With this patch the OProfile Basic Mode Sampling support for System z
is enhanced with a counter file system.  That way hardware sampling
can be configured using the user space tools with only little
modifications.

With the patch by default new cpu_types (s390/z10, s390/z196) are
returned in order to indicate that we are running a CPU which provides
the hardware sampling facility.  Existing user space tools will
complain about an unknown cpu type. In order to be compatible with
existing user space tools the `cpu_type' module parameter has been
added.  Setting the parameter to `timer' will force the module to
return `timer' as cpu_type.  The module will still try to use hardware
sampling if available and the hwsampling virtual filesystem will be
also be available for configuration.  So this has a different effect
than using the generic oprofile module parameter `timer=1'.

If the basic mode sampling is enabled on the machine and the
cpu_type=timer parameter is not used the kernel module will provide
the following virtual filesystem:

/dev/oprofile/0/enabled
/dev/oprofile/0/event
/dev/oprofile/0/count
/dev/oprofile/0/unit_mask
/dev/oprofile/0/kernel
/dev/oprofile/0/user

In the counter file system only the values of 'enabled', 'count',
'kernel', and 'user' are evaluated by the kernel module. Everything
else must contain fixed values.

The 'event' value only supports a single event - HWSAMPLING with value
0.

The 'count' value specifies the hardware sampling rate as it is passed
to the CPU measurement facility.

The 'kernel' and 'user' flags can now be used to filter for samples
when using hardware sampling.

Additionally also the following file will be created:
/dev/oprofile/timer/enabled

This will always be the inverted value of /dev/oprofile/0/enabled. 0
is not accepted without hardware sampling.
Signed-off-by: NAndreas Krebbel <krebbel@linux.vnet.ibm.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

We need this to better test x86 NMI timer mode. Otherwise it is very
hard to setup systems with NMI timer enabled, but we have this e.g. in
virtual machine environments.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

General cleanups to kernel-parameters.txt:
 - add missing $ARCH that are being used/referenced
 - alphabetize the parameter restrictions list
 - spell "IA-64" as listed in arch/ia64/Kconfig instead of "IA64"
 - remove trailing whitespace
 - use hyphen in 32-bit etc.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Usually kernel parameters are documented in kernel-parameters.txt
but user_debug is only documented in the Kconfig. Document the
option and point to the Kconfig help text for more info.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit cdefba03 changed pnp.debug from a boot param to a module param,
which means it needs a value when used on the command line.

CC: Thomas Renninger <trenn@suse.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

There are three choices:

vsyscall=native: Vsyscalls are native code that issues the
corresponding syscalls.

vsyscall=emulate (default): Vsyscalls are emulated by instruction
fault traps, tested in the bad_area path.  The actual contents of
the vsyscall page is the same as the vsyscall=native case except
that it's marked NX.  This way programs that make assumptions about
what the code in the page does will not be confused when they read
that code.

vsyscall=none: Trying to execute a vsyscall will segfault.
Signed-off-by: NAndy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/8449fb3abf89851fd6b2260972666a6f82542284.1312988155.git.luto@mit.eduSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Update kernel-parameters.txt to point users to the authoritative comment
for name_to_dev_t.  In addition, updates other places where some
name_to_dev_t behavior was discussed.  All other references to root=
appear to be for explicit sample usage or just side comments when
discussing other kernel parameters.
Signed-off-by: NWill Drewry <wad@chromium.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

useful for disabling cpuidle to fall back
to architecture-default idle loop

cpuidle drivers and governors will fail to register.
on x86 they'll say so:

intel_idle: intel_idle yielding to (null)
ACPI: acpi_idle yielding to (null)
Signed-off-by: NLen Brown <len.brown@intel.com>

Says for acpi=
                        See also Documentation/power/pm.txt, pci=noacpi

but this file does not exist
Reported-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NLen Brown <len.brown@intel.com>

Instead of unconditionally creating a fixed number of dead loop
devices which need to be investigated by storage handling services,
even when they are never used, we allow distros start with 0
loop devices and have losetup(8) and similar switch to the dynamic
/dev/loop-control interface instead of searching /dev/loop%i for free
devices.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

When a kernel BUG or oops occurs, ChromeOS intends to panic and
immediately reboot, with stacktrace and other messages preserved in RAM
across reboot.

