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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2015-06-22 17:28:14 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2015-07-22 09:58:04 +0200
commit2acb94f43128b5cd375873f9ba82fac968d3ce5d (patch)
treeb825fe17618a75120289e09a2c6910ab8ce62732 /arch/s390/kernel/entry.S
parenta359bb1190f213d282f4934fd461cf440d87dae0 (diff)
s390/nmi: use the normal asynchronous stack for machine checks
If a machine checks is received while the CPU is in the kernel, only the s390_do_machine_check function will be called. The call to s390_handle_mcck is postponed until the CPU returns to user space. Because of this it is safe to use the asynchronous stack for machine checks even if the CPU is already handling an interrupt. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/entry.S')
-rw-r--r--arch/s390/kernel/entry.S25
1 files changed, 9 insertions, 16 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index a721c39d014d..21c1219122af 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -83,7 +83,7 @@ _PIF_WORK = (_PIF_PER_TRAP)
#endif
.endm
- .macro SWITCH_ASYNC savearea,stack,shift,timer
+ .macro SWITCH_ASYNC savearea,timer
tmhh %r8,0x0001 # interrupting from user ?
jnz 1f
lgr %r14,%r9
@@ -94,16 +94,16 @@ _PIF_WORK = (_PIF_PER_TRAP)
brasl %r14,cleanup_critical
tmhh %r8,0x0001 # retest problem state after cleanup
jnz 1f
-0: lg %r14,\stack # are we already on the target stack?
+0: lg %r14,__LC_ASYNC_STACK # are we already on the async stack?
slgr %r14,%r15
- srag %r14,%r14,\shift
+ srag %r14,%r14,STACK_SHIFT
jnz 2f
- CHECK_STACK 1<<\shift,\savearea
+ CHECK_STACK 1<<STACK_SHIFT,\savearea
aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
j 3f
1: LAST_BREAK %r14
UPDATE_VTIME %r14,%r15,\timer
-2: lg %r15,\stack # load target stack
+2: lg %r15,__LC_ASYNC_STACK # load async stack
3: la %r11,STACK_FRAME_OVERHEAD(%r15)
.endm
@@ -539,8 +539,7 @@ ENTRY(io_int_handler)
lg %r12,__LC_THREAD_INFO
larl %r13,cleanup_critical
lmg %r8,%r9,__LC_IO_OLD_PSW
- SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT,\
- __LC_ASYNC_ENTER_TIMER
+ SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
stmg %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
stmg %r8,%r9,__PT_PSW(%r11)
@@ -712,8 +711,7 @@ ENTRY(ext_int_handler)
lg %r12,__LC_THREAD_INFO
larl %r13,cleanup_critical
lmg %r8,%r9,__LC_EXT_OLD_PSW
- SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT,\
- __LC_ASYNC_ENTER_TIMER
+ SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
stmg %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
stmg %r8,%r9,__PT_PSW(%r11)
@@ -892,8 +890,7 @@ ENTRY(mcck_int_handler)
mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
3: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid?
jno .Lmcck_panic # no -> skip cleanup critical
- SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_PANIC_STACK,PAGE_SHIFT,\
- __LC_MCCK_ENTER_TIMER
+ SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER
.Lmcck_skip:
lghi %r14,__LC_GPREGS_SAVE_AREA+64
stmg %r0,%r7,__PT_R0(%r11)
@@ -928,12 +925,8 @@ ENTRY(mcck_int_handler)
lpswe __LC_RETURN_MCCK_PSW
.Lmcck_panic:
- lg %r14,__LC_PANIC_STACK
- slgr %r14,%r15
- srag %r14,%r14,PAGE_SHIFT
- jz 0f
lg %r15,__LC_PANIC_STACK
-0: aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
+ aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
j .Lmcck_skip
#