[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / 9p / trans_rdma.c

/*
 * linux/fs/9p/trans_rdma.c
 *
 * RDMA transport layer based on the trans_fd.c implementation.
 *
 *  Copyright (C) 2008 by Tom Tucker <tom@opengridcomputing.com>
 *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
 *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
 *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
 *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/in.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/ipv6.h>
#include <linux/kthread.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/un.h>
#include <linux/uaccess.h>
#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/file.h>
#include <linux/parser.h>
#include <linux/semaphore.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include <net/9p/transport.h>
#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>

#define P9_PORT			5640
#define P9_RDMA_SQ_DEPTH	32
#define P9_RDMA_RQ_DEPTH	32
#define P9_RDMA_SEND_SGE	4
#define P9_RDMA_RECV_SGE	4
#define P9_RDMA_IRD		0
#define P9_RDMA_ORD		0
#define P9_RDMA_TIMEOUT		30000		/* 30 seconds */
#define P9_RDMA_MAXSIZE		(4*4096)	/* Min SGE is 4, so we can
						 * safely advertise a maxsize
						 * of 64k */

/**
 * struct p9_trans_rdma - RDMA transport instance
 *
 * @state: tracks the transport state machine for connection setup and tear down
 * @cm_id: The RDMA CM ID
 * @pd: Protection Domain pointer
 * @qp: Queue Pair pointer
 * @cq: Completion Queue pointer
 * @dm_mr: DMA Memory Region pointer
 * @lkey: The local access only memory region key
 * @timeout: Number of uSecs to wait for connection management events
 * @sq_depth: The depth of the Send Queue
 * @sq_sem: Semaphore for the SQ
 * @rq_depth: The depth of the Receive Queue.
 * @rq_count: Count of requests in the Receive Queue.
 * @addr: The remote peer's address
 * @req_lock: Protects the active request list
 * @cm_done: Completion event for connection management tracking
 */
struct p9_trans_rdma {
	enum {
		P9_RDMA_INIT,
		P9_RDMA_ADDR_RESOLVED,
		P9_RDMA_ROUTE_RESOLVED,
		P9_RDMA_CONNECTED,
		P9_RDMA_FLUSHING,
		P9_RDMA_CLOSING,
		P9_RDMA_CLOSED,
	} state;
	struct rdma_cm_id *cm_id;
	struct ib_pd *pd;
	struct ib_qp *qp;
	struct ib_cq *cq;
	struct ib_mr *dma_mr;
	u32 lkey;
	long timeout;
	int sq_depth;
	struct semaphore sq_sem;
	int rq_depth;
	atomic_t rq_count;
	struct sockaddr_in addr;
	spinlock_t req_lock;

	struct completion cm_done;
};

/**
 * p9_rdma_context - Keeps track of in-process WR
 *
 * @wc_op: The original WR op for when the CQE completes in error.
 * @busa: Bus address to unmap when the WR completes
 * @req: Keeps track of requests (send)
 * @rc: Keepts track of replies (receive)
 */
struct p9_rdma_req;
struct p9_rdma_context {
	enum ib_wc_opcode wc_op;
	dma_addr_t busa;
	union {
		struct p9_req_t *req;
		struct p9_fcall *rc;
	};
};

/**
 * p9_rdma_opts - Collection of mount options
 * @port: port of connection
 * @sq_depth: The requested depth of the SQ. This really doesn't need
 * to be any deeper than the number of threads used in the client
 * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
 * @timeout: Time to wait in msecs for CM events
 */
struct p9_rdma_opts {
	short port;
	int sq_depth;
	int rq_depth;
	long timeout;
};

/*
 * Option Parsing (code inspired by NFS code)
 */
enum {
	/* Options that take integer arguments */
	Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, Opt_err,
};

static match_table_t tokens = {
	{Opt_port, "port=%u"},
	{Opt_sq_depth, "sq=%u"},
	{Opt_rq_depth, "rq=%u"},
	{Opt_timeout, "timeout=%u"},
	{Opt_err, NULL},
};

/**
 * parse_opts - parse mount options into rdma options structure
 * @params: options string passed from mount
 * @opts: rdma transport-specific structure to parse options into
 *
 * Returns 0 upon success, -ERRNO upon failure
 */
static int parse_opts(char *params, struct p9_rdma_opts *opts)
{
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;
	char *options, *tmp_options;

	opts->port = P9_PORT;
	opts->sq_depth = P9_RDMA_SQ_DEPTH;
	opts->rq_depth = P9_RDMA_RQ_DEPTH;
	opts->timeout = P9_RDMA_TIMEOUT;

	if (!params)
		return 0;

	tmp_options = kstrdup(params, GFP_KERNEL);
	if (!tmp_options) {
		p9_debug(P9_DEBUG_ERROR,
			 "failed to allocate copy of option string\n");
		return -ENOMEM;
	}
	options = tmp_options;

	while ((p = strsep(&options, ",")) != NULL) {
		int token;
		int r;
		if (!*p)
			continue;
		token = match_token(p, tokens, args);
		r = match_int(&args[0], &option);
		if (r < 0) {
			p9_debug(P9_DEBUG_ERROR,
				 "integer field, but no integer?\n");
			continue;
		}
		switch (token) {
		case Opt_port:
			opts->port = option;
			break;
		case Opt_sq_depth:
			opts->sq_depth = option;
			break;
		case Opt_rq_depth:
			opts->rq_depth = option;
			break;
		case Opt_timeout:
			opts->timeout = option;
			break;
		default:
			continue;
		}
	}
	/* RQ must be at least as large as the SQ */
	opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
	kfree(tmp_options);
	return 0;
}

static int
p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
{
	struct p9_client *c = id->context;
	struct p9_trans_rdma *rdma = c->trans;
	switch (event->event) {
	case RDMA_CM_EVENT_ADDR_RESOLVED:
		BUG_ON(rdma->state != P9_RDMA_INIT);
		rdma->state = P9_RDMA_ADDR_RESOLVED;
		break;

	case RDMA_CM_EVENT_ROUTE_RESOLVED:
		BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
		rdma->state = P9_RDMA_ROUTE_RESOLVED;
		break;

	case RDMA_CM_EVENT_ESTABLISHED:
		BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
		rdma->state = P9_RDMA_CONNECTED;
		break;

	case RDMA_CM_EVENT_DISCONNECTED:
		if (rdma)
			rdma->state = P9_RDMA_CLOSED;
		if (c)
			c->status = Disconnected;
		break;

