/* Semaphore to protect creating and releasing a tty. This is shared with
vt.c for deeply disgusting hack reasons */
-DECLARE_MUTEX(tty_sem);
+DEFINE_MUTEX(tty_mutex);
#ifdef CONFIG_UNIX98_PTYS
extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */
return tty;
}
+static void tty_buffer_free_all(struct tty_struct *);
+
static inline void free_tty_struct(struct tty_struct *tty)
{
kfree(tty->write_buf);
+ tty_buffer_free_all(tty);
kfree(tty);
}
return 0;
}
+/*
+ * Tty buffer allocation management
+ */
+
+static void tty_buffer_free_all(struct tty_struct *tty)
+{
+ struct tty_buffer *thead;
+ while((thead = tty->buf.head) != NULL) {
+ tty->buf.head = thead->next;
+ kfree(thead);
+ }
+ while((thead = tty->buf.free) != NULL) {
+ tty->buf.free = thead->next;
+ kfree(thead);
+ }
+ tty->buf.tail = NULL;
+}
+
+static void tty_buffer_init(struct tty_struct *tty)
+{
+ spin_lock_init(&tty->buf.lock);
+ tty->buf.head = NULL;
+ tty->buf.tail = NULL;
+ tty->buf.free = NULL;
+}
+
+static struct tty_buffer *tty_buffer_alloc(size_t size)
+{
+ struct tty_buffer *p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC);
+ if(p == NULL)
+ return NULL;
+ p->used = 0;
+ p->size = size;
+ p->next = NULL;
+ p->active = 0;
+ p->commit = 0;
+ p->read = 0;
+ p->char_buf_ptr = (char *)(p->data);
+ p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size;
+/* printk("Flip create %p\n", p); */
+ return p;
+}
+
+/* Must be called with the tty_read lock held. This needs to acquire strategy
+ code to decide if we should kfree or relink a given expired buffer */
+
+static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
+{
+ /* Dumb strategy for now - should keep some stats */
+/* printk("Flip dispose %p\n", b); */
+ if(b->size >= 512)
+ kfree(b);
+ else {
+ b->next = tty->buf.free;
+ tty->buf.free = b;
+ }
+}
+
+static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
+{
+ struct tty_buffer **tbh = &tty->buf.free;
+ while((*tbh) != NULL) {
+ struct tty_buffer *t = *tbh;
+ if(t->size >= size) {
+ *tbh = t->next;
+ t->next = NULL;
+ t->used = 0;
+ t->commit = 0;
+ t->read = 0;
+ /* DEBUG ONLY */
+/* memset(t->data, '*', size); */
+/* printk("Flip recycle %p\n", t); */
+ return t;
+ }
+ tbh = &((*tbh)->next);
+ }
+ /* Round the buffer size out */
+ size = (size + 0xFF) & ~ 0xFF;
+ return tty_buffer_alloc(size);
+ /* Should possibly check if this fails for the largest buffer we
+ have queued and recycle that ? */
+}
+
+int tty_buffer_request_room(struct tty_struct *tty, size_t size)
+{
+ struct tty_buffer *b, *n;
+ int left;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tty->buf.lock, flags);
+
+ /* OPTIMISATION: We could keep a per tty "zero" sized buffer to
+ remove this conditional if its worth it. This would be invisible
+ to the callers */
+ if ((b = tty->buf.tail) != NULL) {
+ left = b->size - b->used;
+ b->active = 1;
+ } else
+ left = 0;
+
+ if (left < size) {
+ /* This is the slow path - looking for new buffers to use */
+ if ((n = tty_buffer_find(tty, size)) != NULL) {
+ if (b != NULL) {
+ b->next = n;
+ b->active = 0;
+ b->commit = b->used;
+ } else
+ tty->buf.head = n;
+ tty->buf.tail = n;
+ n->active = 1;
+ } else
+ size = left;
+ }
+
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ return size;
+}
+EXPORT_SYMBOL_GPL(tty_buffer_request_room);
+
+int tty_insert_flip_string(struct tty_struct *tty, const unsigned char *chars,
+ size_t size)
+{
+ int copied = 0;
+ do {
+ int space = tty_buffer_request_room(tty, size - copied);
+ struct tty_buffer *tb = tty->buf.tail;
+ /* If there is no space then tb may be NULL */
+ if(unlikely(space == 0))
+ break;
+ memcpy(tb->char_buf_ptr + tb->used, chars, space);
+ memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
