x86/cpuid: make cpuid_class a static const structure

Now that the driver core allows for struct class to be in read-only
memory, move the cpuid_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230620144431.583290-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something. So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: make struct class.devnode() take a const *

The devnode() in struct class should not be modifying the device that is
passed into it, so mark it as a const * and propagate the function
signature changes out into all relevant subsystems that use this
callback.

Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Justin Sanders <justin@coraid.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: John Stultz <jstultz@google.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Sean Young <sean@mess.org>
Cc: Frank Haverkamp <haver@linux.ibm.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Xie Yongji <xieyongji@bytedance.com>
Cc: Gautam Dawar <gautam.dawar@xilinx.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Eli Cohen <elic@nvidia.com>
Cc: Parav Pandit <parav@nvidia.com>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: alsa-devel@alsa-project.org
Cc: dri-devel@lists.freedesktop.org
Cc: kvm@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: linux-block@vger.kernel.org
Cc: linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20221123122523.1332370-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

smp: Cleanup smp_call_function*()

Get rid of the __call_single_node union and cleanup the API a little
to avoid external code relying on the structure layout as much.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 142

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation inc 675 mass ave cambridge ma 02139 usa
either version 2 of the license or at your option any later version
incorporated herein by reference

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 4 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190524100844.465381181@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/cpuid: Allow cpuid_read() to schedule

High latencies can be observed caused by a daemon periodically reading
CPUID on all cpus. On KASAN enabled kernels ~10ms latencies can be
observed. Even without KASAN, sending an IPI to a CPU, which is in a deep
sleep state or in a long hard IRQ disabled section, waiting for the answer
can consume hundreds of microseconds.

cpuid_read() is invoked in preemptible context, so it can be converted to
sleep instead of busy wait.

Switching to smp_call_function_single_async() and a completion allows to
reschedule and reduces CPU usage and latencies.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Link: https://lkml.kernel.org/r/20180323215818.127774-2-edumazet@google.com

x86/cpuid: Move the hotplug callbacks to online

No point to have this file around before the cpu is online and no point to
have it around until the cpu is dead. Get rid of the explicit state.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Siewior <bigeasy@linutronix.de>

x86/cpuid: Convert to hotplug state machine

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: rt@linuxtronix.de
Link: http://lkml.kernel.org/r/20161117183541.8588-3-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86/cpuid: Cleanup cpuid_regs definitions

cpuid_regs is defined multiple times as structure and enum. Rename the enum
and move all of it to processor.h so we don't end up with more instances.

Rename the misnomed register enumeration from CR_* to the obvious CPUID_*.

[ tglx: Rewrote changelog ]

Signed-off-by: He Chen <he.chen@linux.intel.com>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Luwei Kang <luwei.kang@intel.com>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Piotr Luc <Piotr.Luc@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/1478856336-9388-2-git-send-email-he.chen@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

new helpers: no_seek_end_llseek{,_size}()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

x86: Drop bogus __ref / __refdata annotations

The __ref / __refdata annotations used to be needed because of
referencing functions / variables annotated __cpuinit /
__cpuinitdata.

But those annotations vanished during the development of v3.11.

Therefore most of the __ref / __refdata annotations are not needed
anymore. As they may hide legitimate sections mismatches, we
better get rid of them.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1437409973-8927-1-git-send-email-minipli@googlemail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86, cpuid: Use PTR_ERR_OR_ZERO

Replace IS_ERR/PTR_ERR

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Link: http://lkml.kernel.org/r/1413576077-26969-1-git-send-email-fabf@skynet.be
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

x86, cpuid: Fix CPU hotplug callback registration

Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

get_online_cpus();

for_each_online_cpu(cpu)
init_cpu(cpu);

register_cpu_notifier(&foobar_cpu_notifier);

put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

cpu_notifier_register_begin();

for_each_online_cpu(cpu)
init_cpu(cpu);

/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);

cpu_notifier_register_done();

Fix the cpuid code in x86 by using this latter form of callback registration.

Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86: delete __cpuinit usage from all x86 files

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.

This removes all the arch/x86 uses of the __cpuinit macros from
all C files. x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.

