| /* |
| * Copyright (c) 2006 Oracle. All rights reserved. |
| * |
| * This software is available to you under a choice of one of two |
| * licenses. You may choose to be licensed under the terms of the GNU |
| * General Public License (GPL) Version 2, available from the file |
| * COPYING in the main directory of this source tree, or the |
| * OpenIB.org BSD license below: |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials |
| * provided with the distribution. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
| * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
| * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
| * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| * SOFTWARE. |
| * |
| */ |
| #include <linux/kernel.h> |
| #include <linux/in.h> |
| #include <linux/device.h> |
| #include <linux/dmapool.h> |
| |
| #include "rds.h" |
| #include "ib.h" |
| |
| /* |
| * Convert IB-specific error message to RDS error message and call core |
| * completion handler. |
| */ |
| static void rds_ib_send_complete(struct rds_message *rm, |
| int wc_status, |
| void (*complete)(struct rds_message *rm, int status)) |
| { |
| int notify_status; |
| |
| switch (wc_status) { |
| case IB_WC_WR_FLUSH_ERR: |
| return; |
| |
| case IB_WC_SUCCESS: |
| notify_status = RDS_RDMA_SUCCESS; |
| break; |
| |
| case IB_WC_REM_ACCESS_ERR: |
| notify_status = RDS_RDMA_REMOTE_ERROR; |
| break; |
| |
| default: |
| notify_status = RDS_RDMA_OTHER_ERROR; |
| break; |
| } |
| complete(rm, notify_status); |
| } |
| |
| static void rds_ib_send_unmap_data(struct rds_ib_connection *ic, |
| struct rm_data_op *op, |
| int wc_status) |
| { |
| if (op->op_nents) |
| ib_dma_unmap_sg(ic->i_cm_id->device, |
| op->op_sg, op->op_nents, |
| DMA_TO_DEVICE); |
| } |
| |
| static void rds_ib_send_unmap_rdma(struct rds_ib_connection *ic, |
| struct rm_rdma_op *op, |
| int wc_status) |
| { |
| if (op->op_mapped) { |
| ib_dma_unmap_sg(ic->i_cm_id->device, |
| op->op_sg, op->op_nents, |
| op->op_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE); |
| op->op_mapped = 0; |
| } |
| |
| /* If the user asked for a completion notification on this |
| * message, we can implement three different semantics: |
| * 1. Notify when we received the ACK on the RDS message |
| * that was queued with the RDMA. This provides reliable |
| * notification of RDMA status at the expense of a one-way |
| * packet delay. |
| * 2. Notify when the IB stack gives us the completion event for |
| * the RDMA operation. |
| * 3. Notify when the IB stack gives us the completion event for |
| * the accompanying RDS messages. |
| * Here, we implement approach #3. To implement approach #2, |
| * we would need to take an event for the rdma WR. To implement #1, |
| * don't call rds_rdma_send_complete at all, and fall back to the notify |
| * handling in the ACK processing code. |
| * |
| * Note: There's no need to explicitly sync any RDMA buffers using |
| * ib_dma_sync_sg_for_cpu - the completion for the RDMA |
| * operation itself unmapped the RDMA buffers, which takes care |
| * of synching. |
| */ |
| rds_ib_send_complete(container_of(op, struct rds_message, rdma), |
| wc_status, rds_rdma_send_complete); |
| |
| if (op->op_write) |
| rds_stats_add(s_send_rdma_bytes, op->op_bytes); |
| else |
| rds_stats_add(s_recv_rdma_bytes, op->op_bytes); |
| } |
| |
| static void rds_ib_send_unmap_atomic(struct rds_ib_connection *ic, |
| struct rm_atomic_op *op, |
| int wc_status) |
| { |
| /* unmap atomic recvbuf */ |
| if (op->op_mapped) { |
| ib_dma_unmap_sg(ic->i_cm_id->device, op->op_sg, 1, |
| DMA_FROM_DEVICE); |
| op->op_mapped = 0; |
| } |
| |
| rds_ib_send_complete(container_of(op, struct rds_message, atomic), |
| wc_status, rds_atomic_send_complete); |
| |
| if (op->op_type == RDS_ATOMIC_TYPE_CSWP) |
| rds_ib_stats_inc(s_ib_atomic_cswp); |
| else |
| rds_ib_stats_inc(s_ib_atomic_fadd); |
| } |
| |
| /* |
| * Unmap the resources associated with a struct send_work. |
| * |
| * Returns the rm for no good reason other than it is unobtainable |
| * other than by switching on wr.opcode, currently, and the caller, |
| * the event handler, needs it. |
| */ |
| static struct rds_message *rds_ib_send_unmap_op(struct rds_ib_connection *ic, |
| struct rds_ib_send_work *send, |
| int wc_status) |
