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kernel/linux-rt-4.4.41/arch/arm/mach-ux500/platsmp.c 2.64 KB
5113f6f70   김현기   kernel add
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  /*
   * Copyright (C) 2002 ARM Ltd.
   * Copyright (C) 2008 STMicroelctronics.
   * Copyright (C) 2009 ST-Ericsson.
   * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
   *
   * This file is 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/smp.h>
  #include <linux/io.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  
  #include <asm/cacheflush.h>
  #include <asm/smp_plat.h>
  #include <asm/smp_scu.h>
  
  #include "setup.h"
  
  #include "db8500-regs.h"
  #include "id.h"
  
  /* Magic triggers in backup RAM */
  #define UX500_CPU1_JUMPADDR_OFFSET 0x1FF4
  #define UX500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
  
  static void wakeup_secondary(void)
  {
  	struct device_node *np;
  	static void __iomem *backupram;
  
  	np = of_find_compatible_node(NULL, NULL, "ste,dbx500-backupram");
  	if (!np) {
  		pr_err("No backupram base address
  ");
  		return;
  	}
  	backupram = of_iomap(np, 0);
  	of_node_put(np);
  	if (!backupram) {
  		pr_err("No backupram remap
  ");
  		return;
  	}
  
  	/*
  	 * write the address of secondary startup into the backup ram register
  	 * at offset 0x1FF4, then write the magic number 0xA1FEED01 to the
  	 * backup ram register at offset 0x1FF0, which is what boot rom code
  	 * is waiting for. This will wake up the secondary core from WFE.
  	 */
  	writel(virt_to_phys(secondary_startup),
  	       backupram + UX500_CPU1_JUMPADDR_OFFSET);
  	writel(0xA1FEED01,
  	       backupram + UX500_CPU1_WAKEMAGIC_OFFSET);
  
  	/* make sure write buffer is drained */
  	mb();
  	iounmap(backupram);
  }
  
  static void __init ux500_smp_prepare_cpus(unsigned int max_cpus)
  {
  	struct device_node *np;
  	static void __iomem *scu_base;
  	unsigned int ncores;
  	int i;
  
  	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
  	if (!np) {
  		pr_err("No SCU base address
  ");
  		return;
  	}
  	scu_base = of_iomap(np, 0);
  	of_node_put(np);
  	if (!scu_base) {
  		pr_err("No SCU remap
  ");
  		return;
  	}
  
  	scu_enable(scu_base);
  	ncores = scu_get_core_count(scu_base);
  	for (i = 0; i < ncores; i++)
  		set_cpu_possible(i, true);
  	iounmap(scu_base);
  }
  
  static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
  {
  	wakeup_secondary();
  	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
  	return 0;
  }
  
  struct smp_operations ux500_smp_ops __initdata = {
  	.smp_prepare_cpus	= ux500_smp_prepare_cpus,
  	.smp_boot_secondary	= ux500_boot_secondary,
  #ifdef CONFIG_HOTPLUG_CPU
  	.cpu_die		= ux500_cpu_die,
  #endif
  };
  CPU_METHOD_OF_DECLARE(ux500_smp, "ste,dbx500-smp", &ux500_smp_ops);