diff options
Diffstat (limited to 'net/9p/trans_rdma.c')
| -rw-r--r-- | net/9p/trans_rdma.c | 713 |
1 files changed, 713 insertions, 0 deletions
diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c new file mode 100644 index 000000000000..2f1fe5fc1228 --- /dev/null +++ b/net/9p/trans_rdma.c @@ -0,0 +1,713 @@ +/* + * 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> + +#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; + + /* 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"); |