x86/umwait: 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: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-10-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kernel/cpu/umwait.c b/arch/x86/kernel/cpu/umwait.c
index ec8064c..2293efd 100644 (file)
--- a/arch/x86/kernel/cpu/umwait.c
+++ b/arch/x86/kernel/cpu/umwait.c
@@ -232,7 +232,11 @@ static int __init umwait_init(void)
         * Add umwait control interface. Ignore failure, so at least the
         * default values are set up in case the machine manages to boot.
         */
-       dev = cpu_subsys.dev_root;
-       return sysfs_create_group(&dev->kobj, &umwait_attr_group);
+       dev = bus_get_dev_root(&cpu_subsys);
+       if (dev) {
+               ret = sysfs_create_group(&dev->kobj, &umwait_attr_group);
+               put_device(dev);
+       }
+       return ret;
 }
 device_initcall(umwait_init);