v4.19.13 snapshot.
diff --git a/include/linux/tty.h b/include/linux/tty.h
new file mode 100644
index 0000000..808fbfe
--- /dev/null
+++ b/include/linux/tty.h
@@ -0,0 +1,790 @@
+/* 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_driver.h>
+#include <linux/tty_ldisc.h>
+#include <linux/mutex.h>
+#include <linux/tty_flags.h>
+#include <linux/seq_file.h>
+#include <uapi/linux/tty.h>
+#include <linux/rwsem.h>
+#include <linux/llist.h>
+
+
+/*
+ * Lock subclasses for tty locks
+ *
+ * TTY_LOCK_NORMAL is for normal ttys and master ptys.
+ * TTY_LOCK_SLAVE is for slave ptys only.
+ *
+ * Lock subclasses are necessary for handling nested locking with pty pairs.
+ * tty locks which use nested locking:
+ *
+ * legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
+ * The stable lock order is master pty first, then slave pty.
+ * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
+ * Subclassing this lock enables the slave pty to hold its
+ * termios_rwsem when claiming the master tty_buffer lock.
+ * tty_buffer lock - slave ptys can claim nested buffer lock when handling
+ * signal chars. The stable lock order is slave pty, then
+ * master.
+ */
+
+enum {
+ TTY_LOCK_NORMAL = 0,
+ TTY_LOCK_SLAVE,
+};
+
+/*
+ * (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'
+
+struct tty_buffer {
+ union {
+ struct tty_buffer *next;
+ struct llist_node free;
+ };
+ int used;
+ int size;
+ int commit;
+ int read;
+ int flags;
+ /* Data points here */
+ unsigned long data[0];
+};
+
+/* Values for .flags field of tty_buffer */
+#define TTYB_NORMAL 1 /* buffer has no flags buffer */
+
+static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
+{
+ return ((unsigned char *)b->data) + ofs;
+}
+
+static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
+{
+ return (char *)char_buf_ptr(b, ofs) + b->size;
+}
+
+struct tty_bufhead {
+ struct tty_buffer *head; /* Queue head */
+ struct work_struct work;
+ struct mutex lock;
+ atomic_t priority;
+ struct tty_buffer sentinel;
+ struct llist_head free; /* Free queue head */
+ atomic_t mem_used; /* In-use buffers excluding free list */
+ int mem_limit;
+ struct tty_buffer *tail; /* Active buffer */
+};
+/*
+ * When a break, frame error, or parity error happens, these codes are
+ * stuffed into the flags buffer.
+ */
+#define TTY_NORMAL 0
+#define TTY_BREAK 1
+#define TTY_FRAME 2
+#define TTY_PARITY 3
+#define TTY_OVERRUN 4
+
+#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;
+
+/*
+ * Port level information. Each device keeps its own port level information
+ * so provide a common structure for those ports wanting to use common support
+ * routines.
+ *
+ * The tty port has a different lifetime to the tty so must be kept apart.
+ * In addition be careful as tty -> port mappings are valid for the life
+ * of the tty object but in many cases port -> tty mappings are valid only
+ * until a hangup so don't use the wrong path.
