powerpc/64e/interrupt: NMI save irq soft-mask state in C

64e non-maskable interrupts save the state of the irq soft-mask in
asm. This can be done in C in interrupt wrappers as 64s does.

I haven't been able to test this with qemu because it doesn't seem
to cause FSL bookE WDT interrupts.

This makes WatchdogException an NMI interrupt, which affects 32-bit
as well (okay, or create a new handler?)

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210316104206.407354-6-npiggin@gmail.com

1 files changed, 22 insertions, 10 deletions

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 05e7fc4ffb50..b17a55062bb8 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -149,18 +149,32 @@ static inline void interrupt_async_exit_prepare(struct pt_regs *regs, struct int
 
 struct interrupt_nmi_state {
 #ifdef CONFIG_PPC64
-#ifdef CONFIG_PPC_BOOK3S_64
 	u8 irq_soft_mask;
 	u8 irq_happened;
-#endif
 	u8 ftrace_enabled;
 #endif
 };
 
+static inline bool nmi_disables_ftrace(struct pt_regs *regs)
+{
+	/* Allow DEC and PMI to be traced when they are soft-NMI */
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64)) {
+		if (TRAP(regs) == 0x900)
+		       return false;
+		if (TRAP(regs) == 0xf00)
+		       return false;
+	}
+	if (IS_ENABLED(CONFIG_PPC_BOOK3E)) {
+		if (TRAP(regs) == 0x260)
+			return false;
+	}
+
+	return true;
+}
+
 static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct interrupt_nmi_state *state)
 {
 #ifdef CONFIG_PPC64
-#ifdef CONFIG_PPC_BOOK3S_64
 	state->irq_soft_mask = local_paca->irq_soft_mask;
 	state->irq_happened = local_paca->irq_happened;
 
@@ -173,9 +187,8 @@ static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct inte
 	local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
 
 	/* Don't do any per-CPU operations until interrupt state is fixed */
-#endif
-	/* Allow DEC and PMI to be traced when they are soft-NMI */
-	if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260) {
+
+	if (nmi_disables_ftrace(regs)) {
 		state->ftrace_enabled = this_cpu_get_ftrace_enabled();
 		this_cpu_set_ftrace_enabled(0);
 	}
@@ -204,16 +217,14 @@ static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct inter
 	 */
 
 #ifdef CONFIG_PPC64
-	if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260)
+	if (nmi_disables_ftrace(regs))
 		this_cpu_set_ftrace_enabled(state->ftrace_enabled);
 
-#ifdef CONFIG_PPC_BOOK3S_64
 	/* Check we didn't change the pending interrupt mask. */
 	WARN_ON_ONCE((state->irq_happened | PACA_IRQ_HARD_DIS) != local_paca->irq_happened);
 	local_paca->irq_happened = state->irq_happened;
 	local_paca->irq_soft_mask = state->irq_soft_mask;
 #endif
-#endif
 }
 
 /*
@@ -426,6 +437,7 @@ DECLARE_INTERRUPT_HANDLER(SMIException);
 DECLARE_INTERRUPT_HANDLER(handle_hmi_exception);
 DECLARE_INTERRUPT_HANDLER(unknown_exception);
 DECLARE_INTERRUPT_HANDLER_ASYNC(unknown_async_exception);
+DECLARE_INTERRUPT_HANDLER_NMI(unknown_nmi_exception);
 DECLARE_INTERRUPT_HANDLER(instruction_breakpoint_exception);
 DECLARE_INTERRUPT_HANDLER(RunModeException);
 DECLARE_INTERRUPT_HANDLER(single_step_exception);
@@ -449,7 +461,7 @@ DECLARE_INTERRUPT_HANDLER(altivec_assist_exception);
 DECLARE_INTERRUPT_HANDLER(CacheLockingException);
 DECLARE_INTERRUPT_HANDLER(SPEFloatingPointException);
 DECLARE_INTERRUPT_HANDLER(SPEFloatingPointRoundException);
-DECLARE_INTERRUPT_HANDLER(WatchdogException);
+DECLARE_INTERRUPT_HANDLER_NMI(WatchdogException);
 DECLARE_INTERRUPT_HANDLER(kernel_bad_stack);
 
 /* slb.c */