Initial commit: OpenHarmony-v4.0-ReleaseOpenHarmony-v4.0-Release

1 files changed, 444 insertions, 0 deletions

diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c
new file mode 100644
index 000000000..7f7e983e4
--- /dev/null
+++ b/net/smc/smc_rx.c
@@ -0,0 +1,444 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ * Manage RMBE
+ * copy new RMBE data into user space
+ *
+ * Copyright IBM Corp. 2016
+ *
+ * Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
+ */
+
+#include <linux/net.h>
+#include <linux/rcupdate.h>
+#include <linux/sched/signal.h>
+
+#include <net/sock.h>
+
+#include "smc.h"
+#include "smc_core.h"
+#include "smc_cdc.h"
+#include "smc_tx.h" /* smc_tx_consumer_update() */
+#include "smc_rx.h"
+
+/* callback implementation to wakeup consumers blocked with smc_rx_wait().
+ * indirectly called by smc_cdc_msg_recv_action().
+ */
+static void smc_rx_wake_up(struct sock *sk)
+{
+        struct socket_wq *wq;
+
+        /* derived from sock_def_readable() */
+        /* called already in smc_listen_work() */
+        rcu_read_lock();
+        wq = rcu_dereference(sk->sk_wq);
+        if (skwq_has_sleeper(wq))
+                wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
+                                                EPOLLRDNORM | EPOLLRDBAND);
+        sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
+        if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
+            (sk->sk_state == SMC_CLOSED))
+                sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
+        rcu_read_unlock();
+}
+
+/* Update consumer cursor
+ *   @conn   connection to update
+ *   @cons   consumer cursor
+ *   @len    number of Bytes consumed
+ *   Returns:
+ *   1 if we should end our receive, 0 otherwise
+ */
+static int smc_rx_update_consumer(struct smc_sock *smc,
+                                  union smc_host_cursor cons, size_t len)
+{
+        struct smc_connection *conn = &smc->conn;
+        struct sock *sk = &smc->sk;
+        bool force = false;
+        int diff, rc = 0;
+
+        smc_curs_add(conn->rmb_desc->len, &cons, len);
+
+        /* did we process urgent data? */
+        if (conn->urg_state == SMC_URG_VALID || conn->urg_rx_skip_pend) {
+                diff = smc_curs_comp(conn->rmb_desc->len, &cons,
+                                     &conn->urg_curs);
+                if (sock_flag(sk, SOCK_URGINLINE)) {
+                        if (diff == 0) {
+                                force = true;
+                                rc = 1;
+                                conn->urg_state = SMC_URG_READ;
+                        }
+                } else {
+                        if (diff == 1) {
+                                /* skip urgent byte */
+                                force = true;
+                                smc_curs_add(conn->rmb_desc->len, &cons, 1);
+                                conn->urg_rx_skip_pend = false;
+                        } else if (diff < -1)
+                                /* we read past urgent byte */
+                                conn->urg_state = SMC_URG_READ;
+                }
+        }
+
+        smc_curs_copy(&conn->local_tx_ctrl.cons, &cons, conn);
+
+        /* send consumer cursor update if required */
+        /* similar to advertising new TCP rcv_wnd if required */
+        smc_tx_consumer_update(conn, force);
+
+        return rc;
+}
+
+static void smc_rx_update_cons(struct smc_sock *smc, size_t len)
+{
+        struct smc_connection *conn = &smc->conn;
+        union smc_host_cursor cons;
+
+        smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
+        smc_rx_update_consumer(smc, cons, len);
+}
+
+struct smc_spd_priv {
+        struct smc_sock *smc;
+        size_t           len;
+};
+
+static void smc_rx_pipe_buf_release(struct pipe_inode_info *pipe,
+                                    struct pipe_buffer *buf)
+{
+        struct smc_spd_priv *priv = (struct smc_spd_priv *)buf->private;
+        struct smc_sock *smc = priv->smc;
+        struct smc_connection *conn;
+        struct sock *sk = &smc->sk;
+
+        if (sk->sk_state == SMC_CLOSED ||
