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| author | Michael Ellerman <mpe@ellerman.id.au> | 2017-08-23 15:20:10 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-08-23 15:20:10 +0300 |
| commit | 15c659ff9d5b367c886166a9854a89b72c524a68 (patch) | |
| tree | d33acaf62889bf6304f6109dd69923a17ab938be /arch/powerpc/kernel/exceptions-64s.S | |
| parent | 516fa8d0e19d854253460ea7692551e836e7e2b5 (diff) | |
| parent | 1a92a80ad386a1a6e3b36d576d52a1a456394b70 (diff) | |
| download | linux-15c659ff9d5b367c886166a9854a89b72c524a68.tar.xz | |
Merge branch 'fixes' into next
There's a non-trivial dependency between some commits we want to put in
next and the KVM prefetch work around that went into fixes. So merge
fixes into next.
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index a42308b2187b..e66cbb1c6bc2 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1325,10 +1325,18 @@ EXC_VIRT_NONE(0x5800, 0x100) std r10,PACA_EXGEN+EX_R13(r13); \ EXCEPTION_PROLOG_PSERIES_1(soft_nmi_common, _H) +/* + * Branch to soft_nmi_interrupt using the emergency stack. The emergency + * stack is one that is usable by maskable interrupts so long as MSR_EE + * remains off. It is used for recovery when something has corrupted the + * normal kernel stack, for example. The "soft NMI" must not use the process + * stack because we want irq disabled sections to avoid touching the stack + * at all (other than PMU interrupts), so use the emergency stack for this, + * and run it entirely with interrupts hard disabled. + */ EXC_COMMON_BEGIN(soft_nmi_common) mr r10,r1 ld r1,PACAEMERGSP(r13) - ld r1,PACA_NMI_EMERG_SP(r13) subi r1,r1,INT_FRAME_SIZE EXCEPTION_COMMON_NORET_STACK(PACA_EXGEN, 0x900, system_reset, soft_nmi_interrupt, |