x86/MSR: make msr_class a static const structure

Now that the driver core allows for struct class to be in read-only
memory, move the msr_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: "H. Peter Anvin" <hpa@zytor.com>
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
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230620144431.583290-5-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ivan Orlov 2023-06-20 16:44:33 +02:00 committed by Greg Kroah-Hartman
parent f4a5fbfa50
commit 5b87c058bf

View File

@ -39,7 +39,6 @@
#include <asm/cpufeature.h>
#include <asm/msr.h>
static struct class *msr_class;
static enum cpuhp_state cpuhp_msr_state;
enum allow_write_msrs {
@ -235,26 +234,31 @@ static const struct file_operations msr_fops = {
.compat_ioctl = msr_ioctl,
};
static char *msr_devnode(const struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "cpu/%u/msr", MINOR(dev->devt));
}
static const struct class msr_class = {
.name = "msr",
.devnode = msr_devnode,
};
static int msr_device_create(unsigned int cpu)
{
struct device *dev;
dev = device_create(msr_class, NULL, MKDEV(MSR_MAJOR, cpu), NULL,
dev = device_create(&msr_class, NULL, MKDEV(MSR_MAJOR, cpu), NULL,
"msr%d", cpu);
return PTR_ERR_OR_ZERO(dev);
}
static int msr_device_destroy(unsigned int cpu)
{
device_destroy(msr_class, MKDEV(MSR_MAJOR, cpu));
device_destroy(&msr_class, MKDEV(MSR_MAJOR, cpu));
return 0;
}
static char *msr_devnode(const struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "cpu/%u/msr", MINOR(dev->devt));
}
static int __init msr_init(void)
{
int err;
@ -263,12 +267,9 @@ static int __init msr_init(void)
pr_err("unable to get major %d for msr\n", MSR_MAJOR);
return -EBUSY;
}
msr_class = class_create("msr");
if (IS_ERR(msr_class)) {
err = PTR_ERR(msr_class);
err = class_register(&msr_class);
if (err)
goto out_chrdev;
}
msr_class->devnode = msr_devnode;
err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/msr:online",
msr_device_create, msr_device_destroy);
@ -278,7 +279,7 @@ static int __init msr_init(void)
return 0;
out_class:
class_destroy(msr_class);
class_unregister(&msr_class);
out_chrdev:
__unregister_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr");
return err;
@ -288,7 +289,7 @@ module_init(msr_init);
static void __exit msr_exit(void)
{
cpuhp_remove_state(cpuhp_msr_state);
class_destroy(msr_class);
class_unregister(&msr_class);
__unregister_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr");
}
module_exit(msr_exit)