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linux/drivers/s390/net/ctctty.c
David S. Miller b03efcfb21 [NET]: Transform skb_queue_len() binary tests into skb_queue_empty() 
This is part of the grand scheme to eliminate the qlen
member of skb_queue_head, and subsequently remove the
'list' member of sk_buff.

Most users of skb_queue_len() want to know if the queue is
empty or not, and that's trivially done with skb_queue_empty()
which doesn't use the skb_queue_head->qlen member and instead
uses the queue list emptyness as the test.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-08 14:57:23 -07:00

1276 lines
34 KiB
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/*
* $Id: ctctty.c,v 1.29 2005/04/05 08:50:44 mschwide Exp $
*
* CTC / ESCON network driver, tty interface.
*
* Copyright (C) 2001 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Fritz Elfert (elfert@de.ibm.com, felfert@millenux.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/serial_reg.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <linux/devfs_fs_kernel.h>
#include "ctctty.h"
#include "ctcdbug.h"
#define CTC_TTY_MAJOR 43
#define CTC_TTY_MAX_DEVICES 64
#define CTC_ASYNC_MAGIC 0x49344C01 /* for paranoia-checking */
#define CTC_ASYNC_INITIALIZED 0x80000000 /* port was initialized */
#define CTC_ASYNC_NORMAL_ACTIVE 0x20000000 /* Normal device active */
#define CTC_ASYNC_CLOSING 0x08000000 /* Serial port is closing */
#define CTC_ASYNC_CTS_FLOW 0x04000000 /* Do CTS flow control */
#define CTC_ASYNC_CHECK_CD 0x02000000 /* i.e., CLOCAL */
#define CTC_ASYNC_HUP_NOTIFY 0x0001 /* Notify tty on hangups/closes */
#define CTC_ASYNC_NETDEV_OPEN 0x0002 /* Underlying netdev is open */
#define CTC_ASYNC_TX_LINESTAT 0x0004 /* Must send line status */
#define CTC_ASYNC_SPLIT_TERMIOS 0x0008 /* Sep. termios for dialin/out */
#define CTC_TTY_XMIT_SIZE 1024 /* Default bufsize for write */
#define CTC_SERIAL_XMIT_MAX 4000 /* Maximum bufsize for write */
/* Private data (similar to async_struct in <linux/serial.h>) */
typedef struct {
int magic;
int flags; /* defined in tty.h */
int mcr; /* Modem control register */
int msr; /* Modem status register */
int lsr; /* Line status register */
int line;
int count; /* # of fd on device */
int blocked_open; /* # of blocked opens */
struct net_device *netdev;
struct sk_buff_head tx_queue; /* transmit queue */
struct sk_buff_head rx_queue; /* receive queue */
struct tty_struct *tty; /* Pointer to corresponding tty */
wait_queue_head_t open_wait;
wait_queue_head_t close_wait;
struct semaphore write_sem;
struct tasklet_struct tasklet;
struct timer_list stoptimer;
} ctc_tty_info;
/* Description of one CTC-tty */
typedef struct {
struct tty_driver *ctc_tty_device; /* tty-device */
ctc_tty_info info[CTC_TTY_MAX_DEVICES]; /* Private data */
} ctc_tty_driver;
static ctc_tty_driver *driver;
/* Leave this unchanged unless you know what you do! */
#define MODEM_PARANOIA_CHECK
#define MODEM_DO_RESTART
#define CTC_TTY_NAME "ctctty"
static __u32 ctc_tty_magic = CTC_ASYNC_MAGIC;
static int ctc_tty_shuttingdown = 0;
static spinlock_t ctc_tty_lock;
/* ctc_tty_try_read() is called from within ctc_tty_rcv_skb()
* to stuff incoming data directly into a tty's flip-buffer. If the
* flip buffer is full, the packet gets queued up.
*
* Return:
* 1 = Success
* 0 = Failure, data has to be buffered and later processed by
* ctc_tty_readmodem().
*/
static int
ctc_tty_try_read(ctc_tty_info * info, struct sk_buff *skb)
{
int c;
int len;
struct tty_struct *tty;
DBF_TEXT(trace, 5, __FUNCTION__);
if ((tty = info->tty)) {
if (info->mcr & UART_MCR_RTS) {
c = TTY_FLIPBUF_SIZE - tty->flip.count;
len = skb->len;
if (c >= len) {
memcpy(tty->flip.char_buf_ptr, skb->data, len);
memset(tty->flip.flag_buf_ptr, 0, len);
tty->flip.count += len;
tty->flip.char_buf_ptr += len;
tty->flip.flag_buf_ptr += len;
tty_flip_buffer_push(tty);
kfree_skb(skb);
return 1;
}
}
}
return 0;
}
/* ctc_tty_readmodem() is called periodically from within timer-interrupt.
* It tries getting received data from the receive queue an stuff it into
* the tty's flip-buffer.
*/
static int
ctc_tty_readmodem(ctc_tty_info *info)
{
int ret = 1;
struct tty_struct *tty;
DBF_TEXT(trace, 5, __FUNCTION__);
if ((tty = info->tty)) {
if (info->mcr & UART_MCR_RTS) {
int c = TTY_FLIPBUF_SIZE - tty->flip.count;
struct sk_buff *skb;
if ((c > 0) && (skb = skb_dequeue(&info->rx_queue))) {
int len = skb->len;
if (len > c)
len = c;
memcpy(tty->flip.char_buf_ptr, skb->data, len);
skb_pull(skb, len);
memset(tty->flip.flag_buf_ptr, 0, len);
tty->flip.count += len;
tty->flip.char_buf_ptr += len;
tty->flip.flag_buf_ptr += len;
tty_flip_buffer_push(tty);
if (skb->len > 0)
skb_queue_head(&info->rx_queue, skb);
else {
kfree_skb(skb);
ret = !skb_queue_empty(&info->rx_queue);
}
}
}
}
return ret;
}
void
ctc_tty_setcarrier(struct net_device *netdev, int on)
{
int i;
DBF_TEXT(trace, 4, __FUNCTION__);
if ((!driver) || ctc_tty_shuttingdown)
return;
for (i = 0; i < CTC_TTY_MAX_DEVICES; i++)
if (driver->info[i].netdev == netdev) {
ctc_tty_info *info = &driver->info[i];
if (on)
info->msr |= UART_MSR_DCD;
else
info->msr &= ~UART_MSR_DCD;
if ((info->flags & CTC_ASYNC_CHECK_CD) && (!on))
tty_hangup(info->tty);
}
}
void
ctc_tty_netif_rx(struct sk_buff *skb)
{
int i;
ctc_tty_info *info = NULL;
DBF_TEXT(trace, 5, __FUNCTION__);
if (!skb)
return;
if ((!skb->dev) || (!driver) || ctc_tty_shuttingdown) {
dev_kfree_skb(skb);
return;
}
for (i = 0; i < CTC_TTY_MAX_DEVICES; i++)
if (driver->info[i].netdev == skb->dev) {
info = &driver->info[i];
break;
}
if (!info) {
dev_kfree_skb(skb);
return;
}
if (skb->len < 6) {
dev_kfree_skb(skb);
return;
}
if (memcmp(skb->data, &ctc_tty_magic, sizeof(__u32))) {
dev_kfree_skb(skb);
return;
}
skb_pull(skb, sizeof(__u32));
i = *((int *)skb->data);
skb_pull(skb, sizeof(info->mcr));
if (i & UART_MCR_RTS) {
info->msr |= UART_MSR_CTS;
if (info->flags & CTC_ASYNC_CTS_FLOW)
info->tty->hw_stopped = 0;
} else {
info->msr &= ~UART_MSR_CTS;
if (info->flags & CTC_ASYNC_CTS_FLOW)
info->tty->hw_stopped = 1;
}
if (i & UART_MCR_DTR)
info->msr |= UART_MSR_DSR;
else
info->msr &= ~UART_MSR_DSR;
if (skb->len <= 0) {
kfree_skb(skb);
return;
}
/* Try to deliver directly via tty-flip-buf if queue is empty */
if (skb_queue_empty(&info->rx_queue))
if (ctc_tty_try_read(info, skb))
return;
/* Direct deliver failed or queue wasn't empty.
* Queue up for later dequeueing via timer-irq.
*/
skb_queue_tail(&info->rx_queue, skb);
/* Schedule dequeuing */
tasklet_schedule(&info->tasklet);
}
static int
ctc_tty_tint(ctc_tty_info * info)
{
struct sk_buff *skb = skb_dequeue(&info->tx_queue);
int stopped = (info->tty->hw_stopped || info->tty->stopped);
int wake = 1;
int rc;
DBF_TEXT(trace, 4, __FUNCTION__);
if (!info->netdev) {
if (skb)
kfree_skb(skb);
return 0;
}
if (info->flags & CTC_ASYNC_TX_LINESTAT) {
int skb_res = info->netdev->hard_header_len +
sizeof(info->mcr) + sizeof(__u32);
/* If we must update line status,
* create an empty dummy skb and insert it.
*/
if (skb)
skb_queue_head(&info->tx_queue, skb);
skb = dev_alloc_skb(skb_res);
if (!skb) {
printk(KERN_WARNING
"ctc_tty: Out of memory in %s%d tint\n",
CTC_TTY_NAME, info->line);
return 1;
}
skb_reserve(skb, skb_res);
stopped = 0;
wake = 0;
}
if (!skb)
return 0;
if (stopped) {
skb_queue_head(&info->tx_queue, skb);
return 1;
}
#if 0
if (skb->len > 0)
printk(KERN_DEBUG "tint: %d %02x\n", skb->len, *(skb->data));
else
printk(KERN_DEBUG "tint: %d STAT\n", skb->len);
#endif
memcpy(skb_push(skb, sizeof(info->mcr)), &info->mcr, sizeof(info->mcr));
memcpy(skb_push(skb, sizeof(__u32)), &ctc_tty_magic, sizeof(__u32));
rc = info->netdev->hard_start_xmit(skb, info->netdev);
if (rc) {
skb_pull(skb, sizeof(info->mcr) + sizeof(__u32));
if (skb->len > 0)
skb_queue_head(&info->tx_queue, skb);
else
kfree_skb(skb);
} else {
struct tty_struct *tty = info->tty;
info->flags &= ~CTC_ASYNC_TX_LINESTAT;
if (tty) {
tty_wakeup(tty);
}
}
return (skb_queue_empty(&info->tx_queue) ? 0 : 1);
}
/************************************************************
*
* Modem-functions
*
* mostly "stolen" from original Linux-serial.c and friends.
