[PATCH] s390: machine check handler bugs
The new machine check handler still has a few bugs. 1) The system entry time has to be stored in the machine check handler, 2) the machine check return psw may not be stored at the usual place because it might overwrite the return psw of the interrupted context, 3) the return address for the call to s390_handle_mcck in the i/o interrupt handler is not correct, 4) the system call cleanup has to take the different save area of the machine check handler into account, 5) the machine check handler may not call UPDATE_VTIME before CREATE_STACK_FRAME, and 6) the io leave path needs a critical section cleanup to make sure that the TIF_MCCK_PENDING bit is really checked before switching back to user space. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Martin Schwidefsky
committed by
Linus Torvalds
Linus Torvalds
parent
4c139862b8
commit
ae6aa2ea89
@@ -131,14 +131,14 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING)
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stg %r12,__SF_BACKCHAIN(%r15)
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.endm
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.macro RESTORE_ALL sync
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mvc __LC_RETURN_PSW(16),SP_PSW(%r15) # move user PSW to lowcore
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.macro RESTORE_ALL psworg,sync
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mvc \psworg(16),SP_PSW(%r15) # move user PSW to lowcore
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.if !\sync
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ni __LC_RETURN_PSW+1,0xfd # clear wait state bit
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ni \psworg+1,0xfd # clear wait state bit
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.endif
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lmg %r0,%r15,SP_R0(%r15) # load gprs 0-15 of user
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STORE_TIMER __LC_EXIT_TIMER
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lpswe __LC_RETURN_PSW # back to caller
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lpswe \psworg # back to caller
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.endm
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/*
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@@ -233,7 +233,7 @@ sysc_return:
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tm __TI_flags+7(%r9),_TIF_WORK_SVC
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jnz sysc_work # there is work to do (signals etc.)
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sysc_leave:
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RESTORE_ALL 1
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RESTORE_ALL __LC_RETURN_PSW,1
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#
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# recheck if there is more work to do
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@@ -308,8 +308,6 @@ sysc_singlestep:
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jg do_single_step # branch to do_sigtrap
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__critical_end:
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#
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# call syscall_trace before and after system call
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# special linkage: %r12 contains the return address for trace_svc
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@@ -612,7 +610,8 @@ io_return:
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tm __TI_flags+7(%r9),_TIF_WORK_INT
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jnz io_work # there is work to do (signals etc.)
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io_leave:
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RESTORE_ALL 0
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RESTORE_ALL __LC_RETURN_PSW,0
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io_done:
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#ifdef CONFIG_PREEMPT
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io_preempt:
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@@ -711,6 +710,8 @@ ext_no_vtime:
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brasl %r14,do_extint
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j io_return
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__critical_end:
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/*
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* Machine check handler routines
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*/
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@@ -718,6 +719,7 @@ ext_no_vtime:
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mcck_int_handler:
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la %r1,4095 # revalidate r1
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spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # revalidate cpu timer
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mvc __LC_ASYNC_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA-4095(%r1)
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lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
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SAVE_ALL_BASE __LC_SAVE_AREA+64
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la %r12,__LC_MCK_OLD_PSW
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@@ -730,17 +732,8 @@ mcck_int_handler:
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mvc __LC_ASYNC_ENTER_TIMER(8),__LC_LAST_UPDATE_TIMER
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mvc __LC_SYNC_ENTER_TIMER(8),__LC_LAST_UPDATE_TIMER
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mvc __LC_EXIT_TIMER(8),__LC_LAST_UPDATE_TIMER
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0: tm __LC_MCCK_CODE+2,0x08 # mwp of old psw valid?
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jno mcck_no_vtime # no -> no timer update
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tm __LC_MCK_OLD_PSW+1,0x01 # interrupting from user ?
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jz mcck_no_vtime
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UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
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UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
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mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
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mcck_no_vtime:
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#endif
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0:
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tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid?
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0: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid?
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jno mcck_int_main # no -> skip cleanup critical
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tm __LC_MCK_OLD_PSW+1,0x01 # test problem state bit
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jnz mcck_int_main # from user -> load kernel stack
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@@ -756,6 +749,16 @@ mcck_int_main:
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jz 0f
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lg %r15,__LC_PANIC_STACK # load panic stack
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0: CREATE_STACK_FRAME __LC_MCK_OLD_PSW,__LC_SAVE_AREA+64
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#ifdef CONFIG_VIRT_CPU_ACCOUNTING
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tm __LC_MCCK_CODE+2,0x08 # mwp of old psw valid?
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jno mcck_no_vtime # no -> no timer update
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tm __LC_MCK_OLD_PSW+1,0x01 # interrupting from user ?
