1 files changed, 72 insertions, 0 deletions
diff --git a/lib/extensions/pmuv3/aarch32/pmuv3.c b/lib/extensions/pmuv3/aarch32/pmuv3.c
new file mode 100644
index 0000000..effb7e0
--- /dev/null
+++ b/lib/extensions/pmuv3/aarch32/pmuv3.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2023, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <arch_features.h>
+#include <arch_helpers.h>
+#include <lib/extensions/pmuv3.h>
+
+static u_register_t mtpmu_disable_el3(u_register_t sdcr)
+{
+	if (!is_feat_mtpmu_supported()) {
+		return sdcr;
+	}
+
+	/*
+	 * SDCR.MTPME = 0
+	 * FEAT_MTPMU is disabled. The Effective value of PMEVTYPER<n>.MT is
+	 * zero.
+	 */
+	sdcr &= ~SDCR_MTPME_BIT;
+
+	return sdcr;
+}
+
+/*
+ * Applies to all PMU versions. Name is PMUv3 for compatibility with aarch64 and
+ * to not clash with platforms which reuse the PMU name
+ */
+void pmuv3_init_el3(void)
+{
+	u_register_t sdcr = read_sdcr();
+
+	/* ---------------------------------------------------------------------
+	 * Initialise SDCR, setting all the fields rather than relying on hw.
+	 *
+	 * SDCR.SCCD: Set to one so that cycle counting by PMCCNTR is prohibited
+	 *  in Secure state. This bit is RES0 in versions of the architecture
+	 *  earlier than ARMv8.5
+	 *
+	 * SDCR.SPME: Set to zero so that event counting is prohibited in Secure
+	 *  state (and explicitly EL3 with later revisions). If ARMv8.2 Debug is
+	 *  not implemented this bit does not have any effect on the counters
+	 *  unless there is support for the implementation defined
+	 *  authentication interface ExternalSecureNoninvasiveDebugEnabled().
+	 * ---------------------------------------------------------------------
+	 */
+	sdcr = (sdcr | SDCR_SCCD_BIT) & ~SDCR_SPME_BIT;
+	sdcr = mtpmu_disable_el3(sdcr);
+	write_sdcr(sdcr);
+
+	/* ---------------------------------------------------------------------
+	 * Initialise PMCR, setting all fields rather than relying
+	 * on hw. Some fields are architecturally UNKNOWN on reset.
+	 *
+	 * PMCR.DP: Set to one to prohibit cycle counting whilst in Secure mode.
+	 *
+	 * PMCR.X: Set to zero to disable export of events.
+	 *
+	 * PMCR.C: Set to one to reset PMCCNTR.
+	 *
+	 * PMCR.P: Set to one to reset each event counter PMEVCNTR<n> to zero.
+	 *
+	 * PMCR.E: Set to zero to disable cycle and event counters.
+	 * ---------------------------------------------------------------------
+	 */
+
+	write_pmcr(read_pmcr() | PMCR_DP_BIT | PMCR_C_BIT | PMCR_P_BIT |
+		 ~(PMCR_X_BIT | PMCR_E_BIT));
+}