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![Joe Perches](/assets/img/avatar_default.png)
Not including net/atm/ Compiled tested x86 allyesconfig only Added a > 80 column line or two, which I ignored. Existing checkpatch plaints willfully, cheerfully ignored. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
874 lines
26 KiB
C
874 lines
26 KiB
C
/*
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* Copyright (c) 2006 Oracle. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/in.h>
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#include <linux/device.h>
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#include <linux/dmapool.h>
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#include "rds.h"
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#include "rdma.h"
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#include "ib.h"
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static void rds_ib_send_rdma_complete(struct rds_message *rm,
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int wc_status)
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{
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int notify_status;
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switch (wc_status) {
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case IB_WC_WR_FLUSH_ERR:
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return;
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case IB_WC_SUCCESS:
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notify_status = RDS_RDMA_SUCCESS;
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break;
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case IB_WC_REM_ACCESS_ERR:
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notify_status = RDS_RDMA_REMOTE_ERROR;
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break;
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default:
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notify_status = RDS_RDMA_OTHER_ERROR;
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break;
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}
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rds_rdma_send_complete(rm, notify_status);
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}
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static void rds_ib_send_unmap_rdma(struct rds_ib_connection *ic,
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struct rds_rdma_op *op)
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{
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if (op->r_mapped) {
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ib_dma_unmap_sg(ic->i_cm_id->device,
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op->r_sg, op->r_nents,
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op->r_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
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op->r_mapped = 0;
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}
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}
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static void rds_ib_send_unmap_rm(struct rds_ib_connection *ic,
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struct rds_ib_send_work *send,
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int wc_status)
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{
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struct rds_message *rm = send->s_rm;
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rdsdebug("ic %p send %p rm %p\n", ic, send, rm);
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ib_dma_unmap_sg(ic->i_cm_id->device,
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rm->m_sg, rm->m_nents,
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DMA_TO_DEVICE);
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if (rm->m_rdma_op != NULL) {
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rds_ib_send_unmap_rdma(ic, rm->m_rdma_op);
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/* If the user asked for a completion notification on this
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* message, we can implement three different semantics:
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* 1. Notify when we received the ACK on the RDS message
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* that was queued with the RDMA. This provides reliable
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* notification of RDMA status at the expense of a one-way
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* packet delay.
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* 2. Notify when the IB stack gives us the completion event for
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* the RDMA operation.
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* 3. Notify when the IB stack gives us the completion event for
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* the accompanying RDS messages.
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* Here, we implement approach #3. To implement approach #2,
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* call rds_rdma_send_complete from the cq_handler. To implement #1,
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* don't call rds_rdma_send_complete at all, and fall back to the notify
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* handling in the ACK processing code.
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*
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* Note: There's no need to explicitly sync any RDMA buffers using
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* ib_dma_sync_sg_for_cpu - the completion for the RDMA
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* operation itself unmapped the RDMA buffers, which takes care
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* of synching.
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*/
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rds_ib_send_rdma_complete(rm, wc_status);
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if (rm->m_rdma_op->r_write)
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rds_stats_add(s_send_rdma_bytes, rm->m_rdma_op->r_bytes);
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else
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rds_stats_add(s_recv_rdma_bytes, rm->m_rdma_op->r_bytes);
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}
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/* If anyone waited for this message to get flushed out, wake
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* them up now */
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rds_message_unmapped(rm);
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rds_message_put(rm);
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send->s_rm = NULL;
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}
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void rds_ib_send_init_ring(struct rds_ib_connection *ic)
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{
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struct rds_ib_send_work *send;
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u32 i;
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for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) {
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struct ib_sge *sge;
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send->s_rm = NULL;
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send->s_op = NULL;
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send->s_wr.wr_id = i;
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send->s_wr.sg_list = send->s_sge;
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send->s_wr.num_sge = 1;
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send->s_wr.opcode = IB_WR_SEND;
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send->s_wr.send_flags = 0;
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send->s_wr.ex.imm_data = 0;
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sge = rds_ib_data_sge(ic, send->s_sge);
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sge->lkey = ic->i_mr->lkey;
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sge = rds_ib_header_sge(ic, send->s_sge);
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sge->addr = ic->i_send_hdrs_dma + (i * sizeof(struct rds_header));
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sge->length = sizeof(struct rds_header);
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sge->lkey = ic->i_mr->lkey;
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}
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}
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void rds_ib_send_clear_ring(struct rds_ib_connection *ic)
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{
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struct rds_ib_send_work *send;
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u32 i;
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for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) {
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if (send->s_wr.opcode == 0xdead)
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continue;
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if (send->s_rm)
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rds_ib_send_unmap_rm(ic, send, IB_WC_WR_FLUSH_ERR);
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if (send->s_op)
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rds_ib_send_unmap_rdma(ic, send->s_op);
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}
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}
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/*
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* The _oldest/_free ring operations here race cleanly with the alloc/unalloc
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* operations performed in the send path. As the sender allocs and potentially
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* unallocs the next free entry in the ring it doesn't alter which is
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* the next to be freed, which is what this is concerned with.
