[linux-block.git] / include / linux / tty.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_TTY_H
#define _LINUX_TTY_H

#include <linux/fs.h>
#include <linux/major.h>
#include <linux/termios.h>
#include <linux/workqueue.h>
#include <linux/tty_buffer.h>
#include <linux/tty_driver.h>
#include <linux/tty_ldisc.h>
#include <linux/tty_port.h>
#include <linux/mutex.h>
#include <linux/tty_flags.h>
#include <uapi/linux/tty.h>
#include <linux/rwsem.h>
#include <linux/llist.h>


/*
 * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
 * hardcoded at present.)
 */
#define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
#define NR_UNIX98_PTY_RESERVE	1024	  /* Default reserve for main devpts */
#define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */

/*
 * This character is the same as _POSIX_VDISABLE: it cannot be used as
 * a c_cc[] character, but indicates that a particular special character
 * isn't in use (eg VINTR has no character etc)
 */
#define __DISABLED_CHAR '\0'

#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
#define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
#define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
#define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
#define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
#define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
#define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
#define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
#define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
#define LNEXT_CHAR(tty)	((tty)->termios.c_cc[VLNEXT])
#define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])

#define _I_FLAG(tty, f)	((tty)->termios.c_iflag & (f))
#define _O_FLAG(tty, f)	((tty)->termios.c_oflag & (f))
#define _C_FLAG(tty, f)	((tty)->termios.c_cflag & (f))
#define _L_FLAG(tty, f)	((tty)->termios.c_lflag & (f))

#define I_IGNBRK(tty)	_I_FLAG((tty), IGNBRK)
#define I_BRKINT(tty)	_I_FLAG((tty), BRKINT)
#define I_IGNPAR(tty)	_I_FLAG((tty), IGNPAR)
#define I_PARMRK(tty)	_I_FLAG((tty), PARMRK)
#define I_INPCK(tty)	_I_FLAG((tty), INPCK)
#define I_ISTRIP(tty)	_I_FLAG((tty), ISTRIP)
#define I_INLCR(tty)	_I_FLAG((tty), INLCR)
#define I_IGNCR(tty)	_I_FLAG((tty), IGNCR)
#define I_ICRNL(tty)	_I_FLAG((tty), ICRNL)
#define I_IUCLC(tty)	_I_FLAG((tty), IUCLC)
#define I_IXON(tty)	_I_FLAG((tty), IXON)
#define I_IXANY(tty)	_I_FLAG((tty), IXANY)
#define I_IXOFF(tty)	_I_FLAG((tty), IXOFF)
#define I_IMAXBEL(tty)	_I_FLAG((tty), IMAXBEL)
#define I_IUTF8(tty)	_I_FLAG((tty), IUTF8)

#define O_OPOST(tty)	_O_FLAG((tty), OPOST)
#define O_OLCUC(tty)	_O_FLAG((tty), OLCUC)
#define O_ONLCR(tty)	_O_FLAG((tty), ONLCR)
#define O_OCRNL(tty)	_O_FLAG((tty), OCRNL)
#define O_ONOCR(tty)	_O_FLAG((tty), ONOCR)
#define O_ONLRET(tty)	_O_FLAG((tty), ONLRET)
#define O_OFILL(tty)	_O_FLAG((tty), OFILL)
#define O_OFDEL(tty)	_O_FLAG((tty), OFDEL)
#define O_NLDLY(tty)	_O_FLAG((tty), NLDLY)
#define O_CRDLY(tty)	_O_FLAG((tty), CRDLY)
#define O_TABDLY(tty)	_O_FLAG((tty), TABDLY)
#define O_BSDLY(tty)	_O_FLAG((tty), BSDLY)
#define O_VTDLY(tty)	_O_FLAG((tty), VTDLY)
#define O_FFDLY(tty)	_O_FLAG((tty), FFDLY)

#define C_BAUD(tty)	_C_FLAG((tty), CBAUD)
#define C_CSIZE(tty)	_C_FLAG((tty), CSIZE)
#define C_CSTOPB(tty)	_C_FLAG((tty), CSTOPB)
#define C_CREAD(tty)	_C_FLAG((tty), CREAD)
#define C_PARENB(tty)	_C_FLAG((tty), PARENB)
#define C_PARODD(tty)	_C_FLAG((tty), PARODD)
#define C_HUPCL(tty)	_C_FLAG((tty), HUPCL)
#define C_CLOCAL(tty)	_C_FLAG((tty), CLOCAL)
#define C_CIBAUD(tty)	_C_FLAG((tty), CIBAUD)
#define C_CRTSCTS(tty)	_C_FLAG((tty), CRTSCTS)
#define C_CMSPAR(tty)	_C_FLAG((tty), CMSPAR)

#define L_ISIG(tty)	_L_FLAG((tty), ISIG)
#define L_ICANON(tty)	_L_FLAG((tty), ICANON)
#define L_XCASE(tty)	_L_FLAG((tty), XCASE)
#define L_ECHO(tty)	_L_FLAG((tty), ECHO)
#define L_ECHOE(tty)	_L_FLAG((tty), ECHOE)
#define L_ECHOK(tty)	_L_FLAG((tty), ECHOK)
#define L_ECHONL(tty)	_L_FLAG((tty), ECHONL)
#define L_NOFLSH(tty)	_L_FLAG((tty), NOFLSH)
#define L_TOSTOP(tty)	_L_FLAG((tty), TOSTOP)
#define L_ECHOCTL(tty)	_L_FLAG((tty), ECHOCTL)
#define L_ECHOPRT(tty)	_L_FLAG((tty), ECHOPRT)
#define L_ECHOKE(tty)	_L_FLAG((tty), ECHOKE)
#define L_FLUSHO(tty)	_L_FLAG((tty), FLUSHO)
#define L_PENDIN(tty)	_L_FLAG((tty), PENDIN)
#define L_IEXTEN(tty)	_L_FLAG((tty), IEXTEN)
#define L_EXTPROC(tty)	_L_FLAG((tty), EXTPROC)

struct device;
struct signal_struct;
struct tty_operations;