+ */
+
+struct tty_port;
+
+struct tty_port_operations {
+ /* Return 1 if the carrier is raised */
+ int (*carrier_raised)(struct tty_port *port);
+ /* Control the DTR line */
+ void (*dtr_rts)(struct tty_port *port, int raise);
+ /* Called when the last close completes or a hangup finishes
+ IFF the port was initialized. Do not use to free resources. Called
+ under the port mutex to serialize against activate/shutdowns */
+ void (*shutdown)(struct tty_port *port);
+ /* Called under the port mutex from tty_port_open, serialized using
+ the port mutex */
+ /* FIXME: long term getting the tty argument *out* of this would be
+ good for consoles */
+ int (*activate)(struct tty_port *port, struct tty_struct *tty);
+ /* Called on the final put of a port */
+ void (*destruct)(struct tty_port *port);
+};
+
+struct tty_port_client_operations {
+ int (*receive_buf)(struct tty_port *port, const unsigned char *, const unsigned char *, size_t);
+ void (*write_wakeup)(struct tty_port *port);
+};
+
+struct tty_port {
+ struct tty_bufhead buf; /* Locked internally */
+ struct tty_struct *tty; /* Back pointer */
+ struct tty_struct *itty; /* internal back ptr */
+ const struct tty_port_operations *ops; /* Port operations */
+ const struct tty_port_client_operations *client_ops; /* Port client operations */
+ spinlock_t lock; /* Lock protecting tty field */
+ int blocked_open; /* Waiting to open */
+ int count; /* Usage count */
+ wait_queue_head_t open_wait; /* Open waiters */
+ wait_queue_head_t delta_msr_wait; /* Modem status change */
+ unsigned long flags; /* User TTY flags ASYNC_ */
+ unsigned long iflags; /* Internal flags TTY_PORT_ */
+ unsigned char console:1, /* port is a console */
+ low_latency:1; /* optional: tune for latency */
+ struct mutex mutex; /* Locking */
+ struct mutex buf_mutex; /* Buffer alloc lock */
+ unsigned char *xmit_buf; /* Optional buffer */
+ unsigned int close_delay; /* Close port delay */
+ unsigned int closing_wait; /* Delay for output */
+ int drain_delay; /* Set to zero if no pure time
+ based drain is needed else
+ set to size of fifo */
+ struct kref kref; /* Ref counter */
+ void *client_data;
+};
+
+/* tty_port::iflags bits -- use atomic bit ops */
+#define TTY_PORT_INITIALIZED 0 /* device is initialized */
+#define TTY_PORT_SUSPENDED 1 /* device is suspended */
+#define TTY_PORT_ACTIVE 2 /* device is open */
+
+/*
+ * uart drivers: use the uart_port::status field and the UPSTAT_* defines
+ * for s/w-based flow control steering and carrier detection status
+ */
+#define TTY_PORT_CTS_FLOW 3 /* h/w flow control enabled */
+#define TTY_PORT_CHECK_CD 4 /* carrier detect enabled */
+#define TTY_PORT_KOPENED 5 /* device exclusively opened by
+ kernel */
+
+/*
+ * Where all of the state associated with a tty is kept while the tty
+ * is open. Since the termios state should be kept even if the tty
+ * has been closed --- for things like the baud rate, etc --- it is
+ * not stored here, but rather a pointer to the real state is stored
+ * here. Possible the winsize structure should have the same
+ * treatment, but (1) the default 80x24 is usually right and (2) it's
+ * most often used by a windowing system, which will set the correct
+ * size each time the window is created or resized anyway.
+ * - TYT, 9/14/92
+ */
+
+struct tty_operations;
+
+struct tty_struct {
+ int magic;
+ struct kref kref;
+ struct device *dev;
+ struct tty_driver *driver;
+ const struct tty_operations *ops;
+ int index;
+
+ /* Protects ldisc changes: Lock tty not pty */
+ 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;
+ spinlock_t ctrl_lock;
+ spinlock_t flow_lock;
+ /* Termios values are protected by the termios rwsem */
+ struct ktermios termios, termios_locked;
+ struct termiox *termiox; /* May be NULL for unsupported */
+ char name[64];
+ struct pid *pgrp; /* Protected by ctrl lock */
+ struct pid *session;
+ unsigned long flags;
+ int count;
+ struct winsize winsize; /* winsize_mutex */
+ unsigned long stopped:1, /* flow_lock */
+ flow_stopped:1,
+ unused:BITS_PER_LONG - 2;
+ int hw_stopped;
+ unsigned long ctrl_status:8, /* ctrl_lock */
+ packet:1,
+ unused_ctrl:BITS_PER_LONG - 9;
+ unsigned int receive_room; /* Bytes free for queue */
+ 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; /* protects tty_files list */
+ struct list_head tty_files;
+
+#define N_TTY_BUF_SIZE 4096
+
+ int closing;
+ unsigned char *write_buf;
+ int write_cnt;
+ /* If the tty has a pending do_SAK, queue it here - akpm */
+ 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_HALTED 22 /* Line discipline is halted */
+
+/* Values for tty->flow_change */
+#define TTY_THROTTLE_SAFE 1
+#define TTY_UNTHROTTLE_SAFE 2
+
+static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
+{
+ tty->flow_change = val;
+}
+
+static inline void tty_set_flow_change(struct tty_struct *tty, int val)
+{
+ tty->flow_change = val;
+ smp_mb();
+}
+
+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
+extern void tty_kref_put(struct tty_struct *tty);
+extern struct pid *tty_get_pgrp(struct tty_struct *tty);
+extern void tty_vhangup_self(void);
+extern void disassociate_ctty(int priv);
+extern dev_t tty_devnum(struct tty_struct *tty);
+extern void proc_clear_tty(struct task_struct *p);
+extern struct tty_struct *get_current_tty(void);
+/* tty_io.c */
+extern int __init tty_init(void);
+extern const char *tty_name(const struct tty_struct *tty);
+extern struct tty_struct *tty_kopen(dev_t device);
+extern void tty_kclose(struct tty_struct *tty);
+extern int tty_dev_name_to_number(const char *name, dev_t *number);
+extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
+extern void tty_ldisc_unlock(struct tty_struct *tty);
+#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(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;
+
+extern 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;
+}
+
+extern const char *tty_driver_name(const struct tty_struct *tty);
+extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
+extern int __tty_check_change(struct tty_struct *tty, int sig);
+extern int tty_check_change(struct tty_struct *tty);
+extern void __stop_tty(struct tty_struct *tty);
+extern void stop_tty(struct tty_struct *tty);
+extern void __start_tty(struct tty_struct *tty);
+extern void start_tty(struct tty_struct *tty);
+extern int tty_register_driver(struct tty_driver *driver);
+extern int tty_unregister_driver(struct tty_driver *driver);
+extern struct device *tty_register_device(struct tty_driver *driver,
+ unsigned index, struct device *dev);
+extern struct device *tty_register_device_attr(struct tty_driver *driver,
+ unsigned index, struct device *device,
+ void *drvdata,
+ const struct attribute_group **attr_grp);
+extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
+extern void tty_write_message(struct tty_struct *tty, char *msg);
+extern int tty_send_xchar(struct tty_struct *tty, char ch);
+extern int tty_put_char(struct tty_struct *tty, unsigned char c);
+extern int tty_chars_in_buffer(struct tty_struct *tty);
+extern int tty_write_room(struct tty_struct *tty);
+extern void tty_driver_flush_buffer(struct tty_struct *tty);
+extern void tty_throttle(struct tty_struct *tty);
+extern void tty_unthrottle(struct tty_struct *tty);
+extern int tty_throttle_safe(struct tty_struct *tty);
+extern int tty_unthrottle_safe(struct tty_struct *tty);
+extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
+extern int is_current_pgrp_orphaned(void);
+extern void tty_hangup(struct tty_struct *tty);
+extern void tty_vhangup(struct tty_struct *tty);
+extern void tty_vhangup_session(struct tty_struct *tty);
+extern int tty_hung_up_p(struct file *filp);
+extern void do_SAK(struct tty_struct *tty);
+extern void __do_SAK(struct tty_struct *tty);
+extern void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
+extern int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
+extern void session_clear_tty(struct pid *session);
+extern void no_tty(void);
+extern void tty_buffer_free_all(struct tty_port *port);
+extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
+extern void tty_buffer_init(struct tty_port *port);
+extern void tty_buffer_set_lock_subclass(struct tty_port *port);
+extern bool tty_buffer_restart_work(struct tty_port *port);
+extern bool tty_buffer_cancel_work(struct tty_port *port);
+extern void tty_buffer_flush_work(struct tty_port *port);
+extern speed_t tty_termios_baud_rate(struct ktermios *termios);
+extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
+extern void tty_termios_encode_baud_rate(struct ktermios *termios,
+ speed_t ibaud, speed_t obaud);
+extern 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);
+}
+
+extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
+extern int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
+extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
+
+extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
+extern void tty_ldisc_deref(struct tty_ldisc *);
+extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
+extern void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
+extern int tty_ldisc_reinit(struct tty_struct *tty, int disc);
+extern const struct seq_operations tty_ldiscs_seq_ops;
+
+extern void tty_wakeup(struct tty_struct *tty);
+extern void tty_ldisc_flush(struct tty_struct *tty);
+
+extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg);
+extern long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
+ struct file *file, unsigned int cmd, unsigned long arg);
+extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
+extern void tty_default_fops(struct file_operations *fops);
+extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
+extern int tty_alloc_file(struct file *file);
+extern void tty_add_file(struct tty_struct *tty, struct file *file);
+extern void tty_free_file(struct file *file);
+extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
+extern void tty_release_struct(struct tty_struct *tty, int idx);
+extern int tty_release(struct inode *inode, struct file *filp);
+extern void tty_init_termios(struct tty_struct *tty);
+extern void tty_save_termios(struct tty_struct *tty);
+extern int tty_standard_install(struct tty_driver *driver,
+ struct tty_struct *tty);
+
+extern struct mutex tty_mutex;
+
+#define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock))
+
+extern void tty_port_init(struct tty_port *port);
+extern void tty_port_link_device(struct tty_port *port,
+ struct tty_driver *driver, unsigned index);
+extern struct device *tty_port_register_device(struct tty_port *port,
+ struct tty_driver *driver, unsigned index,
+ struct device *device);
+extern struct device *tty_port_register_device_attr(struct tty_port *port,
+ struct tty_driver *driver, unsigned index,
+ struct device *device, void *drvdata,
+ const struct attribute_group **attr_grp);
+extern struct device *tty_port_register_device_serdev(struct tty_port *port,
+ struct tty_driver *driver, unsigned index,
+ struct device *device);
+extern struct device *tty_port_register_device_attr_serdev(struct tty_port *port,
+ struct tty_driver *driver, unsigned index,
+ struct device *device, void *drvdata,
+ const struct attribute_group **attr_grp);
+extern void tty_port_unregister_device(struct tty_port *port,
+ struct tty_driver *driver, unsigned index);
+extern int tty_port_alloc_xmit_buf(struct tty_port *port);
+extern void tty_port_free_xmit_buf(struct tty_port *port);
+extern void tty_port_destroy(struct tty_port *port);
+extern void tty_port_put(struct tty_port *port);
+
+static inline struct tty_port *tty_port_get(struct tty_port *port)
+{
+ if (port && kref_get_unless_zero(&port->kref))
+ return port;
+ return NULL;
+}
+
+/* If the cts flow control is enabled, return true. */
+static inline bool tty_port_cts_enabled(struct tty_port *port)
+{
+ return test_bit(TTY_PORT_CTS_FLOW, &port->iflags);
+}
+
+static inline void tty_port_set_cts_flow(struct tty_port *port, bool val)
+{
+ if (val)
+ set_bit(TTY_PORT_CTS_FLOW, &port->iflags);
+ else
+ clear_bit(TTY_PORT_CTS_FLOW, &port->iflags);
+}
+
+static inline bool tty_port_active(struct tty_port *port)
+{
+ return test_bit(TTY_PORT_ACTIVE, &port->iflags);
+}
+
+static inline void tty_port_set_active(struct tty_port *port, bool val)
+{
+ if (val)
+ set_bit(TTY_PORT_ACTIVE, &port->iflags);
+ else
+ clear_bit(TTY_PORT_ACTIVE, &port->iflags);
+}
+
+static inline bool tty_port_check_carrier(struct tty_port *port)
+{
+ return test_bit(TTY_PORT_CHECK_CD, &port->iflags);
+}
+
+static inline void tty_port_set_check_carrier(struct tty_port *port, bool val)
+{
+ if (val)
+ set_bit(TTY_PORT_CHECK_CD, &port->iflags);
+ else
+ clear_bit(TTY_PORT_CHECK_CD, &port->iflags);
+}
+
+static inline bool tty_port_suspended(struct tty_port *port)
+{
+ return test_bit(TTY_PORT_SUSPENDED, &port->iflags);
+}
+
+static inline void tty_port_set_suspended(struct tty_port *port, bool val)
+{
+ if (val)
+ set_bit(TTY_PORT_SUSPENDED, &port->iflags);
+ else
+ clear_bit(TTY_PORT_SUSPENDED, &port->iflags);
+}
+
+static inline bool tty_port_initialized(struct tty_port *port)
+{
+ return test_bit(TTY_PORT_INITIALIZED, &port->iflags);
+}
+
+static inline void tty_port_set_initialized(struct tty_port *port, bool val)
+{
+ if (val)
+ set_bit(TTY_PORT_INITIALIZED, &port->iflags);
+ else
+ clear_bit(TTY_PORT_INITIALIZED, &port->iflags);
+}
+
+static inline bool tty_port_kopened(struct tty_port *port)
+{
+ return test_bit(TTY_PORT_KOPENED, &port->iflags);
+}
+
+static inline void tty_port_set_kopened(struct tty_port *port, bool val)
+{
+ if (val)
+ set_bit(TTY_PORT_KOPENED, &port->iflags);
+ else
+ clear_bit(TTY_PORT_KOPENED, &port->iflags);
+}
+
+extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
+extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
+extern int tty_port_carrier_raised(struct tty_port *port);
+extern void tty_port_raise_dtr_rts(struct tty_port *port);
+extern void tty_port_lower_dtr_rts(struct tty_port *port);
+extern void tty_port_hangup(struct tty_port *port);
+extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
+extern void tty_port_tty_wakeup(struct tty_port *port);
+extern int tty_port_block_til_ready(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp);
+extern int tty_port_close_start(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp);
+extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
+extern void tty_port_close(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp);
+extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
+ struct tty_struct *tty);
+extern int tty_port_open(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp);
+static inline int tty_port_users(struct tty_port *port)
+{
+ return port->count + port->blocked_open;
+}
+
+extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
+extern int tty_unregister_ldisc(int disc);
+extern int tty_set_ldisc(struct tty_struct *tty, int disc);
+extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
+extern void tty_ldisc_release(struct tty_struct *tty);
+extern int __must_check tty_ldisc_init(struct tty_struct *tty);
+extern void tty_ldisc_deinit(struct tty_struct *tty);
+extern int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
+ char *f, int count);
+
+/* n_tty.c */
+extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
+#ifdef CONFIG_TTY
+extern void __init n_tty_init(void);
+#else
+static inline void n_tty_init(void) { }
+#endif
+
+/* tty_audit.c */
+#ifdef CONFIG_AUDIT
+extern void tty_audit_add_data(struct tty_struct *tty, const void *data,
+ size_t size);
+extern void tty_audit_exit(void);
+extern void tty_audit_fork(struct signal_struct *sig);
+extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
+extern int tty_audit_push(void);
+#else
+static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
+ size_t size)
+{
+}
+static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
+{
+}
+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 */
+extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg);
+extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg);
+
+/* vt.c */
+
+extern int vt_ioctl(struct tty_struct *tty,
+ unsigned int cmd, unsigned long arg);
+
+extern long vt_compat_ioctl(struct tty_struct *tty,
+ unsigned int cmd, unsigned long arg);
+
+/* tty_mutex.c */
+/* functions for preparation of BKL removal */
+extern void tty_lock(struct tty_struct *tty);
+extern int tty_lock_interruptible(struct tty_struct *tty);
+extern void tty_unlock(struct tty_struct *tty);
+extern void tty_lock_slave(struct tty_struct *tty);
+extern void tty_unlock_slave(struct tty_struct *tty);
+extern void tty_set_lock_subclass(struct tty_struct *tty);
+
+#ifdef CONFIG_PROC_FS
+extern void proc_tty_register_driver(struct tty_driver *);
+extern void proc_tty_unregister_driver(struct tty_driver *);
+#else
+static inline void proc_tty_register_driver(struct tty_driver *d) {}
+static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
+#endif
+
+#define tty_msg(fn, tty, f, ...) \
+ fn("%s %s: " f, tty_driver_name(tty), tty_name(tty), ##__VA_ARGS__)
+
+#define tty_debug(tty, f, ...) tty_msg(pr_debug, tty, f, ##__VA_ARGS__)
+#define tty_info(tty, f, ...) tty_msg(pr_info, tty, f, ##__VA_ARGS__)
+#define tty_notice(tty, f, ...) tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
+#define tty_warn(tty, f, ...) tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
+#define tty_err(tty, f, ...) tty_msg(pr_err, tty, f, ##__VA_ARGS__)
+
+#define tty_info_ratelimited(tty, f, ...) \
+ tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
+
+#endif