blob: f372295207fbdb7a0fed2fb418fdb0558a9093ce [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* ARM64 CPU idle arch support
*
* Copyright (C) 2014 ARM Ltd.
* Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
*/
#include <linux/acpi.h>
#include <linux/cpuidle.h>
#include <linux/cpu_pm.h>
#include <linux/psci.h>
#ifdef CONFIG_ACPI_PROCESSOR_IDLE
#include <acpi/processor.h>
#define ARM64_LPI_IS_RETENTION_STATE(arch_flags) (!(arch_flags))
static int psci_acpi_cpu_init_idle(unsigned int cpu)
{
int i, count;
struct acpi_lpi_state *lpi;
struct acpi_processor *pr = per_cpu(processors, cpu);
if (unlikely(!pr || !pr->flags.has_lpi))
return -EINVAL;
/*
* If the PSCI cpu_suspend function hook has not been initialized
* idle states must not be enabled, so bail out
*/
if (!psci_ops.cpu_suspend)
return -EOPNOTSUPP;
count = pr->power.count - 1;
if (count <= 0)
return -ENODEV;
for (i = 0; i < count; i++) {
u32 state;
lpi = &pr->power.lpi_states[i + 1];
/*
* Only bits[31:0] represent a PSCI power_state while
* bits[63:32] must be 0x0 as per ARM ACPI FFH Specification
*/
state = lpi->address;
if (!psci_power_state_is_valid(state)) {
pr_warn("Invalid PSCI power state %#x\n", state);
return -EINVAL;
}
}
return 0;
}
int acpi_processor_ffh_lpi_probe(unsigned int cpu)
{
return psci_acpi_cpu_init_idle(cpu);
}
__cpuidle int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
{
u32 state = lpi->address;
if (ARM64_LPI_IS_RETENTION_STATE(lpi->arch_flags))
return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM_RCU(psci_cpu_suspend_enter,
lpi->index, state);
else
return CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(psci_cpu_suspend_enter,
lpi->index, state);
}
#endif