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path: root/arch/um/drivers/chan_kern.c
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2019-09-15um: Add SPDX headers for files in arch/um/driversAlex Dewar
Convert files to use SPDX header. All files are licensed under the GPLv2. Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-07-02um: Fix IRQ controller regression on console readJouni Malinen
The conversion of UML to use epoll based IRQ controller claimed that clone_one_chan() can safely call um_free_irq() while starting to ignore the delay_free_irq parameter that explicitly noted that the IRQ cannot be freed because this is being called from chan_interrupt(). This resulted in free_irq() getting called in interrupt context ("Trying to free IRQ 6 from IRQ context!"). Fix this by restoring previously used delay_free_irq processing. Fixes: ff6a17989c08 ("Epoll based IRQ controller") Signed-off-by: Jouni Malinen <j@w1.fi> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2018-12-27um: Remove obsolete reenable_XX callsAnton Ivanov
reenable_fd has been a NOP since the introduction of the EPOLL based interrupt controller. reenable_channel() is no longer needed as the flow control is now handled via the write IRQs on the channel. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2018-02-19Epoll based IRQ controllerAnton Ivanov
1. Removes the need to walk the IRQ/Device list to determine who triggered the IRQ. 2. Improves scalability (up to several times performance improvement for cases with 10s of devices). 3. Improves UML baseline IO performance for one disk + one NIC use case by up to 10%. 4. Introduces write poll triggered IRQs. 5. Prerequisite for introducing high performance mmesg family of functions in network IO. 6. Fixes RNG shutdown which was leaking a file descriptor Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2013-03-21Merge 3.9-rc3 into tty-nextGreg Kroah-Hartman
2013-03-18TTY: add tty_port_tty_hangup helperJiri Slaby
It allows for cleaning up on a considerable amount of places. They did port_get, hangup, kref_put. Now the only thing needed is to call tty_port_tty_hangup which does exactly that. And they can also decide whether to consider CLOCAL or completely ignore that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-11um: Use tty_port in SIGWINCH handlerRichard Weinberger
The tty below tty_port might get destroyed by the tty layer while we hold a reference to it. So we have to carry tty_port around... Signed-off-by: Richard Weinberger <richard@nod.at>
2013-01-15TTY: switch tty_flip_buffer_pushJiri Slaby
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. Now, the one where most of tty_port_tty_get gets removed: tty_flip_buffer_push. IOW we also closed all the races in drivers not using tty_port_tty_get at all yet. Also we move tty_flip_buffer_push declaration from include/linux/tty.h to include/linux/tty_flip.h to all others while we are changing it anyway. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: switch tty_insert_flip_charJiri Slaby
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. tty_insert_flip_char is the next one to proceed. This one is used all over the code, so the patch is huge. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: switch tty_buffer_request_room to tty_portJiri Slaby
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty pointer in many call sites. Only tty_port will be needed and hence no more tty_port_tty_get calls in those paths. Here we start with tty_buffer_request_room. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-30UM: TTY: fix build errors now that tty->raw is goneJiri Slaby
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2012-10-09um: get rid of pointless include "..." where include <...> will doAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2012-07-28TTY: um/line, use tty from tty_portJiri Slaby
This means switching to the tty refcounted model so that we will not race with interrupts. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: user-mode-linux-devel@lists.sourceforge.net Signed-off-by: Richard Weinberger <richard@nod.at>
2012-05-21um: Implement um_free_irq()Richard Weinberger
Instead of using chip->release() we can achieve the same using a simple wrapper for free_irq(). We have already um_request_irq(), so um_free_irq() is the perfect counterpart. Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2012-03-25um: switch close_chan() to struct lineAl Viro
... and switch chan_interrupt() to directly calling close_one_chan(), so we can lose delay_free_irq argument of close_chan() as well. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2012-03-25um: race fix: initialize delayed_work *before* registering IRQAl Viro
... since chan_interrupt() might schedule it if there's too much incoming data. Kill task argument of chan_interrupt(), while we are at it - it's always &line->task. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2012-03-25um: switch users of ->chan_list to ->chan_{in,out} (easy cases)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2012-03-25um: sorting out the chan mess, part 1Al Viro
put references to in and out chans associated with line into explicit struct chan * fields in it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2012-03-25um: fix races between line_open() and line_config()Al Viro
