Page poisoning is currently set up as a feature if architectures don't
have architecture debug page_alloc to allow unmapping of pages.  It has
uses apart from that though.  Clearing of the pages on free provides an
increase in security as it helps to limit the risk of information leaks.
Allow page poisoning to be enabled as a separate option independent of
kernel_map pages since the two features do separate work.  Because of
how hiberanation is implemented, the checks on alloc cannot occur if
hibernation is enabled.  The runtime alloc checks can also be enabled
with an option when !HIBERNATION.

Credit to Grsecurity/PaX team for inspiring this work
Signed-off-by: NLaura Abbott <labbott@fedoraproject.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jianyu Zhan <nasa4836@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch extends existing "kernelcore" option and introduces
kernelcore=mirror option.  By specifying "mirror" instead of specifying
the amount of memory, non-mirrored (non-reliable) region will be
arranged into ZONE_MOVABLE.

[akpm@linux-foundation.org: fix build with CONFIG_HAVE_MEMBLOCK_NODE_MAP=n]
Signed-off-by: NTaku Izumi <izumi.taku@jp.fujitsu.com>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steve Capper <steve.capper@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now the noltlbs kernel parameter is also applicable to PPC8xx
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NScott Wood <oss@buserror.net>

Some HP laptops seem to have invalid 64 bit FADT X_PM* addresses
which are causing various boot issues.  In these cases, it would
be useful to force ACPI to use the valid legacy 32 bit equivalent
PM addresses.  Add a acpi_force_32bit_fadt_addr to set the ACPICA
acpi_gbl_use32_bit_fadt_addresses to TRUE to force this override.

Link: https://bugs.launchpad.net/bugs/1529381Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Armada-3700's uart is a simple serial port, which doesn't
support. Configuring the modem control lines. The uart port has a 32
bytes Tx FIFO and a 64 bytes Rx FIFO

The uart driver implements the uart core operations. It also support the
system (early) console based on Armada-3700's serial port.

Known Issue:

The uart driver currently doesn't support clock programming, which means
the baud-rate stays with the default value configured by the bootloader
at boot time

[gregory.clement@free-electrons.com: Rewrite many part which are too long
to enumerate]
Signed-off-by: NWilson Ding <dingwei@marvell.com>
Signed-off-by: NNadav Haklai <nadavh@marvell.com>
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Most newer Rockchip SoCs provide the possibility to use a usb-phy
as passthrough for the debug uart (uart2), making it possible to
for example get console output without needing to open the device.

This patch adds an early_initcall to enable this functionality
conditionally via the commandline and also disables the corresponding
usb controller in the devicetree.

Currently only data for the rk3288 is provided, but at least the
rk3188 and arm64 rk3368 also provide this functionality and will be
enabled later.

On a spliced usb cable the signals are tx on white wire(D+) and
rx on green wire(D-).

The one caveat is that currently the reconfiguration of the phy
happens as early_initcall, as the code depends on the unflattened
devicetree being available. Everything is fine if only a regular
console is active as the console-replay will happen after the
reconfiguation. But with earlycon active output up to smp-init
currently will get lost.

The phy is an optional property for the connected dwc2 controller,
so we still provide the phy device but fail all phy-ops with -EBUSY
to make sure the dwc2 does not try to transmit anything on the
repurposed phy.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>

It may be useful to debug writes to the readonly sections of memory,
so provide a cmdline "rodata=off" to allow for this. This can be
expanded in the future to support "log" and "write" modes, but that
will need to be architecture-specific.

This also makes KDB software breakpoints more usable, as read-only
mappings can now be disabled on any kernel.
Suggested-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Brown <david.brown@linaro.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Cc: linux-arch <linux-arch@vger.kernel.org>
Link: http://lkml.kernel.org/r/1455748879-21872-3-git-send-email-keescook@chromium.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

This sets the bit in 'cr4' to actually enable the protection
keys feature.  We also include a boot-time disable for the
feature "nopku".

Seting X86_CR4_PKE will cause the X86_FEATURE_OSPKE cpuid
bit to appear set.  At this point in boot, identify_cpu()
has already run the actual CPUID instructions and populated
the "cpu features" structures.  We need to go back and
re-run identify_cpu() to make sure it gets updated values.