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jz mcck_no_vtime
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UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
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UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
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mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
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mcck_no_vtime:
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#endif
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lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
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la %r2,SP_PTREGS(%r15) # load pt_regs
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brasl %r14,s390_do_machine_check
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@@ -771,7 +774,7 @@ mcck_int_main:
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jno mcck_return
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brasl %r14,s390_handle_mcck
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mcck_return:
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RESTORE_ALL 0
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RESTORE_ALL __LC_RETURN_MCCK_PSW,0
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#ifdef CONFIG_SMP
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/*
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@@ -833,6 +836,10 @@ cleanup_table_sysc_leave:
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.quad sysc_leave, sysc_work_loop
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cleanup_table_sysc_work_loop:
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.quad sysc_work_loop, sysc_reschedule
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cleanup_table_io_leave:
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.quad io_leave, io_done
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cleanup_table_io_work_loop:
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.quad io_work_loop, io_mcck_pending
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cleanup_critical:
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clc 8(8,%r12),BASED(cleanup_table_system_call)
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@@ -854,11 +861,27 @@ cleanup_critical:
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jl 0f
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clc 8(8,%r12),BASED(cleanup_table_sysc_work_loop+8)
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jl cleanup_sysc_return
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0:
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clc 8(8,%r12),BASED(cleanup_table_io_leave)
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jl 0f
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clc 8(8,%r12),BASED(cleanup_table_io_leave+8)
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jl cleanup_io_leave
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0:
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clc 8(8,%r12),BASED(cleanup_table_io_work_loop)
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jl 0f
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clc 8(8,%r12),BASED(cleanup_table_io_work_loop+8)
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jl cleanup_io_return
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0:
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br %r14
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cleanup_system_call:
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mvc __LC_RETURN_PSW(16),0(%r12)
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cghi %r12,__LC_MCK_OLD_PSW
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je 0f
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la %r12,__LC_SAVE_AREA+32
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j 1f
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0: la %r12,__LC_SAVE_AREA+64
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1:
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#ifdef CONFIG_VIRT_CPU_ACCOUNTING
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clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+8)
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jh 0f
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@@ -868,11 +891,13 @@ cleanup_system_call:
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#endif
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clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn)
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jh 0f
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mvc __LC_SAVE_AREA(32),__LC_SAVE_AREA+32
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0: stg %r13,__LC_SAVE_AREA+40
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mvc __LC_SAVE_AREA(32),0(%r12)
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0: stg %r13,8(%r12)
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stg %r12,__LC_SAVE_AREA+96 # argh
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SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
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CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
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stg %r15,__LC_SAVE_AREA+56
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lg %r12,__LC_SAVE_AREA+96 # argh
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stg %r15,24(%r12)
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llgh %r7,__LC_SVC_INT_CODE
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#ifdef CONFIG_VIRT_CPU_ACCOUNTING
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cleanup_vtime:
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@@ -909,17 +934,21 @@ cleanup_sysc_return:
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cleanup_sysc_leave:
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clc 8(8,%r12),BASED(cleanup_sysc_leave_insn)
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je 0f
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je 2f
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#ifdef CONFIG_VIRT_CPU_ACCOUNTING
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mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
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clc 8(8,%r12),BASED(cleanup_sysc_leave_insn+8)
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je 0f
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je 2f
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#endif
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mvc __LC_RETURN_PSW(16),SP_PSW(%r15)
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mvc __LC_SAVE_AREA+32(32),SP_R12(%r15)
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lmg %r0,%r11,SP_R0(%r15)
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cghi %r12,__LC_MCK_OLD_PSW
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jne 0f
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mvc __LC_SAVE_AREA+64(32),SP_R12(%r15)
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j 1f
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0: mvc __LC_SAVE_AREA+32(32),SP_R12(%r15)
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1: lmg %r0,%r11,SP_R0(%r15)
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lg %r15,SP_R15(%r15)
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0: la %r12,__LC_RETURN_PSW
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2: la %r12,__LC_RETURN_PSW
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br %r14
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cleanup_sysc_leave_insn:
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#ifdef CONFIG_VIRT_CPU_ACCOUNTING
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@@ -927,6 +956,36 @@ cleanup_sysc_leave_insn:
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#endif
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.quad sysc_leave + 12
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cleanup_io_return:
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mvc __LC_RETURN_PSW(8),0(%r12)
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mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_io_work_loop)
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la %r12,__LC_RETURN_PSW
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br %r14
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cleanup_io_leave:
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clc 8(8,%r12),BASED(cleanup_io_leave_insn)
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je 2f
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#ifdef CONFIG_VIRT_CPU_ACCOUNTING
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mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
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clc 8(8,%r12),BASED(cleanup_io_leave_insn+8)
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je 2f
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#endif
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mvc __LC_RETURN_PSW(16),SP_PSW(%r15)
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cghi %r12,__LC_MCK_OLD_PSW
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jne 0f
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mvc __LC_SAVE_AREA+64(32),SP_R12(%r15)
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j 1f
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0: mvc __LC_SAVE_AREA+32(32),SP_R12(%r15)
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1: lmg %r0,%r11,SP_R0(%r15)
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lg %r15,SP_R15(%r15)
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2: la %r12,__LC_RETURN_PSW
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br %r14
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cleanup_io_leave_insn:
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#ifdef CONFIG_VIRT_CPU_ACCOUNTING
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.quad io_leave + 20
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#endif
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.quad io_leave + 16
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/*
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* Integer constants
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*/
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