But the longer we delay, the more likely the user is to poweroff and
lose the info.

panic_timeout (seconds before rebooting) is set by panic= boot option or
sysctl or /proc/sys/kernel/panic; but 0 means wait forever, so at
present we have to delay at least 1 second.

Let a negative number mean reboot immediately (with the small cosmetic
benefit of suppressing that newline-less "Rebooting in %d seconds.."
message).
Signed-off-by: NHugh Dickins <hughd@chromium.org>
Signed-off-by: NMandeep Singh Baines <msb@chromium.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Olaf Hering <olaf@aepfle.de>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The idea is from Avi:
| Maybe it's time to kill off bypass_guest_pf=1.  It's not as effective as
| it used to be, since unsync pages always use shadow_trap_nonpresent_pte,
| and since we convert between the two nonpresent_ptes during sync and unsync.
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch implements the kvm bits of the steal time infrastructure.
The most important part of it, is the steal time clock. It is an
continuous clock that shows the accumulated amount of steal time
since vcpu creation. It is supposed to survive cpu offlining/onlining.

[marcelo: fix build with CONFIG_KVM_GUEST=n]
Signed-off-by: NGlauber Costa <glommer@redhat.com>
Acked-by: NRik van Riel <riel@redhat.com>
Tested-by: NEric B Munson <emunson@mgebm.net>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Avi Kivity <avi@redhat.com>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

pstore only allows one backend to be registered at present, but the
system may provide several. Add a parameter to allow the user to choose
which backend will be used rather than just relying on load order.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

There is a problem with putting the first kernel in EFI virtual mode,
it is that when the second kernel comes up it tries to initialize the
EFI again and once we have put EFI in virtual mode we can not really
do that.

Actually, EFI is not necessary for kdump, we can boot the second kernel
with "noefi" parameter, but the boot will mostly fail because 2nd kernel
cannot find RSDP.

In this situation, we introduced "acpi_rsdp=" kernel parameter, so that
kexec-tools can pass the "noefi acpi_rsdp=X" to the second kernel to
make kdump works. The physical address of the RSDP can be got from
sysfs(/sys/firmware/efi/systab).
Signed-off-by: NTakao Indoh <indou.takao@jp.fujitsu.com>
Reviewed-by: NWANG Cong <amwang@redhat.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

    
Multiple attempts to dynamically reallocate pci resources have
unfortunately lead to regressions. Though we continue to fix the
regressions and fine tune the dynamic-reallocation behavior, we have not
reached a acceptable state yet.
    
This patch provides a interim solution. It disables dynamic reallocation
by default, but adds the ability to enable it through pci=realloc kernel
command line parameter.
Tested-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NRam Pai <linuxram@us.ibm.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Back in 2006 the "udbg-immortal" kernel option has been introduced:

  > commit 3b5e905e
  > Author: Benjamin Herrenschmidt <benh@au1.ibm.com>
  > Date:   Wed Jun 7 12:06:20 2006 +1000
  >
  >  [PATCH] powerpc: Add udbg-immortal kernel option

...but I could not find it documented anywhere in the sources.
This patch adds it to Documentation/kernel-parameters.txt.
Signed-off-by: NChristian Kujau <lists@nerdbynature.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Some USB mass-storage devices have bugs that cause them not to handle
the first READ(10) command they receive correctly.  The Corsair
Padlock v2 returns completely bogus data for its first read (possibly
it returns the data in encrypted form even though the device is
supposed to be unlocked).  The Feiya SD/SDHC card reader fails to
complete the first READ(10) command after it is plugged in or after a
new card is inserted, returning a status code that indicates it thinks
the command was invalid, which prevents the kernel from retrying the
read.

Since the first read of a new device or a new medium is for the
partition sector, the kernel is unable to retrieve the device's
partition table.  Users have to manually issue an "hdparm -z" or
"blockdev --rereadpt" command before they can access the device.

This patch (as1470) works around the problem.  It adds a new quirk
flag, US_FL_INVALID_READ10, indicating that the first READ(10) should
always be retried immediately, as should any failing READ(10) commands
(provided the preceding READ(10) command succeeded, to avoid getting
stuck in a loop).  The patch also adds appropriate unusual_devs
entries containing the new flag.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Tested-by: NSven Geggus <sven-usbst@geggus.net>
Tested-by: NPaul Hartman <paul.hartman+linux@gmail.com>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
CC: <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The "authorized_default" module parameter of usbcore controls the default
for the authorized_default variable of each USB host controller.
-1 is authorized for all devices except wireless (default, old behaviour)
0 is unauthorized for all devices
1 is authorized for all devices
Signed-off-by: NCarl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

There are no externally-visible changes with this. In the loop in the
internal __domain_mapping() function, we simply detect if we are mapping:
  - size >= 2MiB, and
  - virtual address aligned to 2MiB, and
  - physical address aligned to 2MiB, and
  - on hardware that supports superpages.