	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
		break;

	case RDMA_CM_EVENT_ADDR_CHANGE:
	case RDMA_CM_EVENT_ROUTE_ERROR:
	case RDMA_CM_EVENT_DEVICE_REMOVAL:
	case RDMA_CM_EVENT_MULTICAST_JOIN:
	case RDMA_CM_EVENT_MULTICAST_ERROR:
	case RDMA_CM_EVENT_REJECTED:
	case RDMA_CM_EVENT_CONNECT_REQUEST:
	case RDMA_CM_EVENT_CONNECT_RESPONSE:
	case RDMA_CM_EVENT_CONNECT_ERROR:
	case RDMA_CM_EVENT_ADDR_ERROR:
	case RDMA_CM_EVENT_UNREACHABLE:
		c->status = Disconnected;
		rdma_disconnect(rdma->cm_id);
		break;
	default:
		BUG();
	}
	complete(&rdma->cm_done);
	return 0;
}

static void
handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma,
	    struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
{
	struct p9_req_t *req;
	int err = 0;
	int16_t tag;

	req = NULL;
	ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
							 DMA_FROM_DEVICE);

	if (status != IB_WC_SUCCESS)
		goto err_out;

	err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
	if (err)
		goto err_out;

	req = p9_tag_lookup(client, tag);
	if (!req)
		goto err_out;

	req->rc = c->rc;
	req->status = REQ_STATUS_RCVD;
	p9_client_cb(client, req);

	return;

 err_out:
	p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n", req, err, status);
	rdma->state = P9_RDMA_FLUSHING;
	client->status = Disconnected;
}

static void
handle_send(struct p9_client *client, struct p9_trans_rdma *rdma,
	    struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
{
	ib_dma_unmap_single(rdma->cm_id->device,
			    c->busa, c->req->tc->size,
			    DMA_TO_DEVICE);
}

static void qp_event_handler(struct ib_event *event, void *context)
{
	p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
		 event->event, context);
}

static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
{
	struct p9_client *client = cq_context;
	struct p9_trans_rdma *rdma = client->trans;
	int ret;
	struct ib_wc wc;

	ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
	while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
		struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id;

		switch (c->wc_op) {
		case IB_WC_RECV:
			atomic_dec(&rdma->rq_count);
			handle_recv(client, rdma, c, wc.status, wc.byte_len);
			break;

		case IB_WC_SEND:
			handle_send(client, rdma, c, wc.status, wc.byte_len);
			up(&rdma->sq_sem);
			break;

		default:
			pr_err("unexpected completion type, c->wc_op=%d, wc.opcode=%d, status=%d\n",
			       c->wc_op, wc.opcode, wc.status);
			break;
		}
		kfree(c);
	}
}

static void cq_event_handler(struct ib_event *e, void *v)
{
	p9_debug(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
}

static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
{
	if (!rdma)
		return;

	if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
		ib_dereg_mr(rdma->dma_mr);

	if (rdma->qp && !IS_ERR(rdma->qp))
		ib_destroy_qp(rdma->qp);

	if (rdma->pd && !IS_ERR(rdma->pd))
		ib_dealloc_pd(rdma->pd);

	if (rdma->cq && !IS_ERR(rdma->cq))
		ib_destroy_cq(rdma->cq);

	if (rdma->cm_id && !IS_ERR(rdma->cm_id))
		rdma_destroy_id(rdma->cm_id);

	kfree(rdma);
}

static int
post_recv(struct p9_client *client, struct p9_rdma_context *c)
{
	struct p9_trans_rdma *rdma = client->trans;
	struct ib_recv_wr wr, *bad_wr;
	struct ib_sge sge;

	c->busa = ib_dma_map_single(rdma->cm_id->device,
				    c->rc->sdata, client->msize,
				    DMA_FROM_DEVICE);
	if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
		goto error;

	sge.addr = c->busa;
	sge.length = client->msize;
	sge.lkey = rdma->lkey;

	wr.next = NULL;
	c->wc_op = IB_WC_RECV;
	wr.wr_id = (unsigned long) c;
	wr.sg_list = &sge;
	wr.num_sge = 1;
	return ib_post_recv(rdma->qp, &wr, &bad_wr);

 error:
	p9_debug(P9_DEBUG_ERROR, "EIO\n");
	return -EIO;
}

static int rdma_request(struct p9_client *client, struct p9_req_t *req)
{
	struct p9_trans_rdma *rdma = client->trans;
	struct ib_send_wr wr, *bad_wr;
	struct ib_sge sge;
	int err = 0;
	unsigned long flags;
	struct p9_rdma_context *c = NULL;
	struct p9_rdma_context *rpl_context = NULL;

	/* Allocate an fcall for the reply */
	rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
	if (!rpl_context) {
		err = -ENOMEM;
		goto err_close;
	}

