diff options
Diffstat (limited to 'net/rds/iw_send.c')
| -rw-r--r-- | net/rds/iw_send.c | 981 |
1 files changed, 0 insertions, 981 deletions
diff --git a/net/rds/iw_send.c b/net/rds/iw_send.c deleted file mode 100644 index e20bd50..0000000 --- a/net/rds/iw_send.c +++ /dev/null @@ -1,981 +0,0 @@ -/* - * 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 <linux/ratelimit.h> - -#include "rds.h" -#include "iw.h" - -static void rds_iw_send_rdma_complete(struct rds_message *rm, - int wc_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; - } - rds_rdma_send_complete(rm, notify_status); -} - -static void rds_iw_send_unmap_rdma(struct rds_iw_connection *ic, - struct rm_rdma_op *op) -{ - 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; - } -} - -static void rds_iw_send_unmap_rm(struct rds_iw_connection *ic, - struct rds_iw_send_work *send, - int wc_status) -{ - struct rds_message *rm = send->s_rm; - - rdsdebug("ic %p send %p rm %p\n", ic, send, rm); - - ib_dma_unmap_sg(ic->i_cm_id->device, - rm->data.op_sg, rm->data.op_nents, - DMA_TO_DEVICE); - - if (rm->rdma.op_active) { - rds_iw_send_unmap_rdma(ic, &rm->rdma); - - /* 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, - * call rds_rdma_send_complete from the cq_handler. 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_iw_send_rdma_complete(rm, wc_status); - - if (rm->rdma.op_write) - rds_stats_add(s_send_rdma_bytes, rm->rdma.op_bytes); - else - rds_stats_add(s_recv_rdma_bytes, rm->rdma.op_bytes); - } - - /* If anyone waited for this message to get flushed out, wake - * them up now */ - rds_message_unmapped(rm); - - rds_message_put(rm); - send->s_rm = NULL; -} - -void rds_iw_send_init_ring(struct rds_iw_connection *ic) -{ - struct rds_iw_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_rm = NULL; - send->s_op = NULL; - send->s_mapping = NULL; - - send->s_send_wr.next = NULL; - send->s_send_wr.wr_id = i; - send->s_send_wr.sg_list = send->s_sge; - send->s_send_wr.num_sge = 1; - send->s_send_wr.opcode = IB_WR_SEND; - send->s_send_wr.send_flags = 0; - send->s_send_wr.ex.imm_data = 0; - - sge = rds_iw_data_sge(ic, send->s_sge); - sge->lkey = 0; - - sge = rds_iw_header_sge(ic, send->s_sge); - sge->addr = ic->i_send_hdrs_dma + (i * sizeof(struct rds_header)); - sge->length = sizeof(struct rds_header); - sge->lkey = 0; - - send->s_mr = ib_alloc_mr(ic->i_pd, IB_MR_TYPE_MEM_REG, - fastreg_message_size); - if (IS_ERR(send->s_mr)) { - printk(KERN_WARNING "RDS/IW: ib_alloc_mr failed\n"); - break; - } - } -} - -void rds_iw_send_clear_ring(struct rds_iw_connection *ic) -{ - struct rds_iw_send_work *send; - u32 i; - - for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) { - BUG_ON(!send->s_mr); - ib_dereg_mr(send->s_mr); - if (send->s_send_wr.opcode == 0xdead) - continue; - if (send->s_rm) - rds_iw_send_unmap_rm(ic, send, IB_WC_WR_FLUSH_ERR); - if (send->s_op) - rds_iw_send_unmap_rdma(ic, send->s_op); - } -} - -/* - * 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_iw_send_cq_comp_handler(struct ib_cq *cq, void *context) -{ - struct rds_connection *conn = context; - struct rds_iw_connection *ic = conn->c_transport_data; - struct ib_wc wc; - struct rds_iw_send_work *send; - u32 completed; - u32 oldest; - u32 i; - int ret; - - rdsdebug("cq %p conn %p\n", cq, conn); - rds_iw_stats_inc(s_iw_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_iw_stats_inc(s_iw_tx_cq_event); - - if (wc.status != IB_WC_SUCCESS) { - printk(KERN_ERR "WC Error: status = %d opcode = %d\n", wc.status, wc.opcode); - break; - } - - if (wc.opcode == IB_WC_LOCAL_INV && wc.wr_id == RDS_IW_LOCAL_INV_WR_ID) { - ic->i_fastreg_posted = 0; - continue; - } - - if (wc.opcode == IB_WC_REG_MR && wc.wr_id == RDS_IW_REG_WR_ID) { - ic->i_fastreg_posted = 1; - continue; - } - - if (wc.wr_id == RDS_IW_ACK_WR_ID) { - if (time_after(jiffies, ic->i_ack_queued + HZ/2)) - rds_iw_stats_inc(s_iw_tx_stalled); - rds_iw_ack_send_complete(ic); - continue; - } - - oldest = rds_iw_ring_oldest(&ic->i_send_ring); - - completed = rds_iw_ring_completed(&ic->i_send_ring, wc.wr_id, oldest); - - for (i = 0; i < completed; i++) { - send = &ic->i_sends[oldest]; - - /* In the error case, wc.opcode sometimes contains garbage */ - switch (send->s_send_wr.opcode) { - case IB_WR_SEND: - if (send->s_rm) - rds_iw_send_unmap_rm(ic, send, wc.status); - break; - case IB_WR_REG_MR: - case IB_WR_RDMA_WRITE: - case IB_WR_RDMA_READ: - case IB_WR_RDMA_READ_WITH_INV: - /* Nothing to be done - the SG list will be unmapped - * when the SEND completes. */ - break; - default: - printk_ratelimited(KERN_NOTICE - "RDS/IW: %s: unexpected opcode 0x%x in WR!