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/*
* Copyright (C) 2009 ST-Ericsson SA
* this file is heavily 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/jiffies.h>
#include <linux/smp.h>
#include <asm/cacheflush.h>
#include <asm/localtimer.h>
#include <mach/scu.h>
#include <mach/hardware.h>
#include <asm/io.h>
extern void u8500_secondary_startup(void);
/*
* control for which core is the next to come out of the secondary
* boot "holding pen"
*/
volatile int __cpuinitdata pen_release = -1;
static unsigned int __init get_core_count(void)
{
unsigned int ncores;
ncores = __raw_readl(IO_ADDRESS(UX500_SCU_BASE) + SCU_CONFIG);
return (ncores & 0x03) + 1;
}
/*
* Setup the SCU
*/
static void scu_enable(void)
{
u32 scu_ctrl;
scu_ctrl = __raw_readl(IO_ADDRESS(UX500_SCU_BASE) + SCU_CTRL);
scu_ctrl |= 1;
__raw_writel(scu_ctrl, IO_ADDRESS(UX500_SCU_BASE) + SCU_CTRL);
}
static DEFINE_SPINLOCK(boot_lock);
void __cpuinit platform_secondary_init(unsigned int cpu)
{
trace_hardirqs_off();
/*
* if any interrupts are already enabled for the primary
* core (e.g. timer irq), then they will not have been enabled
* for us: do so
*/
gic_cpu_init(0, (void __iomem *)IO_ADDRESS(UX500_GIC_CPU_BASE));
/*
* let the primary processor know we're out of the
* pen, then head off into the C entry point
*/
pen_release = -1;
smp_wmb();
/*
* Synchronise with the boot thread.
*/
spin_lock(&boot_lock);
spin_unlock(&boot_lock);
}
int __cpuinit 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.
*
* Note that "pen_release" is the hardware CPU ID, whereas
* "cpu" is Linux's internal ID.
*/
flush_cache_all();
outer_clean_range(__pa(&secondary_data), __pa(&secondary_data) + 1);
pen_release = cpu;
flush_cache_all();
outer_clean_range(__pa(&pen_release), __pa(&pen_release) + 1);
/*
* XXX
*
* This is a later addition to the booting protocol: the
* bootMonitor now puts secondary cores into WFI, so
* wakeup_secondary() no longer gets the cores moving; we need
* to send a soft interrupt to wake the secondary core.
* Use smp_cross_call() for this, since there's little
* point duplicating the code here
*/
smp_cross_call(cpumask_of(cpu));
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
smp_rmb();
if (pen_release == -1)
break;
udelay(10);
}
/*
* 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)
{
extern void secondary_startup(void);
/* nobody is to be released from the pen yet */
pen_release = -1;
/*
* write the address of secondary startup into the backram0
* register at offset 0x1FF4, then write magic number(0xA1FEED01)
* to the backram0 register at offset 0x1FF0, which is what
* BootMonitor is waiting for
*/
#define U8500_CPU1_JUMPADDR_OFFSET 0x1FF4
__raw_writel(virt_to_phys(u8500_secondary_startup),
(void __iomem *)IO_ADDRESS(UX500_BACKUPRAM0_BASE) +
U8500_CPU1_JUMPADDR_OFFSET);
#define U8500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
__raw_writel(0xA1FEED01,
(void __iomem *)IO_ADDRESS(UX500_BACKUPRAM0_BASE) +
U8500_CPU1_WAKEMAGIC_OFFSET);
mb();
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
void __init smp_init_cpus(void)
{
unsigned int i, ncores = get_core_count();
for (i = 0; i < ncores; i++)
cpu_set(i, cpu_possible_map);
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
unsigned int ncores = get_core_count();
unsigned int cpu = smp_processor_id();
int i;
/* sanity check */
if (ncores == 0) {
printk(KERN_ERR
"U8500: strange CM count of 0? Default to 1\n");
ncores = 1;
}
if (ncores > NR_CPUS) {
printk(KERN_WARNING
"U8500: no. of cores (%d) greater than configured "
"maximum of %d - clipping\n",
ncores, NR_CPUS);
ncores = NR_CPUS;
}
smp_store_cpu_info(cpu);
/*
* are we trying to boot more cores than exist?
*/
if (max_cpus > ncores)
max_cpus = ncores;
/*
* Initialise the present map, which describes the set of CPUs
* actually populated at the present time.
*/
for (i = 0; i < max_cpus; i++)
cpu_set(i, cpu_present_map);
/*
* Do we need any more CPUs? If so, then let them know where
* to start. Note that, on modern versions of MILO, the "poke"
* doesn't actually do anything until each individual core is
* sent a soft interrupt to get it out of WFI
*/
if (max_cpus > 1) {
/*
* Enable the local timer or broadcast device for the
* boot CPU, but only if we have more than one CPU.
*/
percpu_timer_setup();
scu_enable();
wakeup_secondary();
}
}
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