misc: mic: SCIF node queue pair setup management

/*

 * 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 "scif_peer_bus.h"

#include "scif_main.h"

#include "scif_map.h"

void scif_free_qp(struct scif_dev *scifdev)

{

	struct scif_qp *qp = scifdev->qpairs;

	if (!qp)

		return;

	scif_free_coherent((void *)qp->inbound_q.rb_base,

			   qp->local_buf, scifdev, qp->inbound_q.size);

	scif_unmap_single(qp->local_qp, scifdev, sizeof(struct scif_qp));

	kfree(scifdev->qpairs);

	scifdev->qpairs = NULL;

}

static void scif_cleanup_qp(struct scif_dev *dev)

{

	struct scif_qp *qp = &dev->qpairs[0];

	if (!qp)

		return;

	scif_iounmap((void *)qp->remote_qp, sizeof(struct scif_qp), dev);

	scif_iounmap((void *)qp->outbound_q.rb_base,

		     sizeof(struct scif_qp), dev);

	qp->remote_qp = NULL;

	qp->local_write = 0;

	qp->inbound_q.current_write_offset = 0;

	qp->inbound_q.current_read_offset = 0;

	if (scifdev_is_p2p(dev))

		scif_free_qp(dev);

}

void scif_send_acks(struct scif_dev *dev)

{

	struct scifmsg msg;

	if (dev->node_remove_ack_pending) {

		msg.uop = SCIF_NODE_REMOVE_ACK;

		msg.src.node = scif_info.nodeid;

		msg.dst.node = SCIF_MGMT_NODE;

		msg.payload[0] = dev->node;

		scif_nodeqp_send(&scif_dev[SCIF_MGMT_NODE], &msg);

		dev->node_remove_ack_pending = false;

	}

	if (dev->exit_ack_pending) {

		msg.uop = SCIF_EXIT_ACK;

		msg.src.node = scif_info.nodeid;

		msg.dst.node = dev->node;

		scif_nodeqp_send(dev, &msg);

		dev->exit_ack_pending = false;

	}

}

/*

 * scif_cleanup_scifdev

 *

 * @dev: Remote SCIF device.

 * Uninitialize SCIF data structures for remote SCIF device.

 */

void scif_cleanup_scifdev(struct scif_dev *dev)

{

	struct scif_hw_dev *sdev = dev->sdev;

	if (!dev->sdev)

		return;

	if (scifdev_is_p2p(dev)) {

		if (dev->cookie) {

			sdev->hw_ops->free_irq(sdev, dev->cookie, dev);

			dev->cookie = NULL;

		}

		scif_destroy_intr_wq(dev);

	}

	scif_destroy_p2p(dev);

	scif_send_acks(dev);

	if (!dev->node && scif_info.card_initiated_exit) {

		/*

		 * Send an SCIF_EXIT message which is the last message from MIC

		 * to the Host and wait for a SCIF_EXIT_ACK

		 */

		scif_send_exit(dev);

		scif_info.card_initiated_exit = false;

	}

	scif_cleanup_qp(dev);

}

/*

 * scif_remove_node:

 *

 * @node: Node to remove

 */

void scif_handle_remove_node(int node)

{

	struct scif_dev *scifdev = &scif_dev[node];

	struct scif_peer_dev *spdev;

	rcu_read_lock();

	spdev = rcu_dereference(scifdev->spdev);

	rcu_read_unlock();

	if (spdev)

		scif_peer_unregister_device(spdev);

	else

		scif_send_acks(scifdev);

}

static int scif_send_rmnode_msg(int node, int remove_node)

{

	struct scifmsg notif_msg;

	struct scif_dev *dev = &scif_dev[node];

	notif_msg.uop = SCIF_NODE_REMOVE;

	notif_msg.src.node = scif_info.nodeid;

	notif_msg.dst.node = node;

	notif_msg.payload[0] = remove_node;

	return scif_nodeqp_send(dev, &notif_msg);

}

/**

 * scif_node_disconnect:

 *

 * @node_id[in]: source node id.

 * @mgmt_initiated: Disconnection initiated from the mgmt node

 *

 * Disconnect a node from the scif network.

 */

void scif_disconnect_node(u32 node_id, bool mgmt_initiated)

{

	int ret;

	int msg_cnt = 0;

	u32 i = 0;

	struct scif_dev *scifdev = &scif_dev[node_id];

	if (!node_id)

		return;

	atomic_set(&scifdev->disconn_rescnt, 0);

	/* Destroy p2p network */

	for (i = 1; i <= scif_info.maxid; i++) {

		if (i == node_id)

			continue;

		ret = scif_send_rmnode_msg(i, node_id);

		if (!ret)

			msg_cnt++;

	}

	/* Wait for the remote nodes to respond with SCIF_NODE_REMOVE_ACK */

	ret = wait_event_timeout(scifdev->disconn_wq,

				 (atomic_read(&scifdev->disconn_rescnt)

				 == msg_cnt), SCIF_NODE_ALIVE_TIMEOUT);

	/* Tell the card to clean up */

	if (mgmt_initiated && _scifdev_alive(scifdev))

		/*

		 * Send an SCIF_EXIT message which is the last message from Host

		 * to the MIC and wait for a SCIF_EXIT_ACK

		 */

		scif_send_exit(scifdev);

	atomic_set(&scifdev->disconn_rescnt, 0);

	/* Tell the mgmt node to clean up */

	ret = scif_send_rmnode_msg(SCIF_MGMT_NODE, node_id);

	if (!ret)

		/* Wait for mgmt node to respond with SCIF_NODE_REMOVE_ACK */

		wait_event_timeout(scifdev->disconn_wq,

				   (atomic_read(&scifdev->disconn_rescnt) == 1),

				   SCIF_NODE_ALIVE_TIMEOUT);

}

/*

 * Intel MIC Platform Software Stack (MPSS)

 *

 * This file is provided under a dual BSD/GPLv2 license.  When using or

 * redistributing this file, you may do so under either license.