+            sk->sk_state == SMC_PEERFINCLOSEWAIT ||
+            sk->sk_state == SMC_APPFINCLOSEWAIT)
+                goto out;
+        conn = &smc->conn;
+        lock_sock(sk);
+        smc_rx_update_cons(smc, priv->len);
+        release_sock(sk);
+        if (atomic_sub_and_test(priv->len, &conn->splice_pending))
+                smc_rx_wake_up(sk);
+out:
+        kfree(priv);
+        put_page(buf->page);
+        sock_put(sk);
+}
+
+static const struct pipe_buf_operations smc_pipe_ops = {
+        .release = smc_rx_pipe_buf_release,
+        .get = generic_pipe_buf_get
+};
+
+static void smc_rx_spd_release(struct splice_pipe_desc *spd,
+                               unsigned int i)
+{
+        put_page(spd->pages[i]);
+}
+
+static int smc_rx_splice(struct pipe_inode_info *pipe, char *src, size_t len,
+                         struct smc_sock *smc)
+{
+        struct splice_pipe_desc spd;
+        struct partial_page partial;
+        struct smc_spd_priv *priv;
+        int bytes;
+
+        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+        priv->len = len;
+        priv->smc = smc;
+        partial.offset = src - (char *)smc->conn.rmb_desc->cpu_addr;
+        partial.len = len;
+        partial.private = (unsigned long)priv;
+
+        spd.nr_pages_max = 1;
+        spd.nr_pages = 1;
+        spd.pages = &smc->conn.rmb_desc->pages;
+        spd.partial = &partial;
+        spd.ops = &smc_pipe_ops;
+        spd.spd_release = smc_rx_spd_release;
+
+        bytes = splice_to_pipe(pipe, &spd);
+        if (bytes > 0) {
+                sock_hold(&smc->sk);
+                get_page(smc->conn.rmb_desc->pages);
+                atomic_add(bytes, &smc->conn.splice_pending);
+        }
+
+        return bytes;
+}
+
+static int smc_rx_data_available_and_no_splice_pend(struct smc_connection *conn)
+{
+        return atomic_read(&conn->bytes_to_rcv) &&
+               !atomic_read(&conn->splice_pending);
+}
+
+/* blocks rcvbuf consumer until >=len bytes available or timeout or interrupted
+ *   @smc    smc socket
+ *   @timeo  pointer to max seconds to wait, pointer to value 0 for no timeout
+ *   @fcrit  add'l criterion to evaluate as function pointer
+ * Returns:
+ * 1 if at least 1 byte available in rcvbuf or if socket error/shutdown.
+ * 0 otherwise (nothing in rcvbuf nor timeout, e.g. interrupted).
+ */
+int smc_rx_wait(struct smc_sock *smc, long *timeo,
+                int (*fcrit)(struct smc_connection *conn))
+{
+        DEFINE_WAIT_FUNC(wait, woken_wake_function);
+        struct smc_connection *conn = &smc->conn;
+        struct smc_cdc_conn_state_flags *cflags =
+                                        &conn->local_tx_ctrl.conn_state_flags;
+        struct sock *sk = &smc->sk;
+        int rc;
+
+        if (fcrit(conn))
+                return 1;
+        sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+        add_wait_queue(sk_sleep(sk), &wait);
+        rc = sk_wait_event(sk, timeo,
+                           sk->sk_err ||
+                           cflags->peer_conn_abort ||
+                           sk->sk_shutdown & RCV_SHUTDOWN ||
+                           conn->killed ||
+                           fcrit(conn),
+                           &wait);
+        remove_wait_queue(sk_sleep(sk), &wait);
+        sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+        return rc;
+}
+
+static int smc_rx_recv_urg(struct smc_sock *smc, struct msghdr *msg, int len,
+                           int flags)
+{
+        struct smc_connection *conn = &smc->conn;
+        union smc_host_cursor cons;
+        struct sock *sk = &smc->sk;
+        int rc = 0;
+
+        if (sock_flag(sk, SOCK_URGINLINE) ||
+            !(conn->urg_state == SMC_URG_VALID) ||
+            conn->urg_state == SMC_URG_READ)
+                return -EINVAL;
+
+        if (conn->urg_state == SMC_URG_VALID) {
+                if (!(flags & MSG_PEEK))
+                        smc->conn.urg_state = SMC_URG_READ;
+                msg->msg_flags |= MSG_OOB;
+                if (len > 0) {
+                        if (!(flags & MSG_TRUNC))
+                                rc = memcpy_to_msg(msg, &conn->urg_rx_byte, 1);
