arm64: smp: IPI_CPU_STOP and IPI_CPU_CRASH_STOP should try for NMI

There's no reason why IPI_CPU_STOP and IPI_CPU_CRASH_STOP can't be
handled as NMI. They are very simple and everything in them is
NMI-safe. Mark them as things to use NMI for if NMI is available.

Suggested-by: Mark Rutland <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Misono Tomohiro <[email protected]>
Reviewed-by: Sumit Garg <[email protected]>
Acked-by: Mark Rutland <[email protected]>
Tested-by: Mark Rutland <[email protected]>
Tested-by: Chen-Yu Tsai <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/20230906090246.v13.5.Ifadbfd45b22c52edcb499034dd4783d096343260@changeid
Signed-off-by: Catalin Marinas <[email protected]>

Author: dianders

arch/arm64/kernel/smp.c

@@ -946,6 +946,8 @@ static bool ipi_should_be_nmi(enum ipi_msg_type ipi)
 		return false;
 
 	switch (ipi) {
+	case IPI_CPU_STOP:
+	case IPI_CPU_CRASH_STOP:
 	case IPI_CPU_BACKTRACE:
 		return true;
 	default: