mips/loongson/smp: Convert to hotplug state machine

Install the callbacks via the state machine.

[ tglx: Reuse the MIPS_SOC_PREPARE state ]

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160906170457.32393-17-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/mips/loongson64/loongson-3/smp.c

@@ -677,7 +677,7 @@ void play_dead(void)
 	play_dead_at_ckseg1(state_addr);
 }
 
-void loongson3_disable_clock(int cpu)
+static int loongson3_disable_clock(unsigned int cpu)
 {
 	uint64_t core_id = cpu_data[cpu].core;
 	uint64_t package_id = cpu_data[cpu].package;
@@ -688,9 +688,10 @@ void loongson3_disable_clock(int cpu)
 		if (!(loongson_sysconf.workarounds & WORKAROUND_CPUHOTPLUG))
 			LOONGSON_FREQCTRL(package_id) &= ~(1 << (core_id * 4 + 3));
 	}
+	return 0;
 }
 
-void loongson3_enable_clock(int cpu)
+static int loongson3_enable_clock(unsigned int cpu)
 {
 	uint64_t core_id = cpu_data[cpu].core;
 	uint64_t package_id = cpu_data[cpu].package;
@@ -701,34 +702,15 @@ void loongson3_enable_clock(int cpu)
 		if (!(loongson_sysconf.workarounds & WORKAROUND_CPUHOTPLUG))
 			LOONGSON_FREQCTRL(package_id) |= 1 << (core_id * 4 + 3);
 	}
-}
-
-#define CPU_POST_DEAD_FROZEN	(CPU_POST_DEAD | CPU_TASKS_FROZEN)
-static int loongson3_cpu_callback(struct notifier_block *nfb,
-	unsigned long action, void *hcpu)
-{
-	unsigned int cpu = (unsigned long)hcpu;
-
-	switch (action) {
-	case CPU_POST_DEAD:
-	case CPU_POST_DEAD_FROZEN:
-		pr_info("Disable clock for CPU#%d\n", cpu);
-		loongson3_disable_clock(cpu);
-		break;
-	case CPU_UP_PREPARE:
-	case CPU_UP_PREPARE_FROZEN:
-		pr_info("Enable clock for CPU#%d\n", cpu);
-		loongson3_enable_clock(cpu);
-		break;
-	}
-
-	return NOTIFY_OK;
+	return 0;
 }
 
 static int register_loongson3_notifier(void)
 {
-	hotcpu_notifier(loongson3_cpu_callback, 0);
-	return 0;
+	return cpuhp_setup_state_nocalls(CPUHP_MIPS_SOC_PREPARE,
+					 "mips/loongson:prepare",
+					 loongson3_enable_clock,
+					 loongson3_disable_clock);
 }
 early_initcall(register_loongson3_notifier);