xarray: Add range store functionality

This version of xa_store_range() really only supports load and store.
Our only user only needs basic load and store functionality, so there's
no need to do the extra work to support marking and overlapping stores
correctly yet.

Signed-off-by: Matthew Wilcox <willy@infradead.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/core-api/xarray.rst b/Documentation/core-api/xarray.rst
index 463e4c798ec1..a4e705108f42 100644
--- a/Documentation/core-api/xarray.rst
+++ b/Documentation/core-api/xarray.rst
@@ -98,6 +98,13 @@ the XArray by calling :c:func:`xa_for_each`.  You may prefer to use
 :c:func:`xa_find` or :c:func:`xa_find_after` to move to the next present
 entry in the XArray.
 
+Calling :c:func:`xa_store_range` stores the same entry in a range
+of indices.  If you do this, some of the other operations will behave
+in a slightly odd way.  For example, marking the entry at one index
+may result in the entry being marked at some, but not all of the other
+indices.  Storing into one index may result in the entry retrieved by
+some, but not all of the other indices changing.
+
 Finally, you can remove all entries from an XArray by calling
 :c:func:`xa_destroy`.  If the XArray entries are pointers, you may wish
 to free the entries first.  You can do this by iterating over all present
@@ -156,6 +163,7 @@ Takes xa_lock internally:
  * :c:func:`xa_erase_bh`
  * :c:func:`xa_erase_irq`
  * :c:func:`xa_cmpxchg`
+ * :c:func:`xa_store_range`
  * :c:func:`xa_alloc`
  * :c:func:`xa_alloc_bh`
  * :c:func:`xa_alloc_irq`