Embedded systems, which may be very memory-size-sensitive, are
extremely unlikely to ever encounter any 16-bit software, so make it
a CONFIG_EXPERT option to turn off support for any 16-bit software
whatsoever.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com

Make espfix64 a hidden Kconfig option.  This fixes the x86-64 UML
build which had broken due to the non-existence of init_espfix_bsp()
in UML: since UML uses its own Kconfig, this option does not appear in
the UML build.

This also makes it possible to make support for 16-bit segments a
configuration option, for the people who want to minimize the size of
the kernel.
Reported-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Richard Weinberger <richard@nod.at>
Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com

Move x86 over to the generic early ioremap implementation.
Signed-off-by: NMark Salter <msalter@redhat.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently AUDITSYSCALL has a long list of architecture depencency:
       depends on AUDIT && (X86 || PARISC || PPC || S390 || IA64 || UML ||
		SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT) || ALPHA)
The purpose of this patch is to replace it with HAVE_ARCH_AUDITSYSCALL
for simplicity.
Signed-off-by: NAKASHI Takahiro <takahiro.akashi@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com> (arm)
Acked-by: Richard Guy Briggs <rgb@redhat.com> (audit)
Acked-by: Matt Turner <mattst88@gmail.com> (alpha)
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: NEric Paris <eparis@redhat.com>

This patch move the vsyscall_gtod_data handling out of vsyscall_64.c
into an additonal file vsyscall_gtod.c to make the functionality
available for x86 32 bit kernel.

It also adds a new vsyscall_32.c which setup the VVAR page.
Reviewed-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-2-git-send-email-stefani@seibold.netSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The compat vDSO is a complicated hack that's needed to maintain
compatibility with a small range of glibc versions.

This removes it and replaces it with a much simpler hack: a config
option to disable the 32-bit vDSO by default.

This also changes the default value of CONFIG_COMPAT_VDSO to n --
users configuring kernels from scratch almost certainly want that
choice.
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/4bb4690899106eb11430b1186d5cc66ca9d1660c.1394751608.git.luto@amacapital.netSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Add the Kconfig option and bump the kernel header version so that boot
loaders can check whether the handover code is available if they want.

The xloadflags field in the bzImage header is also updated to reflect
that the kernel supports both entry points by setting both of
XLF_EFI_HANDOVER_32 and XLF_EFI_HANDOVER_64 when CONFIG_EFI_MIXED=y.
XLF_CAN_BE_LOADED_ABOVE_4G is disabled so that the kernel text is
guaranteed to be addressable with 32-bits.

Note that no boot loaders should be using the bits set in xloadflags to
decide which entry point to jump to. The entire scheme is based on the
concept that 32-bit bootloaders always jump to ->handover_offset and
64-bit loaders always jump to ->handover_offset + 512. We set both bits
merely to inform the boot loader that it's safe to use the native
handover offset even if the machine type in the PE/COFF header claims
otherwise.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The NUMAQ support seems to be unmaintained, remove it.

Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/n/530CFD6C.7040705@zytor.com

The SGI Visual Workstation seems to be dead; remove support so we
don't have to continue maintaining it.

Cc: Andrey Panin <pazke@donpac.ru>
Cc: Michael Reed <mdr@sgi.com>
Link: http://lkml.kernel.org/r/530CFD6C.7040705@zytor.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The x86 CPU feature modalias handling existed before it was reimplemented
generically. This patch aligns the x86 handling so that it
(a) reuses some more code that is now generic;
(b) uses the generic format for the modalias module metadata entry, i.e., it
    now uses 'cpu:type:x86,venVVVVfamFFFFmodMMMM:feature:,XXXX,YYYY' instead of
    the 'x86cpu:vendor:VVVV:family:FFFF:model:MMMM:feature:,XXXX,YYYY' that was
    used before.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NH. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There should no longer be any IBM x440 systems or those using the
Summit/EXA chipset out in the wild, so remove support for it.

We've done our due diligence in reaching out to any contact information
listed for this chipset and no indication was given that it should be
kept around.
Signed-off-by: NDavid Rientjes <rientjes@google.com>

There should no longer be any ia32-based Unisys ES7000 systems out in
the wild, so remove support for it.

