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Message-ID: <1481556264.17253.57.camel@kernel.crashing.org>
Subject: Re: [powerpc/nmi: RFC 2/2] Keep interrupts enabled even on soft
 disable
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Nicholas Piggin <npiggin@gmail.com>, Balbir Singh <bsingharora@gmail.com>
Cc: linuxppc-dev@ozlabs.org, Michael Ellerman <mpe@ellerman.id.au>, Paul
 Mackerras <paulus@samba.org>
Date: Mon, 12 Dec 2016 09:24:24 -0600
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On Mon, 2016-12-12 at 23:31 +1000, Nicholas Piggin wrote:
> Otherwise, this looks nice if it does the right thing with the interrupt
> controller. It hasn't taken a lot of lines to implement which is very
> cool.

We might want to be a bit careful. It will work with XICS fine, but it
might be trickier with a controller that needs explicit masking
of the just received interrupts like some of the old mac ones. Or MPIC
that you haven't modified to flatten the priorities etc....

Also lazy masking is ppc64 only but irc.c and time.c are shared.

I think we need to make this an "opt-in" based on some bit set by the
platform or the PIC, possibly in ppc_md.

Also note that there's already a PACA field to "recover" an interrupt
snatched by KVM, though it's XICS specific, while your approach is more
generic, you may want to merge the two. Talk to Paulus.

Cheers,
Ben.