From 64bc397914265a9ead8d73b63bb31ab3bdd25f67 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Tue, 6 Oct 2009 16:06:11 +0100 Subject: tty_port: add "tty_port_open" helper For the moment this just moves the USB logic over and fixes the 'what if we open and hangup at the same time' race noticed by Oliver Neukum. Signed-off-by: Alan Cox Cc: Alan Stern Cc: Oliver Neukum Signed-off-by: Greg Kroah-Hartman --- include/linux/tty.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index f0f43d08d8b8..6352ac257fcb 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -190,9 +190,15 @@ struct tty_port_operations { /* 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 */ + 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); }; struct tty_port { @@ -467,6 +473,8 @@ extern int tty_port_close_start(struct tty_port *port, 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_open(struct tty_port *port, + struct tty_struct *tty, struct file *filp); extern inline int tty_port_users(struct tty_port *port) { return port->count + port->blocked_open; -- cgit v1.2.2 From 44e4909e453eaa09c7de409fc9ee4ebefd986c1c Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 30 Nov 2009 13:16:41 +0000 Subject: tty: tty_port: Change the buffer allocator locking We want to be able to do this without regard for the activate/own open method being used which causes a problem using port->mutex. Add another mutex for now. Once everything uses port_open to do buffer allocs we can kill it back off Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- 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 6352ac257fcb..e9269ca1542a 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -212,6 +212,7 @@ struct tty_port { wait_queue_head_t delta_msr_wait; /* Modem status change */ unsigned long flags; /* TTY flags ASY_*/ 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 */ -- cgit v1.2.2 From 568aafc627e2978509e8a80c640ba534d1e843cc Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 30 Nov 2009 13:17:14 +0000 Subject: tty: tty_port: Add a kref object to the tty port Users of tty port need a way to refcount ports when hotplugging is involved. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- include/linux/tty.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index e9269ca1542a..e6da667ba34d 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -199,6 +199,8 @@ struct tty_port_operations { /* 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 { @@ -219,6 +221,7 @@ struct tty_port { 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 */ }; /* @@ -461,6 +464,15 @@ 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 void tty_port_put(struct tty_port *port); + +extern inline struct tty_port *tty_port_get(struct tty_port *port) +{ + if (port) + kref_get(&port->kref); + return 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_port_carrier_raised(struct tty_port *port); -- cgit v1.2.2 From eeb89d918c2fa2b809e464136bbafdaec2aacb30 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 30 Nov 2009 13:18:29 +0000 Subject: tty: push the BKL down into the handlers a bit Start trying to untangle the remaining BKL mess Updated to fix missing unlock_kernel noted by Dan Carpenter Signed-off-by: Alan "I must be out of my tree" Cox Signed-off-by: Greg Kroah-Hartman --- 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 e6da667ba34d..405a9035fe40 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -449,7 +449,7 @@ 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_release(struct inode *inode, struct file *filp); extern int tty_init_termios(struct tty_struct *tty); extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty); -- cgit v1.2.2 From 5ada918b82399eef3afd6a71e3637697d6bd719f Mon Sep 17 00:00:00 2001 From: Bernhard Walle Date: Mon, 14 Dec 2009 18:00:43 -0800 Subject: vt: introduce and use vt_kmsg_redirect() function The kernel offers with TIOCL_GETKMSGREDIRECT ioctl() the possibility to redirect the kernel messages to a specific console. However, since it's not possible to switch to the kernel message console after a panic(), it would be nice if the kernel would print the panic message on the current console. This patch series adds a new interface to access the global kmsg_redirect variable by a function to be able to use it in code where CONFIG_VT_CONSOLE is not set (kernel/panic.c). This patch: Instead of using and exporting a global value kmsg_redirect, introduce a function vt_kmsg_redirect() that both can set and return the console where messages are printed. Change all users of kmsg_redirect (the VT code itself and kernel/power.c) to the new interface. The main advantage is that vt_kmsg_redirect() can also be used when CONFIG_VT_CONSOLE is not set. Signed-off-by: Bernhard Walle Cc: Alan Cox Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/tty.