tty: make tty_ldisc_ops::*buf*() hooks operate on size_t

Count passed to tty_ldisc_ops::receive_buf*(), ::lookahead_buf(), and
returned from ::receive_buf2() is expected to be size_t. So set it to
size_t to unify with the rest of the code.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Max Staudt <max@enpas.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: Matt Johnston <matt@codeconstruct.com.au>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230810091510.13006-16-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/accessibility/speakup/spk_ttyio.c

@@ -71,9 +71,9 @@ static void spk_ttyio_ldisc_close(struct tty_struct *tty)
 	kfree(tty->disc_data);
 }
 
-static int spk_ttyio_receive_buf2(struct tty_struct *tty,
-				  const unsigned char *cp,
-				  const char *fp, int count)
+static size_t spk_ttyio_receive_buf2(struct tty_struct *tty,
+				     const unsigned char *cp, const char *fp,
+				     size_t count)
 {
 	struct spk_ldisc_data *ldisc_data = tty->disc_data;
 	struct spk_synth *synth = ldisc_data->synth;

drivers/bluetooth/hci_ldisc.c

@@ -599,7 +599,7 @@ static void hci_uart_tty_wakeup(struct tty_struct *tty)
  * Return Value:    None
  */
 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
-				 const char *flags, int count)
+				 const char *flags, size_t count)
 {
 	struct hci_uart *hu = tty->disc_data;
 

drivers/input/serio/serport.c

@@ -115,7 +115,8 @@ static void serport_ldisc_close(struct tty_struct *tty)
  */
 
 static void serport_ldisc_receive(struct tty_struct *tty,
-		const unsigned char *cp, const char *fp, int count)
+				  const unsigned char *cp, const char *fp,
+				  size_t count)
 {
 	struct serport *serport = tty->disc_data;
 	unsigned long flags;

drivers/misc/ti-st/st_core.c

@@ -792,7 +792,7 @@ static void st_tty_close(struct tty_struct *tty)
 }
 
 static void st_tty_receive(struct tty_struct *tty, const unsigned char *data,
-			   const char *tty_flags, int count)
+			   const char *tty_flags, size_t count)
 {
 #ifdef VERBOSE
 	print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE,

drivers/net/caif/caif_serial.c

@@ -159,7 +159,7 @@ static inline void debugfs_tx(struct ser_device *ser, const u8 *data, int size)
 #endif
 
 static void ldisc_receive(struct tty_struct *tty, const u8 *data,
-			const char *flags, int count)
+			  const char *flags, size_t count)
 {
 	struct sk_buff *skb = NULL;
 	struct ser_device *ser;

drivers/net/can/can327.c

@@ -886,7 +886,7 @@ static bool can327_is_valid_rx_char(u8 c)
  * functions may be called in parallel.
  */
 static void can327_ldisc_rx(struct tty_struct *tty, const unsigned char *cp,
-			    const char *fp, int count)
+			    const char *fp, size_t count)
 {
 	struct can327 *elm = tty->disc_data;
 	size_t first_new_char_idx;
@@ -904,7 +904,7 @@ static void can327_ldisc_rx(struct tty_struct *tty, const unsigned char *cp,
 	while (count--) {
 		if (elm->rxfill >= CAN327_SIZE_RXBUF) {
 			netdev_err(elm->dev,
-				   "Receive buffer overflowed. Bad chip or wiring? count = %i",
+				   "Receive buffer overflowed. Bad chip or wiring? count = %zu",
 				   count);
 			goto uart_failure;
 		}

drivers/net/can/slcan/slcan-core.c

@@ -776,7 +776,7 @@ static const struct net_device_ops slcan_netdev_ops = {
  */
 static void slcan_receive_buf(struct tty_struct *tty,
 			      const unsigned char *cp, const char *fp,
-			      int count)
+			      size_t count)
 {
 	struct slcan *sl = tty->disc_data;
 

