diff options
Diffstat (limited to 'net/sunrpc/xprtrdma/svc_rdma_transport.c')
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_transport.c | 1357 |
1 files changed, 1357 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c new file mode 100644 index 00000000..73b428be --- /dev/null +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -0,0 +1,1357 @@ +/* + * Copyright (c) 2005-2007 Network Appliance, Inc. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the BSD-type + * license below: + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * Neither the name of the Network Appliance, Inc. nor the names of + * its contributors may be used to endorse or promote products + * derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Author: Tom Tucker <tom@opengridcomputing.com> + */ + +#include <linux/sunrpc/svc_xprt.h> +#include <linux/sunrpc/debug.h> +#include <linux/sunrpc/rpc_rdma.h> +#include <linux/interrupt.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> +#include <rdma/ib_verbs.h> +#include <rdma/rdma_cm.h> +#include <linux/sunrpc/svc_rdma.h> +#include <linux/export.h> +#include "xprt_rdma.h" + +#define RPCDBG_FACILITY RPCDBG_SVCXPRT + +static struct svc_xprt *svc_rdma_create(struct svc_serv *serv, + struct net *net, + struct sockaddr *sa, int salen, + int flags); +static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt); +static void svc_rdma_release_rqst(struct svc_rqst *); +static void dto_tasklet_func(unsigned long data); +static void svc_rdma_detach(struct svc_xprt *xprt); +static void svc_rdma_free(struct svc_xprt *xprt); +static int svc_rdma_has_wspace(struct svc_xprt *xprt); +static void rq_cq_reap(struct svcxprt_rdma *xprt); +static void sq_cq_reap(struct svcxprt_rdma *xprt); + +static DECLARE_TASKLET(dto_tasklet, dto_tasklet_func, 0UL); +static DEFINE_SPINLOCK(dto_lock); +static LIST_HEAD(dto_xprt_q); + +static struct svc_xprt_ops svc_rdma_ops = { + .xpo_create = svc_rdma_create, + .xpo_recvfrom = svc_rdma_recvfrom, + .xpo_sendto = svc_rdma_sendto, + .xpo_release_rqst = svc_rdma_release_rqst, + .xpo_detach = svc_rdma_detach, + .xpo_free = svc_rdma_free, + .xpo_prep_reply_hdr = svc_rdma_prep_reply_hdr, + .xpo_has_wspace = svc_rdma_has_wspace, + .xpo_accept = svc_rdma_accept, +}; + +struct svc_xprt_class svc_rdma_class = { + .xcl_name = "rdma", + .xcl_owner = THIS_MODULE, + .xcl_ops = &svc_rdma_ops, + .xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP, +}; + +struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) +{ + struct svc_rdma_op_ctxt *ctxt; + + while (1) { + ctxt = kmem_cache_alloc(svc_rdma_ctxt_cachep, GFP_KERNEL); + if (ctxt) + break; + schedule_timeout_uninterruptible(msecs_to_jiffies(500)); + } + ctxt->xprt = xprt; + INIT_LIST_HEAD(&ctxt->dto_q); + ctxt->count = 0; + ctxt->frmr = NULL; + atomic_inc(&xprt->sc_ctxt_used); + return ctxt; +} + +void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt) +{ + struct svcxprt_rdma *xprt = ctxt->xprt; + int i; + for (i = 0; i < ctxt->count && ctxt->sge[i].length; i++) { + /* + * Unmap the DMA addr in the SGE if the lkey matches + * the sc_dma_lkey, otherwise, ignore it since it is + * an FRMR lkey and will be unmapped later when the + * last WR that uses it completes. + */ + if (ctxt->sge[i].lkey == xprt->sc_dma_lkey) { + atomic_dec(&xprt->sc_dma_used); + ib_dma_unmap_page(xprt->sc_cm_id->device, + ctxt->sge[i].addr, + ctxt->sge[i].length, + ctxt->direction); + } + } +} + +void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages) +{ + struct svcxprt_rdma *xprt; + int i; + + BUG_ON(!ctxt); + xprt = ctxt->xprt; + if (free_pages) + for (i = 0; i < ctxt->count; i++) + put_page(ctxt->pages[i]); + + kmem_cache_free(svc_rdma_ctxt_cachep, ctxt); + atomic_dec(&xprt->sc_ctxt_used); +} + +/* + * Temporary NFS req mappings are shared across all transport + * instances. These are short lived and should be bounded by the number + * of concurrent server threads * depth of the SQ. + */ +struct svc_rdma_req_map *svc_rdma_get_req_map(void) +{ + struct svc_rdma_req_map *map; + while (1) { + map = kmem_cache_alloc(svc_rdma_map_cachep, GFP_KERNEL); + if (map) + break; + schedule_timeout_uninterruptible(msecs_to_jiffies(500)); + } + map->count = 0; + map->frmr = NULL; + return map; +} + +void svc_rdma_put_req_map(struct svc_rdma_req_map *map) +{ + kmem_cache_free(svc_rdma_map_cachep, map); +} + +/* ib_cq event handler */ +static void cq_event_handler(struct ib_event *event, void *context) +{ + struct svc_xprt *xprt = context; + dprintk("svcrdma: received CQ event id=%d, context=%p\n", + event->event, context); + set_bit(XPT_CLOSE, &xprt->xpt_flags); +} + +/* QP event handler */ +static void qp_event_handler(struct ib_event *event, void *context) +{ + struct svc_xprt *xprt = context; + + switch (event->event) { + /* These