LXR linux/arch/arm/mach-omap2/omap-hotplug.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * OMAP4 SMP cpu-hotplug support
   4 *
   5 * Copyright (C) 2010 Texas Instruments, Inc.
   6 * Author:
   7 *      Santosh Shilimkar <santosh.shilimkar@ti.com>
   8 *
   9 * Platform file needed for the OMAP4 SMP. This file is based on arm
  10 * realview smp platform.
  11 * Copyright (c) 2002 ARM Limited.
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/errno.h>
  16#include <linux/smp.h>
  17#include <linux/io.h>
  18
  19#include "omap-wakeupgen.h"
  20#include "common.h"
  21#include "powerdomain.h"
  22
  23/*
  24 * platform-specific code to shutdown a CPU
  25 * Called with IRQs disabled
  26 */
  27void omap4_cpu_die(unsigned int cpu)
  28{
  29        unsigned int boot_cpu = 0;
  30        void __iomem *base = omap_get_wakeupgen_base();
  31
  32        /*
  33         * we're ready for shutdown now, so do it
  34         */
  35        if (omap_secure_apis_support()) {
  36                if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0)
  37                        pr_err("Secure clear status failed\n");
  38        } else {
  39                writel_relaxed(0, base + OMAP_AUX_CORE_BOOT_0);
  40        }
  41
  42
  43        for (;;) {
  44                /*
  45                 * Enter into low power state
  46                 */
  47                omap4_hotplug_cpu(cpu, PWRDM_POWER_OFF);
  48
  49                if (omap_secure_apis_support())
  50                        boot_cpu = omap_read_auxcoreboot0() >> 9;
  51                else
  52                        boot_cpu =
  53                                readl_relaxed(base + OMAP_AUX_CORE_BOOT_0) >> 5;
  54
  55                if (boot_cpu == smp_processor_id()) {
  56                        /*
  57                         * OK, proper wakeup, we're done
  58                         */
  59                        break;
  60                }
  61                pr_debug("CPU%u: spurious wakeup call\n", cpu);
  62        }
  63}
  64
  65/* Needed by kexec and platform_can_cpu_hotplug() */
  66int omap4_cpu_kill(unsigned int cpu)
  67{
  68        return 1;
  69}
  70