cpu/x86/smm: Add SMM_LEGACY_ASEG

Followup will allow use of PARALLEL_MP with SMM_ASEG so
some guards need to be adjusted.

Change-Id: If032ce2be4749559db0d46ab5ae422afa7666785
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61480
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/cpu/amd/agesa/family15tn/Makefile.inc

@@ -9,4 +9,4 @@ ramstage-y += model_15_init.c
 smm-y += udelay.c
 
 subdirs-y += ../../mtrr
-subdirs-y += ../../smm
+subdirs-$(CONFIG_SMM_LEGACY_ASEG) += ../../smm

src/cpu/amd/smm/Makefile.inc

@@ -1,2 +1,2 @@
 
-ramstage-$(CONFIG_HAVE_SMI_HANDLER) += smm_init.c
+ramstage-y += smm_init.c

src/cpu/x86/Kconfig

@@ -114,6 +114,12 @@ config SMM_TSEG
 	default y
 	depends on !(NO_SMM || SMM_ASEG)
 
+config SMM_LEGACY_ASEG
+	bool
+	default y if HAVE_SMI_HANDLER && SMM_ASEG && LEGACY_SMP_INIT
+	help
+	  SMM support without PARALLEL_MP, to be deprecated.
+
 if SMM_TSEG
 
 config SMM_MODULE_HEAP_SIZE

src/cpu/x86/lapic/lapic_cpu_init.c

@@ -391,7 +391,8 @@ void initialize_cpus(struct bus *cpu_bus)
 	if (is_smp_boot())
 		copy_secondary_start_to_lowest_1M();
 
-	smm_init();
+	if (CONFIG(SMM_LEGACY_ASEG))
+		smm_init();
 
 	/* Initialize the bootstrap processor */
 	cpu_initialize(0);
@@ -403,7 +404,8 @@ void initialize_cpus(struct bus *cpu_bus)
 	if (is_smp_boot())
 		wait_other_cpus_stop(cpu_bus);
 
-	smm_init_completion();
+	if (CONFIG(SMM_LEGACY_ASEG))
+		smm_init_completion();
 
 	if (is_smp_boot())
 		recover_lowest_1M();