	/*
	 * If the request has a buffer, steal it, otherwise
	 * allocate a new one.  Typically, requests should already
	 * have receive buffers allocated and just swap them around
	 */
	if (!req->rc) {
		req->rc = kmalloc(sizeof(struct p9_fcall)+client->msize,
				  GFP_NOFS);
		if (req->rc) {
			req->rc->sdata = (char *) req->rc +
						sizeof(struct p9_fcall);
			req->rc->capacity = client->msize;
		}
	}
	rpl_context->rc = req->rc;
	if (!rpl_context->rc) {
		err = -ENOMEM;
		goto err_free2;
	}

	/*
	 * Post a receive buffer for this request. We need to ensure
	 * there is a reply buffer available for every outstanding
	 * request. A flushed request can result in no reply for an
	 * outstanding request, so we must keep a count to avoid
	 * overflowing the RQ.
	 */
	if (atomic_inc_return(&rdma->rq_count) <= rdma->rq_depth) {
		err = post_recv(client, rpl_context);
		if (err)
			goto err_free1;
	} else
		atomic_dec(&rdma->rq_count);

	/* remove posted receive buffer from request structure */
	req->rc = NULL;

	/* Post the request */
	c = kmalloc(sizeof *c, GFP_NOFS);
	if (!c) {
		err = -ENOMEM;
		goto err_free1;
	}
	c->req = req;

	c->busa = ib_dma_map_single(rdma->cm_id->device,
				    c->req->tc->sdata, c->req->tc->size,
				    DMA_TO_DEVICE);
	if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
		goto error;

	sge.addr = c->busa;
	sge.length = c->req->tc->size;
	sge.lkey = rdma->lkey;

	wr.next = NULL;
	c->wc_op = IB_WC_SEND;
	wr.wr_id = (unsigned long) c;
	wr.opcode = IB_WR_SEND;
	wr.send_flags = IB_SEND_SIGNALED;
	wr.sg_list = &sge;
	wr.num_sge = 1;

	if (down_interruptible(&rdma->sq_sem))
		goto error;

	return ib_post_send(rdma->qp, &wr, &bad_wr);

 error:
	kfree(c);
	kfree(rpl_context->rc);
	kfree(rpl_context);
	p9_debug(P9_DEBUG_ERROR, "EIO\n");
	return -EIO;
 err_free1:
	kfree(rpl_context->rc);
 err_free2:
	kfree(rpl_context);
 err_close:
	spin_lock_irqsave(&rdma->req_lock, flags);
	if (rdma->state < P9_RDMA_CLOSING) {
		rdma->state = P9_RDMA_CLOSING;
		spin_unlock_irqrestore(&rdma->req_lock, flags);
		rdma_disconnect(rdma->cm_id);
	} else
		spin_unlock_irqrestore(&rdma->req_lock, flags);
	return err;
}

static void rdma_close(struct p9_client *client)
{
	struct p9_trans_rdma *rdma;

	if (!client)
		return;

	rdma = client->trans;
	if (!rdma)
		return;

	client->status = Disconnected;
	rdma_disconnect(rdma->cm_id);
	rdma_destroy_trans(rdma);
}

/**
 * alloc_rdma - Allocate and initialize the rdma transport structure
 * @opts: Mount options structure
 */
static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
{
	struct p9_trans_rdma *rdma;

	rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
	if (!rdma)
		return NULL;

	rdma->sq_depth = opts->sq_depth;
	rdma->rq_depth = opts->rq_depth;
	rdma->timeout = opts->timeout;
	spin_lock_init(&rdma->req_lock);
	init_completion(&rdma->cm_done);
	sema_init(&rdma->sq_sem, rdma->sq_depth);
	atomic_set(&rdma->rq_count, 0);

	return rdma;
}

/* its not clear to me we can do anything after send has been posted */
static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
{
	return 1;
}

/**
 * trans_create_rdma - Transport method for creating atransport instance
 * @client: client instance
 * @addr: IP address string
 * @args: Mount options string
 */
static int
rdma_create_trans(struct p9_client *client, const char *addr, char *args)
{
	int err;
	struct p9_rdma_opts opts;
	struct p9_trans_rdma *rdma;
	struct rdma_conn_param conn_param;
	struct ib_qp_init_attr qp_attr;
	struct ib_device_attr devattr;

	/* Parse the transport specific mount options */
	err = parse_opts(args, &opts);
	if (err < 0)
		return err;

	/* Create and initialize the RDMA transport structure */
	rdma = alloc_rdma(&opts);
	if (!rdma)
		return -ENOMEM;

	/* Create the RDMA CM ID */
	rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP,
				     IB_QPT_RC);
	if (IS_ERR(rdma->cm_id))
		goto error;

	/* Associate the client with the transport */
	client->trans = rdma;

	/* Resolve the server's address */
	rdma->addr.sin_family = AF_INET;
	rdma->addr.sin_addr.s_addr = in_aton(addr);
	rdma->addr.sin_port = htons(opts.port);
	err = rdma_resolve_addr(rdma->cm_id, NULL,
				(struct sockaddr *)&rdma->addr,
				rdma->timeout);
	if (err)
		goto error;
	err = wait_for_completion_interruptible(&rdma->cm_done);
	if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
		goto error;

	/* Resolve the route to the server */
	err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
	if (err)
		goto error;
	err = wait_for_completion_interruptible(&rdma->cm_done);
	if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
		goto error;

	/* Query the device attributes */
	err = ib_query_device(rdma->cm_id->device, &devattr);
	if (err)
		goto error;

	/* Create the Completion Queue */
	rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
				cq_event_handler, client,
				opts.sq_depth + opts.rq_depth + 1, 0);
	if (IS_ERR(rdma->cq))
		goto error;
	ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);

	/* Create the Protection Domain */
	rdma->pd = ib_alloc_pd(rdma->cm_id->device);
	if (IS_ERR(rdma->pd))
		goto error;