Pull parse_chan_pair() call into setup_one_line(), under the mutex. We really don't want open() to succeed before parse_chan_pair() had been done (or after it has failed, BTW). We also want "remove con<n>" to free irqs, etc., same as "config con<n>=none". Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02um: kill useless argument of free_chan() and free_one_chan()Al Viro
delay_free_irq is always 0 for those... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02um: take chan_*.h and line.h to arch/um/driversAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2011-07-25um: remove dead codeRichard Weinberger
GCC 4.6's -Wunused-but-set-variable found some dead code. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09um: call free_irq() only on enabled channelsRichard Weinberger
When I use OpenSUSE-11.2 on UML (> 2.6.25) I get lots of such errors: Registering fd 1 twice Irqs : 3, 3 Ids : 0x09cb41a0, 0x09cb4120 ------------[ cut here ]------------ WARNING: at kernel/irq/manage.c:896 __free_irq+0x79/0x11a() Trying to free already-free IRQ 3 Modules linked in: 09dadc6c: [<081b2edb>] dump_stack+0x1c/0x20 09dadc84: [<080716da>] warn_slowpath_common+0x49/0x77 09dadc9c: [<08071772>] warn_slowpath_fmt+0x26/0x2a 09dadcb4: [<08094e08>] __free_irq+0x79/0x11a 09dadce4: [<08094ed6>] free_irq+0x2d/0x49 09dadcf4: [<0805b4bc>] close_one_chan+0x70/0x9c 09dadd0c: [<0805b833>] close_chan+0x17/0x22 09dadd1c: [<0805bdda>] enable_chan+0x70/0x7c 09dadd3c: [<0805cbb7>] line_open+0x34/0x9f 09dadd54: [<0805b21e>] con_open+0x13/0x35 09dadd6c: [<0814dc89>] tty_open+0x285/0x384 09dadda0: [<080b754e>] chrdev_open+0xe0/0xf9 09daddc0: [<080b3fb2>] __dentry_open+0xf3/0x1e2 09dadde4: [<080b4142>] nameidata_to_filp+0x35/0x49 09daddfc: [<080bd270>] do_last+0x409/0x50e 09dade28: [<080bea04>] do_filp_open+0x175/0x446 09dadecc: [<080b3d89>] do_sys_open+0x4a/0x128 09dadf04: [<080b3ea2>] sys_open+0x19/0x21 09dadf28: [<0805ab5a>] handle_syscall+0x7a/0x98 09dadf78: [<08068441>] userspace+0x2c9/0x370 09dadfe0: [<08058bb3>] fork_handler+0x53/0x5b 09dadffc: [<00766564>] 0x766564 ---[ end trace 9ebc1094aaf4bded ]--- This patch fixes the issue. Signed-off-by: Richard Weinberger <richard@nod.at> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28uml: remove a useless functionWANG Cong
arch/um/drivers/chan_kern.c::chan_out_fd() is not used by anyone. Remove it. Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28uml: make a function staticWANG Cong
arch/um/drivers/chan_kern.c::open_chan() can become static. Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16uml: fix console writing bugsJeff Dike
The previous console cleanup patch switched generic_read and generic_write from calling os_{read,write}_file to calling read and write directly. Because the calling convention is different, they now need to get any error from errno rather than the return value. I did this for generic_read, but forgot about generic_write. While chasing some output corruption, I noticed that line_write was unnecessarily calling flush_buffer, and deleted it. I don't understand why, but the corruption disappeared. This is unneeded because there already is a perfectly good mechanism for finding out when the host output device has some room to write data - there is an interrupt that comes in when writes can happen again. line_write calling flush_buffer seemed to just be an attempt to opportunistically get some data out to the host. I also made write_chan short-circuit calling into the host-level code for zero-length writes. Calling libc write with a length of zero conflated write not being able to write anything with asking it not to write anything. Better to just cut it off as soon as possible. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16uml: console subsystem tidyingJeff Dike
This does a lot of cleanup on the UML console system. This patch should be entirely non-functional. The tidying is as follows: header cleanups - the includes should be closer to minimal and complete all printks now have a severity lots of style fixes fd_close is restructured a little in order to reduce the nesting some functions were calling the os_* wrappers when they can call libc directly port_accept had a unnecessary variable it also tested a pid unecessarily before killing it some functions were made static xterm_free is gone, as it was identical to generic_free Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16uml: move userspace code to userspace fileJeff Dike
Move some code from a kernelspace file to a userspace file where it fits better. This enables some tidying which is the subject of a later patch. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31UML: console should handle spurious IRQSJeff Dike
The previous DEBUG_SHIRQ patch missed one case. The console doesn't set its host descriptors non-blocking. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16uml: handle errors on opening host side of consolesJeff Dike
If the host side of a console can't be opened, this will now produce visible error messages. enable_chan now returns a status and this is passed up to con_open and ssl_open, which will complain if anything went wrong. The default host device for the serial line driver is now a pts device rather than a pty device since lots of hosts have LEGACY_PTYS disabled. This had always been failing on such hosts, but silently. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07uml: rename os_{read_write}_file_k back to os_{read_write}_fileJeff Dike
