[PATCH 09/36] x86/microcode: move to use bus_get_dev_root()

[Greg Kroah-Hartman]

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: Borislav Petkov <bp@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
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/microcode/core.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 7a329e561354..3afcf3de0dd4 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -632,6 +632,7 @@ static const struct attribute_group cpu_root_microcode_group = {
 
 static int __init microcode_init(void)
 {
+	struct device *dev_root;
 	struct cpuinfo_x86 *c = &boot_cpu_data;
 	int error;
 
@@ -652,10 +653,14 @@ static int __init microcode_init(void)
 	if (IS_ERR(microcode_pdev))
 		return PTR_ERR(microcode_pdev);
 
-	error = sysfs_create_group(&cpu_subsys.dev_root->kobj, &cpu_root_microcode_group);
-	if (error) {
-		pr_err("Error creating microcode group!\n");
-		goto out_pdev;
+	dev_root = bus_get_dev_root(&cpu_subsys);
+	if (dev_root) {
+		error = sysfs_create_group(&dev_root->kobj, &cpu_root_microcode_group);
+		put_device(dev_root);
+		if (error) {
+			pr_err("Error creating microcode group!\n");
+			goto out_pdev;
+		}
 	}
 
 	/* Do per-CPU setup */
-- 
2.39.2