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To: Nicholas Piggin <npiggin@gmail.com>, linuxppc-dev@lists.ozlabs.org
From: Michael Ellerman <patch-notifications@ellerman.id.au>
Cc: "Shreyas B . Prabhu" <shreyas@linux.vnet.ibm.com>,
 Nicholas Piggin <npiggin@gmail.com>,
 "Gautham R . Shenoy" <ego@linux.vnet.ibm.com>
Subject: Re: powerpc/64s: relocation,
 register save fixes for system reset interrupt
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Date: Thu, 27 Oct 2016 22:38:54 +1100 (AEDT)
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On Thu, 2016-13-10 at 02:17:14 UTC, Nicholas Piggin wrote:
> This patch does a couple of things. First of all, powernv immediately
> explodes when running a relocated kernel, because the system reset
> exception for handling sleeps does not do correct relocated branches.
> 
> Secondly, the sleep handling code trashes the condition and cfar
> registers, which we would like to preserve for debugging purposes (for
> non-sleep case exception).
> 
> This patch changes the exception to use the standard format that saves
> registers before any tests or branches are made. It adds the test for
> idle-wakeup as an "extra" to break out of the normal exception path.
> Then it branches to a relocated idle handler that calls the various
> idle handling functions.
> 
> After this patch, POWER8 CPU simulator now boots powernv kernel that is
> running at non-zero.
> 
> Cc: Balbir Singh <bsingharora@gmail.com>
> Cc: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
> Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> Acked-by: Balbir Singh <bsingharora@gmail.com>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/fb479e44a9e240a23c2d208c2ace23

cheers