ARM: 9411/1: Switch over to GENERIC_CPU_DEVICES using arch_register_cpu()

Currently, almost all architectures have switched to GENERIC_CPU_DEVICES,
except for arm32. Also switch over to GENERIC_CPU_DEVICES, and provide an
arch_register_cpu() that populates the hotpluggable flag for arm32.

The struct cpu in struct cpuinfo_arm is never used directly, remove
it to use the one GENERIC_CPU_DEVICES provides.

This also has the effect of moving the registration of CPUs from subsys to
driver core initialisation, prior to any initcalls running.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Author: ruanjinjie-eng

arch/arm/Kconfig

@@ -64,6 +64,7 @@ config ARM
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
 	select GENERIC_IRQ_IPI if SMP
 	select GENERIC_CPU_AUTOPROBE
+	select GENERIC_CPU_DEVICES
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_IDLE_POLL_SETUP
 	select GENERIC_IRQ_MULTI_HANDLER

arch/arm/include/asm/cpu.h

@@ -11,7 +11,6 @@
 #include <linux/cpu.h>
 
 struct cpuinfo_arm {
-	struct cpu	cpu;
 	u32		cpuid;
 #ifdef CONFIG_SMP
 	unsigned int	loops_per_jiffy;

arch/arm/kernel/setup.c

@@ -1201,20 +1201,13 @@ void __init setup_arch(char **cmdline_p)
 		mdesc->init_early();
 }
 
-
-static int __init topology_init(void)
+int arch_register_cpu(int num)
 {
-	int cpu;
-
-	for_each_possible_cpu(cpu) {
-		struct cpuinfo_arm *cpuinfo = &per_cpu(cpu_data, cpu);
-		cpuinfo->cpu.hotpluggable = platform_can_hotplug_cpu(cpu);
-		register_cpu(&cpuinfo->cpu, cpu);
-	}
+	struct cpu *cpu = &per_cpu(cpu_devices, num);
 
-	return 0;
+	cpu->hotpluggable = platform_can_hotplug_cpu(num);
+	return register_cpu(cpu, num);
 }
-subsys_initcall(topology_init);
 
 #ifdef CONFIG_HAVE_PROC_CPU
 static int __init proc_cpu_init(void)