v4.19.13 snapshot.
diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
new file mode 100644
index 0000000..df564d7
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -0,0 +1,187 @@
+/*
+ * ARM/ARM64 generic CPU idle driver.
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "CPUidle arm: " fmt
+
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/topology.h>
+
+#include <asm/cpuidle.h>
+
+#include "dt_idle_states.h"
+
+/*
+ * arm_enter_idle_state - Programs CPU to enter the specified state
+ *
+ * dev: cpuidle device
+ * drv: cpuidle driver
+ * idx: state index
+ *
+ * Called from the CPUidle framework to program the device to the
+ * specified target state selected by the governor.
+ */
+static int arm_enter_idle_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx)
+{
+ /*
+ * Pass idle state index to arm_cpuidle_suspend which in turn
+ * will call the CPU ops suspend protocol with idle index as a
+ * parameter.
+ */
+ return CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, idx);
+}
+
+static struct cpuidle_driver arm_idle_driver __initdata = {
+ .name = "arm_idle",
+ .owner = THIS_MODULE,
+ /*
+ * State at index 0 is standby wfi and considered standard
+ * on all ARM platforms. If in some platforms simple wfi
+ * can't be used as "state 0", DT bindings must be implemented
+ * to work around this issue and allow installing a special
+ * handler for idle state index 0.
+ */
+ .states[0] = {
+ .enter = arm_enter_idle_state,
+ .exit_latency = 1,
+ .target_residency = 1,
+ .power_usage = UINT_MAX,
+ .name = "WFI",
+ .desc = "ARM WFI",
+ }
+};
+
+static const struct of_device_id arm_idle_state_match[] __initconst = {
+ { .compatible = "arm,idle-state",
+ .data = arm_enter_idle_state },
+ { },
+};
+
+/*
+ * arm_idle_init_cpu
+ *
+ * Registers the arm specific cpuidle driver with the cpuidle
+ * framework. It relies on core code to parse the idle states
+ * and initialize them using driver data structures accordingly.
+ */
+static int __init arm_idle_init_cpu(int cpu)
+{
+ int ret;
+ struct cpuidle_driver *drv;
+ struct cpuidle_device *dev;
+
+ drv = kmemdup(&arm_idle_driver, sizeof(*drv), GFP_KERNEL);
+ if (!drv)
+ return -ENOMEM;
+
+ drv->cpumask = (struct cpumask *)cpumask_of(cpu);
+
+ /*
+ * Initialize idle states data, starting at index 1. This
+ * driver is DT only, if no DT idle states are detected (ret
+ * == 0) let the driver initialization fail accordingly since
+ * there is no reason to initialize the idle driver if only
+ * wfi is supported.
+ */
+ ret = dt_init_idle_driver(drv, arm_idle_state_match, 1);
+ if (ret <= 0) {
+ ret = ret ? : -ENODEV;
+ goto out_kfree_drv;
+ }
+
+ /*
+ * Call arch CPU operations in order to initialize
+ * idle states suspend back-end specific data
+ */
+ ret = arm_cpuidle_init(cpu);
+
+ /*
+ * Allow the initialization to continue for other CPUs, if the reported
+ * failure is a HW misconfiguration/breakage (-ENXIO).
+ */
+ if (ret) {
+ pr_err("CPU %d failed to init idle CPU ops\n", cpu);
+ ret = ret == -ENXIO ? 0 : ret;
+ goto out_kfree_drv;
+ }
+
+ ret = cpuidle_register_driver(drv);
+ if (ret) {
+ if (ret != -EBUSY)
+ pr_err("Failed to register cpuidle driver\n");
+ goto out_kfree_drv;
+ }
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev) {
+ ret = -ENOMEM;
+ goto out_unregister_drv;
+ }
+ dev->cpu = cpu;
+
+ ret = cpuidle_register_device(dev);
+ if (ret) {
+ pr_err("Failed to register cpuidle device for CPU %d\n",
+ cpu);
+ goto out_kfree_dev;
+ }
+
+ return 0;
+
+out_kfree_dev:
+ kfree(dev);
+out_unregister_drv:
+ cpuidle_unregister_driver(drv);
+out_kfree_drv:
+ kfree(drv);
+ return ret;
+}
+
+/*
+ * arm_idle_init - Initializes arm cpuidle driver
+ *
+ * Initializes arm cpuidle driver for all CPUs, if any CPU fails
+ * to register cpuidle driver then rollback to cancel all CPUs
+ * registeration.
+ */
+static int __init arm_idle_init(void)
+{
+ int cpu, ret;
+ struct cpuidle_driver *drv;
+ struct cpuidle_device *dev;
+
+ for_each_possible_cpu(cpu) {
+ ret = arm_idle_init_cpu(cpu);
+ if (ret)
+ goto out_fail;
+ }
+
+ return 0;
+
+out_fail:
+ while (--cpu >= 0) {
+ dev = per_cpu(cpuidle_devices, cpu);
+ drv = cpuidle_get_cpu_driver(dev);
+ cpuidle_unregister_device(dev);
+ cpuidle_unregister_driver(drv);
+ kfree(dev);
+ kfree(drv);
+ }
+
+ return ret;
+}
+device_initcall(arm_idle_init);