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| author | Chen-Yu Tsai <wens@csie.org> | 2018-03-08 18:00:10 +0300 |
|---|---|---|
| committer | Chen-Yu Tsai <wens@csie.org> | 2018-03-10 11:14:46 +0300 |
| commit | 8591743f12636a247bdab56c8c355ea9686f2d97 (patch) | |
| tree | d45c77e057e8a5994b4f69b9158c844a5b44badb /arch/arm/mach-sunxi | |
| parent | c161daea999b9b707d9ffde28ce978d14d5a1185 (diff) | |
| download | linux-8591743f12636a247bdab56c8c355ea9686f2d97.tar.xz | |
ARM: sunxi: mc-smp: Use DT enable-method for sun9i A80 SMP
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>
Diffstat (limited to 'arch/arm/mach-sunxi')
| -rw-r--r-- | arch/arm/mach-sunxi/mc_smp.c | 21 |
1 files changed, 20 insertions, 1 deletions
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()) |