1 files changed, 275 insertions, 0 deletions
diff --git a/drivers/misc/mic/cosm_client/cosm_scif_client.c b/drivers/misc/mic/cosm_client/cosm_scif_client.c
new file mode 100644
index 000000000000..03e98bf1ac15
--- /dev/null
+++ b/drivers/misc/mic/cosm_client/cosm_scif_client.c
@@ -0,0 +1,275 @@
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Intel MIC COSM Client Driver
+ *
+ */
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/kthread.h>
+#include "../cosm/cosm_main.h"
+
+#define COSM_SCIF_MAX_RETRIES 10
+#define COSM_HEARTBEAT_SEND_MSEC (COSM_HEARTBEAT_SEND_SEC * MSEC_PER_SEC)
+
+static struct task_struct *client_thread;
+static scif_epd_t client_epd;
+static struct scif_peer_dev *client_spdev;
+
+/*
+ * Reboot notifier: receives shutdown status from the OS and communicates it
+ * back to the COSM process on the host
+ */
+static int cosm_reboot_event(struct notifier_block *this, unsigned long event,
+			     void *ptr)
+{
+	struct cosm_msg msg = { .id = COSM_MSG_SHUTDOWN_STATUS };
+	int rc;
+
+	event = (event == SYS_RESTART) ? SYSTEM_RESTART : event;
+	dev_info(&client_spdev->dev, "%s %d received event %ld\n",
+		 __func__, __LINE__, event);
+
+	msg.shutdown_status = event;
+	rc = scif_send(client_epd, &msg, sizeof(msg), SCIF_SEND_BLOCK);
+	if (rc < 0)
+		dev_err(&client_spdev->dev, "%s %d scif_send rc %d\n",
+			__func__, __LINE__, rc);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block cosm_reboot = {
+	.notifier_call  = cosm_reboot_event,
+};
+
+/* Set system time from timespec value received from the host */
+static void cosm_set_time(struct cosm_msg *msg)
+{
+	int rc = do_settimeofday64(&msg->timespec);
+
+	if (rc)
+		dev_err(&client_spdev->dev, "%s: %d settimeofday rc %d\n",
+			__func__, __LINE__, rc);
+}
+
+/* COSM client receive message processing */
+static void cosm_client_recv(void)
+{
+	struct cosm_msg msg;
+	int rc;
+
+	while (1) {
+		rc = scif_recv(client_epd, &msg, sizeof(msg), 0);
+		if (!rc) {
+			return;
+		} else if (rc < 0) {
+			dev_err(&client_spdev->dev, "%s: %d rc %d\n",
+				__func__, __LINE__, rc);
+			return;
+		}
+
+		dev_dbg(&client_spdev->dev, "%s: %d rc %d id 0x%llx\n",
+			__func__, __LINE__, rc, msg.id);
+
+		switch (msg.id) {
+		case COSM_MSG_SYNC_TIME:
+			cosm_set_time(&msg);
+			break;
+		case COSM_MSG_SHUTDOWN:
+			orderly_poweroff(true);
+			break;
+		default:
+			dev_err(&client_spdev->dev, "%s: %d unknown id %lld\n",
+				__func__, __LINE__, msg.id);
+			break;
+		}
+	}
+}
+
+/* Initiate connection to the COSM server on the host */
+static int cosm_scif_connect(void)
+{
+	struct scif_port_id port_id;
+	int i, rc;
+
+	client_epd = scif_open();
+	if (!client_epd) {
+		dev_err(&client_spdev->dev, "%s %d scif_open failed\n",
+			__func__, __LINE__);
+		return -ENOMEM;
+	}
+
+	port_id.node = 0;
+	port_id.port = SCIF_COSM_LISTEN_PORT;
+
+	for (i = 0; i < COSM_SCIF_MAX_RETRIES; i++) {
+		rc = scif_connect(client_epd, &port_id);
+		if (rc < 0)
+			msleep(1000);
+		else
+			break;
+	}
+
+	if (rc < 0) {
+		dev_err(&client_spdev->dev, "%s %d scif_connect rc %d\n",
+			__func__, __LINE__, rc);
+		scif_close(client_epd);
+		client_epd = NULL;
+	}
