Module Name: src
Committed By: christos
Date: Mon Apr 30 00:08:03 UTC 2012
Modified Files:
src/sys/arch/x86/x86: identcpu.c
Log Message:
PR/41267: Andrius V: 5.0 RC4 does not detect second CPU in VIA. VIA Eden cpuid
lies about it's ability to do cmpxchg8b. Turn the feature on using the FCR MSR.
Needs pullup to both 5 and 6.
To generate a diff of this commit:
cvs rdiff -u -r1.30 -r1.31 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.
Modified files:
Index: src/sys/arch/x86/x86/identcpu.c
diff -u src/sys/arch/x86/x86/identcpu.c:1.30 src/sys/arch/x86/x86/identcpu.c:1.31
--- src/sys/arch/x86/x86/identcpu.c:1.30 Thu Feb 23 09:45:55 2012
+++ src/sys/arch/x86/x86/identcpu.c Sun Apr 29 20:08:03 2012
@@ -1,4 +1,4 @@
-/* $NetBSD: identcpu.c,v 1.30 2012/02/23 14:45:55 chs Exp $ */
+/* $NetBSD: identcpu.c,v 1.31 2012/04/30 00:08:03 christos Exp $ */
/*-
* Copyright (c) 1999, 2000, 2001, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: identcpu.c,v 1.30 2012/02/23 14:45:55 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: identcpu.c,v 1.31 2012/04/30 00:08:03 christos Exp $");
#include "opt_xen.h"
@@ -380,13 +380,31 @@ static void
cpu_probe_winchip(struct cpu_info *ci)
{
- if (cpu_vendor != CPUVENDOR_IDT ||
- CPUID2FAMILY(ci->ci_signature) != 5)
+ if (cpu_vendor != CPUVENDOR_IDT)
return;
- if (CPUID2MODEL(ci->ci_signature) == 4) {
+ switch (CPUID2FAMILY(ci->ci_signature)) {
+ case 5:
/* WinChip C6 */
- ci->ci_feat_val[0] &= ~CPUID_TSC;
+ if (CPUID2MODEL(ci->ci_signature) == 4)
+ ci->ci_feat_val[0] &= ~CPUID_TSC;
+ break;
+ case 6:
+ /*
+ * VIA Eden ESP
+ *
+ * Quoting from page 3-4 of: "VIA Eden ESP Processor Datasheet"
+ * http://www.via.com.tw/download/mainboards/6/14/Eden20v115.pdf
+ *
+ * 1. The CMPXCHG8B instruction is provided and always enabled,
+ * however, it appears disabled in the corresponding CPUID
+ * function bit 0 to avoid a bug in an early version of
+ * Windows NT. However, this default can be changed via a
+ * bit in the FCR MSR.
+ */
+ ci->ci_feat_val[0] |= CPUID_CX8;
+ wrmsr(MSR_VIA_FCR, rdmsr(MSR_VIA_FCR) | 0x00000001);
+ break;
}
}