/**
 * struct tty_struct - state associated with a tty while open
 *
 * @magic: magic value set early in @alloc_tty_struct to %TTY_MAGIC, for
 *	   debugging purposes
 * @kref: reference counting by tty_kref_get() and tty_kref_put(), reaching zero
 *	  frees the structure
 * @dev: class device or %NULL (e.g. ptys, serdev)
 * @driver: &struct tty_driver operating this tty
 * @ops: &struct tty_operations of @driver for this tty (open, close, etc.)
 * @index: index of this tty (e.g. to construct @name like tty12)
 * @ldisc_sem: protects line discipline changes (@ldisc) -- lock tty not pty
 * @ldisc: the current line discipline for this tty (n_tty by default)
 * @atomic_write_lock: protects against concurrent writers, i.e. locks
 *		       @write_cnt, @write_buf and similar
 * @legacy_mutex: leftover from history (BKL -> BTM -> @legacy_mutex),
 *		  protecting several operations on this tty
 * @throttle_mutex: protects against concurrent tty_throttle_safe() and
 *		    tty_unthrottle_safe() (but not tty_unthrottle())
 * @termios_rwsem: protects @termios and @termios_locked
 * @winsize_mutex: protects @winsize
 * @termios: termios for the current tty, copied from/to @driver.termios
 * @termios_locked: locked termios (by %TIOCGLCKTRMIOS and %TIOCSLCKTRMIOS
 *		    ioctls)
 * @name: name of the tty constructed by tty_line_name() (e.g. ttyS3)
 * @flags: bitwise OR of %TTY_THROTTLED, %TTY_IO_ERROR, ...
 * @count: count of open processes, reaching zero cancels all the work for
 *	   this tty and drops a @kref too (but does not free this tty)
 * @winsize: size of the terminal "window" (cf. @winsize_mutex)
 * @flow: flow settings grouped together, see also @flow.unused
 * @flow.lock: lock for @flow members
 * @flow.stopped: tty stopped/started by stop_tty()/start_tty()
 * @flow.tco_stopped: tty stopped/started by %TCOOFF/%TCOON ioctls (it has
 *		      precedence over @flow.stopped)
 * @flow.unused: alignment for Alpha, so that no members other than @flow.* are
 *		 modified by the same 64b word store. The @flow's __aligned is
 *		 there for the very same reason.
 * @ctrl: control settings grouped together, see also @ctrl.unused
 * @ctrl.lock: lock for @ctrl members
 * @ctrl.pgrp: process group of this tty (setpgrp(2))
 * @ctrl.session: session of this tty (setsid(2)). Writes are protected by both
 *		  @ctrl.lock and @legacy_mutex, readers must use at least one of
 *		  them.
 * @ctrl.pktstatus: packet mode status (bitwise OR of %TIOCPKT_ constants)
 * @ctrl.packet: packet mode enabled
 * @ctrl.unused: alignment for Alpha, see @flow.unused for explanation
 * @hw_stopped: not controlled by the tty layer, under @driver's control for CTS
 *		handling
 * @receive_room: bytes permitted to feed to @ldisc without any being lost
 * @flow_change: controls behavior of throttling, see tty_throttle_safe() and
 *		 tty_unthrottle_safe()
 * @link: link to another pty (master -> slave and vice versa)
 * @fasync: state for %O_ASYNC (for %SIGIO); managed by fasync_helper()
 * @write_wait: concurrent writers are waiting in this queue until they are
 *		allowed to write
 * @read_wait: readers wait for data in this queue
 * @hangup_work: normally a work to perform a hangup (do_tty_hangup()); while
 *		 freeing the tty, (re)used to release_one_tty()
 * @disc_data: pointer to @ldisc's private data (e.g. to &struct n_tty_data)
 * @driver_data: pointer to @driver's private data (e.g. &struct uart_state)
 * @files_lock:	protects @tty_files list
 * @tty_files: list of (re)openers of this tty (i.e. linked &struct
 *	       tty_file_private)
 * @closing: when set during close, n_tty processes only START & STOP chars
 * @write_buf: temporary buffer used during tty_write() to copy user data to
 * @write_cnt: count of bytes written in tty_write() to @write_buf
 * @SAK_work: if the tty has a pending do_SAK, it is queued here
 * @port: persistent storage for this device (i.e. &struct tty_port)
 *
 * All of the state associated with a tty while the tty is open. Persistent
 * storage for tty devices is referenced here as @port and is documented in
 * &struct tty_port.
 */
struct tty_struct {
	int	magic;
	struct kref kref;
	struct device *dev;
	struct tty_driver *driver;
	const struct tty_operations *ops;
	int index;

	struct ld_semaphore ldisc_sem;
	struct tty_ldisc *ldisc;

	struct mutex atomic_write_lock;
	struct mutex legacy_mutex;
	struct mutex throttle_mutex;
	struct rw_semaphore termios_rwsem;
	struct mutex winsize_mutex;
	struct ktermios termios, termios_locked;
	char name[64];
	unsigned long flags;
	int count;
	struct winsize winsize;

	struct {
		spinlock_t lock;
		bool stopped;
		bool tco_stopped;
		unsigned long unused[0];
	} __aligned(sizeof(unsigned long)) flow;

	struct {
		spinlock_t lock;
		struct pid *pgrp;
		struct pid *session;
		unsigned char pktstatus;
		bool packet;
		unsigned long unused[0];
	} __aligned(sizeof(unsigned long)) ctrl;

	int hw_stopped;
	unsigned int receive_room;
	int flow_change;

	struct tty_struct *link;
	struct fasync_struct *fasync;
	wait_queue_head_t write_wait;
	wait_queue_head_t read_wait;
	struct work_struct hangup_work;
	void *disc_data;
	void *driver_data;
	spinlock_t files_lock;
	struct list_head tty_files;

#define N_TTY_BUF_SIZE 4096

	int closing;
	unsigned char *write_buf;
	int write_cnt;
	struct work_struct SAK_work;
	struct tty_port *port;
} __randomize_layout;

/* Each of a tty's open files has private_data pointing to tty_file_private */
struct tty_file_private {
	struct tty_struct *tty;
	struct file *file;
	struct list_head list;
};

/* tty magic number */
#define TTY_MAGIC		0x5401

/*
 * These bits are used in the flags field of the tty structure.
 *
 * So that interrupts won't be able to mess up the queues,
 * copy_to_cooked must be atomic with respect to itself, as must
 * tty->write.  Thus, you must use the inline functions set_bit() and
 * clear_bit() to make things atomic.
 */
#define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
#define TTY_IO_ERROR 		1	/* Cause an I/O error (may be no ldisc too) */
#define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
#define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
#define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
#define TTY_LDISC_OPEN	 	11	/* Line discipline is open */
#define TTY_PTY_LOCK 		16	/* pty private */
#define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
#define TTY_HUPPED 		18	/* Post driver->hangup() */
#define TTY_HUPPING		19	/* Hangup in progress */
#define TTY_LDISC_CHANGING	20	/* Change pending - non-block IO */
#define TTY_LDISC_HALTED	22	/* Line discipline is halted */

static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)
{
	return file->f_flags & O_NONBLOCK ||
		test_bit(TTY_LDISC_CHANGING, &tty->flags);
}

static inline bool tty_io_error(struct tty_struct *tty)
{
	return test_bit(TTY_IO_ERROR, &tty->flags);
}

static inline bool tty_throttled(struct tty_struct *tty)
{
	return test_bit(TTY_THROTTLED, &tty->flags);
}

#ifdef CONFIG_TTY
void tty_kref_put(struct tty_struct *tty);
struct pid *tty_get_pgrp(struct tty_struct *tty);
void tty_vhangup_self(void);
void disassociate_ctty(int priv);
dev_t tty_devnum(struct tty_struct *tty);
void proc_clear_tty(struct task_struct *p);
struct tty_struct *get_current_tty(void);
/* tty_io.c */
int __init tty_init(void);
const char *tty_name(const struct tty_struct *tty);
struct tty_struct *tty_kopen_exclusive(dev_t device);
struct tty_struct *tty_kopen_shared(dev_t device);
void tty_kclose(struct tty_struct *tty);
int tty_dev_name_to_number(const char *name, dev_t *number);
#else
static inline void tty_kref_put(struct tty_struct *tty)
{ }
static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
{ return NULL; }
static inline void tty_vhangup_self(void)
{ }
static inline void disassociate_ctty(int priv)
{ }
static inline dev_t tty_devnum(struct tty_struct *tty)
{ return 0; }
static inline void proc_clear_tty(struct task_struct *p)
{ }
static inline struct tty_struct *get_current_tty(void)
{ return NULL; }
/* tty_io.c */
static inline int __init tty_init(void)
{ return 0; }
static inline const char *tty_name(const struct tty_struct *tty)
{ return "(none)"; }
static inline struct tty_struct *tty_kopen_exclusive(dev_t device)
{ return ERR_PTR(-ENODEV); }
static inline void tty_kclose(struct tty_struct *tty)
{ }
static inline int tty_dev_name_to_number(const char *name, dev_t *number)
{ return -ENOTSUPP; }
#endif

extern struct ktermios tty_std_termios;

int vcs_init(void);

extern struct class *tty_class;

/**
 *	tty_kref_get		-	get a tty reference
 *	@tty: tty device
 *
 *	Return a new reference to a tty object. The caller must hold
 *	sufficient locks/counts to ensure that their existing reference cannot
 *	go away
 */

static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
{
	if (tty)
		kref_get(&tty->kref);
	return tty;
}

const char *tty_driver_name(const struct tty_struct *tty);
void tty_wait_until_sent(struct tty_struct *tty, long timeout);
void stop_tty(struct tty_struct *tty);
void start_tty(struct tty_struct *tty);
void tty_write_message(struct tty_struct *tty, char *msg);
int tty_send_xchar(struct tty_struct *tty, char ch);
int tty_put_char(struct tty_struct *tty, unsigned char c);
unsigned int tty_chars_in_buffer(struct tty_struct *tty);
unsigned int tty_write_room(struct tty_struct *tty);
void tty_driver_flush_buffer(struct tty_struct *tty);
void tty_unthrottle(struct tty_struct *tty);
int tty_throttle_safe(struct tty_struct *tty);
int tty_unthrottle_safe(struct tty_struct *tty);
int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
int tty_get_icount(struct tty_struct *tty,
		struct serial_icounter_struct *icount);
int is_current_pgrp_orphaned(void);
void tty_hangup(struct tty_struct *tty);
void tty_vhangup(struct tty_struct *tty);
int tty_hung_up_p(struct file *filp);
void do_SAK(struct tty_struct *tty);
void __do_SAK(struct tty_struct *tty);
void no_tty(void);
speed_t tty_termios_baud_rate(struct ktermios *termios);
void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud,
		speed_t obaud);
void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud,
		speed_t obaud);

/**
 *	tty_get_baud_rate	-	get tty bit rates
 *	@tty: tty to query
 *
 *	Returns the baud rate as an integer for this terminal. The
 *	termios lock must be held by the caller and the terminal bit
 *	flags may be updated.
 *
 *	Locking: none
 */
static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
{
	return tty_termios_baud_rate(&tty->termios);
}

unsigned char tty_get_char_size(unsigned int cflag);
unsigned char tty_get_frame_size(unsigned int cflag);

void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);

void tty_wakeup(struct tty_struct *tty);

int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
void tty_release_struct(struct tty_struct *tty, int idx);
void tty_init_termios(struct tty_struct *tty);
void tty_save_termios(struct tty_struct *tty);
int tty_standard_install(struct tty_driver *driver,
		struct tty_struct *tty);

extern struct mutex tty_mutex;

/* n_tty.c */
void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
#ifdef CONFIG_TTY
void __init n_tty_init(void);
#else
static inline void n_tty_init(void) { }
#endif

/* tty_audit.c */
#ifdef CONFIG_AUDIT
void tty_audit_exit(void);
void tty_audit_fork(struct signal_struct *sig);
int tty_audit_push(void);
#else
static inline void tty_audit_exit(void)
{
}
static inline void tty_audit_fork(struct signal_struct *sig)
{
}
static inline int tty_audit_push(void)
{
	return 0;
}
#endif

/* tty_ioctl.c */
int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd,
		unsigned long arg);

/* vt.c */

int vt_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg);

long vt_compat_ioctl(struct tty_struct *tty, unsigned int cmd,
		unsigned long arg);

/* tty_mutex.c */
/* functions for preparation of BKL removal */
void tty_lock(struct tty_struct *tty);
int  tty_lock_interruptible(struct tty_struct *tty);
void tty_unlock(struct tty_struct *tty);
void tty_lock_slave(struct tty_struct *tty);
void tty_unlock_slave(struct tty_struct *tty);
void tty_set_lock_subclass(struct tty_struct *tty);

