diff --git a/include/lib/extensions/amu.h b/include/lib/extensions/amu.h
index 692d1ad..6452f7e 100644
--- a/include/lib/extensions/amu.h
+++ b/include/lib/extensions/amu.h
@@ -8,12 +8,40 @@
 #define AMU_H
 
 #include <stdbool.h>
+#include <stdint.h>
+
 #include <context.h>
 
+#include <platform_def.h>
+
 #if __aarch64__
 void amu_enable(bool el2_unused, cpu_context_t *ctx);
 #else
 void amu_enable(bool el2_unused);
 #endif
 
+#if ENABLE_AMU_AUXILIARY_COUNTERS
+/*
+ * AMU data for a single core.
+ */
+struct amu_core {
+	uint16_t enable; /* Mask of auxiliary counters to enable */
+};
+
+/*
+ * Topological platform data specific to the AMU.
+ */
+struct amu_topology {
+	struct amu_core cores[PLATFORM_CORE_COUNT]; /* Per-core data */
+};
+
+#if !ENABLE_AMU_FCONF
+/*
+ * Retrieve the platform's AMU topology. A `NULL` return value is treated as a
+ * non-fatal error, in which case no auxiliary counters will be enabled.
+ */
+const struct amu_topology *plat_amu_topology(void);
+#endif /* ENABLE_AMU_FCONF */
+#endif /* ENABLE_AMU_AUXILIARY_COUNTERS */
+
 #endif /* AMU_H */