objpool: add an iterator and a destructor

Add a function to iterate over object pool entries and a destructor
to free all object pool entries.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

src/include/sof/objpool.h

@@ -8,6 +8,8 @@
 
 #include <sof/list.h>
 
+#include <stdbool.h>
+#include <stddef.h>
 #include <stdint.h>
 
 struct k_heap;
@@ -51,4 +53,28 @@ void *objpool_alloc(struct objpool_head *head, size_t size, uint32_t flags);
  */
 int objpool_free(struct objpool_head *head, void *data);
 
+/**
+ * Free all of the object pool memory
+ *
+ * @param head Pointer to the object pool head.
+ */
+void objpool_prune(struct objpool_head *head);
+
+/* returns true to stop */
+typedef bool (*objpool_iterate_cb)(void *data, void *arg);
+
+/**
+ * Iterate over object pool entries until stopped
+ *
+ * @param head Pointer to the object pool head.
+ * @param cb Callback function
+ * @param arg Callback function argument
+ *
+ * @return 0 on success or a negative error code.
+ *
+ * Call the callback function for each entry in the pool, until it returns true.
+ * If the callback never returns true, return an error.
+ */
+int objpool_iterate(struct objpool_head *head, objpool_iterate_cb cb, void *arg);
+
 #endif

src/lib/objpool.c

@@ -143,3 +143,37 @@ int objpool_free(struct objpool_head *head, void *data)
 
 	return -EINVAL;
 }
+
+void objpool_prune(struct objpool_head *head)
+{
+	struct list_item *next, *tmp;
+
+	list_for_item_safe(next, tmp, &head->list) {
+		list_item_del(next);
+		sof_heap_free(head->heap, container_of(next, struct objpool, list));
+	}
+}
+
+int objpool_iterate(struct objpool_head *head, objpool_iterate_cb cb, void *arg)
+{
+	struct list_item *list;
+
+	list_for_item(list, &head->list) {
+		struct objpool *pobjpool = container_of(list, struct objpool, list);
+		size_t aligned_size = ALIGN_UP(pobjpool->size, sizeof(int));
+		uint32_t mask = pobjpool->mask;
+		unsigned int bit;
+
+		if (!mask)
+			/* all free */
+			continue;
+
+		for (; mask; mask &= ~BIT(bit)) {
+			bit = ffs(mask) - 1;
+			if (cb(pobjpool->data + bit * aligned_size, arg))
+				return 0;
+		}
+	}
+
+	return -ENOENT;
+}