305 lines
8.5 KiB
C
305 lines
8.5 KiB
C
/*
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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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struct smc_cdc_tx_pend {
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struct smc_connection *conn; /* socket connection */
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union smc_host_cursor cursor; /* tx sndbuf cursor sent */
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union smc_host_cursor p_cursor; /* rx RMBE cursor produced */
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u16 ctrl_seq; /* conn. tx sequence # */
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};
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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_sock *smc;
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int diff;
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if (!cdcpend->conn)
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/* already dismissed */
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return;
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smc = container_of(cdcpend->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_size,
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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_size */
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smp_mb__after_atomic();
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smc_curs_write(&cdcpend->conn->tx_curs_fin,
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smc_curs_read(&cdcpend->cursor, cdcpend->conn),
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cdcpend->conn);
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}
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smc_tx_sndbuf_nonfull(smc);
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if (smc->sk.sk_state != SMC_ACTIVE)
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/* wake up smc_close_wait_tx_pends() */
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smc->sk.sk_state_change(&smc->sk);
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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_link *link,
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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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return smc_wr_tx_get_free_slot(link, smc_cdc_tx_handler, wr_buf,
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(struct smc_wr_tx_pend_priv **)pend);
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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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offsetof(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;
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int rc;
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link = &conn->lgr->lnk[SMC_SINGLE_LINK];
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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,
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&conn->local_tx_ctrl, conn);
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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_write(&conn->rx_curs_confirmed,
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smc_curs_read(&conn->local_tx_ctrl.cons, conn),
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conn);
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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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struct smc_cdc_tx_pend *pend;
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struct smc_wr_buf *wr_buf;
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int rc;
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rc = smc_cdc_get_free_slot(&conn->lgr->lnk[SMC_SINGLE_LINK], &wr_buf,
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&pend);
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if (rc)
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return rc;
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return smc_cdc_msg_send(conn, wr_buf, pend);
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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->lgr->lnk[SMC_SINGLE_LINK];
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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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bool smc_cdc_tx_has_pending(struct smc_connection *conn)
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{
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struct smc_link *link = &conn->lgr->lnk[SMC_SINGLE_LINK];
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return smc_wr_tx_has_pending(link, SMC_CDC_MSG_TYPE,
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smc_cdc_tx_filter, (unsigned long)conn);
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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_msg_recv_action(struct smc_sock *smc,
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struct smc_link *link,
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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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if (!cdc->prod_flags.failover_validation) {
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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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}
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smc_curs_write(&prod_old,
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smc_curs_read(&conn->local_rx_ctrl.prod, conn),
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conn);
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smc_curs_write(&cons_old,
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smc_curs_read(&conn->local_rx_ctrl.cons, conn),
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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->rmbe_size, &prod_old,
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&conn->local_rx_ctrl.prod);
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if (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 <= rmbe_size */
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smp_mb__after_atomic();
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smc->sk.sk_data_ready(&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_close_passive_received(smc);
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/* piggy backed tx info */
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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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smc_tx_sndbuf_nonempty(conn);
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/* trigger socket release if connection closed */
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smc_close_wake_tx_prepared(smc);
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}
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/* subsequent patch: trigger socket release if connection closed */
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/* socket connected but not accepted */
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if (!smc->sk.sk_socket)
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return;
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/* data available */
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if ((conn->local_rx_ctrl.prod_flags.write_blocked) ||
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(conn->local_rx_ctrl.prod_flags.cons_curs_upd_req))
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smc_tx_consumer_update(conn);
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}
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/* called under tasklet context */
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static inline void smc_cdc_msg_recv(struct smc_cdc_msg *cdc,
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struct smc_link *link, u64 wr_id)
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{
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struct smc_link_group *lgr = container_of(link, struct smc_link_group,
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lnk[SMC_SINGLE_LINK]);
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struct smc_connection *connection;
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struct smc_sock *smc;
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/* lookup connection */
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read_lock_bh(&lgr->conns_lock);
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connection = smc_lgr_find_conn(ntohl(cdc->token), lgr);
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if (!connection) {
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read_unlock_bh(&lgr->conns_lock);
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return;
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}
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smc = container_of(connection, struct smc_sock, conn);
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sock_hold(&smc->sk);
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read_unlock_bh(&lgr->conns_lock);
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bh_lock_sock(&smc->sk);
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smc_cdc_msg_recv_action(smc, link, 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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/***************************** 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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if (wc->byte_len < offsetof(struct smc_cdc_msg, reserved))
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return; /* short message */
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if (cdc->len != sizeof(*cdc))
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return; /* invalid message */
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smc_cdc_msg_recv(cdc, link, wc->wr_id);
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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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