Introduce PSCI Library Interface ...

This patch introduces the PSCI Library interface. The major changes
introduced are as follows:

* Earlier BL31 was responsible for Architectural initialization during cold
boot via bl31_arch_setup() whereas PSCI was responsible for the same during
warm boot. This functionality is now consolidated by the PSCI library
and it does Architectural initialization via psci_arch_setup() during both
cold and warm boots.

* Earlier the warm boot entry point was always `psci_entrypoint()`. This was
not flexible enough as a library interface. Now PSCI expects the runtime
firmware to provide the entry point via `psci_setup()`. A new function
`bl31_warm_entrypoint` is introduced in BL31 and the previous
`psci_entrypoint()` is deprecated.

* The `smc_helpers.h` is reorganized to separate the SMC Calling Convention
defines from the Trusted Firmware SMC helpers. The former is now in a new
header file `smcc.h` and the SMC helpers are moved to Architecture specific
header.

* The CPU context is used by PSCI for context initialization and
restoration after power down (PSCI Context). It is also used by BL31 for SMC
handling and context management during Normal-Secure world switch (SMC
Context). The `psci_smc_handler()` interface is redefined to not use SMC
helper macros thus enabling to decouple the PSCI context from EL3 runtime
firmware SMC context. This enables PSCI to be integrated with other runtime
firmware using a different SMC context.

NOTE: With this patch the architectural setup done in `bl31_arch_setup()`
is done as part of `psci_setup()` and hence `bl31_platform_setup()` will be
invoked prior to architectural setup. It is highly unlikely that the platform
setup will depend on architectural setup and cause any failure. Please be
be aware of this change in sequence.

Change-Id: I7f497a08d33be234bbb822c28146250cb20dab73

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

Introduce some helper macros for exception vectors ...

This patch introduces some assembler macros to simplify the
declaration of the exception vectors. It abstracts the section
the exception code is put into as well as the alignments
constraints mandated by the ARMv8 architecture. For all TF images,
the exception code has been updated to make use of these macros.

This patch also updates some invalid comments in the exception
vector code.

Change-Id: I35737b8f1c8c24b6da89b0a954c8152a4096fa95

Add 32 bit version of plat_get_syscnt_freq ...

Added plat_get_syscnt_freq2, which is a 32 bit variant of the 64 bit
plat_get_syscnt_freq. The old one has been flagged as deprecated.
Common code has been updated to use this new version. Porting guide
has been updated.

Change-Id: I9e913544926c418970972bfe7d81ee88b4da837e

Dump platform-defined regs in crash reporting ...

It is up to the platform to implement the new plat_crash_print_regs macro to
report all relevant platform registers helpful for troubleshooting.

plat_crash_print_regs merges or calls previously defined plat_print_gic_regs
and plat_print_interconnect_regs macros for each existing platforms.

NOTE: THIS COMMIT REQUIRES ALL PLATFORMS THAT ENABLE THE `CRASH_REPORTING`
BUILD FLAG TO MIGRATE TO USE THE NEW `plat_crash_print_regs()` MACRO. BY
DEFAULT, `CRASH_REPORTING` IS ENABLED IN DEBUG BUILDS FOR ALL PLATFORMS.

Fixes: arm-software/tf-issues#373

Signed-off-by: Gerald Lejeune <gerald.lejeune@st.com>

Add ISR_EL1 to crash report ...

Bring ISR bits definition as a mnemonic for troublershooters as well.

Signed-off-by: Gerald Lejeune <gerald.lejeune@st.com>

Enable asynchronous abort exceptions during boot ...

Asynchronous abort exceptions generated by the platform during cold boot are
not taken in EL3 unless SCR_EL3.EA is set.

Therefore EA bit is set along with RES1 bits in early BL1 and BL31 architecture
initialisation. Further write accesses to SCR_EL3 preserve these bits during
cold boot.

A build flag controls SCR_EL3.EA value to keep asynchronous abort exceptions
being trapped by EL3 after cold boot or not.

For further reference SError Interrupts are also known as asynchronous external
aborts.

On Cortex-A53 revisions below r0p2, asynchronous abort exceptions are taken in
EL3 whatever the SCR_EL3.EA value is.

Fixes arm-software/tf-issues#368

Signed-off-by: Gerald Lejeune <gerald.lejeune@st.com>

Remove all non-configurable dead loops ...

Added a new platform porting function plat_panic_handler, to allow
platforms to handle unexpected error situations. It must be
implemented in assembly as it may be called before the C environment
is initialized. A default implementation is provided, which simply
spins.

Corrected all dead loops in generic code to call this function
instead. This includes the dead loop that occurs at the end of the
call to panic().

All unnecesary wfis from bl32/tsp/aarch64/tsp_exceptions.S have
been removed.

