Currently the PTE special supports is turned on in per architecture
header files.  Most of the time, it is defined in
arch/*/include/asm/pgtable.h depending or not on some other per
architecture static definition.

This patch introduce a new configuration variable to manage this
directly in the Kconfig files.  It would later replace
__HAVE_ARCH_PTE_SPECIAL.

Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:

arm
 __HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.

powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
 - arch/powerpc/include/asm/book3s/64/pgtable.h
 - arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.

sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64

There is no functional change introduced by this patch.

Link: http://lkml.kernel.org/r/1523433816-14460-2-git-send-email-ldufour@linux.vnet.ibm.com


Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <albert@sifive.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Christophe LEROY <christophe.leroy@c-s.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The removal of this file appears to have been premature; it's not a feature
enabled by Kconfig, but it's a arch-level feature regardless.  Put it back
for now until some happy future time when we decide how we really want to
document such features.

This reverts commit 2bef69a3.

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

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Uses '!RWSEM_GENERIC_SPINLOCK' in place of 'Optimized asm/rwsem.h' as
Kconfig for 'rwsem-optimized': the new Kconfig expresses this feature
equivalently, while also enabling the script 'features-refresh.sh' to
operate on the corresponding arch support status file. Also refreshes
the status matrix by using the script 'features-refresh.sh'.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Commit 6077776b split 'HAVE_BPF_JIT' into cBPF and eBPF variant.
Adds arch support status files for the new variants, and removes the
status file corresponding to 'HAVE_BPT_JIT'. The new status matrices
were auto-generated using the script 'features-refresh.sh'.

Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Now that the script 'features-refresh.sh' is available, uses this script
to refresh all the arch-support.txt files in place.

Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Provides the script:

	Documentation/features/scripts/features-refresh.sh

which operates on the arch-support.txt files and refreshes them in place.

This way [1],

   "[...] we soft- decouple the refreshing of the entries from the
    introduction of the features, while still making it all easy to
    keep sync and to extend."

[1] http://lkml.kernel.org/r/20180328122211.GA25420@andrea



Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

There is no arch specific code required for dma-debug, so there is no
need to opt into the support either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>

A number of architecture ports are obsolete and getting dropped,
so we no longer want to track the respective features.

We already removed the lines for metag and mn10300, this does
the same edits for all the others.

For the remaining 21 architectures, this shows how many are known
to implement each given feature:

19 time/modern-timekeeping/arch-support.txt
19 time/clockevents/arch-support.txt
15 core/tracehook/arch-support.txt
14 core/generic-idle-thread/arch-support.txt
13 locking/lockdep/arch-support.txt
12 io/dma-api-debug/arch-support.txt
11 debug/kgdb/arch-support.txt
10 time/virt-cpuacct/arch-support.txt
 9 debug/kretprobes/arch-support.txt
 9 debug/kprobes/arch-support.txt
 8 vm/THP/arch-support.txt
 8 vm/pte_special/arch-support.txt
 8 vm/numa-memblock/arch-support.txt
 8 io/sg-chain/arch-support.txt
 7 perf/kprobes-event/arch-support.txt
 7 locking/rwsem-optimized/arch-support.txt
 7 debug/gcov-profile-all/arch-support.txt
 7 core/jump-labels/arch-support.txt
 7 core/BPF-JIT/arch-support.txt
 6 vm/ELF-ASLR/arch-support.txt
 6 time/context-tracking/arch-support.txt
 6 seccomp/seccomp-filter/arch-support.txt
 6 debug/stackprotector/arch-support.txt
 5 time/irq-time-acct/arch-support.txt
 5 io/dma-contiguous/arch-support.txt
 5 debug/uprobes/arch-support.txt
 4 vm/ioremap_prot/arch-support.txt
 4 time/arch-tick-broadcast/arch-support.txt
 4 perf/perf-stackdump/arch-support.txt
 4 perf/perf-regs/arch-support.txt
 3 debug/KASAN/arch-support.txt
 2 vm/PG_uncached/arch-support.txt
 2 vm/huge-vmap/arch-support.txt
 2 sched/numa-balancing/arch-support.txt
 2 sched/membarrier-sync-core/arch-support.txt
 2 locking/cmpxchg-local/arch-support.txt
 2 debug/optprobes/arch-support.txt
 2 debug/kprobes-on-ftrace/arch-support.txt
 1 vm/TLB/arch-support.txt
 1 locking/queued-spinlocks/arch-support.txt
 1 locking/queued-rwlocks/arch-support.txt
 1 debug/user-ret-profiler/arch-support.txt
 0 lib/strncasecmp/arch-support.txt

