Re: [PATCH 12/13] powerpc: Add a Kconfig and a functions to set new soft_enabled mask

On Friday 16 September 2016 04:26 PM, Nicholas Piggin wrote:

On Thu, 15 Sep 2016 18:32:02 +0530
Madhavan Srinivasan [off-list ref] wrote:

quoted

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 9e5e9a6d4147..ae31b1e85fdb 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c

@@ -209,6 +209,10 @@ notrace void arch_local_irq_restore(unsigned long en)
  	unsigned char irq_happened;
  	unsigned int replay;
  
+#ifdef CONFIG_IRQ_DEBUG_SUPPORT
+	WARN_ON(en & local_paca->soft_enabled & ~IRQ_DISABLE_MASK_LINUX);
+#endif
+
  	/* Write the new soft-enabled value */
  	soft_enabled_set(en);
  

Oh one other quick thing I just noticed: you could put this debug
check into your soft_enabled accessors.

OK. Will move it.

We did decide it's okay for your masking level to go both ways,
didn't we? I.e.,

local_irq_disable();
local_irq_pmu_save(flags);
local_irq_pmu_restore(flags);
local_irq_enable();

-> LINUX -> LINUX|PMU -> LINUX ->

This means PMU interrupts would not get replayed despite being
enabled here. In practice I think that doesn't matter/can't happen
because a PMU interrupt while masked would hard disable anyway. A
comment explaining it might be nice though.

Yes. I though i did the comment. Apologies. Will respin
with the comment.

Maddy

Thanks,
Nick