copy_from_user_nmi() is used in oprofile and perf. Moving it to other
library functions like copy_from_user(). As this is x86 code for 32
and 64 bits, create a new file usercopy.c for unified code.
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110607172413.GJ20052@erda.amd.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

This patch:

 - fixes typos in comments and clarifies the text
 - renames obscure p4_event_alias::original and ::alter members to
   ::original and ::alternative as appropriate
 - drops parenthesis from the return of p4_get_alias_event()

No functional changes.
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/r/20110721160625.GX7492@sunSigned-off-by: NIngo Molnar <mingo@elte.hu>

Fix the printk_once() so that it actually prints (didn't print before
due to a stray comma.)

[ hpa: changed to an incremental patch and adjusted the description
  accordingly. ]
Signed-off-by: NLen Brown <len.brown@intel.com>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1107151732480.18606@x980
Cc: <table@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Instead of hw_nmi_watchdog_set_attr() weak function
and appropriate x86_pmu::hw_watchdog_set_attr() call
we introduce even alias mechanism which allow us
to drop this routines completely and isolate quirks
of Netburst architecture inside P4 PMU code only.

The main idea remains the same though -- to allow
nmi-watchdog and perf top run simultaneously.

Note the aliasing mechanism applies to generic
PERF_COUNT_HW_CPU_CYCLES event only because arbitrary
event (say passed as RAW initially) might have some
additional bits set inside ESCR register changing
the behaviour of event and we can't guarantee anymore
that alias event will give the same result.

P.S. Thanks a huge to Don and Steven for for testing
     and early review.
Acked-by: NDon Zickus <dzickus@redhat.com>
Tested-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Stephane Eranian <eranian@google.com>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20110708201712.GS23657@sunSigned-off-by: NSteven Rostedt <rostedt@goodmis.org>

Since 2.6.36 (23016bf0), Linux prints the existence of "epb" in /proc/cpuinfo,
Since 2.6.38 (d5532ee7), the x86_energy_perf_policy(8) utility has
been available in-tree to update MSR_IA32_ENERGY_PERF_BIAS.

However, the typical BIOS fails to initialize the MSR, presumably
because this is handled by high-volume shrink-wrap operating systems...

Linux distros, on the other hand, do not yet invoke x86_energy_perf_policy(8).
As a result, WSM-EP, SNB, and later hardware from Intel will run in its
default hardware power-on state (performance), which assumes that users
care for performance at all costs and not for energy efficiency.
While that is fine for performance benchmarks, the hardware's intended default
operating point is "normal" mode...

Initialize the MSR to the "normal" by default during kernel boot.

x86_energy_perf_policy(8) is available to change the default after boot,
should the user have a different preference.
Signed-off-by: NLen Brown <len.brown@intel.com>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1107140051020.18606@x980Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@kernel.org>

The v1 PMU does not have any fixed counters.  Using the v2 constraints,
which do have fixed counters, causes an additional choice to be present
in the weight calculation, but not when actually scheduling the event,
leading to an event being not scheduled at all.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1309362157-6596-3-git-send-email-avi@redhat.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

Add a NODE level to the generic cache events which is used to measure
local vs remote memory accesses. Like all other cache events, an
ACCESS is HIT+MISS, if there is no way to distinguish between reads
and writes do reads only etc..

The below needs filling out for !x86 (which I filled out with
unsupported events).

I'm fairly sure ARM can leave it like that since it doesn't strike me as
an architecture that even has NUMA support. SH might have something since
it does appear to have some NUMA bits.

Sparc64, PowerPC and MIPS certainly want a good look there since they
clearly are NUMA capable.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Miller <davem@davemloft.net>
Cc: Anton Blanchard <anton@samba.org>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1303508226.4865.8.camel@laptopSigned-off-by: NIngo Molnar <mingo@elte.hu>

Since the OFFCORE registers are fully symmetric, try the other one
when the specified one is already in use.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1306141897.18455.8.camel@twinsSigned-off-by: NIngo Molnar <mingo@elte.hu>

This patch adds Intel Sandy Bridge offcore_response support by
providing the low-level constraint table for those events.

On Sandy Bridge, there are two offcore_response events. Each uses
its own dedictated extra register. But those registers are NOT shared
between sibling CPUs when HT is on unlike Nehalem/Westmere. They are
always private to each CPU. But they still need to be controlled within
an event group. All events within an event group must use the same
value for the extra MSR. That's not controlled by the second patch in
this series.

Furthermore on Sandy Bridge, the offcore_response events have NO
counter constraints contrary to what the official documentation
indicates, so drop the events from the contraint table.
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110606145712.GA7304@quadSigned-off-by: NIngo Molnar <mingo@elte.hu>

The validate_group() function needs to validate events with
extra shared regs. Within an event group, only events with
the same value for the extra reg can co-exist. This was not
checked by validate_group() because it was missing the
shared_regs logic.

This patch changes the allocation of the fake cpuc used for
validation to also point to a fake shared_regs structure such
that group events be properly testing.

It modifies __intel_shared_reg_get_constraints() to use
spin_lock_irqsave() to avoid lockdep issues.
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110606145708.GA7279@quadSigned-off-by: NIngo Molnar <mingo@elte.hu>

This patch improves the code managing the extra shared registers
used for offcore_response events on Intel Nehalem/Westmere. The
idea is to use static allocation instead of dynamic allocation.
This simplifies greatly the get and put constraint routines for
those events.

The patch also renames per_core to shared_regs because the same
data structure gets used whether or not HT is on. When HT is
off, those events still need to coordination because they use
a extra MSR that has to be shared within an event group.
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110606145703.GA7258@quadSigned-off-by: NIngo Molnar <mingo@elte.hu>

Since only samples call perf_output_sample() its much saner (and more
correct) to put the sample logic in there than in the
perf_output_begin()/perf_output_end() pair.

Saves a useless argument, reduces conditionals and shrinks
struct perf_output_handle, win!
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-2crpvsx3cqu67q3zqjbnlpsc@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.

For the various event classes:

  - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
  - tracepoint: nmi=0; since tracepoint could be from NMI context.
  - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

Due to restriction and specifics of Netburst PMU we need a separated
event for NMI watchdog. In particular every Netburst event
consumes not just a counter and a config register, but also an
additional ESCR register.

Since ESCR registers are grouped upon counters (i.e. if ESCR is occupied
for some event there is no room for another event to enter until its
released) we need to pick up the "least" used ESCR (or the most available
one) for nmi-watchdog purposes -- so MSR_P4_CRU_ESCR2/3 was chosen.

With this patch nmi-watchdog and perf top should be able to run simultaneously.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
Tested-and-reviewed-by: NDon Zickus <dzickus@redhat.com>
Tested-and-reviewed-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110623124918.GC13050@sunSigned-off-by: NIngo Molnar <mingo@elte.hu>

There are many functions named mce_* so use a new prefix for the subset
of functions related to sysfs support.

And since f3c6ea1b introduces
syscore_ops, use the prefix mce_syscore for some functions related to
power management which were in sysdev_class before.

  Before:			After:
   mce_device   		 mce_sysdev
   mce_sysclass 		 mce_sysdev_class
   mce_attrs    		 mce_sysdev_attrs
   mce_dev_initialized  	 mce_sysdev_initialized
   mce_create_device    	 mce_sysdev_create
   mce_remove_device    	 mce_sysdev_remove

   mce_suspend  		 mce_syscore_suspend
   mce_shutdown 		 mce_syscore_shutdown
   mce_resume   		 mce_syscore_resume
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED81B.8020506@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

There are many functions named mce_* so use a new prefix for the subset
of functions dealing with the character device /dev/mcelog.

This change doesn't impact the mce-inject module because the exported
symbol mce_chrdev_ops already has the prefix, therefore it is left
unchanged.

  Before:			After:
   mce_wait			 mce_chrdev_wait
   mce_state_lock		 mce_chrdev_state_lock
   open_count   		 mce_chrdev_open_count
   open_exclu   		 mce_chrdev_open_exclu
   mce_open			 mce_chrdev_open
   mce_release  		 mce_chrdev_release
   mce_read_mutex		 mce_chrdev_read_mutex
   mce_read			 mce_chrdev_read
   mce_poll			 mce_chrdev_poll
   mce_ioctl    		 mce_chrdev_ioctl
   mce_log_device		 mce_chrdev_device
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED7CD.3040500@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

Use a temporary local variable m to simplify the code. No change in
logic.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED7A8.8020307@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

Use temporary local variable sysdev to simplify the code. No change in
logic.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED777.7080205@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

Because "ancient CPUs" like p5 and winchip don't have X86_FEATURE_MCA
(I suppose so), mcheck_cpu_init() on such CPUs will return at check of
mce_available() after __mcheck_cpu_ancient_init().

It is hard to know this implicit behavior without knowing the CPUs
well. So make it clear that we leave mcheck_cpu_init() when the CPU is
initialized in __mcheck_cpu_ancient_init().
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED74B.20502@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

This patch introduces mce_gather_info() which is to be called at the
beginning of error handling and gathers minimum error information from
proper error registers (and saved registers).

As the result of mce_get_rip() is integrated, unnecessary zeroing
is removed. This also takes care of saving RIP which is required to
make some decision about error severity for SRAR errors, instead of
retrieving it later in the handler.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED71A.1060906@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

Follow other MCi register defines. Plus define MCI_MISC_ADDR_LSB() and
MCI_MISC_ADDR_MODE().
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED6E8.9090509@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

The MCE handler uses a special vector for self IPI to invoke
post-emergency processing in an interrupt context, e.g. call an
NMI-unsafe function, wakeup loggers, schedule time-consuming work for
recovery, etc.

This mechanism is now generalized by the following commit:

 > e360adbe
 > Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
 > Date:   Thu Oct 14 14:01:34 2010 +0800
 >
 >  irq_work: Add generic hardirq context callbacks
 >
 >  Provide a mechanism that allows running code in IRQ context. It is
 >  most useful for NMI code that needs to interact with the rest of the
 >  system -- like wakeup a task to drain buffers.
 :

So change to use provided generic mechanism.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED6B2.6080005@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

More specifically:

- sort bits in the macros
- use BITCLR/BITSET
- coordinate message pattern
- use m for struct mce
- cleanup for severities_debugfs_init()

No functional change.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED679.9090503@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

The current format of an item in this table is:
  condition(param, ..., level, message [, condition2 ...])

So we have to check both an item's head and tail to find the conditions
which match the item.

Format them in a more straight forward manner:
  item(level, message, condition [, condition2 ...])
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED61F.5010502@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

The table looks very complicated and hard to read for people other than
skilled developers. So let's clean it up a bit. At first, change format
to ease reading elements in the table.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED5EB.6050400@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

The "Spurious not enabled" entry is redundant: the "Not enabled" entry
earlier in the table will cover this case.

The "Action required; unknown MCACOD" entry shouldn't specify MCACOD in
the .mask field. Current code will only match for mcacod==0 rather than
all AR=1 entries.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Link: http://lkml.kernel.org/r/4DEED5BC.8030703@jp.fujitsu.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

We'd rather that modern machines not check if HLT works on
every entry into idle, for the benefit of machines that had
marginal electricals 15-years ago.  If those machines are still running
the upstream kernel, they can use "idle=poll".  The only difference
will be that they'll now invoke HLT in machine_hlt().

cc: x86@kernel.org # .39.x
Signed-off-by: NLen Brown <len.brown@intel.com>

The workaround for AMD erratum 400 uses the term "c1e" falsely suggesting:
1. Intel C1E is somehow involved
2. All AMD processors with C1E are involved

Use the string "amd_c1e" instead of simply "c1e" to clarify that
this workaround is specific to AMD's version of C1E.
Use the string "e400" to clarify that the workaround is specific
to AMD processors with Erratum 400.

This patch is text-substitution only, with no functional change.

cc: x86@kernel.org
Acked-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Commit b87cf80a added support for
ARAT (Always Running APIC timer) on AMD processors that are not
affected by erratum 400. This erratum is present on certain processor
families and prevents APIC timer from waking up the CPU when it
is in a deep C state, including C1E state.

Determining whether a processor is affected by this erratum may
have some corner cases and handling these cases is somewhat
complicated. In the interest of simplicity we won't claim ARAT
support on processor families below 0x12 and will go back to
broadcasting timer when going idle.
Signed-off-by: NBoris Ostrovsky <ostr@amd64.org>
Link: http://lkml.kernel.org/r/1306423192-19774-1-git-send-email-ostr@amd64.orgTested-by: NBoris Petkov <borislav.petkov@amd.com>
Cc: Hans Rosenfeld <Hans.Rosenfeld@amd.com>
Cc: Andreas Herrmann <Andreas.Herrmann3@amd.com>
Cc: Chuck Ebbert <cebbert@redhat.com>
Cc: stable@kernel.org # 32.x, 38.x, 39.x
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

This patch removes a check that causes incorrect scheduler
domain setup (SMP instead of SMT) and bootlog warning messages
when cpuid extensions for topology enumeration are not supported
and the number of processors reported to the OS is smaller than
smp_num_siblings.
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NNikhil P Rao <nikhil.rao@intel.com>
Link: http://lkml.kernel.org/r/1306343921.19325.1.camel@fedora13Signed-off-by: NIngo Molnar <mingo@elte.hu>

The setup_smep function gets calle at resume time too, and is thus not a
pure __init function.  When marked as __init, it gets thrown out after
the kernel has initialized, and when the kernel is suspended and
resumed, the code will no longer be around, and we'll get a nice "kernel
tried to execute NX-protected page" oops because the page is no longer
marked executable.
Reported-and-tested-by: NParag Warudkar <parag.lkml@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix these kernel compilation warnings:

 WARNING: arch/x86/built-in.o(.cpuinit.text+0x1e07): Section mismatch ...
 WARNING: arch/x86/built-in.o(.cpuinit.text+0x1b10): Section mismatch ...

introduced by:

  de5397ad: x86, cpu: Enable/disable Supervisor Mode Execution Protection

Change disable_smep from __initdata to __cpuinitdata.
Change setup_smep() from __init to __cpuinit.
Reported-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Cc: Asit K Mallick <asit.k.mallick@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1305930797-11409-1-git-send-email-fenghua.yu@intel.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

The workaround for Bugzilla:

	https://bugzilla.kernel.org/show_bug.cgi?id=33012

introduced a read and a write to the MC4 mask msr.

Unfortunatly this MSR is not emulated by the KVM hypervisor
so that the kernel will get a #GP and crashes when applying
this workaround when running inside KVM.

This issue was reported as:

	https://bugzilla.kernel.org/show_bug.cgi?id=35132

and is fixed with this patch. The change just let the kernel
ignore any #GP it gets while accessing this MSR by using the
_safe msr access methods.
Reported-by: NTörök Edwin <edwintorok@gmail.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org> # .39.x
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NDave Jones <davej@redhat.com>

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>

If kernel intends to use enhanced REP MOVSB/STOSB, it must ensure
IA32_MISC_ENABLE.Fast_String_Enable (bit 0) is set and CPUID.(EAX=07H, ECX=0H):
EBX[bit 9] also reports 1.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1305671358-14478-3-git-send-email-fenghua.yu@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

CPUID leaf 7, subleaf 0 returns the maximum subleaf in EAX, not the
number of subleaves.  Since so far only subleaf 0 is defined (and only
the EBX bitfield) we do not need to qualify the test.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1305660806-17519-1-git-send-email-fenghua.yu@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@kernel.org> 2.6.36..39

Trying to enable the local APIC timer on early K8 revisions
uncovers a number of other issues with it, in conjunction with
the C1E enter path on AMD. Fixing those causes much more churn
and troubles than the benefit of using that timer brings so
don't enable it on K8 at all, falling back to the original
functionality the kernel had wrt to that.
Reported-and-bisected-by: NNick Bowler <nbowler@elliptictech.com>
Cc: Boris Ostrovsky <Boris.Ostrovsky@amd.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Hans Rosenfeld <hans.rosenfeld@amd.com>
Cc: Nick Bowler <nbowler@elliptictech.com>
Cc: Joerg-Volker-Peetz <jvpeetz@web.de>
Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/1305636919-31165-3-git-send-email-bp@amd64.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

This reverts commit e20a2d20, as it crashes
certain boxes with specific AMD CPU models.

Moving the lower endpoint of the Erratum 400 check to accomodate
earlier K8 revisions (A-E) opens a can of worms which is simply
not worth to fix properly by tweaking the errata checking
framework:

* missing IntPenging MSR on revisions < CG cause #GP:

http://marc.info/?l=linux-kernel&m=130541471818831

* makes earlier revisions use the LAPIC timer instead of the C1E
idle routine which switches to HPET, thus not waking up in
deeper C-states:

http://lkml.org/lkml/2011/4/24/20

Therefore, leave the original boundary starting with K8-revF.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Steppings A1 and B0 of Celeron Covington are currently misdetected as
Pentium II (Dixon). Fix it by removing the stepping check.

[ hpa: this fixes this specific bug... the CPUID documentation
  specifies that the L2 cache size can disambiguate additional CPUs;
  this patch does not fix that. ]
Signed-off-by: NOndrej Zary <linux@rainbow-software.org>
Link: http://lkml.kernel.org/r/201105162138.15416.linux@rainbow-software.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>