Commit a72f4187 authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
Browse files

tty: convert "TTY Struct Flags" to an enum 



Convert TTY_* macros (flags) to an enum. This allows for easier
kernel-doc (the comment needed fine tuning), grouping of these nicely,
and proper checking.

Note that these are bit positions. So they are used such as
test_bit(TTY_THROTTLED, ...). Given these are not the user API (only
in-kernel API/ABI), the bit positions are NOT preserved in this patch.
All are renumbered naturally using the enum-auto-numbering.

Signed-off-by: default avatarJiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-2-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d2fa8e52

Documentation/driver-api/tty/tty_struct.rst

+1 −1
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ TTY Struct Flags 
================



.. kernel-doc:: include/linux/tty.h

   :doc: TTY Struct Flags

   :identifiers: tty_struct_flags



TTY Struct Reference

====================

include/linux/tty.h

+27 −25
Original line number Diff line number Diff line
@@ -251,7 +251,7 @@ struct tty_file_private { 
};



/**

 * DOC: TTY Struct Flags

 * enum tty_struct_flags - TTY Struct Flags

 *

 * These bits are used in the :c:member:`tty_struct.flags` field.

 *
@@ -260,62 +260,64 @@ struct tty_file_private { 
 * tty->write.  Thus, you must use the inline functions set_bit() and

 * clear_bit() to make things atomic.

 *

 * TTY_THROTTLED

 * @TTY_THROTTLED:

 *	Driver input is throttled. The ldisc should call

 *	:c:member:`tty_driver.unthrottle()` in order to resume reception when

 *	it is ready to process more data (at threshold min).

 *

 * TTY_IO_ERROR

 * @TTY_IO_ERROR:

 *	If set, causes all subsequent userspace read/write calls on the tty to

 *	fail, returning -%EIO. (May be no ldisc too.)

 *

 * TTY_OTHER_CLOSED

 * @TTY_OTHER_CLOSED:

 *	Device is a pty and the other side has closed.

 *

 * TTY_EXCLUSIVE

 * @TTY_EXCLUSIVE:

 *	Exclusive open mode (a single opener).

 *

 * TTY_DO_WRITE_WAKEUP

 * @TTY_DO_WRITE_WAKEUP:

 *	If set, causes the driver to call the

 *	:c:member:`tty_ldisc_ops.write_wakeup()` method in order to resume

 *	transmission when it can accept more data to transmit.

 *

 * TTY_LDISC_OPEN

 * @TTY_LDISC_OPEN:

 *	Indicates that a line discipline is open. For debugging purposes only.

 *

 * TTY_PTY_LOCK

 * @TTY_PTY_LOCK:

 *	A flag private to pty code to implement %TIOCSPTLCK/%TIOCGPTLCK logic.

 *

 * TTY_NO_WRITE_SPLIT

 * @TTY_NO_WRITE_SPLIT:

 *	Prevent driver from splitting up writes into smaller chunks (preserve

 *	write boundaries to driver).

 *

 * TTY_HUPPED

 * @TTY_HUPPED:

 *	The TTY was hung up. This is set post :c:member:`tty_driver.hangup()`.

 *

 * TTY_HUPPING

 * @TTY_HUPPING:

 *	The TTY is in the process of hanging up to abort potential readers.

 *

 * TTY_LDISC_CHANGING

 * @TTY_LDISC_CHANGING:

 *	Line discipline for this TTY is being changed. I/O should not block

 *	when this is set. Use tty_io_nonblock() to check.

 *

 * TTY_LDISC_HALTED

 * @TTY_LDISC_HALTED:

 *	Line discipline for this TTY was stopped. No work should be queued to

 *	this ldisc.

 */

#define TTY_THROTTLED		0

#define TTY_IO_ERROR		1

#define TTY_OTHER_CLOSED	2

#define TTY_EXCLUSIVE		3

#define TTY_DO_WRITE_WAKEUP	5

#define TTY_LDISC_OPEN		11

#define TTY_PTY_LOCK		16

#define TTY_NO_WRITE_SPLIT	17

#define TTY_HUPPED		18

#define TTY_HUPPING		19

#define TTY_LDISC_CHANGING	20

#define TTY_LDISC_HALTED	22

enum tty_struct_flags {

	TTY_THROTTLED,

	TTY_IO_ERROR,

	TTY_OTHER_CLOSED,

	TTY_EXCLUSIVE,

	TTY_DO_WRITE_WAKEUP,

	TTY_LDISC_OPEN,

	TTY_PTY_LOCK,

	TTY_NO_WRITE_SPLIT,

	TTY_HUPPED,

	TTY_HUPPING,

	TTY_LDISC_CHANGING,

	TTY_LDISC_HALTED,

};



static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)

{