We *could* simply re-populate the 11th word of the cpuid
data, but this is probably quick enough.

Also note that with the cpu_has() check and X86_FEATURE_PKU
present in disabled-features.h, we do not need an #ifdef
for setup_pku().
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210229.6708027C@viggo.jf.intel.com
[ Small readability edits. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Add cgroup_no_v1= to kernel-parameters.txt, and a small blurb to
cgroup-v2.txt section about transitioning from cgroup to cgroup2.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NTejun Heo <tj@kernel.org>

Workqueue used to guarantee local execution for work items queued
without explicit target CPU.  The guarantee is gone now which can
break some usages in subtle ways.  To flush out those cases, this
patch implements a debug feature which forces round-robin CPU
selection for all such work items.

The debug feature defaults to off and can be enabled with a kernel
parameter.  The default can be flipped with a debug config option.

If you hit this commit during bisection, please refer to 041bd12e
("Revert "workqueue: make sure delayed work run in local cpu"") for
more information and ping me.
Signed-off-by: NTejun Heo <tj@kernel.org>

This adds a chicken bit to turn off INVPCID in case something goes
wrong.  It's an early_param() because we do TLB flushes before we
parse __setup() parameters.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/f586317ed1bc2b87aee652267e515b90051af385.1454096309.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

schedstats is very useful during debugging and performance tuning but it
incurs overhead to calculate the stats. As such, even though it can be
disabled at build time, it is often enabled as the information is useful.

This patch adds a kernel command-line and sysctl tunable to enable or
disable schedstats on demand (when it's built in). It is disabled
by default as someone who knows they need it can also learn to enable
it when necessary.

The benefits are dependent on how scheduler-intensive the workload is.
If it is then the patch reduces the number of cycles spent calculating
the stats with a small benefit from reducing the cache footprint of the
scheduler.

These measurements were taken from a 48-core 2-socket
machine with Xeon(R) E5-2670 v3 cpus although they were also tested on a
single socket machine 8-core machine with Intel i7-3770 processors.

netperf-tcp
                           4.5.0-rc1             4.5.0-rc1
                             vanilla          nostats-v3r1
Hmean    64         560.45 (  0.00%)      575.98 (  2.77%)
Hmean    128        766.66 (  0.00%)      795.79 (  3.80%)
Hmean    256        950.51 (  0.00%)      981.50 (  3.26%)
Hmean    1024      1433.25 (  0.00%)     1466.51 (  2.32%)
Hmean    2048      2810.54 (  0.00%)     2879.75 (  2.46%)
Hmean    3312      4618.18 (  0.00%)     4682.09 (  1.38%)
Hmean    4096      5306.42 (  0.00%)     5346.39 (  0.75%)
Hmean    8192     10581.44 (  0.00%)    10698.15 (  1.10%)
Hmean    16384    18857.70 (  0.00%)    18937.61 (  0.42%)

Small gains here, UDP_STREAM showed nothing intresting and neither did
the TCP_RR tests. The gains on the 8-core machine were very similar.

tbench4
                                 4.5.0-rc1             4.5.0-rc1
                                   vanilla          nostats-v3r1
Hmean    mb/sec-1         500.85 (  0.00%)      522.43 (  4.31%)
Hmean    mb/sec-2         984.66 (  0.00%)     1018.19 (  3.41%)
Hmean    mb/sec-4        1827.91 (  0.00%)     1847.78 (  1.09%)
Hmean    mb/sec-8        3561.36 (  0.00%)     3611.28 (  1.40%)
Hmean    mb/sec-16       5824.52 (  0.00%)     5929.03 (  1.79%)
Hmean    mb/sec-32      10943.10 (  0.00%)    10802.83 ( -1.28%)
Hmean    mb/sec-64      15950.81 (  0.00%)    16211.31 (  1.63%)
Hmean    mb/sec-128     15302.17 (  0.00%)    15445.11 (  0.93%)
Hmean    mb/sec-256     14866.18 (  0.00%)    15088.73 (  1.50%)
Hmean    mb/sec-512     15223.31 (  0.00%)    15373.69 (  0.99%)
Hmean    mb/sec-1024    14574.25 (  0.00%)    14598.02 (  0.16%)
Hmean    mb/sec-2048    13569.02 (  0.00%)    13733.86 (  1.21%)
Hmean    mb/sec-3072    12865.98 (  0.00%)    13209.23 (  2.67%)

