IB/srpt: Change default behavior from using SRQ to using RC
Although in the RC mode more resources are needed that mode has three
advantages over SRQ:
- It works with all RDMA adapters, even those that do not support
SRQ.
- Posting WRs and polling WCs does not trigger lock contention
because only one thread at a time accesses a WR or WC queue in
non-SRQ mode.
- The end-to-end flow control mechanism is used.
>From the IB spec:
C9-150.2.1: For QPs that are not associated with an SRQ, each HCA
receive queue shall generate end-to-end flow control credits. If
a QP is associated with an SRQ, the HCA receive queue shall not
generate end-to-end flow control credits.
Add new configfs attributes that allow to configure which mode to use
(/sys/kernel/config/target/srpt/$GUID/$GUID/attrib/use_srq). Note:
only the attribute for port 1 is relevant on multi-port adapters.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Bart Van Assche
Doug Ledford
parent
74333f1223
commit
dea262094c
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@ -295,6 +295,7 @@ static void srpt_get_ioc(struct srpt_port *sport, u32 slot,
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{
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struct srpt_device *sdev = sport->sdev;
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struct ib_dm_ioc_profile *iocp;
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int send_queue_depth;
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iocp = (struct ib_dm_ioc_profile *)mad->data;
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@ -310,6 +311,12 @@ static void srpt_get_ioc(struct srpt_port *sport, u32 slot,
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return;
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}
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if (sdev->use_srq)
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send_queue_depth = sdev->srq_size;
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else
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send_queue_depth = min(SRPT_RQ_SIZE,
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sdev->device->attrs.max_qp_wr);
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memset(iocp, 0, sizeof(*iocp));
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strcpy(iocp->id_string, SRPT_ID_STRING);
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iocp->guid = cpu_to_be64(srpt_service_guid);
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@ -322,7 +329,7 @@ static void srpt_get_ioc(struct srpt_port *sport, u32 slot,
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iocp->io_subclass = cpu_to_be16(SRP_IO_SUBCLASS);
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iocp->protocol = cpu_to_be16(SRP_PROTOCOL);
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iocp->protocol_version = cpu_to_be16(SRP_PROTOCOL_VERSION);
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iocp->send_queue_depth = cpu_to_be16(sdev->srq_size);
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iocp->send_queue_depth = cpu_to_be16(send_queue_depth);
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iocp->rdma_read_depth = 4;
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iocp->send_size = cpu_to_be32(srp_max_req_size);
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iocp->rdma_size = cpu_to_be32(min(sport->port_attrib.srp_max_rdma_size,
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@ -686,6 +693,9 @@ static void srpt_free_ioctx_ring(struct srpt_ioctx **ioctx_ring,
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{
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int i;
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if (!ioctx_ring)
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return;
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for (i = 0; i < ring_size; ++i)
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srpt_free_ioctx(sdev, ioctx_ring[i], dma_size, dir);
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kfree(ioctx_ring);
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@ -757,7 +767,7 @@ static bool srpt_test_and_set_cmd_state(struct srpt_send_ioctx *ioctx,
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/**
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* srpt_post_recv() - Post an IB receive request.
