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