Linux-libre 4.6.2-gnu

1 files changed, 0 insertions, 904 deletions

diff --git a/net/rds/iw_recv.c b/net/rds/iw_recv.c
deleted file mode 100644
index a66d1794b..000000000
--- a/net/rds/iw_recv.c
+++ /dev/null
@@ -1,904 +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/slab.h>
-#include <linux/pci.h>
-#include <linux/dma-mapping.h>
-#include <rdma/rdma_cm.h>
-
-#include "rds.h"
-#include "iw.h"
-
-static struct kmem_cache *rds_iw_incoming_slab;
-static struct kmem_cache *rds_iw_frag_slab;
-static atomic_t	rds_iw_allocation = ATOMIC_INIT(0);
-
-static void rds_iw_frag_drop_page(struct rds_page_frag *frag)
-{
-	rdsdebug("frag %p page %p\n", frag, frag->f_page);
-	__free_page(frag->f_page);
-	frag->f_page = NULL;
-}
-
-static void rds_iw_frag_free(struct rds_page_frag *frag)
-{
-	rdsdebug("frag %p page %p\n", frag, frag->f_page);
-	BUG_ON(frag->f_page);
-	kmem_cache_free(rds_iw_frag_slab, frag);
-}
-
-/*
- * We map a page at a time.  Its fragments are posted in order.  This
- * is called in fragment order as the fragments get send completion events.
- * Only the last frag in the page performs the unmapping.
- *
- * It's OK for ring cleanup to call this in whatever order it likes because
- * DMA is not in flight and so we can unmap while other ring entries still
- * hold page references in their frags.
- */
-static void rds_iw_recv_unmap_page(struct rds_iw_connection *ic,
-				   struct rds_iw_recv_work *recv)
-{
-	struct rds_page_frag *frag = recv->r_frag;
-
-	rdsdebug("recv %p frag %p page %p\n", recv, frag, frag->f_page);
-	if (frag->f_mapped)
-		ib_dma_unmap_page(ic->i_cm_id->device,
-			       frag->f_mapped,
-			       RDS_FRAG_SIZE, DMA_FROM_DEVICE);
-	frag->f_mapped = 0;
-}
-
-void rds_iw_recv_init_ring(struct rds_iw_connection *ic)
-{
-	struct rds_iw_recv_work *recv;
-	u32 i;
-
-	for (i = 0, recv = ic->i_recvs; i < ic->i_recv_ring.w_nr; i++, recv++) {
-		struct ib_sge *sge;
-
-		recv->r_iwinc = NULL;
-		recv->r_frag = NULL;
-
-		recv->r_wr.next = NULL;
-		recv->r_wr.wr_id = i;
-		recv->r_wr.sg_list = recv->r_sge;
-		recv->r_wr.num_sge = RDS_IW_RECV_SGE;
-
-		sge = rds_iw_data_sge(ic, recv->r_sge);
-		sge->addr = 0;
-		sge->length = RDS_FRAG_SIZE;
-		sge->lkey = 0;
-
-		sge = rds_iw_header_sge(ic, recv->r_sge);
-		sge->addr = ic->i_recv_hdrs_dma + (i * sizeof(struct rds_header));
-		sge->length = sizeof(struct rds_header);
-		sge->lkey = 0;
-	}
-}
-
-static void rds_iw_recv_clear_one(struct rds_iw_connection *ic,
-				  struct rds_iw_recv_work *recv)
-{
-	if (recv->r_iwinc) {
-		rds_inc_put(&recv->r_iwinc->ii_inc);
-		recv->r_iwinc = NULL;
-	}
-	if (recv->r_frag) {
-		rds_iw_recv_unmap_page(ic, recv);
-		if (recv->r_frag->f_page)
-			rds_iw_frag_drop_page(recv->r_frag);
-		rds_iw_frag_free(recv->r_frag);
