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/*
* SH-X3 SMP
*
* Copyright (C) 2007 - 2010 Paul Mundt
* Copyright (C) 2007 Magnus Damm
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* 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)
{
unsigned int message = (unsigned int)(long)arg;
unsigned int cpu = hard_smp_processor_id();
unsigned int offs = 4 * cpu;
unsigned int x;
x = __raw_readl(0xfe410070 + offs); /* C0INITICI..CnINTICI */
x &= (1 << (message << 2));
__raw_writel(x, 0xfe410080 + offs); /* C0INTICICLR..CnINTICICLR */
smp_message_recv(message);
return IRQ_HANDLED;
}
static void shx3_smp_setup(void)
{
unsigned int cpu = 0;
int i, num;
init_cpu_possible(cpumask_of(cpu));
/* Enable light sleep for the boot CPU */
__raw_writel(__raw_readl(STBCR_REG(cpu)) | STBCR_LTSLP, STBCR_REG(cpu));
__cpu_number_map[0] = 0;
__cpu_logical_map[0] = 0;
/*
* Do this stupidly for now.. we don't have an easy way to probe
* for the total number of cores.
*/
for (i = 1, num = 0; i < NR_CPUS; i++) {
set_cpu_possible(i, true);
__cpu_number_map[i] = ++num;
__cpu_logical_map[num] = i;
}
printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
}
static void shx3_prepare_cpus(unsigned int max_cpus)
{
int i;
BUILD_BUG_ON(SMP_MSG_NR >= 8);
for (i = 0; i < SMP_MSG_NR; i++)
request_irq(104 + i, ipi_interrupt_handler,
IRQF_PERCPU, "IPI", (void *)(long)i);
for (i = 0; i < max_cpus; i++)
set_cpu_present(i, true);
}
static void shx3_start_cpu(unsigned int cpu, unsigned long entry_point)
{
if (__in_29bit_mode())
__raw_writel(entry_point, RESET_REG(cpu));
else
__raw_writel(virt_to_phys(entry_point), RESET_REG(cpu));
if (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP))
__raw_writel(STBCR_MSTP, STBCR_REG(cpu));
while (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP))
cpu_relax();
/* Start up secondary processor by sending a reset */
__raw_writel(STBCR_RESET | STBCR_LTSLP, STBCR_REG(cpu));
}
static unsigned int shx3_smp_processor_id(void)
{
return __raw_readl(0xff000048); /* CPIDR */
}
static void shx3_send_ipi(unsigned int cpu, unsigned int message)
{
unsigned long addr = 0xfe410070 + (cpu * 4);
BUG_ON(cpu >= 4);
__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
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 shx3_cpu_notifier = {
.notifier_call = shx3_cpu_callback,
};
static int 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,
};
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