Patch from Lennert Buytenhek

Add the necessary kernel bits for crunch task switching.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Lennert Buytenhek

This patch makes it possible to get/set a task's Crunch state via
the ptrace(2) system call.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Lennert Buytenhek

This patch makes the kernel save Crunch state in userland signal frames,
so that any userland signal handler can safely use the Crunch coprocessor
without corrupting the Crunch state of the code it preempted.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Lennert Buytenhek

ixp23xx was including asm/hardware.h in its version of uncompress.h,
to get at the physical address of the debug UART, but this include was
causing various inline functions that are totally unrelated to the
decompressor, defined in headers in include/asm-arm/arch-ixp23xx, to
be included in the decompressor image.

Include asm/arch/ixp23xx.h instead, and move the sole inline function
in ixp23xx.h to another header.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Andrew Victor

Remove the remaining legacy __virt_to_bus__is_a_macro and
__bus_to_virt__is_a_macro defines in some ARM platforms.
Signed-off-by: NAndrew Victor <andrew@sanpeople.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Ben Dooks

If only the S3C2412 based machines are selected,
then the regs-dsc.h does not export the S3C2412_DSC
registers as it is wrapped in CONFIG_CPU_S3C2440.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Back in the days when we had armo (26-bit) and armv (32-bit) combined,
we had an additional layer to the uaccess macros to ensure correct
typing.  Since we no longer have 26-bit in this tree, we no longer
need this layer, so eliminate it.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Remove NO_FORMAT_VEC conditional check. It is not used or defined anywhere.
Signed-off-by: NGreg Ungerer <gerg@uclinux.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make struct proc_ipmi_root static.

Besides this, tremove removes an unused #ifdef CONFIG_PROC_FS from
include/linux/ipmi.h.
Acked-by: NCorey Minyard <minyard@acm.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When the priority of a task, which is blocked on a lock, changes we must
propagate this change into the PI lock chain.  Therefor the chain walk code
is changed to get rid of the references to current to avoid false positives
in the deadlock detector, as setscheduler might be called by a task which
holds the lock on which the task whose priority is changed is blocked.

Also add some comments about the get/put_task_struct usage to avoid
confusion.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This adds the actual pi-futex implementation, based on rt-mutexes.

[dino@in.ibm.com: fix an oops-causing race]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NDinakar Guniguntala <dino@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

RT-mutex tester: scriptable tester for rt mutexes, which allows userspace
scripting of mutex unit-tests (and dynamic tests as well), using the actual
rt-mutex implementation of the kernel.

[akpm@osdl.org: fixlet]
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Runtime debugging functionality for rt-mutexes.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Core functions for the rt-mutex subsystem.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add framework to boost/unboost the priority of RT tasks.

This consists of:

 - caching the 'normal' priority in ->normal_prio
 - providing a functions to set/get the priority of the task
 - make sched_setscheduler() aware of boosting

The effective_prio() cleanups also fix a priority-calculation bug pointed out
by Andrey Gelman, in set_user_nice().

has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Andrey Gelman <agelman@012.net.il>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add the priority-sorted list (plist) implementation.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Introduce a new WARN_ON variant: WARN_ON_SMP(cond).
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add debug_check_no_locks_freed(), as a central inline to add
bad-lock-free-debugging functionality to.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We are pleased to announce "lightweight userspace priority inheritance" (PI)
support for futexes.  The following patchset and glibc patch implements it,
ontop of the robust-futexes patchset which is included in 2.6.16-mm1.

We are calling it lightweight for 3 reasons:

 - in the user-space fastpath a PI-enabled futex involves no kernel work
   (or any other PI complexity) at all.  No registration, no extra kernel
   calls - just pure fast atomic ops in userspace.

 - in the slowpath (in the lock-contention case), the system call and
   scheduling pattern is in fact better than that of normal futexes, due to
   the 'integrated' nature of FUTEX_LOCK_PI.  [more about that further down]

 - the in-kernel PI implementation is streamlined around the mutex
   abstraction, with strict rules that keep the implementation relatively
   simple: only a single owner may own a lock (i.e.  no read-write lock
   support), only the owner may unlock a lock, no recursive locking, etc.

  Priority Inheritance - why, oh why???
  -------------------------------------

Many of you heard the horror stories about the evil PI code circling Linux for
years, which makes no real sense at all and is only used by buggy applications
and which has horrible overhead.  Some of you have dreaded this very moment,
when someone actually submits working PI code ;-)

So why would we like to see PI support for futexes?

