mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 17:59:32 +00:00
![David Howells](/assets/img/avatar_default.png)
Drop the smc_sendpage() code as smc_sendmsg() just passes the call down to the underlying TCP socket and smc_tx_sendpage() is just a wrapper around its sendmsg implementation. Signed-off-by: David Howells <dhowells@redhat.com> cc: Karsten Graul <kgraul@linux.ibm.com> cc: Wenjia Zhang <wenjia@linux.ibm.com> cc: Jan Karcher <jaka@linux.ibm.com> cc: "D. Wythe" <alibuda@linux.alibaba.com> cc: Tony Lu <tonylu@linux.alibaba.com> cc: Wen Gu <guwen@linux.alibaba.com> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Link: https://lore.kernel.org/r/20230623225513.2732256-10-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
762 lines
22 KiB
C
762 lines
22 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Shared Memory Communications over RDMA (SMC-R) and RoCE
|
|
*
|
|
* Manage send buffer.
|
|
* Producer:
|
|
* Copy user space data into send buffer, if send buffer space available.
|
|
* Consumer:
|
|
* Trigger RDMA write into RMBE of peer and send CDC, if RMBE space available.
|
|
*
|
|
* Copyright IBM Corp. 2016
|
|
*
|
|
* Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
|
|
*/
|
|
|
|
#include <linux/net.h>
|
|
#include <linux/rcupdate.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/sched/signal.h>
|
|
|
|
#include <net/sock.h>
|
|
#include <net/tcp.h>
|
|
|
|
#include "smc.h"
|
|
#include "smc_wr.h"
|
|
#include "smc_cdc.h"
|
|
#include "smc_close.h"
|
|
#include "smc_ism.h"
|
|
#include "smc_tx.h"
|
|
#include "smc_stats.h"
|
|
#include "smc_tracepoint.h"
|
|
|
|
#define SMC_TX_WORK_DELAY 0
|
|
|
|
/***************************** sndbuf producer *******************************/
|
|
|
|
/* callback implementation for sk.sk_write_space()
|
|
* to wakeup sndbuf producers that blocked with smc_tx_wait().
|
|
* called under sk_socket lock.
|
|
*/
|
|
static void smc_tx_write_space(struct sock *sk)
|
|
{
|
|
struct socket *sock = sk->sk_socket;
|
|
struct smc_sock *smc = smc_sk(sk);
|
|
struct socket_wq *wq;
|
|
|
|
/* similar to sk_stream_write_space */
|
|
if (atomic_read(&smc->conn.sndbuf_space) && sock) {
|
|
if (test_bit(SOCK_NOSPACE, &sock->flags))
|
|
SMC_STAT_RMB_TX_FULL(smc, !smc->conn.lnk);
|
|
clear_bit(SOCK_NOSPACE, &sock->flags);
|
|
rcu_read_lock();
|
|
wq = rcu_dereference(sk->sk_wq);
|
|
if (skwq_has_sleeper(wq))
|
|
wake_up_interruptible_poll(&wq->wait,
|
|
EPOLLOUT | EPOLLWRNORM |
|
|
EPOLLWRBAND);
|
|
if (wq && wq->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN))
|
|
sock_wake_async(wq, SOCK_WAKE_SPACE, POLL_OUT);
|
|
rcu_read_unlock();
|
|
}
|
|
}
|
|
|
|
/* Wakeup sndbuf producers that blocked with smc_tx_wait().
|
|
* Cf. tcp_data_snd_check()=>tcp_check_space()=>tcp_new_space().
|
|
*/
|
|
void smc_tx_sndbuf_nonfull(struct smc_sock *smc)
|
|
{
|
|
if (smc->sk.sk_socket &&
|
|
test_bit(SOCK_NOSPACE, &smc->sk.sk_socket->flags))
|
|
smc->sk.sk_write_space(&smc->sk);
|
|
}
|
|
|
|
/* blocks sndbuf producer until at least one byte of free space available
|
|
* or urgent Byte was consumed
|
|
*/
|
|
static int smc_tx_wait(struct smc_sock *smc, int flags)
|
|
{
|
|
DEFINE_WAIT_FUNC(wait, woken_wake_function);
|
|
struct smc_connection *conn = &smc->conn;
|
|
struct sock *sk = &smc->sk;
|
|
long timeo;
|
|
int rc = 0;
|
|
|
|
/* similar to sk_stream_wait_memory */
|
|
timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
|
|
add_wait_queue(sk_sleep(sk), &wait);
|
|
while (1) {
|
|
sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
|
|
if (sk->sk_err ||
|
|
(sk->sk_shutdown & SEND_SHUTDOWN) ||
|
|
conn->killed ||
|
|
conn->local_tx_ctrl.conn_state_flags.peer_done_writing) {
|
|
rc = -EPIPE;
|
|
break;
|
|
}
|
|
if (smc_cdc_rxed_any_close(conn)) {
|
|
rc = -ECONNRESET;
|
|
break;
|
|
}
|
|
if (!timeo) {
|
|
/* ensure EPOLLOUT is subsequently generated */
|
|
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
|
|
rc = -EAGAIN;
|
|
break;
|
|
}
|
|
if (signal_pending(current)) {
|
|
rc = sock_intr_errno(timeo);
|
|
break;
|
|
}
|
|
sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
|
|
if (atomic_read(&conn->sndbuf_space) && !conn->urg_tx_pend)
|
|
break; /* at least 1 byte of free & no urgent data */
|
|
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
|
|
sk_wait_event(sk, &timeo,
|
|
READ_ONCE(sk->sk_err) ||
|
|
(READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN) ||
|
|
smc_cdc_rxed_any_close(conn) ||
|
|
(atomic_read(&conn->sndbuf_space) &&
|
|
!conn->urg_tx_pend),
|
|
&wait);
|
|
}
|
|
remove_wait_queue(sk_sleep(sk), &wait);
|
|
return rc;
|
|
}
|
|
|
|
static bool smc_tx_is_corked(struct smc_sock *smc)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(smc->clcsock->sk);
|
|
|
|
return (tp->nonagle & TCP_NAGLE_CORK) ? true : false;
|
|
}
|
|
|
|
/* If we have pending CDC messages, do not send:
|
|
* Because CQE of this CDC message will happen shortly, it gives
|
|
* a chance to coalesce future sendmsg() payload in to one RDMA Write,
|
|
* without need for a timer, and with no latency trade off.
|
|
* Algorithm here:
|
|
* 1. First message should never cork
|
|
* 2. If we have pending Tx CDC messages, wait for the first CDC
|
|
* message's completion
|
|
* 3. Don't cork to much data in a single RDMA Write to prevent burst
|
|
* traffic, total corked message should not exceed sendbuf/2
|
|
*/
|
|
static bool smc_should_autocork(struct smc_sock *smc)
|
|
{
|
|
struct smc_connection *conn = &smc->conn;
|
|
int corking_size;
|
|
|
|
corking_size = min_t(unsigned int, conn->sndbuf_desc->len >> 1,
|
|
sock_net(&smc->sk)->smc.sysctl_autocorking_size);
|
|
|
|
if (atomic_read(&conn->cdc_pend_tx_wr) == 0 ||
|
|
smc_tx_prepared_sends(conn) > corking_size)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
static bool smc_tx_should_cork(struct smc_sock *smc, struct msghdr *msg)
|
|
{
|
|
struct smc_connection *conn = &smc->conn;
|
|
|
|
if (smc_should_autocork(smc))
|
|
return true;
|
|
|
|
/* for a corked socket defer the RDMA writes if
|
|
* sndbuf_space is still available. The applications
|
|
* should known how/when to uncork it.
|
|
*/
|
|
if ((msg->msg_flags & MSG_MORE ||
|
|
smc_tx_is_corked(smc)) &&
|
|
atomic_read(&conn->sndbuf_space))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/* sndbuf producer: main API called by socket layer.
|
|
* called under sock lock.