[1] https://lkml.org/lkml/2013/5/20/589

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: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Use get_online_cpus to avoid races involving CPU hotplug

If arch/x86/kernel/cpuid.c is a module, a CPU might offline or online
between the for_each_online_cpu() loop and the call to
register_hotcpu_notifier in cpuid_init or the call to
unregister_hotcpu_notifier in cpuid_exit. The potential races can
lead to leaks/duplicates, attempts to destroy non-existant devices, or
random pointer dereferences.

For example, in cpuid_exit if:

for_each_online_cpu(cpu)
cpuid_device_destroy(cpu);
class_destroy(cpuid_class);
__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
<----- CPU onlines
unregister_hotcpu_notifier(&cpuid_class_cpu_notifier);

the hotcpu notifier will attempt to create a device for the
cpuid_class, which the module already destroyed.

This fix surrounds for_each_online_cpu and register_hotcpu_notifier or
unregister_hotcpu_notifier with get_online_cpus+put_online_cpus.

Tested on a VM.

Signed-off-by: Silas Boyd-Wickizer <sbw@mit.edu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Disintegrate asm/system.h for X86

Disintegrate asm/system.h for X86.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
cc: x86@kernel.org

CPU: Introduce ARCH_HAS_CPU_AUTOPROBE and X86 parts

This patch is based on Andi Kleen's work:
Implement autoprobing/loading of modules serving CPU
specific features (x86cpu autoloading).

And Kay Siever's work to get rid of sysdev cpu structures
and making use of struct device instead.

Before, the cpuid driver had to be loaded to get the x86cpu
autoloading feature. With this patch autoloading works through
the /sys/devices/system/cpu object

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Add driver auto probing for x86 features v4

There's a growing number of drivers that support a specific x86 feature
or CPU. Currently loading these drivers currently on a generic
distribution requires various driver specific hacks and it often
doesn't work.

This patch adds auto probing for drivers based on the x86 cpuid
information, in particular based on vendor/family/model number
and also based on CPUID feature bits.

For example a common issue is not loading the SSE 4.2 accelerated
CRC module: this can significantly lower the performance of BTRFS
which relies on fast CRC.

Another issue is loading the right CPUFREQ driver for the current CPU.
Currently distributions often try all all possible driver until
one sticks, which is not really a good way to do this.

It works with existing udev without any changes. The code
exports the x86 information as a generic string in sysfs
that can be matched by udev's pattern matching.

This scheme does not support numeric ranges, so if you want to
handle e.g. ranges of model numbers they have to be encoded
in ASCII or simply all models or families listed. Fixing
that would require changing udev.

Another issue is that udev will happily load all drivers that match,
there is currently no nice way to stop a specific driver from
being loaded if it's not needed (e.g. if you don't need fast CRC)
But there are not that many cpu specific drivers around and they're
all not that bloated, so this isn't a particularly serious issue.

Originally this patch added the modalias to the normal cpu
sysdevs. However sysdevs don't have all the infrastructure
needed for udev, so it couldn't really autoload drivers.
This patch instead adds the CPU modaliases to the cpuid devices,
which are real devices with full support for udev. This implies
that the cpuid driver has to be loaded to use this.

This patch just adds infrastructure, some driver conversions
in followups.

Thanks to Kay for helping with some sysfs magic.

v2: Constifcation, some updates
v4: (trenn@suse.de):
- Use kzalloc instead of kmalloc to terminate modalias buffer
- Use uppercase hex values to match correctly against hex values containing
letters

Cc: Dave Jones <davej@redhat.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jen Axboe <axboe@kernel.dk>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

switch device_get_devnode() and ->devnode() to umode_t *

both callers of device_get_devnode() are only interested in lower 16bits
and nobody tries to return anything wider than 16bit anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

BKL: remove extraneous #include <smp_lock.h>

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86: convert cpu notifier to return encapsulate errno value

By the previous modification, the cpu notifier can return encapsulate
errno value. This converts the cpu notifiers for msr, cpuid, and
therm_throt.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

x86, msr/cpuid: Pass the number of minors when unregistering MSR and CPUID drivers.

