Merge tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big set of tty and serial driver changes for 6.6-rc1.

  Lots of cleanups in here this cycle, and some driver updates. Short
  summary is:

   - Jiri's continued work to make the tty code and apis be a bit more
     sane with regards to modern kernel coding style and types

   - cpm_uart driver updates

   - n_gsm updates and fixes

   - meson driver updates

   - sc16is7xx driver updates

   - 8250 driver updates for different hardware types

   - qcom-geni driver fixes

   - tegra serial driver change

   - stm32 driver updates

   - synclink_gt driver cleanups

   - tty structure size reduction

  All of these have been in linux-next this week with no reported
  issues. The last bit of cleanups from Jiri and the tty structure size
  reduction came in last week, a bit late but as they were just style
  changes and size reductions, I figured they should get into this merge
  cycle so that others can work on top of them with no merge conflicts"

* tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
  tty: shrink the size of struct tty_struct by 40 bytes
  tty: n_tty: deduplicate copy code in n_tty_receive_buf_real_raw()
  tty: n_tty: extract ECHO_OP processing to a separate function
  tty: n_tty: unify counts to size_t
  tty: n_tty: use u8 for chars and flags
  tty: n_tty: simplify chars_in_buffer()
  tty: n_tty: remove unsigned char casts from character constants
  tty: n_tty: move newline handling to a separate function
  tty: n_tty: move canon handling to a separate function
  tty: n_tty: use MASK() for masking out size bits
  tty: n_tty: make n_tty_data::num_overrun unsigned
  tty: n_tty: use time_is_before_jiffies() in n_tty_receive_overrun()
  tty: n_tty: use 'num' for writes' counts
  tty: n_tty: use output character directly
  tty: n_tty: make flow of n_tty_receive_buf_common() a bool
  Revert "tty: serial: meson: Add a earlycon for the T7 SoC"
  Documentation: devices.txt: Fix minors for ttyCPM*
  Documentation: devices.txt: Remove ttySIOC*
  Documentation: devices.txt: Remove ttyIOC*
  serial: 8250_bcm7271: improve bcm7271 8250 port
  ...

1 files changed, 20 insertions, 30 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 27d8e3a1aace..8a94e5a43c6d 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -270,7 +270,7 @@ static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
 }
 
 /* Caller must hold tty_lock */
-static int check_tty_count(struct tty_struct *tty, const char *routine)
+static void check_tty_count(struct tty_struct *tty, const char *routine)
 {
 #ifdef CHECK_TTY_COUNT
 	struct list_head *p;
@@ -290,10 +290,8 @@ static int check_tty_count(struct tty_struct *tty, const char *routine)
 	if (tty->count != (count + kopen_count)) {
 		tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n",
 			 routine, tty->count, count, kopen_count);
-		return (count + kopen_count);
 	}
 #endif
-	return 0;
 }
 
 /**
@@ -845,19 +843,18 @@ static void tty_update_time(struct tty_struct *tty, bool mtime)
  * data or clears the cookie. The cookie may be something that the
  * ldisc maintains state for and needs to free.
  */
-static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty,
-		struct file *file, struct iov_iter *to)
+static ssize_t iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty,
+				struct file *file, struct iov_iter *to)
 {
-	int retval = 0;
 	void *cookie = NULL;
 	unsigned long offset = 0;
 	char kernel_buf[64];
-	size_t count = iov_iter_count(to);
+	ssize_t retval = 0;
+	size_t copied, count = iov_iter_count(to);
 
 	do {
-		int size, copied;
+		ssize_t size = min(count, sizeof(kernel_buf));
 
-		size = count > sizeof(kernel_buf) ? sizeof(kernel_buf) : count;
 		size = ld->ops->read(tty, file, kernel_buf, size, &cookie, offset);
 		if (!size)
 			break;
@@ -914,11 +911,11 @@ static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty,
  */
 static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to)
 {
-	int i;
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file_inode(file);
 	struct tty_struct *tty = file_tty(file);
 	struct tty_ldisc *ld;
+	ssize_t ret;
 
 	if (tty_paranoia_check(tty, inode, "tty_read"))
 		return -EIO;
@@ -931,15 +928,15 @@ static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to)
 	ld = tty_ldisc_ref_wait(tty);
 	if (!ld)
 		return hung_up_tty_read(iocb, to);
-	i = -EIO;
+	ret = -EIO;
 	if (ld->ops->read)
-		i = iterate_tty_read(ld, tty, file, to);
+		ret = iterate_tty_read(ld, tty, file, to);
 	tty_ldisc_deref(ld);
 
-	if (i > 0)
+	if (ret > 0)
 		tty_update_time(tty, false);
 
-	return i;
+	return ret;
 }
 
 void tty_write_unlock(struct tty_struct *tty)
@@ -948,7 +945,7 @@ void tty_write_unlock(struct tty_struct *tty)
 	wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT);
 }
 
-int tty_write_lock(struct tty_struct *tty, int ndelay)
+int tty_write_lock(struct tty_struct *tty, bool ndelay)
 {
 	if (!mutex_trylock(&tty->atomic_write_lock)) {
 		if (ndelay)
@@ -963,15 +960,11 @@ int tty_write_lock(struct tty_struct *tty, int ndelay)
  * Split writes up in sane blocksizes to avoid
  * denial-of-service type attacks
  */
-static inline ssize_t do_tty_write(
-	ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t),
-	struct tty_struct *tty,
-	struct file *file,
-	struct iov_iter *from)
+static ssize_t iterate_tty_write(struct tty_ldisc *ld, struct tty_struct *tty,
+				 struct file *file, struct iov_iter *from)
 {
-	size_t count = iov_iter_count(from);
+	size_t chunk, count = iov_iter_count(from);
 	ssize_t ret, written = 0;
-	unsigned int chunk;
 
 	ret = tty_write_lock(tty, file->f_flags & O_NDELAY);
 	if (ret < 0)
@@ -1015,16 +1008,13 @@ static inline ssize_t do_tty_write(
 
 	/* Do the write .. */
 	for (;;) {
-		size_t size = count;
-
-		if (size > chunk)
-			size = chunk;
+		size_t size = min(chunk, count);
 
 		ret = -EFAULT;
 		if (copy_from_iter(tty->write_buf, size, from) != size)
 			break;
 
-		ret = write(tty, file, tty->write_buf, size);
+		ret = ld->ops->write(tty, file, tty->write_buf, size);
 		if (ret <= 0)
 			break;
 
@@ -1095,7 +1085,7 @@ static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_
 	if (!ld->ops->write)
 		ret = -EIO;
 	else
-		ret = do_tty_write(ld->ops->write, tty, file, from);
+		ret = iterate_tty_write(ld, tty, file, from);
 	tty_ldisc_deref(ld);
 	return ret;
 }
@@ -1162,7 +1152,7 @@ int tty_send_xchar(struct tty_struct *tty, char ch)
 		return 0;
 	}
 
-	if (tty_write_lock(tty, 0) < 0)
+	if (tty_write_lock(tty, false) < 0)
 		return -ERESTARTSYS;
 
 	down_read(&tty->termios_rwsem);
@@ -2488,7 +2478,7 @@ static int send_break(struct tty_struct *tty, unsigned int duration)
 		retval = tty->ops->break_ctl(tty, duration);
 	else {
 		/* Do the work ourselves */
-		if (tty_write_lock(tty, 0) < 0)
+		if (tty_write_lock(tty, false) < 0)
 			return -EINTR;
 		retval = tty->ops->break_ctl(tty, -1);
 		if (retval)