diff options
Diffstat (limited to 'drivers/tty/n_gsm.c')
-rw-r--r-- | drivers/tty/n_gsm.c | 144 |
1 files changed, 87 insertions, 57 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index c43b683b6eb8..1e8e8ce55959 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -108,7 +108,7 @@ struct gsm_mux_net { */ struct gsm_msg { - struct gsm_msg *next; + struct list_head list; u8 addr; /* DLCI address + flags */ u8 ctrl; /* Control byte + flags */ unsigned int len; /* Length of data block (can be zero) */ @@ -245,8 +245,7 @@ struct gsm_mux { unsigned int tx_bytes; /* TX data outstanding */ #define TX_THRESH_HI 8192 #define TX_THRESH_LO 2048 - struct gsm_msg *tx_head; /* Pending data packets */ - struct gsm_msg *tx_tail; + struct list_head tx_list; /* Pending data packets */ /* Control messages */ struct timer_list t2_timer; /* Retransmit timer for commands */ @@ -489,7 +488,7 @@ static void gsm_print_packet(const char *hdr, int addr, int cr, default: if (!(control & 0x01)) { pr_cont("I N(S)%d N(R)%d", - (control & 0x0E) >> 1, (control & 0xE) >> 5); + (control & 0x0E) >> 1, (control & 0xE0) >> 5); } else switch (control & 0x0F) { case RR: pr_cont("RR(%d)", (control & 0xE0) >> 5); @@ -663,7 +662,7 @@ static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, m->len = len; m->addr = addr; m->ctrl = ctrl; - m->next = NULL; + INIT_LIST_HEAD(&m->list); return m; } @@ -673,22 +672,21 @@ static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, * * The tty device has called us to indicate that room has appeared in * the transmit queue. Ram more data into the pipe if we have any + * If we have been flow-stopped by a CMD_FCOFF, then we can only + * send messages on DLCI0 until CMD_FCON * * FIXME: lock against link layer control transmissions */ static void gsm_data_kick(struct gsm_mux *gsm) { - struct gsm_msg *msg = gsm->tx_head; + struct gsm_msg *msg, *nmsg; int len; int skip_sof = 0; - /* FIXME: We need to apply this solely to data messages */ - if (gsm->constipated) - return; - - while (gsm->tx_head != NULL) { - msg = gsm->tx_head; + list_for_each_entry_safe(msg, nmsg, &gsm->tx_list, list) { + if (gsm->constipated && msg->addr) + continue; if (gsm->encoding != 0) { gsm->txframe[0] = GSM1_SOF; len = gsm_stuff_frame(msg->data, @@ -711,14 +709,13 @@ static void gsm_data_kick(struct gsm_mux *gsm) len - skip_sof) < 0) break; /* FIXME: Can eliminate one SOF in many more cases */ - gsm->tx_head = msg->next; - if (gsm->tx_head == NULL) - gsm->tx_tail = NULL; gsm->tx_bytes -= msg->len; - kfree(msg); /* For a burst of frames skip the extra SOF within the burst */ skip_sof = 1; + + list_del(&msg->list); + kfree(msg); } } @@ -768,11 +765,7 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) msg->data = dp; /* Add to the actual output queue */ - if (gsm->tx_tail) - gsm->tx_tail->next = msg; - else - gsm->tx_head = msg; - gsm->tx_tail = msg; + list_add_tail(&msg->list, &gsm->tx_list); gsm->tx_bytes += msg->len; gsm_data_kick(gsm); } @@ -875,7 +868,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, /* dlci->skb is locked by tx_lock */ if (dlci->skb == NULL) { - dlci->skb = skb_dequeue(&dlci->skb_list); + dlci->skb = skb_dequeue_tail(&dlci->skb_list); if (dlci->skb == NULL) return 0; first = 1; @@ -886,7 +879,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, if (len > gsm->mtu) { if (dlci->adaption == 3) { /* Over long frame, bin it */ - kfree_skb(dlci->skb); + dev_kfree_skb_any(dlci->skb); dlci->skb = NULL; return 0; } @@ -899,8 +892,11 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, /* FIXME: need a timer or something to kick this so it can't get stuck with no work outstanding and no buffer free */ - if (msg == NULL) + if (msg == NULL) { + skb_queue_tail(&dlci->skb_list, dlci->skb); + dlci->skb = NULL; return -ENOMEM; + } dp = msg->data; if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */ @@ -912,7 +908,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, skb_pull(dlci->skb, len); __gsm_data_queue(dlci, msg); if (last) { - kfree_skb(dlci->skb); + dev_kfree_skb_any(dlci->skb); dlci->skb = NULL; } return size; @@ -971,16 +967,22 @@ static void gsm_dlci_data_sweep(struct gsm_mux *gsm) static void gsm_dlci_data_kick(struct gsm_dlci *dlci) { unsigned long flags; + int sweep; + + if (dlci->constipated) + return; spin_lock_irqsave(&dlci->gsm->tx_lock, flags); /* If we have nothing running then we need to fire up */ + sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO); if (dlci->gsm->tx_bytes == 0) { if (dlci->net) gsm_dlci_data_output_framed(dlci->gsm, dlci); else gsm_dlci_data_output(dlci->gsm, dlci); - } else if (dlci->gsm->tx_bytes < TX_THRESH_LO) - gsm_dlci_data_sweep(dlci->gsm); + } + if (sweep) + gsm_dlci_data_sweep(dlci->gsm); spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); } @@ -1027,6 +1029,7 @@ static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, { int mlines = 0; u8 brk = 0; + int fc; /* The modem status command can either contain one octet (v.24 signals) or two octets (v.24 signals + break signals). The length field will @@ -1038,19 +1041,21 @@ static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, else { brk = modem & 0x7f; modem = (modem >> 7) & 0x7f; - }; + } /* Flow control/ready to communicate */ - if (modem & MDM_FC) { + fc = (modem & MDM_FC) || !(modem & MDM_RTR); + if (fc && !dlci->constipated) { /* Need to throttle our output on this device */ dlci->constipated = 1; - } - if (modem & MDM_RTC) { - mlines |= TIOCM_DSR | TIOCM_DTR; + } else if (!fc && dlci->constipated) { dlci->constipated = 0; gsm_dlci_data_kick(dlci); } + /* Map modem bits */ + if (modem & MDM_RTC) + mlines |= TIOCM_DSR | TIOCM_DTR; if (modem & MDM_RTR) mlines |= TIOCM_RTS | TIOCM_CTS; if (modem & MDM_IC) @@ -1061,7 +1066,7 @@ static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, /* Carrier drop -> hangup */ if (tty) { if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD)) - if (!(tty->termios->c_cflag & CLOCAL)) + if (!(tty->termios.c_cflag & CLOCAL)) tty_hangup(tty); if (brk & 0x01) tty_insert_flip_char(tty, 0, TTY_BREAK); @@ -1190,6 +1195,8 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, u8 *data, int clen) { u8 buf[1]; + unsigned long flags; + switch (command) { case CMD_CLD: { struct gsm_dlci *dlci = gsm->dlci[0]; @@ -1206,16 +1213,18 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, gsm_control_reply(gsm, CMD_TEST, data, clen); break; case CMD_FCON: - /* Modem wants us to STFU */ - gsm->constipated = 1; - gsm_control_reply(gsm, CMD_FCON, NULL, 0); - break; - case CMD_FCOFF: /* Modem can accept data again */ gsm->constipated = 0; - gsm_control_reply(gsm, CMD_FCOFF, NULL, 0); + gsm_control_reply(gsm, CMD_FCON, NULL, 0); /* Kick the link in case it is idling */ + spin_lock_irqsave(&gsm->tx_lock, flags); gsm_data_kick(gsm); + spin_unlock_irqrestore(&gsm->tx_lock, flags); + break; + case CMD_FCOFF: + /* Modem wants us to STFU */ + gsm->constipated = 1; + gsm_control_reply(gsm, CMD_FCOFF, NULL, 0); break; case CMD_MSC: /* Out of band modem line change indicator for a DLCI */ @@ -1668,7 +1677,7 @@ static void gsm_dlci_free(struct kref *ref) dlci->gsm->dlci[dlci->addr] = NULL; kfifo_free(dlci->fifo); while ((dlci->skb = skb_dequeue(&dlci->skb_list))) - kfree_skb(dlci->skb); + dev_kfree_skb(dlci->skb); kfree(dlci); } @@ -2007,7 +2016,7 @@ void gsm_cleanup_mux(struct gsm_mux *gsm) { int i; struct gsm_dlci *dlci = gsm->dlci[0]; - struct gsm_msg *txq; + struct gsm_msg *txq, *ntxq; struct gsm_control *gc; gsm->dead = 1; @@ -2042,11 +2051,9 @@ void gsm_cleanup_mux(struct