Some tidying as suggested by Grant Grundler.

Nuke local bit-counting function from sata_mv in favour of using hweight16().
Also add a short explanation for the 15msec timeout used when waiting for empty/idle.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Convert sata_mv's EH for FIS-based switching (FBS) over to the
sequence recommended by Marvell.  This enables us to catch/analyze
multiple failed links on a port-multiplier when using NCQ.

To do this, we clear the ERR_DEV bit in the EDMA Halt-Conditions register,
so that the EDMA engine doesn't self-disable on the first NCQ error.

Our EH code sets the MV_PP_FLAG_DELAYED_EH flag to prevent new commands
being queued while we await completion of all outstanding NCQ commands
on all links of the failed PM.

The SATA Test Control register tells us which links have failed,
so we must only wait for any other active links to finish up
before we stop the EDMA and run the .error_handler afterward.

The patch also includes skeleton code for handling of non-NCQ FBS operation.
This is more for documentation purposes right now, as that mode is not yet
enabled in sata_mv.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Introduce a new "delayed error handling" mechanism in sata_mv,
to enable us to eventually deal with multiple simultaneous NCQ
failures on a single host link when a PM is present.

This involves a port flag (MV_PP_FLAG_DELAYED_EH) to prevent new
commands being queued, and a pmp bitmap to indicate which pmp links
had NCQ errors.

The new mv_pmp_error_handler() uses those values to invoke
ata_eh_analyze_ncq_error() on each failed link, prior to freezing
the port and passing control to sata_pmp_error_handler().

This is based upon a strategy suggested by Tejun.

For now, we just implement the delayed mechanism.
The next patch in this series will add the multiple-NCQ EH code
to take advantage of it.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Export ata_eh_analyze_ncq_error() for subsequent use by sata_mv,
as suggested by Tejun.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Separate out the inner loop body of mv_host_intr()
into it's own function called mv_port_intr().

This should help maintainabilty.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Remove the unwanted reads of hc_irq_cause from mv_host_intr(),
thereby removing a bug whereby we were not always reading it when needed..
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Sigh.  Undo some earlier changes to mv_port_intr(),
so that we now read/clear SError again in all cases.

Arrange the top of the function to be as close as possible
to what we need for a later update (in this series) for ERR_DEV handling.

Fix things so that libata-eh can attempt a READ_LOG_EXT_10H
in response to a failed NCQ command, by just doing a local
mv_eh_freeze() rather than ata_port_freeze().

This will now fully handle NCQ errors much of the time,
but more fixes are needed for FBS/PMP, and for certain chip errata.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Rearrange mv_config_fbs() to more closely follow the (corrected) datasheet
recommendations for NCQ and FIS-based switching (FBS).

Also, maintain a port flag to let us know when FBS is enabled.
We will make more use of that flag later in this patch series.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Part 1 of workaround for errata "sata#25" for the 60x1 series
(the second half of this errata workaround is still in development.

Bit22 of the GPIO port has to be set "on" when in NCQ mode.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

The EDMA engine cannot tolerate a mix of NCQ/non-NCQ commands,
and cannot be used for PIO at all.  So we need to prevent libata
from trying to feed us such mixtures.

Introduce mv_qc_defer() for this purpose, and use it for all chip versions.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

When performing EH, it is recommended to wait for the EDMA engine
to empty out requests-in-progress before disabling EDMA.

Introduce code to poll the EDMA_STATUS register for idle/empty bits
before disabling EDMA.  For non-EH operation, this will normally exit
without delay, other than the register read.

A later series of patches may focus on eliminating this and various
other register reads (when possible) throughout the driver,
but for now we're focussing on solid reliablity.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Some of the GenIIe EDMA optimizations should not be used
for non-PCI (SOC) devices, and nor for certain configurations
of conventional PCI (non PCI-X, PCIe) buses.

Logic taken/simplified from that in the Marvell proprietary driver.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

More cosmetic changes; no code changes.

 -- try and improve consistency of naming.
 -- add missing _OFS to tails of register offset definitions.
 -- rename mv_setup_ifctl() to mv_setup_ifcfg(), since that's what it really does.
 -- remove/move some dead comments
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

This patch adds Intel SCH chipsets (AF82US15W, AF82US15L, AF82UL11L)
PATA controller support.
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

On certain configurations (certain macbooks), even though all the
conditions for SIDPR access described in the datasheet are met,
actually reading those registers just returns 0 and have no effect on
write.  Verify SIDPR is actually working before enabling it.

