| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Shared Memory Communications over RDMA (SMC-R) and RoCE |
| * |
| * Connection Data Control (CDC) |
| * handles flow control |
| * |
| * Copyright IBM Corp. 2016 |
| * |
| * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com> |
| */ |
| |
| #include <linux/spinlock.h> |
| |
| #include "smc.h" |
| #include "smc_wr.h" |
| #include "smc_cdc.h" |
| #include "smc_tx.h" |
| #include "smc_rx.h" |
| #include "smc_close.h" |
| |
| /********************************** send *************************************/ |
| |
| /* handler for send/transmission completion of a CDC msg */ |
| static void smc_cdc_tx_handler(struct smc_wr_tx_pend_priv *pnd_snd, |
| struct smc_link *link, |
| enum ib_wc_status wc_status) |
| { |
| struct smc_cdc_tx_pend *cdcpend = (struct smc_cdc_tx_pend *)pnd_snd; |
| struct smc_connection *conn = cdcpend->conn; |
| struct smc_sock *smc; |
| int diff; |
| |
| smc = container_of(conn, struct smc_sock, conn); |
| bh_lock_sock(&smc->sk); |
| if (!wc_status) { |
| diff = smc_curs_diff(cdcpend->conn->sndbuf_desc->len, |
| &cdcpend->conn->tx_curs_fin, |
| &cdcpend->cursor); |
| /* sndbuf_space is decreased in smc_sendmsg */ |
| smp_mb__before_atomic(); |
| atomic_add(diff, &cdcpend->conn->sndbuf_space); |
| /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ |
| smp_mb__after_atomic(); |
| smc_curs_copy(&conn->tx_curs_fin, &cdcpend->cursor, conn); |
| smc_curs_copy(&conn->local_tx_ctrl_fin, &cdcpend->p_cursor, |
| conn); |
| conn->tx_cdc_seq_fin = cdcpend->ctrl_seq; |
| } |
| |
| if (atomic_dec_and_test(&conn->cdc_pend_tx_wr) && |
| unlikely(wq_has_sleeper(&conn->cdc_pend_tx_wq))) |
| wake_up(&conn->cdc_pend_tx_wq); |
| WARN_ON(atomic_read(&conn->cdc_pend_tx_wr) < 0); |
| |
| smc_tx_sndbuf_nonfull(smc); |
| bh_unlock_sock(&smc->sk); |
| } |
| |
| int smc_cdc_get_free_slot(struct smc_connection *conn, |
| struct smc_link *link, |
| struct smc_wr_buf **wr_buf, |
| struct smc_rdma_wr **wr_rdma_buf, |
| struct smc_cdc_tx_pend **pend) |
| { |
| int rc; |
| |
| rc = smc_wr_tx_get_free_slot(link, smc_cdc_tx_handler, wr_buf, |
| wr_rdma_buf, |
| (struct smc_wr_tx_pend_priv **)pend); |
| if (conn->killed) { |
| /* abnormal termination */ |
| if (!rc) |
| smc_wr_tx_put_slot(link, |
| (struct smc_wr_tx_pend_priv *)(*pend)); |
| rc = -EPIPE; |
| } |
| return rc; |
| } |
| |
| static inline void smc_cdc_add_pending_send(struct smc_connection *conn, |
| struct smc_cdc_tx_pend *pend) |
| { |
| BUILD_BUG_ON_MSG( |
| sizeof(struct smc_cdc_msg) > SMC_WR_BUF_SIZE, |
| "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_cdc_msg)"); |
| BUILD_BUG_ON_MSG( |
| offsetofend(struct smc_cdc_msg, reserved) > SMC_WR_TX_SIZE, |
| "must adapt SMC_WR_TX_SIZE to sizeof(struct smc_cdc_msg); if not all smc_wr upper layer protocols use the same message size any more, must start to set link->wr_tx_sges[i].length on each individual smc_wr_tx_send()"); |
| BUILD_BUG_ON_MSG( |
| sizeof(struct smc_cdc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE, |
