Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c
new file mode 100644
index 0000000..b0ce9bc
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-haltpoll.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * cpuidle driver for haltpoll governor.
+ *
+ * Copyright 2019 Red Hat, Inc. and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ * Authors: Marcelo Tosatti <mtosatti@redhat.com>
+ */
+
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+#include <linux/module.h>
+#include <linux/sched/idle.h>
+#include <linux/kvm_para.h>
+#include <linux/cpuidle_haltpoll.h>
+
+static struct cpuidle_device __percpu *haltpoll_cpuidle_devices;
+static enum cpuhp_state haltpoll_hp_state;
+
+static int default_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ if (current_clr_polling_and_test()) {
+ local_irq_enable();
+ return index;
+ }
+ default_idle();
+ return index;
+}
+
+static struct cpuidle_driver haltpoll_driver = {
+ .name = "haltpoll",
+ .governor = "haltpoll",
+ .states = {
+ { /* entry 0 is for polling */ },
+ {
+ .enter = default_enter_idle,
+ .exit_latency = 1,
+ .target_residency = 1,
+ .power_usage = -1,
+ .name = "haltpoll idle",
+ .desc = "default architecture idle",
+ },
+ },
+ .safe_state_index = 0,
+ .state_count = 2,
+};
+
+static int haltpoll_cpu_online(unsigned int cpu)
+{
+ struct cpuidle_device *dev;
+
+ dev = per_cpu_ptr(haltpoll_cpuidle_devices, cpu);
+ if (!dev->registered) {
+ dev->cpu = cpu;
+ if (cpuidle_register_device(dev)) {
+ pr_notice("cpuidle_register_device %d failed!\n", cpu);
+ return -EIO;
+ }
+ arch_haltpoll_enable(cpu);
+ }
+
+ return 0;
+}
+
+static int haltpoll_cpu_offline(unsigned int cpu)
+{
+ struct cpuidle_device *dev;
+
+ dev = per_cpu_ptr(haltpoll_cpuidle_devices, cpu);
+ if (dev->registered) {
+ arch_haltpoll_disable(cpu);
+ cpuidle_unregister_device(dev);
+ }
+
+ return 0;
+}
+
+static void haltpoll_uninit(void)
+{
+ if (haltpoll_hp_state)
+ cpuhp_remove_state(haltpoll_hp_state);
+ cpuidle_unregister_driver(&haltpoll_driver);
+
+ free_percpu(haltpoll_cpuidle_devices);
+ haltpoll_cpuidle_devices = NULL;
+}
+
+static int __init haltpoll_init(void)
+{
+ int ret;
+ struct cpuidle_driver *drv = &haltpoll_driver;
+
+ /* Do not load haltpoll if idle= is passed */
+ if (boot_option_idle_override != IDLE_NO_OVERRIDE)
+ return -ENODEV;
+
+ cpuidle_poll_state_init(drv);
+
+ if (!kvm_para_available() ||
+ !kvm_para_has_hint(KVM_HINTS_REALTIME))
+ return -ENODEV;
+
+ ret = cpuidle_register_driver(drv);
+ if (ret < 0)
+ return ret;
+
+ haltpoll_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+ if (haltpoll_cpuidle_devices == NULL) {
+ cpuidle_unregister_driver(drv);
+ return -ENOMEM;
+ }
+
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "cpuidle/haltpoll:online",
+ haltpoll_cpu_online, haltpoll_cpu_offline);
+ if (ret < 0) {
+ haltpoll_uninit();
+ } else {
+ haltpoll_hp_state = ret;
+ ret = 0;
+ }
+
+ return ret;
+}
+
+static void __exit haltpoll_exit(void)
+{
+ haltpoll_uninit();
+}
+
+module_init(haltpoll_init);
+module_exit(haltpoll_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marcelo Tosatti <mtosatti@redhat.com>");