We'd like to see it done purely for technological reasons.  We dont think it's
a buggy concept, we think it's useful functionality to offer to applications,
which functionality cannot be achieved in other ways.  We also think it's the
right thing to do, and we think we've got the right arguments and the right
numbers to prove that.  We also believe that we can address all the
counter-arguments as well.  For these reasons (and the reasons outlined below)
we are submitting this patch-set for upstream kernel inclusion.

What are the benefits of PI?

  The short reply:
  ----------------

User-space PI helps achieving/improving determinism for user-space
applications.  In the best-case, it can help achieve determinism and
well-bound latencies.  Even in the worst-case, PI will improve the statistical
distribution of locking related application delays.

  The longer reply:
  -----------------

Firstly, sharing locks between multiple tasks is a common programming
technique that often cannot be replaced with lockless algorithms.  As we can
see it in the kernel [which is a quite complex program in itself], lockless
structures are rather the exception than the norm - the current ratio of
lockless vs.  locky code for shared data structures is somewhere between 1:10
and 1:100.  Lockless is hard, and the complexity of lockless algorithms often
endangers to ability to do robust reviews of said code.  I.e.  critical RT
apps often choose lock structures to protect critical data structures, instead
of lockless algorithms.  Furthermore, there are cases (like shared hardware,
or other resource limits) where lockless access is mathematically impossible.

Media players (such as Jack) are an example of reasonable application design
with multiple tasks (with multiple priority levels) sharing short-held locks:
for example, a highprio audio playback thread is combined with medium-prio
construct-audio-data threads and low-prio display-colory-stuff threads.  Add
video and decoding to the mix and we've got even more priority levels.

So once we accept that synchronization objects (locks) are an unavoidable fact
of life, and once we accept that multi-task userspace apps have a very fair
expectation of being able to use locks, we've got to think about how to offer
the option of a deterministic locking implementation to user-space.

Most of the technical counter-arguments against doing priority inheritance
only apply to kernel-space locks.  But user-space locks are different, there
we cannot disable interrupts or make the task non-preemptible in a critical
section, so the 'use spinlocks' argument does not apply (user-space spinlocks
have the same priority inversion problems as other user-space locking
constructs).  Fact is, pretty much the only technique that currently enables
good determinism for userspace locks (such as futex-based pthread mutexes) is
priority inheritance:

Currently (without PI), if a high-prio and a low-prio task shares a lock [this
is a quite common scenario for most non-trivial RT applications], even if all
critical sections are coded carefully to be deterministic (i.e.  all critical
sections are short in duration and only execute a limited number of
instructions), the kernel cannot guarantee any deterministic execution of the
high-prio task: any medium-priority task could preempt the low-prio task while
it holds the shared lock and executes the critical section, and could delay it
indefinitely.

  Implementation:
  ---------------

As mentioned before, the userspace fastpath of PI-enabled pthread mutexes
involves no kernel work at all - they behave quite similarly to normal
futex-based locks: a 0 value means unlocked, and a value==TID means locked.
(This is the same method as used by list-based robust futexes.) Userspace uses
atomic ops to lock/unlock these mutexes without entering the kernel.

To handle the slowpath, we have added two new futex ops:

  FUTEX_LOCK_PI
  FUTEX_UNLOCK_PI

If the lock-acquire fastpath fails, [i.e.  an atomic transition from 0 to TID
fails], then FUTEX_LOCK_PI is called.  The kernel does all the remaining work:
if there is no futex-queue attached to the futex address yet then the code
looks up the task that owns the futex [it has put its own TID into the futex
value], and attaches a 'PI state' structure to the futex-queue.  The pi_state
includes an rt-mutex, which is a PI-aware, kernel-based synchronization
object.  The 'other' task is made the owner of the rt-mutex, and the
FUTEX_WAITERS bit is atomically set in the futex value.  Then this task tries
to lock the rt-mutex, on which it blocks.  Once it returns, it has the mutex
acquired, and it sets the futex value to its own TID and returns.  Userspace
has no other work to perform - it now owns the lock, and futex value contains
FUTEX_WAITERS|TID.

If the unlock side fastpath succeeds, [i.e.  userspace manages to do a TID ->
0 atomic transition of the futex value], then no kernel work is triggered.

