mm: delete checks for xor_unlock_is_negative_byte()

Architectures which don't define their own use the one in
asm-generic/bitops/lock.h. Get rid of all the ifdefs around "maybe we
don't have it".

Link: https://lkml.kernel.org/r/20231004165317.1061855-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

m68k: implement xor_unlock_is_negative_byte

Using EOR to clear the guaranteed-to-be-set lock bit will test the
negative flag just like the x86 implementation. This should be more
efficient than the generic implementation in filemap.c. It would be
better if m68k had __GCC_ASM_FLAG_OUTPUTS__.

Coldfire doesn't have a byte-sized EOR, so we test bit 7 after the EOR,
which is a second memory access, but it's slightly better than the current
C code.

Link: https://lkml.kernel.org/r/20231004165317.1061855-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

provide arch_test_bit_acquire for architectures that define test_bit

Some architectures define their own arch_test_bit and they also need
arch_test_bit_acquire, otherwise they won't compile. We also clean up
the code by using the generic test_bit if that is equivalent to the
arch-specific version.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 8238b4579866 ("wait_on_bit: add an acquire memory barrier")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bitops: unify non-atomic bitops prototypes across architectures

Currently, there is a mess with the prototypes of the non-atomic
bitops across the different architectures:

ret bool, int, unsigned long
nr int, long, unsigned int, unsigned long
addr volatile unsigned long *, volatile void *

Thankfully, it doesn't provoke any bugs, but can sometimes make
the compiler angry when it's not handy at all.
Adjust all the prototypes to the following standard:

ret bool retval can be only 0 or 1
nr unsigned long native; signed makes no sense
addr volatile unsigned long * bitmaps are arrays of ulongs

Next, some architectures don't define 'arch_' versions as they don't
support instrumentation, others do. To make sure there is always the
same set of callables present and to ease any potential future
changes, make them all follow the rule:
* architecture-specific files define only 'arch_' versions;
* non-prefixed versions can be defined only in asm-generic files;
and place the non-prefixed definitions into a new file in
asm-generic to be included by non-instrumented architectures.

Finally, add some static assertions in order to prevent people from
making a mess in this room again.
I also used the %__always_inline attribute consistently, so that
they always get resolved to the actual operations.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

m68k: bitops: Change __fls to return and accept unsigned long

As per asm-generic definition and other architectures __fls should
return and accept unsigned long as its parameter.

No functional change is expected as return value should fit in unsigned
long.

Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Link: https://lore.kernel.org/r/20220527115345.2588775-3-amadeuszx.slawinski@linux.intel.com
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

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>

m68knommu: Remove MCPU32 config symbol

As of commit a3595962d82495f5 ("m68knommu: remove obsolete 68360
support"), nothing selects MCPU32 anymore.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

arch: rearrange headers inclusion order in asm/bitops for m68k, sh and h8300

m68k and sh include bitmap/{find,le}.h prior to ffs/fls headers. New
fast-path implementation in find.h requires ffs/fls. Reordering the
headers inclusion sequence helps to prevent compile-time implicit function
declaration error.

[yury.norov@gmail.com: h8300: rearrange headers inclusion order in asm/bitops]
Link: https://lkml.kernel.org/r/20210406183625.794227-1-yury.norov@gmail.com

Link: https://lkml.kernel.org/r/20210401003153.97325-5-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Alexey Klimov <aklimov@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Jianpeng Ma <jianpeng.ma@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fls: change parameter to unsigned int

When testing in userspace, UBSAN pointed out that shifting into the sign
bit is undefined behaviour. It doesn't really make sense to ask for the
highest set bit of a negative value, so just turn the argument type into
an unsigned int.

Some architectures (eg ppc) already had it declared as an unsigned int,
so I don't expect too many problems.

Link: http://lkml.kernel.org/r/20181105221117.31828-1-willy@infradead.org
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

m68k/bitops: convert __ffs to match generic declaration

The generic bitops declare __ffs as

static inline unsigned long __ffs(unsigned long word);

Convert the m68k version to match the generic declaration.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

locking/atomics/m68k: Don't use <asm-generic/bitops/lock.h>

<asm-generic/bitops/lock.h> is shortly going to be built on top of the
atomic_long_*() API, which introduces a nasty circular dependency for
m68k where <linux/atomic.h> pulls in <linux/bitops.h> via:

linux/atomic.h
asm/atomic.h
linux/irqflags.h
asm/irqflags.h
linux/preempt.h
asm/preempt.h
asm-generic/preempt.h
linux/thread_info.h
asm/thread_info.h
asm/page.h
asm-generic/getorder.h
linux/log2.h
linux/bitops.h

Since m68k isn't SMP and doesn't support ACQUIRE/RELEASE barriers, we
can just define the lock bitops in terms of the atomic bitops in the
<asm/bitops.h> header.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: yamada.masahiro@socionext.com
Link: https://lore.kernel.org/lkml/1529412794-17720-3-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

lib: optimize cpumask_next_and()

We've measured that we spend ~0.6% of sys cpu time in cpumask_next_and().
It's essentially a joined iteration in search for a non-zero bit, which is
currently implemented as a lookup join (find a nonzero bit on the lhs,
lookup the rhs to see if it's set there).

