Use the APIC to determine the hardware processor id - x86_64
authorFernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Wed, 9 May 2007 09:33:28 +0000 (02:33 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Wed, 9 May 2007 19:30:48 +0000 (12:30 -0700)
commitdd988528f4a7d64908b427c251d727f3c3e88add
tree6a11ed178206e7310be3ddc2524a278db6fec5bb
parenta36166c6ef45081fea6eeaf5ca785d7ed786b6e2
Use the APIC to determine the hardware processor id - x86_64

hard_smp_processor_id used to be just a macro that hard-coded
hard_smp_processor_id to 0 in the non SMP case.  When booting non SMP kernels
on hardware where the boot ioapic id is not 0 this turns out to be a problem.
This is happens frequently in the case of kdump and once in a great while in
the case of real hardware.

Use the APIC to determine the hardware processor id in both UP and SMP kernels
to fix this issue.

Notice that hard_smp_processor_id is only used by SMP code or by code that
works with apics so we do not need to handle the case when apics are not
present and hard_smp_processor_id should never be called there.

Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Acked-by: Andi Kleen <ak@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/asm-x86_64/smp.h