If the unlock fastpath fails (because the FUTEX_WAITERS bit is set), then
FUTEX_UNLOCK_PI is called, and the kernel unlocks the futex on the behalf of
userspace - and it also unlocks the attached pi_state->rt_mutex and thus wakes
up any potential waiters.

Note that under this approach, contrary to other PI-futex approaches, there is
no prior 'registration' of a PI-futex.  [which is not quite possible anyway,
due to existing ABI properties of pthread mutexes.]

Also, under this scheme, 'robustness' and 'PI' are two orthogonal properties
of futexes, and all four combinations are possible: futex, robust-futex,
PI-futex, robust+PI-futex.

  glibc support:
  --------------

Ulrich Drepper and Jakub Jelinek have written glibc support for PI-futexes
(and robust futexes), enabling robust and PI (PTHREAD_PRIO_INHERIT) POSIX
mutexes.  (PTHREAD_PRIO_PROTECT support will be added later on too, no
additional kernel changes are needed for that).  [NOTE: The glibc patch is
obviously inofficial and unsupported without matching upstream kernel
functionality.]

the patch-queue and the glibc patch can also be downloaded from:

  http://redhat.com/~mingo/PI-futex-patches/

Many thanks go to the people who helped us create this kernel feature: Steven
Rostedt, Esben Nielsen, Benedikt Spranger, Daniel Walker, John Cooper, Arjan
van de Ven, Oleg Nesterov and others.  Credits for related prior projects goes
to Dirk Grambow, Inaky Perez-Gonzalez, Bill Huey and many others.

Clean up the futex code, before adding more features to it:

 - use u32 as the futex field type - that's the ABI
 - use __user and pointers to u32 instead of unsigned long
 - code style / comment style cleanups
 - rename hash-bucket name from 'bh' to 'hb'.

I checked the pre and post futex.o object files to make sure this
patch has no code effects.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in
/sys/devices/system/cpu/ control the MC/SMT power savings policy for the
scheduler.

Based on the values (1-enable, 0-disable) for these controls, sched groups
cpu power will be determined for different domains.  When power savings
policy is enabled and under light load conditions, scheduler will minimize
the physical packages/cpu cores carrying the load and thus conserving
power(with a perf impact based on the workload characteristics...  see OLS
2005 CMP kernel scheduler paper for more details..)
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Con Kolivas <kernel@kolivas.org>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Try to handle mem allocation failures in build_sched_domains by bailing out
and cleaning up thus-far allocated memory.  The patch has a direct consequence
that we disable load balancing completely (even at sibling level) upon *any*
memory allocation failure.

[Lee.Schermerhorn@hp.com: bugfix]
Signed-off-by: NSrivatsa Vaddagir <vatsa@in.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Problem:

The introduction of separate run queues per CPU has brought with it "nice"
enforcement problems that are best described by a simple example.

For the sake of argument suppose that on a single CPU machine with a
nice==19 hard spinner and a nice==0 hard spinner running that the nice==0
task gets 95% of the CPU and the nice==19 task gets 5% of the CPU.  Now
suppose that there is a system with 2 CPUs and 2 nice==19 hard spinners and
2 nice==0 hard spinners running.  The user of this system would be entitled
to expect that the nice==0 tasks each get 95% of a CPU and the nice==19
tasks only get 5% each.  However, whether this expectation is met is pretty
much down to luck as there are four equally likely distributions of the
tasks to the CPUs that the load balancing code will consider to be balanced
with loads of 2.0 for each CPU.  Two of these distributions involve one
nice==0 and one nice==19 task per CPU and in these circumstances the users
expectations will be met.  The other two distributions both involve both
nice==0 tasks being on one CPU and both nice==19 being on the other CPU and
each task will get 50% of a CPU and the user's expectations will not be
met.

