linux.git/arch/powerpc/kernel, branch v3.16-rc2

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2014-06-13T03:11:38+00:00

Pull more powerpc updates from Ben Herrenschmidt:
 "Here are the remaining bits I was mentioning earlier.  Mostly bug
  fixes and new selftests from Michael (yay !).  He also removed the WSP
  platform and A2 core support which were dead before release, so less
  clutter.

  One little "feature" I snuck in is the doorbell IPI support for
  non-virtualized P8 which speeds up IPIs significantly between threads
  of a core"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (34 commits)
  powerpc/book3s: Fix some ABIv2 issues in machine check code
  powerpc/book3s: Fix guest MC delivery mechanism to avoid soft lockups in guest.
  powerpc/book3s: Increment the mce counter during machine_check_early call.
  powerpc/book3s: Add stack overflow check in machine check handler.
  powerpc/book3s: Fix machine check handling for unhandled errors
  powerpc/eeh: Dump PE location code
  powerpc/powernv: Enable POWER8 doorbell IPIs
  powerpc/cpuidle: Only clear LPCR decrementer wakeup bit on fast sleep entry
  powerpc/powernv: Fix killed EEH event
  powerpc: fix typo 'CONFIG_PMAC'
  powerpc: fix typo 'CONFIG_PPC_CPU'
  powerpc/powernv: Don't escalate non-existing frozen PE
  powerpc/eeh: Report frozen parent PE prior to child PE
  powerpc/eeh: Clear frozen state for child PE
  powerpc/powernv: Reduce panic timeout from 180s to 10s
  powerpc/xmon: avoid format string leaking to printk
  selftests/powerpc: Add tests of PMU EBBs
  selftests/powerpc: Add support for skipping tests
  selftests/powerpc: Put the test in a separate process group
  selftests/powerpc: Fix instruction loop for ABIv2 (LE)
  ...

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

2014-06-13T02:42:15+00:00

Pull more scheduler updates from Ingo Molnar:
 "Second round of scheduler changes:
   - try-to-wakeup and IPI reduction speedups, from Andy Lutomirski
   - continued power scheduling cleanups and refactorings, from Nicolas
     Pitre
   - misc fixes and enhancements"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Delete extraneous extern for to_ratio()
  sched/idle: Optimize try-to-wake-up IPI
  sched/idle: Simplify wake_up_idle_cpu()
  sched/idle: Clear polling before descheduling the idle thread
  sched, trace: Add a tracepoint for IPI-less remote wakeups
  cpuidle: Set polling in poll_idle
  sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...)
  sched: Rename capacity related flags
  sched: Final power vs. capacity cleanups
  sched: Remove remaining dubious usage of "power"
  sched: Let 'struct sched_group_power' care about CPU capacity
  sched/fair: Disambiguate existing/remaining "capacity" usage
  sched/fair: Change "has_capacity" to "has_free_capacity"
  sched/fair: Remove "power" from 'struct numa_stats'
  sched: Fix signedness bug in yield_to()
  sched/fair: Use time_after() in record_wakee()
  sched/balancing: Reduce the rate of needless idle load balancing
  sched/fair: Fix unlocked reads of some cfs_b->quota/period

Merge commit '3cf2f34' into sched/core, to fix build error

2014-06-12T11:46:37+00:00

Fix this dependency on the locking tree's smp_mb*() API changes:

  kernel/sched/idle.c:247:3: error: implicit declaration of function ‘smp_mb__after_atomic’ [-Werror=implicit-function-declaration]

Signed-off-by: Ingo Molnar

powerpc/book3s: Fix some ABIv2 issues in machine check code

2014-06-11T23:41:33+00:00

Commit 2749a2f26a7c (powerpc/book3s: Fix machine check handling for
unhandled errors) introduced a few ABIv2 issues.

We can maintain ABIv1 and ABIv2 compatibility by branching to the
function rather than the dot symbol.

Fixes: 2749a2f26a7c ("powerpc/book3s: Fix machine check handling for unhandled errors")
Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

powerpc/book3s: Increment the mce counter during machine_check_early call.

2014-06-11T09:15:14+00:00

We don't see MCE counter getting increased in /proc/interrupts which gives
false impression of no MCE occurred even when there were MCE events.
The machine check early handling was added for PowerKVM and we missed to
increment the MCE count in the early handler.

We also increment mce counters in the machine_check_exception call, but
in most cases where we handle the error hypervisor never reaches there
unless its fatal and we want to crash. Only during fatal situation we may
see double increment of mce count. We need to fix that. But for
now it always good to have some count increased instead of zero.

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt

powerpc/book3s: Add stack overflow check in machine check handler.

2014-06-11T09:15:13+00:00

Currently machine check handler does not check for stack overflow for
nested machine check. If we hit another MCE while inside the machine check
handler repeatedly from same address then we get into risk of stack
overflow which can cause huge memory corruption. This patch limits the
nested MCE level to 4 and panic when we cross level 4.

