x86/cpu/amd: Set X86_FEATURE_EXTD_APICID for future processors
authorAravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Mon, 27 Apr 2015 15:25:51 +0000 (10:25 -0500)
committerIngo Molnar <mingo@kernel.org>
Wed, 6 May 2015 09:16:53 +0000 (11:16 +0200)
commitb9d16a2a21aa9c264a29dd84d6f7b03581517a03
treed19e817b13e27e6aece2af7ce78d259e3273166d
parent1b4574292e9d2d37b3bb437c9e778fd2bba8e170
x86/cpu/amd: Set X86_FEATURE_EXTD_APICID for future processors

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: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Borislav 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.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/kernel/cpu/amd.c