PR/53420 CVS commit: src/sys/arch/x86

["Maya Rashish" <maya%netbsd.org@localhost>]

The following reply was made to PR kern/53420; it has been noted by GNATS.

From: "Maya Rashish" <maya%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/53420 CVS commit: src/sys/arch/x86
Date: Wed, 4 Jul 2018 07:55:57 +0000

 Module Name:	src
 Committed By:	maya
 Date:		Wed Jul  4 07:55:57 UTC 2018
 
 Modified Files:
 	src/sys/arch/x86/include: specialreg.h
 	src/sys/arch/x86/x86: identcpu.c
 
 Log Message:
 Disable MWAIT/MONITOR on Apollo Lake CPUs to workaround APL30 errata.
 
 We use MWAIT/MONITOR to hatch secondary CPUs. The errata means that
 the wakeup may not happen, so SMP boot fails.
 Use wrmsr to disable it in hardware too, for extra paranoia.
 
 PR port-amd64/53420,
 also reported on netbsd-users by joern clausen and ssartor.
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.126 -r1.127 src/sys/arch/x86/include/specialreg.h
 cvs rdiff -u -r1.78 -r1.79 src/sys/arch/x86/x86/identcpu.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.