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  1. 21 6月, 2016 2 次提交
  3. 09 2月, 2016 1 次提交
  5. 13 1月, 2016 1 次提交
  7. 27 12月, 2015 1 次提交
    • R
      powerpc/powernv: Add a kmsg_dumper that flushes console output on panic · affddff6
      由 Russell Currey 提交于 
      On BMC machines, console output is controlled by the OPAL firmware and is
only flushed when its pollers are called.  When the kernel is in a panic
state, it no longer calls these pollers and thus console output does not
completely flush, causing some output from the panic to be lost.

Output is only actually lost when the kernel is configured to not power off
or reboot after panic (i.e. CONFIG_PANIC_TIMEOUT is set to 0) since OPAL
flushes the console buffer as part of its power down routines.  Before this
patch, however, only partial output would be printed during the timeout wait.

This patch adds a new kmsg_dumper which gets called at panic time to ensure
panic output is not lost.  It accomplishes this by calling OPAL_CONSOLE_FLUSH
in the OPAL API, and if that is not available, the pollers are called enough
times to (hopefully) completely flush the buffer.

The flushing mechanism will only affect output printed at and before the
kmsg_dump call in kernel/panic.c:panic().  As such, the "end Kernel panic"
message may still be truncated as follows:

>Call Trace:
>[c000000f1f603b00] [c0000000008e9458] dump_stack+0x90/0xbc (unreliable)
>[c000000f1f603b30] [c0000000008e7e78] panic+0xf8/0x2c4
>[c000000f1f603bc0] [c000000000be4860] mount_block_root+0x288/0x33c
>[c000000f1f603c80] [c000000000be4d14] prepare_namespace+0x1f4/0x254
>[c000000f1f603d00] [c000000000be43e8] kernel_init_freeable+0x318/0x350
>[c000000f1f603dc0] [c00000000000bd74] kernel_init+0x24/0x130
>[c000000f1f603e30] [c0000000000095b0] ret_from_kernel_thread+0x5c/0xac
>---[ end Kernel panic - not

This functionality is implemented as a kmsg_dumper as it seems to be the
most sensible way to introduce platform-specific functionality to the
panic function.
Signed-off-by: NRussell Currey <ruscur@russell.cc>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      affddff6
  9. 20 8月, 2015 1 次提交
  11. 06 8月, 2015 1 次提交
  13. 16 7月, 2015 1 次提交
  15. 05 6月, 2015 1 次提交
  17. 22 5月, 2015 3 次提交
    • A
      powerpc/powernv: Add a virtual irqchip for opal events · 9f0fd049
      由 Alistair Popple 提交于 
      Whenever an interrupt is received for opal the linux kernel gets a
bitfield indicating certain events that have occurred and need handling
by the various device drivers. Currently this is handled using a
notifier interface where we call every device driver that has
registered to receive opal events.

This approach has several drawbacks. For example each driver has to do
its own checking to see if the event is relevant as well as event
masking. There is also no easy method of recording the number of times
we receive particular events.

This patch solves these issues by exposing opal events via the
standard interrupt APIs by adding a new interrupt chip and
domain. Drivers can then register for the appropriate events using
standard kernel calls such as irq_of_parse_and_map().
Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      9f0fd049
    • A
      powerpc/powernv: Reorder OPAL subsystem initialisation · 96e023e7
      由 Alistair Popple 提交于 
      Most of the OPAL subsystems are always compiled in for PowerNV and
many of them need to be initialised before or after other OPAL
subsystems. Rather than trying to control this ordering through
machine initcalls it is clearer and easier to control initialisation
order with explicit calls in opal_init.
Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Cc: Mahesh Jagannath Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      96e023e7
    • S
      powerpc/powernv: Introduce sysfs control for fastsleep workaround behavior · 5703d2f4
      由 Shreyas B. Prabhu 提交于 
      Fastsleep is one of the idle state which cpuidle subsystem currently
uses on power8 machines. In this state L2 cache is brought down to a
threshold voltage. Therefore when the core is in fastsleep, the
communication between L2 and L3 needs to be fenced. But there is a bug
in the current power8 chips surrounding this fencing.

OPAL provides a workaround which precludes the possibility of hitting
this bug. But running with this workaround applied causes checkstop
if any correctable error in L2 cache directory is detected. Hence OPAL
also provides a way to undo the workaround.

In the existing implementation, workaround is applied by the last thread
of the core entering fastsleep and undone by the first thread waking up.
But this has a performance cost. These OPAL calls account for roughly
4000 cycles everytime the core has to enter or wakeup from fastsleep.

This patch introduces a sysfs attribute (fastsleep_workaround_applyonce)
to choose the behavior of this workaround.

By default, fastsleep_workaround_applyonce = 0. In this case, workaround
is applied/undone everytime the core enters/exits fastsleep.

fastsleep_workaround_applyonce = 1. In this case the workaround is
applied once on all the cores and never undone. This can be triggered by
echo 1 > /sys/devices/system/cpu/fastsleep_workaround_applyonce

For simplicity this attribute can be modified only once. Implying, once
fastsleep_workaround_applyonce is changed to 1, it cannot be reverted
to the default state.
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      5703d2f4
  19. 11 4月, 2015 1 次提交
  21. 31 3月, 2015 1 次提交
  23. 25 3月, 2015 1 次提交
  25. 16 3月, 2015 2 次提交
  27. 04 2月, 2015 1 次提交
  29. 22 1月, 2015 1 次提交
  31. 15 12月, 2014 3 次提交
    • S
      powernv/powerpc: Add winkle support for offline cpus · 77b54e9f
      由 Shreyas B. Prabhu 提交于 
      Winkle is a deep idle state supported in power8 chips. A core enters
winkle when all the threads of the core enter winkle. In this state
power supply to the entire chiplet i.e core, private L2 and private L3
is turned off. As a result it gives higher powersavings compared to
sleep.

But entering winkle results in a total hypervisor state loss. Hence the
hypervisor context has to be preserved before entering winkle and
restored upon wake up.

Power-on Reset Engine (PORE) is a dedicated engine which is responsible
for powering on the chiplet during wake up. It can be programmed to
restore the register contests of a few specific registers. This patch
uses PORE to restore register state wherever possible and uses stack to
save and restore rest of the necessary registers.

With hypervisor state restore things fall under three categories-
per-core state, per-subcore state and per-thread state. To manage this,
extend the infrastructure introduced for sleep. Mainly we add a paca
variable subcore_sibling_mask. Using this and the core_idle_state we can
distingush first thread in core and subcore.
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      77b54e9f
    • S
      powernv/cpuidle: Redesign idle states management · 7cba160a
      由 Shreyas B. Prabhu 提交于 
      Deep idle states like sleep and winkle are per core idle states. A core
enters these states only when all the threads enter either the
particular idle state or a deeper one. There are tasks like fastsleep
hardware bug workaround and hypervisor core state save which have to be
done only by the last thread of the core entering deep idle state and
similarly tasks like timebase resync, hypervisor core register restore
that have to be done only by the first thread waking up from these
state.

The current idle state management does not have a way to distinguish the
first/last thread of the core waking/entering idle states. Tasks like
timebase resync are done for all the threads. This is not only is
suboptimal, but can cause functionality issues when subcores and kvm is
involved.

This patch adds the necessary infrastructure to track idle states of
threads in a per-core structure. It uses this info to perform tasks like
fastsleep workaround and timebase resync only once per core.
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Originally-by: NPreeti U. Murthy <preeti@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      7cba160a
    • S
      powerpc/powernv: Enable Offline CPUs to enter deep idle states · 8eb8ac89
      由 Shreyas B. Prabhu 提交于 
      The secondary threads should enter deep idle states so as to gain maximum
powersavings when the entire core is offline. To do so the offline path
must be made aware of the available deepest idle state. Hence probe the
device tree for the possible idle states in powernv core code and
expose the deepest idle state through flags.