|
|
*/
|
|
int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len)
|
|
{
|
|
size_t copylen, send_done = 0, send_remaining = len;
|
|
size_t chunk_len, chunk_off, chunk_len_sum;
|
|
struct smc_connection *conn = &smc->conn;
|
|
union smc_host_cursor prep;
|
|
struct sock *sk = &smc->sk;
|
|
char *sndbuf_base;
|
|
int tx_cnt_prep;
|
|
int writespace;
|
|
int rc, chunk;
|
|
|
|
/* This should be in poll */
|
|
sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
|
|
|
|
if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) {
|
|
rc = -EPIPE;
|
|
goto out_err;
|
|
}
|
|
|
|
if (sk->sk_state == SMC_INIT)
|
|
return -ENOTCONN;
|
|
|
|
if (len > conn->sndbuf_desc->len)
|
|
SMC_STAT_RMB_TX_SIZE_SMALL(smc, !conn->lnk);
|
|
|
|
if (len > conn->peer_rmbe_size)
|
|
SMC_STAT_RMB_TX_PEER_SIZE_SMALL(smc, !conn->lnk);
|
|
|
|
if (msg->msg_flags & MSG_OOB)
|
|
SMC_STAT_INC(smc, urg_data_cnt);
|
|
|
|
while (msg_data_left(msg)) {
|
|
if (smc->sk.sk_shutdown & SEND_SHUTDOWN ||
|
|
(smc->sk.sk_err == ECONNABORTED) ||
|
|
conn->killed)
|
|
return -EPIPE;
|
|
if (smc_cdc_rxed_any_close(conn))
|
|
return send_done ?: -ECONNRESET;
|
|
|
|
if (msg->msg_flags & MSG_OOB)
|
|
conn->local_tx_ctrl.prod_flags.urg_data_pending = 1;
|
|
|
|
if (!atomic_read(&conn->sndbuf_space) || conn->urg_tx_pend) {
|
|
if (send_done)
|
|
return send_done;
|
|
rc = smc_tx_wait(smc, msg->msg_flags);
|
|
if (rc)
|
|
goto out_err;
|
|
continue;
|
|
}
|
|
|
|
/* initialize variables for 1st iteration of subsequent loop */
|
|
/* could be just 1 byte, even after smc_tx_wait above */
|
|
writespace = atomic_read(&conn->sndbuf_space);
|
|
/* not more than what user space asked for */
|
|
copylen = min_t(size_t, send_remaining, writespace);
|
|
/* determine start of sndbuf */
|
|
sndbuf_base = conn->sndbuf_desc->cpu_addr;
|
|
smc_curs_copy(&prep, &conn->tx_curs_prep, conn);
|
|
tx_cnt_prep = prep.count;
|
|
/* determine chunks where to write into sndbuf */
|
|
/* either unwrapped case, or 1st chunk of wrapped case */
|
|
chunk_len = min_t(size_t, copylen, conn->sndbuf_desc->len -
|
|
tx_cnt_prep);
|
|
chunk_len_sum = chunk_len;
|
|
chunk_off = tx_cnt_prep;
|
|
for (chunk = 0; chunk < 2; chunk++) {
|
|
rc = memcpy_from_msg(sndbuf_base + chunk_off,
|
|
msg, chunk_len);
|
|
if (rc) {
|
|
smc_sndbuf_sync_sg_for_device(conn);
|
|
if (send_done)
|
|
return send_done;
|
|
goto out_err;
|
|
}
|
|
send_done += chunk_len;
|
|
send_remaining -= chunk_len;
|
|
|
|
if (chunk_len_sum == copylen)
|
|
break; /* either on 1st or 2nd iteration */
|
|
/* prepare next (== 2nd) iteration */
|
|
chunk_len = copylen - chunk_len; /* remainder */
|
|
chunk_len_sum += chunk_len;
|
|
chunk_off = 0; /* modulo offset in send ring buffer */
|
|
}
|
|
smc_sndbuf_sync_sg_for_device(conn);
|
|
/* update cursors */
|
|
smc_curs_add(conn->sndbuf_desc->len, &prep, copylen);
|
|
smc_curs_copy(&conn->tx_curs_prep, &prep, conn);
|
|
/* increased in send tasklet smc_cdc_tx_handler() */
|
|
smp_mb__before_atomic();
|
|
atomic_sub(copylen, &conn->sndbuf_space);
|
|
/* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
|
|
smp_mb__after_atomic();
|
|
/* since we just produced more new data into sndbuf,
|
|
* trigger sndbuf consumer: RDMA write into peer RMBE and CDC
|
|
*/
|
|
if ((msg->msg_flags & MSG_OOB) && !send_remaining)
|
|
conn->urg_tx_pend = true;
|
|
/* If we need to cork, do nothing and wait for the next
|
|
