kernel: add `k_heap_array_get`

Add `k_heap_array_get` as an alternative to `sys_heap_array_get`, which
only returns statically defined heaps (those defined with
`K_HEAP_DEFINE` or `K_HEAP_DEFINE_NOCACHE`), but doesn't depend on the
application guessing a value for `CONFIG_SYS_HEAP_ARRAY_SIZE`.

Signed-off-by: Jordan Yates <jordan@embeint.com>

doc/releases/release-notes-4.2.rst

@@ -132,6 +132,7 @@ New APIs and options
  * :c:func:`timespec_normalize`
  * :c:func:`timespec_from_timeout`
  * :c:func:`timespec_to_timeout`
+ * :c:func:`k_heap_array_get`
 
 * I2C
 

include/zephyr/kernel.h

@@ -5854,6 +5854,17 @@ void k_heap_free(struct k_heap *h, void *mem) __attribute_nonnull(1);
 #define K_HEAP_DEFINE_NOCACHE(name, bytes)			\
 	Z_HEAP_DEFINE_IN_SECT(name, bytes, __nocache)
 
+/** @brief Get the array of statically defined heaps
+ *
+ * Returns the pointer to the start of the static heap array.
+ * Static heaps are those declared through one of the `K_HEAP_DEFINE`
+ * macros.
+ *
+ * @param heap Pointer to location where heap array address is written
+ * @return Number of static heaps
+ */
+int k_heap_array_get(struct k_heap **heap);
+
 /**
  * @}
  */

kernel/kheap.c

@@ -12,6 +12,17 @@
 #include <ksched.h>
 #include <wait_q.h>
 
+int k_heap_array_get(struct k_heap **heap)
+{
+	int num;
+
+	/* Pointer to the start of the heap array */
+	STRUCT_SECTION_GET(k_heap, 0, heap);
+	/* Number of statically defined heaps */
+	STRUCT_SECTION_COUNT(k_heap, &num);
+	return num;
+}
+
 void k_heap_init(struct k_heap *heap, void *mem, size_t bytes)
 {
 	z_waitq_init(&heap->wait_q);