[coreboot-gerrit] Change in coreboot[master]: lib/cbmem_top: Add a common cbmem_top implementation

[Arthur Heymans (Code Review)]

Arthur Heymans has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/36273 )

Change subject: lib/cbmem_top: Add a common cbmem_top implementation
......................................................................

lib/cbmem_top: Add a common cbmem_top implementation

This adds a common cbmem_top implementation to be used by all coreboot
target. To ease the review process it is currently guarded by a
Kconfig symbol to be able to make transition platforms/arch step by
step.

To avoid a lot of preprocessor and/or changing file inclusion all
current cbmem_top implementations will be renamed cbmem_top_romstage
and called by the common cbmem_top function.

Change-Id: Ie767542ee25483acc9a56785ce20a885e9a63098
Signed-off-by: Arthur Heymans 
---
M src/include/cbmem.h
M src/lib/Kconfig
M src/lib/Makefile.inc
A src/lib/cbmem_top.c
4 files changed, 38 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/73/36273/1

diff --git a/src/include/cbmem.h b/src/include/cbmem.h
index f972ba6..a6cd277 100644
--- a/src/include/cbmem.h
+++ b/src/include/cbmem.h
@@ -74,7 +74,9 @@
  * upper limit.
  * x86 boards or chipsets must return NULL before the cbmem backing store has
  * been initialized. */
+extern uintptr_t _cbmem_top_ptr;
 void *cbmem_top(void);
+void *cbmem_top_romstage(void);

/* Add a cbmem entry of a given size and id. These return NULL on failure. The
  * add function performs a find first and do not check against the original
diff --git a/src/lib/Kconfig b/src/lib/Kconfig
index cb1e4a5..aede4b3 100644
--- a/src/lib/Kconfig
+++ b/src/lib/Kconfig
@@ -24,6 +24,12 @@
    help
      Selected by features that require `libhwbase` in ramstage.

+config RAMSTAGE_CBMEM_TOP_ARG
+	bool
+	help
+	  Select this if stages run after romstage get the cbmem_top
+	  pointer the function arguments when called from romstage.
+
 config FLATTENED_DEVICE_TREE
    bool
    help
diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index e5678ff..0c569c5 100644
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -149,6 +149,7 @@
 ramstage-$(CONFIG_PAYLOAD_FIT_SUPPORT) += fit.c
 ramstage-$(CONFIG_PAYLOAD_FIT_SUPPORT) += fit_payload.c

+romstage-$(CONFIG_RAMSTAGE_CBMEM_TOP_ARG) += cbmem_top.c
 romstage-y += cbmem_common.c
 romstage-y += imd_cbmem.c
 romstage-y += imd.c
diff --git a/src/lib/cbmem_top.c b/src/lib/cbmem_top.c
new file mode 100644
index 0000000..6eee0d5
--- /dev/null
+++ b/src/lib/cbmem_top.c
@@ -0,0 +1,29 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * 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 <cbmem.h>
+
+#if !ENV_ROMSTAGE
+void *cbmem_top(void)
+{
+	return (void *)_cbmem_top_ptr;
+}
+#else
+void *cbmem_top(void)
+{
+	/* TODO use a static variable once NO_CAR_GLOBAL_MIGRATION
+	   is implemented */
+	return cbmem_top_romstage();
+}
+
+#endif