| /* | |
| * 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. | |
| * | |
| * This program is distributed in the hope that it will be useful, | |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| * GNU General Public License for more details. | |
| * | |
| * Copyright (C) 2013 ARM Limited | |
| * | |
| * Author: Will Deacon <will.deacon@arm.com> | |
| */ | |
| #define pr_fmt(fmt) "psci: " fmt | |
| #include <linux/init.h> | |
| #include <linux/of.h> | |
| #include <linux/smp.h> | |
| #include <linux/delay.h> | |
| #include <linux/psci.h> | |
| #include <linux/mm.h> | |
| #include <uapi/linux/psci.h> | |
| #include <asm/compiler.h> | |
| #include <asm/cpu_ops.h> | |
| #include <asm/errno.h> | |
| #include <asm/smp_plat.h> | |
| static int __init cpu_psci_cpu_init(unsigned int cpu) | |
| { | |
| return 0; | |
| } | |
| static int __init cpu_psci_cpu_prepare(unsigned int cpu) | |
| { | |
| if (!psci_ops.cpu_on) { | |
| pr_err("no cpu_on method, not booting CPU%d\n", cpu); | |
| return -ENODEV; | |
| } | |
| return 0; | |
| } | |
| static int cpu_psci_cpu_boot(unsigned int cpu) | |
| { | |
| int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa_symbol(secondary_entry)); | |
| if (err) | |
| pr_err("failed to boot CPU%d (%d)\n", cpu, err); | |
| return err; | |
| } | |
| #ifdef CONFIG_HOTPLUG_CPU | |
| static int cpu_psci_cpu_disable(unsigned int cpu) | |
| { | |
| /* Fail early if we don't have CPU_OFF support */ | |
| if (!psci_ops.cpu_off) | |
| return -EOPNOTSUPP; | |
| /* Trusted OS will deny CPU_OFF */ | |
| if (psci_tos_resident_on(cpu)) | |
| return -EPERM; | |
| return 0; | |
| } | |
| static void cpu_psci_cpu_die(unsigned int cpu) | |
| { | |
| int ret; | |
| /* | |
| * There are no known implementations of PSCI actually using the | |
| * power state field, pass a sensible default for now. | |
| */ | |
| u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN << | |
| PSCI_0_2_POWER_STATE_TYPE_SHIFT; | |
| ret = psci_ops.cpu_off(state); | |
| pr_crit("unable to power off CPU%u (%d)\n", cpu, ret); | |
| } | |
| static int cpu_psci_cpu_kill(unsigned int cpu) | |
| { | |
| int err, i; | |
| if (!psci_ops.affinity_info) | |
| return 0; | |
| /* | |
| * cpu_kill could race with cpu_die and we can | |
| * potentially end up declaring this cpu undead | |
| * while it is dying. So, try again a few times. | |
| */ | |
| for (i = 0; i < 10; i++) { | |
| err = psci_ops.affinity_info(cpu_logical_map(cpu), 0); | |
| if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) { | |
| pr_info("CPU%d killed.\n", cpu); | |
| return 0; | |
| } | |
| msleep(10); | |
| pr_info("Retrying again to check for CPU kill\n"); | |
| } | |
| pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n", | |
| cpu, err); | |
| return -ETIMEDOUT; | |
| } | |
| #endif | |
| const struct cpu_operations cpu_psci_ops = { | |
| .name = "psci", | |
| #ifdef CONFIG_CPU_IDLE | |
| .cpu_init_idle = psci_cpu_init_idle, | |
| .cpu_suspend = psci_cpu_suspend_enter, | |
| #endif | |
| .cpu_init = cpu_psci_cpu_init, | |
| .cpu_prepare = cpu_psci_cpu_prepare, | |
| .cpu_boot = cpu_psci_cpu_boot, | |
| #ifdef CONFIG_HOTPLUG_CPU | |
| .cpu_disable = cpu_psci_cpu_disable, | |
| .cpu_die = cpu_psci_cpu_die, | |
| .cpu_kill = cpu_psci_cpu_kill, | |
| #endif | |
| }; | |