v4.19.13 snapshot.
diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
new file mode 100644
index 0000000..ed5dcf0
--- /dev/null
+++ b/net/smc/smc_cdc.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ * Connection Data Control (CDC)
+ * handles flow control
+ *
+ * Copyright IBM Corp. 2016
+ *
+ * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
+ */
+
+#include <linux/spinlock.h>
+
+#include "smc.h"
+#include "smc_wr.h"
+#include "smc_cdc.h"
+#include "smc_tx.h"
+#include "smc_rx.h"
+#include "smc_close.h"
+
+/********************************** send *************************************/
+
+struct smc_cdc_tx_pend {
+ struct smc_connection *conn; /* socket connection */
+ union smc_host_cursor cursor; /* tx sndbuf cursor sent */
+ union smc_host_cursor p_cursor; /* rx RMBE cursor produced */
+ u16 ctrl_seq; /* conn. tx sequence # */
+};
+
+/* handler for send/transmission completion of a CDC msg */
+static void smc_cdc_tx_handler(struct smc_wr_tx_pend_priv *pnd_snd,
+ struct smc_link *link,
+ enum ib_wc_status wc_status)
+{
+ struct smc_cdc_tx_pend *cdcpend = (struct smc_cdc_tx_pend *)pnd_snd;
+ struct smc_connection *conn = cdcpend->conn;
+ struct smc_sock *smc;
+ int diff;
+
+ if (!conn)
+ /* already dismissed */
+ return;
+
+ smc = container_of(conn, struct smc_sock, conn);
+ bh_lock_sock(&smc->sk);
+ if (!wc_status) {
+ diff = smc_curs_diff(cdcpend->conn->sndbuf_desc->len,
+ &cdcpend->conn->tx_curs_fin,
+ &cdcpend->cursor);
+ /* sndbuf_space is decreased in smc_sendmsg */
+ smp_mb__before_atomic();
+ atomic_add(diff, &cdcpend->conn->sndbuf_space);
+ /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
+ smp_mb__after_atomic();
+ smc_curs_copy(&conn->tx_curs_fin, &cdcpend->cursor, conn);
+ }
+ smc_tx_sndbuf_nonfull(smc);
+ bh_unlock_sock(&smc->sk);
+}
+
+int smc_cdc_get_free_slot(struct smc_connection *conn,
+ struct smc_wr_buf **wr_buf,
+ struct smc_cdc_tx_pend **pend)
+{
+ struct smc_link *link = &conn->lgr->lnk[SMC_SINGLE_LINK];
+ int rc;
+
+ rc = smc_wr_tx_get_free_slot(link, smc_cdc_tx_handler, wr_buf,
+ (struct smc_wr_tx_pend_priv **)pend);
+ if (!conn->alert_token_local)
+ /* abnormal termination */
+ rc = -EPIPE;
+ return rc;
+}
+
+static inline void smc_cdc_add_pending_send(struct smc_connection *conn,
+ struct smc_cdc_tx_pend *pend)
+{
+ BUILD_BUG_ON_MSG(
+ sizeof(struct smc_cdc_msg) > SMC_WR_BUF_SIZE,
+ "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_cdc_msg)");
+ BUILD_BUG_ON_MSG(
+ sizeof(struct smc_cdc_msg) != SMC_WR_TX_SIZE,
