x86: display extended apic registers with print_local_APIC and cpu_debug code

Both print_local_APIC (used when apic=debug kernel param is set) and
cpu_debug code missed support for some extended APIC registers that
I'd like to see.

This adds support to show:

 - extended APIC feature register
 - extended APIC control register
 - extended LVT registers

[ Impact: print more debug info ]

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <20090508162350.GO29045@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 2afe145..65b824c 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1739,7 +1739,7 @@
 
 __apicdebuginit(void) print_local_APIC(void *dummy)
 {
-	unsigned int v, ver, maxlvt;
+	unsigned int i, v, ver, maxlvt;
 	u64 icr;
 
 	if (apic_verbosity == APIC_QUIET)
@@ -1827,6 +1827,18 @@
 	printk(KERN_DEBUG "... APIC TMCCT: %08x\n", v);
 	v = apic_read(APIC_TDCR);
 	printk(KERN_DEBUG "... APIC TDCR: %08x\n", v);
+
+	if (boot_cpu_has(X86_FEATURE_EXTAPIC)) {
+		v = apic_read(APIC_EFEAT);
+		maxlvt = (v >> 16) & 0xff;
+		printk(KERN_DEBUG "... APIC EFEAT: %08x\n", v);
+		v = apic_read(APIC_ECTRL);
+		printk(KERN_DEBUG "... APIC ECTRL: %08x\n", v);
+		for (i = 0; i < maxlvt; i++) {
+			v = apic_read(APIC_EILVTn(i));
+			printk(KERN_DEBUG "... APIC EILVT%d: %08x\n", i, v);
+		}
+	}
 	printk("\n");
 }