Tegra: enable 'signed-comparison' compilation warning/errors ...

This patch enables the 'sign-compare' flag, to enable warning/errors
for comparisons between signed/unsigned variables. The warning has
been enabled for all the Tegra platforms, to start with.

Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

Merge pull request #925 from dp-arm/dp/spdx ...

Use SPDX license identifiers

Use SPDX license identifiers ...

To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.

NOTE: Files that have been imported by FreeBSD have not been modified.

[0]: https://spdx.org/

Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

Update terminology: standard SMC to yielding SMC ...

Since Issue B (November 2016) of the SMC Calling Convention document
standard SMC calls are renamed to yielding SMC calls to help avoid
confusion with the standard service SMC range, which remains unchanged.

http://infocenter.arm.com/help/topic/com.arm.doc.den0028b/ARM_DEN0028B_SMC_Calling_Convention.pdf

This patch adds a new define for yielding SMC call type and deprecates
the current standard SMC call type. The tsp is migrated to use this new
terminology and, additionally, the documentation and code comments are
updated to use this new terminology.

Change-Id: I0d7cc0224667ee6c050af976745f18c55906a793
Signed-off-by: David Cunado <david.cunado@arm.com>

AArch32: Add API to invoke runtime service handler ...

This patch adds an API in runtime service framework to
invoke the registered handler corresponding to the SMC function
identifier. This is helpful for AArch32 because the number of
arguments required by the handler is more than registers
available as per AArch32 program calling conventions and
requires the use of stack. Hence this new API will do the
necessary argument setup and invoke the appropriate
handler. Although this API is primarily intended for AArch32,
it can be used for AArch64 as well.

Change-Id: Iefa15947fe5a1df55b0859886e677446a0fd7241

Merge pull request #673 from soby-mathew/sm/coverity_issue ...

Improve debug assertion for runtime svc number

Improve debug assertion for runtime svc number ...

This patch improves the debug assertion for runtime svc number
 - Remove useless comparison ensuring that the number of descriptors
   is a positive number. The variable is an unsigned integer so can't
   be negative.
 - Check that the end address of the descriptors is sane relative
   to the start address.

Change-Id: Iea7be6b34e33b8b1cbd394eb923cc834ea964831

Make runtime_svc_init() function more robust ...

- Added some debug assertions checking that the runtime services
   indexes computed by get_unique_oen() are sane.

 - Do not print the name of the service when its descriptor is
   invalid. If the descriptor is corrupted then its name field
   could be corrupted as well and we would end up reading an
   arbitrary amount of invalid memory.

Change-Id: I16f61065277d01fe1555d5a9cf743f7b52ccaa60

Improvements to runtime service init code ...

Light refactoring of the code in runtime_svc.c file.

 - Declare validate_rt_svc_desc()'s argument as const.

 - Remove 'goto' path in runtime_svc_init(). It was used in one
   place only.

 - Improve code readability by declaring a local variable holding the
   service pointer.

Change-Id: I3b15c5adb9f37b786b5b993a9be70ea9dd017a83

Introduce `el3_runtime` and `PSCI` libraries ...

This patch moves the PSCI services and BL31 frameworks like context
management and per-cpu data into new library components `PSCI` and
`el3_runtime` respectively. This enables PSCI to be built independently from
BL31. A new `psci_lib.mk` makefile is introduced which adds the relevant
PSCI library sources and gets included by `bl31.mk`. Other changes which
are done as part of this patch are:

* The runtime services framework is now moved to the `common/` folder to
  enable reuse.
* The `asm_macros.S` and `assert_macros.S` helpers are moved to architecture
  specific folder.
* The `plat_psci_common.c` is moved from the `plat/common/aarch64/` folder
  to `plat/common` folder. The original file location now has a stub which
  just includes the file from new location to maintain platform compatibility.

Most of the changes wouldn't affect platform builds as they just involve
changes to the generic bl1.mk and bl31.mk makefiles.

NOTE: THE `plat_psci_common.c` FILE HAS MOVED LOCATION AND THE STUB FILE AT
THE ORIGINAL LOCATION IS NOW DEPRECATED. PLATFORMS SHOULD MODIFY THEIR
MAKEFILES TO INCLUDE THE FILE FROM THE NEW LOCATION.

