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Diffstat (limited to 'include/linux/tty.h')
| -rw-r--r-- | include/linux/tty.h | 712 |
1 files changed, 712 insertions, 0 deletions
diff --git a/include/linux/tty.h b/include/linux/tty.h new file mode 100644 index 000000000..d76631f61 --- /dev/null +++ b/include/linux/tty.h @@ -0,0 +1,712 @@ +#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> +#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 { + 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 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 */ +}; + +/* + * 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; + 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 + + 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; +}; + +/* 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_OTHER_DONE 6 /* Closed pty has completed input processing */ +#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_LDISC_HALTED 22 /* Line discipline is halted */ + +#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty)) + +/* 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(); +} + +#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 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 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_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 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 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_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 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(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(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 void free_tty_struct(struct tty_struct *tty); +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 mutex tty_mutex; +extern spinlock_t tty_files_lock; + +#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_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 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 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 ldisc); +extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); +extern void tty_ldisc_release(struct tty_struct *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); + +static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p, + char *f, int count) +{ + if (ld->ops->receive_buf2) + count = ld->ops->receive_buf2(ld->tty, p, f, count); + else { + count = min_t(int, count, ld->tty->receive_room); + if (count) + ld->ops->receive_buf(ld->tty, p, f, count); + } + return count; +} + + +/* 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_current(void); +#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_current(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 __lockfunc tty_lock(struct tty_struct *tty); +extern void __lockfunc tty_unlock(struct tty_struct *tty); +extern void __lockfunc tty_lock_slave(struct tty_struct *tty); +extern void __lockfunc tty_unlock_slave(struct tty_struct *tty); +extern void tty_set_lock_subclass(struct tty_struct *tty); +/* + * 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)) \ + __ret = __wait_event_interruptible_tty(tty, wq, \ + condition); \ + __ret; \ +}) + +#define __wait_event_interruptible_tty(tty, wq, condition) \ + ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ + tty_unlock(tty); \ + schedule(); \ + tty_lock(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 + +#endif |