Without this patch, the points 1-9 in the list are rendered as an HTML
blockquote containing a list, causing them to be indented further than
the rest of the list.

While at it, also fix the quotation marks around G and P.
Signed-off-by: NJonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

SPCR is currently only enabled or ARM64 and x86 can use SPCR to setup
an early console.

General fixes include updating Documentation & Kconfig (for x86),
updating comments, and changing parse_spcr() to acpi_parse_spcr(),
and earlycon_init_is_deferred to earlycon_acpi_spcr_enable to be
more descriptive.

On x86, many systems have a valid SPCR table but the table version is
not 2 so the table version check must be a warning.

On ARM64 when the kernel parameter earlycon is used both the early console
and console are enabled.  On x86, only the earlycon should be enabled by
by default.  Modify acpi_parse_spcr() to allow options for initializing
the early console and console separately.
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Reviewed-by: NMark Salter <msalter@redhat.com>
Tested-by: NMark Salter <msalter@redhat.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Edits for grammar, punctuation, and a doubled-up word.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Michael Jamet <michael.jamet@intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Yehezkel Bernat <yehezkel.bernat@intel.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

The 'noreplace-paravirt' option disables paravirt patching, leaving the
original pv indirect calls in place.

That's highly incompatible with retpolines, unless we want to uglify
paravirt even further and convert the paravirt calls to retpolines.

As far as I can tell, the option doesn't seem to be useful for much
other than introducing surprising corner cases and making the kernel
vulnerable to Spectre v2.  It was probably a debug option from the early
paravirt days.  So just remove it.
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Link: https://lkml.kernel.org/r/20180131041333.2x6blhxirc2kclrq@treble

As explained by Michal Marek at https://lkml.org/lkml/2011/8/31/189
silentoldconfig has become a misnomer. It has become an internal interface
so remove it from "make help" and Documentation/ to stop confusing people
using it as seen for instance at
https://chromium-review.googlesource.com/835632 Don't remove it from
kconfig/Makefile yet not to break any (other) tool using it.

On the other hand, correct and expand its description in the help of
the (internal) scripts/kconfig/conf.c
Signed-off-by: NMarc Herbert <marc.herbert@intel.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

L2 CDP can be controlled by kernel parameter "rdt=".
If "rdt=l2cdp", L2 CDP is turned on.
If "rdt=!l2cdp", L2 CDP is turned off.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: Vikas" <vikas.shivappa@intel.com>
Cc: Sai Praneeth" <sai.praneeth.prakhya@intel.com>
Cc: Reinette" <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/1513810644-78015-7-git-send-email-fenghua.yu@intel.com

Add a spectre_v2= option to select the mitigation used for the indirect
branch speculation vulnerability.

Currently, the only option available is retpoline, in its various forms.
This will be expanded to cover the new IBRS/IBPB microcode features.

The RETPOLINE_AMD feature relies on a serializing LFENCE for speculation
control. For AMD hardware, only set RETPOLINE_AMD if LFENCE is a
serializing instruction, which is indicated by the LFENCE_RDTSC feature.

[ tglx: Folded back the LFENCE/AMD fixes and reworked it so IBRS
  	integration becomes simple ]
Signed-off-by: NDavid Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515707194-20531-5-git-send-email-dwmw@amazon.co.uk

Only try to enable a 64-bit window on AMD CPUs when "pci=big_root_window"
is specified.

This taints the kernel because the new 64-bit window uses address space we
don't know anything about, and it may contain unreported devices or memory
that would conflict with the window.

The pci_amd_enable_64bit_bar() quirk that enables the window is specific to
AMD CPUs.  The generic solution would be to have the firmware enable the
window and describe it in the host bridge's _CRS method, or at least
describe it in the _PRS method so the OS would have the option of enabling
it.
Signed-off-by: NChristian König <christian.koenig@amd.com>
[bhelgaas: changelog, extend doc, mention taint in dmesg]
Signed-off-by: NBjorn Helgaas <helgaas@kernel.org>

The cross-release lockdep functionality has been removed in:

   e966eaee: ("locking/lockdep: Remove the cross-release locking checks")

... leaving the kernel parameter docs behind. The code handling
the parameter does not exist so this is a plain documentation change.
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: byungchul.park@lge.com
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20180108152731.27613-1-dsterba@suse.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add some details about how PTI works, what some of the downsides
are, and how to debug it when things go wrong.

