| Message ID | 20180308150012.19045-3-wens@csie.org (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
On Thu, Mar 08, 2018 at 11:00:10PM +0800, Chen-Yu Tsai wrote: > 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. > > Signed-off-by: Chen-Yu Tsai <wens@csie.org> Acked-by: Maxime Ripard <maxime.ripard@bootlin.com> Thanks! Maxime
On Thu, Mar 08, 2018 at 11:00:10PM +0800, Chen-Yu Tsai wrote: > 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. > > Signed-off-by: Chen-Yu Tsai <wens@csie.org> > --- > Documentation/devicetree/bindings/arm/cpus.txt | 1 + Reviewed-by: Rob Herring <robh@kernel.org> > arch/arm/mach-sunxi/mc_smp.c | 21 ++++++++++++++++++++- > 2 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt index f4a777039f03..76655d0d67c2 100644 --- a/Documentation/devicetree/bindings/arm/cpus.txt +++ b/Documentation/devicetree/bindings/arm/cpus.txt @@ -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" diff --git a/arch/arm/mach-sunxi/mc_smp.c b/arch/arm/mach-sunxi/mc_smp.c index 9db6c4ed5861..86e90b038555 100644 --- a/arch/arm/mach-sunxi/mc_smp.c +++ b/arch/arm/mach-sunxi/mc_smp.c @@ -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())
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. Signed-off-by: Chen-Yu Tsai <wens@csie.org> --- Documentation/devicetree/bindings/arm/cpus.txt | 1 + arch/arm/mach-sunxi/mc_smp.c | 21 ++++++++++++++++++++- 2 files changed, 21 insertions(+), 1 deletion(-)