[PATCH 4/8] powerpc/64s: fix POWER9 machine check handler from stop state

[Nicholas Piggin]

On Fri, 17 Mar 2017 12:49:27 +1000
Nicholas Piggin <npiggin at gmail.com> wrote:

> On Thu, 16 Mar 2017 18:10:48 +0530
> Mahesh Jagannath Salgaonkar <mahesh at linux.vnet.ibm.com> wrote:
> 
> > On 03/14/2017 02:53 PM, Nicholas Piggin wrote:  

> > Looks like we are not winding up.. Shouldn't we ? What if we may end up
> > in pnv_wakeup_noloss() which assumes that no GPRs are lost. Am I missing
> > anything ?  
> 
> Hmm, on second look, I don't think any non-volatile GPRs are overwritten
> in this path. But this MCE is a slow path, and it is a much longer path
> than the system reset idle wakeup... So I'll add the napstatelost with
> a comment.

On third look, I'll just add the comment. The windup does not restore
non-volatile GPRs either, and in general we're careful not to use them
in exception handlers. So I think it's okay.

Thanks,
Nick