kernel: mempool: add z_thread_aligned_alloc

This adds a new z_thread_aligned_alloc() to do memory allocation
with required alignment.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>

kernel/include/kernel_internal.h

@@ -46,6 +46,22 @@ extern char *z_setup_new_thread(struct k_thread *new_thread,
 				void *p1, void *p2, void *p3,
 				int prio, uint32_t options, const char *name);
 
+/**
+ * @brief Allocate aligned memory from the current thread's resource pool
+ *
+ * Threads may be assigned a resource pool, which will be used to allocate
+ * memory on behalf of certain kernel and driver APIs. Memory reserved
+ * in this way should be freed with k_free().
+ *
+ * If called from an ISR, the k_malloc() system heap will be used if it exists.
+ *
+ * @param align Required memory alignment
+ * @param size Memory allocation size
+ * @return A pointer to the allocated memory, or NULL if there is insufficient
+ * RAM in the pool or there is no pool to draw memory from
+ */
+void *z_thread_aligned_alloc(size_t align, size_t size);
+
 /**
  * @brief Allocate some memory from the current thread's resource pool
  *
@@ -59,7 +75,10 @@ extern char *z_setup_new_thread(struct k_thread *new_thread,
  * @return A pointer to the allocated memory, or NULL if there is insufficient
  * RAM in the pool or there is no pool to draw memory from
  */
-void *z_thread_malloc(size_t size);
+static inline void *z_thread_malloc(size_t size)
+{
+	return z_thread_aligned_alloc(0, size);
+}
 
 /* set and clear essential thread flag */
 

kernel/mempool.c

@@ -37,11 +37,6 @@ static void *z_heap_aligned_alloc(struct k_heap *heap, size_t align, size_t size
 	return mem + excess;
 }
 
-static void *z_heap_malloc(struct k_heap *heap, size_t size)
-{
-	return z_heap_aligned_alloc(heap, sizeof(void *), size);
-}
-
 void k_free(void *ptr)
 {
 	struct k_heap **heap_ref;
@@ -98,7 +93,7 @@ void k_thread_system_pool_assign(struct k_thread *thread)
 #define _SYSTEM_HEAP	NULL
 #endif
 
-void *z_thread_malloc(size_t size)
+void *z_thread_aligned_alloc(size_t align, size_t size)
 {
 	void *ret;
 	struct k_heap *heap;
@@ -110,7 +105,7 @@ void *z_thread_malloc(size_t size)
 	}
 
 	if (heap) {
-		ret = z_heap_malloc(heap, size);
+		ret = z_heap_aligned_alloc(heap, align, size);
 	} else {
 		ret = NULL;
 	}