*
************************************************************/
static inline int
ctc_tty_paranoia_check(ctc_tty_info * info, char *name, const char *routine)
{
#ifdef MODEM_PARANOIA_CHECK
if (!info) {
printk(KERN_WARNING "ctc_tty: null info_struct for %s in %s\n",
name, routine);
return 1;
}
if (info->magic != CTC_ASYNC_MAGIC) {
printk(KERN_WARNING "ctc_tty: bad magic for info struct %s in %s\n",
name, routine);
return 1;
}
#endif
return 0;
}
static void
ctc_tty_inject(ctc_tty_info *info, char c)
{
int skb_res;
struct sk_buff *skb;
DBF_TEXT(trace, 4, __FUNCTION__);
if (ctc_tty_shuttingdown)
return;
skb_res = info->netdev->hard_header_len + sizeof(info->mcr) +
sizeof(__u32) + 1;
skb = dev_alloc_skb(skb_res);
if (!skb) {
printk(KERN_WARNING
"ctc_tty: Out of memory in %s%d tx_inject\n",
CTC_TTY_NAME, info->line);
return;
}
skb_reserve(skb, skb_res);
*(skb_put(skb, 1)) = c;
skb_queue_head(&info->tx_queue, skb);
tasklet_schedule(&info->tasklet);
}
static void
ctc_tty_transmit_status(ctc_tty_info *info)
{
DBF_TEXT(trace, 5, __FUNCTION__);
if (ctc_tty_shuttingdown)
return;
info->flags |= CTC_ASYNC_TX_LINESTAT;
tasklet_schedule(&info->tasklet);
}
static void
ctc_tty_change_speed(ctc_tty_info * info)
{
unsigned int cflag;
unsigned int quot;
int i;
DBF_TEXT(trace, 3, __FUNCTION__);
if (!info->tty || !info->tty->termios)
return;
cflag = info->tty->termios->c_cflag;
quot = i = cflag & CBAUD;
if (i & CBAUDEX) {
i &= ~CBAUDEX;
if (i < 1 || i > 2)
info->tty->termios->c_cflag &= ~CBAUDEX;
else
i += 15;
}
if (quot) {
info->mcr |= UART_MCR_DTR;
info->mcr |= UART_MCR_RTS;
ctc_tty_transmit_status(info);
} else {
info->mcr &= ~UART_MCR_DTR;
info->mcr &= ~UART_MCR_RTS;
ctc_tty_transmit_status(info);
return;
}
/* CTS flow control flag and modem status interrupts */
if (cflag & CRTSCTS) {
info->flags |= CTC_ASYNC_CTS_FLOW;
} else
info->flags &= ~CTC_ASYNC_CTS_FLOW;
if (cflag & CLOCAL)
info->flags &= ~CTC_ASYNC_CHECK_CD;
else {
info->flags |= CTC_ASYNC_CHECK_CD;
}
}
static int
ctc_tty_startup(ctc_tty_info * info)
{
DBF_TEXT(trace, 3, __FUNCTION__);
if (info->flags & CTC_ASYNC_INITIALIZED)
return 0;
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "starting up %s%d ...\n", CTC_TTY_NAME, info->line);
#endif
/*
* Now, initialize the UART
*/
info->mcr = UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2;
if (info->tty)
clear_bit(TTY_IO_ERROR, &info->tty->flags);
/*
* and set the speed of the serial port
*/
ctc_tty_change_speed(info);
info->flags |= CTC_ASYNC_INITIALIZED;
if (!(info->flags & CTC_ASYNC_NETDEV_OPEN))
info->netdev->open(info->netdev);
info->flags |= CTC_ASYNC_NETDEV_OPEN;
return 0;
}
static void
ctc_tty_stopdev(unsigned long data)
{
ctc_tty_info *info = (ctc_tty_info *)data;
if ((!info) || (!info->netdev) ||
(info->flags & CTC_ASYNC_INITIALIZED))
return;
info->netdev->stop(info->netdev);
info->flags &= ~CTC_ASYNC_NETDEV_OPEN;
}
/*
* This routine will shutdown a serial port; interrupts are disabled, and
* DTR is dropped if the hangup on close termio flag is on.
