Commit graph

17905 commits

Author SHA1 Message Date
John(Jung-Ik) Lee
d15d6e6cc3 libata: Add pata_atp867x driver for Artop/Acard ATP867X controllers
This is a new pata driver for ARTOP 867X 64bit 4-channel UDMA133 ATA ctrls.
Based on the Atp867 data sheet rev 1.2, Acard, and in part on early ide codes
from Eric Uhrhane <ericu@google.com>.

Signed-off-by: John(Jung-Ik) Lee <jilee@google.com>
Reviewed-by:  Grant Grundler <grundler@google.com>
Reviewed-by:  Gwendal Gringo <gwendal@google.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-09-17 16:47:06 -04:00
Peter Zijlstra
2667de81f3 perf_counter: Allow for a wakeup watermark
Currently we wake the mmap() consumer once every PAGE_SIZE of data
and/or once event wakeup_events when specified.

For high speed sampling this results in too many wakeups wrt. the
buffer size, hence change this.

We move the default wakeup limit to 1/4-th the buffer size, and
provide for means to manually specify this limit.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-17 22:08:26 +02:00
Ingo Molnar
45bd00d31d Merge branch 'linus' into tracing/core
Merge reason: Pick up kernel/softirq.c update for dependent fix.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-17 20:53:10 +02:00
Jesse Barnes
e2d4304b7d PCI: fix VGA arbiter header file
Remove reference to vgaarb.c and replace it with a comment about the
arbiter itself.

Reported-by: Tiago Vignatti <tiago.vignatti@nokia.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-09-17 10:05:28 -07:00
Linus Torvalds
3aee0605a4 Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/dvrabel/uwb
* 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/dvrabel/uwb:
  uwb: avoid radio controller reset loops
  uwb: stop uwbd thread if rc->start() fails
  uwb: handle radio controller events with out-of-range IDs correctly
2009-09-17 09:44:09 -07:00
Stephen Rothwell
c0826574dd nfsd: return success for non-NFS4 nfs4_state_start
Today's linux-next build (sparc64_defconfig) failed like this:

In file included from arch/sparc/kernel/sys_sparc32.c:32:
include/linux/nfsd/nfsd.h: In function 'nfs4_state_start':
include/linux/nfsd/nfsd.h:177: error: no return statement in function returning non-void

Caused by commit 29ab23cc5d ("nfsd4: allow
nfs4 state startup to fail").  Please, if you add code that depends on a
CONFIG option, build with that option enabled and disabled.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-09-17 11:30:32 -04:00
Mark Brown
37bce07077 mfd: Convert WM8350 to use request_threaded_irq()
Instead of hand rolling our own variant.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 15:48:18 +02:00
Jiri Kosina
c4c259bcc2 HID: consolidate connect and disconnect into core code
HID core registers input, hidraw and hiddev devices, but leaves
unregistering it up to the individual driver, which is not really nice.
Let's move all the logic to the core.

Reported-by: Marcel Holtmann <marcel@holtmann.org>
Reported-by: Brian Rogers <brian@xyzw.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-09-17 15:15:11 +02:00
Peter Zijlstra
ad4b78bbcb sched: Add new wakeup preemption mode: WAKEUP_RUNNING
Create a new wakeup preemption mode, preempt towards tasks that run
shorter on avg. It sets next buddy to be sure we actually run the task
we preempted for.

Test results:

 root@twins:~# while :; do :; done &
 [1] 6537
 root@twins:~# while :; do :; done &
 [2] 6538
 root@twins:~# while :; do :; done &
 [3] 6539
 root@twins:~# while :; do :; done &
 [4] 6540

 root@twins:/home/peter# ./latt -c4 sleep 4
 Entries: 48 (clients=4)

 Averages:
 ------------------------------
        Max          4750 usec
        Avg           497 usec
        Stdev         737 usec

 root@twins:/home/peter# echo WAKEUP_RUNNING > /debug/sched_features

 root@twins:/home/peter# ./latt -c4 sleep 4
 Entries: 48 (clients=4)

 Averages:
 ------------------------------
        Max            14 usec
        Avg             5 usec
        Stdev           3 usec

Disabled by default - needs more testing.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <new-submission>
2009-09-17 10:17:25 +02:00
Linus Walleij
d619bc143e regulator: AB3100 support
This adds support for the regulators found in the AB3100
Mixed-Signal IC.

