[PATCH v2 0/6] Add Armv8-R AArch64 support

[Luca Fancellu]

Currently, we cannot boot Linux with boot-wrapper on Armv8-R AArch64:
1. The Armv8-R AArch64 profile does not support the EL3.
2. The Armv8-R AArch64 EL2 only supports a PMSA, which Linux does not
support. So it's necessary to drop into EL1 before entering the kernel.
3. There is no EL2 booting code for Armv8-R AArch64 and no
configuration for dropping to EL1 in boot-wrapper.

These patches enable boot-wrapper booting Linux with Armv8-R AArch64.

This is a rework and rebase of a serie already present upstream [1], apart
from patch 3 which is addressing a small bug and patch 6 and 7 which are
introducing support for PSCI boot through hvc conduit and Xen boot under Armv8-R
AArch64.

[1] https://patchwork.kernel.org/project/linux-arm-kernel/cover/20210525062509.201464-1-jaxson.han@arm.com/

Changes from v1:
 - Dropped patch 4 regarding GIC changes, it's not needed anymore.

Luca Fancellu (6):
  aarch64: Rename labels and prepare for lower EL booting
  aarch64: Prepare for lower EL booting
  aarch64: Remove TSCXT bit set from SCTLR_EL2_RESET
  aarch64: Introduce EL2 boot code for Armv8-R AArch64
  aarch64: Support PSCI for Armv8-R AArch64
  aarch64: Start Xen on Armv8-R at EL2

 Makefile.am                    |  6 ++-
 arch/aarch64/boot.S            | 75 ++++++++++++++++++++++++++++++----
 arch/aarch64/include/asm/cpu.h | 15 ++++++-
 arch/aarch64/init.c            | 44 ++++++++++++++++++--
 configure.ac                   | 16 +++++---
 5 files changed, 138 insertions(+), 18 deletions(-)

-- 
2.34.1