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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-25 13:43:55 +08:00
linux-next/include/linux/tty.h
Joe Millenbach 4f73bc4dd3 tty: Added a CONFIG_TTY option to allow removal of TTY
The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-meter output is below.

The bulk of this patch consists of Kconfig changes adding "depends on
TTY" to various serial devices and similar drivers that require the TTY
layer.  Ideally, these dependencies would occur on a common intermediate
symbol such as SERIO, but most drivers "select SERIO" rather than
"depends on SERIO", and "select" does not respect dependencies.

bloat-o-meter output comparing our previous minimal to new minimal by
removing TTY.  The list is filtered to not show removed entries with awk
'$3 != "-"' as the list was very long.

add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
function                                     old     new   delta
chr_dev_init                                 166     170      +4
allow_signal                                  80      82      +2
static.__warned                              143     142      -1
disallow_signal                               63      62      -1
__set_special_pids                            95      94      -1
unregister_console                           126     121      -5
start_kernel                                 546     541      -5
register_console                             593     588      -5
copy_from_user                                45      40      -5
sys_setsid                                   128     120      -8
sys_vhangup                                   32      19     -13
do_exit                                     1543    1526     -17
bitmap_zero                                   60      40     -20
arch_local_irq_save                          137     117     -20
release_task                                 674     652     -22
static.spin_unlock_irqrestore                308     260     -48

Signed-off-by: Joe Millenbach <jmillenbach@gmail.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-18 16:15:27 -08:00