 *

 * GPL LICENSE SUMMARY

 *

 * Copyright(c) 2014 Intel Corporation.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of version 2 of the GNU General Public License 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.

 *

 * BSD LICENSE

 *

 * Copyright(c) 2014 Intel Corporation.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * * Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * * Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in

 *   the documentation and/or other materials provided with the

 *   distribution.

 * * Neither the name of Intel Corporation nor the names of its

 *   contributors may be used to endorse or promote products derived

 *   from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * Intel SCIF driver.

 *

 */

#ifndef SCIF_NODEQP

#define SCIF_NODEQP

#include "scif_rb.h"

#include "scif_peer_bus.h"

#define SCIF_INIT 1  /* First message sent to the peer node for discovery */

#define SCIF_EXIT 2  /* Last message from the peer informing intent to exit */

#define SCIF_EXIT_ACK 3 /* Response to SCIF_EXIT message */

#define SCIF_NODE_ADD 4  /* Tell Online nodes a new node exits */

#define SCIF_NODE_ADD_ACK 5  /* Confirm to mgmt node sequence is finished */

#define SCIF_NODE_ADD_NACK 6 /* SCIF_NODE_ADD failed */

#define SCIF_NODE_REMOVE 7 /* Request to deactivate a SCIF node */

#define SCIF_NODE_REMOVE_ACK 8 /* Response to a SCIF_NODE_REMOVE message */

#define SCIF_MAX_MSG SCIF_NODE_REMOVE_ACK

/*

 * struct scifmsg - Node QP message format

 *

 * @src: Source information

 * @dst: Destination information

 * @uop: The message opcode

 * @payload: Unique payload format for each message

 */

struct scifmsg {

	struct scif_port_id src;

	struct scif_port_id dst;

	u32 uop;

	u64 payload[4];

} __packed;

/*

 * struct scif_qp - Node Queue Pair

 *

 * Interesting structure -- a little difficult because we can only

 * write across the PCIe, so any r/w pointer we need to read is

 * local. We only need to read the read pointer on the inbound_q

 * and read the write pointer in the outbound_q

 *

 * @magic: Magic value to ensure the peer sees the QP correctly

 * @outbound_q: The outbound ring buffer for sending messages

 * @inbound_q: The inbound ring buffer for receiving messages

 * @local_write: Local write index

 * @local_read: Local read index

 * @remote_qp: The remote queue pair

 * @local_buf: DMA address of local ring buffer

 * @local_qp: DMA address of the local queue pair data structure

 * @remote_buf: DMA address of remote ring buffer

 * @qp_state: QP state i.e. online or offline used for P2P

 * @send_lock: synchronize access to outbound queue

 * @recv_lock: Synchronize access to inbound queue

 */

struct scif_qp {

	u64 magic;

#define SCIFEP_MAGIC 0x5c1f000000005c1fULL

	struct scif_rb outbound_q;

	struct scif_rb inbound_q;

	u32 local_write __aligned(64);

	u32 local_read __aligned(64);

	struct scif_qp *remote_qp;

	dma_addr_t local_buf;

	dma_addr_t local_qp;

	dma_addr_t remote_buf;

	u32 qp_state;

#define SCIF_QP_OFFLINE 0xdead

#define SCIF_QP_ONLINE 0xc0de

	spinlock_t send_lock;

	spinlock_t recv_lock;

};

/*

 * struct scif_loopb_msg - An element in the loopback Node QP message list.

 *

 * @msg - The SCIF node QP message

 * @list - link in the list of messages

 */

struct scif_loopb_msg {

	struct scifmsg msg;

	struct list_head list;

};

int scif_nodeqp_send(struct scif_dev *scifdev, struct scifmsg *msg);

int _scif_nodeqp_send(struct scif_dev *scifdev, struct scifmsg *msg);

void scif_nodeqp_intrhandler(struct scif_dev *scifdev, struct scif_qp *qp);

int scif_loopb_msg_handler(struct scif_dev *scifdev, struct scif_qp *qp);

int scif_setup_qp(struct scif_dev *scifdev);

int scif_qp_response(phys_addr_t phys, struct scif_dev *dev);

int scif_setup_qp_connect(struct scif_qp *qp, dma_addr_t *qp_offset,

			  int local_size, struct scif_dev *scifdev);

int scif_setup_qp_accept(struct scif_qp *qp, dma_addr_t *qp_offset,

			 dma_addr_t phys, int local_size,

			 struct scif_dev *scifdev);

int scif_setup_qp_connect_response(struct scif_dev *scifdev,

				   struct scif_qp *qp, u64 payload);

int scif_setup_loopback_qp(struct scif_dev *scifdev);

int scif_destroy_loopback_qp(struct scif_dev *scifdev);

void scif_poll_qp_state(struct work_struct *work);

void scif_qp_response_ack(struct work_struct *work);

void scif_destroy_p2p(struct scif_dev *scifdev);

void scif_send_exit(struct scif_dev *scifdev);

static inline struct device *scif_get_peer_dev(struct scif_dev *scifdev)

{

	struct scif_peer_dev *spdev;

	struct device *spdev_ret;

	rcu_read_lock();

	spdev = rcu_dereference(scifdev->spdev);

	if (spdev)

		spdev_ret = get_device(&spdev->dev);

	else

		spdev_ret = ERR_PTR(-ENODEV);

	rcu_read_unlock();

	return spdev_ret;

}

static inline void scif_put_peer_dev(struct device *dev)

{

	put_device(dev);

}

#endif  /* SCIF_NODEQP */