are considered benign events */ + case IB_EVENT_PATH_MIG: + case IB_EVENT_COMM_EST: + case IB_EVENT_SQ_DRAINED: + case IB_EVENT_QP_LAST_WQE_REACHED: + dprintk("svcrdma: QP event %d received for QP=%p\n", + event->event, event->element.qp); + break; + /* These are considered fatal events */ + case IB_EVENT_PATH_MIG_ERR: + case IB_EVENT_QP_FATAL: + case IB_EVENT_QP_REQ_ERR: + case IB_EVENT_QP_ACCESS_ERR: + case IB_EVENT_DEVICE_FATAL: + default: + dprintk("svcrdma: QP ERROR event %d received for QP=%p, " + "closing transport\n", + event->event, event->element.qp); + set_bit(XPT_CLOSE, &xprt->xpt_flags); + break; + } +} + +/* + * Data Transfer Operation Tasklet + * + * Walks a list of transports with I/O pending, removing entries as + * they are added to the server's I/O pending list. Two bits indicate + * if SQ, RQ, or both have I/O pending. The dto_lock is an irqsave + * spinlock that serializes access to the transport list with the RQ + * and SQ interrupt handlers. + */ +static void dto_tasklet_func(unsigned long data) +{ + struct svcxprt_rdma *xprt; + unsigned long flags; + + spin_lock_irqsave(&dto_lock, flags); + while (!list_empty(&dto_xprt_q)) { + xprt = list_entry(dto_xprt_q.next, + struct svcxprt_rdma, sc_dto_q); + list_del_init(&xprt->sc_dto_q); + spin_unlock_irqrestore(&dto_lock, flags); + + rq_cq_reap(xprt); + sq_cq_reap(xprt); + + svc_xprt_put(&xprt->sc_xprt); + spin_lock_irqsave(&dto_lock, flags); + } + spin_unlock_irqrestore(&dto_lock, flags); +} + +/* + * Receive Queue Completion Handler + * + * Since an RQ completion handler is called on interrupt context, we + * need to defer the handling of the I/O to a tasklet + */ +static void rq_comp_handler(struct ib_cq *cq, void *cq_context) +{ + struct svcxprt_rdma *xprt = cq_context; + unsigned long flags; + + /* Guard against unconditional flush call for destroyed QP */ + if (atomic_read(&xprt->sc_xprt.xpt_ref.refcount)==0) + return; + + /* + * Set the bit regardless of whether or not it's on the list + * because it may be on the list already due to an SQ + * completion. + */ + set_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags); + + /* + * If this transport is not already on the DTO transport queue, + * add it + */ + spin_lock_irqsave(&dto_lock, flags); + if (list_empty(&xprt->sc_dto_q)) { + svc_xprt_get(&xprt->sc_xprt); + list_add_tail(&xprt->sc_dto_q, &dto_xprt_q); + } + spin_unlock_irqrestore(&dto_lock, flags); + + /* Tasklet does all the work to avoid irqsave locks. */ + tasklet_schedule(&dto_tasklet); +} + +/* + * rq_cq_reap - Process the RQ CQ. + * + * Take all completing WC off the CQE and enqueue the associated DTO + * context on the dto_q for the transport. + * + * Note that caller must hold a transport reference. + */ +static void rq_cq_reap(struct svcxprt_rdma *xprt) +{ + int ret; + struct ib_wc wc; + struct svc_rdma_op_ctxt *ctxt = NULL; + + if (!test_and_clear_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags)) + return; + + ib_req_notify_cq(xprt->sc_rq_cq, IB_CQ_NEXT_COMP); + atomic_inc(&rdma_stat_rq_poll); + + while ((ret = ib_poll_cq(xprt->sc_rq_cq, 1, &wc)) > 0) { + ctxt = (struct svc_rdma_op_ctxt *)(unsigned long)wc.wr_id; + ctxt->wc_status = wc.status; + ctxt->byte_len = wc.byte_len; + svc_rdma_unmap_dma(ctxt); + if (wc.status != IB_WC_SUCCESS) { + /* Close the transport */ + dprintk("svcrdma: transport closing putting ctxt %p\n", ctxt); + set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); + svc_rdma_put_context(ctxt, 1); + svc_xprt_put(&xprt->sc_xprt); + continue; + } + spin_lock_bh(&xprt->sc_rq_dto_lock); + list_add_tail(&ctxt->dto_q, &xprt->sc_rq_dto_q); + spin_unlock_bh(&xprt->sc_rq_dto_lock); + svc_xprt_put(&xprt->sc_xprt); + } + + if (ctxt) + atomic_inc(&rdma_stat_rq_prod); + + set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags); + /* + * If data arrived before established event, + * don't enqueue. This defers RPC I/O until the + * RDMA connection is complete. + */ + if (!test_bit(RDMAXPRT_CONN_PENDING, &xprt->sc_flags)) + svc_xprt_enqueue(&xprt->sc_xprt); +} + +/* + * Process a completion context + */ +static void process_context(struct svcxprt_rdma *xprt, + struct svc_rdma_op_ctxt *ctxt) +{ + svc_rdma_unmap_dma(ctxt); + + switch (ctxt->wr_op) { + case IB_WR_SEND: + if (test_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags)) + svc_rdma_put_frmr(xprt, ctxt->frmr); + svc_rdma_put_context(ctxt, 1); + break; + + case IB_WR_RDMA_WRITE: + svc_rdma_put_context(ctxt, 0); + break; + + case IB_WR_RDMA_READ: + case IB_WR_RDMA_READ_WITH_INV: + if (test_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags)) { + struct svc_rdma_op_ctxt *read_hdr = ctxt->read_hdr; + BUG_ON(!read_hdr); + if (test_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags)) + svc_rdma_put_frmr(xprt, ctxt->frmr); + spin_lock_bh(&xprt->sc_rq_dto_lock); + set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags); + list_add_tail(&read_hdr->dto_q, + &xprt->sc_read_complete_q); + spin_unlock_bh(&xprt->sc_rq_dto_lock); + svc_xprt_enqueue(&xprt->sc_xprt); + } + svc_rdma_put_context(ctxt, 0); + break; + + default: + printk(KERN_ERR "svcrdma: unexpected completion type, " + "opcode=%d\n", + ctxt->wr_op); + break; + } +} + +/* + * Send Queue Completion Handler - potentially called on interrupt context. + * + * Note that caller must hold a transport reference. + */ +static void sq_cq_reap(struct svcxprt_rdma *xprt) +{ + struct svc_rdma_op_ctxt *ctxt = NULL; + struct ib_wc wc; + struct ib_cq *cq = xprt->sc_sq_cq; + int ret; + + if (!test_and_clear_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags)) + return; + + ib_req_notify_cq(xprt->sc_sq_cq, IB_CQ_NEXT_COMP); + atomic_inc(&rdma_stat_sq_poll); + while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) { + if (wc.status != IB_WC_SUCCESS) + /* Close the transport */ + set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); + + /* Decrement used SQ WR count */ + atomic_dec(&xprt->sc_sq_count); + wake_up(&xprt->sc_send_wait); + + ctxt = (struct svc_rdma_op_ctxt *)(unsigned long)wc.wr_id; + if (ctxt) + process_context(xprt, ctxt); + + svc_xprt_put(&xprt->sc_xprt); + } + + if (ctxt) + atomic_inc(&rdma_stat_sq_prod); +} + +static void sq_comp_handler(struct ib_cq *cq, void *cq_context) +{ + struct svcxprt_rdma *xprt = cq_context; + unsigned long flags; + + /* Guard against unconditional flush call for destroyed QP */ + if (atomic_read(&xprt->sc_xprt.xpt_ref.refcount)==0) + return; + + /* + * Set the bit regardless of whether or not it's on the list + * because it may be on the list already due to an RQ + * completion. + */ + set_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags); + + /* + * If this transport is not already on the DTO transport queue, + * add it + */ + spin_lock_irqsave(&dto_lock, flags); + if (list_empty(&xprt->sc_dto_q)) { + svc_xprt_get(&xprt->sc_xprt); + list_add_tail(&xprt->sc_dto_q, &dto_xprt_q); + } + spin_unlock_irqrestore(&dto_lock, flags); + + /* Tasklet does all the work to avoid irqsave locks. */ + tasklet_schedule(&dto_tasklet); +} + +static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv, + int listener) +{ + struct svcxprt_rdma *cma_xprt = kzalloc(sizeof *cma_xprt, GFP_KERNEL); + + if (!cma_xprt) + return NULL; + svc_xprt_init(&init_net, &svc_rdma_class, &cma_xprt->sc_xprt, serv); + INIT_LIST_HEAD(&cma_xprt->sc_accept_q); + INIT_LIST_HEAD(&cma_xprt->sc_dto_q); + INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q); + INIT_LIST_HEAD(&cma_xprt->sc_read_complete_q); + INIT_LIST_HEAD(&cma_xprt->sc_frmr_q); + init_waitqueue_head(&cma_xprt->sc_send_wait); + + spin_lock_init(&cma_xprt->sc_lock); + spin_lock_init(&cma_xprt->sc_rq_dto_lock); + spin_lock_init(&cma_xprt->sc_frmr_q_lock); + + cma_xprt->sc_ord = svcrdma_ord; + + cma_xprt->sc_max_req_size = svcrdma_max_req_size; + cma_xprt->sc_max_requests = svcrdma_max_requests; + cma_xprt->sc_sq_depth = svcrdma_max_requests * RPCRDMA_SQ_DEPTH_MULT; + atomic_set(&cma_xprt->sc_sq_count, 0); + atomic_set(&cma_xprt->sc_ctxt_used, 0); + + if (listener) + set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags); + + return cma_xprt; +} + +struct page *svc_rdma_get_page(void) +{ + struct page *page; + + while ((page = alloc_page(GFP_KERNEL)) == NULL) { + /* If we can't get memory, wait a bit and try again */ + printk(KERN_INFO "svcrdma: out of memory...retrying in 1000 " + "jiffies.\n"); + schedule_timeout_uninterruptible(msecs_to_jiffies(1000)); + } + return page; +} + +int svc_rdma_post_recv(struct svcxprt_rdma *xprt) +{ + struct ib_recv_wr recv_wr, *bad_recv_wr; + struct svc_rdma_op_ctxt *ctxt; + struct page *page; + dma_addr_t pa; + int sge_no; + int buflen; + int ret; + + ctxt = svc_rdma_get_context(xprt); + buflen = 0; + ctxt->direction = DMA_FROM_DEVICE; + for (sge_no = 0; buflen < xprt->sc_max_req_size; sge_no++) { + BUG_ON(sge_no >= xprt->sc_max_sge); + page = svc_rdma_get_page(); + ctxt->pages[sge_no] = page; + pa = ib_dma_map_page(xprt->sc_cm_id->device, + page, 0, PAGE_SIZE, + DMA_FROM_DEVICE); + if (ib_dma_mapping_error(xprt->sc_cm_id->device, pa)) + goto err_put_ctxt; + atomic_inc(&xprt->sc_dma_used); + ctxt->sge[sge_no].addr = pa; + ctxt->sge[sge_no].length = PAGE_SIZE; + ctxt->sge[sge_no].lkey = xprt->sc_dma_lkey; + ctxt->count = sge_no + 1; + buflen += PAGE_SIZE; + } + recv_wr.next = NULL; + recv_wr.sg_list = &ctxt->sge[0]; + recv_wr.num_sge = ctxt->count; + recv_wr.wr_id = (u64)(unsigned long)ctxt; + + svc_xprt_get(&xprt->sc_xprt); + ret = ib_post_recv(xprt->sc_qp, &recv_wr, &bad_recv_wr); + if (ret) { + svc_rdma_unmap_dma(ctxt); + svc_rdma_put_context(ctxt, 