Since the  device tree is probed by the cpuidle driver as well, move
the parameters required to discover the idle states into an appropriate
common place to both the driver and the powernv core code.

Another point is that fastsleep idle state may require workarounds in
the kernel to function properly. This workaround is introduced in the
subsequent patches. However neither the cpuidle driver or the hotplug
path need be bothered about this workaround.

They will be taken care of by the core powernv code.
Originally-by: NSrivatsa S. Bhat <srivatsa@mit.edu>
Signed-off-by: NPreeti U. Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Reviewed-by: NPaul Mackerras <paulus@samba.org>

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      8eb8ac89
  33. 14 12月, 2014 1 次提交
  35. 02 12月, 2014 1 次提交
  37. 17 11月, 2014 1 次提交
    • N
      rtc/tpo: Driver to support rtc and wakeup on PowerNV platform · 16b1d26e
      由 Neelesh Gupta 提交于 
      The patch implements the OPAL rtc driver that binds with the rtc
driver subsystem. The driver uses the platform device infrastructure
to probe the rtc device and register it to rtc class framework. The
'wakeup' is supported depending upon the property 'has-tpo' present
in the OF node. It provides a way to load the generic rtc driver in
in the absence of an OPAL driver.

The patch also moves the existing OPAL rtc get/set time interfaces to the
new driver and exposes the necessary OPAL calls using EXPORT_SYMBOL_GPL.

Test results:
-------------
Host:
[root@tul169p1 ~]# ls -l /sys/class/rtc/
total 0
lrwxrwxrwx 1 root root 0 Oct 14 03:07 rtc0 -> ../../devices/opal-rtc/rtc/rtc0
[root@tul169p1 ~]# cat /sys/devices/opal-rtc/rtc/rtc0/time
08:10:07
[root@tul169p1 ~]# echo `date '+%s' -d '+ 2 minutes'` > /sys/class/rtc/rtc0/wakealarm
[root@tul169p1 ~]# cat /sys/class/rtc/rtc0/wakealarm
1413274345
[root@tul169p1 ~]#

FSP:
$ smgr mfgState
standby
$ rtim timeofday

System time is valid: 2014/10/14 08:12:04.225115

$ smgr mfgState
ipling
$

CC: devicetree@vger.kernel.org
CC: tglx@linutronix.de
CC: rtc-linux@googlegroups.com
CC: a.zummo@towertech.it
Signed-off-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      16b1d26e
  39. 12 11月, 2014 1 次提交
  41. 08 10月, 2014 1 次提交
  43. 30 9月, 2014 2 次提交
  45. 25 9月, 2014 1 次提交
  47. 13 8月, 2014 1 次提交
  49. 05 8月, 2014 5 次提交
  51. 25 6月, 2014 1 次提交
    • M
      powerpc/powernv: Remove OPAL v1 takeover · e2500be2
      由 Michael Ellerman 提交于 
      In commit 27f44888 "Add OPAL takeover from PowerVM" we added support
for "takeover" on OPAL v1 machines.

This was a mode of operation where we would boot under pHyp, and query
for the presence of OPAL. If detected we would then do a special
sequence to take over the machine, and the kernel would end up running
in hypervisor mode.

OPAL v1 was never a supported product, and was never shipped outside
IBM. As far as we know no one is still using it.

Newer versions of OPAL do not use the takeover mechanism. Although the
query for OPAL should be harmless on machines with newer OPAL, we have
seen a machine where it causes a crash in Open Firmware.

The code in early_init_devtree() to copy boot_command_line into cmd_line
was added in commit 817c21ad "Get kernel command line accross OPAL
takeover", and AFAIK is only used by takeover, so should also be
removed.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      e2500be2
  53. 11 6月, 2014 1 次提交
  55. 05 6月, 2014 2 次提交