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*/
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static int srpt_post_recv(struct srpt_device *sdev,
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static int srpt_post_recv(struct srpt_device *sdev, struct srpt_rdma_ch *ch,
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struct srpt_recv_ioctx *ioctx)
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{
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struct ib_sge list;
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@ -774,7 +784,10 @@ static int srpt_post_recv(struct srpt_device *sdev,
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wr.sg_list = &list;
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wr.num_sge = 1;
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if (sdev->use_srq)
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return ib_post_srq_recv(sdev->srq, &wr, &bad_wr);
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else
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return ib_post_recv(ch->qp, &wr, &bad_wr);
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}
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/**
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@ -1517,7 +1530,7 @@ static void srpt_handle_new_iu(struct srpt_rdma_ch *ch,
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break;
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}
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srpt_post_recv(ch->sport->sdev, recv_ioctx);
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srpt_post_recv(ch->sport->sdev, ch, recv_ioctx);
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return;
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out_wait:
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@ -1616,7 +1629,7 @@ static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
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struct srpt_device *sdev = sport->sdev;
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const struct ib_device_attr *attrs = &sdev->device->attrs;
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u32 srp_sq_size = sport->port_attrib.srp_sq_size;
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int ret;
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int i, ret;
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WARN_ON(ch->rq_size < 1);
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@ -1640,7 +1653,6 @@ static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
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= (void(*)(struct ib_event *, void*))srpt_qp_event;
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qp_init->send_cq = ch->cq;
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qp_init->recv_cq = ch->cq;
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qp_init->srq = sdev->srq;
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qp_init->sq_sig_type = IB_SIGNAL_REQ_WR;
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qp_init->qp_type = IB_QPT_RC;
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/*
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@ -1654,6 +1666,12 @@ static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
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qp_init->cap.max_rdma_ctxs = srp_sq_size / 2;
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qp_init->cap.max_send_sge = min(attrs->max_sge, SRPT_MAX_SG_PER_WQE);
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qp_init->port_num = ch->sport->port;
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if (sdev->use_srq) {
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qp_init->srq = sdev->srq;
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} else {
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qp_init->cap.max_recv_wr = ch->rq_size;
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qp_init->cap.max_recv_sge = qp_init->cap.max_send_sge;
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}
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ch->qp = ib_create_qp(sdev->pd, qp_init);
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if (IS_ERR(ch->qp)) {
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@ -1669,6 +1687,10 @@ static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
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goto err_destroy_cq;
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}
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if (!sdev->use_srq)
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for (i = 0; i < ch->rq_size; i++)
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srpt_post_recv(sdev, ch, ch->ioctx_recv_ring[i]);
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atomic_set(&ch->sq_wr_avail, qp_init->cap.max_send_wr);
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pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d cm_id= %p\n",
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@ -1818,6 +1840,10 @@ static void srpt_release_channel_work(struct work_struct *w)
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ch->sport->sdev, ch->rq_size,
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ch->rsp_size, DMA_TO_DEVICE);
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srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_recv_ring,
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sdev, ch->rq_size,
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srp_max_req_size, DMA_FROM_DEVICE);
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mutex_lock(&sdev->mutex);
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list_del_init(&ch->list);
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if (ch->release_done)
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@ -1975,6 +2001,19 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
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ch->ioctx_ring[i]->ch = ch;
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list_add_tail(&ch->ioctx_ring[i]->free_list, &ch->free_list);
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}
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if (!sdev->use_srq) {
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ch->ioctx_recv_ring = (struct srpt_recv_ioctx **)
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srpt_alloc_ioctx_ring(ch->sport->sdev, ch->rq_size,
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sizeof(*ch->ioctx_recv_ring[0]),
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srp_max_req_size,
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DMA_FROM_DEVICE);
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if (!ch->ioctx_recv_ring) {
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pr_err("rejected SRP_LOGIN_REQ because creating a new QP RQ ring failed.\n");
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rej->reason =
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cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
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goto free_ring;
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}
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}
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ret = srpt_create_ch_ib(ch);
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if (ret) {
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@ -1982,7 +2021,7 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
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SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
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pr_err("rejected SRP_LOGIN_REQ because creating"
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" a new RDMA channel failed.\n");
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goto free_ring;
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goto free_recv_ring;
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}
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ret = srpt_ch_qp_rtr(ch, ch->qp);
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@ -2073,6 +2112,11 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
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destroy_ib:
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srpt_destroy_ch_ib(ch);
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free_recv_ring:
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srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_recv_ring,
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ch->sport->sdev, ch->rq_size,
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srp_max_req_size, DMA_FROM_DEVICE);
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free_ring:
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srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
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ch->sport->sdev, ch->rq_size,
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@ -2502,20 +2546,38 @@ static void srpt_add_one(struct ib_device *device)
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srq_attr.attr.srq_limit = 0;
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srq_attr.srq_type = IB_SRQT_BASIC;
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sdev->srq = ib_create_srq(sdev->pd, &srq_attr);
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if (IS_ERR(sdev->srq))
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sdev->srq = sdev->port[0].port_attrib.use_srq ?