| { |
| struct rds_message *rm = NULL; |
| |
| /* In the error case, wc.opcode sometimes contains garbage */ |
| switch (send->s_wr.opcode) { |
| case IB_WR_SEND: |
| if (send->s_op) { |
| rm = container_of(send->s_op, struct rds_message, data); |
| rds_ib_send_unmap_data(ic, send->s_op, wc_status); |
| } |
| break; |
| case IB_WR_RDMA_WRITE: |
| case IB_WR_RDMA_READ: |
| if (send->s_op) { |
| rm = container_of(send->s_op, struct rds_message, rdma); |
| rds_ib_send_unmap_rdma(ic, send->s_op, wc_status); |
| } |
| break; |
| case IB_WR_ATOMIC_FETCH_AND_ADD: |
| case IB_WR_ATOMIC_CMP_AND_SWP: |
| if (send->s_op) { |
| rm = container_of(send->s_op, struct rds_message, atomic); |
| rds_ib_send_unmap_atomic(ic, send->s_op, wc_status); |
| } |
| break; |
| default: |
| if (printk_ratelimit()) |
| printk(KERN_NOTICE |
| "RDS/IB: %s: unexpected opcode 0x%x in WR!\n", |
| __func__, send->s_wr.opcode); |
| break; |
| } |
| |
| send->s_wr.opcode = 0xdead; |
| |
| return rm; |
| } |
| |
| void rds_ib_send_init_ring(struct rds_ib_connection *ic) |
| { |
| struct rds_ib_send_work *send; |
| u32 i; |
| |
| for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) { |
| struct ib_sge *sge; |
| |
| send->s_op = NULL; |
| |
| send->s_wr.wr_id = i; |
| send->s_wr.sg_list = send->s_sge; |
| send->s_wr.ex.imm_data = 0; |
| |
| sge = &send->s_sge[0]; |
| sge->addr = ic->i_send_hdrs_dma + (i * sizeof(struct rds_header)); |
| sge->length = sizeof(struct rds_header); |
| sge->lkey = ic->i_mr->lkey; |
| |
| send->s_sge[1].lkey = ic->i_mr->lkey; |
| } |
| } |
| |
| void rds_ib_send_clear_ring(struct rds_ib_connection *ic) |
| { |
| struct rds_ib_send_work *send; |
| u32 i; |
| |
| for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) { |
| if (send->s_op && send->s_wr.opcode != 0xdead) |
| rds_ib_send_unmap_op(ic, send, IB_WC_WR_FLUSH_ERR); |
| } |
| } |
| |
| /* |
| * The _oldest/_free ring operations here race cleanly with the alloc/unalloc |
| * operations performed in the send path. As the sender allocs and potentially |
| * unallocs the next free entry in the ring it doesn't alter which is |
| * the next to be freed, which is what this is concerned with. |
| */ |
| void rds_ib_send_cq_comp_handler(struct ib_cq *cq, void *context) |
| { |
| struct rds_connection *conn = context; |
| struct rds_ib_connection *ic = conn->c_transport_data; |
| struct rds_message *rm = NULL; |
| struct ib_wc wc; |
| struct rds_ib_send_work *send; |
| u32 completed; |
| u32 oldest; |
| u32 i = 0; |
| int ret; |
| |
| rdsdebug("cq %p conn %p\n", cq, conn); |
| rds_ib_stats_inc(s_ib_tx_cq_call); |
| ret = ib_req_notify_cq(cq, IB_CQ_NEXT_COMP); |
| if (ret) |
| rdsdebug("ib_req_notify_cq send failed: %d\n", ret); |
| |
| while (ib_poll_cq(cq, 1, &wc) > 0) { |
| rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n", |
| (unsigned long long)wc.wr_id, wc.status, wc.byte_len, |
| be32_to_cpu(wc.ex.imm_data)); |
| rds_ib_stats_inc(s_ib_tx_cq_event); |
| |
| if (wc.wr_id == RDS_IB_ACK_WR_ID) { |
| if (ic->i_ack_queued + HZ/2 < jiffies) |
| rds_ib_stats_inc(s_ib_tx_stalled); |
| rds_ib_ack_send_complete(ic); |
| continue; |
| } |
| |
| oldest = rds_ib_ring_oldest(&ic->i_send_ring); |
| |
| completed = rds_ib_ring_completed(&ic->i_send_ring, wc.wr_id, oldest); |
| |
| for (i = 0; i < completed; i++) { |
| send = &ic->i_sends[oldest]; |
| |
| rm = rds_ib_send_unmap_op(ic, send, wc.status); |
| |
| if (send->s_queued + HZ/2 < jiffies) |
| rds_ib_stats_inc(s_ib_tx_stalled); |
| |
| if (&send->s_op == &rm->m_final_op) { |
| /* If anyone waited for this message to get flushed out, wake |
| * them up now */ |
| rds_message_unmapped(rm); |
| |
| rds_message_put(rm); |
| send->s_op = NULL; |
| } |
| |
| oldest = (oldest + 1) % ic->i_send_ring.w_nr; |
| } |
| |
| rds_ib_ring_free(&ic->i_send_ring, completed); |
| |
| 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 %pI4 " |
| "had status %u, disconnecting and reconnecting\n", |
| &conn->c_faddr, wc.status); |
| } |
| } |
| } |
| |
| /* |
| * 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 reciever'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 |
| * grabs c_send_lock 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("rds_ib_send_grab_credits(%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("rds_ib_send_add_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 void 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; |
