x86/mm/init.c: Copy ucode from initrd image to kernel memory

Before initrd image is freed, copy valid ucode patches from initrd image
to kernel memory. The saved ucode will be used to update AP in resume
or hotplug.

Signed-off-by: Fenghua Yu <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: H. Peter Anvin <[email protected]>

arch/x86/mm/init.c

@@ -16,6 +16,7 @@
 #include <asm/tlb.h>
 #include <asm/proto.h>
 #include <asm/dma.h>		/* for MAX_DMA_PFN */
+#include <asm/microcode.h>
 
 #include "mm_internal.h"
 
@@ -534,6 +535,15 @@ void free_initmem(void)
 #ifdef CONFIG_BLK_DEV_INITRD
 void __init free_initrd_mem(unsigned long start, unsigned long end)
 {
+#ifdef CONFIG_MICROCODE_EARLY
+	/*
+	 * Remember, initrd memory may contain microcode or other useful things.
+	 * Before we lose initrd mem, we need to find a place to hold them
+	 * now that normal virtual memory is enabled.
+	 */
+	save_microcode_in_initrd();
+#endif
+
 	/*
 	 * end could be not aligned, and We can not align that,
 	 * decompresser could be confused by aligned initrd_end