* sendmsg() call or push on tx completion
|
|
*/
|
|
if (!smc_tx_should_cork(smc, msg))
|
|
smc_tx_sndbuf_nonempty(conn);
|
|
|
|
trace_smc_tx_sendmsg(smc, copylen);
|
|
} /* while (msg_data_left(msg)) */
|
|
|
|
return send_done;
|
|
|
|
out_err:
|
|
rc = sk_stream_error(sk, msg->msg_flags, rc);
|
|
/* make sure we wake any epoll edge trigger waiter */
|
|
if (unlikely(rc == -EAGAIN))
|
|
sk->sk_write_space(sk);
|
|
return rc;
|
|
}
|
|
|
|
/***************************** sndbuf consumer *******************************/
|
|
|
|
/* sndbuf consumer: actual data transfer of one target chunk with ISM write */
|
|
int smcd_tx_ism_write(struct smc_connection *conn, void *data, size_t len,
|
|
u32 offset, int signal)
|
|
{
|
|
int rc;
|
|
|
|
rc = smc_ism_write(conn->lgr->smcd, conn->peer_token,
|
|
conn->peer_rmbe_idx, signal, conn->tx_off + offset,
|
|
data, len);
|
|
if (rc)
|
|
conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
|
|
return rc;
|
|
}
|
|
|
|
/* sndbuf consumer: actual data transfer of one target chunk with RDMA write */
|
|
static int smc_tx_rdma_write(struct smc_connection *conn, int peer_rmbe_offset,
|
|
int num_sges, struct ib_rdma_wr *rdma_wr)
|
|
{
|
|
struct smc_link_group *lgr = conn->lgr;
|
|
struct smc_link *link = conn->lnk;
|
|
int rc;
|
|
|
|
rdma_wr->wr.wr_id = smc_wr_tx_get_next_wr_id(link);
|
|
rdma_wr->wr.num_sge = num_sges;
|
|
rdma_wr->remote_addr =
|
|
lgr->rtokens[conn->rtoken_idx][link->link_idx].dma_addr +
|
|
/* RMBE within RMB */
|
|
conn->tx_off +
|
|
/* offset within RMBE */
|
|
peer_rmbe_offset;
|
|
rdma_wr->rkey = lgr->rtokens[conn->rtoken_idx][link->link_idx].rkey;
|
|
rc = ib_post_send(link->roce_qp, &rdma_wr->wr, NULL);
|
|
if (rc)
|
|
smcr_link_down_cond_sched(link);
|
|
return rc;
|
|
}
|
|
|
|
/* sndbuf consumer */
|
|
static inline void smc_tx_advance_cursors(struct smc_connection *conn,
|
|
union smc_host_cursor *prod,
|
|
union smc_host_cursor *sent,
|
|
size_t len)
|
|
{
|
|
smc_curs_add(conn->peer_rmbe_size, prod, len);
|
|
/* increased in recv tasklet smc_cdc_msg_rcv() */
|
|
smp_mb__before_atomic();
|
|
/* data in flight reduces usable snd_wnd */
|
|
atomic_sub(len, &conn->peer_rmbe_space);
|
|
/* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */
|
|
smp_mb__after_atomic();
|
|
smc_curs_add(conn->sndbuf_desc->len, sent, len);
|
|
}
|
|
|
|
/* SMC-R helper for smc_tx_rdma_writes() */
|
|
static int smcr_tx_rdma_writes(struct smc_connection *conn, size_t len,
|
|
size_t src_off, size_t src_len,
|
|
size_t dst_off, size_t dst_len,
|
|
struct smc_rdma_wr *wr_rdma_buf)
|
|
{
|
|
struct smc_link *link = conn->lnk;
|
|
|
|
dma_addr_t dma_addr =
|
|
sg_dma_address(conn->sndbuf_desc->sgt[link->link_idx].sgl);
|
|
u64 virt_addr = (uintptr_t)conn->sndbuf_desc->cpu_addr;
|
|
int src_len_sum = src_len, dst_len_sum = dst_len;
|
|
int sent_count = src_off;
|
|
int srcchunk, dstchunk;
|
|
int num_sges;
|
|
int rc;
|
|
|
|
for (dstchunk = 0; dstchunk < 2; dstchunk++) {
|
|
struct ib_rdma_wr *wr = &wr_rdma_buf->wr_tx_rdma[dstchunk];
|
|
struct ib_sge *sge = wr->wr.sg_list;
|
|
u64 base_addr = dma_addr;
|
|
|
|
if (dst_len < link->qp_attr.cap.max_inline_data) {
|
|
base_addr = virt_addr;
|
|
wr->wr.send_flags |= IB_SEND_INLINE;
|
|
} else {
|
|
wr->wr.send_flags &= ~IB_SEND_INLINE;
|
|
}
|
|
|
|
num_sges = 0;
|
|
for (srcchunk = 0; srcchunk < 2; srcchunk++) {
|
|
sge[srcchunk].addr = conn->sndbuf_desc->is_vm ?