drivers/net/hamradio/6pack.c

@@ -428,7 +428,7 @@ out:
  * and sent on to some IP layer for further processing.
  */
 static void sixpack_receive_buf(struct tty_struct *tty,
-	const unsigned char *cp, const char *fp, int count)
+	const unsigned char *cp, const char *fp, size_t count)
 {
 	struct sixpack *sp;
 	int count1;

drivers/net/hamradio/mkiss.c

@@ -875,7 +875,7 @@ static int mkiss_ioctl(struct tty_struct *tty, unsigned int cmd,
  * and sent on to the AX.25 layer for further processing.
  */
 static void mkiss_receive_buf(struct tty_struct *tty, const unsigned char *cp,
-	const char *fp, int count)
+			      const char *fp, size_t count)
 {
 	struct mkiss *ax = mkiss_get(tty);
 

drivers/net/mctp/mctp-serial.c

@@ -392,7 +392,7 @@ static void mctp_serial_push(struct mctp_serial *dev, unsigned char c)
 
 static void mctp_serial_tty_receive_buf(struct tty_struct *tty,
 					const unsigned char *c,
-					const char *f, int len)
+					const char *f, size_t len)
 {
 	struct mctp_serial *dev = tty->disc_data;
 	int i;

drivers/net/ppp/ppp_async.c

@@ -331,7 +331,7 @@ ppp_asynctty_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
 /* May sleep, don't call from interrupt level or with interrupts disabled */
 static void
 ppp_asynctty_receive(struct tty_struct *tty, const unsigned char *buf,
-		  const char *cflags, int count)
+		     const char *cflags, size_t count)
 {
 	struct asyncppp *ap = ap_get(tty);
 	unsigned long flags;

drivers/net/ppp/ppp_synctty.c

@@ -324,7 +324,7 @@ ppp_synctty_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
 /* May sleep, don't call from interrupt level or with interrupts disabled */
 static void
 ppp_sync_receive(struct tty_struct *tty, const unsigned char *buf,
-		  const char *cflags, int count)
+		 const char *cflags, size_t count)
 {
 	struct syncppp *ap = sp_get(tty);
 	unsigned long flags;

drivers/net/slip/slip.c

@@ -686,7 +686,7 @@ static void sl_setup(struct net_device *dev)
  */
 
 static void slip_receive_buf(struct tty_struct *tty, const unsigned char *cp,
-		const char *fp, int count)
+			     const char *fp, size_t count)
 {
 	struct slip *sl = tty->disc_data;
 

drivers/tty/n_gsm.c

@@ -3490,7 +3490,7 @@ static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
 }
 
 static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
-			      const char *fp, int count)
+			      const char *fp, size_t count)
 {
 	struct gsm_mux *gsm = tty->disc_data;
 	char flags = TTY_NORMAL;

drivers/tty/n_hdlc.c

@@ -370,12 +370,12 @@ static void n_hdlc_tty_wakeup(struct tty_struct *tty)
  * interpreted as one HDLC frame.
  */
 static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data,
-			       const char *flags, int count)
+			       const char *flags, size_t count)
 {
 	register struct n_hdlc *n_hdlc = tty->disc_data;
 	register struct n_hdlc_buf *buf;
 
-	pr_debug("%s() called count=%d\n", __func__, count);
+	pr_debug("%s() called count=%zu\n", __func__, count);
 
 	if (count > maxframe) {
 		pr_debug("rx count>maxframesize, data discarded\n");

drivers/tty/n_tty.c

@@ -1480,7 +1480,7 @@ n_tty_receive_char_lnext(struct tty_struct *tty, unsigned char c, char flag)
 
 /* Caller must ensure count > 0 */
 static void n_tty_lookahead_flow_ctrl(struct tty_struct *tty, const unsigned char *cp,
-				      const unsigned char *fp, unsigned int count)
+				      const unsigned char *fp, size_t count)
 {
 	struct n_tty_data *ldata = tty->disc_data;
 	unsigned char flag = TTY_NORMAL;
@@ -1662,12 +1662,13 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
  *	claims non-exclusive %termios_rwsem
  *	publishes commit_head or canon_head
  */
-static int
+static size_t
 n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp,
 			 const char *fp, int count, int flow)
 {
 	struct n_tty_data *ldata = tty->disc_data;
-	int room, n, rcvd = 0, overflow;
+	size_t rcvd = 0;
+	int room, n, overflow;
 
 	down_read(&tty->termios_rwsem);
 
