psci

2019-11-09 14:38:34

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在setup_arch 中會啟動psci的init if (acpi_disabled) psci_dt_init(); else psci_acpi_init();可見dtb和acpi分別調用不同的函數初始，以acpi為例int __init psci_acpi_init(void){ if (!acpi_psci_PResent()) { pr_info("is not implemented in ACPI./n"); return -EOPNOTSUPP; } pr_info("probing for conduit method from ACPI./n"); if (acpi_psci_use_hvc()) invoke_psci_fn = __invoke_psci_fn_hvc; else invoke_psci_fn = __invoke_psci_fn_smc; return psci_probe();}其中psci和atf有兩種方式，一種是hvc，一種是smc，主流是smc，具體是通過acpi_psci_use_hvc來判斷。bool __init acpi_psci_use_hvc(void){ return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;}可見是通過FADT表中的flag決定得。最后調用psci_probestatic int __init psci_probe(void){ u32 ver = psci_get_version(); psci_0_2_set_functions(); return 0;}在psci_probe 中調用psci_0_2_set_functions來設定psci執行函數static void __init psci_0_2_set_functions(void){ pr_info("Using standard PSCI v0.2 function IDs/n"); psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_FN_NATIVE(0_2, CPU_SUSPEND); psci_ops.cpu_suspend = psci_cpu_suspend; psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF; psci_ops.cpu_off = psci_cpu_off; psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON); psci_ops.cpu_on = psci_cpu_on; psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE); psci_ops.migrate = psci_migrate; psci_ops.affinity_info = psci_affinity_info; psci_ops.migrate_info_type = psci_migrate_info_type; arm_pm_restart = psci_sys_reset; pm_power_off = psci_sys_poweroff;}主要是填充psci_ops這個結構體。后續就可以直接調用psci_ops來處理問題static int cpu_psci_cpu_boot(unsigned int cpu){ int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa(secondary_entry)); if (err) pr_err("failed to boot CPU%d (%d)/n", cpu, err); return err;}

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