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path: root/drivers/char/hvc_console.c
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2006-03-28[PATCH] powerpc: hvc_console updatesRyan S. Arnold
These are some updates from both Ryan and Arnd for the hvc_console driver: The main point is to enable the inclusion of a console driver for rtas, which is currrently needed for the cell platform. Also shuffle around some data-type declarations and moves some functions out of include/asm-ppc64/hvconsole.h and into a new drivers/char/hvc_console.h file. Signed-off-by: "Ryan S. Arnold" <rsa@us.ibm.com> Signed-off-by: Arnd Bergmann <abergman@de.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-27[PATCH] powerpc: HVC init raceMichael Neuling
I've been hitting a crash on boot where tty_open is being called before the hvc console driver setup is complete. This fixes the problem. Thanks to benh for his help on this. Signed-off-by: Michael Neuling <mikey@neuling.org> Acked-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24[PATCH] Fix race condition in hvc console.Michal Ostrowski
tty_schedule_flip() would schedule a thread that would call flush_to_ldisc(). If tty_buffer_request_room() gets called prior to that thread running -- which is likely in this loop in hvc_poll(), it would set the active flag in the tty buffer and consequently flush_to_ldisc() would ignore it. The result is that input on the hvc console is not processed. This fix calls tty_flip_buffer_push (and flags the tty as "low_latency"). The push to the ldisc thus happens synchronously. Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.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>
2005-09-14[PATCH] hvc_console: start kernel thread before registering ttyAnton Blanchard
Its possible that we can write to the hvc_console tty as soon it is registered. Recently this started happening due to (what looks like) a change to the hotplug code. Unfortunately at this stage we have not started the khvcd kernel thread and oops. The solution is to start the kernel thread before registering the tty. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: Register ops when setting up hvc_consoleMilton Miller
When registering the hvc console port, register a list of ops (read and write) to go with it, instead of calling fixed function names. This allows different ports to encode the data differently. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: Separate hvc_console and vio code 2Milton Miller
Remove all the vio device driver code from hvc_console.c This will allow us to separate hvsi, hvc, and allow hvc_console to be used without the ppc64 vio layer. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: Separate hvc_console and vio codeMilton Miller
Separate the console setup routines of the hvc_console and the vio layer. Remove the call to find_init_vty from hvc_console.c. Fail the setup routine if the console doesn't exist, but register the console again when the specified channel is instantiated. This scheme maintains the print buffer semantics while eliminating callout and call back for the console code. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: Add some sanity checksMilton Miller
Check if a vterm was registered before accepting it as a console. Check that a slot hasn't been probed with a tty in hvc_instantiate(). Check that a slot hasn't been free'ed when handing out console device. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: Statically initialize the vtermnos arrayMilton Miller
Statically initialize the vtermnos array. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: remove num_vterms and some dead codeMilton Miller
num_vterms hasn't been used since the hotplug support went in. Also, remove a dead code line from a list_for_each_entry conversion. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: Add missing includeMilton Miller
hvc_console checks MAGIC_SYSRQ and XMON config vars. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: Unregister the console in the exit routine.Milton Miller
Be thorough in our exit routine, since it says it is there to be so. Unregistering without registering is safe (checked in 2.6.10). Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: MAGIC_SYSRQ should only be on console channelMilton Miller
Guard the MAGIC_SYSRQ ^O to be just on the console channel. Make the other channels more transparent. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: Dont always kick the poll thread in interruptMilton Miller
Have the hvc console code try to pull characters immediately when receiving an interrupt, and kick the poll thread only if the immediate poll indicates it needed a call back to do more work. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: Match vio and console devices using vterm numbersMilton Miller
Use the vterm numbers to match the vio devices being probed with the indices already allocated via the console initcall function hvc_find_vtys. The old code required hvc_find_vtys to "guess" the matching devices the vio subsystem would find and its probe order. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] hvc_console: Rearrange codeMilton Miller
Milton Miller has done a lot of work to clean up our hvc_console code. One of the important things the following patch series does is separate the VIO layer from the hvc_console code. With the VIO specific code removed any ppc64 platform, or even any architecture, can use hvc_console as a generic polling console. You simply have to supply a get_chars and put_chars method and hvc_console does the rest of the work. You can even use it for an interrupt driven console. This patch: Rearrange the code in drivers/char/hvc_console.c to make future patches smaller. No actual code changes, just ordering of the functions in the file. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Anton Blanchard <anton@samba.org> 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!