This patch adds IRQ_TIME_ACCOUNTING option on x86 and runtime enables it
when TSC is enabled.

This change just enables fine grained irq time accounting, isn't used yet.
Following patches use it for different purposes.
Signed-off-by: NVenkatesh Pallipadi <venki@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286237003-12406-6-git-send-email-venki@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

After commit 852972ac (ACPI: Disable
ASPM if the platform won't provide _OSC control for PCIe) control of
the PCIe Capability Structure is unconditionally requested by
acpi_pci_root_add(), which in principle may cause problems to
happen in two ways.  First, the BIOS may refuse to give control of
the PCIe Capability Structure if it is not asked for any of the
_OSC features depending on it at the same time.  Second, the BIOS may
assume that control of the _OSC features depending on the PCIe
Capability Structure will be requested in the future and may behave
incorrectly if that doesn't happen.  For this reason, control of
the PCIe Capability Structure should always be requested along with
control of any other _OSC features that may depend on it (ie. PCIe
native PME, PCIe native hot-plug, PCIe AER).

Rework the PCIe port driver so that (1) it checks which native PCIe
port services can be enabled, according to the BIOS, and (2) it
requests control of all these services simultaneously.  In
particular, this causes pcie_portdrv_probe() to fail if the BIOS
refuses to grant control of the PCIe Capability Structure, which
means that no native PCIe port services can be enabled for the PCIe
Root Complex the given port belongs to.  If that happens, ASPM is
disabled to avoid problems with mishandling it by the part of the
PCIe hierarchy for which control of the PCIe Capability Structure
has not been received.

Make it possible to override this behavior using 'pcie_ports=native'
(use the PCIe native services regardless of the BIOS response to the
control request), or 'pcie_ports=compat' (do not use the PCIe native
services at all).

Accordingly, rework the existing PCIe port service drivers so that
they don't request control of the services directly.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Introduce kernel command line switch pcie_ports= allowing one to
disable all of the native PCIe port services, so that PCIe ports
are treated like PCI-to-PCI bridges.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

It is not immediately clear what this option causes to become
ignored. The actual meaning is that it is not necessary to unplug the
emulated devices to safely use the PV ones, even if the platform does
not support the unplug protocol. (pressumably the user will only add
this option if they have ensured that their domain configuration is
safe).

I think xen_emul_unplug=unnecessary better captures this.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Acked-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: NStefano Stabellini <Stefano.Stabellini@eu.citrix.com>

this allows the user to disable pvhvm and revert to emulated devices
in case of a system misconfiguration (e.g. initramfs with only
emulated drivers in it).
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Acked-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: NStefano Stabellini <Stefano.Stabellini@eu.citrix.com>

Move SCSI parameters from kernel-parameters.txt to their own text file.

This continues a trend of moving non-core parameters out of
kernel-parameters.txt.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To keep panic_timeout accuracy when running under a hypervisor, the
current implementation only spins on long time (1 second) calls to mdelay.
 That brings a good effect, but the problem is the keyboard LEDs don't
blink at all on that situation.

This patch changes to call to panic_blink_enter() between every mdelay and
keeps blinking in spite of long spin timer mode.

The time to call to mdelay is now 100ms.  Even this change will keep
panic_timeout accuracy enough when running under a hypervisor.
Signed-off-by: NTAMUKI Shoichi <tamuki@linet.gr.jp>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: NDmitry Torokhov <dtor@mail.ru>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide MMIO32 support in 8250_early (aka earlycon)

[randy.dunlap@oracle.com: fix printk format warnings]
[akpm@linux-foundation.org: fix printk args some more]
Signed-off-by: NSamium Gromoff <_deepfire@feelingofgreen.ru>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Allow disabling the source id checking while programming the interrupt
remap table entry. Useful for debugging or working around the broken
source id checks on some platforms.
Signed-off-by: NChris Wright <chrisw@redhat.com>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Acked-by: NWeidong Han <weidong.han@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Update the kgdb docs to include information about kernel mode setting support.

