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1018 lines
30 KiB
1018 lines
30 KiB
/* |
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* Copyright (c) 2006, 2019 Oracle and/or its affiliates. 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 <linux/ratelimit.h> |
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|
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#include "rds_single_path.h" |
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#include "rds.h" |
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#include "ib.h" |
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#include "ib_mr.h" |
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|
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/* |
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* Convert IB-specific error message to RDS error message and call core |
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* completion handler. |
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*/ |
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static void rds_ib_send_complete(struct rds_message *rm, |
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int wc_status, |
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void (*complete)(struct rds_message *rm, int status)) |
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{ |
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int notify_status; |
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|
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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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|
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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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|
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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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|
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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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complete(rm, notify_status); |
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} |
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|
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static void rds_ib_send_unmap_data(struct rds_ib_connection *ic, |
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struct rm_data_op *op, |
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int wc_status) |
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{ |
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if (op->op_nents) |
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ib_dma_unmap_sg(ic->i_cm_id->device, |
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op->op_sg, op->op_nents, |
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DMA_TO_DEVICE); |
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} |
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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 rm_rdma_op *op, |
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int wc_status) |
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{ |
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if (op->op_mapped) { |
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ib_dma_unmap_sg(ic->i_cm_id->device, |
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op->op_sg, op->op_nents, |
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op->op_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE); |
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op->op_mapped = 0; |
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} |
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|
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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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* we would need to take an event for the rdma WR. 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_complete(container_of(op, struct rds_message, rdma), |
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wc_status, rds_rdma_send_complete); |
