soc/intel/apollolake: Add cbmem_top() implementation

On Apollolake CPU memory mapping is similar to previous SoC, and
we place CBMEM right under TSEG.

Change-Id: I606f690449ba98af6e9fc3074d677c7287892164
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/13883
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 27 insertions, 0 deletions

diff --git a/src/soc/intel/apollolake/memmap.c b/src/soc/intel/apollolake/memmap.c
new file mode 100644
index 0000000000..bfff9652da
--- /dev/null
+++ b/src/soc/intel/apollolake/memmap.c
@@ -0,0 +1,27 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2015 Intel Corp.
+ * (Written by Andrey Petrov <andrey.petrov@intel.com> for 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <arch/io.h>
+#include <cbmem.h>
+#include <device/pci.h>
+#include <soc/northbridge.h>
+#include <soc/pci_devs.h>
+
+static uintptr_t smm_region_start(void)
+{
+	return ALIGN_DOWN(pci_read_config32(NB_DEV_ROOT, TSEG), 1*MiB);
+}
+
+void *cbmem_top(void)
+{
+	return (void *)smm_region_start();
+}