Implement a direct join (find a nonzero bit on the incrementally built
join). Also add generic bitmap benchmarks in the new `test_find_bit`
module for new function (see `find_next_and_bit` in [2] and [3] below).

For cpumask_next_and, direct benchmarking shows that it's 1.17x to 14x
faster with a geometric mean of 2.1 on 32 CPUs [1]. No impact on memory
usage. Note that on Arm, the new pure-C implementation still outperforms
the old one that uses a mix of C and asm (`find_next_bit`) [3].

[1] Approximate benchmark code:

```
unsigned long src1p[nr_cpumask_longs] = {pattern1};
unsigned long src2p[nr_cpumask_longs] = {pattern2};
for (/*a bunch of repetitions*/) {
for (int n = -1; n <= nr_cpu_ids; ++n) {
asm volatile("" : "+rm"(src1p)); // prevent any optimization
asm volatile("" : "+rm"(src2p));
unsigned long result = cpumask_next_and(n, src1p, src2p);
asm volatile("" : "+rm"(result));
}
}
```

Results:
pattern1 pattern2 time_before/time_after
0x0000ffff 0x0000ffff 1.65
0x0000ffff 0x00005555 2.24
0x0000ffff 0x00001111 2.94
0x0000ffff 0x00000000 14.0
0x00005555 0x0000ffff 1.67
0x00005555 0x00005555 1.71
0x00005555 0x00001111 1.90
0x00005555 0x00000000 6.58
0x00001111 0x0000ffff 1.46
0x00001111 0x00005555 1.49
0x00001111 0x00001111 1.45
0x00001111 0x00000000 3.10
0x00000000 0x0000ffff 1.18
0x00000000 0x00005555 1.18
0x00000000 0x00001111 1.17
0x00000000 0x00000000 1.25
-----------------------------
geo.mean 2.06

[2] test_find_next_bit, X86 (skylake)

[ 3913.477422] Start testing find_bit() with random-filled bitmap
[ 3913.477847] find_next_bit: 160868 cycles, 16484 iterations
[ 3913.477933] find_next_zero_bit: 169542 cycles, 16285 iterations
[ 3913.478036] find_last_bit: 201638 cycles, 16483 iterations
[ 3913.480214] find_first_bit: 4353244 cycles, 16484 iterations
[ 3913.480216] Start testing find_next_and_bit() with random-filled
bitmap
[ 3913.481074] find_next_and_bit: 89604 cycles, 8216 iterations
[ 3913.481075] Start testing find_bit() with sparse bitmap
[ 3913.481078] find_next_bit: 2536 cycles, 66 iterations
[ 3913.481252] find_next_zero_bit: 344404 cycles, 32703 iterations
[ 3913.481255] find_last_bit: 2006 cycles, 66 iterations
[ 3913.481265] find_first_bit: 17488 cycles, 66 iterations
[ 3913.481266] Start testing find_next_and_bit() with sparse bitmap
[ 3913.481272] find_next_and_bit: 764 cycles, 1 iterations

[3] test_find_next_bit, arm (v7 odroid XU3).

[ 267.206928] Start testing find_bit() with random-filled bitmap
[ 267.214752] find_next_bit: 4474 cycles, 16419 iterations
[ 267.221850] find_next_zero_bit: 5976 cycles, 16350 iterations
[ 267.229294] find_last_bit: 4209 cycles, 16419 iterations
[ 267.279131] find_first_bit: 1032991 cycles, 16420 iterations
[ 267.286265] Start testing find_next_and_bit() with random-filled
bitmap
[ 267.302386] find_next_and_bit: 2290 cycles, 8140 iterations
[ 267.309422] Start testing find_bit() with sparse bitmap
[ 267.316054] find_next_bit: 191 cycles, 66 iterations
[ 267.322726] find_next_zero_bit: 8758 cycles, 32703 iterations
[ 267.329803] find_last_bit: 84 cycles, 66 iterations
[ 267.336169] find_first_bit: 4118 cycles, 66 iterations
[ 267.342627] Start testing find_next_and_bit() with sparse bitmap
[ 267.356919] find_next_and_bit: 91 cycles, 1 iterations

[courbet@google.com: v6]
Link: http://lkml.kernel.org/r/20171129095715.23430-1-courbet@google.com
[geert@linux-m68k.org: m68k/bitops: always include <asm-generic/bitops/find.h>]
Link: http://lkml.kernel.org/r/1512556816-28627-1-git-send-email-geert@linux-m68k.org
Link: http://lkml.kernel.org/r/20171128131334.23491-1-courbet@google.com
Signed-off-by: Clement Courbet <courbet@google.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

m68k/bitops: Correct signature of test_bit()

mm/filemap.c: In function ‘clear_bit_unlock_is_negative_byte’:
mm/filemap.c:933: warning: passing argument 2 of ‘test_bit’ discards qualifiers from pointer target type

Make the bitmask pointed to by the "vaddr" parameter volatile to fix
this, like is done on other architectures.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch,m68k: Convert smp_mb__*()

m68k uses asm-generic/barrier.h and its smp_mb() is barrier(),
therefore we can use the generic versions that use smp_mb().

