[PATCH 1/4] firmware: arm_sdei: add SDEI_EVENT_SIGNAL support

[Doug Anderson]

Hi,

On Wed, Jun 3, 2026 at 7:36 AM Kiryl Shutsemau <kirill at shutemov.name> wrote:
>
> From: "Kiryl Shutsemau (Meta)" <kas at kernel.org>
>
> Add sdei_event_signal(), a thin wrapper over the SDEI_EVENT_SIGNAL call
> (DEN0054) that makes the software-signalled event (event 0) pending on a
> target PE -- delivered NMI-like even when that PE has interrupts masked.
> It takes no locks, so it is safe to call from NMI / crash context.
>
> Signed-off-by: Kiryl Shutsemau (Meta) <kas at kernel.org>
> ---
>  drivers/firmware/arm_sdei.c   | 12 ++++++++++++
>  include/linux/arm_sdei.h      |  6 ++++++
>  include/uapi/linux/arm_sdei.h |  1 +
>  3 files changed, 19 insertions(+)

I'd never looked at SDEI before this (so my review is probably not
terribly strong), but this looks reasonable to me.

Reviewed-by: Douglas Anderson <dianders at chromium.org>