Decision to use a 4-bit mask or 8-bit mask in default_get_apic_id()
is controlled by setting capability bit X86_FEATURE_EXTD_APICID.

Currently, we detect extended APIC ID support by accessing Link
Transaction Control register D18F0x68 in PCI config space.

But, not even that is needed as we can safely postulate that future
AMD processors will support 8-bit APIC IDs and we can simply set that
feature bit on them, without the PCI access.
Signed-off-by: NAravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jacob Shin <jacob.w.shin@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@linux.intel.com
Cc: hecmargi@upv.es
Cc: mgorman@suse.de
Link: http://lkml.kernel.org/r/1430148351-9013-1-git-send-email-Aravind.Gopalakrishnan@amd.comSigned-off-by: NIngo Molnar <mingo@kernel.org>