All identifiers, regardless of use, that start with two underscores are
reserved. This means they can't be used in header guards.

The style that this project is now to use the full name of the file in
capital letters followed by 'H'. For example, for a file called
"uart_example.h", the header guard is UART_EXAMPLE_H.

The exceptions are files that are imported from other projects:

- CryptoCell driver
- dt-bindings folders
- zlib headers

Change-Id: I50561bf6c88b491ec440d0c8385c74650f3c106e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Only use synchronous calls to enter the Secure Partition in order to
simplify the SMC handling code.

Change-Id: Ia501a045585ee0836b9151141ad3bd11d0971be2
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Instead of just knowing if the Secure Partition is being initialized or
not, this generic state enum can be used to tell if the Secure Partition
is busy and to add more states in the future if needed.

Also, the spinlock of the secure_partition_context_t structure now only
protects against concurrent accesses to the state of the secure
partition. Previously, it used to lock down the whole structure, thus
preventing one CPU to access any of its fields while another CPU was
executing the partition.

Change-Id: I51215328e2ca8ea2452f92e4a1cb237415958b22
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

The current internal names are too long, which makes it hard to write
code as many lines overflow the limit and need to be split, which may
not help the reader.

Change-Id: I072bdc8f3dd125255063ffa7f02500e5228fc9a1
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

This is done in order to make it easier to read the file spm_main.c.

Change-Id: I21e765154c1682a319a3bc47a19a42fd736e910e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Move all information related to a Secure Partition to the struct
secure_partition_context_t.

This requires an in-depth refactor because most of the previous code of
SPM relied on global information.

Change-Id: I0a23e93817dcc191ce1d7506b8bc671d376123c4
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

The Secure Partition should be able to be used from any CPU, not just
the lead one. This patch point the secure contexts of all secondary
CPUs to the same one used by the lead CPU for the Secure Partition. This
way, they can also use it.

In order to prevent more than one CPU from using the Secure Partition at
the same time, a lock has been added.

Change-Id: Ica76373127c3626498b06c558a4874ce72201ff7
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Whether a Secure Partition is being initialized or not is something
related to that specific partition, so it should be saved with the
rest of the information related to it.

Change-Id: Ie8a780f70df83fb03ef9c01ba37960208d9b5319
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

A Secure Partition is a software execution environment instantiated in
S-EL0 that can be used to implement simple management and security
services. Since S-EL0 is an unprivileged exception level, a Secure
Partition relies on privileged firmware e.g. ARM Trusted Firmware to be
granted access to system and processor resources. Essentially, it is a
software sandbox that runs under the control of privileged software in
the Secure World and accesses the following system resources:

- Memory and device regions in the system address map.
- PE system registers.
- A range of asynchronous exceptions e.g. interrupts.
- A range of synchronous exceptions e.g. SMC function identifiers.

A Secure Partition enables privileged firmware to implement only the
absolutely essential secure services in EL3 and instantiate the rest in
a partition. Since the partition executes in S-EL0, its implementation
cannot be overly complex.

The component in ARM Trusted Firmware responsible for managing a Secure
Partition is called the Secure Partition Manager (SPM). The SPM is
responsible for the following:

- Validating and allocating resources requested by a Secure Partition.
- Implementing a well defined interface that is used for initialising a
  Secure Partition.
- Implementing a well defined interface that is used by the normal world
  and other secure services for accessing the services exported by a
  Secure Partition.
- Implementing a well defined interface that is used by a Secure
  Partition to fulfil service requests.
- Instantiating the software execution environment required by a Secure
  Partition to fulfil a service request.

Change-Id: I6f7862d6bba8732db5b73f54e789d717a35e802f
Co-authored-by: Douglas Raillard <douglas.raillard@arm.com>
Co-authored-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Co-authored-by: Achin Gupta <achin.gupta@arm.com>
Co-authored-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>