intel/smm/gen1: Use smm_subregion()

Change-Id: I371ed41f485b3143e47f091681198d6674928897
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34740
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/gm45/memmap.c b/src/northbridge/intel/gm45/memmap.c
index 6e2f703..7479a78 100644
--- a/src/northbridge/intel/gm45/memmap.c
+++ b/src/northbridge/intel/gm45/memmap.c
@@ -23,9 +23,9 @@
 #include <device/pci_def.h>
 #include <console/console.h>
 #include <cpu/x86/mtrr.h>
+#include <cpu/x86/smm.h>
 #include <cbmem.h>
 #include <program_loading.h>
-#include <stage_cache.h>
 #include <cpu/intel/smm_reloc.h>
 #include "gm45.h"
 
@@ -84,7 +84,7 @@
 	}
 }
 
-u32 northbridge_get_tseg_base(void)
+static uintptr_t northbridge_get_tseg_base(void)
 {
 	const pci_devfn_t dev = PCI_DEV(0, 0, 0);
 
@@ -107,7 +107,7 @@
 	return tor;
 }
 
-u32 northbridge_get_tseg_size(void)
+static size_t northbridge_get_tseg_size(void)
 {
 	const u8 esmramc = pci_read_config8(PCI_DEV(0, 0, 0), D0F0_ESMRAMC);
 	return decode_tseg_size(esmramc) << 10;
@@ -123,14 +123,10 @@
 	return (void *) top_of_ram;
 }
 
-void stage_cache_external_region(void **base, size_t *size)
+void smm_region(uintptr_t *start, size_t *size)
 {
-	/* The stage cache lives at the end of the TSEG region.
-	 * The top of RAM is defined to be the TSEG base address.
-	 */
-	*size = CONFIG_SMM_RESERVED_SIZE;
-	*base = (void *)((uintptr_t)northbridge_get_tseg_base()
-		+ northbridge_get_tseg_size() - CONFIG_SMM_RESERVED_SIZE);
+	*start = northbridge_get_tseg_base();
+	*size = northbridge_get_tseg_size();
 }
 
 void fill_postcar_frame(struct postcar_frame *pcf)