+ tb->used += space;
+ copied += space;
+ chars += space;
+ }
+ /* There is a small chance that we need to split the data over
+ several buffers. If this is the case we must loop */
+ while (unlikely(size > copied));
+ return copied;
+}
+EXPORT_SYMBOL(tty_insert_flip_string);
+
+int tty_insert_flip_string_flags(struct tty_struct *tty,
+ const unsigned char *chars, const char *flags, size_t size)
+{
+ int copied = 0;
+ do {
+ int space = tty_buffer_request_room(tty, size - copied);
+ struct tty_buffer *tb = tty->buf.tail;
+ /* If there is no space then tb may be NULL */
+ if(unlikely(space == 0))
+ break;
+ memcpy(tb->char_buf_ptr + tb->used, chars, space);
+ memcpy(tb->flag_buf_ptr + tb->used, flags, space);
+ tb->used += space;
+ copied += space;
+ chars += space;
+ flags += space;
+ }
+ /* There is a small chance that we need to split the data over
+ several buffers. If this is the case we must loop */
+ while (unlikely(size > copied));
+ return copied;
+}
+EXPORT_SYMBOL_GPL(tty_insert_flip_string_flags);
+
+void tty_schedule_flip(struct tty_struct *tty)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ if (tty->buf.tail != NULL) {
+ tty->buf.tail->active = 0;
+ tty->buf.tail->commit = tty->buf.tail->used;
+ }
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ schedule_delayed_work(&tty->buf.work, 1);
+}
+EXPORT_SYMBOL(tty_schedule_flip);
+
+/*
+ * Prepare a block of space in the buffer for data. Returns the length
+ * available and buffer pointer to the space which is now allocated and
+ * accounted for as ready for normal characters. This is used for drivers
+ * that need their own block copy routines into the buffer. There is no
+ * guarantee the buffer is a DMA target!
+ */
+
+int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars, size_t size)
+{
+ int space = tty_buffer_request_room(tty, size);
+ if (likely(space)) {
+ struct tty_buffer *tb = tty->buf.tail;
+ *chars = tb->char_buf_ptr + tb->used;
+ memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
+ tb->used += space;
+ }
+ return space;
+}
+
+EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
+
+/*
+ * Prepare a block of space in the buffer for data. Returns the length
+ * available and buffer pointer to the space which is now allocated and
+ * accounted for as ready for characters. This is used for drivers
+ * that need their own block copy routines into the buffer. There is no
+ * guarantee the buffer is a DMA target!
+ */
+
+int tty_prepare_flip_string_flags(struct tty_struct *tty, unsigned char **chars, char **flags, size_t size)
+{
+ int space = tty_buffer_request_room(tty, size);
+ if (likely(space)) {
+ struct tty_buffer *tb = tty->buf.tail;
+ *chars = tb->char_buf_ptr + tb->used;
+ *flags = tb->flag_buf_ptr + tb->used;
+ tb->used += space;
+ }
+ return space;
+}
+
+EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
+
+
+
/*
* This is probably overkill for real world processors but
* they are not on hot paths so a little discipline won't do
struct tty_ldisc *ld;
unsigned long flags;
- if (disc < N_TTY || disc >= NR_LDISCS)
- BUG();
+ BUG_ON(disc < N_TTY || disc >= NR_LDISCS);
spin_lock_irqsave(&tty_ldisc_lock, flags);
ld = &tty_ldiscs[disc];
- if(ld->refcount == 0)
- BUG();
- ld->refcount --;
+ BUG_ON(ld->refcount == 0);
+ ld->refcount--;
module_put(ld->owner);
spin_unlock_irqrestore(&tty_ldisc_lock, flags);
}
{
unsigned long flags;
- if(ld == NULL)
- BUG();
+ BUG_ON(ld == NULL);
spin_lock_irqsave(&tty_ldisc_lock, flags);
if(ld->refcount == 0)
if (ld == NULL)
return -EINVAL;
+ /*
+ * No more input please, we are switching. The new ldisc
+ * will update this value in the ldisc open function
+ */
+
+ tty->receive_room = 0;
+
+ /*
+ * Problem: What do we do if this blocks ?
