dect/linux-2.6
Archived
14
0
Fork 0
Code Releases Activity

sh: CPU hotplug support for SH-X3 SMP.

Browse source 
This wires up CPU hotplug for SH-X3 SMP CPUs. Presently only secondary
cores can be hotplugged given that the boot CPU has to contend with the
broadcast timer. When real local timers are implemented this restriction
can be lifted.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Paul Mundt 2010-04-26 19:09:57 +09:00
parent 763142d1ef
commit e7dc951eec
1 changed files with 47 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

47
arch/sh/kernel/cpu/sh4a/smp-shx3.c
View file

@ -9,16 +9,22 @@
* for more details.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/cpumask.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/cpu.h>
#include <asm/sections.h>
#define STBCR_REG(phys_id) (0xfe400004 | (phys_id << 12))
#define RESET_REG(phys_id) (0xfe400008 | (phys_id << 12))
#define STBCR_MSTP 0x00000001
#define STBCR_RESET 0x00000002
#define STBCR_SLEEP 0x00000004
#define STBCR_LTSLP 0x80000000
static irqreturn_t ipi_interrupt_handler(int irq, void *arg)
@ -110,10 +116,51 @@ static void shx3_send_ipi(unsigned int cpu, unsigned int message)
__raw_writel(1 << (message << 2), addr); /* C0INTICI..CnINTICI */
}
static void shx3_update_boot_vector(unsigned int cpu)
{
__raw_writel(STBCR_MSTP, STBCR_REG(cpu));
while (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP))
cpu_relax();
__raw_writel(STBCR_RESET, STBCR_REG(cpu));
}
static int __cpuinit
shx3_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned int)hcpu;
switch (action) {
case CPU_UP_PREPARE:
shx3_update_boot_vector(cpu);
break;
case CPU_ONLINE:
pr_info("CPU %u is now online\n", cpu);
break;
case CPU_DEAD:
break;
}
return NOTIFY_OK;
}
static struct notifier_block __cpuinitdata shx3_cpu_notifier = {
.notifier_call = shx3_cpu_callback,
};
static int __cpuinit register_shx3_cpu_notifier(void)
{
register_hotcpu_notifier(&shx3_cpu_notifier);
return 0;
}
late_initcall(register_shx3_cpu_notifier);
struct plat_smp_ops shx3_smp_ops = {
.smp_setup = shx3_smp_setup,
.prepare_cpus = shx3_prepare_cpus,
.start_cpu = shx3_start_cpu,
.smp_processor_id = shx3_smp_processor_id,
.send_ipi = shx3_send_ipi,
.cpu_die = native_cpu_die,
.cpu_disable = native_cpu_disable,
.play_dead = native_play_dead,
};