Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2376 insertions, 0 deletions

diff --git a/drivers/rapidio/rio_cm.c b/drivers/rapidio/rio_cm.c
new file mode 100644
index 000000000..db4c26528
--- /dev/null
+++ b/drivers/rapidio/rio_cm.c
@@ -0,0 +1,2376 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * rio_cm - RapidIO Channelized Messaging Driver
+ *
+ * Copyright 2013-2016 Integrated Device Technology, Inc.
+ * Copyright (c) 2015, Prodrive Technologies
+ * Copyright (c) 2015, RapidIO Trade Association
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/rio.h>
+#include <linux/rio_drv.h>
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <linux/interrupt.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/reboot.h>
+#include <linux/bitops.h>
+#include <linux/printk.h>
+#include <linux/rio_cm_cdev.h>
+
+#define DRV_NAME        "rio_cm"
+#define DRV_VERSION     "1.0.0"
+#define DRV_AUTHOR      "Alexandre Bounine <alexandre.bounine@idt.com>"
+#define DRV_DESC        "RapidIO Channelized Messaging Driver"
+#define DEV_NAME	"rio_cm"
+
+/* Debug output filtering masks */
+enum {
+	DBG_NONE	= 0,
+	DBG_INIT	= BIT(0), /* driver init */
+	DBG_EXIT	= BIT(1), /* driver exit */
+	DBG_MPORT	= BIT(2), /* mport add/remove */
+	DBG_RDEV	= BIT(3), /* RapidIO device add/remove */
+	DBG_CHOP	= BIT(4), /* channel operations */
+	DBG_WAIT	= BIT(5), /* waiting for events */
+	DBG_TX		= BIT(6), /* message TX */
+	DBG_TX_EVENT	= BIT(7), /* message TX event */
+	DBG_RX_DATA	= BIT(8), /* inbound data messages */
+	DBG_RX_CMD	= BIT(9), /* inbound REQ/ACK/NACK messages */
+	DBG_ALL		= ~0,
+};
+
+#ifdef DEBUG
+#define riocm_debug(level, fmt, arg...) \
+	do { \
+		if (DBG_##level & dbg_level) \
+			pr_debug(DRV_NAME ": %s " fmt "\n", \
+				__func__, ##arg); \
+	} while (0)
+#else
+#define riocm_debug(level, fmt, arg...) \
+		no_printk(KERN_DEBUG pr_fmt(DRV_NAME fmt "\n"), ##arg)
+#endif
+
+#define riocm_warn(fmt, arg...) \
+	pr_warn(DRV_NAME ": %s WARNING " fmt "\n", __func__, ##arg)
+
+#define riocm_error(fmt, arg...) \
+	pr_err(DRV_NAME ": %s ERROR " fmt "\n", __func__, ##arg)
+
+
+static int cmbox = 1;
+module_param(cmbox, int, S_IRUGO);
+MODULE_PARM_DESC(cmbox, "RapidIO Mailbox number (default 1)");
+
+static int chstart = 256;
+module_param(chstart, int, S_IRUGO);
+MODULE_PARM_DESC(chstart,
+		 "Start channel number for dynamic allocation (default 256)");
+
+#ifdef DEBUG
+static u32 dbg_level = DBG_NONE;
+module_param(dbg_level, uint, S_IWUSR | S_IRUGO);
+MODULE_PARM_DESC(dbg_level, "Debugging output level (default 0 = none)");
+#endif
+
+MODULE_AUTHOR(DRV_AUTHOR);
+MODULE_DESCRIPTION(DRV_DESC);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+
+#define RIOCM_TX_RING_SIZE	128
+#define RIOCM_RX_RING_SIZE	128
+#define RIOCM_CONNECT_TO	3 /* connect response TO (in sec) */
+
+#define RIOCM_MAX_CHNUM		0xffff /* Use full range of u16 field */
+#define RIOCM_CHNUM_AUTO	0
+#define RIOCM_MAX_EP_COUNT	0x10000 /* Max number of endpoints */
+
+enum rio_cm_state {
+	RIO_CM_IDLE,
+	RIO_CM_CONNECT,
+	RIO_CM_CONNECTED,
+	RIO_CM_DISCONNECT,
+	RIO_CM_CHAN_BOUND,
+	RIO_CM_LISTEN,
+	RIO_CM_DESTROYING,
+};
+
+enum rio_cm_pkt_type {
+	RIO_CM_SYS	= 0xaa,
+	RIO_CM_CHAN	= 0x55,
+};
+
+enum rio_cm_chop {
+	CM_CONN_REQ,
+	CM_CONN_ACK,
+	CM_CONN_CLOSE,
+	CM_DATA_MSG,
+};
+
+struct rio_ch_base_bhdr {
+	u32 src_id;
+	u32 dst_id;
+#define RIO_HDR_LETTER_MASK 0xffff0000
+#define RIO_HDR_MBOX_MASK   0x0000ffff
+	u8  src_mbox;
+	u8  dst_mbox;
+	u8  type;
+} __attribute__((__packed__));
+
+struct rio_ch_chan_hdr {
+	struct rio_ch_base_bhdr bhdr;
+	u8 ch_op;
+	u16 dst_ch;
+	u16 src_ch;
+	u16 msg_len;
+	u16 rsrvd;
+} __attribute__((__packed__));
+
+struct tx_req {
+	struct list_head node;
+	struct rio_dev   *rdev;
+	void		 *buffer;
+	size_t		 len;
+};
+
+struct cm_dev {
+	struct list_head	list;
+	struct rio_mport	*mport;
+	void			*rx_buf[RIOCM_RX_RING_SIZE];
+	int			rx_slots;
+	struct mutex		rx_lock;
+
+	void			*tx_buf[RIOCM_TX_RING_SIZE];
+	int			tx_slot;
+	int			tx_cnt;
+	int			tx_ack_slot;
+	struct list_head	tx_reqs;
+	spinlock_t		tx_lock;
+
+	struct list_head	peers;
+	u32			npeers;
+	struct workqueue_struct *rx_wq;
+	struct work_struct	rx_work;
+};
+
+struct chan_rx_ring {
+	void	*buf[RIOCM_RX_RING_SIZE];
+	int	head;
+	int	tail;
+	int	count;
+
+	/* Tracking RX buffers reported to upper level */
+	void	*inuse[RIOCM_RX_RING_SIZE];
+	int	inuse_cnt;
+};
+
+struct rio_channel {
+	u16			id;	/* local channel ID */
+	struct kref		ref;	/* channel refcount */
+	struct file		*filp;
+	struct cm_dev		*cmdev;	/* associated CM device object */
+	struct rio_dev		*rdev;	/* remote RapidIO device */
+	enum rio_cm_state	state;
+	int			error;
+	spinlock_t		lock;
+	void			*context;
+	u32			loc_destid;	/* local destID */
+	u32			rem_destid;	/* remote destID */
+	u16			rem_channel;	/* remote channel ID */
+	struct list_head	accept_queue;
+	struct list_head	ch_node;
+	struct completion	comp;
+	struct completion	comp_close;
+	struct chan_rx_ring	rx_ring;
+};
+
+struct cm_peer {
+	struct list_head node;
+	struct rio_dev *rdev;
+};
+
+struct rio_cm_work {
+	struct work_struct work;
+	struct cm_dev *cm;
+	void *data;
+};
+
+struct conn_req {
+	struct list_head node;
+	u32 destid;	/* requester destID */
+	u16 chan;	/* requester channel ID */
+	struct cm_dev *cmdev;
+};
+
+/*
+ * A channel_dev structure represents a CM_CDEV
+ * @cdev	Character device
+ * @dev		Associated device object
+ */
+struct channel_dev {
+	struct cdev	cdev;
+	struct device	*dev;
+};
+
+static struct rio_channel *riocm_ch_alloc(u16 ch_num);
+static void riocm_ch_free(struct kref *ref);
+static int riocm_post_send(struct cm_dev *cm, struct rio_dev *rdev,
+			   void *buffer, size_t len);
+static int riocm_ch_close(struct rio_channel *ch);
+
+static DEFINE_SPINLOCK(idr_lock);
+static DEFINE_IDR(ch_idr);
+
+static LIST_HEAD(cm_dev_list);
+static DECLARE_RWSEM(rdev_sem);
+
+static struct class *dev_class;
+static unsigned int dev_major;
+static unsigned int dev_minor_base;
+static dev_t dev_number;
+static struct channel_dev riocm_cdev;
+
+#define is_msg_capable(src_ops, dst_ops)			\
+			((src_ops & RIO_SRC_OPS_DATA_MSG) &&	\
+			 (dst_ops & RIO_DST_OPS_DATA_MSG))
+#define dev_cm_capable(dev) \
+	is_msg_capable(dev->src_ops, dev->dst_ops)
+
+static int riocm_cmp(struct rio_channel *ch, enum rio_cm_state cmp)
+{
+	int ret;
+
+	spin_lock_bh(&ch->lock);
+	ret = (ch->state == cmp);
+	spin_unlock_bh(&ch->lock);
+	return ret;
+}
+
+static int riocm_cmp_exch(struct rio_channel *ch,
+			   enum rio_cm_state cmp, enum rio_cm_state exch)
+{
+	int ret;
+
+	spin_lock_bh(&ch->lock);
+	ret = (ch->state == cmp);
+	if (ret)
+		ch->state = exch;
+	spin_unlock_bh(&ch->lock);
+	return ret;
+}
+
+static enum rio_cm_state riocm_exch(struct rio_channel *ch,
+				    enum rio_cm_state exch)
+{
+	enum rio_cm_state old;
+
+	spin_lock_bh(&ch->lock);
+	old = ch->state;
+	ch->state = exch;
+	spin_unlock_bh(&ch->lock);
+	return old;
+}
+
+static struct rio_channel *riocm_get_channel(u16 nr)
+{
+	struct rio_channel *ch;
+
+	spin_lock_bh(&idr_lock);
+	ch = idr_find(&ch_idr, nr);
+	if (ch)
+		kref_get(&ch->ref);
+	spin_unlock_bh(&idr_lock);
+	return ch;
+}
+
+static void riocm_put_channel(struct rio_channel *ch)
+{
+	kref_put(&ch->ref, riocm_ch_free);
+}
+
+static void *riocm_rx_get_msg(struct cm_dev *cm)
+{
+	void *msg;
+	int i;
+
+	msg = rio_get_inb_message(cm->mport, cmbox);
+	if (msg) {
+		for (i = 0; i < RIOCM_RX_RING_SIZE; i++) {
+			if (cm->rx_buf[i] == msg) {
