There are some AMD CPU models which have thresholding banks but which
cannot generate a thresholding interrupt. This is denoted by the bit
MCi_MISC[IntP]. Make sure to check that bit before assigning the
thresholding interrupt handler.
Signed-off-by: NChen Yucong <slaoub@gmail.com>
[ Boris: save an indentation level and rewrite commit message. ]
Link: http://lkml.kernel.org/r/1412662128.28440.18.camel@debianSigned-off-by: NBorislav Petkov <bp@suse.de>

Aravind had the good question about why we're assigning a
software-defined bank when reporting error thresholding errors instead
of simply using the bank which reports the last error causing the
overflow.

Digging through git history, it pointed to

95268664 ("[PATCH] x86_64: mce_amd support for family 0x10 processors")

which added that functionality. The problem with this, however, is that
tools don't know about software-defined banks and get puzzled. So drop
that K8_MCE_THRESHOLD_BASE and simply use the hw bank reporting the
thresholding interrupt.

Save us a couple of MSR reads while at it.
Reported-by: NAravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
Link: https://lkml.kernel.org/r/5435B206.60402@amd.comSigned-off-by: NBorislav Petkov <bp@suse.de>

Assigning to mce_threshold_vector is loop-invariant code in
mce_amd_feature_init(). So do it only once, out of loop body.
Signed-off-by: NChen Yucong <slaoub@gmail.com>
Link: http://lkml.kernel.org/r/1412263212.8085.6.camel@debian
[ Boris: commit message corrections. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>

mce_setup() does not gather the content of IA32_MCG_STATUS, so it
should be read explicitly. Moreover, we need to clear IA32_MCx_STATUS
to avoid that mce_log() logs the processed threshold event again
at next time.

But we do the logging ourselves and machine_check_poll() is completely
useless there. So kill it.
Signed-off-by: NChen Yucong <slaoub@gmail.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>

Avoid open coded calculations for bank MSRs by hiding the index
of higher bank MSRs in well-defined macros.

No semantic changes.
Signed-off-by: NChen Yucong <slaoub@gmail.com>
Link: http://lkml.kernel.org/r/1411438561-24319-1-git-send-email-slaoub@gmail.comSigned-off-by: NBorislav Petkov <bp@suse.de>

Use watchdog_enable_hardlockup_detector() to set hard lockup detection's
default value to false.  It's risky to run this detection in a guest, as
false positives are easy to trigger, especially if the host is
overcommitted.
Signed-off-by: NUlrich Obergfell <uobergfe@redhat.com>
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

x86_64 allnoconfig:

arch/x86/kernel/cpu/common.c:968: warning: 'syscall32_cpu_init' defined but not used

Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

David Howells brought to my attention the mails generated by kbuild test
bot and following sparse warnings were present.  This patch fixes these
warnings.

  arch/x86/kernel/kexec-bzimage64.c:270:5: warning: symbol 'bzImage64_probe' was not declared. Should it be static?
  arch/x86/kernel/kexec-bzimage64.c:328:6: warning: symbol 'bzImage64_load' was not declared. Should it be static?
  arch/x86/kernel/kexec-bzimage64.c:517:5: warning: symbol 'bzImage64_cleanup' was not declared. Should it be static?
  arch/x86/kernel/kexec-bzimage64.c:531:5: warning: symbol 'bzImage64_verify_sig' was not declared. Should it be static?
  arch/x86/kernel/kexec-bzimage64.c:546:23: warning: symbol 'kexec_bzImage64_ops' was not declared. Should it be static?
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Reported-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a check if crashk_res_low exists just like GART region does.  If
crashk_res_low doesn't exist, calling exclude_mem_range is unnecessary.

Meanwhile, since crashk_res_low has been initialized at definition, it's
safe just use "if (crashk_low_res.end)" to check if it's exist.  And this
can make it consistent with other places of check.
Signed-off-by: NBaoquan He <bhe@redhat.com>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A variable cannot be both __read_mostly and const. This
is a meaningless combination.

Just make it only const.

This fixes the LTO build with numachip enabled.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1411533139-25708-1-git-send-email-andi@firstfloor.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Intel processors which don't report cache information via cpuid(2)
or cpuid(4) need quirk code in the legacy_cache_size callback to
report this data. For Intel that callback is is intel_size_cache().

