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>
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>
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>
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>
line_setup is changed to return the device which it set up, rather than just
success or failure. This will be important in the line-config patch.
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>
Some structure fields were being dynamically initialized when they could be
initialized at compile-time instead. This also makes some declarations static
(in the C sense).
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>
A bit of restructuring which eliminates the all_allowed argument (which is
mconsole-specific) to line_setup. That logic is moved to the mconsole
callback.
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>
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>
This patch replaces instances of "sizeof(foo)/sizeof(foo[0])" with
ARRAY_SIZE(foo), which expands to the same thing.
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>
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>
There are a few functions which are declared to return something, but don't.
These are actually infinite loops which are forced to be declared as non-void.
This makes them all return 0.
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>
There were a bunch of calls to uml_strdup dating from before kstrdup was
introduced. This changes those calls. It doesn't eliminate the definition
since there is still a couple of calls in userspace code (which should
probably call the libc strdup).
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>
Fix some exit path bugs in the daemon driver.
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>
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>
We were using a long series of (stupid) wrappers which all call
generic_console_write(). Since the wrappers only change the 4th param, which
is unused by the called proc, remove them and call generic_console_write()
directly.
If needed at any time in the future to reintroduce this stuff, the member
could be moved to a generic struct, to avoid this duplicated handling.
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>
printk clears the host errno (I verified this in debugging and it's reasonable
enough, given that it ends via a write call on some fd, especially since
printk() goes on /dev/tty0 which is often the host stdout). So save errno
earlier. There's no reason to change the printk calls to use -err rather than
errno - the assignment can't clear errno.
And in the first failure path, we used to return 0 too (and this time more
clearly), which is totally wrong. 0 is a success fd, which is then registered
and gives a "registering fd twice" warning.
Finally, fix up some whitespace.
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>
This allows us to eliminate the casts in the drivers, and eventually
remove the use of the device_driver function pointer methods for
platform device drivers.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Use schedule_timeout_interruptible() instead of
set_current_state()/schedule_timeout() to reduce kernel size.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The serial UML OS-abstraction layer patch (um/kernel dir).
This moves all systemcalls from helper.c file under os-Linux dir
Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ifa->ifa_address and ifa->ifa_mask are defined as __u32, but used as if they
were char[4].
Network code uses htons() to convert it. So UML's method to access these
fields is wrong for bigendians (e.g. s390)
I replaced bytewise copying by memcpy(), maybe even that might be removed, if
ifa->ifa_address/mask may be used immediately.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Convert everyone who uses platform_bus_type to include
linux/platform_device.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
The patch to use host AIO support that I submitted early after 2.6.13 exposed
some problems in the block driver. I have fixes for these, but am not
comfortable putting them into 2.6.14 at this late date. So, this patch reverts
the use of host AIO.
I will resubmit the original patch, plus fixes to the driver after 2.6.14
in order to get a reasonable amount of testing before they're exposed to
the general public.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix whitespace - I split this off the previous patch for easier review.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
After restoring the existing code, make it work also when included in
kernelspace code (which isn't currently the case, but at least this will prevent
people from "fixing" it as just happened).
Whitespace is fixed in next patch - it cluttered the diff too much.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Commit 44456d37b5, between 2.6.13-rc3 and -rc4,
was a "nice cleanup" which broke something. Revert the offending part.
It broke because:
a) because this part doesn't fall under the description
b) the author didn't know what he was doing here
c) the author didn't try to compile the existing code and see that it worked
perfectly.
d) the author didn't ask us what was happening
e) you didn't either, and somebody there should have learned that UML is a bit
different.
In fact, UML is special in linking to host libc and using its includes.
In particular, since host includes always define both __BIG_ENDIAN and
__LITTLE_ENDIAN, ntohll() macros started thinking to be in a big-endian world;
and on-disk compatibility was broken.
Many thanks go to Nix for reporting the problem and correctly diagnosing an
endianness problem.
Btw, this patch restores the previous code, which worked; but the definitions
would be uncorrect if used in kernelspace files.
Next patch addresses that.
Cc: Nix <nix@esperi.org.uk>, Olaf Hering <olh@suse.de>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Revert commit 12ebcd73e4, i.e. [PATCH] uml: run
mconsole "sysrq" in process context on request from Jeff Dike.
a) sysrq may be run when the scheduler is non-functioning
b) the warning I wanted to fix actually came from the fault handler run in
atomic context. But I fixed that not to take the semaphore in a separate
patch.
c) the fault handler is run because of a fault, and that fault was
unaffected by this patch.
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>
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>
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>
Things are breaking horribly with sysrq called in interrupt context. I want
to try to fix it, but probably this is simpler. To tell the truth, sysrq is
normally run in interrupt context, so there shouldn't be any problem.
There's also a warning from the fault handler because it's run in atomic
context (I have a patch for that, only I deferred it). This is why I'm doing
this.
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>
The poster child for this patch is the third tuntap_user hunk. When an ioctl
fails, it properly closes the opened file descriptor and returns. However,
the close resets errno to 0, and the 'return errno' that follows returns 0
rather than the value that ioctl set. This caused the caller to believe that
the device open succeeded and had opened file descriptor 0, which caused no
end of interesting behavior.
The rest of this patch is a pass through the UML sources looking for places
where errno could be reset before being passed back out. A common culprit is
printk, which could call write, being called before errno is returned.
In some cases, where the code ends up being much smaller, I just deleted the
printk.