Rename os_{read_write}_file_k back to os_{read_write}_file, delete the originals and their bogus infrastructure, and fix all the callers. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07uml: change remaining callers of os_{read_write}_fileJeff Dike
Convert all remaining os_{read_write}_file users to use the simple {read,write} wrappers, os_{read_write}_file_k. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07uml: remove user_util.hJeff Dike
user_util.h isn't needed any more, so delete it and remove all includes of it. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-29[PATCH] uml: irq locking fixesJeff Dike
As the comment immediately preceding this points out, this list is changed in irq context, so it needs to be protected with spin_lock_irqsave in process context when it is processed. Sometimes, gcc should just compile the comments and forget the code. The IRQ side of this was better, in the sense that it blocked and unblocked interrupts, but it still should have saved and restored them. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] uml: mostly const a structureJeff Dike
The chan_opts structure is mostly const, and needs no locking. Comment the lack of locking on the one field that can change. Make all the other fields const. It turned out that console_open_chan didn't use its chan_opts argument, so that is deleted from the function and its callers. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] uml: lock the irqs_to_free listJeff Dike
Fix (i.e. add some) the locking around the irqs_to_free list. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] uml: return hotplug errors to hostJeff Dike
I noticed that errors happening while hotplugging devices from the host were never returned back to the mconsole client. In some cases, success was returned instead of even an information-free error. This patch cleans that up by having the low-level configuration code pass back an error string along with an error code. At the top level, which knows whether it is early boot time or responding to an mconsole request, the string is printk'd or returned to the mconsole client. There are also whitespace and trivial code cleanups in the surrounding code. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-05WorkQueue: Fix up arch-specific work items where possibleDavid Howells
Fix up arch-specific work items where possible to use the new work_struct and delayed_work structs. Three places that enqueue bits of their stack and then return have been marked with #error as this is not permitted. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-09-27[PATCH] uml: const more dataJeff Dike
Make lots of structures const in order to make it obvious that they need no locking. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] uml: Use ARRAY_SIZE more assiduouslyJeff Dike
There were a bunch of missed ARRAY_SIZE opportunities. Also, some formatting fixes in the affected areas of code. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] uml: some harmless sparse warning fixesPaolo 'Blaisorblade' Giarrusso
Fix some simple sparse warnings - a lot more staticness and a misplaced __user. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10[PATCH] TTY layer buffering revampAlan Cox
The API and code have been through various bits of initial review by serial driver people but they definitely need to live somewhere for a while so the unconverted drivers can get knocked into shape, existing drivers that have been updated can be better tuned and bugs whacked out. This replaces the tty flip buffers with kmalloc objects in rings. In the normal situation for an IRQ driven serial port at typical speeds the behaviour is pretty much the same, two buffers end up allocated and the kernel cycles between them as before. When there are delays or at high speed we now behave far better as the buffer pool can grow a bit rather than lose characters. This also means that we can operate at higher speeds reliably. For drivers that receive characters in blocks (DMA based, USB and especially virtualisation) the layer allows a lot of driver specific code that works around the tty layer with private secondary queues to be removed. The IBM folks need this sort of layer, the smart serial port people do, the virtualisers do (because a virtualised tty typically operates at infinite speed rather than emulating 9600 baud). Finally many drivers had invalid and unsafe attempts to avoid buffer overflows by directly invoking tty methods extracted out of the innards of work queue structs. These are no longer needed and all go away. That fixes various random hangs with serial ports on overflow. The other change in here is to optimise the receive_room path that is used by some callers. It turns out that only one ldisc uses receive room except asa constant and it updates it far far less than the value is read. We thus make it a variable not a function call. I expect the code to contain bugs due to the size alone but I'll be watching and squashing them and feeding out new patches as it goes. Because the buffers now dynamically expand you should only run out of buffering when the kernel runs out of memory