[PATCH drm-next v2 03/16] maple_tree: split up MA_STATE() macro

Danilo Krummrich
2023-02-17T13:46:13Z

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_iter {
struct ma_state mas;
struct sample_mgr *mgr;
struct sample_entry *entry;
};

\#define SAMPLE_ITER(name, __mgr) \
struct sample_iter name = { \
.mas = __MA_STATE(&(__mgr)->mt, 0, 0),
.mgr = __mgr,
.entry = NULL,
}

\#define sample_iter_for_each_range(it__, start__, end__) \
for ((it__).mas.index = start__, (it__).entry = mas_find(&(it__).mas, end__ - 1); \
(it__).entry; (it__).entry = mas_find(&(it__).mas, end__ - 1))

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 e594db58a0f1..ca04c900e51a 100644
--- a/include/linux/maple_tree.h
+++ b/include/linux/maple_tree.h
@@ -424,8 +424,8 @@ 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(mt, first, end) \
+ { \
.tree = mt, \
.index = first, \
.last = end, \
@@ -435,6 +435,9 @@ struct ma_wr_state {
.alloc = NULL, \
}

+#define MA_STATE(name, mt, first, end) \
+ struct ma_state name = __MA_STATE(mt, first, end)
+
#define MA_WR_STATE(name, ma_state, wr_entry) \
struct ma_wr_state name = { \
.mas = ma_state, \
--
2.39.1