WIP: xtensa: SMP clockevent

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
WIP: xtensa: keep a3 and excsave1 on entry to exception handlers

Based on the SMP patch by Joe Taylor and subsequent fixes.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
WIP: rework fast_alloca handler

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
WIP: xtensa: add SMP support

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
WIP

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
WIP: fix for sched_clock

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
WIP: xtensa: enable kernel preemption

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>