\n", - __func__, send->s_send_wr.opcode); - break; - } - - send->s_send_wr.opcode = 0xdead; - send->s_send_wr.num_sge = 1; - if (time_after(jiffies, send->s_queued + HZ/2)) - rds_iw_stats_inc(s_iw_tx_stalled); - - /* If a RDMA operation produced an error, signal this right - * away. If we don't, the subsequent SEND that goes with this - * RDMA will be canceled with ERR_WFLUSH, and the application - * never learn that the RDMA failed. */ - if (unlikely(wc.status == IB_WC_REM_ACCESS_ERR && send->s_op)) { - struct rds_message *rm; - - rm = rds_send_get_message(conn, send->s_op); - if (rm) - rds_iw_send_rdma_complete(rm, wc.status); - } - - oldest = (oldest + 1) % ic->i_send_ring.w_nr; - } - - rds_iw_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_iw_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 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_iw_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_iw_send_grab_credits(struct rds_iw_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_iw_send_add_credits(struct rds_connection *conn, unsigned int credits) -{ - struct rds_iw_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_iw_stats_inc(s_iw_rx_credit_updates); -} - -void rds_iw_advertise_credits(struct rds_connection *conn, unsigned int posted) -{ - struct rds_iw_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_iw_xmit_populate_wr(struct rds_iw_connection *ic, - struct rds_iw_send_work *send, unsigned int pos, - unsigned long buffer, unsigned int length, - int send_flags) -{ - struct ib_sge *sge; - - WARN_ON(pos != send - ic->i_sends); - - send->s_send_wr.send_flags = send_flags; - send->s_send_wr.opcode = IB_WR_SEND; - send->s_send_wr.num_sge = 2; - send->s_send_wr.next = NULL; - send->s_queued = jiffies; - send->s_op = NULL; - - if (length != 0) { - sge = rds_iw_data_sge(ic, send->s_sge); - sge->addr = buffer; - sge->length = length; - sge->lkey = rds_iw_local_dma_lkey(ic); - - sge = rds_iw_header_sge(ic, send->s_sge); - } else { - /* We're sending a packet with no payload. There is only - * one SGE */ - send->s_send_wr.num_sge = 1; - sge = &send->s_sge[0]; - } - - sge->addr = ic->i_send_hdrs_dma + (pos * sizeof(struct rds_header)); - sge->length = sizeof(struct rds_header); - sge->lkey = rds_iw_local_dma_lkey(ic); -} - -/* - * 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_iw_xmit(struct rds_connection *conn, struct rds_message *rm, - unsigned int hdr_off, unsigned int sg, unsigned int off) -{ - struct rds_iw_connection *ic = conn->c_transport_data; - struct ib_device *dev = ic->i_cm_id->device; - struct rds_iw_send_work *send = NULL; - struct rds_iw_send_work *first; - struct rds_iw_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)); - - /* Fastreg support */ - if (rds_rdma_cookie_key(rm->m_rdma_cookie) && !ic->i_fastreg_posted) { - ret = -EAGAIN; - goto out; - } - - /* 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_iw_ring_alloc(&ic->i_send_ring, i, &pos); - if (work_alloc == 0) { - set_bit(RDS_LL_SEND_FULL, &conn->c_flags); - rds_iw_stats_inc(s_iw_tx_ring_full); - ret = -ENOMEM; - goto out; - } - - credit_alloc = work_alloc; - if (ic->i_flowctl) { - credit_alloc = rds_iw_send_grab_credits(ic, work_alloc, &posted, 0, RDS_MAX_ADV_CREDIT); - adv_credits += posted; - if (credit_alloc < work_alloc) { - rds_iw_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_iw_stats_inc(s_iw_tx_throttle); - ret = -ENOMEM; - goto out; - } - } - - /* map the message the first time we see it */ - if (!ic->i_rm) { - /* - printk(KERN_NOTICE "rds_iw_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->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_iw_stats_inc(s_iw_tx_sg_mapping_failure); - rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc); - ret = -ENOMEM; /* XXX ? */ - goto out; - } - } else { - rm->data.op_count = 0; - } - - ic->i_unsignaled_wrs = rds_iw_sysctl_max_unsig_wrs; - ic->i_unsignaled_bytes = rds_iw_sysctl_max_unsig_bytes; - rds_message_addref(rm); - rm->data.op_dmasg = 0; - rm->data.op_dmaoff = 0; - 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->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_iw_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_iw_ring_alloc first. */ - rm->m_inc.i_hdr.h_ack = cpu_to_be64(rds_iw_piggyb_ack(ic)); - rds_message_make_checksum(&rm->m_inc.i_hdr); - - /* - * Update adv_credits since we reset the ACK_REQUIRED bit. - */ - rds_iw_send_grab_credits(ic, 0, &posted, 1, RDS_MAX_ADV_CREDIT - adv_credits); - adv_credits += posted; - BUG_ON(adv_credits > 255); - } - - send = &ic->i_sends[pos]; - first = send; - prev = NULL; - scat = &rm->data.op_sg[rm->data.op_dmasg]; - 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->rdma.op_active && rm->rdma.op_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_iw_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->data.op_sg[rm->data.op_count]; i++) { - unsigned int len; - - send = &ic->i_sends[pos]; - - len = min(RDS_FRAG_SIZE, - ib_sg_dma_len(dev, scat) - rm->data.op_dmaoff); - rds_iw_xmit_populate_wr(ic, send, pos, - ib_sg_dma_address(dev, scat) + rm->data.op_dmaoff, 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_iw_sysctl_max_unsig_wrs; - send->s_send_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_iw_sysctl_max_unsig_bytes; - send->s_send_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_send_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED; - - rdsdebug("send %p wr %p num_sge %u next %p\n", send, - &send->s_send_wr, send->s_send_wr.num_sge, send->s_send_wr.next); - - sent += len; - rm->data.op_dmaoff += len; - if (rm->data.op_dmaoff == ib_sg_dma_len(dev, scat)) { - scat++; - rm->data.op_dmaoff = 0; - rm->data.op_dmasg++; - } - -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_iw_stats_inc(s_iw_tx_credit_updates); - } - - if (prev) - prev->s_send_wr.next = &send->s_send_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->data.op_sg[rm->data.op_count]) { - prev->s_rm = ic->i_rm; - prev->s_send_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED; - ic->i_rm = NULL; - } - - if (i < work_alloc) { - rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc - i); - work_alloc = i; - } - if (ic->i_flowctl && i < credit_alloc) - rds_iw_send_add_credits(conn, credit_alloc - i); - - /* XXX need to worry about failed_wr and partial sends. */ - failed_wr = &first->s_send_wr; - ret = ib_post_send(ic->i_cm_id->qp, &first->s_send_wr, &failed_wr); - rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic, - first, &first->s_send_wr, ret, failed_wr); - BUG_ON(failed_wr != &first->s_send_wr); - if (ret) { - printk(KERN_WARNING "RDS/IW: ib_post_send to %pI4 " - "returned %d\n", &conn->c_faddr, ret); - rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc); - if (prev->s_rm) { - ic->i_rm = prev->s_rm; - prev->s_rm = NULL; - } - goto out; - } - - ret = sent; -out: - BUG_ON(adv_credits); - return ret; -} - -static int rds_iw_build_send_reg(struct rds_iw_send_work *send, - struct scatterlist *sg, - int sg_nents) -{ - int n; - - n = ib_map_mr_sg(send->s_mr, sg, sg_nents, PAGE_SIZE); - if (unlikely(n != sg_nents)) - return n < 0 ? n : -EINVAL; - - send->s_reg_wr.wr.opcode = IB_WR_REG_MR; - send->s_reg_wr.wr.wr_id = 0; - send->s_reg_wr.wr.num_sge = 0; - send->s_reg_wr.mr = send->s_mr; - send->s_reg_wr.key = send->s_mr->rkey; - send->s_reg_wr.access = IB_ACCESS_REMOTE_WRITE; - - ib_update_fast_reg_key(send->s_mr, send->s_remap_count++); - - return 0; -} - -int rds_iw_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op) -{ - struct rds_iw_connection *ic = conn->c_transport_data; - struct rds_iw_send_work *send = NULL; - struct rds_iw_send_work *first; - struct rds_iw_send_work *prev; - struct ib_send_wr *failed_wr; - struct rds_iw_device *rds_iwdev; - struct scatterlist *scat; - unsigned long len; - u64 remote_addr = op->op_remote_addr; - u32 pos, fr_pos; - u32 work_alloc; - u32 i; - u32 j; - int sent; - int