+ "must adapt SMC_WR_TX_SIZE to sizeof(struct smc_cdc_msg); if not all smc_wr upper layer protocols use the same message size any more, must start to set link->wr_tx_sges[i].length on each individual smc_wr_tx_send()");
+ BUILD_BUG_ON_MSG(
+ sizeof(struct smc_cdc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
+ "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_cdc_tx_pend)");
+ pend->conn = conn;
+ pend->cursor = conn->tx_curs_sent;
+ pend->p_cursor = conn->local_tx_ctrl.prod;
+ pend->ctrl_seq = conn->tx_cdc_seq;
+}
+
+int smc_cdc_msg_send(struct smc_connection *conn,
+ struct smc_wr_buf *wr_buf,
+ struct smc_cdc_tx_pend *pend)
+{
+ struct smc_link *link;
+ int rc;
+
+ link = &conn->lgr->lnk[SMC_SINGLE_LINK];
+
+ smc_cdc_add_pending_send(conn, pend);
+
+ conn->tx_cdc_seq++;
+ conn->local_tx_ctrl.seqno = conn->tx_cdc_seq;
+ smc_host_msg_to_cdc((struct smc_cdc_msg *)wr_buf,
+ &conn->local_tx_ctrl, conn);
+ rc = smc_wr_tx_send(link, (struct smc_wr_tx_pend_priv *)pend);
+ if (!rc)
+ smc_curs_copy(&conn->rx_curs_confirmed,
+ &conn->local_tx_ctrl.cons, conn);
+
+ return rc;
+}
+
+static int smcr_cdc_get_slot_and_msg_send(struct smc_connection *conn)
+{
+ struct smc_cdc_tx_pend *pend;
+ struct smc_wr_buf *wr_buf;
+ int rc;
+
+ rc = smc_cdc_get_free_slot(conn, &wr_buf, &pend);
+ if (rc)
+ return rc;
+
+ return smc_cdc_msg_send(conn, wr_buf, pend);
+}
+
+int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn)
+{
+ int rc;
+
+ if (conn->lgr->is_smcd) {
+ spin_lock_bh(&conn->send_lock);
+ rc = smcd_cdc_msg_send(conn);
+ spin_unlock_bh(&conn->send_lock);
+ } else {
+ rc = smcr_cdc_get_slot_and_msg_send(conn);
+ }
+
+ return rc;
+}
+
+static bool smc_cdc_tx_filter(struct smc_wr_tx_pend_priv *tx_pend,
+ unsigned long data)
+{
+ struct smc_connection *conn = (struct smc_connection *)data;
+ struct smc_cdc_tx_pend *cdc_pend =
+ (struct smc_cdc_tx_pend *)tx_pend;
+
+ return cdc_pend->conn == conn;
+}
+
+static void smc_cdc_tx_dismisser(struct smc_wr_tx_pend_priv *tx_pend)
+{
+ struct smc_cdc_tx_pend *cdc_pend =
+ (struct smc_cdc_tx_pend *)tx_pend;
+
+ cdc_pend->conn = NULL;
+}
+
+void smc_cdc_tx_dismiss_slots(struct smc_connection *conn)
+{
+ struct smc_link *link = &conn->lgr->lnk[SMC_SINGLE_LINK];
+
+ smc_wr_tx_dismiss_slots(link, SMC_CDC_MSG_TYPE,
+ smc_cdc_tx_filter, smc_cdc_tx_dismisser,
+ (unsigned long)conn);
+}
+
+/* Send a SMC-D CDC header.
+ * This increments the free space available in our send buffer.
+ * Also update the confirmed receive buffer with what was sent to the peer.
