x86: nmi - add sensible names to nmi_watchdog boot param

Impact: introduce nmi_watchdog=lapic and nmi_watchdog=ioapic aliases

Add sensible names as "lapic" and "ioapic" to
nmi_watchdog boot parameter. Sometimes it is not
that easy to recall what exactly nmi_watchdog=1
does mean so we allow the using of symbolic names here.

Old numeric values remain valid.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/nmi.c

@@ -199,12 +199,17 @@ static int __init setup_nmi_watchdog(char *str)
 		++str;
 	}
 
-	get_option(&str, &nmi);
-
-	if (nmi >= NMI_INVALID)
-		return 0;
+	if (!strncmp(str, "lapic", 5))
+		nmi_watchdog = NMI_LOCAL_APIC;
+	else if (!strncmp(str, "ioapic", 6))
+		nmi_watchdog = NMI_IO_APIC;
+	else {
+		get_option(&str, &nmi);
+		if (nmi >= NMI_INVALID)
+			return 0;
+		nmi_watchdog = nmi;
+	}
 
-	nmi_watchdog = nmi;
 	return 1;
 }
 __setup("nmi_watchdog=", setup_nmi_watchdog);