It further also defines platform data for the ST-Ericsson
U300 platform and extends the AB3100 MFD driver so that
platform/board data with regulation constraints and an init
function can be passed down all the way from the board to
the regulators.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:25 +02:00
Samuel Ortiz
8aba721b23 mfd: Fix ab3100-otp build failure
ab3100.h should include linux/workqueue.h for otp to build properly.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:23 +02:00
Amit Kucheria
ebf0bd366e mfd: Add support for TWL4030/5030 dynamic power switching
The TWL4030/5030 family of multifunction devices allows board-specific
control of the the various regulators, clock and reset lines through
'scripts' that are loaded into its memory. This allows for Dynamic Power
Switching (DPS).

Implement board-independent core support for DPS that is then used by
board-specific code to load custom DPS scripts.

Signed-off-by: Amit Kucheria <amit.kucheria@verdurent.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:22 +02:00
Sascha Hauer
8238addcc5 mfd: Add Freescale MC13783 driver
This driver provides the core Freescale MC13783 support. It
registers the client platform_devices and provides access
to the A/D converter.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:19 +02:00
Linus Walleij
956f25a677 mfd: AB3100 accessor function cleanups
This adds the _interruptible suffix to the AB3100 accessor
functions on par with mutex_lock_interruptible() that's used
for blocking simultaneous calls to the AB3100 acessor functions.
Since these accesses are slow on a 100kHz I2C bus and may line
up waiting for the mutex, we need to handle interruption by
system shutdown or kill signals and may just as well denote that
in the function names.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:15 +02:00
Mark Brown
d1c6b4fe66 regulator: Add WM831x LDO support
The WM831x series of devices provide three types of LDO:

 - General purpose LDOs supporting voltages from 0.9-3.3V
 - High performance analogue LDOs supporting voltages from 1-3.5V
 - Very low power consumption LDOs intended to support always on
   functionality.

This patch adds support for all three kinds of LDO. Each regulator
is probed as an individual platform device with resources used to
provide the register map location of the regulator. Mixed hardware
and software control of regulators is not current supported.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:09 +02:00
Mark Brown
e4ee831f94 regulator: Add WM831x DC-DC buck convertor support
The WM831x series of devices all have 3 DC-DC buck convertors. This
driver implements software control for these regulators via the
regulator API.  Use with split hardware/software control of individual
regulators is not supported, though regulators not controlled by
software may be controlled via the hardware control interfaces.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:06 +02:00
Mark Brown
be721979dd regulator: Provide mode to status conversion function
This is useful for implementing get_status() in terms of get_mode().

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:05 +02:00
Mark Brown
0c73b992dd input: Add support for the WM831x ON pin
The WM831x series of PMICs support control of initial power on
through the ON pin on the device with soft control of the pin
at other times. Represent this to userspace as KEY_POWER.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:02 +02:00
Mark Brown
e4b736f18f gpio: Add WM831X GPIO driver
Add support for the GPIO pins on the WM831x. No direct support is
currently supplied for configuring non-gpiolib functionality such
as pull configuration and alternate functions, soft configuration
of these will be provided in a future patch.

Currently use of these pins as interrupts is not supported due to
the ongoing issues with generic irq not support interrupt controllers
on interrupt driven buses. Users can directly request the interrupts
with the wm831x-specific APIs currently provided if required.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:01 +02:00
Mark Brown
698659d5f7 mfd: Export ISEL values from WM831x core
The current settings which can be used with the WM831x current sinks
can't easily be mapped between register values and currents at run
time without a lookup table since the values scale logarithmically
to match the way the human eye interprets brightness. This lookup
table is inclided in the core since several drivers need to use it.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:47:00 +02:00
Mark Brown
6704e5171b mfd: Add basic WM831x OTP support
The WM831x series of devices use OTP (One Time Programmable, a type
of PROM) to store system configuration. At run time this data is
visible via registers.

