[PATCH for-next 3/6] RDMA/rxe: Save object pointer in pool element

[Bob Pearson <rpearsonhpe@xxxxxxxxx>]

In rxe_pool.c currently there are many cases where it is necessary to
compute the offset from a pool element struct to the object containing
the pool element in a type independent way. By saving a pointer to the
object when they are created extra work can be saved.

Signed-off-by: Bob Pearson <rpearsonhpe@xxxxxxxxx>
---
 drivers/infiniband/sw/rxe/rxe_pool.c | 16 +++++++++-------
 drivers/infiniband/sw/rxe/rxe_pool.h |  1 +
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index e9d74ad3f0b7..4caaecdb0d68 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -337,6 +337,7 @@ void *rxe_alloc_locked(struct rxe_pool *pool)
 	elem = (struct rxe_pool_entry *)(obj + pool->elem_offset);
 
 	elem->pool = pool;
+	elem->obj = obj;
 	kref_init(&elem->ref_cnt);
 
 	return obj;
@@ -349,7 +350,7 @@ void *rxe_alloc_locked(struct rxe_pool *pool)
 void *rxe_alloc(struct rxe_pool *pool)
 {
 	unsigned long flags;
-	u8 *obj;
+	void *obj;
 
 	write_lock_irqsave(&pool->pool_lock, flags);
 	obj = rxe_alloc_locked(pool);
@@ -364,6 +365,7 @@ int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_entry *elem)
 		goto out_cnt;
 
 	elem->pool = pool;
+	elem->obj = (u8 *)elem - pool->elem_offset;
 	kref_init(&elem->ref_cnt);
 
 	return 0;
@@ -378,13 +380,13 @@ void rxe_elem_release(struct kref *kref)
 	struct rxe_pool_entry *elem =
 		container_of(kref, struct rxe_pool_entry, ref_cnt);
 	struct rxe_pool *pool = elem->pool;
-	u8 *obj;
+	void *obj;
 
 	if (pool->cleanup)
 		pool->cleanup(elem);
 
 	if (!(pool->flags & RXE_POOL_NO_ALLOC)) {
-		obj = (u8 *)elem - pool->elem_offset;
+		obj = elem->obj;
 		kfree(obj);
 	}
 
@@ -395,7 +397,7 @@ void *rxe_pool_get_index_locked(struct rxe_pool *pool, u32 index)
 {
 	struct rb_node *node;
 	struct rxe_pool_entry *elem;
-	u8 *obj;
+	void *obj;
 
 	node = pool->index.tree.rb_node;
 
@@ -412,7 +414,7 @@ void *rxe_pool_get_index_locked(struct rxe_pool *pool, u32 index)
 
 	if (node) {
 		kref_get(&elem->ref_cnt);
-		obj = (u8 *)elem - pool->elem_offset;
+		obj = elem->obj;
 	} else {
 		obj = NULL;
 	}
@@ -436,7 +438,7 @@ void *rxe_pool_get_key_locked(struct rxe_pool *pool, void *key)
 {
 	struct rb_node *node;
 	struct rxe_pool_entry *elem;
-	u8 *obj;
+	void *obj;
 	int cmp;
 
 	node = pool->key.tree.rb_node;
@@ -457,7 +459,7 @@ void *rxe_pool_get_key_locked(struct rxe_pool *pool, void *key)
 
 	if (node) {
 		kref_get(&elem->ref_cnt);
-		obj = (u8 *)elem - pool->elem_offset;
+		obj = elem->obj;
 	} else {
 		obj = NULL;
 	}
diff --git a/drivers/infiniband/sw/rxe/rxe_pool.h b/drivers/infiniband/sw/rxe/rxe_pool.h
index cd962dc5de9d..570bda77f4a6 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.h
+++ b/drivers/infiniband/sw/rxe/rxe_pool.h
@@ -46,6 +46,7 @@ struct rxe_type_info {
 
 struct rxe_pool_entry {
 	struct rxe_pool		*pool;
+	void			*obj;
 	struct kref		ref_cnt;
 	struct list_head	list;
 
-- 
2.30.2