There was another case where a caller of run_helper looked at errno after a
failure, rather than the return value of run_helper, which was the errno value
that it wanted.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
linux/inet.h isn't needed, and on my system, is empty.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This removes a file which is no longer used.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch implements a stack trace for a thread, not unlike sysrq-t does.
The advantage to this is that a break point can be placed on showreqs, so that
upon showing the stack, you jump immediately into the debugger. While sysrq-t
does the same thing, sysrq-t shows *all* threads stacks. It also doesn't work
right now. In the future, I thought it might be acceptable to make this show
all pids stacks, but perhaps leaving well enough alone and just using sysrq-t
would be okay. For now, upon receiving the stack command, UML switches
context to that thread, dumps its registers, and then switches context back to
the original thread. Since UML compacts all threads into one of 4 host
threads, this sort of mechanism could be expanded in the future to include
other debugging helpers that sysrq does not cover.
Note by jdike - The main benefit to this is that it brings an arbitrary thread
back into context, where it can be examined by gdb. The fact that it dumps it
stack is secondary. This provides the capability to examine a sleeping
thread, which has existed in tt mode, but not in skas mode until now.
Also, the other threads, that sysrq doesn't cover, can be gdb-ed directly
anyway.
Signed-off-by: Allan Graves<allan.graves@gmail.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds AIO support to the ubd driver.
The driver breaks a struct request into IO requests to the host, based on the
hardware segments in the request and on any COW blocks covered by the request.
The ubd IO thread is gone, since there is now an equivalent thread in the AIO
module.
There is provision for multiple outstanding requests now. Requests aren't
retired until all pieces of it have been completed. The AIO requests have a
shared count, which is decremented as IO operations come in until it reaches
0. This can be possibly moved to the request struct - haven't looked at this
yet.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This cleans up the error path in ubd_open, causing it now to call ubd_close
appropriately when something fails.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If a SIGWINCH comes in, while winch_thread() isn't waiting in wait(),
winch_thread could miss signals. It isn't very probable, that anyone will
see this causing trouble, as it would need a very special timing, that a
missed SIGWINCH results in a wrong window size.
So, this is a minor problem. But why not fix, as it can be done so easy?
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
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>
- copy_from_user() can fail; ->write() must check its return value.
- severe buffer overruns both in ->read() and ->write() - lseek to the
end (i.e. to mmapper_size) and
if (count + *ppos > mmapper_size)
count = count + *ppos - mmapper_size;
will do absolutely nothing. Then it will call
copy_to_user(buf,&v_buf[*ppos],count);
with obvious results (similar for ->write()).
Fixed by turning read to simple_read_from_buffer() and by doing
normal limiting of count in ->write().
- gratitious lock_kernel() in ->mmap() - it's useless there.
- lots of gratuitous includes.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
printk() calls should include appropriate KERN_* constant.
Signed-off-by: Christophe Lucas <clucas@rotomalug.org>
Signed-off-by: Domen Puncer <domen@coderock.org>
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>
Just a Kbuild subtlety, not listing a target file inside targets causes it
to be rebuilt each time, and as a consequence everything depending on it is
rebuilt.
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>
turn many #if $undefined_string into #ifdef $undefined_string to fix some
warnings after -Wno-def was added to global CFLAGS
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch replaces the deprecated MODULE_PARM function by the new
module_param function.
Signed-off-by: Dominik Hackl <dominik@hackl.dhs.org>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The pcap support was not working because of some linking problems (expressing
the construct in Kbuild was a bit difficult) and because there was no user
request. Now that this has come back, here's the support.
This has been tested and works on both 32 and 64-bit hosts, even when
"cross-"building 32-bit binaries.
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>
Replace a semaphore (winch_handler_sem) used in atomic code with a
spinlock, and reduces as needed the amount of protected code to the bare
minimum (for instance no kmalloc calls are needed).
This fixes the last problems with spinlocking (in UP mode with DEBUG
options); the semaphore, taken inside spinlocks, caused a "spin_lock was
already locked" warning, without this patch.
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>
Clean up the hot-unplugging code. There is now an id procedure which is
called to figure out what device we're talking to. The error messages from
that are now done from mconsole_remove instead of the driver. remove is now
called with the device number, after it has been checked, so doesn't need to
do sanity checking on it.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Here's a small patch to remove a few unnessesary NULL pointer checks before
kfree() in arch/um/drivers/daemon_user.c
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This occurrence of free_irq_by_irq_and_dev() was missed when converting UML
to the use of hw_controller_type->release.
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>
With Chris Wedgwood <cw@f00f.org>
Currently UML must explicitly call the UML-specific
free_irq_by_irq_and_dev() for each free_irq call it's done.
This is needed because ->shutdown and/or ->disable are only called when the
last "action" for that irq is removed.
Instead, for UML shared IRQs (UML IRQs are very often, if not always,
shared), for each dev_id some setup is done, which must be cleared on the
release of that fd. For instance, for each open console a new instance
(i.e. new dev_id) of the same IRQ is requested().
Exactly, a fd is stored in an array (pollfds), which is after read by a
host thread and passed to poll(). Each event registered by poll() triggers
an interrupt. So, for each free_irq() we must remove the corresponding
host fd from the table, which we do via this -release() method.
In this patch we add an appropriate hook for this, and remove all uses of
it by pointing the hook to the said procedure; this is safe to do since the
said procedure.
Also some cosmetic improvements are included.
This is heavily based on some work by Chris Wedgwood, which however didn't
get the patch merged for something I'd call a "misunderstanding" (the need
for this patch wasn't cleanly explained, thus adding the generic hook was
felt as undesirable).
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
CC: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