*/
static void
ctc_tty_shutdown(ctc_tty_info * info)
{
DBF_TEXT(trace, 3, __FUNCTION__);
if (!(info->flags & CTC_ASYNC_INITIALIZED))
return;
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "Shutting down %s%d ....\n", CTC_TTY_NAME, info->line);
#endif
info->msr &= ~UART_MSR_RI;
if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
info->mcr &= ~(UART_MCR_DTR | UART_MCR_RTS);
if (info->tty)
set_bit(TTY_IO_ERROR, &info->tty->flags);
mod_timer(&info->stoptimer, jiffies + (10 * HZ));
skb_queue_purge(&info->tx_queue);
skb_queue_purge(&info->rx_queue);
info->flags &= ~CTC_ASYNC_INITIALIZED;
}
/* ctc_tty_write() is the main send-routine. It is called from the upper
* levels within the kernel to perform sending data. Depending on the
* online-flag it either directs output to the at-command-interpreter or
* to the lower level. Additional tasks done here:
* - If online, check for escape-sequence (+++)
* - If sending audio-data, call ctc_tty_DLEdown() to parse DLE-codes.
* - If receiving audio-data, call ctc_tty_end_vrx() to abort if needed.
* - If dialing, abort dial.
*/
static int
ctc_tty_write(struct tty_struct *tty, const u_char * buf, int count)
{
int c;
int total = 0;
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
DBF_TEXT(trace, 5, __FUNCTION__);
if (ctc_tty_shuttingdown)
goto ex;
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_write"))
goto ex;
if (!tty)
goto ex;
if (!info->netdev) {
total = -ENODEV;
goto ex;
}
while (1) {
struct sk_buff *skb;
int skb_res;
c = (count < CTC_TTY_XMIT_SIZE) ? count : CTC_TTY_XMIT_SIZE;
if (c <= 0)
break;
skb_res = info->netdev->hard_header_len + sizeof(info->mcr) +
+ sizeof(__u32);
skb = dev_alloc_skb(skb_res + c);
if (!skb) {
printk(KERN_WARNING
"ctc_tty: Out of memory in %s%d write\n",
CTC_TTY_NAME, info->line);
break;
}
skb_reserve(skb, skb_res);
memcpy(skb_put(skb, c), buf, c);
skb_queue_tail(&info->tx_queue, skb);
buf += c;
total += c;
count -= c;
}
if (!skb_queue_empty(&info->tx_queue)) {
info->lsr &= ~UART_LSR_TEMT;
tasklet_schedule(&info->tasklet);
}
ex:
DBF_TEXT(trace, 6, __FUNCTION__);
return total;
}
static int
ctc_tty_write_room(struct tty_struct *tty)
{
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_write_room"))
return 0;
return CTC_TTY_XMIT_SIZE;
}
static int
ctc_tty_chars_in_buffer(struct tty_struct *tty)
{
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_chars_in_buffer"))
return 0;
return 0;
}
static void
ctc_tty_flush_buffer(struct tty_struct *tty)
{
ctc_tty_info *info;
unsigned long flags;
DBF_TEXT(trace, 4, __FUNCTION__);
if (!tty)
goto ex;
spin_lock_irqsave(&ctc_tty_lock, flags);
info = (ctc_tty_info *) tty->driver_data;
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_flush_buffer")) {
spin_unlock_irqrestore(&ctc_tty_lock, flags);
goto ex;
}
skb_queue_purge(&info->tx_queue);
info->lsr |= UART_LSR_TEMT;
spin_unlock_irqrestore(&ctc_tty_lock, flags);
wake_up_interruptible(&tty->write_wait);
tty_wakeup(tty);
ex:
DBF_TEXT_(trace, 2, "ex: %s ", __FUNCTION__);
return;
}
static void
ctc_tty_flush_chars(struct tty_struct *tty)
{
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
DBF_TEXT(trace, 4, __FUNCTION__);
if (ctc_tty_shuttingdown)
return;
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_flush_chars"))
return;
if (tty->stopped || tty->hw_stopped || skb_queue_empty(&info->tx_queue))
return;
tasklet_schedule(&info->tasklet);
}
/*
* ------------------------------------------------------------
* ctc_tty_throttle()
*
* This routine is called by the upper-layer tty layer to signal that
* incoming characters should be throttled.
* ------------------------------------------------------------
*/
static void
ctc_tty_throttle(struct tty_struct *tty)
{
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
DBF_TEXT(trace, 4, __FUNCTION__);
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_throttle"))
return;
info->mcr &= ~UART_MCR_RTS;
if (I_IXOFF(tty))
ctc_tty_inject(info, STOP_CHAR(tty));
ctc_tty_transmit_status(info);
}
static void
ctc_tty_unthrottle(struct tty_struct *tty)
{
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
DBF_TEXT(trace, 4, __FUNCTION__);
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_unthrottle"))
return;
info->mcr |= UART_MCR_RTS;
if (I_IXOFF(tty))
ctc_tty_inject(info, START_CHAR(tty));
ctc_tty_transmit_status(info);
}
/*
* ------------------------------------------------------------
* ctc_tty_ioctl() and friends
* ------------------------------------------------------------
*/
/*
* ctc_tty_get_lsr_info - get line status register info
*
* Purpose: Let user call ioctl() to get info when the UART physically
* is emptied. On bus types like RS485, the transmitter must
* release the bus after transmitting. This must be done when
* the transmit shift register is empty, not be done when the
* transmit holding register is empty. This functionality
* allows RS485 driver to be written in user space.
