MdePkg/SmmPeriodicSmiLib: Get Periodic SMI Context More Robustly

MdePkg/SmmPeriodicSmiLib: Get Periodic SMI Context More Robustly

The PeriodicSmiDispatchFunction() in SmmPeriodicSmiLib may assert
with "Bad CR signature".

Currently, the SetActivePeriodicSmiLibraryHandler() function
(invoked at the beginning of the PeriodicSmiDispatchFunction()
function) attempts to locate the PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT
structure pointer for the current periodic SMI from a given
EFI_SMM_PERIODIC_TIMER_REGISTER_CONTEXT (RegiserContext) structure
pointer (using the CR macro).

The RegisterContext structure pointer passed to the
PeriodicSmiDispatchFunction() is assumed to point to the same
RegisterContext structure address given to the
SmmPeriodicTimerDispatch2 protocol Register() API in
PeriodicSmiEnable().

However, certain SmmPeriodicTimerDispatch2 implementation may copy
the RegisterContext to a local buffer and pass that address as the
context to PeriodicSmiDispatchFunction() in which case usage of the
CR macro to find the parent structure base fails.

The patch uses the LookupPeriodicSmiLibraryHandler() function to
find the PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT structure pointer.
This works even in this scenario since the DispatchHandle returned
from the SmmPeriodicTimerDispatch2 Register() function uniquely
identifies that registration.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>