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https://github.com/torvalds/linux
synced 2024-09-06 18:01:05 +00:00
Phonet: use atomic for packet TX window
GPRS TX flow control won't need to lock the underlying socket anymore. Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
parent
57c81fffc8
commit
be677730a0
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@ -35,12 +35,12 @@ struct pep_sock {
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struct sock *listener;
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struct sk_buff_head ctrlreq_queue;
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#define PNPIPE_CTRLREQ_MAX 10
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atomic_t tx_credits;
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int ifindex;
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u16 peer_type; /* peer type/subtype */
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u8 pipe_handle;
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u8 rx_credits;
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u8 tx_credits;
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u8 rx_fc; /* RX flow control */
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u8 tx_fc; /* TX flow control */
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u8 init_enable; /* auto-enable at creation */
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@ -225,6 +225,7 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
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{
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struct pep_sock *pn = pep_sk(sk);
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struct pnpipehdr *hdr = pnp_hdr(skb);
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int wake = 0;
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if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
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return -EINVAL;
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@ -241,16 +242,16 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
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case PN_LEGACY_FLOW_CONTROL:
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switch (hdr->data[4]) {
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case PEP_IND_BUSY:
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pn->tx_credits = 0;
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atomic_set(&pn->tx_credits, 0);
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break;
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case PEP_IND_READY:
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pn->tx_credits = 1;
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atomic_set(&pn->tx_credits, wake = 1);
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break;
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}
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break;
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case PN_ONE_CREDIT_FLOW_CONTROL:
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if (hdr->data[4] == PEP_IND_READY)
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pn->tx_credits = 1;
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atomic_set(&pn->tx_credits, wake = 1);
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break;
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}
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break;
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@ -258,10 +259,7 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
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case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
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if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
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break;
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if (pn->tx_credits + hdr->data[4] > 0xff)
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pn->tx_credits = 0xff;
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else
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pn->tx_credits += hdr->data[4];
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atomic_add(wake = hdr->data[4], &pn->tx_credits);
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break;
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default:
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@ -269,7 +267,7 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
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(unsigned)hdr->data[1]);
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return -EOPNOTSUPP;
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}
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if (pn->tx_credits)
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if (wake)
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sk->sk_write_space(sk);
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return 0;
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}
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@ -343,7 +341,7 @@ static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
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}
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/* fall through */
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case PNS_PEP_DISABLE_REQ:
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pn->tx_credits = 0;
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atomic_set(&pn->tx_credits, 0);
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pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
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break;
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@ -390,7 +388,7 @@ static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
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/* fall through */
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case PNS_PIPE_ENABLED_IND:
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if (!pn_flow_safe(pn->tx_fc)) {
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pn->tx_credits = 1;
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atomic_set(&pn->tx_credits, 1);
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sk->sk_write_space(sk);
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}
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if (sk->sk_state == TCP_ESTABLISHED)
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@ -504,8 +502,9 @@ static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
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newpn->pn_sk.resource = pn->pn_sk.resource;
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skb_queue_head_init(&newpn->ctrlreq_queue);
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newpn->pipe_handle = pipe_handle;
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atomic_set(&newpn->tx_credits, 0);
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newpn->peer_type = peer_type;
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newpn->rx_credits = newpn->tx_credits = 0;
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newpn->rx_credits = 0;
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newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
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newpn->init_enable = enabled;
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@ -821,14 +820,18 @@ static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
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struct pep_sock *pn = pep_sk(sk);
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struct pnpipehdr *ph;
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if (pn_flow_safe(pn->tx_fc) &&
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!atomic_add_unless(&pn->tx_credits, -1, 0)) {
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kfree_skb(skb);
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return -ENOBUFS;
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}
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skb_push(skb, 3);
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skb_reset_transport_header(skb);
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ph = pnp_hdr(skb);
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ph->utid = 0;
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ph->message_id = PNS_PIPE_DATA;
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ph->pipe_handle = pn->pipe_handle;
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if (pn_flow_safe(pn->tx_fc) && pn->tx_credits)
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pn->tx_credits--;
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return pn_skb_send(sk, skb, &pipe_srv);
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}
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@ -866,7 +869,7 @@ static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
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BUG_ON(sk->sk_state != TCP_ESTABLISHED);
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/* Wait until flow control allows TX */
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done = pn->tx_credits > 0;
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done = atomic_read(&pn->tx_credits);
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while (!done) {
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DEFINE_WAIT(wait);
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@ -881,7 +884,7 @@ static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
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prepare_to_wait(&sk->sk_socket->wait, &wait,
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TASK_INTERRUPTIBLE);
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done = sk_wait_event(sk, &timeo, pn->tx_credits > 0);
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done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
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finish_wait(&sk->sk_socket->wait, &wait);
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if (sk->sk_state != TCP_ESTABLISHED)
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@ -895,7 +898,8 @@ static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
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goto out;
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skb_reserve(skb, MAX_PHONET_HEADER + 3);
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if (sk->sk_state != TCP_ESTABLISHED || !pn->tx_credits)
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if (sk->sk_state != TCP_ESTABLISHED ||
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!atomic_read(&pn->tx_credits))
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goto disabled; /* sock_alloc_send_skb might sleep */
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}
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@ -917,7 +921,7 @@ int pep_writeable(struct sock *sk)
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{
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struct pep_sock *pn = pep_sk(sk);
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return (sk->sk_state == TCP_ESTABLISHED) ? pn->tx_credits : 0;
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return atomic_read(&pn->tx_credits);
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}
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int pep_write(struct sock *sk, struct sk_buff *skb)
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@ -227,7 +227,7 @@ static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
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if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
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return POLLHUP;
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if (sk->sk_state == TCP_ESTABLISHED && pn->tx_credits)
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if (sk->sk_state == TCP_ESTABLISHED && atomic_read(&pn->tx_credits))
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mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
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return mask;
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