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ARM: 6391/1: ux500: add CPU hotplug support

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Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Sundar Iyer <sundar.iyer@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Sundar Iyer 2010-09-15 10:45:51 +01:00 committed by Russell King
parent f0a7a98d1d
commit 9d704c04ff
3 changed files with 78 additions and 0 deletions
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1
arch/arm/mach-ux500/Makefile
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@ -8,4 +8,5 @@ obj-$(CONFIG_UX500_SOC_DB8500) += cpu-db8500.o devices-db8500.o prcmu.o
obj-$(CONFIG_MACH_U8500_MOP) += board-mop500.o board-mop500-sdi.o
obj-$(CONFIG_MACH_U5500) += board-u5500.o
obj-$(CONFIG_SMP) += platsmp.o headsmp.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o

75
arch/arm/mach-ux500/hotplug.c Normal file
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@ -0,0 +1,75 @@
/*
* Copyright (C) STMicroelectronics 2009
* Copyright (C) ST-Ericsson SA 2010
*
* License Terms: GNU General Public License v2
* Based on ARM realview platform
*
* Author: Sundar Iyer <sundar.iyer@stericsson.com>
*
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/smp.h>
#include <linux/completion.h>
#include <asm/cacheflush.h>
extern volatile int pen_release;
static DECLARE_COMPLETION(cpu_killed);
static inline void platform_do_lowpower(unsigned int cpu)
{
flush_cache_all();
/* we put the platform to just WFI */
for (;;) {
__asm__ __volatile__("dsb\n\t" "wfi\n\t"
: : : "memory");
if (pen_release == cpu) {
/*
* OK, proper wakeup, we're done
*/
break;
}
}
}
int platform_cpu_kill(unsigned int cpu)
{
return wait_for_completion_timeout(&cpu_killed, 5000);
}
/*
* platform-specific code to shutdown a CPU
*
* Called with IRQs disabled
*/
void platform_cpu_die(unsigned int cpu)
{
#ifdef DEBUG
unsigned int this_cpu = hard_smp_processor_id();
if (cpu != this_cpu) {
printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n",
this_cpu, cpu);
BUG();
}
#endif
printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
complete(&cpu_killed);
/* directly enter low power state, skipping secure registers */
platform_do_lowpower(cpu);
}
int platform_cpu_disable(unsigned int cpu)
{
/*
* we don't allow CPU 0 to be shutdown (it is still too special
* e.g. clock tick interrupts)
*/
return cpu == 0 ? -EPERM : 0;
}

2
arch/arm/mach-ux500/platsmp.c
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@ -78,6 +78,8 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
__cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
outer_clean_range(__pa(&pen_release), __pa(&pen_release) + 1);
smp_cross_call(cpumask_of(cpu));
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
if (pen_release == -1)