-		recv->r_frag = NULL;
-	}
-}
-
-void rds_iw_recv_clear_ring(struct rds_iw_connection *ic)
-{
-	u32 i;
-
-	for (i = 0; i < ic->i_recv_ring.w_nr; i++)
-		rds_iw_recv_clear_one(ic, &ic->i_recvs[i]);
-
-	if (ic->i_frag.f_page)
-		rds_iw_frag_drop_page(&ic->i_frag);
-}
-
-static int rds_iw_recv_refill_one(struct rds_connection *conn,
-				  struct rds_iw_recv_work *recv,
-				  gfp_t kptr_gfp, gfp_t page_gfp)
-{
-	struct rds_iw_connection *ic = conn->c_transport_data;
-	dma_addr_t dma_addr;
-	struct ib_sge *sge;
-	int ret = -ENOMEM;
-
-	if (!recv->r_iwinc) {
-		if (!atomic_add_unless(&rds_iw_allocation, 1, rds_iw_sysctl_max_recv_allocation)) {
-			rds_iw_stats_inc(s_iw_rx_alloc_limit);
-			goto out;
-		}
-		recv->r_iwinc = kmem_cache_alloc(rds_iw_incoming_slab,
-						 kptr_gfp);
-		if (!recv->r_iwinc) {
-			atomic_dec(&rds_iw_allocation);
-			goto out;
-		}
-		INIT_LIST_HEAD(&recv->r_iwinc->ii_frags);
-		rds_inc_init(&recv->r_iwinc->ii_inc, conn, conn->c_faddr);
-	}
-
-	if (!recv->r_frag) {
-		recv->r_frag = kmem_cache_alloc(rds_iw_frag_slab, kptr_gfp);
-		if (!recv->r_frag)
-			goto out;
-		INIT_LIST_HEAD(&recv->r_frag->f_item);
-		recv->r_frag->f_page = NULL;
-	}
-
-	if (!ic->i_frag.f_page) {
-		ic->i_frag.f_page = alloc_page(page_gfp);
-		if (!ic->i_frag.f_page)
-			goto out;
-		ic->i_frag.f_offset = 0;
-	}
-
-	dma_addr = ib_dma_map_page(ic->i_cm_id->device,
-				  ic->i_frag.f_page,
-				  ic->i_frag.f_offset,
-				  RDS_FRAG_SIZE,
-				  DMA_FROM_DEVICE);
-	if (ib_dma_mapping_error(ic->i_cm_id->device, dma_addr))
-		goto out;
-
-	/*
-	 * Once we get the RDS_PAGE_LAST_OFF frag then rds_iw_frag_unmap()
-	 * must be called on this recv.  This happens as completions hit
-	 * in order or on connection shutdown.
-	 */
-	recv->r_frag->f_page = ic->i_frag.f_page;
-	recv->r_frag->f_offset = ic->i_frag.f_offset;
-	recv->r_frag->f_mapped = dma_addr;
-
-	sge = rds_iw_data_sge(ic, recv->r_sge);
-	sge->addr = dma_addr;
-	sge->length = RDS_FRAG_SIZE;
-
-	sge = rds_iw_header_sge(ic, recv->r_sge);
-	sge->addr = ic->i_recv_hdrs_dma + (recv - ic->i_recvs) * sizeof(struct rds_header);
-	sge->length = sizeof(struct rds_header);
-
-	get_page(recv->r_frag->f_page);
-
-	if (ic->i_frag.f_offset < RDS_PAGE_LAST_OFF) {
-		ic->i_frag.f_offset += RDS_FRAG_SIZE;
-	} else {
-		put_page(ic->i_frag.f_page);
-		ic->i_frag.f_page = NULL;
-		ic->i_frag.f_offset = 0;
-	}
-
-	ret = 0;
-out:
-	return ret;
-}
-
-/*
- * This tries to allocate and post unused work requests after making sure that
- * they have all the allocations they need to queue received fragments into
- * sockets.  The i_recv_mutex is held here so that ring_alloc and _unalloc
- * pairs don't go unmatched.
- *
- * -1 is returned if posting fails due to temporary resource exhaustion.
