[PATCH for-next v3 03/10] 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
it in a type independent way where the offset is different for each type.
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 | 30 ++++++++++++++++------------
 drivers/infiniband/sw/rxe/rxe_pool.h |  1 +
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index 86251145705f..2655bd372f59 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -220,7 +220,8 @@ static int rxe_insert_key(struct rxe_pool *pool, struct rxe_pool_entry *new)
 		elem = rb_entry(parent, struct rxe_pool_entry, key_node);
 
 		cmp = memcmp((u8 *)elem + pool->key.key_offset,
-			     (u8 *)new + pool->key.key_offset, pool->key.key_size);
+			     (u8 *)new + pool->key.key_offset,
+			     pool->key.key_size);
 
 		if (cmp == 0) {
 			pr_warn("key already exists!\n");
@@ -325,7 +326,7 @@ void __rxe_drop_index(struct rxe_pool_entry *elem)
 void *rxe_alloc_locked(struct rxe_pool *pool)
 {
 	struct rxe_pool_entry *elem;
-	u8 *obj;
+	void *obj;
 
 	if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
 		goto out_cnt;
@@ -334,9 +335,10 @@ void *rxe_alloc_locked(struct rxe_pool *pool)
 	if (!obj)
 		goto out_cnt;
 
-	elem = (struct rxe_pool_entry *)(obj + pool->elem_offset);
+	elem = (struct rxe_pool_entry *)((u8 *)obj + pool->elem_offset);
 
 	elem->pool = pool;
+	elem->obj = obj;
 	kref_init(&elem->ref_cnt);
 
 	return obj;
@@ -350,7 +352,7 @@ void *rxe_alloc(struct rxe_pool *pool)
 {
 	struct rxe_pool_entry *elem;
 	unsigned long flags;
-	u8 *obj;
+	void *obj;
 
 	write_lock_irqsave(&pool->pool_lock, flags);
 	if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
@@ -364,8 +366,9 @@ void *rxe_alloc(struct rxe_pool *pool)
 	}
 
 	write_lock_irqsave(&pool->pool_lock, flags);
-	elem = (struct rxe_pool_entry *)(obj + pool->elem_offset);
+	elem = (struct rxe_pool_entry *)((u8 *)obj + pool->elem_offset);
 	elem->pool = pool;
+	elem->obj = obj;
 	kref_init(&elem->ref_cnt);
 	write_unlock_irqrestore(&pool->pool_lock, flags);
 
@@ -386,6 +389,7 @@ 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);
 	write_unlock_irqrestore(&pool->pool_lock, flags);
 
@@ -402,13 +406,13 @@ 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);
 	}
 
@@ -419,7 +423,7 @@ 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;
 
@@ -436,7 +440,7 @@ 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;
 	}
@@ -446,7 +450,7 @@ void *rxe_pool_get_index_locked(struct rxe_pool *pool, u32 index)
 
 void *rxe_pool_get_index(struct rxe_pool *pool, u32 index)
 {
-	u8 *obj;
+	void *obj;
 	unsigned long flags;
 
 	read_lock_irqsave(&pool->pool_lock, flags);
@@ -460,7 +464,7 @@ 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;
@@ -481,7 +485,7 @@ 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;
 	}
@@ -491,7 +495,7 @@ void *rxe_pool_get_key_locked(struct rxe_pool *pool, void *key)
 
 void *rxe_pool_get_key(struct rxe_pool *pool, void *key)
 {
-	u8 *obj;
+	void *obj;
 	unsigned long flags;
 
 	read_lock_irqsave(&pool->pool_lock, flags);
diff --git a/drivers/infiniband/sw/rxe/rxe_pool.h b/drivers/infiniband/sw/rxe/rxe_pool.h
index fb10e0098415..e9bda4b14f86 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