[Randy Dunlap <rdunlap@xenotime.net>: grammatical corrections]

CC: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

The Linux kernel assigns BARs that a BIOS did not assign, most likely
to handle broken BIOSes that didn't enumerate the devices correctly.
On UV the BIOS purposely doesn't assign I/O BARs for certain devices/
drivers we know don't use them (examples, LSI SAS, Qlogic FC, ...).
We purposely don't assign these I/O BARs because I/O Space is a very
limited resource.  There is only 64k of I/O Space, and in a PCIe
topology that space gets divided up into 4k chucks (this is due to
the fact that a pci-to-pci bridge's I/O decoder is aligned at 4k)...
Thus a system can have at most 16 cards with I/O BARs: (64k / 4k = 16)

SGI needs to scale to >16 devices with I/O BARs.  So by not assigning
I/O BARs on devices we know don't use them, we can do that (iff the
kernel doesn't go and assign these BARs that the BIOS purposely didn't
assign).

This patch will not assign a resource to a device BAR if that BAR was
not assigned by the BIOS, and the kernel cmdline option 'pci=nobar'
was specified.   This patch is closely modeled after the 'pci=norom'
option that currently exists in the tree.
Signed-off-by: NMike Habeck <habeck@sgi.com>
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Now that all arches have been converted over to use generic time via
clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME
config option and simplify the generic code.
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Add a xen_emul_unplug command line option to the kernel to unplug
xen emulated disks and nics.

Set the default value of xen_emul_unplug depending on whether or
not the Xen PV frontends and the Xen platform PCI driver have
been compiled for this kernel (modules or built-in are both OK).

The user can specify xen_emul_unplug=ignore to enable PV drivers on HVM
even if the host platform doesn't support unplug.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Commit 2a6b6976
(ACPI: Store NVS state even when entering suspend to RAM) caused the
ACPI suspend code save the NVS area during suspend and restore it
during resume unconditionally, although it is known that some systems
need to use acpi_sleep=s4_nonvs for hibernation to work.  To allow
the affected systems to avoid saving and restoring the NVS area
during suspend to RAM and resume, introduce kernel command line
option acpi_sleep=nonvs and make acpi_sleep=s4_nonvs work as its
alias temporarily (add acpi_sleep=s4_nonvs to the feature removal
file).

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16396 .
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: Ntomas m <tmezzadra@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

via following scripts

      FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

      sed -i \
        -e 's/lmb/memblock/g' \
        -e 's/LMB/MEMBLOCK/g' \
        $FILES

      for N in $(find . -name lmb.[ch]); do
        M=$(echo $N | sed 's/lmb/memblock/g')
        mv $N $M
      done

and remove some wrong change like lmbench and dlmb etc.

also move memblock.c from lib/ to mm/
Suggested-by: NIngo Molnar <mingo@elte.hu>
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

CONFIG_NF_CT_ACCT has been deprecated for awhile and
was originally scheduled for removal by 2.6.29.

Removing support for this config option also stops
this deprecation warning message in the kernel log.

[   61.669627] nf_conntrack version 0.5.0 (16384 buckets, 65536 max)
[   61.669850] CONFIG_NF_CT_ACCT is deprecated and will be removed soon. Please use
[   61.669852] nf_conntrack.acct=1 kernel parameter, acct=1 nf_conntrack module option or
[   61.669853] sysctl net.netfilter.nf_conntrack_acct=1 to enable it.
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
[Patrick: changed default value to 0]
Signed-off-by: NPatrick McHardy <kaber@trash.net>

Commit c7f48656
(PCI PM: PCIe PME root port service driver) causes the native PCIe
PME signaling to be used by default, if the BIOS allows the kernel to
control the standard configuration registers of PCIe root ports.
However, the native PCIe PME is coupled to the native PCIe hotplug
and calling pcie_pme_acpi_setup() makes some BIOSes expect that
the native PCIe hotplug will be used as well.  That, in turn, causes
problems to appear on systems where the PCIe hotplug driver is not
loaded.  The usual symptom, as reported by Jaroslav Kameník and
others, is that the ACPI GPE associated with PCIe hotplug keeps
firing continuously causing kacpid to take substantial percentage
of CPU time.

To work around this issue, change the default so that the native
PCIe PME signaling is only used if directly requested with the help
of the pcie_pme= command line switch.

Fixes https://bugzilla.kernel.org/show_bug.cgi?id=15924 , which is
a listed regression from 2.6.33.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Reported-by: NJaroslav Kameník <jaroslav@kamenik.cz>
Tested-by: NAntoni Grzymala <antekgrzymala@gmail.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Move sound (OSS & ALSA) kernel parameters to their own files.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Add dump_id libata.force parameter.  If specified, libata dumps full
IDENTIFY data during device configuration.  This is to aid debugging.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Larry Baker <baker@usgs.gov>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Move the limited watchdog driver help from kernel-parameters.txt
to Documentation/watchdog/watchdog-parameters.txt and add info to it
for all watchdog drivers except the ones that have driver-specific
files already.

