Impact: Fix possible failure to calibrate the TSC on Vmware near 4 GHz
The current version of the code to get the tsc frequency from
the VMware hypervisor, will be broken on processor with frequency
(4G-1) HZ, because on such processors eax will have UINT_MAX
and that would be legitimate.
We instead check that EBX did change to decide if we were able to
read the frequency from the hypervisor.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: Changes timekeeping on Vmware (or with tsc=reliable).
This is achieved by resetting the CLOCKSOURCE_MUST_VERIFY flag.
We add a tsc=reliable commandline option to enable this.
This enables legacy hardware without HPET, LAPIC, or ACPI timers
to enter high-resolution timer mode.
Along with that have extended this to be used in virtualization environement
too. Now we also set this flag if the X86_FEATURE_TSC_RELIABLE bit is set.
This is important since there is a wrap-around problem with the acpi_pm timer.
The acpi_pm counter is just 24bits and this can overflow in ~4 seconds. With
the NO_HZ kernels in virtualized environment, there can be situations when
the guest is descheduled for longer duration, as a result we may miss the wrap
of the acpi counter. When TSC is used as a clocksource and acpi_pm timer is
being used as the watchdog clocksource this error in acpi_pm results in TSC
being marked as unstable, and essentially results in time dropping in chunks
of 4 seconds whenever this wrap is missed. Since the virtualized TSC is
reliable on VMware, we should always use the TSCs clocksource on VMware, so
we skip the verfication at runtime, by checking for the feature bit.
Since we reset the flag for mgeode systems too, i have combined
the mgeode case with the feature bit check.
Signed-off-by: Jeff Hansen <jhansen@cardaccess-inc.com>
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Dan Hecht <dhecht@vmware.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: Changes timebase calibration on Vmware.
Use the synthetic TSC_RELIABLE bit to workaround virtualization anomalies.
Virtual TSCs can be kept nearly in sync, but because the virtual TSC
offset is set by software, it's not perfect. So, the TSC
synchronization test can fail. Even then the TSC can be used as a
clocksource since the VMware platform exports a reliable TSC to the
guest for timekeeping purposes. Use this bit to check if we need to
skip the TSC sync checks.
Along with this also set the CONSTANT_TSC bit when on VMware, since we
still want to use TSC as clocksource on VM running over hardware which
has unsynchronized TSC's (opteron's), since the hypervisor will take
care of providing consistent TSC to the guest.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Dan Hecht <dhecht@vmware.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: Changes timebase calibration on Vmware.
v3->v2 : Abstract the hypervisor detection and feature (tsc_freq) request
behind a hypervisor.c file
v2->v1 : Add a x86_hyper_vendor field to the cpuinfo_x86 structure.
This avoids multiple calls to the hypervisor detection function.
This patch adds function to detect if we are running under VMware.
The current way to check if we are on VMware is following,
# check if "hypervisor present bit" is set, if so read the 0x40000000
cpuid leaf and check for "VMwareVMware" signature.
# if the above fails, check the DMI vendors name for "VMware" string
if we find one we query the VMware hypervisor port to check if we are
under VMware.
The DMI + "VMware hypervisor port check" is needed for older VMware products,
which don't implement the hypervisor signature cpuid leaf.
Also note that since we are checking for the DMI signature the hypervisor
port should never be accessed on native hardware.
This patch also adds a hypervisor_get_tsc_freq function, instead of
calibrating the frequency which can be error prone in virtualized
environment, we ask the hypervisor for it. We get the frequency from
the hypervisor by accessing the hypervisor port if we are running on VMware.
Other hypervisors too can add code to the generic routine to get frequency on
their platform.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Dan Hecht <dhecht@vmware.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: None, bit reservation only
Add a synthetic TSC_RELIABLE feature bit which will be used to mark
TSC as reliable so that we could skip all the runtime checks for
TSC stablity, which have false positives in virtual environment.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Dan Hecht <dhecht@vmware.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: build fix on certain UP configs
fix:
arch/x86/kernel/cpu/common.c: In function 'cpu_init':
arch/x86/kernel/cpu/common.c:1141: error: 'boot_cpu_id' undeclared (first use in this function)
arch/x86/kernel/cpu/common.c:1141: error: (Each undeclared identifier is reported only once
arch/x86/kernel/cpu/common.c:1141: error: for each function it appears in.)
Pull in asm/smp.h on UP, so that we get the definition of
boot_cpu_id.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
lguest: fix irq vectors.
lguest: fix early_ioremap.
lguest: fix example launcher compile after moved asm-x86 dir.
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: remove sched-design.txt from 00-INDEX
sched: change sched_debug's mode to 0444
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ftrace: handle archs that do not support irqs_disabled_flags
do_IRQ: cannot handle IRQ -1 vector 0x20 cpu 0
------------[ cut here ]------------
kernel BUG at arch/x86/kernel/irq_32.c:219!
