arm64: add CPU_HOTPLUG infrastructure
This patch adds the basic infrastructure necessary to support
CPU_HOTPLUG on arm64, based on the arm implementation. Actual hotplug
support will depend on an implementation's cpu_operations (e.g. PSCI).
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h
index 1a98dbf..c4cdb5e 100644
--- a/arch/arm64/include/asm/cpu_ops.h
+++ b/arch/arm64/include/asm/cpu_ops.h
@@ -34,6 +34,11 @@
* @cpu_boot: Boots a cpu into the kernel.
* @cpu_postboot: Optionally, perform any post-boot cleanup or necesary
* synchronisation. Called from the cpu being booted.
+ * @cpu_disable: Prepares a cpu to die. May fail for some mechanism-specific
+ * reason, which will cause the hot unplug to be aborted. Called
+ * from the cpu to be killed.
+ * @cpu_die: Makes a cpu leave the kernel. Must not fail. Called from the
+ * cpu being killed.
*/
struct cpu_operations {
const char *name;
@@ -41,6 +46,10 @@
int (*cpu_prepare)(unsigned int);
int (*cpu_boot)(unsigned int);
void (*cpu_postboot)(void);
+#ifdef CONFIG_HOTPLUG_CPU
+ int (*cpu_disable)(unsigned int cpu);
+ void (*cpu_die)(unsigned int cpu);
+#endif
};
extern const struct cpu_operations *cpu_ops[NR_CPUS];