Re: [PATCH v4 0/3] firmware: xilinx: Clean up firmware and EL3 state on kexec

[Michal Simek <michal.simek@amd.com>]

On 7/29/26 14:25, Jay Buddhabhatti wrote:
> During a kexec restart, only the kernel is reloaded while the state held
> in EL3 and platform firmware persists. This leaves the freshly booted
> kernel out of sync with secure firmware for things like the SGI number,
> shutdown scope, allocated peripheral devices and registered notifier
> callbacks, which can lead to unexpected behaviour after a kexec.
> 
> Introduce a mechanism to clear the stale EL3 and platform firmware state
> so the reloaded kernel starts from a clean baseline:
> 
>    - Add TF_A_CLEAR_PM_STATE to clear EL3 PM subsystem state.
>    - Add PM_DEV_ALL_PERIPH to release all peripheral devices in one call.
>    - Add PM_ALL_NOTIFIERS to unregister all notifier callbacks in one call.
> 
> On a graceful kexec reboot the cleanup is performed from
> zynqmp_firmware_shutdown(); on a crash (kdump) restart it is performed
> from zynqmp_firmware_probe() of the reloaded kernel. Each cleanup step
> is guarded by a feature check so it degrades gracefully on firmware
> versions that do not implement the new APIs.
> 
> Changes in v4:
>    - Modified platform check to restrict kexec cleanup to Versal and
>      Versal Net platforms only
>    - Used EL3 firmware instead of TF-A in descriptions and comments
> 
> Changes in v3:
>    - Corrected subject prefix
> 
> Changes in v2:
>    - Drop patch 4/4 (feature check improvements) from this series per
>      review feedback. Those changes are sent separately as:
>      "[PATCH 1/2] firmware: xilinx: Use TF-A feature check for
>      TF-A-specific APIs" and "[PATCH 2/2] firmware: xilinx: Propagate
>      actual error from feature check"
> 
> Jay Buddhabhatti (3):
>    firmware: xilinx: Add support to clear EL3 PM state
>    firmware: xilinx: Release all peripheral devices from firmware
>    firmware: xilinx: Clear firmware notifiers across kexec transitions
> 
>   drivers/firmware/xilinx/zynqmp.c     | 86 +++++++++++++++++++++++++++-
>   include/linux/firmware/xlnx-zynqmp.h | 10 +++-
>   2 files changed, 94 insertions(+), 2 deletions(-)
> 

Applied.
M