gsm_mux *gsm) if (gsm->dlci[i]) gsm_dlci_release(gsm->dlci[i]); /* Now wipe the queues */ - for (txq = gsm->tx_head; txq != NULL; txq = gsm->tx_head) { - gsm->tx_head = txq->next; + list_for_each_entry_safe(txq, ntxq, &gsm->tx_list, list) kfree(txq); - } - gsm->tx_tail = NULL; + INIT_LIST_HEAD(&gsm->tx_list); } EXPORT_SYMBOL_GPL(gsm_cleanup_mux); @@ -2157,6 +2164,7 @@ struct gsm_mux *gsm_alloc_mux(void) } spin_lock_init(&gsm->lock); kref_init(&gsm->ref); + INIT_LIST_HEAD(&gsm->tx_list); gsm->t1 = T1; gsm->t2 = T2; @@ -2273,7 +2281,7 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp, gsm->error(gsm, *dp, flags); break; default: - WARN_ONCE("%s: unknown flag %d\n", + WARN_ONCE(1, "%s: unknown flag %d\n", tty_name(tty, buf), flags); break; } @@ -2377,12 +2385,12 @@ static void gsmld_write_wakeup(struct tty_struct *tty) /* Queue poll */ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); + spin_lock_irqsave(&gsm->tx_lock, flags); gsm_data_kick(gsm); if (gsm->tx_bytes < TX_THRESH_LO) { - spin_lock_irqsave(&gsm->tx_lock, flags); gsm_dlci_data_sweep(gsm); - spin_unlock_irqrestore(&gsm->tx_lock, flags); } + spin_unlock_irqrestore(&gsm->tx_lock, flags); } /** @@ -2868,14 +2876,14 @@ static const struct tty_port_operations gsm_port_ops = { .dtr_rts = gsm_dtr_rts, }; - -static int gsmtty_open(struct tty_struct *tty, struct file *filp) +static int gsmtty_install(struct tty_driver *driver, struct tty_struct *tty) { struct gsm_mux *gsm; struct gsm_dlci *dlci; - struct tty_port *port; unsigned int line = tty->index; unsigned int mux = line >> 6; + bool alloc = false; + int ret; line = line & 0x3F; @@ -2889,14 +2897,35 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp) gsm = gsm_mux[mux]; if (gsm->dead) return -EL2HLT; + /* If DLCI 0 is not yet fully open return an error. This is ok from a locking + perspective as we don't have to worry about this if DLCI0 is lost */ + if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN) + return -EL2NSYNC; dlci = gsm->dlci[line]; - if (dlci == NULL) + if (dlci == NULL) { + alloc = true; dlci = gsm_dlci_alloc(gsm, line); + } if (dlci == NULL) return -ENOMEM; - port = &dlci->port; - port->count++; + ret = tty_port_install(&dlci->port, driver, tty); + if (ret) { + if (alloc) + dlci_put(dlci); + return ret; + } + tty->driver_data = dlci; + + return 0; +} + +static int gsmtty_open(struct tty_struct *tty, struct file *filp) +{ + struct gsm_dlci *dlci = tty->driver_data; + struct tty_port *port = &dlci->port; + + port->count++; dlci_get(dlci); dlci_get(dlci->gsm->dlci[0]); mux_get(dlci->gsm); @@ -3043,13 +3072,13 @@ static void gsmtty_set_termios(struct tty_struct *tty, struct ktermios *old) the RPN control message. This however rapidly gets nasty as we then have to remap modem signals each way according to whether our virtual cable is null modem etc .. */ - tty_termios_copy_hw(tty->termios, old); + tty_termios_copy_hw(&tty->termios, old); } static void gsmtty_throttle(struct tty_struct *tty) { struct gsm_dlci *dlci = tty->driver_data; - if (tty->termios->c_cflag & CRTSCTS) + if (tty->termios.c_cflag & CRTSCTS) dlci->modem_tx &= ~TIOCM_DTR; dlci->throttled = 1; /* Send an MSC with DTR cleared */ @@ -3059,7 +3088,7 @@ static void gsmtty_throttle(struct tty_struct *tty) static void gsmtty_unthrottle(struct tty_struct *tty) { struct gsm_dlci *dlci = tty->driver_data; - if (tty->termios->c_cflag & CRTSCTS) + if (tty->termios.c_cflag & CRTSCTS) dlci->modem_tx |= TIOCM_DTR; dlci->throttled = 0; /* Send an MSC with DTR set */ @@ -3085,6 +3114,7 @@ static int gsmtty_break_ctl(struct tty_struct *tty, int state) /* Virtual ttys for the demux */ static const struct tty_operations gsmtty_ops = { + .install = gsmtty_install, .open = gsmtty_open, .close = gsmtty_close, .write = gsmtty_write, |