Change-Id: I67cb85f6112fa8e77bd62f5718efcef4173d8134

Miscellaneous doc fixes for v1.2 ...

Change-Id: I6f49bd779f2a4d577c6443dd160290656cdbc59b

Remove dashes from image names: 'BL3-x' --> 'BL3x' ...

This patch removes the dash character from the image name, to
follow the image terminology in the Trusted Firmware Wiki page:

    https://github.com/ARM-software/arm-trusted-firmware/wiki

Changes apply to output messages, comments and documentation.

non-ARM platform files have been left unmodified.

Change-Id: Ic2a99be4ed929d52afbeb27ac765ceffce46ed76

Move context management code to common location ...

The upcoming Firmware Update feature needs transitioning across
Secure/Normal worlds to complete the FWU process and hence requires
context management code to perform this task.

Currently context management code is part of BL31 stage only.
This patch moves the code from (include)/bl31 to (include)/common.
Some function declarations/definitions and macros have also moved
to different files to help code sharing.

Change-Id: I3858b08aecdb76d390765ab2b099f457873f7b0c

Fix issue in Floating point register restore ...

The `fpregs_context_restore()` function used to restore the floating point
regsiter context had a typo error wherein it was doing `str` instead of
`ldr` for a register. This issue remained undetected becuase none of the ARM
Standard development platforms save and restore the floating point register
context when a context switch is done. This patch corrects the issue.

Change-Id: Id178e0ba254a5e0a4a844f54b39d71dc34e0f6ea

Merge pull request #443 from achingupta/sb/el3_payloads-cb_single_cpu ...

Add support to boot EL3 payloads and only a single CPU at cold reset

Introduce COLD_BOOT_SINGLE_CPU build option ...

This patch introduces a new build option named COLD_BOOT_SINGLE_CPU,
which allows platforms that only release a single CPU out of reset to
slightly optimise their cold boot code, both in terms of code size
and performance.

COLD_BOOT_SINGLE_CPU defaults to 0, which assumes that the platform
may release several CPUs out of reset. In this case, the cold reset
code needs to coordinate all CPUs via the usual primary/secondary
CPU distinction.

If a platform guarantees that only a single CPU will ever be released
out of reset, there is no need to arbitrate execution ; the notion of
primary and secondary CPUs itself no longer exists. Such platforms
may set COLD_BOOT_SINGLE_CPU to 1 in order to compile out the
primary/secondary CPU identification in the cold reset code.

All ARM standard platforms can release several CPUs out of reset
so they use COLD_BOOT_SINGLE_CPU=0. However, on CSS platforms like
Juno, bringing up more than one CPU at reset should only be attempted
when booting an EL3 payload, as it is not fully supported in the
normal boot flow.

For platforms using COLD_BOOT_SINGLE_CPU=1, the following 2 platform
APIs become optional:
  - plat_secondary_cold_boot_setup();
  - plat_is_my_cpu_primary().
The Porting Guide has been updated to reflect that.

User Guide updated as well.

Change-Id: Ic5b474e61b7aec1377d1e0b6925d17dfc376c46b

Remove the IMF_READ_INTERRUPT_ID build option ...

The IMF_READ_INTERRUPT_ID build option enables a feature where the interrupt
ID of the highest priority pending interrupt is passed as a parameter to the
interrupt handler registered for that type of interrupt. This additional read
of highest pending interrupt id from GIC is problematic as it is possible that
the original interrupt may get deasserted and another interrupt of different
type maybe become the highest pending interrupt. Hence it is safer to prevent
such behaviour by removing the IMF_READ_INTERRUPT_ID build option.

The `id` parameter of the interrupt handler `interrupt_type_handler_t` is
now made a reserved parameter with this patch. It will always contain
INTR_ID_UNAVAILABLE.

Fixes ARM-software/tf-issues#307

Change-Id: I2173aae1dd37edad7ba6bdfb1a99868635fa34de

Make generic code work in presence of system caches ...

On the ARMv8 architecture, cache maintenance operations by set/way on the last
level of integrated cache do not affect the system cache. This means that such a
flush or clean operation could result in the data being pushed out to the system
cache rather than main memory. Another CPU could access this data before it
enables its data cache or MMU. Such accesses could be serviced from the main
memory instead of the system cache. If the data in the sysem cache has not yet
been flushed or evicted to main memory then there could be a loss of
coherency. The only mechanism to guarantee that the main memory will be updated
is to use cache maintenance operations to the PoC by MVA(See section D3.4.11
(System level caches) of ARMv8-A Reference Manual (Issue A.g/ARM DDI0487A.G).

This patch removes the reliance of Trusted Firmware on the flush by set/way
operation to ensure visibility of data in the main memory. Cache maintenance
operations by MVA are now used instead. The following are the broad category of
changes:

1. The RW areas of BL2/BL31/BL32 are invalidated by MVA before the C runtime is
   initialised. This ensures that any stale cache lines at any level of cache
   are removed.

