1 files changed, 139 insertions, 0 deletions
diff --git a/sys/dev/psci/smccc_errata.c b/sys/dev/psci/smccc_errata.c
new file mode 100644
index 000000000000..ebfc0f8b67ee
--- /dev/null
+++ b/sys/dev/psci/smccc_errata.c
@@ -0,0 +1,139 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2024 Arm Ltd
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * A driver for the Arm Errata Management Firmware Interface (Errata ABI).
+ * This queries into the SMCCC firmware for the status of errata using the
+ * interface documented in den0100 [1].
+ *
+ * [1] https://developer.arm.com/documentation/den0100/latest
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/eventhandler.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/module.h>
+#include <sys/random.h>
+
+#include <dev/psci/psci.h>
+#include <dev/psci/smccc.h>
+
+#include <machine/cpu_feat.h>
+
+#define	ERRATA_HIGHER_EL_MITIGATION	3
+#define	ERRATA_NOT_AFFECTED		2
+#define	ERRATA_AFFECTED			1
+
+#define	EM_VERSION		SMCCC_FUNC_ID(SMCCC_FAST_CALL,		\
+    SMCCC_32BIT_CALL, SMCCC_STD_SECURE_SERVICE_CALLS, 0xf0u)
+#define	 EM_VERSION_MIN	0x10000L
+#define	EM_FEATURES		SMCCC_FUNC_ID(SMCCC_FAST_CALL,		\
+    SMCCC_32BIT_CALL, SMCCC_STD_SECURE_SERVICE_CALLS, 0xf1u)
+#define	EM_CPU_ERRATUM_FEATURES	SMCCC_FUNC_ID(SMCCC_FAST_CALL,		\
+    SMCCC_32BIT_CALL, SMCCC_STD_SECURE_SERVICE_CALLS, 0xf2u)
+
+static device_identify_t errata_identify;
+static device_probe_t errata_probe;
+static device_attach_t errata_attach;
+static cpu_feat_errata errata_cpu_feat_errata_check(const struct cpu_feat *,
+    u_int);
+
+static void
+errata_identify(driver_t *driver, device_t parent)
+{
+	int32_t version;
+
+	/* Check if Errata ABI is supported */
+	if (smccc_arch_features(EM_VERSION) != SMCCC_RET_SUCCESS)
+		return;
+
+	/* Check we have Errata 1.0 or later */
+	version = psci_call(EM_VERSION, 0, 0, 0);
+	if (version < EM_VERSION_MIN)
+		return;
+
+	if (BUS_ADD_CHILD(parent, 0, "errata", DEVICE_UNIT_ANY) == NULL)
+		device_printf(parent, "add errata child failed\n");
+}
+
+static int
+errata_probe(device_t dev)
+{
+	device_set_desc(dev, "Arm SMCCC Errata Management");
+	return (BUS_PROBE_NOWILDCARD);
+}
+
+static int
+errata_attach(device_t dev)
+{
+	/* Check for EM_CPU_ERRATUM_FEATURES. It's mandatory, so should exist */
+	if (arm_smccc_invoke(EM_FEATURES, EM_CPU_ERRATUM_FEATURES, NULL) < 0) {
+		device_printf(dev,
+		    "EM_CPU_ERRATUM_FEATURES is not implemented\n");
+		return (ENXIO);
+	}
+
+	cpu_feat_register_errata_check(errata_cpu_feat_errata_check);
+
+	return (0);
+}
+
+static cpu_feat_errata
+errata_cpu_feat_errata_check(const struct cpu_feat *feat __unused, u_int errata_id)
+{
+	struct arm_smccc_res res;
+
+	switch(arm_smccc_invoke(EM_CPU_ERRATUM_FEATURES, errata_id, 0, &res)) {
+	default:
+		return (ERRATA_UNKNOWN);
+	case ERRATA_NOT_AFFECTED:
+		return (ERRATA_NONE);
+	case ERRATA_AFFECTED:
+		return (ERRATA_AFFECTED);
+	case ERRATA_HIGHER_EL_MITIGATION:
+		return (ERRATA_FW_MITIGAION);
+	}
+}
+
+static device_method_t errata_methods[] = {
+	DEVMETHOD(device_identify,	errata_identify),
+	DEVMETHOD(device_probe,		errata_probe),
+	DEVMETHOD(device_attach,	errata_attach),
+
+	DEVMETHOD_END
+};
+
+static driver_t errata_driver = {
+	"errata",
+	errata_methods,
+	0
+};
+
+DRIVER_MODULE(errata, smccc, errata_driver, 0, 0);