Note that the list does not include riscv or nds32 yet, these still
need to be added.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Remove the MN10300 arch as the hardware is defunct.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Masahiro Yamada <yamada.masahiro@socionext.com>
cc: linux-am33-list@redhat.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Remove any remaining references to the Meta architecture in
Documentation/, primarily from Documentation/features/.

Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-metag@vger.kernel.org
Cc: linux-doc@vger.kernel.org

Ensure we gather architecture requirements about each architecture
supporting the "sync_core" membarrier command in a single file under
Documentation/features.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: David Sehr <sehr@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/1518208256-22034-1-git-send-email-mathieu.desnoyers@efficios.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

The list-arch.sh script considers lines beginning with "#" as match for
the feature table.

Given that those tables are never in lines beginning with "#",
add a reverse grep on "^#" when matching the "ok/TODO" state of
the architecture.

This allows adding comments within the feature files, for instance
describing the architecture requirements for the feature in each
architecture.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/1518282058-24226-1-git-send-email-mathieu.desnoyers@efficios.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

Ensure we gather architecture requirements about each architecture
supporting the "sync_core" membarrier command in a single file under
Documentation/features.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: David Sehr <sehr@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/1518208256-22034-1-git-send-email-mathieu.desnoyers@efficios.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

Cover kernel addresses above 0x90000000 by the shadow map. Enable
HAVE_ARCH_KASAN when MMU is enabled. Provide kasan_early_init that fills
shadow map with writable copies of kasan_zero_page. Call
kasan_early_init right after mmu initialization in the setup_arch.
Provide kasan_init that allocates proper shadow map pages from the
memblock and puts these pages into the shadow map for addresses from
VMALLOC area to the end of KSEG. Call kasan_init right after memblock
initialization. Don't use KASAN for the boot code, MMU and KASAN
initialization and page fault handler. Make kernel stack size 4 times
larger when KASAN is enabled to avoid stack overflows.
GCC 7.3, 8 or newer is required to build the xtensa kernel with KASAN.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

The implementation is adopted from the ARM arch. GCC 7.3, 8 or newer is
required for building the xtensa kernel with SSP.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Relevant part is:
arch/x86/Kconfig: select HAVE_ARCH_KASAN  if X86_64 && SPARSEMEM_VMEMMAP

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Since commit 64e2a42b ("parisc: Add ARCH_TRACEHOOK and regset
support") in v4.7, parisc selects HAVE_ARCH_TRACEHOOK, so update its
entry in Documentation/features from TODO to ok.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The AVR32 architecture support has been removed from the Linux kernel,
hence remove all references to it from Documentation.

Signed-off-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Signed-off-by: Håvard Skinnemoen <hskinnemoen@gmail.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Allow kprobes to be placed on ftrace _mcount() call sites. This optimization
avoids the use of a trap, by riding on ftrace infrastructure.

This depends on HAVE_DYNAMIC_FTRACE_WITH_REGS which depends on MPROFILE_KERNEL,
which is only currently enabled on powerpc64le with newer toolchains.

Based on the x86 code by Masami.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

xtensa supports DMA API debug and contiguous DMA, mark it as such.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

This should have been part of 40e084a5 ('MIPS: Add uprobes support.').

