init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()

commit 439e17576eb47f26b78c5bbc72e344d4206d2327 upstream

Invoke the X86ism mem_encrypt_init() from X86 arch_cpu_finalize_init() and
remove the weak fallback from the core code.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.670360645@linutronix.de
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/x86/kernel/cpu/common.c

@@ -18,6 +18,7 @@
 #include <linux/init.h>
 #include <linux/kprobes.h>
 #include <linux/kgdb.h>
+#include <linux/mem_encrypt.h>
 #include <linux/smp.h>
 #include <linux/cpu.h>
 #include <linux/io.h>
@@ -2240,4 +2241,14 @@ void __init arch_cpu_finalize_init(void)
 	} else {
 		fpu__init_check_bugs();
 	}
+
+	/*
+	 * This needs to be called before any devices perform DMA
+	 * operations that might use the SWIOTLB bounce buffers. It will
+	 * mark the bounce buffers as decrypted so that their usage will
+	 * not cause "plain-text" data to be decrypted when accessed. It
+	 * must be called after late_time_init() so that Hyper-V x86/x64
+	 * hypercalls work when the SWIOTLB bounce buffers are decrypted.
+	 */
+	mem_encrypt_init();
 }