linux-stable.git/arch/powerpc/platforms, branch linux-3.7.y

powerpc: Add missing NULL terminator to avoid boot panic on PPC40x

2013-01-17T16:45:45+00:00

commit e6449c9b2d90c1bd9a5985bf05ddebfd1631cd6b upstream.

The missing NULL terminator can cause a panic on
PPC405 boards during boot:

  Linux/PowerPC load: console=ttyS0,115200 root=/dev/mtdblock1 rootfstype=squashfs,jffs2 noinitrd init=/etc/preinit
  Finalizing device tree... flat tree at 0x6a5160
  bootconsole [udbg0] enabled
  Page fault in user mode with in_atomic() = 1 mm = (null)
  NIP = c0275f50  MSR = fffffffe
  Oops: Weird page fault, sig: 11 [#1]
  PowerPC 40x Platform
  Modules linked in:
  NIP: c0275f50 LR: c0275f60 CTR: c0280000
  REGS: c0275eb0 TRAP: 636f7265   Not tainted  (3.7.1)
  MSR: fffffffe  CR: c06a6190  XER: 00000001
  TASK = c02662a8[0] 'swapper' THREAD: c0274000
  GPR00: c0275ec0 c000c658 c027c4bf 00000000 c0275ee0 c000a0ec c020a1a8 c020a1f0
  GPR08: c020f631 c020f404 c025f078 c025f080 c0275f10
   Call Trace:
   ---[ end trace 31fd0ba7d8756001 ]---

  Kernel panic - not syncing: Attempted to kill the idle task!

The panic happens since commit 9597abe00c1bab2aedce6b49866bf6d1e81c9eed
(sections: fix section conflicts in arch/powerpc), however the root
cause of this is that the NULL terminator were not added in commit
a4f740cf33f7f6c164bbde3c0cdbcc77b0c4997c (of/flattree: Add of_flat_dt_match()
helper function).

Signed-off-by: Gabor Juhos 
Cc: Grant Likely 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/eeh: Do not invalidate PE properly

2012-11-25T22:14:16+00:00

While the EEH does recovery on the specific PE that has PCI errors,
the PCI devices belonging to the PE will be removed and the PE will
be marked as invalid since we still need the information stored in
the PE. We only invalidate the PE when it doesn't have associated
EEH devices and valid child PEs. However, the code used to check
that is wrong. The patch fixes that.

Signed-off-by: Gavin Shan 
Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Fix oops with MSIs when missing EEH PEs

2012-11-23T02:26:05+00:00

The new EEH code introduced a small regression, if the EEH PEs
are missin (which happens currently in qemu for example), it
will deref a NULL pointer in the MSI code.

Signed-off-by: Alexey Kardashevskiy 
Signed-off-by: Benjamin Herrenschmidt

powerpc: 52xx: nop out unsupported critical IRQs

2012-10-25T20:05:32+00:00

Currently, when booting MPC52xx based platforms, we get:

        mpc52xx_irqhost_map: invalid irq: virq=16, l1=0, l2=3
        irq: irq-16==>hwirq-0x3 mapping failed: -22
        [WARNing skipped]

The warning is wrong since the mapping itself is valid. However, there is no
support for that type of IRQ currently. Print a proper warning and bind the irq
to a no_irq chip.

Signed-off-by: Wolfram Sang 
Cc: John Bonesio 
Cc: Anatolij Gustschin 
Cc: Grant Likely 
Signed-off-by: Anatolij Gustschin

cpuidle/powerpc: Fix snooze state problem in the cpuidle design on pseries.

2012-10-17T23:57:25+00:00

Earlier without cpuidle framework on pseries, the native arch
idle routine comprised of both snooze and nap
states.  smt_snooze_delay variable was used to delay
the idle process entry to deeper idle state like  nap.
With the coming of cpuidle, this arch specific idle was replaced
by two different idle routines, one for supporting snooze and other
for nap. This enabled addition of more
low level idle states on pseries in the future.

On adopting the generic cpuidle framework for POWER systems,
the decision of which idle state to choose from,  given a predicted
idle time is taken by the menu governor based on
target_residency and  exit_latency of the idle states.
target_residency is the minimum time to be resident in that idle state.
Exit_latency is time taken to exit out of idle state.
Deeper the idle state, both the target residency and exit latency
would be higher.