+ */
+
tty_wait_until_sent(tty, 0);
if (tty->ldisc.num == ldisc) {
* we say so later on.
*/
- work = cancel_delayed_work(&tty->flip.work);
+ work = cancel_delayed_work(&tty->buf.work);
/*
- * Wait for ->hangup_work and ->flip.work handlers to terminate
+ * Wait for ->hangup_work and ->buf.work handlers to terminate
*/
flush_scheduled_work();
/* Restart it in case no characters kick it off. Safe if
already running */
if (work)
- schedule_delayed_work(&tty->flip.work, 1);
+ schedule_delayed_work(&tty->buf.work, 1);
return retval;
}
p->signal->tty = NULL;
if (!p->signal->leader)
continue;
- send_group_sig_info(SIGHUP, SEND_SIG_PRIV, p);
- send_group_sig_info(SIGCONT, SEND_SIG_PRIV, p);
+ group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);
+ group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);
if (tty->pgrp > 0)
p->signal->tty_old_pgrp = tty->pgrp;
} while_each_task_pid(tty->session, PIDTYPE_SID, p);
lock_kernel();
- down(&tty_sem);
+ mutex_lock(&tty_mutex);
tty = current->signal->tty;
if (tty) {
tty_pgrp = tty->pgrp;
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
tty_vhangup(tty);
} else {
kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit);
kill_pg(current->signal->tty_old_pgrp, SIGCONT, on_exit);
}
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
unlock_kernel();
return;
}
}
/* Must lock changes to tty_old_pgrp */
- down(&tty_sem);
+ mutex_lock(&tty_mutex);
current->signal->tty_old_pgrp = 0;
tty->session = 0;
tty->pgrp = -1;
p->signal->tty = NULL;
} while_each_task_pid(current->signal->session, PIDTYPE_SID, p);
read_unlock(&tasklist_lock);
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
unlock_kernel();
}
ssize_t ret = 0, written = 0;
unsigned int chunk;
- if (down_interruptible(&tty->atomic_write)) {
+ if (mutex_lock_interruptible(&tty->atomic_write_lock)) {
return -ERESTARTSYS;
}
if (count < chunk)
chunk = count;
- /* write_buf/write_cnt is protected by the atomic_write semaphore */
+ /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
if (tty->write_cnt < chunk) {
unsigned char *buf;
buf = kmalloc(chunk, GFP_KERNEL);
if (!buf) {
- up(&tty->atomic_write);
+ mutex_unlock(&tty->atomic_write_lock);
return -ENOMEM;
}
kfree(tty->write_buf);
inode->i_mtime = current_fs_time(inode->i_sb);
ret = written;
}
- up(&tty->atomic_write);
+ mutex_unlock(&tty->atomic_write_lock);
return ret;
}
/*
* WSH 06/09/97: Rewritten to remove races and properly clean up after a
- * failed open. The new code protects the open with a semaphore, so it's
- * really quite straightforward. The semaphore locking can probably be
+ * failed open. The new code protects the open with a mutex, so it's
+ * really quite straightforward. The mutex locking can probably be
* relaxed for the (most common) case of reopening a tty.