+                        len = 1;
+                        smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
+                        if (smc_curs_diff(conn->rmb_desc->len, &cons,
+                                          &conn->urg_curs) > 1)
+                                conn->urg_rx_skip_pend = true;
+                        /* Urgent Byte was already accounted for, but trigger
+                         * skipping the urgent byte in non-inline case
+                         */
+                        if (!(flags & MSG_PEEK))
+                                smc_rx_update_consumer(smc, cons, 0);
+                } else {
+                        msg->msg_flags |= MSG_TRUNC;
+                }
+
+                return rc ? -EFAULT : len;
+        }
+
+        if (sk->sk_state == SMC_CLOSED || sk->sk_shutdown & RCV_SHUTDOWN)
+                return 0;
+
+        return -EAGAIN;
+}
+
+static bool smc_rx_recvmsg_data_available(struct smc_sock *smc)
+{
+        struct smc_connection *conn = &smc->conn;
+
+        if (smc_rx_data_available(conn))
+                return true;
+        else if (conn->urg_state == SMC_URG_VALID)
+                /* we received a single urgent Byte - skip */
+                smc_rx_update_cons(smc, 0);
+        return false;
+}
+
+/* smc_rx_recvmsg - receive data from RMBE
+ * @msg:        copy data to receive buffer
+ * @pipe:       copy data to pipe if set - indicates splice() call
+ *
+ * rcvbuf consumer: main API called by socket layer.
+ * Called under sk lock.
+ */
+int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg,
+                   struct pipe_inode_info *pipe, size_t len, int flags)
+{
+        size_t copylen, read_done = 0, read_remaining = len;
+        size_t chunk_len, chunk_off, chunk_len_sum;
+        struct smc_connection *conn = &smc->conn;
+        int (*func)(struct smc_connection *conn);
+        union smc_host_cursor cons;
+        int readable, chunk;
+        char *rcvbuf_base;
+        struct sock *sk;
+        int splbytes;
+        long timeo;
+        int target;             /* Read at least these many bytes */
+        int rc;
+
+        if (unlikely(flags & MSG_ERRQUEUE))
+                return -EINVAL; /* future work for sk.sk_family == AF_SMC */
+
+        sk = &smc->sk;
+        if (sk->sk_state == SMC_LISTEN)
+                return -ENOTCONN;
+        if (flags & MSG_OOB)
+                return smc_rx_recv_urg(smc, msg, len, flags);
+        timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
+        target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
+
+        /* we currently use 1 RMBE per RMB, so RMBE == RMB base addr */
+        rcvbuf_base = conn->rx_off + conn->rmb_desc->cpu_addr;
+
+        do { /* while (read_remaining) */
+                if (read_done >= target || (pipe && read_done))
+                        break;
+
+                if (conn->killed)
+                        break;
+
+                if (smc_rx_recvmsg_data_available(smc))
+                        goto copy;
+
+                if (sk->sk_shutdown & RCV_SHUTDOWN) {
+                        /* smc_cdc_msg_recv_action() could have run after
+                         * above smc_rx_recvmsg_data_available()
+                         */
+                        if (smc_rx_recvmsg_data_available(smc))
+                                goto copy;
+                        break;
+                }
+
+                if (read_done) {
+                        if (sk->sk_err ||
+                            sk->sk_state == SMC_CLOSED ||
+                            !timeo ||
+                            signal_pending(current))
+                                break;
+                } else {
+                        if (sk->sk_err) {
+                                read_done = sock_error(sk);
+                                break;
+                        }
+                        if (sk->sk_state == SMC_CLOSED) {
+                                if (!sock_flag(sk, SOCK_DONE)) {
+                                        /* This occurs when user tries to read
+                                         * from never connected socket.
