bd82x6x, ibexpeak, lynxpoint: Ensure 0-filling of uninited GNVS vars.

Change-Id: I672c3ca9e7f30a21330cf1920a25b1ab38b3f282
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/7015
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/southbridge/intel/bd82x6x/lpc.c

@@ -33,6 +33,7 @@
 #include <arch/acpigen.h>
 #include <drivers/intel/gma/i915.h>
 #include <cbmem.h>
+#include <string.h>
 #include "pch.h"
 #include "nvs.h"
 
@@ -680,6 +681,9 @@ static unsigned long southbridge_fill_ssdt(unsigned long current, const char *oe
 
 	if (gnvs) {
 		int scopelen;
+
+		memset(gnvs, 0, sizeof (*gnvs));
+
 		acpi_create_gnvs(gnvs);
 		/* IGD OpRegion Base Address */
 		gnvs->aslb = (u32)opregion;

src/southbridge/intel/ibexpeak/lpc.c

@@ -34,6 +34,7 @@
 #include <arch/acpigen.h>
 #include <drivers/intel/gma/i915.h>
 #include <cbmem.h>
+#include <string.h>
 #include "pch.h"
 #include "nvs.h"
 
@@ -674,6 +675,9 @@ static unsigned long southbridge_fill_ssdt(unsigned long current, const char *oe
 
 	if (gnvs) {
 		int scopelen;
+
+		memset(gnvs, 0, sizeof (*gnvs));
+
 		acpi_create_gnvs(gnvs);
 		/* IGD OpRegion Base Address */
 		gnvs->aslb = (u32)opregion;

src/southbridge/intel/lynxpoint/lpc.c

@@ -745,7 +745,14 @@ static void set_subsystem(device_t dev, unsigned vendor, unsigned device)
 
 static unsigned long southbridge_fill_ssdt(unsigned long current, const char *oem_table_id)
 {
-	global_nvs_t *gnvs = cbmem_add (CBMEM_ID_ACPI_GNVS, sizeof (*gnvs));
+	global_nvs_t *gnvs;
+
+	gnvs = cbmem_find(CBMEM_ID_ACPI_GNVS);
+	if (!gnvs) {
+		gnvs = cbmem_add(CBMEM_ID_ACPI_GNVS, sizeof (*gnvs));
+		if (gnvs)
+			memset(gnvs, 0, sizeof(*gnvs));
+	}
 
 	if (gnvs) {
 		int scopelen;