1); + svc_xprt_put(&xprt->sc_xprt); + } + return ret; + + err_put_ctxt: + svc_rdma_unmap_dma(ctxt); + svc_rdma_put_context(ctxt, 1); + return -ENOMEM; +} + +/* + * This function handles the CONNECT_REQUEST event on a listening + * endpoint. It is passed the cma_id for the _new_ connection. The context in + * this cma_id is inherited from the listening cma_id and is the svc_xprt + * structure for the listening endpoint. + * + * This function creates a new xprt for the new connection and enqueues it on + * the accept queue for the listent xprt. When the listen thread is kicked, it + * will call the recvfrom method on the listen xprt which will accept the new + * connection. + */ +static void handle_connect_req(struct rdma_cm_id *new_cma_id, size_t client_ird) +{ + struct svcxprt_rdma *listen_xprt = new_cma_id->context; + struct svcxprt_rdma *newxprt; + struct sockaddr *sa; + + /* Create a new transport */ + newxprt = rdma_create_xprt(listen_xprt->sc_xprt.xpt_server, 0); + if (!newxprt) { + dprintk("svcrdma: failed to create new transport\n"); + return; + } + newxprt->sc_cm_id = new_cma_id; + new_cma_id->context = newxprt; + dprintk("svcrdma: Creating newxprt=%p, cm_id=%p, listenxprt=%p\n", + newxprt, newxprt->sc_cm_id, listen_xprt); + + /* Save client advertised inbound read limit for use later in accept. */ + newxprt->sc_ord = client_ird; + + /* Set the local and remote addresses in the transport */ + sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr; + svc_xprt_set_remote(&newxprt->sc_xprt, sa, svc_addr_len(sa)); + sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr; + svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa)); + + /* + * Enqueue the new transport on the accept queue of the listening + * transport + */ + spin_lock_bh(&listen_xprt->sc_lock); + list_add_tail(&newxprt->sc_accept_q, &listen_xprt->sc_accept_q); + spin_unlock_bh(&listen_xprt->sc_lock); + + /* + * Can't use svc_xprt_received here because we are not on a + * rqstp thread + */ + set_bit(XPT_CONN, &listen_xprt->sc_xprt.xpt_flags); + svc_xprt_enqueue(&listen_xprt->sc_xprt); +} + +/* + * Handles events generated on the listening endpoint. These events will be + * either be incoming connect requests or adapter removal events. + */ +static int rdma_listen_handler(struct rdma_cm_id *cma_id, + struct rdma_cm_event *event) +{ + struct svcxprt_rdma *xprt = cma_id->context; + int ret = 0; + + switch (event->event) { + case RDMA_CM_EVENT_CONNECT_REQUEST: + dprintk("svcrdma: Connect request on cma_id=%p, xprt = %p, " + "event=%d\n", cma_id, cma_id->context, event->event); + handle_connect_req(cma_id, + event->param.conn.initiator_depth); + break; + + case RDMA_CM_EVENT_ESTABLISHED: + /* Accept complete */ + dprintk("svcrdma: Connection completed on LISTEN xprt=%p, " + "cm_id=%p\n", xprt, cma_id); + break; + + case RDMA_CM_EVENT_DEVICE_REMOVAL: + dprintk("svcrdma: Device removal xprt=%p, cm_id=%p\n", + xprt, cma_id); + if (xprt) + set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); + break; + + default: + dprintk("svcrdma: Unexpected event on listening endpoint %p, " + "event=%d\n", cma_id, event->event); + break; + } + + return ret; +} + +static int rdma_cma_handler(struct rdma_cm_id *cma_id, + struct rdma_cm_event *event) +{ + struct svc_xprt *xprt = cma_id->context; + struct svcxprt_rdma *rdma = + container_of(xprt, struct svcxprt_rdma, sc_xprt); + switch (event->event) { + case RDMA_CM_EVENT_ESTABLISHED: + /* Accept complete */ + svc_xprt_get(xprt); + dprintk("svcrdma: Connection completed on DTO xprt=%p, " + "cm_id=%p\n", xprt, cma_id); + clear_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags); + svc_xprt_enqueue(xprt); + break; + case RDMA_CM_EVENT_DISCONNECTED: + dprintk("svcrdma: Disconnect on DTO xprt=%p, cm_id=%p\n", + xprt, cma_id); + if (xprt) { + set_bit(XPT_CLOSE, &xprt->xpt_flags); + svc_xprt_enqueue(xprt); + svc_xprt_put(xprt); + } + break; + case RDMA_CM_EVENT_DEVICE_REMOVAL: + dprintk("svcrdma: Device removal cma_id=%p, xprt = %p, " + "event=%d\n", cma_id, xprt, event->event); + if (xprt) { + set_bit(XPT_CLOSE, &xprt->xpt_flags); + svc_xprt_enqueue(xprt); + } + break; + default: + dprintk("svcrdma: Unexpected event on DTO endpoint %p, " + "event=%d\n", cma_id, event->event); + break; + } + return 0; +} + +/* + * Create a listening RDMA service endpoint. + */ +static struct svc_xprt *svc_rdma_create(struct svc_serv *serv, + struct net *net, + struct sockaddr *sa, int salen, + int flags) +{ + struct rdma_cm_id *listen_id; + struct svcxprt_rdma *cma_xprt; + struct svc_xprt *xprt; + int ret; + + dprintk("svcrdma: Creating RDMA socket\n"); + if (sa->sa_family != AF_INET) { + dprintk("svcrdma: Address family %d is not supported.