x86/microcode: Unmodularize the microcode driver

Make CONFIG_MICROCODE a bool. It was practically a bool already anyway,
since early loader was forcing it to =y.

Regardless, there's no real reason to have something be a module which
gets built-in on the majority of installations out there. And its not
like there's noticeable change in functionality - we still can load late
microcode - just the module glue disappears.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1445334889-300-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/Kconfig

@@ -1123,7 +1123,8 @@ config X86_REBOOTFIXUPS
 	  Say N otherwise.
 
 config MICROCODE
-	tristate "CPU microcode loading support"
+	bool "CPU microcode loading support"
+	default y
 	depends on CPU_SUP_AMD || CPU_SUP_INTEL
 	select FW_LOADER
 	---help---
@@ -1174,7 +1175,7 @@ config MICROCODE_AMD_EARLY
 
 config MICROCODE_EARLY
 	bool "Early load microcode"
-	depends on MICROCODE=y && BLK_DEV_INITRD
+	depends on MICROCODE && BLK_DEV_INITRD
 	select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
 	select MICROCODE_AMD_EARLY if MICROCODE_AMD
 	default y

arch/x86/include/asm/microcode.h

@@ -55,6 +55,12 @@ struct ucode_cpu_info {
 };
 extern struct ucode_cpu_info ucode_cpu_info[];
 
+#ifdef CONFIG_MICROCODE
+int __init microcode_init(void);
+#else
+static inline int __init microcode_init(void)	{ return 0; };
+#endif
+
 #ifdef CONFIG_MICROCODE_INTEL
 extern struct microcode_ops * __init init_intel_microcode(void);
 #else

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

@@ -523,7 +523,7 @@ static struct microcode_ops microcode_amd_ops = {
 
 struct microcode_ops * __init init_amd_microcode(void)
 {
-	struct cpuinfo_x86 *c = &cpu_data(0);
+	struct cpuinfo_x86 *c = &boot_cpu_data;
 
 	if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 0x10) {
 		pr_warning("AMD CPU family 0x%x not supported\n", c->x86);

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

@@ -487,9 +487,9 @@ static struct attribute_group cpu_root_microcode_group = {
 	.attrs = cpu_root_microcode_attrs,
 };
 
-static int __init microcode_init(void)
+int __init microcode_init(void)
 {
-	struct cpuinfo_x86 *c = &cpu_data(0);
+	struct cpuinfo_x86 *c = &boot_cpu_data;
 	int error;
 
 	if (paravirt_enabled() || dis_ucode_ldr)
@@ -560,35 +560,3 @@ static int __init microcode_init(void)
 	return error;
 
 }
-module_init(microcode_init);
-
-static void __exit microcode_exit(void)
-{
-	struct cpuinfo_x86 *c = &cpu_data(0);
-
-	microcode_dev_exit();
-
-	unregister_hotcpu_notifier(&mc_cpu_notifier);
-	unregister_syscore_ops(&mc_syscore_ops);
-
-	sysfs_remove_group(&cpu_subsys.dev_root->kobj,
-			   &cpu_root_microcode_group);
-
-	get_online_cpus();
-	mutex_lock(&microcode_mutex);
-
-	subsys_interface_unregister(&mc_cpu_interface);
-
-	mutex_unlock(&microcode_mutex);
-	put_online_cpus();
-
-	platform_device_unregister(microcode_pdev);
-
-	microcode_ops = NULL;
-
-	if (c->x86_vendor == X86_VENDOR_AMD)
-		exit_amd_microcode();
-
-	pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
-}
-module_exit(microcode_exit);

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

@@ -264,7 +264,7 @@ static struct microcode_ops microcode_intel_ops = {
 
 struct microcode_ops * __init init_intel_microcode(void)
 {
-	struct cpuinfo_x86 *c = &cpu_data(0);
+	struct cpuinfo_x86 *c = &boot_cpu_data;
 
 	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
 	    cpu_has(c, X86_FEATURE_IA64)) {

arch/x86/kernel/setup.c

@@ -111,6 +111,7 @@
 #include <asm/mce.h>
 #include <asm/alternative.h>
 #include <asm/prom.h>
+#include <asm/microcode.h>
 
 /*
  * max_low_pfn_mapped: highest direct mapped pfn under 4GB
@@ -1239,6 +1240,8 @@ void __init setup_arch(char **cmdline_p)
 	if (efi_enabled(EFI_BOOT))
 		efi_apply_memmap_quirks();
 #endif
+
+	microcode_init();
 }
 
 #ifdef CONFIG_X86_32