+				cm->rx_buf[i] = NULL;
+				cm->rx_slots++;
+				break;
+			}
+		}
+
+		if (i == RIOCM_RX_RING_SIZE)
+			riocm_warn("no record for buffer 0x%p", msg);
+	}
+
+	return msg;
+}
+
+/*
+ * riocm_rx_fill - fills a ring of receive buffers for given cm device
+ * @cm: cm_dev object
+ * @nent: max number of entries to fill
+ *
+ * Returns: none
+ */
+static void riocm_rx_fill(struct cm_dev *cm, int nent)
+{
+	int i;
+
+	if (cm->rx_slots == 0)
+		return;
+
+	for (i = 0; i < RIOCM_RX_RING_SIZE && cm->rx_slots && nent; i++) {
+		if (cm->rx_buf[i] == NULL) {
+			cm->rx_buf[i] = kmalloc(RIO_MAX_MSG_SIZE, GFP_KERNEL);
+			if (cm->rx_buf[i] == NULL)
+				break;
+			rio_add_inb_buffer(cm->mport, cmbox, cm->rx_buf[i]);
+			cm->rx_slots--;
+			nent--;
+		}
+	}
+}
+
+/*
+ * riocm_rx_free - frees all receive buffers associated with given cm device
+ * @cm: cm_dev object
+ *
+ * Returns: none
+ */
+static void riocm_rx_free(struct cm_dev *cm)
+{
+	int i;
+
+	for (i = 0; i < RIOCM_RX_RING_SIZE; i++) {
+		if (cm->rx_buf[i] != NULL) {
+			kfree(cm->rx_buf[i]);
+			cm->rx_buf[i] = NULL;
+		}
+	}
+}
+
+/*
+ * riocm_req_handler - connection request handler
+ * @cm: cm_dev object
+ * @req_data: pointer to the request packet
+ *
+ * Returns: 0 if success, or
+ *          -EINVAL if channel is not in correct state,
+ *          -ENODEV if cannot find a channel with specified ID,
+ *          -ENOMEM if unable to allocate memory to store the request
+ */
+static int riocm_req_handler(struct cm_dev *cm, void *req_data)
+{
+	struct rio_channel *ch;
+	struct conn_req *req;
+	struct rio_ch_chan_hdr *hh = req_data;
+	u16 chnum;
+
+	chnum = ntohs(hh->dst_ch);
+
+	ch = riocm_get_channel(chnum);
+
+	if (!ch)
+		return -ENODEV;
+
+	if (ch->state != RIO_CM_LISTEN) {
+		riocm_debug(RX_CMD, "channel %d is not in listen state", chnum);
+		riocm_put_channel(ch);
+		return -EINVAL;
+	}
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req) {
+		riocm_put_channel(ch);
+		return -ENOMEM;
+	}
+
+	req->destid = ntohl(hh->bhdr.src_id);
+	req->chan = ntohs(hh->src_ch);
+	req->cmdev = cm;
+
+	spin_lock_bh(&ch->lock);
+	list_add_tail(&req->node, &ch->accept_queue);
+	spin_unlock_bh(&ch->lock);
+	complete(&ch->comp);
+	riocm_put_channel(ch);
+
+	return 0;
+}
+
+/*
+ * riocm_resp_handler - response to connection request handler
+ * @resp_data: pointer to the response packet
+ *
+ * Returns: 0 if success, or
+ *          -EINVAL if channel is not in correct state,
+ *          -ENODEV if cannot find a channel with specified ID,
+ */
+static int riocm_resp_handler(void *resp_data)
+{
+	struct rio_channel *ch;
+	struct rio_ch_chan_hdr *hh = resp_data;
+	u16 chnum;
+
+	chnum = ntohs(hh->dst_ch);
+	ch = riocm_get_channel(chnum);
+	if (!ch)
+		return -ENODEV;
+
+	if (ch->state != RIO_CM_CONNECT) {
+		riocm_put_channel(ch);
+		return -EINVAL;
+	}
+
+	riocm_exch(ch, RIO_CM_CONNECTED);
+	ch->rem_channel = ntohs(hh->src_ch);
+	complete(&ch->comp);
+	riocm_put_channel(ch);
+
+	return 0;
+}
+
+/*
+ * riocm_close_handler - channel close request handler
+ * @req_data: pointer to the request packet
+ *
+ * Returns: 0 if success, or
+ *          -ENODEV if cannot find a channel with specified ID,
+ *            + error codes returned by riocm_ch_close.
+ */
+static int riocm_close_handler(void *data)
+{
+	struct rio_channel *ch;
+	struct rio_ch_chan_hdr *hh = data;
+	int ret;
+
+	riocm_debug(RX_CMD, "for ch=%d", ntohs(hh->dst_ch));
+
+	spin_lock_bh(&idr_lock);
+	ch = idr_find(&ch_idr, ntohs(hh->dst_ch));
+	if (!ch) {
+		spin_unlock_bh(&idr_lock);
+		return -ENODEV;
+	}
+	idr_remove(&ch_idr, ch->id);
+	spin_unlock_bh(&idr_lock);
+
+	riocm_exch(ch, RIO_CM_DISCONNECT);
+
+	ret = riocm_ch_close(ch);
+	if (ret)
+		riocm_debug(RX_CMD, "riocm_ch_close() returned %d", ret);
+
+	return 0;
+}
+
+/*
+ * rio_cm_handler - function that services request (non-data) packets
+ * @cm: cm_dev object
+ * @data: pointer to the packet
+ */
+static void rio_cm_handler(struct cm_dev *cm, void *data)
+{
+	struct rio_ch_chan_hdr *hdr;
+
+	if (!rio_mport_is_running(cm->mport))
+		goto out;
+
+	hdr = data;
+
+	riocm_debug(RX_CMD, "OP=%x for ch=%d from %d",
+		    hdr->ch_op, ntohs(hdr->dst_ch), ntohs(hdr->src_ch));
+
+	switch (hdr->ch_op) {
+	case CM_CONN_REQ:
+		riocm_req_handler(cm, data);
+		break;
+	case CM_CONN_ACK:
+		riocm_resp_handler(data);
+		break;
+	case CM_CONN_CLOSE:
+		riocm_close_handler(data);
+		break;
+	default:
+		riocm_error("Invalid packet header");
+		break;
+	}
+out:
+	kfree(data);
+}
+
+/*
+ * rio_rx_data_handler - received data packet handler
+ * @cm: cm_dev object
+ * @buf: data packet
+ *
+ * Returns: 0 if success, or
+ *          -ENODEV if cannot find a channel with specified ID,
+ *          -EIO if channel is not in CONNECTED state,
+ *          -ENOMEM if channel RX queue is full (packet discarded)
+ */
+static int rio_rx_data_handler(struct cm_dev *cm, void *buf)
+{
+	struct rio_ch_chan_hdr *hdr;
+	struct rio_channel *ch;
+
+	hdr = buf;
+
+	riocm_debug(RX_DATA, "for ch=%d", ntohs(hdr->dst_ch));
+
+	ch = riocm_get_channel(ntohs(hdr->dst_ch));
+	if (!ch) {
+		/* Discard data message for non-existing channel */
+		kfree(buf);
+		return -ENODEV;
+	}
+
+	/* Place pointer to the buffer into channel's RX queue */
+	spin_lock(&ch->lock);
+
+	if (ch->state != RIO_CM_CONNECTED) {
+		/* Channel is not ready to receive data, discard a packet */
+		riocm_debug(RX_DATA, "ch=%d is in wrong state=%d",
+			    ch->id, ch->state);
+		spin_unlock(&ch->lock);
+		kfree(buf);
+		riocm_put_channel(ch);
+		return -EIO;
+	}
+
+	if (ch->rx_ring.count == RIOCM_RX_RING_SIZE) {
+		/* If RX ring is full, discard a packet */
+		riocm_debug(RX_DATA, "ch=%d is full", ch->id);
+		spin_unlock(&ch->lock);
+		kfree(buf);
+		riocm_put_channel(ch);
+		return -ENOMEM;
+	}
+
+	ch->rx_ring.buf[ch->rx_ring.head] = buf;
+	ch->rx_ring.head++;
+	ch->rx_ring.count++;
+	ch->rx_ring.head %= RIOCM_RX_RING_SIZE;
+
+	complete(&ch->comp);
+
+	spin_unlock(&ch->lock);
+	riocm_put_channel(ch);
+
+	return 0;
+}
+
+/*
+ * rio_ibmsg_handler - inbound message packet handler
+ */
+static void rio_ibmsg_handler(struct work_struct *work)
+{
+	struct cm_dev *cm = container_of(work, struct cm_dev, rx_work);
+	void *data;
+	struct rio_ch_chan_hdr *hdr;
+
+	if (!rio_mport_is_running(cm->mport))
+		return;
+
+	while (1) {
+		mutex_lock(&cm->rx_lock);
+		data = riocm_rx_get_msg(cm);
+		if (data)
+			riocm_rx_fill(cm, 1);
+		mutex_unlock(&cm->rx_lock);
+
+		if (data == NULL)
+			break;
+
+		hdr = data;
+
+		if (hdr->bhdr.type != RIO_CM_CHAN) {
+			/* For now simply discard packets other than channel */
+			riocm_error("Unsupported TYPE code (0x%x). Msg dropped",
+				    hdr->bhdr.type);
+			kfree(data);
+			continue;
+		}
+
+		/* Process a channel message */
+		if (hdr->ch_op == CM_DATA_MSG)
+			rio_rx_data_handler(cm, data);
+		else
+			rio_cm_handler(cm, data);
+	}
+}
+
+static void riocm_inb_msg_event(struct rio_mport *mport, void *dev_id,
+				int mbox, int slot)
+{
+	struct cm_dev *cm = dev_id;
+
+	if (rio_mport_is_running(cm->mport) && !work_pending(&cm->rx_work))
+		queue_work(cm->rx_wq, &cm->rx_work);
+}
+
+/*
+ * rio_txcq_handler - TX completion handler
+ * @cm: cm_dev object
+ * @slot: TX queue slot
+ *
+ * TX completion handler also ensures that pending request packets are placed
+ * into transmit queue as soon as a free slot becomes available. This is done
+ * to give higher priority to request packets during high intensity data flow.
