intel/skylake: add function is_secondary_thread()

There are MSRs that are programmable per-core not per-thread, so add
a function to check whether current executing CPU is a primary core
or a "hyperthreaded"/secondary core. For instance when trying to
program Core PRMRR MSRs(per-core) with mp_init, cpu exception is thrown
from the secondary thread. This function was used to avoid that.

Potentially this function can be put to common code or arch/x86 or cpu/x86.

BUG=chrome-os-partner:62438
BRANCH=NONE
TEST=Tested on Eve, verified core PRMRR MSRs get programmed only on primary
thread avoiding exeception.

Change-Id: Ic9648351fadf912164a39206788859baf3e5c173
Signed-off-by: Robbie Zhang <robbie.zhang@intel.com>
Reviewed-on: https://review.coreboot.org/18366
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

0 files changed, 0 insertions, 0 deletions