This patch enables calling of cpu_detect_cache_sizes() inside of
init_intel() and hence the calling of the legacy_cache callback in
intel_size_cache(). Adding this call will ensure that PIII Tualatin
currently in intel_size_cache() and Quark SoC X1000 being added to
intel_size_cache() in this patch will report their respective cache
sizes.

This model of calling cpu_detect_cache_sizes() is consistent with
AMD/Via/Cirix/Transmeta and Centaur.

Also added is a string to idenitfy the Quark as Quark SoC X1000
giving better and more descriptive output via /proc/cpuinfo

Adding cpu_detect_cache_sizes to init_intel() will enable calling
of intel_size_cache() on Intel processors which currently no code
can reach. Therefore this patch will also re-enable reporting
of PIII Tualatin cache size information as well as add
Quark SoC X1000 support.

Comment text and cache flow logic suggested by Thomas Gleixner
Signed-off-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: davej@redhat.com
Cc: hmh@hmh.eng.br
Link: http://lkml.kernel.org/r/1412641189-12415-3-git-send-email-pure.logic@nexus-software.ieSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Quark SoC X1000 advertises Page Global Enable for it's
Translation Lookaside Buffer via cpuid. The silicon does not
in fact support PGE and hence will not flush the TLB when CR4.PGE
is rewritten. The Quark documentation makes clear the necessity to
instead rewrite CR3 in order to flush any TLB entries, irrespective
of the state of CR4.PGE or an individual PTE.PGE

See Intel Quark Core DevMan_001.pdf section 6.4.11

In setup.c setup_arch() the code will load_cr3() and then do a
__flush_tlb_all().

On Quark the entire TLB will be flushed at the load_cr3().
The __flush_tlb_all() have no effect and can be safely ignored.

Later on in the boot process we switch off the flag for cpu_has_pge()
which means that subsequent calls to __flush_tlb_all() will
call __flush_tlb() not __flush_tlb_global() flushing the TLB in the
correct way via load_cr3() not CR4.PGE rewrite

This patch documents the behaviour of flushing the TLB for Quark in
setup_arch()

Comment text suggested by Thomas Gleixner
Signed-off-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: davej@redhat.com
Cc: hmh@hmh.eng.br
Link: http://lkml.kernel.org/r/1412641189-12415-2-git-send-email-pure.logic@nexus-software.ieSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The NT flag doesn't do anything in long mode other than causing IRET
to #GP.  Oddly, CPL3 code can still set NT using popf.

Entry via hardware or software interrupt clears NT automatically, so
the only relevant entries are fast syscalls.

If user code causes kernel code to run with NT set, then there's at
least some (small) chance that it could cause trouble.  For example,
user code could cause a call to EFI code with NT set, and who knows
what would happen?  Apparently some games on Wine sometimes do
this (!), and, if an IRET return happens, they will segfault.  That
segfault cannot be handled, because signal delivery fails, too.

This patch programs the CPU to clear NT on entry via SYSCALL (both
32-bit and 64-bit, by my reading of the AMD APM), and it clears NT
in software on entry via SYSENTER.

To save a few cycles, this borrows a trick from Jan Beulich in Xen:
it checks whether NT is set before trying to clear it.  As a result,
it seems to have very little effect on SYSENTER performance on my
machine.

There's another minor bug fix in here: it looks like the CFI
annotations were wrong if CONFIG_AUDITSYSCALL=n.

Testers beware: on Xen, SYSENTER with NT set turns into a GPF.

I haven't touched anything on 32-bit kernels.

The syscall mask change comes from a variant of this patch by Anish
Bhatt.

Note to stable maintainers: there is no known security issue here.
A misguided program can set NT and cause the kernel to try and fail
to deliver SIGSEGV, crashing the program.  This patch fixes Far Cry
on Wine: https://bugs.winehq.org/show_bug.cgi?id=33275

Cc: <stable@vger.kernel.org>
Reported-by: NAnish Bhatt <anish@chelsio.com>
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/395749a5d39a29bd3e4b35899cf3a3c1340e5595.1412189265.git.luto@amacapital.netSigned-off-by: NH. Peter Anvin <hpa@zytor.com>

PMU checking can fail due to various reasons. On native machine, this
is mostly caused by faulty hardware and it is reasonable to use
KERN_ERR in reporting. However, when kernel is running on virtualized
environment, this checking can fail if virtual PMU is not supported
(e.g. KVM on AMD host). It is annoying to see an error message on
splash screen, even though we know such failure is benign on
virtualized environment.

This patch checks if the kernel is running in a virtualized environment.
If so, it will use KERN_INFO in reporting, which reduces the syslog
priority of them. This patch was tested successfully on KVM.
Signed-off-by: NWei Huang <wei@redhat.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Link: http://lkml.kernel.org/r/1411617314-24659-1-git-send-email-wei@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

I was looking for the trinity oops cause in the uncore driver.
(so far didn't found it)

However I found this tiny race: when a box is set up two threads on the
same CPU, they may be setting up the box in parallel (e.g. with kernel
preemption). This could lead to the reference count being increasing
too much. Always recheck there is no existing cpu reference inside the lock.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Link: http://lkml.kernel.org/r/1411424826-15629-1-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit:

  cebf15eb ("x86, sched: Add new topology for multi-NUMA-node CPUs")

some code to try to detect the situation where we have a NUMA node
inside of the "DIE" sched domain.

It detected this by looking for cpus which match_die() but do not match
NUMA nodes via topology_same_node().

I wrote it up as:

	if (match_die(c, o) == !topology_same_node(c, o))

which actually seemed to work some of the time, albiet
accidentally.

It should have been doing an &&, not an ==.

This code essentially chopped off the "DIE" domain on one of
Andrew Morton's systems.  He reported that this patch fixed his
issue.
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Reported-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Lan Tianyu <tianyu.lan@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Link: http://lkml.kernel.org/r/20140930214546.FD481CFF@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

___preempt_schedule() does SAVE_ALL/RESTORE_ALL but this is
suboptimal, we do not need to save/restore the callee-saved
register. And we already have arch/x86/lib/thunk_*.S which
implements the similar asm wrappers, so it makes sense to
redefine ___preempt_schedule() as "THUNK ..." and remove
preempt.S altogether.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NAndy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140921184153.GA23727@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The following bug can be triggered by hot adding and removing a large number of
xen domain0's vcpus repeatedly:

	BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: [..] find_busiest_group
	PGD 5a9d5067 PUD 13067 PMD 0
	Oops: 0000 [#3] SMP
	[...]
	Call Trace:
	load_balance
	? _raw_spin_unlock_irqrestore
	idle_balance
	__schedule
	schedule
	schedule_timeout
	? lock_timer_base
	schedule_timeout_uninterruptible
	msleep
	lock_device_hotplug_sysfs
	online_store
	dev_attr_store
	sysfs_write_file
	vfs_write
	SyS_write
	system_call_fastpath

Last level cache shared mask is built during CPU up and the
build_sched_domain() routine takes advantage of it to setup
the sched domain CPU topology.

However, llc_shared_mask is not released during CPU disable,
which leads to an invalid sched domainCPU topology.

This patch fix it by releasing the llc_shared_mask correctly
during CPU disable.

Yasuaki also reported that this can happen on real hardware:

  https://lkml.org/lkml/2014/7/22/1018

His case is here:

	==
	Here is an example on my system.
	My system has 4 sockets and each socket has 15 cores and HT is
	enabled. In this case, each core of sockes is numbered as
	follows:

		 | CPU#
	Socket#0 | 0-14 , 60-74
	Socket#1 | 15-29, 75-89
	Socket#2 | 30-44, 90-104
	Socket#3 | 45-59, 105-119

	Then llc_shared_mask of CPU#30 has 0x3fff80000001fffc0000000.

	It means that last level cache of Socket#2 is shared with
	CPU#30-44 and 90-104.

	When hot-removing socket#2 and #3, each core of sockets is
	numbered as follows:

		 | CPU#
	Socket#0 | 0-14 , 60-74
	Socket#1 | 15-29, 75-89

	But llc_shared_mask is not cleared. So llc_shared_mask of CPU#30
	remains having 0x3fff80000001fffc0000000.

	After that, when hot-adding socket#2 and #3, each core of
	sockets is numbered as follows:

		 | CPU#
	Socket#0 | 0-14 , 60-74
	Socket#1 | 15-29, 75-89
	Socket#2 | 30-59
	Socket#3 | 90-119

	Then llc_shared_mask of CPU#30 becomes
	0x3fff8000fffffffc0000000. It means that last level cache of
	Socket#2 is shared with CPU#30-59 and 90-104. So the mask has
	the wrong value.
Signed-off-by: NWanpeng Li <wanpeng.li@linux.intel.com>
Tested-by: NLinn Crosetto <linn@hp.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NToshi Kani <toshi.kani@hp.com>
Reviewed-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1411547885-48165-1-git-send-email-wanpeng.li@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Quark x1000 advertises PGE via the standard CPUID method
PGE bits exist in Quark X1000's PTEs. In order to flush
an individual PTE it is necessary to reload CR3 irrespective
of the PTE.PGE bit.

See Quark Core_DevMan_001.pdf section 6.4.11

This bug was fixed in Galileo kernels, unfixed vanilla kernels are expected to
crash and burn on this platform.
Signed-off-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Borislav Petkov <bp@alien8.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1411514784-14885-1-git-send-email-pure.logic@nexus-software.ieSigned-off-by: NIngo Molnar <mingo@kernel.org>

With certain kernel configurations, CPU offline consumes more than
100ms during S3.

It's a timing related issue: native_cpu_die() would occasionally fall
into a 100ms sleep when the CPU idle loop thread marked the CPU state
to DEAD too slowly.

What native_cpu_die() does is that it polls the CPU state and waits
for 100ms if CPU state hasn't been marked to DEAD. The 100ms sleep
doesn't make sense and is purely historic.

To avoid such long sleeping, this patch adds a 'struct completion'
to each CPU, waits for the completion in native_cpu_die() and wakes
up the completion when the CPU state is marked to DEAD.

Tested on an Intel Xeon server with 48 cores, Ivybridge and on
Haswell laptops. The CPU offlining cost on these machines is
reduced from more than 100ms to less than 5ms. The system
suspend time is reduced by 2.3s on the servers.

Borislav and Prarit also helped to test the patch on an AMD
machine and a few systems of various sizes and configurations
(multi-socket, single-socket, no hyper threading, etc.). No
issues were seen.
Tested-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: srostedt@redhat.com
Cc: toshi.kani@hp.com
Cc: imammedo@redhat.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1409039025-32310-1-git-send-email-tianyu.lan@intel.com
[ Improved a few minor details in the code, cleaned up the changelog. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

This patch restructures the memory controller (IMC) uncore PMU support
for client SNB/IVB/HSW processors. The main change is that it can now
cope with more than one PCI device ID per processor model. There are
many flavors of memory controllers for each processor. They have
different PCI device ID, yet they behave the same w.r.t. the memory
controller PMU that we are interested in.

The patch now supports two distinct memory controllers for IVB
processors: one for mobile, one for desktop.
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140917090616.GA11281@quad
Cc: ak@linux.intel.com
Cc: kan.liang@intel.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The PCU frequency band filters use 8 bit each in a register.
When setting up the value the shift value was not correctly
scaled, which resulted in all filters except for band 0 to
be zero. Fix the scaling.

This allows to correctly monitor multiple uncore frequency bands.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1409872109-31645-5-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The IvyBridge-EP uncore driver was missing three filter flags:
NC, ISOC, C6 which are useful in some cases. Support them in the same way
as the Haswell EP driver, by allowing to set them and exposing
them in the sysfs formats.

Also fix a typo in a define.

Relies on the Haswell EP driver to be applied earlier.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1409872109-31645-4-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Current code registers PMUs for all possible uncore pci devices.
This is not good because, on some machines, one or more uncore pci
devices can be missing. The missing pci device make corresponding
PMU unusable. Register the PMU only if the uncore device exists.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1409872109-31645-3-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The uncore subsystem in Haswell-EP is similar to Sandy/Ivy
Bridge-EP. There are some differences in config register
encoding and pci device IDs. The Haswell-EP uncore also
supports a few new events. Add the Haswell-EP driver to
the snbep split driver.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
[ Add missing break. Add imc events. Add cbox nc/isoc/c6. ]
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1409872109-31645-2-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Use the newly added Broadwell cache event list for Haswell too.
All Haswell and Broadwell events and offcore masks used in these lists
are identical.

However Haswell is very different from the Sandy Bridge
list that was used previously. That fixes a wide range of mis-counting
cache events.

The node events are now only for retired memory events, so prefetching
and speculative memory accesses are not included. They are PEBS
capable now, which makes it much easier to sample for them, plus it's
possible to create address maps with -d.

The prefetch events are gone now. They way the hardware counts
them is very misleading (some prefetches included, others not), so
it seemed best to leave them out.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1409683455-29168-5-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

On Broadwell INST_RETIRED.ALL cannot be used with any period
that doesn't have the lowest 6 bits cleared. And the period
should not be smaller than 128.

Add a new callback to enforce this, and set it for Broadwell.

This is erratum BDM57 and BDM11.

How does this handle the case when an app requests a specific
period with some of the bottom bits set

The apps thinks it is sampling at X occurences per sample, when it is
in fact at X - 63 (worst case).

Short answer:

Any useful instruction sampling period needs to be 4-6 orders
of magnitude larger than 128, as an PMI every 128 instructions
would instantly overwhelm the system and be throttled.
So the +-64 error from this is really small compared to the
period, much smaller than normal system jitter.

Long answer:

<write up by Peter:>

IFF we guarantee perf_event_attr::sample_period >= 128.

Suppose we start out with sample_period=192; then we'll set period_left
to 192, we'll end up with left = 128 (we truncate the lower bits). We
get an interrupt, find that period_left = 64 (>0 so we return 0 and
don't get an overflow handler), up that to 128. Then we trigger again,
at n=256. Then we find period_left = -64 (<=0 so we return 1 and do get
an overflow). We increment with sample_period so we get left = 128. We
fire again, at n=384, period_left = 0 (<=0 so we return 1 and get an
overflow). And on and on.

So while the individual interrupts are 'wrong' we get then with
interval=256,128 in exactly the right ratio to average out at 192. And
this works for everything >=128.

So the num_samples*fixed_period thing is still entirely correct +- 127,
which is good enough I'd say, as you already have that error anyhow.

So no need to 'fix' the tools, al we need to do is refuse to create
INST_RETIRED:ALL events with sample_period < 128.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
Cc: Mark Davies <junk@eslaf.co.uk>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1409683455-29168-4-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add Broadwell support for Broadwell Client to perf.  This is very
similar to Haswell.  It uses a new cache event table, because there
were various changes there.

The constraint list has one new event that needs to be handled over
Haswell.

The PEBS event list is the same, so we reuse Haswell's.

[fengguang.wu: make intel_bdw_event_constraints[] static]
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1409683455-29168-3-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add names for each Haswell model as requested by Peter.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1409683455-29168-2-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

71 is a Broadwell, not a Haswell. The model number was added
by mistake earlier.

Remove it for now, until it can be re-added later with
real Broadwell support.

In practice it does not cause a lot of issues because the Broadwell
PMU is very similar to Haswell, but some details were wrong,
and it's better to handle it correctly.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Link: http://lkml.kernel.org/r/1409683455-29168-1-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

I'm getting the spew below when booting with Haswell (Xeon
E5-2699 v3) CPUs and the "Cluster-on-Die" (CoD) feature enabled
in the BIOS.  It seems similar to the issue that some folks from
AMD ran in to on their systems and addressed in this commit:

  161270fc ("x86/smp: Fix topology checks on AMD MCM CPUs")

Both these Intel and AMD systems break an assumption which is
being enforced by topology_sane(): a socket may not contain more
than one NUMA node.

AMD special-cased their system by looking for a cpuid flag.  The
Intel mode is dependent on BIOS options and I do not know of a
way which it is enumerated other than the tables being parsed
during the CPU bringup process.  In other words, we have to trust
the ACPI tables <shudder>.

This detects the situation where a NUMA node occurs at a place in
the middle of the "CPU" sched domains.  It replaces the default
topology with one that relies on the NUMA information from the
firmware (SRAT table) for all levels of sched domains above the
hyperthreads.

This also fixes a sysfs bug.  We used to freak out when we saw
the "mc" group cross a node boundary, so we stopped building the
MC group.  MC gets exported as the 'core_siblings_list' in
/sys/devices/system/cpu/cpu*/topology/ and this caused CPUs with
the same 'physical_package_id' to not be listed together in
'core_siblings_list'.  This violates a statement from
Documentation/ABI/testing/sysfs-devices-system-cpu:

	core_siblings: internal kernel map of cpu#'s hardware threads
	within the same physical_package_id.

	core_siblings_list: human-readable list of the logical CPU
	numbers within the same physical_package_id as cpu#.

The sysfs effects here cause an issue with the hwloc tool where
it gets confused and thinks there are more sockets than are
physically present.

Before this patch, there are two packages:

# cd /sys/devices/system/cpu/
# cat cpu*/topology/physical_package_id | sort | uniq -c
     18 0
     18 1

But 4 _sets_ of core siblings:

# cat cpu*/topology/core_siblings_list | sort | uniq -c
      9 0-8
      9 18-26
      9 27-35
      9 9-17

After this set, there are only 2 sets of core siblings, which
is what we expect for a 2-socket system.

# cat cpu*/topology/physical_package_id | sort | uniq -c
     18 0
     18 1
# cat cpu*/topology/core_siblings_list | sort | uniq -c
     18 0-17
     18 18-35

Example spew:
...
	NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter.
	 #2  #3  #4  #5  #6  #7  #8
	.... node  #1, CPUs:    #9
	------------[ cut here ]------------
	WARNING: CPU: 9 PID: 0 at /home/ak/hle/linux-hle-2.6/arch/x86/kernel/smpboot.c:306 topology_sane.isra.2+0x74/0x90()
	sched: CPU #9's mc-sibling CPU #0 is not on the same node! [node: 1 != 0]. Ignoring dependency.
	Modules linked in:
	CPU: 9 PID: 0 Comm: swapper/9 Not tainted 3.17.0-rc1-00293-g8e01c4d-dirty #631
	Hardware name: Intel Corporation S2600WTT/S2600WTT, BIOS GRNDSDP1.86B.0036.R05.1407140519 07/14/2014
	0000000000000009 ffff88046ddabe00 ffffffff8172e485 ffff88046ddabe48
	ffff88046ddabe38 ffffffff8109691d 000000000000b001 0000000000000009
	ffff88086fc12580 000000000000b020 0000000000000009 ffff88046ddabe98
	Call Trace:
	[<ffffffff8172e485>] dump_stack+0x45/0x56
	[<ffffffff8109691d>] warn_slowpath_common+0x7d/0xa0
	[<ffffffff8109698c>] warn_slowpath_fmt+0x4c/0x50
	[<ffffffff81074f94>] topology_sane.isra.2+0x74/0x90
	[<ffffffff8107530e>] set_cpu_sibling_map+0x31e/0x4f0
	[<ffffffff8107568d>] start_secondary+0x1ad/0x240
	---[ end trace 3fe5f587a9fcde61 ]---
	#10 #11 #12 #13 #14 #15 #16 #17
	.... node  #2, CPUs:   #18 #19 #20 #21 #22 #23 #24 #25 #26
	.... node  #3, CPUs:   #27 #28 #29 #30 #31 #32 #33 #34 #35
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
[ Added LLC domain and s/match_mc/match_die/ ]
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: brice.goglin@gmail.com
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/20140918193334.C065EBCE@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

On x86_64, kernel text mappings are mapped read-only with CONFIG_DEBUG_RODATA.
In that case, KVM will fail to patch VMCALL instructions to VMMCALL
as required on AMD processors.

The failure mode is currently a divide-by-zero exception, which obviously
is a KVM bug that has to be fixed.  However, picking the right instruction
between VMCALL and VMMCALL will be faster and will help if you cannot upgrade
the hypervisor.
Reported-by: NChris Webb <chris@arachsys.com>
Tested-by: NChris Webb <chris@arachsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Since the arch is found locally in __audit_syscall_entry(), there is no need to
pass it in as a parameter.  Delete it from the parameter list.

x86* was the only arch to call __audit_syscall_entry() directly and did so from
assembly code.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-audit@redhat.com
Signed-off-by: NEric Paris <eparis@redhat.com>

---

As this patch relies on changes in the audit tree, I think it
appropriate to send it through my tree rather than the x86 tree.

We have a function where the arch can be queried, syscall_get_arch().
So rather than have every single piece of arch specific code use and/or
duplicate syscall_get_arch(), just have the audit code use the
syscall_get_arch() code.
Based-on-patch-by: NRichard Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: microblaze-uclinux@itee.uq.edu.au
Cc: linux-mips@linux-mips.org
Cc: linux@lists.openrisc.net
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: linux-xtensa@linux-xtensa.org
Cc: x86@kernel.org

Makes the IOSF sideband available through debugfs. Allows
developers to experiment with using the sideband to provide
debug and analytical tools for units on the SoC.
Signed-off-by: NDavid E. Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1411017231-20807-4-git-send-email-david.e.box@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add Braswell PCI ID to list of supported ID's for the IOSF driver.
Signed-off-by: NDavid E. Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1411017231-20807-2-git-send-email-david.e.box@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

When compiling with CONFIG_DEBUG_FS=n, GCC emits an unused
variable warning for pmc_atom.c because "ret" is used only
within the CONFIG_DEBUG_FS block.

This patch adds a dummy #ifdef for pmc_dbgfs_register() when
CONFIG_DEBUG_FS=n to simplify the code and remove the warning.
Signed-off-by: NMartin Kelly <martkell@amazon.com>
Acked-by: N"Li, Aubrey" <aubrey.li@linux.intel.com>
Cc: vishwesh.m.rudramuni@intel.com
Link: http://lkml.kernel.org/r/1410963476-8360-1-git-send-email-martin@martingkelly.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

intel_init_thermal() is called from a) at the time of system initializing
and b) at the time of system resume to initialize thermal
monitoring.

In case when thermal monitoring is handled by SMI, we get to know it via
printk(). Currently it gives the message at both cases, but its okay if
we get it only once and no need to get the same message at every time
system resumes.

So, limit showing this message only at system boot time by avoid showing
at system resume and reduce abusing kernel log buffer.
Signed-off-by: NRakib Mullick <rakib.mullick@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1411068135.5121.10.camel@localhost.localdomainSigned-off-by: NIngo Molnar <mingo@kernel.org>

Hang is observed on virtual machines during CPU hotplug,
especially in big guests with many CPUs. (It reproducible
more often if host is over-committed).

It happens because master CPU gives up waiting on
secondary CPU and allows it to run wild. As result
AP causes locking or crashing system. For example
as described here:

  https://lkml.org/lkml/2014/3/6/257

If master CPU have sent STARTUP IPI successfully,
and AP signalled to master CPU that it's ready
to start initialization, make master CPU wait
indefinitely till AP is onlined.

To ensure that AP won't ever run wild, make it
wait at early startup till master CPU confirms its
intention to wait for AP. If AP doesn't respond in 10
seconds, the master CPU will timeout and cancel
AP onlining.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Tested-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1403266991-12233-1-git-send-email-imammedo@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

In arch/x86/kernel/setup.c::trim_bios_range(), the codes
introduced by 1b5576e6 (base on d8a9e6a5), it updates the first
4Kb of memory to be E820_RESERVED region. That's because it's a
BIOS owned area but generally not listed in the E820 table:

  e820: BIOS-provided physical RAM map:
  BIOS-e820: [mem 0x0000000000000000-0x0000000000096fff] usable
  BIOS-e820: [mem 0x0000000000097000-0x0000000000097fff] reserved
  ...
  e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
  e820: remove [mem 0x000a0000-0x000fffff] usable

But the region of first 4Kb didn't register to nosave memory:

  PM: Registered nosave memory: [mem 0x00097000-0x00097fff]
  PM: Registered nosave memory: [mem 0x000a0000-0x000fffff]

The code in e820_mark_nosave_regions() assumes the first e820
area to be RAM, so it causes the first 4Kb E820_RESERVED region
ignored when register to nosave. This patch removed assumption
of the first e820 area.
Signed-off-by: NLee, Chun-Yi <jlee@suse.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <len.brown@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Link: http://lkml.kernel.org/r/1410491038-17576-1-git-send-email-jlee@suse.comSigned-off-by: NIngo Molnar <mingo@kernel.org>