Add a driver for the ARM Power State Coordination Interface (PSCI). This

handles versions 0.1 and 0.2 of the standard on 32-bit ARM.

With this driver we can shutdown in QEMU. Further work is needed to
turn secondary cores on on boot and to support later revisions of the
specification.

Submitted by:	Robin Randhawa <Robin.Randhawa at ARM.com>
Sponsored by:	The FreeBSD Foundation

1 files changed, 286 insertions, 0 deletions

diff --git a/sys/dev/psci/psci.c b/sys/dev/psci/psci.c
new file mode 100644
index 000000000000..67f700a89b5a
--- /dev/null
+++ b/sys/dev/psci/psci.c
@@ -0,0 +1,286 @@
+/*-
+ * Copyright (c) 2014 Robin Randhawa
+ * All rights reserved.
+ *
+ * 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.
+ *
+ */
+
+/*
+ * This implements support for ARM's Power State Co-ordination Interface
+ * [PSCI]. The implementation adheres to version 0.2 of the PSCI specification
+ * but also supports v0.1. PSCI standardizes operations such as system reset, CPU
+ * on/off/suspend. PSCI requires a compliant firmware implementation.
+ *
+ * The PSCI specification used for this implementation is available at:
+ *
+ * <http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0022b/index.html>.
+ *
+ * TODO:
+ * - Add support for remaining PSCI calls [this implementation only
+ *   supports get_version, system_reset and cpu_on].
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/eventhandler.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/reboot.h>
+
+#include <machine/bus.h>
+
+#include <dev/fdt/fdt_common.h>
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+
+#include <dev/psci/psci.h>
+
+struct psci_softc {
+	device_t        dev;
+
+	psci_callfn_t	psci_call;
+	uint32_t	psci_fnids[PSCI_FN_MAX];
+};
+
+static int psci_v0_1_init(device_t dev);
+static int psci_v0_2_init(device_t dev);
+
+struct psci_softc *psci_softc = NULL;
+
+static struct ofw_compat_data compat_data[] = {
+	{"arm,psci-0.2",        (uintptr_t)psci_v0_2_init},
+	{"arm,psci",            (uintptr_t)psci_v0_1_init},
+	{NULL,                  0}
+};
+
+static int psci_probe(device_t dev);
+static int psci_attach(device_t dev);
+static void psci_shutdown(void *, int);
+
+static device_method_t psci_methods[] = {
+	DEVMETHOD(device_probe,     psci_probe),
+	DEVMETHOD(device_attach,    psci_attach),
+
+	DEVMETHOD_END
+};
+
+static driver_t psci_driver = {
+	"psci",
+	psci_methods,
+	sizeof(struct psci_softc),
+};
+
+static devclass_t psci_devclass;
+
+EARLY_DRIVER_MODULE(psci, simplebus, psci_driver, psci_devclass, 0, 0,
+    BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
+EARLY_DRIVER_MODULE(psci, ofwbus, psci_driver, psci_devclass, 0, 0,
+    BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
+
+static int
+psci_probe(device_t dev)
+{
+	const struct ofw_compat_data *ocd;
+
+	if (!ofw_bus_status_okay(dev))
+		return (ENXIO);
+
+	ocd = ofw_bus_search_compatible(dev, compat_data);
+	if (ocd->ocd_str == NULL)
+		return (ENXIO);
+
+	device_set_desc(dev, "ARM Power State Co-ordination Interface Driver");
+
+	return (BUS_PROBE_SPECIFIC);
+}
+
+static int
+psci_attach(device_t dev)
+{
+	struct psci_softc *sc = device_get_softc(dev);
+	const struct ofw_compat_data *ocd;
+	psci_initfn_t psci_init;
+	phandle_t node;
+	char method[16];
+
+	if (psci_softc != NULL)
+		return (ENXIO);
+
+	ocd = ofw_bus_search_compatible(dev, compat_data);
+	psci_init = (psci_initfn_t)ocd->ocd_data;
+	KASSERT(psci_init != NULL, ("PSCI init function cannot be NULL"));
+
+	node = ofw_bus_get_node(dev);
+	if ((OF_getprop(node, "method", method, sizeof(method))) > 0) {
+		if (strcmp(method, "hvc") == 0)
+			sc->psci_call = psci_hvc_despatch;
+		else if (strcmp(method, "smc") == 0)
+			sc->psci_call = psci_smc_despatch;
+		else {
+			device_printf(dev,
+			   "psci_attach: PSCI conduit \"%s\" invalid\n",
+			    method);
+			return (ENXIO);
+		}
+	} else {
+		device_printf(dev,
+		    "psci_attach: PSCI conduit not supplied in the DT\n");
+		return (ENXIO);
+	}
+
+	if (psci_init(dev))
+		return (ENXIO);
+
+	psci_softc = sc;
+
+	return (0);
+}
+
+static int
+psci_get_version(struct psci_softc *sc)
+{
+	uint32_t fnid;
+
+	/* PSCI version wasn't supported in v0.1. */
+	fnid = sc->psci_fnids[PSCI_FN_VERSION];
+	if (fnid)
+		return (sc->psci_call(fnid, 0, 0, 0));
+
+	return (PSCI_RETVAL_NOT_SUPPORTED);
+}
+
+int
+psci_cpu_on(unsigned long cpu, unsigned long entry, unsigned long context_id)
+{
+
+	/* PSCI v0.1 and v0.2 both support cpu_on. */
+	return(psci_softc->psci_call(psci_softc->psci_fnids[PSCI_FN_CPU_ON], cpu,
+	    entry, context_id));
+}
+
+static void
+psci_shutdown(void *xsc, int howto)
+{
+	uint32_t fn = 0;
+
+	/* PSCI system_off and system_reset werent't supported in v0.1. */
+	if ((howto & RB_POWEROFF) != 0)
+		fn = psci_softc->psci_fnids[PSCI_FN_SYSTEM_OFF];
+	else if ((howto & RB_HALT) == 0)
+		fn = psci_softc->psci_fnids[PSCI_FN_SYSTEM_RESET];
+
+	if (fn)
+		psci_softc->psci_call(fn, 0, 0, 0);
+
+	/* System reset and off do not return. */
+}
+
+static int
+psci_v0_1_init(device_t dev)
+{
+	struct psci_softc *sc = device_get_softc(dev);
+	int psci_fn;
+	uint32_t psci_fnid;
+	phandle_t node;
+	int len;
+
+
+	/* Zero out the function ID table - Is this needed ? */
+	for (psci_fn = PSCI_FN_VERSION, psci_fnid = PSCI_FNID_VERSION;
+	    psci_fn < PSCI_FN_MAX; psci_fn++, psci_fnid++)
+		sc->psci_fnids[psci_fn] = 0;
+
+	/* PSCI v0.1 doesn't specify function IDs. Get them from DT */
+	node = ofw_bus_get_node(dev);
+
+	if ((len = OF_getproplen(node, "cpu_suspend")) > 0) {
+		OF_getencprop(node, "cpu_suspend", &psci_fnid, len);
+		sc->psci_fnids[PSCI_FN_CPU_SUSPEND] = psci_fnid;
+	}
+
+	if ((len = OF_getproplen(node, "cpu_on")) > 0) {
+		OF_getencprop(node, "cpu_on", &psci_fnid, len);
+		sc->psci_fnids[PSCI_FN_CPU_ON] = psci_fnid;
+	}
+
+	if ((len = OF_getproplen(node, "cpu_off")) > 0) {
+		OF_getencprop(node, "cpu_off", &psci_fnid, len);
+		sc->psci_fnids[PSCI_FN_CPU_OFF] = psci_fnid;
+	}
+
+	if ((len = OF_getproplen(node, "migrate")) > 0) {
+		OF_getencprop(node, "migrate", &psci_fnid, len);
+		sc->psci_fnids[PSCI_FN_MIGRATE] = psci_fnid;
+	}
+
+	if (bootverbose)
+		device_printf(dev, "PSCI version 0.1 available\n");
+
+	return(0);
+}
+
+static int
+psci_v0_2_init(device_t dev)
+{
+	struct psci_softc *sc = device_get_softc(dev);
+	int version;
+
+	/* PSCI v0.2 specifies explicit function IDs. */
+	sc->psci_fnids[PSCI_FN_VERSION]		    = PSCI_FNID_VERSION;
+	sc->psci_fnids[PSCI_FN_CPU_SUSPEND]	    = PSCI_FNID_CPU_SUSPEND;
+	sc->psci_fnids[PSCI_FN_CPU_OFF]		    = PSCI_FNID_CPU_OFF;
+	sc->psci_fnids[PSCI_FN_CPU_ON]		    = PSCI_FNID_CPU_ON;
+	sc->psci_fnids[PSCI_FN_AFFINITY_INFO]	    = PSCI_FNID_AFFINITY_INFO;
+	sc->psci_fnids[PSCI_FN_MIGRATE]		    = PSCI_FNID_MIGRATE;
+	sc->psci_fnids[PSCI_FN_MIGRATE_INFO_TYPE]   = PSCI_FNID_MIGRATE_INFO_TYPE;
+	sc->psci_fnids[PSCI_FN_MIGRATE_INFO_UP_CPU] = PSCI_FNID_MIGRATE_INFO_UP_CPU;
+	sc->psci_fnids[PSCI_FN_SYSTEM_OFF]	    = PSCI_FNID_SYSTEM_OFF;
+	sc->psci_fnids[PSCI_FN_SYSTEM_RESET]	    = PSCI_FNID_SYSTEM_RESET;
+
+	version = psci_get_version(sc);
+
+	if (version == PSCI_RETVAL_NOT_SUPPORTED)
+		return (1);
+
+	if ((PSCI_VER_MAJOR(version) != 0) && (PSCI_VER_MINOR(version) != 2)) {
+		device_printf(dev, "PSCI version number mismatched with DT\n");
+		return (1);
+	}
+
+	if (bootverbose)
+		device_printf(dev, "PSCI version 0.2 available\n");
+
+	/*
+	 * We only register this for v0.2 since v0.1 doesn't support
+	 * system_reset.
+	 */
+	EVENTHANDLER_REGISTER(shutdown_final, psci_shutdown, sc,
+	    SHUTDOWN_PRI_LAST);
+
+	return (0);
+}