+                                         */
+                                        read_done = -ENOTCONN;
+                                        break;
+                                }
+                                break;
+                        }
+                        if (!timeo)
+                                return -EAGAIN;
+                        if (signal_pending(current)) {
+                                read_done = sock_intr_errno(timeo);
+                                break;
+                        }
+                }
+
+                if (!smc_rx_data_available(conn)) {
+                        smc_rx_wait(smc, &timeo, smc_rx_data_available);
+                        continue;
+                }
+
+copy:
+                /* initialize variables for 1st iteration of subsequent loop */
+                /* could be just 1 byte, even after waiting on data above */
+                readable = atomic_read(&conn->bytes_to_rcv);
+                splbytes = atomic_read(&conn->splice_pending);
+                if (!readable || (msg && splbytes)) {
+                        if (splbytes)
+                                func = smc_rx_data_available_and_no_splice_pend;
+                        else
+                                func = smc_rx_data_available;
+                        smc_rx_wait(smc, &timeo, func);
+                        continue;
+                }
+
+                smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
+                /* subsequent splice() calls pick up where previous left */
+                if (splbytes)
+                        smc_curs_add(conn->rmb_desc->len, &cons, splbytes);
+                if (conn->urg_state == SMC_URG_VALID &&
+                    sock_flag(&smc->sk, SOCK_URGINLINE) &&
+                    readable > 1)
+                        readable--;     /* always stop at urgent Byte */
+                /* not more than what user space asked for */
+                copylen = min_t(size_t, read_remaining, readable);
+                /* determine chunks where to read from rcvbuf */
+                /* either unwrapped case, or 1st chunk of wrapped case */
+                chunk_len = min_t(size_t, copylen, conn->rmb_desc->len -
+                                  cons.count);
+                chunk_len_sum = chunk_len;
+                chunk_off = cons.count;
+                smc_rmb_sync_sg_for_cpu(conn);
+                for (chunk = 0; chunk < 2; chunk++) {
+                        if (!(flags & MSG_TRUNC)) {
+                                if (msg) {
+                                        rc = memcpy_to_msg(msg, rcvbuf_base +
+                                                           chunk_off,
+                                                           chunk_len);
+                                } else {
+                                        rc = smc_rx_splice(pipe, rcvbuf_base +
+                                                        chunk_off, chunk_len,
+                                                        smc);
+                                }
+                                if (rc < 0) {
+                                        if (!read_done)
+                                                read_done = -EFAULT;
+                                        smc_rmb_sync_sg_for_device(conn);
+                                        goto out;
+                                }
+                        }
+                        read_remaining -= chunk_len;
+                        read_done += 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 recv ring buffer */
+                }
+                smc_rmb_sync_sg_for_device(conn);
+
+                /* update cursors */
+                if (!(flags & MSG_PEEK)) {
+                        /* increased in recv tasklet smc_cdc_msg_rcv() */
+                        smp_mb__before_atomic();
+                        atomic_sub(copylen, &conn->bytes_to_rcv);
+                        /* guarantee 0 <= bytes_to_rcv <= rmb_desc->len */
+                        smp_mb__after_atomic();
+                        if (msg && smc_rx_update_consumer(smc, cons, copylen))
+                                goto out;
+                }
+        } while (read_remaining);
+out:
+        return read_done;
+}
+
+/* Initialize receive properties on connection establishment. NB: not __init! */
+void smc_rx_init(struct smc_sock *smc)
+{
+        smc->sk.sk_data_ready = smc_rx_wake_up;
+        atomic_set(&smc->conn.splice_pending, 0);
+        smc->conn.urg_state = SMC_URG_READ;
+}