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)
+{
+ 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->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;
+ /* 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 = tty->buf.tail, *n;
+ int left = 0;
+
+ /* 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 != NULL)
+ left = b->size - b->used;
+ if(left >= size)
+ return size;
+ /* This is the slow path - looking for new buffers to use */
+ n = tty_buffer_find(tty, size);
+ if(n == NULL)
+ return left;
+ if(b != NULL)
+ b->next = n;
+ else
+ tty->buf.head = n;
+ tty->buf.tail = n;
+ return size;
+}
+
+EXPORT_SYMBOL_GPL(tty_buffer_request_room);
+
+int tty_insert_flip_string(struct tty_struct *tty, 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;
+/* printk("Flip insert %d.\n", 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);
+
+int tty_insert_flip_string_flags(struct tty_struct *tty, unsigned char *chars, 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);
+
+
+/*
+ * 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);
+ 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);
+ 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
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;
}
check_tty_count(tty, "do_tty_hangup");
file_list_lock();
/* This breaks for file handles being sent over AF_UNIX sockets ? */
- list_for_each_entry(filp, &tty->tty_files, f_list) {
+ list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) {
if (filp->f_op->write == redirected_tty_write)
cons_filp = filp;
if (filp->f_op->write != tty_write)
/* Release locally allocated memory ... nothing placed in slots */
free_mem_out:
- if (o_tp)
- kfree(o_tp);
+ kfree(o_tp);
if (o_tty)
free_tty_struct(o_tty);
- if (ltp)
- kfree(ltp);
- if (tp)
- kfree(tp);
+ kfree(ltp);
+ kfree(tp);
free_tty_struct(tty);
fail_no_mem:
*/
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();
/*
* 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;
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;
- }
- count = tty->flip.count;
- tty->flip.count = 0;
+ while((tbuf = tty->buf.head) != NULL) {
+ tty->buf.head = tbuf->next;
+ if (tty->buf.head == NULL)
+ tty->buf.tail = NULL;
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+ /* printk("Process buffer %p for %d\n", tbuf, tbuf->used); */
+ disc->receive_buf(tty, tbuf->char_buf_ptr,
+ tbuf->flag_buf_ptr,
+ tbuf->used);
+ spin_lock_irqsave(&tty->read_lock, flags);
+ tty_buffer_free(tty, tbuf);
+ }
spin_unlock_irqrestore(&tty->read_lock, flags);
-
- disc->receive_buf(tty, cp, fp, count);
out:
tty_ldisc_deref(disc);
}
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);
projects / linux-2.6-omap-h63xx.git / blobdiff