	/* Cache the DMA lkey in the transport */
	rdma->dma_mr = NULL;
	if (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
		rdma->lkey = rdma->cm_id->device->local_dma_lkey;
	else {
		rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE);
		if (IS_ERR(rdma->dma_mr))
			goto error;
		rdma->lkey = rdma->dma_mr->lkey;
	}

	/* Create the Queue Pair */
	memset(&qp_attr, 0, sizeof qp_attr);
	qp_attr.event_handler = qp_event_handler;
	qp_attr.qp_context = client;
	qp_attr.cap.max_send_wr = opts.sq_depth;
	qp_attr.cap.max_recv_wr = opts.rq_depth;
	qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
	qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
	qp_attr.qp_type = IB_QPT_RC;
	qp_attr.send_cq = rdma->cq;
	qp_attr.recv_cq = rdma->cq;
	err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
	if (err)
		goto error;
	rdma->qp = rdma->cm_id->qp;

	/* Request a connection */
	memset(&conn_param, 0, sizeof(conn_param));
	conn_param.private_data = NULL;
	conn_param.private_data_len = 0;
	conn_param.responder_resources = P9_RDMA_IRD;
	conn_param.initiator_depth = P9_RDMA_ORD;
	err = rdma_connect(rdma->cm_id, &conn_param);
	if (err)
		goto error;
	err = wait_for_completion_interruptible(&rdma->cm_done);
	if (err || (rdma->state != P9_RDMA_CONNECTED))
		goto error;

	client->status = Connected;

	return 0;

error:
	rdma_destroy_trans(rdma);
	return -ENOTCONN;
}

static struct p9_trans_module p9_rdma_trans = {
	.name = "rdma",
	.maxsize = P9_RDMA_MAXSIZE,
	.def = 0,
	.owner = THIS_MODULE,
	.create = rdma_create_trans,
	.close = rdma_close,
	.request = rdma_request,
	.cancel = rdma_cancel,
};

/**
 * p9_trans_rdma_init - Register the 9P RDMA transport driver
 */
static int __init p9_trans_rdma_init(void)
{
	v9fs_register_trans(&p9_rdma_trans);
	return 0;
}

static void __exit p9_trans_rdma_exit(void)
{
	v9fs_unregister_trans(&p9_rdma_trans);
}

module_init(p9_trans_rdma_init);
module_exit(p9_trans_rdma_exit);

MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
MODULE_DESCRIPTION("RDMA Transport for 9P");
MODULE_LICENSE("Dual BSD/GPL");
Commit	Line	Data
fc79d4b1 TT	1	/*
	2	* linux/fs/9p/trans_rdma.c
	3	*
	4	* RDMA transport layer based on the trans_fd.c implementation.
	5	*
	6	* Copyright (C) 2008 by Tom Tucker <tom@opengridcomputing.com>
	7	* Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
	8	* Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
	9	* Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
	10	* Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2
	14	* as published by the Free Software Foundation.
	15	*
	16	* This program is distributed in the hope that it will be useful,
	17	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	19	* GNU General Public License for more details.
	20	*
	21	* You should have received a copy of the GNU General Public License
	22	* along with this program; if not, write to:
	23	* Free Software Foundation
	24	* 51 Franklin Street, Fifth Floor
	25	* Boston, MA 02111-1301 USA
	26	*
	27	*/
	28
5d385153 JP	29	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
5d385153 JP	30
fc79d4b1 TT	31	#include <linux/in.h>
	32	#include <linux/module.h>
	33	#include <linux/net.h>
	34	#include <linux/ipv6.h>
	35	#include <linux/kthread.h>
	36	#include <linux/errno.h>
	37	#include <linux/kernel.h>
	38	#include <linux/un.h>
	39	#include <linux/uaccess.h>
	40	#include <linux/inet.h>
	41	#include <linux/idr.h>
	42	#include <linux/file.h>
	43	#include <linux/parser.h>
	44	#include <linux/semaphore.h>
5a0e3ad6	45	#include <linux/slab.h>
fc79d4b1 TT	46	#include <net/9p/9p.h>
	47	#include <net/9p/client.h>
	48	#include <net/9p/transport.h>
	49	#include <rdma/ib_verbs.h>
	50	#include <rdma/rdma_cm.h>
fc79d4b1 TT	51
	52	#define P9_PORT 5640
	53	#define P9_RDMA_SQ_DEPTH 32
	54	#define P9_RDMA_RQ_DEPTH 32
	55	#define P9_RDMA_SEND_SGE 4
	56	#define P9_RDMA_RECV_SGE 4
	57	#define P9_RDMA_IRD 0
	58	#define P9_RDMA_ORD 0
	59	#define P9_RDMA_TIMEOUT 30000 /* 30 seconds */
	60	#define P9_RDMA_MAXSIZE (44096) / Min SGE is 4, so we can
	61	* safely advertise a maxsize
	62	* of 64k */
	63
fc79d4b1 TT	64	/**
	65	* struct p9_trans_rdma - RDMA transport instance
	66	*
	67	* @state: tracks the transport state machine for connection setup and tear down
	68	* @cm_id: The RDMA CM ID
	69	* @pd: Protection Domain pointer
	70	* @qp: Queue Pair pointer
	71	* @cq: Completion Queue pointer
0e15597e	72	* @dm_mr: DMA Memory Region pointer
fc79d4b1 TT	73	* @lkey: The local access only memory region key
	74	* @timeout: Number of uSecs to wait for connection management events
	75	* @sq_depth: The depth of the Send Queue
	76	* @sq_sem: Semaphore for the SQ
	77	* @rq_depth: The depth of the Receive Queue.
0e15597e	78	* @rq_count: Count of requests in the Receive Queue.
fc79d4b1 TT	79	* @addr: The remote peer's address
fc79d4b1 TT	80	* @req_lock: Protects the active request list
fc79d4b1 TT	81	* @cm_done: Completion event for connection management tracking
	82	*/
	83	struct p9_trans_rdma {
	84	enum {
	85	P9_RDMA_INIT,
	86	P9_RDMA_ADDR_RESOLVED,
	87	P9_RDMA_ROUTE_RESOLVED,
	88	P9_RDMA_CONNECTED,
	89	P9_RDMA_FLUSHING,
	90	P9_RDMA_CLOSING,
	91	P9_RDMA_CLOSED,
	92	} state;
	93	struct rdma_cm_id *cm_id;
	94	struct ib_pd *pd;
	95	struct ib_qp *qp;
	96	struct ib_cq *cq;
	97	struct ib_mr *dma_mr;
	98	u32 lkey;
	99	long timeout;
	100	int sq_depth;
	101	struct semaphore sq_sem;
	102	int rq_depth;
	103	atomic_t rq_count;
	104	struct sockaddr_in addr;
	105	spinlock_t req_lock;
	106
	107	struct completion cm_done;
	108	};
	109
	110	/**
	111	* p9_rdma_context - Keeps track of in-process WR
	112	*
	113	* @wc_op: The original WR op for when the CQE completes in error.
	114	* @busa: Bus address to unmap when the WR completes
	115	* @req: Keeps track of requests (send)
	116	* @rc: Keepts track of replies (receive)
	117	*/
	118	struct p9_rdma_req;
	119	struct p9_rdma_context {
	120	enum ib_wc_opcode wc_op;
	121	dma_addr_t busa;
	122	union {
	123	struct p9_req_t *req;
	124	struct p9_fcall *rc;
	125	};
	126	};
	127
	128	/**
	129	* p9_rdma_opts - Collection of mount options
	130	* @port: port of connection
	131	* @sq_depth: The requested depth of the SQ. This really doesn't need
	132	* to be any deeper than the number of threads used in the client
	133	* @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
	134	* @timeout: Time to wait in msecs for CM events
	135	*/
	136	struct p9_rdma_opts {
	137	short port;
	138	int sq_depth;
	139	int rq_depth;
	140	long timeout;
	141	};
	142
	143	/*
	144	* Option Parsing (code inspired by NFS code)
145	*/
146	enum {
147	/* Options that take integer arguments */
148	Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, Opt_err,
149	};
150
151	static match_table_t tokens = {
152	{Opt_port, "port=%u"},
153	{Opt_sq_depth, "sq=%u"},
154	{Opt_rq_depth, "rq=%u"},
155	{Opt_timeout, "timeout=%u"},
156	{Opt_err, NULL},
157	};
158
159	/**
0e15597e AK	160	* parse_opts - parse mount options into rdma options structure
	161	* @params: options string passed from mount
	162	* @opts: rdma transport-specific structure to parse options into
fc79d4b1 TT	163	*
	164	* Returns 0 upon success, -ERRNO upon failure
	165	*/
	166	static int parse_opts(char params, struct p9_rdma_opts opts)
	167	{