663 lines
24 KiB
C

#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 <uapi/linux/tty.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'
struct tty_buffer {
struct tty_buffer *next;
char *char_buf_ptr;
unsigned char *flag_buf_ptr;
int used;
int size;
int commit;
int read;
/* Data points here */
unsigned long data[0];
};
/*
* We default to dicing tty buffer allocations to this many characters
* in order to avoid multiple page allocations. We know the size of
* tty_buffer itself but it must also be taken into account that the
* the buffer is 256 byte aligned. See tty_buffer_find for the allocation
* logic this must match
*/
#define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF)
struct tty_bufhead {
struct work_struct work;
spinlock_t lock;
struct tty_buffer *head; /* Queue head */
struct tty_buffer *tail; /* Active buffer */
struct tty_buffer *free; /* Free queue head */
int memory_used; /* Buffer space used excluding
free queue */
};
/*
* 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 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);
void (*drop)(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 {
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 */
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 close_wait; /* Close waiters */
wait_queue_head_t delta_msr_wait; /* Modem status change */
unsigned long flags; /* TTY flags ASY_*/
unsigned long iflags; /* TTYP_ internal flags */
#define TTYP_FLUSHING 1 /* Flushing to ldisc in progress */
#define TTYP_FLUSHPENDING 2 /* Queued buffer flush pending */
unsigned char console:1, /* port is a console */
low_latency:1; /* direct buffer flush */
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 */
};
/*
* 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 mutex ldisc_mutex;
struct tty_ldisc *ldisc;
struct mutex atomic_write_lock;
struct mutex legacy_mutex;
struct mutex termios_mutex;
spinlock_t ctrl_lock;
/* Termios values are protected by the termios mutex */
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; /* termios mutex */
unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
unsigned char warned:1;
unsigned char ctrl_status; /* ctrl_lock */
unsigned int receive_room; /* Bytes free for queue */
struct tty_struct *link;
struct fasync_struct *fasync;
int alt_speed; /* For magic substitution of 38400 bps */
wait_queue_head_t write_wait;
wait_queue_head_t read_wait;
struct work_struct hangup_work;
void *disc_data;
void *driver_data;
struct list_head tty_files;
#define N_TTY_BUF_SIZE 4096
unsigned char closing:1;
unsigned short minimum_to_wake;
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;
};
/* 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_DEBUG 4 /* Debugging */
#define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */
#define TTY_PUSH 6 /* n_tty private */
#define TTY_CLOSING 7 /* ->close() in progress */
#define TTY_LDISC 9 /* Line discipline attached */
#define TTY_LDISC_CHANGING 10 /* Line discipline changing */
#define TTY_LDISC_OPEN 11 /* Line discipline is open */
#define TTY_HW_COOK_OUT 14 /* Hardware can do output cooking */
#define TTY_HW_COOK_IN 15 /* Hardware can do input cooking */
#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 21 /* ->hangup() in progress */
#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
#ifdef CONFIG_TTY
extern void console_init(void);
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);
#else
static inline void console_init(void)
{ }
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; }
#endif
extern void tty_write_flush(struct tty_struct *);
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 int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
const char *routine);
extern char *tty_name(struct tty_struct *tty, char *buf);
extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
extern int tty_check_change(struct tty_struct *tty);
extern void stop_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 int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
int buflen);
extern void tty_write_message(struct tty_struct *tty, char *msg);
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_do_resize(struct tty_struct *tty, struct winsize *ws);
extern void tty_driver_remove_tty(struct tty_driver *driver,
struct tty_struct *tty);
extern void tty_free_termios(struct tty_struct *tty);
extern int is_current_pgrp_orphaned(void);
extern int is_ignored(int sig);
extern int tty_signal(int sig, struct tty_struct *tty);
extern void tty_hangup(struct tty_struct *tty);
extern void tty_vhangup(struct tty_struct *tty);
extern void tty_vhangup_locked(struct tty_struct *tty);
extern void tty_unhangup(struct file *filp);
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 no_tty(void);
extern void tty_flush_to_ldisc(struct tty_struct *tty);
extern void tty_buffer_free_all(struct tty_port *port);
extern void tty_buffer_flush(struct tty_struct *tty);
extern void tty_buffer_init(struct tty_port *port);
extern speed_t tty_get_baud_rate(struct tty_struct *tty);
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);
extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
extern int tty_termios_hw_change(struct ktermios *a, 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);
extern const struct file_operations tty_ldiscs_proc_fops;
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 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(void);
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 void free_tty_struct(struct tty_struct *tty);
extern void initialize_tty_struct(struct tty_struct *tty,
struct tty_driver *driver, int idx);
extern void deinitialize_tty_struct(struct tty_struct *tty);
extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
extern int tty_release(struct inode *inode, struct file *filp);
extern int tty_init_termios(struct tty_struct *tty);
extern int tty_standard_install(struct tty_driver *driver,
struct tty_struct *tty);
extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
extern struct mutex tty_mutex;
extern spinlock_t tty_files_lock;
extern void tty_write_unlock(struct tty_struct *tty);
extern int tty_write_lock(struct tty_struct *tty, int ndelay);
#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 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(&port->kref);
return port;
}
/* If the cts flow control is enabled, return true. */
static inline bool tty_port_cts_enabled(struct tty_port *port)
{
return port->flags & ASYNC_CTS_FLOW;
}
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 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 ldisc);
extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
extern void tty_ldisc_init(struct tty_struct *tty);
extern void tty_ldisc_deinit(struct tty_struct *tty);
extern void tty_ldisc_begin(void);
/* This last one is just for the tty layer internals and shouldn't be used elsewhere */
extern void tty_ldisc_enable(struct tty_struct *tty);
/* n_tty.c */
extern struct tty_ldisc_ops tty_ldisc_N_TTY;
extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
/* tty_audit.c */
#ifdef CONFIG_AUDIT
extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
size_t size, unsigned icanon);
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 void tty_audit_push(struct tty_struct *tty);
extern int tty_audit_push_task(struct task_struct *tsk,
kuid_t loginuid, u32 sessionid);
#else
static inline void tty_audit_add_data(struct tty_struct *tty,
unsigned char *data, size_t size, unsigned icanon)
{
}
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 void tty_audit_push(struct tty_struct *tty)
{
}
static inline int tty_audit_push_task(struct task_struct *tsk,
kuid_t loginuid, u32 sessionid)
{
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);
/* serial.c */
extern void serial_console_init(void);
/* pcxx.c */
extern int pcxe_open(struct tty_struct *tty, struct file *filp);
/* 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 __lockfunc tty_lock(struct tty_struct *tty);
extern void __lockfunc tty_unlock(struct tty_struct *tty);
extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
struct tty_struct *tty2);
extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
struct tty_struct *tty2);
/*
* this shall be called only from where BTM is held (like close)
*
* We need this to ensure nobody waits for us to finish while we are waiting.
* Without this we were encountering system stalls.
*
* This should be indeed removed with BTM removal later.
*
* Locking: BTM required. Nobody is allowed to hold port->mutex.
*/
static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
long timeout)
{
tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
tty_wait_until_sent(tty, timeout);
tty_lock(tty);
}
/*
* wait_event_interruptible_tty -- wait for a condition with the tty lock held
*
* The condition we are waiting for might take a long time to
* become true, or might depend on another thread taking the
* BTM. In either case, we need to drop the BTM to guarantee
* forward progress. This is a leftover from the conversion
* from the BKL and should eventually get removed as the BTM
* falls out of use.
*
* Do not use in new code.
*/
#define wait_event_interruptible_tty(tty, wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) { \
__wait_event_interruptible_tty(tty, wq, condition, __ret); \
} \
__ret; \
})
#define __wait_event_interruptible_tty(tty, wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
if (condition) \
break; \
if (!signal_pending(current)) { \
tty_unlock(tty); \
schedule(); \
tty_lock(tty); \
continue; \
} \
ret = -ERESTARTSYS; \
break; \
} \
finish_wait(&wq, &__wait); \
} while (0)
#endif