Added cpu hotplug handlers. cpu_add_execute() onlines requested
cpus for hot-add & online operations, and cpu_del_execute()
offlines them for hot-delete & offline operations. They are
also used for rollback as well.
cpu_del_validate() fails a request if cpu0 is requested to delete.
Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>
---
drivers/base/cpu.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 107 insertions(+)
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 6345294..05534ad 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -13,6 +13,8 @@
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/percpu.h>
+#include <linux/list.h>
+#include <linux/sys_hotplug.h>
#include "base.h"
@@ -324,10 +326,115 @@ static void __init cpu_dev_register_generic(void)
#endif
}
+#ifdef CONFIG_HOTPLUG_CPU
+static int cpu_del_execute(struct shp_request *req, int rollback);
+
+static int cpu_add_execute(struct shp_request *req, int rollback)
+{
+ struct shp_device *shp_dev;
+ u32 cpu;
+ int ret;
+
+ if (rollback)
+ return cpu_del_execute(req, 0);
+
+ list_for_each_entry(shp_dev, &req->dev_list, list) {
+ if (shp_dev->class != SHP_CLS_CPU)
+ continue;
+
+ cpu = shp_dev->info.cpu.cpu_id;
+
+ if (cpu_online(cpu))
+ continue;
+
+ ret = cpu_up(cpu);
+ if (!ret) {
+ /* REVISIT: need a way to set a cpu dev for hot-plug */
+ if (shp_is_online_op(req->operation))
+ kobject_uevent(&shp_dev->device->kobj,
+ KOBJ_ONLINE);
+ } else {
+ pr_err("cpu: Failed to online cpu %d\n", cpu);
+ /* fall-thru */
+ }
+ }
+
+ return 0;
+}
+
+static int cpu_del_validate(struct shp_request *req, int rollback)
+{
+ struct shp_device *shp_dev;
+
+ if (rollback)
+ return 0;
+
+ list_for_each_entry(shp_dev, &req->dev_list, list) {
+ if (shp_dev->class != SHP_CLS_CPU)
+ continue;
+
+ /*
+ * cpu 0 cannot be offlined. This check can be removed when
+ * cpu 0 offline is supported.
+ */
+ if (shp_dev->info.cpu.cpu_id == 0)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int cpu_del_execute(struct shp_request *req, int rollback)
+{
+ struct shp_device *shp_dev;
+ u32 cpu;
+ int ret;
+
+ if (rollback)
+ return cpu_add_execute(req, 0);
+
+ list_for_each_entry(shp_dev, &req->dev_list, list) {
+ if (shp_dev->class != SHP_CLS_CPU)
+ continue;
+
+ cpu = shp_dev->info.cpu.cpu_id;
+
+ if (!cpu_online(cpu))
+ continue;
+
+ ret = cpu_down(cpu);
+ if (!ret) {
+ /* REVISIT: need a way to set a cpu dev for hot-plug */
+ if (shp_is_online_op(req->operation))
+ kobject_uevent(&shp_dev->device->kobj,
+ KOBJ_OFFLINE);
+ } else {
+ pr_err("cpu: Failed to offline cpu %d\n", cpu);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static void __init cpu_shp_init(void)
+{
+ shp_register_handler(SHP_ADD_EXECUTE, cpu_add_execute,
+ SHP_CPU_ADD_EXECUTE_ORDER);
+ shp_register_handler(SHP_DEL_VALIDATE, cpu_del_validate,
+ SHP_CPU_DEL_VALIDATE_ORDER);
+ shp_register_handler(SHP_DEL_EXECUTE, cpu_del_execute,
+ SHP_CPU_DEL_EXECUTE_ORDER);
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
void __init cpu_dev_init(void)
{
if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups))
panic("Failed to register CPU subsystem");
cpu_dev_register_generic();
+#ifdef CONFIG_HOTPLUG_CPU
+ cpu_shp_init();
+#endif
}
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