x86/microcode: Parse built-in microcode early

Apparently, people do build microcode into the kernel image, i.e.
CONFIG_FIRMWARE_IN_KERNEL=y.

Make that work in the early loader which is where microcode should be
preferably loaded anyway.

Note that you need to specify the microcode filename with the path
relative to the toplevel firmware directory (the same like the late
loading method) in CONFIG_EXTRA_FIRMWARE=y so that early loader can
find it.

I.e., something like this (Intel variant):

  CONFIG_FIRMWARE_IN_KERNEL=y
  CONFIG_EXTRA_FIRMWARE="intel-ucode/06-3a-09"
  CONFIG_EXTRA_FIRMWARE_DIR="/lib/firmware/"

While at it, add me to the loader copyright boilerplate.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microcode.h
index 2fb20d6f7e23..9e6278c7140e 100644
--- a/arch/x86/include/asm/microcode.h
+++ b/arch/x86/include/asm/microcode.h
@@ -1,6 +1,8 @@
 #ifndef _ASM_X86_MICROCODE_H
 #define _ASM_X86_MICROCODE_H
 
+#include <linux/earlycpio.h>
+
 #define native_rdmsr(msr, val1, val2)			\
 do {							\
 	u64 __val = native_read_msr((msr));		\
@@ -152,6 +154,7 @@ extern void __init load_ucode_bsp(void);
 extern void load_ucode_ap(void);
 extern int __init save_microcode_in_initrd(void);
 void reload_early_microcode(void);
+extern bool get_builtin_firmware(struct cpio_data *cd, const char *name);
 #else
 static inline void __init load_ucode_bsp(void) {}
 static inline void load_ucode_ap(void) {}
@@ -160,6 +163,9 @@ static inline int __init save_microcode_in_initrd(void)
 	return 0;
 }
 static inline void reload_early_microcode(void) {}
+static inline bool get_builtin_firmware(struct cpio_data *cd, const char *name)
+{
+	return false;
+}
 #endif
-
 #endif /* _ASM_X86_MICROCODE_H */