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path: root/drivers/tty/n_hdlc.c
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Diffstat (limited to 'drivers/tty/n_hdlc.c')
-rw-r--r--drivers/tty/n_hdlc.c106
1 files changed, 49 insertions, 57 deletions
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 47d32281032..644ddb841d9 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -97,13 +97,11 @@
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/errno.h>
-#include <linux/smp_lock.h>
#include <linux/string.h> /* used in new tty drivers */
#include <linux/signal.h> /* used in new tty drivers */
#include <linux/if.h>
#include <linux/bitops.h>
-#include <asm/system.h>
#include <asm/termios.h>
#include <asm/uaccess.h>
@@ -418,7 +416,7 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
__FILE__,__LINE__,tbuf,tbuf->count);
/* Send the next block of data to device */
- tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
+ set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
actual = tty->ops->write(tty, tbuf->buf, tbuf->count);
/* rollback was possible and has been done */
@@ -460,7 +458,7 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
}
if (!tbuf)
- tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
+ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
/* Clear the re-entry flag */
spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
@@ -492,7 +490,7 @@ static void n_hdlc_tty_wakeup(struct tty_struct *tty)
return;
if (tty != n_hdlc->tty) {
- tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
+ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
return;
}
@@ -581,8 +579,9 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
__u8 __user *buf, size_t nr)
{
struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
- int ret;
+ int ret = 0;
struct n_hdlc_buf *rbuf;
+ DECLARE_WAITQUEUE(wait, current);
if (debuglevel >= DEBUG_LEVEL_INFO)
printk("%s(%d)n_hdlc_tty_read() called\n",__FILE__,__LINE__);
@@ -598,57 +597,55 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
return -EFAULT;
}
- tty_lock();
+ add_wait_queue(&tty->read_wait, &wait);
for (;;) {
if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
- tty_unlock();
- return -EIO;
+ ret = -EIO;
+ break;
}
+ if (tty_hung_up_p(file))
+ break;
- n_hdlc = tty2n_hdlc (tty);
- if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC ||
- tty != n_hdlc->tty) {
- tty_unlock();
- return 0;
- }
+ set_current_state(TASK_INTERRUPTIBLE);
rbuf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);
- if (rbuf)
+ if (rbuf) {
+ if (rbuf->count > nr) {
+ /* too large for caller's buffer */
+ ret = -EOVERFLOW;
+ } else {
+ if (copy_to_user(buf, rbuf->buf, rbuf->count))
+ ret = -EFAULT;
+ else
+ ret = rbuf->count;
+ }
+
+ if (n_hdlc->rx_free_buf_list.count >
+ DEFAULT_RX_BUF_COUNT)
+ kfree(rbuf);
+ else
+ n_hdlc_buf_put(&n_hdlc->rx_free_buf_list, rbuf);
break;
+ }
/* no data */
if (file->f_flags & O_NONBLOCK) {
- tty_unlock();
- return -EAGAIN;
+ ret = -EAGAIN;
+ break;
}
-
- interruptible_sleep_on (&tty->read_wait);
+
+ schedule();
+
if (signal_pending(current)) {
- tty_unlock();
- return -EINTR;
+ ret = -EINTR;
+ break;
}
}
-
- if (rbuf->count > nr)
- /* frame too large for caller's buffer (discard frame) */
- ret = -EOVERFLOW;
- else {
- /* Copy the data to the caller's buffer */
- if (copy_to_user(buf, rbuf->buf, rbuf->count))
- ret = -EFAULT;
- else
- ret = rbuf->count;
- }
-
- /* return HDLC buffer to free list unless the free list */
- /* count has exceeded the default value, in which case the */
- /* buffer is freed back to the OS to conserve memory */
- if (n_hdlc->rx_free_buf_list.count > DEFAULT_RX_BUF_COUNT)
- kfree(rbuf);
- else
- n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,rbuf);
- tty_unlock();
+
+ remove_wait_queue(&tty->read_wait, &wait);
+ __set_current_state(TASK_RUNNING);
+
return ret;
} /* end of n_hdlc_tty_read() */
@@ -691,14 +688,15 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
count = maxframe;
}
- tty_lock();
-
add_wait_queue(&tty->write_wait, &wait);
- set_current_state(TASK_INTERRUPTIBLE);
+
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
- /* Allocate transmit buffer */
- /* sleep until transmit buffer available */
- while (!(tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list))) {
+ tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list);
+ if (tbuf)
+ break;
+
if (file->f_flags & O_NONBLOCK) {
error = -EAGAIN;
break;
@@ -719,7 +717,7 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
}
}
- set_current_state(TASK_RUNNING);
+ __set_current_state(TASK_RUNNING);
remove_wait_queue(&tty->write_wait, &wait);
if (!error) {
@@ -731,7 +729,7 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
n_hdlc_buf_put(&n_hdlc->tx_buf_list,tbuf);
n_hdlc_send_frames(n_hdlc,tty);
}
- tty_unlock();
+
return error;
} /* end of n_hdlc_tty_write() */
@@ -850,13 +848,11 @@ static struct n_hdlc *n_hdlc_alloc(void)
{
struct n_hdlc_buf *buf;
int i;
- struct n_hdlc *n_hdlc = kmalloc(sizeof(*n_hdlc), GFP_KERNEL);
+ struct n_hdlc *n_hdlc = kzalloc(sizeof(*n_hdlc), GFP_KERNEL);
if (!n_hdlc)
return NULL;
- memset(n_hdlc, 0, sizeof(*n_hdlc));
-
n_hdlc_buf_list_init(&n_hdlc->rx_free_buf_list);
n_hdlc_buf_list_init(&n_hdlc->tx_free_buf_list);
n_hdlc_buf_list_init(&n_hdlc->rx_buf_list);
@@ -954,8 +950,6 @@ static char hdlc_register_ok[] __initdata =
KERN_INFO "N_HDLC line discipline registered.\n";
static char hdlc_register_fail[] __initdata =
KERN_ERR "error registering line discipline: %d\n";
-static char hdlc_init_fail[] __initdata =
- KERN_INFO "N_HDLC: init failure %d\n";
static int __init n_hdlc_init(void)
{
@@ -975,8 +969,6 @@ static int __init n_hdlc_init(void)
else
printk(hdlc_register_fail, status);
- if (status)
- printk(hdlc_init_fail, status);
return status;
} /* end of init_module() */
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 08:11:12 +0000