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-s5dvosrb7qhvpmtaffwfn0zg@git.kernel.org
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-m68k@lists.linux-m68k.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

m68k: merge mmu and non-mmu bitops.h

The following patch merges the mmu and non-mmu versions of the m68k
bitops.h files. Now there is a good deal of difference between the two
files, but none of it is actually an mmu specific difference. It is
all about the specific m68k/coldfire varient we are targeting. So it
makes an awful lot of sense to merge these into a single bitops.h.

There is a number of ways I can see to factor this code. The approach
I have taken here is to keep the various versions of each macro/function
type together. This means that there is some ifdefery with each to handle
each CPU type.

I have added some comments in a couple of appropriate places to try
and make it clear what the differences we are dealing with are.
Specifically the instruction and addressing mode differences we have
to deal with.

The merged form keeps the same underlying optimizations for each CPU
type for all the general bit clear/set/change and find bit operations.
It does switch to using the generic le operations though, instead of
any local varients.

Build tested on ColdFire, 68328, 68360 (which is cpu32) and 68020+.
Run tested on ColdFire and ARAnyM.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

m68k,m68knommu: merge header files

Merge header files for m68k and m68knommu to the single location:

arch/m68k/include/asm

The majority of this patch was the result of the
script that is included in the changelog below.

The script was originally written by Arnd Bergman and
exten by me to cover a few more files.

When the header files differed the script uses the following:

The original m68k file is named <file>_mm.h [mm for memory manager]
The m68knommu file is named <file>_no.h [no for no memory manager]

The files uses the following include guard:

This include gaurd works as the m68knommu toolchain set
the __uClinux__ symbol - so this should work in userspace too.

Merging the header files for m68k and m68knommu exposes the
(unexpected?) ABI differences thus it is easier to actually
identify these and thus to fix them.

The commit has been build tested with both a m68k and
a m68knommu toolchain - with success.

The commit has also been tested with "make headers_check"
and this patch fixes make headers_check for m68knommu.

The script used:
TARGET=arch/m68k/include/asm
SOURCE=arch/m68knommu/include/asm

INCLUDE="cachectl.h errno.h fcntl.h hwtest.h ioctls.h ipcbuf.h \
linkage.h math-emu.h md.h mman.h movs.h msgbuf.h openprom.h \
oplib.h poll.h posix_types.h resource.h rtc.h sembuf.h shmbuf.h \
shm.h shmparam.h socket.h sockios.h spinlock.h statfs.h stat.h \
termbits.h termios.h tlb.h types.h user.h"

EQUAL="auxvec.h cputime.h device.h emergency-restart.h futex.h \
ioctl.h irq_regs.h kdebug.h local.h mutex.h percpu.h \
sections.h topology.h"

NOMUUFILES="anchor.h bootstd.h coldfire.h commproc.h dbg.h \
elia.h flat.h m5206sim.h m520xsim.h m523xsim.h m5249sim.h \
m5272sim.h m527xsim.h m528xsim.h m5307sim.h m532xsim.h \
m5407sim.h m68360_enet.h m68360.h m68360_pram.h m68360_quicc.h \
m68360_regs.h MC68328.h MC68332.h MC68EZ328.h MC68VZ328.h \
mcfcache.h mcfdma.h mcfmbus.h mcfne.h mcfpci.h mcfpit.h \
mcfsim.h mcfsmc.h mcftimer.h mcfuart.h mcfwdebug.h \
nettel.h quicc_simple.h smp.h"

FILES="atomic.h bitops.h bootinfo.h bug.h bugs.h byteorder.h cache.h \
cacheflush.h checksum.h current.h delay.h div64.h \
dma-mapping.h dma.h elf.h entry.h fb.h fpu.h hardirq.h hw_irq.h io.h \
irq.h kmap_types.h machdep.h mc146818rtc.h mmu.h mmu_context.h \
module.h page.h page_offset.h param.h pci.h pgalloc.h \
pgtable.h processor.h ptrace.h scatterlist.h segment.h \
setup.h sigcontext.h siginfo.h signal.h string.h system.h swab.h \
thread_info.h timex.h tlbflush.h traps.h uaccess.h ucontext.h \
unaligned.h unistd.h"

mergefile() {
BASE=${1%.h}
git mv ${SOURCE}/$1 ${TARGET}/${BASE}_no.h
git mv ${TARGET}/$1 ${TARGET}/${BASE}_mm.h

cat << EOF > ${TARGET}/$1
EOF

git add ${TARGET}/$1
}

set -e

mkdir -p ${TARGET}

git mv include/asm-m68k/* ${TARGET}
rmdir include/asm-m68k

git rm ${SOURCE}/Kbuild
for F in $INCLUDE $EQUAL; do
git rm ${SOURCE}/$F
done

for F in $NOMUUFILES; do
git mv ${SOURCE}/$F ${TARGET}/$F
done

for F in $FILES ; do
mergefile $F
done

rmdir arch/m68knommu/include/asm
rmdir arch/m68knommu/include

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>