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*/
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void rds_ib_send_cq_comp_handler(struct ib_cq *cq, void *context)
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{
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struct rds_connection *conn = context;
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struct rds_ib_connection *ic = conn->c_transport_data;
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struct ib_wc wc;
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struct rds_ib_send_work *send;
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u32 completed;
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u32 oldest;
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u32 i = 0;
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int ret;
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rdsdebug("cq %p conn %p\n", cq, conn);
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rds_ib_stats_inc(s_ib_tx_cq_call);
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ret = ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
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if (ret)
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rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
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while (ib_poll_cq(cq, 1, &wc) > 0) {
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rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n",
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(unsigned long long)wc.wr_id, wc.status, wc.byte_len,
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be32_to_cpu(wc.ex.imm_data));
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rds_ib_stats_inc(s_ib_tx_cq_event);
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if (wc.wr_id == RDS_IB_ACK_WR_ID) {
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if (ic->i_ack_queued + HZ/2 < jiffies)
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rds_ib_stats_inc(s_ib_tx_stalled);
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rds_ib_ack_send_complete(ic);
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continue;
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}
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oldest = rds_ib_ring_oldest(&ic->i_send_ring);
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completed = rds_ib_ring_completed(&ic->i_send_ring, wc.wr_id, oldest);
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for (i = 0; i < completed; i++) {
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send = &ic->i_sends[oldest];
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/* In the error case, wc.opcode sometimes contains garbage */
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switch (send->s_wr.opcode) {
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case IB_WR_SEND:
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if (send->s_rm)
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rds_ib_send_unmap_rm(ic, send, wc.status);
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break;
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case IB_WR_RDMA_WRITE:
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case IB_WR_RDMA_READ:
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/* Nothing to be done - the SG list will be unmapped
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* when the SEND completes. */
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break;
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default:
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if (printk_ratelimit())
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printk(KERN_NOTICE
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"RDS/IB: %s: unexpected opcode 0x%x in WR!\n",
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__func__, send->s_wr.opcode);
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break;
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}
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send->s_wr.opcode = 0xdead;
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send->s_wr.num_sge = 1;
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if (send->s_queued + HZ/2 < jiffies)
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rds_ib_stats_inc(s_ib_tx_stalled);
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/* If a RDMA operation produced an error, signal this right
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* away. If we don't, the subsequent SEND that goes with this
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* RDMA will be canceled with ERR_WFLUSH, and the application
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* never learn that the RDMA failed. */
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if (unlikely(wc.status == IB_WC_REM_ACCESS_ERR && send->s_op)) {
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struct rds_message *rm;
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rm = rds_send_get_message(conn, send->s_op);
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if (rm)
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rds_ib_send_rdma_complete(rm, wc.status);
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}
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oldest = (oldest + 1) % ic->i_send_ring.w_nr;
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}
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rds_ib_ring_free(&ic->i_send_ring, completed);
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if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags) ||
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test_bit(0, &conn->c_map_queued))
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queue_delayed_work(rds_wq, &conn->c_send_w, 0);
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/* We expect errors as the qp is drained during shutdown */
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if (wc.status != IB_WC_SUCCESS && rds_conn_up(conn)) {
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rds_ib_conn_error(conn,
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"send completion on %pI4 "
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"had status %u, disconnecting and reconnecting\n",
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&conn->c_faddr, wc.status);
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}
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}
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}
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/*
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* This is the main function for allocating credits when sending
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* messages.