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ib_create_srq(sdev->pd, &srq_attr) : ERR_PTR(-ENOTSUPP);
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if (IS_ERR(sdev->srq)) {
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pr_debug("ib_create_srq() failed: %ld\n", PTR_ERR(sdev->srq));
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/* SRQ not supported. */
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sdev->use_srq = false;
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} else {
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pr_debug("create SRQ #wr= %d max_allow=%d dev= %s\n",
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sdev->srq_size, sdev->device->attrs.max_srq_wr,
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device->name);
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sdev->use_srq = true;
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sdev->ioctx_ring = (struct srpt_recv_ioctx **)
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srpt_alloc_ioctx_ring(sdev, sdev->srq_size,
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sizeof(*sdev->ioctx_ring[0]),
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srp_max_req_size,
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DMA_FROM_DEVICE);
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if (!sdev->ioctx_ring)
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goto err_pd;
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pr_debug("%s: create SRQ #wr= %d max_allow=%d dev= %s\n",
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__func__, sdev->srq_size, sdev->device->attrs.max_srq_wr,
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device->name);
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for (i = 0; i < sdev->srq_size; ++i)
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srpt_post_recv(sdev, NULL, sdev->ioctx_ring[i]);
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}
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if (!srpt_service_guid)
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srpt_service_guid = be64_to_cpu(device->node_guid);
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sdev->cm_id = ib_create_cm_id(device, srpt_cm_handler, sdev);
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if (IS_ERR(sdev->cm_id))
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goto err_srq;
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goto err_ring;
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/* print out target login information */
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pr_debug("Target login info: id_ext=%016llx,ioc_guid=%016llx,"
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@ -2535,16 +2597,6 @@ static void srpt_add_one(struct ib_device *device)
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srpt_event_handler);
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ib_register_event_handler(&sdev->event_handler);
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sdev->ioctx_ring = (struct srpt_recv_ioctx **)
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srpt_alloc_ioctx_ring(sdev, sdev->srq_size,
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sizeof(*sdev->ioctx_ring[0]),
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srp_max_req_size, DMA_FROM_DEVICE);
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if (!sdev->ioctx_ring)
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goto err_event;
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for (i = 0; i < sdev->srq_size; ++i)
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srpt_post_recv(sdev, sdev->ioctx_ring[i]);
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WARN_ON(sdev->device->phys_port_cnt > ARRAY_SIZE(sdev->port));
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for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
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@ -2554,12 +2606,13 @@ static void srpt_add_one(struct ib_device *device)
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sport->port_attrib.srp_max_rdma_size = DEFAULT_MAX_RDMA_SIZE;
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sport->port_attrib.srp_max_rsp_size = DEFAULT_MAX_RSP_SIZE;
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sport->port_attrib.srp_sq_size = DEF_SRPT_SQ_SIZE;
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sport->port_attrib.use_srq = false;
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INIT_WORK(&sport->work, srpt_refresh_port_work);
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if (srpt_refresh_port(sport)) {
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pr_err("MAD registration failed for %s-%d.\n",
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sdev->device->name, i);
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goto err_ring;
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goto err_event;
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}
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}
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@ -2572,16 +2625,16 @@ static void srpt_add_one(struct ib_device *device)
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pr_debug("added %s.\n", device->name);
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return;
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err_ring:
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srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
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sdev->srq_size, srp_max_req_size,
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DMA_FROM_DEVICE);
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err_event:
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ib_unregister_event_handler(&sdev->event_handler);
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err_cm:
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ib_destroy_cm_id(sdev->cm_id);
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err_srq:
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err_ring:
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if (sdev->use_srq)
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ib_destroy_srq(sdev->srq);
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srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
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sdev->srq_size, srp_max_req_size,
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DMA_FROM_DEVICE);
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err_pd:
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ib_dealloc_pd(sdev->pd);
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free_dev:
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@ -2625,12 +2678,12 @@ static void srpt_remove_one(struct ib_device *device, void *client_data)
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spin_unlock(&srpt_dev_lock);
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srpt_release_sdev(sdev);
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if (sdev->use_srq)
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ib_destroy_srq(sdev->srq);
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ib_dealloc_pd(sdev->pd);
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srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