@@ -1744,13 +1745,14 @@ n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp,
 }
 
 static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
-			      const char *fp, int count)
+			      const char *fp, size_t count)
 {
 	n_tty_receive_buf_common(tty, cp, fp, count, 0);
 }
 
-static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
-			      const char *fp, int count)
+static size_t n_tty_receive_buf2(struct tty_struct *tty,
+				 const unsigned char *cp, const char *fp,
+				 size_t count)
 {
 	return n_tty_receive_buf_common(tty, cp, fp, count, 1);
 }

include/linux/tty_ldisc.h

@@ -162,7 +162,7 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *	Optional. Can sleep.
  *
  * @receive_buf: [DRV] ``void ()(struct tty_struct *tty,
- *		       const unsigned char *cp, const char *fp, int count)``
+ *		       const unsigned char *cp, const char *fp, size_t count)``
  *
  *	This function is called by the low-level tty driver to send characters
  *	received by the hardware to the line discpline for processing. @cp is
@@ -191,8 +191,8 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *
  *	Optional.
  *
- * @receive_buf2: [DRV] ``int ()(struct tty_struct *tty,
- *			const unsigned char *cp, const char *fp, int count)``
+ * @receive_buf2: [DRV] ``ssize_t ()(struct tty_struct *tty,
+ *			const unsigned char *cp, const char *fp, size_t count)``
  *
  *	This function is called by the low-level tty driver to send characters
  *	received by the hardware to the line discpline for processing. @cp is a
@@ -205,7 +205,7 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *	Optional.
  *
  * @lookahead_buf: [DRV] ``void ()(struct tty_struct *tty,
- *			const unsigned char *cp, const char *fp, int count)``
+ *			const unsigned char *cp, const char *fp, size_t count)``
  *
  *	This function is called by the low-level tty driver for characters
  *	not eaten by ->receive_buf() or ->receive_buf2(). It is useful for
@@ -256,13 +256,13 @@ struct tty_ldisc_ops {
 	 * The following routines are called from below.
 	 */
 	void	(*receive_buf)(struct tty_struct *tty, const unsigned char *cp,
-			       const char *fp, int count);
+			       const char *fp, size_t count);
 	void	(*write_wakeup)(struct tty_struct *tty);
 	void	(*dcd_change)(struct tty_struct *tty, bool active);
-	int	(*receive_buf2)(struct tty_struct *tty, const unsigned char *cp,
-				const char *fp, int count);
+	size_t	(*receive_buf2)(struct tty_struct *tty, const unsigned char *cp,
+				const char *fp, size_t count);
 	void	(*lookahead_buf)(struct tty_struct *tty, const unsigned char *cp,
-				 const unsigned char *fp, unsigned int count);
+				 const unsigned char *fp, size_t count);
 
 	struct  module *owner;
 };

net/nfc/nci/uart.c

@@ -296,7 +296,7 @@ static int nci_uart_default_recv_buf(struct nci_uart *nu, const u8 *data,
  * Return Value:    None
  */
 static void nci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
-				 const char *flags, int count)
+				 const char *flags, size_t count)
 {
 	struct nci_uart *nu = tty->disc_data;
 

sound/soc/codecs/cx20442.c

@@ -259,7 +259,7 @@ static void v253_hangup(struct tty_struct *tty)
 
 /* Line discipline .receive_buf() */
 static void v253_receive(struct tty_struct *tty, const unsigned char *cp,
-		const char *fp, int count)
+			 const char *fp, size_t count)
 {
 	struct snd_soc_component *component = tty->disc_data;
 	struct cx20442_priv *cx20442;