1 files changed, 93 insertions, 9 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