Also document the kernel parameter: 'pti/nopti'.
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NRandy Dunlap <rdunlap@infradead.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
Cc: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
Cc: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
Cc: Richard Fellner <richard.fellner@student.tugraz.at>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andi Lutomirsky <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180105174436.1BC6FA2B@viggo.jf.intel.com

0day and kernelCI automatically parse kernel log - basically some sort
of grepping using the pre-defined text patterns - in order to detect
and report regressions/errors. There are several sources they get the
kernel logs from:

a) dmesg or /proc/ksmg

   This is the preferred way. Because `dmesg --raw' (see later Note)
   and /proc/kmsg output contains facility and log level, which greatly
   simplifies grepping for EMERG/ALERT/CRIT/ERR messages.

b) serial consoles

   This option is harder to maintain, because serial console messages
   don't contain facility and log level.

This patch introduces a `console_msg_format=' command line option,
to switch between different message formatting on serial consoles.
For the time being we have just two options - default and syslog.
The "default" option just keeps the existing format. While the
"syslog" option makes serial console messages to appear in syslog
format [syslog() syscall], matching the `dmesg -S --raw' and
`cat /proc/kmsg' output formats:

- facility and log level
- time stamp (depends on printk_time/PRINTK_TIME)
- message

	<%u>[time stamp] text\n

NOTE: while Kevin and Fengguang talk about "dmesg --raw", it's actually
"dmesg -S --raw" that always prints messages in syslog format [per
Petr Mladek]. Running "dmesg --raw" may produce output in non-syslog
format sometimes. console_msg_format=syslog enables syslog format,
thus in documentation we mention "dmesg -S --raw", not "dmesg --raw".

Per Kevin Hilman:

: Right now we can get this info from a "dmesg --raw" after bootup,
: but it would be really nice in certain automation frameworks to
: have a kernel command-line option to enable printing of loglevels
: in default boot log.
:
: This is especially useful when ingesting kernel logs into advanced
: search/analytics frameworks (I'm playing with and ELK stack: Elastic
: Search, Logstash, Kibana).
:
: The other important reason for having this on the command line is that
: for testing linux-next (and other bleeding edge developer branches),
: it's common that we never make it to userspace, so can't even run
: "dmesg --raw" (or equivalent.)  So we really want this on the primary
: boot (serial) console.

Per Fengguang Wu, 0day scripts should quickly benefit from that
feature, because they will be able to switch to a more reliable
parsing, based on messages' facility and log levels [1]:

`#{grep} -a -E -e '^<[0123]>' -e '^kern  :(err   |crit  |alert |emerg )'

instead of doing text pattern matching

`#{grep} -a -F -f /lkp/printk-error-messages #{kmsg_file} |
      grep -a -v -E -f #{LKP_SRC}/etc/oops-pattern |
      grep -a -v -F -f #{LKP_SRC}/etc/kmsg-blacklist`

[1] https://github.com/fengguang/lkp-tests/blob/master/lib/dmesg.rb

Link: http://lkml.kernel.org/r/20171221054149.4398-1-sergey.senozhatsky@gmail.com
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: NFengguang Wu <fengguang.wu@intel.com>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Tested-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NPetr Mladek <pmladek@suse.com>

There are two consumers of apic=: the APIC debug level and the low
level generic architecture code, but Linux just documented the first
one.

Append the second description.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: rdunlap@infradead.org
Cc: corbet@lwn.net
Link: https://lkml.kernel.org/r/20171204040313.24824-2-douly.fnst@cn.fujitsu.com

Keep the "nopti" optional for traditional reasons.

[ tglx: Don't allow force on when running on XEN PV and made 'on'
	printout conditional ]
Requested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171212133952.10177-1-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add the initial files for kernel page table isolation, with a minimal init
function and the boot time detection for this misfeature.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: NIngo Molnar <mingo@kernel.org>

When we reserve regions because the user specified a "reserve=" parameter,
set the resource type to either IORESOURCE_IO (for regions below 0x10000)
or IORESOURCE_MEM.  The test for 0x10000 is just a heuristic; obviously
there can be memory below 0x10000 as well.