ret; - int num_sge; - int sg_nents; - - rds_iwdev = ib_get_client_data(ic->i_cm_id->device, &rds_iw_client); - - /* map the message 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_iw_stats_inc(s_iw_tx_sg_mapping_failure); - ret = -ENOMEM; /* XXX ? */ - goto out; - } - - op->op_mapped = 1; - } - - if (!op->op_write) { - /* Alloc space on the send queue for the fastreg */ - work_alloc = rds_iw_ring_alloc(&ic->i_send_ring, 1, &fr_pos); - if (work_alloc != 1) { - rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc); - rds_iw_stats_inc(s_iw_tx_ring_full); - ret = -ENOMEM; - goto out; - } - } - - /* - * 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_iwdev->max_sge); - - work_alloc = rds_iw_ring_alloc(&ic->i_send_ring, i, &pos); - if (work_alloc != i) { - rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc); - rds_iw_stats_inc(s_iw_tx_ring_full); - ret = -ENOMEM; - goto out; - } - - send = &ic->i_sends[pos]; - if (!op->op_write) { - first = prev = &ic->i_sends[fr_pos]; - } else { - first = send; - prev = NULL; - } - scat = &op->op_sg[0]; - sent = 0; - num_sge = op->op_count; - sg_nents = 0; - - for (i = 0; i < work_alloc && scat != &op->op_sg[op->op_count]; i++) { - send->s_rdma_wr.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_iw_sysctl_max_unsig_wrs; - send->s_rdma_wr.wr.send_flags = IB_SEND_SIGNALED; - } - - /* To avoid the need to have the plumbing to invalidate the fastreg_mr used - * for local access after RDS is finished with it, using - * IB_WR_RDMA_READ_WITH_INV will invalidate it after the read has completed. - */ - if (op->op_write) - send->s_rdma_wr.wr.opcode = IB_WR_RDMA_WRITE; - else - send->s_rdma_wr.wr.opcode = IB_WR_RDMA_READ_WITH_INV; - - send->s_rdma_wr.remote_addr = remote_addr; - send->s_rdma_wr.rkey = op->op_rkey; - send->s_op = op; - - if (num_sge > rds_iwdev->max_sge) { - send->s_rdma_wr.wr.num_sge = rds_iwdev->max_sge; - num_sge -= rds_iwdev->max_sge; - } else - send->s_rdma_wr.wr.num_sge = num_sge; - - send->s_rdma_wr.wr.next = NULL; - - if (prev) - prev->s_send_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 = ib_sg_dma_len(ic->i_cm_id->device, scat); - - if (send->s_rdma_wr.wr.opcode == IB_WR_RDMA_READ_WITH_INV) - sg_nents++; - else { - 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 = rds_iw_local_dma_lkey(ic); - } - - sent += len; - rdsdebug("ic %p sent %d remote_addr %llu\n", ic, sent, remote_addr); - remote_addr += len; - - scat++; - } - - if (send->s_rdma_wr.wr.opcode == IB_WR_RDMA_READ_WITH_INV) { - send->s_rdma_wr.wr.num_sge = 1; - send->s_sge[0].addr = conn->c_xmit_rm->m_rs->rs_user_addr; - send->s_sge[0].length = conn->c_xmit_rm->m_rs->rs_user_bytes; - send->s_sge[0].lkey = ic->i_sends[fr_pos].s_mr->lkey; - } - - rdsdebug("send %p wr %p num_sge %u next %p\n", send, - &send->s_rdma_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; - } - - /* if we finished the message then send completion owns it */ - if (scat == &op->op_sg[op->op_count]) - first->s_rdma_wr.wr.send_flags = IB_SEND_SIGNALED; - - if (i < work_alloc) { - rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc - i); - work_alloc = i; - } - - /* On iWARP, local memory access by a remote system (ie, RDMA Read) is not - * recommended. Putting the lkey on the wire is a security hole, as it can - * allow for memory access to all of memory on the remote system. Some - * adapters do not allow using the lkey for this at all. To bypass this use a - * fastreg_mr (or possibly a dma_mr) - */ - if (!op->op_write) { - ret = rds_iw_build_send_reg(&ic->i_sends[fr_pos], - &op->op_sg[0], sg_nents); - if (ret) { - printk(KERN_WARNING "RDS/IW: failed to reg send mem\n"); - goto out; - } - work_alloc++; - } - - 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, ret, failed_wr); - BUG_ON(failed_wr != &first->s_rdma_wr.wr); - if (ret) { - printk(KERN_WARNING "RDS/IW: rdma ib_post_send to %pI4 " - "returned %d\n", &conn->c_faddr, ret); - rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc); - goto out; - } - -out: - return ret; -} - -void rds_iw_xmit_complete(struct rds_connection *conn) -{ - struct rds_iw_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_iw_attempt_ack(ic); -} |
