firmware: xilinx: Clear firmware notifiers across kexec transitions

During a kexec restart, only the kernel is reloaded but notifier callbacks
in firmware persist, causing state mismatches between kernel and firmware.

To address this, introduce PM_ALL_NOTIFIERS node ID to unregister all
notifier callbacks during kexec. On a graceful kexec restart, this occurs
in zynqmp_firmware_shutdown(). On a crash kernel restart, it happens in
zynqmp_firmware_probe() in the reloaded kernel.

Unregistering all notifiers depends on firmware support for the
PM_ALL_NOTIFIERS node ID. On firmware that does not implement it (the
feature check reports a version below PM_API_VERSION_3) the step is
skipped and a warning such as "Firmware doesn't support unregister all
notifiers at once" is logged, e.g. on Versal NET firmware that predates
this API.

Signed-off-by: Jay Buddhabhatti <jay.buddhabhatti@amd.com>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Reviewed-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
Link: https://patch.msgid.link/20260729122522.3732875-4-jay.buddhabhatti@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>

0 files changed, 0 insertions, 0 deletions