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ARM: tango: add HOTPLUG_CPU support

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

Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
This commit is contained in:
Marc Gonzalez 2016-06-29 14:21:42 +02:00 committed by Olof Johansson
parent 06de15694b
commit 222de7bfdf
2 changed files with 39 additions and 1 deletions
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36
arch/arm/mach-tango/platsmp.c
View file

@ -1,3 +1,4 @@
#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);

4
arch/arm/mach-tango/smc.h
View file

@ -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)