| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* |
| 3 | * |
| 4 | * Copyright (C) 2013 ARM Limited |
| 5 | * |
| 6 | * Author: Will Deacon <will.deacon@arm.com> |
| 7 | */ |
| 8 | |
| 9 | #define pr_fmt(fmt) "psci: " fmt |
| 10 | |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/of.h> |
| 13 | #include <linux/smp.h> |
| 14 | #include <linux/delay.h> |
| 15 | #include <linux/psci.h> |
| 16 | #include <linux/mm.h> |
| 17 | |
| 18 | #include <uapi/linux/psci.h> |
| 19 | |
| 20 | #include <asm/cpu_ops.h> |
| 21 | #include <asm/errno.h> |
| 22 | #include <asm/smp_plat.h> |
| 23 | |
| 24 | static int __init cpu_psci_cpu_init(unsigned int cpu) |
| 25 | { |
| 26 | return 0; |
| 27 | } |
| 28 | |
| 29 | static int __init cpu_psci_cpu_prepare(unsigned int cpu) |
| 30 | { |
| 31 | if (!psci_ops.cpu_on) { |
| 32 | pr_err("no cpu_on method, not booting CPU%d\n", cpu); |
| 33 | return -ENODEV; |
| 34 | } |
| 35 | |
| 36 | return 0; |
| 37 | } |
| 38 | |
| 39 | static int cpu_psci_cpu_boot(unsigned int cpu) |
| 40 | { |
| 41 | int err = psci_ops.cpu_on(cpu_logical_map(cpu), |
| 42 | __pa_function(secondary_entry)); |
| 43 | if (err) |
| 44 | pr_err("failed to boot CPU%d (%d)\n", cpu, err); |
| 45 | |
| 46 | return err; |
| 47 | } |
| 48 | |
| 49 | #ifdef CONFIG_HOTPLUG_CPU |
| 50 | static bool cpu_psci_cpu_can_disable(unsigned int cpu) |
| 51 | { |
| 52 | return !psci_tos_resident_on(cpu); |
| 53 | } |
| 54 | |
| 55 | static int cpu_psci_cpu_disable(unsigned int cpu) |
| 56 | { |
| 57 | /* Fail early if we don't have CPU_OFF support */ |
| 58 | if (!psci_ops.cpu_off) |
| 59 | return -EOPNOTSUPP; |
| 60 | |
| 61 | /* Trusted OS will deny CPU_OFF */ |
| 62 | if (psci_tos_resident_on(cpu)) |
| 63 | return -EPERM; |
| 64 | |
| 65 | return 0; |
| 66 | } |
| 67 | |
| 68 | static void cpu_psci_cpu_die(unsigned int cpu) |
| 69 | { |
| 70 | /* |
| 71 | * There are no known implementations of PSCI actually using the |
| 72 | * power state field, pass a sensible default for now. |
| 73 | */ |
| 74 | u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN << |
| 75 | PSCI_0_2_POWER_STATE_TYPE_SHIFT; |
| 76 | |
| 77 | psci_ops.cpu_off(state); |
| 78 | } |
| 79 | |
| 80 | static int cpu_psci_cpu_kill(unsigned int cpu) |
| 81 | { |
| 82 | int err; |
| 83 | unsigned long start, end; |
| 84 | |
| 85 | if (!psci_ops.affinity_info) |
| 86 | return 0; |
| 87 | /* |
| 88 | * cpu_kill could race with cpu_die and we can |
| 89 | * potentially end up declaring this cpu undead |
| 90 | * while it is dying. So, try again a few times. |
| 91 | */ |
| 92 | |
| 93 | start = jiffies; |
| 94 | end = start + msecs_to_jiffies(100); |
| 95 | do { |
| 96 | err = psci_ops.affinity_info(cpu_logical_map(cpu), 0); |
| 97 | if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) { |
| 98 | pr_info("CPU%d killed (polled %d ms)\n", cpu, |
| 99 | jiffies_to_msecs(jiffies - start)); |
| 100 | return 0; |
| 101 | } |
| 102 | |
| 103 | usleep_range(100, 1000); |
| 104 | } while (time_before(jiffies, end)); |
| 105 | |
| 106 | pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n", |
| 107 | cpu, err); |
| 108 | return -ETIMEDOUT; |
| 109 | } |
| 110 | #endif |
| 111 | |
| 112 | const struct cpu_operations cpu_psci_ops = { |
| 113 | .name = "psci", |
| 114 | .cpu_init = cpu_psci_cpu_init, |
| 115 | .cpu_prepare = cpu_psci_cpu_prepare, |
| 116 | .cpu_boot = cpu_psci_cpu_boot, |
| 117 | #ifdef CONFIG_HOTPLUG_CPU |
| 118 | .cpu_can_disable = cpu_psci_cpu_can_disable, |
| 119 | .cpu_disable = cpu_psci_cpu_disable, |
| 120 | .cpu_die = cpu_psci_cpu_die, |
| 121 | .cpu_kill = cpu_psci_cpu_kill, |
| 122 | #endif |
| 123 | }; |
| 124 | |