Add support for asynchronous FIQ handling in TSP ...

This patch adds support in the TSP to handle FIQ interrupts that are
generated when execution is in the TSP. S-EL1 interrupt are handled
normally and execution resumes at the instruction where the exception
was originally taken. S-EL3 interrupts i.e. any interrupt not
recognized by the TSP are handed to the TSPD. Execution resumes
normally once such an interrupt has been handled at EL3.

Change-Id: Ia3ada9a4fb15670afcc12538a6456f21efe58a8f

Add support for synchronous FIQ handling in TSP ...

This patch adds support in the TSP for handling S-EL1 interrupts
handed over by the TSPD. It includes GIC support in its platform port,
updates various statistics related to FIQ handling, exports an entry
point that the TSPD can use to hand over interrupts and defines the
handover protocol w.r.t what context is the TSP expected to preserve
and the state in which the entry point is invoked by the TSPD.

Change-Id: I93b22e5a8133400e4da366f5fc862f871038df39

Use secure timer to generate S-EL1 interrupts ...

This patch adds support in the TSP to program the secure physical
generic timer to generate a EL-1 interrupt every half second. It also
adds support for maintaining the timer state across power management
operations. The TSPD ensures that S-EL1 can access the timer by
programming the SCR_EL3.ST bit.

This patch does not actually enable the timer. This will be done in a
subsequent patch once the complete framework for handling S-EL1
interrupts is in place.

Change-Id: I1b3985cfb50262f60824be3a51c6314ce90571bc

Introduce interrupt handling framework in BL3-1 ...

This patch adds a common handler for FIQ and IRQ exceptions in the
BL3-1 runtime exception vector table. This function determines the
interrupt type and calls its handler. A crash is reported if an
inconsistency in the interrupt management framework is detected. In
the event of a spurious interrupt, execution resumes from the
instruction where the interrupt was generated.

This patch also removes 'cm_macros.S' as its contents have been moved
to 'runtime_exceptions.S'

Change-Id: I3c85ecf8eaf43a3fac429b119ed0bd706d2e2093

Introduce platform api to access an ARM GIC ...

This patch introduces a set of functions which allow generic firmware
code e.g. the interrupt management framework to access the platform
interrupt controller. APIs for finding the type and id of the highest
pending interrupt, acknowledging and EOIing an interrupt and finding
the security state of an interrupt have been added. It is assumed that
the platform interrupt controller implements the v2.0 of the ARM GIC
architecture specification. Support for v3.0 of the specification for
managing interrupts in EL3 and the platform port will be added in the
future.

Change-Id: Ib3a01c2cf3e3ab27806930f1be79db2b29f91bcf

Introduce interrupt registration framework in BL3-1 ...

This patch introduces a framework for registering interrupts routed to
EL3. The interrupt routing model is governed by the SCR_EL3.IRQ and
FIQ bits and the security state an interrupt is generated in. The
framework recognizes three type of interrupts depending upon which
exception level and security state they should be handled in
i.e. Secure EL1 interrupts, Non-secure interrupts and EL3
interrupts. It provides an API and macros that allow a runtime service
to register an handler for a type of interrupt and specify the routing
model. The framework validates the routing model and uses the context
management framework to ensure that it is applied to the SCR_EL3 prior
to entry into the target security state. It saves the handler in
internal data structures. An API is provided to retrieve the handler
when an interrupt of a particular type is asserted. Registration is
expected to be done once by the primary CPU. The same handler and
routing model is used for all CPUs.

Support for EL3 interrupts will be added to the framework in the
future. A makefile flag has been added to allow the FVP port choose
between ARM GIC v2 and v3 support in EL3. The latter version is
currently unsupported.

A framework for handling interrupts in BL3-1 will be introduced in
subsequent patches. The default routing model in the absence of any
handlers expects no interrupts to be routed to EL3.

Change-Id: Idf7c023b34fcd4800a5980f2bef85e4b5c29e649

Add context library API to change a bit in SCR_EL3 ...

This patch adds an API to write to any bit in the SCR_EL3 member of
the 'cpu_context' structure of the current CPU for a specified
security state. This API will be used in subsequent patches which
introduce interrupt management in EL3 to specify the interrupt routing
model when execution is not in EL3.