\n", sa->sa_family); + return ERR_PTR(-EAFNOSUPPORT); + } + cma_xprt = rdma_create_xprt(serv, 1); + if (!cma_xprt) + return ERR_PTR(-ENOMEM); + xprt = &cma_xprt->sc_xprt; + + listen_id = rdma_create_id(rdma_listen_handler, cma_xprt, RDMA_PS_TCP, + IB_QPT_RC); + if (IS_ERR(listen_id)) { + ret = PTR_ERR(listen_id); + dprintk("svcrdma: rdma_create_id failed = %d\n", ret); + goto err0; + } + + ret = rdma_bind_addr(listen_id, sa); + if (ret) { + dprintk("svcrdma: rdma_bind_addr failed = %d\n", ret); + goto err1; + } + cma_xprt->sc_cm_id = listen_id; + + ret = rdma_listen(listen_id, RPCRDMA_LISTEN_BACKLOG); + if (ret) { + dprintk("svcrdma: rdma_listen failed = %d\n", ret); + goto err1; + } + + /* + * We need to use the address from the cm_id in case the + * caller specified 0 for the port number. + */ + sa = (struct sockaddr *)&cma_xprt->sc_cm_id->route.addr.src_addr; + svc_xprt_set_local(&cma_xprt->sc_xprt, sa, salen); + + return &cma_xprt->sc_xprt; + + err1: + rdma_destroy_id(listen_id); + err0: + kfree(cma_xprt); + return ERR_PTR(ret); +} + +static struct svc_rdma_fastreg_mr *rdma_alloc_frmr(struct svcxprt_rdma *xprt) +{ + struct ib_mr *mr; + struct ib_fast_reg_page_list *pl; + struct svc_rdma_fastreg_mr *frmr; + + frmr = kmalloc(sizeof(*frmr), GFP_KERNEL); + if (!frmr) + goto err; + + mr = ib_alloc_fast_reg_mr(xprt->sc_pd, RPCSVC_MAXPAGES); + if (IS_ERR(mr)) + goto err_free_frmr; + + pl = ib_alloc_fast_reg_page_list(xprt->sc_cm_id->device, + RPCSVC_MAXPAGES); + if (IS_ERR(pl)) + goto err_free_mr; + + frmr->mr = mr; + frmr->page_list = pl; + INIT_LIST_HEAD(&frmr->frmr_list); + return frmr; + + err_free_mr: + ib_dereg_mr(mr); + err_free_frmr: + kfree(frmr); + err: + return ERR_PTR(-ENOMEM); +} + +static void rdma_dealloc_frmr_q(struct svcxprt_rdma *xprt) +{ + struct svc_rdma_fastreg_mr *frmr; + + while (!list_empty(&xprt->sc_frmr_q)) { + frmr = list_entry(xprt->sc_frmr_q.next, + struct svc_rdma_fastreg_mr, frmr_list); + list_del_init(&frmr->frmr_list); + ib_dereg_mr(frmr->mr); + ib_free_fast_reg_page_list(frmr->page_list); + kfree(frmr); + } +} + +struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *rdma) +{ + struct svc_rdma_fastreg_mr *frmr = NULL; + + spin_lock_bh(&rdma->sc_frmr_q_lock); + if (!list_empty(&rdma->sc_frmr_q)) { + frmr = list_entry(rdma->sc_frmr_q.next, + struct svc_rdma_fastreg_mr, frmr_list); + list_del_init(&frmr->frmr_list); + frmr->map_len = 0; + frmr->page_list_len = 0; + } + spin_unlock_bh(&rdma->sc_frmr_q_lock); + if (frmr) + return frmr; + + return rdma_alloc_frmr(rdma); +} + +static void frmr_unmap_dma(struct svcxprt_rdma *xprt, + struct svc_rdma_fastreg_mr *frmr) +{ + int page_no; + for (page_no = 0; page_no < frmr->page_list_len; page_no++) { + dma_addr_t addr = frmr->page_list->page_list[page_no]; + if (ib_dma_mapping_error(frmr->mr->device, addr)) + continue; + atomic_dec(&xprt->sc_dma_used); + ib_dma_unmap_page(frmr->mr->device, addr, PAGE_SIZE, + frmr->direction); + } +} + +void svc_rdma_put_frmr(struct svcxprt_rdma *rdma, + struct svc_rdma_fastreg_mr *frmr) +{ + if (frmr) { + frmr_unmap_dma(rdma, frmr); + spin_lock_bh(&rdma->sc_frmr_q_lock); + BUG_ON(!list_empty(&frmr->frmr_list)); + list_add(&frmr->frmr_list, &rdma->sc_frmr_q); + spin_unlock_bh(&rdma->sc_frmr_q_lock); + } +} + +/* + * This is the xpo_recvfrom function for listening endpoints. Its + * purpose is to accept incoming connections. The CMA callback handler + * has already created a new transport and attached it to the new CMA + * ID. + * + * There is a queue of pending connections hung on the listening + * transport. This queue contains the new svc_xprt structure. This + * function takes svc_xprt structures off the accept_q and completes + * the connection. + */ +static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) +{ + struct svcxprt_rdma *listen_rdma; + struct svcxprt_rdma *newxprt = NULL; + struct rdma_conn_param conn_param; + struct ib_qp_init_attr qp_attr; + struct ib_device_attr devattr; + int uninitialized_var(dma_mr_acc); + int need_dma_mr; + int ret; + int i; + + listen_rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); + clear_bit(XPT_CONN, &xprt->xpt_flags); + /* Get the next entry off the accept list */ + spin_lock_bh(&listen_rdma->sc_lock); + if (!list_empty(&listen_rdma->sc_accept_q)) { + newxprt = list_entry(listen_rdma->sc_accept_q.next, + struct svcxprt_rdma, sc_accept_q); + list_del_init(&newxprt->sc_accept_q); + } + if (!list_empty(&listen_rdma->sc_accept_q)) + set_bit(XPT_CONN, &listen_rdma->sc_xprt.xpt_flags); + spin_unlock_bh(&listen_rdma->sc_lock); + if (!newxprt) + return NULL; + + dprintk("svcrdma: newxprt from accept queue = %p, cm_id=%p\n", + newxprt, newxprt->sc_cm_id); + + ret = ib_query_device(newxprt->sc_cm_id->device, &devattr); + if (ret) { + dprintk("svcrdma: could not query device attributes on " + "device %p, rc=%d\n", newxprt->sc_cm_id->device, ret); + goto errout; + } + + /* Qualify the transport resource defaults with the + * capabilities of this particular device */ + newxprt->sc_max_sge = min((size_t)devattr.max_sge, + (size_t)RPCSVC_MAXPAGES); + newxprt->sc_max_requests = min((size_t)devattr.max_qp_wr, + (size_t)svcrdma_max_requests); + newxprt->sc_sq_depth = RPCRDMA_SQ_DEPTH_MULT * newxprt->sc_max_requests; + + /* + * Limit ORD based on client limit, local device limit, and + * configured svcrdma limit. + */ + newxprt->sc_ord = min_t(size_t, devattr.max_qp_rd_atom, newxprt->sc_ord); + newxprt->sc_ord = min_t(size_t, svcrdma_ord, newxprt->sc_ord); + + newxprt->sc_pd = ib_alloc_pd(newxprt->sc_cm_id->device); + if (IS_ERR(newxprt->sc_pd)) { + dprintk("svcrdma: error creating PD for connect request\n"); + goto errout; + } + newxprt->sc_sq_cq = ib_create_cq(newxprt->sc_cm_id->device, + sq_comp_handler, + cq_event_handler, + newxprt, + newxprt->sc_sq_depth, + 0); + if (IS_ERR(newxprt->sc_sq_cq)) { + dprintk("svcrdma: error creating SQ CQ for connect request\n"); + goto errout; + } + newxprt->sc_rq_cq = ib_create_cq(newxprt->sc_cm_id->device, + rq_comp_handler, + cq_event_handler, + newxprt, + newxprt->sc_max_requests, + 0); + if (IS_ERR(newxprt->sc_rq_cq)) { + dprintk("svcrdma: error creating RQ CQ for connect request\n"); + goto errout; + } + + memset(&qp_attr, 0, sizeof qp_attr); + qp_attr.event_handler = qp_event_handler; + qp_attr.qp_context = &newxprt->sc_xprt; + qp_attr.cap.max_send_wr = newxprt->sc_sq_depth; + qp_attr.cap.max_recv_wr = newxprt->sc_max_requests; + qp_attr.cap.max_send_sge = newxprt->sc_max_sge; + qp_attr.cap.max_recv_sge = newxprt->sc_max_sge; + qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR; + qp_attr.qp_type = IB_QPT_RC; + qp_attr.send_cq = newxprt->sc_sq_cq; + qp_attr.recv_cq = newxprt->sc_rq_cq; + dprintk("svcrdma: newxprt->sc_cm_id=%p, newxprt->sc_pd=%p\n" + " cm_id->device=%p, sc_pd->device=%p\n" + " cap.max_send_wr = %d\n" + " cap.max_recv_wr = %d\n" + " cap.max_send_sge = %d\n" + " cap.max_recv_sge = %d\n", + newxprt->sc_cm_id, newxprt->sc_pd, + newxprt->sc_cm_id->device, newxprt->sc_pd->device, + qp_attr.cap.max_send_wr, + qp_attr.cap.max_recv_wr, + qp_attr.cap.max_send_sge, + qp_attr.cap.max_recv_sge); + + ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, &qp_attr); + if (ret) { + /* + * XXX: This is a hack. We need a xx_request_qp interface + * that will adjust the qp_attr's with a best-effort + * number + */ + qp_attr.cap.max_send_sge -= 2; + qp_attr.cap.max_recv_sge -= 2; + ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, + &qp_attr); + if (ret) { + dprintk("svcrdma: failed to create QP, ret=%d\n", ret); + goto errout; + } + newxprt->sc_max_sge = qp_attr.cap.max_send_sge; + newxprt->sc_max_sge = qp_attr.cap.max_recv_sge; + newxprt->sc_sq_depth = qp_attr.cap.max_send_wr; + newxprt->sc_max_requests = qp_attr.cap.max_recv_wr; + } + newxprt->sc_qp = newxprt->sc_cm_id->qp; + + /* + * Use the most secure set of MR resources based on the + * transport type and available memory management features in + * the device. Here's the table implemented below: + * + * Fast Global DMA Remote WR + * Reg LKEY MR Access + * Sup'd Sup'd Needed Needed + * + * IWARP N N Y Y + * N Y Y Y + * Y N Y N + * Y Y N - + * + * IB N N Y N + * N Y N - + * Y N Y N + * Y Y N - + * + * NB: iWARP requires remote write access for the data sink + * of an RDMA_READ. IB does not. + */ + if (devattr.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) { + newxprt->sc_frmr_pg_list_len = + devattr.max_fast_reg_page_list_len; + newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_FAST_REG; + } + + /* + * Determine if a DMA MR is required and if so, what privs are required + */ + switch (rdma_node_get_transport(newxprt->sc_cm_id->device->node_type)) { + case RDMA_TRANSPORT_IWARP: + newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_READ_W_INV; + if (!(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG)) { + need_dma_mr = 1; + dma_mr_acc = + (IB_ACCESS_LOCAL_WRITE | + IB_ACCESS_REMOTE_WRITE); + } else if (!(devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)) { + need_dma_mr = 1; + dma_mr_acc = IB_ACCESS_LOCAL_WRITE; + } else + need_dma_mr = 0; + break; + case RDMA_TRANSPORT_IB: + if (!(devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)) { + need_dma_mr = 1; + dma_mr_acc = IB_ACCESS_LOCAL_WRITE; + } else + need_dma_mr = 0; + break; + default: + goto errout; + } + + /* Create the DMA MR if needed, otherwise, use the DMA LKEY */ + if (need_dma_mr) { + /* Register all of physical memory */ + newxprt->sc_phys_mr = + ib_get_dma_mr(newxprt->sc_pd, dma_mr_acc); + if (IS_ERR(newxprt->sc_phys_mr)) { + dprintk("svcrdma: Failed to create DMA MR ret=%d\n", + ret); + goto errout; + } + newxprt->sc_dma_lkey = newxprt->sc_phys_mr->lkey; + } else + newxprt->sc_dma_lkey = + newxprt->sc_cm_id->device->local_dma_lkey; + + /* Post receive buffers */ + for (i = 0; i < newxprt->sc_max_requests; i++) { + ret = svc_rdma_post_recv(newxprt); + if (ret) { + dprintk("svcrdma: failure posting receive buffers\n"); + goto errout; + } + } + + /* Swap out the handler */ + newxprt->sc_cm_id->event_handler = rdma_cma_handler; + + /* + * Arm the CQs for the SQ and RQ before accepting so we can't + * miss the first message + */ + ib_req_notify_cq(newxprt->sc_sq_cq, IB_CQ_NEXT_COMP); + ib_req_notify_cq(newxprt->sc_rq_cq, IB_CQ_NEXT_COMP); + + /* Accept Connection */ + set_bit(RDMAXPRT_CONN_PENDING, &newxprt->sc_flags); + memset(&conn_param, 0, sizeof conn_param); + conn_param.responder_resources = 0; + conn_param.initiator_depth = newxprt->sc_ord; + ret = rdma_accept(newxprt->sc_cm_id, &conn_param); + if (ret) { + dprintk("svcrdma: failed to accept new connection, ret=%d\n", + ret); + goto errout; + } + + dprintk("svcrdma: new connection %p accepted with the following " + "attributes:\n" + " local_ip : %pI4\n" + " local_port : %d\n" + " remote_ip : %pI4\n" + " remote_port : %d\n" + " max_sge : %d\n" + " sq_depth : %d\n" + " max_requests : %d\n" + " ord : %d\n", + newxprt, + &((struct sockaddr_in *)&newxprt->sc_cm_id-> + route.addr.src_addr)->sin_addr.s_addr, + ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id-> + route.addr.src_addr)->sin_port), + &((struct sockaddr_in *)&newxprt->sc_cm_id-> + route.addr.dst_addr)->sin_addr.s_addr, + ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id-> + route.addr.dst_addr)->sin_port), + newxprt->sc_max_sge, + newxprt->sc_sq_depth, + newxprt->sc_max_requests, + newxprt->sc_ord); + + return &newxprt->sc_xprt; + + errout: + dprintk("svcrdma: failure accepting new connection rc=%d.\n", ret); + /* Take a reference in case the DTO handler runs */ + svc_xprt_get(&newxprt->sc_xprt); + if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp)) + ib_destroy_qp(newxprt->sc_qp); + rdma_destroy_id(newxprt->sc_cm_id); + /* This call to put will destroy the transport */ + svc_xprt_put(&newxprt->sc_xprt); + return NULL; +} + +static void svc_rdma_release_rqst(struct svc_rqst *rqstp) +{ +} + +/* + * When connected, an svc_xprt has at least two references: + * + * - A reference held by the cm_id between the ESTABLISHED and + * DISCONNECTED events. If the remote peer disconnected first, this + * reference could be gone. + * + * - A reference held by the svc_recv code that called this function + * as part of close processing. + * + * At a minimum one references should still be held. + */ +static void svc_rdma_detach(struct svc_xprt *xprt) +{ + struct svcxprt_rdma *rdma = + container_of(xprt, struct svcxprt_rdma, sc_xprt); + dprintk("svc: svc_rdma_detach(%p)\n", xprt); + + /* Disconnect and flush posted WQE */ + rdma_disconnect(rdma->sc_cm_id); +} + +static void __svc_rdma_free(struct work_struct *work) +{ + struct svcxprt_rdma *rdma = + container_of(work, struct svcxprt_rdma, sc_work); + dprintk("svcrdma: svc_rdma_free(%p)\n", rdma); + + /* We should only be called from kref_put */ + BUG_ON(atomic_read(&rdma->sc_xprt.xpt_ref.refcount) != 0); + + /* + * Destroy queued, but not processed read completions. Note + * that this cleanup has to be done before destroying the + * cm_id because the device ptr is needed to unmap the dma in + * svc_rdma_put_context. + */ + while (!list_empty(&rdma->sc_read_complete_q)) { + struct svc_rdma_op_ctxt *ctxt; + ctxt = list_entry(rdma->sc_read_complete_q.next, + struct svc_rdma_op_ctxt, + dto_q); + list_del_init(&ctxt->dto_q); + svc_rdma_put_context(ctxt, 1); + } + + /* Destroy queued, but not processed recv completions */ + while (!list_empty(&rdma->sc_rq_dto_q)) { + struct svc_rdma_op_ctxt *ctxt; + ctxt = list_entry(rdma->sc_rq_dto_q.next, + struct svc_rdma_op_ctxt, + dto_q); + list_del_init(&ctxt->dto_q); + svc_rdma_put_context(ctxt, 1); + } + + /* Warn if we leaked a resource or under-referenced */ + WARN_ON(atomic_read(&rdma->sc_ctxt_used) != 0); + WARN_ON(atomic_read(&rdma->sc_dma_used) != 0); + + /* De-allocate fastreg mr */ + rdma_dealloc_frmr_q(rdma); + + /* Destroy the QP if present (not a listener) */ + if (rdma->sc_qp && !IS_ERR(rdma->sc_qp)) + ib_destroy_qp(rdma->sc_qp); + + if (rdma->sc_sq_cq && !IS_ERR(rdma->sc_sq_cq)) + ib_destroy_cq(rdma->sc_sq_cq); + + if (rdma->sc_rq_cq && !IS_ERR(rdma->sc_rq_cq)) + ib_destroy_cq(rdma->sc_rq_cq); + + if (rdma->sc_phys_mr && !IS_ERR(rdma->sc_phys_mr)) + ib_dereg_mr(rdma->sc_phys_mr); + + if (rdma->sc_pd && !IS_ERR(rdma->sc_pd)) + ib_dealloc_pd(rdma->sc_pd); + + /* Destroy the CM ID */ + rdma_destroy_id(rdma->sc_cm_id); + + kfree(rdma); +} + +static void svc_rdma_free(struct svc_xprt *xprt) +{ + struct