+ */
+static void rio_txcq_handler(struct cm_dev *cm, int slot)
+{
+	int ack_slot;
+
+	/* ATTN: Add TX completion notification if/when direct buffer
+	 * transfer is implemented. At this moment only correct tracking
+	 * of tx_count is important.
+	 */
+	riocm_debug(TX_EVENT, "for mport_%d slot %d tx_cnt %d",
+		    cm->mport->id, slot, cm->tx_cnt);
+
+	spin_lock(&cm->tx_lock);
+	ack_slot = cm->tx_ack_slot;
+
+	if (ack_slot == slot)
+		riocm_debug(TX_EVENT, "slot == ack_slot");
+
+	while (cm->tx_cnt && ((ack_slot != slot) ||
+	       (cm->tx_cnt == RIOCM_TX_RING_SIZE))) {
+
+		cm->tx_buf[ack_slot] = NULL;
+		++ack_slot;
+		ack_slot &= (RIOCM_TX_RING_SIZE - 1);
+		cm->tx_cnt--;
+	}
+
+	if (cm->tx_cnt < 0 || cm->tx_cnt > RIOCM_TX_RING_SIZE)
+		riocm_error("tx_cnt %d out of sync", cm->tx_cnt);
+
+	WARN_ON((cm->tx_cnt < 0) || (cm->tx_cnt > RIOCM_TX_RING_SIZE));
+
+	cm->tx_ack_slot = ack_slot;
+
+	/*
+	 * If there are pending requests, insert them into transmit queue
+	 */
+	if (!list_empty(&cm->tx_reqs) && (cm->tx_cnt < RIOCM_TX_RING_SIZE)) {
+		struct tx_req *req, *_req;
+		int rc;
+
+		list_for_each_entry_safe(req, _req, &cm->tx_reqs, node) {
+			list_del(&req->node);
+			cm->tx_buf[cm->tx_slot] = req->buffer;
+			rc = rio_add_outb_message(cm->mport, req->rdev, cmbox,
+						  req->buffer, req->len);
+			kfree(req->buffer);
+			kfree(req);
+
+			++cm->tx_cnt;
+			++cm->tx_slot;
+			cm->tx_slot &= (RIOCM_TX_RING_SIZE - 1);
+			if (cm->tx_cnt == RIOCM_TX_RING_SIZE)
+				break;
+		}
+	}
+
+	spin_unlock(&cm->tx_lock);
+}
+
+static void riocm_outb_msg_event(struct rio_mport *mport, void *dev_id,
+				 int mbox, int slot)
+{
+	struct cm_dev *cm = dev_id;
+
+	if (cm && rio_mport_is_running(cm->mport))
+		rio_txcq_handler(cm, slot);
+}
+
+static int riocm_queue_req(struct cm_dev *cm, struct rio_dev *rdev,
+			   void *buffer, size_t len)
+{
+	unsigned long flags;
+	struct tx_req *treq;
+
+	treq = kzalloc(sizeof(*treq), GFP_KERNEL);
+	if (treq == NULL)
+		return -ENOMEM;
+
+	treq->rdev = rdev;
+	treq->buffer = buffer;
+	treq->len = len;
+
+	spin_lock_irqsave(&cm->tx_lock, flags);
+	list_add_tail(&treq->node, &cm->tx_reqs);
+	spin_unlock_irqrestore(&cm->tx_lock, flags);
+	return 0;
+}
+
+/*
+ * riocm_post_send - helper function that places packet into msg TX queue
+ * @cm: cm_dev object
+ * @rdev: target RapidIO device object (required by outbound msg interface)
+ * @buffer: pointer to a packet buffer to send
+ * @len: length of data to transfer
+ * @req: request priority flag
+ *
+ * Returns: 0 if success, or error code otherwise.
+ */
+static int riocm_post_send(struct cm_dev *cm, struct rio_dev *rdev,
+			   void *buffer, size_t len)
+{
+	int rc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cm->tx_lock, flags);
+
+	if (cm->mport == NULL) {
+		rc = -ENODEV;
+		goto err_out;
+	}
+
+	if (cm->tx_cnt == RIOCM_TX_RING_SIZE) {
+		riocm_debug(TX, "Tx Queue is full");
+		rc = -EBUSY;
+		goto err_out;
+	}
+
+	cm->tx_buf[cm->tx_slot] = buffer;
+	rc = rio_add_outb_message(cm->mport, rdev, cmbox, buffer, len);
+
+	riocm_debug(TX, "Add buf@%p destid=%x tx_slot=%d tx_cnt=%d",
+		 buffer, rdev->destid, cm->tx_slot, cm->tx_cnt);
+
+	++cm->tx_cnt;
+	++cm->tx_slot;
+	cm->tx_slot &= (RIOCM_TX_RING_SIZE - 1);
+
+err_out:
+	spin_unlock_irqrestore(&cm->tx_lock, flags);
+	return rc;
+}
+
+/*
+ * riocm_ch_send - sends a data packet to a remote device
+ * @ch_id: local channel ID
+ * @buf: pointer to a data buffer to send (including CM header)
+ * @len: length of data to transfer (including CM header)
+ *
+ * ATTN: ASSUMES THAT THE HEADER SPACE IS RESERVED PART OF THE DATA PACKET
+ *
+ * Returns: 0 if success, or
+ *          -EINVAL if one or more input parameters is/are not valid,
+ *          -ENODEV if cannot find a channel with specified ID,
+ *          -EAGAIN if a channel is not in CONNECTED state,
+ *	    + error codes returned by HW send routine.
+ */
+static int riocm_ch_send(u16 ch_id, void *buf, int len)
+{
+	struct rio_channel *ch;
+	struct rio_ch_chan_hdr *hdr;
+	int ret;
+
+	if (buf == NULL || ch_id == 0 || len == 0 || len > RIO_MAX_MSG_SIZE)
+		return -EINVAL;
+
+	ch = riocm_get_channel(ch_id);
+	if (!ch) {
+		riocm_error("%s(%d) ch_%d not found", current->comm,
+			    task_pid_nr(current), ch_id);
+		return -ENODEV;
+	}
+
+	if (!riocm_cmp(ch, RIO_CM_CONNECTED)) {
+		ret = -EAGAIN;
+		goto err_out;
+	}
+
+	/*
+	 * Fill buffer header section with corresponding channel data
+	 */
+	hdr = buf;
+
+	hdr->bhdr.src_id = htonl(ch->loc_destid);
+	hdr->bhdr.dst_id = htonl(ch->rem_destid);
+	hdr->bhdr.src_mbox = cmbox;
+	hdr->bhdr.dst_mbox = cmbox;
+	hdr->bhdr.type = RIO_CM_CHAN;
+	hdr->ch_op = CM_DATA_MSG;
+	hdr->dst_ch = htons(ch->rem_channel);
+	hdr->src_ch = htons(ch->id);
+	hdr->msg_len = htons((u16)len);
+
+	/* ATTN: the function call below relies on the fact that underlying
+	 * HW-specific add_outb_message() routine copies TX data into its own
+	 * internal transfer buffer (true for all RIONET compatible mport
+	 * drivers). Must be reviewed if mport driver uses the buffer directly.
+	 */
+
+	ret = riocm_post_send(ch->cmdev, ch->rdev, buf, len);
+	if (ret)
+		riocm_debug(TX, "ch %d send_err=%d", ch->id, ret);
+err_out:
+	riocm_put_channel(ch);
+	return ret;
+}
+
+static int riocm_ch_free_rxbuf(struct rio_channel *ch, void *buf)
+{
+	int i, ret = -EINVAL;
+
+	spin_lock_bh(&ch->lock);
+
+	for (i = 0; i < RIOCM_RX_RING_SIZE; i++) {
+		if (ch->rx_ring.inuse[i] == buf) {
+			ch->rx_ring.inuse[i] = NULL;
+			ch->rx_ring.inuse_cnt--;
+			ret = 0;
+			break;
+		}
+	}
+
+	spin_unlock_bh(&ch->lock);
+
+	if (!ret)
+		kfree(buf);
+
+	return ret;
+}
+
+/*
+ * riocm_ch_receive - fetch a data packet received for the specified channel
+ * @ch: local channel ID
+ * @buf: pointer to a packet buffer
+ * @timeout: timeout to wait for incoming packet (in jiffies)
+ *
+ * Returns: 0 and valid buffer pointer if success, or NULL pointer and one of:
+ *          -EAGAIN if a channel is not in CONNECTED state,
+ *          -ENOMEM if in-use tracking queue is full,
+ *          -ETIME if wait timeout expired,
+ *	    -EINTR if wait was interrupted.
+ */
+static int riocm_ch_receive(struct rio_channel *ch, void **buf, long timeout)
+{
+	void *rxmsg = NULL;
+	int i, ret = 0;
+	long wret;
+
+	if (!riocm_cmp(ch, RIO_CM_CONNECTED)) {
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	if (ch->rx_ring.inuse_cnt == RIOCM_RX_RING_SIZE) {
+		/* If we do not have entries to track buffers given to upper
+		 * layer, reject request.
