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authorJoao Martins <joao.m.martins@oracle.com>2019-09-02 11:40:31 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-09-03 09:36:36 +0200
commit97d3eb9da84cae0548359b0aecb8619faad003b7 (patch)
tree69c7f83cbc5a28db819ff39b31ddb4917ef600fb /drivers/cpuidle
parentb7e7fffd3e8c81aa0654ed4c9f7a142b4c4dab1a (diff)
cpuidle-haltpoll: vcpu hotplug support
When cpus != maxcpus cpuidle-haltpoll will fail to register all vcpus past the online ones and thus fail to register the idle driver. This is because cpuidle_add_sysfs() will return with -ENODEV as a consequence from get_cpu_device() return no device for a non-existing CPU. Instead switch to cpuidle_register_driver() and manually register each of the present cpus through cpuhp_setup_state() callbacks and future ones that get onlined or offlined. This mimmics similar logic that intel_idle does. Fixes: fa86ee90eb11 ("add cpuidle-haltpoll driver") Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/cpuidle-haltpoll.c68
1 files changed, 63 insertions, 5 deletions
diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c
index 9ac093dcbb01..56d8ab814466 100644
--- a/drivers/cpuidle/cpuidle-haltpoll.c
+++ b/drivers/cpuidle/cpuidle-haltpoll.c
@@ -11,12 +11,16 @@
*/
#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)
{
@@ -46,6 +50,46 @@ static struct cpuidle_driver haltpoll_driver = {
.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;
@@ -56,17 +100,31 @@ static int __init haltpoll_init(void)
if (!kvm_para_available())
return 0;
- ret = cpuidle_register(&haltpoll_driver, NULL);
- if (ret == 0)
- arch_haltpoll_enable();
+ 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)
{
- arch_haltpoll_disable();
- cpuidle_unregister(&haltpoll_driver);
+ haltpoll_uninit();
}
module_init(haltpoll_init);