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|
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if (op->op_write) |
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rds_stats_add(s_send_rdma_bytes, op->op_bytes); |
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else |
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rds_stats_add(s_recv_rdma_bytes, op->op_bytes); |
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} |
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|
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static void rds_ib_send_unmap_atomic(struct rds_ib_connection *ic, |
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struct rm_atomic_op *op, |
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int wc_status) |
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{ |
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/* unmap atomic recvbuf */ |
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if (op->op_mapped) { |
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ib_dma_unmap_sg(ic->i_cm_id->device, op->op_sg, 1, |
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DMA_FROM_DEVICE); |
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op->op_mapped = 0; |
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} |
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|
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rds_ib_send_complete(container_of(op, struct rds_message, atomic), |
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wc_status, rds_atomic_send_complete); |
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|
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if (op->op_type == RDS_ATOMIC_TYPE_CSWP) |
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rds_ib_stats_inc(s_ib_atomic_cswp); |
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else |
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rds_ib_stats_inc(s_ib_atomic_fadd); |
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} |
|
|
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/* |
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* Unmap the resources associated with a struct send_work. |
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* |
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* Returns the rm for no good reason other than it is unobtainable |
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* other than by switching on wr.opcode, currently, and the caller, |
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* the event handler, needs it. |
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*/ |
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static struct rds_message *rds_ib_send_unmap_op(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 = NULL; |
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|
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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_op) { |
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rm = container_of(send->s_op, struct rds_message, data); |
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rds_ib_send_unmap_data(ic, send->s_op, wc_status); |
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} |
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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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if (send->s_op) { |
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rm = container_of(send->s_op, struct rds_message, rdma); |
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rds_ib_send_unmap_rdma(ic, send->s_op, wc_status); |
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} |
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break; |
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case IB_WR_ATOMIC_FETCH_AND_ADD: |
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case IB_WR_ATOMIC_CMP_AND_SWP: |
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if (send->s_op) { |
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rm = container_of(send->s_op, struct rds_message, atomic); |
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rds_ib_send_unmap_atomic(ic, send->s_op, wc_status); |