*/
static int init_dev(struct tty_driver *driver, int idx,
success:
*ret_tty = tty;
- /* All paths come through here to release the semaphore */
+ /* All paths come through here to release the mutex */
end_init:
return retval;
/* Guard against races with tty->count changes elsewhere and
opens on /dev/tty */
- down(&tty_sem);
+ mutex_lock(&tty_mutex);
tty_closing = tty->count <= 1;
o_tty_closing = o_tty &&
(o_tty->count <= (pty_master ? 1 : 0));
- up(&tty_sem);
do_sleep = 0;
if (tty_closing) {
printk(KERN_WARNING "release_dev: %s: read/write wait queue "
"active!\n", tty_name(tty, buf));
+ mutex_unlock(&tty_mutex);
schedule();
}
* both sides, and we've completed the last operation that could
* block, so it's safe to proceed with closing.
*/
-
- down(&tty_sem);
if (pty_master) {
if (--o_tty->count < 0) {
printk(KERN_WARNING "release_dev: bad pty slave count "
tty->count, tty_name(tty, buf));
tty->count = 0;
}
- up(&tty_sem);
/*
* We've decremented tty->count, so we need to remove this file
read_unlock(&tasklist_lock);
}
+ mutex_unlock(&tty_mutex);
+
/* check whether both sides are closing ... */
if (!tty_closing || (o_tty && !o_tty_closing))
return;
*/
clear_bit(TTY_LDISC, &tty->flags);
clear_bit(TTY_DONT_FLIP, &tty->flags);
- cancel_delayed_work(&tty->flip.work);
+ cancel_delayed_work(&tty->buf.work);
/*
- * Wait for ->hangup_work and ->flip.work handlers to terminate
+ * Wait for ->hangup_work and ->buf.work handlers to terminate
*/
flush_scheduled_work();
index = -1;
retval = 0;
- down(&tty_sem);
+ mutex_lock(&tty_mutex);
if (device == MKDEV(TTYAUX_MAJOR,0)) {
if (!current->signal->tty) {
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
return -ENXIO;
}
driver = current->signal->tty->driver;
noctty = 1;
goto got_driver;
}
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
return -ENODEV;
}
driver = get_tty_driver(device, &index);
if (!driver) {
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
return -ENODEV;
}
got_driver:
retval = init_dev(driver, index, &tty);
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
if (retval)
return retval;
}
up(&allocated_ptys_lock);
- down(&tty_sem);
+ mutex_lock(&tty_mutex);
retval = init_dev(ptm_driver, index, &tty);
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
if (retval)
goto out;
return 0;
out1:
release_dev(filp);
+ return retval;
out:
down(&allocated_ptys_lock);
idr_remove(&allocated_ptys, index);
tty_hangup(tty);
#else
struct tty_struct *tty = arg;
- struct task_struct *p;
+ struct task_struct *g, *p;
int session;
int i;
struct file *filp;
tty->driver->flush_buffer(tty);
read_lock(&tasklist_lock);
+ /* Kill the entire session */
do_each_task_pid(session, PIDTYPE_SID, p) {
- if (p->signal->tty == tty || session > 0) {
+ printk(KERN_NOTICE "SAK: killed process %d"
+ " (%s): p->signal->session==tty->session\n",
+ p->pid, p->comm);
+ send_sig(SIGKILL, p, 1);
+ } while_each_task_pid(session, PIDTYPE_SID, p);
+ /* Now kill any processes that happen to have the
+ * tty open.
+ */
+ do_each_thread(g, p) {
+ if (p->signal->tty == tty) {
printk(KERN_NOTICE "SAK: killed process %d"
" (%s): p->signal->session==tty->session\n",
p->pid, p->comm);
rcu_read_unlock();
}
task_unlock(p);
- } while_each_task_pid(session, PIDTYPE_SID, p);
+ } while_each_thread(g, p);
read_unlock(&tasklist_lock);
#endif
}
/*
* This routine is called out of the software interrupt to flush data
- * from the flip buffer to the line discipline.
+ * from the buffer chain to the line discipline.
