We can monitor the effectiveness of our power management of both the
kernel and hypervisor by probing the timer interrupt. For example, on
this box we see 10.37s timer interrupts on an idle core:

<idle>-0     [010]  3900.671297: timer_interrupt_entry: pt_regs=c0000000ce1e7b10
<idle>-0     [010]  3900.671302: timer_interrupt_exit: pt_regs=c0000000ce1e7b10

<idle>-0     [010]  3911.042963: timer_interrupt_entry: pt_regs=c0000000ce1e7b10
<idle>-0     [010]  3911.042968: timer_interrupt_exit: pt_regs=c0000000ce1e7b10

<idle>-0     [010]  3921.414630: timer_interrupt_entry: pt_regs=c0000000ce1e7b10
<idle>-0     [010]  3921.414635: timer_interrupt_exit: pt_regs=c0000000ce1e7b10

Since we have a 207MHz decrementer it will go negative and fire every 10.37s
even if Linux is completely idle.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This adds powerpc-specific tracepoints for interrupt entry and exit.

While we already have generic irq_handler_entry and irq_handler_exit
tracepoints there are cases on our virtualised powerpc machines where an
interrupt is presented to the OS, but subsequently handled by the hypervisor.
This means no OS interrupt handler is invoked.

Here is an example on a POWER6 machine with the patch below applied:

<idle>-0     [006]  3243.949840744: irq_entry: pt_regs=c0000000ce31fb10
<idle>-0     [006]  3243.949850520: irq_exit: pt_regs=c0000000ce31fb10

<idle>-0     [007]  3243.950218208: irq_entry: pt_regs=c0000000ce323b10
<idle>-0     [007]  3243.950224080: irq_exit: pt_regs=c0000000ce323b10

<idle>-0     [000]  3244.021879320: irq_entry: pt_regs=c000000000a63aa0
<idle>-0     [000]  3244.021883616: irq_handler_entry: irq=87 handler=eth0
<idle>-0     [000]  3244.021887328: irq_handler_exit: irq=87 return=handled
<idle>-0     [000]  3244.021897408: irq_exit: pt_regs=c000000000a63aa0

Here we see two phantom interrupts (no handler was invoked), followed
by a real interrupt for eth0. Without the tracepoints in this patch we
would have missed the phantom interrupts.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Hook up the alignment-faults and emulation-faults events for powerpc.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

perf_event wants a separate event for alignment and emulation faults,
so create another emulation event.  This will make it easy to hook in
perf_event at one spot.

We pass in regs which will be required for these events.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Add two more software events that are common to many cpus.

Alignment faults: When a load or store is not aligned properly.

Emulation faults: When an instruction is emulated in software.

Both cause a very significant slowdown (100x or worse), so identifying and
fixing them is very important.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

In continuous sampling mode we want the SDAR to update.  While we can
select between dcache misses and ERAT (L1-TLB) misses, a decent default
is to enable both.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

When we take an exception and the SDAR isn't synchronised we currently
log 0 as the address.  Unfortunately this is a pretty common value, so
use ~0UL instead.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: sbp2: provide fallback if mgt_ORB_timeout is missing
  ieee1394: add documentation entry to MAINTAINERS
  ieee1394: update URLs in debugging-via-ohci1394.txt

* branch 'tty-fixes':
  tty: use the new 'flush_delayed_work()' helper to do ldisc flush
  workqueue: add 'flush_delayed_work()' to run and wait for delayed work
  Make flush_to_ldisc properly handle parallel calls

Merge branch 'topic/x86-lds-nits' of git://git.kernel.org/pub/scm/linux/kernel/git/frob/linux-2.6-roland

* 'topic/x86-lds-nits' of git://git.kernel.org/pub/scm/linux/kernel/git/frob/linux-2.6-roland:
  x86: linker script syntax nits

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  watchdog: Fix rio watchdog probe function
  sparc64: Set IRQF_DISABLED on LDC channel IRQs.
  sparc64: Fix D-cache flushing on swapin from SW devices.
  sparc64: Fix niagara2 perf IRQ bits.

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] sclp_vt220 build fix
  [S390] cio: change misleading console logic
  [S390] call home support: fix proc handler
  [S390] dasd: use idal for device characteristics
  [S390] Add highgprs facility to /proc/cpuinfo
  [S390] dasd: fix locking bug
  [S390] tape390: Fix request queue handling in block driver
  [S390] hypfs: Use subcode 6 if subcode 7 is not available

* 'sh/for-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: Fix a TRACE_IRQS_OFF typo.
  sh: Optimize the setup_rt_frame() I-cache flush.
  sh: Populate initial secondary CPU info from boot_cpu_data.
  sh: Tidy up SMP cpuinfo.
  sh: Use boot_cpu_data for FPU tests in sigcontext paths.
  sh: ftrace: Fix up syscall tracepoint support.
  sh: force dcache flush if dcache_dirty bit set.
  sh: update die() output.

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

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  oprofile: warn on freeing event buffer too early
  oprofile: fix race condition in event_buffer free
  lockdep: Use cpu_clock() for lockstat

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

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf events: Update MAINTAINERS entry file patterns
  perf tools: Remove static debugfs path from parse-events
  perf tools: Fix the NO_64BIT build on pure 64-bit systems
  perf tools: Fix const char type propagation

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

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Fix missing kernel-doc notation
  Revert "x86, timers: Check for pending timers after (device) interrupts"
  sched: Update the clock of runqueue select_task_rq() selected

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

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing/filters: Fix memory leak when setting a filter
  tracing: fix trace_vprintk call

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86/paravirt: Use normal calling sequences for irq enable/disable
  x86: fix kernel panic on 32 bits when profiling
  x86: Fix Suspend to RAM freeze on Acer Aspire 1511Lmi laptop
  x86, vmi: Mark VMI deprecated and schedule it for removal

The linker scripts grew some use of weirdly wrong linker script syntax.
It happens to work, but it's not what the syntax is documented to be.
Clean it up to use the official syntax.
Signed-off-by: Roland McGrath <roland@redhat.com>
CC: Ian Lance Taylor <iant@google.com>

The Unit_Characteristics entry of an SBP-2 unit directory is not
mandatory as far as I can tell.  If it is missing, we would probably
fail to log in into the target because firewire-sbp2 would not wait for
status after it sent the login request.

