The branch main has been updated by andrew:
URL:
https://cgit.FreeBSD.org/src/commit/?id=a87dd74125d290791d7259ceeab9507bada9987e
commit a87dd74125d290791d7259ceeab9507bada9987e
Author: Cristian Marussi <cristian.maru...@arm.com>
AuthorDate: 2023-10-23 18:07:06 +0000
Commit: Andrew Turner <and...@freebsd.org>
CommitDate: 2024-04-11 09:58:57 +0000
scmi: Add an SCMI VirtIO transport driver
Add an SCMI transport driver based on the virtio-scmi backend.
Reviewed by: andrew, bryanv
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D43048
---
sys/conf/files.arm64 | 1 +
sys/dev/firmware/arm/scmi.c | 15 +-
sys/dev/firmware/arm/scmi.h | 2 +
sys/dev/firmware/arm/scmi_virtio.c | 298 +++++++++++++++++++++++++++++++++++++
4 files changed, 313 insertions(+), 3 deletions(-)
diff --git a/sys/conf/files.arm64 b/sys/conf/files.arm64
index a22ffa2b7f0c..632fbab5070d 100644
--- a/sys/conf/files.arm64
+++ b/sys/conf/files.arm64
@@ -275,6 +275,7 @@ dev/firmware/arm/scmi_clk.c optional fdt
scmi
dev/firmware/arm/scmi_if.m optional fdt scmi
dev/firmware/arm/scmi_mailbox.c optional fdt scmi
dev/firmware/arm/scmi_smc.c optional fdt scmi
+dev/firmware/arm/scmi_virtio.c optional fdt scmi
dev/firmware/arm/scmi_shmem.c optional fdt scmi
dev/gpio/pl061.c optional pl061 gpio
diff --git a/sys/dev/firmware/arm/scmi.c b/sys/dev/firmware/arm/scmi.c
index 945c2b2e9f6e..ef4bcbf13996 100644
--- a/sys/dev/firmware/arm/scmi.c
+++ b/sys/dev/firmware/arm/scmi.c
@@ -484,10 +484,19 @@ scmi_process_response(struct scmi_softc *sc, uint32_t hdr)
mtx_lock_spin(&req->mtx);
req->done = true;
- if (!req->timed_out)
- wakeup(req);
- else
+ if (!req->timed_out) {
+ /*
+ * Consider the case in which a polled message is picked
+ * by chance on the IRQ path on another CPU: setting poll_done
+ * will terminate the other poll loop.
+ */
+ if (!req->msg.polling)
+ wakeup(req);
+ else
+ atomic_store_rel_int(&req->msg.poll_done, 1);
+ } else {
timed_out = true;
+ }
mtx_unlock_spin(&req->mtx);
if (timed_out)
diff --git a/sys/dev/firmware/arm/scmi.h b/sys/dev/firmware/arm/scmi.h
index 572422594292..345ae6eeb03a 100644
--- a/sys/dev/firmware/arm/scmi.h
+++ b/sys/dev/firmware/arm/scmi.h
@@ -62,12 +62,14 @@ struct scmi_softc {
struct scmi_msg {
bool polling;
+ int poll_done;
uint32_t tx_len;
uint32_t rx_len;
#define SCMI_MSG_HDR_SIZE (sizeof(uint32_t))
uint32_t hdr;
uint8_t payld[];
};
+#define hdr_to_msg(h) __containerof((h), struct scmi_msg, hdr)
void *scmi_buf_get(device_t dev, uint8_t protocol_id, uint8_t message_id,
int tx_payd_sz, int rx_payld_sz);
diff --git a/sys/dev/firmware/arm/scmi_virtio.c
b/sys/dev/firmware/arm/scmi_virtio.c
new file mode 100644
index 000000000000..12cbb9ecefd5
--- /dev/null
+++ b/sys/dev/firmware/arm/scmi_virtio.c
@@ -0,0 +1,298 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2023 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.
