soc/intel/cannonlake: Fill the SMI usage

Add SMM support for Cannonlake on top of common SMM, also include the
SMM relocate support.

Change-Id: I9aab141c528709b30804d327804c4031c59fcfff
Signed-off-by: Lijian Zhao <lijian.zhao@intel.com>
Reviewed-on: https://review.coreboot.org/21543
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/cannonlake/memmap.c

@@ -23,9 +23,64 @@
 #include <intelblocks/systemagent.h>
 #include <soc/bootblock.h>
 #include <soc/pci_devs.h>
+#include <soc/smm.h>
 #include <soc/systemagent.h>
 #include <stdlib.h>
 
+void smm_region(void **start, size_t *size)
+{
+	*start = (void *)sa_get_tseg_base();
+	*size = sa_get_tseg_size();
+}
+
+/*
+ *        Subregions within SMM
+ *     +-------------------------+ BGSM
+ *     |          IED            | IED_REGION_SIZE
+ *     +-------------------------+
+ *     |  External Stage Cache   | SMM_RESERVED_SIZE
+ *     +-------------------------+
+ *     |      code and data      |
+ *     |         (TSEG)          |
+ *     +-------------------------+ TSEG
+ */
+int smm_subregion(int sub, void **start, size_t *size)
+{
+	uintptr_t sub_base;
+	size_t sub_size;
+	void *smm_base;
+	const size_t ied_size = CONFIG_IED_REGION_SIZE;
+	const size_t cache_size = CONFIG_SMM_RESERVED_SIZE;
+
+	smm_region(&smm_base, &sub_size);
+	sub_base = (uintptr_t)smm_base;
+
+	switch (sub) {
+	case SMM_SUBREGION_HANDLER:
+		/* Handler starts at the base of TSEG. */
+		sub_size -= ied_size;
+		sub_size -= cache_size;
+		break;
+	case SMM_SUBREGION_CACHE:
+		/* External cache is in the middle of TSEG. */
+		sub_base += sub_size - (ied_size + cache_size);
+		sub_size = cache_size;
+		break;
+	case SMM_SUBREGION_CHIPSET:
+		/* IED is at the top. */
+		sub_base += sub_size - ied_size;
+		sub_size = ied_size;
+		break;
+	default:
+		return -1;
+	}
+
+	*start = (void *)sub_base;
+	*size = sub_size;
+
+	return 0;
+}
+
 static void *top_of_ram_register(void)
 {
 	int num;