It also renames the cm_set_el3_elr() function to cm_set_elr_el3()
which is more in line with the system register name being targeted by
the API.

Change-Id: I310fa7d8f827ad3f350325eca2fb28cb350a85ed

Rework 'state' field usage in per-cpu TSP context ...

This patch lays the foundation for using the per-cpu 'state' field in
the 'tsp_context' structure for other flags apart from the power state
of the TSP.

It allocates 2 bits for the power state, introduces the necessary
macros to manipulate the power state in the 'state' field and
accordingly reworks all use of the TSP_STATE_* states.

It also allocates a flag bit to determine if the TSP is handling a
standard SMC. If this flag is set then the TSP was interrupted due to
non-secure or EL3 interupt depending upon the chosen routing
model. Macros to get, set and clear this flag have been added as
well. This flag will be used by subsequent patches.

Change-Id: Ic6ee80bd5895812c83b35189cf2c3be70a9024a6

Merge pull request #78 from jeenuv:tf-issues-148

Add build configuration for timer save/restore ...

At present, non-secure timer register contents are saved and restored as
part of world switch by BL3-1. This effectively means that the
non-secure timer stops, and non-secure timer interrupts are prevented
from asserting until BL3-1 switches back, introducing latency for
non-secure services. Often, secure world might depend on alternate
sources for secure interrupts (secure timer or platform timer) instead
of non-secure timers, in which case this save and restore is
unnecessary.

This patch introduces a boolean build-time configuration NS_TIMER_SWITCH
to choose whether or not to save and restore non-secure timer registers
upon world switch. The default choice is made not to save and restore
them.

Fixes ARM-software/tf-issues#148

Change-Id: I1b9d623606acb9797c3e0b02fb5ec7c0a414f37e

Document summary of build options in user guide ...

Change-Id: I6bd077955bf3780168a874705974bbe72ea0f5f1

Reorganize build options ...

At present, various build options are initialized at various places in
the Makefile. This patch gathers all build option declarations at the
top of the Makefile and assigns them default values.

Change-Id: I9f527bc8843bf69c00cb754dc60377bdb407a951

Introduce convenience functions to build ...

This patch introduces two convenience functions to the build system:

  - assert_boolean: asserts that a given option is assigned either 0 or
    1 as values

  - add_define: helps add/append macro definitions to build tool command
    line. This also introduces the variable DEFINES which is used to
    collect and pass all relevant configurations to build tools

Change-Id: I3126894b034470d39858ebb3bd183bda681c7126

Rework BL3-1 unhandled exception handling and reporting ...

This patch implements the register reporting when unhandled exceptions are
taken in BL3-1. Unhandled exceptions will result in a dump of registers
to the console, before halting execution by that CPU. The Crash Stack,
previously called the Exception Stack, is used for this activity.
This stack is used to preserve the CPU context and runtime stack
contents for debugging and analysis.

This also introduces the per_cpu_ptr_cache, referenced by tpidr_el3,
to provide easy access to some of BL3-1 per-cpu data structures.
Initially, this is used to provide a pointer to the Crash stack.

panic() now prints the the error file and line number in Debug mode
and prints the PC value in release mode.

The Exception Stack is renamed to Crash Stack with this patch.
The original intention of exception stack is no longer valid
since we intend to support several valid exceptions like IRQ
and FIQ in the trusted firmware context. This stack is now
utilized for dumping and reporting the system state when a
crash happens and hence the rename.

Fixes ARM-software/tf-issues#79 Improve reporting of unhandled exception

Change-Id: I260791dc05536b78547412d147193cdccae7811a

Merge pull request #71 from sandrine-bailleux:sb/fix-tsp-fvp-makefile

Merge pull request #69 from sandrine-bailleux:sb/split-mmu-fcts-per-el

Merge pull request #68 from jcastillo-arm/jc/tf-issues/137 ...

Change-Id: If8744c38c2d5c50caa7454b055e2ba418cf1e8bf

Merge pull request #66 from athoelke/tzc-config-fix ...

Fixes for TZC configuration on FVP

fvp: Use the right implem. of plat_report_exception() in BL3-2 ...