*/
static int
ctc_tty_get_lsr_info(ctc_tty_info * info, uint __user *value)
{
u_char status;
uint result;
ulong flags;
DBF_TEXT(trace, 4, __FUNCTION__);
spin_lock_irqsave(&ctc_tty_lock, flags);
status = info->lsr;
spin_unlock_irqrestore(&ctc_tty_lock, flags);
result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
put_user(result, value);
return 0;
}
static int ctc_tty_tiocmget(struct tty_struct *tty, struct file *file)
{
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
u_char control,
status;
uint result;
ulong flags;
DBF_TEXT(trace, 4, __FUNCTION__);
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_ioctl"))
return -ENODEV;
if (tty->flags & (1 << TTY_IO_ERROR))
return -EIO;
control = info->mcr;
spin_lock_irqsave(&ctc_tty_lock, flags);
status = info->msr;
spin_unlock_irqrestore(&ctc_tty_lock, flags);
result = ((control & UART_MCR_RTS) ? TIOCM_RTS : 0)
| ((control & UART_MCR_DTR) ? TIOCM_DTR : 0)
| ((status & UART_MSR_DCD) ? TIOCM_CAR : 0)
| ((status & UART_MSR_RI) ? TIOCM_RNG : 0)
| ((status & UART_MSR_DSR) ? TIOCM_DSR : 0)
| ((status & UART_MSR_CTS) ? TIOCM_CTS : 0);
return result;
}
static int
ctc_tty_tiocmset(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear)
{
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
DBF_TEXT(trace, 4, __FUNCTION__);
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_ioctl"))
return -ENODEV;
if (tty->flags & (1 << TTY_IO_ERROR))
return -EIO;
if (set & TIOCM_RTS)
info->mcr |= UART_MCR_RTS;
if (set & TIOCM_DTR)
info->mcr |= UART_MCR_DTR;
if (clear & TIOCM_RTS)
info->mcr &= ~UART_MCR_RTS;
if (clear & TIOCM_DTR)
info->mcr &= ~UART_MCR_DTR;
if ((set | clear) & (TIOCM_RTS|TIOCM_DTR))
ctc_tty_transmit_status(info);
return 0;
}
static int
ctc_tty_ioctl(struct tty_struct *tty, struct file *file,
uint cmd, ulong arg)
{
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
int error;
int retval;
DBF_TEXT(trace, 4, __FUNCTION__);
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_ioctl"))
return -ENODEV;
if (tty->flags & (1 << TTY_IO_ERROR))
return -EIO;
switch (cmd) {
case TCSBRK: /* SVID version: non-zero arg --> no break */
#ifdef CTC_DEBUG_MODEM_IOCTL
printk(KERN_DEBUG "%s%d ioctl TCSBRK\n", CTC_TTY_NAME, info->line);
#endif
retval = tty_check_change(tty);
if (retval)
return retval;
tty_wait_until_sent(tty, 0);
return 0;
case TCSBRKP: /* support for POSIX tcsendbreak() */
#ifdef CTC_DEBUG_MODEM_IOCTL
printk(KERN_DEBUG "%s%d ioctl TCSBRKP\n", CTC_TTY_NAME, info->line);
#endif
retval = tty_check_change(tty);
if (retval)
return retval;
tty_wait_until_sent(tty, 0);
return 0;
case TIOCGSOFTCAR:
#ifdef CTC_DEBUG_MODEM_IOCTL
printk(KERN_DEBUG "%s%d ioctl TIOCGSOFTCAR\n", CTC_TTY_NAME,
info->line);
#endif
error = put_user(C_CLOCAL(tty) ? 1 : 0, (ulong __user *) arg);
return error;
case TIOCSSOFTCAR:
#ifdef CTC_DEBUG_MODEM_IOCTL
printk(KERN_DEBUG "%s%d ioctl TIOCSSOFTCAR\n", CTC_TTY_NAME,
info->line);
#endif
error = get_user(arg, (ulong __user *) arg);
if (error)
return error;
tty->termios->c_cflag =
((tty->termios->c_cflag & ~CLOCAL) |
(arg ? CLOCAL : 0));
return 0;
case TIOCSERGETLSR: /* Get line status register */
#ifdef CTC_DEBUG_MODEM_IOCTL
printk(KERN_DEBUG "%s%d ioctl TIOCSERGETLSR\n", CTC_TTY_NAME,
info->line);
#endif
if (access_ok(VERIFY_WRITE, (void __user *) arg, sizeof(uint)))
return ctc_tty_get_lsr_info(info, (uint __user *) arg);
else
return -EFAULT;
default:
#ifdef CTC_DEBUG_MODEM_IOCTL
printk(KERN_DEBUG "UNKNOWN ioctl 0x%08x on %s%d\n", cmd,
CTC_TTY_NAME, info->line);
#endif
return -ENOIOCTLCMD;
}
return 0;
}
static void
ctc_tty_set_termios(struct tty_struct *tty, struct termios *old_termios)
{
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
unsigned int cflag = tty->termios->c_cflag;
DBF_TEXT(trace, 4, __FUNCTION__);
ctc_tty_change_speed(info);
/* Handle transition to B0 */
if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
info->mcr &= ~(UART_MCR_DTR|UART_MCR_RTS);
ctc_tty_transmit_status(info);
}
/* Handle transition from B0 to other */
if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
info->mcr |= UART_MCR_DTR;
if (!(tty->termios->c_cflag & CRTSCTS) ||
!test_bit(TTY_THROTTLED, &tty->flags)) {
info->mcr |= UART_MCR_RTS;
}
ctc_tty_transmit_status(info);
}
/* Handle turning off CRTSCTS */
if ((old_termios->c_cflag & CRTSCTS) &&
!(tty->termios->c_cflag & CRTSCTS))
tty->hw_stopped = 0;
}
/*
* ------------------------------------------------------------
* ctc_tty_open() and friends
* ------------------------------------------------------------
*/
static int
ctc_tty_block_til_ready(struct tty_struct *tty, struct file *filp, ctc_tty_info *info)
{
DECLARE_WAITQUEUE(wait, NULL);
int do_clocal = 0;
unsigned long flags;
int retval;
DBF_TEXT(trace, 4, __FUNCTION__);
/*
* If the device is in the middle of being closed, then block
* until it's done, and then try again.
*/
if (tty_hung_up_p(filp) ||
(info->flags & CTC_ASYNC_CLOSING)) {
if (info->flags & CTC_ASYNC_CLOSING)
wait_event(info->close_wait,
!(info->flags & CTC_ASYNC_CLOSING));
#ifdef MODEM_DO_RESTART
if (info->flags & CTC_ASYNC_HUP_NOTIFY)
return -EAGAIN;
else
return -ERESTARTSYS;
#else
return -EAGAIN;
#endif
}
/*
* If non-blocking mode is set, then make the check up front
* and then exit.
*/
if ((filp->f_flags & O_NONBLOCK) ||
(tty->flags & (1 << TTY_IO_ERROR))) {
info->flags |= CTC_ASYNC_NORMAL_ACTIVE;
return 0;
}
if (tty->termios->c_cflag & CLOCAL)
do_clocal = 1;
/*
* Block waiting for the carrier detect and the line to become
* free (i.e., not in use by the callout). While we are in
* this loop, info->count is dropped by one, so that
* ctc_tty_close() knows when to free things. We restore it upon
* exit, either normal or abnormal.
*/
retval = 0;
add_wait_queue(&info->open_wait, &wait);
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "ctc_tty_block_til_ready before block: %s%d, count = %d\n",
CTC_TTY_NAME, info->line, info->count);
#endif
spin_lock_irqsave(&ctc_tty_lock, flags);
if (!(tty_hung_up_p(filp)))
info->count--;
spin_unlock_irqrestore(&ctc_tty_lock, flags);
info->blocked_open++;
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
if (tty_hung_up_p(filp) ||
!(info->flags & CTC_ASYNC_INITIALIZED)) {
#ifdef MODEM_DO_RESTART
if (info->flags & CTC_ASYNC_HUP_NOTIFY)
retval = -EAGAIN;
else
retval = -ERESTARTSYS;
#else
retval = -EAGAIN;
#endif
break;
}
if (!(info->flags & CTC_ASYNC_CLOSING) &&
(do_clocal || (info->msr & UART_MSR_DCD))) {
break;
}
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "ctc_tty_block_til_ready blocking: %s%d, count = %d\n",
CTC_TTY_NAME, info->line, info->count);
#endif
schedule();
}
current->state = TASK_RUNNING;
remove_wait_queue(&info->open_wait, &wait);
if (!tty_hung_up_p(filp))
info->count++;
info->blocked_open--;
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "ctc_tty_block_til_ready after blocking: %s%d, count = %d\n",
CTC_TTY_NAME, info->line, info->count);
#endif
if (retval)
return retval;
info->flags |= CTC_ASYNC_NORMAL_ACTIVE;
return 0;
}
/*
* This routine is called whenever a serial port is opened. It
* enables interrupts for a serial port, linking in its async structure into
* the IRQ chain. It also performs the serial-specific
* initialization for the tty structure.
