xtensa: enable KCSAN

Prefix arch-specific barrier macros with '__' to make use of instrumented
generic macros.
Prefix arch-specific bitops with 'arch_' to make use of instrumented
generic functions.
Provide stubs for 64-bit atomics when building with KCSAN.
Disable KCSAN instrumentation in arch/xtensa/boot.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Marco Elver <elver@google.com>

include: move find.h from asm_generic to linux

find_bit API and bitmap API are closely related, but inclusion paths
are different - include/asm-generic and include/linux, correspondingly.
In the past it made a lot of troubles due to circular dependencies
and/or undefined symbols. Fix this by moving find.h under include/linux.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

xtensa: use "m" constraint instead of "a" in bitops.h assembly

Use "m" constraint instead of "r" for the address, as "m" allows
compiler to access adjacent locations using base + offset, while "r"
requires updating the base register every time.

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

xtensa: use named assembly arguments in bitops.h

Numeric assembly arguments are hard to understand and assembly code that
uses them is hard to modify. Use named arguments in BIT_OP and
TEST_AND_BIT_OP macros.

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

xtensa: use macros to generate *_bit and test_and_*_bit functions

Parameterize macros with function name, opcode and inversion pattern.
This reduces code duplication removing 2/3 of definitions.

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

xtensa: fix change_bit in exclusive access option

change_bit implementation for XCHAL_HAVE_EXCLUSIVE case changes all bits
except the one required due to copy-paste error from clear_bit.

Cc: stable@vger.kernel.org # v5.2+
Fixes: f7c34874f04a ("xtensa: add exclusive atomics support")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: add exclusive atomics support

Implement atomic primitives using exclusive access opcodes available in
the recent xtensa cores.
Since l32ex/s32ex don't have any memory ordering guarantees don't define
__smp_mb__before_atomic/__smp_mb__after_atomic to make them use memw.

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

xtensa: drop ifdef __KERNEL__ from kernel-only headers

These headers are not exported to userspace, so they're never used
without __KERNEL__ defined. Drop these ifdef statements.

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

xtensa: fix __ffs result type

Make __ffs result type unsigned long to match generic asm
implementation. This fixes the following build warning:

mm/nobootmem.c: In function '__free_pages_memory':
include/linux/kernel.h:742:17: warning: comparison of distinct pointer
types lacks a cast
(void) (&_min1 == &_min2); \
^
mm/nobootmem.c:100:11: note: in expansion of macro 'min'
order = min(MAX_ORDER - 1UL, __ffs(start));

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

arch,xtensa: Convert smp_mb__*()

Xtensa SMP has compare-and-swap which is fully serializing, therefore
its exising smp_mb__{before,after}_clear_bit() appear unduly heavy.

Implement the new barriers as barrier().

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-e9rqjxr1m1ejsob9p433kmji@git.kernel.org
Cc: Chris Zankel <chris@zankel.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

xtensa: add SMP support

This is largely based on SMP code from the xtensa-2.6.29-smp tree by
Piet Delaney, Marc Gauthier, Joe Taylor, Christian Zankel (and possibly
other Tensilica folks).

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

xtensa: add s32c1i-based bitops implementations

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

Disintegrate asm/system.h for Xtensa

Disintegrate asm/system.h for Xtensa.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Chris Zankel <chris@zankel.net>

asm-generic: add another generic ext2 atomic bitops

The majority of architectures implement ext2 atomic bitops as
test_and_{set,clear}_bit() without spinlock.

This adds this type of generic implementation in ext2-atomic-setbit.h and
use it wherever possible.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Suggested-by: Andreas Dilger <adilger@dilger.ca>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bitops: remove minix bitops from asm/bitops.h

minix bit operations are only used by minix filesystem and useless by
other modules. Because byte order of inode and block bitmaps is different
on each architecture like below:

m68k:
big-endian 16bit indexed bitmaps

h8300, microblaze, s390, sparc, m68knommu:
big-endian 32 or 64bit indexed bitmaps

m32r, mips, sh, xtensa:
big-endian 32 or 64bit indexed bitmaps for big-endian mode
little-endian bitmaps for little-endian mode

Others:
little-endian bitmaps

In order to move minix bit operations from asm/bitops.h to architecture
independent code in minix filesystem, this provides two config options.

CONFIG_MINIX_FS_BIG_ENDIAN_16BIT_INDEXED is only selected by m68k.
CONFIG_MINIX_FS_NATIVE_ENDIAN is selected by the architectures which use
native byte order bitmaps (h8300, microblaze, s390, sparc, m68knommu,
m32r, mips, sh, xtensa). The architectures which always use little-endian
bitmaps do not select these options.

Finally, we can remove minix bit operations from asm/bitops.h for all
architectures.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Michal Simek <monstr@monstr.eu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bitops: remove ext2 non-atomic bitops from asm/bitops.h

As the result of conversions, there are no users of ext2 non-atomic bit
operations except for ext2 filesystem itself. Now we can put them into
architecture independent code in ext2 filesystem, and remove from
asm/bitops.h for all architectures.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bitops: introduce little-endian bitops for most architectures

Introduce little-endian bit operations to the big-endian architectures
which do not have native little-endian bit operations and the
little-endian architectures. (alpha, avr32, blackfin, cris, frv, h8300,
ia64, m32r, mips, mn10300, parisc, sh, sparc, tile, x86, xtensa)

These architectures can just include generic implementation
(asm-generic/bitops/le.h).

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Zankel <chris@zankel.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

xtensa: move headers files to arch/xtensa/include

Move all header files for xtensa to arch/xtensa/include and platform and
variant header files to the appropriate arch/xtensa/platforms/ and
arch/xtensa/variants/ directories.

Moving the files gets also rid of all uses of symlinks in the Makefile.

This has been completed already for the majority of the architectures
and xtensa is one out of six missing.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Chris Zankel <chris@zankel.net>