From: Michael Ellerman <mpe@ellerman.id.au>
To: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>,
linuxppc-dev <linuxppc-dev@ozlabs.org>,
Paul Mackerras <paulus@samba.org>
Cc: KVM <kvm@vger.kernel.org>, KVM-PPC <kvm-ppc@vger.kernel.org>
Subject: Re: [1/3] Powernv: Remove the usage of PACAR1 from opal wrappers
Date: Fri, 18 Mar 2016 14:33:31 +1100 (AEDT) [thread overview]
Message-ID: <3qR9mW32mxz9sCk@ozlabs.org> (raw)
In-Reply-To: <20160114031457.1287.32132.stgit@mars>
On Thu, 2016-14-01 at 03:14:58 UTC, Mahesh Salgaonkar wrote:
> From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
>
> OPAL_CALL wrapper code sticks the r1 (stack pointer) into PACAR1 purely
> for debugging purpose only. The power7_wakeup* functions relies on stack
> pointer saved in PACAR1. Any opal call made using opal wrapper (directly
> or in-directly) before we fall through power7_wakeup*, then it ends up
> replacing r1 in PACAR1(r13) leading to kernel panic. So far we don't see
> any issues because we have never made any opal calls using OPAL wrapper
> before power7_wakeup*. But the subsequent HMI patch would need to invoke
> C calls during cpu wakeup/idle path that in-directly makes opal call using
> opal wrapper. This patch facilitates the subsequent HMI patch by removing
> usage of PACAR1 from opal call wrapper.
>
> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
cheers
prev parent reply other threads:[~2016-03-18 3:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-14 3:14 [PATCH 1/3] Powernv: Remove the usage of PACAR1 from opal wrappers Mahesh J Salgaonkar
2016-01-14 3:15 ` [PATCH 2/3] powerpc/book3s: Fix TB corruption in guest exit path on HMI interrupt Mahesh J Salgaonkar
2016-03-18 4:51 ` Paul Mackerras
2016-05-15 4:21 ` Mahesh Jagannath Salgaonkar
2016-01-14 3:15 ` [PATCH 3/3] KVM: PPC: Book3S HV: Fix soft lockups in KVM on HMI for time base errors Mahesh J Salgaonkar
2016-03-18 3:33 ` Michael Ellerman [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3qR9mW32mxz9sCk@ozlabs.org \
--to=mpe@ellerman.id.au \
--cc=kvm-ppc@vger.kernel.org \
--cc=kvm@vger.kernel.org \
--cc=linuxppc-dev@ozlabs.org \
--cc=mahesh@linux.vnet.ibm.com \
--cc=paulus@samba.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).