1 files changed, 295 insertions, 0 deletions
diff --git a/kernel/ethosu_mailbox.c b/kernel/ethosu_mailbox.c
new file mode 100644
index 0000000..23a356e
--- /dev/null
+++ b/kernel/ethosu_mailbox.c
@@ -0,0 +1,295 @@
+/*
+ * (C) COPYRIGHT 2020 ARM Limited. All rights reserved.
+ *
+ * This program is free software and is provided to you under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation, and any use by you of this program is subject to the terms
+ * of such GNU licence.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ */
+
+/****************************************************************************
+ * Includes
+ ****************************************************************************/
+
+#include "ethosu_mailbox.h"
+
+#include "ethosu_buffer.h"
+#include "ethosu_core_interface.h"
+#include "ethosu_device.h"
+
+#include <linux/resource.h>
+#include <linux/uio.h>
+
+/****************************************************************************
+ * Functions
+ ****************************************************************************/
+
+static void ethosu_core_set_size(struct ethosu_buffer *buf,
+				 struct ethosu_core_buffer *cbuf)
+{
+	cbuf->ptr = (uint32_t)buf->dma_addr + buf->offset;
+	cbuf->size = (uint32_t)buf->size;
+}
+
+static void ethosu_core_set_capacity(struct ethosu_buffer *buf,
+				     struct ethosu_core_buffer *cbuf)
+{
+	cbuf->ptr = (uint32_t)buf->dma_addr + buf->offset + buf->size;
+	cbuf->size = (uint32_t)buf->capacity - buf->offset - buf->size;
+}
+
+static size_t ethosu_queue_available(struct ethosu_core_queue *queue)
+{
+	size_t size = queue->header.write - queue->header.read;
+
+	if (queue->header.read > queue->header.write)
+		size += queue->header.size;
+
+	return size;
+}
+
+static size_t ethosu_queue_capacity(struct ethosu_core_queue *queue)
+{
+	return queue->header.size - ethosu_queue_available(queue);
+}
+
+static int ethosu_queue_write(struct ethosu_mailbox *mbox,
+			      const struct kvec *vec,
+			      size_t length)
+{
+	struct ethosu_core_queue *queue = mbox->in_queue;
+	uint8_t *dst = &queue->data[0];
+	uint32_t wpos = queue->header.write;
+	size_t total_size;
+	size_t i;
+	int ret;
+
+	for (i = 0, total_size = 0; i < length; i++)
+		total_size += vec[i].iov_len;
+
+	if (total_size > ethosu_queue_capacity(queue))
+		return -EINVAL;
+
+	for (i = 0; i < length; i++) {
+		const uint8_t *src = vec[i].iov_base;
+		const uint8_t *end = src + vec[i].iov_len;
+
+		while (src < end) {
+			dst[wpos] = *src++;
+			wpos = (wpos + 1) % queue->header.size;
+		}
+	}
+
+	queue->header.write = wpos;
+
+	ret = mbox_send_message(mbox->tx, queue);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ethosu_queue_write_msg(struct ethosu_mailbox *mbox,
+				  uint32_t type,
+				  void *data,
+				  size_t length)
+{
+	struct ethosu_core_msg msg = { .type = type, .length = length };
+	const struct kvec vec[2] = {
+		{ &msg, sizeof(msg) },
+		{ data, length      }
+	};
+
+	return ethosu_queue_write(mbox, vec, 2);
+}
+
+static int ethosu_queue_read(struct ethosu_mailbox *mbox,
+			     void *data,
+			     size_t length)
+{
+	struct ethosu_core_queue *queue = mbox->out_queue;
+	uint8_t *src = &queue->data[0];
+	uint8_t *dst = (uint8_t *)data;
+	const uint8_t *end = dst + length;
+	uint32_t rpos = queue->header.read;
+
+	if (length > ethosu_queue_available(queue))
+		return -ENOMSG;
+
+	while (dst < end) {
+		*dst++ = src[rpos];
+		rpos = (rpos + 1) % queue->header.size;
+	}
+
+	queue->header.read = rpos;
+
+	return 0;
+}
+
+int ethosu_mailbox_read(struct ethosu_mailbox *mbox,
+			struct ethosu_core_msg *header,
+			void *data,
+			size_t length)
+{
+	int ret;
+
+	/* Read message header */
+	ret = ethosu_queue_read(mbox, header, sizeof(*header));
+	if (ret)
+		return ret;
+