Small gains of 2-4% at low thread counts and otherwise flat.  The
gains on the 8-core machine were slightly different

tbench4 on 8-core i7-3770 single socket machine
Hmean    mb/sec-1        442.59 (  0.00%)      448.73 (  1.39%)
Hmean    mb/sec-2        796.68 (  0.00%)      794.39 ( -0.29%)
Hmean    mb/sec-4       1322.52 (  0.00%)     1343.66 (  1.60%)
Hmean    mb/sec-8       2611.65 (  0.00%)     2694.86 (  3.19%)
Hmean    mb/sec-16      2537.07 (  0.00%)     2609.34 (  2.85%)
Hmean    mb/sec-32      2506.02 (  0.00%)     2578.18 (  2.88%)
Hmean    mb/sec-64      2511.06 (  0.00%)     2569.16 (  2.31%)
Hmean    mb/sec-128     2313.38 (  0.00%)     2395.50 (  3.55%)
Hmean    mb/sec-256     2110.04 (  0.00%)     2177.45 (  3.19%)
Hmean    mb/sec-512     2072.51 (  0.00%)     2053.97 ( -0.89%)

In constract, this shows a relatively steady 2-3% gain at higher thread
counts. Due to the nature of the patch and the type of workload, it's
not a surprise that the result will depend on the CPU used.

hackbench-pipes
                         4.5.0-rc1             4.5.0-rc1
                           vanilla          nostats-v3r1
Amean    1        0.0637 (  0.00%)      0.0660 ( -3.59%)
Amean    4        0.1229 (  0.00%)      0.1181 (  3.84%)
Amean    7        0.1921 (  0.00%)      0.1911 (  0.52%)
Amean    12       0.3117 (  0.00%)      0.2923 (  6.23%)
Amean    21       0.4050 (  0.00%)      0.3899 (  3.74%)
Amean    30       0.4586 (  0.00%)      0.4433 (  3.33%)
Amean    48       0.5910 (  0.00%)      0.5694 (  3.65%)
Amean    79       0.8663 (  0.00%)      0.8626 (  0.43%)
Amean    110      1.1543 (  0.00%)      1.1517 (  0.22%)
Amean    141      1.4457 (  0.00%)      1.4290 (  1.16%)
Amean    172      1.7090 (  0.00%)      1.6924 (  0.97%)
Amean    192      1.9126 (  0.00%)      1.9089 (  0.19%)

Some small gains and losses and while the variance data is not included,
it's close to the noise. The UMA machine did not show anything particularly
different

pipetest
                             4.5.0-rc1             4.5.0-rc1
                               vanilla          nostats-v2r2
Min         Time        4.13 (  0.00%)        3.99 (  3.39%)
1st-qrtle   Time        4.38 (  0.00%)        4.27 (  2.51%)
2nd-qrtle   Time        4.46 (  0.00%)        4.39 (  1.57%)
3rd-qrtle   Time        4.56 (  0.00%)        4.51 (  1.10%)
Max-90%     Time        4.67 (  0.00%)        4.60 (  1.50%)
Max-93%     Time        4.71 (  0.00%)        4.65 (  1.27%)
Max-95%     Time        4.74 (  0.00%)        4.71 (  0.63%)
Max-99%     Time        4.88 (  0.00%)        4.79 (  1.84%)
Max         Time        4.93 (  0.00%)        4.83 (  2.03%)
Mean        Time        4.48 (  0.00%)        4.39 (  1.91%)
Best99%Mean Time        4.47 (  0.00%)        4.39 (  1.91%)
Best95%Mean Time        4.46 (  0.00%)        4.38 (  1.93%)
Best90%Mean Time        4.45 (  0.00%)        4.36 (  1.98%)
Best50%Mean Time        4.36 (  0.00%)        4.25 (  2.49%)
Best10%Mean Time        4.23 (  0.00%)        4.10 (  3.13%)
Best5%Mean  Time        4.19 (  0.00%)        4.06 (  3.20%)
Best1%Mean  Time        4.13 (  0.00%)        4.00 (  3.39%)

Small improvement and similar gains were seen on the UMA machine.