*/
static int
ctc_tty_open(struct tty_struct *tty, struct file *filp)
{
ctc_tty_info *info;
unsigned long saveflags;
int retval,
line;
DBF_TEXT(trace, 3, __FUNCTION__);
line = tty->index;
if (line < 0 || line > CTC_TTY_MAX_DEVICES)
return -ENODEV;
info = &driver->info[line];
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_open"))
return -ENODEV;
if (!info->netdev)
return -ENODEV;
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "ctc_tty_open %s, count = %d\n", tty->name,
info->count);
#endif
spin_lock_irqsave(&ctc_tty_lock, saveflags);
info->count++;
tty->driver_data = info;
info->tty = tty;
spin_unlock_irqrestore(&ctc_tty_lock, saveflags);
/*
* Start up serial port
*/
retval = ctc_tty_startup(info);
if (retval) {
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "ctc_tty_open return after startup\n");
#endif
return retval;
}
retval = ctc_tty_block_til_ready(tty, filp, info);
if (retval) {
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "ctc_tty_open return after ctc_tty_block_til_ready \n");
#endif
return retval;
}
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "ctc_tty_open %s successful...\n", tty->name);
#endif
return 0;
}
static void
ctc_tty_close(struct tty_struct *tty, struct file *filp)
{
ctc_tty_info *info = (ctc_tty_info *) tty->driver_data;
ulong flags;
ulong timeout;
DBF_TEXT(trace, 3, __FUNCTION__);
if (!info || ctc_tty_paranoia_check(info, tty->name, "ctc_tty_close"))
return;
spin_lock_irqsave(&ctc_tty_lock, flags);
if (tty_hung_up_p(filp)) {
spin_unlock_irqrestore(&ctc_tty_lock, flags);
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "ctc_tty_close return after tty_hung_up_p\n");
#endif
return;
}
if ((tty->count == 1) && (info->count != 1)) {
/*
* Uh, oh. tty->count is 1, which means that the tty
* structure will be freed. Info->count should always
* be one in these conditions. If it's greater than
* one, we've got real problems, since it means the
* serial port won't be shutdown.
*/
printk(KERN_ERR "ctc_tty_close: bad port count; tty->count is 1, "
"info->count is %d\n", info->count);
info->count = 1;
}
if (--info->count < 0) {
printk(KERN_ERR "ctc_tty_close: bad port count for %s%d: %d\n",
CTC_TTY_NAME, info->line, info->count);
info->count = 0;
}
if (info->count) {
local_irq_restore(flags);
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "ctc_tty_close after info->count != 0\n");
#endif
return;
}
info->flags |= CTC_ASYNC_CLOSING;
tty->closing = 1;
/*
* At this point we stop accepting input. To do this, we
* disable the receive line status interrupts, and tell the
* interrupt driver to stop checking the data ready bit in the
* line status register.
*/
if (info->flags & CTC_ASYNC_INITIALIZED) {
tty_wait_until_sent(tty, 30*HZ); /* 30 seconds timeout */
/*
* Before we drop DTR, make sure the UART transmitter
* has completely drained; this is especially
* important if there is a transmit FIFO!
*/
timeout = jiffies + HZ;
while (!(info->lsr & UART_LSR_TEMT)) {
spin_unlock_irqrestore(&ctc_tty_lock, flags);
msleep(500);
spin_lock_irqsave(&ctc_tty_lock, flags);
if (time_after(jiffies,timeout))
break;
}
}
ctc_tty_shutdown(info);
if (tty->driver->flush_buffer) {
skb_queue_purge(&info->tx_queue);
info->lsr |= UART_LSR_TEMT;
}
tty_ldisc_flush(tty);
info->tty = 0;
tty->closing = 0;
if (info->blocked_open) {
msleep_interruptible(500);
wake_up_interruptible(&info->open_wait);
}
info->flags &= ~(CTC_ASYNC_NORMAL_ACTIVE | CTC_ASYNC_CLOSING);
wake_up_interruptible(&info->close_wait);
spin_unlock_irqrestore(&ctc_tty_lock, flags);
#ifdef CTC_DEBUG_MODEM_OPEN
printk(KERN_DEBUG "ctc_tty_close normal exit\n");
#endif
}
/*
* ctc_tty_hangup() --- called by tty_hangup() when a hangup is signaled.
*/
static void
ctc_tty_hangup(struct tty_struct *tty)
{
ctc_tty_info *info = (ctc_tty_info *)tty->driver_data;
unsigned long saveflags;
DBF_TEXT(trace, 3, __FUNCTION__);
if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_hangup"))
return;
ctc_tty_shutdown(info);
info->count = 0;
info->flags &= ~CTC_ASYNC_NORMAL_ACTIVE;
spin_lock_irqsave(&ctc_tty_lock, saveflags);
info->tty = 0;
spin_unlock_irqrestore(&ctc_tty_lock, saveflags);
wake_up_interruptible(&info->open_wait);
}
/*
* For all online tty's, try sending data to
* the lower levels.
