x86-64: extend MCE CPU quirk handling

At least on my Barcelona, I see MCE log entries after cold boot caused
by BIOS not properly clearing the respective registers. Therefore, this
patch extends the workaround to families 0x10 and 0x11 (the latter just
for completeness, I have nothing to verify this against).
At the same time, provide a way to make these entries visible via the
'mce=bootlog' command line option even on these machines.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/mcheck/mce_64.c

@@ -49,7 +49,7 @@ static int banks;
 static unsigned long bank[NR_BANKS] = { [0 ... NR_BANKS-1] = ~0UL };
 static unsigned long notify_user;
 static int rip_msr;
-static int mce_bootlog = 1;
+static int mce_bootlog = -1;
 static atomic_t mce_events;
 
 static char trigger[128];
@@ -471,10 +471,12 @@ static void mce_init(void *dummy)
 static void __cpuinit mce_cpu_quirks(struct cpuinfo_x86 *c)
 {
 	/* This should be disabled by the BIOS, but isn't always */
-	if (c->x86_vendor == X86_VENDOR_AMD && c->x86 == 15) {
+	if (c->x86_vendor == X86_VENDOR_AMD) {
+		if(c->x86 == 15)
 			/* disable GART TBL walk error reporting, which trips off
 			   incorrectly with the IOMMU & 3ware & Cerberus. */
 			clear_bit(10, &bank[4]);
+		if(c->x86 <= 17 && mce_bootlog < 0)
 			/* Lots of broken BIOS around that don't clear them
 			   by default and leave crap in there. Don't log. */
 			mce_bootlog = 0;