+		 */
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	wret = wait_for_completion_interruptible_timeout(&ch->comp, timeout);
+
+	riocm_debug(WAIT, "wait on %d returned %ld", ch->id, wret);
+
+	if (!wret)
+		ret = -ETIME;
+	else if (wret == -ERESTARTSYS)
+		ret = -EINTR;
+	else
+		ret = riocm_cmp(ch, RIO_CM_CONNECTED) ? 0 : -ECONNRESET;
+
+	if (ret)
+		goto out;
+
+	spin_lock_bh(&ch->lock);
+
+	rxmsg = ch->rx_ring.buf[ch->rx_ring.tail];
+	ch->rx_ring.buf[ch->rx_ring.tail] = NULL;
+	ch->rx_ring.count--;
+	ch->rx_ring.tail++;
+	ch->rx_ring.tail %= RIOCM_RX_RING_SIZE;
+	ret = -ENOMEM;
+
+	for (i = 0; i < RIOCM_RX_RING_SIZE; i++) {
+		if (ch->rx_ring.inuse[i] == NULL) {
+			ch->rx_ring.inuse[i] = rxmsg;
+			ch->rx_ring.inuse_cnt++;
+			ret = 0;
+			break;
+		}
+	}
+
+	if (ret) {
+		/* We have no entry to store pending message: drop it */
+		kfree(rxmsg);
+		rxmsg = NULL;
+	}
+
+	spin_unlock_bh(&ch->lock);
+out:
+	*buf = rxmsg;
+	return ret;
+}
+
+/*
+ * riocm_ch_connect - sends a connect request to a remote device
+ * @loc_ch: local channel ID
+ * @cm: CM device to send connect request
+ * @peer: target RapidIO device
+ * @rem_ch: remote channel ID
+ *
+ * Returns: 0 if success, or
+ *          -EINVAL if the channel is not in IDLE state,
+ *          -EAGAIN if no connection request available immediately,
+ *          -ETIME if ACK response timeout expired,
+ *          -EINTR if wait for response was interrupted.
+ */
+static int riocm_ch_connect(u16 loc_ch, struct cm_dev *cm,
+			    struct cm_peer *peer, u16 rem_ch)
+{
+	struct rio_channel *ch = NULL;
+	struct rio_ch_chan_hdr *hdr;
+	int ret;
+	long wret;
+
+	ch = riocm_get_channel(loc_ch);
+	if (!ch)
+		return -ENODEV;
+
+	if (!riocm_cmp_exch(ch, RIO_CM_IDLE, RIO_CM_CONNECT)) {
+		ret = -EINVAL;
+		goto conn_done;
+	}
+
+	ch->cmdev = cm;
+	ch->rdev = peer->rdev;
+	ch->context = NULL;
+	ch->loc_destid = cm->mport->host_deviceid;
+	ch->rem_channel = rem_ch;
+
+	/*
+	 * Send connect request to the remote RapidIO device
+	 */
+
+	hdr = kzalloc(sizeof(*hdr), GFP_KERNEL);
+	if (hdr == NULL) {
+		ret = -ENOMEM;
+		goto conn_done;
+	}
+
+	hdr->bhdr.src_id = htonl(ch->loc_destid);
+	hdr->bhdr.dst_id = htonl(peer->rdev->destid);
+	hdr->bhdr.src_mbox = cmbox;
+	hdr->bhdr.dst_mbox = cmbox;
+	hdr->bhdr.type = RIO_CM_CHAN;
+	hdr->ch_op = CM_CONN_REQ;
+	hdr->dst_ch = htons(rem_ch);
+	hdr->src_ch = htons(loc_ch);
+
+	/* ATTN: the function call below relies on the fact that underlying
+	 * HW-specific add_outb_message() routine copies TX data into its
+	 * internal transfer buffer. Must be reviewed if mport driver uses
+	 * this buffer directly.
+	 */
+	ret = riocm_post_send(cm, peer->rdev, hdr, sizeof(*hdr));
+
+	if (ret != -EBUSY) {
+		kfree(hdr);
+	} else {
+		ret = riocm_queue_req(cm, peer->rdev, hdr, sizeof(*hdr));
+		if (ret)
+			kfree(hdr);
+	}
+
+	if (ret) {
+		riocm_cmp_exch(ch, RIO_CM_CONNECT, RIO_CM_IDLE);
+		goto conn_done;
+	}
+
+	/* Wait for connect response from the remote device */
+	wret = wait_for_completion_interruptible_timeout(&ch->comp,
+							 RIOCM_CONNECT_TO * HZ);
+	riocm_debug(WAIT, "wait on %d returns %ld", ch->id, wret);
+
+	if (!wret)
+		ret = -ETIME;
+	else if (wret == -ERESTARTSYS)
+		ret = -EINTR;
+	else
+		ret = riocm_cmp(ch, RIO_CM_CONNECTED) ? 0 : -1;
+
+conn_done:
+	riocm_put_channel(ch);
+	return ret;
+}
+
+static int riocm_send_ack(struct rio_channel *ch)
+{
+	struct rio_ch_chan_hdr *hdr;
+	int ret;
+
+	hdr = kzalloc(sizeof(*hdr), GFP_KERNEL);
+	if (hdr == NULL)
+		return -ENOMEM;
+
+	hdr->bhdr.src_id = htonl(ch->loc_destid);
+	hdr->bhdr.dst_id = htonl(ch->rem_destid);
+	hdr->dst_ch = htons(ch->rem_channel);
+	hdr->src_ch = htons(ch->id);
+	hdr->bhdr.src_mbox = cmbox;
+	hdr->bhdr.dst_mbox = cmbox;
+	hdr->bhdr.type = RIO_CM_CHAN;
+	hdr->ch_op = CM_CONN_ACK;
+
+	/* ATTN: the function call below relies on the fact that underlying
+	 * add_outb_message() routine copies TX data into its internal transfer
+	 * buffer. Review if switching to direct buffer version.
+	 */
+	ret = riocm_post_send(ch->cmdev, ch->rdev, hdr, sizeof(*hdr));
+
+	if (ret == -EBUSY && !riocm_queue_req(ch->cmdev,
+					      ch->rdev, hdr, sizeof(*hdr)))
+		return 0;
+	kfree(hdr);
+
+	if (ret)
+		riocm_error("send ACK to ch_%d on %s failed (ret=%d)",
+			    ch->id, rio_name(ch->rdev), ret);
+	return ret;
+}
+
+/*
+ * riocm_ch_accept - accept incoming connection request
+ * @ch_id: channel ID
+ * @new_ch_id: local mport device
+ * @timeout: wait timeout (if 0 non-blocking call, do not wait if connection
+ *           request is not available).
+ *
+ * Returns: pointer to new channel struct if success, or error-valued pointer:
+ *          -ENODEV - cannot find specified channel or mport,
+ *          -EINVAL - the channel is not in IDLE state,
+ *          -EAGAIN - no connection request available immediately (timeout=0),
+ *          -ENOMEM - unable to allocate new channel,
+ *          -ETIME - wait timeout expired,
+ *          -EINTR - wait was interrupted.
+ */
+static struct rio_channel *riocm_ch_accept(u16 ch_id, u16 *new_ch_id,
+					   long timeout)
+{
+	struct rio_channel *ch;
+	struct rio_channel *new_ch;
+	struct conn_req *req;
+	struct cm_peer *peer;
+	int found = 0;
+	int err = 0;
+	long wret;
+
+	ch = riocm_get_channel(ch_id);
+	if (!ch)
+		return ERR_PTR(-EINVAL);
+
+	if (!riocm_cmp(ch, RIO_CM_LISTEN)) {
+		err = -EINVAL;
+		goto err_put;
+	}
+
+	/* Don't sleep if this is a non blocking call */
+	if (!timeout) {
+		if (!try_wait_for_completion(&ch->comp)) {
+			err = -EAGAIN;
+			goto err_put;
+		}
+	} else {
+		riocm_debug(WAIT, "on %d", ch->id);
+
+		wret = wait_for_completion_interruptible_timeout(&ch->comp,
+								 timeout);
+		if (!wret) {
+			err = -ETIME;
+			goto err_put;
+		} else if (wret == -ERESTARTSYS) {
+			err = -EINTR;
+			goto err_put;
+		}
+	}
+
+	spin_lock_bh(&ch->lock);
+
+	if (ch->state != RIO_CM_LISTEN) {
+		err = -ECANCELED;
+	} else if (list_empty(&ch->accept_queue)) {
+		riocm_debug(WAIT, "on %d accept_queue is empty on completion",
+			    ch->id);
+		err = -EIO;
+	}
+
+	spin_unlock_bh(&ch->lock);
+
+	if (err) {
+		riocm_debug(WAIT, "on %d returns %d", ch->id, err);
+		goto err_put;
+	}
+
+	/* Create new channel for this connection */
+	new_ch = riocm_ch_alloc(RIOCM_CHNUM_AUTO);
+
+	if (IS_ERR(new_ch)) {
+		riocm_error("failed to get channel for new req (%ld)",
+			PTR_ERR(new_ch));
+		err = -ENOMEM;
+		goto err_put;
+	}
+
+	spin_lock_bh(&ch->lock);
+
+	req = list_first_entry(&ch->accept_queue, struct conn_req, node);
+	list_del(&req->node);
+	new_ch->cmdev = ch->cmdev;
+	new_ch->loc_destid = ch->loc_destid;
+	new_ch->rem_destid = req->destid;
+	new_ch->rem_channel = req->chan;
+
+	spin_unlock_bh(&ch->lock);
+	riocm_put_channel(ch);
+	ch = NULL;
+	kfree(req);
+
+	down_read(&rdev_sem);
+	/* Find requester's device object */
+	list_for_each_entry(peer, &new_ch->cmdev->peers, node) {
+		if (peer->rdev->destid == new_ch->rem_destid) {
+			riocm_debug(RX_CMD, "found matching device(%s)",
+				    rio_name(peer->rdev));
+			found = 1;
+			break;
+		}
+	}
+	up_read(&rdev_sem);
+
+	if (!found) {
+		/* If peer device object not found, simply ignore the request */
+		err = -ENODEV;
+		goto err_put_new_ch;
+	}
+
+	new_ch->rdev = peer->rdev;
+	new_ch->state = RIO_CM_CONNECTED;
+	spin_lock_init(&new_ch->lock);
+
+	/* Acknowledge the connection request. */
+	riocm_send_ack(new_ch);
+
+	*new_ch_id = new_ch->id;
+	return new_ch;
+
+err_put_new_ch:
+	spin_lock_bh(&idr_lock);
+	idr_remove(&ch_idr, new_ch->id);
+	spin_unlock_bh(&idr_lock);
+	riocm_put_channel(new_ch);
+
+err_put:
+	if (ch)
+		riocm_put_channel(ch);
+	*new_ch_id = 0;
+	return ERR_PTR(err);
+}
+
+/*
+ * riocm_ch_listen - puts a channel into LISTEN state
+ * @ch_id: channel ID
+ *
+ * Returns: 0 if success, or
+ *          -EINVAL if the specified channel does not exists or
+ *                  is not in CHAN_BOUND state.
