From: Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com>
To: linuxppc-dev <linuxppc-dev@ozlabs.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: KVM-PPC <kvm-ppc@vger.kernel.org>, KVM <kvm@vger.kernel.org>
Subject: [PATCH 1/3] Powernv: Remove the usage of PACAR1 from opal wrappers
Date: Thu, 14 Jan 2016 08:44:58 +0530 [thread overview]
Message-ID: <20160114031457.1287.32132.stgit@mars> (raw)
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>
---
arch/powerpc/platforms/powernv/opal-wrappers.S | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index b7a464f..62fe496 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -64,7 +64,6 @@ END_FTR_SECTION(0, 1); \
OPAL_BRANCH(opal_tracepoint_entry) \
mfcr r12; \
stw r12,8(r1); \
- std r1,PACAR1(r13); \
li r11,0; \
mfmsr r12; \
ori r11,r11,MSR_EE; \
@@ -127,7 +126,6 @@ opal_tracepoint_entry:
mfcr r12
std r11,16(r1)
stw r12,8(r1)
- std r1,PACAR1(r13)
li r11,0
mfmsr r12
ori r11,r11,MSR_EE
next reply other threads:[~2016-01-14 3:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-14 3:14 Mahesh J Salgaonkar [this message]
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 ` [1/3] Powernv: Remove the usage of PACAR1 from opal wrappers Michael Ellerman
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=20160114031457.1287.32132.stgit@mars \
--to=mahesh@linux.vnet.ibm.com \
--cc=kvm-ppc@vger.kernel.org \
--cc=kvm@vger.kernel.org \
--cc=linuxppc-dev@ozlabs.org \
--cc=mpe@ellerman.id.au \
--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).