mirror of https://gitee.com/openkylin/linux.git
150 lines
3.9 KiB
C
150 lines
3.9 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 in __cpuinit section.
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*/
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static int ncores;
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/* Secondary CPU kernel startup is a 2 step process. The primary CPU
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* starts the secondary CPU by giving it the address of the kernel and
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* then sending it an event to wake it up. The secondary CPU then
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* starts the kernel and tells the primary CPU it's up and running.
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*/
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static void __cpuinit zynq_secondary_init(unsigned int cpu)
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{
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/*
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* if any interrupts are already enabled for the primary
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* core (e.g. timer irq), then they will not have been enabled
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* for us: do so
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*/
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gic_secondary_init(0);
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}
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int __cpuinit 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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if (cpu > ncores) {
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pr_warn("CPU No. is not available in the system\n");
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return -1;
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}
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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 (__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((__force void *)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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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 __cpuinit zynq_boot_secondary(unsigned int cpu,
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struct task_struct *idle)
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{
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return zynq_cpun_start(virt_to_phys(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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int i;
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/*
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* Initialise the present map, which describes the set of CPUs
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* actually populated at the present time.
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*/
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for (i = 0; i < max_cpus; i++)
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set_cpu_present(i, true);
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scu_enable(zynq_scu_base);
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}
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struct smp_operations zynq_smp_ops __initdata = {
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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_secondary_init = zynq_secondary_init,
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.smp_boot_secondary = zynq_boot_secondary,
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};
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