misc: mic: SCIF module initialization

SCIF module initialization, DMA mapping, ioremap wrapper APIs
and debugfs hooks. SCIF gets probed by the SCIF hardware bus
if SCIF devices were registered by base drivers. A MISC device
is registered to provide the SCIF character device interface.

Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/mic/scif/scif_main.c b/drivers/misc/mic/scif/scif_main.c
new file mode 100644
index 0000000..82792b1
--- /dev/null
+++ b/drivers/misc/mic/scif/scif_main.c
@@ -0,0 +1,391 @@
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2014 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.
+ *
+ * Intel SCIF driver.
+ *
+ */
+#include <linux/module.h>
+#include <linux/idr.h>
+
+#include <linux/mic_common.h>
+#include "../common/mic_dev.h"
+#include "../bus/scif_bus.h"
+#include "scif_peer_bus.h"
+#include "scif_main.h"
+#include "scif_map.h"
+
+struct scif_info scif_info = {
+	.mdev = {
+		.minor = MISC_DYNAMIC_MINOR,
+		.name = "scif",
+		.fops = &scif_fops,
+	}
+};
+
+struct scif_dev *scif_dev;
+static atomic_t g_loopb_cnt;
+
+/* Runs in the context of intr_wq */
+static void scif_intr_bh_handler(struct work_struct *work)
+{
+	struct scif_dev *scifdev =
+			container_of(work, struct scif_dev, intr_bh);
+
+	if (scifdev_self(scifdev))
+		scif_loopb_msg_handler(scifdev, scifdev->qpairs);
+	else
+		scif_nodeqp_intrhandler(scifdev, scifdev->qpairs);
+}
+
+int scif_setup_intr_wq(struct scif_dev *scifdev)
+{
+	if (!scifdev->intr_wq) {
+		snprintf(scifdev->intr_wqname, sizeof(scifdev->intr_wqname),
+			 "SCIF INTR %d", scifdev->node);
+		scifdev->intr_wq =
+			alloc_ordered_workqueue(scifdev->intr_wqname, 0);
+		if (!scifdev->intr_wq)
+			return -ENOMEM;
+		INIT_WORK(&scifdev->intr_bh, scif_intr_bh_handler);
+	}
+	return 0;
+}
+
+void scif_destroy_intr_wq(struct scif_dev *scifdev)
+{
+	if (scifdev->intr_wq) {
+		destroy_workqueue(scifdev->intr_wq);
+		scifdev->intr_wq = NULL;
+	}
+}
+
+irqreturn_t scif_intr_handler(int irq, void *data)
+{
+	struct scif_dev *scifdev = data;
+	struct scif_hw_dev *sdev = scifdev->sdev;
+
+	sdev->hw_ops->ack_interrupt(sdev, scifdev->db);
+	queue_work(scifdev->intr_wq, &scifdev->intr_bh);
+	return IRQ_HANDLED;
+}
+
+static int scif_peer_probe(struct scif_peer_dev *spdev)
+{
+	struct scif_dev *scifdev = &scif_dev[spdev->dnode];
+
+	mutex_lock(&scif_info.conflock);
+	scif_info.total++;
+	scif_info.maxid = max_t(u32, spdev->dnode, scif_info.maxid);
+	mutex_unlock(&scif_info.conflock);
+	rcu_assign_pointer(scifdev->spdev, spdev);
+
+	/* In the future SCIF kernel client devices will be added here */
+	dev_info(&spdev->dev, "Peer added dnode %d\n",
+		 spdev->dnode);
+	return 0;
+}
+
+static void scif_peer_remove(struct scif_peer_dev *spdev)
+{
+	struct scif_dev *scifdev = &scif_dev[spdev->dnode];
+
+	/* In the future SCIF kernel client devices will be removed here */
+	spdev = rcu_dereference(scifdev->spdev);
+	if (spdev)
+		RCU_INIT_POINTER(scifdev->spdev, NULL);
+	synchronize_rcu();
+
+	mutex_lock(&scif_info.conflock);
+	scif_info.total--;
+	mutex_unlock(&scif_info.conflock);
+	dev_info(&spdev->dev, "Peer removed dnode %d\n",
+		 spdev->dnode);
+}
+
+static void scif_qp_setup_handler(struct work_struct *work)
+{
+	struct scif_dev *scifdev = container_of(work, struct scif_dev,
