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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * ARM64 CPU idle arch support4 *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#include <acpi/processor.h>14 15#define ARM64_LPI_IS_RETENTION_STATE(arch_flags) (!(arch_flags))16 17static int psci_acpi_cpu_init_idle(unsigned int cpu)18{19 int i, count;20 struct acpi_lpi_state *lpi;21 struct acpi_processor *pr = per_cpu(processors, cpu);22 23 if (unlikely(!pr || !pr->flags.has_lpi))24 return -EINVAL;25 26 /*27 * If the PSCI cpu_suspend function hook has not been initialized28 * idle states must not be enabled, so bail out29 */30 if (!psci_ops.cpu_suspend)31 return -EOPNOTSUPP;32 33 count = pr->power.count - 1;34 if (count <= 0)35 return -ENODEV;36 37 for (i = 0; i < count; i++) {38 u32 state;39 40 lpi = &pr->power.lpi_states[i + 1];41 /*42 * Only bits[31:0] represent a PSCI power_state while43 * bits[63:32] must be 0x0 as per ARM ACPI FFH Specification44 */45 state = lpi->address;46 if (!psci_power_state_is_valid(state)) {47 pr_warn("Invalid PSCI power state %#x\n", state);48 return -EINVAL;49 }50 }51 52 return 0;53}54 55int acpi_processor_ffh_lpi_probe(unsigned int cpu)56{57 return psci_acpi_cpu_init_idle(cpu);58}59 60__cpuidle int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)61{62 u32 state = lpi->address;63 64 if (ARM64_LPI_IS_RETENTION_STATE(lpi->arch_flags))65 return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM_RCU(psci_cpu_suspend_enter,66 lpi->index, state);67 else68 return CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(psci_cpu_suspend_enter,69 lpi->index, state);70}71