+	dev_info(mbox->dev, "mbox: Read msg header. type=%u, length=%u",
+		 header->type, header->length);
+
+	/* Check that payload is not larger than allocated buffer */
+	if (header->length > length)
+		return -ENOMEM;
+
+	/* Ready payload data */
+	ret = ethosu_queue_read(mbox, data, header->length);
+	if (ret)
+		return -EBADMSG;
+
+	return 0;
+}
+
+int ethosu_mailbox_ping(struct ethosu_mailbox *mbox)
+{
+	return ethosu_queue_write_msg(mbox, ETHOSU_CORE_MSG_PING, NULL, 0);
+}
+
+int ethosu_mailbox_inference(struct ethosu_mailbox *mbox,
+			     void *user_arg,
+			     struct ethosu_buffer *ifm,
+			     struct ethosu_buffer *ofm,
+			     struct ethosu_buffer *network)
+{
+	struct ethosu_core_inference_req inf;
+
+	inf.user_arg = (ptrdiff_t)user_arg;
+	ethosu_core_set_size(ifm, &inf.ifm);
+	ethosu_core_set_capacity(ofm, &inf.ofm);
+	ethosu_core_set_size(network, &inf.network);
+
+	return ethosu_queue_write_msg(mbox, ETHOSU_CORE_MSG_INFERENCE_REQ,
+				      &inf, sizeof(inf));
+}
+
+static void ethosu_mailbox_rx_work(struct work_struct *work)
+{
+	struct ethosu_mailbox *mbox = container_of(work, typeof(*mbox), work);
+
+	mbox->callback(mbox->user_arg);
+}
+
+static void ethosu_mailbox_rx_callback(struct mbox_client *client,
+				       void *message)
+{
+	struct ethosu_mailbox *mbox =
+		container_of(client, typeof(*mbox), client);
+
+	dev_info(mbox->dev, "mbox: Received message.\n");
+
+	queue_work(mbox->wq, &mbox->work);
+}
+
+static void ethosu_mailbox_tx_done(struct mbox_client *client,
+				   void *message,
+				   int r)
+{
+	if (r)
+		dev_warn(client->dev, "mbox: Failed sending message (%d)\n", r);
+	else
+		dev_info(client->dev, "mbox: Message sent\n");
+}
+
+int ethosu_mailbox_init(struct ethosu_mailbox *mbox,
+			struct device *dev,
+			struct resource *in_queue,
+			struct resource *out_queue,
+			ethosu_mailbox_cb callback,
+			void *user_arg)
+{
+	int ret;
+
+	mbox->dev = dev;
+	mbox->callback = callback;
+	mbox->user_arg = user_arg;
+
+	mbox->client.dev = dev;
+	mbox->client.rx_callback = ethosu_mailbox_rx_callback;
+	mbox->client.tx_prepare = NULL; /* preparation of data is handled
+	                                 * through the
+	                                 * queue functions */
+	mbox->client.tx_done = ethosu_mailbox_tx_done;
+	mbox->client.tx_block = true;
+	mbox->client.knows_txdone = false;
+	mbox->client.tx_tout = 500;
+
+	mbox->in_queue = devm_ioremap_resource(mbox->dev, in_queue);
+	if (IS_ERR(mbox->in_queue))
+		return PTR_ERR(mbox->in_queue);
+
+	mbox->out_queue = devm_ioremap_resource(mbox->dev, out_queue);
+	if (IS_ERR(mbox->out_queue)) {
+		ret = PTR_ERR(mbox->out_queue);
+		goto unmap_in_queue;
+	}
+
+	mbox->wq = create_singlethread_workqueue("ethosu_workqueue");
+	if (!mbox->wq) {
+		dev_err(mbox->dev, "Failed to create work queue\n");
+		ret = -EINVAL;
+		goto unmap_out_queue;
+	}
+
+	INIT_WORK(&mbox->work, ethosu_mailbox_rx_work);
+
+	mbox->tx = mbox_request_channel_byname(&mbox->client, "tx");
+	if (IS_ERR(mbox->tx)) {
+		dev_warn(mbox->dev, "mbox: Failed to request tx channel\n");
+		ret = PTR_ERR(mbox->tx);
+		goto workqueue_destroy;
+	}
+
+	mbox->rx = mbox_request_channel_byname(&mbox->client, "rx");
+	if (IS_ERR(mbox->rx)) {
+		dev_info(dev, "mbox: Using same channel for RX and TX\n");
+		mbox->rx = mbox->tx;
+	}
+
+	return 0;
+
+workqueue_destroy:
+	destroy_workqueue(mbox->wq);
+
+unmap_out_queue:
+	devm_iounmap(mbox->dev, mbox->out_queue);
+
+unmap_in_queue:
+	devm_iounmap(mbox->dev, mbox->in_queue);
+
+	return ret;
+}
+
+void ethosu_mailbox_deinit(struct ethosu_mailbox *mbox)
+{
+	if (mbox->rx != mbox->tx)
+		mbox_free_channel(mbox->rx);
+
+	mbox_free_channel(mbox->tx);
+	destroy_workqueue(mbox->wq);
+	devm_iounmap(mbox->dev, mbox->out_queue);
+	devm_iounmap(mbox->dev, mbox->in_queue);
+}