(and likewise for larger superpages).

We automatically use a superpage for such mappings. We never have to
worry about *breaking* superpages, since we trust that we will always
*unmap* the same range that was mapped. So all we need to do is ensure
that dma_pte_clear_range() will also cope with superpages.

Adjust pfn_to_dma_pte() to take a superpage 'level' as an argument, so
it can return a PTE at the appropriate level rather than always
extending the page tables all the way down to level 1. Again, this is
simplified by the fact that we should never encounter existing small
pages when we're creating a mapping; any old mapping that used the same
virtual range will have been entirely removed and its obsolete page
tables freed.

Provide an 'intel_iommu=sp_off' argument on the command line as a
chicken bit. Not that it should ever be required.

==

The original commit seen in the iommu-2.6.git was Youquan's
implementation (and completion) of my own half-baked code which I'd
typed into an email. Followed by half a dozen subsequent 'fixes'.

I've taken the unusual step of rewriting history and collapsing the
original commits in order to keep the main history simpler, and make
life easier for the people who are going to have to backport this to
older kernels. And also so I can give it a more coherent commit comment
which (hopefully) gives a better explanation of what's going on.

The original sequence of commits leading to identical code was:

Youquan Song (3):
      intel-iommu: super page support
      intel-iommu: Fix superpage alignment calculation error
      intel-iommu: Fix superpage level calculation error in dma_pfn_level_pte()

David Woodhouse (4):
      intel-iommu: Precalculate superpage support for dmar_domain
      intel-iommu: Fix hardware_largepage_caps()
      intel-iommu: Fix inappropriate use of superpages in __domain_mapping()
      intel-iommu: Fix phys_pfn in __domain_mapping for sglist pages
Signed-off-by: NYouquan Song <youquan.song@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The noswapaccount parameter has been deprecated since 2.6.38 without any
complaints from users so we can remove it.  swapaccount=0|1 can be used
instead.

As we are removing the parameter we can also clean up swapaccount because
it doesn't have to accept an empty string anymore (to match noswapaccount)
and so we can push = into __setup macro rather than checking "=1" resp.
"=0" strings
Signed-off-by: NMichal Hocko <mhocko@suse.cz>
Cc: Hiroyuki Kamezawa <kamezawa.hiroyuki@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commits ae38c78a
and 00914025 added quirk flags
US_FL_NO_READ_DISC_INFO and US_FL_NO_READ_CAPACITY_16 to
the usb-storage driver. However they did not add the corresponding flags
to adjust_quirks() in usb.c, so there was no facility for a user
to over-ride/add them via the quirks module parameter.
Signed-off-by: NKarl Relton <karllinuxtest.relton@ntlworld.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Enable/disable newly documented SMEP (Supervisor Mode Execution Protection) CPU
feature in kernel. CR4.SMEP (bit 20) is 0 at power-on. If the feature is
supported by CPU (X86_FEATURE_SMEP), enable SMEP by setting CR4.SMEP. New kernel
option nosmep disables the feature even if the feature is supported by CPU.

[ hpa: moved the call to setup_smep() until after the vendor-specific
  initialization; that ensures that CPUID features are unmasked.  We
  will still run it before we have userspace (never mind uncontrolled
  userspace). ]
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
LKML-Reference: <1305157865-31727-1-git-send-email-fenghua.yu@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

acpi_sleep=s4_nonvs is superseded by acpi_sleep=nonvs, so remove it.
Signed-off-by: NWANG Cong <amwang@redhat.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Acked-by: NLen Brown <lenb@kernel.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Fix some minor typos:
 * informations => information
 * there own => their own
 * these => this
Signed-off-by: NSylvestre Ledru <sylvestre.ledru@scilab.org>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a little more info for some of the panic-related kernel parameters.
Fix "oops=panic" to fit in 80 columns.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Reviewed-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

On some architectures, the boot process involves de-registering the boot
console (early boot), initialize drivers and then re-register the console.