Solution:

The solution to this problem that is implemented in the attached patch is
to use weighted loads when determining if the system is balanced and, when
an imbalance is detected, to move an amount of weighted load between run
queues (as opposed to a number of tasks) to restore the balance.  Once
again, the easiest way to explain why both of these measures are necessary
is to use a simple example.  Suppose that (in a slight variation of the
above example) that we have a two CPU system with 4 nice==0 and 4 nice=19
hard spinning tasks running and that the 4 nice==0 tasks are on one CPU and
the 4 nice==19 tasks are on the other CPU.  The weighted loads for the two
CPUs would be 4.0 and 0.2 respectively and the load balancing code would
move 2 tasks resulting in one CPU with a load of 2.0 and the other with
load of 2.2.  If this was considered to be a big enough imbalance to
justify moving a task and that task was moved using the current
move_tasks() then it would move the highest priority task that it found and
this would result in one CPU with a load of 3.0 and the other with a load
of 1.2 which would result in the movement of a task in the opposite
direction and so on -- infinite loop.  If, on the other hand, an amount of
load to be moved is calculated from the imbalance (in this case 0.1) and
move_tasks() skips tasks until it find ones whose contributions to the
weighted load are less than this amount it would move two of the nice==19
tasks resulting in a system with 2 nice==0 and 2 nice=19 on each CPU with
loads of 2.1 for each CPU.

One of the advantages of this mechanism is that on a system where all tasks
have nice==0 the load balancing calculations would be mathematically
identical to the current load balancing code.

Notes:

struct task_struct:

has a new field load_weight which (in a trade off of space for speed)
stores the contribution that this task makes to a CPU's weighted load when
it is runnable.

struct runqueue:

has a new field raw_weighted_load which is the sum of the load_weight
values for the currently runnable tasks on this run queue.  This field
always needs to be updated when nr_running is updated so two new inline
functions inc_nr_running() and dec_nr_running() have been created to make
sure that this happens.  This also offers a convenient way to optimize away
this part of the smpnice mechanism when CONFIG_SMP is not defined.

int try_to_wake_up():

in this function the value SCHED_LOAD_BALANCE is used to represent the load
contribution of a single task in various calculations in the code that
decides which CPU to put the waking task on.  While this would be a valid
on a system where the nice values for the runnable tasks were distributed
evenly around zero it will lead to anomalous load balancing if the
distribution is skewed in either direction.  To overcome this problem
SCHED_LOAD_SCALE has been replaced by the load_weight for the relevant task
or by the average load_weight per task for the queue in question (as
appropriate).

int move_tasks():

The modifications to this function were complicated by the fact that
active_load_balance() uses it to move exactly one task without checking
whether an imbalance actually exists.  This precluded the simple
overloading of max_nr_move with max_load_move and necessitated the addition
of the latter as an extra argument to the function.  The internal
implementation is then modified to move up to max_nr_move tasks and
max_load_move of weighted load.  This slightly complicates the code where
move_tasks() is called and if ever active_load_balance() is changed to not
use move_tasks() the implementation of move_tasks() should be simplified
accordingly.

struct sched_group *find_busiest_group():

Similar to try_to_wake_up(), there are places in this function where
SCHED_LOAD_SCALE is used to represent the load contribution of a single
task and the same issues are created.  A similar solution is adopted except
that it is now the average per task contribution to a group's load (as
opposed to a run queue) that is required.  As this value is not directly
available from the group it is calculated on the fly as the queues in the
groups are visited when determining the busiest group.

A key change to this function is that it is no longer to scale down
*imbalance on exit as move_tasks() uses the load in its scaled form.

void set_user_nice():

has been modified to update the task's load_weight field when it's nice
value and also to ensure that its run queue's raw_weighted_load field is
updated if it was runnable.

From: "Siddha, Suresh B" <suresh.b.siddha@intel.com>

With smpnice, sched groups with highest priority tasks can mask the imbalance
between the other sched groups with in the same domain.  This patch fixes some
of the listed down scenarios by not considering the sched groups which are
lightly loaded.

a) on a simple 4-way MP system, if we have one high priority and 4 normal
   priority tasks, with smpnice we would like to see the high priority task
   scheduled on one cpu, two other cpus getting one normal task each and the
   fourth cpu getting the remaining two normal tasks.  but with current
   smpnice extra normal priority task keeps jumping from one cpu to another
   cpu having the normal priority task.  This is because of the
   busiest_has_loaded_cpus, nr_loaded_cpus logic..  We are not including the
   cpu with high priority task in max_load calculations but including that in
   total and avg_load calcuations..  leading to max_load < avg_load and load
   balance between cpus running normal priority tasks(2 Vs 1) will always show
   imbalanace as one normal priority and the extra normal priority task will
   keep moving from one cpu to another cpu having normal priority task..