	168	char *p;
	169	substring_t args[MAX_OPT_ARGS];
	170	int option;
d8c8a9e3	171	char options, tmp_options;
fc79d4b1 TT	172
	173	opts->port = P9_PORT;
	174	opts->sq_depth = P9_RDMA_SQ_DEPTH;
	175	opts->rq_depth = P9_RDMA_RQ_DEPTH;
	176	opts->timeout = P9_RDMA_TIMEOUT;
	177
	178	if (!params)
	179	return 0;
	180
d8c8a9e3 EVH	181	tmp_options = kstrdup(params, GFP_KERNEL);
d8c8a9e3 EVH	182	if (!tmp_options) {
5d385153 JP	183	p9_debug(P9_DEBUG_ERROR,
5d385153 JP	184	"failed to allocate copy of option string\n");
fc79d4b1 TT	185	return -ENOMEM;
fc79d4b1 TT	186	}
d8c8a9e3	187	options = tmp_options;
fc79d4b1 TT	188
	189	while ((p = strsep(&options, ",")) != NULL) {
	190	int token;
	191	int r;
	192	if (!*p)
	193	continue;
	194	token = match_token(p, tokens, args);
	195	r = match_int(&args[0], &option);
	196	if (r < 0) {
5d385153 JP	197	p9_debug(P9_DEBUG_ERROR,
5d385153 JP	198	"integer field, but no integer?\n");
fc79d4b1 TT	199	continue;
	200	}
	201	switch (token) {
	202	case Opt_port:
	203	opts->port = option;
	204	break;
	205	case Opt_sq_depth:
	206	opts->sq_depth = option;
	207	break;
	208	case Opt_rq_depth:
	209	opts->rq_depth = option;
	210	break;
	211	case Opt_timeout:
	212	opts->timeout = option;
	213	break;
	214	default:
	215	continue;
	216	}
	217	}
	218	/* RQ must be at least as large as the SQ */
	219	opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
d8c8a9e3	220	kfree(tmp_options);
fc79d4b1 TT	221	return 0;
	222	}
	223
	224	static int
	225	p9_cm_event_handler(struct rdma_cm_id id, struct rdma_cm_event event)
	226	{
	227	struct p9_client *c = id->context;
	228	struct p9_trans_rdma *rdma = c->trans;
	229	switch (event->event) {
	230	case RDMA_CM_EVENT_ADDR_RESOLVED:
	231	BUG_ON(rdma->state != P9_RDMA_INIT);
	232	rdma->state = P9_RDMA_ADDR_RESOLVED;
	233	break;
	234
	235	case RDMA_CM_EVENT_ROUTE_RESOLVED:
	236	BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
	237	rdma->state = P9_RDMA_ROUTE_RESOLVED;
	238	break;
	239
	240	case RDMA_CM_EVENT_ESTABLISHED:
	241	BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
	242	rdma->state = P9_RDMA_CONNECTED;
	243	break;
	244
	245	case RDMA_CM_EVENT_DISCONNECTED:
	246	if (rdma)
	247	rdma->state = P9_RDMA_CLOSED;
	248	if (c)
	249	c->status = Disconnected;
	250	break;
	251
	252	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
	253	break;
	254
	255	case RDMA_CM_EVENT_ADDR_CHANGE:
	256	case RDMA_CM_EVENT_ROUTE_ERROR:
	257	case RDMA_CM_EVENT_DEVICE_REMOVAL:
	258	case RDMA_CM_EVENT_MULTICAST_JOIN:
	259	case RDMA_CM_EVENT_MULTICAST_ERROR:
	260	case RDMA_CM_EVENT_REJECTED:
	261	case RDMA_CM_EVENT_CONNECT_REQUEST:
	262	case RDMA_CM_EVENT_CONNECT_RESPONSE:
	263	case RDMA_CM_EVENT_CONNECT_ERROR:
	264	case RDMA_CM_EVENT_ADDR_ERROR:
	265	case RDMA_CM_EVENT_UNREACHABLE:
	266	c->status = Disconnected;
	267	rdma_disconnect(rdma->cm_id);
	268	break;
	269	default:
	270	BUG();
	271	}
	272	complete(&rdma->cm_done);
	273	return 0;
	274	}
	275
	276	static void
	277	handle_recv(struct p9_client client, struct p9_trans_rdma rdma,
	278	struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
	279	{
	280	struct p9_req_t *req;
	281	int err = 0;
	282	int16_t tag;
	283
	284	req = NULL;
285	ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
286	DMA_FROM_DEVICE);
287
288	if (status != IB_WC_SUCCESS)
289	goto err_out;
290
291	err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
292	if (err)
293	goto err_out;
294
295	req = p9_tag_lookup(client, tag);
296	if (!req)
297	goto err_out;
298
299	req->rc = c->rc;
1bab88b2	300	req->status = REQ_STATUS_RCVD;
fc79d4b1 TT	301	p9_client_cb(client, req);
	302
	303	return;
	304
	305	err_out:
5d385153	306	p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n", req, err, status);
fc79d4b1 TT	307	rdma->state = P9_RDMA_FLUSHING;
fc79d4b1 TT	308	client->status = Disconnected;
fc79d4b1 TT	309	}
	310
	311	static void
	312	handle_send(struct p9_client client, struct p9_trans_rdma rdma,
	313	struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
	314	{
	315	ib_dma_unmap_single(rdma->cm_id->device,
	316	c->busa, c->req->tc->size,
	317	DMA_TO_DEVICE);
	318	}
	319
	320	static void qp_event_handler(struct ib_event event, void context)
	321	{
5d385153 JP	322	p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
5d385153 JP	323	event->event, context);
fc79d4b1 TT	324	}
	325
	326	static void cq_comp_handler(struct ib_cq cq, void cq_context)
	327	{
	328	struct p9_client *client = cq_context;
	329	struct p9_trans_rdma *rdma = client->trans;
	330	int ret;
	331	struct ib_wc wc;
	332
	333	ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
	334	while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
	335	struct p9_rdma_context c = (void ) (unsigned long) wc.wr_id;
	336
	337	switch (c->wc_op) {
	338	case IB_WC_RECV:
	339	atomic_dec(&rdma->rq_count);
	340	handle_recv(client, rdma, c, wc.status, wc.byte_len);
	341	break;
	342
	343	case IB_WC_SEND:
	344	handle_send(client, rdma, c, wc.status, wc.byte_len);
	345	up(&rdma->sq_sem);
	346	break;
	347
	348	default:
5d385153	349	pr_err("unexpected completion type, c->wc_op=%d, wc.opcode=%d, status=%d\n",
fc79d4b1 TT	350	c->wc_op, wc.opcode, wc.status);
	351	break;
	352	}
	353	kfree(c);
	354	}
	355	}
	356
	357	static void cq_event_handler(struct ib_event e, void v)
	358	{
