src/arch/x86: Use core apic id to get cpu_index()

This cpu_index() implementation assumes that cpu_index() function
might always getting called from coreboot context (ESP stack
pointer will always refer to coreboot).

This might not be true in case of proposed PI spec MP_SERVICES_PPI
implementation, where FSP context (stack pointer refers to fsp)
will request to get cpu_index(), natural alignment logic will
use ESP and retrieve struct cpu_info *ci from (stack_top - 8 byte).
This is not the place where cpu_index is actually stored by
ramstage c_start.S

Hence this patch tries to remove those dependencies while retrieving
cpu_index(), rather it uses cpuid to fetch lapic id and matches with
cpus_default_apic_id[] variable to return correct cpu_index().

BRANCH=none
BUG=b:79562868
TEST=Ensures functions can be run on APs without any failure and
cpu_index() also provides correct index number.

Change-Id: I55023a3e0cf42f0496d45bc6af8ead447f402350
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/26346
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions