1 files changed, 38 insertions, 0 deletions
diff --git a/lib/extensions/mpam/mpam.c b/lib/extensions/mpam/mpam.c
new file mode 100644
index 0000000..884d480
--- /dev/null
+++ b/lib/extensions/mpam/mpam.c
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2018-2022, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdbool.h>
+
+#include <arch.h>
+#include <arch_features.h>
+#include <arch_helpers.h>
+#include <lib/extensions/mpam.h>
+
+void mpam_enable(bool el2_unused)
+{
+	/* Check if MPAM is implemented */
+	if (get_mpam_version() == 0U) {
+		return;
+	}
+
+	/*
+	 * Enable MPAM, and disable trapping to EL3 when lower ELs access their
+	 * own MPAM registers.
+	 */
+	write_mpam3_el3(MPAM3_EL3_MPAMEN_BIT);
+
+	/*
+	 * If EL2 is implemented but unused, disable trapping to EL2 when lower
+	 * ELs access their own MPAM registers.
+	 */
+	if (el2_unused) {
+		write_mpam2_el2(0ULL);
+
+		if ((read_mpamidr_el1() & MPAMIDR_HAS_HCR_BIT) != 0U) {
+			write_mpamhcr_el2(0ULL);
+		}
+	}
+}