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