virtio-mmio: console device

Added virtio console device support.

Signed-off-by: Dan Milea <[email protected]>

lib/include/openamp/virtio_serial_drv.h

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2022 Wind River Systems, Inc.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef VIRTIO_SERIAL_H
+#define VIRTIO_SERIAL_H
+
+#include <openamp/virtqueue.h>
+#include <openamp/virtio.h>
+#include <metal/device.h>
+
+#define VQIN_SIZE    4
+#define VQOUT_SIZE   4
+
+struct virtio_serial_chan {
+	atomic_long tx_inuse;
+	atomic_long rx_inuse;
+	bool rxpoll_active;
+	bool txpoll_active;
+	uint8_t rxpoll;
+	uint8_t txpoll;
+};
+
+struct virtio_serial_data {
+	struct virtio_serial_chan *chan0;
+};
+
+typedef void (*con_funcptr)(void *);
+
+/**
+ * @brief Initialize a VIRTIO console device.
+ *
+ * @param[in] vdev Pointer to virtio_device structure.
+ * @param[in] vqs Array of pointers to the virtqueues used by the device.
+ * @param[in] vq_names Array of pointers to the virtqueues names.
+ * @param[in] cbs Array of function pointers to call on virtqueue kick.
+ * @param[in] cb_args Array of pointers to parameters for kick callbacks.
+ * @param[in] vq_count Number of virtqueues the device uses.
+ *
+ * @return int 0 for success.
+ */
+
+int virtio_serial_init(struct virtio_device *vdev, struct virtqueue **vqs, char **vq_names,
+			    con_funcptr *cbs, void **cb_args, int vq_count);
+
+/**
+ * @brief Poll console input queue for data.
+ *
+ * @param[in] vdev Pointer to virtio_device structure.
+ * @param[out] p_char Output char.
+ *
+ * @return int 0 for success.
+ */
+
+int virtio_serial_poll_in(const struct virtio_device *vdev, unsigned char *p_char);
+
+/**
+ * @brief Send data routine.
+ *
+ * @param[in] vdev Pointer to virtio_device structure.
+ * @param[in] out_char Character to send.
+ *
+ * @return int 0 for success.
+ */
+
+void virtio_serial_poll_out(const struct virtio_device *vdev, unsigned char out_char);
+
+#endif /* VIRTIO_SERIAL_H */
+

lib/virtio_mmio/CMakeLists.txt

@@ -2,4 +2,5 @@ if (WITH_VIRTIO_MMIO_DRV)
 collect (PROJECT_LIB_SOURCES virtio_mmio_drv.c)
 collect (PROJECT_LIB_SOURCES virtio_rng_drv.c)
 collect (PROJECT_LIB_SOURCES virtio_net_drv.c)
+collect (PROJECT_LIB_SOURCES virtio_serial_drv.c)
 endif (WITH_VIRTIO_MMIO_DRV)