Change-Id: I6bd87d5b59424995c6a65ef8076d4fda91ad5e86

Move include and source files to logical locations ...

Move almost all system include files to a logical sub-directory
under ./include. The only remaining system include directories
not under ./include are specific to the platform. Move the
corresponding source files to match the include directory
structure.

Also remove pm.h as it is no longer used.

Change-Id: Ie5ea6368ec5fad459f3e8a802ad129135527f0b3

Tolerate runtime service initialization failure ...

At present, the firmware panics if a runtime service fails to
initialize. An earlier patch had implemented late binding for all
runtime service handlers.

With that in place, this patch allows the firmware to proceed even when
a service fails to initialize.

Change-Id: I6cf4de2cecea9719f4cd48272a77cf459b080d4e

Add support for handling runtime service requests ...

This patch uses the reworked exception handling support to handle
runtime service requests through SMCs following the SMC calling
convention. This is a giant commit since all the changes are
inter-related. It does the following:

1. Replace the old exception handling mechanism with the new one
2. Enforce that SP_EL0 is used C runtime stacks.
3. Ensures that the cold and warm boot paths use the 'cpu_context'
   structure to program an ERET into the next lower EL.
4. Ensures that SP_EL3 always points to the next 'cpu_context'
   structure prior to an ERET into the next lower EL
5. Introduces a PSCI SMC handler which completes the use of PSCI as a
   runtime service

Change-Id: I661797f834c0803d2c674d20f504df1b04c2b852
Co-authored-by: Achin Gupta <achin.gupta@arm.com>

Introduce new exception handling framework ...

This patch introduces the reworked exception handling logic which lays
the foundation for accessing runtime services in later patches. The
type of an exception has a greater say in the way it is
handled. SP_EL3 is used as the stack pointer for:

1. Determining the type of exception and handling the unexpected ones
   on the exception stack

2. Saving and restoring the essential general purpose and system
   register state after exception entry and prior to exception exit.

SP_EL0 is used as the stack pointer for handling runtime service
requests e.g. SMCs. A new structure for preserving general purpose
register state has been added to the 'cpu_context' structure. All
assembler ensures that it does not use callee saved registers
(x19-x29). The C runtime preserves them across functions calls. Hence
EL3 code does not have to save and restore them explicitly.

Since the exception handling framework has undergone substantial change,
the changes have been kept in separate files to aid readability. These
files will replace the existing ones in subsequent patches.

Change-Id: Ice418686592990ff7a4260771e8d6676e6c8c5ef

Add runtime services framework ...

This patch introduces the framework to enable registration and
initialisation of runtime services. PSCI is registered and initialised
as a runtime service. Handling of runtime service requests will be
implemented in subsequent patches.

Change-Id: Id21e7ddc5a33d42b7d6e455b41155fc5441a9547

Update year in copyright text to 2014 ...

Change-Id: Ic7fb61aabae1d515b9e6baf3dd003807ff42da60

psci: fix error due to a non zero context id ...

In the previous psci implementation, the psci_afflvl_power_on_finish()
function would run into an error condition if the value of the context
id parameter in the cpu_on and cpu_suspend psci calls was != 0. The
parameter was being restored as the return value of the affinity level
0 finisher function. A non zero context id would be treated as an
error condition. This would prevent successful wake up of the cpu from
a power down state. Also, the contents of the general purpose
registers were not being cleared upon return to the non-secure world
after a cpu power up. This could potentially allow the non-secure
world to view secure data.

This patch ensures that all general purpose registers are set to ~0
prior to the final eret that drops the execution to the non-secure
world. The context id is used to initialize the general purpose
register x0 prior to re-entry into the non-secure world and is no
longer restored as a function return value. A platform helper
(platform_get_stack()) has been introduced to facilitate this change.

Change-Id: I2454911ffd75705d6aa8609a5d250d9b26fa097c

Enable third party contributions ...

- Add instructions for contributing to ARM Trusted Firmware.

- Update copyright text in all files to acknowledge contributors.

Change-Id: I9311aac81b00c6c167d2f8c889aea403b84450e5

ARMv8 Trusted Firmware release v0.2