refactor(arm/common): gate coherency behind flag

Introduce a macro guard so platform coherency functions are only
compiled when HW_ASSISTED_COHERENCY is 0 (disabled). Many platforms
enable HW-assist

refactor(arm/common): gate coherency behind flag

Introduce a macro guard so platform coherency functions are only
compiled when HW_ASSISTED_COHERENCY is 0 (disabled). Many platforms
enable HW-assisted coherency by default, so compiling empty
definitions is unnecessary.

This refactor removes those empty functions for Arm CSS platforms.

Change-Id: I102ead46960e9da2d8b968f60cbfd3e5e5da1096
Signed-off-by: Ahmed Azeem <ahmed.azeem@arm.com>

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refactor(gicv3): clarify redistributor base address usage with USE_GIC_DRIVER=3

The GICv3 driver has 2 methods of discovering the redistributors:
a) via setting gicr_base - done at boot and assumes

refactor(gicv3): clarify redistributor base address usage with USE_GIC_DRIVER=3

The GICv3 driver has 2 methods of discovering the redistributors:
a) via setting gicr_base - done at boot and assumes all GICR frames are
contiguous. This is the original method.

b) via gicv3_rdistif_probe() - called from platform code and requires
gicr_base == 0. It relaxes the requirement for frames to be
contiguous, like in a multichip configuration, and defers the
discovery to core bringup. This was introduced later.

Configurations possible with option a) are also possible with option b)
with only slightly different behaviour. USE_GIC_DRIVER=3 inherited
option b) from plat_gicv3_base.c and as such option a) is unusable.
However, it is unclear from code how this should be used. Clarify this
by requiring platforms initialise with gic_set_gicr_frames() and
adding relevant comments.

Also rename plat_arm_override_gicr_frames() to gic_set_gicr_frames() as
this is not plat arm specific and a part of the generic GIC driver.

Change-Id: I61d77211f8e65dc54cf9904069b500d26a06b5a5
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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refactor(arm): unify SPSR retrieval logic

Consolidate platform-specific SPSR setup logic into a single
arm_get_spsr() function that accepts an image_id to select between BL32
and BL33. This reduces

refactor(arm): unify SPSR retrieval logic

Consolidate platform-specific SPSR setup logic into a single
arm_get_spsr() function that accepts an image_id to select between BL32
and BL33. This reduces duplication and simplifies control over SPSR
generation for later stages, particularly BL33.

The SPD remains responsible for setting the SPSR for BL32.

Change-Id: Ibbba708d607e7676989f5c7ceffe33d7bb2195f1
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>

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refactor(gic): promote most of the GIC driver to common code

More often than not, Arm based systems include some revision of a GIC.
There are two ways of adding support for them in platform code - c

refactor(gic): promote most of the GIC driver to common code

More often than not, Arm based systems include some revision of a GIC.
There are two ways of adding support for them in platform code - calling
the top-level helpers from plat/arm/common/arm_gicvX.c or by using the
driver directly. Both of these methods allow for a high degree of
customisation - most functions are defined to be weak and there are no
calls to any of them in generic code.

As it turns out, requirements around those GICs are largely the same.
Platforms that use arm_gicvX.c use the helpers identically among each
other. Platforms that use the driver directly tend to end up with calls
that look a lot like the arm_gicvX.c helpers and the weakness of the
functions are never exercised.

All of this results in a lot of code duplication to do what is
essentially the same thing. Even though it's not a lot of code, when
multiplied among many platforms it becomes significant and makes
refactoring it quite difficult. It's also bug prone since the steps are
a little convoluted and things are likely to work even with subtle
errors (see 50009f61177421118f42d6a000611ba0e613d54b).

So promote as much of the GIC to be called from common code. Do the
setup in bl31_main() and have every PSCI method do the state management
directly instead of delegating it to the platform hooks. We can base
this implementation on arm_gicvX.c since they already offer logical
names and have worked quite well so far with minimal changes.

The main benefit of doing this is reduced code duplication. If we assume
that, outside of some platform setup, GIC management is identical, then
a platform can add support by telling the build system, regardless of
GIC revision. The other benefit is performance - BL31 and PSCI already
know the core_pos and they can pass it as an argument instead of having
to call plat_my_core_pos(). Now, the only platform specific GIC actions
necessary are the saving and restoring of context on entering and
exiting a power domain. The PSCI library does not keep track of this so
it is unable perform it itself. The routines themselves are also
provided.

For compatibility all of this is hidden behind a build flag. Platforms
are encouraged to adopt this driver, but it would not be practical to
convert and validate every GIC based platform.

This patch renames the functions in question to follow the
gic_<function>() convention. This allows the names to be version
agnostic.

Finally, drop the weak definitions - they are unused, likely to remain
so, and can be added back if the need arises.

Change-Id: I5b5267f4b72f633fb1096400ec8e4b208694135f
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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feat(arm): support AArch32 booting with handoff

Configre SP-MIN to receive information via the firmare handoff
framework. In BL1 and BL2, select the 32-bit variants of the SRAM layout
and entry poin

feat(arm): support AArch32 booting with handoff

Configre SP-MIN to receive information via the firmare handoff
framework. In BL1 and BL2, select the 32-bit variants of the SRAM layout
and entry point info to enable booting in aarch32 mode. In SP-MIN
process expected data directly from the transfer list in secure memory.

Change-Id: If0417cdd4c47b772332eb6fd4b71ef0ea474f0fa
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>

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refactor(arm): simplify early platform setup functions

Refactor `arm_sp_min_early_platform_setup` to accept generic
`u_register_r` values to support receiving firmware handoff boot
arguments in comm

refactor(arm): simplify early platform setup functions

Refactor `arm_sp_min_early_platform_setup` to accept generic
`u_register_r` values to support receiving firmware handoff boot
arguments in common code. This has the added benefit of simplifying the
interface into common early platform setup.

Change-Id: Idfc3d41f94f2bf3a3a0c7ca39f6b9b0013836e3a
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>

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fix(juno): remove incorrect assert in sp min boot

There may be some valid configurations where a bootloader runs
before sp_min. In this case the bootloader may pass arguments through
the general pur

fix(juno): remove incorrect assert in sp min boot

There may be some valid configurations where a bootloader runs
before sp_min. In this case the bootloader may pass arguments through
the general purpose registers when passing control to sp_min causing
the assert to fail. Although sp_min may not use the content of the
registers requiring them to be zero seems unnecessary.

Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>
Change-Id: I96fdc79626968830985bdd540f89e73b213de7d8

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