[PATCH drm-next v5 02/14] maple_tree: split up MA_STATE() macro

Danilo Krummrich
2023-06-20T00:43:31Z

Split up the MA_STATE() macro such that components using the maple tree
can easily inherit from struct ma_state and build custom tree walk
macros to hide their internals from users.

Example:

struct sample_iterator {
struct ma_state mas;
struct sample_mgr *mgr;
};

\#define SAMPLE_ITERATOR(name, __mgr, start) \
struct sample_iterator name = { \
.mas = MA_STATE_INIT(&(__mgr)->mt, start, 0), \
.mgr = __mgr, \
}

\#define sample_iter_for_each_range(it__, entry__, end__) \
mas_for_each(&(it__).mas, entry__, end__)

--

struct sample *sample;
SAMPLE_ITERATOR(si, min);

sample_iter_for_each_range(&si, sample, max) {
frob(mgr, sample);
}

Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
---
include/linux/maple_tree.h | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h
index 1fadb5f5978b..87d55334f1c2 100644
--- a/include/linux/maple_tree.h
+++ b/include/linux/maple_tree.h
@@ -423,8 +423,8 @@ struct ma_wr_state {
#define MA_ERROR(err) \
((struct maple_enode *)(((unsigned long)err << 2) | 2UL))

-#define MA_STATE(name, mt, first, end) \
- struct ma_state name = { \
+#define MA_STATE_INIT(mt, first, end) \
+ { \
.tree = mt, \
.index = first, \
.last = end, \
@@ -435,6 +435,9 @@ struct ma_wr_state {
.mas_flags = 0, \
}

+#define MA_STATE(name, mt, first, end) \
+ struct ma_state name = MA_STATE_INIT(mt, first, end)
+
#define MA_WR_STATE(name, ma_state, wr_entry) \
struct ma_wr_state name = { \
.mas = ma_state, \
--
2.40.1