5d385153	359	p9_debug(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
fc79d4b1 TT	360	}
	361
	362	static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
	363	{
	364	if (!rdma)
	365	return;
	366
	367	if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
	368	ib_dereg_mr(rdma->dma_mr);
	369
	370	if (rdma->qp && !IS_ERR(rdma->qp))
	371	ib_destroy_qp(rdma->qp);
	372
	373	if (rdma->pd && !IS_ERR(rdma->pd))
	374	ib_dealloc_pd(rdma->pd);
	375
	376	if (rdma->cq && !IS_ERR(rdma->cq))
	377	ib_destroy_cq(rdma->cq);
	378
	379	if (rdma->cm_id && !IS_ERR(rdma->cm_id))
	380	rdma_destroy_id(rdma->cm_id);
	381
	382	kfree(rdma);
	383	}
	384
	385	static int
	386	post_recv(struct p9_client client, struct p9_rdma_context c)
	387	{
	388	struct p9_trans_rdma *rdma = client->trans;
	389	struct ib_recv_wr wr, *bad_wr;
	390	struct ib_sge sge;
	391
	392	c->busa = ib_dma_map_single(rdma->cm_id->device,
	393	c->rc->sdata, client->msize,
	394	DMA_FROM_DEVICE);
	395	if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
	396	goto error;
	397
	398	sge.addr = c->busa;
	399	sge.length = client->msize;
	400	sge.lkey = rdma->lkey;
	401
	402	wr.next = NULL;
	403	c->wc_op = IB_WC_RECV;
	404	wr.wr_id = (unsigned long) c;
	405	wr.sg_list = &sge;
	406	wr.num_sge = 1;
	407	return ib_post_recv(rdma->qp, &wr, &bad_wr);
	408
	409	error:
5d385153	410	p9_debug(P9_DEBUG_ERROR, "EIO\n");
fc79d4b1 TT	411	return -EIO;
	412	}
	413
	414	static int rdma_request(struct p9_client client, struct p9_req_t req)
	415	{
	416	struct p9_trans_rdma *rdma = client->trans;
	417	struct ib_send_wr wr, *bad_wr;
	418	struct ib_sge sge;
	419	int err = 0;
	420	unsigned long flags;
	421	struct p9_rdma_context *c = NULL;
	422	struct p9_rdma_context *rpl_context = NULL;
	423
	424	/* Allocate an fcall for the reply */
eeff66ef	425	rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
1d6400c7 DB	426	if (!rpl_context) {
1d6400c7 DB	427	err = -ENOMEM;
fc79d4b1	428	goto err_close;
1d6400c7	429	}
fc79d4b1 TT	430
	431	/*
	432	* If the request has a buffer, steal it, otherwise
	433	* allocate a new one. Typically, requests should already
	434	* have receive buffers allocated and just swap them around
	435	*/
	436	if (!req->rc) {
	437	req->rc = kmalloc(sizeof(struct p9_fcall)+client->msize,
eeff66ef	438	GFP_NOFS);
fc79d4b1 TT	439	if (req->rc) {
	440	req->rc->sdata = (char *) req->rc +
	441	sizeof(struct p9_fcall);
	442	req->rc->capacity = client->msize;
	443	}
	444	}
	445	rpl_context->rc = req->rc;
	446	if (!rpl_context->rc) {
1d6400c7 DB	447	err = -ENOMEM;
1d6400c7 DB	448	goto err_free2;
fc79d4b1 TT	449	}
	450
	451	/*
	452	* Post a receive buffer for this request. We need to ensure
	453	* there is a reply buffer available for every outstanding
	454	* request. A flushed request can result in no reply for an
	455	* outstanding request, so we must keep a count to avoid
	456	* overflowing the RQ.
	457	*/
	458	if (atomic_inc_return(&rdma->rq_count) <= rdma->rq_depth) {
	459	err = post_recv(client, rpl_context);
1d6400c7 DB	460	if (err)
1d6400c7 DB	461	goto err_free1;
fc79d4b1 TT	462	} else
	463	atomic_dec(&rdma->rq_count);
	464
	465	/* remove posted receive buffer from request structure */
	466	req->rc = NULL;
	467
	468	/* Post the request */
eeff66ef	469	c = kmalloc(sizeof *c, GFP_NOFS);
1d6400c7 DB	470	if (!c) {
	471	err = -ENOMEM;
	472	goto err_free1;
	473	}
fc79d4b1 TT	474	c->req = req;
	475
	476	c->busa = ib_dma_map_single(rdma->cm_id->device,
	477	c->req->tc->sdata, c->req->tc->size,
	478	DMA_TO_DEVICE);
	479	if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
	480	goto error;
	481
	482	sge.addr = c->busa;
	483	sge.length = c->req->tc->size;
	484	sge.lkey = rdma->lkey;
	485
	486	wr.next = NULL;
	487	c->wc_op = IB_WC_SEND;
	488	wr.wr_id = (unsigned long) c;
	489	wr.opcode = IB_WR_SEND;
	490	wr.send_flags = IB_SEND_SIGNALED;
	491	wr.sg_list = &sge;
	492	wr.num_sge = 1;
	493
	494	if (down_interruptible(&rdma->sq_sem))
	495	goto error;
	496
	497	return ib_post_send(rdma->qp, &wr, &bad_wr);
	498
	499	error:
1d6400c7 DB	500	kfree(c);
	501	kfree(rpl_context->rc);
	502	kfree(rpl_context);
5d385153	503	p9_debug(P9_DEBUG_ERROR, "EIO\n");
fc79d4b1	504	return -EIO;
1d6400c7 DB	505	err_free1:
	506	kfree(rpl_context->rc);
	507	err_free2:
	508	kfree(rpl_context);
fc79d4b1 TT	509	err_close:
	510	spin_lock_irqsave(&rdma->req_lock, flags);
	511	if (rdma->state < P9_RDMA_CLOSING) {
	512	rdma->state = P9_RDMA_CLOSING;
	513	spin_unlock_irqrestore(&rdma->req_lock, flags);
	514	rdma_disconnect(rdma->cm_id);
	515	} else
	516	spin_unlock_irqrestore(&rdma->req_lock, flags);
	517	return err;
	518	}
	519
	520	static void rdma_close(struct p9_client *client)
	521	{
	522	struct p9_trans_rdma *rdma;
	523
	524	if (!client)
	525	return;
	526
	527	rdma = client->trans;
	528	if (!rdma)
	529	return;
	530
	531	client->status = Disconnected;
	532	rdma_disconnect(rdma->cm_id);
	533	rdma_destroy_trans(rdma);
	534	}
	535
	536	/**
	537	* alloc_rdma - Allocate and initialize the rdma transport structure
fc79d4b1 TT	538	* @opts: Mount options structure
	539	*/
	540	static struct p9_trans_rdma alloc_rdma(struct p9_rdma_opts opts)
	541	{
	542	struct p9_trans_rdma *rdma;
	543
	544	rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
	545	if (!rdma)
	546	return NULL;
	547