| "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_cdc_tx_pend)"); |
| pend->conn = conn; |
| pend->cursor = conn->tx_curs_sent; |
| pend->p_cursor = conn->local_tx_ctrl.prod; |
| pend->ctrl_seq = conn->tx_cdc_seq; |
| } |
| |
| int smc_cdc_msg_send(struct smc_connection *conn, |
| struct smc_wr_buf *wr_buf, |
| struct smc_cdc_tx_pend *pend) |
| { |
| struct smc_link *link = conn->lnk; |
| union smc_host_cursor cfed; |
| int rc; |
| |
| smc_cdc_add_pending_send(conn, pend); |
| |
| conn->tx_cdc_seq++; |
| conn->local_tx_ctrl.seqno = conn->tx_cdc_seq; |
| smc_host_msg_to_cdc((struct smc_cdc_msg *)wr_buf, conn, &cfed); |
| |
| atomic_inc(&conn->cdc_pend_tx_wr); |
| smp_mb__after_atomic(); /* Make sure cdc_pend_tx_wr added before post */ |
| |
| rc = smc_wr_tx_send(link, (struct smc_wr_tx_pend_priv *)pend); |
| if (!rc) { |
| smc_curs_copy(&conn->rx_curs_confirmed, &cfed, conn); |
| conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0; |
| } else { |
| conn->tx_cdc_seq--; |
| conn->local_tx_ctrl.seqno = conn->tx_cdc_seq; |
| atomic_dec(&conn->cdc_pend_tx_wr); |
| } |
| |
| return rc; |
| } |
| |
| /* send a validation msg indicating the move of a conn to an other QP link */ |
| int smcr_cdc_msg_send_validation(struct smc_connection *conn, |
| struct smc_cdc_tx_pend *pend, |
| struct smc_wr_buf *wr_buf) |
| { |
| struct smc_host_cdc_msg *local = &conn->local_tx_ctrl; |
| struct smc_link *link = conn->lnk; |
| struct smc_cdc_msg *peer; |
| int rc; |
| |
| peer = (struct smc_cdc_msg *)wr_buf; |
| peer->common.type = local->common.type; |
| peer->len = local->len; |
| peer->seqno = htons(conn->tx_cdc_seq_fin); /* seqno last compl. tx */ |
| peer->token = htonl(local->token); |
| peer->prod_flags.failover_validation = 1; |
| |
| /* We need to set pend->conn here to make sure smc_cdc_tx_handler() |
| * can handle properly |
| */ |
| smc_cdc_add_pending_send(conn, pend); |
| |
| atomic_inc(&conn->cdc_pend_tx_wr); |
| smp_mb__after_atomic(); /* Make sure cdc_pend_tx_wr added before post */ |
| |
| rc = smc_wr_tx_send(link, (struct smc_wr_tx_pend_priv *)pend); |
| if (unlikely(rc)) |
| atomic_dec(&conn->cdc_pend_tx_wr); |
| |
| return rc; |
| } |
| |
| static int smcr_cdc_get_slot_and_msg_send(struct smc_connection *conn) |
| { |
| struct smc_cdc_tx_pend *pend; |
| struct smc_wr_buf *wr_buf; |
| struct smc_link *link; |
| bool again = false; |
| int rc; |
| |
| again: |
| link = conn->lnk; |
| if (!smc_wr_tx_link_hold(link)) |
| return -ENOLINK; |
| rc = smc_cdc_get_free_slot(conn, link, &wr_buf, NULL, &pend); |
| if (rc) |
| goto put_out; |
| |
| spin_lock_bh(&conn->send_lock); |
| if (link != conn->lnk) { |
| /* link of connection changed, try again one time*/ |
| spin_unlock_bh(&conn->send_lock); |
| smc_wr_tx_put_slot(link, |
| (struct smc_wr_tx_pend_priv *)pend); |
| smc_wr_tx_link_put(link); |
| if (again) |
| return -ENOLINK; |
| again = true; |
| goto again; |
| } |
| rc = smc_cdc_msg_send(conn, wr_buf, pend); |
| spin_unlock_bh(&conn->send_lock); |
| put_out: |
| smc_wr_tx_link_put(link); |
| return rc; |
| } |
| |