This is reported by Ryan Roth in bz#10512.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Ryan Roth <ryan.roth@ch2m.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Some controllers (jmb and inic162x) use 0x77 and 0x7f to indicate that
the device isn't ready yet.  It looks like they use 0xff if device
presence is detected but connection isn't established.  0x77 or 0x7f
after connection is established and use the value from signature FIS
after receiving it.

This patch implements ata_check_ready(), which takes TF status value
and determines whether the port is ready or not considering the above
and other conditions, and use it in @check_ready() functions.  This is
safe as both 0x77 and 0x7f aren't valid ready status value even though
they have BSY bit cleared.

This fixes hot plug detection failures which can be triggered with
certain drives if they aren't already spun up when the data connector
is hot plugged.

Tested on sil, sil24, ahci (jmb/ich), piix and inic162x combined with
eight drives from all major vendors.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  mlx4_core: Support creation of FMRs with pages smaller than 4K
  IB/ehca: Fix function return types
  RDMA/cxgb3: Bump up the MPA connection setup timeout.
  RDMA/cxgb3: Silently ignore close reply after abort.
  RDMA/cxgb3: QP flush fixes
  IB/ipoib: Fix transmit queue stalling forever
  IB/mlx4: Fix off-by-one errors in calls to mlx4_ib_free_cq_buf()

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-fixes:
  sched: default to n for GROUP_SCHED and FAIR_GROUP_SCHED
  sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
  sched, x86: add HAVE_UNSTABLE_SCHED_CLOCK
  sched: fix cpu clock
  sched: fair-group: fix a Div0 error of the fair group scheduler
  sched: fix missing locking in sched_domains code
  sched: make clock sync tunable by architecture code
  sched: fix debugging
  sched: fix sched_info_switch not being called according to documentation
  sched: fix hrtick_start_fair and CPU-Hotplug
  sched: fix SCHED_FAIR wake-idle logic error
  sched: fix RT task-wakeup logic
  sched: add statics, don't return void expressions
  sched: add debug checks to idle functions
  sched: remove old sched doc
  sched: make rt_sched_class, idle_sched_class static
  sched: optimize calc_delta_mine()
  sched: fix normalized sleeper

Don't hard code a test against a minimum page shift of 12, since the
device may support smaller pages.  Test against the actual smallest
page size from the device capabilities.
Signed-off-by: Oren Duer <oren@mellanox.co.il>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

Also remove duplicate assignment of local_ca_ack_delay and change
min_t check for local_ca_ack_delay to u8 instead of int.

Signed-off-by: Stefan Roscher <stefan.roscher at de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

* 'powerpc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
  [POWERPC] Assign PDE->data before gluing PDE into /proc tree
  [POWERPC] devres: Add devm_ioremap_prot()
  [POWERPC] macintosh: ADB driver: adb_handler_sem semaphore to mutex
  [POWERPC] macintosh: windfarm_smu_sat: semaphore to mutex
  [POWERPC] macintosh: therm_pm72: driver_lock semaphore to mutex

Commit 06916639 ("driver-core: add
dev_name() to help transition away from using bus_id") added a static
inline dev_name() and used it in dev_printk.

Unfortunately, drivers/edac/edac_core.h defines a macro called
dev_name().  Rename the latter.

Diagnosis by Tony Breeds and Michael Ellerman.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

GROUP_SCHED is confirmed to cause unacceptable latencies, see:

   http://lkml.org/lkml/2008/5/2/370.

Mark it EXPERIMENTAL and default to no for now.
Signed-off-by: Parag Warudkar <parag.warudkar@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

this replaces the rq->clock stuff (and possibly cpu_clock()).

 - architectures that have an 'imperfect' hardware clock can set
   CONFIG_HAVE_UNSTABLE_SCHED_CLOCK

 - the 'jiffie' window might be superfulous when we update tick_gtod
   before the __update_sched_clock() call in sched_clock_tick()

 - cpu_clock() might be implemented as:

     sched_clock_cpu(smp_processor_id())

   if the accuracy proves good enough - how far can TSC drift in a
   single jiffie when considering the filtering and idle hooks?

[ mingo@elte.hu: various fixes and cleanups ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

add the HAVE_UNSTABLE_SCHED_CLOCK, for architectures to select.

the next change utilizes it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

David Miller pointed it out that nothing in cpu_clock() sets
prev_cpu_time. This caused __sync_cpu_clock() to be called
all the time - against the intention of this code.

The result was that in practice we hit a global spinlock every
time cpu_clock() is called - which - even though cpu_clock()
is used for tracing and debugging, is suboptimal.

