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![Allen Pais](/assets/img/avatar_default.png)
In preparation for unconditionally passing the struct tasklet_struct pointer to all tasklet callbacks, switch to using the new tasklet_setup() and from_tasklet() to pass the tasklet pointer explicitly. Signed-off-by: Romain Perier <romain.perier@gmail.com> Signed-off-by: Allen Pais <apais@linux.microsoft.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
475 lines
14 KiB
C
475 lines
14 KiB
C
// 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 <ubraun@linux.vnet.ibm.com>
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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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if (!conn)
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/* already dismissed */
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return;
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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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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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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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}
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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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rc = smc_wr_tx_send(link, (struct smc_wr_tx_pend_priv *)pend);
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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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rc = smc_cdc_get_free_slot(conn, link, &wr_buf, NULL, &pend);
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if (rc)
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return rc;
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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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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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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 (!conn->lgr || (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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static bool smc_cdc_tx_filter(struct smc_wr_tx_pend_priv *tx_pend,
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unsigned long data)
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{
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struct smc_connection *conn = (struct smc_connection *)data;
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struct smc_cdc_tx_pend *cdc_pend =
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(struct smc_cdc_tx_pend *)tx_pend;
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return cdc_pend->conn == conn;
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}
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static void smc_cdc_tx_dismisser(struct smc_wr_tx_pend_priv *tx_pend)
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{
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struct smc_cdc_tx_pend *cdc_pend =
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(struct smc_cdc_tx_pend *)tx_pend;
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cdc_pend->conn = NULL;
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}
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void smc_cdc_tx_dismiss_slots(struct smc_connection *conn)
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{
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struct smc_link *link = conn->lnk;
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smc_wr_tx_dismiss_slots(link, SMC_CDC_MSG_TYPE,
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smc_cdc_tx_filter, smc_cdc_tx_dismisser,
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(unsigned long)conn);
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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);
|
|
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;
|
|
}
|