| int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn) |
| { |
| int rc; |
| |
| if (!conn->lgr || (conn->lgr->is_smcd && conn->lgr->peer_shutdown)) |
| return -EPIPE; |
| |
| if (conn->lgr->is_smcd) { |
| spin_lock_bh(&conn->send_lock); |
| rc = smcd_cdc_msg_send(conn); |
| spin_unlock_bh(&conn->send_lock); |
| } else { |
| rc = smcr_cdc_get_slot_and_msg_send(conn); |
| } |
| |
| return rc; |
| } |
| |
| void smc_cdc_wait_pend_tx_wr(struct smc_connection *conn) |
| { |
| wait_event(conn->cdc_pend_tx_wq, !atomic_read(&conn->cdc_pend_tx_wr)); |
| } |
| |
| /* Send a SMC-D CDC header. |
| * This increments the free space available in our send buffer. |
| * Also update the confirmed receive buffer with what was sent to the peer. |
| */ |
| int smcd_cdc_msg_send(struct smc_connection *conn) |
| { |
| struct smc_sock *smc = container_of(conn, struct smc_sock, conn); |
| union smc_host_cursor curs; |
| struct smcd_cdc_msg cdc; |
| int rc, diff; |
| |
| memset(&cdc, 0, sizeof(cdc)); |
| cdc.common.type = SMC_CDC_MSG_TYPE; |
| curs.acurs.counter = atomic64_read(&conn->local_tx_ctrl.prod.acurs); |
| cdc.prod.wrap = curs.wrap; |
| cdc.prod.count = curs.count; |
| curs.acurs.counter = atomic64_read(&conn->local_tx_ctrl.cons.acurs); |
| cdc.cons.wrap = curs.wrap; |
| cdc.cons.count = curs.count; |
| cdc.cons.prod_flags = conn->local_tx_ctrl.prod_flags; |
| cdc.cons.conn_state_flags = conn->local_tx_ctrl.conn_state_flags; |
| rc = smcd_tx_ism_write(conn, &cdc, sizeof(cdc), 0, 1); |
| if (rc) |
| return rc; |
| smc_curs_copy(&conn->rx_curs_confirmed, &curs, conn); |
| conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0; |
| /* Calculate transmitted data and increment free send buffer space */ |
| diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin, |
| &conn->tx_curs_sent); |
| /* increased by confirmed number of bytes */ |
| smp_mb__before_atomic(); |
| atomic_add(diff, &conn->sndbuf_space); |
| /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ |
| smp_mb__after_atomic(); |
| smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn); |
| |
| smc_tx_sndbuf_nonfull(smc); |
| return rc; |
| } |
| |
| /********************************* receive ***********************************/ |
| |
| static inline bool smc_cdc_before(u16 seq1, u16 seq2) |
| { |
| return (s16)(seq1 - seq2) < 0; |
| } |
| |
| static void smc_cdc_handle_urg_data_arrival(struct smc_sock *smc, |
| int *diff_prod) |
| { |
| struct smc_connection *conn = &smc->conn; |
| char *base; |
| |
| /* new data included urgent business */ |
| smc_curs_copy(&conn->urg_curs, &conn->local_rx_ctrl.prod, conn); |
| conn->urg_state = SMC_URG_VALID; |
| if (!sock_flag(&smc->sk, SOCK_URGINLINE)) |
| /* we'll skip the urgent byte, so don't account for it */ |
| (*diff_prod)--; |
| base = (char *)conn->rmb_desc->cpu_addr + conn->rx_off; |
| if (conn->urg_curs.count) |
| conn->urg_rx_byte = *(base + conn->urg_curs.count - 1); |
| else |
| conn->urg_rx_byte = *(base + conn->rmb_desc->len - 1); |
| sk_send_sigurg(&smc->sk); |
| } |
| |