We've done our due diligence in reaching out to any contact information
listed for this system and no indication was given that it should be
kept around.
Signed-off-by: NDavid Rientjes <rientjes@google.com>

This patch fixes the following warning:

  warning: (X86_INTEL_MID) selects INTEL_SCU_IPC which has unmet direct dependencies (X86 && X86_PLATFORM_DEVICES && X86_INTEL_MID)

It happens because when selected, X86_INTEL_MID tries to select
INTEL_SCU_IPC regardless all its dependencies are met or not.

This patch fixes it by adding the missing X86_PLATFORM_DEVICES
dependency to X86_INTEL_MID.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NDavid Cohen <david.a.cohen@linux.intel.com>
Link: http://lkml.kernel.org/r/1390329699-20782-1-git-send-email-david.a.cohen@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Remove an outdated reference to "most personal computers" having only one
CPU, and change the use of "singleprocessor" and "single processor" in
CONFIG_SMP's documentation to "uniprocessor" across all arches where that
documentation is present.
Signed-off-by: NRobert Graffham <psquid@psquid.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch makes a couple of changes to the SMBIOS/DMI scanning
code so it can be used on other archs (such as ARM and arm64):
(a) wrap the calls to ioremap()/iounmap(), this allows the use of a
    flavor of ioremap() more suitable for random unaligned access;
(b) allow the non-EFI fallback probe into hardcoded physical address
    0xF0000 to be disabled.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NGrant Likely <grant.likely@linaro.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The actual data lives in the Intel download center, and that ought to also
be a reliable way to continue to find it. Unfortunately the actual URL
needed for doing it directly is about a foot long so give instructions.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/20140120180056.7173.62222.stgit@alan.etchedpixels.co.ukSigned-off-by: NH. Peter Anvin <hpa@zytor.com>

We want to support all Intel MID (Mobile Internet Device) platforms
with a single config selection. This patch removes deprecated
CONFIG_X86_MDFLD and X86_WANT_INTEL_MID options in favor of having
CONFIG_X86_INTEL_MID only.
Signed-off-by: NDavid Cohen <david.a.cohen@linux.intel.com>
Link: http://lkml.kernel.org/r/1387244246-20714-1-git-send-email-david.a.cohen@linux.intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The help text for RANDOMIZE_BASE_MAX_OFFSET was confusing. This has been
clarified, and updated to be an export-only tunable.
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20131210202745.GA2961@www.outflux.netAcked-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

We've grown a bunch of microcode loader files all prefixed with
"microcode_". They should be under cpu/ because this is strictly
CPU-related functionality so do that and drop the prefix since they're
in their own directory now which gives that prefix. :)

While at it, drop MICROCODE_INTEL_LIB config item and stash the
functionality under CONFIG_MICROCODE_INTEL as it was its only user.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Tested-by: NAravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>

Current Intel SOC cores use a MailBox Interface (MBI) to provide access to
configuration registers on devices (called units) connected to the system
fabric. This is a support driver that implements access to this interface on
those platforms that can enumerate the device using PCI. Initial support is for
BayTrail, for which port definitons are provided. This is a requirement for
implementing platform specific features (e.g. RAPL driver requires this to
perform platform specific power management using the registers in PUNIT).
Dependant modules should select IOSF_MBI in their respective Kconfig
configuraiton. Serialized access is handled by all exported routines with
spinlocks.

The API includes 3 functions for access to unit registers:

int iosf_mbi_read(u8 port, u8 opcode, u32 offset, u32 *mdr)
int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr)
int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask)

port:	indicating the unit being accessed
opcode:	the read or write port specific opcode
offset:	the register offset within the port
mdr:	the register data to be read, written, or modified
mask:	bit locations in mdr to change

Returns nonzero on error

Note: GPU code handles access to the GFX unit. Therefore access to that unit
with this driver is disallowed to avoid conflicts.
Signed-off-by: NDavid E. Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1389216471-734-1-git-send-email-david.e.box@linux.intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>

Architectures which might use an i8042 for serial IO to keyboard,
mouse, etc should select ARCH_MIGHT_HAVE_PC_SERIO.
Signed-off-by: NMark Salter <msalter@redhat.com>
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Instead of duplicating the CC_STACKPROTECTOR Kconfig and
Makefile logic in each architecture, switch to using
HAVE_CC_STACKPROTECTOR and keep everything in one place. This
retains the x86-specific bug verification scripts.
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@linux-mips.org
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/1387481759-14535-2-git-send-email-keescook@chromium.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Introduce mul_u64_u32_shr() as proposed by Andy a while back; it
allows using 64x64->128 muls on 64bit archs and recent GCC
which defines __SIZEOF_INT128__ and __int128.