Improve documentation of the "reserve=" parameter.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The "isolcpus=" and "nohz_full=" boot parameters depend on CPU Isolation
support. Let's document that.
Signed-off-by: NFrederic Weisbecker <frederic@kernel.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: kernel test robot <xiaolong.ye@intel.com>
Link: http://lkml.kernel.org/r/1513275507-29200-4-git-send-email-frederic@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

WMI is the bus inside kernel, so, we may access the GUID via
/sys/bus/wmi instead of doing this through /sys/devices path.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NMario Limonciello <mario.limonciello@dell.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The acpi_mask_gpe= kernel parameter documentation states that the range
of mask is 128 GPEs (0x00 to 0x7F).  The acpi_masked_gpes mask is a u64 so
only 64 GPEs (0x00 to 0x3F) can really be masked.

Use a bitmap of size 0xFF instead of a u64 for the GPE mask so 256
GPEs can be masked.

Fixes: 9c4aa1ee (ACPI / sysfs: Provide quirk mechanism to prevent GPE flooding)
Signed-off-by: NPrarit Bharava <prarit@redhat.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit ac1f5912 ("kernel/watchdog.c: add sysctl knob
hardlockup_panic") added the hardlockup_panic sysctl, but did not add it
to Documentation/sysctl/kernel.txt.  Add this, and reference it from the
corresponding entry in Documentation/admin-guide/kernel-parameters.txt.
Signed-off-by: NScott Wood <swood@redhat.com>
Acked-by: NChristoph von Recklinghausen <crecklin@redhat.com>
Acked-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

The URLs in mono.rst redirect to pages on www.mono-project.com, so let's
update them. I took the liberty to update the compilation instructions
to the Linux-specific version, because readers of the kernel
documentation will most likely use Linux.
Signed-off-by: NJonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

The purpose of torture_runnable is to allow rcutorture and locktorture
to be started and stopped via sysfs when they are built into the kernel
(as in not compiled as loadable modules).  However, the 0444 permissions
for both instances of torture_runnable prevent this use case from ever
being put into practice.  Given that there have been no complaints
about this deficiency, it is reasonable to conclude that no one actually
makes use of this sysfs capability.  The perf_runnable module parameter
for rcuperf is in the same situation.

This commit therefore removes both torture_runnable instances as well
as perf_runnable.
Reported-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The ACPI code supporting system transitions to sleep states uses
an internal blacklist to apply special handling to some machines
reported to behave incorrectly in some ways.

However, some entries of that blacklist cover problematic as well as
non-problematic systems, so give the users of the latter a chance to
ignore the blacklist and run their systems in the default way by
adding acpi_sleep=nobl to the kernel command line.

For example, that allows the users of Dell XPS13 9360 systems not
affected by the issue that caused the blacklist entry for this
machine to be added by commit 71630b7a (ACPI / PM: Blacklist Low
Power S0 Idle _DSM for Dell XPS13 9360) to use suspend-to-idle with
the Low Power S0 Idle _DSM interface which in principle should be
more energy-efficient than S3 on them.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Correctly the formatting of several additions to the profile= option
that have been added by using <profiletype> and listing the choices
for it.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Fix minor typo.

Fix missing words in explaining parsing of last line number.

Link: http://lkml.kernel.org/r/ebb7ff42-4945-103f-d5b4-f07a6f3343a7@infradead.orgSigned-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix up makefiles, remove references, and git rm kmemcheck.