b) 4-way system with HT (8 logical processors).  Package-P0 T0 has a
   highest priority task, T1 is idle.  Package-P1 Both T0 and T1 have 1 normal
   priority task each..  P2 and P3 are idle.  With this patch, one of the
   normal priority tasks on P1 will be moved to P2 or P3..

c) With the current weighted smp nice calculations, it doesn't always make
   sense to look at the highest weighted runqueue in the busy group..
   Consider a load balance scenario on a DP with HT system, with Package-0
   containing one high priority and one low priority, Package-1 containing one
   low priority(with other thread being idle)..  Package-1 thinks that it need
   to take the low priority thread from Package-0.  And find_busiest_queue()
   returns the cpu thread with highest priority task..  And ultimately(with
   help of active load balance) we move high priority task to Package-1.  And
   same continues with Package-0 now, moving high priority task from package-1
   to package-0..  Even without the presence of active load balance, load
   balance will fail to balance the above scenario..  Fix find_busiest_queue
   to use "imbalance" when it is lightly loaded.

[kernel@kolivas.org: sched: store weighted load on up]
[kernel@kolivas.org: sched: add discrete weighted cpu load function]
[suresh.b.siddha@intel.com: sched: remove dead code]
Signed-off-by: NPeter Williams <pwil3058@bigpond.com.au>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NCon Kolivas <kernel@kolivas.org>
Cc: John Hawkes <hawkes@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use of dev_dbg() and friends is considered good practice.  dev_dbg() needs a
struct device *devp, but nsc_gpio is only a helper module, so it doesnt
have/need its own.  To provide devp to the user-modules (scx200 & pc8736x
_gpio), we add it to the vtable, and set it during init.

Also squeeze nsc_gpio_dump()'s format a little.

[  199.259879]  pc8736x_gpio.0: io09: 0x0044 TS OD PUE  EDGE LO DEBOUNCE
Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Now that the read(), write() file-ops are dispatching gpio-ops via the vtable,
they are generic, and can be moved 'verbatim' to the nsc_gpio common-support
module.  After the move, various symbols are renamed to update 'scx200_' to
'nsc_', and headers are adjusted accordingly.
Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Abstract the gpio operations into a new nsc_gpio_ops vtable.
Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Per kernel headers, device minor numbers are unsigned ints.  Do the same in
this driver.
Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

GPIO SUPPORT FOR SCx200 & PC8736x

The patch-set reworks the 2.4 vintage scx200_gpio driver for modern 2.6, and
refactors GPIO support to reuse it in a new driver for the GPIO on PC-8736x
chips.  Its handy for the Soekris.com net-4801, which has both chips.

These patches have been seen recently on Kernel-Mentors, and then
Kernel-Newbies ML, where Jesper Juhl kindly reviewed it.  His feedback has
been incorporated.  Thanks Jesper !

Its also gone to soekris-tech@soekris.com for possible testing by linux folks,
I've gotten 1 promise so far.  Theyre mostly BSD folk over there, but we'll
see..

Device-file & Sysfs

The driver preserves the existing device-file interface, including the
write/cmd set, but adds v to 'view' the pin-settings & configs by inducing,
via gpio_dump(), a dev_info() call.  Its a fairly crappy way to get status,
but it sticks to the syslog approach, conservatively.

Allowing users to voluntarily trigger logging is good, it gives them a
familiar way to confirm their app's control & use of the pins, and I've thus
reduced the pin-mode-updates from dev_info to dev_dbg.

I've recently bolted on a proto sysfs interface for both new drivers.  Im not
including those patches here; they (the patch + doc-pre-patch) are still quite
raw (and unreviewed on KNML), and since they 'invent' a convention for GPIO, a
proper vetting is needed.  Since this patchset is much bigger than my previous
ones, Id like to keep things simpler, and address it 1st, before bolting on
more stuff.

The driver-split

The Geode CPU and the PC-87366 Super-IO chip have GPIO units which share a
common pin-architecture (same pin features, with same bits controlling), but
with different addressing mechanics and port organizations.

The vintage driver expresses the pin capabilities with pin-mode commands
[OoPpTt],etc that change the pin configurations, and since the 2 chips share
pin-arch, we can reuse the read(), write() commands, once the implementation
is suitably adjusted.

The patchset adds a vtable: struct nsc_gpio_ops, to abstract the existing gpio
operations, then adjusts fileops.write() code to invoke operations via that
vtable.  Driver specific open()s set private_data to the vtable so its
available for use by write().