| } |
| } |
| |
| /* |
| * 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; |
| 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; |
| |
| 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); |
| return sizeof(struct rds_header) + RDS_CONG_MAP_BYTES; |
| } |
| |
| /* 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; |
| } |
| |
| 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); |
| 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[sg]; |
| 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 * sizeof(struct rds_header)); |
| send->s_sge[0].length = sizeof(struct rds_header); |
| |
| 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, ib_sg_dma_len(dev, scat) - off); |
| send->s_wr.num_sge = 2; |
| |
| send->s_sge[1].addr = ib_sg_dma_address(dev, scat) + off; |
| send->s_sge[1].length = len; |
| |
| bytes_sent += len; |
| off += len; |
| if (off == ib_sg_dma_len(dev, scat)) { |
| scat++; |
| off = 0; |
| } |
| } |
| |
| rds_ib_set_wr_signal_state(ic, send, 0); |
| |
| /* |
| * Always signal the last one if we're stopping due to flow control. |
| */ |
| if (ic->i_flowctl && 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); |
| |
| 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); |
| } |
| |
| 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; |
| 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); |
| |
| /* 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_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; |
| struct ib_send_wr *failed_wr; |
| struct rds_ib_device *rds_ibdev; |
| u32 pos; |
| u32 work_alloc; |
| int ret; |
| |
| rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client); |
| |
| work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, 1, &pos); |
| if (work_alloc != 1) { |
| rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); |
| 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_wr.opcode = IB_WR_ATOMIC_CMP_AND_SWP; |
| send->s_wr.wr.atomic.compare_add = op->op_compare; |
| send->s_wr.wr.atomic.swap = op->op_swap_add; |
| } else { /* FADD */ |
| send->s_wr.opcode = IB_WR_ATOMIC_FETCH_AND_ADD; |
| send->s_wr.wr.atomic.compare_add = op->op_swap_add; |
| send->s_wr.wr.atomic.swap = 0; |
| } |
| rds_ib_set_wr_signal_state(ic, send, op->op_notify); |
| send->s_wr.num_sge = 1; |
| send->s_wr.next = NULL; |
| send->s_wr.wr.atomic.remote_addr = op->op_remote_addr; |
| send->s_wr.wr.atomic.rkey = op->op_rkey; |
| |
| /* 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 = ib_sg_dma_address(ic->i_cm_id->device, op->op_sg); |
| send->s_sge[0].length = ib_sg_dma_len(ic->i_cm_id->device, op->op_sg); |
| send->s_sge[0].lkey = ic->i_mr->lkey; |
| |
| rdsdebug("rva %Lx rpa %Lx len %u\n", op->op_remote_addr, |
| send->s_sge[0].addr, send->s_sge[0].length); |
| |
| failed_wr = &send->s_wr; |
| ret = ib_post_send(ic->i_cm_id->qp, &send->s_wr, &failed_wr); |
| rdsdebug("ic %p send %p (wr %p) ret %d wr %p\n", ic, |
| send, &send->s_wr, ret, failed_wr); |
| BUG_ON(failed_wr != &send->s_wr); |
| if (ret) { |
| printk(KERN_WARNING "RDS/IB: atomic 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 != &send->s_wr)) { |
| printk(KERN_WARNING "RDS/IB: atomic ib_post_send() rc=%d, but failed_wqe updated!\n", ret); |
| BUG_ON(failed_wr != &send->s_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; |
| struct ib_send_wr *failed_wr; |
| struct rds_ib_device *rds_ibdev; |
| struct scatterlist *scat; |
| unsigned long len; |
| u64 remote_addr = op->op_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 op the first time we see it */ |
| 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; |
| } |
| |
| /* |
| * 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->op_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->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; |
| |
| 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_wr.wr.rdma.remote_addr = remote_addr; |
| send->s_wr.wr.rdma.rkey = op->op_rkey; |
| 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->op_sg[op->op_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 (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); |
| } |