Link: http://lkml.kernel.org/r/20171007030159.22241-4-alexander.levin@verizon.comSigned-off-by: NSasha Levin <alexander.levin@verizon.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Tim Hansen <devtimhansen@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All it takes is the has_v4 flag to be set in gic_kvm_info
as well as "kvm-arm.vgic_v4_enable=1" being passed on the
command line for GICv4 to be enabled in KVM.
Acked-by: NChristoffer Dall <cdall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

There is a lot of broken firmware out there that don't really
expose the information the kernel requires when it comes with dealing
with GICv2:

(1) Firmware that only describes the first 4kB of GICv2
(2) Firmware that describe 128kB of CPU interface, while
    the usable portion of the address space is between
    60 and 68kB

So far, we only deal with (2). But we have platforms exhibiting
behaviour (1), resulting in two sub-cases:
(a) The GIC is occupying 8kB, as required by the GICv2 architecture
(b) It is actually spread 128kB, and this is likely to be a version
    of (2)

This patch tries to work around both (a) and (b) by poking at
the outside of the described memory region, and try to work out
what is actually there. This is of course unsafe, and should
only be enabled if there is no way to otherwise fix the DT provided
by the firmware (we provide a "irqchip.gicv2_force_probe" option
to that effect).

Note that for the time being, we restrict ourselves to GICv2
implementations provided by ARM, since there I have no knowledge
of an alternative implementations. This could be relaxed if such
an implementation comes to light on a broken platform.
Reviewed-by: NChristoffer Dall <cdall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Document the latest updates on the isolcpus= boot option. While at it,
let's also fix the details about the preferred way to isolate a set of
CPUs from the scheduler general domains. Cpusets offer a much better
interface to achieve that.
Signed-off-by: NFrederic Weisbecker <frederic@kernel.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1509419914-16179-1-git-send-email-frederic@kernel.org
[ Clarified the text some more, marked the boot option deprecated. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

- Use the same file name in the explanation and in the example (conex.c vs
sonixj.c)
- Add a missing ':' in a :ref: tag which leads to incorrect Shpinx output
- Add some missing ',' and ';'
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Johan Hovold reported a heavy performance regression caused by lockdep
cross-release:

 > Boot time (from "Linux version" to login prompt) had in fact doubled
 > since 4.13 where it took 17 seconds (with my current config) compared to
 > the 35 seconds I now see with 4.14-rc4.
 >
 > I quick bisect pointed to lockdep and specifically the following commit:
 >
 >	28a903f6 ("locking/lockdep: Handle non(or multi)-acquisition
 >	               of a crosslock")
 >
 > which I've verified is the commit which doubled the boot time (compared
 > to 28a903f6^) (added by lockdep crossrelease series [1]).

Currently cross-release performs unwind on every acquisition, but that
is very expensive.

This patch makes unwind optional and disables it by default and only
records acquire_ip.

Full stack traces are sometimes required for full analysis, in which
case a boot paramter, crossrelease_fullstack, can be specified.

On my qemu Ubuntu machine (x86_64, 4 cores, 512M), the regression was
fixed. We measure boot times with 'perf stat --null --repeat 10 $QEMU',
where $QEMU launches a kernel with init=/bin/true:

1. No lockdep enabled:

 Performance counter stats for 'qemu_booting_time.sh bzImage' (10 runs):

       2.756558155 seconds time elapsed                    ( +-  0.09% )

2. Lockdep enabled:

 Performance counter stats for 'qemu_booting_time.sh bzImage' (10 runs):

       2.968710420 seconds time elapsed                    ( +-  0.12% )

3. Lockdep enabled + cross-release enabled:

 Performance counter stats for 'qemu_booting_time.sh bzImage' (10 runs):

       3.153839636 seconds time elapsed                    ( +-  0.31% )

4. Lockdep enabled + cross-release enabled + this patch applied:

 Performance counter stats for 'qemu_booting_time.sh bzImage' (10 runs):

       2.963669551 seconds time elapsed                    ( +-  0.11% )

I.e. lockdep cross-release performance is now indistinguishable from
vanilla lockdep.
Bisected-by: NJohan Hovold <johan@kernel.org>
Analyzed-by: NThomas Gleixner <tglx@linutronix.de>
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Reported-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NByungchul Park <byungchul.park@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: amir73il@gmail.com
Cc: axboe@kernel.dk
Cc: darrick.wong@oracle.com
Cc: david@fromorbit.com
Cc: hch@infradead.org
Cc: idryomov@gmail.com
Cc: johannes.berg@intel.com
Cc: kernel-team@lge.com
Cc: linux-block@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-xfs@vger.kernel.org
Cc: oleg@redhat.com
Cc: tj@kernel.org
Link: http://lkml.kernel.org/r/1508921765-15396-5-git-send-email-byungchul.park@lge.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently the kernel relies on firmware to inform it whether or not the
CPU supports HTM and as long as the kernel was built with
CONFIG_PPC_TRANSACTIONAL_MEM=y then it will allow userspace to make
use of the facility.