+	return rc < 0 ? rc : 0;
+}
+
+/* Close host SCIF connection */
+static void cosm_scif_connect_exit(void)
+{
+	if (client_epd) {
+		scif_close(client_epd);
+		client_epd = NULL;
+	}
+}
+
+/*
+ * COSM SCIF client thread function: waits for messages from the host and sends
+ * a heartbeat to the host
+ */
+static int cosm_scif_client(void *unused)
+{
+	struct cosm_msg msg = { .id = COSM_MSG_HEARTBEAT };
+	struct scif_pollepd pollepd;
+	int rc;
+
+	allow_signal(SIGKILL);
+
+	while (!kthread_should_stop()) {
+		pollepd.epd = client_epd;
+		pollepd.events = POLLIN;
+
+		rc = scif_poll(&pollepd, 1, COSM_HEARTBEAT_SEND_MSEC);
+		if (rc < 0) {
+			if (-EINTR != rc)
+				dev_err(&client_spdev->dev,
+					"%s %d scif_poll rc %d\n",
+					__func__, __LINE__, rc);
+			continue;
+		}
+
+		if (pollepd.revents & POLLIN)
+			cosm_client_recv();
+
+		msg.id = COSM_MSG_HEARTBEAT;
+		rc = scif_send(client_epd, &msg, sizeof(msg), SCIF_SEND_BLOCK);
+		if (rc < 0)
+			dev_err(&client_spdev->dev, "%s %d scif_send rc %d\n",
+				__func__, __LINE__, rc);
+	}
+
+	dev_dbg(&client_spdev->dev, "%s %d Client thread stopped\n",
+		__func__, __LINE__);
+	return 0;
+}
+
+static void cosm_scif_probe(struct scif_peer_dev *spdev)
+{
+	int rc;
+
+	dev_dbg(&spdev->dev, "%s %d: dnode %d\n",
+		__func__, __LINE__, spdev->dnode);
+
+	/* We are only interested in the host with spdev->dnode == 0 */
+	if (spdev->dnode)
+		return;
+
+	client_spdev = spdev;
+	rc = cosm_scif_connect();
+	if (rc)
+		goto exit;
+
+	rc = register_reboot_notifier(&cosm_reboot);
+	if (rc) {
+		dev_err(&spdev->dev,
+			"reboot notifier registration failed rc %d\n", rc);
+		goto connect_exit;
+	}
+
+	client_thread = kthread_run(cosm_scif_client, NULL, "cosm_client");
+	if (IS_ERR(client_thread)) {
+		rc = PTR_ERR(client_thread);
+		dev_err(&spdev->dev, "%s %d kthread_run rc %d\n",
+			__func__, __LINE__, rc);
+		goto unreg_reboot;
+	}
+	return;
+unreg_reboot:
+	unregister_reboot_notifier(&cosm_reboot);
+connect_exit:
+	cosm_scif_connect_exit();
+exit:
+	client_spdev = NULL;
+}
+
+static void cosm_scif_remove(struct scif_peer_dev *spdev)
+{
+	int rc;
+
+	dev_dbg(&spdev->dev, "%s %d: dnode %d\n",
+		__func__, __LINE__, spdev->dnode);
+
+	if (spdev->dnode)
+		return;
+
+	if (!IS_ERR_OR_NULL(client_thread)) {
+		rc = send_sig(SIGKILL, client_thread, 0);
+		if (rc) {
+			pr_err("%s %d send_sig rc %d\n",
+			       __func__, __LINE__, rc);
+			return;
+		}
+		kthread_stop(client_thread);
+	}
+	unregister_reboot_notifier(&cosm_reboot);
+	cosm_scif_connect_exit();
+	client_spdev = NULL;
+}
+
+static struct scif_client scif_client_cosm = {
+	.name = KBUILD_MODNAME,
+	.probe = cosm_scif_probe,
+	.remove = cosm_scif_remove,
+};
+
+static int __init cosm_client_init(void)
+{
+	int rc = scif_client_register(&scif_client_cosm);
+
+	if (rc)
+		pr_err("scif_client_register failed rc %d\n", rc);
+	return rc;
+}
+
+static void __exit cosm_client_exit(void)
+{
+	scif_client_unregister(&scif_client_cosm);
+}
+
+module_init(cosm_client_init);
+module_exit(cosm_client_exit);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Intel(R) MIC card OS state management client driver");
+MODULE_LICENSE("GPL v2");