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt

powerpc/book3s: Fix machine check handling for unhandled errors

2014-06-11T09:15:13+00:00

Current code does not check for unhandled/unrecovered errors and return from
interrupt if it is recoverable exception which in-turn triggers same machine
check exception in a loop causing hypervisor to be unresponsive.

This patch fixes this situation and forces hypervisor to panic for
unhandled/unrecovered errors.

This patch also fixes another issue where unrecoverable_exception routine
was called in real mode in case of unrecoverable exception (MSR_RI = 0).
This causes another exception vector 0x300 (data access) during system crash
leading to confusion while debugging cause of the system crash.

Also turn ME bit off while going down, so that when another MCE is hit during
panic path, system will checkstop and hypervisor will get restarted cleanly
by SP.

With the above fixes we now throw correct console messages (see below) while
crashing the system in case of unhandled/unrecoverable machine checks.

--------------
Severe Machine check interrupt [[Not recovered]
  Initiator: CPU
  Error type: UE [Instruction fetch]
    Effective address: 0000000030002864
Oops: Machine check, sig: 7 [#1]
SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in: bork(O) bridge stp llc kvm [last unloaded: bork]
CPU: 36 PID: 55162 Comm: bash Tainted: G           O 3.14.0mce #1
task: c000002d72d022d0 ti: c000000007ec0000 task.ti: c000002d72de4000
NIP: 0000000030002864 LR: 00000000300151a4 CTR: 000000003001518c
REGS: c000000007ec3d80 TRAP: 0200   Tainted: G           O  (3.14.0mce)
MSR: 9000000000041002   CR: 28222848  XER: 20000000
CFAR: 0000000030002838 DAR: d0000000004d0000 DSISR: 00000000 SOFTE: 1
GPR00: 000000003001512c 0000000031f92cb0 0000000030078af0 0000000030002864
GPR04: d0000000004d0000 0000000000000000 0000000030002864 ffffffffffffffc9
GPR08: 0000000000000024 0000000030008af0 000000000000002c c00000000150e728
GPR12: 9000000000041002 0000000031f90000 0000000010142550 0000000040000000
GPR16: 0000000010143cdc 0000000000000000 00000000101306fc 00000000101424dc
GPR20: 00000000101424e0 000000001013c6f0 0000000000000000 0000000000000000
GPR24: 0000000010143ce0 00000000100f6440 c000002d72de7e00 c000002d72860250
GPR28: c000002d72860240 c000002d72ac0038 0000000000000008 0000000000040000
NIP [0000000030002864] 0x30002864
LR [00000000300151a4] 0x300151a4
Call Trace:
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
---[ end trace 7285f0beac1e29d3 ]---

Sending IPI to other CPUs
IPI complete
OPAL V3 detected !
--------------

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt

powerpc/eeh: Dump PE location code

2014-06-11T09:12:23+00:00

As Ben suggested, it's meaningful to dump PE's location code
for site engineers when hitting EEH errors. The patch introduces
function eeh_pe_loc_get() to retireve the location code from
dev-tree so that we can output it when hitting EEH errors.

If primary PE bus is root bus, the PHB's dev-node would be tried
prior to root port's dev-node. Otherwise, the upstream bridge's
dev-node of the primary PE bus will be check for the location code
directly.

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

powerpc/powernv: Enable POWER8 doorbell IPIs

2014-06-11T07:05:12+00:00

This patch enables POWER8 doorbell IPIs on powernv.

Since doorbells can only IPI within a core, we test to see when we can use
doorbells and if not we fall back to XICS.  This also enables hypervisor
doorbells to wakeup us up from nap/sleep via the LPCR PECEDH bit.

Based on tests by Anton, the best case IPI latency between two threads dropped
from 894ns to 512ns.

Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt

powerpc/powernv: Fix killed EEH event

2014-06-11T07:04:33+00:00

On PowerNV platform, EEH errors are reported by IO accessors or poller
driven by interrupt. After the PE is isolated, we won't produce EEH
event for the PE. The current implementation has possibility of EEH
event lost in this way:

The interrupt handler queues one "special" event, which drives the poller.
EEH thread doesn't pick the special event yet. IO accessors kicks in, the
frozen PE is marked as "isolated" and EEH event is queued to the list.
EEH thread runs because of special event and purge all existing EEH events.
However, we never produce an other EEH event for the frozen PE. Eventually,
the PE is marked as "isolated" and we don't have EEH event to recover it.

The patch fixes the issue to keep EEH events for PEs that have been
marked as "isolated" with the help of additional "force" help to
eeh_remove_event().

Reported-by: Rolf Brudeseth 
Signed-off-by: Gavin Shan 
Signed-off-by: Benjamin Herrenschmidt