x86/microcode/amd: Cache builtin/initrd microcode early

mainline inclusion
from mainline-v6.7-rc1
commit a7939f01672034a58ad3fdbce69bb6c665ce0024
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I8XRMW


CVE: NA

--------------------------------

There is no reason to scan builtin/initrd microcode on each AP.

Cache the builtin/initrd microcode in an early initcall so that the
early AP loader can utilize the cache.

The existing fs initcall which invoked save_microcode_in_initrd_amd() is
still required to maintain the initrd_gone flag. Rename it accordingly.
This will be removed once the AP loader code is converted to use the
cache.

Intel-SIG: commit a7939f016720 x86/microcode/amd: Cache builtin/initrd microcode early.
Microcode restructuring backport.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231017211723.187566507@linutronix.de


[ Aubrey Li: amend commit log ]
Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>