x86/sev: Add missing __init annotations to SEV init routines

Currently, get_secrets_page() is only reachable from the following call
chain:

  __init snp_init_platform_device():
    get_secrets_page()

so mark it as __init as well. This is also needed since it calls
early_memremap(), which is also an __init routine.

Similarly, get_jump_table_addr() is only reachable from the following
call chain:

  __init setup_real_mode():
    sme_sev_setup_real_mode():
      sev_es_setup_ap_jump_table():
        get_jump_table_addr()

so mark get_jump_table_addr() and everything up that call chain as
__init as well. This is also needed since future patches will add a
call to get_secrets_page(), which needs to be __init due to the reasons
stated above.
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220422135624.114172-2-michael.roth@amd.com

arch/x86/kernel/sev.c

@@ -558,7 +558,7 @@ void noinstr __sev_es_nmi_complete(void)
 	__sev_put_ghcb(&state);
 }
 
-static u64 get_jump_table_addr(void)
+static u64 __init get_jump_table_addr(void)
 {
 	struct ghcb_state state;
 	unsigned long flags;
@@ -1077,7 +1077,7 @@ void snp_set_wakeup_secondary_cpu(void)
 	apic->wakeup_secondary_cpu = wakeup_cpu_via_vmgexit;
 }
 
-int sev_es_setup_ap_jump_table(struct real_mode_header *rmh)
+int __init sev_es_setup_ap_jump_table(struct real_mode_header *rmh)
 {
 	u16 startup_cs, startup_ip;
 	phys_addr_t jump_table_pa;
@@ -2171,7 +2171,7 @@ static struct platform_device sev_guest_device = {
 	.id		= -1,
 };
 
-static u64 get_secrets_page(void)
+static u64 __init get_secrets_page(void)
 {
 	u64 pa_data = boot_params.cc_blob_address;
 	struct cc_blob_sev_info info;

arch/x86/realmode/init.c

@@ -67,7 +67,7 @@ void __init reserve_real_mode(void)
 	memblock_reserve(0, SZ_1M);
 }
 
-static void sme_sev_setup_real_mode(struct trampoline_header *th)
+static void __init sme_sev_setup_real_mode(struct trampoline_header *th)
 {
 #ifdef CONFIG_AMD_MEM_ENCRYPT
 	if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))