The vtable gets the gpio_dump() too, since its user-friendly, and (could be
construed as) part of the current device-file interface.  To support use of
dev_dbg() in write() & _dump(), the vtable gets a dev ptr too, set by both
scx200 & pc8736x _gpio drivers.

heres how the pins are presented in syslog:

[ 1890.176223]  scx200_gpio.0: io00: 0x0044 TS OD PUE  EDGE LO DEBOUNCE
[ 1890.287223]  scx200_gpio.0: io01: 0x0003 OE PP PUD  EDGE LO

nsc_gpio.c: new file is new home of several file-ops methods, which are
modified to get their vtable from filp->private_data, and use it where needed.

scx200_gpio.c: keeps some of its existing gpio routines, but now wires them up
via the vtable (they're invoked by nsc_gpio.c:nsc_gpio_write() thru this
vtable).  A driver-spcific open() initializes filp->private_data with the
vtable.

Once the split is clean, and the scx200_gpio driver is working, we copy and
modify the function and variable names, and rework the access-method bodies
for the different addressing scheme.

Heres a working overview of the patchset:

# series file for GPIO

# Spring Cleaning
gpio-scx/patch.preclean        # scripts/Lindent fixes, editor-ctrl comments

# API Modernization

gpio-scx/patch.api26        # what I learned from LDD3
gpio-scx/patch.platform-dev-2    # get pdev, support for dev_dbg()
gpio-scx/patch.unsigned-minor    # fix to match std practice

# Debuggability

gpio-scx/patch.dump-diet    # shrink gpio_dump()
gpio-scx/patch.viewpins        # add new 'command' to call dump()
gpio-scx/patch.init-refactor    # pull shadow-register init to sub

# Access-Abstraction (add vtable)

gpio-scx/patch.access-vtable    # introduce nsg_gpio_ops vtable, w dump
gpio-scx/patch.vtable-calls    # add & use the vtable in scx200_gpio
gpio-scx/patch.nscgpio-shell    # add empty driver for common-fops

# move code under abstraction
gpio-scx/patch.migrate-fops    # move file-ops methods from scx200_gpio
gpio-scx/patch.common-dump    # mv scx200.c:scx200_gpio_dump() to nsc_gpio.c
gpio-scx/patch.add-pc8736x-gpio    # add new driver, like old, w chip adapt
# gpio-scx/patch.add-DEBUG    # enable all dev_dbg()s

# Cleanups

# finish printk -> dev_dbg() etc
gpio-scx/patch.pdev-pc8736x    # new drvr needs pdev too,
gpio-scx/patch.devdbg-nscgpio    # add device to 'vtable', use in dev_dbg()

# gpio-scx/patch.pin-config-view    # another 'c' 'command'
# gpio-scx/quiet-getset        # take out excess dbg stuff (pretty quiet
now)
gpio-scx/patch.shadow-current    # imitate scx200_gpio's shadow regs in
pc87*

# post KMentors-post patches ..

gpio-scx/patch.mutexes        # use mutexes for config-locks
gpio-scx/patch.viewpins-values    # extend dump to obsolete separate 'c' cmd

gpio-scx/patch.kconfig        # add stuff for kbuild

# TBC
# combine api26 with pdev, which is just one step.
# merge c&v commands to single do-all-fn
# delay viewpins, dump-diet should also un-ifdef it too.

diff.sys-gpio-rollup-1

This patch:

Removed editor format-control comments, and used scripts/Lindent to clean up
whitespace, then deleted the bogus chunks :-(
Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Define new macros register_hotcpu_notifier() and unregister_hotcpu_notifier()
that redefines register_cpu_notifier() and unregister_cpu_notifier() for use
only when HOTPLUG_CPU is defined.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

CPUs come online only at init time (unless CONFIG_HOTPLUG_CPU is defined).
So, cpu_notifier functionality need to be available only at init time.

This patch makes register_cpu_notifier() available only at init time, unless
CONFIG_HOTPLUG_CPU is defined.

This patch exports register_cpu_notifier() and unregister_cpu_notifier() only
if CONFIG_HOTPLUG_CPU is defined.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add operations for the call_rcu_bh() variant of RCU.  Also add an
rcu_batches_completed_bh() function, which is needed by rcutorture.
Signed-off-by: NPaul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We include config.h on the compiler command line. There's no need for it
to be included again.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

locking init cleanups:

 - convert " = SPIN_LOCK_UNLOCKED" to spin_lock_init() or DEFINE_SPINLOCK()
 - convert rwlocks in a similar manner

this patch was generated automatically.