	548	rdma->sq_depth = opts->sq_depth;
	549	rdma->rq_depth = opts->rq_depth;
	550	rdma->timeout = opts->timeout;
	551	spin_lock_init(&rdma->req_lock);
	552	init_completion(&rdma->cm_done);
	553	sema_init(&rdma->sq_sem, rdma->sq_depth);
	554	atomic_set(&rdma->rq_count, 0);
	555
	556	return rdma;
	557	}
	558
	559	/* its not clear to me we can do anything after send has been posted */
	560	static int rdma_cancel(struct p9_client client, struct p9_req_t req)
	561	{
	562	return 1;
	563	}
	564
	565	/**
	566	* trans_create_rdma - Transport method for creating atransport instance
	567	* @client: client instance
	568	* @addr: IP address string
	569	* @args: Mount options string
	570	*/
	571	static int
	572	rdma_create_trans(struct p9_client client, const char addr, char *args)
	573	{
	574	int err;
	575	struct p9_rdma_opts opts;
	576	struct p9_trans_rdma *rdma;
	577	struct rdma_conn_param conn_param;
	578	struct ib_qp_init_attr qp_attr;
	579	struct ib_device_attr devattr;
	580
	581	/* Parse the transport specific mount options */
	582	err = parse_opts(args, &opts);
	583	if (err < 0)
	584	return err;
	585
	586	/* Create and initialize the RDMA transport structure */
	587	rdma = alloc_rdma(&opts);
	588	if (!rdma)
	589	return -ENOMEM;
	590
	591	/* Create the RDMA CM ID */
b26f9b99 SH	592	rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP,
b26f9b99 SH	593	IB_QPT_RC);
fc79d4b1 TT	594	if (IS_ERR(rdma->cm_id))
	595	goto error;
	596
517ac45a TT	597	/* Associate the client with the transport */
	598	client->trans = rdma;
	599
fc79d4b1 TT	600	/* Resolve the server's address */
	601	rdma->addr.sin_family = AF_INET;
	602	rdma->addr.sin_addr.s_addr = in_aton(addr);
	603	rdma->addr.sin_port = htons(opts.port);
	604	err = rdma_resolve_addr(rdma->cm_id, NULL,
	605	(struct sockaddr *)&rdma->addr,
	606	rdma->timeout);
	607	if (err)
	608	goto error;
	609	err = wait_for_completion_interruptible(&rdma->cm_done);
	610	if (err \|\| (rdma->state != P9_RDMA_ADDR_RESOLVED))
	611	goto error;
	612
	613	/* Resolve the route to the server */
	614	err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
	615	if (err)
	616	goto error;
	617	err = wait_for_completion_interruptible(&rdma->cm_done);
	618	if (err \|\| (rdma->state != P9_RDMA_ROUTE_RESOLVED))
	619	goto error;
	620
	621	/* Query the device attributes */
	622	err = ib_query_device(rdma->cm_id->device, &devattr);
	623	if (err)
	624	goto error;
	625
	626	/* Create the Completion Queue */
	627	rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
	628	cq_event_handler, client,
	629	opts.sq_depth + opts.rq_depth + 1, 0);
	630	if (IS_ERR(rdma->cq))
	631	goto error;
	632	ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
	633
	634	/* Create the Protection Domain */
	635	rdma->pd = ib_alloc_pd(rdma->cm_id->device);
	636	if (IS_ERR(rdma->pd))
	637	goto error;
	638
	639	/* Cache the DMA lkey in the transport */
	640	rdma->dma_mr = NULL;
	641	if (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
	642	rdma->lkey = rdma->cm_id->device->local_dma_lkey;
	643	else {
	644	rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE);
	645	if (IS_ERR(rdma->dma_mr))
	646	goto error;
	647	rdma->lkey = rdma->dma_mr->lkey;
	648	}
	649
	650	/* Create the Queue Pair */
	651	memset(&qp_attr, 0, sizeof qp_attr);
	652	qp_attr.event_handler = qp_event_handler;
	653	qp_attr.qp_context = client;
	654	qp_attr.cap.max_send_wr = opts.sq_depth;
	655	qp_attr.cap.max_recv_wr = opts.rq_depth;
	656	qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
	657	qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
	658	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
	659	qp_attr.qp_type = IB_QPT_RC;
	660	qp_attr.send_cq = rdma->cq;
	661	qp_attr.recv_cq = rdma->cq;
	662	err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
	663	if (err)
664	goto error;
665	rdma->qp = rdma->cm_id->qp;
666
667	/* Request a connection */
668	memset(&conn_param, 0, sizeof(conn_param));
669	conn_param.private_data = NULL;
670	conn_param.private_data_len = 0;
671	conn_param.responder_resources = P9_RDMA_IRD;
672	conn_param.initiator_depth = P9_RDMA_ORD;
673	err = rdma_connect(rdma->cm_id, &conn_param);
674	if (err)
675	goto error;
676	err = wait_for_completion_interruptible(&rdma->cm_done);
677	if (err \|\| (rdma->state != P9_RDMA_CONNECTED))
678	goto error;
679
fc79d4b1 TT	680	client->status = Connected;
	681
	682	return 0;
	683
	684	error:
	685	rdma_destroy_trans(rdma);
	686	return -ENOTCONN;
	687	}
	688
	689	static struct p9_trans_module p9_rdma_trans = {
	690	.name = "rdma",
	691	.maxsize = P9_RDMA_MAXSIZE,
	692	.def = 0,
	693	.owner = THIS_MODULE,
	694	.create = rdma_create_trans,
	695	.close = rdma_close,
	696	.request = rdma_request,
	697	.cancel = rdma_cancel,
	698	};
	699
	700	/**
	701	* p9_trans_rdma_init - Register the 9P RDMA transport driver
	702	*/
	703	static int __init p9_trans_rdma_init(void)
	704	{
	705	v9fs_register_trans(&p9_rdma_trans);
	706	return 0;
	707	}
	708
	709	static void __exit p9_trans_rdma_exit(void)
	710	{
	711	v9fs_unregister_trans(&p9_rdma_trans);
	712	}
	713
	714	module_init(p9_trans_rdma_init);
	715	module_exit(p9_trans_rdma_exit);
	716
	717	MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
	718	MODULE_DESCRIPTION("RDMA Transport for 9P");
	719	MODULE_LICENSE("Dual BSD/GPL");