Pass the number of minors when unregistering MSR and CPUID drivers.

Reported-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: Dean Nelson <dnelson@redhat.com>
LKML-Reference: <20100127023722.GA22305@sgi.com>
Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

x86, msr/cpuid: Register enough minors for the MSR and CPUID drivers

register_chrdev() hardcodes registering 256 minors, presumably to
avoid breaking old drivers. However, we need to register enough
minors so that we have all possible CPUs.

checkpatch warns on this patch, but the patch is correct: NR_CPUS here
is a static *upper bound* on the *maximum CPU index* (not *number of
CPUs!*) and that is what we want.

Reported-and-tested-by: Russ Anderson <rja@sgi.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <tip-*@git.kernel.org>

x86, cpuid: Simplify the code in cpuid_open

Peter picked up my patch for tip/x86/cpu that removes the bkl in
cpuid_open. Ingo subsequently merged that into tip/master.

This patch folds back in tglx's 55968ede164ae523692f00717f50cd926f1382a0
to my patch that removed the bkl.

This simplifies the code, and makes it consistent with the changes to
kill the bkl in msr.c as well.

Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Kacur <jkacur@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

x86, cpuid: Remove the bkl from cpuid_open()

Most of the variables are local to the function. It IS possible that
for struct cpuinfo_x86 *c c could point to the same area. However,
this is used read only.

Signed-off-by: John Kacur <jkacur@redhat.com>
LKML-Reference: <alpine.LFD.2.00.0910072016190.15183@localhost.localdomain>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Driver-Core: extend devnode callbacks to provide permissions

This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver Core: x86: add nodename for cpuid and msr drivers.

This adds support to the x86 cpuid and msr drivers to report the proper
device name to userspace for their devices.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

x86: cleanup some remaining usages of NR_CPUS where s/b nr_cpu_ids

Impact: Reduce future system panics due to cpumask operations using NR_CPUS

Insure that code does not look at bits >= nr_cpu_ids as when cpumasks are
allocated based on nr_cpu_ids, these extra bits will not be defined.

Also some other minor updates:

* change in to use cpu accessor function set_cpu_present() instead of
directly accessing cpu_present_map w/cpu_clear() [arch/x86/kernel/reboot.c]

* use cpumask_of() instead of &cpumask_of_cpu() [arch/x86/kernel/reboot.c]

* optimize some cpu_mask_to_apicid_and functions.

Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

x86: cpuid.c fix style problems

Impact: cleanup

Fixes style problems:

WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
ERROR: "foo * bar" should be "foo *bar"
ERROR: trailing whitespace
WARNING: usage of NR_CPUS is often wrong - consider using cpu_possible(), num_possible_cpus(), for_each_possible_cpu(), etc

total: 2 errors, 2 warnings

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

device create: misc: convert device_create_drvdata to device_create

Now that device_create() has been audited, rename things back to the
original call to be sane.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

x86: cpuid: correct return value on partial operations

Return the correct return value when the CPUID driver partially
completes a request (we should return the number of bytes actually
read or written, instead of the error code.)

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

x86: cpuid: propagate error from smp_call_function_single()

Propagate error (-ENXIO) from smp_call_function_single() in the CPUID
driver. This can happen when a CPU is unplugged while the CPUID
driver is open.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/kernel/cpuid.c: removed duplicated #include

Removed duplicated include file <linux/smp_lock.h> in
arch/x86/kernel/cpuid.c.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

device create: x86: convert device_create to device_create_drvdata

device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

smp_call_function: get rid of the unused nonatomic/retry argument

It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

x86: cdev lock_kernel() pushdown

Push the cdev lock_kernel() call down into the x86 msr and cpuid drivers.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

PM: Remove destroy_suspended_device()

After 2.6.24 there was a plan to make the PM core acquire all device
semaphores during a suspend/hibernation to protect itself from
concurrent operations involving device objects. That proved to be
too heavy-handed and we found a better way to achieve the goal, but
before it happened, we had introduced the functions
device_pm_schedule_removal() and destroy_suspended_device() to allow
drivers to "safely" destroy a suspended device and we had adapted some
drivers to use them. Now that these functions are no longer necessary,
it seems reasonable to remove them and modify their users to use the
normal device unregistration instead.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

x86: cpuid, msr: use inode mutex instead of big kernel lock

Instead of grabbing the BKL on seek, use the inode mutex in the style
of generic_file_llseek().