Motivation:

 - cleanliness
 - lockdep needs control of lock initialization, which the open-coded
   variants do not give
 - it's also useful for -rt and for lock debugging in general
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- add a proper prototype for the following global function:
  - buffer_init()

- make the following needlessly global function static:
  - end_buffer_async_write()
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add more poison values to include/linux/poison.h.  It's not clear to me
whether some others should be added or not, so I haven't added any of
these:

./include/linux/libata.h:#define ATA_TAG_POISON		0xfafbfcfdU
./arch/ppc/8260_io/fcc_enet.c:1918:	memset((char *)(&(immap->im_dprambase[(mem_addr+64)])), 0x88, 32);
./drivers/usb/mon/mon_text.c:429:	memset(mem, 0xe5, sizeof(struct mon_event_text));
./drivers/char/ftape/lowlevel/ftape-ctl.c:738:		memset(ft_buffer[i]->address, 0xAA, FT_BUFF_SIZE);
./drivers/block/sx8.c:/* 0xf is just arbitrary, non-zero noise; this is sorta like poisoning */
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update two drivers to use poison.h.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Localize poison values into one header file for better documentation and
easier/quicker debugging and so that the same values won't be used for
multiple purposes.

Use these constants in core arch., mm, driver, and fs code.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Acked-by: NMatt Mackall <mpm@selenic.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Move the i386 VDSO down into a vma and thus randomize it.

Besides the security implications, this feature also helps debuggers, which
can COW a vma-backed VDSO just like a normal DSO and can thus do
single-stepping and other debugging features.

It's good for hypervisors (Xen, VMWare) too, which typically live in the same
high-mapped address space as the VDSO, hence whenever the VDSO is used, they
get lots of guest pagefaults and have to fix such guest accesses up - which
slows things down instead of speeding things up (the primary purpose of the
VDSO).

There's a new CONFIG_COMPAT_VDSO (default=y) option, which provides support
for older glibcs that still rely on a prelinked high-mapped VDSO.  Newer
distributions (using glibc 2.3.3 or later) can turn this option off.  Turning
it off is also recommended for security reasons: attackers cannot use the
predictable high-mapped VDSO page as syscall trampoline anymore.

There is a new vdso=[0|1] boot option as well, and a runtime
/proc/sys/vm/vdso_enabled sysctl switch, that allows the VDSO to be turned
on/off.

(This version of the VDSO-randomization patch also has working ELF
coredumping, the previous patch crashed in the coredumping code.)

This code is a combined work of the exec-shield VDSO randomization
code and Gerd Hoffmann's hypervisor-centric VDSO patch. Rusty Russell
started this patch and i completed it.

[akpm@osdl.org: cleanups]
[akpm@osdl.org: compile fix]
[akpm@osdl.org: compile fix 2]
[akpm@osdl.org: compile fix 3]
[akpm@osdl.org: revernt MAXMEM change]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Cc: Gerd Hoffmann <kraxel@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Using C code for current_thread_info() lets the compiler optimize it.
With gcc 4.0.2, kernel is smaller:

    text           data     bss     dec     hex filename
 3645212         555556  312024 4512792  44dc18 2.6.17-rc6-nb-post/vmlinux
 3647276         555556  312024 4514856  44e428 2.6.17-rc6-nb/vmlinux
 -------
   -2064
Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Move the phys_core_id and cpu_core_id to cpuinfo_x86 structure.  Similar
patch for x86_64 is already accepted by Andi earlier this week.

[akpm@osdl.org: fix warning]
Signed-off-by: NRohit Seth <rohitseth@google.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove the limit of 256 interrupt vectors by changing the value stored in
orig_{e,r}ax to be the complemented interrupt vector.  The orig_{e,r}ax
needs to be < 0 to allow the signal code to distinguish between return from
interrupt and return from syscall.  With this change applied, NR_IRQS can
be > 256.

Xen extends the IRQ numbering space to include room for dynamically
allocated virtual interrupts (in the range 256-511), which requires a more
permissive interface to do_IRQ.
Signed-off-by: NIan Pratt <ian.pratt@xensource.com>
Signed-off-by: NChristian Limpach <Christian.Limpach@cl.cam.ac.uk>
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>