Merge pull request #1751 from vwadekar/tegra-scatter-file-support ...

Tegra scatter file support

Minor changes to documentation and comments ...

Fix some typos and clarify some sentences.

Change-Id: Id276d1ced9a991b4eddc5c47ad9a825e6b29ef74
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Tegra: Support for scatterfile for the BL31 image ...

This patch provides support for using the scatterfile format as
the linker script with the 'armlink' linker for Tegra platforms.

In order to enable the scatterfile usage the following changes
have been made:

* provide mapping for ld.S symbols in bl_common.h
* include bl_common.h from all the affected files
* update the makefile rules to use the scatterfile and armlink
  to compile BL31
* update pubsub.h to add sections to the scatterfile

NOTE: THIS CHANGE HAS BEEN VERIFIED WITH TEGRA PLATFORMS ONLY.

Change-Id: I7bb78b991c97d74a842e5635c74cb0b18e0fce67
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

Add ARMv8.3-PAuth registers to CPU context ...

ARMv8.3-PAuth adds functionality that supports address authentication of
the contents of a register before that register is used as the target of
an indirect branch, or as a load.

This feature is supported only in AArch64 state.

This feature is mandatory in ARMv8.3 implementations.

This feature adds several registers to EL1. A new option called
CTX_INCLUDE_PAUTH_REGS has been added to select if the TF needs to save
them during Non-secure <-> Secure world switches. This option must be
enabled if the hardware has the registers or the values will be leaked
during world switches.

To prevent leaks, this patch also disables pointer authentication in the
Secure world if CTX_INCLUDE_PAUTH_REGS is 0. Any attempt to use it will
be trapped in EL3.

Change-Id: I27beba9907b9a86c6df1d0c5bf6180c972830855
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Cleanup context handling library ...

Minor style cleanup.

Change-Id: Ief19dece41a989e2e8157859a265701549f6c585
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

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>

Standardise header guards across codebase ...

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>

context_mgmt: Fix MISRA defects ...

The macro EL_IMPLEMENTED() has been deprecated in favour of the new
function el_implemented().

Change-Id: Ic9b1b81480b5e019b50a050e8c1a199991bf0ca9
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Fix MISRA defects in workaround and errata framework ...

No functional changes.

Change-Id: Iaab0310848be587b635ce5339726e92a50f534e0
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

context_mgmt: Remove deprecated interfaces ...

Change-Id: I2d4a21a80a768bc422e9707e6d7e98d20a716275
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: Ensure SDEI handler executes with CVE-2018-3639 mitigation enabled ...

When dynamic mitigation is used, the SDEI handler is required to
execute with the mitigation enabled by default, regardless of the
mitigation state for lower ELs.  This means that if the kernel or
hypervisor explicitly disables the mitigation and then later when the
event is dispatched, the dispatcher will remember the mitigation state
for the lower ELs but force the mitigation to be on during the SDEI
handler execution.  When the SDEI handler returns, it will restore the
mitigation state.

This behaviour is described in "Firmware interfaces for mitigating
cache speculation vulnerabilities System Software on Arm Systems"[0].

[0] https://developer.arm.com/cache-speculation-vulnerability-firmware-specification

Change-Id: I8dd60b736be0aa9e832b0f92d67a401fdeb417f4
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

Merge pull request #1392 from dp-arm/dp/cve_2018_3639 ...

Implement workaround for CVE-2018-3639 on Cortex A57/A72/A73 and A75

context_mgmt: Make cm_init_context_common public ...

This function can be currently accessed through the wrappers
cm_init_context_by_index() and cm_init_my_context(). However, they only
work on contexts that are associated to a CPU.

By making this function public, it is possible to set up a context that
isn't associated to any CPU. For consistency, it has been renamed to
cm_setup_context().

Change-Id: Ib2146105abc8137bab08745a8adb30ca2c4cedf4
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Add support for dynamic mitigation for CVE-2018-3639 ...

Some CPUS may benefit from using a dynamic mitigation approach for
CVE-2018-3639.  A new SMC interface is defined to allow software
executing in lower ELs to enable or disable the mitigation for their
execution context.

It should be noted that regardless of the state of the mitigation for
lower ELs, code executing in EL3 is always mitigated against
CVE-2018-3639.

NOTE: This change is a compatibility break for any platform using
the declare_cpu_ops_workaround_cve_2017_5715 macro.  Migrate to
the declare_cpu_ops_wa macro instead.