- */
-int rds_iw_recv_refill(struct rds_connection *conn, gfp_t kptr_gfp,
-		       gfp_t page_gfp, int prefill)
-{
-	struct rds_iw_connection *ic = conn->c_transport_data;
-	struct rds_iw_recv_work *recv;
-	struct ib_recv_wr *failed_wr;
-	unsigned int posted = 0;
-	int ret = 0;
-	u32 pos;
-
-	while ((prefill || rds_conn_up(conn)) &&
-	       rds_iw_ring_alloc(&ic->i_recv_ring, 1, &pos)) {
-		if (pos >= ic->i_recv_ring.w_nr) {
-			printk(KERN_NOTICE "Argh - ring alloc returned pos=%u\n",
-					pos);
-			ret = -EINVAL;
-			break;
-		}
-
-		recv = &ic->i_recvs[pos];
-		ret = rds_iw_recv_refill_one(conn, recv, kptr_gfp, page_gfp);
-		if (ret) {
-			ret = -1;
-			break;
-		}
-
-		/* XXX when can this fail? */
-		ret = ib_post_recv(ic->i_cm_id->qp, &recv->r_wr, &failed_wr);
-		rdsdebug("recv %p iwinc %p page %p addr %lu ret %d\n", recv,
-			 recv->r_iwinc, recv->r_frag->f_page,
-			 (long) recv->r_frag->f_mapped, ret);
-		if (ret) {
-			rds_iw_conn_error(conn, "recv post on "
-			       "%pI4 returned %d, disconnecting and "
-			       "reconnecting\n", &conn->c_faddr,
-			       ret);
-			ret = -1;
-			break;
-		}
-
-		posted++;
-	}
-
-	/* We're doing flow control - update the window. */
-	if (ic->i_flowctl && posted)
-		rds_iw_advertise_credits(conn, posted);
-
-	if (ret)
-		rds_iw_ring_unalloc(&ic->i_recv_ring, 1);
-	return ret;
-}
-
-static void rds_iw_inc_purge(struct rds_incoming *inc)
-{
-	struct rds_iw_incoming *iwinc;
-	struct rds_page_frag *frag;
-	struct rds_page_frag *pos;
-
-	iwinc = container_of(inc, struct rds_iw_incoming, ii_inc);
-	rdsdebug("purging iwinc %p inc %p\n", iwinc, inc);
-
-	list_for_each_entry_safe(frag, pos, &iwinc->ii_frags, f_item) {
-		list_del_init(&frag->f_item);
-		rds_iw_frag_drop_page(frag);
-		rds_iw_frag_free(frag);
-	}
-}
-
-void rds_iw_inc_free(struct rds_incoming *inc)
-{
-	struct rds_iw_incoming *iwinc;
-
-	iwinc = container_of(inc, struct rds_iw_incoming, ii_inc);
-
-	rds_iw_inc_purge(inc);
-	rdsdebug("freeing iwinc %p inc %p\n", iwinc, inc);
-	BUG_ON(!list_empty(&iwinc->ii_frags));
-	kmem_cache_free(rds_iw_incoming_slab, iwinc);
-	atomic_dec(&rds_iw_allocation);
-	BUG_ON(atomic_read(&rds_iw_allocation) < 0);
-}
-
-int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
-{
-	struct rds_iw_incoming *iwinc;
-	struct rds_page_frag *frag;
-	unsigned long to_copy;
-	unsigned long frag_off = 0;
-	int copied = 0;
-	int ret;
-	u32 len;
-
-	iwinc = container_of(inc, struct rds_iw_incoming, ii_inc);
-	frag = list_entry(iwinc->ii_frags.next, struct rds_page_frag, f_item);
-	len = be32_to_cpu(inc->i_hdr.h_len);
-
-	while (iov_iter_count(to) && copied < len) {
-		if (frag_off == RDS_FRAG_SIZE) {
-			frag = list_entry(frag->f_item.next,
-					  struct rds_page_frag, f_item);
-			frag_off = 0;
-		}
-		to_copy = min_t(unsigned long, iov_iter_count(to),
-				RDS_FRAG_SIZE - frag_off);
-		to_copy = min_t(unsigned long, to_copy, len - copied);
-
-		/* XXX needs + offset for multiple recvs per page */
-		rds_stats_add(s_copy_to_user, to_copy);
-		ret = copy_page_to_iter(frag->f_page,
-					frag->f_offset + frag_off,
-					to_copy,
-					to);
-		if (ret != to_copy)
-			return -EFAULT;
-
-		frag_off += to_copy;
-		copied += to_copy;
-	}
-
-	return copied;
-}
-
-/* ic starts out kzalloc()ed */
-void rds_iw_recv_init_ack(struct rds_iw_connection *ic)
-{
-	struct ib_send_wr *wr = &ic->i_ack_wr;
-	struct ib_sge *sge = &ic->i_ack_sge;
-
-	sge->addr = ic->i_ack_dma;
-	sge->length = sizeof(struct rds_header);
-	sge->lkey = rds_iw_local_dma_lkey(ic);
-
-	wr->sg_list = sge;
-	wr->num_sge = 1;
-	wr->opcode = IB_WR_SEND;
-	wr->wr_id = RDS_IW_ACK_WR_ID;
-	wr->send_flags = IB_SEND_SIGNALED | IB_SEND_SOLICITED;
-}
-
-/*
- * You'd think that with reliable IB connections you wouldn't need to ack
- * messages that have been received.  The problem is that IB hardware generates
- * an ack message before it has DMAed the message into memory.  This creates a
- * potential message loss if the HCA is disabled for any reason between when it
- * sends the ack and before the message is DMAed and processed.  This is only a
- * potential issue if another HCA is available for fail-over.