for real. That means a lot of the horrible hacks high performance drivers used to do just aren't needed any more. Description: tty_insert_flip_char is an old API and continues to work as before, as does tty_flip_buffer_push() [this is why many drivers dont need modification]. It does now also return the number of chars inserted There are also tty_buffer_request_room(tty, len) which asks for a buffer block of the length requested and returns the space found. This improves efficiency with hardware that knows how much to transfer. and tty_insert_flip_string_flags(tty, str, flags, len) to insert a string of characters and flags For a smart interface the usual code is len = tty_request_buffer_room(tty, amount_hardware_says); tty_insert_flip_string(tty, buffer_from_card, len); More description! At the moment tty buffers are attached directly to the tty. This is causing a lot of the problems related to tty layer locking, also problems at high speed and also with bursty data (such as occurs in virtualised environments) I'm working on ripping out the flip buffers and replacing them with a pool of dynamically allocated buffers. This allows both for old style "byte I/O" devices and also helps virtualisation and smart devices where large blocks of data suddenely materialise and need storing. So far so good. Lots of drivers reference tty->flip.*. Several of them also call directly and unsafely into function pointers it provides. This will all break. Most drivers can use tty_insert_flip_char which can be kept as an API but others need more. At the moment I've added the following interfaces, if people think more will be needed now is a good time to say int tty_buffer_request_room(tty, size) Try and ensure at least size bytes are available, returns actual room (may be zero). At the moment it just uses the flipbuf space but that will change. Repeated calls without characters being added are not cumulative. (ie if you call it with 1, 1, 1, and then 4 you'll have four characters of space. The other functions will also try and grow buffers in future but this will be a more efficient way when you know block sizes. int tty_insert_flip_char(tty, ch, flag) As before insert a character if there is room. Now returns 1 for success, 0 for failure. int tty_insert_flip_string(tty, str, len) Insert a block of non error characters. Returns the number inserted. int tty_prepare_flip_string(tty, strptr, len) Adjust the buffer to allow len characters to be added. Returns a buffer pointer in strptr and the length available. This allows for hardware that needs to use functions like insl or mencpy_fromio. Signed-off-by: Alan Cox <alan@redhat.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] uml: Add throttling to console driverJeff Dike
This patch adds support for throttling and unthrottling input when the tty driver can't handle it. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] uml: Fix flip_buf full handlingJeff Dike
When the tty flip_buf is full, it's a good idea to delay the input processing for a jiffy, rather than just scheduling the tasklet immediately. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] uml: Simplify console opening/closing and irq registrationJeff Dike
This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] uml: move console configurationJeff Dike
This patch changes when console devices are configured in order to prepare the ground for the next patch. parse_chan_pair is now done earlier, when initcalls are run, rather than when the device is opened. When a host device disappears, the channel list is closed, but not freed. This is required by the previous change. line_config now takes the options structure as an argument, and line_open doesn't. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] uml: Remove unneeded structure fieldJeff Dike
This removes a structure field which turned out to be pointless, and references to it. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] uml: Formatting changesJeff Dike
This patch makes a bunch of non-functional changes - return(foo); becomes return foo; some statements are broken across lines for readability some trailing whitespace is cleaned up open_one_chan took four arguments, three of which could be deduced from the first. Accordingly, they were eliminated. some examples of "} else {" had a newline added some whitespace cleanup in the indentation lines_init got some control flow cleanup some long lines were broken removed another emacs-specific C formatting comment Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13[PATCH] uml console channels: fix the API of console_writePaolo 'Blaisorblade' Giarrusso
Since the 4th param is unused, remove it altogether. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22[PATCH] uml: replace printk with "stack-friendly" printf - to report console ↵Paolo 'Blaisorblade' Giarrusso
failure User get *a lot* confused when consoles don't work but we don't report anything. And, as reported in the comment, using printk to report "your console doesn't work" isn't likely to go that far. Fix the problem on the base of this: stack consumption by host printf(). Use kernel sprintf() and os_write_file, using a wild guess that one page will be enough for the message, to preallocate the buffer with kmalloc(). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>