+ */
+static int riocm_ch_listen(u16 ch_id)
+{
+	struct rio_channel *ch = NULL;
+	int ret = 0;
+
+	riocm_debug(CHOP, "(ch_%d)", ch_id);
+
+	ch = riocm_get_channel(ch_id);
+	if (!ch)
+		return -EINVAL;
+	if (!riocm_cmp_exch(ch, RIO_CM_CHAN_BOUND, RIO_CM_LISTEN))
+		ret = -EINVAL;
+	riocm_put_channel(ch);
+	return ret;
+}
+
+/*
+ * riocm_ch_bind - associate a channel object and an mport device
+ * @ch_id: channel ID
+ * @mport_id: local mport device ID
+ * @context: pointer to the additional caller's context
+ *
+ * Returns: 0 if success, or
+ *          -ENODEV if cannot find specified mport,
+ *          -EINVAL if the specified channel does not exist or
+ *                  is not in IDLE state.
+ */
+static int riocm_ch_bind(u16 ch_id, u8 mport_id, void *context)
+{
+	struct rio_channel *ch = NULL;
+	struct cm_dev *cm;
+	int rc = -ENODEV;
+
+	riocm_debug(CHOP, "ch_%d to mport_%d", ch_id, mport_id);
+
+	/* Find matching cm_dev object */
+	down_read(&rdev_sem);
+	list_for_each_entry(cm, &cm_dev_list, list) {
+		if ((cm->mport->id == mport_id) &&
+		     rio_mport_is_running(cm->mport)) {
+			rc = 0;
+			break;
+		}
+	}
+
+	if (rc)
+		goto exit;
+
+	ch = riocm_get_channel(ch_id);
+	if (!ch) {
+		rc = -EINVAL;
+		goto exit;
+	}
+
+	spin_lock_bh(&ch->lock);
+	if (ch->state != RIO_CM_IDLE) {
+		spin_unlock_bh(&ch->lock);
+		rc = -EINVAL;
+		goto err_put;
+	}
+
+	ch->cmdev = cm;
+	ch->loc_destid = cm->mport->host_deviceid;
+	ch->context = context;
+	ch->state = RIO_CM_CHAN_BOUND;
+	spin_unlock_bh(&ch->lock);
+err_put:
+	riocm_put_channel(ch);
+exit:
+	up_read(&rdev_sem);
+	return rc;
+}
+
+/*
+ * riocm_ch_alloc - channel object allocation helper routine
+ * @ch_num: channel ID (1 ... RIOCM_MAX_CHNUM, 0 = automatic)
+ *
+ * Return value: pointer to newly created channel object,
+ *               or error-valued pointer
+ */
+static struct rio_channel *riocm_ch_alloc(u16 ch_num)
+{
+	int id;
+	int start, end;
+	struct rio_channel *ch;
+
+	ch = kzalloc(sizeof(*ch), GFP_KERNEL);
+	if (!ch)
+		return ERR_PTR(-ENOMEM);
+
+	if (ch_num) {
+		/* If requested, try to obtain the specified channel ID */
+		start = ch_num;
+		end = ch_num + 1;
+	} else {
+		/* Obtain channel ID from the dynamic allocation range */
+		start = chstart;
+		end = RIOCM_MAX_CHNUM + 1;
+	}
+
+	idr_preload(GFP_KERNEL);
+	spin_lock_bh(&idr_lock);
+	id = idr_alloc_cyclic(&ch_idr, ch, start, end, GFP_NOWAIT);
+	spin_unlock_bh(&idr_lock);
+	idr_preload_end();
+
+	if (id < 0) {
+		kfree(ch);
+		return ERR_PTR(id == -ENOSPC ? -EBUSY : id);
+	}
+
+	ch->id = (u16)id;
+	ch->state = RIO_CM_IDLE;
+	spin_lock_init(&ch->lock);
+	INIT_LIST_HEAD(&ch->accept_queue);
+	INIT_LIST_HEAD(&ch->ch_node);
+	init_completion(&ch->comp);
+	init_completion(&ch->comp_close);
+	kref_init(&ch->ref);
+	ch->rx_ring.head = 0;
+	ch->rx_ring.tail = 0;
+	ch->rx_ring.count = 0;
+	ch->rx_ring.inuse_cnt = 0;
+
+	return ch;
+}
+
+/*
+ * riocm_ch_create - creates a new channel object and allocates ID for it
+ * @ch_num: channel ID (1 ... RIOCM_MAX_CHNUM, 0 = automatic)
+ *
+ * Allocates and initializes a new channel object. If the parameter ch_num > 0
+ * and is within the valid range, riocm_ch_create tries to allocate the
+ * specified ID for the new channel. If ch_num = 0, channel ID will be assigned
+ * automatically from the range (chstart ... RIOCM_MAX_CHNUM).
+ * Module parameter 'chstart' defines start of an ID range available for dynamic
+ * allocation. Range below 'chstart' is reserved for pre-defined ID numbers.
+ * Available channel numbers are limited by 16-bit size of channel numbers used
+ * in the packet header.
+ *
+ * Return value: PTR to rio_channel structure if successful (with channel number
+ *               updated via pointer) or error-valued pointer if error.
+ */
+static struct rio_channel *riocm_ch_create(u16 *ch_num)
+{
+	struct rio_channel *ch = NULL;
+
+	ch = riocm_ch_alloc(*ch_num);
+
+	if (IS_ERR(ch))
+		riocm_debug(CHOP, "Failed to allocate channel %d (err=%ld)",
+			    *ch_num, PTR_ERR(ch));
+	else
+		*ch_num = ch->id;
+
+	return ch;
+}
+
+/*
+ * riocm_ch_free - channel object release routine
+ * @ref: pointer to a channel's kref structure
+ */
+static void riocm_ch_free(struct kref *ref)
+{
+	struct rio_channel *ch = container_of(ref, struct rio_channel, ref);
+	int i;
+
+	riocm_debug(CHOP, "(ch_%d)", ch->id);
+
+	if (ch->rx_ring.inuse_cnt) {
+		for (i = 0;
+		     i < RIOCM_RX_RING_SIZE && ch->rx_ring.inuse_cnt; i++) {
+			if (ch->rx_ring.inuse[i] != NULL) {
+				kfree(ch->rx_ring.inuse[i]);
+				ch->rx_ring.inuse_cnt--;
+			}
+		}
+	}
+
+	if (ch->rx_ring.count)
+		for (i = 0; i < RIOCM_RX_RING_SIZE && ch->rx_ring.count; i++) {
+			if (ch->rx_ring.buf[i] != NULL) {
+				kfree(ch->rx_ring.buf[i]);
+				ch->rx_ring.count--;
+			}
+		}
+
+	complete(&ch->comp_close);
+}
+
+static int riocm_send_close(struct rio_channel *ch)
+{
+	struct rio_ch_chan_hdr *hdr;
+	int ret;
+
+	/*
+	 * Send CH_CLOSE notification to the remote RapidIO device
+	 */
+
+	hdr = kzalloc(sizeof(*hdr), GFP_KERNEL);
+	if (hdr == NULL)
+		return -ENOMEM;
+
+	hdr->bhdr.src_id = htonl(ch->loc_destid);
+	hdr->bhdr.dst_id = htonl(ch->rem_destid);
+	hdr->bhdr.src_mbox = cmbox;
+	hdr->bhdr.dst_mbox = cmbox;
+	hdr->bhdr.type = RIO_CM_CHAN;
+	hdr->ch_op = CM_CONN_CLOSE;
+	hdr->dst_ch = htons(ch->rem_channel);
+	hdr->src_ch = htons(ch->id);
+
+	/* ATTN: the function call below relies on the fact that underlying
+	 * add_outb_message() routine copies TX data into its internal transfer
+	 * buffer. Needs to be reviewed if switched to direct buffer mode.