Change-Id: I3509a9337ad217bbd96de9f380c4ff8bf7917013
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

AArch64: Introduce External Abort handling ...

At present, any External Abort routed to EL3 is reported as an unhandled
exception and cause a panic. This patch enables ARM Trusted Firmware to
handle External Aborts routed to EL3.

With this patch, when an External Abort is received at EL3, its handling
is delegated to plat_ea_handler() function. Platforms can provide their
own implementation of this function. This patch adds a weak definition
of the said function that prints out a message and just panics.

In order to support handling External Aborts at EL3, the build option
HANDLE_EA_EL3_FIRST must be set to 1.

Before this patch, HANDLE_EA_EL3_FIRST wasn't passed down to
compilation; this patch fixes that too.

Change-Id: I4d07b7e65eb191ff72d63b909ae9512478cd01a1
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

Fix MISRA rule 8.4 in common code ...

Rule 8.4: A compatible declaration shall be visible when
          an object or function with external linkage is defined.

Change-Id: I26e042cb251a6f9590afa1340fdac73e42f23979
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

Optimize/cleanup BPIALL workaround ...

In the initial implementation of this workaround we used a dedicated
workaround context to save/restore state.  This patch reduces the
footprint as no additional context is needed.

Additionally, this patch reduces the memory loads and stores by 20%,
reduces the instruction count and exploits static branch prediction to
optimize the SMC path.

Change-Id: Ia9f6bf06fbf8a9037cfe7f1f1fb32e8aec38ec7d
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

Merge pull request #1197 from dp-arm/dp/amu ...

AMUv1 support

Add PubSub events for CPU powerdown/powerup ...

The suspend hook is published at the start of a CPU powerdown
operation.  The resume hook is published at the end of a CPU powerup
operation.

Change-Id: I50c05e2dde0d33834095ac41b4fcea4c161bb434
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

Workaround for CVE-2017-5715 on Cortex A73 and A75 ...

Invalidate the Branch Target Buffer (BTB) on entry to EL3 by
temporarily dropping into AArch32 Secure-EL1 and executing the
`BPIALL` instruction.

This is achieved by using 3 vector tables.  There is the runtime
vector table which is used to handle exceptions and 2 additional
tables which are required to implement this workaround.  The
additional tables are `vbar0` and `vbar1`.

The sequence of events for handling a single exception is
as follows:

1) Install vector table `vbar0` which saves the CPU context on entry
   to EL3 and sets up the Secure-EL1 context to execute in AArch32 mode
   with the MMU disabled and I$ enabled.  This is the default vector table.

2) Before doing an ERET into Secure-EL1, switch vbar to point to
   another vector table `vbar1`.  This is required to restore EL3 state
   when returning from the workaround, before proceeding with normal EL3
   exception handling.

3) While in Secure-EL1, the `BPIALL` instruction is executed and an
   SMC call back to EL3 is performed.

4) On entry to EL3 from Secure-EL1, the saved context from step 1) is
   restored.  The vbar is switched to point to `vbar0` in preparation to
   handle further exceptions.  Finally a branch to the runtime vector
   table entry is taken to complete the handling of the original
   exception.

This workaround is enabled by default on the affected CPUs.

NOTE
====

There are 4 different stubs in Secure-EL1.  Each stub corresponds to
an exception type such as Sync/IRQ/FIQ/SError.  Each stub will move a
different value in `R0` before doing an SMC call back into EL3.
Without this piece of information it would not be possible to know
what the original exception type was as we cannot use `ESR_EL3` to
distinguish between IRQs and FIQs.

Change-Id: I90b32d14a3735290b48685d43c70c99daaa4b434
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

Refactor Statistical Profiling Extensions implementation ...

Factor out SPE operations in a separate file.  Use the publish
subscribe framework to drain the SPE buffers before entering secure
world.  Additionally, enable SPE before entering normal world.

A side effect of this change is that the profiling buffers are now
only drained when a transition from normal world to secure world
happens.  Previously they were drained also on return from secure
world, which is unnecessary as SPE is not supported in S-EL1.

Change-Id: I17582c689b4b525770dbb6db098b3a0b5777b70a
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

Move FPEXC32_EL2 to FP Context ...

The FPEXC32_EL2 register controls SIMD and FP functionality when the
lower ELs are executing in AArch32 mode. It is architecturally mapped
to AArch32 system register FPEXC.