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*
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* Conceptually, we have two counters:
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* - send credits: this tells us how many WRs we're allowed
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* to submit without overruning the reciever's queue. For
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* each SEND WR we post, we decrement this by one.
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*
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* - posted credits: this tells us how many WRs we recently
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* posted to the receive queue. This value is transferred
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* to the peer as a "credit update" in a RDS header field.
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* Every time we transmit credits to the peer, we subtract
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* the amount of transferred credits from this counter.
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*
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* It is essential that we avoid situations where both sides have
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* exhausted their send credits, and are unable to send new credits
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* to the peer. We achieve this by requiring that we send at least
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* one credit update to the peer before exhausting our credits.
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* When new credits arrive, we subtract one credit that is withheld
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* until we've posted new buffers and are ready to transmit these
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* credits (see rds_ib_send_add_credits below).
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*
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* The RDS send code is essentially single-threaded; rds_send_xmit
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* grabs c_send_lock to ensure exclusive access to the send ring.
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* However, the ACK sending code is independent and can race with
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* message SENDs.
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*
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* In the send path, we need to update the counters for send credits
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* and the counter of posted buffers atomically - when we use the
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* last available credit, we cannot allow another thread to race us
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* and grab the posted credits counter. Hence, we have to use a
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* spinlock to protect the credit counter, or use atomics.
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*
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* Spinlocks shared between the send and the receive path are bad,
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* because they create unnecessary delays. An early implementation
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* using a spinlock showed a 5% degradation in throughput at some
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* loads.
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*
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* This implementation avoids spinlocks completely, putting both
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* counters into a single atomic, and updating that atomic using
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* atomic_add (in the receive path, when receiving fresh credits),
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* and using atomic_cmpxchg when updating the two counters.
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*/
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int rds_ib_send_grab_credits(struct rds_ib_connection *ic,
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u32 wanted, u32 *adv_credits, int need_posted, int max_posted)
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{
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unsigned int avail, posted, got = 0, advertise;
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long oldval, newval;
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*adv_credits = 0;
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if (!ic->i_flowctl)
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return wanted;
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try_again:
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advertise = 0;
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oldval = newval = atomic_read(&ic->i_credits);
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posted = IB_GET_POST_CREDITS(oldval);
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avail = IB_GET_SEND_CREDITS(oldval);
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rdsdebug("rds_ib_send_grab_credits(%u): credits=%u posted=%u\n",
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wanted, avail, posted);
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/* The last credit must be used to send a credit update. */
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if (avail && !posted)
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avail--;
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if (avail < wanted) {
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struct rds_connection *conn = ic->i_cm_id->context;
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/* Oops, there aren't that many credits left! */
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set_bit(RDS_LL_SEND_FULL, &conn->c_flags);
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got = avail;
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} else {
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/* Sometimes you get what you want, lalala. */
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got = wanted;
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}
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newval -= IB_SET_SEND_CREDITS(got);
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/*
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* If need_posted is non-zero, then the caller wants
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* the posted regardless of whether any send credits are
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* available.
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*/
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if (posted && (got || need_posted)) {
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advertise = min_t(unsigned int, posted, max_posted);
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newval -= IB_SET_POST_CREDITS(advertise);
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}
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/* Finally bill everything */
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if (atomic_cmpxchg(&ic->i_credits, oldval, newval) != oldval)
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goto try_again;
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*adv_credits = advertise;
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return got;
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}
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void rds_ib_send_add_credits(struct rds_connection *conn, unsigned int credits)
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{
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struct rds_ib_connection *ic = conn->c_transport_data;
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if (credits == 0)
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return;
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rdsdebug("rds_ib_send_add_credits(%u): current=%u%s\n",
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credits,
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IB_GET_SEND_CREDITS(atomic_read(&ic->i_credits)),
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test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ? ", ll_send_full" : "");
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atomic_add(IB_SET_SEND_CREDITS(credits), &ic->i_credits);
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if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags))
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queue_delayed_work(rds_wq, &conn->c_send_w, 0);
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WARN_ON(IB_GET_SEND_CREDITS(credits) >= 16384);
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rds_ib_stats_inc(s_ib_rx_credit_updates);
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}
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void rds_ib_advertise_credits(struct rds_connection *conn, unsigned int posted)
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{
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struct rds_ib_connection *ic = conn->c_transport_data;
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if (posted == 0)
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return;
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atomic_add(IB_SET_POST_CREDITS(posted), &ic->i_credits);
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/* Decide whether to send an update to the peer now.
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* If we would send a credit update for every single buffer we
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* post, we would end up with an ACK storm (ACK arrives,
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* consumes buffer, we refill the ring, send ACK to remote
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* advertising the newly posted buffer... ad inf)
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*
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* Performance pretty much depends on how often we send
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* credit updates - too frequent updates mean lots of ACKs.
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* Too infrequent updates, and the peer will run out of
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* credits and has to throttle.
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* For the time being, 16 seems to be a good compromise.
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*/
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if (IB_GET_POST_CREDITS(atomic_read(&ic->i_credits)) >= 16)
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set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
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}
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static inline void
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rds_ib_xmit_populate_wr(struct rds_ib_connection *ic,
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struct rds_ib_send_work *send, unsigned int pos,
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unsigned long buffer, unsigned int length,
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int send_flags)
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{
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struct ib_sge *sge;
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WARN_ON(pos != send - ic->i_sends);
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send->s_wr.send_flags = send_flags;
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send->s_wr.opcode = IB_WR_SEND;
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send->s_wr.num_sge = 2;
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send->s_wr.next = NULL;
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send->s_queued = jiffies;
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send->s_op = NULL;
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if (length != 0) {
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sge = rds_ib_data_sge(ic, send->s_sge);
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sge->addr = buffer;
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sge->length = length;
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sge->lkey = ic->i_mr->lkey;
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sge = rds_ib_header_sge(ic, send->s_sge);
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} else {
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/* We're sending a packet with no payload. There is only
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* one SGE */
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send->s_wr.num_sge = 1;
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sge = &send->s_sge[0];
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}
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sge->addr = ic->i_send_hdrs_dma + (pos * sizeof(struct rds_header));
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sge->length = sizeof(struct rds_header);
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sge->lkey = ic->i_mr->lkey;
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}
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/*
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* This can be called multiple times for a given message. The first time
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* we see a message we map its scatterlist into the IB device so that
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* we can provide that mapped address to the IB scatter gather entries
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* in the IB work requests. We translate the scatterlist into a series