+	 */
+	ret = riocm_post_send(ch->cmdev, ch->rdev, hdr, sizeof(*hdr));
+
+	if (ret == -EBUSY && !riocm_queue_req(ch->cmdev, ch->rdev,
+					      hdr, sizeof(*hdr)))
+		return 0;
+	kfree(hdr);
+
+	if (ret)
+		riocm_error("ch(%d) send CLOSE failed (ret=%d)", ch->id, ret);
+
+	return ret;
+}
+
+/*
+ * riocm_ch_close - closes a channel object with specified ID (by local request)
+ * @ch: channel to be closed
+ */
+static int riocm_ch_close(struct rio_channel *ch)
+{
+	unsigned long tmo = msecs_to_jiffies(3000);
+	enum rio_cm_state state;
+	long wret;
+	int ret = 0;
+
+	riocm_debug(CHOP, "ch_%d by %s(%d)",
+		    ch->id, current->comm, task_pid_nr(current));
+
+	state = riocm_exch(ch, RIO_CM_DESTROYING);
+	if (state == RIO_CM_CONNECTED)
+		riocm_send_close(ch);
+
+	complete_all(&ch->comp);
+
+	riocm_put_channel(ch);
+	wret = wait_for_completion_interruptible_timeout(&ch->comp_close, tmo);
+
+	riocm_debug(WAIT, "wait on %d returns %ld", ch->id, wret);
+
+	if (wret == 0) {
+		/* Timeout on wait occurred */
+		riocm_debug(CHOP, "%s(%d) timed out waiting for ch %d",
+		       current->comm, task_pid_nr(current), ch->id);
+		ret = -ETIMEDOUT;
+	} else if (wret == -ERESTARTSYS) {
+		/* Wait_for_completion was interrupted by a signal */
+		riocm_debug(CHOP, "%s(%d) wait for ch %d was interrupted",
+			current->comm, task_pid_nr(current), ch->id);
+		ret = -EINTR;
+	}
+
+	if (!ret) {
+		riocm_debug(CHOP, "ch_%d resources released", ch->id);
+		kfree(ch);
+	} else {
+		riocm_debug(CHOP, "failed to release ch_%d resources", ch->id);
+	}
+
+	return ret;
+}
+
+/*
+ * riocm_cdev_open() - Open character device
+ */
+static int riocm_cdev_open(struct inode *inode, struct file *filp)
+{
+	riocm_debug(INIT, "by %s(%d) filp=%p ",
+		    current->comm, task_pid_nr(current), filp);
+
+	if (list_empty(&cm_dev_list))
+		return -ENODEV;
+
+	return 0;
+}
+
+/*
+ * riocm_cdev_release() - Release character device
+ */
+static int riocm_cdev_release(struct inode *inode, struct file *filp)
+{
+	struct rio_channel *ch, *_c;
+	unsigned int i;
+	LIST_HEAD(list);
+
+	riocm_debug(EXIT, "by %s(%d) filp=%p",
+		    current->comm, task_pid_nr(current), filp);
+
+	/* Check if there are channels associated with this file descriptor */
+	spin_lock_bh(&idr_lock);
+	idr_for_each_entry(&ch_idr, ch, i) {
+		if (ch && ch->filp == filp) {
+			riocm_debug(EXIT, "ch_%d not released by %s(%d)",
+				    ch->id, current->comm,
+				    task_pid_nr(current));
+			idr_remove(&ch_idr, ch->id);
+			list_add(&ch->ch_node, &list);
+		}
+	}
+	spin_unlock_bh(&idr_lock);
+
+	if (!list_empty(&list)) {
+		list_for_each_entry_safe(ch, _c, &list, ch_node) {
+			list_del(&ch->ch_node);
+			riocm_ch_close(ch);
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * cm_ep_get_list_size() - Reports number of endpoints in the network
+ */
+static int cm_ep_get_list_size(void __user *arg)
+{
+	u32 __user *p = arg;
+	u32 mport_id;
+	u32 count = 0;
+	struct cm_dev *cm;
+
+	if (get_user(mport_id, p))
+		return -EFAULT;
+	if (mport_id >= RIO_MAX_MPORTS)
+		return -EINVAL;
+
+	/* Find a matching cm_dev object */
+	down_read(&rdev_sem);
+	list_for_each_entry(cm, &cm_dev_list, list) {
+		if (cm->mport->id == mport_id) {
+			count = cm->npeers;
+			up_read(&rdev_sem);
+			if (copy_to_user(arg, &count, sizeof(u32)))
+				return -EFAULT;
+			return 0;
+		}
+	}
+	up_read(&rdev_sem);
+
+	return -ENODEV;
+}
+
+/*
+ * cm_ep_get_list() - Returns list of attached endpoints
+ */
+static int cm_ep_get_list(void __user *arg)
+{
+	struct cm_dev *cm;
+	struct cm_peer *peer;
+	u32 info[2];
+	void *buf;
+	u32 nent;
+	u32 *entry_ptr;
+	u32 i = 0;
+	int ret = 0;
+
+	if (copy_from_user(&info, arg, sizeof(info)))
+		return -EFAULT;
+
+	if (info[1] >= RIO_MAX_MPORTS || info[0] > RIOCM_MAX_EP_COUNT)
+		return -EINVAL;
+
+	/* Find a matching cm_dev object */
+	down_read(&rdev_sem);
+	list_for_each_entry(cm, &cm_dev_list, list)
+		if (cm->mport->id == (u8)info[1])
+			goto found;
+
+	up_read(&rdev_sem);
+	return -ENODEV;
+
+found:
+	nent = min(info[0], cm->npeers);
+	buf = kcalloc(nent + 2, sizeof(u32), GFP_KERNEL);
+	if (!buf) {
+		up_read(&rdev_sem);
+		return -ENOMEM;
+	}
+
+	entry_ptr = (u32 *)((uintptr_t)buf + 2*sizeof(u32));
+
+	list_for_each_entry(peer, &cm->peers, node) {
+		*entry_ptr = (u32)peer->rdev->destid;
+		entry_ptr++;
+		if (++i == nent)
+			break;
+	}
+	up_read(&rdev_sem);
+
+	((u32 *)buf)[0] = i; /* report an updated number of entries */
+	((u32 *)buf)[1] = info[1]; /* put back an mport ID */
+	if (copy_to_user(arg, buf, sizeof(u32) * (info[0] + 2)))
+		ret = -EFAULT;
+
+	kfree(buf);
+	return ret;
+}
+
+/*
+ * cm_mport_get_list() - Returns list of available local mport devices
+ */
+static int cm_mport_get_list(void __user *arg)
+{
+	int ret = 0;
+	u32 entries;
+	void *buf;
+	struct cm_dev *cm;
+	u32 *entry_ptr;
+	int count = 0;
+
+	if (copy_from_user(&entries, arg, sizeof(entries)))
+		return -EFAULT;
+	if (entries == 0 || entries > RIO_MAX_MPORTS)
+		return -EINVAL;
+	buf = kcalloc(entries + 1, sizeof(u32), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Scan all registered cm_dev objects */
+	entry_ptr = (u32 *)((uintptr_t)buf + sizeof(u32));
+	down_read(&rdev_sem);
+	list_for_each_entry(cm, &cm_dev_list, list) {
+		if (count++ < entries) {
+			*entry_ptr = (cm->mport->id << 16) |
+				      cm->mport->host_deviceid;
+			entry_ptr++;
+		}
+	}
+	up_read(&rdev_sem);
+
+	*((u32 *)buf) = count; /* report a real number of entries */
+	if (copy_to_user(arg, buf, sizeof(u32) * (count + 1)))
+		ret = -EFAULT;
+
+	kfree(buf);
+	return ret;
+}
+
+/*
+ * cm_chan_create() - Create a message exchange channel
+ */
+static int cm_chan_create(struct file *filp, void __user *arg)
+{
+	u16 __user *p = arg;
+	u16 ch_num;
+	struct rio_channel *ch;
+
+	if (get_user(ch_num, p))
+		return -EFAULT;
+
+	riocm_debug(CHOP, "ch_%d requested by %s(%d)",
+		    ch_num, current->comm, task_pid_nr(current));
+	ch = riocm_ch_create(&ch_num);
+	if (IS_ERR(ch))
+		return PTR_ERR(ch);
+
+	ch->filp = filp;
+	riocm_debug(CHOP, "ch_%d created by %s(%d)",
+		    ch_num, current->comm, task_pid_nr(current));
+	return put_user(ch_num, p);
+}
+
+/*
+ * cm_chan_close() - Close channel
+ * @filp:	Pointer to file object
+ * @arg:	Channel to close
+ */
+static int cm_chan_close(struct file *filp, void __user *arg)
+{
+	u16 __user *p = arg;
+	u16 ch_num;
+	struct rio_channel *ch;
+
+	if (get_user(ch_num, p))
+		return -EFAULT;
+
+	riocm_debug(CHOP, "ch_%d by %s(%d)",
+		    ch_num, current->comm, task_pid_nr(current));
+
+	spin_lock_bh(&idr_lock);
+	ch = idr_find(&ch_idr, ch_num);
+	if (!ch) {
+		spin_unlock_bh(&idr_lock);
+		return 0;
+	}
+	if (ch->filp != filp) {
+		spin_unlock_bh(&idr_lock);
+		return -EINVAL;
+	}
+	idr_remove(&ch_idr, ch->id);
+	spin_unlock_bh(&idr_lock);
+
+	return riocm_ch_close(ch);
+}
+
+/*
+ * cm_chan_bind() - Bind channel
+ * @arg:	Channel number
+ */
+static int cm_chan_bind(void __user *arg)
+{
+	struct rio_cm_channel chan;
+
+	if (copy_from_user(&chan, arg, sizeof(chan)))
+		return -EFAULT;
+	if (chan.mport_id >= RIO_MAX_MPORTS)
+		return -EINVAL;
+
+	return riocm_ch_bind(chan.id, chan.mport_id, NULL);
+}
+
+/*
+ * cm_chan_listen() - Listen on channel
+ * @arg:	Channel number
+ */
+static int cm_chan_listen(void __user *arg)
+{
+	u16 __user *p = arg;
+	u16 ch_num;
+
+	if (get_user(ch_num, p))
+		return -EFAULT;
+
+	return riocm_ch_listen(ch_num);
+}
+
+/*
+ * cm_chan_accept() - Accept incoming connection
+ * @filp:	Pointer to file object
+ * @arg:	Channel number
+ */
+static int cm_chan_accept(struct file *filp, void __user *arg)
+{
+	struct rio_cm_accept param;
+	long accept_to;
+	struct rio_channel *ch;
+
+	if (copy_from_user(&param, arg, sizeof(param)))
+		return -EFAULT;
+
+	riocm_debug(CHOP, "on ch_%d by %s(%d)",
+		    param.ch_num, current->comm, task_pid_nr(current));
+
+	accept_to = param.wait_to ?