#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	#ifndef _LINUX_TTY_H
	3	#define _LINUX_TTY_H
	4
ae92c1f5 FF	5	#include <linux/fs.h>
	6	#include <linux/major.h>
	7	#include <linux/termios.h>
	8	#include <linux/workqueue.h>
8d29e002	9	#include <linux/tty_buffer.h>
ae92c1f5 FF	10	#include <linux/tty_driver.h>
ae92c1f5 FF	11	#include <linux/tty_ldisc.h>
67b94be4	12	#include <linux/tty_port.h>
ae92c1f5	13	#include <linux/mutex.h>
ba3fe7ab	14	#include <linux/tty_flags.h>
607ca46e	15	#include <uapi/linux/tty.h>
6a1c0680	16	#include <linux/rwsem.h>
809850b7	17	#include <linux/llist.h>
ae92c1f5	18
ae92c1f5	19
ae92c1f5 FF	20	/*
	21	* (Note: the *_driver.minor_start values 1, 64, 128, 192 are
	22	* hardcoded at present.)
	23	*/
	24	#define NR_UNIX98_PTY_DEFAULT 4096 /* Default maximum for Unix98 ptys */
e9aba515	25	#define NR_UNIX98_PTY_RESERVE 1024 /* Default reserve for main devpts */
ae92c1f5 FF	26	#define NR_UNIX98_PTY_MAX (1 << MINORBITS) /* Absolute limit */
ae92c1f5 FF	27
1da177e4 LT	28	/*
	29	* This character is the same as _POSIX_VDISABLE: it cannot be used as
	30	* a c_cc[] character, but indicates that a particular special character
	31	* isn't in use (eg VINTR has no character etc)
	32	*/
	33	#define __DISABLED_CHAR '\0'
	34
adc8d746 AC	35	#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
	36	#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
	37	#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
	38	#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
	39	#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
	40	#define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
	41	#define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
	42	#define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
	43	#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
	44	#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
	45	#define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
	46	#define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
	47	#define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
	48	#define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
	49	#define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
	50	#define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
	51	#define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
1da177e4	52
adc8d746 AC	53	#define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
	54	#define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
	55	#define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
	56	#define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
7a4d29f4 AC	57
	58	#define I_IGNBRK(tty) _I_FLAG((tty), IGNBRK)
	59	#define I_BRKINT(tty) _I_FLAG((tty), BRKINT)
	60	#define I_IGNPAR(tty) _I_FLAG((tty), IGNPAR)
	61	#define I_PARMRK(tty) _I_FLAG((tty), PARMRK)
	62	#define I_INPCK(tty) _I_FLAG((tty), INPCK)
	63	#define I_ISTRIP(tty) _I_FLAG((tty), ISTRIP)
	64	#define I_INLCR(tty) _I_FLAG((tty), INLCR)
	65	#define I_IGNCR(tty) _I_FLAG((tty), IGNCR)
	66	#define I_ICRNL(tty) _I_FLAG((tty), ICRNL)
	67	#define I_IUCLC(tty) _I_FLAG((tty), IUCLC)
	68	#define I_IXON(tty) _I_FLAG((tty), IXON)
	69	#define I_IXANY(tty) _I_FLAG((tty), IXANY)
	70	#define I_IXOFF(tty) _I_FLAG((tty), IXOFF)
	71	#define I_IMAXBEL(tty) _I_FLAG((tty), IMAXBEL)
	72	#define I_IUTF8(tty) _I_FLAG((tty), IUTF8)
	73
	74	#define O_OPOST(tty) _O_FLAG((tty), OPOST)
	75	#define O_OLCUC(tty) _O_FLAG((tty), OLCUC)
	76	#define O_ONLCR(tty) _O_FLAG((tty), ONLCR)
	77	#define O_OCRNL(tty) _O_FLAG((tty), OCRNL)
	78	#define O_ONOCR(tty) _O_FLAG((tty), ONOCR)
	79	#define O_ONLRET(tty) _O_FLAG((tty), ONLRET)
	80	#define O_OFILL(tty) _O_FLAG((tty), OFILL)
	81	#define O_OFDEL(tty) _O_FLAG((tty), OFDEL)
	82	#define O_NLDLY(tty) _O_FLAG((tty), NLDLY)
	83	#define O_CRDLY(tty) _O_FLAG((tty), CRDLY)
	84	#define O_TABDLY(tty) _O_FLAG((tty), TABDLY)
	85	#define O_BSDLY(tty) _O_FLAG((tty), BSDLY)
	86	#define O_VTDLY(tty) _O_FLAG((tty), VTDLY)
	87	#define O_FFDLY(tty) _O_FLAG((tty), FFDLY)
	88
	89	#define C_BAUD(tty) _C_FLAG((tty), CBAUD)
	90	#define C_CSIZE(tty) _C_FLAG((tty), CSIZE)
	91	#define C_CSTOPB(tty) _C_FLAG((tty), CSTOPB)
	92	#define C_CREAD(tty) _C_FLAG((tty), CREAD)
	93	#define C_PARENB(tty) _C_FLAG((tty), PARENB)
	94	#define C_PARODD(tty) _C_FLAG((tty), PARODD)
	95	#define C_HUPCL(tty) _C_FLAG((tty), HUPCL)
	96	#define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL)
	97	#define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD)
	98	#define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS)
e58b57a3	99	#define C_CMSPAR(tty) _C_FLAG((tty), CMSPAR)
7a4d29f4 AC	100
	101	#define L_ISIG(tty) _L_FLAG((tty), ISIG)
	102	#define L_ICANON(tty) _L_FLAG((tty), ICANON)
	103	#define L_XCASE(tty) _L_FLAG((tty), XCASE)
	104	#define L_ECHO(tty) _L_FLAG((tty), ECHO)
	105	#define L_ECHOE(tty) _L_FLAG((tty), ECHOE)
	106	#define L_ECHOK(tty) _L_FLAG((tty), ECHOK)
	107	#define L_ECHONL(tty) _L_FLAG((tty), ECHONL)
	108	#define L_NOFLSH(tty) _L_FLAG((tty), NOFLSH)
	109	#define L_TOSTOP(tty) _L_FLAG((tty), TOSTOP)
	110	#define L_ECHOCTL(tty) _L_FLAG((tty), ECHOCTL)
	111	#define L_ECHOPRT(tty) _L_FLAG((tty), ECHOPRT)
	112	#define L_ECHOKE(tty) _L_FLAG((tty), ECHOKE)
	113	#define L_FLUSHO(tty) _L_FLAG((tty), FLUSHO)
	114	#define L_PENDIN(tty) _L_FLAG((tty), PENDIN)
	115	#define L_IEXTEN(tty) _L_FLAG((tty), IEXTEN)
26df6d13	116	#define L_EXTPROC(tty) _L_FLAG((tty), EXTPROC)
1da177e4 LT	117
1da177e4 LT	118	struct device;
522ed776	119	struct signal_struct;
f34d7a5b AC	120	struct tty_operations;
f34d7a5b AC	121
6e94dbc7 JS	122	/**
	123	* struct tty_struct - state associated with a tty while open
	124	*
18e6c075 JS	125	* @magic: magic value set early in @alloc_tty_struct to %TTY_MAGIC, for
	126	* debugging purposes
	127	* @kref: reference counting by tty_kref_get() and tty_kref_put(), reaching zero
	128	* frees the structure
	129	* @dev: class device or %NULL (e.g. ptys, serdev)
	130	* @driver: &struct tty_driver operating this tty
	131	* @ops: &struct tty_operations of @driver for this tty (open, close, etc.)
	132	* @index: index of this tty (e.g. to construct @name like tty12)
	133	* @ldisc_sem: protects line discipline changes (@ldisc) -- lock tty not pty
	134	* @ldisc: the current line discipline for this tty (n_tty by default)
	135	* @atomic_write_lock: protects against concurrent writers, i.e. locks
	136	* @write_cnt, @write_buf and similar
	137	* @legacy_mutex: leftover from history (BKL -> BTM -> @legacy_mutex),
	138	* protecting several operations on this tty
	139	* @throttle_mutex: protects against concurrent tty_throttle_safe() and
	140	* tty_unthrottle_safe() (but not tty_unthrottle())
	141	* @termios_rwsem: protects @termios and @termios_locked
	142	* @winsize_mutex: protects @winsize
	143	* @termios: termios for the current tty, copied from/to @driver.termios
	144	* @termios_locked: locked termios (by %TIOCGLCKTRMIOS and %TIOCSLCKTRMIOS
	145	* ioctls)
	146	* @name: name of the tty constructed by tty_line_name() (e.g. ttyS3)
	147	* @flags: bitwise OR of %TTY_THROTTLED, %TTY_IO_ERROR, ...
	148	* @count: count of open processes, reaching zero cancels all the work for
	149	* this tty and drops a @kref too (but does not free this tty)
	150	* @winsize: size of the terminal "window" (cf. @winsize_mutex)
	151	* @flow: flow settings grouped together, see also @flow.unused
	152	* @flow.lock: lock for @flow members
	153	* @flow.stopped: tty stopped/started by stop_tty()/start_tty()
	154	* @flow.tco_stopped: tty stopped/started by %TCOOFF/%TCOON ioctls (it has
	155	* precedence over @flow.stopped)
6e94dbc7 JS	156	* @flow.unused: alignment for Alpha, so that no members other than @flow.* are
	157	* modified by the same 64b word store. The @flow's __aligned is
	158	* there for the very same reason.
18e6c075 JS	159	* @ctrl: control settings grouped together, see also @ctrl.unused
18e6c075 JS	160	* @ctrl.lock: lock for @ctrl members
64d608db JS	161	* @ctrl.pgrp: process group of this tty (setpgrp(2))
64d608db JS	162	* @ctrl.session: session of this tty (setsid(2)). Writes are protected by both
18e6c075	163	* @ctrl.lock and @legacy_mutex, readers must use at least one of
64d608db	164	* them.
18e6c075	165	* @ctrl.pktstatus: packet mode status (bitwise OR of %TIOCPKT_ constants)
64d608db	166	* @ctrl.packet: packet mode enabled
18e6c075 JS	167	* @ctrl.unused: alignment for Alpha, see @flow.unused for explanation
	168	* @hw_stopped: not controlled by the tty layer, under @driver's control for CTS
	169	* handling
	170	* @receive_room: bytes permitted to feed to @ldisc without any being lost
	171	* @flow_change: controls behavior of throttling, see tty_throttle_safe() and
	172	* tty_unthrottle_safe()
	173	* @link: link to another pty (master -> slave and vice versa)
	174	* @fasync: state for %O_ASYNC (for %SIGIO); managed by fasync_helper()
	175	* @write_wait: concurrent writers are waiting in this queue until they are
	176	* allowed to write
	177	* @read_wait: readers wait for data in this queue
	178	* @hangup_work: normally a work to perform a hangup (do_tty_hangup()); while
	179	* freeing the tty, (re)used to release_one_tty()
	180	* @disc_data: pointer to @ldisc's private data (e.g. to &struct n_tty_data)
	181	* @driver_data: pointer to @driver's private data (e.g. &struct uart_state)
	182	* @files_lock: protects @tty_files list
	183	* @tty_files: list of (re)openers of this tty (i.e. linked &struct
	184	* tty_file_private)
	185	* @closing: when set during close, n_tty processes only START & STOP chars
	186	* @write_buf: temporary buffer used during tty_write() to copy user data to
	187	* @write_cnt: count of bytes written in tty_write() to @write_buf
	188	* @SAK_work: if the tty has a pending do_SAK, it is queued here
	189	* @port: persistent storage for this device (i.e. &struct tty_port)
6e94dbc7 JS	190	*
6e94dbc7 JS	191	* All of the state associated with a tty while the tty is open. Persistent
18e6c075 JS	192	* storage for tty devices is referenced here as @port and is documented in
18e6c075 JS	193	* &struct tty_port.
6e94dbc7	194	*/
1da177e4 LT	195	struct tty_struct {
1da177e4 LT	196	int magic;
9c9f4ded	197	struct kref kref;
18e6c075	198	struct device *dev;
1da177e4	199	struct tty_driver *driver;
f34d7a5b	200	const struct tty_operations *ops;
1da177e4	201	int index;
c65c9bc3	202
36697529	203	struct ld_semaphore ldisc_sem;
c65c9bc3 AC	204	struct tty_ldisc *ldisc;
c65c9bc3 AC	205
bddc7152	206	struct mutex atomic_write_lock;
89c8d91e	207	struct mutex legacy_mutex;
d8c1f929	208	struct mutex throttle_mutex;
6a1c0680	209	struct rw_semaphore termios_rwsem;
dee4a0be	210	struct mutex winsize_mutex;
adc8d746	211	struct ktermios termios, termios_locked;
1da177e4	212	char name[64];
1da177e4 LT	213	unsigned long flags;
1da177e4 LT	214	int count;
18e6c075	215	struct winsize winsize;
6e94dbc7 JS	216
	217	struct {
	218	spinlock_t lock;
	219	bool stopped;
	220	bool tco_stopped;
	221	unsigned long unused[0];
	222	} __aligned(sizeof(unsigned long)) flow;
	223
64d608db JS	224	struct {
	225	spinlock_t lock;
	226	struct pid *pgrp;
	227	struct pid *session;
	228	unsigned char pktstatus;
	229	bool packet;
	230	unsigned long unused[0];
	231	} __aligned(sizeof(unsigned long)) ctrl;
	232
d7a855bd	233	int hw_stopped;
18e6c075	234	unsigned int receive_room;
70bc1264	235	int flow_change;
1da177e4 LT	236
	237	struct tty_struct *link;
	238	struct fasync_struct *fasync;
1da177e4 LT	239	wait_queue_head_t write_wait;
	240	wait_queue_head_t read_wait;
	241	struct work_struct hangup_work;
	242	void *disc_data;
	243	void *driver_data;
18e6c075	244	spinlock_t files_lock;
1da177e4 LT	245	struct list_head tty_files;
	246
	247	#define N_TTY_BUF_SIZE 4096
6f67048c	248
413ba638	249	int closing;
1da177e4 LT	250	unsigned char *write_buf;
1da177e4 LT	251	int write_cnt;
1da177e4	252	struct work_struct SAK_work;
6f67048c	253	struct tty_port *port;
3859a271	254	} __randomize_layout;
1da177e4	255
d996b62a NP	256	/* Each of a tty's open files has private_data pointing to tty_file_private */
	257	struct tty_file_private {
	258	struct tty_struct *tty;
	259	struct file *file;
	260	struct list_head list;
	261	};
	262
1da177e4 LT	263	/* tty magic number */
	264	#define TTY_MAGIC 0x5401
	265
	266	/*
	267	* These bits are used in the flags field of the tty structure.
7a4d29f4	268	*
1da177e4 LT	269	* So that interrupts won't be able to mess up the queues,
	270	* copy_to_cooked must be atomic with respect to itself, as must
	271	* tty->write. Thus, you must use the inline functions set_bit() and
	272	* clear_bit() to make things atomic.
	273	*/
	274	#define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */
7a4d29f4	275	#define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */
1da177e4 LT	276	#define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */
1da177e4 LT	277	#define TTY_EXCLUSIVE 3 /* Exclusive open mode */
1da177e4	278	#define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */
c65c9bc3	279	#define TTY_LDISC_OPEN 11 /* Line discipline is open */
1da177e4 LT	280	#define TTY_PTY_LOCK 16 /* pty private */
	281	#define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */
	282	#define TTY_HUPPED 18 /* Post driver->hangup() */
28b0f8a6	283	#define TTY_HUPPING 19 /* Hangup in progress */
c96cf923	284	#define TTY_LDISC_CHANGING 20 /* Change pending - non-block IO */
21622939	285	#define TTY_LDISC_HALTED 22 /* Line discipline is halted */
1da177e4	286
c96cf923 DS	287	static inline bool tty_io_nonblock(struct tty_struct tty, struct file file)
	288	{
	289	return file->f_flags & O_NONBLOCK \|\|
	290	test_bit(TTY_LDISC_CHANGING, &tty->flags);
	291	}
	292
18900ca6 PH	293	static inline bool tty_io_error(struct tty_struct *tty)
	294	{
	295	return test_bit(TTY_IO_ERROR, &tty->flags);
	296	}
	297
97ef38b8 PH	298	static inline bool tty_throttled(struct tty_struct *tty)
	299	{
	300	return test_bit(TTY_THROTTLED, &tty->flags);
	301	}
	302
4f73bc4d	303	#ifdef CONFIG_TTY
78941934 JS	304	void tty_kref_put(struct tty_struct *tty);
	305	struct pid tty_get_pgrp(struct tty_struct tty);
	306	void tty_vhangup_self(void);
	307	void disassociate_ctty(int priv);
	308	dev_t tty_devnum(struct tty_struct *tty);
	309	void proc_clear_tty(struct task_struct *p);
	310	struct tty_struct *get_current_tty(void);
4f73bc4d	311	/* tty_io.c */
78941934 JS	312	int __init tty_init(void);
	313	const char tty_name(const struct tty_struct tty);
	314	struct tty_struct *tty_kopen_exclusive(dev_t device);
	315	struct tty_struct *tty_kopen_shared(dev_t device);
	316	void tty_kclose(struct tty_struct *tty);
	317	int tty_dev_name_to_number(const char name, dev_t number);
4f73bc4d	318	#else
4f73bc4d JM	319	static inline void tty_kref_put(struct tty_struct *tty)
	320	{ }
	321	static inline struct pid tty_get_pgrp(struct tty_struct tty)
	322	{ return NULL; }
	323	static inline void tty_vhangup_self(void)
	324	{ }
	325	static inline void disassociate_ctty(int priv)
	326	{ }
	327	static inline dev_t tty_devnum(struct tty_struct *tty)
	328	{ return 0; }
	329	static inline void proc_clear_tty(struct task_struct *p)
	330	{ }
	331	static inline struct tty_struct *get_current_tty(void)
	332	{ return NULL; }
	333	/* tty_io.c */
	334	static inline int __init tty_init(void)
	335	{ return 0; }
188e3c5c AB	336	static inline const char tty_name(const struct tty_struct tty)
188e3c5c AB	337	{ return "(none)"; }
4ea3cd65	338	static inline struct tty_struct *tty_kopen_exclusive(dev_t device)
a09ac397 OK	339	{ return ERR_PTR(-ENODEV); }
	340	static inline void tty_kclose(struct tty_struct *tty)
	341	{ }
fc61ed51 OK	342	static inline int tty_dev_name_to_number(const char name, dev_t number)
fc61ed51 OK	343	{ return -ENOTSUPP; }
4f73bc4d JM	344	#endif
4f73bc4d JM	345
edc6afc5	346	extern struct ktermios tty_std_termios;
1da177e4	347
78941934	348	int vcs_init(void);
1da177e4	349
d81ed103 AC	350	extern struct class *tty_class;
d81ed103 AC	351
9c9f4ded AC	352	/**
	353	* tty_kref_get - get a tty reference
	354	* @tty: tty device
	355	*
	356	* Return a new reference to a tty object. The caller must hold
	357	* sufficient locks/counts to ensure that their existing reference cannot
	358	* go away
	359	*/
	360
14bfc987	361	static inline struct tty_struct tty_kref_get(struct tty_struct tty)
9c9f4ded AC	362	{
	363	if (tty)
	364	kref_get(&tty->kref);
	365	return tty;
	366	}
9c9f4ded	367
78941934 JS	368	const char tty_driver_name(const struct tty_struct tty);
	369	void tty_wait_until_sent(struct tty_struct *tty, long timeout);
	370	void stop_tty(struct tty_struct *tty);
	371	void start_tty(struct tty_struct *tty);
	372	void tty_write_message(struct tty_struct tty, char msg);
	373	int tty_send_xchar(struct tty_struct *tty, char ch);
	374	int tty_put_char(struct tty_struct *tty, unsigned char c);
	375	unsigned int tty_chars_in_buffer(struct tty_struct *tty);
	376	unsigned int tty_write_room(struct tty_struct *tty);
	377	void tty_driver_flush_buffer(struct tty_struct *tty);
	378	void tty_unthrottle(struct tty_struct *tty);
	379	int tty_throttle_safe(struct tty_struct *tty);
	380	int tty_unthrottle_safe(struct tty_struct *tty);
	381	int tty_do_resize(struct tty_struct tty, struct winsize ws);
	382	int tty_get_icount(struct tty_struct *tty,
	383	struct serial_icounter_struct *icount);
	384	int is_current_pgrp_orphaned(void);
	385	void tty_hangup(struct tty_struct *tty);
	386	void tty_vhangup(struct tty_struct *tty);
	387	int tty_hung_up_p(struct file *filp);
	388	void do_SAK(struct tty_struct *tty);
	389	void __do_SAK(struct tty_struct *tty);
	390	void no_tty(void);
	391	speed_t tty_termios_baud_rate(struct ktermios *termios);
	392	void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud,
	393	speed_t obaud);
	394	void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud,
	395	speed_t obaud);
6865ff22 JS	396
	397	/**
	398	* tty_get_baud_rate - get tty bit rates
	399	* @tty: tty to query
	400	*
	401	* Returns the baud rate as an integer for this terminal. The
	402	* termios lock must be held by the caller and the terminal bit
	403	* flags may be updated.
	404	*
	405	* Locking: none
	406	*/
	407	static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
	408	{
	409	return tty_termios_baud_rate(&tty->termios);
	410	}
	411
654ee49b JS	412	unsigned char tty_get_char_size(unsigned int cflag);
	413	unsigned char tty_get_frame_size(unsigned int cflag);
	414
78941934 JS	415	void tty_termios_copy_hw(struct ktermios new, struct ktermios old);
	416	int tty_termios_hw_change(const struct ktermios a, const struct ktermios b);
	417	int tty_set_termios(struct tty_struct tty, struct ktermios kt);
1da177e4	418
78941934	419	void tty_wakeup(struct tty_struct *tty);
1da177e4	420
dcc223e8	421	int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
78941934 JS	422	int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
	423	struct tty_struct tty_init_dev(struct tty_driver driver, int idx);
	424	void tty_release_struct(struct tty_struct *tty, int idx);
	425	void tty_init_termios(struct tty_struct *tty);
	426	void tty_save_termios(struct tty_struct *tty);
	427	int tty_standard_install(struct tty_driver *driver,
66d450e8	428	struct tty_struct *tty);
24ec839c	429
70522e12	430	extern struct mutex tty_mutex;
1da177e4 LT	431
1da177e4 LT	432	/* n_tty.c */
78941934	433	void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
0c688614	434	#ifdef CONFIG_TTY
78941934	435	void __init n_tty_init(void);
0c688614 NP	436	#else
	437	static inline void n_tty_init(void) { }
	438	#endif
1da177e4	439
522ed776 MT	440	/* tty_audit.c */
522ed776 MT	441	#ifdef CONFIG_AUDIT
78941934 JS	442	void tty_audit_exit(void);
	443	void tty_audit_fork(struct signal_struct *sig);
	444	int tty_audit_push(void);
522ed776	445	#else
522ed776 MT	446	static inline void tty_audit_exit(void)
	447	{
	448	}
	449	static inline void tty_audit_fork(struct signal_struct *sig)
	450	{
	451	}
37282a77	452	static inline int tty_audit_push(void)
522ed776	453	{
3c80fe4a	454	return 0;
522ed776	455	}
522ed776 MT	456	#endif
522ed776 MT	457
1da177e4	458	/* tty_ioctl.c */
7c783601 JS	459	int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd,
7c783601 JS	460	unsigned long arg);
1da177e4	461
1da177e4 LT	462	/* vt.c */
1da177e4 LT	463
78941934	464	int vt_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
1da177e4	465
78941934 JS	466	long vt_compat_ioctl(struct tty_struct *tty, unsigned int cmd,
78941934 JS	467	unsigned long arg);
e9216651	468
b07471fa	469	/* tty_mutex.c */
ec79d605	470	/* functions for preparation of BKL removal */
78941934 JS	471	void tty_lock(struct tty_struct *tty);
	472	int tty_lock_interruptible(struct tty_struct *tty);
	473	void tty_unlock(struct tty_struct *tty);
	474	void tty_lock_slave(struct tty_struct *tty);
	475	void tty_unlock_slave(struct tty_struct *tty);
	476	void tty_set_lock_subclass(struct tty_struct *tty);
be1bc288	477
1da177e4	478	#endif