|
|
(virt_addr + src_off) : (base_addr + src_off);
|
|
sge[srcchunk].length = src_len;
|
|
if (conn->sndbuf_desc->is_vm)
|
|
sge[srcchunk].lkey =
|
|
conn->sndbuf_desc->mr[link->link_idx]->lkey;
|
|
num_sges++;
|
|
|
|
src_off += src_len;
|
|
if (src_off >= conn->sndbuf_desc->len)
|
|
src_off -= conn->sndbuf_desc->len;
|
|
/* modulo in send ring */
|
|
if (src_len_sum == dst_len)
|
|
break; /* either on 1st or 2nd iteration */
|
|
/* prepare next (== 2nd) iteration */
|
|
src_len = dst_len - src_len; /* remainder */
|
|
src_len_sum += src_len;
|
|
}
|
|
rc = smc_tx_rdma_write(conn, dst_off, num_sges, wr);
|
|
if (rc)
|
|
return rc;
|
|
if (dst_len_sum == len)
|
|
break; /* either on 1st or 2nd iteration */
|
|
/* prepare next (== 2nd) iteration */
|
|
dst_off = 0; /* modulo offset in RMBE ring buffer */
|
|
dst_len = len - dst_len; /* remainder */
|
|
dst_len_sum += dst_len;
|
|
src_len = min_t(int, dst_len, conn->sndbuf_desc->len -
|
|
sent_count);
|
|
src_len_sum = src_len;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* SMC-D helper for smc_tx_rdma_writes() */
|
|
static int smcd_tx_rdma_writes(struct smc_connection *conn, size_t len,
|
|
size_t src_off, size_t src_len,
|
|
size_t dst_off, size_t dst_len)
|
|
{
|
|
int src_len_sum = src_len, dst_len_sum = dst_len;
|
|
int srcchunk, dstchunk;
|
|
int rc;
|
|
|
|
for (dstchunk = 0; dstchunk < 2; dstchunk++) {
|
|
for (srcchunk = 0; srcchunk < 2; srcchunk++) {
|
|
void *data = conn->sndbuf_desc->cpu_addr + src_off;
|
|
|
|
rc = smcd_tx_ism_write(conn, data, src_len, dst_off +
|
|
sizeof(struct smcd_cdc_msg), 0);
|
|
if (rc)
|
|
return rc;
|
|
dst_off += src_len;
|
|
src_off += src_len;
|
|
if (src_off >= conn->sndbuf_desc->len)
|
|
src_off -= conn->sndbuf_desc->len;
|
|
/* modulo in send ring */
|
|
if (src_len_sum == dst_len)
|
|
break; /* either on 1st or 2nd iteration */
|
|
/* prepare next (== 2nd) iteration */
|
|
src_len = dst_len - src_len; /* remainder */
|
|
src_len_sum += src_len;
|
|
}
|
|
if (dst_len_sum == len)
|
|
break; /* either on 1st or 2nd iteration */
|
|
/* prepare next (== 2nd) iteration */
|
|
dst_off = 0; /* modulo offset in RMBE ring buffer */
|
|
dst_len = len - dst_len; /* remainder */
|
|
dst_len_sum += dst_len;
|
|
src_len = min_t(int, dst_len, conn->sndbuf_desc->len - src_off);
|
|
src_len_sum = src_len;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit;
|
|
* usable snd_wnd as max transmit
|
|
*/
|
|
static int smc_tx_rdma_writes(struct smc_connection *conn,
|
|
struct smc_rdma_wr *wr_rdma_buf)
|
|
{
|
|
size_t len, src_len, dst_off, dst_len; /* current chunk values */
|
|
union smc_host_cursor sent, prep, prod, cons;
|
|
struct smc_cdc_producer_flags *pflags;
|
|
int to_send, rmbespace;
|
|
int rc;
|
|
|
|
/* source: sndbuf */
|
|
smc_curs_copy(&sent, &conn->tx_curs_sent, conn);
|
|
smc_curs_copy(&prep, &conn->tx_curs_prep, conn);
|
