platform/x86/intel/ifs: Add scan test support

platform/x86/intel/ifs: Add scan test support

In a core, the scan engine is shared between sibling cpus.

When a Scan test (for a particular core) is triggered by the user,
the scan chunks are executed on all the threads on the core using
stop_core_cpuslocked.

Scan may be aborted by some reasons. Scan test will be aborted in certain
circumstances such as when interrupt occurred or cpu does not have enough
power budget for scan. In this case, the kernel restart scan from the chunk
where it stopped. Scan will also be aborted when the test is failed. In
this case, the test is immediately stopped without retry.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220506225410.1652287-9-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>