From e04957365b21066285557e42ffe16d8330d46c02 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:36:58 +0100 Subject: tty: split the buffering from tty_io The two are basically independent chunks of code so lets split them up for readability and sanity. It also makes the API boundaries much clearer. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 0cbec74..7271c62 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -347,6 +347,9 @@ extern void __do_SAK(struct tty_struct *tty); extern void disassociate_ctty(int priv); extern void no_tty(void); extern void tty_flip_buffer_push(struct tty_struct *tty); +extern void tty_buffer_free_all(struct tty_struct *tty); +extern void tty_buffer_flush(struct tty_struct *tty); +extern void tty_buffer_init(struct tty_struct *tty); 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); -- cgit v1.1 From 348eb12e5598be97400c749d3d93a71856ae0b2b Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:37:17 +0100 Subject: pps: Reserve a line discipline number for PPS Add a new line discipline for "pulse per second" devices connected to a serial port. Signed-off-by: Rodolfo Giometti Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 7271c62..e3612c3 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -23,7 +23,7 @@ */ #define NR_UNIX98_PTY_DEFAULT 4096 /* Default maximum for Unix98 ptys */ #define NR_UNIX98_PTY_MAX (1 << MINORBITS) /* Absolute limit */ -#define NR_LDISCS 18 +#define NR_LDISCS 19 /* line disciplines */ #define N_TTY 0 @@ -45,6 +45,7 @@ #define N_HCI 15 /* Bluetooth HCI UART */ #define N_GIGASET_M101 16 /* Siemens Gigaset M101 serial DECT adapter */ #define N_SLCAN 17 /* Serial / USB serial CAN Adaptors */ +#define N_PPS 18 /* Pulse per Second */ /* * This character is the same as _POSIX_VDISABLE: it cannot be used as -- cgit v1.1 From 9c9f4ded90a59eee84e15f5fd38c03d60184e112 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:37:26 +0100 Subject: tty: Add a kref count Introduce a kref to the tty structure and use it to protect the tty->signal tty references. For now we don't introduce it for anything else. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index e3612c3..b6e6c26 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -209,6 +209,7 @@ struct tty_operations; struct tty_struct { int magic; + struct kref kref; struct tty_driver *driver; const struct tty_operations *ops; int index; @@ -311,6 +312,23 @@ extern int kmsg_redirect; extern void console_init(void); extern int vcs_init(void); +/** + * 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 + */ + +extern inline struct tty_struct *tty_kref_get(struct tty_struct *tty) +{ + if (tty) + kref_get(&tty->kref); + return tty; +} +extern void tty_kref_put(struct tty_struct *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); -- cgit v1.1 From 1d65b4a088de407e99714fdc27862449db04fb5c Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:38:18 +0100 Subject: tty: Add termiox We need a way to describe the various additional modes and flow control features that random weird hardware shows up and software such as wine wants to emulate as Windows supports them. TCGETX/TCSETX and the termiox ioctl are a SYS5 extension that we might as well adopt. This patches adds the structures and the basic ioctl interfaces when the TCGETX etc defines are added for an architecture. Drivers wishing to use this stuff need to add new methods. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index b6e6c26..b64d10b 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -219,6 +219,7 @@ struct tty_struct { 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; -- cgit v1.1 From 4a90f09b20f4622dcbff1f0e1e6bae1704f8ad8c Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:39:46 +0100 Subject: tty: usb-serial krefs Use kref in the USB serial drivers so that we don't free tty structures from under the URB receive handlers as has historically been the case if you were unlucky. This also gives us a framework for general tty drivers to use tty_port objects and refcount. Contains two err->dev_err changes merged together to fix clashes in the -next tree. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index b64d10b..c30ed8d 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -182,6 +182,7 @@ struct signal_struct; struct tty_port { struct tty_struct *tty; /* Back pointer */ + 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 */ @@ -405,6 +406,8 @@ extern int tty_write_lock(struct tty_struct *tty, int ndelay); extern void tty_port_init(struct tty_port *port); extern int tty_port_alloc_xmit_buf(struct tty_port *port); extern void tty_port_free_xmit_buf(struct tty_port *port); +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_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc); extern int tty_unregister_ldisc(int disc); -- cgit v1.1 From 2cb5998b5f0ccc886fdda3509059eef297b49577 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:40:30 +0100 Subject: tty: the vhangup syscall is racy We now have the infrastructure to sort this out but rather than teaching the syscall tty lock rules we move