// SPDX-License-Identifier: GPL-2.0-only
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/*
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*
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* Copyright (C) 2013 ARM Limited
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*
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* Author: Will Deacon <will.deacon@arm.com>
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*/
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#define pr_fmt(fmt) "psci: " fmt
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#include <linux/init.h>
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#include <linux/of.h>
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#include <linux/smp.h>
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#include <linux/delay.h>
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#include <linux/psci.h>
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#include <linux/mm.h>
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#include <uapi/linux/psci.h>
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#include <asm/cpu_ops.h>
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#include <asm/errno.h>
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#include <asm/smp_plat.h>
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static int __init cpu_psci_cpu_init(unsigned int cpu)
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{
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return 0;
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}
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static int __init cpu_psci_cpu_prepare(unsigned int cpu)
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{
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if (!psci_ops.cpu_on) {
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pr_err("no cpu_on method, not booting CPU%d\n", cpu);
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return -ENODEV;
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}
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return 0;
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}
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static int cpu_psci_cpu_boot(unsigned int cpu)
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{
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int err = psci_ops.cpu_on(cpu_logical_map(cpu),
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__pa_function(secondary_entry));
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if (err)
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pr_err("failed to boot CPU%d (%d)\n", cpu, err);
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return err;
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}
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#ifdef CONFIG_HOTPLUG_CPU
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static bool cpu_psci_cpu_can_disable(unsigned int cpu)
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{
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return !psci_tos_resident_on(cpu);
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}
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static int cpu_psci_cpu_disable(unsigned int cpu)
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{
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/* Fail early if we don't have CPU_OFF support */
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if (!psci_ops.cpu_off)
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return -EOPNOTSUPP;
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/* Trusted OS will deny CPU_OFF */
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if (psci_tos_resident_on(cpu))
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return -EPERM;
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return 0;
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}
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static void cpu_psci_cpu_die(unsigned int cpu)
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{
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/*
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* There are no known implementations of PSCI actually using the
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* power state field, pass a sensible default for now.
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*/
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u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN <<
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PSCI_0_2_POWER_STATE_TYPE_SHIFT;
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psci_ops.cpu_off(state);
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}
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static int cpu_psci_cpu_kill(unsigned int cpu)
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{
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int err;
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unsigned long start, end;
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if (!psci_ops.affinity_info)
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return 0;
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/*
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* cpu_kill could race with cpu_die and we can
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* potentially end up declaring this cpu undead
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* while it is dying. So, try again a few times.
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*/
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start = jiffies;
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end = start + msecs_to_jiffies(100);
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do {
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err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
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if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
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pr_info("CPU%d killed (polled %d ms)\n", cpu,
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jiffies_to_msecs(jiffies - start));
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return 0;
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}
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usleep_range(100, 1000);
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} while (time_before(jiffies, end));
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pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
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cpu, err);
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return -ETIMEDOUT;
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}
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#endif
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const struct cpu_operations cpu_psci_ops = {
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.name = "psci",
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.cpu_init = cpu_psci_cpu_init,
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.cpu_prepare = cpu_psci_cpu_prepare,
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.cpu_boot = cpu_psci_cpu_boot,
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#ifdef CONFIG_HOTPLUG_CPU
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.cpu_can_disable = cpu_psci_cpu_can_disable,
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.cpu_disable = cpu_psci_cpu_disable,
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.cpu_die = cpu_psci_cpu_die,
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.cpu_kill = cpu_psci_cpu_kill,
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#endif
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};
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