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

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

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

- Make some variables and functions static, since they don't need to be
  global.

- Remove an unused function - arch/um/kernel/time.c::sched_clock().

- Clean the style a bit as complained by checkpatch.pl.

Cc: 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>

The random driver would essentially hang if the host's /dev/random returned
-EAGAIN.  There was a test of need_resched followed by a schedule inside the
loop, but that didn't help and it's the wrong way to work anyway.

The right way is to ask for an interrupt when there is input available from
the host and handle it then rather than polling.

Now, when the host's /dev/random returns -EAGAIN, the driver asks for a wakeup
when there's randomness available again and sleeps.  The interrupt routine
just wakes up whatever processes are sleeping on host_read_wait.

There is an atomic_t, host_sleep_count, which counts the number of processes
waiting for randomness.  When this reaches zero, the interrupt is disabled.

An added complication is that async I/O notification was only recently added
to /dev/random (by me), so essentially all hosts will lack it.  So, we use the
sigio workaround here, which is to have a separate thread poll on the
descriptor and send an interrupt when there is input on it.  This mechanism is
activated when a process gets -EAGAIN (activating this multiple times is
harmless, if a bit wasteful) and deactivated by the last process still
waiting.

The module name was changed from "random" to "hw_random" in order for udev to
recognize it.

The sigio workaround needed some changes.  sigio_broken was added for cases
when we know that async notification doesn't work.  This is now called from
maybe_sigio_broken, which deals with pts devices.

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>

Reintroduce uml_kmalloc for the benefit of UML libc code.  The
previous tactic of declaring __kmalloc so it could be called directly
from the libc side of the house turned out to be getting too intimate
with slab, and it doesn't work with slob.

So, the uml_kmalloc wrapper is back.  It calls kmalloc or whatever
that translates into, and libc code calls it.

kfree is left alone since that still works, leaving a somewhat
inconsistent API.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Style fixes in arch/um/os-Linux/irq.c and arch/um/os-Linux/sigio.c:
	Updated copyrights
	trimmed includes
	added severity indicators to printks
	CodingStyle fixes
	turned an bunch of panics into printks
	call some libc functions directly instead of going through the
os_* wrappers

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>

Signed-off-by: Lucas Woods <woodzy@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch also does some improvements for uml code.  Improvements include
dropping unnecessary cast, killing some unnecessary code and still some
constifying for pointers etc..

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
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>

UML had two wrapper procedures for kmalloc, um_kmalloc and um_kmalloc_atomic
because the flag constants weren't available in userspace code.
kern_constants.h had made kernel constants available for a long time, so there
is no need for these wrappers any more.  Rather, userspace code calls kmalloc
directly with the userspace versions of the gfp flags.

kmalloc isn't a real procedure, so I had to essentially copy the inline
wrapper around __kmalloc.

vmalloc also had its own wrapper for no good reason.  This is now gone.

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>