ARM: cpuidle: Add support for cpuidle-haltpoll driver for ARM

hulk inclusion
category: feature
bugzilla: NA
CVE: NA

Add support for cpuidle-haltpoll driver for ARM.
Allow arm to use the couidle-haltpoll driver.
Signed-off-by: NXiangyou Xie <xiexiangyou@huawei.com>
Signed-off-by: NYubo Miao <miaoyubo@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Reviewed-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/Kconfig

@@ -288,6 +288,9 @@ config ARCH_SUPPORTS_UPROBES
 config ARCH_PROC_KCORE_TEXT
 	def_bool y
 
+config ARCH_HAS_CPU_RELAX
+	def_bool y
+
 source "arch/arm64/Kconfig.platforms"
 
 source "kernel/livepatch/Kconfig"

arch/arm64/kernel/process.c

@@ -133,6 +133,10 @@ void arch_cpu_idle(void)
 	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
 }
 
+#if defined(CONFIG_HALTPOLL_CPUIDLE_MODULE)
+EXPORT_SYMBOL(arch_cpu_idle);
+#endif
+
 #ifdef CONFIG_HOTPLUG_CPU
 void arch_cpu_idle_dead(void)
 {

drivers/cpuidle/Kconfig

@@ -34,7 +34,7 @@ config CPU_IDLE_GOV_TEO
 
 config CPU_IDLE_GOV_HALTPOLL
 	bool "Haltpoll governor (for virtualized systems)"
-	depends on KVM_GUEST
+	depends on KVM_GUEST || ARM64
 	help
 	  This governor implements haltpoll idle state selection, to be
 	  used in conjunction with the haltpoll cpuidle driver, allowing
@@ -63,7 +63,7 @@ endmenu
 
 config HALTPOLL_CPUIDLE
 	tristate "Halt poll cpuidle driver"
-	depends on X86 && KVM_GUEST
+	depends on (X86 && KVM_GUEST) || ARM64
 	default y
 	help
 	  This option enables halt poll cpuidle driver, which allows to poll

drivers/cpuidle/cpuidle-haltpoll.c

@@ -96,7 +96,7 @@ static void haltpoll_uninit(void)
 
 static bool haltpoll_want(void)
 {
-	return kvm_para_has_hint(KVM_HINTS_REALTIME) || force;
+	return kvm_para_has_hint(KVM_HINTS_REALTIME);
 }
 
 static int __init haltpoll_init(void)
@@ -106,7 +106,7 @@ static int __init haltpoll_init(void)
 
 	cpuidle_poll_state_init(drv);
 
-	if (!kvm_para_available() || !haltpoll_want())
+	if (!force && (!kvm_para_available() || !haltpoll_want()))
 		return -ENODEV;
 
 	ret = cpuidle_register_driver(drv);

drivers/cpuidle/governors/haltpoll.c

@@ -39,6 +39,10 @@ module_param(guest_halt_poll_grow_start, uint, 0644);
 static bool guest_halt_poll_allow_shrink __read_mostly = true;
 module_param(guest_halt_poll_allow_shrink, bool, 0644);
 
+static bool enable __read_mostly;
+module_param(enable, bool, 0444);
+MODULE_PARM_DESC(enable, "Load unconditionally");
+
 /**
  * haltpoll_select - selects the next idle state to enter
  * @drv: cpuidle driver containing state data
@@ -141,7 +145,7 @@ static struct cpuidle_governor haltpoll_governor = {
 
 static int __init init_haltpoll(void)
 {
-	if (kvm_para_available())
+	if (kvm_para_available() || enable)
 		return cpuidle_register_governor(&haltpoll_governor);
 
 	return 0;

drivers/cpuidle/poll_state.c

@@ -8,6 +8,9 @@
 #include <linux/sched.h>
 #include <linux/sched/clock.h>
 #include <linux/sched/idle.h>
+#ifdef CONFIG_ARM64
+#include <linux/cpu.h>
+#endif
 
 #define POLL_IDLE_RELAX_COUNT	200