UML's supposed nanosecond clock interacts badly with NTP when NTP
decides that the clock has drifted ahead and needs to be slowed down.
Slowing down the clock is done by decrementing the cycle-to-nanosecond
multiplier, which is 1.  Decrementing that gives you 0 and time is
stopped.

This is fixed by switching to a microsecond clock, with a multiplier
of 1000.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a proper extern for late_time_init in include/linux/init.h
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Joe Perches noticed some printks in smp.c that needed fixing.

While I was in there, I did the usual tidying in arch/um/kernel, which
should be fairly style-clean at this point:
	copyright updates
	emacs formatting comments removal
	include tidying
	style fixes

Cc: Joe Perches <joe@perches.com>
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are various uses of powers of 1000, plus the odd BILLION constant in the
time code.  However, there are perfectly good definitions of *SEC_PER_*SEC in
linux/time.h which can be used instaed.

These are replaced directly in kernel code.  Userspace code imports those
constants as UM_*SEC_PER_*SEC and uses these.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Enable tickless support.

CONFIG_TICK_ONESHOT and CONFIG_NO_HZ are enabled.

itimer_clockevent gets CLOCK_EVT_FEAT_ONESHOT and an implementation of
.set_next_event.

CONFIG_UML_REAL_TIME_CLOCK goes away because it only makes sense when there is
a clock ticking away all the time.  timer_handler now just calls do_IRQ once
without trying to figure out how many ticks to emulate.

The idle loop now needs to turn ticking on and off.

Userspace ticks keep happening as usual.  However, the userspace loop keep
track of when the next wakeup should happen and suppresses process ticks until
that happens.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add clocksource support.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Enable CONFIG_GENERIC_CLOCKEVENTS.

timer_irq gets its name changed to timer_handler, and becomes the recipient of
timer signals.

The clock_event_device is set up to imitate the current ticking clock, i.e.
CLOCK_EVT_FEAT_ONESHOT is not enabled yet.

disable_timer now doesn't ignore SIGALRM and SIGVTALRM because that breaks
delay calibration.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Enable CONFIG_GENERIC_TIME.

As a side-effect of this, the UML implementations of do_gettimeofday and
do_settimeofday go away, as these are provided by generic code.  set_time also
goes away since it was only used by do_settimeofday.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move timer signal initialization from init_irq_signals to a new function,
timer_init.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

set_interval took a timer type as an argument, but it always specified a
virtual timer.  So, it is not needed, and it is gone, and set_interval is
simplified appropriately.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Eliminate hz() since its only purpose was to provide a kernel-space constant
to userspace code.  This can be done instead by providing the constant
directly through kernel_constants.h.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Formatting changes in the files which have been changed in the course
of folding foo_skas functions into their callers.  These include:
	copyright updates
	header file trimming
	style fixes
	adding severity to printks

These changes should be entirely non-functional.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch makes a number of simplifications enabled by the removal of
CHOOSE_MODE.  There were lots of functions that looked like

	int foo(args){
		foo_skas(args);
	}

The bodies of foo_skas are now folded into foo, and their declarations (and
sometimes entire header files) are deleted.

In addition, the union uml_pt_regs, which was a union between the tt and skas
register formats, is now a struct, with the tt-mode arm of the union being
removed.

It turns out that usr2_handler was unused, so it is gone.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The next stage after removing code which depends on CONFIG_MODE_TT is removing
the CHOOSE_MODE abstraction, which provided both compile-time and run-time
branching to either tt-mode or skas-mode code.

This patch removes choose-mode.h and all inclusions of it, and replaces all
CHOOSE_MODE invocations with the skas branch.  This leaves a number of trivial
functions which will be dealt with in a later patch.

There are some changes in the uaccess and tls support which go somewhat beyond
this and eliminate some of the now-redundant functions.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ever-vigilant users of linode.com noticed that an idle 2.6 UML has a
persistent load average of ~.4.

It turns out that because the UML timer handler processed softirqs before
actually delivering the tick, the tick was counted in the context of the idle
thread about half the time.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the current timekeeping, !CONFIG_UML_REAL_TIME_CLOCK has
inconsistent behavior.  Previously, gettimeofday could be (and was)
isolated from the clock ticking.  Now, it's not, so when
CONFIG_UML_REAL_TIME_CLOCK is disabled, gettimeofday must progress in
lockstep with the clock, making it fully virtual.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

user_util.h isn't needed any more, so delete it and remove all includes of it.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

prev_nsecs and delta need to be arrays, and indexed by CPU number.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Real fix for UML pt_regs stuff.  Note set_irq_regs() logics in there...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Pass ticks to do_timer() and update_times(), and adjust x86_64 and s390
timer interrupt handler with this change.