|
/* cf. wmem_alloc - (snd_max - snd_una) */
|
|
to_send = smc_curs_diff(conn->sndbuf_desc->len, &sent, &prep);
|
|
if (to_send <= 0)
|
|
return 0;
|
|
|
|
/* destination: RMBE */
|
|
/* cf. snd_wnd */
|
|
rmbespace = atomic_read(&conn->peer_rmbe_space);
|
|
if (rmbespace <= 0) {
|
|
struct smc_sock *smc = container_of(conn, struct smc_sock,
|
|
conn);
|
|
SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk);
|
|
return 0;
|
|
}
|
|
smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
|
|
smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
|
|
|
|
/* if usable snd_wnd closes ask peer to advertise once it opens again */
|
|
pflags = &conn->local_tx_ctrl.prod_flags;
|
|
pflags->write_blocked = (to_send >= rmbespace);
|
|
/* cf. usable snd_wnd */
|
|
len = min(to_send, rmbespace);
|
|
|
|
/* initialize variables for first iteration of subsequent nested loop */
|
|
dst_off = prod.count;
|
|
if (prod.wrap == cons.wrap) {
|
|
/* the filled destination area is unwrapped,
|
|
* hence the available free destination space is wrapped
|
|
* and we need 2 destination chunks of sum len; start with 1st
|
|
* which is limited by what's available in sndbuf
|
|
*/
|
|
dst_len = min_t(size_t,
|
|
conn->peer_rmbe_size - prod.count, len);
|
|
} else {
|
|
/* the filled destination area is wrapped,
|
|
* hence the available free destination space is unwrapped
|
|
* and we need a single destination chunk of entire len
|
|
*/
|
|
dst_len = len;
|
|
}
|
|
/* dst_len determines the maximum src_len */
|
|
if (sent.count + dst_len <= conn->sndbuf_desc->len) {
|
|
/* unwrapped src case: single chunk of entire dst_len */
|
|
src_len = dst_len;
|
|
} else {
|
|
/* wrapped src case: 2 chunks of sum dst_len; start with 1st: */
|
|
src_len = conn->sndbuf_desc->len - sent.count;
|
|
}
|
|
|
|
if (conn->lgr->is_smcd)
|
|
rc = smcd_tx_rdma_writes(conn, len, sent.count, src_len,
|
|
dst_off, dst_len);
|
|
else
|
|
rc = smcr_tx_rdma_writes(conn, len, sent.count, src_len,
|
|
dst_off, dst_len, wr_rdma_buf);
|
|
if (rc)
|
|
return rc;
|
|
|
|
if (conn->urg_tx_pend && len == to_send)
|
|
pflags->urg_data_present = 1;
|
|
smc_tx_advance_cursors(conn, &prod, &sent, len);
|
|
/* update connection's cursors with advanced local cursors */
|
|
smc_curs_copy(&conn->local_tx_ctrl.prod, &prod, conn);
|
|
/* dst: peer RMBE */
|
|
smc_curs_copy(&conn->tx_curs_sent, &sent, conn);/* src: local sndbuf */
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Wakeup sndbuf consumers from any context (IRQ or process)
|
|
* since there is more data to transmit; usable snd_wnd as max transmit
|
|
*/
|
|
static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn)
|
|
{
|
|
struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags;
|
|
struct smc_link *link = conn->lnk;
|
|
struct smc_rdma_wr *wr_rdma_buf;
|
|
struct smc_cdc_tx_pend *pend;
|
|
struct smc_wr_buf *wr_buf;
