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/*
* Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
* Copyright (C) 2013 Ma Haijun <mahaijuns@gmail.com>
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <asm/cacheflush.h>
#include <asm/cp15.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
extern void ox820_secondary_startup(void);
extern void ox820_cpu_die(unsigned int cpu);
static void __iomem *cpu_ctrl;
static void __iomem *gic_cpu_ctrl;
#define HOLDINGPEN_CPU_OFFSET 0xc8
#define HOLDINGPEN_LOCATION_OFFSET 0xc4
#define GIC_NCPU_OFFSET(cpu) (0x100 + (cpu)*0x100)
#define GIC_CPU_CTRL 0x00
#define GIC_CPU_CTRL_ENABLE 1
int __init ox820_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
/*
* Write the address of secondary startup into the
* system-wide flags register. The BootMonitor waits
* until it receives a soft interrupt, and then the
* secondary CPU branches to this address.
*/
writel(virt_to_phys(ox820_secondary_startup),
cpu_ctrl + HOLDINGPEN_LOCATION_OFFSET);
writel(cpu, cpu_ctrl + HOLDINGPEN_CPU_OFFSET);
/*
* Enable GIC cpu interface in CPU Interface Control Register
*/
writel(GIC_CPU_CTRL_ENABLE,
gic_cpu_ctrl + GIC_NCPU_OFFSET(cpu) + GIC_CPU_CTRL);
/*
* Send the secondary CPU a soft interrupt, thereby causing
* the boot monitor to read the system wide flags register,
* and branch to the address found there.
*/
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
return 0;
}
static void __init ox820_smp_prepare_cpus(unsigned int max_cpus)
{
struct device_node *np;
void __iomem *scu_base;
np = of_find_compatible_node(NULL, NULL, "arm,arm11mp-scu");
scu_base = of_iomap(np, 0);
of_node_put(np);
if (!scu_base)
return;
/* Remap CPU Interrupt Interface Registers */
np = of_find_compatible_node(NULL, NULL, "arm,arm11mp-gic");
gic_cpu_ctrl = of_iomap(np, 1);
of_node_put(np);
if (!gic_cpu_ctrl)
goto unmap_scu;
np = of_find_compatible_node(NULL, NULL, "oxsemi,ox820-sys-ctrl");
cpu_ctrl = of_iomap(np, 0);
of_node_put(np);
if (!cpu_ctrl)
goto unmap_scu;
scu_enable(scu_base);
flush_cache_all();
unmap_scu:
iounmap(scu_base);
}
static const struct smp_operations ox820_smp_ops __initconst = {
.smp_prepare_cpus = ox820_smp_prepare_cpus,
.smp_boot_secondary = ox820_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = ox820_cpu_die,
#endif
};
CPU_METHOD_OF_DECLARE(ox820_smp, "oxsemi,ox820-smp", &ox820_smp_ops);
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