Sanitise includes across codebase ...

Enforce full include path for includes. Deprecate old paths.

The following folders inside include/lib have been left unchanged:

- include/lib/cpus/${ARCH}
- include/lib/el3_runtime/${ARCH}

The reason for this change is that having a global namespace for
includes isn't a good idea. It defeats one of the advantages of having
folders and it introduces problems that are sometimes subtle (because
you may not know the header you are actually including if there are two
of them).

For example, this patch had to be created because two headers were
called the same way: e0ea0928d5b7 ("Fix gpio includes of mt8173 platform
to avoid collision."). More recently, this patch has had similar
problems: 46f9b2c3a282 ("drivers: add tzc380 support").

This problem was introduced in commit 4ecca33988b9 ("Move include and
source files to logical locations"). At that time, there weren't too
many headers so it wasn't a real issue. However, time has shown that
this creates problems.

Platforms that want to preserve the way they include headers may add the
removed paths to PLAT_INCLUDES, but this is discouraged.

Change-Id: I39dc53ed98f9e297a5966e723d1936d6ccf2fc8f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SDEI: MISRA fixes ...

These changes address most of the required MISRA rules. In the process,
some from generic code is also fixed.

No functional changes.

Change-Id: I6235a355e006f0b1c7c1c4d811b3964a64d0434f
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

SDEI: Make dispatches synchronous ...

SDEI event dispatches currently only sets up the Non-secure context
before returning to the caller. The actual dispatch only happens upon
exiting EL3 next time.

However, for various error handling scenarios, it's beneficial to have
the dispatch happen synchronously. I.e. when receiving SDEI interrupt,
or for a successful sdei_dispatch_event() call, the event handler is
executed; and upon the event completion, dispatcher execution resumes
after the point of dispatch. The jump primitives introduced in the
earlier patch facilitates this feature.

With this patch:

  - SDEI interrupts and calls to sdei_dispatch_event prepares the NS
    context for event dispatch, then sets a jump point, and immediately
    exits EL3. This results in the client handler executing in
    Non-secure.

  - When the SDEI client completes the dispatched event, the SDEI
    dispatcher does a longjmp to the jump pointer created earlier. For
    the caller of the sdei_dispatch_event() in particular, this would
    appear as if call returned successfully.

The dynamic workaround for CVE_2018_3639 is slightly shifted around as
part of related minor refactoring. It doesn't affect the workaround
functionality.

Documentation updated.

NOTE: This breaks the semantics of the explicit dispatch API, and any
exiting usages should be carefully reviewed.

Change-Id: Ib9c876d27ea2af7fb22de49832e55a0da83da3f9
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

SDEI: Allow platforms to define explicit events ...

The current macros only allow to define dynamic and statically-bound
SDEI events. However, there ought be a mechanism to define SDEI events
that are explicitly dispatched; i.e., events that are dispatched as a
result of a previous secure interrupt or other exception

This patch introduces SDEI_EXPLICIT_EVENT() macro to define an explicit
event. They must be placed under private mappings. Only the priority
flags are allowed to be additionally specified.

Documentation updated.

Change-Id: I2e12f5571381195d6234c9dfbd5904608ad41db3
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

SDEI: Fix type of register count ...

Register count is currently declared as unsigned, where as there are
asserts in place to check it being negative during unregister. These are
flagged as never being true.

Change-Id: I34f00f0ac5bf88205791e9c1298a175dababe7c8
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

SDEI: Add API for explicit dispatch ...

This allows for other EL3 components to schedule an SDEI event dispatch
to Normal world upon the next ERET. The API usage constrains are set out
in the SDEI dispatcher documentation.

Documentation to follow.

Change-Id: Id534bae0fd85afc94523490098c81f85c4e8f019
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

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>