um: fix 3 instances of -Wmissing-prototypes

Fixes the following build errors observed from W=1 builds:
arch/um/drivers/xterm_kern.c:35:5: warning: no previous prototype for
function 'xterm_fd' [-Wmissing-prototypes]
35 | int xterm_fd(int socket, int *pid_out)
| ^
arch/um/drivers/xterm_kern.c:35:1: note: declare 'static' if the
function is not intended to be used outside of this translation unit
35 | int xterm_fd(int socket, int *pid_out)
| ^
| static
arch/um/drivers/chan_kern.c:183:6: warning: no previous prototype for
function 'free_irqs' [-Wmissing-prototypes]
183 | void free_irqs(void)
| ^
arch/um/drivers/chan_kern.c:183:1: note: declare 'static' if the
function is not intended to be used outside of this translation unit
183 | void free_irqs(void)
| ^
| static
arch/um/drivers/slirp_kern.c:18:6: warning: no previous prototype for
function 'slirp_init' [-Wmissing-prototypes]
18 | void slirp_init(struct net_device *dev, void *data)
| ^
arch/um/drivers/slirp_kern.c:18:1: note: declare 'static' if the
function is not intended to be used outside of this translation unit
18 | void slirp_init(struct net_device *dev, void *data)
| ^
| static

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308081050.sZEw4cQ5-lkp@intel.com/
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Support dynamic IRQ allocation

It's cumbersome and error-prone to keep adding fixed IRQ numbers,
and for proper device wakeup support for the virtio/vhost-user
support we need to have different IRQs for each device. Even if
in theory two IRQs (with and without wake) might be sufficient,
it's much easier to reason about it when we have dynamic number
assignment. It also makes it easier to add new devices that may
dynamically exist or depending on the configuration, etc.

Add support for this, up to 64 IRQs (the same limit as epoll FDs
we have right now). Since it's not easy to port all the existing
places to dynamic allocation (some data is statically initialized)
keep the low numbers are reserved for the existing hard-coded IRQ
numbers.

Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Add SPDX headers for files in arch/um/drivers

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>

um: get rid of pointless include "..." where include <...> will do

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: remove IRQF_SAMPLE_RANDOM which is now a no-op

With the changes in the random tree, IRQF_SAMPLE_RANDOM is now a
no-op; interrupt randomness is now collected unconditionally in a very
low-overhead fashion; see commit 775f4b297b. The IRQF_SAMPLE_RANDOM
flag was scheduled to be removed in 2009 on the
feature-removal-schedule, so this patch is preparation for the final
removal of this flag.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>

um: Implement um_free_irq()

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>

um: irq: Remove IRQF_DISABLED

Since commit [e58aa3d2: genirq: Run irq handlers with interrupts disabled],
We run all interrupt handlers with interrupts disabled
and we even check and yell when an interrupt handler
returns with interrupts enabled (see commit [b738a50a:
genirq: Warn when handler enables interrupts]).

So now this flag is a NOOP and can be removed.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

uml: xterm driver tidying

Major tidying of the xterm console driver:
got rid of the tt-mode gdb support
tidied up the includes
fixed lots of style violations
replaced os_* calls with glibc calls in xterm.c
all printk calls now have a severity indicator
the error paths of xterm_open are closer to being right

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>

[PATCH] uml pt_regs fixes

Real fix for UML pt_regs stuff. Note set_irq_regs() logics in there...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] irq-flags: UM: Use the new IRQF_ constants

Use the new IRQF_ constants and remove the SA_INTERRUPT define

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: 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>

[PATCH] uml: add and use generic hw_controller_type->release

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>

[PATCH] uml: inclusion cleanup

The completion cleanup got rid of some semaphores, but didn't remove the
inclusion of asm/semaphore.h from xterm_kern.c.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Linux-2.6.12-rc2

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!