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} |
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break; |
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default: |
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printk_ratelimited(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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return rm; |
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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_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.ex.imm_data = 0; |
|
|
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sge = &send->s_sge[0]; |
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sge->addr = ic->i_send_hdrs_dma[i]; |
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|
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sge->length = sizeof(struct rds_header); |
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sge->lkey = ic->i_pd->local_dma_lkey; |
|
|
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send->s_sge[1].lkey = ic->i_pd->local_dma_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_op && send->s_wr.opcode != 0xdead) |
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rds_ib_send_unmap_op(ic, send, IB_WC_WR_FLUSH_ERR); |
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} |
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} |
|
|
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/* |
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* The only fast path caller always has a non-zero nr, so we don't |
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* bother testing nr before performing the atomic sub. |
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*/ |
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static void rds_ib_sub_signaled(struct rds_ib_connection *ic, int nr) |
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{ |
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if ((atomic_sub_return(nr, &ic->i_signaled_sends) == 0) && |
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waitqueue_active(&rds_ib_ring_empty_wait)) |
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wake_up(&rds_ib_ring_empty_wait); |
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BUG_ON(atomic_read(&ic->i_signaled_sends) < 0); |
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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_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc) |
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{ |
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struct rds_message *rm = NULL; |
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struct rds_connection *conn = ic->conn; |
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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 nr_sig = 0; |
|
|
|
|
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rdsdebug("wc wr_id 0x%llx status %u (%s) byte_len %u imm_data %u\n", |
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(unsigned long long)wc->wr_id, wc->status, |
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ib_wc_status_msg(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 (time_after(jiffies, ic->i_ack_queued + HZ / 2)) |
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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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return; |
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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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|
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for (i = 0; i < completed; i++) { |
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send = &ic->i_sends[oldest]; |
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if (send->s_wr.send_flags & IB_SEND_SIGNALED) |
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nr_sig++; |
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|
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rm = rds_ib_send_unmap_op(ic, send, wc->status); |
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|
