[PATCH v4 0/5] initialize SCTRL2_ELx

[Yeoreum Yun]

Gentle ping in case of forgotten.

On Thu, Aug 21, 2025 at 06:24:03PM +0100, Yeoreum Yun wrote:
> This series introduces initial support for the SCTLR2_ELx registers in Linux.
> The feature is optional starting from ARMv8.8/ARMv9.3,
> and becomes mandatory from ARMv8.9/ARMv9.4.
>
> Currently, Linux has no strict need to modify SCTLR2_ELx--
> at least assuming that firmware initializes
> these registers to reasonable defaults.
>
> However, several upcoming architectural features will require configuring
> control bits in these registers.
> Notable examples include FEAT_PAuth_LR and FEAT_CPA2.
>
> Patch History
> ==============
> from v3 to v4:
>   - integrate set_sctlr2_elx() and __set_sctlr2_elx() to set_sctlr2_elx()
>     without isb()
>   - fix the wrong register setting in set_sctlr2_elx().
>   - add initialise SCTLR2_EL2 at HVC_SOFT_RESTART.
>   - https://lore.kernel.org/all/20250813120118.3953541-1-yeoreum.yun@arm.com/
>
> from v2 to v3:
>   - rewrite commit messages.
>   - fix missing SCTLR2_EL2 synchonization at boot.
>   - merging the __kvm_host_psci_cpu_entry() changes into patch #1
>   - https://lore.kernel.org/all/20250811163340.1561893-1-yeoreum.yun@arm.com/
>
> from v1 to v2:
>   - rebase to v6.17-rc1
>   - https://lore.kernel.org/all/20250804121724.3681531-1-yeoreum.yun@arm.com/
>
> Yeoreum Yun (5):
>   arm64: make SCTLR2_EL1 accessible
>   arm64: initialise SCTLR2_ELx register at boot time
>   arm64: save/restore SCTLR2_EL1 when cpu_suspend()/resume()
>   arm64: initialise SCTLR2_EL1 at cpu_soft_restart()
>   arm64: make the per-task SCTLR2_EL1
>
>  arch/arm64/include/asm/assembler.h   | 15 +++++++++++++++
>  arch/arm64/include/asm/el2_setup.h   | 17 +++++++++++++++--
>  arch/arm64/include/asm/processor.h   |  3 +++
>  arch/arm64/include/asm/suspend.h     |  2 +-
>  arch/arm64/include/asm/sysreg.h      |  5 +++++
>  arch/arm64/kernel/cpu-reset.S        |  4 ++++
>  arch/arm64/kernel/head.S             |  5 +++++
>  arch/arm64/kernel/hyp-stub.S         | 10 ++++++++++
>  arch/arm64/kernel/process.c          |  9 +++++++++
>  arch/arm64/kvm/hyp/nvhe/hyp-init.S   |  3 +++
>  arch/arm64/kvm/hyp/nvhe/psci-relay.c |  3 +++
>  arch/arm64/mm/proc.S                 | 24 ++++++++++++++++--------
>  12 files changed, 89 insertions(+), 11 deletions(-)
>
>
> base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
> --
> LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}
>

--
Sincerely,
Yeoreum Yun