linux-stable/net/smc/smc_cdc.c
Ursula Braun 50c6b20eff net/smc: fix final cleanup sequence for SMCD devices
If peer announces shutdown, use the link group terminate worker for
local cleanup of link groups and connections to terminate link group
in proper context.

Make sure link groups are cleaned up first before destroying the
event queue of the SMCD device, because link group cleanup may
raise events.

Send signal shutdown only if peer has not done it already.

Send socket abort or close only, if peer has not already announced
shutdown.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-15 12:28:28 -08:00

407 lines
12 KiB
C

// 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 *************************************/
/* 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_rdma_wr **wr_rdma_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,
wr_rdma_buf,
(struct smc_wr_tx_pend_priv **)pend);
if (conn->killed)
/* 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(
offsetofend(struct smc_cdc_msg, reserved) > 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)
{
union smc_host_cursor cfed;
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, &cfed);
rc = smc_wr_tx_send(link, (struct smc_wr_tx_pend_priv *)pend);
if (!rc) {
smc_curs_copy(&conn->rx_curs_confirmed, &cfed, conn);
conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0;
}
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, NULL, &pend);
if (rc)
return rc;
spin_lock_bh(&conn->send_lock);
rc = smc_cdc_msg_send(conn, wr_buf, pend);
spin_unlock_bh(&conn->send_lock);
return rc;
}
int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn)
{
int rc;
if (!conn->lgr || (conn->lgr->is_smcd && conn->lgr->peer_shutdown))
return -EPIPE;
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);
union smc_host_cursor curs;
struct smcd_cdc_msg cdc;
int rc, diff;
memset(&cdc, 0, sizeof(cdc));
cdc.common.type = SMC_CDC_MSG_TYPE;
curs.acurs.counter = atomic64_read(&conn->local_tx_ctrl.prod.acurs);
cdc.prod.wrap = curs.wrap;
cdc.prod.count = curs.count;
curs.acurs.counter = atomic64_read(&conn->local_tx_ctrl.cons.acurs);
cdc.cons.wrap = curs.wrap;
cdc.cons.count = curs.count;
cdc.cons.prod_flags = conn->local_tx_ctrl.prod_flags;
cdc.cons.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, &curs, conn);
conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0;
/* 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)
smc->sk.sk_data_ready(&smc->sk);
if (conn->local_rx_ctrl.prod_flags.urg_data_pending)
conn->urg_state = SMC_URG_NOTYET;
}
/* trigger sndbuf consumer: RDMA write into peer RMBE and CDC */
if ((diff_cons && smc_tx_prepared_sends(conn)) ||
conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
conn->local_rx_ctrl.prod_flags.urg_data_pending)
smc_tx_sndbuf_nonempty(conn);
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 *data_cdc;
struct smcd_cdc_msg cdc;
struct smc_sock *smc;
if (!conn || conn->killed)
return;
data_cdc = (struct smcd_cdc_msg *)conn->rmb_desc->cpu_addr;
smcd_curs_copy(&cdc.prod, &data_cdc->prod, conn);
smcd_curs_copy(&cdc.cons, &data_cdc->cons, conn);
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;
}