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if (time_after(jiffies, send->s_queued + HZ / 2)) |
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rds_ib_stats_inc(s_ib_tx_stalled); |
|
|
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if (send->s_op) { |
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if (send->s_op == rm->m_final_op) { |
|
/* If anyone waited for this message to get |
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* flushed out, wake them up now |
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*/ |
|
rds_message_unmapped(rm); |
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} |
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rds_message_put(rm); |
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send->s_op = NULL; |
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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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rds_ib_sub_signaled(ic, nr_sig); |
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nr_sig = 0; |
|
|
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if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags) || |
|
test_bit(0, &conn->c_map_queued)) |
|
queue_delayed_work(rds_wq, &conn->c_send_w, 0); |
|
|
|
/* We expect errors as the qp is drained during shutdown */ |
|
if (wc->status != IB_WC_SUCCESS && rds_conn_up(conn)) { |
|
rds_ib_conn_error(conn, "send completion on <%pI6c,%pI6c,%d> had status %u (%s), vendor err 0x%x, disconnecting and reconnecting\n", |
|
&conn->c_laddr, &conn->c_faddr, |
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conn->c_tos, wc->status, |
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ib_wc_status_msg(wc->status), wc->vendor_err); |
|
} |
|
} |
|
|
|
/* |
|
* This is the main function for allocating credits when sending |
|
* messages. |
|
* |
|
* Conceptually, we have two counters: |
|
* - send credits: this tells us how many WRs we're allowed |
|
* to submit without overruning the receiver's queue. For |
|
* each SEND WR we post, we decrement this by one. |
|
* |
|
* - posted credits: this tells us how many WRs we recently |
|
* posted to the receive queue. This value is transferred |
|
* to the peer as a "credit update" in a RDS header field. |
|
* Every time we transmit credits to the peer, we subtract |
|
* the amount of transferred credits from this counter. |
|
* |
|
* It is essential that we avoid situations where both sides have |
|
* exhausted their send credits, and are unable to send new credits |
|
* to the peer. We achieve this by requiring that we send at least |
|
* one credit update to the peer before exhausting our credits. |
|
* When new credits arrive, we subtract one credit that is withheld |
|
* until we've posted new buffers and are ready to transmit these |
|
* credits (see rds_ib_send_add_credits below). |
|
* |
|
* The RDS send code is essentially single-threaded; rds_send_xmit |
|
* sets RDS_IN_XMIT to ensure exclusive access to the send ring. |
|
* However, the ACK sending code is independent and can race with |
|
* message SENDs. |
|
* |
|
* In the send path, we need to update the counters for send credits |
|
* and the counter of posted buffers atomically - when we use the |
|
* last available credit, we cannot allow another thread to race us |
|
* and grab the posted credits counter. Hence, we have to use a |
|
* spinlock to protect the credit counter, or use atomics. |
|
* |
|
* Spinlocks shared between the send and the receive path are bad, |
|
* because they create unnecessary delays. An early implementation |
|
* using a spinlock showed a 5% degradation in throughput at some |
|
* loads. |
|
* |
|
* This implementation avoids spinlocks completely, putting both |
|
* counters into a single atomic, and updating that atomic using |
|
* atomic_add (in the receive path, when receiving fresh credits), |
|
* and using atomic_cmpxchg when updating the two counters. |
|
*/ |
|
int rds_ib_send_grab_credits(struct rds_ib_connection *ic, |
|
u32 wanted, u32 *adv_credits, int need_posted, int max_posted) |
|
{ |
|
unsigned int avail, posted, got = 0, advertise; |
|
long oldval, newval; |
|
|
|
*adv_credits = 0; |
|
if (!ic->i_flowctl) |