- *
- * When the remote host receives our ack they'll free the sent message from
- * their send queue.  To decrease the latency of this we always send an ack
- * immediately after we've received messages.
- *
- * For simplicity, we only have one ack in flight at a time.  This puts
- * pressure on senders to have deep enough send queues to absorb the latency of
- * a single ack frame being in flight.  This might not be good enough.
- *
- * This is implemented by have a long-lived send_wr and sge which point to a
- * statically allocated ack frame.  This ack wr does not fall under the ring
- * accounting that the tx and rx wrs do.  The QP attribute specifically makes
- * room for it beyond the ring size.  Send completion notices its special
- * wr_id and avoids working with the ring in that case.
- */
-#ifndef KERNEL_HAS_ATOMIC64
-static void rds_iw_set_ack(struct rds_iw_connection *ic, u64 seq,
-				int ack_required)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&ic->i_ack_lock, flags);
-	ic->i_ack_next = seq;
-	if (ack_required)
-		set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
-	spin_unlock_irqrestore(&ic->i_ack_lock, flags);
-}
-
-static u64 rds_iw_get_ack(struct rds_iw_connection *ic)
-{
-	unsigned long flags;
-	u64 seq;
-
-	clear_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
-
-	spin_lock_irqsave(&ic->i_ack_lock, flags);
-	seq = ic->i_ack_next;
-	spin_unlock_irqrestore(&ic->i_ack_lock, flags);
-
-	return seq;
-}
-#else
-static void rds_iw_set_ack(struct rds_iw_connection *ic, u64 seq,
-				int ack_required)
-{
-	atomic64_set(&ic->i_ack_next, seq);
-	if (ack_required) {
-		smp_mb__before_atomic();
-		set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
-	}
-}
-
-static u64 rds_iw_get_ack(struct rds_iw_connection *ic)
-{
-	clear_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
-	smp_mb__after_atomic();
-
-	return atomic64_read(&ic->i_ack_next);
-}
-#endif
-
-
-static void rds_iw_send_ack(struct rds_iw_connection *ic, unsigned int adv_credits)
-{
-	struct rds_header *hdr = ic->i_ack;
-	struct ib_send_wr *failed_wr;
-	u64 seq;
-	int ret;
-
-	seq = rds_iw_get_ack(ic);
-
-	rdsdebug("send_ack: ic %p ack %llu\n", ic, (unsigned long long) seq);
-	rds_message_populate_header(hdr, 0, 0, 0);
-	hdr->h_ack = cpu_to_be64(seq);
-	hdr->h_credit = adv_credits;
-	rds_message_make_checksum(hdr);
-	ic->i_ack_queued = jiffies;
-
-	ret = ib_post_send(ic->i_cm_id->qp, &ic->i_ack_wr, &failed_wr);
-	if (unlikely(ret)) {
-		/* Failed to send. Release the WR, and
-		 * force another ACK.