The gain is small but it stands to reason that doing less work in the
scheduler is a good thing. The downside is that the lack of schedstats and
tracepoints may be surprising to experts doing performance analysis until
they find the existence of the schedstats= parameter or schedstats sysctl.
It will be automatically activated for latencytop and sleep profiling to
alleviate the problem. For tracepoints, there is a simple warning as it's
not safe to activate schedstats in the context when it's known the tracepoint
may be wanted but is unavailable.
Signed-off-by: NMel Gorman <mgorman@techsingularity.net>
Reviewed-by: NMatt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <mgalbraith@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1454663316-22048-1-git-send-email-mgorman@techsingularity.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

If we isolate CPUs, then we don't want random device interrupts on them. Even
w/o the user space irq balancer enabled we can end up with irqs on non boot
cpus and chasing newly requested interrupts is a tedious task.

Allow to restrict the default irq affinity mask.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1602031948190.25254@nanosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

This patch provides a way of working around a slight regression
introduced by commit 84638335 ("mm: rework virtual memory
accounting").

Before that commit RLIMIT_DATA have control only over size of the brk
region.  But that change have caused problems with all existing versions
of valgrind, because it set RLIMIT_DATA to zero.

This patch fixes rlimit check (limit actually in bytes, not pages) and
by default turns it into warning which prints at first VmData misuse:

  "mmap: top (795): VmData 516096 exceed data ulimit 512000.  Will be forbidden soon."

Behavior is controlled by boot param ignore_rlimit_data=y/n and by sysfs
/sys/module/kernel/parameters/ignore_rlimit_data.  For now it set to "y".

[akpm@linux-foundation.org: tweak kernel-parameters.txt text[
Signed-off-by: NKonstantin Khlebnikov <koct9i@gmail.com>
Link: http://lkml.kernel.org/r/20151228211015.GL2194@uranusReported-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Kees Cook <keescook@google.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move them to a separate header and have the following
dependency:

  x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h

This makes it easier to use the header in asm code and not
include the whole cpufeature.h and add guards for asm.
Suggested-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Kmem accounting might incur overhead that some users can't put up with.
Besides, the implementation is still considered unstable.  So let's
provide a way to disable it for those users who aren't happy with it.

To disable kmem accounting for cgroup2, pass cgroup.memory=nokmem at
boot time.
Signed-off-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add an `ieee754=' kernel parameter to control IEEE Std 754 conformance
mode.

Use separate flags copied from the respective CPU feature flags, and
adjusted according to the conformance mode selected, to make binaries
requesting individual NaN encoding modes accepted or rejected as needed.
Update the initial setting for FCSR and, in the full FPU emulation mode,
its read-only mask accordingly.  Accept the mode selection requested for
legacy processors as well.

As with the EF_MIPS_NAN2008 ELF file header flag adjust both ABS2008 and
NAN2008 bits at the same time, to match the choice made for hardware
currently implemented.
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11481/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Socket memory can be a significant share of overall memory consumed by
common workloads.  In order to provide reasonable resource isolation in
the unified hierarchy, this type of memory needs to be included in the
tracking/accounting of a cgroup under active memory resource control.

Overhead is only incurred when a non-root control group is created AND
the memory controller is instructed to track and account the memory
footprint of that group.  cgroup.memory=nosocket can be specified on the
boot commandline to override any runtime configuration and forcibly
exclude socket memory from active memory resource control.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

People complained that setting the PCI config space access mechanism
through "pci=conf1" or "pci=conf2" on the command line is not really
documented. Yeah, can you blame them? Look at what we have now.

So try to improve the situation a bit by explaining what those "conf1"
and "conf2" things actually mean.

See http://wiki.osdev.org/PCI for more info.
Suggested-by: NEric Morton <Eric.Morton@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
[jc: Added the above URL to the document too]
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Instead of defining a new field in the uart_amba_port structure, use the
existing iotype field of the uart_port structure, which is intended for
this purpose.  If we need to use 32-bit register access, we set iotype
to UPIO_MEM32, otherwise we set it to UPIO_MEM.