+ */
+
+#include <sys/cdefs.h>
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/cpu.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+
+#include <dev/fdt/simplebus.h>
+#include <dev/fdt/fdt_common.h>
+#include <dev/ofw/ofw_bus_subr.h>
+
+#include <dev/virtio/scmi/virtio_scmi.h>
+
+#include "scmi.h"
+#include "scmi_protocols.h"
+
+#define SCMI_VIRTIO_POLLING_INTERVAL_MS 2
+
+struct scmi_virtio_softc {
+ struct scmi_softc base;
+ device_t virtio_dev;
+ int cmdq_sz;
+ int evtq_sz;
+ void *p2a_pool;
+};
+
+static void scmi_virtio_callback(void *, unsigned int, void *);
+static void *scmi_virtio_p2a_pool_init(device_t, unsigned int);
+static int scmi_virtio_transport_init(device_t);
+static void scmi_virtio_transport_cleanup(device_t);
+static int scmi_virtio_xfer_msg(device_t, struct scmi_msg *);
+static int scmi_virtio_poll_msg(device_t, struct scmi_msg *, unsigned int);
+static void scmi_virtio_clear_channel(device_t, void *);
+static int scmi_virtio_probe(device_t);
+static int scmi_virtio_attach(device_t);
+
+static void
+scmi_virtio_callback(void *msg, unsigned int len, void *priv)
+{
+ struct scmi_virtio_softc *sc;
+ uint32_t hdr;
+
+ sc = priv;
+
+ if (msg == NULL || len < sizeof(hdr)) {
+ device_printf(sc->virtio_dev, "Ignoring malformed message.\n");
+ return;
+ }
+
+ hdr = le32toh(*((uint32_t *)msg));
+ scmi_rx_irq_callback(sc->base.dev, msg, hdr);
+}
+
+static void *
+scmi_virtio_p2a_pool_init(device_t dev, unsigned int max_msg)
+{
+ struct scmi_virtio_softc *sc;
+ void *pool;
+ uint8_t *buf;
+ int i;
+
+ sc = device_get_softc(dev);
+
+ pool = mallocarray(max_msg, SCMI_MAX_MSG_SIZE, M_DEVBUF,
+ M_ZERO | M_WAITOK);
+
+ for (i = 0, buf = pool; i < max_msg; i++, buf += SCMI_MAX_MSG_SIZE) {
+ /* Feed platform with pre-allocated P2A buffers */
+ virtio_scmi_message_enqueue(sc->virtio_dev,
+ VIRTIO_SCMI_CHAN_P2A, buf, 0, SCMI_MAX_MSG_SIZE);
+ }
+
+ device_printf(dev,
+ "Fed %d initial P2A buffers to platform.\n", max_msg);
+
+ return (pool);
+}
+
+static void
+scmi_virtio_clear_channel(device_t dev, void *msg)
+{
+ struct scmi_virtio_softc *sc;
+
+ sc = device_get_softc(dev);
+ virtio_scmi_message_enqueue(sc->virtio_dev, VIRTIO_SCMI_CHAN_P2A,
+ msg, 0, SCMI_MAX_MSG_SIZE);
+}
+
+static int
+scmi_virtio_transport_init(device_t dev)
+{
+ struct scmi_virtio_softc *sc;
+ int ret;
+
+ sc = device_get_softc(dev);
+
+ sc->cmdq_sz = virtio_scmi_channel_size_get(sc->virtio_dev,
+ VIRTIO_SCMI_CHAN_A2P);
+ sc->evtq_sz = virtio_scmi_channel_size_get(sc->virtio_dev,
+ VIRTIO_SCMI_CHAN_P2A);
+
+ if (!sc->cmdq_sz) {
+ device_printf(dev,
+ "VirtIO cmdq virtqueue not found. Aborting.\n");
+ return (ENXIO);
+ }
+
+ /*
+ * P2A buffers are owned by the platform initially; allocate a feed an
+ * appropriate number of buffers.
+ */
+ if (sc->evtq_sz != 0) {
+ sc->p2a_pool = scmi_virtio_p2a_pool_init(dev, sc->evtq_sz);
+ if (sc->p2a_pool == NULL)
+ return (ENOMEM);
+ }
+
+ /* Note that setting a callback also enables that VQ interrupts */
+ ret = virtio_scmi_channel_callback_set(sc->virtio_dev,
+ VIRTIO_SCMI_CHAN_A2P, scmi_virtio_callback, sc);
+ if (ret) {
+ device_printf(dev, "Failed to set VirtIO cmdq callback.\n");
+ return (ENXIO);
+ }
+
+ device_printf(dev,
+ "VirtIO cmdq virtqueue configured - cmdq_sz:%d\n", sc->cmdq_sz);
+
+ /* P2A channel is optional */
+ if (sc->evtq_sz) {
+ ret = virtio_scmi_channel_callback_set(sc->virtio_dev,
+ VIRTIO_SCMI_CHAN_P2A, scmi_virtio_callback, sc);