+ */
+int smcd_cdc_msg_send(struct smc_connection *conn)
+{
+ struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
+ struct smcd_cdc_msg cdc;
+ int rc, diff;
+
+ memset(&cdc, 0, sizeof(cdc));
+ cdc.common.type = SMC_CDC_MSG_TYPE;
+ cdc.prod_wrap = conn->local_tx_ctrl.prod.wrap;
+ cdc.prod_count = conn->local_tx_ctrl.prod.count;
+
+ cdc.cons_wrap = conn->local_tx_ctrl.cons.wrap;
+ cdc.cons_count = conn->local_tx_ctrl.cons.count;
+ cdc.prod_flags = conn->local_tx_ctrl.prod_flags;
+ cdc.conn_state_flags = conn->local_tx_ctrl.conn_state_flags;
+ rc = smcd_tx_ism_write(conn, &cdc, sizeof(cdc), 0, 1);
+ if (rc)
+ return rc;
+ smc_curs_copy(&conn->rx_curs_confirmed, &conn->local_tx_ctrl.cons,
+ conn);
+ /* Calculate transmitted data and increment free send buffer space */
+ diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin,
+ &conn->tx_curs_sent);
+ /* increased by confirmed number of bytes */
+ smp_mb__before_atomic();
+ atomic_add(diff, &conn->sndbuf_space);
+ /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
+ smp_mb__after_atomic();
+ smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn);
+
+ smc_tx_sndbuf_nonfull(smc);
+ return rc;
+}
+
+/********************************* receive ***********************************/
+
+static inline bool smc_cdc_before(u16 seq1, u16 seq2)
+{
+ return (s16)(seq1 - seq2) < 0;
+}
+
+static void smc_cdc_handle_urg_data_arrival(struct smc_sock *smc,
+ int *diff_prod)
+{
+ struct smc_connection *conn = &smc->conn;
+ char *base;
+
+ /* new data included urgent business */
+ smc_curs_copy(&conn->urg_curs, &conn->local_rx_ctrl.prod, conn);
+ conn->urg_state = SMC_URG_VALID;
+ if (!sock_flag(&smc->sk, SOCK_URGINLINE))
+ /* we'll skip the urgent byte, so don't account for it */
+ (*diff_prod)--;
+ base = (char *)conn->rmb_desc->cpu_addr + conn->rx_off;
+ if (conn->urg_curs.count)
+ conn->urg_rx_byte = *(base + conn->urg_curs.count - 1);
+ else
+ conn->urg_rx_byte = *(base + conn->rmb_desc->len - 1);
+ sk_send_sigurg(&smc->sk);
+}
+
+static void smc_cdc_msg_recv_action(struct smc_sock *smc,
+ struct smc_cdc_msg *cdc)
+{
+ union smc_host_cursor cons_old, prod_old;
+ struct smc_connection *conn = &smc->conn;
+ int diff_cons, diff_prod;
+
+ smc_curs_copy(&prod_old, &conn->local_rx_ctrl.prod, conn);
+ smc_curs_copy(&cons_old, &conn->local_rx_ctrl.cons, conn);
+ smc_cdc_msg_to_host(&conn->local_rx_ctrl, cdc, conn);
+
+ diff_cons = smc_curs_diff(conn->peer_rmbe_size, &cons_old,
+ &conn->local_rx_ctrl.cons);
+ if (diff_cons) {
+ /* peer_rmbe_space is decreased during data transfer with RDMA
+ * write
+ */
+ smp_mb__before_atomic();
+ atomic_add(diff_cons, &conn->peer_rmbe_space);
+ /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */
+ smp_mb__after_atomic();
+ }
+
+ diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old,
+ &conn->local_rx_ctrl.prod);
+ if (diff_prod) {
+ if (conn->local_rx_ctrl.prod_flags.urg_data_present)
+ smc_cdc_handle_urg_data_arrival(smc, &diff_prod);
+ /* bytes_to_rcv is decreased in smc_recvmsg */
+ smp_mb__before_atomic();
+ atomic_add(diff_prod, &conn->bytes_to_rcv);
+ /* guarantee 0 <= bytes_to_rcv <= rmb_desc->len */
+ smp_mb__after_atomic();
+ smc->sk.sk_data_ready(&smc->sk);
+ } else {
+ if (conn->local_rx_ctrl.prod_flags.write_blocked ||
+ conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
+ conn->local_rx_ctrl.prod_flags.urg_data_pending) {
+ if (conn->local_rx_ctrl.prod_flags.urg_data_pending)
+ conn->urg_state = SMC_URG_NOTYET;
+ /* force immediate tx of current consumer cursor, but
+ * under send_lock to guarantee arrival in seqno-order
+ */
+ if (smc->sk.sk_state != SMC_INIT)
+ smc_tx_sndbuf_nonempty(conn);
+ }
+ }
+
+ /* piggy backed tx info */
+ /* trigger sndbuf consumer: RDMA write into peer RMBE and CDC */
+ if (diff_cons && smc_tx_prepared_sends(conn)) {
+ smc_tx_sndbuf_nonempty(conn);
+ /* trigger socket release if connection closed */
+ smc_close_wake_tx_prepared(smc);
+ }
+ if (diff_cons && conn->urg_tx_pend &&
+ atomic_read(&conn->peer_rmbe_space) == conn->peer_rmbe_size) {
+ /* urg data confirmed by peer, indicate we're ready for more */
+ conn->urg_tx_pend = false;
+ smc->sk.sk_write_space(&smc->sk);
+ }
+
+ if (conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) {
+ smc->sk.sk_err = ECONNRESET;
+ conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
+ }
+ if (smc_cdc_rxed_any_close_or_senddone(conn)) {
+ smc->sk.sk_shutdown |= RCV_SHUTDOWN;
+ if (smc->clcsock && smc->clcsock->sk)
+ smc->clcsock->sk->sk_shutdown |= RCV_SHUTDOWN;
+ sock_set_flag(&smc->sk, SOCK_DONE);
+ sock_hold(&smc->sk); /* sock_put in close_work */
+ if (!schedule_work(&conn->close_work))
+ sock_put(&smc->sk);
+ }
+}
+
+/* called under tasklet context */
+static void smc_cdc_msg_recv(struct smc_sock *smc, struct smc_cdc_msg *cdc)
+{
+ sock_hold(&smc->sk);
+ bh_lock_sock(&smc->sk);
+ smc_cdc_msg_recv_action(smc, cdc);
+ bh_unlock_sock(&smc->sk);
+ sock_put(&smc->sk); /* no free sk in softirq-context */
+}
+
+/* Schedule a tasklet for this connection. Triggered from the ISM device IRQ
+ * handler to indicate update in the DMBE.
+ *
+ * Context:
+ * - tasklet context
+ */
+static void smcd_cdc_rx_tsklet(unsigned long data)
+{
+ struct smc_connection *conn = (struct smc_connection *)data;
+ struct smcd_cdc_msg cdc;
+ struct smc_sock *smc;
+
+ if (!conn)
+ return;
+
+ memcpy(&cdc, conn->rmb_desc->cpu_addr, sizeof(cdc));
+ smc = container_of(conn, struct smc_sock, conn);
+ smc_cdc_msg_recv(smc, (struct smc_cdc_msg *)&cdc);
+}
+
+/* Initialize receive tasklet. Called from ISM device IRQ handler to start
+ * receiver side.
+ */
+void smcd_cdc_rx_init(struct smc_connection *conn)
+{
+ tasklet_init(&conn->rx_tsklet, smcd_cdc_rx_tsklet, (unsigned long)conn);
+}
+
+/***************************** init, exit, misc ******************************/
+
+static void smc_cdc_rx_handler(struct ib_wc *wc, void *buf)
+{
+ struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
+ struct smc_cdc_msg *cdc = buf;
+ struct smc_connection *conn;
+ struct smc_link_group *lgr;
+ struct smc_sock *smc;
+
+ if (wc->byte_len < offsetof(struct smc_cdc_msg, reserved))
+ return; /* short message */
+ if (cdc->len != SMC_WR_TX_SIZE)
+ return; /* invalid message */
+
+ /* lookup connection */
+ lgr = smc_get_lgr(link);
+ read_lock_bh(&lgr->conns_lock);
+ conn = smc_lgr_find_conn(ntohl(cdc->token), lgr);
+ read_unlock_bh(&lgr->conns_lock);
+ if (!conn)
+ return;
+ smc = container_of(conn, struct smc_sock, conn);
+
+ if (!cdc->prod_flags.failover_validation) {
+ 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;
+}