-		 */
-		clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
-		set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
-
-		rds_iw_stats_inc(s_iw_ack_send_failure);
-
-		rds_iw_conn_error(ic->conn, "sending ack failed\n");
-	} else
-		rds_iw_stats_inc(s_iw_ack_sent);
-}
-
-/*
- * There are 3 ways of getting acknowledgements to the peer:
- *  1.	We call rds_iw_attempt_ack from the recv completion handler
- *	to send an ACK-only frame.
- *	However, there can be only one such frame in the send queue
- *	at any time, so we may have to postpone it.
- *  2.	When another (data) packet is transmitted while there's
- *	an ACK in the queue, we piggyback the ACK sequence number
- *	on the data packet.
- *  3.	If the ACK WR is done sending, we get called from the
- *	send queue completion handler, and check whether there's
- *	another ACK pending (postponed because the WR was on the
- *	queue). If so, we transmit it.
- *
- * We maintain 2 variables:
- *  -	i_ack_flags, which keeps track of whether the ACK WR
- *	is currently in the send queue or not (IB_ACK_IN_FLIGHT)
- *  -	i_ack_next, which is the last sequence number we received
- *
- * Potentially, send queue and receive queue handlers can run concurrently.
- * It would be nice to not have to use a spinlock to synchronize things,
- * but the one problem that rules this out is that 64bit updates are
- * not atomic on all platforms. Things would be a lot simpler if
- * we had atomic64 or maybe cmpxchg64 everywhere.
- *
- * Reconnecting complicates this picture just slightly. When we
- * reconnect, we may be seeing duplicate packets. The peer
- * is retransmitting them, because it hasn't seen an ACK for
- * them. It is important that we ACK these.
- *
- * ACK mitigation adds a header flag "ACK_REQUIRED"; any packet with
- * this flag set *MUST* be acknowledged immediately.
- */
-
-/*
- * When we get here, we're called from the recv queue handler.
- * Check whether we ought to transmit an ACK.
- */
-void rds_iw_attempt_ack(struct rds_iw_connection *ic)
-{
-	unsigned int adv_credits;
-
-	if (!test_bit(IB_ACK_REQUESTED, &ic->i_ack_flags))
-		return;
-
-	if (test_and_set_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags)) {
-		rds_iw_stats_inc(s_iw_ack_send_delayed);
-		return;
-	}
-
-	/* Can we get a send credit? */
-	if (!rds_iw_send_grab_credits(ic, 1, &adv_credits, 0, RDS_MAX_ADV_CREDIT)) {
-		rds_iw_stats_inc(s_iw_tx_throttle);
-		clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
-		return;
-	}
-
-	clear_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
-	rds_iw_send_ack(ic, adv_credits);
-}
-
-/*
- * We get here from the send completion handler, when the
- * adapter tells us the ACK frame was sent.
- */
-void rds_iw_ack_send_complete(struct rds_iw_connection *ic)
-{
-	clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
-	rds_iw_attempt_ack(ic);
-}
-
-/*
- * This is called by the regular xmit code when it wants to piggyback
- * an ACK on an outgoing frame.
- */
-u64 rds_iw_piggyb_ack(struct rds_iw_connection *ic)
-{
-	if (test_and_clear_bit(IB_ACK_REQUESTED, &ic->i_ack_flags))
-		rds_iw_stats_inc(s_iw_ack_send_piggybacked);
-	return rds_iw_get_ack(ic);
-}
-
-/*
- * It's kind of lame that we're copying from the posted receive pages into
- * long-lived bitmaps.  We could have posted the bitmaps and rdma written into
- * them.  But receiving new congestion bitmaps should be a *rare* event, so
- * hopefully we won't need to invest that complexity in making it more
- * efficient.  By copying we can share a simpler core with TCP which has to
- * copy.