Correct minor comments and MODULE_PARM_DESC() text in 2 places.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

This patch adds the capability to use the usb debug port with the
kernel debugger.  It is also still possible to use this functionality
with or without the earlyprintk=dbgpX.  It is possible to use the
kgdbwait boot argument to debug very early in the kernel start up code.

There are two ways to use this driver extension with a kernel boot argument.

1) kgdbdbgp=#   -- Where # is the number of the usb debug controller

   You must use sysrq-g to break into the kernel debugger on another
   connection type other than the dbgp.

2) kgdbdbgp=#debugControlNum#,#Seconds#

   In this mode, the usb debug port is polled every #Seconds# for
   character input.  It is possible to use gdb or press control-c to
   break into the kernel debugger.

From the implementation perspective there are 3 high level changes.

1) Allow variable retries for the the hardware via dbgp_bulk_read().

   The amount of retries for the dbgp_bulk_read() needed to be
   variable instead of fixed.  We do not want to poll at all when the
   kernel is operating in interrupt driven mode.  The polling only
   occurs if the kernel was booted when specifying some number of
   seconds via the kgdbdbgp boot argument (IE kgdbdbgp=0,1).  In this
   case the loop count is reduced to 1 so as introduce the smallest
   amount of latency as possible.

2) Save the bulk IN endpoint address for use by the kgdb code.

3) The addition of the kgdb interface code.

   This consisted of adding in a character read function for the dbgp
   as well as a polling thread to allow the dbgp to interrupt the
   kernel execution.  The rest is the typical kgdb I/O api.

CC: Eric Biederman <ebiederm@xmission.com>
CC: Yinghai Lu <yhlu.kernel@gmail.com>
CC: linux-usb@vger.kernel.org
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>

The ekgdboc= differs from kgdboc= in that you can begin debuggin as
soon as the exceptions are setup and the kgdb I/O driver is available,
instead of waiting until the tty subsystem is available.

CC: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>

Update the kgdb docs to reflect the new directory structure and API.

Merge in the kdb shell information.

[Randy Dunlap <rdunlap@xenotime.net>: grammatical corrections]

CC: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>

This patch adds in the kdb PS/2 keyboard driver.  This was mostly a
direct port from the original kdb where I cleaned up the code against
checkpatch.pl and added the glue to stitch it into kgdb.

This patch also enables early kdb debug via kgdbwait and the keyboard.

All the access to configure kdb using either a serial console or the
keyboard is done via kgdboc.

If you want to use only the keyboard and want to break in early you
would add to your kernel command arguments:

    kgdboc=kbd kgdbwait

If you wanted serial and or the keyboard access you could use:

    kgdboc=kbd,ttyS0

You can also configure kgdboc as a kernel module or at run time with
the sysfs where you can activate and deactivate kgdb.

Turn it on:
    echo kbd,ttyS0 > /sys/module/kgdboc/parameters/kgdboc

Turn it off:
    echo "" > /sys/module/kgdboc/parameters/kgdboc
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Reviewed-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

ERST is a way provided by APEI to save and retrieve hardware error
record to and from some simple persistent storage (such as flash).

The Linux kernel support implementation is quite simple and workable
in NMI context. So it can be used to save hardware error record into
flash in hardware error exception or NMI handler, where other more
complex persistent storage such as disk is not usable. After saving
hardware error records via ERST in hardware error exception or NMI
handler, the error records can be retrieved and logged into disk or
network after a clean reboot.

For more information about ERST, please refer to ACPI Specification
version 4.0, section 17.4.

This patch incorporate fixes from Jin Dongming.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
CC: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add document for APEI, including kernel parameters and EINJ debug file
sytem interface.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The new nmi_watchdog (which uses the perf event subsystem) is very
similar in structure to the softlockup detector.  Using Ingo's
suggestion, I combined the two functionalities into one file:
kernel/watchdog.c.

Now both the nmi_watchdog (or hardlockup detector) and softlockup
detector sit on top of the perf event subsystem, which is run every
60 seconds or so to see if there are any lockups.