|
return wanted; |
|
|
|
try_again: |
|
advertise = 0; |
|
oldval = newval = atomic_read(&ic->i_credits); |
|
posted = IB_GET_POST_CREDITS(oldval); |
|
avail = IB_GET_SEND_CREDITS(oldval); |
|
|
|
rdsdebug("wanted=%u credits=%u posted=%u\n", |
|
wanted, avail, posted); |
|
|
|
/* The last credit must be used to send a credit update. */ |
|
if (avail && !posted) |
|
avail--; |
|
|
|
if (avail < wanted) { |
|
struct rds_connection *conn = ic->i_cm_id->context; |
|
|
|
/* Oops, there aren't that many credits left! */ |
|
set_bit(RDS_LL_SEND_FULL, &conn->c_flags); |
|
got = avail; |
|
} else { |
|
/* Sometimes you get what you want, lalala. */ |
|
got = wanted; |
|
} |
|
newval -= IB_SET_SEND_CREDITS(got); |
|
|
|
/* |
|
* If need_posted is non-zero, then the caller wants |
|
* the posted regardless of whether any send credits are |
|
* available. |
|
*/ |
|
if (posted && (got || need_posted)) { |
|
advertise = min_t(unsigned int, posted, max_posted); |
|
newval -= IB_SET_POST_CREDITS(advertise); |
|
} |
|
|
|
/* Finally bill everything */ |
|
if (atomic_cmpxchg(&ic->i_credits, oldval, newval) != oldval) |
|
goto try_again; |
|
|
|
*adv_credits = advertise; |
|
return got; |
|
} |
|
|
|
void rds_ib_send_add_credits(struct rds_connection *conn, unsigned int credits) |
|
{ |
|
struct rds_ib_connection *ic = conn->c_transport_data; |
|
|
|
if (credits == 0) |
|
return; |
|
|
|
rdsdebug("credits=%u current=%u%s\n", |
|
credits, |
|
IB_GET_SEND_CREDITS(atomic_read(&ic->i_credits)), |
|
test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ? ", ll_send_full" : ""); |
|
|
|
atomic_add(IB_SET_SEND_CREDITS(credits), &ic->i_credits); |
|
if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags)) |
|
queue_delayed_work(rds_wq, &conn->c_send_w, 0); |
|
|
|
WARN_ON(IB_GET_SEND_CREDITS(credits) >= 16384); |
|
|
|
rds_ib_stats_inc(s_ib_rx_credit_updates); |
|
} |
|
|
|
void rds_ib_advertise_credits(struct rds_connection *conn, unsigned int posted) |
|
{ |
|
struct rds_ib_connection *ic = conn->c_transport_data; |
|
|
|
if (posted == 0) |
|
return; |
|
|
|
atomic_add(IB_SET_POST_CREDITS(posted), &ic->i_credits); |
|
|
|
/* Decide whether to send an update to the peer now. |
|
* If we would send a credit update for every single buffer we |
|
* post, we would end up with an ACK storm (ACK arrives, |
|
* consumes buffer, we refill the ring, send ACK to remote |
|
* advertising the newly posted buffer... ad inf) |
|
* |
|
* Performance pretty much depends on how often we send |
|
* credit updates - too frequent updates mean lots of ACKs. |
|
* Too infrequent updates, and the peer will run out of |
|
* credits and has to throttle. |
|
* For the time being, 16 seems to be a good compromise. |
|
*/ |
|
if (IB_GET_POST_CREDITS(atomic_read(&ic->i_credits)) >= 16) |
|
set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags); |
|
} |
|
|
|
static inline int rds_ib_set_wr_signal_state(struct rds_ib_connection *ic, |
|
struct rds_ib_send_work *send, |
|
bool notify) |
|
{ |
|
/* |
|
* 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 || notify) { |
|
ic->i_unsignaled_wrs = rds_ib_sysctl_max_unsig_wrs; |
|
send->s_wr.send_flags |= IB_SEND_SIGNALED; |
|
return 1; |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* This can be called multiple times for a given message. The first time |
|
* we see a message we map its scatterlist into the IB device so that |
|
* we can provide that mapped address to the IB scatter gather entries |
|
* in the IB work requests. We translate the scatterlist into a series |
|
* of work requests that fragment the message. These work requests complete |
|
* in order so we pass ownership of the message to the completion handler |
|
* once we send the final fragment. |
|
* |
|
* 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; |
|
const struct ib_send_wr *failed_wr; |
|
struct scatterlist *scat; |
|
u32 pos; |
|
u32 i; |
|
u32 work_alloc; |
|
u32 credit_alloc = 0; |
|
u32 posted; |
|
u32 adv_credits = 0; |
|
int send_flags = 0; |
|
int bytes_sent = 0; |
|
int ret; |
|
int flow_controlled = 0; |
|
int nr_sig = 0; |
|
|
|
BUG_ON(off % RDS_FRAG_SIZE); |
|
BUG_ON(hdr_off != 0 && hdr_off != sizeof(struct rds_header)); |