2. Updates to global data in runtime firmware (BL31) by the primary CPU are made
   visible to secondary CPUs using a cache clean operation by MVA.

3. Cache maintenance by set/way operations are only used prior to power down.

NOTE: NON-UPSTREAM TRUSTED FIRMWARE CODE SHOULD MAKE EQUIVALENT CHANGES IN
ORDER TO FUNCTION CORRECTLY ON PLATFORMS WITH SUPPORT FOR SYSTEM CACHES.

Fixes ARM-software/tf-issues#205

Change-Id: I64f1b398de0432813a0e0881d70f8337681f6e9a

PSCI: Migrate TF to the new platform API and CM helpers ...

This patch migrates the rest of Trusted Firmware excluding Secure Payload and
the dispatchers to the new platform and context management API. The per-cpu
data framework APIs which took MPIDRs as their arguments are deleted and only
the ones which take core index as parameter are retained.

Change-Id: I839d05ad995df34d2163a1cfed6baa768a5a595d

Merge pull request #310 from sandrine-bailleux/sb/tf-issue-304-phase1 ...

Enhance BL3-1 entrypoint handling to support non-TF boot firmware - Phase 1

Introduce PROGRAMMABLE_RESET_ADDRESS build option ...

This patch introduces a new platform build option, called
PROGRAMMABLE_RESET_ADDRESS, which tells whether the platform has
a programmable or fixed reset vector address.

If the reset vector address is fixed then the code relies on the
platform_get_entrypoint() mailbox mechanism to figure out where
it is supposed to jump. On the other hand, if it is programmable
then it is assumed that the platform code will program directly
the right address into the RVBAR register (instead of using the
mailbox redirection) so the mailbox is ignored in this case.

Change-Id: If59c3b11fb1f692976e1d8b96c7e2da0ebfba308

Rationalize reset handling code ...

The attempt to run the CPU reset code as soon as possible after reset
results in highly complex conditional code relating to the
RESET_TO_BL31 option.

This patch relaxes this requirement a little. In the BL1, BL3-1 and
PSCI entrypoints code, the sequence of operations is now as follows:
 1) Detect whether it is a cold or warm boot;
 2) For cold boot, detect whether it is the primary or a secondary
    CPU. This is needed to handle multiple CPUs entering cold reset
    simultaneously;
 3) Run the CPU init code.

This patch also abstracts the EL3 registers initialisation done by
the BL1, BL3-1 and PSCI entrypoints into common code.

This improves code re-use and consolidates the code flows for
different types of systems.

NOTE: THE FUNCTION plat_secondary_cold_boot() IS NOW EXPECTED TO
NEVER RETURN. THIS PATCH FORCES PLATFORM PORTS THAT RELIED ON THE
FORMER RETRY LOOP AT THE CALL SITE TO MODIFY THEIR IMPLEMENTATION.
OTHERWISE, SECONDARY CPUS WILL PANIC.

Change-Id: If5ecd74d75bee700b1bd718d23d7556b8f863546

Fix handling of spurious interrupts in BL3_1 ...

There are couple of issues with how the interrupt routing framework in BL3_1
handles spurious interrupts.

1. In the macro 'handle_interrupt_exception', if a spurious interrupt is
   detected by plat_ic_get_pending_interrupt_type(), then execution jumps to
   'interrupt_exit_\label'. This macro uses the el3_exit() function to return to
   the original exception level. el3_exit() attempts to restore the SPSR_EL3 and
   ELR_EL3 registers with values from the current CPU context. Since these
   registers were not saved in this code path, it programs stale values into
   these registers. This leads to unpredictable behaviour after the execution of
   the ERET instruction.

2. When an interrupt is routed to EL3, it could be de-asserted before the
   GICC_HPPIR is read in plat_ic_get_pending_interrupt_type(). There could be
   another interrupt pending at the same time e.g. a non-secure interrupt. Its
   type will be returned instead of the original interrupt. This would result in
   a call to get_interrupt_type_handler(). The firmware will panic if the
   handler for this type of interrupt has not been registered.

This patch fixes the first problem by saving SPSR_EL3 and ELR_EL3 early in the
'handle_interrupt_exception' macro, instead of only doing so once the validity
of the interrupt has been determined.

The second problem is fixed by returning execution back to the lower exception
level through the 'interrupt_exit_\label' label instead of treating it as an
error condition. The 'interrupt_error_\label' label has been removed since it is
no longer used.

Fixes ARM-software/tf-issues#305

Change-Id: I81c729a206d461084db501bb81b44dff435021e8

Add support to indicate size and end of assembly functions ...

In order for the symbol table in the ELF file to contain the size of
functions written in assembly, it is necessary to report it to the
assembler using the .size directive.

