Commit 222de7bf authored by Marc Gonzalez's avatar Marc Gonzalez Committed by Olof Johansson
Browse files

ARM: tango: add HOTPLUG_CPU support 



cpu_die() and cpu_kill() are implemented in firmware.

Signed-off-by: default avatarMarc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
parent 06de1569

arch/arm/mach-tango/platsmp.c

+36 −0
Original line number Diff line number Diff line 
#include <linux/delay.h>

#include <linux/init.h>

#include <linux/smp.h>

#include "smc.h"
@@ -9,8 +10,43 @@ static int tango_boot_secondary(unsigned int cpu, struct task_struct *idle) 
	return 0;

}



#ifdef CONFIG_HOTPLUG_CPU

/*

 * cpu_kill() and cpu_die() run concurrently on different cores.

 * Firmware will only "kill" a core once it has properly "died".

 * Try a few times to kill a core before giving up, and sleep

 * between tries to give that core enough time to die.

 */

static int tango_cpu_kill(unsigned int cpu)

{

	int i, err;



	for (i = 0; i < 10; ++i) {

		msleep(10);

		err = tango_aux_core_kill(cpu);

		if (!err)

			return true;

	}



	return false;

}



static void tango_cpu_die(unsigned int cpu)

{

	while (tango_aux_core_die(cpu) < 0)

		cpu_relax();



	panic("cpu %d failed to die\n", cpu);

}

#else

#define tango_cpu_kill	NULL

#define tango_cpu_die	NULL

#endif



static const struct smp_operations tango_smp_ops __initconst = {

	.smp_boot_secondary	= tango_boot_secondary,

	.cpu_kill		= tango_cpu_kill,

	.cpu_die		= tango_cpu_die,

};



CPU_METHOD_OF_DECLARE(tango4_smp, "sigma,tango4-smp", &tango_smp_ops);

arch/arm/mach-tango/smc.h

+3 −1
Original line number Diff line number Diff line
@@ -2,4 +2,6 @@ extern int tango_smc(unsigned int val, unsigned int service); 


#define tango_set_l2_control(val)	tango_smc(val, 0x102)

#define tango_start_aux_core(val)	tango_smc(val, 0x104)

#define tango_set_aux_boot_addr(val)	tango_smc((unsigned int)val, 0x105)
 
#define tango_set_aux_boot_addr(val)	tango_smc(val, 0x105)

#define tango_aux_core_die(val)		tango_smc(val, 0x121)

#define tango_aux_core_kill(val)	tango_smc(val, 0x122)