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authorMark Rutland <mark.rutland@arm.com>2013-10-24 20:30:19 +0100
committerMark Brown <broonie@linaro.org>2013-12-11 21:12:28 +0000
commit8cea5d72615ec55b8e31d8d4a066a38041e0dca2 (patch)
treed430d3eee1d73dd508f68a345691a5253ef4d9e2
parentd3bde2dcb4434ae9f905d9286e36feb59953f1e3 (diff)
downloadlinux-linaro-stable-8cea5d72615ec55b8e31d8d4a066a38041e0dca2.tar.gz
arm64: add PSCI CPU_OFF-based hotplug support
This patch adds support for using PSCI CPU_OFF calls for CPU hotplug. With this code it is possible to hot unplug CPUs with "psci" as their boot-method, as long as there's an appropriate cpu_off function id specified in the psci node. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> (cherry picked from commit 831ccf79b46e02f31cfd16c66df9d5600f635155) Signed-off-by: Mark Brown <broonie@linaro.org>
-rw-r--r--arch/arm64/kernel/psci.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index fb56b6158344..4f97db3d7363 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -256,11 +256,41 @@ static int cpu_psci_cpu_boot(unsigned int cpu)
return err;
}
+#ifdef CONFIG_HOTPLUG_CPU
+static int cpu_psci_cpu_disable(unsigned int cpu)
+{
+ /* Fail early if we don't have CPU_OFF support */
+ if (!psci_ops.cpu_off)
+ return -EOPNOTSUPP;
+ return 0;
+}
+
+static void cpu_psci_cpu_die(unsigned int cpu)
+{
+ int ret;
+ /*
+ * There are no known implementations of PSCI actually using the
+ * power state field, pass a sensible default for now.
+ */
+ struct psci_power_state state = {
+ .type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
+ };
+
+ ret = psci_ops.cpu_off(state);
+
+ pr_crit("psci: unable to power off CPU%u (%d)\n", cpu, ret);
+}
+#endif
+
const struct cpu_operations cpu_psci_ops = {
.name = "psci",
.cpu_init = cpu_psci_cpu_init,
.cpu_prepare = cpu_psci_cpu_prepare,
.cpu_boot = cpu_psci_cpu_boot,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_disable = cpu_psci_cpu_disable,
+ .cpu_die = cpu_psci_cpu_die,
+#endif
};
#endif