[PATCH] Revert nmi_known_cpu() check during boot option parsing

Commit f2802e7f571c05f9a901b1f5bd144aa730ccc88e and its x86 version
(b7471c6da94d30d3deadc55986cc38d1ff57f9ca) adds nmi_known_cpu() check
while parsing boot options in x86_64 and i386.

With that, "nmi_watchdog=2" stops working for me on Intel Core 2 CPU
based system.

The problem is, setup_nmi_watchdog is called while parsing the boot
option and identify_cpu is not done yet.  So, the return value of
nmi_known_cpu() is not valid at this point.

So revert that check.  This should not have any adverse effect as the
nmi_known_cpu() check is done again later in enable_lapic_nmi_watchdog().

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/i386/kernel/nmi.c

@@ -310,13 +310,7 @@ static int __init setup_nmi_watchdog(char *str)
 
 	if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
 		return 0;
-	/*
-	 * If any other x86 CPU has a local APIC, then
-	 * please test the NMI stuff there and send me the
-	 * missing bits. Right now Intel P6/P4 and AMD K7 only.
-	 */
-	if ((nmi == NMI_LOCAL_APIC) && (nmi_known_cpu() == 0))
-		return 0;  /* no lapic support */
+
 	nmi_watchdog = nmi;
 	return 1;
 }

arch/x86_64/kernel/nmi.c

@@ -302,8 +302,6 @@ int __init setup_nmi_watchdog(char *str)
 	if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
 		return 0;
 
-	if ((nmi == NMI_LOCAL_APIC) && (nmi_known_cpu() == 0))
-		return 0;  /* no lapic support */
 	nmi_watchdog = nmi;
 	return 1;
 }