For early console, specify the "mmio32" option on the kernel command-line.
Example:

        earlycon=pl011,mmio32,0x3ced1000
Signed-off-by: NTimur Tabi <timur@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The brd driver has never supported the ramdisk_blocksize kernel
parameter that was in the rd driver it replaced, so remove
mention of this parameter from comments and Documentation.

Commit 9db5579b ("rewrite rd") replaced rd with brd, keeping
a brd_blocksize variable in struct brd_device but never using it.

Commit a2cba291 ("brd: get rid of unused members from struct
brd_device") removed the unused variable.

Commit f5abc8e7 ("Documentation/blockdev/ramdisk.txt: updates")
removed mentions of ramdisk_blocksize from that file.
Signed-off-by: NRobert Elliott <elliott@hpe.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

This patch introduces a command line parameter apic_extnmi:

 apic_extnmi=( bsp|all|none )

The default value is "bsp" and this is the current behavior: only the
Boot-Strapping Processor receives an external NMI.

"all" allows external NMIs to be broadcast to all CPUs. This would
raise the success rate of panic on NMI when BSP hangs in NMI context
or the external NMI is swallowed by other NMI handlers on the BSP.

If you specify "none", no CPUs receive external NMIs. This is useful for
the dump capture kernel so that it cannot be shot down by accidentally
pressing the external NMI button (on platforms which have it) while
saving a crash dump.
Signed-off-by: NHidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Bandan Das <bsd@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: kexec@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20151210014632.25437.43778.stgit@softrsSigned-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Currently, 8-bit (MMIO) and 32-bit (MMIO32) register interfaces are
supported for the 8250 console, but the 16-bit (MMIO16) is not.
The 8250 UART device on my board is connected to a 16-bit bus and
my main motivation is to use earlycon with it.
(Refer to arch/arm/boot/dts/uniphier-support-card.dtsi)
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Workqueue stalls can happen from a variety of usage bugs such as
missing WQ_MEM_RECLAIM flag or concurrency managed work item
indefinitely staying RUNNING.  These stalls can be extremely difficult
to hunt down because the usual warning mechanisms can't detect
workqueue stalls and the internal state is pretty opaque.

To alleviate the situation, this patch implements workqueue lockup
detector.  It periodically monitors all worker_pools periodically and,
if any pool failed to make forward progress longer than the threshold
duration, triggers warning and dumps workqueue state as follows.

 BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 31s!
 Showing busy workqueues and worker pools:
 workqueue events: flags=0x0
   pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=17/256
     pending: monkey_wrench_fn, e1000_watchdog, cache_reap, vmstat_shepherd, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, cgroup_release_agent
 workqueue events_power_efficient: flags=0x80
   pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256
     pending: check_lifetime, neigh_periodic_work
 workqueue cgroup_pidlist_destroy: flags=0x0
   pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1
     pending: cgroup_pidlist_destroy_work_fn
 ...

The detection mechanism is controller through kernel parameter
workqueue.watchdog_thresh and can be updated at runtime through the
sysfs module parameter file.

v2: Decoupled from softlockup control knobs.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NDon Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Andrew Morton <akpm@linux-foundation.org>

The rcu_expedited, rcu_normal, and rcu_normal_after_boot kernel boot
parameters are pointless in the case of TINY_RCU because in that case
synchronous grace periods, both expedited and normal, are no-ops.
However, these three symbols contribute several hundred bytes of bloat.
This commit therefore uses CPP directives to avoid compiling this code
in TINY_RCU kernels.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Expedited grace periods can speed up boot, but are undesirable in
aggressive real-time systems.  This commit therefore introduces a
kernel parameter rcupdate.rcu_normal_after_boot that disables
expedited grace periods just before init is spawned.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Although expedited grace periods can be quite useful, and although their
OS jitter has been greatly reduced, they can still pose problems for
extreme real-time workloads.  This commit therefore adds a rcu_normal
kernel boot parameter (which can also be manipulated via sysfs)
to suppress expedited grace periods, that is, to treat requests for
expedited grace periods as if they were requests for normal grace periods.
If both rcu_expedited and rcu_normal are specified, rcu_normal wins.
This means that if you are relying on expedited grace periods to speed up
boot, you will want to specify rcu_expedited on the kernel command line,
and then specify rcu_normal via sysfs once boot completes.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The documentation wrongly implied that it is a core parameter.
That is not true. If usbcore is compiled as a module, a module
parameter needs a prefix.
Signed-off-by: NOliver Neukum <oneukum@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The usbfs_snoop facility can be very useful for debugging problems
involving usbfs.  However, it always prints out the entire contents of
every URB.  When dealing with large quantities of data, this can be
less than helpful.