|
|
|
/* Do not send cong updates to IB loopback */ |
|
if (conn->c_loopback |
|
&& rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) { |
|
rds_cong_map_updated(conn->c_fcong, ~(u64) 0); |
|
scat = &rm->data.op_sg[sg]; |
|
ret = max_t(int, RDS_CONG_MAP_BYTES, scat->length); |
|
return sizeof(struct rds_header) + ret; |
|
} |
|
|
|
/* FIXME we may overallocate here */ |
|
if (be32_to_cpu(rm->m_inc.i_hdr.h_len) == 0) |
|
i = 1; |
|
else |
|
i = DIV_ROUND_UP(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; |
|
} |
|
|
|
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 = 1; |
|
} |
|
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_data_op) { |
|
if (rm->data.op_nents) { |
|
rm->data.op_count = ib_dma_map_sg(dev, |
|
rm->data.op_sg, |
|
rm->data.op_nents, |
|
DMA_TO_DEVICE); |
|
rdsdebug("ic %p mapping rm %p: %d\n", ic, rm, rm->data.op_count); |
|
if (rm->data.op_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->data.op_count = 0; |
|
} |
|
|
|
rds_message_addref(rm); |
|
rm->data.op_dmasg = 0; |
|
rm->data.op_dmaoff = 0; |
|
ic->i_data_op = &rm->data; |
|
|
|
/* 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->rdma.op_active) { |
|
struct rds_ext_header_rdma ext_hdr; |
|
|
|
ext_hdr.h_rdma_rkey = cpu_to_be32(rm->rdma.op_rkey); |
|
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. |
|
*/ |
|
if (ic->i_flowctl) { |
|
rds_ib_send_grab_credits(ic, 0, &posted, 1, RDS_MAX_ADV_CREDIT - adv_credits); |
|
adv_credits += posted; |
|
BUG_ON(adv_credits > 255); |
|
} |
|
} |
|
|
|
/* 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->rdma.op_active && rm->rdma.op_fence) |
|
send_flags = IB_SEND_FENCE; |
|
|
|
/* Each frag gets a header. Msgs may be 0 bytes */ |
|
send = &ic->i_sends[pos]; |
|
first = send; |
|
prev = NULL; |
|
scat = &ic->i_data_op->op_sg[rm->data.op_dmasg]; |
|
i = 0; |
|
do { |
|
unsigned int len = 0; |
|
|
|
/* Set up the header */ |
|
send->s_wr.send_flags = send_flags; |
|
send->s_wr.opcode = IB_WR_SEND; |
|
send->s_wr.num_sge = 1; |
|
send->s_wr.next = NULL; |
|
send->s_queued = jiffies; |
|
send->s_op = NULL; |
|
|
|
send->s_sge[0].addr = ic->i_send_hdrs_dma[pos]; |
|
|
|
send->s_sge[0].length = sizeof(struct rds_header); |
|
send->s_sge[0].lkey = ic->i_pd->local_dma_lkey; |
|
|
|
ib_dma_sync_single_for_cpu(ic->rds_ibdev->dev, |
|
ic->i_send_hdrs_dma[pos], |
|
sizeof(struct rds_header), |
|
DMA_TO_DEVICE); |
|
memcpy(ic->i_send_hdrs[pos], &rm->m_inc.i_hdr, |
|
sizeof(struct rds_header)); |
|
|
|
|
|
/* Set up the data, if present */ |
|
if (i < work_alloc |
|
&& scat != &rm->data.op_sg[rm->data.op_count]) { |
|
len = min(RDS_FRAG_SIZE, |
|
sg_dma_len(scat) - rm->data.op_dmaoff); |
|
send->s_wr.num_sge = 2; |
|
|
|
send->s_sge[1].addr = sg_dma_address(scat); |
|
send->s_sge[1].addr += rm->data.op_dmaoff; |
|
send->s_sge[1].length = len; |
|
send->s_sge[1].lkey = ic->i_pd->local_dma_lkey; |
|
|
|
bytes_sent += len; |
|
rm->data.op_dmaoff += len; |
|
if (rm->data.op_dmaoff == sg_dma_len(scat)) { |
|
scat++; |
|
rm->data.op_dmasg++; |
|
rm->data.op_dmaoff = 0; |
|
} |
|
} |
|
|
|
rds_ib_set_wr_signal_state(ic, send, false); |
|
|
|
/* |
|
* Always signal the last one if we're stopping due to flow control. |
|
*/ |
|
if (ic->i_flowctl && flow_controlled && i == (work_alloc - 1)) { |
|
rds_ib_set_wr_signal_state(ic, send, true); |
|
send->s_wr.send_flags |= IB_SEND_SOLICITED; |
|
} |
|
|
|
if (send->s_wr.send_flags & IB_SEND_SIGNALED) |
|
nr_sig++; |
|
|
|
rdsdebug("send %p wr %p num_sge %u next %p\n", send, |
|
&send->s_wr, send->s_wr.num_sge, send->s_wr.next); |
|
|
|
if (ic->i_flowctl && 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); |
|
} |
|
ib_dma_sync_single_for_device(ic->rds_ibdev->dev, |
|
ic->i_send_hdrs_dma[pos], |
|
sizeof(struct rds_header), |
|
DMA_TO_DEVICE); |
|
|
|
if (prev) |
|
prev->s_wr.next = &send->s_wr; |
|
prev = send; |
|
|
|
pos = (pos + 1) % ic->i_send_ring.w_nr; |
|
send = &ic->i_sends[pos]; |
|
i++; |
|
|
|
} while (i < work_alloc |
|
&& scat != &rm->data.op_sg[rm->data.op_count]); |
|
|
|
/* 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) |
|
bytes_sent += sizeof(struct rds_header); |
|
|
|
