From 8c99377e614f8abfd881c34611002b2af5ab1ee8 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 9 Feb 2023 10:35:56 +0100 Subject: driver core: bus: add bus_get_dev_root() function Instead of poking around in the struct bus_type directly for the dev_root pointer, provide a function to return it properly reference counted, if it is present in the bus. This will be needed to move the pointer out of struct bus_type in the future. Use the function in the driver core code at the same time it is introduced to verify that it works properly. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20230209093556.19132-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'drivers/base/core.c') diff --git a/drivers/base/core.c b/drivers/base/core.c index 2712a1a1e959..f9297c68214a 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -3173,8 +3173,9 @@ static DEFINE_MUTEX(gdp_mutex); static struct kobject *get_device_parent(struct device *dev, struct device *parent) { + struct kobject *kobj = NULL; + if (dev->class) { - struct kobject *kobj = NULL; struct kobject *parent_kobj; struct kobject *k; @@ -3222,8 +3223,15 @@ static struct kobject *get_device_parent(struct device *dev, } /* subsystems can specify a default root directory for their devices */ - if (!parent && dev->bus && dev->bus->dev_root) - return &dev->bus->dev_root->kobj; + if (!parent && dev->bus) { + struct device *dev_root = bus_get_dev_root(dev->bus); + + if (dev_root) { + kobj = &dev_root->kobj; + put_device(dev_root); + return kobj; + } + } if (parent) return &parent->kobj; -- cgit