This is a note to let you know that I've just added the patch titled
powerpc: Fix /proc/cpuinfo revision for POWER9 DD2
to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-fix-proc-cpuinfo-revision-for-power9-dd2.patch
and it can be found in the queue-4.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
rom 64ebb9a208c6e66316329a6d9101815d1ee06fa9 Mon Sep 17 00:00:00 2001
From: Michael Neuling <mikey@xxxxxxxxxxx>
Date: Thu, 15 Jun 2017 11:53:16 +1000
Subject: powerpc: Fix /proc/cpuinfo revision for POWER9 DD2
From: Michael Neuling <mikey@xxxxxxxxxxx>
commit 64ebb9a208c6e66316329a6d9101815d1ee06fa9 upstream.
The P9 PVR bits 12-15 don't indicate a revision but instead different
chip configurations. From BookIV we have:
Bits Configuration
0 : Scale out 12 cores
1 : Scale out 24 cores
2 : Scale up 12 cores
3 : Scale up 24 cores
DD1 doesn't use this but DD2 does. Linux will mostly use the "Scale
out 24 core" configuration (ie. SMT4 not SMT8) which results in a PVR
of 0x004e1200. The reported revision in /proc/cpuinfo is hence
reported incorrectly as "18.0".
This patch fixes this to mask off only the relevant bits for the major
revision (ie. bits 8-11) for POWER9.
Signed-off-by: Michael Neuling <mikey@xxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Stewart Smith <stewart@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/setup-common.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -335,6 +335,10 @@ static int show_cpuinfo(struct seq_file
maj = ((pvr >> 8) & 0xFF) - 1;
min = pvr & 0xFF;
break;
+ case 0x004e: /* POWER9 bits 12-15 give chip type */
+ maj = (pvr >> 8) & 0x0F;
+ min = pvr & 0xFF;
+ break;
default:
maj = (pvr >> 8) & 0xFF;
min = pvr & 0xFF;
Patches currently in stable-queue which might be from mikey@xxxxxxxxxxx are
queue-4.12/powerpc-fix-proc-cpuinfo-revision-for-power9-dd2.patch