cpu/hotplug: move to use bus_get_dev_root()

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-7-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 6c0a92ca6bb59c2cb9f2069de409d51f0d359b40..c59b73d13a3a5d1908e2c4ff878f9823526a21ac 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -2569,22 +2569,33 @@ static const struct attribute_group cpuhp_smt_attr_group = {
 
 static int __init cpu_smt_sysfs_init(void)
 {
-       return sysfs_create_group(&cpu_subsys.dev_root->kobj,
-                                 &cpuhp_smt_attr_group);
+       struct device *dev_root;
+       int ret = -ENODEV;
+
+       dev_root = bus_get_dev_root(&cpu_subsys);
+       if (dev_root) {
+               ret = sysfs_create_group(&dev_root->kobj, &cpuhp_smt_attr_group);
+               put_device(dev_root);
+       }
+       return ret;
 }
 
 static int __init cpuhp_sysfs_init(void)
 {
+       struct device *dev_root;
        int cpu, ret;
 
        ret = cpu_smt_sysfs_init();
        if (ret)
                return ret;
 
-       ret = sysfs_create_group(&cpu_subsys.dev_root->kobj,
-                                &cpuhp_cpu_root_attr_group);
-       if (ret)
-               return ret;
+       dev_root = bus_get_dev_root(&cpu_subsys);
+       if (dev_root) {
+               ret = sysfs_create_group(&dev_root->kobj, &cpuhp_cpu_root_attr_group);
+               put_device(dev_root);
+               if (ret)
+                       return ret;
+       }
 
        for_each_possible_cpu(cpu) {
                struct device *dev = get_cpu_device(cpu);