- */
-static void rds_iw_cong_recv(struct rds_connection *conn,
-			      struct rds_iw_incoming *iwinc)
-{
-	struct rds_cong_map *map;
-	unsigned int map_off;
-	unsigned int map_page;
-	struct rds_page_frag *frag;
-	unsigned long frag_off;
-	unsigned long to_copy;
-	unsigned long copied;
-	uint64_t uncongested = 0;
-	void *addr;
-
-	/* catch completely corrupt packets */
-	if (be32_to_cpu(iwinc->ii_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES)
-		return;
-
-	map = conn->c_fcong;
-	map_page = 0;
-	map_off = 0;
-
-	frag = list_entry(iwinc->ii_frags.next, struct rds_page_frag, f_item);
-	frag_off = 0;
-
-	copied = 0;
-
-	while (copied < RDS_CONG_MAP_BYTES) {
-		uint64_t *src, *dst;
-		unsigned int k;
-
-		to_copy = min(RDS_FRAG_SIZE - frag_off, PAGE_SIZE - map_off);
-		BUG_ON(to_copy & 7); /* Must be 64bit aligned. */
-
-		addr = kmap_atomic(frag->f_page);
-
-		src = addr + frag_off;
-		dst = (void *)map->m_page_addrs[map_page] + map_off;
-		for (k = 0; k < to_copy; k += 8) {
-			/* Record ports that became uncongested, ie
-			 * bits that changed from 0 to 1. */
-			uncongested |= ~(*src) & *dst;
-			*dst++ = *src++;
-		}
-		kunmap_atomic(addr);
-
-		copied += to_copy;
-
-		map_off += to_copy;
-		if (map_off == PAGE_SIZE) {
-			map_off = 0;
-			map_page++;
-		}
-
-		frag_off += to_copy;
-		if (frag_off == RDS_FRAG_SIZE) {
-			frag = list_entry(frag->f_item.next,
-					  struct rds_page_frag, f_item);
-			frag_off = 0;
-		}
-	}
-
-	/* the congestion map is in little endian order */
-	uncongested = le64_to_cpu(uncongested);
-
-	rds_cong_map_updated(map, uncongested);
-}
-
-/*
- * Rings are posted with all the allocations they'll need to queue the
- * incoming message to the receiving socket so this can't fail.
- * All fragments start with a header, so we can make sure we're not receiving
- * garbage, and we can tell a small 8 byte fragment from an ACK frame.
- */
-struct rds_iw_ack_state {
-	u64		ack_next;
-	u64		ack_recv;
-	unsigned int	ack_required:1;
-	unsigned int	ack_next_valid:1;
-	unsigned int	ack_recv_valid:1;
-};
-
-static void rds_iw_process_recv(struct rds_connection *conn,
-				struct rds_iw_recv_work *recv, u32 byte_len,
-				struct rds_iw_ack_state *state)
-{
-	struct rds_iw_connection *ic = conn->c_transport_data;
-	struct rds_iw_incoming *iwinc = ic->i_iwinc;
-	struct rds_header *ihdr, *hdr;
-
-	/* XXX shut down the connection if port 0,0 are seen? */
-
-	rdsdebug("ic %p iwinc %p recv %p byte len %u\n", ic, iwinc, recv,
-		 byte_len);
-
-	if (byte_len < sizeof(struct rds_header)) {
-		rds_iw_conn_error(conn, "incoming message "
-		       "from %pI4 didn't include a "
-		       "header, disconnecting and "
-		       "reconnecting\n",
-		       &conn->c_faddr);
-		return;
-	}
-	byte_len -= sizeof(struct rds_header);
-
-	ihdr = &ic->i_recv_hdrs[recv - ic->i_recvs];
-
-	/* Validate the checksum. */
-	if (!rds_message_verify_checksum(ihdr)) {
-		rds_iw_conn_error(conn, "incoming message "
-		       "from %pI4 has corrupted header - "
-		       "forcing a reconnect\n",
-		       &conn->c_faddr);
-		rds_stats_inc(s_recv_drop_bad_checksum);
-		return;
-	}
-
-	/* Process the ACK sequence which comes with every packet */
-	state->ack_recv = be64_to_cpu(ihdr->h_ack);
-	state->ack_recv_valid = 1;
-
-	/* Process the credits update if there was one */
-	if (ihdr->h_credit)
-		rds_iw_send_add_credits(conn, ihdr->h_credit);
-
-	if (ihdr->h_sport == 0 && ihdr->h_dport == 0 && byte_len == 0) {
-		/* This is an ACK-only packet. The fact that it gets
-		 * special treatment here is that historically, ACKs
-		 * were rather special beasts.
