RDMA/rxe: Save object pointer in pool element

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.

Link: https://lore.kernel.org/r/20211103050241.61293-5-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index 50a92ec..2761010 100644 (file)
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -225,7 +225,8 @@ static int rxe_insert_key(struct rxe_pool *pool, struct rxe_pool_elem *new)
                elem = rb_entry(parent, struct rxe_pool_elem, 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");
@@ -326,7 +327,7 @@ void __rxe_drop_index(struct rxe_pool_elem *elem)
 void *rxe_alloc_locked(struct rxe_pool *pool)
 {
        struct rxe_pool_elem *elem;
-       u8 *obj;
+       void *obj;
 
        if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
                goto out_cnt;
@@ -335,9 +336,10 @@ void *rxe_alloc_locked(struct rxe_pool *pool)
        if (!obj)
                goto out_cnt;
 
-       elem = (struct rxe_pool_elem *)(obj + pool->elem_offset);
+       elem = (struct rxe_pool_elem *)((u8 *)obj + pool->elem_offset);
 
        elem->pool = pool;
+       elem->obj = obj;
        kref_init(&elem->ref_cnt);
 
        return obj;
@@ -350,7 +352,7 @@ out_cnt:
 void *rxe_alloc(struct rxe_pool *pool)
 {
        struct rxe_pool_elem *elem;
-       u8 *obj;
+       void *obj;
 
        if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
                goto out_cnt;
@@ -359,9 +361,10 @@ void *rxe_alloc(struct rxe_pool *pool)
        if (!obj)
                goto out_cnt;
 
-       elem = (struct rxe_pool_elem *)(obj + pool->elem_offset);
+       elem = (struct rxe_pool_elem *)((u8 *)obj + pool->elem_offset);
 
        elem->pool = pool;
+       elem->obj = obj;
        kref_init(&elem->ref_cnt);
 
        return obj;
@@ -377,6 +380,7 @@ int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_elem *elem)
                goto out_cnt;
 
        elem->pool = pool;
+       elem->obj = (u8 *)elem - pool->elem_offset;
        kref_init(&elem->ref_cnt);
 
        return 0;
@@ -391,13 +395,13 @@ void rxe_elem_release(struct kref *kref)
        struct rxe_pool_elem *elem =
                container_of(kref, struct rxe_pool_elem, 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);
        }
 
@@ -408,7 +412,7 @@ void *rxe_pool_get_index_locked(struct rxe_pool *pool, u32 index)
 {
        struct rb_node *node;
        struct rxe_pool_elem *elem;
-       u8 *obj;
+       void *obj;
 
        node = pool->index.tree.rb_node;
 
@@ -425,7 +429,7 @@ 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;
        }
@@ -435,7 +439,7 @@ 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;
 
        read_lock_bh(&pool->pool_lock);
        obj = rxe_pool_get_index_locked(pool, index);
@@ -448,7 +452,7 @@ void *rxe_pool_get_key_locked(struct rxe_pool *pool, void *key)
 {
        struct rb_node *node;
        struct rxe_pool_elem *elem;
-       u8 *obj;
+       void *obj;
        int cmp;
 
        node = pool->key.tree.rb_node;
@@ -469,7 +473,7 @@ 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;
        }
@@ -479,7 +483,7 @@ 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;
 
        read_lock_bh(&pool->pool_lock);
        obj = rxe_pool_get_key_locked(pool, key);

diff --git a/drivers/infiniband/sw/rxe/rxe_pool.h b/drivers/infiniband/sw/rxe/rxe_pool.h
index 591e1c0..c9fa842 100644 (file)
--- a/drivers/infiniband/sw/rxe/rxe_pool.h
+++ b/drivers/infiniband/sw/rxe/rxe_pool.h
@@ -32,6 +32,7 @@ enum rxe_elem_type {
 
 struct rxe_pool_elem {
        struct rxe_pool         *pool;
+       void                    *obj;
        struct kref             ref_cnt;
        struct list_head        list;