driver/intel/fsp2.0: Add External stage cache region helper

If ramstage caching outside CBMEM is enabled
i.e CONFIG_CACHE_RELOCATED_RAMSTAGE_OUTSIDE_CBMEM, then a
helper function to determine the caching region in SMM
should be implemented. Add the same to FSP2.0 driver.
FSP1.1 driver had the same implementation hence copied stage_cache.c.

The SoC code should implement the smm_subregion to provide
the base and size of the caching region within SMM. The fsp/memmap.h
provides the prototype and we will reuse the same from FPS 1.1.

Change-Id: I4412a710391dc0cee044b96403c50260c3534e6f
Signed-off-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-on: https://review.coreboot.org/16312
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)

src/drivers/intel/fsp2_0/Makefile.inc

@@ -23,6 +23,7 @@ romstage-$(CONFIG_DISPLAY_UPD_DATA) += upd_display.c
 romstage-$(CONFIG_VERIFY_HOBS) += hob_verify.c
 romstage-y += util.c
 romstage-y += memory_init.c
+romstage-$(CONFIG_CACHE_RELOCATED_RAMSTAGE_OUTSIDE_CBMEM) += stage_cache.c
 
 ramstage-y += debug.c
 ramstage-y += graphics.c
@@ -32,6 +33,7 @@ ramstage-$(CONFIG_DISPLAY_HOBS) += hob_display.c
 ramstage-$(CONFIG_VERIFY_HOBS) += hob_verify.c
 ramstage-y += notify.c
 ramstage-y += silicon_init.c
+ramstage-$(CONFIG_CACHE_RELOCATED_RAMSTAGE_OUTSIDE_CBMEM) += stage_cache.c
 ramstage-$(CONFIG_DISPLAY_UPD_DATA) += upd_display.c
 ramstage-y += util.c
 

src/drivers/intel/fsp2_0/include/fsp/memmap.h

@@ -0,0 +1,47 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2015-2016 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _COMMON_MEMMAP_H_
+#define _COMMON_MEMMAP_H_
+
+#include <types.h>
+
+/*
+ * mmap_region_granularity must to return a size which is a positive non-zero
+ * integer multiple of the SMM size when SMM is in use.  When not using SMM,
+ * this value should be set to 8 MiB.
+ */
+size_t mmap_region_granularity(void);
+
+/* Fills in the arguments for the entire SMM region covered by chipset
+ * protections. e.g. TSEG. */
+void smm_region(void **start, size_t *size);
+
+enum {
+	/* SMM handler area. */
+	SMM_SUBREGION_HANDLER,
+	/* SMM cache region. */
+	SMM_SUBREGION_CACHE,
+	/* Chipset specific area. */
+	SMM_SUBREGION_CHIPSET,
+	/* Total sub regions supported. */
+	SMM_SUBREGION_NUM,
+};
+
+/* Fills in the start and size for the requested SMM subregion. Returns
+ * 0 on susccess, < 0 on failure. */
+int smm_subregion(int sub, void **start, size_t *size);
+
+#endif /* _COMMON_MEMMAP_H_ */

src/drivers/intel/fsp2_0/stage_cache.c

@@ -0,0 +1,28 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 Google Inc.
+ * Copyright (C) 2015 Intel Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <console/console.h>
+#include <fsp/memmap.h>
+#include <stage_cache.h>
+
+void stage_cache_external_region(void **base, size_t *size)
+{
+	if (smm_subregion(SMM_SUBREGION_CACHE, base, size)) {
+		printk(BIOS_ERR, "ERROR: No cache SMM subregion.\n");
+		*base = NULL;
+		*size = 0;
+	}
+}