| /* |
| * 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 |
| }; |
| |