the hard work into a tty helper Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index c30ed8d..e00393a 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -361,6 +361,7 @@ 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_self(void); extern void tty_unhangup(struct file *filp); extern int tty_hung_up_p(struct file *filp); extern void do_SAK(struct tty_struct *tty); -- cgit v1.1 From feebed6515a113eeb33919e9557a8b9710ea627c Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:41:30 +0100 Subject: tty: shutdown method Right now there are various drivers that try to use tty->count to know when they get the final close. Aristeau Rozanski showed while debugging the vt sysfs race that this isn't entirely safe. Instead of driver side tricks to work around this introduce a shutdown which is called when the tty is being destructed. This also means that the shutdown method is tied into the refcounting. Use this to rework the console close/sysfs logic. Remove lots of special case code from the tty core code. The pty code can now have a shutdown() method that replaces the special case hackery in the tree free up paths. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index e00393a..6e39c70 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -354,7 +354,8 @@ 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 tty_struct *real_tty, struct winsize *ws); - +extern void tty_shutdown(struct tty_struct *tty); +extern void tty_free_termios(struct tty_struct *tty); extern int is_current_pgrp_orphaned(void); extern struct pid *tty_get_pgrp(struct tty_struct *tty); extern int is_ignored(int sig); -- cgit v1.1 From d81ed10307027e1643a65ab5fe17cc01233d376d Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:41:42 +0100 Subject: tty: Remove more special casing and out of place code Carry on pushing code out of tty_io when it belongs to other drivers. I'm not 100% happy with some of this and it will be worth revisiting some of the exports later when the restructuring work is done. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 6e39c70..6cc7ccc 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -314,6 +314,8 @@ extern int kmsg_redirect; extern void console_init(void); extern int vcs_init(void); +extern struct class *tty_class; + /** * tty_kref_get - get a tty reference * @tty: tty device @@ -398,6 +400,10 @@ extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg); 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); +extern void tty_default_fops(struct file_operations *fops); +extern int tty_init_dev(struct tty_driver *driver, int idx, + struct tty_struct **ret_tty, int first_ok); +extern void tty_release_dev(struct file *filp); extern struct mutex tty_mutex; -- cgit v1.1 From 73ec06fc5f5c8e1097a7a4a4ab2d7c6c3a007e81 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:42:29 +0100 Subject: tty: Finish fixing up the init_dev interface to use ERR_PTR Original suggestion and proposal from Sukadev Bhattiprolu. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 6cc7ccc..54523a3 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -401,8 +401,8 @@ 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); extern void tty_default_fops(struct file_operations *fops); -extern int tty_init_dev(struct tty_driver *driver, int idx, - struct tty_struct **ret_tty, int first_ok); +extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, + int first_ok); extern void tty_release_dev(struct file *filp); extern struct mutex tty_mutex; -- cgit v1.1 From bf970ee46e0fb363c8df4393229121d54330a98e Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:42:39 +0100 Subject: tty: extract the pty init time special cases The majority of the remaining init_dev code is pty special cases. We refactor this code into the driver->install method. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 54523a3..3c7c757 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -401,9 +401,14 @@ 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); extern void tty_default_fops(struct file_operations *fops); +extern struct tty_struct *alloc_tty_struct(void); +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 struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, int first_ok); extern void tty_release_dev(struct file *filp); +extern int tty_init_termios(struct tty_struct *tty); extern struct mutex tty_mutex; -- cgit v1.1 From 47afa7a5a8a8fb9e60cdb6a3bd612e07c37e9d90 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:44:17 +0100 Subject: tty: some ICANON magic is in the wrong places Move the set up on ldisc change into the ldisc Move the INQ/OUTQ cases into the driver not in shared ioctl code where it gives bogus answers for other ldisc values Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 3c7c757..3b8121d 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -466,7 +466,7 @@ static inline void tty_audit_push_task(struct task_struct *tsk, #endif /* tty_ioctl.c */ -extern int n_tty_ioctl(struct tty_struct *tty, struct file *file, +extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg); /* serial.c */ -- cgit v1.1