*/
static void
ctc_tty_task(unsigned long arg)
{
ctc_tty_info *info = (void *)arg;
unsigned long saveflags;
int again;
DBF_TEXT(trace, 3, __FUNCTION__);
spin_lock_irqsave(&ctc_tty_lock, saveflags);
if ((!ctc_tty_shuttingdown) && info) {
again = ctc_tty_tint(info);
if (!again)
info->lsr |= UART_LSR_TEMT;
again |= ctc_tty_readmodem(info);
if (again) {
tasklet_schedule(&info->tasklet);
}
}
spin_unlock_irqrestore(&ctc_tty_lock, saveflags);
}
static struct tty_operations ctc_ops = {
.open = ctc_tty_open,
.close = ctc_tty_close,
.write = ctc_tty_write,
.flush_chars = ctc_tty_flush_chars,
.write_room = ctc_tty_write_room,
.chars_in_buffer = ctc_tty_chars_in_buffer,
.flush_buffer = ctc_tty_flush_buffer,
.ioctl = ctc_tty_ioctl,
.throttle = ctc_tty_throttle,
.unthrottle = ctc_tty_unthrottle,
.set_termios = ctc_tty_set_termios,
.hangup = ctc_tty_hangup,
.tiocmget = ctc_tty_tiocmget,
.tiocmset = ctc_tty_tiocmset,
};
int
ctc_tty_init(void)
{
int i;
ctc_tty_info *info;
struct tty_driver *device;
DBF_TEXT(trace, 2, __FUNCTION__);
driver = kmalloc(sizeof(ctc_tty_driver), GFP_KERNEL);
if (driver == NULL) {
printk(KERN_WARNING "Out of memory in ctc_tty_modem_init\n");
return -ENOMEM;
}
memset(driver, 0, sizeof(ctc_tty_driver));
device = alloc_tty_driver(CTC_TTY_MAX_DEVICES);
if (!device) {
kfree(driver);
printk(KERN_WARNING "Out of memory in ctc_tty_modem_init\n");
return -ENOMEM;
}
device->devfs_name = "ctc/" CTC_TTY_NAME;
device->name = CTC_TTY_NAME;
device->major = CTC_TTY_MAJOR;
device->minor_start = 0;
device->type = TTY_DRIVER_TYPE_SERIAL;
device->subtype = SERIAL_TYPE_NORMAL;
device->init_termios = tty_std_termios;
device->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
device->flags = TTY_DRIVER_REAL_RAW;
device->driver_name = "ctc_tty",
tty_set_operations(device, &ctc_ops);
if (tty_register_driver(device)) {
printk(KERN_WARNING "ctc_tty: Couldn't register serial-device\n");
put_tty_driver(device);
kfree(driver);
return -1;
}
driver->ctc_tty_device = device;
for (i = 0; i < CTC_TTY_MAX_DEVICES; i++) {
info = &driver->info[i];
init_MUTEX(&info->write_sem);
tasklet_init(&info->tasklet, ctc_tty_task,
(unsigned long) info);
info->magic = CTC_ASYNC_MAGIC;
info->line = i;
info->tty = 0;
info->count = 0;
info->blocked_open = 0;
init_waitqueue_head(&info->open_wait);
init_waitqueue_head(&info->close_wait);
skb_queue_head_init(&info->tx_queue);
skb_queue_head_init(&info->rx_queue);
init_timer(&info->stoptimer);
info->stoptimer.function = ctc_tty_stopdev;
info->stoptimer.data = (unsigned long)info;
info->mcr = UART_MCR_RTS;
}
return 0;
}
int
ctc_tty_register_netdev(struct net_device *dev) {
int ttynum;
char *err;
char *p;
DBF_TEXT(trace, 2, __FUNCTION__);
if ((!dev) || (!dev->name)) {
printk(KERN_WARNING
"ctc_tty_register_netdev called "
"with NULL dev or NULL dev-name\n");
return -1;
}
/*
* If the name is a format string the caller wants us to
* do a name allocation : format string must end with %d
*/
if (strchr(dev->name, '%'))
{
int err = dev_alloc_name(dev, dev->name); // dev->name is changed by this
if (err < 0) {
printk(KERN_DEBUG "dev_alloc returned error %d\n", err);
return err;
}
}
for (p = dev->name; p && ((*p < '0') || (*p > '9')); p++);
ttynum = simple_strtoul(p, &err, 0);
if ((ttynum < 0) || (ttynum >= CTC_TTY_MAX_DEVICES) ||
(err && *err)) {
printk(KERN_WARNING
"ctc_tty_register_netdev called "
"with number in name '%s'\n", dev->name);
return -1;
}
if (driver->info[ttynum].netdev) {
printk(KERN_WARNING
"ctc_tty_register_netdev called "
"for already registered device '%s'\n",
dev->name);
return -1;
}
driver->info[ttynum].netdev = dev;
return 0;
}
void
ctc_tty_unregister_netdev(struct net_device *dev) {
int i;
unsigned long saveflags;
ctc_tty_info *info = NULL;
DBF_TEXT(trace, 2, __FUNCTION__);
spin_lock_irqsave(&ctc_tty_lock, saveflags);
for (i = 0; i < CTC_TTY_MAX_DEVICES; i++)
if (driver->info[i].netdev == dev) {
info = &driver->info[i];
break;
}
if (info) {
info->netdev = NULL;
skb_queue_purge(&info->tx_queue);
skb_queue_purge(&info->rx_queue);
}
spin_unlock_irqrestore(&ctc_tty_lock, saveflags);
}
void
ctc_tty_cleanup(void) {
unsigned long saveflags;
DBF_TEXT(trace, 2, __FUNCTION__);
spin_lock_irqsave(&ctc_tty_lock, saveflags);
ctc_tty_shuttingdown = 1;
spin_unlock_irqrestore(&ctc_tty_lock, saveflags);
tty_unregister_driver(driver->ctc_tty_device);
put_tty_driver(driver->ctc_tty_device);
kfree(driver);
driver = NULL;
}
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