While at it, also:

- move the irq disabling to the outest layer,
  this should make cpu_clock() warp-free when called with irqs
  enabled.

- use long long instead of cycles_t - for platforms where cycles_t
  is 32-bit.
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

When I echoed 0 into the "cpu.shares" file, a Div0 error occured.

We found it is caused by the following calling.

   sched_group_set_shares(tg, shares)
       set_se_shares(tg->se[i], shares/nr_cpu_ids)
           __set_se_shares(se, shares)
               div64_64((1ULL<<32), shares)

When the echoed value was less than the number of processores, the result of the
sentence "shares/nr_cpu_ids" was 0, and then the system called div64() to divide
the result, the Div0 error occured.

It is unnecessary that the shares value is divided by nr_cpu_ids, I think.
Because in the function  __update_group_shares_cpu() and init_tg_cfs_entry(),
the shares value isn't divided by nr_cpu_ids when setting shares of the sched
entity.

This patch fixes this bug. And echoing ULONG_MAX value into cpu.shares also
causes Div0 error, so we set a macro MAX_SHARES to limit the max value of
shares.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Concurrent calls to detach_destroy_domains and arch_init_sched_domains
were prevented by the old scheduler subsystem cpu hotplug mutex. When
this got converted to get_online_cpus() the locking got broken.
Unlike before now several processes can concurrently enter the critical
sections that were protected by the old lock.

So use the already present doms_cur_mutex to protect these sections again.

Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

make time_sync_thresh tunable to architecture code.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Revert debugging commit 7ba2e74a.
print_cfs_rq_tasks() can induce live-lock if a task is dequeued
during list traversal.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

http://bugzilla.kernel.org/show_bug.cgi?id=10545

sched_stats.h says that __sched_info_switch is "called when prev !=
next" in the comment.  sched.c should therefore do that.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Gautham R Shenoy reported:

 > While running the usual CPU-Hotplug stress tests on linux-2.6.25,
 > I noticed the following in the console logs.
 >
 > This is a wee bit difficult to reproduce. In the past 10 runs I hit this
 > only once.
 >
 > ------------[ cut here ]------------
 >
 > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65()
 >
 > Just wondering if we are doing a good job at handling the cancellation
 > of any per-cpu scheduler timers during CPU-Hotplug.

This looks like its indeed not cancelled at all and migrates the it to
another cpu. Fix it via a proper hotplug notifier mechanism.
Reported-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

We currently use an optimization to skip the overhead of wake-idle
processing if more than one task is assigned to a run-queue.  The
assumption is that the system must already be load-balanced or we
wouldnt be overloaded to begin with.

The problem is that we are looking at rq->nr_running, which may include
RT tasks in addition to CFS tasks.  Since the presence of RT tasks
really has no bearing on the balance status of CFS tasks, this throws
the calculation off.

This patch changes the logic to only consider the number of CFS tasks
when making the decision to optimze the wake-idle.
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
CC: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Dmitry Adamushko pointed out a logic error in task_wake_up_rt() where we
will always evaluate to "true".  You can find the thread here:

http://lkml.org/lkml/2008/4/22/296

In reality, we only want to try to push tasks away when a wake up request is
not going to preempt the current task.  So lets fix it.

Note: We introduce test_tsk_need_resched() instead of open-coding the flag
check so that the merge-conflict with -rt should help remind us that we
may need to support NEEDS_RESCHED_DELAYED in the future, too.
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
CC: Dmitry Adamushko <dmitry.adamushko@gmail.com>
CC: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Noticed by sparse:
kernel/sched.c:760:20: warning: symbol 'sched_feat_names' was not declared. Should it be static?
kernel/sched.c:767:5: warning: symbol 'sched_feat_open' was not declared. Should it be static?
kernel/sched_fair.c:845:3: warning: returning void-valued expression
kernel/sched.c:4386:3: warning: returning void-valued expression
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: "Justin Mattock" <justinmattock@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Fabio Checconi noticed that Documentation/scheduler/sched-design.txt was
a stale copy of the old scheduler. Remove it.
Reported-by: Fabio Checconi <fabio@gandalf.sssup.it>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

The C files are included directly in sched.c, so they are
effectively static.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Joel noticed that the !lw->inv_weight contition isn't unlikely anymore so
remove the unlikely annotation. Also, remove the two div64_u64() inv_weight
calculations, which makes them rely on the calc_delta_mine() path as well.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Joel Schopp <jschopp@austin.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Normalized sleeper uses calc_delta*() which requires that the rq load is
already updated, so move account_entity_enqueue() before place_entity()
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>