+						qp_dwork.work);
+	struct scif_hw_dev *sdev = scifdev->sdev;
+	dma_addr_t da = 0;
+	int err;
+
+	if (scif_is_mgmt_node()) {
+		struct mic_bootparam *bp = sdev->dp;
+
+		da = bp->scif_card_dma_addr;
+		scifdev->rdb = bp->h2c_scif_db;
+	} else {
+		struct mic_bootparam __iomem *bp = sdev->rdp;
+
+		da = readq(&bp->scif_host_dma_addr);
+		scifdev->rdb = ioread8(&bp->c2h_scif_db);
+	}
+	if (da) {
+		err = scif_qp_response(da, scifdev);
+		if (err)
+			dev_err(&scifdev->sdev->dev,
+				"scif_qp_response err %d\n", err);
+	} else {
+		schedule_delayed_work(&scifdev->qp_dwork,
+				      msecs_to_jiffies(1000));
+	}
+}
+
+static int scif_setup_scifdev(struct scif_hw_dev *sdev)
+{
+	int i;
+	u8 num_nodes;
+
+	if (sdev->snode) {
+		struct mic_bootparam __iomem *bp = sdev->rdp;
+
+		num_nodes = ioread8(&bp->tot_nodes);
+	} else {
+		struct mic_bootparam *bp = sdev->dp;
+
+		num_nodes = bp->tot_nodes;
+	}
+	scif_dev = kcalloc(num_nodes, sizeof(*scif_dev), GFP_KERNEL);
+	if (!scif_dev)
+		return -ENOMEM;
+	for (i = 0; i < num_nodes; i++) {
+		struct scif_dev *scifdev = &scif_dev[i];
+
+		scifdev->node = i;
+		scifdev->exit = OP_IDLE;
+		init_waitqueue_head(&scifdev->disconn_wq);
+		mutex_init(&scifdev->lock);
+		INIT_WORK(&scifdev->init_msg_work, scif_qp_response_ack);
+		INIT_DELAYED_WORK(&scifdev->p2p_dwork,
+				  scif_poll_qp_state);
+		INIT_DELAYED_WORK(&scifdev->qp_dwork,
+				  scif_qp_setup_handler);
+		INIT_LIST_HEAD(&scifdev->p2p);
+		RCU_INIT_POINTER(scifdev->spdev, NULL);
+	}
+	return 0;
+}
+
+static void scif_destroy_scifdev(void)
+{
+	kfree(scif_dev);
+}
+
+static int scif_probe(struct scif_hw_dev *sdev)
+{
+	struct scif_dev *scifdev;
+	int rc;
+
+	dev_set_drvdata(&sdev->dev, sdev);
+	if (1 == atomic_add_return(1, &g_loopb_cnt)) {
+		struct scif_dev *loopb_dev;
+
+		rc = scif_setup_scifdev(sdev);
+		if (rc)
+			goto exit;
+		scifdev = &scif_dev[sdev->dnode];
+		scifdev->sdev = sdev;
+		loopb_dev = &scif_dev[sdev->snode];
+		loopb_dev->sdev = sdev;
+		rc = scif_setup_loopback_qp(loopb_dev);
+		if (rc)
+			goto free_sdev;
+	} else {
+		scifdev = &scif_dev[sdev->dnode];
+		scifdev->sdev = sdev;
+	}
+	rc = scif_setup_intr_wq(scifdev);
+	if (rc)
+		goto destroy_loopb;
+	rc = scif_setup_qp(scifdev);
+	if (rc)
+		goto destroy_intr;
+	scifdev->db = sdev->hw_ops->next_db(sdev);
+	scifdev->cookie = sdev->hw_ops->request_irq(sdev, scif_intr_handler,
+						    "SCIF_INTR", scifdev,
+						    scifdev->db);
+	if (IS_ERR(scifdev->cookie)) {
+		rc = PTR_ERR(scifdev->cookie);
+		goto free_qp;
+	}
+	if (scif_is_mgmt_node()) {
+		struct mic_bootparam *bp = sdev->dp;
+
+		bp->c2h_scif_db = scifdev->db;
+		bp->scif_host_dma_addr = scifdev->qp_dma_addr;
+	} else {
+		struct mic_bootparam __iomem *bp = sdev->rdp;
+
+		iowrite8(scifdev->db, &bp->h2c_scif_db);
+		writeq(scifdev->qp_dma_addr, &bp->scif_card_dma_addr);
+	}
+	schedule_delayed_work(&scifdev->qp_dwork,
+			      msecs_to_jiffies(1000));
+	return rc;
+free_qp:
+	scif_free_qp(scifdev);
+destroy_intr:
+	scif_destroy_intr_wq(scifdev);
+destroy_loopb:
+	if (atomic_dec_and_test(&g_loopb_cnt))
+		scif_destroy_loopback_qp(&scif_dev[sdev->snode]);
+free_sdev:
+	scif_destroy_scifdev();
+exit:
+	return rc;
+}
+
+void scif_stop(struct scif_dev *scifdev)
+{
+	struct scif_dev *dev;
+	int i;
+