This patch removes FPEXC32_EL2 register from the System Register context
and adds it to the floating-point context. EL3 only saves / restores the
floating-point context if the build option CTX_INCLUDE_FPREGS is set to 1.

The rationale for this change is that if the Secure world is using FP
functionality and EL3 is not managing the FP context, then the Secure
world will save / restore the appropriate FP registers.

NOTE - this is a break in behaviour in the unlikely case that
CTX_INCLUDE_FPREGS is set to 0 and the platform contains an AArch32
Secure Payload that modifies FPEXC, but does not save and restore
this register

Change-Id: Iab80abcbfe302752d52b323b4abcc334b585c184
Signed-off-by: David Cunado <david.cunado@arm.com>

BL31: Introduce Exception Handling Framework ...

EHF is a framework that allows dispatching of EL3 interrupts to their
respective handlers in EL3.

This framework facilitates the firmware-first error handling policy in
which asynchronous exceptions may be routed to EL3. Such exceptions may
be handed over to respective exception handlers. Individual handlers
might further delegate exception handling to lower ELs.

The framework associates the delegated execution to lower ELs with a
priority value. For interrupts, this corresponds to the priorities
programmed in GIC; for other types of exceptions, viz. SErrors or
Synchronous External Aborts, individual dispatchers shall explicitly
associate delegation to a secure priority. In order to prevent lower
priority interrupts from preempting higher priority execution, the
framework provides helpers to control preemption by virtue of
programming Priority Mask register in the interrupt controller.

This commit allows for handling interrupts targeted at EL3. Exception
handlers own interrupts by assigning them a range of secure priorities,
and registering handlers for each priority range it owns.

Support for exception handling in BL31 image is enabled by setting the
build option EL3_EXCEPTION_HANDLING=1.

Documentation to follow.

NOTE: The framework assumes the priority scheme supported by platform
interrupt controller is compliant with that of ARM GIC architecture (v2
or later).

Change-Id: I7224337e4cea47c6ca7d7a4ca22a3716939f7e42
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

Merge pull request #1151 from JoelHutton/jh/MISRA-Mandatory ...

Change sizeof to use type of struct not function

Change sizeof to use type of struct not function ...

Change sizeof call so it references a static type instead of return of
a function in order to be MISRA compliant.

Change-Id: I6f1adb206073d6cd200156e281b8d76249e3af0e
Signed-off-by: Joel Hutton <joel.hutton@arm.com>

aarch64: Add PubSub events to capture security state transitions ...

Add events that trigger before entry to normal/secure world.  The
events trigger after the normal/secure context has been restored.

Similarly add events that trigger after leaving normal/secure world.
The events trigger after the normal/secure context has been saved.

Change-Id: I1b48a7ea005d56b1f25e2b5313d77e67d2f02bc5
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

PSCI: Publish CPU ON event ...

This allows other EL3 components to subscribe to CPU on events.

Update Firmware Design guide to list psci_cpu_on_finish as an available
event.

Change-Id: Ida774afe0f9cdce4021933fcc33a9527ba7aaae2
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

BL31: Introduce Publish and Subscribe framework ...

This light-weight framework enables some EL3 components to publish
events which other EL3 components can subscribe to. Publisher can
optionally pass opaque data for subscribers. The order in which
subscribers are called is not defined.

Firmware design updated.

Change-Id: I24a3a70b2b1dedcb1f73cf48313818aebf75ebb6
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

Init and save / restore of PMCR_EL0 / PMCR ...

Currently TF does not initialise the PMCR_EL0 register in
the secure context or save/restore the register.

In particular, the DP field may not be set to one to prohibit
cycle counting in the secure state, even though event counting
generally is prohibited via the default setting of MDCR_EL3.SMPE
to 0.

This patch initialises PMCR_EL0.DP to one in the secure state
to prohibit cycle counting and also initialises other fields
that have an architectually UNKNOWN reset value.

Additionally, PMCR_EL0 is added to the list of registers that are
saved and restored during a world switch.

Similar changes are made for PMCR for the AArch32 execution state.

NOTE: secure world code at lower ELs that assume other values in PMCR_EL0
will be impacted.

Change-Id: Iae40e8c0a196d74053accf97063ebc257b4d2f3a
Signed-off-by: David Cunado <david.cunado@arm.com>