This patch ameliorates the situation by adding a module parameter to
usbcore for controlling the maximum number of bytes to print when
snooping an URB.  This makes debugging much easier.  For backward
compatibility, the default value is set unreasonably high.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a boot option that strictly manages the MSR unavailable bits.
This catches kernel uses of FP/Altivec/SPE that would otherwise
corrupt user state.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Revert commit 053f56de (Documentation: kernel_parameters for Intel P
state driver) as the code documented by it has been reverted already.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In many cases of hardlockup reports, it's actually not possible to know
why it triggered, because the CPU that got stuck is usually waiting on a
resource (with IRQs disabled) in posession of some other CPU is holding.

IOW, we are often looking at the stacktrace of the victim and not the
actual offender.

Introduce sysctl / cmdline parameter that makes it possible to have
hardlockup detector perform all-CPU backtrace.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Reviewed-by: NAaron Tomlin <atomlin@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Acked-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

commit aa2110cb (ACPI: add boot option acpi=copy_dsdt to fix corrupt
DSDT) added copy_dsdt as an ACPI boot option, but did not add it to ACPI
format options in Documentation/kernel-parameters.txt.  Fix that.
Signed-off-by: NRami Rosen <ramirose@gmail.com>
[ rjw: Subject & changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add support for DT and command line based earlycon support for
lpuart and lpuart32 used on Freescale Vybrid and and QorIQ LS1021A
processors.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Added new option "no_acpi" for not using ACPI processor performance
control objects in Intel P state driver.
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: NKristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch introduces new boot option named "efi_fake_mem".
By specifying this parameter, you can add arbitrary attribute
to specific memory range.
This is useful for debugging of Address Range Mirroring feature.

For example, if "efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000"
is specified, the original (firmware provided) EFI memmap will be
updated so that the specified memory regions have
EFI_MEMORY_MORE_RELIABLE attribute (0x10000):

 <original>
   efi: mem36: [Conventional Memory|  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x00000020a0000000) (129536MB)

 <updated>
   efi: mem36: [Conventional Memory|  |MR|  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x0000000180000000) (2048MB)
   efi: mem37: [Conventional Memory|  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000180000000-0x00000010a0000000) (61952MB)
   efi: mem38: [Conventional Memory|  |MR|  |  |  |   |WB|WT|WC|UC] range=[0x00000010a0000000-0x0000001120000000) (2048MB)
   efi: mem39: [Conventional Memory|  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000001120000000-0x00000020a0000000) (63488MB)

And you will find that the following message is output:

   efi: Memory: 4096M/131455M mirrored memory
Signed-off-by: NTaku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The kernel NMI watchdog acts as both a hardlockup and softlockup detector.
However, the kernel parameter nmi_watchdog can only enable or disable the
hardlockup detector. Clarify that in the documentation.
Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

This commit loosens rcutree.rcu_fanout_leaf range checks
and replaces a panic() with a fallback to compile-time values.
This fallback is accompanied by a WARN_ON(), and both occur when the
rcutree.rcu_fanout_leaf value is too small to accommodate the number of
CPUs.  For example, given the current four-level limit for the rcu_node
tree, a system with more than 16 CPUs built with CONFIG_FANOUT=2 must
have rcutree.rcu_fanout_leaf larger than 2.
Reported-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Enable VT-d Posted-Interrtups and add a command line
parameter for it.
Signed-off-by: NFeng Wu <feng.wu@intel.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NJoerg Roedel <joro@8bytes.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This form of the earlycon parameter was added by commit fb11ffe7
("of/fdt: add FDT serial scanning for earlycon") without documentation.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>