Commit 9b355cdb authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman Committed by Borislav Petkov (AMD)
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x86/microcode: Move away from using a fake platform device 



Downloading firmware needs a device to hang off of, and so a platform device
seemed like the simplest way to do this.  Now that we have a faux device
interface, use that instead as this "microcode device" is not anything
resembling a platform device at all.

Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarSohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/2025070121-omission-small-9308@gregkh
parent d7b8f8e2

arch/x86/kernel/cpu/microcode/core.c

+7 −7
Original line number Diff line number Diff line
@@ -17,8 +17,8 @@ 


#define pr_fmt(fmt) "microcode: " fmt



#include <linux/platform_device.h>

#include <linux/stop_machine.h>

#include <linux/device/faux.h>

#include <linux/syscore_ops.h>

#include <linux/miscdevice.h>

#include <linux/capability.h>
@@ -249,7 +249,7 @@ static void reload_early_microcode(unsigned int cpu) 
}



/* fake device for request_firmware */

static struct platform_device	*microcode_pdev;

static struct faux_device *microcode_fdev;



#ifdef CONFIG_MICROCODE_LATE_LOADING

/*
@@ -690,7 +690,7 @@ static int load_late_locked(void) 
	if (!setup_cpus())

		return -EBUSY;



	switch (microcode_ops->request_microcode_fw(0, &microcode_pdev->dev)) {

	switch (microcode_ops->request_microcode_fw(0, &microcode_fdev->dev)) {

	case UCODE_NEW:

		return load_late_stop_cpus(false);

	case UCODE_NEW_SAFE:
@@ -841,9 +841,9 @@ static int __init microcode_init(void) 
	if (early_data.new_rev)

		pr_info_once("Updated early from: 0x%08x\n", early_data.old_rev);



	microcode_pdev = platform_device_register_simple("microcode", -1, NULL, 0);

	if (IS_ERR(microcode_pdev))

		return PTR_ERR(microcode_pdev);

	microcode_fdev = faux_device_create("microcode", NULL, NULL);

	if (!microcode_fdev)

		return -ENODEV;



	dev_root = bus_get_dev_root(&cpu_subsys);

	if (dev_root) {
@@ -862,7 +862,7 @@ static int __init microcode_init(void) 
	return 0;



 out_pdev:

	platform_device_unregister(microcode_pdev);

	faux_device_destroy(microcode_fdev);

	return error;



}