kexec: Add helper to report an active kexec reboot

A shutdown callback in a loadable module may need to distinguish a
kexec reboot from a normal restart, halt, or poweroff. The Hyper-V
VMBus driver needs this distinction when moving its kexec cleanup into
a common syscore shutdown callback.

Add kexec_is_in_progress() and export it to GPL modules so the callback
can remain guarded when VMBus is built as a module. Provide a false
inline implementation when CONFIG_KEXEC_CORE is disabled.

The helper reports only the normal kexec reboot path. Crash kexec and
preserve-context kexec do not set this state.

Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Bradley Morgan <brads@mainlining.org>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

0 files changed, 0 insertions, 0 deletions