-		 */
-		rds_iw_stats_inc(s_iw_ack_received);
-
-		/*
-		 * Usually the frags make their way on to incs and are then freed as
-		 * the inc is freed.  We don't go that route, so we have to drop the
-		 * page ref ourselves.  We can't just leave the page on the recv
-		 * because that confuses the dma mapping of pages and each recv's use
-		 * of a partial page.  We can leave the frag, though, it will be
-		 * reused.
-		 *
-		 * FIXME: Fold this into the code path below.
-		 */
-		rds_iw_frag_drop_page(recv->r_frag);
-		return;
-	}
-
-	/*
-	 * If we don't already have an inc on the connection then this
-	 * fragment has a header and starts a message.. copy its header
-	 * into the inc and save the inc so we can hang upcoming fragments
-	 * off its list.
-	 */
-	if (!iwinc) {
-		iwinc = recv->r_iwinc;
-		recv->r_iwinc = NULL;
-		ic->i_iwinc = iwinc;
-
-		hdr = &iwinc->ii_inc.i_hdr;
-		memcpy(hdr, ihdr, sizeof(*hdr));
-		ic->i_recv_data_rem = be32_to_cpu(hdr->h_len);
-
-		rdsdebug("ic %p iwinc %p rem %u flag 0x%x\n", ic, iwinc,
-			 ic->i_recv_data_rem, hdr->h_flags);
-	} else {
-		hdr = &iwinc->ii_inc.i_hdr;
-		/* We can't just use memcmp here; fragments of a
-		 * single message may carry different ACKs */
-		if (hdr->h_sequence != ihdr->h_sequence ||
-		    hdr->h_len != ihdr->h_len ||
-		    hdr->h_sport != ihdr->h_sport ||
-		    hdr->h_dport != ihdr->h_dport) {
-			rds_iw_conn_error(conn,
-				"fragment header mismatch; forcing reconnect\n");
-			return;
-		}
-	}
-
-	list_add_tail(&recv->r_frag->f_item, &iwinc->ii_frags);
-	recv->r_frag = NULL;
-
-	if (ic->i_recv_data_rem > RDS_FRAG_SIZE)
-		ic->i_recv_data_rem -= RDS_FRAG_SIZE;
-	else {
-		ic->i_recv_data_rem = 0;
-		ic->i_iwinc = NULL;
-
-		if (iwinc->ii_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP)
-			rds_iw_cong_recv(conn, iwinc);
-		else {
-			rds_recv_incoming(conn, conn->c_faddr, conn->c_laddr,
-					  &iwinc->ii_inc, GFP_ATOMIC);
-			state->ack_next = be64_to_cpu(hdr->h_sequence);
-			state->ack_next_valid = 1;
-		}
-
-		/* Evaluate the ACK_REQUIRED flag *after* we received
-		 * the complete frame, and after bumping the next_rx
-		 * sequence. */
-		if (hdr->h_flags & RDS_FLAG_ACK_REQUIRED) {
-			rds_stats_inc(s_recv_ack_required);
-			state->ack_required = 1;
-		}
-
-		rds_inc_put(&iwinc->ii_inc);
-	}
-}
-
-/*
- * Plucking the oldest entry from the ring can be done concurrently with
- * the thread refilling the ring.  Each ring operation is protected by
- * spinlocks and the transient state of refilling doesn't change the
- * recording of which entry is oldest.
- *
- * This relies on IB only calling one cq comp_handler for each cq so that
- * there will only be one caller of rds_recv_incoming() per RDS connection.
- */
-void rds_iw_recv_cq_comp_handler(struct ib_cq *cq, void *context)
-{
-	struct rds_connection *conn = context;
-	struct rds_iw_connection *ic = conn->c_transport_data;
-
-	rdsdebug("conn %p cq %p\n", conn, cq);
-
-	rds_iw_stats_inc(s_iw_rx_cq_call);
-
-	tasklet_schedule(&ic->i_recv_tasklet);
-}
-
-static inline void rds_poll_cq(struct rds_iw_connection *ic,
-			       struct rds_iw_ack_state *state)
-{
-	struct rds_connection *conn = ic->conn;
-	struct ib_wc wc;
-	struct rds_iw_recv_work *recv;
-
-	while (ib_poll_cq(ic->i_recv_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_rx_cq_event);
-
-		recv = &ic->i_recvs[rds_iw_ring_oldest(&ic->i_recv_ring)];
-
-		rds_iw_recv_unmap_page(ic, recv);
-
-		/*
-		 * Also process recvs in connecting state because it is possible
-		 * to get a recv completion _before_ the rdmacm ESTABLISHED
-		 * event is processed.
