x2apic: fix reserved APIC register accesses in print_local_APIC()
APIC_ARBPRI is a reserved register for XAPIC and beyond.
APIC_RRR is a reserved register except for 82489DX, APIC for Pentium processors.
APIC_EOI is a write only register.
APIC_DFR is reserved in x2apic mode.
Access to these registers in x2apic will result in #GP fault. Fix these
apic register accesses.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index d28128e..93ceb19 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -1751,21 +1751,30 @@
printk(KERN_DEBUG "... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);
if (APIC_INTEGRATED(ver)) { /* !82489DX */
- v = apic_read(APIC_ARBPRI);
- printk(KERN_DEBUG "... APIC ARBPRI: %08x (%02x)\n", v,
- v & APIC_ARBPRI_MASK);
+ if (!APIC_XAPIC(ver)) {
+ v = apic_read(APIC_ARBPRI);
+ printk(KERN_DEBUG "... APIC ARBPRI: %08x (%02x)\n", v,
+ v & APIC_ARBPRI_MASK);
+ }
v = apic_read(APIC_PROCPRI);
printk(KERN_DEBUG "... APIC PROCPRI: %08x\n", v);
}
- v = apic_read(APIC_EOI);
- printk(KERN_DEBUG "... APIC EOI: %08x\n", v);
- v = apic_read(APIC_RRR);
- printk(KERN_DEBUG "... APIC RRR: %08x\n", v);
+ /*
+ * Remote read supported only in the 82489DX and local APIC for
+ * Pentium processors.
+ */
+ if (!APIC_INTEGRATED(ver) || maxlvt == 3) {
+ v = apic_read(APIC_RRR);
+ printk(KERN_DEBUG "... APIC RRR: %08x\n", v);
+ }
+
v = apic_read(APIC_LDR);
printk(KERN_DEBUG "... APIC LDR: %08x\n", v);
- v = apic_read(APIC_DFR);
- printk(KERN_DEBUG "... APIC DFR: %08x\n", v);
+ if (!x2apic_enabled()) {
+ v = apic_read(APIC_DFR);
+ printk(KERN_DEBUG "... APIC DFR: %08x\n", v);
+ }
v = apic_read(APIC_SPIV);
printk(KERN_DEBUG "... APIC SPIV: %08x\n", v);