kernel.git/arch/m68k/include/asm/bitops.h, branch linux-5.18.y

include: move find.h from asm_generic to linux

2022-01-15T16:47:31Z

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 Tested-by: Wolfram Sang Acked-by: Geert Uytterhoeven

m68knommu: Remove MCPU32 config symbol

2021-10-25T22:46:27Z

As of commit a3595962d82495f5 ("m68knommu: remove obsolete 68360 support"), nothing selects MCPU32 anymore. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Ungerer

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

2021-05-07T02:24:11Z

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 Acked-by: Geert Uytterhoeven Acked-by: Rasmus Villemoes Reviewed-by: Andy Shevchenko Tested-by: Guenter Roeck Cc: Alexey Klimov Cc: Arnd Bergmann Cc: David Sterba Cc: Dennis Zhou Cc: Jianpeng Ma Cc: Joe Perches Cc: John Paul Adrian Glaubitz Cc: Josh Poimboeuf Cc: Rich Felker Cc: Stefano Brivio Cc: Wei Yang Cc: Wolfram Sang Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fls: change parameter to unsigned int

2019-01-04T21:13:46Z

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 Acked-by: Thomas Gleixner Acked-by: Geert Uytterhoeven Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-08-13T19:23:39Z

Pull locking/atomics update from Thomas Gleixner: "The locking, atomics and memory model brains delivered: - A larger update to the atomics code which reworks the ordering barriers, consolidates the atomic primitives, provides the new atomic64_fetch_add_unless() primitive and cleans up the include hell. - Simplify cmpxchg() instrumentation and add instrumentation for xchg() and cmpxchg_double(). - Updates to the memory model and documentation" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits) locking/atomics: Rework ordering barriers locking/atomics: Instrument cmpxchg_double*() locking/atomics: Instrument xchg() locking/atomics: Simplify cmpxchg() instrumentation locking/atomics/x86: Reduce arch_cmpxchg64*() instrumentation tools/memory-model: Rename litmus tests to comply to norm7 tools/memory-model/Documentation: Fix typo, smb->smp sched/Documentation: Update wake_up() & co. memory-barrier guarantees locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock() sched/core: Use smp_mb() in wake_woken_function() tools/memory-model: Add informal LKMM documentation to MAINTAINERS locking/atomics/Documentation: Describe atomic_set() as a write operation tools/memory-model: Make scripts executable tools/memory-model: Remove ACCESS_ONCE() from model tools/memory-model: Remove ACCESS_ONCE() from recipes locking/memory-barriers.txt/kokr: Update Korean translation to fix broken DMA vs. MMIO ordering example MAINTAINERS: Add Daniel Lustig as an LKMM reviewer tools/memory-model: Fix ISA2+pooncelock+pooncelock+pombonce name tools/memory-model: Add litmus test for full multicopy atomicity locking/refcount: Always allow checked forms ...

m68k/bitops: convert __ffs to match generic declaration

2018-07-29T08:48:18Z

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 Acked-by: Greg Ungerer Signed-off-by: Geert Uytterhoeven

locking/atomics/m68k: Don't use

2018-06-21T10:52:11Z

is shortly going to be built on top of the atomic_long_*() API, which introduces a nasty circular dependency for m68k where pulls in 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 header. Signed-off-by: Will Deacon Acked-by: Geert Uytterhoeven Acked-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner 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

lib: optimize cpumask_next_and()

2018-02-07T02:32:44Z

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 ] 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 Signed-off-by: Geert Uytterhoeven Cc: Yury Norov Cc: Geert Uytterhoeven Cc: Alexey Dobriyan Cc: Rasmus Villemoes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

m68k/bitops: Correct signature of test_bit()

2017-03-20T10:25:15Z

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

arch,m68k: Convert smp_mb__*()

2014-04-18T12:20:37Z

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 Acked-by: Paul E. McKenney Link: http://lkml.kernel.org/n/tip-s5dvosrb7qhvpmtaffwfn0zg@git.kernel.org Cc: Geert Uytterhoeven Cc: Linus Torvalds Cc: linux-kernel@vger.kernel.org Cc: linux-m68k@lists.linux-m68k.org Signed-off-by: Ingo Molnar