-		 */
-		if (rds_conn_up(conn) || rds_conn_connecting(conn)) {
-			/* We expect errors as the qp is drained during shutdown */
-			if (wc.status == IB_WC_SUCCESS) {
-				rds_iw_process_recv(conn, recv, wc.byte_len, state);
-			} else {
-				rds_iw_conn_error(conn, "recv completion on "
-				       "%pI4 had status %u, disconnecting and "
-				       "reconnecting\n", &conn->c_faddr,
-				       wc.status);
-			}
-		}
-
-		rds_iw_ring_free(&ic->i_recv_ring, 1);
-	}
-}
-
-void rds_iw_recv_tasklet_fn(unsigned long data)
-{
-	struct rds_iw_connection *ic = (struct rds_iw_connection *) data;
-	struct rds_connection *conn = ic->conn;
-	struct rds_iw_ack_state state = { 0, };
-
-	rds_poll_cq(ic, &state);
-	ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
-	rds_poll_cq(ic, &state);
-
-	if (state.ack_next_valid)
-		rds_iw_set_ack(ic, state.ack_next, state.ack_required);
-	if (state.ack_recv_valid && state.ack_recv > ic->i_ack_recv) {
-		rds_send_drop_acked(conn, state.ack_recv, NULL);
-		ic->i_ack_recv = state.ack_recv;
-	}
-	if (rds_conn_up(conn))
-		rds_iw_attempt_ack(ic);
-
-	/* If we ever end up with a really empty receive ring, we're
-	 * in deep trouble, as the sender will definitely see RNR
-	 * timeouts. */
-	if (rds_iw_ring_empty(&ic->i_recv_ring))
-		rds_iw_stats_inc(s_iw_rx_ring_empty);
-
-	/*
-	 * If the ring is running low, then schedule the thread to refill.
-	 */
-	if (rds_iw_ring_low(&ic->i_recv_ring))
-		queue_delayed_work(rds_wq, &conn->c_recv_w, 0);
-}
-
-int rds_iw_recv(struct rds_connection *conn)
-{
-	struct rds_iw_connection *ic = conn->c_transport_data;
-	int ret = 0;
-
-	rdsdebug("conn %p\n", conn);
-
-	/*
-	 * If we get a temporary posting failure in this context then
-	 * we're really low and we want the caller to back off for a bit.
-	 */
-	mutex_lock(&ic->i_recv_mutex);
-	if (rds_iw_recv_refill(conn, GFP_KERNEL, GFP_HIGHUSER, 0))
-		ret = -ENOMEM;
-	else
-		rds_iw_stats_inc(s_iw_rx_refill_from_thread);
-	mutex_unlock(&ic->i_recv_mutex);
-
-	if (rds_conn_up(conn))
-		rds_iw_attempt_ack(ic);
-
-	return ret;
-}
-
-int rds_iw_recv_init(void)
-{
-	struct sysinfo si;
-	int ret = -ENOMEM;
-
-	/* Default to 30% of all available RAM for recv memory */
-	si_meminfo(&si);
-	rds_iw_sysctl_max_recv_allocation = si.totalram / 3 * PAGE_SIZE / RDS_FRAG_SIZE;
-
-	rds_iw_incoming_slab = kmem_cache_create("rds_iw_incoming",
-					sizeof(struct rds_iw_incoming),
-					0, 0, NULL);
-	if (!rds_iw_incoming_slab)
-		goto out;
-
-	rds_iw_frag_slab = kmem_cache_create("rds_iw_frag",
-					sizeof(struct rds_page_frag),
-					0, 0, NULL);
-	if (!rds_iw_frag_slab)
-		kmem_cache_destroy(rds_iw_incoming_slab);
-	else
-		ret = 0;
-out:
-	return ret;
-}
-
-void rds_iw_recv_exit(void)
-{
-	kmem_cache_destroy(rds_iw_incoming_slab);
-	kmem_cache_destroy(rds_iw_frag_slab);
-}