diff options
| -rw-r--r-- | src/commonlib/include/commonlib/region.h | 7 | ||||
| -rw-r--r-- | src/commonlib/region.c | 12 |
2 files changed, 19 insertions, 0 deletions
diff --git a/src/commonlib/include/commonlib/region.h b/src/commonlib/include/commonlib/region.h index cc4ee289d2..35d48ade85 100644 --- a/src/commonlib/include/commonlib/region.h +++ b/src/commonlib/include/commonlib/region.h @@ -121,6 +121,13 @@ static inline void *rdev_mmap_full(const struct region_device *rd) return rdev_mmap(rd, 0, region_device_sz(rd)); } +/* + * Compute relative offset of the child (c) w.r.t. the parent (p). Returns < 0 + * when child is not within the parent's region. + */ +ssize_t rdev_relative_offset(const struct region_device *p, + const struct region_device *c); + struct mem_region_device { char *base; struct region_device rdev; diff --git a/src/commonlib/region.c b/src/commonlib/region.c index 8b0b0d9748..2cd273a883 100644 --- a/src/commonlib/region.c +++ b/src/commonlib/region.c @@ -48,6 +48,18 @@ static const struct region_device *rdev_root(const struct region_device *rdev) 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; |