Currently the only explicitly supported feature is that the unique
ID provided by every WM831x device is exported to user space via
sysfs. Other configuration data may be read by system-specific
code in the pre_init() and post_init() platform data operations.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:59 +02:00
Mark Brown
63aed85e35 mfd: Conditionally add WM831x backlight subdevice
The WM831x backlight driver requires at least the specification of the
current sink to use and a maximum current to allow them to function and
will actively interfere with other users of the regulators it uses if
misconfigured so only register the subdevice for it if this platform
data has been supplied.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:58 +02:00
Mark Brown
7e9f9fd4b8 mfd: Add WM831x AUXADC support
The WM831x contains an auxiliary ADC with a number of switchable
inputs which is used to monitor some of the voltages and
temperatures in the system and has some external inputs which can be
used for machine specific purposes. Provide an API allowing drivers
to read values from the ADC.

An internal reference voltage is provided to allow callibration of
the ADC. This is used to calibrate the device at startup.

The hardware also supports continuous readings and digital comparators.
These are not yet supported by the driver.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:58 +02:00
Mark Brown
7d4d0a3e73 mfd: Add WM831x interrupt support
The WM831x includes an interrupt controller managing interrupts for
the various functions on the chip. This patch adds support for the
core interrupt block on the device.

Ideally this would be supported by genirq, particularly for the
GPIOs, but currently genirq is unable to cope with controllers on
interrupt driven buses so we cut'n'paste the generic interface.
Once genirq is able to cope chips like this it should be a case
of filing the prefixes off the code and redoing wm831x-irq.c to
move over.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:57 +02:00
Mark Brown
d2bedfe7a8 mfd: Initial core support for WM831x series devices
The WM831x series of devices are register compatible processor power
management subsystems, providing regulator and power path management
facilities along with other services like watchdog, RTC and touch
panel controllers.

This patch adds very basic support, providing basic single register
I2C access, handling of the security key and registration of the
devices.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:57 +02:00
Mark Brown
3bed6e415f mfd: Allow multiple MFD cells with the same name
Provide basic support for MFDs having multiple cells of a given
type with different IDs by adding an id to the mfd_cell structure
and then adding that to the id passed in to mfd_add_devices().

As it stands this approach requires that MFDs using this feature
deal with ensuring that there aren't any ID collisions resulting
from multiple MFDs of the same type being instantiated. This needs
to happen with the existing code too, but with this approach there
is a knock on effect on the IDs for non-duplicated devices.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:56 +02:00
Daniel Ribeiro
327bc3a3ef mfd: Remove VIB defines from pcap header file
Vibrator will be accessed via the pcap-regulator driver, no need to expose its
bits in the header file.

Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:55 +02:00
Paul Fertser
8d360d8c03 mfd: fix wrong define for 10bit pcf50633 ADC mode
The 10 bits definition was the 8 bits one.

Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:54 +02:00
Paul Fertser
ed52e62ebe mfd: use a dedicated workqueue for pcf50633 irq processing
Using the default kernel "events" workqueue causes problems with
synchronous adc readings if initiated from some task on the same
workqueue.

I had a deadlock trying to use pcf50633_adc_sync_read from a
power_supply class driver because the reading was initiated from the
workqueue and it waited for the irq processing to complete (to get the
result) and that was put on the same workqueue.

Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:53 +02:00
Mark Brown
fb6c023a2b hwmon: Add WM835x PMIC hardware monitoring driver
This driver provides reporting of the status supply voltage rails
of the WM835x series of PMICs via the hwmon API.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:51 +02:00
Daniel Ribeiro
e9a22635b0 mfd: add ezx_pcap_setbits
Provides an atomic set_bits functions, as needed by the pcap-regulator
driver.

Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:47 +02:00
Daniel Ribeiro
ecd78cbdb9 mfd: add set_ts_bits for pcap
Some TS controller bits are on the same register as the ADC control, save
TS specific bits and export a set_ts_bits function so the TS driver can set
it with the adc_mutex lock held.

Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:46 +02:00
Daniel Ribeiro
9f7b07d6cc mfd: Introduce irq_to_pcap()
Export an irq_to_pcap function to get pcap irq number, for the keypad driver.

Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2009-09-17 09:46:45 +02:00
Jan Kara
9c28cbccec jbd: Journal block numbers can ever be only 32-bit use unsigned int for them
It does not make sense to store block number for journal as unsigned long
since they can be only 32-bit (because of on-disk format limitation). So
change in-memory structures and variables to use unsigned int instead.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-09-16 17:44:10 +02:00
Linus Torvalds
ab86e5765d Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev
  debugfs: Modify default debugfs directory for debugging pktcdvd.
  debugfs: Modified default dir of debugfs for debugging UHCI.
  debugfs: Change debugfs directory of IWMC3200
  debugfs: Change debuhgfs directory of trace-events-sample.h
  debugfs: Fix mount directory of debugfs by default in events.txt
  hpilo: add poll f_op
  hpilo: add interrupt handler
  hpilo: staging for interrupt handling
  driver core: platform_device_add_data(): use kmemdup()
  Driver core: Add support for compatibility classes
  uio: add generic driver for PCI 2.3 devices
  driver-core: move dma-coherent.c from kernel to driver/base
  mem_class: fix bug
  mem_class: use minor as index instead of searching the array
  driver model: constify attribute groups
  UIO: remove 'default n' from Kconfig
  Driver core: Add accessor for device platform data
  Driver core: move dev_get/set_drvdata to drivers/base/dd.c
  Driver core: add new device to bus's list before probing
2009-09-16 08:27:10 -07:00
Linus Torvalds
4406c56d0a Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (75 commits)
  PCI hotplug: clean up acpi_run_hpp()
  PCI hotplug: acpiphp: use generic pci_configure_slot()
  PCI hotplug: shpchp: use generic pci_configure_slot()
  PCI hotplug: pciehp: use generic pci_configure_slot()
  PCI hotplug: add pci_configure_slot()
  PCI hotplug: clean up acpi_get_hp_params_from_firmware() interface
  PCI hotplug: acpiphp: don't cache hotplug_params in acpiphp_bridge
  PCI hotplug: acpiphp: remove superfluous _HPP/_HPX evaluation
  PCI: Clear saved_state after the state has been restored
  PCI PM: Return error codes from pci_pm_resume()
  PCI: use dev_printk in quirk messages
  PCI / PCIe portdrv: Fix pcie_portdrv_slot_reset()
  PCI Hotplug: convert acpi_pci_detect_ejectable() to take an acpi_handle
  PCI Hotplug: acpiphp: find bridges the easy way
  PCI: pcie portdrv: remove unused variable
  PCI / ACPI PM: Propagate wake-up enable for devices w/o ACPI support
  ACPI PM: Replace wakeup.prepared with reference counter
  PCI PM: Introduce device flag wakeup_prepared
  PCI / ACPI PM: Rework some debug messages
  PCI PM: Simplify PCI wake-up code
  ...

Fixed up conflict in arch/powerpc/kernel/pci_64.c due to OF device tree
scanning having been moved and merged for the 32- and 64-bit cases.  The
'needs_freset' initialization added in 6e19314cc ("PCI/powerpc: support
PCIe fundamental reset") is now in arch/powerpc/kernel/pci_of_scan.c.
2009-09-16 07:49:54 -07:00
Peter Zijlstra
182a85f8a1 sched: Disable wakeup balancing
Sysbench thinks SD_BALANCE_WAKE is too agressive and kbuild doesn't
really mind too much, SD_BALANCE_NEWIDLE picks up most of the
slack.