To fulfil the above requirements, this patch introduces an 'endfunc'
macro which contains the .endfunc and .size directives. It also adds
a .func directive to the 'func' assembler macro.

The .func/.endfunc have been used so the assembler can fail if
endfunc is omitted.

Fixes ARM-Software/tf-issues#295

Change-Id: If8cb331b03d7f38fe7e3694d4de26f1075b278fc
Signed-off-by: Kévin Petit <kevin.petit@arm.com>

Initialise cpu ops after enabling data cache ...

The cpu-ops pointer was initialized before enabling the data cache in the cold
and warm boot paths. This required a DCIVAC cache maintenance operation to
invalidate any stale cache lines resident in other cpus.

This patch moves this initialization to the bl31_arch_setup() function
which is always called after the data cache and MMU has been enabled.

This change removes the need:
 1. for the DCIVAC cache maintenance operation.
 2. to initialise the CPU ops upon resumption from a PSCI CPU_SUSPEND
    call since memory contents are always preserved in this case.

Change-Id: Ibb2fa2f7460d1a1f1e721242025e382734c204c6

Call reset handlers upon BL3-1 entry. ...

This patch adds support to call the reset_handler() function in BL3-1 in the
cold and warm boot paths when another Boot ROM reset_handler() has already run.

This means the BL1 and BL3-1 versions of the CPU and platform specific reset
handlers may execute different code to each other. This enables a developer to
perform additional actions or undo actions already performed during the first
call of the reset handlers e.g. apply additional errata workarounds.

Typically, the reset handler will be first called from the BL1 Boot ROM. Any
additional functionality can be added to the reset handler when it is called
from BL3-1 resident in RW memory. The constant FIRST_RESET_HANDLER_CALL is used
to identify whether this is the first version of the reset handler code to be
executed or an overridden version of the code.

The Cortex-A57 errata workarounds are applied only if they have not already been
applied.

Fixes ARM-software/tf-issue#275

Change-Id: Id295f106e4fda23d6736debdade2ac7f2a9a9053

Remove coherent memory from the BL memory maps ...

This patch extends the build option `USE_COHERENT_MEMORY` to
conditionally remove coherent memory from the memory maps of
all boot loader stages. The patch also adds necessary
documentation for coherent memory removal in firmware-design,
porting and user guides.

Fixes ARM-Software/tf-issues#106

Change-Id: I260e8768c6a5c2efc402f5804a80657d8ce38773

Miscellaneous documentation fixes ...

This patch gathers miscellaneous minor fixes to the documentation, and comments
in the source code.

Change-Id: I631e3dda5abafa2d90f464edaee069a1e58b751b
Co-Authored-By: Soby Mathew <soby.mathew@arm.com>
Co-Authored-By: Dan Handley <dan.handley@arm.com>

Add CPU specific crash reporting handlers ...

This patch adds handlers for dumping Cortex-A57 and Cortex-A53 specific register
state to the CPU specific operations framework. The contents of CPUECTLR_EL1 are
dumped currently.

Change-Id: I63d3dbfc4ac52fef5e25a8cf6b937c6f0975c8ab

Add CPU specific power management operations ...

This patch adds CPU core and cluster power down sequences to the CPU specific
operations framework introduced in a earlier patch. Cortex-A53, Cortex-A57 and
generic AEM sequences have been added. The latter is suitable for the
Foundation and Base AEM FVPs. A pointer to each CPU's operations structure is
saved in the per-cpu data so that it can be easily accessed during power down
seqeunces.

An optional platform API has been introduced to allow a platform to disable the
Accelerator Coherency Port (ACP) during a cluster power down sequence. The weak
definition of this function (plat_disable_acp()) does not take any action. It
should be overriden with a strong definition if the ACP is present on a
platform.

Change-Id: I8d09bd40d2f528a28d2d3f19b77101178778685d

Introduce framework for CPU specific operations ...

This patch introduces a framework which will allow CPUs to perform
implementation defined actions after a CPU reset, during a CPU or cluster power
down, and when a crash occurs. CPU specific reset handlers have been implemented
in this patch. Other handlers will be implemented in subsequent patches.

Also moved cpu_helpers.S to the new directory lib/cpus/aarch64/.

Change-Id: I1ca1bade4d101d11a898fb30fea2669f9b37b956

Unmask SError interrupt and clear SCR_EL3.EA bit ...

This patch disables routing of external aborts from lower exception levels to
EL3 and ensures that a SError interrupt generated as a result of execution in
EL3 is taken locally instead of a lower exception level.

The SError interrupt is enabled in the TSP code only when the operation has not
been directly initiated by the normal world. This is to prevent the possibility
of an asynchronous external abort which originated in normal world from being
taken when execution is in S-EL1.

Fixes ARM-software/tf-issues#153

Change-Id: I157b996c75996d12fd86d27e98bc73dd8bce6cd5