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 (!region_is_subregion(&p->region, &c->region))
return -1;
return region_device_offset(c) - region_device_offset(p);
}
int rdev_munmap(const struct region_device *rd, void *mapping)
{
const struct region_device *rdev;
rdev = rdev_root(rd);
return rdev->ops->munmap(rdev, mapping);
}
void *rdev_mmap(const struct region_device *rd, size_t offset, size_t size)
{
const struct region_device *rdev;
struct region req = {
.offset = offset,
.size = size,
};
if (!normalize_and_ok(&rd->region, &req))
return NULL;
rdev = rdev_root(rd);
return rdev->ops->mmap(rdev, req.offset, req.size);
}
ssize_t rdev_readat(const struct region_device *rd, void *b, size_t offset,
size_t size)
{
const struct region_device *rdev;
struct region req = {
.offset = offset,
.size = size,
};
if (!normalize_and_ok(&rd->region, &req))
return -1;
rdev = rdev_root(rd);
return rdev->ops->readat(rdev, b, req.offset, req.size);
}
int rdev_chain(struct region_device *child, const struct region_device *parent,
size_t offset, size_t size)
{
struct region req = {
.offset = offset,
.size = size,
};
if (!normalize_and_ok(&parent->region, &req))
return -1;
/* Keep track of root region device. Note the offsets are relative
* to the root device. */
child->root = rdev_root(parent);
child->ops = NULL;
child->region.offset = req.offset;
child->region.size = req.size;
return 0;
}
ssize_t rdev_eraseat(const struct region_device *rd, size_t offset,
size_t size)
{
const struct region_device *rdev;
struct region req = {
.offset = offset,
.size = size,
};
if (!normalize_and_ok(&rd->region, &req))
return -1;
rdev = rdev_root(rd);
/* If the eraseat ptr is NULL we assume that the erase
* function was completed successfully. */
if (rdev->ops->eraseat == NULL)
return size;
return rdev->ops->eraseat(rdev, req.offset, req.size);
}