On a dual socket, quad core, dual thread nehalem system:

sysbench (--num_threads=16):

 SD_BALANCE_WAKE-: 13982 tx/s
 SD_BALANCE_WAKE+: 15688 tx/s

kbuild (-j16):

 SD_BALANCE_WAKE-: 47.648295846  seconds time elapsed   ( +-   0.312% )
 SD_BALANCE_WAKE+: 47.608607360  seconds time elapsed   ( +-   0.026% )

(same within noise)

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-16 16:44:33 +02:00
Jens Axboe
b6e51316da writeback: separate starting of sync vs opportunistic writeback
bdi_start_writeback() is currently split into two paths, one for
WB_SYNC_NONE and one for WB_SYNC_ALL. Add bdi_sync_writeback()
for WB_SYNC_ALL writeback and let bdi_start_writeback() handle
only WB_SYNC_NONE.

Push down the writeback_control allocation and only accept the
parameters that make sense for each function. This cleans up
the API considerably.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-16 15:18:52 +02:00
Jens Axboe
cfc4ba5365 writeback: use RCU to protect bdi_list
Now that bdi_writeback_all() no longer handles integrity writeback,
it doesn't have to block anymore. This means that we can switch
bdi_list reader side protection to RCU.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-16 15:18:51 +02:00
Jens Axboe
32a88aa1b6 fs: Assign bdi in super_block
We do this automatically in get_sb_bdev() from the set_bdev_super()
callback. Filesystems that have their own private backing_dev_info
must assign that in ->fill_super().

Note that ->s_bdi assignment is required for proper writeback!

Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-16 15:18:51 +02:00
Jens Axboe
1fe06ad892 writeback: get rid of wbc->for_writepages
It's only set, it's never checked. Kill it.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-16 15:16:18 +02:00
Jens Axboe
2c96ce9f20 fs: remove bdev->bd_inode_backing_dev_info
It has been unused since it was introduced in:

commit 520808bf20e90fdbdb320264ba7dd5cf9d47dcac
Author: Andrew Morton <akpm@osdl.org>
Date:   Fri May 21 00:46:17 2004 -0700

    [PATCH] block device layer: separate backing_dev_info infrastructure

So lets just kill it.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-16 15:16:18 +02:00
Andi Kleen
6a46079cf5 HWPOISON: The high level memory error handler in the VM v7
Add the high level memory handler that poisons pages
that got corrupted by hardware (typically by a two bit flip in a DIMM
or a cache) on the Linux level. The goal is to prevent everyone
from accessing these pages in the future.

This done at the VM level by marking a page hwpoisoned
and doing the appropriate action based on the type of page
it is.

The code that does this is portable and lives in mm/memory-failure.c

To quote the overview comment:

High level machine check handler. Handles pages reported by the
hardware as being corrupted usually due to a 2bit ECC memory or cache
failure.

This focuses on pages detected as corrupted in the background.
When the current CPU tries to consume corruption the currently
running process can just be killed directly instead. This implies
that if the error cannot be handled for some reason it's safe to
just ignore it because no corruption has been consumed yet. Instead
when that happens another machine check will happen.

Handles page cache pages in various states. The tricky part
here is that we can access any page asynchronous to other VM
users, because memory failures could happen anytime and anywhere,
possibly violating some of their assumptions. This is why this code
has to be extremely careful. Generally it tries to use normal locking
rules, as in get the standard locks, even if that means the
error handling takes potentially a long time.

Some of the operations here are somewhat inefficient and have non
linear algorithmic complexity, because the data structures have not
been optimized for this case. This is in particular the case
for the mapping from a vma to a process. Since this case is expected
to be rare we hope we can get away with this.

There are in principle two strategies to kill processes on poison:
- just unmap the data and wait for an actual reference before
killing
- kill as soon as corruption is detected.
Both have advantages and disadvantages and should be used
in different situations. Right now both are implemented and can
be switched with a new sysctl vm.memory_failure_early_kill
The default is early kill.

