[PATCH 10/36] x86/umwait: move to use bus_get_dev_root()

From: Greg Kroah-Hartman
Date: Mon Mar 13 2023 - 14:31:51 EST


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@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
Note, this is a patch that is a prepatory cleanup as part of a larger
series of patches that is working on resolving some old driver core
design mistakes. It will build and apply cleanly on top of 6.3-rc2 on
its own, but I'd prefer if I could take it through my driver-core tree
so that the driver core changes can be taken through there for 6.4-rc1.

arch/x86/kernel/cpu/umwait.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/umwait.c b/arch/x86/kernel/cpu/umwait.c
index ec8064c0ae03..2293efd6ffa6 100644
--- 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);
--
2.39.2