From: Borislav Petkov <bp@suse.de>

Date: Wed, 25 May 2022 18:12:29 +0200

Subject: x86/microcode: Rip out the OLD_INTERFACE

Git-commit: 181b6f40e9ea80c76756d4d0cdeed396016c487e

Patch-mainline: 5.19-rc1

References: jsc#PED-1072

Everything should be using the early initrd loading by now.

Signed-off-by: Borislav Petkov <bp@suse.de>

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Link: https://lore.kernel.org/r/20220525161232.14924-2-bp@alien8.de

Signed-off-by: Jiri Slaby <jslaby@suse.cz>

---

 arch/x86/Kconfig                     |   12 ----

 arch/x86/kernel/cpu/microcode/core.c |  100 -----------------------------------

 2 files changed, 112 deletions(-)

--- a/arch/x86/Kconfig

+++ b/arch/x86/Kconfig

@@ -1367,18 +1367,6 @@ config MICROCODE_AMD

 	  If you select this option, microcode patch loading support for AMD

 	  processors will be enabled.

-config MICROCODE_OLD_INTERFACE

-	bool "Ancient loading interface (DEPRECATED)"

-	default n

-	depends on MICROCODE

-	help

-	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface

-	  which was used by userspace tools like iucode_tool and microcode.ctl.

-	  It is inadequate because it runs too late to be able to properly

-	  load microcode on a machine and it needs special tools. Instead, you

-	  should've switched to the early loading method with the initrd or

-	  builtin microcode by now: Documentation/x86/microcode.rst

-

 config X86_MSR

 	tristate "/dev/cpu/*/msr - Model-specific register support"

 	help

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

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

@@ -390,98 +390,6 @@ static int apply_microcode_on_target(int

 	return ret;

 }

-#ifdef CONFIG_MICROCODE_OLD_INTERFACE

-static int do_microcode_update(const void __user *buf, size_t size)

-{

-	int error = 0;

-	int cpu;

-

-	for_each_online_cpu(cpu) {

-		struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

-		enum ucode_state ustate;

-

-		if (!uci->valid)

-			continue;

-

-		ustate = microcode_ops->request_microcode_user(cpu, buf, size);

-		if (ustate == UCODE_ERROR) {

-			error = -1;

-			break;

-		} else if (ustate == UCODE_NEW) {

-			apply_microcode_on_target(cpu);

-		}

-	}

-

-	return error;

-}

-

-static int microcode_open(struct inode *inode, struct file *file)

-{

-	return capable(CAP_SYS_RAWIO) ? stream_open(inode, file) : -EPERM;

-}

-

-static ssize_t microcode_write(struct file *file, const char __user *buf,

-			       size_t len, loff_t *ppos)

-{

-	ssize_t ret = -EINVAL;

-	unsigned long nr_pages = totalram_pages();

-

-	if ((len >> PAGE_SHIFT) > nr_pages) {

-		pr_err("too much data (max %ld pages)\n", nr_pages);

-		return ret;

-	}

-

-	cpus_read_lock();

-	mutex_lock(&microcode_mutex);

-

-	if (do_microcode_update(buf, len) == 0)

-		ret = (ssize_t)len;

-

-	if (ret > 0)

-		perf_check_microcode();

-

-	mutex_unlock(&microcode_mutex);

-	cpus_read_unlock();

-

-	return ret;

-}

-

-static const struct file_operations microcode_fops = {

-	.owner			= THIS_MODULE,

-	.write			= microcode_write,

-	.open			= microcode_open,

-	.llseek		= no_llseek,

-};

-

-static struct miscdevice microcode_dev = {

-	.minor			= MICROCODE_MINOR,

-	.name			= "microcode",

-	.nodename		= "cpu/microcode",

-	.fops			= &microcode_fops,

-};

-

-static int __init microcode_dev_init(void)

-{

-	int error;

-

-	error = misc_register(&microcode_dev);

-	if (error) {

-		pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);

-		return error;

-	}

-

-	return 0;

-}

-

-static void __exit microcode_dev_exit(void)

-{

-	misc_deregister(&microcode_dev);

-}

-#else

-#define microcode_dev_init()	0

-#define microcode_dev_exit()	do { } while (0)

-#endif

-

 /* fake device for request_firmware */

 static struct platform_device	*microcode_pdev;

@@ -873,10 +781,6 @@ static int __init microcode_init(void)

 		goto out_driver;

 	}

-	error = microcode_dev_init();

-	if (error)

-		goto out_ucode_group;

-

 	register_syscore_ops(&mc_syscore_ops);

 	cpuhp_setup_state_nocalls(CPUHP_AP_MICROCODE_LOADER, "x86/microcode:starting",

 				  mc_cpu_starting, NULL);

@@ -887,10 +791,6 @@ static int __init microcode_init(void)

 	return 0;

- out_ucode_group:

-	sysfs_remove_group(&cpu_subsys.dev_root->kobj,

-			   &cpu_root_microcode_group);

-

  out_driver:

 	cpus_read_lock();

 	mutex_lock(&microcode_mutex);