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* of work requests that fragment the message. These work requests complete
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* in order so we pass ownership of the message to the completion handler
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* once we send the final fragment.
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*
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* The RDS core uses the c_send_lock to only enter this function once
|
|
* per connection. This makes sure that the tx ring alloc/unalloc pairs
|
|
* don't get out of sync and confuse the ring.
|
|
*/
|
|
int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
|
|
unsigned int hdr_off, unsigned int sg, unsigned int off)
|
|
{
|
|
struct rds_ib_connection *ic = conn->c_transport_data;
|
|
struct ib_device *dev = ic->i_cm_id->device;
|
|
struct rds_ib_send_work *send = NULL;
|
|
struct rds_ib_send_work *first;
|
|
struct rds_ib_send_work *prev;
|
|
struct ib_send_wr *failed_wr;
|
|
struct scatterlist *scat;
|
|
u32 pos;
|
|
u32 i;
|
|
u32 work_alloc;
|
|
u32 credit_alloc;
|
|
u32 posted;
|
|
u32 adv_credits = 0;
|
|
int send_flags = 0;
|
|
int sent;
|
|
int ret;
|
|
int flow_controlled = 0;
|
|
|
|
BUG_ON(off % RDS_FRAG_SIZE);
|
|
BUG_ON(hdr_off != 0 && hdr_off != sizeof(struct rds_header));
|
|
|
|
/* FIXME we may overallocate here */
|
|
if (be32_to_cpu(rm->m_inc.i_hdr.h_len) == 0)
|
|
i = 1;
|
|
else
|
|
i = ceil(be32_to_cpu(rm->m_inc.i_hdr.h_len), RDS_FRAG_SIZE);
|
|
|
|
work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, i, &pos);
|
|
if (work_alloc == 0) {
|
|
set_bit(RDS_LL_SEND_FULL, &conn->c_flags);
|
|
rds_ib_stats_inc(s_ib_tx_ring_full);
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
credit_alloc = work_alloc;
|
|
if (ic->i_flowctl) {
|
|
credit_alloc = rds_ib_send_grab_credits(ic, work_alloc, &posted, 0, RDS_MAX_ADV_CREDIT);
|
|
adv_credits += posted;
|
|
if (credit_alloc < work_alloc) {
|
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - credit_alloc);
|
|
work_alloc = credit_alloc;
|
|
flow_controlled++;
|
|
}
|
|
if (work_alloc == 0) {
|
|
set_bit(RDS_LL_SEND_FULL, &conn->c_flags);
|
|
rds_ib_stats_inc(s_ib_tx_throttle);
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* map the message the first time we see it */
|
|
if (ic->i_rm == NULL) {
|
|
/*
|
|
printk(KERN_NOTICE "rds_ib_xmit prep msg dport=%u flags=0x%x len=%d\n",
|
|
be16_to_cpu(rm->m_inc.i_hdr.h_dport),
|
|
rm->m_inc.i_hdr.h_flags,
|
|
be32_to_cpu(rm->m_inc.i_hdr.h_len));
|
|
*/
|
|
if (rm->m_nents) {
|
|
rm->m_count = ib_dma_map_sg(dev,
|
|
rm->m_sg, rm->m_nents, DMA_TO_DEVICE);
|
|
rdsdebug("ic %p mapping rm %p: %d\n", ic, rm, rm->m_count);
|
|
if (rm->m_count == 0) {
|
|
rds_ib_stats_inc(s_ib_tx_sg_mapping_failure);
|
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
|
|
ret = -ENOMEM; /* XXX ? */
|
|
goto out;
|
|
}
|
|
} else {
|
|
rm->m_count = 0;
|
|
}
|
|
|
|
ic->i_unsignaled_wrs = rds_ib_sysctl_max_unsig_wrs;
|
|
ic->i_unsignaled_bytes = rds_ib_sysctl_max_unsig_bytes;
|
|
rds_message_addref(rm);
|
|
ic->i_rm = rm;
|
|
|
|
/* Finalize the header */
|
|
if (test_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags))
|
|
rm->m_inc.i_hdr.h_flags |= RDS_FLAG_ACK_REQUIRED;
|
|
if (test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags))
|
|
rm->m_inc.i_hdr.h_flags |= RDS_FLAG_RETRANSMITTED;
|
|
|
|
/* If it has a RDMA op, tell the peer we did it. This is
|
|
* used by the peer to release use-once RDMA MRs. */
|
|
if (rm->m_rdma_op) {
|
|
struct rds_ext_header_rdma ext_hdr;
|
|
|
|
ext_hdr.h_rdma_rkey = cpu_to_be32(rm->m_rdma_op->r_key);
|
|
rds_message_add_extension(&rm->m_inc.i_hdr,
|
|
RDS_EXTHDR_RDMA, &ext_hdr, sizeof(ext_hdr));
|
|
}
|
|
if (rm->m_rdma_cookie) {
|
|
rds_message_add_rdma_dest_extension(&rm->m_inc.i_hdr,
|
|
rds_rdma_cookie_key(rm->m_rdma_cookie),
|
|
rds_rdma_cookie_offset(rm->m_rdma_cookie));
|
|
}
|
|
|
|
/* Note - rds_ib_piggyb_ack clears the ACK_REQUIRED bit, so
|
|
* we should not do this unless we have a chance of at least
|
|
* sticking the header into the send ring. Which is why we
|
|
* should call rds_ib_ring_alloc first. */
|
|
rm->m_inc.i_hdr.h_ack = cpu_to_be64(rds_ib_piggyb_ack(ic));
|
|
rds_message_make_checksum(&rm->m_inc.i_hdr);
|
|
|
|
/*
|
|
* Update adv_credits since we reset the ACK_REQUIRED bit.