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 405a9035fe40..ef3a2947b102 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -350,8 +350,6 @@ extern void tty_write_flush(struct tty_struct *); extern struct ktermios tty_std_termios; -extern int kmsg_redirect; - extern void console_init(void); extern int vcs_init(void); -- cgit v1.2.2 From 2427b8e3eaea3719e53bbed7b3375382c3aa6f13 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Fri, 15 Jan 2010 17:01:11 -0800 Subject: tty.h: make tty_port_get() static inline I get a few dozen of these warnings when using gcc (GCC) 4.4.1 20090725 (Red Hat 4.4.1-2): In file included from mmotm-2010-0113-1217/init/do_mounts.c:5: mmotm-2010-0113-1217/include/linux/tty.h: In function 'tty_port_get': mmotm-2010-0113-1217/include/linux/tty.h:469: warning: '______f' is static but declared in inline function 'tty_port_get' which is not static so make the function static inline. [akpm@linux-foundation.org: may as well convert tty_port_users() also] Signed-off-by: Randy Dunlap Cc: Alan Cox Signed-off-by: Andrew Morton 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 ef3a2947b102..6abfcf5b5887 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -464,7 +464,7 @@ 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_put(struct tty_port *port); -extern inline struct tty_port *tty_port_get(struct tty_port *port) +static inline struct tty_port *tty_port_get(struct tty_port *port) { if (port) kref_get(&port->kref); @@ -486,7 +486,7 @@ extern void tty_port_close(struct tty_port *port, struct tty_struct *tty, struct file *filp); extern int tty_port_open(struct tty_port *port, struct tty_struct *tty, struct file *filp); -extern inline int tty_port_users(struct tty_port *port) +static inline int tty_port_users(struct tty_port *port) { return port->count + port->blocked_open; } -- cgit v1.2.2 From d9661adfb8e53a7647360140af3b92284cbe52d4 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Thu, 18 Feb 2010 16:43:47 +0000 Subject: tty: Keep the default buffering to sub-page units We allocate during interrupts so while our buffering is normally diced up small anyway on some hardware at speed we can pressure the VM excessively for page pairs. We don't really need big buffers to be linear so don't try so hard. In order to make this work well we will tidy up excess callers to request_room, which cannot itself enforce this break up. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- include/linux/tty.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 6abfcf5b5887..d96e5882f129 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -68,6 +68,16 @@ struct tty_buffer { unsigned long data[0]; }; +/* + * We default to dicing tty buffer allocations to this many characters + * in order to avoid multiple page allocations. We assume tty_buffer itself + * is under 256 bytes. See tty_buffer_find for the allocation logic this + * must match + */ + +#define TTY_BUFFER_PAGE ((PAGE_SIZE - 256) / 2) + + struct tty_bufhead { struct delayed_work work; spinlock_t lock; -- cgit v1.2.2 From 572b9adbd40b5565dc413db04af9cc234f72bf19 Mon Sep 17 00:00:00 2001 From: Rodolfo Giometti Date: Wed, 10 Mar 2010 15:23:46 -0800 Subject: ldisc n_tty: add new method n_tty_inherit_ops() This new method can be used to init a new struct tty_ldisc_ops as the default tty_ldisc_N_TTY struct. Signed-off-by: Rodolfo Giometti Cc: David Woodhouse Cc: Greg KH Cc: Alan Cox Cc: Alexander Gordeev Signed-off-by: Andrew Morton 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 d96e5882f129..568369a86306 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -514,6 +514,7 @@ 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 -- cgit v1.2.2 From 352fa6ad16b89f8ffd1a93b4419b1a8f2259feab Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 2 Mar 2010 22:24:19 +0000 Subject: tty: Take a 256 byte padding into account when buffering below sub-page units The TTY layer takes some care to ensure that only sub-page allocations are made with interrupts disabled. It does this by setting a goal of "TTY_BUFFER_PAGE" to allocate. Unfortunately, while TTY_BUFFER_PAGE takes the size of tty_buffer into account, it fails to account that tty_buffer_find() rounds the buffer size out to the next 256 byte boundary before adding on the size of the tty_buffer. This patch adjusts the TTY_BUFFER_PAGE calculation to take into account the size of the tty_buffer and the padding. Once applied, tty_buffer_alloc() should not require high-order allocations. Signed-off-by: Mel Gorman Cc: stable Signed-off-by: Greg Kroah-Hartman --- include/linux/tty.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 568369a86306..593228a520e1 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -70,12 +70,13 @@ struct tty_buffer { /* * We default to dicing tty buffer allocations to this many characters - * in order to avoid multiple page allocations. We assume tty_buffer itself - * is under 256 bytes. See tty_buffer_find for the allocation logic this - * must match + * 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 - 256) / 2) +#define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF) struct tty_bufhead { -- cgit v1.2.2 From 336cee42dd52824e360ab419eab4e8888eb054ec Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Mon, 8 Mar 2010 21:50:11 -0600 Subject: tty_port,usb-console: Fix usb serial console open/close regression Commit e1108a63e10d344284011cccc06328b2cd3e5da3 ("usb_serial: Use the shutdown() operation") breaks the ability to use a usb console starting in 2.6.33. This was observed when using console=ttyUSB0,115200 as a boot argument with an FTDI device. The error is: ftdi_sio ttyUSB0: ftdi_submit_read_urb - failed submitting read urb, error -22 The handling of the ASYNCB_INITIALIZED changed in 2.6.32 such that in tty_port_shutdown() it always clears the flag if it is set. The fix is to add a variable to the tty_port struct to indicate when the tty port is a console. CC: Alan Cox CC: Alan Stern CC: Oliver Neukum CC: Andrew Morton Signed-off-by: Jason Wessel Signed-off-by: Greg Kroah-Hartman --- 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 593228a520e1..4409967db0c4 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -224,6 +224,7 @@ struct tty_port { 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 */ struct mutex mutex; /* Locking */ struct mutex buf_mutex; /* Buffer alloc lock */ unsigned char *xmit_buf; /* Optional buffer */ -- cgit v1.2.2