Change in ...coreboot[master]: src/arch/x86: Use core apic id to get cpu_index()

[Subrata Banik (Code Review)]

Hello Patrick Rudolph, Aaron Durbin, ron minnich, Paul Menzel, build bot (Jenkins),

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/26346

to look at the new patch set (#12).

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

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 true incase 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 retriving cpu_index(),
rather it uses cpuid to fetch lapic id and matches with cpu_mp structure to get
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 
---
M src/arch/x86/cpu.c
M src/arch/x86/include/arch/cpu.h
2 files changed, 20 insertions(+), 7 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/46/26346/12