The fix moves the cleanup of tgt->mgt_orb_timeout into a place where it
is executed exactly once before login, rather than 0..n times depending
on the target's config ROM.  With targets with one or more
Unit_Characteristics entries, the result is the same as before.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

This way all flush_to_ldisc work is always done through the workqueues,
and we thus have a single point of serialization.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

It basically turns a delayed work into an immediate work, and then waits
for it to finish.

Fix this build error:

	next-20091013 randconfig build on s390x build breaks with

drivers/s390/built-in.o:(.data+0x3354): undefined reference to `sclp_vt220_pm_event_fn'
Reported-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <michael.holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Use cio_is_console() in io_subchannel_probe to indicate that the
special handling is console specific. As long as there is no other
subchannel for which this might be true, it is misleading to speak
of "early devices". Should more of these devices be introduced,
a cleanup of all console special handling is in order anyway.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

8d65af78 "sysctl: remove "struct file *" argument of ->proc_handler"
removed the struct file argument from all proc_handlers but didn't
change the call home proc handler (or call home was merged later).

So fix this now.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Hans-Joachim Picht <hans@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

If the rdc_buffer is above 2G we need indirect addresssing so we have
to use an idaw to give the rdc_buffer to the ccw.
If the rdc_buffer is under 2G nothing changes.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

This patch makes the hwcap bit for the high gprs feature to be visible
in /proc/cpuinfo.
Signed-off-by: Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Replace spin_lock with spin_lock_irqsave in dasd_eckd_restore_device.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

When setting a channel attached tape online under Linux 2.6.31, the

"vol_id" process from udev hangs in sync_page():
 2 sync_page+144 [0x1dfaac]
 3 __wait_on_bit_lock+194 [0x58c23e]
 4 __lock_page+116 [0x1df9dc]
 5 truncate_inode_pages_range+728 [0x1ed7cc]
 6 __blkdev_put+244 [0x25f738]
 7 __fput+300 [0x229c4c]
 8 filp_close+122 [0x225a3a]

The reason for that is an error in the request queue handling. It can
happen that we fetch a request, but do not process it further because
the number of queued requests exceeds TAPEBLOCK_MIN_REQUEUE.
To fix this, we should call blk_peek_request() instead of
blk_fetch_request() in the while condition and fetch the request in
the loop body afterwards.

This bug was introduced with the patch "block: implement and enforce
request peek/start/fetch" (9934c8c0)
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Hypfs never worked on systems that only provide D204 subcode 6.
In these cases we nevertheless used subcode 7. With this fix, we
use subcode 6, if it is available and the system does not provide
subcode 7.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

After sucessfully registering the misc device the driver iounmaps the
hardware registers and kfree's the device data structure. Ouch !

This was introduced with commit e42311d7 (riowatchdog: Convert to
pure OF driver) and went unnoticed for more than a year :)

Return success instead of dropping into the error cleanup code path.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The resume_userspace path had TRACE_IRQS_OFF written incorrectly and so
never handled the transition properly. This was fixed once before but
seems to have made it back in the tree. Fix it for good.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This only needs to flush the return code via the legacy path, and just
invalidates uselessly otherwise. This makes the behaviour consistent for
all of the trampoline setup paths.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

The secondary CPU info was seeing corrupted results due to not entering
all of the setup paths taken by the boot CPU. So we just memcpy() the
boot cpu data over directly, and then fix up the per-CPU bits.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Trivial change for cleaning up the cpuinfo pretty printing on SMP, adds a
newline between CPUs.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

We do not want to use smp_processor_id() from these paths, as they trip
preempt BUGs. Switch the test over to the boot cpu directly.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cciss: Add cciss_allow_hpsa module parameter
  cciss: Fix multiple calls to pci_release_regions
  blk-settings: fix function parameter kernel-doc notation
  writeback: kill space in debugfs item name
  writeback: account IO throttling wait as iowait
  elv_iosched_store(): fix strstrip() misuse
  cfq-iosched: avoid probable slice overrun when idling
  cfq-iosched: apply bool value where we return 0/1
  cfq-iosched: fix think time allowed for seekers
  cfq-iosched: fix the slice residual sign
  cfq-iosched: abstract out the 'may this cfqq dispatch' logic
  block: use proper BLK_RW_ASYNC in blk_queue_start_tag()
  block: Seperate read and write statistics of in_flight requests v2
  block: get rid of kblock_schedule_delayed_work()
  cfq-iosched: fix possible problem with jiffies wraparound
  cfq-iosched: fix issue with rq-rq merging and fifo list ordering

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: fix compile warnings

* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes:
  kbuild: revert "save ARCH & CROSS_COMPILE ..."
  warn about use of uninstalled kernel headers
  kbuild: mkcompile_h: trivial cleanups
  kbuild: fix warning when domainname is not available
  kbuild: Fix size_append issue for bzip2/lzma kernel
  kbuild,scripts: use non-builtin echo for '-e'
  kbuild: fix the binrpm-pkg target to work with KBUILD_OUTPUT set