+			msecs_to_jiffies(param.wait_to) : 0;
+
+	ch = riocm_ch_accept(param.ch_num, &param.ch_num, accept_to);
+	if (IS_ERR(ch))
+		return PTR_ERR(ch);
+	ch->filp = filp;
+
+	riocm_debug(CHOP, "new ch_%d for %s(%d)",
+		    ch->id, current->comm, task_pid_nr(current));
+
+	if (copy_to_user(arg, &param, sizeof(param)))
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ * cm_chan_connect() - Connect on channel
+ * @arg:	Channel information
+ */
+static int cm_chan_connect(void __user *arg)
+{
+	struct rio_cm_channel chan;
+	struct cm_dev *cm;
+	struct cm_peer *peer;
+	int ret = -ENODEV;
+
+	if (copy_from_user(&chan, arg, sizeof(chan)))
+		return -EFAULT;
+	if (chan.mport_id >= RIO_MAX_MPORTS)
+		return -EINVAL;
+
+	down_read(&rdev_sem);
+
+	/* Find matching cm_dev object */
+	list_for_each_entry(cm, &cm_dev_list, list) {
+		if (cm->mport->id == chan.mport_id) {
+			ret = 0;
+			break;
+		}
+	}
+
+	if (ret)
+		goto err_out;
+
+	if (chan.remote_destid >= RIO_ANY_DESTID(cm->mport->sys_size)) {
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	/* Find corresponding RapidIO endpoint device object */
+	ret = -ENODEV;
+
+	list_for_each_entry(peer, &cm->peers, node) {
+		if (peer->rdev->destid == chan.remote_destid) {
+			ret = 0;
+			break;
+		}
+	}
+
+	if (ret)
+		goto err_out;
+
+	up_read(&rdev_sem);
+
+	return riocm_ch_connect(chan.id, cm, peer, chan.remote_channel);
+err_out:
+	up_read(&rdev_sem);
+	return ret;
+}
+
+/*
+ * cm_chan_msg_send() - Send a message through channel
+ * @arg:	Outbound message information
+ */
+static int cm_chan_msg_send(void __user *arg)
+{
+	struct rio_cm_msg msg;
+	void *buf;
+	int ret;
+
+	if (copy_from_user(&msg, arg, sizeof(msg)))
+		return -EFAULT;
+	if (msg.size > RIO_MAX_MSG_SIZE)
+		return -EINVAL;
+
+	buf = memdup_user((void __user *)(uintptr_t)msg.msg, msg.size);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	ret = riocm_ch_send(msg.ch_num, buf, msg.size);
+
+	kfree(buf);
+	return ret;
+}
+
+/*
+ * cm_chan_msg_rcv() - Receive a message through channel
+ * @arg:	Inbound message information
+ */
+static int cm_chan_msg_rcv(void __user *arg)
+{
+	struct rio_cm_msg msg;
+	struct rio_channel *ch;
+	void *buf;
+	long rxto;
+	int ret = 0, msg_size;
+
+	if (copy_from_user(&msg, arg, sizeof(msg)))
+		return -EFAULT;
+
+	if (msg.ch_num == 0 || msg.size == 0)
+		return -EINVAL;
+
+	ch = riocm_get_channel(msg.ch_num);
+	if (!ch)
+		return -ENODEV;
+
+	rxto = msg.rxto ? msecs_to_jiffies(msg.rxto) : MAX_SCHEDULE_TIMEOUT;
+
+	ret = riocm_ch_receive(ch, &buf, rxto);
+	if (ret)
+		goto out;
+
+	msg_size = min(msg.size, (u16)(RIO_MAX_MSG_SIZE));
+
+	if (copy_to_user((void __user *)(uintptr_t)msg.msg, buf, msg_size))
+		ret = -EFAULT;
+
+	riocm_ch_free_rxbuf(ch, buf);
+out:
+	riocm_put_channel(ch);
+	return ret;
+}
+
+/*
+ * riocm_cdev_ioctl() - IOCTL requests handler
+ */
+static long
+riocm_cdev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case RIO_CM_EP_GET_LIST_SIZE:
+		return cm_ep_get_list_size((void __user *)arg);
+	case RIO_CM_EP_GET_LIST:
+		return cm_ep_get_list((void __user *)arg);
+	case RIO_CM_CHAN_CREATE:
+		return cm_chan_create(filp, (void __user *)arg);
+	case RIO_CM_CHAN_CLOSE:
+		return cm_chan_close(filp, (void __user *)arg);
+	case RIO_CM_CHAN_BIND:
+		return cm_chan_bind((void __user *)arg);
+	case RIO_CM_CHAN_LISTEN:
+		return cm_chan_listen((void __user *)arg);
+	case RIO_CM_CHAN_ACCEPT:
+		return cm_chan_accept(filp, (void __user *)arg);
+	case RIO_CM_CHAN_CONNECT:
+		return cm_chan_connect((void __user *)arg);
+	case RIO_CM_CHAN_SEND:
+		return cm_chan_msg_send((void __user *)arg);
+	case RIO_CM_CHAN_RECEIVE:
+		return cm_chan_msg_rcv((void __user *)arg);
+	case RIO_CM_MPORT_GET_LIST:
+		return cm_mport_get_list((void __user *)arg);
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static const struct file_operations riocm_cdev_fops = {
+	.owner		= THIS_MODULE,
+	.open		= riocm_cdev_open,
+	.release	= riocm_cdev_release,
+	.unlocked_ioctl = riocm_cdev_ioctl,
+};
+
+/*
+ * riocm_add_dev - add new remote RapidIO device into channel management core
+ * @dev: device object associated with RapidIO device
+ * @sif: subsystem interface
+ *
+ * Adds the specified RapidIO device (if applicable) into peers list of
+ * the corresponding channel management device (cm_dev).
+ */
+static int riocm_add_dev(struct device *dev, struct subsys_interface *sif)
+{
+	struct cm_peer *peer;
+	struct rio_dev *rdev = to_rio_dev(dev);
+	struct cm_dev *cm;
+
+	/* Check if the remote device has capabilities required to support CM */
+	if (!dev_cm_capable(rdev))
+		return 0;
+
+	riocm_debug(RDEV, "(%s)", rio_name(rdev));
+
+	peer = kmalloc(sizeof(*peer), GFP_KERNEL);
+	if (!peer)
+		return -ENOMEM;
+
+	/* Find a corresponding cm_dev object */
+	down_write(&rdev_sem);
+	list_for_each_entry(cm, &cm_dev_list, list) {
+		if (cm->mport == rdev->net->hport)
+			goto found;
+	}
+
+	up_write(&rdev_sem);
+	kfree(peer);
+	return -ENODEV;
+
+found:
+	peer->rdev = rdev;
+	list_add_tail(&peer->node, &cm->peers);
+	cm->npeers++;
+
+	up_write(&rdev_sem);
+	return 0;
+}
+
+/*
+ * riocm_remove_dev - remove remote RapidIO device from channel management core
+ * @dev: device object associated with RapidIO device
+ * @sif: subsystem interface
+ *
+ * Removes the specified RapidIO device (if applicable) from peers list of
+ * the corresponding channel management device (cm_dev).
+ */
+static void riocm_remove_dev(struct device *dev, struct subsys_interface *sif)
+{
+	struct rio_dev *rdev = to_rio_dev(dev);
+	struct cm_dev *cm;
+	struct cm_peer *peer;
+	struct rio_channel *ch, *_c;
+	unsigned int i;
+	bool found = false;
+	LIST_HEAD(list);
+
+	/* Check if the remote device has capabilities required to support CM */
+	if (!dev_cm_capable(rdev))
+		return;
+
+	riocm_debug(RDEV, "(%s)", rio_name(rdev));
+
+	/* Find matching cm_dev object */
+	down_write(&rdev_sem);
+	list_for_each_entry(cm, &cm_dev_list, list) {
+		if (cm->mport == rdev->net->hport) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		up_write(&rdev_sem);
+		return;
+	}
+
+	/* Remove remote device from the list of peers */
+	found = false;
+	list_for_each_entry(peer, &cm->peers, node) {
+		if (peer->rdev == rdev) {
+			riocm_debug(RDEV, "removing peer %s", rio_name(rdev));
+			found = true;
+			list_del(&peer->node);
+			cm->npeers--;
+			kfree(peer);
+			break;
+		}
+	}
+
+	up_write(&rdev_sem);
+
+	if (!found)
+		return;
+
+	/*
+	 * Release channels associated with this peer
+	 */
+
+	spin_lock_bh(&idr_lock);
+	idr_for_each_entry(&ch_idr, ch, i) {
+		if (ch && ch->rdev == rdev) {
+			if (atomic_read(&rdev->state) != RIO_DEVICE_SHUTDOWN)
+				riocm_exch(ch, RIO_CM_DISCONNECT);
+			idr_remove(&ch_idr, ch->id);
+			list_add(&ch->ch_node, &list);
+		}
+	}
+	spin_unlock_bh(&idr_lock);
+
+	if (!list_empty(&list)) {
+		list_for_each_entry_safe(ch, _c, &list, ch_node) {
+			list_del(&ch->ch_node);
+			riocm_ch_close(ch);
+		}
+	}
+}
+
+/*
+ * riocm_cdev_add() - Create rio_cm char device
+ * @devno: device number assigned to device (MAJ + MIN)
+ */
+static int riocm_cdev_add(dev_t devno)
+{
+	int ret;
+
+	cdev_init(&riocm_cdev.cdev, &riocm_cdev_fops);
+	riocm_cdev.cdev.owner = THIS_MODULE;
+	ret = cdev_add(&riocm_cdev.cdev, devno, 1);
+	if (ret < 0) {
+		riocm_error("Cannot register a device with error %d", ret);
+		return ret;
+	}
+
+	riocm_cdev.dev = device_create(dev_class, NULL, devno, NULL, DEV_NAME);
+	if (IS_ERR(riocm_cdev.dev)) {
+		cdev_del(&riocm_cdev.cdev);
+		return PTR_ERR(riocm_cdev.dev);
+	}
+
+	riocm_debug(MPORT, "Added %s cdev(%d:%d)",
+		    DEV_NAME, MAJOR(devno), MINOR(devno));
+
+	return 0;
+}
+
+/*
+ * riocm_add_mport - add new local mport device into channel management core
+ * @dev: device object associated with mport
+ * @class_intf: class interface
+ *
+ * When a new mport device is added, CM immediately reserves inbound and
+ * outbound RapidIO mailboxes that will be used.
+ */
+static int riocm_add_mport(struct device *dev,
+			   struct class_interface *class_intf)
+{
+	int rc;
+	int i;
+	struct cm_dev *cm;
+	struct rio_mport *mport = to_rio_mport(dev);
+
+	riocm_debug(MPORT, "add mport %s", mport->name);
+
+	cm = kzalloc(sizeof(*cm), GFP_KERNEL);
+	if (!cm)
+		return -ENOMEM;
+
+	cm->mport = mport;
+
+	rc = rio_request_outb_mbox(mport, cm, cmbox,
+				   RIOCM_TX_RING_SIZE, riocm_outb_msg_event);
+	if (rc) {
+		riocm_error("failed to allocate OBMBOX_%d on %s",
+			    cmbox, mport->name);
+		kfree(cm);
+		return -ENODEV;
+	}
+
+	rc = rio_request_inb_mbox(mport, cm, cmbox,
+				  RIOCM_RX_RING_SIZE, riocm_inb_msg_event);
+	if (rc) {
+		riocm_error("failed to allocate IBMBOX_%d on %s",
+			    cmbox, mport->name);
+		rio_release_outb_mbox(mport, cmbox);
+		kfree(cm);
+		return -ENODEV;
+	}
+
+	cm->rx_wq = create_workqueue(DRV_NAME "/rxq");
+	if (!cm->rx_wq) {
+		rio_release_inb_mbox(mport, cmbox);
+		rio_release_outb_mbox(mport, cmbox);
+		kfree(cm);
+		return -ENOMEM;
+	}
+
+	/*
+	 * Allocate and register inbound messaging buffers to be ready
+	 * to receive channel and system management requests
+	 */
+	for (i = 0; i < RIOCM_RX_RING_SIZE; i++)
+		cm->rx_buf[i] = NULL;
+
+	cm->rx_slots = RIOCM_RX_RING_SIZE;
+	mutex_init(&cm->rx_lock);
+	riocm_rx_fill(cm, RIOCM_RX_RING_SIZE);
+	INIT_WORK(&cm->rx_work, rio_ibmsg_handler);
+
+	cm->tx_slot = 0;
+	cm->tx_cnt = 0;
+	cm->tx_ack_slot = 0;
+	spin_lock_init(&cm->tx_lock);
+
+	INIT_LIST_HEAD(&cm->peers);
+	cm->npeers = 0;
+	INIT_LIST_HEAD(&cm->tx_reqs);
+
+	down_write(&rdev_sem);
+	list_add_tail(&cm->list, &cm_dev_list);
+	up_write(&rdev_sem);
+
+	return 0;
+}
+
+/*
+ * riocm_remove_mport - remove local mport device from channel management core
+ * @dev: device object associated with mport
+ * @class_intf: class interface
+ *
+ * Removes a local mport device from the list of registered devices that provide
+ * channel management services. Returns an error if the specified mport is not
+ * registered with the CM core.
+ */
+static void riocm_remove_mport(struct device *dev,
+			       struct class_interface *class_intf)
+{
+	struct rio_mport *mport = to_rio_mport(dev);
+	struct cm_dev *cm;
+	struct cm_peer *peer, *temp;
+	struct rio_channel *ch, *_c;
+	unsigned int i;
+	bool found = false;
+	LIST_HEAD(list);
+
+	riocm_debug(MPORT, "%s", mport->name);
+
+	/* Find a matching cm_dev object */
+	down_write(&rdev_sem);
+	list_for_each_entry(cm, &cm_dev_list, list) {
+		if (cm->mport == mport) {
+			list_del(&cm->list);
+			found = true;
+			break;
+		}
+	}
+	up_write(&rdev_sem);
+	if (!found)
+		return;
+
+	flush_workqueue(cm->rx_wq);
+	destroy_workqueue(cm->rx_wq);
+
+	/* Release channels bound to this mport */
+	spin_lock_bh(&idr_lock);
+	idr_for_each_entry(&ch_idr, ch, i) {
+		if (ch->cmdev == cm) {
+			riocm_debug(RDEV, "%s drop ch_%d",
+				    mport->name, ch->id);
+			idr_remove(&ch_idr, ch->id);
+			list_add(&ch->ch_node, &list);
+		}
+	}
+	spin_unlock_bh(&idr_lock);
+
+	if (!list_empty(&list)) {
+		list_for_each_entry_safe(ch, _c, &list, ch_node) {
+			list_del(&ch->ch_node);
+			riocm_ch_close(ch);
+		}
+	}
+
+	rio_release_inb_mbox(mport, cmbox);
+	rio_release_outb_mbox(mport, cmbox);
+
+	/* Remove and free peer entries */
+	if (!list_empty(&cm->peers))
+		riocm_debug(RDEV, "ATTN: peer list not empty");
+	list_for_each_entry_safe(peer, temp, &cm->peers, node) {
+		riocm_debug(RDEV, "removing peer %s", rio_name(peer->rdev));
+		list_del(&peer->node);
+		kfree(peer);
+	}
+
+	riocm_rx_free(cm);
+	kfree(cm);
+	riocm_debug(MPORT, "%s done", mport->name);
+}
+
+static int rio_cm_shutdown(struct notifier_block *nb, unsigned long code,
+	void *unused)
+{
+	struct rio_channel *ch;
+	unsigned int i;
+	LIST_HEAD(list);
+
+	riocm_debug(EXIT, ".");
+
+	/*
+	 * If there are any channels left in connected state send
+	 * close notification to the connection partner.
+	 * First build a list of channels that require a closing
+	 * notification because function riocm_send_close() should
+	 * be called outside of spinlock protected code.
+	 */
+	spin_lock_bh(&idr_lock);
+	idr_for_each_entry(&ch_idr, ch, i) {
+		if (ch->state == RIO_CM_CONNECTED) {
+			riocm_debug(EXIT, "close ch %d", ch->id);
+			idr_remove(&ch_idr, ch->id);
+			list_add(&ch->ch_node, &list);
+		}
+	}
+	spin_unlock_bh(&idr_lock);
+
+	list_for_each_entry(ch, &list, ch_node)
+		riocm_send_close(ch);
+
+	return NOTIFY_DONE;
+}
+
+/*
+ * riocm_interface handles addition/removal of remote RapidIO devices
+ */
+static struct subsys_interface riocm_interface = {
+	.name		= "rio_cm",
+	.subsys		= &rio_bus_type,
+	.add_dev	= riocm_add_dev,
+	.remove_dev	= riocm_remove_dev,
+};
+
+/*
+ * rio_mport_interface handles addition/removal local mport devices
+ */
+static struct class_interface rio_mport_interface __refdata = {
+	.class = &rio_mport_class,
+	.add_dev = riocm_add_mport,
+	.remove_dev = riocm_remove_mport,
+};
+
+static struct notifier_block rio_cm_notifier = {
+	.notifier_call = rio_cm_shutdown,
+};
+
+static int __init riocm_init(void)
+{
+	int ret;
+
+	/* Create device class needed by udev */
+	dev_class = class_create(THIS_MODULE, DRV_NAME);
+	if (IS_ERR(dev_class)) {
+		riocm_error("Cannot create " DRV_NAME " class");
+		return PTR_ERR(dev_class);
+	}
+
+	ret = alloc_chrdev_region(&dev_number, 0, 1, DRV_NAME);
+	if (ret) {
+		class_destroy(dev_class);
+		return ret;
+	}
+
+	dev_major = MAJOR(dev_number);
+	dev_minor_base = MINOR(dev_number);
+	riocm_debug(INIT, "Registered class with %d major", dev_major);
+
+	/*
+	 * Register as rapidio_port class interface to get notifications about
+	 * mport additions and removals.
+	 */
+	ret = class_interface_register(&rio_mport_interface);
+	if (ret) {
+		riocm_error("class_interface_register error: %d", ret);
+		goto err_reg;
+	}
+
+	/*
+	 * Register as RapidIO bus interface to get notifications about
+	 * addition/removal of remote RapidIO devices.
+	 */
+	ret = subsys_interface_register(&riocm_interface);
+	if (ret) {
+		riocm_error("subsys_interface_register error: %d", ret);
+		goto err_cl;
+	}
+
+	ret = register_reboot_notifier(&rio_cm_notifier);
+	if (ret) {
+		riocm_error("failed to register reboot notifier (err=%d)", ret);
+		goto err_sif;
+	}
+
+	ret = riocm_cdev_add(dev_number);
+	if (ret) {
+		unregister_reboot_notifier(&rio_cm_notifier);
+		ret = -ENODEV;
+		goto err_sif;
+	}
+
+	return 0;
+err_sif:
+	subsys_interface_unregister(&riocm_interface);
+err_cl:
+	class_interface_unregister(&rio_mport_interface);
+err_reg:
+	unregister_chrdev_region(dev_number, 1);
+	class_destroy(dev_class);
+	return ret;
+}
+
+static void __exit riocm_exit(void)
+{
+	riocm_debug(EXIT, "enter");
+	unregister_reboot_notifier(&rio_cm_notifier);
+	subsys_interface_unregister(&riocm_interface);
+	class_interface_unregister(&rio_mport_interface);
+	idr_destroy(&ch_idr);
+
+	device_unregister(riocm_cdev.dev);
+	cdev_del(&(riocm_cdev.cdev));
+
+	class_destroy(dev_class);
+	unregister_chrdev_region(dev_number, 1);
+}
+
+late_initcall(riocm_init);
+module_exit(riocm_exit);