This mechanism introduces a window in which no printk can happen on the
console and messages are buffered and then printed once the new console is
available.

If a kernel crashes during this window, all it's left on the boot console
is "console [foo] enabled, bootconsole disabled" making debug of the crash
rather 'interesting'.

By adding "keep_bootcon" option, do not unregister the boot console, that
will allow to printk everything that is happening up to the crash.

The option is clearly meant only for debugging purposes as it introduces
lots of duplicated info printed on console, but will make bug report from
users easier as it doesn't require a kernel build just to figure out where
we crash.
Signed-off-by: NFabio M. Di Nitto <fabbione@fabbione.net>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a cpu is considered stuck, instead of limping along and just printing
a warning, it is sometimes preferred to just panic, let kdump capture the
vmcore and reboot.  This gets the machine back into a stable state quickly
while saving the info that got it into a stuck state to begin with.

Add a Kconfig option to allow users to set the hardlockup to panic
by default.  Also add in a 'nmi_watchdog=nopanic' to override this.

[akpm@linux-foundation.org: fix strncmp length]
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: NWANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The oops=panic cmdline option is not x86 specific, move it to generic code.
Update documentation.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The new behaviour is enabled using the new module parameter
'nfs4_disable_idmapping'.

Note that if the server rejects an unmapped uid or gid, then
the client will automatically switch back to using the idmapper.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If firmware allows us to map all of a partition's memory for DMA on a
particular bridge, create a 1:1 mapping of that memory. Add hooks for
dealing with hotplug events. Dynamic DMA windows can use larger than the
default page size, and we use the largest one possible.
Signed-off-by: NNishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Add a commandline parameter "threadirqs" which forces all interrupts except
those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to
allow retrieving better debug data from crashing interrupt handlers. If
"threadirqs" is not enabled on the kernel command line, then there is no
impact in the interrupt hotpath.

Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after
marking the interrupts which cant be threaded IRQF_NO_THREAD. All
interrupts which have IRQF_TIMER set are implict marked
IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded.

Forced threading hard interrupts also forces all soft interrupt
handling into thread context.

When enabled it might slow down things a bit, but for debugging problems in
interrupt code it's a reasonable penalty as it does not immediately
crash and burn the machine when an interrupt handler is buggy.

Some test results on a Core2Duo machine:

Cache cold run of:
 # time git grep irq_desc

      non-threaded       threaded
 real 1m18.741s          1m19.061s
 user 0m1.874s           0m1.757s
 sys  0m5.843s           0m5.427s

 # iperf -c server
non-threaded
[  3]  0.0-10.0 sec  1.09 GBytes   933 Mbits/sec
[  3]  0.0-10.0 sec  1.09 GBytes   934 Mbits/sec
[  3]  0.0-10.0 sec  1.09 GBytes   933 Mbits/sec
threaded
[  3]  0.0-10.0 sec  1.09 GBytes   939 Mbits/sec
[  3]  0.0-10.0 sec  1.09 GBytes   934 Mbits/sec
[  3]  0.0-10.0 sec  1.09 GBytes   937 Mbits/sec
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110223234956.772668648@linutronix.de>

Update the "log_buf_len" description to use [KMG] syntax for the
buffer size.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The '[KMG]' suffix is commonly described after a number of kernel
parameter values documentation.  Explicitly state its semantics.
Signed-off-by: NAhmed S. Darwish <darwish.07@gmail.com>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Complete the crashkernel= kernel parameter documentation.
Signed-off-by: NAhmed S. Darwish <darwish.07@gmail.com>
Acked-by: NSimon Horman <horms@verge.net.au>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A B C D E ...
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Enable async PF in a guest if async PF capability is discovered.
Acked-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

i8042 controller present in Dell Vostro V13 errorneously signals spurious
timeouts.

Introduce i8042.notimeout parameter for ignoring i8042-signalled timeouts
and apply this quirk automatically for Dell Vostro V13, based on DMI match.

In addition to that, this machine also needs to be added to nomux blacklist.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

re:
  commit e9d376f0
  Author: Jason Baron <jbaron@redhat.com>
  Date:   Thu Feb 5 11:51:38 2009 -0500

    dynamic debug: combine dprintk and dynamic printk

Above commit obsoleted the kernel parameter, and even removed its
entry in kernel-parameters.txt, but got reinsterted through
0cb55ad2 ("docs: alphabetize entries in kernel-parameters.txt")
Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>