MIPS: Add arch generic CPU hotplug

Each platform has to add support for CPU hotplugging itself by providing
suitable definitions for the cpu_disable and cpu_die of the smp_ops
methods and setting SYS_SUPPORTS_HOTPLUG_CPU.  A platform should only set
SYS_SUPPORTS_HOTPLUG_CPU once all it's smp_ops definitions have the
necessary changes.  This patch contains the changes to the dummy smp_ops
definition for uni-processor systems.

Parts of the code contributed by Cavium Inc.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 23 insertions, 0 deletions

diff --git a/arch/mips/include/asm/smp-ops.h b/arch/mips/include/asm/smp-ops.h
index 64ffc0290b84..fd545547b8aa 100644
--- a/arch/mips/include/asm/smp-ops.h
+++ b/arch/mips/include/asm/smp-ops.h
@@ -26,6 +26,10 @@ struct plat_smp_ops {
         void (*boot_secondary)(int cpu, struct task_struct *idle);
         void (*smp_setup)(void);
         void (*prepare_cpus)(unsigned int max_cpus);
+#ifdef CONFIG_HOTPLUG_CPU
+        int (*cpu_disable)(void);
+        void (*cpu_die)(unsigned int cpu);
+#endif
 };
 
 extern void register_smp_ops(struct plat_smp_ops *ops);
diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h
index 2f83fa8631db..01f813dc3888 100644
--- a/arch/mips/include/asm/smp.h
+++ b/arch/mips/include/asm/smp.h
@@ -41,6 +41,7 @@ extern int __cpu_logical_map[NR_CPUS];
 /* Octeon - Tell another core to flush its icache */
 #define SMP_ICACHE_FLUSH        0x4
 
+extern cpumask_t cpu_callin_map;
 
 extern void asmlinkage smp_bootstrap(void);
 
@@ -56,6 +57,24 @@ static inline void smp_send_reschedule(int cpu)
         mp_ops->send_ipi_single(cpu, SMP_RESCHEDULE_YOURSELF);
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+static inline int __cpu_disable(void)
+{
+        extern struct plat_smp_ops *mp_ops;     /* private */
+
+        return mp_ops->cpu_disable();
+}
+
+static inline void __cpu_die(unsigned int cpu)
+{
+        extern struct plat_smp_ops *mp_ops;     /* private */
+
+        mp_ops->cpu_die(cpu);
+}
+
+extern void play_dead(void);
+#endif
+
 extern asmlinkage void smp_call_function_interrupt(void);
 
 extern void arch_send_call_function_single_ipi(int cpu);