diff options
Diffstat (limited to 'net/rds/iw_recv.c')
| -rw-r--r-- | net/rds/iw_recv.c | 904 |
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 a66d1794b2d0..000000000000 --- 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); -} |