commonlib: Add function to compute relative offsets from two region_devices.
Provide a helper function which returns the relative offset
between 2 region_devices that have a parent-child child relationship.
BUG=chrome-os-partner:48412
BUG=chromium:445938
BRANCH=None
TEST=Utilized and booted on glados.
Change-Id: Ie0041b33e73a6601748f1289e98b6f1f8756eb11
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/12782
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/src/commonlib/region.c b/src/commonlib/region.c
index 8b0b0d9..2cd273a 100644
--- a/src/commonlib/region.c
+++ b/src/commonlib/region.c
@@ -48,6 +48,18 @@
return rdev->root;
}
+ssize_t rdev_relative_offset(const struct region_device *p,
+ const struct region_device *c)
+{
+ if (rdev_root(p) != rdev_root(c))
+ return -1;
+
+ if (!is_subregion(&p->region, &c->region))
+ return -1;
+
+ return region_device_offset(c) - region_device_offset(p);
+}
+
void *rdev_mmap(const struct region_device *rd, size_t offset, size_t size)
{
const struct region_device *rdev;