i3c: master: use kzalloc_flex

Simplifies allocations by using a flexible array member in this struct.

Add __counted_by to get extra runtime analysis.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260312001534.24423-1-rosenp@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: neheb

drivers/i3c/master.c

@@ -2820,10 +2820,10 @@ struct i3c_generic_ibi_slot {
 struct i3c_generic_ibi_pool {
 	spinlock_t lock;
 	unsigned int num_slots;
-	struct i3c_generic_ibi_slot *slots;
 	void *payload_buf;
 	struct list_head free_slots;
 	struct list_head pending;
+	struct i3c_generic_ibi_slot slots[] __counted_by(num_slots);
 };
 
 /**
@@ -2851,7 +2851,6 @@ void i3c_generic_ibi_free_pool(struct i3c_generic_ibi_pool *pool)
 	WARN_ON(nslots != pool->num_slots);
 
 	kfree(pool->payload_buf);
-	kfree(pool->slots);
 	kfree(pool);
 }
 EXPORT_SYMBOL_GPL(i3c_generic_ibi_free_pool);
@@ -2874,20 +2873,16 @@ i3c_generic_ibi_alloc_pool(struct i3c_dev_desc *dev,
 	unsigned int i;
 	int ret;
 
-	pool = kzalloc_obj(*pool);
+	pool = kzalloc_flex(*pool, slots, req->num_slots);
 	if (!pool)
 		return ERR_PTR(-ENOMEM);
 
+	pool->num_slots = req->num_slots;
+
 	spin_lock_init(&pool->lock);
 	INIT_LIST_HEAD(&pool->free_slots);
 	INIT_LIST_HEAD(&pool->pending);
 
-	pool->slots = kzalloc_objs(*slot, req->num_slots);
-	if (!pool->slots) {
-		ret = -ENOMEM;
-		goto err_free_pool;
-	}
-
 	if (req->max_payload_len) {
 		pool->payload_buf = kcalloc(req->num_slots,
 					    req->max_payload_len, GFP_KERNEL);
@@ -2906,7 +2901,6 @@ i3c_generic_ibi_alloc_pool(struct i3c_dev_desc *dev,
 					  (i * req->max_payload_len);
 
 		list_add_tail(&slot->node, &pool->free_slots);
-		pool->num_slots++;
 	}
 
 	return pool;