alloc: Add possibility to read memory usage in runtime

Such a function may be used to monitor memory leaks and system
utilization.

Signed-off-by: Karol Trzcinski <karolx.trzcinski@linux.intel.com>

src/include/sof/lib/mm_heap.h

@@ -86,6 +86,14 @@ void free_heap(enum mem_zone zone);
 void heap_trace_all(int force);
 void heap_trace(struct mm_heap *heap, int size);
 
+/** Fetch runtime information about heap, like used and free memory space
+ * @param zone to check, see enum mem_zone.
+ * @param index heap index, eg. cpu core index for any *SYS* zone
+ * @param out output variable
+ * @return error code or zero
+ */
+int heap_info(enum mem_zone zone, int index, struct mm_info *out);
+
 /* retrieve memory map pointer */
 static inline struct mm *memmap_get(void)
 {

src/lib/alloc.c

@@ -1069,3 +1069,46 @@ void init_heap(struct sof *sof)
 
 	platform_shared_commit(memmap, sizeof(*memmap));
 }
+
+int heap_info(enum mem_zone zone, int index, struct mm_info *out)
+{
+	struct mm *memmap = memmap_get();
+	struct mm_heap *heap;
+
+	if (!out)
+		goto error;
+
+	switch (zone) {
+	case SOF_MEM_ZONE_SYS:
+		if (index >= PLATFORM_HEAP_SYSTEM)
+			goto error;
+		heap = memmap->system + index;
+		break;
+	case SOF_MEM_ZONE_SYS_RUNTIME:
+		if (index >= PLATFORM_HEAP_SYSTEM_RUNTIME)
+			goto error;
+		heap = memmap->system_runtime + index;
+		break;
+	case SOF_MEM_ZONE_RUNTIME:
+		if (index >= PLATFORM_HEAP_RUNTIME)
+			goto error;
+		heap = memmap->runtime + index;
+		break;
+	case SOF_MEM_ZONE_BUFFER:
+		if (index >= PLATFORM_HEAP_BUFFER)
+			goto error;
+		heap = memmap->buffer + index;
+		break;
+	default:
+		goto error;
+	}
+
+	spin_lock(&memmap->lock);
+	*out = heap->info;
+	spin_unlock(&memmap->lock);
+	return 0;
+error:
+	tr_err(&mem_tr, "heap_info(): failed for zone 0x%x index %d out ptr 0x%x", zone, index,
+	       (uint32_t)out);
+	return -EINVAL;
+}