We're not ISA: we have a 1:1 mapping from vectors to irqs.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
dmi_scan_machine breaks under lguest:
lguest: unhandled trap 14 at 0xc04edeae (0xffa00000)
This is because we use current_cr3 for the read_cr3() paravirt
function, and it isn't set until the first cr3 change. We got away
with it until this happened.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
fix:
arch/x86/kernel/cpu/common.c: In function 'early_identify_cpu':
arch/x86/kernel/cpu/common.c:553: error: 'struct cpuinfo_x86' has no member named 'cpu_index'
as cpu_index is only available on SMP.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix /proc/cpuinfo output on x86/Voyager
Ever since
| commit 92cb7612ae
| Author: Mike Travis <travis@sgi.com>
| Date: Fri Oct 19 20:35:04 2007 +0200
|
| x86: convert cpuinfo_x86 array to a per_cpu array
We've had an extra field in cpuinfo_x86 which is cpu_index.
Unfortunately, voyager has never initialised this, although the only
noticeable impact seems to be that /proc/cpuinfo shows all zeros for
the processor ids.
Anyway, fix this by initialising the boot CPU properly and setting the
index when the secondaries update.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build fix on x86/Voyager
Given commits like this:
| Author: Suresh Siddha <suresh.b.siddha@intel.com>
| Date: Tue Jul 29 10:29:19 2008 -0700
|
| x86, xsave: enable xsave/xrstor on cpus with xsave support
Which deliberately expose boot cpu dependence to pieces of the system,
I think it's time to explicitly have a variable for it to prevent this
continual misassumption that the boot CPU is zero.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build fix on non-lockdep architectures
Some architectures do not support a way to read the irq flags that
is set from "local_irq_save(flags)" to determine if interrupts were
disabled or enabled. Ftrace uses this information to display to the user
if the trace occurred with interrupts enabled or disabled.
Besides the fact that those archs that do not support this will fail to
compile, unless they fix it, we do not want to have the trace simply
say interrupts were not disabled or they were enabled, without knowing
the real answer.
This patch adds a 'X' in the output to let the user know that the
architecture they are running on does not support a way for the tracer
to determine if interrupts were enabled or disabled. It also lets those
same archs compile with tracing enabled.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: allow /dev/mem mmaps on non-PAT CPUs/platforms
Fix mmap to /dev/mem when CONFIG_X86_PAT is off and CONFIG_STRICT_DEVMEM is
off
mmap to /dev/mem on kernel memory has been failing since the
introduction of PAT (CONFIG_STRICT_DEVMEM=n case). Seems like
the check to avoid cache aliasing with PAT is kicking in even
when PAT is disabled. The bug seems to have crept in 2.6.26.
This patch makes sure that the mmap to regular
kernel memory succeeds if CONFIG_STRICT_DEVMEM=n and
PAT is disabled, and the checks to avoid cache aliasing
still happens if PAT is enabled.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Tested-by: Tim Sirianni <tim@scalemp.com>
Cc: <stable@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix build failure on x86/Voyager
Before:
| commit 329513a35d
| Author: Yinghai Lu <yhlu.kernel@gmail.com>
| Date: Wed Jul 2 18:54:40 2008 -0700
|
| x86: move prefill_possible_map calling early
prefill_possible_mask() was hidden under CONFIG_HOTPLUG_CPU rendering
it invisitble to voyager. Since this commit it's exposed, but not
provided by the voyager subarch, so add a dummy stub to fix the link
breakage.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix x86/Voyager boot
CONFIG_SMP is used for features which work on *all* x86 boxes.
CONFIG_X86_SMP is used for standard PC like x86 boxes (for things like
multi core and apics)
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: boot up secondary CPUs as well on x86/Voyager systems
This commit:
| commit 3e9704739d
| Author: Glauber Costa <gcosta@redhat.com>
| Date: Wed May 28 13:01:54 2008 -0300
|
| x86: boot secondary cpus through initial_code
removed the use of initialize_secondary. However, it didn't update
voyager, so the secondary cpus no longer boot. Fix this by adding the
initial_code switch to voyager as well.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes:
Fix incompatibility with versions of Perl less than 5.6.0
kbuild: do not include arch/<ARCH>/include/asm in find-sources twice.
kbuild: tag with git revision when git describe is missing
kbuild: prevent modpost from looking for a .cmd file for a static library linked into a module
kbuild: fix KBUILD_EXTRA_SYMBOLS
adjust init section definitions
scripts/checksyscalls.sh: fix for non-gnu sed
scripts/package: don't break if %{_smp_mflags} isn't set
kbuild: setlocalversion: dont include svn change count
kbuild: improve check-symlink
kbuild: mkspec - fix build rpm
* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
[PATCH] Switch all my contributions stuff to a single common address
[WATCHDOG] pci: use pci_ioremap_bar() in drivers/watchdog
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
CHAR: Delete old and now unused M48T35 RTC driver for SGI IP27.
CHAR: Delete old and now unused DS1286 driver.
MIPS: Sort out CPU type to name translation.
MIPS: Use the new byteorder headers
MIPS: Probe for watch registers on cores of all vendors, not just MTI.
MIPS: Switch FPU emulator trap to BREAK instruction.