|
|
*/
|
|
rds_ib_send_grab_credits(ic, 0, &posted, 1, RDS_MAX_ADV_CREDIT - adv_credits);
|
|
adv_credits += posted;
|
|
BUG_ON(adv_credits > 255);
|
|
} else if (ic->i_rm != rm)
|
|
BUG();
|
|
|
|
send = &ic->i_sends[pos];
|
|
first = send;
|
|
prev = NULL;
|
|
scat = &rm->m_sg[sg];
|
|
sent = 0;
|
|
i = 0;
|
|
|
|
/* Sometimes you want to put a fence between an RDMA
|
|
* READ and the following SEND.
|
|
* We could either do this all the time
|
|
* or when requested by the user. Right now, we let
|
|
* the application choose.
|
|
*/
|
|
if (rm->m_rdma_op && rm->m_rdma_op->r_fence)
|
|
send_flags = IB_SEND_FENCE;
|
|
|
|
/*
|
|
* We could be copying the header into the unused tail of the page.
|
|
* That would need to be changed in the future when those pages might
|
|
* be mapped userspace pages or page cache pages. So instead we always
|
|
* use a second sge and our long-lived ring of mapped headers. We send
|
|
* the header after the data so that the data payload can be aligned on
|
|
* the receiver.
|
|
*/
|
|
|
|
/* handle a 0-len message */
|
|
if (be32_to_cpu(rm->m_inc.i_hdr.h_len) == 0) {
|
|
rds_ib_xmit_populate_wr(ic, send, pos, 0, 0, send_flags);
|
|
goto add_header;
|
|
}
|
|
|
|
/* if there's data reference it with a chain of work reqs */
|
|
for (; i < work_alloc && scat != &rm->m_sg[rm->m_count]; i++) {
|
|
unsigned int len;
|
|
|
|
send = &ic->i_sends[pos];
|
|
|
|
len = min(RDS_FRAG_SIZE, ib_sg_dma_len(dev, scat) - off);
|
|
rds_ib_xmit_populate_wr(ic, send, pos,
|
|
ib_sg_dma_address(dev, scat) + off, len,
|
|
send_flags);
|
|
|
|
/*
|
|
* We want to delay signaling completions just enough to get
|
|
* the batching benefits but not so much that we create dead time
|
|
* on the wire.
|
|
*/
|
|
if (ic->i_unsignaled_wrs-- == 0) {
|
|
ic->i_unsignaled_wrs = rds_ib_sysctl_max_unsig_wrs;
|
|
send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
|
|
}
|
|
|
|
ic->i_unsignaled_bytes -= len;
|
|
if (ic->i_unsignaled_bytes <= 0) {
|
|
ic->i_unsignaled_bytes = rds_ib_sysctl_max_unsig_bytes;
|
|
send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
|
|
}
|
|
|
|
/*
|
|
* Always signal the last one if we're stopping due to flow control.
|
|
*/
|
|
if (flow_controlled && i == (work_alloc-1))
|
|
send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
|
|
|
|
rdsdebug("send %p wr %p num_sge %u next %p\n", send,
|
|
&send->s_wr, send->s_wr.num_sge, send->s_wr.next);
|
|
|
|
sent += len;
|
|
off += len;
|
|
if (off == ib_sg_dma_len(dev, scat)) {
|
|
scat++;
|
|
off = 0;
|
|
}
|
|
|
|
add_header:
|
|
/* Tack on the header after the data. The header SGE should already
|
|
* have been set up to point to the right header buffer. */
|
|
memcpy(&ic->i_send_hdrs[pos], &rm->m_inc.i_hdr, sizeof(struct rds_header));
|
|
|
|
if (0) {
|
|
struct rds_header *hdr = &ic->i_send_hdrs[pos];
|
|
|
|
printk(KERN_NOTICE "send WR dport=%u flags=0x%x len=%d\n",
|
|
be16_to_cpu(hdr->h_dport),
|
|
hdr->h_flags,
|
|
be32_to_cpu(hdr->h_len));
|
|
}
|
|
if (adv_credits) {
|
|
struct rds_header *hdr = &ic->i_send_hdrs[pos];
|
|
|
|
/* add credit and redo the header checksum */
|
|
hdr->h_credit = adv_credits;
|
|
rds_message_make_checksum(hdr);
|
|
adv_credits = 0;
|
|
rds_ib_stats_inc(s_ib_tx_credit_updates);
|
|
}
|
|
|
|
if (prev)
|
|
prev->s_wr.next = &send->s_wr;
|
|
prev = send;
|
|
|
|
pos = (pos + 1) % ic->i_send_ring.w_nr;
|
|
}
|
|
|
|
/* Account the RDS header in the number of bytes we sent, but just once.
