summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kernel/cpuidle.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/kernel/cpuidle.c')
-rw-r--r--arch/arm64/kernel/cpuidle.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpuidle.c b/arch/arm64/kernel/cpuidle.c
new file mode 100644
index 000000000..4150e308e
--- /dev/null
+++ b/arch/arm64/kernel/cpuidle.c
@@ -0,0 +1,76 @@
+// 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/of.h>
+#include <linux/of_device.h>
+#include <linux/psci.h>
+
+#ifdef CONFIG_ACPI
+
+#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);
+}
+
+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(psci_cpu_suspend_enter,
+ lpi->index, state);
+ else
+ return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter,
+ lpi->index, state);
+}
+#endif