MIPS: SMP: Do not initialize __cpu_number_map/__cpu_logical_map for CPU 0.
MIPS: Consider value of c0_ebase when computing value of exception base.
MIPS: Clean up MIPSxx-optimized bitop functions
MIPS: New feature test macro cpu_has_mips_r
MIPS: RBTX4927: Add GPIO-LED support
MIPS: TXx9: Fix RBTX4939 ethernet address initialization
* git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6:
fdomain_cs: Sort out modules with duplicate description
pcmcia: Whine harder about use of EXCLUSIVE
pcmcia: IRQ_TYPE_EXCLUSIVE is long obsoleted
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
SUNRPC: Fix potential race in put_rpccred()
SUNRPC: Fix rpcauth_prune_expired
NFS: Convert nfs_attr_generation_counter into an atomic_long
SUNRPC: Respond promptly to server TCP resets
When we close we must clear the extra reference we got when we read
port->tty. Setting the port tty NULL will clear the kref held by the driver
but not the one we obtained ourselves while doing the lookup.
Signed-off-by: Alan Cox <alan@redhat.com>
Tested-by: Helge Hafting <helge.hafting@aitel.hist.no>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
i2c-s3c2410: Correct use of ! and &
i2c: The i2c mailing list is moving
scx200_i2c: Add missing class parameter
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
USB: prevent autosuspend during hub initialization
USB: Unusual dev for the "Kyocera / Contax SL300R T*" digital camera.
USB: usbtmc: Use explicit unsigned type for input buffer instead of char*
USB: fix crash when URBs are unlinked after the device is gone
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ALSA: ASoC: Fix WM9713 ALC Decay Time name
ALSA: ASoC: Fix some minor errors in mpc5200 psc i2s driver
ALSA: ASoC: Fix mono controls after conversion to support full int masks
ALSA: sound/ice1712: indentation & braces disagree - add braces
ALSA: usb - Add quirk for Edirol UA-25EX advanced modes
sound: struct device - replace bus_id with dev_name(), dev_set_name()
ALSA: hda - Add reboot notifier
ALSA: Warn when control names are truncated
ALSA: intel8x0 - add Dell Optiplex GX620 (AD1981B) to AC97 clock whitelist
ALSA: hda - Fix SPDIF mute on IDT/STAC codecs
ALSA: hda: Add HDA vendor ID for Wolfson Microelectronics
ALSA: hda - Add another HP model for AD1884A
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ftrace: fix trace_nop config select
ftrace: perform an initialization for ftrace to enable it
Fix compile error below:
LD drivers/spi/built-in.o
CC [M] drivers/spi/spi_gpio.o
In file included from drivers/spi/spi_gpio.c:26:
include/linux/spi/spi_bitbang.h:23: error: field `work' has incomplete type
make[2]: *** [drivers/spi/spi_gpio.o] Error 1
make[1]: *** [drivers/spi] Error 2
make: *** [drivers] Error 2
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Junjiro R. Okajima reported a problem where knfsd crashes if you are
using it to export shmemfs objects and run strict overcommit. In this
situation the current->mm based modifier to the overcommit goes through a
NULL pointer.
We could simply check for NULL and skip the modifier but we've caught
other real bugs in the past from mm being NULL here - cases where we did
need a valid mm set up (eg the exec bug about a year ago).
To preserve the checks and get the logic we want shuffle the checking
around and add a new helper to the vm_ security wrappers
Also fix a current->mm reference in nommu that should use the passed mm
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix build]
Reported-by: Junjiro R. Okajima <hooanon05@yahoo.co.jp>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ipmi_devintf module contains the userspace interface for IPMI devices,
yet will not be loaded automatically with a system interface handler
driver.
Add a MODULE_ALIAS for the "platform:ipmi_si" MODALIAS exported by the
ipmi_si driver, so that userspace knows of the recommendation.
Signed-off-by: Scott James Remnant <scott@ubuntu.com>
Cc: Tim Gardner <tcanonical@tpi.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: <stable@kernel.org> [2.6.27.x, maybe earlier?]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix deadlock in fb_compat_ioctl. fb_compat_ioctl acquires a mutex and
calls fb_ioctl that tries to acquire that mutex too. A regression added
during BKL removal.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tAdd adds device_init_wakeup() ivokation to probe function of
s3c2410_rtc_driver. Without of this wakealarm sysfs attribute does not
initialise.
Signed-off-by: Yauhen Kharuzhy <jekhor@gmail.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Put the kernel-doc for might_sleep() _immediately_ before the macro
(no intervening lines). Otherwise kernel-doc complains like so:
Warning(linux-2.6.27-rc3-git2//include/linux/kernel.h:129): No description found for parameter 'file'
Warning(linux-2.6.27-rc3-git2//include/linux/kernel.h:129): No description found for parameter 'line'
because kernel-doc is looking at the wrong function prototype (i.e.,
__might_sleep). [Yes, I have a todo note to myself to check/warn for that
inconsistency in scripts/kernel-doc.]
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <Uwe.Kleine-Koenig@digi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alok Kataria