ARM: sunxi: mc-smp: Use DT enable-method for sun9i A80 SMP (8591743f) · Commits · 戴 / test

Instead of having an early init function check the machine compatible and installing multi-cluster SMP support for the A80 if it matches, use a new cpu enable-method string. This makes the platform support future proof in case anyone manages to add PSCI support. The original init code for the SMP support is changed into the .prepare_cpus callback in the smp_operations structure. Instead of panicing when resources are missing like on some platforms, our code merely guards against engaging SMP or CPU hotplug and returns an error. Acked-by:

Maxime Ripard <maxime.ripard@bootlin.com> Reviewed-by:

Rob Herring <robh@kernel.org> Signed-off-by:

Chen-Yu Tsai <wens@csie.org>

Documentation/devicetree/bindings/arm/cpus.txt

+1 −0

Original line number	Diff line number	Diff line
		@@ -198,6 +198,7 @@ described below.
		"actions,s500-smp"
		"allwinner,sun6i-a31"
		"allwinner,sun8i-a23"
		"allwinner,sun9i-a80-smp"
		"amlogic,meson8-smp"
		"amlogic,meson8b-smp"
		"arm,realview-smp"

arch/arm/mach-sunxi/mc_smp.c

+20 −1

Original line number	Diff line number	Diff line
		@@ -690,7 +690,26 @@ static int __init sunxi_mc_smp_init(void)
		struct resource res;
		int ret;

		if (!of_machine_is_compatible("allwinner,sun9i-a80"))
		/*
		* Don't bother checking the "cpus" node, as an enable-method
		* property in that node is undocumented.
		*/
		node = of_cpu_device_node_get(0);
		if (!node)
		return -ENODEV;

		/*
		* We can't actually use the enable-method magic in the kernel.
		* Our loopback / trampoline code uses the CPU suspend framework,
		* which requires the identity mapping be available. It would not
		* yet be available if we used the .init_cpus or .prepare_cpus
		* callbacks in smp_operations, which we would use if we were to
		* use CPU_METHOD_OF_DECLARE
		*/
		ret = of_property_match_string(node, "enable-method",
		"allwinner,sun9i-a80-smp");
		of_node_put(node);
		if (ret)
		return -ENODEV;

		if (!sunxi_mc_smp_cpu_table_init())

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