|
|
int rc;
|
|
|
|
if (!link || !smc_wr_tx_link_hold(link))
|
|
return -ENOLINK;
|
|
rc = smc_cdc_get_free_slot(conn, link, &wr_buf, &wr_rdma_buf, &pend);
|
|
if (rc < 0) {
|
|
smc_wr_tx_link_put(link);
|
|
if (rc == -EBUSY) {
|
|
struct smc_sock *smc =
|
|
container_of(conn, struct smc_sock, conn);
|
|
|
|
if (smc->sk.sk_err == ECONNABORTED)
|
|
return sock_error(&smc->sk);
|
|
if (conn->killed)
|
|
return -EPIPE;
|
|
rc = 0;
|
|
mod_delayed_work(conn->lgr->tx_wq, &conn->tx_work,
|
|
SMC_TX_WORK_DELAY);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
spin_lock_bh(&conn->send_lock);
|
|
if (link != conn->lnk) {
|
|
/* link of connection changed, tx_work will restart */
|
|
smc_wr_tx_put_slot(link,
|
|
(struct smc_wr_tx_pend_priv *)pend);
|
|
rc = -ENOLINK;
|
|
goto out_unlock;
|
|
}
|
|
if (!pflags->urg_data_present) {
|
|
rc = smc_tx_rdma_writes(conn, wr_rdma_buf);
|
|
if (rc) {
|
|
smc_wr_tx_put_slot(link,
|
|
(struct smc_wr_tx_pend_priv *)pend);
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
rc = smc_cdc_msg_send(conn, wr_buf, pend);
|
|
if (!rc && pflags->urg_data_present) {
|
|
pflags->urg_data_pending = 0;
|
|
pflags->urg_data_present = 0;
|
|
}
|
|
|
|
out_unlock:
|
|
spin_unlock_bh(&conn->send_lock);
|
|
smc_wr_tx_link_put(link);
|
|
return rc;
|
|
}
|
|
|
|
static int smcd_tx_sndbuf_nonempty(struct smc_connection *conn)
|
|
{
|
|
struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags;
|
|
int rc = 0;
|
|
|
|
spin_lock_bh(&conn->send_lock);
|
|
if (!pflags->urg_data_present)
|
|
rc = smc_tx_rdma_writes(conn, NULL);
|
|
if (!rc)
|
|
rc = smcd_cdc_msg_send(conn);
|
|
|
|
if (!rc && pflags->urg_data_present) {
|
|
pflags->urg_data_pending = 0;
|
|
pflags->urg_data_present = 0;
|
|
}
|
|
spin_unlock_bh(&conn->send_lock);
|
|
return rc;
|
|
}
|
|
|
|
static int __smc_tx_sndbuf_nonempty(struct smc_connection *conn)
|
|
{
|
|
struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
|
|
int rc = 0;
|
|
|
|
/* No data in the send queue */
|
|
if (unlikely(smc_tx_prepared_sends(conn) <= 0))
|
|
goto out;
|
|
|
|
/* Peer don't have RMBE space */
|
|
if (unlikely(atomic_read(&conn->peer_rmbe_space) <= 0)) {
|
|
SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk);
|
|
goto out;
|
|
}
|
|
|
|
if (conn->killed ||
|
|
conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) {
|
|
rc = -EPIPE; /* connection being aborted */
|
|
goto out;
|
|
}
|
|
if (conn->lgr->is_smcd)
|
|
rc = smcd_tx_sndbuf_nonempty(conn);
|
|
else
|
|
rc = smcr_tx_sndbuf_nonempty(conn);
|
|
|
|
if (!rc) {
|
|
/* trigger socket release if connection is closing */
|
|
smc_close_wake_tx_prepared(smc);
|
|
}
|
|
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
int smc_tx_sndbuf_nonempty(struct smc_connection *conn)
|
|
{
|
|
int rc;
|
|
|
|
/* This make sure only one can send simultaneously to prevent wasting
|
|
* of CPU and CDC slot.
