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/*
* Copyright (C) 2002 ARM Ltd.
* Copyright (C) 2008 STMicroelctronics.
* Copyright (C) 2009 ST-Ericsson.
* Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
*
* This file is based on arm realview platform
*
* 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/init.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include "setup.h"
#include "db8500-regs.h"
#include "id.h"
static void __iomem *scu_base;
static void __iomem *backupram;
/* This is called from headsmp.S to wakeup the secondary core */
extern void u8500_secondary_startup(void);
/*
* Write pen_release in a way that is guaranteed to be visible to all
* observers, irrespective of whether they're taking part in coherency
* or not. This is necessary for the hotplug code to work reliably.
*/
static void write_pen_release(int val)
{
pen_release = val;
smp_wmb();
sync_cache_w(&pen_release);
}
static DEFINE_SPINLOCK(boot_lock);
static void ux500_secondary_init(unsigned int cpu)
{
/*
* let the primary processor know we're out of the
* pen, then head off into the C entry point
*/
write_pen_release(-1);
/*
* Synchronise with the boot thread.
*/
spin_lock(&boot_lock);
spin_unlock(&boot_lock);
}
static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
unsigned long timeout;
/*
* set synchronisation state between this boot processor
* and the secondary one
*/
spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
* the holding pen - release it, then wait for it to flag
* that it has been released by resetting pen_release.
*/
write_pen_release(cpu_logical_map(cpu));
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
if (pen_release == -1)
break;
}
/*
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
static void __init wakeup_secondary(void)
{
/*
* write the address of secondary startup into the backup ram register
* at offset 0x1FF4, then write the magic number 0xA1FEED01 to the
* backup ram register at offset 0x1FF0, which is what boot rom code
* is waiting for. This would wake up the secondary core from WFE
*/
#define UX500_CPU1_JUMPADDR_OFFSET 0x1FF4
__raw_writel(virt_to_phys(u8500_secondary_startup),
backupram + UX500_CPU1_JUMPADDR_OFFSET);
#define UX500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
__raw_writel(0xA1FEED01,
backupram + UX500_CPU1_WAKEMAGIC_OFFSET);
/* make sure write buffer is drained */
mb();
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init ux500_smp_init_cpus(void)
{
unsigned int i, ncores;
struct device_node *np;
np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
scu_base = of_iomap(np, 0);
of_node_put(np);
if (!scu_base)
return;
backupram = ioremap(U8500_BACKUPRAM0_BASE, SZ_8K);
ncores = scu_get_core_count(scu_base);
/* sanity check */
if (ncores > nr_cpu_ids) {
pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
ncores, nr_cpu_ids);
ncores = nr_cpu_ids;
}
for (i = 0; i < ncores; i++)
set_cpu_possible(i, true);
}
static void __init ux500_smp_prepare_cpus(unsigned int max_cpus)
{
scu_enable(scu_base);
wakeup_secondary();
}
struct smp_operations ux500_smp_ops __initdata = {
.smp_init_cpus = ux500_smp_init_cpus,
.smp_prepare_cpus = ux500_smp_prepare_cpus,
.smp_secondary_init = ux500_secondary_init,
.smp_boot_secondary = ux500_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = ux500_cpu_die,
#endif
};
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