There may be situations where it would be advantageous for the kernel
to not allow userspace to use HTM, currently the only way to achieve
this is to recompile the kernel with CONFIG_PPC_TRANSACTIONAL_MEM=n.

This patch adds a simple commandline option so that HTM can be
disabled at boot time.
Signed-off-by: NCyril Bur <cyrilbur@gmail.com>
[mpe: Simplify to a bool, move to prom.c, put doco in the right place.
 Always disable, regardless of initial state, to avoid user confusion.]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Implement CPU alternatives, which allows to optionally patch newer
instructions at runtime, based on CPU facilities availability.

A new kernel boot parameter "noaltinstr" disables patching.

Current implementation is derived from x86 alternatives. Although
ideal instructions padding (when altinstr is longer then oldinstr)
is added at compile time, and no oldinstr nops optimization has to be
done at runtime. Also couple of compile time sanity checks are done:
1. oldinstr and altinstr must be <= 254 bytes long,
2. oldinstr and altinstr must not have an odd length.

alternative(oldinstr, altinstr, facility);
alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2);

Both compile time and runtime padding consists of either 6/4/2 bytes nop
or a jump (brcl) + 2 bytes nop filler if padding is longer then 6 bytes.

.altinstructions and .altinstr_replacement sections are part of
__init_begin : __init_end region and are freed after initialization.
Signed-off-by: NVasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Make media doc refs valid.
Signed-off-by: NTom Saeger <tom.saeger@oracle.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Make `input` document refs valid including:
  - joystick
  - joystick-parport
Signed-off-by: NTom Saeger <tom.saeger@oracle.com>
Reviewed-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Make admin-guide document refs valid.
Signed-off-by: NTom Saeger <tom.saeger@oracle.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Commit:

  8309f86c ("x86/tsc: Provide 'tsc=unstable' boot parameter")

added a new 'tsc=unstable' parameter, but didn't document it.

Document it.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: <corbet@lwn.net>
Cc: <pasha.tatashin@oracle.com>
Cc: <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1507539813-11420-1-git-send-email-douly.fnst@cn.fujitsu.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

When rcutorture sees the rcutorture.stall_cpu kernel boot parameter,
it loops with preemption disabled, which does in fact normally
generate an RCU CPU stall warning message.  However, there are test
scenarios that need the stalling CPU to have interrupts disabled.
This commit therefore adds an rcutorture.stall_cpu_irqsoff kernel
boot parameter that causes the stalling CPU to disable interrupts.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Commit 7aa7a036 (PM: docs: Delete the obsolete states.txt
document) forgot to update kernel-parameters.txt with a reference
to the new sleep-states.rst document and it still points to
states.txt that was dropped, so fix it now.

Fixes: 7aa7a036 (PM: docs: Delete the obsolete states.txt document)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

It should say what that <integer> range is and what that integer value
means. I had to look at the code...
Signed-off-by: NBorislav Petkov <bp@suse.de>
[jc: changed non-null to nonzero]
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

ThunderboltIP is a protocol created by Apple to tunnel IP/ethernet
traffic over a Thunderbolt cable. The protocol consists of configuration
phase where each side sends ThunderboltIP login packets (the protocol is
determined by UUID in the XDomain packet header) over the configuration
channel. Once both sides get positive acknowledgment to their login
packet, they configure high-speed DMA path accordingly. This DMA path is
then used to transmit and receive networking traffic.

This patch creates a virtual ethernet interface the host software can
use in the same way as any other networking interface. Once the
interface is brought up successfully network packets get tunneled over
the Thunderbolt cable to the remote host and back.

The connection is terminated by sending a ThunderboltIP logout packet
over the configuration channel. We do this when the network interface is
brought down by user or the driver is unloaded.
Signed-off-by: NAmir Levy <amir.jer.levy@intel.com>
Signed-off-by: NMichael Jamet <michael.jamet@intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NYehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>