#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/module.h>
+#include <linux/ratelimit.h>
/**
* tty_buffer_free_all - free buffers used by a tty
struct tty_bufhead *buf = &port->buf;
struct tty_buffer *thead;
- while ((thead = buf->head) != NULL) {
- buf->head = thead->next;
- tty_buffer_free(port, thead);
+ if (unlikely(buf->head == NULL))
+ return;
+ while ((thead = buf->head->next) != NULL) {
+ tty_buffer_free(port, buf->head);
+ buf->head = thead;
}
- buf->tail = NULL;
+ WARN_ON(buf->head != buf->tail);
+ buf->head->read = buf->head->commit;
}
/**
have queued and recycle that ? */
}
/**
- * __tty_buffer_request_room - grow tty buffer if needed
+ * tty_buffer_request_room - grow tty buffer if needed
* @tty: tty structure
* @size: size desired
*
* Make at least size bytes of linear space available for the tty
* buffer. If we fail return the size we managed to find.
- * Locking: Caller must hold port->buf.lock
+ *
+ * Locking: Takes port->buf.lock
*/
-static int __tty_buffer_request_room(struct tty_port *port, size_t size)
+int tty_buffer_request_room(struct tty_port *port, size_t size)
{
struct tty_bufhead *buf = &port->buf;
struct tty_buffer *b, *n;
int left;
+ unsigned long flags;
+ spin_lock_irqsave(&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 */
} else
size = left;
}
-
+ spin_unlock_irqrestore(&buf->lock, flags);
return size;
}
-
-
-/**
- * tty_buffer_request_room - grow tty buffer if needed
- * @tty: tty structure
- * @size: size desired
- *
- * Make at least size bytes of linear space available for the tty
- * buffer. If we fail return the size we managed to find.
- *
- * Locking: Takes port->buf.lock
- */
-int tty_buffer_request_room(struct tty_struct *tty, size_t size)
-{
- struct tty_port *port = tty->port;
- unsigned long flags;
- int length;
-
- spin_lock_irqsave(&port->buf.lock, flags);
- length = __tty_buffer_request_room(port, size);
- spin_unlock_irqrestore(&port->buf.lock, flags);
- return length;
-}
EXPORT_SYMBOL_GPL(tty_buffer_request_room);
/**
* tty_insert_flip_string_fixed_flag - Add characters to the tty buffer
- * @tty: tty structure
+ * @port: tty port
* @chars: characters
* @flag: flag value for each character
* @size: size
* Locking: Called functions may take port->buf.lock
*/
-int tty_insert_flip_string_fixed_flag(struct tty_struct *tty,
+int tty_insert_flip_string_fixed_flag(struct tty_port *port,
const unsigned char *chars, char flag, size_t size)
{
- struct tty_bufhead *buf = &tty->port->buf;
int copied = 0;
do {
int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
- int space;
- unsigned long flags;
- struct tty_buffer *tb;
-
- spin_lock_irqsave(&buf->lock, flags);
- space = __tty_buffer_request_room(tty->port, goal);
- tb = buf->tail;
+ int space = tty_buffer_request_room(port, goal);
+ struct tty_buffer *tb = port->buf.tail;
/* If there is no space then tb may be NULL */
if (unlikely(space == 0)) {
- spin_unlock_irqrestore(&buf->lock, flags);
break;
}
memcpy(tb->char_buf_ptr + tb->used, chars, space);
memset(tb->flag_buf_ptr + tb->used, flag, space);
tb->used += space;
- spin_unlock_irqrestore(&buf->lock, flags);
copied += space;
chars += space;
/* There is a small chance that we need to split the data over
/**
* tty_insert_flip_string_flags - Add characters to the tty buffer
- * @tty: tty structure
+ * @port: tty port
* @chars: characters
* @flags: flag bytes
* @size: size
* Locking: Called functions may take port->buf.lock
*/
-int tty_insert_flip_string_flags(struct tty_struct *tty,
+int tty_insert_flip_string_flags(struct tty_port *port,
const unsigned char *chars, const char *flags, size_t size)
{
- struct tty_bufhead *buf = &tty->port->buf;
int copied = 0;
do {
int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
- int space;
- unsigned long __flags;
- struct tty_buffer *tb;
-
- spin_lock_irqsave(&buf->lock, __flags);
- space = __tty_buffer_request_room(tty->port, goal);
- tb = buf->tail;
+ int space = tty_buffer_request_room(port, goal);
+ struct tty_buffer *tb = port->buf.tail;