To detect hardlockups, cpus not responding to interrupts, I
implemented an hrtimer that runs 5 times for every perf event
overflow event.  If that stops counting on a cpu, then the cpu is
most likely in trouble.

To detect softlockups, tasks not yielding to the scheduler, I used the
previous kthread idea that now gets kicked every time the hrtimer fires.
If the kthread isn't being scheduled neither is anyone else and the
warning is printed to the console.

I tested this on x86_64 and both the softlockup and hardlockup paths
work.

V2:
- cleaned up the Kconfig and softlockup combination
- surrounded hardlockup cases with #ifdef CONFIG_PERF_EVENTS_NMI
- seperated out the softlockup case from perf event subsystem
- re-arranged the enabling/disabling nmi watchdog from proc space
- added cpumasks for hardlockup failure cases
- removed fallback to soft events if no PMU exists for hard events

V3:
- comment cleanups
- drop support for older softlockup code
- per_cpu cleanups
- completely remove software clock base hardlockup detector
- use per_cpu masking on hard/soft lockup detection
- #ifdef cleanups
- rename config option NMI_WATCHDOG to LOCKUP_DETECTOR
- documentation additions

V4:
- documentation fixes
- convert per_cpu to __get_cpu_var
- powerpc compile fixes

V5:
- split apart warn flags for hard and soft lockups

TODO:
- figure out how to make an arch-agnostic clock2cycles call
  (if possible) to feed into perf events as a sample period

[fweisbec: merged conflict patch]
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
LKML-Reference: <1273266711-18706-2-git-send-email-dzickus@redhat.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

This patch adds a command line option to tell the AMD IOMMU
driver to not initialize any IOMMU it finds.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

According to libata-core correctly around line 6572:

	/* parse id */
	p = strchr(id, '.');
	...

the optional device is separated from the port in the libata.force ID
by a point or dot instead of by a colon.

Fix documentation to reflect this.
Signed-off-by: NRoman Fietze <roman.fietze@telemotive.de>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

The ftrace_dump_on_oops kernel parameter, sysctl and sysrq let one
dump every cpu buffers when an oops or panic happens.

It's nice when you have few cpus but it may take ages if have many,
plus you miss the real origin of the problem in all the cpu traces.

Sometimes, all you need is to dump the cpu buffer that triggered the
opps, most of the time it is our main interest.

This patch modifies ftrace_dump_on_oops to handle this choice.

The ftrace_dump_on_oops kernel parameter, when it comes alone, has
the same behaviour than before. But ftrace_dump_on_oops=orig_cpu
will only dump the buffer of the cpu that oops'ed.

Similarly, sysctl kernel.ftrace_dump_on_oops=1 and
echo 1 > /proc/sys/kernel/ftrace_dump_on_oops keep their previous
behaviour. But setting 2 jumps into cpu origin dump mode.

v2: Fix double setup
v3: Fix spelling issues reported by Randy Dunlap
v4: Also update __ftrace_dump in the selftests
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>

Some BIOS on Toshiba machines corrupt the DSDT, so add a new
boot option acpi=copy_dsdt to workaround it.
Add warning message to ask users to use this option if corrupt DSDT detected.

Also build a DMI blacklist to check it and automatically copy DSDT.

https://bugzilla.kernel.org/show_bug.cgi?id=14679Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Support for the share and fullflush parameters was removed.
Remove the documentation about them too.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Add a workaround for TPM's which fail to flush last written
PCR values in a TPM_SaveState, in preparation for suspend.
Signed-off-by: NDavid Safford <safford@watson.ibm.com>
Acked-by: NRajiv Andrade <srajiv@linux.vnet.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Now that we check for physically present processors before blindly
evaluating _PDC, we no longer need to maintain a DMI opt-in table
nor a kernel param.
Acked-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

acpi=ht was important in 2003 -- before ACPI was
universally deployed and enabled by default in
the major Linux distributions.

At that time, there were a fair number of people who
or chose to, or needed to, run with acpi=off,
yet also wanted access to Hyper-threading.

Today we find that many invocations of "acpi=ht"
are accidental, and thus is it possible that it
is doing more harm than good.