Currently update_times() calculates ticks by "jiffies - wall_jiffies", but
callers of do_timer() should know how many ticks to update.  Passing ticks
get rid of this redundant calculation.  Also there are another redundancy
pointed out by Martin Schwidefsky.

This cleanup make a barrier added by
5aee405c needless.  So this patch removes
it.

As a bonus, this cleanup make wall_jiffies can be removed easily, since now
wall_jiffies is always synced with jiffies.  (This patch does not really
remove wall_jiffies.  It would be another cleanup patch)
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Acked-by: NRussell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: N"Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

um_timer shouldn't add local_offset to the host time since get_time already
did it.  This threw off sleep when a settimeofday or equivalent had happened.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

timer_irq_inited was useless, so it is removed.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

set_interval returns an error instead of panicing if setitimer fails.  Some of
its callers now check the return.

enable_timer is largely tt-mode-specific, so it is marked as such, and the
only skas-mode caller is made to call set-interval instead.

user_time_init was a no-value-added wrapper around set_interval, so it is
gone.

Since set_interval is now called from kernel code, callers no longer pass
ITIMER_* to it.  Instead, they pass a flag which is converted into ITIMER_REAL
or ITIMER_VIRTUAL.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Move most *_kern.c files in arch/um/kernel to *.c.  This makes UML somewhat
more closely resemble the other arches.

[akpm@osdl.org: use the new INTF_* flags]
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Get rid of a user of timer_irq_inited (and first_tick) by observing that
prev_ticks can be used to decide if this is the first call.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This cleans up the mess that is the timer initialization.  There used to be
two timer handlers - one that basically ran during delay loop calibration and
one that handled the timer afterwards.  There were also two sets of timer
initialization code - one that starts in user code and calls into the kernel
side of the house, and one that starts in kernel code and calls user code.

This eliminates one timer handler and consolidates the two sets of
initialization code.

[akpm@osdl.org: use new INTF_ flags]
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use the new IRQF_ constants and remove the SA_INTERRUPT define
Signed-off-by: NThomas 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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove um_time() and um_stime() syscalls since they are identical to
system-wide ones.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

do_timer must be called with xtime_lock held.  I'm not sure boot_timer_handler
needs this, however I don't think it hurts: it simply disables irq and takes a
spinlock.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Change a variable from unsigned to signed in order to get sign-extension
when the thing is negated.  Without this, uptime is horribly confused.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

From: Jeff Dike <jdike@addtoit.com>

Initialize wall_to_monotonic correctly.  This fixes a problem where sleeps
lasted about one secone less than they should.  This also called for a bit of
code restructuring, following a patch which Blaisorblade had been keeping.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

inet_init, which schedules, is called before the UML timer_init, which sets
up the timer.  The result is the interval timers being manipulated before
the appropriate signal handlers are established, causing unhandled timers.

This is fixed by making timer_init be called earlier.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Some fixes to make softints work in tt mode.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Current implementation of boot_timer_handler isn't usable for s390.  So I
changed its name to do_boot_timer_handler, taking (struct sigcontext *)sc as
argument.  do_boot_timer_handler is called from new boot_timer_handler() in
arch/um/os-Linux/signal.c, which uses the same mechanisms as other signal
handler to find out sigcontext pointer.
Signed-off-by: NBodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from time.c file under os-Linux dir and joins
time.c and tine_kernel.c files
Signed-off-by: NGennady Sharapov <Gennady.V.Sharapov@intel.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Define jiffies_64 in kernel/timer.c rather than having 24 duplicated
defines in each architecture.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

update_process_times was missing its irq_enter/irq_exit wrapper.  This caused
ksoftirqd to be scheduled on every clock tick.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

user_time_init_skas and user_time_init_tt were essentially the same.  So, this
merges them, deleting the mode-specific functions and declarations.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

s390 has fast read access to realtime clock (nanosecond resolution).  So it
makes sense to have an arch-specific implementation not only of __delay, but
__udelay also.
Signed-off-by: NBodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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!