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fixes: 40e084a5 ("MIPS: Add uprobes support.")
Acked-by: Jonathan Corbet <corbet@lwn.net>
Cc: linux-mips@linux-mips.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14392/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

With perf regs support enabled for powerpc, in commit ed4a4ef8
("powerpc/perf: Add support for sampling interrupt register state"),
the support for obtaining perf user stack dump is already enabled. This
patch declares the support for same and also updates documentation to
mark the support for perf-regs and perf-stackdump.

Signed-off-by: Chandan Kumar <chandan.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This wires up the existing generic huge-vmap feature, which allows
ioremap() to use PMD or PUD sized block mappings. It also adds support
to the unmap path for dealing with block mappings, which will allow us
to unmap the __init region using unmap_kernel_range() in a subsequent
patch.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Commit 669f6f96 introduced
the script list-arch.sh, which uses the command "arch":

ARCH=${1:-$(arch | sed 's/x86_64/x86/' | sed 's/i386/x86/')}

It turns out that the "arch" command does not exist in my system (arch
distro). Google found man pages which say "arch is deprecated command since
release util-linux 2.13. Use uname -m" (util-linux 2.13 was released in 2007).
I also found a debian bug reporting the lack of arch and being told to use
uname -m https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=446023



But then, why it works in some distros? Apparently coreutils gained an
optional arch command that needs to be explicitly enabled during compilation.
Some distros enable it, others don't. Sigh.

Signed-off-by: Diego Calleja <diegocg@gmail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Move the generic implementation to <linux/dma-mapping.h> now that all
architectures support it and remove the HAVE_DMA_ATTR Kconfig symbol now
that everyone supports them.

[valentinrothberg@gmail.com: remove leftovers in Kconfig]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Helge Deller <deller@gmx.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With new refcounting we don't need to mark PMDs splitting.  Let's drop
code to handle this.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This brings SECCOMP_MODE_STRICT and SECCOMP_MODE_FILTER support through
prctl(2) and seccomp(2) to User-mode Linux for i386 and x86_64
subarchitectures.

secure_computing() is called first in handle_syscall() so that the
syscall emulation will be aborted quickly if matching a seccomp rule.

This is inspired from Meredydd Luff's patch
(https://gerrit.chromium.org/gerrit/21425

).

Signed-off-by: Mickaël Salaün <mic@digikod.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: David Drysdale <drysdale@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Kees Cook <keescook@chromium.org>

arm64 relies on the arm_arch_timer for sched_clock, so we can select
HAVE_IRQ_TIME_ACCOUNTING and have the core sched-clock code enable the
feature at runtime based on the rate.

Reported-by: Mario Smarduch <m.smarduch@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

Change metag Transparent Huge Pages (THP) support from .. to TODO. Meta2
has variable sized pages, between 4KB and 4MB, specified at the 1st
level page table level, and already supports hugetlbfs, so supporting
THP is theoretically possible too.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-metag@vger.kernel.org
Cc: linux-doc@vger.kernel.org

Documentation/features/vm: add feature description and arch support status for batched TLB flush after unmap

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>

The previous patches added arch support matrices for more than 40 generic kernel features
that need per architecture support.

The structure of the feature descriptions is the following:

Each feature has its own directory under Documentation/features/subsystem_name/feature_name/,
and the arch-support.txt file shows its current arch porting status.

For example, lockdep support is shown the following way:

    triton:~/tip> cat Documentation/features/locking/lockdep/arch-support.txt
    #
    # Feature name:          lockdep
    #         Kconfig:       LOCKDEP_SUPPORT
    #         description:   arch supports the runtime locking correctness debug facility
    #
        -----------------------
        |         arch |status|
        -----------------------
        |       alpha: | TODO |
        |         arc: |  ok  |
        |         arm: |  ok  |
        |       arm64: |  ok  |
        |       avr32: |  ok  |
        |    blackfin: |  ok  |
        |         c6x: | TODO |
        |        cris: | TODO |
        |         frv: | TODO |
        |       h8300: | TODO |
        |     hexagon: |  ok  |
        |        ia64: | TODO |
        |        m32r: | TODO |
        |        m68k: | TODO |
        |       metag: |  ok  |
        |  microblaze: |  ok  |
        |        mips: |  ok  |
        |     mn10300: | TODO |
        |       nios2: | TODO |
        |    openrisc: | TODO |
        |      parisc: | TODO |
        |     powerpc: |  ok  |
        |        s390: |  ok  |
        |       score: |  ok  |
        |          sh: |  ok  |
        |       sparc: |  ok  |
        |        tile: |  ok  |
        |          um: |  ok  |
        |   unicore32: |  ok  |
        |         x86: |  ok  |
        |      xtensa: |  ok  |
        -----------------------

For generic kernel features that need architecture support, the
arch-support.txt file in each feature directory shows the arch
support matrix, for all upstream Linux architectures.

The meaning of entries in the tables is:

    | ok |  # feature supported by the architecture
    |TODO|  # feature not yet supported by the architecture
    | .. |  # feature cannot be supported by the hardware

This directory structure can be used in the future to add other
files - such as porting guides, testing description, etc.

The Documentation/features/ hierarchy may also include generic
kernel features that works on every architecture, in that case
the arch-support.txt file will list every architecture as
supported.

To list an architecture's unsupported features, just do something
like:

  triton:~/tip>  git grep -lE 'x86.*TODO' Documentation/features/*/*/arch-support.txt
  Documentation/features/lib/strncasecmp/arch-support.txt
  Documentation/features/time/arch-tick-broadcast/arch-support.txt

which will print the list of not yet supported features.

The Documentation/features/list-arch.sh script will print the current
support matrix of one architecture:

  triton:~/tip> Documentation/features/list-arch.sh
  #
  # Kernel feature support matrix of the 'x86' architecture:
  #
      core/ BPF-JIT              :  ok  |                        HAVE_BPF_JIT #  arch supports BPF JIT optimizations
      core/ generic-idle-thread  :  ok  |             GENERIC_SMP_IDLE_THREAD #  arch makes use of the generic SMP idle thread facility
      core/ jump-labels          :  ok  |                HAVE_ARCH_JUMP_LABEL #  arch supports live patched, high efficiency branches
      core/ tracehook            :  ok  |                 HAVE_ARCH_TRACEHOOK #  arch supports tracehook (ptrace) register handling APIs
     debug/ gcov-profile-all     :  ok  |           ARCH_HAS_GCOV_PROFILE_ALL #  arch supports whole-kernel GCOV code coverage profiling
     debug/ KASAN                :  ok  |                     HAVE_ARCH_KASAN #  arch supports the KASAN runtime memory checker
     debug/ kgdb                 :  ok  |                      HAVE_ARCH_KGDB #  arch supports the kGDB kernel debugger
     debug/ kprobes              :  ok  |                        HAVE_KPROBES #  arch supports live patched kernel probe
     debug/ kprobes-on-ftrace    :  ok  |              HAVE_KPROBES_ON_FTRACE #  arch supports combined kprobes and ftrace live patching
     debug/ kretprobes           :  ok  |                     HAVE_KRETPROBES #  arch supports kernel function-return probes
     debug/ optprobes            :  ok  |                      HAVE_OPTPROBES #  arch supports live patched optprobes
     debug/ stackprotector       :  ok  |              HAVE_CC_STACKPROTECTOR #  arch supports compiler driven stack overflow protection
     debug/ uprobes              :  ok  |               ARCH_SUPPORTS_UPROBES #  arch supports live patched user probes
     debug/ user-ret-profiler    :  ok  |           HAVE_USER_RETURN_NOTIFIER #  arch supports user-space return from system call profiler
        io/ dma-api-debug        :  ok  |                  HAVE_DMA_API_DEBUG #  arch supports DMA debug facilities
        io/ dma-contiguous       :  ok  |                 HAVE_DMA_CONTIGUOUS #  arch supports the DMA CMA (continuous memory allocator)
        io/ dma_map_attrs        :  ok  |                      HAVE_DMA_ATTRS #  arch provides dma_*map*_attrs() APIs
        io/ sg-chain             :  ok  |                   ARCH_HAS_SG_CHAIN #  arch supports chained scatter-gather lists
       lib/ strncasecmp          : TODO |             __HAVE_ARCH_STRNCASECMP #  arch provides an optimized strncasecmp() function
   locking/ cmpxchg-local        :  ok  |                  HAVE_CMPXCHG_LOCAL #  arch supports the this_cpu_cmpxchg() API
   locking/ lockdep              :  ok  |                     LOCKDEP_SUPPORT #  arch supports the runtime locking correctness debug facility
   locking/ queued-rwlocks       :  ok  |             ARCH_USE_QUEUED_RWLOCKS #  arch supports queued rwlocks
   locking/ queued-spinlocks     :  ok  |           ARCH_USE_QUEUED_SPINLOCKS #  arch supports queued spinlocks
   locking/ rwsem-optimized      :  ok  |               Optimized asm/rwsem.h #  arch provides optimized rwsem APIs
      perf/ kprobes-event        :  ok  |      HAVE_REGS_AND_STACK_ACCESS_API #  arch supports kprobes with perf events
      perf/ perf-regs            :  ok  |                      HAVE_PERF_REGS #  arch supports perf events register access
      perf/ perf-stackdump       :  ok  |           HAVE_PERF_USER_STACK_DUMP #  arch supports perf events stack dumps
     sched/ numa-balancing       :  ok  |        ARCH_SUPPORTS_NUMA_BALANCING #  arch supports NUMA balancing
   seccomp/ seccomp-filter       :  ok  |            HAVE_ARCH_SECCOMP_FILTER #  arch supports seccomp filters
      time/ arch-tick-broadcast  : TODO |             ARCH_HAS_TICK_BROADCAST #  arch provides tick_broadcast()
      time/ clockevents          :  ok  |                 GENERIC_CLOCKEVENTS #  arch support generic clock events
      time/ context-tracking     :  ok  |               HAVE_CONTEXT_TRACKING #  arch supports context tracking for NO_HZ_FULL
      time/ irq-time-acct        :  ok  |            HAVE_IRQ_TIME_ACCOUNTING #  arch supports precise IRQ time accounting
      time/ modern-timekeeping   :  ok  |            !ARCH_USES_GETTIMEOFFSET #  arch does not use arch_gettimeoffset() anymore
      time/ virt-cpuacct         :  ok  |            HAVE_VIRT_CPU_ACCOUNTING #  arch supports precise virtual CPU time accounting
        vm/ ELF-ASLR             :  ok  |              ARCH_HAS_ELF_RANDOMIZE #  arch randomizes the stack, heap and binary images of ELF binaries
        vm/ huge-vmap            :  ok  |                 HAVE_ARCH_HUGE_VMAP #  arch supports the ioremap_pud_enabled() and ioremap_pmd_enabled() VM APIs
        vm/ ioremap_prot         :  ok  |                   HAVE_IOREMAP_PROT #  arch has ioremap_prot()
        vm/ numa-memblock        :  ok  |              HAVE_MEMBLOCK_NODE_MAP #  arch supports NUMA aware memblocks
        vm/ PG_uncached          :  ok  |               ARCH_USES_PG_UNCACHED #  arch supports the PG_uncached page flag
        vm/ pmdp_splitting_flush :  ok  |    __HAVE_ARCH_PMDP_SPLITTING_FLUSH #  arch supports the pmdp_splitting_flush() VM API
        vm/ pte_special          :  ok  |             __HAVE_ARCH_PTE_SPECIAL #  arch supports the pte_special()/pte_mkspecial() VM APIs
        vm/ THP                  :  ok  |      HAVE_ARCH_TRANSPARENT_HUGEPAGE #  arch supports transparent hugepages

Cc: <linux-api@vger.kernel.org>
Cc: <linux-arch@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Cc: <linux-api@vger.kernel.org>
Cc: <linux-arch@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>