soc/amd/cezanne: Disable Co-op multitasking

There are gremlins in the system. thread_coop_enable has an assert. This
is currently problematic for two reasons.

   assert(current->can_yield <= 0);

When doing smm_do_relocate we are entering a deadlock. The root cause
hasn't been quite found yet, but it's related to co-op multi-threading.

For some reason the assert in thread_coop_enable is firing when
releasing the console_lock spin lock. I'm assuming cpu_info hasn't been
initialized yet. The assert tries to perform a printk, but since the
console_lock is still held we end up in a dead lock. This dead lock will
generally not happen after a warm reset. Again I'm assuming because the
cpu_info struct has some valid values at this point.

For now disable multi-tasking until we fix the cpu_info initialization.

BUG=b:194391185
TEST=Boot guybrush to OS

Co-developed-by: nikolai.vyssotski@amd.corp-partner.google.com
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: Ia3143f538a31b5aaaea104aa1d8bcf44e6dcb528
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57005
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Reviewed-by: Nikolai Vyssotski <nikolai.vyssotski@amd.corp-partner.google.com>
Reviewed-by: Jason Glenesk <jason.glenesk@gmail.com>
Reviewed-by: Rob Barnes <robbarnes@google.com>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions