Commit graph

11259 commits

Author SHA1 Message Date
H. Peter Anvin
4532b305e8 x86, asm: Clean up and simplify <asm/cmpxchg.h>
Remove the __xg() hack to create a memory barrier near xchg and
cmpxchg; it has been there since 1.3.11 but should not be necessary
with "asm volatile" and a "memory" clobber, neither of which were
there in the original implementation.

However, we *should* make this a volatile reference.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <AANLkTikAmaDPji-TVDarmG1yD=fwbffcsmEU=YEuP+8r@mail.gmail.com>
2010-07-28 15:24:09 -07:00
Hans Rosenfeld
1be85a6d93 x86, cpu: Use AMD errata checking framework for erratum 383
Use the AMD errata checking framework instead of open-coding the test.

Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
LKML-Reference: <1280336972-865982-3-git-send-email-hans.rosenfeld@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-07-28 13:12:31 -07:00
Hans Rosenfeld
9d8888c2a2 x86, cpu: Clean up AMD erratum 400 workaround
Remove check_c1e_idle() and use the new AMD errata checking framework
instead.

Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
LKML-Reference: <1280336972-865982-2-git-send-email-hans.rosenfeld@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-07-28 13:12:11 -07:00
Hans Rosenfeld
d78d671db4 x86, cpu: AMD errata checking framework
Errata are defined using the AMD_LEGACY_ERRATUM() or AMD_OSVW_ERRATUM()
macros. The latter is intended for newer errata that have an OSVW id
assigned, which it takes as first argument. Both take a variable number
of family-specific model-stepping ranges created by AMD_MODEL_RANGE().

Iff an erratum has an OSVW id, OSVW is available on the CPU, and the
OSVW id is known to the hardware, it is used to determine whether an
erratum is present. Otherwise, the model-stepping ranges are matched
against the current CPU to find out whether the erratum applies.

For certain special errata, the code using this framework might have to
conduct further checks to make sure an erratum is really (not) present.

Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
LKML-Reference: <1280336972-865982-1-git-send-email-hans.rosenfeld@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-07-28 13:12:04 -07:00
H. Peter Anvin
7d50d07da2 Merge remote branch 'linus/master' into x86/cpu 2010-07-28 13:11:28 -07:00
Eric Paris
bbaa4168b2 fanotify: sys_fanotify_mark declartion
This patch simply declares the new sys_fanotify_mark syscall

int fanotify_mark(int fanotify_fd, unsigned int flags, u64_mask,
		  int dfd const char *pathname)

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 09:58:55 -04:00
Eric Paris
11637e4b7d fanotify: fanotify_init syscall declaration
This patch defines a new syscall fanotify_init() of the form:

int sys_fanotify_init(unsigned int flags, unsigned int event_f_flags,
		      unsigned int priority)

This syscall is used to create and fanotify group.  This is very similar to
the inotify_init() syscall.

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 09:58:55 -04:00
H. Peter Anvin
18642a57df x86, vdso: Don't quote $nm in the script for checking vdso references
Don't quote $nm in the script for checking the vdso for external
references.  Doing so breaks multiword constructs, like using
CROSS_COMPILE='ccache '.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <20100728134252.2e4c27cf.sfr@canb.auug.org.au>
2010-07-27 23:52:29 -07:00
H. Peter Anvin
69309a0590 x86, asm: Clean up and simplify set_64bit()
Clean up and simplify set_64bit().  This code is quite old (1.3.11)
and contains a fair bit of auxilliary machinery that current versions
of gcc handle just fine automatically.  Worse, the auxilliary
machinery can actually cause an unnecessary spill to memory.

Furthermore, the loading of the old value inside the loop in the
32-bit case is unnecessary: if the value doesn't match, the CMPXCHG8B
instruction will already have loaded the "new previous" value for us.

Clean up the comment, too, and remove page references to obsolete
versions of the Intel SDM.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <tip-*@vger.kernel.org>
2010-07-27 23:29:52 -07:00
H. Peter Anvin
d3608b5681 Merge remote branch 'origin/x86/urgent' into x86/asm 2010-07-27 23:28:28 -07:00
Jeremy Fitzhardinge
c7f52cdc2f support multiple .discard.* sections to avoid section type conflicts
gcc 4.4.4 will complain if you use a .discard section for both text and
data ("causes a section type conflict").  Add support for ".discard.*"
sections, and use .discard.text for a dummy function in the x86
RESERVE_BRK() macro.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-27 22:45:19 -07:00
H. Peter Anvin
113fc5a6e8 x86: Add memory modify constraints to xchg() and cmpxchg()
xchg() and cmpxchg() modify their memory operands, not merely read
them.  For some versions of gcc the "memory" clobber has apparently
dealt with the situation, but not for all.

Originally-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Glauber Costa <glommer@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Peter Palfrader <peter@palfrader.org>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Zachary Amsden <zamsden@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: <stable@kernel.org>
LKML-Reference: <4C4F7277.8050306@zytor.com>
2010-07-27 17:14:02 -07:00
Joerg Roedel
7a42c4ff02 Merge branches 'iommu-api/2.6.36' and 'amd-iommu/2.6.36' into iommu/2.6.36 2010-07-27 18:19:32 +02:00
Konrad Rzeszutek Wilk
bbbe57386e pci-swiotlb-xen: Add glue code to setup dma_ops utilizing xen_swiotlb_*
functions.

We add the glue code that sets up a dma_ops structure with the
xen_swiotlb_* functions. The code turns on xen_swiotlb flag
when it detects it is running under Xen and it is either
in privileged mode or the iommu=soft flag was passed in.

It also disables the bare-metal SWIOTLB if the Xen-SWIOTLB has
been enabled.

Note: The Xen-SWIOTLB is only built when CONFIG_XEN is enabled.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Albert Herranz <albert_herranz@yahoo.es>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
2010-07-27 11:51:02 -04:00
Jeremy Fitzhardinge
d2cb214551 xen/mmu: inhibit vmap aliases rather than trying to clear them out
Rather than trying to deal with aliases once they appear, just completely
inhibit them.  Mostly the removal of aliases was managable, but it comes
unstuck in xen_create_contiguous_region() because it gets executed at
interrupt time (as a result of dma_alloc_coherent()), which causes all
sorts of confusion in the vmap code, as it was never intended to be run
in interrupt context.

This has the unfortunate side effect of removing all the unmap batching
the vmap code so carefully added, but that can't be helped.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-07-27 11:50:41 -04:00
Joerg Roedel
80a506b8fd x86/amd-iommu: Export cache-coherency capability
This patch exports the capability of the AMD IOMMU to force
cache coherency of DMA transactions through the IOMMU-API.
This is required to disable some nasty hacks in KVM when
this capability is not available.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2010-07-27 17:14:24 +02:00
John Stultz
f12a15be63 x86: Convert common clocksources to use clocksource_register_hz/khz
This converts the most common of the x86 clocksources over to use
clocksource_register_hz/khz.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-11-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-27 12:40:55 +02:00
John Stultz
7615856ebf timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset
update_vsyscall() did not provide the wall_to_monotoinc offset,
so arch specific implementations tend to reference wall_to_monotonic
directly. This limits future cleanups in the timekeeping core, so
this patch fixes the update_vsyscall interface to provide
wall_to_monotonic, allowing wall_to_monotonic to be made static
as planned in Documentation/feature-removal-schedule.txt

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tony Luck <tony.luck@intel.com>
LKML-Reference: <1279068988-21864-7-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-27 12:40:54 +02:00
John Stultz
592913ecb8 time: Kill off CONFIG_GENERIC_TIME
Now that all arches have been converted over to use generic time via
clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME
config option and simplify the generic code.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-27 12:40:54 +02:00
John Stultz
8c73626ab2 x86: Fix vtime/file timestamp inconsistencies
Due to vtime calling vgettimeofday(), its possible that an application
could call  time();create("stuff",O_RDRW);  only to see the file's
creation timestamp to be before the value returned by time.

A similar way to reproduce the issue is to compare the vsyscall time()
with the syscall time(), and observe ordering issues.

The modified test case from Oleg Nesterov below can illustrate this:

int main(void)
{
	time_t sec1,sec2;
	do {
		sec1 = time(&sec2);
		sec2 = syscall(__NR_time, NULL);
	} while (sec1 <= sec2);

	printf("vtime: %d.000000\n", sec1);
	printf("time: %d.000000\n", sec2);
	return 0;
}

The proper fix is to make vtime use the same time value as
current_kernel_time() (which is exported via update_vsyscall) instead of
vgettime().

Thanks to Jiri Olsa for bringing up the issue and catching bugs in
earlier verisons of this fix.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
LKML-Reference: <1279068988-21864-2-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-27 12:40:53 +02:00
Jeremy Fitzhardinge
b43275d661 xen/pvhvm: fix build problem when !CONFIG_XEN
x86_hyper_xen_hvm is only defined when Xen is enabled in the kernel
config.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-26 23:13:28 -07:00
Stefano Stabellini
5915100106 x86: Call HVMOP_pagetable_dying on exit_mmap.
When a pagetable is about to be destroyed, we notify Xen so that the
hypervisor can clear the related shadow pagetable.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-26 23:13:26 -07:00
Stefano Stabellini
c1c5413ad5 x86: Unplug emulated disks and nics.
Add a xen_emul_unplug command line option to the kernel to unplug
xen emulated disks and nics.

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

The user can specify xen_emul_unplug=ignore to enable PV drivers on HVM
even if the host platform doesn't support unplug.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-26 23:13:25 -07:00
Stefano Stabellini
409771d258 x86: Use xen_vcpuop_clockevent, xen_clocksource and xen wallclock.
Use xen_vcpuop_clockevent instead of hpet and APIC timers as main
clockevent device on all vcpus, use the xen wallclock time as wallclock
instead of rtc and use xen_clocksource as clocksource.
The pv clock algorithm needs to work correctly for the xen_clocksource
and xen wallclock to be usable, only modern Xen versions offer a
reliable pv clock in HVM guests (XENFEAT_hvm_safe_pvclock).

Using the hpet as clocksource means a VMEXIT every time we read/write to
the hpet mmio addresses, pvclock give us a better rating without
VMEXITs. Same goes for the xen wallclock and xen_vcpuop_clockevent

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Don Dutile <ddutile@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-26 23:13:25 -07:00
Linus Torvalds
1a041a23da Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Do not try to disable hpet if it hasn't been initialized before
  x86, i8259: Only register sysdev if we have a real 8259 PIC
2010-07-26 16:02:07 -07:00
Linus Torvalds
ee13cbdec4 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] powernow-k8: Limit Pstate transition latency check
  [CPUFREQ] Fix PCC driver error path
  [CPUFREQ] fix double freeing in error path of pcc-cpufreq
  [CPUFREQ] pcc driver should check for pcch method before calling _OSC
  [CPUFREQ] fix memory leak in cpufreq_add_dev
  [CPUFREQ] revert "[CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)"
2010-07-26 15:35:53 -07:00
Borislav Petkov
3581ced3b6 [CPUFREQ] powernow-k8: Limit Pstate transition latency check
The Pstate transition latency check was added for broken F10h BIOSen
which wrongly contain a value of 0 for transition and bus master
latency. Fam11h and later, however, (will) have similar transition
latency so extend that behavior for them too.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-07-26 15:25:34 -04:00
Matthew Garrett
179ee43465 [CPUFREQ] Fix PCC driver error path
The PCC cpufreq driver unmaps the mailbox address range if any CPUs fail to
initialise, but doesn't do anything to remove the registered CPUs from the
cpufreq core resulting in failures further down the line. We're better off
simply returning a failure - the cpufreq core will unregister us cleanly if
we end up with no successfully registered CPUs. Tidy up the failure path
and also add a sanity check to ensure that the firmware gives us a realistic
frequency - the core deals badly with that being set to 0.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-07-26 15:25:34 -04:00
Daniel J Blueman
3847d223f2 [CPUFREQ] fix double freeing in error path of pcc-cpufreq
Prevent double freeing on error path.

Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-07-26 15:25:34 -04:00
Matthew Garrett
47f8bcf362 [CPUFREQ] pcc driver should check for pcch method before calling _OSC
The pcc specification documents an _OSC method that's incompatible with the
one defined as part of the ACPI spec. This shouldn't be a problem as both
are supposed to be guarded with a UUID. Unfortunately approximately nobody
(including HP, who wrote this spec) properly check the UUID on entry to the
_OSC call. Right now this could result in surprising behaviour if the pcc
driver performs an _OSC call on a machine that doesn't implement the pcc
specification. Check whether the PCCH method exists first in order to reduce
this probability.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-07-26 15:25:34 -04:00
Linus Torvalds
20ba5efb9c Merge branch 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Use kmalloc() instead of vmalloc() for KVM_[GS]ET_MSR
  KVM: MMU: fix conflict access permissions in direct sp
2010-07-26 08:18:18 -07:00
Len Brown
0e1cf38889 Merge branch 'bugzilla-16396' into release 2010-07-24 23:26:22 -04:00
Rafael J. Wysocki
72ad5d77fb ACPI / Sleep: Allow the NVS saving to be skipped during suspend to RAM
Commit 2a6b69765a
(ACPI: Store NVS state even when entering suspend to RAM) caused the
ACPI suspend code save the NVS area during suspend and restore it
during resume unconditionally, although it is known that some systems
need to use acpi_sleep=s4_nonvs for hibernation to work.  To allow
the affected systems to avoid saving and restoring the NVS area
during suspend to RAM and resume, introduce kernel command line
option acpi_sleep=nonvs and make acpi_sleep=s4_nonvs work as its
alias temporarily (add acpi_sleep=s4_nonvs to the feature removal
file).

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16396 .

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: tomas m <tmezzadra@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-07-24 23:26:09 -04:00
Stefano Stabellini
ff4878089e x86: Do not try to disable hpet if it hasn't been initialized before
hpet_disable is called unconditionally on machine reboot if hpet support
is compiled in the kernel.
hpet_disable only checks if the machine is hpet capable but doesn't make
sure that hpet has been initialized.

[ tglx: Made it a one liner and removed the redundant hpet_address check ]

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Venkatesh Pallipadi <venki@google.com>
LKML-Reference: <alpine.DEB.2.00.1007211726240.22235@kaball-desktop>
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-23 12:53:00 +02:00
Avi Kivity
7a73c0283d KVM: Use kmalloc() instead of vmalloc() for KVM_[GS]ET_MSR
We don't need more than a page, and vmalloc() is slower (much
slower recently due to a regression).

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-07-23 09:07:14 +03:00
Xiao Guangrong
6aa0b9dec5 KVM: MMU: fix conflict access permissions in direct sp
In no-direct mapping, we mark sp is 'direct' when we mapping the
guest's larger page, but its access is encoded form upper page-struct
entire not include the last mapping, it will cause access conflict.

For example, have this mapping:
        [W]
      / PDE1 -> |---|
  P[W]          |   | LPA
      \ PDE2 -> |---|
        [R]

P have two children, PDE1 and PDE2, both PDE1 and PDE2 mapping the
same lage page(LPA). The P's access is WR, PDE1's access is WR,
PDE2's access is RO(just consider read-write permissions here)

When guest access PDE1, we will create a direct sp for LPA, the sp's
access is from P, is W, then we will mark the ptes is W in this sp.

Then, guest access PDE2, we will find LPA's shadow page, is the same as
PDE's, and mark the ptes is RO.

So, if guest access PDE1, the incorrect #PF is occured.

Fixed by encode the last mapping access into direct shadow page

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-07-23 09:07:04 +03:00
Stefano Stabellini
016b6f5fe8 xen: Add suspend/resume support for PV on HVM guests.
Suspend/resume requires few different things on HVM: the suspend
hypercall is different; we don't need to save/restore memory related
settings; except the shared info page and the callback mechanism.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22 16:46:21 -07:00
Sheng Yang
38e20b07ef x86/xen: event channels delivery on HVM.
Set the callback to receive evtchns from Xen, using the
callback vector delivery mechanism.

The traditional way for receiving event channel notifications from Xen
is via the interrupts from the platform PCI device.
The callback vector is a newer alternative that allow us to receive
notifications on any vcpu and doesn't need any PCI support: we allocate
a vector exclusively to receive events, in the vector handler we don't
need to interact with the vlapic, therefore we avoid a VMEXIT.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22 16:45:59 -07:00
Sheng Yang
bee6ab53e6 x86: early PV on HVM features initialization.
Initialize basic pv on hvm features adding a new Xen HVM specific
hypervisor_x86 structure.

Don't try to initialize xen-kbdfront and xen-fbfront when running on HVM
because the backends are not available.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22 16:45:35 -07:00
Jeremy Fitzhardinge
18f19aa62a xen: Add support for HVM hypercalls.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2010-07-22 16:45:31 -07:00
Len Brown
4a973f2495 Merge branch 'bugzilla-15886' into release 2010-07-22 18:18:28 -04:00
Len Brown
718be4aaf3 ACPI: skip checking BM_STS if the BIOS doesn't ask for it
It turns out that there is a bit in the _CST for Intel FFH C3
that tells the OS if we should be checking BM_STS or not.

Linux has been unconditionally checking BM_STS.
If the chip-set is configured to enable BM_STS,
it can retard or completely prevent entry into
deep C-states -- as illustrated by turbostat:

http://userweb.kernel.org/~lenb/acpi/utils/pmtools/turbostat/

ref: Intel Processor Vendor-Specific ACPI Interface Specification
table 4 "_CST FFH GAS Field Encoding"
Bit 1: Set to 1 if OSPM should use Bus Master avoidance for this C-state

https://bugzilla.kernel.org/show_bug.cgi?id=15886

Signed-off-by: Len Brown <len.brown@intel.com>
2010-07-22 16:54:27 -04:00
Thomas Renninger
4c21adf26f x86 cpufreq, perf: Make trace_power_frequency cpufreq driver independent
and fix the broken case if a core's frequency depends on others.

trace_power_frequency was only implemented in a rather ungeneric
way in acpi-cpufreq driver's target() function only.