| static void smc_cdc_msg_validate(struct smc_sock *smc, struct smc_cdc_msg *cdc, |
| struct smc_link *link) |
| { |
| struct smc_connection *conn = &smc->conn; |
| u16 recv_seq = ntohs(cdc->seqno); |
| s16 diff; |
| |
| /* check that seqnum was seen before */ |
| diff = conn->local_rx_ctrl.seqno - recv_seq; |
| if (diff < 0) { /* diff larger than 0x7fff */ |
| /* drop connection */ |
| conn->out_of_sync = 1; /* prevent any further receives */ |
| spin_lock_bh(&conn->send_lock); |
| conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; |
| conn->lnk = link; |
| spin_unlock_bh(&conn->send_lock); |
| sock_hold(&smc->sk); /* sock_put in abort_work */ |
| if (!queue_work(smc_close_wq, &conn->abort_work)) |
| sock_put(&smc->sk); |
| } |
| } |
| |
| static void smc_cdc_msg_recv_action(struct smc_sock *smc, |
| struct smc_cdc_msg *cdc) |
| { |
| union smc_host_cursor cons_old, prod_old; |
| struct smc_connection *conn = &smc->conn; |
| int diff_cons, diff_prod; |
| |
| smc_curs_copy(&prod_old, &conn->local_rx_ctrl.prod, conn); |
| smc_curs_copy(&cons_old, &conn->local_rx_ctrl.cons, conn); |
| smc_cdc_msg_to_host(&conn->local_rx_ctrl, cdc, conn); |
| |
| diff_cons = smc_curs_diff(conn->peer_rmbe_size, &cons_old, |
| &conn->local_rx_ctrl.cons); |
| if (diff_cons) { |
| /* peer_rmbe_space is decreased during data transfer with RDMA |
| * write |
| */ |
| smp_mb__before_atomic(); |
| atomic_add(diff_cons, &conn->peer_rmbe_space); |
| /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ |
| smp_mb__after_atomic(); |
| } |
| |
| diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old, |
| &conn->local_rx_ctrl.prod); |
| if (diff_prod) { |
| if (conn->local_rx_ctrl.prod_flags.urg_data_present) |
| smc_cdc_handle_urg_data_arrival(smc, &diff_prod); |
| /* bytes_to_rcv is decreased in smc_recvmsg */ |
| smp_mb__before_atomic(); |
| atomic_add(diff_prod, &conn->bytes_to_rcv); |
| /* guarantee 0 <= bytes_to_rcv <= rmb_desc->len */ |
| smp_mb__after_atomic(); |
| smc->sk.sk_data_ready(&smc->sk); |
| } else { |
| if (conn->local_rx_ctrl.prod_flags.write_blocked) |
| smc->sk.sk_data_ready(&smc->sk); |
| if (conn->local_rx_ctrl.prod_flags.urg_data_pending) |
| conn->urg_state = SMC_URG_NOTYET; |
| } |
| |
| /* trigger sndbuf consumer: RDMA write into peer RMBE and CDC */ |
| if ((diff_cons && smc_tx_prepared_sends(conn)) || |
| conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || |
| conn->local_rx_ctrl.prod_flags.urg_data_pending) |
| smc_tx_sndbuf_nonempty(conn); |
| |
| if (diff_cons && conn->urg_tx_pend && |
| atomic_read(&conn->peer_rmbe_space) == conn->peer_rmbe_size) { |
| /* urg data confirmed by peer, indicate we're ready for more */ |
| conn->urg_tx_pend = false; |
| smc->sk.sk_write_space(&smc->sk); |
| } |
| |
| if (conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) { |
| smc->sk.sk_err = ECONNRESET; |
| conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; |
| } |
| if (smc_cdc_rxed_any_close_or_senddone(conn)) { |
| smc->sk.sk_shutdown |= RCV_SHUTDOWN; |
| if (smc->clcsock && smc->clcsock->sk) |
| smc->clcsock->sk->sk_shutdown |= RCV_SHUTDOWN; |
