net/smc: urgent data support
Add support for out of band data send and receive.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
index 8d2c079..a7e8d63 100644
--- a/net/smc/smc_cdc.c
+++ b/net/smc/smc_cdc.c
@@ -164,6 +164,28 @@ 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_write(&conn->urg_curs,
+ smc_curs_read(&conn->local_rx_ctrl.prod, conn),
+ 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;
+ 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)
{
@@ -194,15 +216,25 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc,
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)) {
- 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
+ */
+ smc_tx_sndbuf_nonempty(conn);
+ }
}
/* piggy backed tx info */
@@ -212,6 +244,12 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc,
/* 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;