(This new method will be used by the scheduler.)
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: fweisbec@gmail.com
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-hxjoeuzmrcaumR0uZwjpe2pv@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Correct spelling typo in Kconfig.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

We've switched over every architecture that supports SMP to it, so
remove the new useless config variable.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Enable PMD split page table lock for X86_64 and PAE.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: NAlex Thorlton <athorlton@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Reviewed-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Depending on availability, mix the RDRAND and RDTSC entropy together with
XOR. Only when neither is available should the i8254 be used. Update
the Kconfig documentation to reflect this. Additionally, since bits
used for entropy is masked elsewhere, drop the needless masking in
the get_random_long(). Similarly, use the entire TSC, not just the low
32 bits.

Finally, to improve the starting entropy, do a simple hashing of a
build-time versions string and the boot-time boot_params structure for
some additional level of unpredictability.
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20131111222839.GA28616@www.outflux.netSigned-off-by: NH. Peter Anvin <hpa@zytor.com>

The MAXSMP option is intended to enable silly large numbers of
CPUs for testing purposes.  The current value of 4096 isn't very
silly any longer as there are actual SGI machines that approach
6096 CPUs when taking HT into account.

Increase the value to a nice round 8192 to account for this and
allow for short term future increases.
Signed-off-by: NJosh Boyer <jwboyer@fedoraproject.org>
Cc: prarit@redhat.com
Cc: Russ Anderson <rja@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20131105143816.GK9944@hansolo.jdub.homelinux.org
[ Tweaked it so that MAXSMP simply sets the maximum of the normal range. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The current range for SMP configs is 2 - 512 CPUs, or a full
4096 in the case of MAXSMP.  There are machines that have 1024
CPUs in them today and configuring a kernel for that means you
are forced to set MAXSMP.  This adds additional unnecessary
overhead.  While that overhead might be considered tiny for
large machines, it isn't necessarily so if you are building a
kernel that runs across a wide variety of machines.

To cover the range of more common machines today, we allow
NR_CPUS to be up to 4096 when CPUMASK_OFFSTACK is enabled.
Signed-off-by: NJosh Boyer <jwboyer@fedoraproject.org>
Cc: prarit@redhat.com
Cc: Russ Anderson <rja@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20131105143728.GJ9944@hansolo.jdub.homelinux.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Since the paravirt spinlock optimizations went into the v3.12 kernel
we have a very good performance benefit for paravirtualized KVM / Xen
kernels. Also we no longer suffer from 5% side effect on native
kernel that is mentioned in the Kconfig entry.

So update the Kconfig entry accordingly.

pvspinlock benefit on KVM link:

  https://lkml.org/lkml/2013/8/6/178

Attilio's tests on native kernel impact:

  http://blog.xen.org/index.php/2012/05/11/benchmarking-the-new-pv-ticketlock-implementation/Signed-off-by: NRaghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: <konrad.wilk@oracle.com>
Cc: <linux@eikelenboom.it>
Cc: <gleb@redhat.com>
Cc: <pbonzini@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1382371508-3843-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com
[ Updated the changelog. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Architectures which support CONFIG_PARPORT_PC should select
ARCH_MIGHT_HAVE_PC_PARPORT.
Signed-off-by: NMark Salter <msalter@redhat.com>
Acked-by: NIngo Molnar <mingo@redhat.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: x86@kernel.org

I have a randconfig here which has enabled only

  CONFIG_MICROCODE=y
  CONFIG_MICROCODE_OLD_INTERFACE=y

with both

  # CONFIG_MICROCODE_INTEL is not set
  # CONFIG_MICROCODE_AMD is not set

off. Which makes building the microcode functionality a little
pointless. Don't do that in such cases then.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1381682189-14470-1-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

On 64-bit, this raises the maximum location to -1 GiB (from -1.5 GiB),
the upper limit currently, since the kernel fixmap page mappings need
to be moved to use the other 1 GiB (which would be the theoretical
limit when building with -mcmodel=kernel).
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1381450698-28710-7-git-send-email-keescook@chromium.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

This allows decompress_kernel to return a new location for the kernel to
be relocated to. Additionally, enforces CONFIG_PHYSICAL_START as the
minimum relocation position when building with CONFIG_RELOCATABLE.

