BL31: Add SDEI dispatcher
The implementation currently supports only interrupt-based SDEI events,
and supports all interfaces as defined by SDEI specification version
1.0 [1].
Introduce the build option SDEI_SUPPORT to include SDEI dispatcher in
BL31.
Update user guide and porting guide. SDEI documentation to follow.
[1] http://infocenter.arm.com/help/topic/com.arm.doc.den0054a/ARM_DEN0054A_Software_Delegated_Exception_Interface.pdf
Change-Id: I758b733084e4ea3b27ac77d0259705565842241a
Co-authored-by: Yousuf A <yousuf.sait@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/docs/porting-guide.rst b/docs/porting-guide.rst
index af933fd..f020ec9 100644
--- a/docs/porting-guide.rst
+++ b/docs/porting-guide.rst
@@ -1904,6 +1904,74 @@
assertion is raised if the value of the constant is not aligned to the cache
line boundary.
+SDEI porting requirements
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The SDEI dispatcher requires the platform to provide the following macros
+and functions, of which some are optional, and some others mandatory.
+
+Macros
+......
+
+Macro: PLAT_SDEI_NORMAL_PRI [mandatory]
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This macro must be defined to the EL3 exception priority level associated with
+Normal SDEI events on the platform. This must have a higher value (therefore of
+lower priority) than ``PLAT_SDEI_CRITICAL_PRI``.
+
+Macro: PLAT_SDEI_CRITICAL_PRI [mandatory]
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This macro must be defined to the EL3 exception priority level associated with
+Critical SDEI events on the platform. This must have a lower value (therefore of
+higher priority) than ``PLAT_SDEI_NORMAL_PRI``.
+
+It's recommended that SDEI exception priorities in general are assigned the
+lowest among Secure priorities. Among the SDEI exceptions, Critical SDEI
+priority must be higher than Normal SDEI priority.
+
+Functions
+.........
+
+Function: int plat_sdei_validate_entry_point(uintptr_t ep) [optional]
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+::
+
+ Argument: uintptr_t
+ Return: int
+
+This function validates the address of client entry points provided for both
+event registration and *Complete and Resume* SDEI calls. The function takes one
+argument, which is the address of the handler the SDEI client requested to
+register. The function must return ``0`` for successful validation, or ``-1``
+upon failure.
+
+The default implementation always returns ``0``. On ARM platforms, this function
+is implemented to translate the entry point to physical address, and further to
+ensure that the address is located in Non-secure DRAM.
+
+Function: void plat_sdei_handle_masked_trigger(uint64_t mpidr, unsigned int intr) [optional]
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+::
+
+ Argument: uint64_t
+ Argument: unsigned int
+ Return: void
+
+SDEI specification requires that a PE comes out of reset with the events masked.
+The client therefore is expected to call ``PE_UNMASK`` to unmask SDEI events on
+the PE. No SDEI events can be dispatched until such time.
+
+Should a PE receive an interrupt that was bound to an SDEI event while the
+events are masked on the PE, the dispatcher implementation invokes the function
+``plat_sdei_handle_masked_trigger``. The MPIDR of the PE that received the
+interrupt and the interrupt ID are passed as parameters.
+
+The default implementation only prints out a warning message.
+
Power State Coordination Interface (in BL31)
--------------------------------------------