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authorTom Tucker <tom@opengridcomputing.com>2008-10-22 18:47:39 -0500
committerEric Van Hensbergen <ericvh@opteron.(none)>2008-10-22 18:47:39 -0500
commitfc79d4b104f0eb8c2a7242150eaf8756ced4c344 (patch)
treeb8e9974570ca194acc3ebd24ba7a864bba80c477 /net/9p
parentea2e7996fc892e9becfed9145fdcefd59f697718 (diff)
9p: rdma: RDMA Transport Support for 9P
This patch implements the RDMA transport provider for 9P. It allows mounts to be performed over iWARP and IB capable network interfaces. Signed-off-by: Tom Tucker <tom@opengridcomputing.com> Signed-off-by: Latchesar Ionkov <lionkov@lanl.gov>
Diffstat (limited to 'net/9p')
-rw-r--r--net/9p/Kconfig6
-rw-r--r--net/9p/Makefile4
-rw-r--r--net/9p/trans_rdma.c712
3 files changed, 722 insertions, 0 deletions
diff --git a/net/9p/Kconfig b/net/9p/Kconfig
index ff34c5acc130..c42c0c400bf9 100644
--- a/net/9p/Kconfig
+++ b/net/9p/Kconfig
@@ -20,6 +20,12 @@ config NET_9P_VIRTIO
This builds support for a transports between
guest partitions and a host partition.
+config NET_9P_RDMA
+ depends on NET_9P && INFINIBAND && EXPERIMENTAL
+ tristate "9P RDMA Transport (Experimental)"
+ help
+ This builds support for a RDMA transport.
+
config NET_9P_DEBUG
bool "Debug information"
depends on NET_9P
diff --git a/net/9p/Makefile b/net/9p/Makefile
index 1041b7bd12e2..198a640d53a6 100644
--- a/net/9p/Makefile
+++ b/net/9p/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_NET_9P) := 9pnet.o
obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
+obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
9pnet-objs := \
mod.o \
@@ -11,3 +12,6 @@ obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
9pnet_virtio-objs := \
trans_virtio.o \
+
+9pnet_rdma-objs := \
+ trans_rdma.o \
diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
new file mode 100644
index 000000000000..8d6cc4777aae
--- /dev/null
+++ b/net/9p/trans_rdma.c
@@ -0,0 +1,712 @@
+/*
+ * 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
+ *
+ */
+
+#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 <net/9p/9p.h>
+#include <net/9p/client.h>
+#include <net/9p/transport.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/rdma_cm.h>
+#include <rdma/ib_verbs.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 */
+
+#define P9_RDMA_MAX_SGE (P9_RDMA_MAXSIZE >> PAGE_SHIFT)
+/**
+ * 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
+ * @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.
+ * @addr: The remote peer's address
+ * @req_lock: Protects the active request list
+ * @send_wait: Wait list when the SQ fills up
+ * @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_options - parse mount options into session structure
+ * @options: options string passed from mount
+ * @opts: 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;
+ int ret;
+
+ 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;
+
+ options = kstrdup(params, GFP_KERNEL);
+ if (!options) {
+ P9_DPRINTK(P9_DEBUG_ERROR,
+ "failed to allocate copy of option string\n");
+ return -ENOMEM;
+ }
+
+ 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_DPRINTK(P9_DEBUG_ERROR,
+ "integer field, but no integer?\n");
+ ret = r;
+ 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(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;
+ p9_client_cb(client, req);
+
+ return;
+
+ err_out:
+ P9_DPRINTK(P9_DEBUG_ERROR, "req %p err %d status %d\n",
+ req, err, status);
+ rdma->state = P9_RDMA_FLUSHING;
+ client->status = Disconnected;
+ return;
+}
+
+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_DPRINTK(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:
+ printk(KERN_ERR "9prdma: 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_DPRINTK(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_DPRINTK(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_KERNEL);
+ if (!rpl_context)
+ 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_KERNEL);
+ 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) {
+ kfree(rpl_context);
+ goto err_close;
+ }
+
+ /*
+ * 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) {
+ kfree(rpl_context->rc);
+ kfree(rpl_context);
+ goto err_close;
+ }
+ } else
+ atomic_dec(&rdma->rq_count);
+
+ /* remove posted receive buffer from request structure */
+ req->rc = NULL;
+
+ /* Post the request */
+ c = kmalloc(sizeof *c, GFP_KERNEL);
+ if (!c)
+ goto err_close;
+ 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:
+ P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
+ return -EIO;
+
+ 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
+ * @msize: MTU
+ * @dotu: Extension attribute
+ * @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);
+ if (IS_ERR(rdma->cm_id))
+ goto error;
+
+ /* 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->trans = rdma;
+ 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");

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