Add support for inference cancellation

Send cancel inference messages to the ethosu subsystem to abort
inference execution there.  Also mark inference as aborted in the
linux driver stack itself, so pending inference messages are not
resent when resetting the firmware.

Change-Id: I244c2b119fd7995d14e3859815abf2a00c7f0583

1 files changed, 198 insertions, 0 deletions

diff --git a/kernel/ethosu_cancel_inference.c b/kernel/ethosu_cancel_inference.c
new file mode 100644
index 0000000..09778ee
--- /dev/null
+++ b/kernel/ethosu_cancel_inference.c
@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2022 Arm Limited.
+ *
+ * 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_cancel_inference.h"
+
+#include "ethosu_core_interface.h"
+#include "ethosu_device.h"
+#include "ethosu_inference.h"
+
+#include <linux/wait.h>
+
+/****************************************************************************
+ * Defines
+ ****************************************************************************/
+
+#define CANCEL_INFERENCE_RESP_TIMEOUT_MS 2000
+
+/****************************************************************************
+ * Functions
+ ****************************************************************************/
+
+static void ethosu_cancel_inference_destroy(struct kref *kref)
+{
+	struct ethosu_cancel_inference *cancellation =
+		container_of(kref, struct ethosu_cancel_inference, kref);
+
+	dev_info(cancellation->edev->dev,
+		 "Cancel inference destroy. handle=0x%p\n", cancellation);
+	list_del(&cancellation->msg.list);
+	/* decrease the reference on the inference we are refering to */
+	ethosu_inference_put(cancellation->inf);
+	devm_kfree(cancellation->edev->dev, cancellation);
+}
+
+static int ethosu_cancel_inference_send(
+	struct ethosu_cancel_inference *cancellation)
+{
+	return ethosu_mailbox_cancel_inference(&cancellation->edev->mailbox,
+					       cancellation, cancellation->inf);
+}
+
+static void ethosu_cancel_inference_fail(struct ethosu_mailbox_msg *msg)
+{
+	struct ethosu_cancel_inference *cancellation =
+		container_of(msg, typeof(*cancellation), msg);
+
+	if (completion_done(&cancellation->done))
+		return;
+
+	cancellation->errno = -EFAULT;
+	cancellation->uapi->status = ETHOSU_UAPI_STATUS_ERROR;
+	complete(&cancellation->done);
+}
+
+static int ethosu_cancel_inference_complete(struct ethosu_mailbox_msg *msg)
+{
+	struct ethosu_cancel_inference *cancellation =
+		container_of(msg, typeof(*cancellation), msg);
+
+	if (completion_done(&cancellation->done))
+		return 0;
+
+	cancellation->errno = 0;
+	cancellation->uapi->status =
+		cancellation->inf->done &&
+		cancellation->inf->status != ETHOSU_UAPI_STATUS_OK ?
+		ETHOSU_UAPI_STATUS_OK :
+		ETHOSU_UAPI_STATUS_ERROR;
+	complete(&cancellation->done);
+
+	return 0;
+}
+
+int ethosu_cancel_inference_request(struct ethosu_inference *inf,
+				    struct ethosu_uapi_cancel_inference_status *uapi)
+{
+	struct ethosu_cancel_inference *cancellation;
+	int ret;
+	int timeout;
+
+	if (inf->done) {
+		uapi->status = ETHOSU_UAPI_STATUS_ERROR;
+
+		return 0;
+	}
+
+	cancellation =
+		devm_kzalloc(inf->edev->dev,
+			     sizeof(struct ethosu_cancel_inference),
+			     GFP_KERNEL);
+	if (!cancellation)
+		return -ENOMEM;
+
+	/* increase ref count on the inference we are refering to */
+	ethosu_inference_get(inf);
+	/* mark inference ABORTING to avoid resending the inference message */
+	inf->status = ETHOSU_CORE_STATUS_ABORTING;
+
+	cancellation->edev = inf->edev;
+	cancellation->inf = inf;
+	cancellation->uapi = uapi;
+	kref_init(&cancellation->kref);
+	init_completion(&cancellation->done);
+	cancellation->msg.fail = ethosu_cancel_inference_fail;
+
+	/* Never resend messages but always complete, since we have restart the
+	 * whole firmware and marked the inference as aborted */
+	cancellation->msg.resend = ethosu_cancel_inference_complete;
+
+	/* Add cancel inference to pending list */
+	list_add(&cancellation->msg.list,
+		 &cancellation->edev->mailbox.pending_list);
+
+	ret = ethosu_cancel_inference_send(cancellation);
+	if (0 != ret)
+		goto put_kref;
+
+	/* Unlock the mutex before going to block on the condition */
+	mutex_unlock(&cancellation->edev->mutex);
+	/* wait for response to arrive back */
+	timeout = wait_for_completion_timeout(&cancellation->done,
+					      msecs_to_jiffies(
+						      CANCEL_INFERENCE_RESP_TIMEOUT_MS));
+	/* take back the mutex before resuming to do anything */
+	ret = mutex_lock_interruptible(&cancellation->edev->mutex);
+	if (0 != ret)
+		goto put_kref;
+
+	if (0 == timeout /* timed out*/) {
+		dev_warn(inf->edev->dev,
+			 "Msg: Cancel Inference response lost - timeout\n");
+		ret = -EIO;
+		goto put_kref;
+	}
+
+	if (cancellation->errno) {
+		ret = cancellation->errno;
+		goto put_kref;
+	}
+
+put_kref:
+	kref_put(&cancellation->kref, &ethosu_cancel_inference_destroy);
+
+	return ret;
+}
+
+void ethosu_cancel_inference_rsp(struct ethosu_device *edev,
+				 struct ethosu_core_cancel_inference_rsp *rsp)
+{
+	struct ethosu_cancel_inference *cancellation =
+		(struct ethosu_cancel_inference *)rsp->user_arg;
+	int ret;
+
+	ret = ethosu_mailbox_find(&edev->mailbox, &cancellation->msg);
+	if (ret) {
+		dev_warn(edev->dev,
+			 "Handle not found in cancel inference list. handle=0x%p\n",
+			 rsp);
+
+		return;
+	}
+
+	if (completion_done(&cancellation->done))
+		return;
+
+	cancellation->errno = 0;
+	switch (rsp->status) {
+	case ETHOSU_CORE_STATUS_OK:
+		cancellation->uapi->status = ETHOSU_UAPI_STATUS_OK;
+		break;
+	case ETHOSU_CORE_STATUS_ERROR:
+		cancellation->uapi->status = ETHOSU_UAPI_STATUS_ERROR;
+		break;
+	}
+
+	complete(&cancellation->done);
+}