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| author |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2015-06-22 17:28:14 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2015-07-22 09:58:04 +0200 |
| commit | 2acb94f43128b5cd375873f9ba82fac968d3ce5d (patch) | |
| tree | b825fe17618a75120289e09a2c6910ab8ce62732 /arch | |
| parent | s390/kernel: squeeze a few more cycles out of the system call handler (diff) | |
| download | linux-dev-2acb94f43128b5cd375873f9ba82fac968d3ce5d.tar.xz linux-dev-2acb94f43128b5cd375873f9ba82fac968d3ce5d.zip | |
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')
| -rw-r--r-- | arch/s390/kernel/entry.S | 25 |
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 # |