svcxprt_rdma *rdma = + container_of(xprt, struct svcxprt_rdma, sc_xprt); + INIT_WORK(&rdma->sc_work, __svc_rdma_free); + queue_work(svc_rdma_wq, &rdma->sc_work); +} + +static int svc_rdma_has_wspace(struct svc_xprt *xprt) +{ + struct svcxprt_rdma *rdma = + container_of(xprt, struct svcxprt_rdma, sc_xprt); + + /* + * If there are fewer SQ WR available than required to send a + * simple response, return false. + */ + if ((rdma->sc_sq_depth - atomic_read(&rdma->sc_sq_count) < 3)) + return 0; + + /* + * ...or there are already waiters on the SQ, + * return false. + */ + if (waitqueue_active(&rdma->sc_send_wait)) + return 0; + + /* Otherwise return true. */ + return 1; +} + +/* + * Attempt to register the kvec representing the RPC memory with the + * device. + * + * Returns: + * NULL : The device does not support fastreg or there were no more + * fastreg mr. + * frmr : The kvec register request was successfully posted. + * <0 : An error was encountered attempting to register the kvec. + */ +int svc_rdma_fastreg(struct svcxprt_rdma *xprt, + struct svc_rdma_fastreg_mr *frmr) +{ + struct ib_send_wr fastreg_wr; + u8 key; + + /* Bump the key */ + key = (u8)(frmr->mr->lkey & 0x000000FF); + ib_update_fast_reg_key(frmr->mr, ++key); + + /* Prepare FASTREG WR */ + memset(&fastreg_wr, 0, sizeof fastreg_wr); + fastreg_wr.opcode = IB_WR_FAST_REG_MR; + fastreg_wr.send_flags = IB_SEND_SIGNALED; + fastreg_wr.wr.fast_reg.iova_start = (unsigned long)frmr->kva; + fastreg_wr.wr.fast_reg.page_list = frmr->page_list; + fastreg_wr.wr.fast_reg.page_list_len = frmr->page_list_len; + fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT; + fastreg_wr.wr.fast_reg.length = frmr->map_len; + fastreg_wr.wr.fast_reg.access_flags = frmr->access_flags; + fastreg_wr.wr.fast_reg.rkey = frmr->mr->lkey; + return svc_rdma_send(xprt, &fastreg_wr); +} + +int svc_rdma_send(struct svcxprt_rdma *xprt, struct ib_send_wr *wr) +{ + struct ib_send_wr *bad_wr, *n_wr; + int wr_count; + int i; + int ret; + + if (test_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags)) + return -ENOTCONN; + + BUG_ON(wr->send_flags != IB_SEND_SIGNALED); + wr_count = 1; + for (n_wr = wr->next; n_wr; n_wr = n_wr->next) + wr_count++; + + /* If the SQ is full, wait until an SQ entry is available */ + while (1) { + spin_lock_bh(&xprt->sc_lock); + if (xprt->sc_sq_depth < atomic_read(&xprt->sc_sq_count) + wr_count) { + spin_unlock_bh(&xprt->sc_lock); + atomic_inc(&rdma_stat_sq_starve); + + /* See if we can opportunistically reap SQ WR to make room */ + sq_cq_reap(xprt); + + /* Wait until SQ WR available if SQ still full */ + wait_event(xprt->sc_send_wait, + atomic_read(&xprt->sc_sq_count) < + xprt->sc_sq_depth); + if (test_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags)) + return -ENOTCONN; + continue; + } + /* Take a transport ref for each WR posted */ + for (i = 0; i < wr_count; i++) + svc_xprt_get(&xprt->sc_xprt); + + /* Bump used SQ WR count and post */ + atomic_add(wr_count, &xprt->sc_sq_count); + ret = ib_post_send(xprt->sc_qp, wr, &bad_wr); + if (ret) { + set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); + atomic_sub(wr_count, &xprt->sc_sq_count); + for (i = 0; i < wr_count; i ++) + svc_xprt_put(&xprt->sc_xprt); + dprintk("svcrdma: failed to post SQ WR rc=%d, " + "sc_sq_count=%d, sc_sq_depth=%d\n", + ret, atomic_read(&xprt->sc_sq_count), + xprt->sc_sq_depth); + } + spin_unlock_bh(&xprt->sc_lock); + if (ret) + wake_up(&xprt->sc_send_wait); + break; + } + return ret; +} + +void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp, + enum rpcrdma_errcode err) +{ + struct ib_send_wr err_wr; + struct page *p; + struct svc_rdma_op_ctxt *ctxt; + u32 *va; + int length; + int ret; + + p = svc_rdma_get_page(); + va = page_address(p); + + /* XDR encode error */ + length = svc_rdma_xdr_encode_error(xprt, rmsgp, err, va); + + ctxt = svc_rdma_get_context(xprt); + ctxt->direction = DMA_FROM_DEVICE; + ctxt->count = 1; + ctxt->pages[0] = p; + + /* Prepare SGE for local address */ + ctxt->sge[0].addr = ib_dma_map_page(xprt->sc_cm_id->device, + p, 0, length, DMA_FROM_DEVICE); + if (ib_dma_mapping_error(xprt->sc_cm_id->device, ctxt->sge[0].addr)) { + put_page(p); + svc_rdma_put_context(ctxt, 1); + return; + } + atomic_inc(&xprt->sc_dma_used); + ctxt->sge[0].lkey = xprt->sc_dma_lkey; + ctxt->sge[0].length = length; + + /* Prepare SEND WR */ + memset(&err_wr, 0, sizeof err_wr); + ctxt->wr_op = IB_WR_SEND; + err_wr.wr_id = (unsigned long)ctxt; + err_wr.sg_list = ctxt->sge; + err_wr.num_sge = 1; + err_wr.opcode = IB_WR_SEND; + err_wr.send_flags = IB_SEND_SIGNALED; + + /* Post It */ + ret = svc_rdma_send(xprt, &err_wr); + if (ret) { + dprintk("svcrdma: Error %d posting send for protocol error\n", + ret); + svc_rdma_unmap_dma(ctxt); + svc_rdma_put_context(ctxt, 1); + } +} |