*/
static void flush_to_ldisc(void *private_)
{
struct tty_struct *tty = (struct tty_struct *) private_;
- unsigned char *cp;
- char *fp;
- int count;
unsigned long flags;
struct tty_ldisc *disc;
+ struct tty_buffer *tbuf;
+ int count;
+ char *char_buf;
+ unsigned char *flag_buf;
disc = tty_ldisc_ref(tty);
if (disc == NULL) /* !TTY_LDISC */
/*
* Do it after the next timer tick:
*/
- schedule_delayed_work(&tty->flip.work, 1);
+ schedule_delayed_work(&tty->buf.work, 1);
goto out;
}
- spin_lock_irqsave(&tty->read_lock, flags);
- if (tty->flip.buf_num) {
- cp = tty->flip.char_buf + TTY_FLIPBUF_SIZE;
- fp = tty->flip.flag_buf + TTY_FLIPBUF_SIZE;
- tty->flip.buf_num = 0;
- tty->flip.char_buf_ptr = tty->flip.char_buf;
- tty->flip.flag_buf_ptr = tty->flip.flag_buf;
- } else {
- cp = tty->flip.char_buf;
- fp = tty->flip.flag_buf;
- tty->flip.buf_num = 1;
- tty->flip.char_buf_ptr = tty->flip.char_buf + TTY_FLIPBUF_SIZE;
- tty->flip.flag_buf_ptr = tty->flip.flag_buf + TTY_FLIPBUF_SIZE;
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ while((tbuf = tty->buf.head) != NULL) {
+ while ((count = tbuf->commit - tbuf->read) != 0) {
+ char_buf = tbuf->char_buf_ptr + tbuf->read;
+ flag_buf = tbuf->flag_buf_ptr + tbuf->read;
+ tbuf->read += count;
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ disc->receive_buf(tty, char_buf, flag_buf, count);
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ }
+ if (tbuf->active)
+ break;
+ tty->buf.head = tbuf->next;
+ if (tty->buf.head == NULL)
+ tty->buf.tail = NULL;
+ tty_buffer_free(tty, tbuf);
}
- count = tty->flip.count;
- tty->flip.count = 0;
- spin_unlock_irqrestore(&tty->read_lock, flags);
-
- disc->receive_buf(tty, cp, fp, count);
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
out:
tty_ldisc_deref(disc);
}
void tty_flip_buffer_push(struct tty_struct *tty)
{
+ unsigned long flags;
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ if (tty->buf.tail != NULL) {
+ tty->buf.tail->active = 0;
+ tty->buf.tail->commit = tty->buf.tail->used;
+ }
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+
if (tty->low_latency)
flush_to_ldisc((void *) tty);
else
- schedule_delayed_work(&tty->flip.work, 1);
+ schedule_delayed_work(&tty->buf.work, 1);
}
EXPORT_SYMBOL(tty_flip_buffer_push);
+
/*
* This subroutine initializes a tty structure.
*/
tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
tty->pgrp = -1;
tty->overrun_time = jiffies;
- tty->flip.char_buf_ptr = tty->flip.char_buf;
- tty->flip.flag_buf_ptr = tty->flip.flag_buf;
- INIT_WORK(&tty->flip.work, flush_to_ldisc, tty);
- init_MUTEX(&tty->flip.pty_sem);
+ tty->buf.head = tty->buf.tail = NULL;
+ tty_buffer_init(tty);
+ INIT_WORK(&tty->buf.work, flush_to_ldisc, tty);
+ init_MUTEX(&tty->buf.pty_sem);
init_MUTEX(&tty->termios_sem);
init_waitqueue_head(&tty->write_wait);
init_waitqueue_head(&tty->read_wait);
INIT_WORK(&tty->hangup_work, do_tty_hangup, tty);
- sema_init(&tty->atomic_read, 1);
- sema_init(&tty->atomic_write, 1);
+ mutex_init(&tty->atomic_read_lock);
+ mutex_init(&tty->atomic_write_lock);
spin_lock_init(&tty->read_lock);
INIT_LIST_HEAD(&tty->tty_files);
INIT_WORK(&tty->SAK_work, NULL, NULL);
projects / karo-tx-linux.git / blobdiff