lkml.org 
[lkml]   [2017]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.12 65/65] powerpc: Fix /proc/cpuinfo revision for POWER9 DD2
Date
4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michael Neuling <mikey@neuling.org>

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@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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;

\
 
 \ /
  Last update: 2017-08-15 03:23    [W:0.277 / U:0.416 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site