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sdev->srq_size, srp_max_req_size, DMA_FROM_DEVICE);
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sdev->ioctx_ring = NULL;
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ib_dealloc_pd(sdev->pd);
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kfree(sdev);
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}
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@ -2928,14 +2981,43 @@ static ssize_t srpt_tpg_attrib_srp_sq_size_store(struct config_item *item,
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return count;
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}
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static ssize_t srpt_tpg_attrib_use_srq_show(struct config_item *item,
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char *page)
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{
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struct se_portal_group *se_tpg = attrib_to_tpg(item);
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struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
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return sprintf(page, "%d\n", sport->port_attrib.use_srq);
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}
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static ssize_t srpt_tpg_attrib_use_srq_store(struct config_item *item,
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const char *page, size_t count)
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{
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struct se_portal_group *se_tpg = attrib_to_tpg(item);
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struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
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unsigned long val;
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int ret;
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ret = kstrtoul(page, 0, &val);
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if (ret < 0)
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return ret;
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if (val != !!val)
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return -EINVAL;
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sport->port_attrib.use_srq = val;
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return count;
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}
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CONFIGFS_ATTR(srpt_tpg_attrib_, srp_max_rdma_size);
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CONFIGFS_ATTR(srpt_tpg_attrib_, srp_max_rsp_size);
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CONFIGFS_ATTR(srpt_tpg_attrib_, srp_sq_size);
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CONFIGFS_ATTR(srpt_tpg_attrib_, use_srq);
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static struct configfs_attribute *srpt_tpg_attrib_attrs[] = {
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&srpt_tpg_attrib_attr_srp_max_rdma_size,
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&srpt_tpg_attrib_attr_srp_max_rsp_size,
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&srpt_tpg_attrib_attr_srp_sq_size,
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&srpt_tpg_attrib_attr_use_srq,
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NULL,
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};
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@ -252,6 +252,7 @@ enum rdma_ch_state {
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* @free_list: Head of list with free send I/O contexts.
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* @state: channel state. See also enum rdma_ch_state.
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* @ioctx_ring: Send ring.
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* @ioctx_recv_ring: Receive I/O context ring.
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* @list: Node for insertion in the srpt_device.rch_list list.
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* @cmd_wait_list: List of SCSI commands that arrived before the RTU event. This
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* list contains struct srpt_ioctx elements and is protected
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@ -281,6 +282,7 @@ struct srpt_rdma_ch {
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struct list_head free_list;
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enum rdma_ch_state state;
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struct srpt_send_ioctx **ioctx_ring;
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struct srpt_recv_ioctx **ioctx_recv_ring;
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struct list_head list;
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struct list_head cmd_wait_list;
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struct se_session *sess;
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@ -295,11 +297,13 @@ struct srpt_rdma_ch {
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* @srp_max_rdma_size: Maximum size of SRP RDMA transfers for new connections.
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* @srp_max_rsp_size: Maximum size of SRP response messages in bytes.
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* @srp_sq_size: Shared receive queue (SRQ) size.
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* @use_srq: Whether or not to use SRQ.
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*/
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struct srpt_port_attrib {
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u32 srp_max_rdma_size;
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u32 srp_max_rsp_size;
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u32 srp_sq_size;
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bool use_srq;
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};
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/**
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@ -347,6 +351,7 @@ struct srpt_port {
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* @srq: Per-HCA SRQ (shared receive queue).
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* @cm_id: Connection identifier.
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* @srq_size: SRQ size.
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* @use_srq: Whether or not to use SRQ.
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* @ioctx_ring: Per-HCA SRQ.
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* @rch_list: Per-device channel list -- see also srpt_rdma_ch.list.
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* @ch_releaseQ: Enables waiting for removal from rch_list.
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@ -362,6 +367,7 @@ struct srpt_device {
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struct ib_srq *srq;
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struct ib_cm_id *cm_id;
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int srq_size;
|
||||
bool use_srq;
|
||||
struct srpt_recv_ioctx **ioctx_ring;
|
||||
struct list_head rch_list;
|
||||
wait_queue_head_t ch_releaseQ;
|
||||
|
|
|
|||
Loading…
Reference in New Issue