fmap: Add get_fmap_flash_offset()

CB:35377 changed the behavior of find_fmap_directory() to return
pointer to CBMEM_ID_FMAP if fmap is cached in
cbmem. lb_boot_media_params() calls find_fmap_directory to add offset
of fmap in flash to coreboot table. However, because of the change in
behavior of find_fmap_directory(), it ended up adding 0 as the offset.

This change adds a new function get_fmap_flash_offset() which returns
the offset of fmap in flash. Ideally, all payloads should move to
using the FMAP from CBMEM. However, in order to maintain compatibility
with payloads which are not updated, ensure that fmap_offset is
updated correctly.

Since find_fmap_directory() is no longer used outside fmap.c, this
change also removes it from fmap.h and limits scope to fmap.c.

In a follow up patch, we need to push a change to libpayload to expose
the fmap cache pointer to lib_sysinfo.

BUG=b:141723751

Change-Id: I7ff6e8199143d1a992a83d7de1e3b44813b733f4
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35639
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Shelley Chen <shchen@google.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/lib/fmap.c b/src/lib/fmap.c
index f0074186da..a427102210 100644
--- a/src/lib/fmap.c
+++ b/src/lib/fmap.c
@@ -31,7 +31,12 @@
 static int fmap_print_once CAR_GLOBAL;
 static struct mem_region_device fmap_cache CAR_GLOBAL;
 
-int find_fmap_directory(struct region_device *fmrd)
+uint64_t get_fmap_flash_offset(void)
+{
+	return FMAP_OFFSET;
+}
+
+static int find_fmap_directory(struct region_device *fmrd)
 {
 	const struct region_device *boot;
 	struct fmap *fmap;