The soft nmi handler does not reconcile interrupt state, so it should
not return via the normal ret_from_except path. Return like other NMIs,
using the EXCEPTION_RESTORE_REGS macro.
This becomes important when the scv interrupt is implemented, which
must handle soft-masked interrupts that have r13 set to something other
than the PACA -- returning to kernel in this case must restore r13.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
v3:
- save/restore irq soft mask state like other NMIs rather than a normal
reconcile, to avoid soft mask warnings or possibly worse.
arch/powerpc/kernel/exceptions-64s.S | 29 +++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S
b/arch/powerpc/kernel/exceptions-64s.S
index 6ff5ea236b17..5ddfc32cacad 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2713,6 +2713,7 @@ EXC_VIRT_NONE(0x5800, 0x100)
INT_DEFINE_BEGIN(soft_nmi)
IVEC=0x900
ISTACK=0
+ IRECONCILE=0 /* Soft-NMI may fire under local_irq_disable */
INT_DEFINE_END(soft_nmi)
/*
@@ -2731,9 +2732,35 @@ EXC_COMMON_BEGIN(soft_nmi_common)
subi r1,r1,INT_FRAME_SIZE
__GEN_COMMON_BODY soft_nmi
bl save_nvgprs
+
+ /*
+ * Set IRQS_ALL_DISABLED and save PACAIRQHAPPENED (see
+ * system_reset_common)
+ */
+ li r10,IRQS_ALL_DISABLED
+ stb r10,PACAIRQSOFTMASK(r13)
+ lbz r10,PACAIRQHAPPENED(r13)
+ std r10,_DAR(r1)
+ ori r10,r10,PACA_IRQ_HARD_DIS
+ stb r10,PACAIRQHAPPENED(r13)
+
addi r3,r1,STACK_FRAME_OVERHEAD
bl soft_nmi_interrupt
- b ret_from_except
+
+ /* Clear MSR_RI before setting SRR0 and SRR1. */
+ li r9,0
+ mtmsrd r9,1
+
+ /*
+ * Restore soft mask settings.
+ */
+ ld r10,_DAR(r1)
+ stb r10,PACAIRQHAPPENED(r13)
+ ld r10,SOFTE(r1)
+ stb r10,PACAIRQSOFTMASK(r13)
+
+ EXCEPTION_RESTORE_REGS hsrr=0
+ RFI_TO_KERNEL
#endif /* CONFIG_PPC_WATCHDOG */
--
2.23.0