|
|
* Record whether someone has tried to push while we are pushing.
|
|
*/
|
|
if (atomic_inc_return(&conn->tx_pushing) > 1)
|
|
return 0;
|
|
|
|
again:
|
|
atomic_set(&conn->tx_pushing, 1);
|
|
smp_wmb(); /* Make sure tx_pushing is 1 before real send */
|
|
rc = __smc_tx_sndbuf_nonempty(conn);
|
|
|
|
/* We need to check whether someone else have added some data into
|
|
* the send queue and tried to push but failed after the atomic_set()
|
|
* when we are pushing.
|
|
* If so, we need to push again to prevent those data hang in the send
|
|
* queue.
|
|
*/
|
|
if (unlikely(!atomic_dec_and_test(&conn->tx_pushing)))
|
|
goto again;
|
|
|
|
return rc;
|
|
}
|
|
|
|
/* Wakeup sndbuf consumers from process context
|
|
* since there is more data to transmit. The caller
|
|
* must hold sock lock.
|
|
*/
|
|
void smc_tx_pending(struct smc_connection *conn)
|
|
{
|
|
struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
|
|
int rc;
|
|
|
|
if (smc->sk.sk_err)
|
|
return;
|
|
|
|
rc = smc_tx_sndbuf_nonempty(conn);
|
|
if (!rc && conn->local_rx_ctrl.prod_flags.write_blocked &&
|
|
!atomic_read(&conn->bytes_to_rcv))
|
|
conn->local_rx_ctrl.prod_flags.write_blocked = 0;
|
|
}
|
|
|
|
/* Wakeup sndbuf consumers from process context
|
|
* since there is more data to transmit in locked
|
|
* sock.
|
|
*/
|
|
void smc_tx_work(struct work_struct *work)
|
|
{
|
|
struct smc_connection *conn = container_of(to_delayed_work(work),
|
|
struct smc_connection,
|
|
tx_work);
|
|
struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
|
|
|
|
lock_sock(&smc->sk);
|
|
smc_tx_pending(conn);
|
|
release_sock(&smc->sk);
|
|
}
|
|
|
|
void smc_tx_consumer_update(struct smc_connection *conn, bool force)
|
|
{
|
|
union smc_host_cursor cfed, cons, prod;
|
|
int sender_free = conn->rmb_desc->len;
|
|
int to_confirm;
|
|
|
|
smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
|
|
smc_curs_copy(&cfed, &conn->rx_curs_confirmed, conn);
|
|
to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons);
|
|
if (to_confirm > conn->rmbe_update_limit) {
|
|
smc_curs_copy(&prod, &conn->local_rx_ctrl.prod, conn);
|
|
sender_free = conn->rmb_desc->len -
|
|
smc_curs_diff_large(conn->rmb_desc->len,
|
|
&cfed, &prod);
|
|
}
|
|
|
|
if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
|
|
force ||
|
|
((to_confirm > conn->rmbe_update_limit) &&
|
|
((sender_free <= (conn->rmb_desc->len / 2)) ||
|
|
conn->local_rx_ctrl.prod_flags.write_blocked))) {
|
|
if (conn->killed ||
|
|
conn->local_rx_ctrl.conn_state_flags.peer_conn_abort)
|
|
return;
|
|
if ((smc_cdc_get_slot_and_msg_send(conn) < 0) &&
|
|
!conn->killed) {
|
|
queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work,
|
|
SMC_TX_WORK_DELAY);
|
|
return;
|
|
}
|
|
}
|
|
if (conn->local_rx_ctrl.prod_flags.write_blocked &&
|
|
!atomic_read(&conn->bytes_to_rcv))
|
|
conn->local_rx_ctrl.prod_flags.write_blocked = 0;
|
|
}
|
|
|
|
/***************************** send initialize *******************************/
|
|
|
|
/* Initialize send properties on connection establishment. NB: not __init! */
|
|
void smc_tx_init(struct smc_sock *smc)
|
|
{
|
|
smc->sk.sk_write_space = smc_tx_write_space;
|
|
}
|