-> Move the call to trace_power_frequency to
   cpufreq.c:cpufreq_notify_transition() where CPUFREQ_POSTCHANGE
   notifier is triggered.
   This will support power frequency tracing by all cpufreq
   drivers.

trace_power_frequency did not trace frequency changes correctly
when the userspace governor was used or when CPU cores'
frequency depend on each other.

-> Moving this into the CPUFREQ_POSTCHANGE notifier and pass the cpu
   which gets switched automatically fixes this.

Robert Schoene provided some important fixes on top of my
initial quick shot version which are integrated in this patch:
- Forgot some changes in power_end trace (TP_printk/variable names)
- Variable dummy in power_end must now be cpu_id
- Use static 64 bit variable instead of unsigned int for cpu_id

[akpm@linux-foundation.org: build fix]
Signed-off-by: Thomas Renninger <trenn@suse.de>
Cc: davej@codemonkey.org.uk
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Dave Jones <davej@codemonkey.org.uk>
Acked-by: Arjan van de Ven <arjan@infradead.org>
Cc: Robert Schoene <robert.schoene@tu-dresden.de>
Tested-by: Robert Schoene <robert.schoene@tu-dresden.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2010-07-22 12:08:27 +02:00
Brian Gerst
650fb4393d x86-64: Simplify loading initial_gs
Load initial_gs as two 32-bit values instead of splitting a 64-bit value.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1279371808-24804-3-git-send-email-brgerst@gmail.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-07-21 21:23:51 -07:00
Brian Gerst
cfaa71ee97 x86: Use symbolic MSR names
Use symbolic MSR names instead of hardcoding the MSR index.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1279371808-24804-2-git-send-email-brgerst@gmail.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-07-21 21:23:40 -07:00
Brian Gerst
8c06585d64 x86: Remove redundant K6 MSRs
MSR_K6_EFER is unused, and MSR_K6_STAR is redundant with MSR_STAR.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1279371808-24804-1-git-send-email-brgerst@gmail.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-07-21 21:23:05 -07:00
Roland McGrath
0327559151 x86: auditsyscall: fix fastpath return value after reschedule
In the CONFIG_AUDITSYSCALL fast-path for x86 64-bit system calls,
we can pass a bad return value and/or error indication for the
system call to audit_syscall_exit().  This happens when
TIF_NEED_RESCHED was set as the system call returned, so we went
out to schedule() and came back to the exit-audit fast-path.  The
fix is to reload the user return value register from the pt_regs
before using it for audit_syscall_exit().

Both the 32-bit kernel's fast path and the 64-bit kernel's 32-bit
system call fast paths work slightly differently, so that they
always leave the fast path entirely to reschedule and don't return
there, so they don't have the analogous bugs.

Reported-by: Alexander Viro <aviro@redhat.com>
Signed-off-by: Roland McGrath <roland@redhat.com>
2010-07-21 17:44:12 -07:00
H. Peter Anvin
1cff92d8fd x86, xsave: Make xstate_enable_boot_cpu() __init, protect on CPU 0
xstate_enable_boot_cpu() is, as the name implies, only used on the
boot CPU; furthermore, it invokes alloc_bootmem(), which is __init;
hence it needs to be tagged __init rather than __cpuinit.

Furthermore, it is *not* safe in the long run to rely on CPU 0 only
coming online during the early boot -- at some point we're going to
support offlining (and re-onlining) the boot CPU, and at that point we
must not call xstate_enable_boot_cpu() again.

The code is a fair bit more obscure than one would like, because the
__ref overrides aren't quite powerful enough.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <4C476236.1020302@zytor.com>
2010-07-21 15:33:54 -07:00
Robert Richter
4995b9dba9 x86, xsave: Add __init attribute to setup_xstate_features()
This is called only from initialization code.

Signed-off-by: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1279731838-1522-6-git-send-email-robert.richter@amd.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-07-21 14:06:05 -07:00
Robert Richter
45c2d7f462 x86, xsave: Make init_xstate_buf static
The pointer is only used in xsave.c. Making it static.

Signed-off-by: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1279731838-1522-5-git-send-email-robert.richter@amd.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-07-21 14:06:05 -07:00