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-rw-r--r--net/rds/iw_send.c981
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);
-}
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