The patch does some rmap data structure walking on its own to collect
processes to kill. This is unusual because normally all rmap data structure
knowledge is in rmap.c only. I put it here for now to keep
everything together and rmap knowledge has been seeping out anyways

Includes contributions from Johannes Weiner, Chris Mason, Fengguang Wu,
Nick Piggin (who did a lot of great work) and others.

Cc: npiggin@suse.de
Cc: riel@redhat.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
2009-09-16 11:50:15 +02:00
Andi Kleen
4db96cf077 HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
This allows processes to override their early/late kill
behaviour on hardware memory errors.

Typically applications which are memory error aware is
better of with early kill (see the error as soon
as possible), all others with late kill (only
see the error when the error is really impacting execution)

There's a global sysctl, but this way an application
can set its specific policy.

We're using two bits, one to signify that the process
stated its intention and that

I also made the prctl future proof by enforcing
the unused arguments are 0.

The state is inherited to children.

Note this makes us officially run out of process flags
on 32bit, but the next patch can easily add another field.

Manpage patch will be supplied separately.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 11:50:14 +02:00
Andi Kleen
2571873621 HWPOISON: Define a new error_remove_page address space op for async truncation
Truncating metadata pages is not safe right now before
we haven't audited all file systems.

To enable truncation only for data address space define
a new address_space callback error_remove_page.

This is used for memory_failure.c memory error handling.

This can be then set to truncate_inode_page()

This patch just defines the new operation and adds documentation.

Callers and users come in followon patches.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 11:50:13 +02:00
Wu Fengguang
83f786680a HWPOISON: Add invalidate_inode_page
Add a simple way to invalidate a single page
This is just a refactoring of the truncate.c code.
Originally from Fengguang, modified by Andi Kleen.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 11:50:13 +02:00
Nick Piggin
750b4987b0 HWPOISON: Refactor truncate to allow direct truncating of page v2
Extract out truncate_inode_page() out of the truncate path so that
it can be used by memory-failure.c

[AK: description, headers, fix typos]
v2: Some white space changes from Fengguang Wu

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 11:50:12 +02:00
Andi Kleen
888b9f7c58 HWPOISON: Handle hardware poisoned pages in try_to_unmap
When a page has the poison bit set replace the PTE with a poison entry.
This causes the right error handling to be done later when a process runs
into it.

v2: add a new flag to not do that (needed for the memory-failure handler
later) (Fengguang)
v3: remove unnecessary is_migration_entry() test (Fengguang, Minchan)

Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 11:50:11 +02:00
Andi Kleen
14fa31b89c HWPOISON: Use bitmask/action code for try_to_unmap behaviour
try_to_unmap currently has multiple modi (migration, munlock, normal unmap)
which are selected by magic flag variables. The logic is not very straight
forward, because each of these flag change multiple behaviours (e.g.
migration turns off aging, not only sets up migration ptes etc.)
Also the different flags interact in magic ways.

A later patch in this series adds another mode to try_to_unmap, so
this becomes quickly unmanageable.

Replace the different flags with a action code (migration, munlock, munmap)
and some additional flags as modifiers (ignore mlock, ignore aging).
This makes the logic more straight forward and allows easier extension
to new behaviours. Change all the caller to declare what they want to
do.

This patch is supposed to be a nop in behaviour. If anyone can prove
it is not that would be a bug.

Cc: Lee.Schermerhorn@hp.com
Cc: npiggin@suse.de

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 11:50:10 +02:00
Andi Kleen
d1737fdbec HWPOISON: Add basic support for poisoned pages in fault handler v3
- Add a new VM_FAULT_HWPOISON error code to handle_mm_fault. Right now
architectures have to explicitely enable poison page support, so
this is forward compatible to all architectures. They only need
to add it when they enable poison page support.
- Add poison page handling in swap in fault code

v2: Add missing delayacct_clear_flag (Hidehiro Kawai)
v3: Really use delayacct_clear_flag (Hidehiro Kawai)

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 11:50:06 +02:00