With CONFIG_RANDOMIZE_BASE set, the choose_kernel_location routine
will select a new location to decompress the kernel, though here it is
presently a no-op. The kernel command line option "nokaslr" is introduced
to bypass these routines.
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1381450698-28710-3-git-send-email-keescook@chromium.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Improve the explanation of this config option.

Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/n/tip-gUMmysvsbl3mccbyf6olmxqg@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The AMD_GART driver was made EXPERT/EMBEDDED a long time
ago to avoid unbootable 64bit systems with 32bit only devices.

This was before swiotlb was there, which does the job
of this fallback today. SWIOTLB is always on, so systems
should always boot.

The drawback is that every system has to compile that
driver in (it cannot be a module).

Also:
 - Newer AMD CPUs (the APUs) don't seem to have AMD_GART support
   at all anymore.

 - Newer AMD platforms have a much better real IOMMU

 - The AMD GART driver was never very good (lots of overhead,
   e.g. in flushing due to some workarounds) and it's doubtful it's
   really better than SWIOTLB.

 - On older K8 systems it didn't even work with all chipsets.

 - The 32bit device bounce buffer case should be rare/
   non performance critical these days anyways.

 - On non AMD systems it is not needed at all.

So drop the EXPERT dependency on AMD_GART and remove the
default y. The driver can be still compiled in, just
it's an explicit decision now, and people who don't want
it can unselect it.

I also clarified the description a bit.

This allows to save ~8K text on most modern x86-64 systems.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1380922676-23007-1-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit ebd97be6 ('PCI: remove ARCH_SUPPORTS_MSI kconfig option')
removed the ARCH_SUPPORTS_MSI option which architectures could select
to indicate that they support MSI. Now, all architectures are supposed
to build fine when MSI support is enabled: instead of having the
architecture tell *when* MSI support can be used, it's up to the
architecture code to ensure that MSI support can be enabled.

On x86, commit ebd97be6 removed the following line:

  select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)

Which meant that MSI support was only available when the local APIC
and I/O APIC were enabled. While this is always true on SMP or x86-64,
it is not necessarily the case on i386 !SMP.

The below patch makes sure that the local APIC and I/O APIC support is
always enabled when MSI support is enabled. To do so, it:

 * Ensures the X86_UP_APIC option is not visible when PCI_MSI is
   enabled. This is the option that allows, on UP machines, to enable
   or not the APIC support. It is already not visible on SMP systems,
   or x86-64 systems, for example. We're simply also making it
   invisible on i386 MSI systems.

 * Ensures that the X86_LOCAL_APIC and X86_IO_APIC options are 'y'
   when PCI_MSI is enabled.

Notice that this change requires a change in drivers/iommu/Kconfig to
avoid a recursive Kconfig dependencey. The AMD_IOMMU option selects
PCI_MSI, but was depending on X86_IO_APIC. This dependency is no
longer needed: as soon as PCI_MSI is selected, the presence of
X86_IO_APIC is guaranteed. Moreover, the AMD_IOMMU already depended on
X86_64, which already guaranteed that X86_IO_APIC was enabled, so this
dependency was anyway redundant.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: http://lkml.kernel.org/r/1380794354-9079-1-git-send-email-thomas.petazzoni@free-electrons.comReported-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

x86-64 runs irq_exit() under the irq stack. So it can afford
to run softirqs in hardirq exit without the need to switch
the stacks. The hardirq stack is good enough for that.

Now x86-64 runs softirqs in the hardirq stack anyway, so what we
mostly skip is some needless per cpu refcounting updates there.

x86-32 is not concerned because it only runs the irq handler on
the irq stack.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@au1.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@au1.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Andrew Morton <akpm@linux-foundation.org>

Move efi-stub.txt out of x86 directory and into common directory
in preparation for adding ARM EFI stub support.
Signed-off-by: NRoy Franz <roy.franz@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Commit d7c53c9e enabled ARCH_CPU_PROBE_RELEASE on x86 in order to
serialize CPU online/offline operations.  Although it is the config
option to enable CPU hotplug test interfaces, probe & release, it is
also the option to enable cpu_hotplug_driver_lock() as well.  Therefore,
this option had to be enabled on x86 with dummy arch_cpu_probe() and
arch_cpu_release().

Since then, lock_device_hotplug() was introduced to serialize CPU
online/offline & hotplug operations.  Therefore, this config option
is no longer required for the serialization.  This patch disables
this config option on x86 and revert the changes made by commit
d7c53c9e.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>