/* if we finished the message then send completion owns it */ |
|
if (scat == &rm->data.op_sg[rm->data.op_count]) { |
|
prev->s_op = ic->i_data_op; |
|
prev->s_wr.send_flags |= IB_SEND_SOLICITED; |
|
if (!(prev->s_wr.send_flags & IB_SEND_SIGNALED)) |
|
nr_sig += rds_ib_set_wr_signal_state(ic, prev, true); |
|
ic->i_data_op = NULL; |
|
} |
|
|
|
/* Put back wrs & credits we didn't use */ |
|
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); |
|
|
|
if (nr_sig) |
|
atomic_add(nr_sig, &ic->i_signaled_sends); |
|
|
|
/* 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 %pI6c " |
|
"returned %d\n", &conn->c_faddr, ret); |
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); |
|
rds_ib_sub_signaled(ic, nr_sig); |
|
if (prev->s_op) { |
|
ic->i_data_op = prev->s_op; |
|
prev->s_op = NULL; |
|
} |
|
|
|
rds_ib_conn_error(ic->conn, "ib_post_send failed\n"); |
|
goto out; |
|
} |
|
|
|
ret = bytes_sent; |
|
out: |
|
BUG_ON(adv_credits); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Issue atomic operation. |
|
* A simplified version of the rdma case, we always map 1 SG, and |
|
* only 8 bytes, for the return value from the atomic operation. |
|
*/ |
|
int rds_ib_xmit_atomic(struct rds_connection *conn, struct rm_atomic_op *op) |
|
{ |
|
struct rds_ib_connection *ic = conn->c_transport_data; |
|
struct rds_ib_send_work *send = NULL; |
|
const struct ib_send_wr *failed_wr; |
|
u32 pos; |
|
u32 work_alloc; |
|
int ret; |
|
int nr_sig = 0; |
|
|
|
work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, 1, &pos); |
|
if (work_alloc != 1) { |
|
rds_ib_stats_inc(s_ib_tx_ring_full); |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
/* address of send request in ring */ |
|
send = &ic->i_sends[pos]; |
|
send->s_queued = jiffies; |
|
|
|
if (op->op_type == RDS_ATOMIC_TYPE_CSWP) { |
|
send->s_atomic_wr.wr.opcode = IB_WR_MASKED_ATOMIC_CMP_AND_SWP; |
|
send->s_atomic_wr.compare_add = op->op_m_cswp.compare; |
|
send->s_atomic_wr.swap = op->op_m_cswp.swap; |
|
send->s_atomic_wr.compare_add_mask = op->op_m_cswp.compare_mask; |
|
send->s_atomic_wr.swap_mask = op->op_m_cswp.swap_mask; |
|
} else { /* FADD */ |
|
send->s_atomic_wr.wr.opcode = IB_WR_MASKED_ATOMIC_FETCH_AND_ADD; |
|
send->s_atomic_wr.compare_add = op->op_m_fadd.add; |
|
send->s_atomic_wr.swap = 0; |
|
send->s_atomic_wr.compare_add_mask = op->op_m_fadd.nocarry_mask; |
|
send->s_atomic_wr.swap_mask = 0; |
|
} |
|
send->s_wr.send_flags = 0; |
|
nr_sig = rds_ib_set_wr_signal_state(ic, send, op->op_notify); |
|
send->s_atomic_wr.wr.num_sge = 1; |
|
send->s_atomic_wr.wr.next = NULL; |
|
send->s_atomic_wr.remote_addr = op->op_remote_addr; |
|
send->s_atomic_wr.rkey = op->op_rkey; |
|
send->s_op = op; |
|
rds_message_addref(container_of(send->s_op, struct rds_message, atomic)); |
|
|
|
/* map 8 byte retval buffer to the device */ |
|
ret = ib_dma_map_sg(ic->i_cm_id->device, op->op_sg, 1, DMA_FROM_DEVICE); |
|
rdsdebug("ic %p mapping atomic op %p. mapped %d pg\n", ic, op, ret); |
|
if (ret != 1) { |
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); |
|
rds_ib_stats_inc(s_ib_tx_sg_mapping_failure); |
|
ret = -ENOMEM; /* XXX ? */ |
|
goto out; |
|
} |
|
|
|
/* Convert our struct scatterlist to struct ib_sge */ |
|
send->s_sge[0].addr = sg_dma_address(op->op_sg); |
|
send->s_sge[0].length = sg_dma_len(op->op_sg); |
|
send->s_sge[0].lkey = ic->i_pd->local_dma_lkey; |
|
|
|
rdsdebug("rva %Lx rpa %Lx len %u\n", op->op_remote_addr, |
|
send->s_sge[0].addr, send->s_sge[0].length); |
|
|
|
if (nr_sig) |
|
atomic_add(nr_sig, &ic->i_signaled_sends); |
|
|
|
failed_wr = &send->s_atomic_wr.wr; |
|
ret = ib_post_send(ic->i_cm_id->qp, &send->s_atomic_wr.wr, &failed_wr); |
|
rdsdebug("ic %p send %p (wr %p) ret %d wr %p\n", ic, |
|
send, &send->s_atomic_wr, ret, failed_wr); |
|
BUG_ON(failed_wr != &send->s_atomic_wr.wr); |
|
if (ret) { |
|
printk(KERN_WARNING "RDS/IB: atomic ib_post_send to %pI6c " |
|
"returned %d\n", &conn->c_faddr, ret); |
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); |
|
rds_ib_sub_signaled(ic, nr_sig); |
|
goto out; |
|
} |
|
|
|
if (unlikely(failed_wr != &send->s_atomic_wr.wr)) { |
|
printk(KERN_WARNING "RDS/IB: atomic ib_post_send() rc=%d, but failed_wqe updated!\n", ret); |