| sock_set_flag(&smc->sk, SOCK_DONE); |
| sock_hold(&smc->sk); /* sock_put in close_work */ |
| if (!queue_work(smc_close_wq, &conn->close_work)) |
| sock_put(&smc->sk); |
| } |
| } |
| |
| /* called under tasklet context */ |
| static void smc_cdc_msg_recv(struct smc_sock *smc, struct smc_cdc_msg *cdc) |
| { |
| sock_hold(&smc->sk); |
| bh_lock_sock(&smc->sk); |
| smc_cdc_msg_recv_action(smc, cdc); |
| bh_unlock_sock(&smc->sk); |
| sock_put(&smc->sk); /* no free sk in softirq-context */ |
| } |
| |
| /* Schedule a tasklet for this connection. Triggered from the ISM device IRQ |
| * handler to indicate update in the DMBE. |
| * |
| * Context: |
| * - tasklet context |
| */ |
| static void smcd_cdc_rx_tsklet(struct tasklet_struct *t) |
| { |
| struct smc_connection *conn = from_tasklet(conn, t, rx_tsklet); |
| struct smcd_cdc_msg *data_cdc; |
| struct smcd_cdc_msg cdc; |
| struct smc_sock *smc; |
| |
| if (!conn || conn->killed) |
| return; |
| |
| data_cdc = (struct smcd_cdc_msg *)conn->rmb_desc->cpu_addr; |
| smcd_curs_copy(&cdc.prod, &data_cdc->prod, conn); |
| smcd_curs_copy(&cdc.cons, &data_cdc->cons, conn); |
| smc = container_of(conn, struct smc_sock, conn); |
| smc_cdc_msg_recv(smc, (struct smc_cdc_msg *)&cdc); |
| } |
| |
| /* Initialize receive tasklet. Called from ISM device IRQ handler to start |
| * receiver side. |
| */ |
| void smcd_cdc_rx_init(struct smc_connection *conn) |
| { |
| tasklet_setup(&conn->rx_tsklet, smcd_cdc_rx_tsklet); |
| } |
| |
| /***************************** init, exit, misc ******************************/ |
| |
| static void smc_cdc_rx_handler(struct ib_wc *wc, void *buf) |
| { |
| struct smc_link *link = (struct smc_link *)wc->qp->qp_context; |
| struct smc_cdc_msg *cdc = buf; |
| struct smc_connection *conn; |
| struct smc_link_group *lgr; |
| struct smc_sock *smc; |
| |
| if (wc->byte_len < offsetof(struct smc_cdc_msg, reserved)) |
| return; /* short message */ |
| if (cdc->len != SMC_WR_TX_SIZE) |
| return; /* invalid message */ |
| |
| /* lookup connection */ |
| lgr = smc_get_lgr(link); |
| read_lock_bh(&lgr->conns_lock); |
| conn = smc_lgr_find_conn(ntohl(cdc->token), lgr); |
| read_unlock_bh(&lgr->conns_lock); |
| if (!conn || conn->out_of_sync) |
| return; |
| smc = container_of(conn, struct smc_sock, conn); |
| |
| if (cdc->prod_flags.failover_validation) { |
| smc_cdc_msg_validate(smc, cdc, link); |
| return; |
| } |
| if (smc_cdc_before(ntohs(cdc->seqno), |
| conn->local_rx_ctrl.seqno)) |
| /* received seqno is old */ |
| return; |
| |
| smc_cdc_msg_recv(smc, cdc); |
| } |
| |
| static struct smc_wr_rx_handler smc_cdc_rx_handlers[] = { |
| { |
| .handler = smc_cdc_rx_handler, |
| .type = SMC_CDC_MSG_TYPE |
| }, |
| { |
| .handler = NULL, |
| } |
| }; |
| |
| int __init smc_cdc_init(void) |
| { |
| struct smc_wr_rx_handler *handler; |
| int rc = 0; |
| |
| for (handler = smc_cdc_rx_handlers; handler->handler; handler++) { |
| INIT_HLIST_NODE(&handler->list); |
| rc = smc_wr_rx_register_handler(handler); |
| if (rc) |
| break; |
| } |
| return rc; |
| } |