diff options
| -rw-r--r-- | arch/x86/kernel/process.c | 2 | ||||
| -rw-r--r-- | drivers/cpuidle/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/cpuidle/Makefile | 1 | ||||
| -rw-r--r-- | drivers/cpuidle/cpuidle-haltpoll.c | 68 |
4 files changed, 79 insertions, 1 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 75fea0d48c0e..5e94c4354d4e 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -580,7 +580,7 @@ void __cpuidle default_idle(void) safe_halt(); trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); } -#ifdef CONFIG_APM_MODULE +#if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE) EXPORT_SYMBOL(default_idle); #endif diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig index a4ac31e4a58c..cc8efc56be7d 100644 --- a/drivers/cpuidle/Kconfig +++ b/drivers/cpuidle/Kconfig @@ -51,6 +51,15 @@ depends on PPC source "drivers/cpuidle/Kconfig.powerpc" endmenu +config HALTPOLL_CPUIDLE + tristate "Halt poll cpuidle driver" + depends on X86 && KVM_GUEST + default y + help + This option enables halt poll cpuidle driver, which allows to poll + before halting in the guest (more efficient than polling in the + host via halt_poll_ns for some scenarios). + endif config ARCH_NEEDS_CPU_IDLE_COUPLED diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile index 9d7176cee3d3..240227474cd9 100644 --- a/drivers/cpuidle/Makefile +++ b/drivers/cpuidle/Makefile @@ -7,6 +7,7 @@ obj-y += cpuidle.o driver.o governor.o sysfs.o governors/ obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o obj-$(CONFIG_DT_IDLE_STATES) += dt_idle_states.o obj-$(CONFIG_ARCH_HAS_CPU_RELAX) += poll_state.o +obj-$(CONFIG_HALTPOLL_CPUIDLE) += cpuidle-haltpoll.o ################################################################################## # ARM SoC drivers diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c new file mode 100644 index 000000000000..35cfb53e9287 --- /dev/null +++ b/drivers/cpuidle/cpuidle-haltpoll.c @@ -0,0 +1,68 @@ +// 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/cpuidle.h> +#include <linux/module.h> +#include <linux/sched/idle.h> +#include <linux/kvm_para.h> + +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", + .owner = THIS_MODULE, + .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 __init haltpoll_init(void) +{ + struct cpuidle_driver *drv = &haltpoll_driver; + + cpuidle_poll_state_init(drv); + + if (!kvm_para_available()) + return 0; + + return cpuidle_register(&haltpoll_driver, NULL); +} + +static void __exit haltpoll_exit(void) +{ + cpuidle_unregister(&haltpoll_driver); +} + +module_init(haltpoll_init); +module_exit(haltpoll_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Marcelo Tosatti <mtosatti@redhat.com>"); |