/* If there is no space then tb may be NULL */
if (unlikely(space == 0)) {
- spin_unlock_irqrestore(&buf->lock, __flags);
break;
}
memcpy(tb->char_buf_ptr + tb->used, chars, space);
memcpy(tb->flag_buf_ptr + tb->used, flags, space);
tb->used += space;
- spin_unlock_irqrestore(&buf->lock, __flags);
copied += space;
chars += space;
flags += space;
/**
* tty_schedule_flip - push characters to ldisc
- * @tty: tty to push from
+ * @port: tty port to push from
*
* Takes any pending buffers and transfers their ownership to the
* ldisc side of the queue. It then schedules those characters for
* Locking: Takes port->buf.lock
*/
-void tty_schedule_flip(struct tty_struct *tty)
+void tty_schedule_flip(struct tty_port *port)
{
- struct tty_bufhead *buf = &tty->port->buf;
+ struct tty_bufhead *buf = &port->buf;
unsigned long flags;
- WARN_ON(tty->low_latency);
+ WARN_ON(port->low_latency);
spin_lock_irqsave(&buf->lock, flags);
if (buf->tail != NULL)
/**
* tty_prepare_flip_string - make room for characters
- * @tty: tty
+ * @port: tty port
* @chars: return pointer for character write area
* @size: desired size
*
* Locking: May call functions taking port->buf.lock
*/
-int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars,
+int tty_prepare_flip_string(struct tty_port *port, unsigned char **chars,
size_t size)
{
- struct tty_bufhead *buf = &tty->port->buf;
- int space;
- unsigned long flags;
- struct tty_buffer *tb;
-
- spin_lock_irqsave(&buf->lock, flags);
- space = __tty_buffer_request_room(tty->port, size);
-
- tb = buf->tail;
+ int space = tty_buffer_request_room(port, size);
if (likely(space)) {
+ struct tty_buffer *tb = port->buf.tail;
*chars = tb->char_buf_ptr + tb->used;
memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
tb->used += space;
}
- spin_unlock_irqrestore(&buf->lock, flags);
return space;
}
EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
/**
* tty_prepare_flip_string_flags - make room for characters
- * @tty: tty
+ * @port: tty port
* @chars: return pointer for character write area
* @flags: return pointer for status flag write area
* @size: desired size
* Locking: May call functions taking port->buf.lock
*/
-int tty_prepare_flip_string_flags(struct tty_struct *tty,
+int tty_prepare_flip_string_flags(struct tty_port *port,
unsigned char **chars, char **flags, size_t size)
{
- struct tty_bufhead *buf = &tty->port->buf;
- int space;
- unsigned long __flags;
- struct tty_buffer *tb;
-
- spin_lock_irqsave(&buf->lock, __flags);
- space = __tty_buffer_request_room(tty->port, size);
-
- tb = buf->tail;
+ int space = tty_buffer_request_room(port, size);
if (likely(space)) {
+ struct tty_buffer *tb = port->buf.tail;
*chars = tb->char_buf_ptr + tb->used;
*flags = tb->flag_buf_ptr + tb->used;
tb->used += space;
}
- spin_unlock_irqrestore(&buf->lock, __flags);
return space;
}
EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
*/
void tty_flush_to_ldisc(struct tty_struct *tty)
{
- if (!tty->low_latency)
+ if (!tty->port->low_latency)
flush_work(&tty->port->buf.work);
}
/**
* tty_flip_buffer_push - terminal
- * @tty: tty to push
+ * @port: tty port to push
*
* Queue a push of the terminal flip buffers to the line discipline. This
- * function must not be called from IRQ context if tty->low_latency is set.
+ * function must not be called from IRQ context if port->low_latency is
+ * set.
*
* In the event of the queue being busy for flipping the work will be
* held off and retried later.
* Locking: tty buffer lock. Driver locks in low latency mode.
*/
-void tty_flip_buffer_push(struct tty_struct *tty)
+void tty_flip_buffer_push(struct tty_port *port)
{
- struct tty_bufhead *buf = &tty->port->buf;
+ struct tty_bufhead *buf = &port->buf;
unsigned long flags;
spin_lock_irqsave(&buf->lock, flags);
buf->tail->commit = buf->tail->used;
spin_unlock_irqrestore(&buf->lock, flags);
- if (tty->low_latency)
+ if (port->low_latency)
flush_to_ldisc(&buf->work);
else
schedule_work(&buf->work);
projects / firefly-linux-kernel-4.4.55.git / blobdiff