Commit 52a119fe authored by Ashok Raj's avatar Ashok Raj Committed by Linus Torvalds
Browse files

[PATCH] make smp_prepare_cpu to a weak function 



I really wish smp_prepare_cpu() would disappear eventually.  In the interim
this is ideally a weak function, so we dont end up changing several places
to define this dummy in headers.

Today since the dummy declaration is done only in drivers/base/cpu.c but
the function is called in kernel/power/smp.c i get undefined reference in
my cpu hotplug code for x86_64 under development.

Signed-off-by: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e1367daf

drivers/base/cpu.c

+5 −4
Original line number Diff line number Diff line
@@ -16,9 +16,10 @@ struct sysdev_class cpu_sysdev_class = { 
EXPORT_SYMBOL(cpu_sysdev_class);



#ifdef CONFIG_HOTPLUG_CPU

#ifndef __HAVE_ARCH_SMP_PREPARE_CPU

#define smp_prepare_cpu(cpu) (0)

#endif

int __attribute__((weak)) smp_prepare_cpu (int cpu)

{

	return 0;

}



static ssize_t show_online(struct sys_device *dev, char *buf)

{
@@ -41,7 +42,7 @@ static ssize_t store_online(struct sys_device *dev, const char *buf, 
		break;

	case '1':

		ret = smp_prepare_cpu(cpu->sysdev.id);

		if (ret == 0)

		if (!ret)

			ret = cpu_up(cpu->sysdev.id);

		break;

	default:

include/asm-i386/smp.h

+0 −3
Original line number Diff line number Diff line
@@ -51,9 +51,6 @@ extern u8 x86_cpu_to_apicid[]; 
#ifdef CONFIG_HOTPLUG_CPU

extern void cpu_exit_clear(void);

extern void cpu_uninit(void);



#define __HAVE_ARCH_SMP_PREPARE_CPU

extern int smp_prepare_cpu(int cpu);

#endif



/*

include/linux/cpu.h

+1 −0
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ extern struct semaphore cpucontrol; 
	register_cpu_notifier(&fn##_nb);			\

}

int cpu_down(unsigned int cpu);

extern int __attribute__((weak)) smp_prepare_cpu(int cpu);

#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))

#else

#define lock_cpu_hotplug()	do { } while (0)

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