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: cpuid: allow querying %ecx-sensitive CPUID levels

After /dev/*/cpuid was introduced, Intel changed the semantics of the
CPUID instruction to be sentitive to %ecx as well as %eax. This patch
allows querying of %ecx-sensitive levels by placing the %ecx value in
the upper 32 bits of the file position (lower 32 bits always were used
for the %eax value.)

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: fix section mismatch warnings when referencing notifiers

Fix the following warnings:
WARNING: arch/x86/kernel/built-in.o(.exit.text+0xf8): Section mismatch in reference from the function msr_exit() to the variable .cpuinit.data:msr_class_cpu_notifier
WARNING: arch/x86/kernel/built-in.o(.exit.text+0x158): Section mismatch in reference from the function cpuid_exit() to the variable .cpuinit.data:cpuid_class_cpu_notifier
WARNING: arch/x86/kernel/built-in.o(.exit.text+0x171): Section mismatch in reference from the function microcode_exit() to the variable .cpuinit.data:mc_cpu_notifier

In all three cases there were a function annotated __exit
that referenced a variable annotated __cpuinitdata.

The fix was to replace the annotation of the notifier
with __refdata to tell modpost that the reference to
a _cpuinit function in the notifier are OK.
The unregister call that references the notifier
variable will simple delete the function pointer
so there is no problem ignoring the reference.

Note: This looks like another case where __cpuinit
has been used as replacement for proper use
of CONFIG_HOTPLUG_CPU to decide what code are used for
HOTPLUG_CPU.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

x86: remove unneded casts

x86: remove unneeded casts

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

PM: Acquire device locks on suspend

This patch reorganizes the way suspend and resume notifications are
sent to drivers. The major changes are that now the PM core acquires
every device semaphore before calling the methods, and calls to
device_add() during suspends will fail, while calls to device_del()
during suspends will block.

It also provides a way to safely remove a suspended device with the
help of the PM core, by using the device_pm_schedule_removal() callback
introduced specifically for this purpose, and updates two drivers (msr
and cpuid) that need to use it.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

x86: convert cpuinfo_x86 array to a per_cpu array

cpu_data is currently an array defined using NR_CPUS. This means that
we overallocate since we will rarely really use maximum configured cpus.
When NR_CPU count is raised to 4096 the size of cpu_data becomes
3,145,728 bytes.

These changes were adopted from the sparc64 (and ia64) code. An
additional field was added to cpuinfo_x86 to be a non-ambiguous cpu
index. This corresponds to the index into a cpumask_t as well as the
per_cpu index. It's used in various places like show_cpuinfo().

cpu_data is defined to be the boot_cpu_data structure for the NON-SMP
case.

Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

i386: do cpuid_device_create() in CPU_UP_PREPARE instead of CPU_ONLINE.

Do cpuid_device_create() in CPU_UP_PREPARE instead of CPU_ONLINE.

[ tglx: arch/x86 adaptation ]

Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

i386: simplify smp_call_function_single() call sequence in cpuid

smp_call_function_single() now knows how to call the function on the
current cpu.

[ tglx: arch/x86 adaptation ]

Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

i386: misc cpuinit annotations

cpuid_class_cpu_callback() is callback function of a CPU hotplug
notifier_block (that is already marked as __cpuinitdata). Therefore
it can safely be marked as __cpuinit.

cpuid_device_create() is only referenced from other functions that
are __cpuinit or __init. So it can also be safely marked __cpuinit.

[ tglx: arch/x86 adaptation ]

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Delete filenames in comments.

Since the x86 merge, lots of files that referenced their own filenames
are no longer correct. Rather than keep them up to date, just delete
them, as they add no real value.

Additionally:
- fix up comment formatting in scx200_32.c
- Remove a credit from myself in setup_64.c from a time when we had no SCM
- remove longwinded history from tsc_32.c which can be figured out from
git.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

i386: move kernel

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>