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path: root/arch/um/drivers/chan_kern.c
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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>
2005-09-22[PATCH] uml: use GFP_ATOMIC for allocations under spinlocks.Paolo 'Blaisorblade' Giarrusso
setup_initial_poll is only called with sigio_lock() held, so use appropriate allocation. Also, parse_chan() can also be called when holding a spinlock (see line_open() -> parse_chan_pair()). I have sporadic problems (spinlock taken twice, with spinlock debugging on UP) which could be caused by a sequence like "take spinlock, alloc and go to sleep, take again the spinlock in the other thread". 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>
2005-05-20[PATCH] uml: Change printf to printk in console driverJeff Dike
From: Al Viro - we have error messages with KERN_ERR in them, so they should be printk-ed rather than printf-ed. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01[PATCH] uml: redo console lockingPaolo 'Blaisorblade' Giarrusso
Fix some console locking problems (including scheduling in atomic) and various reorderings and cleanup in that code. Not yet ready for 2.6.12 probably. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!