|
|
* The caller has no concept of fragmentation. */
|
|
if (hdr_off == 0)
|
|
sent += sizeof(struct rds_header);
|
|
|
|
/* if we finished the message then send completion owns it */
|
|
if (scat == &rm->m_sg[rm->m_count]) {
|
|
prev->s_rm = ic->i_rm;
|
|
prev->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
|
|
ic->i_rm = NULL;
|
|
}
|
|
|
|
if (i < work_alloc) {
|
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - i);
|
|
work_alloc = i;
|
|
}
|
|
if (ic->i_flowctl && i < credit_alloc)
|
|
rds_ib_send_add_credits(conn, credit_alloc - i);
|
|
|
|
/* XXX need to worry about failed_wr and partial sends. */
|
|
failed_wr = &first->s_wr;
|
|
ret = ib_post_send(ic->i_cm_id->qp, &first->s_wr, &failed_wr);
|
|
rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic,
|
|
first, &first->s_wr, ret, failed_wr);
|
|
BUG_ON(failed_wr != &first->s_wr);
|
|
if (ret) {
|
|
printk(KERN_WARNING "RDS/IB: ib_post_send to %pI4 "
|
|
"returned %d\n", &conn->c_faddr, ret);
|
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
|
|
if (prev->s_rm) {
|
|
ic->i_rm = prev->s_rm;
|
|
prev->s_rm = NULL;
|
|
}
|
|
/* Finesse this later */
|
|
BUG();
|
|
goto out;
|
|
}
|
|
|
|
ret = sent;
|
|
out:
|
|
BUG_ON(adv_credits);
|
|
return ret;
|
|
}
|
|
|
|
int rds_ib_xmit_rdma(struct rds_connection *conn, struct rds_rdma_op *op)
|
|
{
|
|
struct rds_ib_connection *ic = conn->c_transport_data;
|
|
struct rds_ib_send_work *send = NULL;
|
|
struct rds_ib_send_work *first;
|
|
struct rds_ib_send_work *prev;
|
|
struct ib_send_wr *failed_wr;
|
|
struct rds_ib_device *rds_ibdev;
|
|
struct scatterlist *scat;
|
|
unsigned long len;
|
|
u64 remote_addr = op->r_remote_addr;
|
|
u32 pos;
|
|
u32 work_alloc;
|
|
u32 i;
|
|
u32 j;
|
|
int sent;
|
|
int ret;
|
|
int num_sge;
|
|
|
|
rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client);
|
|
|
|
/* map the message the first time we see it */
|
|
if (!op->r_mapped) {
|
|
op->r_count = ib_dma_map_sg(ic->i_cm_id->device,
|
|
op->r_sg, op->r_nents, (op->r_write) ?
|
|
DMA_TO_DEVICE : DMA_FROM_DEVICE);
|
|
rdsdebug("ic %p mapping op %p: %d\n", ic, op, op->r_count);
|
|
if (op->r_count == 0) {
|
|
rds_ib_stats_inc(s_ib_tx_sg_mapping_failure);
|
|
ret = -ENOMEM; /* XXX ? */
|
|
goto out;
|
|
}
|
|
|
|
op->r_mapped = 1;
|
|
}
|
|
|
|
/*
|
|
* Instead of knowing how to return a partial rdma read/write we insist that there
|
|
* be enough work requests to send the entire message.