On FVP, the file 'plat/fvp/aarch64/plat_helpers.S' contains an
FVP-specific implementation of the function 'plat_report_exception()',
which is meant to override the default implementation. However, this
file was not included into the BL3-2 image, meaning it was still
using the default implementation. This patch fixes the FVP makefile
to compile this file in.

Change-Id: I3d44b9ec3a9de7e2762e0887d3599b185d3e28d2

Fix C accessors to GIC distributor registers with set/clear semantics ...

This patch fixes C accessors to GIC registers that follow a set/clear
semantic to change the state of an interrupt, instead of read/write/modify.
These registers are:
  Set-Enable
  Clear-Enable
  Set-Pending
  Clear-Pending
  Set-Active
  Clear-Active
For instance, to enable an interrupt we write a one to the corresponding bit
in the Set-Enable register, whereas to disable it we write a one to the
corresponding bit in the Clear-Enable register.

Fixes ARM-software/tf-issues#137

Change-Id: I3b66bad94d0b28e0fe08c9042bac0bf5ffa07944

Fixes for TZC configuration on FVP ...

The TZC configuration on FVP was incorrectly allowing both secure
and non-secure accesses to the DRAM, which can cause aliasing
problems for software. It was also not enabling virtio access on
some models.

This patch fixes both of those issues. The patch also enabless
non-secure access to the DDR RAM for all devices with defined IDs.

The third region of DDR RAM has been removed from the configuration
as this is not used in any of the FVP models.

Fixes ARM-software/tf-issues#150
Fixes ARM-software/tf-issues#151

Change-Id: I60ad5daaf55e14f178affb8afd95d17e7537abd7

fvp: Provide per-EL MMU setup functions ...

Instead of having a single version of the MMU setup functions for all
bootloader images that can execute either in EL3 or in EL1, provide
separate functions for EL1 and EL3. Each bootloader image can then
call the appropriate version of these functions. The aim is to reduce
the amount of code compiled in each BL image by embedding only what's
needed (e.g. BL1 to embed only EL3 variants).

Change-Id: Ib86831d5450cf778ae78c9c1f7553fe91274c2fa

Introduce IS_IN_ELX() macros ...

The goal of these macros is to improve code readability by providing
a concise way to check whether we are running in the expected
exception level.

Change-Id: If9aebadfb6299a5196e9a582b442f0971d9909b1

Merge pull request #65 from vikramkanigiri/vk/console_init ...

Ensure a console is initialized before it is used

Merge pull request #63 from soby-mathew/sm/save_callee_saved_registers_in_cpu_context-1 ...

Preserve x19-x29 across world switch for exception handling

Ensure a console is initialized before it is used ...

This patch moves console_init() to bl32_early_platform_setup(). It
also ensures that console_init() is called in each
blX_early_platform_setup() function before the console is used
e.g. through a printf call in an assert() statement.

Fixes ARM-software/TF-issues#127

Change-Id: I5b1f17e0152bab674d807d2a95ff3689c5d4794e

Merge pull request #62 from athoelke/set-little-endian-v2 ...

Set processor endianness immediately after RESET v2

Preserve x19-x29 across world switch for exception handling ...

Previously exception handlers in BL3-1, X19-X29 were not saved
and restored on every SMC/trap into EL3. Instead these registers
were 'saved as needed' as a side effect of the A64 ABI used by the C
compiler.

That approach failed when world switching but was not visible
with the TSP/TSPD code because the TSP is 64-bit, did not
clobber these registers when running and did not support pre-emption
by normal world interrupts. These scenarios showed
that the values in these registers can be passed through a world
switch, which broke the normal and trusted world assumptions
about these registers being preserved.

The Ideal solution saves and restores these registers when a
world switch occurs - but that type of implementation is more complex.
So this patch always saves and restores these registers on entry and
exit of EL3.

Fixes ARM-software/tf-issues#141

Change-Id: I9a727167bbc594454e81cf78a97ca899dfb11c27

Merge pull request #58 from athoelke/optimise-cache-flush-v2 ...

Optimise data cache clean/invalidate operation v2

Merge pull request #61 from athoelke/use-mrs-msr-from-assembler-v2 ...

Use MRS/MSR instructions in assembler code v2