lib/virtio_mmio/virtio_serial_drv.c

@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2022 Wind River Systems, Inc.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <openamp/open_amp.h>
+#include <openamp/virtqueue.h>
+#include <openamp/virtio.h>
+#include <openamp/virtio_drv.h>
+#include <metal/device.h>
+#include <openamp/virtio_serial_drv.h>
+
+int virtio_serial_init(struct virtio_device *vdev, struct virtqueue **vqs, char **vq_names,
+			    void (**cbs)(void *), void **cb_args, int vq_count)
+{
+	uint32_t devid, features;
+	struct virtqueue *vq = NULL;
+	int i;
+
+	if (!vdev) {
+		return -EINVAL;
+	}
+
+	vdev->vrings_info = metal_allocate_memory(sizeof(struct virtio_vring_info) * vq_count);
+	if (!vdev->vrings_info) {
+		return -ENOMEM;
+	}
+
+	devid = virtio_get_devid(vdev);
+	if (devid != VIRTIO_ID_CONSOLE) {
+		metal_log(METAL_LOG_ERROR, "Expected devid %04x, got %04x\n",
+			  VIRTIO_ID_CONSOLE, devid);
+		metal_free_memory(vdev->vrings_info);
+		return -ENODEV;
+	}
+	virtio_device_set_status(vdev, VIRTIO_CONFIG_STATUS_DRIVER);
+	virtio_device_set_features(vdev, 0/*VIRTIO_F_NOTIFY_ON_EMPTY*/);
+	features = virtio_device_get_features(vdev);
+	metal_log(METAL_LOG_DEBUG, "features: %08x\n", features);
+
+	for (i = 0; i < vq_count; i++) {
+		/* TODO: update API for compatibility with other transports like
+		 * remoteproc virtio
+		 */
+		vq = virtio_drv_setup_virtqueue(
+				vdev,
+				i,
+				vqs[i],
+				cbs[i],
+				cb_args[i],
+				vq_names[i]
+				);
+
+		if (!vq) {
+			return -1;
+		}
+	}
+
+	virtio_device_set_status(vdev, VIRTIO_CONFIG_STATUS_DRIVER_OK);
+
+	for (i = 0; i < vq_count; i++) {
+		virtqueue_kick(vq);
+	}
+
+	return 0;
+}
+
+int virtio_serial_poll_in(const struct virtio_device *vdev, unsigned char *p_char)
+{
+	struct virtio_serial_chan *chan = NULL;
+	struct virtqueue *vq = NULL;
+	int ret = -1;
+	long exp = 0;
+	void *cookie = NULL;
+	struct virtqueue_buf vb[1] = {0};
+
+	if (!vdev || !vdev->priv) {
+		return -EINVAL;
+	}
+
+	chan = ((struct virtio_serial_data *)(vdev->priv))->chan0;
+
+	if (!chan) {
+		return -EINVAL;
+	}
+
+	vq = vdev->vrings_info[0].vq;
+
+	if (!atomic_compare_exchange_strong(&chan->rx_inuse, &exp, 1)) {
+		return ret;
+	}
+
+	if (chan->rxpoll_active) {
+		cookie = virtqueue_get_buffer(vq, NULL, NULL);
+
+		if (!cookie) {
+			/* Nothing received yet */
+			atomic_store(&chan->rx_inuse, 0);
+			return -1;
+		}
+		*p_char = chan->rxpoll;
+		ret = 0;
+	}
+
+	vb[0].buf = &chan->rxpoll;
+	vb[0].len = 1;
+
+	virtqueue_add_buffer(vq, vb, 0, 1, (void *)(uintptr_t)1);
+	virtqueue_kick(vq);
+	chan->rxpoll_active = true;
+	atomic_store(&chan->rx_inuse, 0);
+
+	return ret;
+}
+
+void virtio_serial_poll_out(const struct virtio_device *vdev, unsigned char out_char)
+{
+	struct virtio_serial_chan *chan = NULL;
+	struct virtqueue *vq = NULL;
+	struct virtqueue_buf vb[1] = {0};
+	uint8_t *data = NULL;
+	long exp = 0;
+
+	if (!vdev) {
+		return;
+	}
+
+	chan = ((struct virtio_serial_data *)(vdev->priv))->chan0;
+
+	if (!chan) {
+		return;
+	}
+
+	data = &chan->txpoll;
+	vq = vdev->vrings_info[1].vq;
+
+	if (!atomic_compare_exchange_strong(&chan->tx_inuse, &exp, 1)) {
+		return;
+	}
+
+	if (virtqueue_full(vq)) {
+		virtqueue_get_buffer(vq, NULL, NULL);
+	}
+
+	if (virtqueue_full(vq)) {
+		atomic_store(&chan->tx_inuse, 0);
+		return;
+	}
+
+	data[0] = out_char;
+	vb[0].buf = data;
+	vb[0].len = 1;
+
+	virtqueue_add_buffer(vq, vb, 1, 0, (void *)(uintptr_t)1);
+	virtqueue_kick(vq);
+	atomic_store(&chan->tx_inuse, 0);
+}