|
|
*/
|
|
i = ceil(op->r_count, rds_ibdev->max_sge);
|
|
|
|
work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, i, &pos);
|
|
if (work_alloc != i) {
|
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
|
|
rds_ib_stats_inc(s_ib_tx_ring_full);
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
send = &ic->i_sends[pos];
|
|
first = send;
|
|
prev = NULL;
|
|
scat = &op->r_sg[0];
|
|
sent = 0;
|
|
num_sge = op->r_count;
|
|
|
|
for (i = 0; i < work_alloc && scat != &op->r_sg[op->r_count]; i++) {
|
|
send->s_wr.send_flags = 0;
|
|
send->s_queued = jiffies;
|
|
/*
|
|
* We want to delay signaling completions just enough to get
|
|
* the batching benefits but not so much that we create dead time on the wire.
|
|
*/
|
|
if (ic->i_unsignaled_wrs-- == 0) {
|
|
ic->i_unsignaled_wrs = rds_ib_sysctl_max_unsig_wrs;
|
|
send->s_wr.send_flags = IB_SEND_SIGNALED;
|
|
}
|
|
|
|
send->s_wr.opcode = op->r_write ? IB_WR_RDMA_WRITE : IB_WR_RDMA_READ;
|
|
send->s_wr.wr.rdma.remote_addr = remote_addr;
|
|
send->s_wr.wr.rdma.rkey = op->r_key;
|
|
send->s_op = op;
|
|
|
|
if (num_sge > rds_ibdev->max_sge) {
|
|
send->s_wr.num_sge = rds_ibdev->max_sge;
|
|
num_sge -= rds_ibdev->max_sge;
|
|
} else {
|
|
send->s_wr.num_sge = num_sge;
|
|
}
|
|
|
|
send->s_wr.next = NULL;
|
|
|
|
if (prev)
|
|
prev->s_wr.next = &send->s_wr;
|
|
|
|
for (j = 0; j < send->s_wr.num_sge && scat != &op->r_sg[op->r_count]; j++) {
|
|
len = ib_sg_dma_len(ic->i_cm_id->device, scat);
|
|
send->s_sge[j].addr =
|
|
ib_sg_dma_address(ic->i_cm_id->device, scat);
|
|
send->s_sge[j].length = len;
|
|
send->s_sge[j].lkey = ic->i_mr->lkey;
|
|
|
|
sent += len;
|
|
rdsdebug("ic %p sent %d remote_addr %llu\n", ic, sent, remote_addr);
|
|
|
|
remote_addr += len;
|
|
scat++;
|
|
}
|
|
|
|
rdsdebug("send %p wr %p num_sge %u next %p\n", send,
|
|
&send->s_wr, send->s_wr.num_sge, send->s_wr.next);
|
|
|
|
prev = send;
|
|
if (++send == &ic->i_sends[ic->i_send_ring.w_nr])
|
|
send = ic->i_sends;
|
|
}
|
|
|
|
/* if we finished the message then send completion owns it */
|
|
if (scat == &op->r_sg[op->r_count])
|
|
prev->s_wr.send_flags = IB_SEND_SIGNALED;
|
|
|
|
if (i < work_alloc) {
|
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - i);
|
|
work_alloc = i;
|
|
}
|
|
|
|
failed_wr = &first->s_wr;
|
|
ret = ib_post_send(ic->i_cm_id->qp, &first->s_wr, &failed_wr);
|
|
rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic,
|
|
first, &first->s_wr, ret, failed_wr);
|
|
BUG_ON(failed_wr != &first->s_wr);
|
|
if (ret) {
|
|
printk(KERN_WARNING "RDS/IB: rdma ib_post_send to %pI4 "
|
|
"returned %d\n", &conn->c_faddr, ret);
|
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
|
|
goto out;
|
|
}
|
|
|
|
if (unlikely(failed_wr != &first->s_wr)) {
|
|
printk(KERN_WARNING "RDS/IB: ib_post_send() rc=%d, but failed_wqe updated!\n", ret);
|
|
BUG_ON(failed_wr != &first->s_wr);
|
|
}
|
|
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
void rds_ib_xmit_complete(struct rds_connection *conn)
|
|
{
|
|
struct rds_ib_connection *ic = conn->c_transport_data;
|
|
|
|
/* We may have a pending ACK or window update we were unable
|
|
* to send previously (due to flow control). Try again. */
|
|
rds_ib_attempt_ack(ic);
|
|
}
|