+	for (i = scif_info.maxid; i >= 0; i--) {
+		dev = &scif_dev[i];
+		if (scifdev_self(dev))
+			continue;
+		scif_handle_remove_node(i);
+	}
+}
+
+static void scif_remove(struct scif_hw_dev *sdev)
+{
+	struct scif_dev *scifdev = &scif_dev[sdev->dnode];
+
+	if (scif_is_mgmt_node()) {
+		struct mic_bootparam *bp = sdev->dp;
+
+		bp->c2h_scif_db = -1;
+		bp->scif_host_dma_addr = 0x0;
+	} else {
+		struct mic_bootparam __iomem *bp = sdev->rdp;
+
+		iowrite8(-1, &bp->h2c_scif_db);
+		writeq(0x0, &bp->scif_card_dma_addr);
+	}
+	if (scif_is_mgmt_node()) {
+		scif_disconnect_node(scifdev->node, true);
+	} else {
+		scif_info.card_initiated_exit = true;
+		scif_stop(scifdev);
+	}
+	if (atomic_dec_and_test(&g_loopb_cnt))
+		scif_destroy_loopback_qp(&scif_dev[sdev->snode]);
+	if (scifdev->cookie) {
+		sdev->hw_ops->free_irq(sdev, scifdev->cookie, scifdev);
+		scifdev->cookie = NULL;
+	}
+	scif_destroy_intr_wq(scifdev);
+	cancel_delayed_work(&scifdev->qp_dwork);
+	scif_free_qp(scifdev);
+	scifdev->rdb = -1;
+	scifdev->sdev = NULL;
+}
+
+static struct scif_peer_driver scif_peer_driver = {
+	.driver.name =	KBUILD_MODNAME,
+	.driver.owner =	THIS_MODULE,
+	.probe = scif_peer_probe,
+	.remove = scif_peer_remove,
+};
+
+static struct scif_hw_dev_id id_table[] = {
+	{ MIC_SCIF_DEV, SCIF_DEV_ANY_ID },
+	{ 0 },
+};
+
+static struct scif_driver scif_driver = {
+	.driver.name =	KBUILD_MODNAME,
+	.driver.owner =	THIS_MODULE,
+	.id_table = id_table,
+	.probe = scif_probe,
+	.remove = scif_remove,
+};
+
+static int _scif_init(void)
+{
+	spin_lock_init(&scif_info.eplock);
+	spin_lock_init(&scif_info.nb_connect_lock);
+	spin_lock_init(&scif_info.port_lock);
+	mutex_init(&scif_info.conflock);
+	mutex_init(&scif_info.connlock);
+	INIT_LIST_HEAD(&scif_info.uaccept);
+	INIT_LIST_HEAD(&scif_info.listen);
+	INIT_LIST_HEAD(&scif_info.zombie);
+	INIT_LIST_HEAD(&scif_info.connected);
+	INIT_LIST_HEAD(&scif_info.disconnected);
+	INIT_LIST_HEAD(&scif_info.nb_connect_list);
+	init_waitqueue_head(&scif_info.exitwq);
+	scif_info.en_msg_log = 0;
+	scif_info.p2p_enable = 1;
+	INIT_WORK(&scif_info.misc_work, scif_misc_handler);
+	idr_init(&scif_ports);
+	return 0;
+}
+
+static void _scif_exit(void)
+{
+	idr_destroy(&scif_ports);
+	scif_destroy_scifdev();
+}
+
+static int __init scif_init(void)
+{
+	struct miscdevice *mdev = &scif_info.mdev;
+	int rc;
+
+	_scif_init();
+	rc = scif_peer_bus_init();
+	if (rc)
+		goto exit;
+	rc = scif_peer_register_driver(&scif_peer_driver);
+	if (rc)
+		goto peer_bus_exit;
+	rc = scif_register_driver(&scif_driver);
+	if (rc)
+		goto unreg_scif_peer;
+	rc = misc_register(mdev);
+	if (rc)
+		goto unreg_scif;
+	scif_init_debugfs();
+	return 0;
+unreg_scif:
+	scif_unregister_driver(&scif_driver);
+unreg_scif_peer:
+	scif_peer_unregister_driver(&scif_peer_driver);
+peer_bus_exit:
+	scif_peer_bus_exit();
+exit:
+	_scif_exit();
+	return rc;
+}
+
+static void __exit scif_exit(void)
+{
+	scif_exit_debugfs();
+	misc_deregister(&scif_info.mdev);
+	scif_unregister_driver(&scif_driver);
+	scif_peer_unregister_driver(&scif_peer_driver);
+	scif_peer_bus_exit();
+	_scif_exit();
+}
+
+module_init(scif_init);
+module_exit(scif_exit);
+
+MODULE_DEVICE_TABLE(scif, id_table);
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Intel(R) SCIF driver");
+MODULE_LICENSE("GPL v2");