+ if (ret == 0) {
+ device_printf(dev,
+ "VirtIO evtq virtqueue configured - evtq_sz:%d\n",
+ sc->evtq_sz);
+ } else {
+ device_printf(dev,
+ "Failed to set VirtIO evtq callback.Skip.\n");
+ sc->evtq_sz = 0;
+ }
+ }
+
+ sc->base.trs_desc.reply_timo_ms = 100;
+
+ return (0);
+}
+
+static void
+scmi_virtio_transport_cleanup(device_t dev)
+{
+ struct scmi_virtio_softc *sc;
+
+ sc = device_get_softc(dev);
+
+ if (sc->evtq_sz != 0) {
+ virtio_scmi_channel_callback_set(sc->virtio_dev,
+ VIRTIO_SCMI_CHAN_P2A, NULL, NULL);
+ free(sc->p2a_pool, M_DEVBUF);
+ }
+
+ virtio_scmi_channel_callback_set(sc->virtio_dev,
+ VIRTIO_SCMI_CHAN_A2P, NULL, NULL);
+}
+
+static int
+scmi_virtio_xfer_msg(device_t dev, struct scmi_msg *msg)
+{
+ struct scmi_virtio_softc *sc;
+
+ sc = device_get_softc(dev);
+
+ return (virtio_scmi_message_enqueue(sc->virtio_dev,
+ VIRTIO_SCMI_CHAN_A2P, &msg->hdr, msg->tx_len, msg->rx_len));
+}
+
+static int
+scmi_virtio_poll_msg(device_t dev, struct scmi_msg *msg, unsigned int tmo_ms)
+{
+ struct scmi_virtio_softc *sc;
+ device_t vdev;
+ int tmo_loops;
+
+ sc = device_get_softc(dev);
+ vdev = sc->virtio_dev;
+
+ tmo_loops = tmo_ms / SCMI_VIRTIO_POLLING_INTERVAL_MS;
+ while (tmo_loops-- && atomic_load_acq_int(&msg->poll_done) == 0) {
+ struct scmi_msg *rx_msg;
+ void *rx_buf;
+ uint32_t rx_len;
+
+ rx_buf = virtio_scmi_message_poll(vdev, &rx_len);
+ if (rx_buf == NULL) {
+ DELAY(SCMI_VIRTIO_POLLING_INTERVAL_MS * 1000);
+ continue;
+ }
+
+ rx_msg = hdr_to_msg(rx_buf);
+ rx_msg->rx_len = rx_len;
+ /* Complete the polling on any poll path */
+ if (rx_msg->polling)
+ atomic_store_rel_int(&rx_msg->poll_done, 1);
+
+ if (__predict_true(rx_msg == msg))
+ break;
+
+ /*
+ * Polling returned an unexpected message: either a message
+ * polled by some other thread of execution or a message not
+ * supposed to be polled.
+ */
+ device_printf(dev, "POLLED OoO HDR:|%08X| - polling:%d\n",
+ rx_msg->hdr, rx_msg->polling);
+
+ if (!rx_msg->polling)
+ scmi_rx_irq_callback(sc->base.dev, rx_msg, rx_msg->hdr);
+ }
+
+ return (tmo_loops > 0 ? 0 : ETIMEDOUT);
+}
+
+static int
+scmi_virtio_probe(device_t dev)
+{
+ if (!ofw_bus_is_compatible(dev, "arm,scmi-virtio"))
+ return (ENXIO);
+
+ if (!ofw_bus_status_okay(dev))
+ return (ENXIO);
+
+ device_set_desc(dev, "ARM SCMI VirtIO Transport driver");
+
+ return (BUS_PROBE_DEFAULT);
+}
+
+static int
+scmi_virtio_attach(device_t dev)
+{
+ struct scmi_virtio_softc *sc;
+
+ sc = device_get_softc(dev);
+ sc->virtio_dev = virtio_scmi_transport_get();
+ if (sc->virtio_dev == NULL)
+ return (1);
+
+ /* When attach fails there is nothing to cleanup*/
+ return (scmi_attach(dev));
+}
+
+static device_method_t scmi_virtio_methods[] = {
+ DEVMETHOD(device_probe, scmi_virtio_probe),
+ DEVMETHOD(device_attach, scmi_virtio_attach),
+
+ /* SCMI interface */
+ DEVMETHOD(scmi_transport_init, scmi_virtio_transport_init),
+ DEVMETHOD(scmi_transport_cleanup, scmi_virtio_transport_cleanup),
+ DEVMETHOD(scmi_xfer_msg, scmi_virtio_xfer_msg),
+ DEVMETHOD(scmi_poll_msg, scmi_virtio_poll_msg),
+ DEVMETHOD(scmi_clear_channel, scmi_virtio_clear_channel),
+
+ DEVMETHOD_END
+};
+
+DEFINE_CLASS_1(scmi_virtio, scmi_virtio_driver, scmi_virtio_methods,
+ sizeof(struct scmi_virtio_softc), scmi_driver);
+
+/* Needs to be after the mmio_sram driver */
+DRIVER_MODULE(scmi_virtio, simplebus, scmi_virtio_driver, 0, 0);
+MODULE_VERSION(scmi_virtio, 1);