In 2.6.34, we warn on invocation of acpi=ht.
In 2.6.35, we delete the boot option.
Signed-off-by: NLen Brown <len.brown@intel.com>

Distros generally (I looked at Debian, RHEL5 and SLES11) seem to
enable CONFIG_HIGHPTE for any x86 configuration which has highmem
enabled. This means that the overhead applies even to machines which
have a fairly modest amount of high memory and which therefore do not
really benefit from allocating PTEs in high memory but still pay the
price of the additional mapping operations.

Running kernbench on a 4G box I found that with CONFIG_HIGHPTE=y but
no actual highptes being allocated there was a reduction in system
time used from 59.737s to 55.9s.

With CONFIG_HIGHPTE=y and highmem PTEs being allocated:
  Average Optimal load -j 4 Run (std deviation):
  Elapsed Time 175.396 (0.238914)
  User Time 515.983 (5.85019)
  System Time 59.737 (1.26727)
  Percent CPU 263.8 (71.6796)
  Context Switches 39989.7 (4672.64)
  Sleeps 42617.7 (246.307)

With CONFIG_HIGHPTE=y but with no highmem PTEs being allocated:
  Average Optimal load -j 4 Run (std deviation):
  Elapsed Time 174.278 (0.831968)
  User Time 515.659 (6.07012)
  System Time 55.9 (1.07799)
  Percent CPU 263.8 (71.266)
  Context Switches 39929.6 (4485.13)
  Sleeps 42583.7 (373.039)

This patch allows the user to control the allocation of PTEs in
highmem from the command line ("userpte=nohigh") but retains the
status-quo as the default.

It is possible that some simple heuristic could be developed which
allows auto-tuning of this option however I don't have a sufficiently
large machine available to me to perform any particularly meaningful
experiments. We could probably handwave up an argument for a threshold
at 16G of total RAM.

Assuming 768M of lowmem we have 196608 potential lowmem PTE
pages. Each page can map 2M of RAM in a PAE-enabled configuration,
meaning a maximum of 384G of RAM could potentially be mapped using
lowmem PTEs.

Even allowing generous factor of 10 to account for other required
lowmem allocations, generous slop to account for page sharing (which
reduces the total amount of RAM mappable by a given number of PT
pages) and other innacuracies in the estimations it would seem that
even a 32G machine would not have a particularly pressing need for
highmem PTEs. I think 32G could be considered to be at the upper bound
of what might be sensible on a 32 bit machine (although I think in
practice 64G is still supported).

It's seems questionable if HIGHPTE is even a win for any amount of RAM
you would sensibly run a 32 bit kernel on rather than going 64 bit.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
LKML-Reference: <1266403090-20162-1-git-send-email-ian.campbell@citrix.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Moorestown platform does not have PIT or HPET platform timers.  Instead it
has a bank of eight APB timers.  The number of available timers to the os
is exposed via SFI mtmr tables.  All APB timer interrupts are routed via
ioapic rtes and delivered as MSI.
Currently, we use timer 0 and 1 for per cpu clockevent devices, timer 2
for clocksource.
Signed-off-by: NJacob Pan <jacob.jun.pan@intel.com>
LKML-Reference: <43F901BD926A4E43B106BF17856F0755A318D2D2@orsmsx508.amr.corp.intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The main benefit of using ACPI host bridge window information is that
we can do better resource allocation in systems with multiple host bridges,
e.g., http://bugzilla.kernel.org/show_bug.cgi?id=14183

Sometimes we need _CRS information even if we only have one host bridge,
e.g., https://bugs.launchpad.net/ubuntu/+source/linux/+bug/341681

Most of these systems are relatively new, so this patch turns on
"pci=use_crs" only on machines with a BIOS date of 2008 or newer.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Apparently, some machines may have problems with PCI run-time power
management if MSIs are used for the native PCIe PME signaling.  In
particular, on the MSI Wind U-100 PCIe PME interrupts are not
generated by a PCIe root port after a resume from suspend to RAM, if
the system wake-up was triggered by a PME from the device attached to
this port.  [It doesn't help to free the interrupt on suspend and
request it back on resume, even if that is done along with disabling
the MSI and re-enabling it, respectively.]  However, if INTx
interrupts are used for this purpose on the same machine, everything
works just fine.

For this reason, add a kernel command line switch allowing one to
request that MSIs be not used for the native PCIe PME signaling,
introduce a DMI table allowing us to blacklist machines that need
this switch to be set by default and put the MSI Wind U-100 into this
table.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>