1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ARM64 CPU idle arch support 4 * 5 * Copyright (C) 2014 ARM Ltd. 6 * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> 7 */ 8 9 #include <linux/acpi.h> 10 #include <linux/cpuidle.h> 11 #include <linux/cpu_pm.h> 12 #include <linux/psci.h> 13 14 #ifdef CONFIG_ACPI_PROCESSOR_IDLE 15 16 #include <acpi/processor.h> 17 18 #define ARM64_LPI_IS_RETENTION_STATE(arch_flags) (!(arch_flags)) 19 psci_acpi_cpu_init_idle(unsigned int cpu)20static int psci_acpi_cpu_init_idle(unsigned int cpu) 21 { 22 int i, count; 23 struct acpi_lpi_state *lpi; 24 struct acpi_processor *pr = per_cpu(processors, cpu); 25 26 if (unlikely(!pr || !pr->flags.has_lpi)) 27 return -EINVAL; 28 29 /* 30 * If the PSCI cpu_suspend function hook has not been initialized 31 * idle states must not be enabled, so bail out 32 */ 33 if (!psci_ops.cpu_suspend) 34 return -EOPNOTSUPP; 35 36 count = pr->power.count - 1; 37 if (count <= 0) 38 return -ENODEV; 39 40 for (i = 0; i < count; i++) { 41 u32 state; 42 43 lpi = &pr->power.lpi_states[i + 1]; 44 /* 45 * Only bits[31:0] represent a PSCI power_state while 46 * bits[63:32] must be 0x0 as per ARM ACPI FFH Specification 47 */ 48 state = lpi->address; 49 if (!psci_power_state_is_valid(state)) { 50 pr_warn("Invalid PSCI power state %#x\n", state); 51 return -EINVAL; 52 } 53 } 54 55 return 0; 56 } 57 acpi_processor_ffh_lpi_probe(unsigned int cpu)58int acpi_processor_ffh_lpi_probe(unsigned int cpu) 59 { 60 return psci_acpi_cpu_init_idle(cpu); 61 } 62 acpi_processor_ffh_lpi_enter(struct acpi_lpi_state * lpi)63__cpuidle int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 64 { 65 u32 state = lpi->address; 66 67 if (ARM64_LPI_IS_RETENTION_STATE(lpi->arch_flags)) 68 return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM_RCU(psci_cpu_suspend_enter, 69 lpi->index, state); 70 else 71 return CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(psci_cpu_suspend_enter, 72 lpi->index, state); 73 } 74 #endif 75
