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/*
* This file contains Xilinx specific SMP code, used to start up
* the second processor.
*
* Copyright (C) 2011-2013 Xilinx
*
* based on linux/arch/arm/mach-realview/platsmp.c
*
* Copyright (C) 2002 ARM Ltd.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/export.h>
#include <linux/jiffies.h>
#include <linux/init.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/smp_scu.h>
#include <linux/irqchip/arm-gic.h>
#include "common.h"
/*
* Store number of cores in the system
* Because of scu_get_core_count() must be in __init section and can't
* be called from zynq_cpun_start() because it is not in __init section.
*/
static int ncores;
int zynq_cpun_start(u32 address, int cpu)
{
u32 trampoline_code_size = &zynq_secondary_trampoline_end -
&zynq_secondary_trampoline;
/* MS: Expectation that SLCR are directly map and accessible */
/* Not possible to jump to non aligned address */
if (!(address & 3) && (!address || (address >= trampoline_code_size))) {
/* Store pointer to ioremap area which points to address 0x0 */
static u8 __iomem *zero;
u32 trampoline_size = &zynq_secondary_trampoline_jump -
&zynq_secondary_trampoline;
zynq_slcr_cpu_stop(cpu);
if (address) {
if (__pa(PAGE_OFFSET)) {
zero = ioremap(0, trampoline_code_size);
if (!zero) {
pr_warn("BOOTUP jump vectors not accessible\n");
return -1;
}
} else {
zero = (__force u8 __iomem *)PAGE_OFFSET;
}
/*
* This is elegant way how to jump to any address
* 0x0: Load address at 0x8 to r0
* 0x4: Jump by mov instruction
* 0x8: Jumping address
*/
memcpy((__force void *)zero, &zynq_secondary_trampoline,
trampoline_size);
writel(address, zero + trampoline_size);
flush_cache_all();
outer_flush_range(0, trampoline_code_size);
smp_wmb();
if (__pa(PAGE_OFFSET))
iounmap(zero);
}
zynq_slcr_cpu_start(cpu);
return 0;
}
pr_warn("Can't start CPU%d: Wrong starting address %x\n", cpu, address);
return -1;
}
EXPORT_SYMBOL(zynq_cpun_start);
static int zynq_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
return zynq_cpun_start(__pa_symbol(secondary_startup), cpu);
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init zynq_smp_init_cpus(void)
{
int i;
ncores = scu_get_core_count(zynq_scu_base);
for (i = 0; i < ncores && i < CONFIG_NR_CPUS; i++)
set_cpu_possible(i, true);
}
static void __init zynq_smp_prepare_cpus(unsigned int max_cpus)
{
scu_enable(zynq_scu_base);
}
/**
* zynq_secondary_init - Initialize secondary CPU cores
* @cpu: CPU that is initialized
*
* This function is in the hotplug path. Don't move it into the
* init section!!
*/
static void zynq_secondary_init(unsigned int cpu)
{
zynq_core_pm_init();
}
#ifdef CONFIG_HOTPLUG_CPU
static int zynq_cpu_kill(unsigned cpu)
{
unsigned long timeout = jiffies + msecs_to_jiffies(50);
while (zynq_slcr_cpu_state_read(cpu))
if (time_after(jiffies, timeout))
return 0;
zynq_slcr_cpu_stop(cpu);
return 1;
}
/**
* zynq_cpu_die - Let a CPU core die
* @cpu: Dying CPU
*
* Platform-specific code to shutdown a CPU.
* Called with IRQs disabled on the dying CPU.
*/
static void zynq_cpu_die(unsigned int cpu)
{
zynq_slcr_cpu_state_write(cpu, true);
/*
* there is no power-control hardware on this platform, so all
* we can do is put the core into WFI; this is safe as the calling
* code will have already disabled interrupts
*/
for (;;)
cpu_do_idle();
}
#endif
const struct smp_operations zynq_smp_ops __initconst = {
.smp_init_cpus = zynq_smp_init_cpus,
.smp_prepare_cpus = zynq_smp_prepare_cpus,
.smp_boot_secondary = zynq_boot_secondary,
.smp_secondary_init = zynq_secondary_init,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = zynq_cpu_die,
.cpu_kill = zynq_cpu_kill,
#endif
};
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