory", "cc" );
-#else /* CONFIG_ARCH_S390X */
-        asm volatile (
-                "    larl  %0,0f\n"
-                "    stg   %0,8(%1)\n"
-                "    lpswe 0(%1)\n"
-                "0:  larl  %0,1f\n"
-                "    stg   %0,8(%1)\n"
-                "    ni    1(%1),0xf9\n"
-                "    lpswe 0(%1)\n"
-                "1:"
-                : "=&a" (reg) : "a" (&wait_psw) : "memory", "cc" );
-#endif /* CONFIG_ARCH_S390X */
+        local_mcck_disable();
+        if (test_thread_flag(TIF_MCCK_PENDING)) {
+                local_mcck_enable();
+                local_irq_enable();
+                s390_handle_mcck();
+                return;
+        }
+
+        /* Wait for external, I/O or machine check interrupt. */
+        __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_WAIT |
+                        PSW_MASK_IO | PSW_MASK_EXT);
 }
 
 void cpu_idle(void)
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index df83215beac3..eb7be0ad7175 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -414,7 +414,8 @@ setup_lowcore(void)
         lc->program_new_psw.mask = PSW_KERNEL_BITS;
         lc->program_new_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
-        lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
+        lc->mcck_new_psw.mask =
+                PSW_KERNEL_BITS & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
         lc->mcck_new_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
         lc->io_new_psw.mask = PSW_KERNEL_BITS;
@@ -424,12 +425,18 @@ setup_lowcore(void)
         lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
         lc->async_stack = (unsigned long)
                 __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
-#ifdef CONFIG_CHECK_STACK
         lc->panic_stack = (unsigned long)
                 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
-#endif
         lc->current_task = (unsigned long) init_thread_union.thread_info.task;
         lc->thread_info = (unsigned long) &init_thread_union;
+#ifndef CONFIG_ARCH_S390X
+        if (MACHINE_HAS_IEEE) {
+                lc->extended_save_area_addr = (__u32)
+                        __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
+                /* enable extended save area */
+                ctl_set_bit(14, 29);
+        }
+#endif
 #ifdef CONFIG_ARCH_S390X
         if (MACHINE_HAS_DIAG44)
                 lc->diag44_opcode = 0x83000044;
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 93c71fef99dc..50c335067cfe 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -773,13 +773,24 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 
                 *(lowcore_ptr[i]) = S390_lowcore;
                 lowcore_ptr[i]->async_stack = stack + (ASYNC_SIZE);
-#ifdef CONFIG_CHECK_STACK
                 stack = __get_free_pages(GFP_KERNEL,0);
                 if (stack == 0ULL)
                         panic("smp_boot_cpus failed to allocate memory\n");
                 lowcore_ptr[i]->panic_stack = stack + (PAGE_SIZE);
+#ifndef __s390x__
+                if (MACHINE_HAS_IEEE) {
+                        lowcore_ptr[i]->extended_save_area_addr =
+                                (__u32) __get_free_pages(GFP_KERNEL,0);
+                        if (lowcore_ptr[i]->extended_save_area_addr == 0)
+                                panic("smp_boot_cpus failed to "
+                                      "allocate memory\n");
+                }
 #endif
         }
+#ifndef __s390x__
+        if (MACHINE_HAS_IEEE)
+                ctl_set_bit(14, 29); /* enable extended save area */
+#endif
         set_prefix((u32)(unsigned long) lowcore_ptr[smp_processor_id()]);
 
         for_each_cpu(cpu)