|
BUG_ON(failed_wr != &send->s_atomic_wr.wr); |
|
} |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
int rds_ib_xmit_rdma(struct rds_connection *conn, struct rm_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; |
|
const struct ib_send_wr *failed_wr; |
|
struct scatterlist *scat; |
|
unsigned long len; |
|
u64 remote_addr = op->op_remote_addr; |
|
u32 max_sge = ic->rds_ibdev->max_sge; |
|
u32 pos; |
|
u32 work_alloc; |
|
u32 i; |
|
u32 j; |
|
int sent; |
|
int ret; |
|
int num_sge; |
|
int nr_sig = 0; |
|
u64 odp_addr = op->op_odp_addr; |
|
u32 odp_lkey = 0; |
|
|
|
/* map the op the first time we see it */ |
|
if (!op->op_odp_mr) { |
|
if (!op->op_mapped) { |
|
op->op_count = |
|
ib_dma_map_sg(ic->i_cm_id->device, op->op_sg, |
|
op->op_nents, |
|
(op->op_write) ? DMA_TO_DEVICE : |
|
DMA_FROM_DEVICE); |
|
rdsdebug("ic %p mapping op %p: %d\n", ic, op, |
|
op->op_count); |
|
if (op->op_count == 0) { |
|
rds_ib_stats_inc(s_ib_tx_sg_mapping_failure); |
|
ret = -ENOMEM; /* XXX ? */ |
|
goto out; |
|
} |
|
op->op_mapped = 1; |
|
} |
|
} else { |
|
op->op_count = op->op_nents; |
|
odp_lkey = rds_ib_get_lkey(op->op_odp_mr->r_trans_private); |
|
} |
|
|
|
/* |
|
* 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 = DIV_ROUND_UP(op->op_count, 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->op_sg[0]; |
|
sent = 0; |
|
num_sge = op->op_count; |
|
|
|
for (i = 0; i < work_alloc && scat != &op->op_sg[op->op_count]; i++) { |
|
send->s_wr.send_flags = 0; |
|
send->s_queued = jiffies; |
|
send->s_op = NULL; |
|
|
|
if (!op->op_notify) |
|
nr_sig += rds_ib_set_wr_signal_state(ic, send, |
|
op->op_notify); |
|
|
|
send->s_wr.opcode = op->op_write ? IB_WR_RDMA_WRITE : IB_WR_RDMA_READ; |
|
send->s_rdma_wr.remote_addr = remote_addr; |
|
send->s_rdma_wr.rkey = op->op_rkey; |
|
|
|
if (num_sge > max_sge) { |
|
send->s_rdma_wr.wr.num_sge = max_sge; |
|
num_sge -= max_sge; |
|
} else { |
|
send->s_rdma_wr.wr.num_sge = num_sge; |
|
} |
|
|
|
send->s_rdma_wr.wr.next = NULL; |
|
|
|
if (prev) |
|
prev->s_rdma_wr.wr.next = &send->s_rdma_wr.wr; |
|
|
|
for (j = 0; j < send->s_rdma_wr.wr.num_sge && |
|
scat != &op->op_sg[op->op_count]; j++) { |
|
len = sg_dma_len(scat); |
|
if (!op->op_odp_mr) { |
|
send->s_sge[j].addr = sg_dma_address(scat); |
|
send->s_sge[j].lkey = ic->i_pd->local_dma_lkey; |
|
} else { |
|
send->s_sge[j].addr = odp_addr; |
|
send->s_sge[j].lkey = odp_lkey; |
|
} |
|
send->s_sge[j].length = len; |
|
|
|
sent += len; |
|
rdsdebug("ic %p sent %d remote_addr %llu\n", ic, sent, remote_addr); |
|
|
|
remote_addr += len; |
|
odp_addr += len; |
|
scat++; |
|
} |
|
|
|
rdsdebug("send %p wr %p num_sge %u next %p\n", send, |
|
&send->s_rdma_wr.wr, |
|
send->s_rdma_wr.wr.num_sge, |
|
send->s_rdma_wr.wr.next); |
|
|
|
prev = send; |
|
if (++send == &ic->i_sends[ic->i_send_ring.w_nr]) |
|
send = ic->i_sends; |
|
} |
|
|
|
/* give a reference to the last op */ |
|
if (scat == &op->op_sg[op->op_count]) { |
|
prev->s_op = op; |
|
rds_message_addref(container_of(op, struct rds_message, rdma)); |
|
} |
|
|
|
if (i < work_alloc) { |
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - i); |
|
work_alloc = i; |
|
} |
|
|
|
if (nr_sig) |
|
atomic_add(nr_sig, &ic->i_signaled_sends); |
|
|
|
failed_wr = &first->s_rdma_wr.wr; |
|
ret = ib_post_send(ic->i_cm_id->qp, &first->s_rdma_wr.wr, &failed_wr); |
|
rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic, |
|
first, &first->s_rdma_wr.wr, ret, failed_wr); |
|
BUG_ON(failed_wr != &first->s_rdma_wr.wr); |
|
if (ret) { |
|
printk(KERN_WARNING "RDS/IB: rdma ib_post_send to %pI6c " |
|
"returned %d\n", &conn->c_faddr, ret); |
|
rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); |
|
rds_ib_sub_signaled(ic, nr_sig); |
|
goto out; |
|
} |
|
|
|
if (unlikely(failed_wr != &first->s_rdma_wr.wr)) { |
|
printk(KERN_WARNING "RDS/IB: ib_post_send() rc=%d, but failed_wqe updated!\n", ret); |
|
BUG_ON(failed_wr != &first->s_rdma_wr.wr); |
|
} |
|
|
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
void rds_ib_xmit_path_complete(struct rds_conn_path *cp) |
|
{ |
|
struct rds_connection *conn = cp->cp_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); |
|
}
|
|
|