In the current design, smt_snooze_delay is used as target_residency
for the  snooze state which is incorrect, as it is not the
minimum but the maximum duration to be in snooze state.
This would  result in the governor in taking bad decision,
as presently target_residency of nap < target_residency of snooze
inspite of nap being deeper idle state.

This patch aims to fix this problem by replacing the smt_snooze_delay loop
in snooze state, with the need_resched()  as the governor is aware of
entry and exit of various idle transitions based on which
next idle time prediction.

The governor is intelligent enough to determine the idle state the needs to
be transitioned to and maintains a whole of heuristics including
io load, previous idle states predictions etc for the same, based on
which idle state entry decision is taken.

With this fix, of setting target_residency of snooze to 0
					     nap to smt_snooze_delay
if the predicted idle time is less
than smt_snooze_delay (target_residency of nap)
value governor would pick snooze state, else nap. This adhers to the
previous native idle design.

Signed-off-by: Deepthi Dharwar 
Signed-off-by: Benjamin Herrenschmidt

cpuidle/powerpc: Fix smt_snooze_delay functionality.

2012-10-17T23:57:24+00:00

smt_snooze_delay was designed to  delay idle loop's nap entry
in the native idle code before it got  ported over to use as part of
the cpuidle framework.

A -ve value  assigned to smt_snooze_delay should result in
busy looping, in other words disabling the entry to nap state.

	- https://lists.ozlabs.org/pipermail/linuxppc-dev/2010-May/082450.html

This particular functionality can be achieved currently by
echo 1 > /sys/devices/system/cpu/cpu*/state1/disable
but it is broken when one assigns -ve value to  the smt_snooze_delay
variable either via sysfs entry or ppc64_cpu util.

This patch aims to fix this, by disabling nap state when smt_snooze_delay
variable is set to -ve value.

Signed-off-by: Deepthi Dharwar 
Signed-off-by: Benjamin Herrenschmidt

cpuidle/powerpc: Fix target residency initialisation in pseries cpuidle

2012-10-17T23:57:24+00:00

Remove the redundant target residency initialisation in pseries_cpuidle_driver_init().
This is currently over-writing the residency time updated as part of the static
table, resulting in  all the idle states having the same target
residency of 100us which is incorrect. This may result in the menu governor making
wrong state decisions.

Signed-off-by: Deepthi Dharwar 
Signed-off-by: Benjamin Herrenschmidt

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

2012-10-13T01:05:52+00:00

Pull third pile of kernel_execve() patches from Al Viro:
 "The last bits of infrastructure for kernel_thread() et.al., with
  alpha/arm/x86 use of those.  Plus sanitizing the asm glue and
  do_notify_resume() on alpha, fixing the "disabled irq while running
  task_work stuff" breakage there.

  At that point the rest of kernel_thread/kernel_execve/sys_execve work
  can be done independently for different architectures.  The only
  pending bits that do depend on having all architectures converted are
  restrictred to fs/* and kernel/* - that'll obviously have to wait for
  the next cycle.

  I thought we'd have to wait for all of them done before we start
  eliminating the longjump-style insanity in kernel_execve(), but it
  turned out there's a very simple way to do that without flagday-style
  changes."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  alpha: switch to saner kernel_execve() semantics
  arm: switch to saner kernel_execve() semantics
  x86, um: convert to saner kernel_execve() semantics
  infrastructure for saner ret_from_kernel_thread semantics
  make sure that kernel_thread() callbacks call do_exit() themselves
  make sure that we always have a return path from kernel_execve()
  ppc: eeh_event should just use kthread_run()
  don't bother with kernel_thread/kernel_execve for launching linuxrc
  alpha: get rid of switch_stack argument of do_work_pending()
  alpha: don't bother passing switch_stack separately from regs
  alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c
  alpha: simplify TIF_NEED_RESCHED handling

ppc: eeh_event should just use kthread_run()

2012-10-12T01:40:31+00:00

Signed-off-by: Al Viro

arch/powerpc/platforms/pseries/hotplug-memory.c: section removal cleanups

2012-10-10T23:50:14+00:00

Followups to d760afd4d257 ("memory-hotplug: suppress "Trying to free
nonexistent resource " warning").

 - use unsigned long type, as overflows are conceivable

 - rename `i' to the less-misleading and more informative `section'

Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds