Commit f4a5fbfa authored by Ivan Orlov's avatar Ivan Orlov Committed by Greg Kroah-Hartman
Browse files

x86/cpuid: make cpuid_class a static const structure 



Now that the driver core allows for struct class to be in read-only
memory, move the cpuid_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: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarIvan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230620144431.583290-4-gregkh@linuxfoundation.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 32944855

arch/x86/kernel/cpuid.c

+16 −15
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ 
#include <asm/processor.h>

#include <asm/msr.h>



static struct class *cpuid_class;

static enum cpuhp_state cpuhp_cpuid_state;



struct cpuid_regs_done {
@@ -124,26 +123,31 @@ static const struct file_operations cpuid_fops = { 
	.open = cpuid_open,

};



static char *cpuid_devnode(const struct device *dev, umode_t *mode)

{

	return kasprintf(GFP_KERNEL, "cpu/%u/cpuid", MINOR(dev->devt));

}



static const struct class cpuid_class = {

	.name		= "cpuid",

	.devnode	= cpuid_devnode,

};



static int cpuid_device_create(unsigned int cpu)

{

	struct device *dev;



	dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu), NULL,

	dev = device_create(&cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu), NULL,

			    "cpu%d", cpu);

	return PTR_ERR_OR_ZERO(dev);

}



static int cpuid_device_destroy(unsigned int cpu)

{

	device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));

	device_destroy(&cpuid_class, MKDEV(CPUID_MAJOR, cpu));

	return 0;

}



static char *cpuid_devnode(const struct device *dev, umode_t *mode)

{

	return kasprintf(GFP_KERNEL, "cpu/%u/cpuid", MINOR(dev->devt));

}



static int __init cpuid_init(void)

{

	int err;
@@ -154,12 +158,9 @@ static int __init cpuid_init(void) 
		       CPUID_MAJOR);

		return -EBUSY;

	}

	cpuid_class = class_create("cpuid");

	if (IS_ERR(cpuid_class)) {

		err = PTR_ERR(cpuid_class);

	err = class_register(&cpuid_class);

	if (err)

		goto out_chrdev;

	}

	cpuid_class->devnode = cpuid_devnode;



	err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/cpuid:online",

				cpuid_device_create, cpuid_device_destroy);
@@ -170,7 +171,7 @@ static int __init cpuid_init(void) 
	return 0;



out_class:

	class_destroy(cpuid_class);

	class_unregister(&cpuid_class);

out_chrdev:

	__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");

	return err;
@@ -180,7 +181,7 @@ module_init(cpuid_init); 
static void __exit cpuid_exit(void)

{

	cpuhp_remove_state(cpuhp_cpuid_state);

	class_destroy(cpuid_class);

	class_unregister(&cpuid_class);

	__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");

}

module_exit(cpuid_exit);