/*
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
* Copyright (c) 2010, Code Aurora Forum. 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/init.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/irqchip/arm-gic.h>
#include <asm/cacheflush.h>
#include <asm/cputype.h>
#include <asm/mach-types.h>
#include <asm/smp_plat.h>
#include "scm-boot.h"
#include "common.h"
#define VDD_SC1_ARRAY_CLAMP_GFS_CTL 0x15A0
#define SCSS_CPU1CORE_RESET 0xD80
#define SCSS_DBG_STATUS_CORE_PWRDUP 0xE64
extern void msm_secondary_startup(void);
static DEFINE_SPINLOCK(boot_lock);
static inline int get_core_count(void)
{
/* 1 + the PART[1:0] field of MIDR */
return ((read_cpuid_id() >> 4) & 3) + 1;
}
static void __cpuinit msm_secondary_init(unsigned int cpu)
{
/*
* 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_secondary_init(0);
/*
* 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);
}
static __cpuinit void prepare_cold_cpu(unsigned int cpu)
{
int ret;
ret = scm_set_boot_addr(virt_to_phys(msm_secondary_startup),
SCM_FLAG_COLDBOOT_CPU1);
if (ret == 0) {
void __iomem *sc1_base_ptr;
sc1_base_ptr = ioremap_nocache(0x00902000, SZ_4K*2);
if (sc1_base_ptr) {
writel(0, sc1_base_ptr + VDD_SC1_ARRAY_CLAMP_GFS_CTL);
writel(0, sc1_base_ptr + SCSS_CPU1CORE_RESET);
writel(3, sc1_base_ptr + SCSS_DBG_STATUS_CORE_PWRDUP);
iounmap(sc1_base_ptr);
}
} else
printk(KERN_DEBUG "Failed to set secondary core boot "
"address\n");
}
static int __cpuinit msm_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
unsigned long timeout;
static int cold_boot_done;
/* Only need to bring cpu out of reset this way once */
if (cold_boot_done == false) {
prepare_cold_cpu(cpu);
cold_boot_done = true;
}
/*
* 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.
*/
pen_release = cpu_logical_map(cpu);
__cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
/*
* 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));
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;
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system. The msm8x60
* does not support the ARM SCU, so just set the possible cpu mask to
* NR_CPUS.
*/
static void __init msm_smp_init_cpus(void)
{
unsigned int i, ncores = get_core_count();
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 msm_smp_prepare_cpus(unsigned int max_cpus)
{
}
struct smp_operations msm_smp_ops __initdata = {
.smp_init_cpus = msm_smp_init_cpus,
.smp_prepare_cpus = msm_smp_prepare_cpus,
.smp_secondary_init = msm_secondary_init,
.smp_boot_secondary = msm_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = msm_cpu_die,
#endif
};
