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2022-07-14arm: align find_bit declarations with generic kernelYury Norov1-8/+10
ARM has their own implementation for find_bit functions, and function declarations are different with those in generic headers. Fix it. Signed-off-by: Yury Norov <yury.norov@gmail.com>
2022-01-15include: move find.h from asm_generic to linuxYury Norov1-1/+0
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>
2018-07-30ARM: 8785/1: use compiler built-ins for ffs and flsNicolas Pitre1-83/+9
On ARMv5 and above, it is beneficial to use compiler built-ins such as __builtin_ffs() and __builtin_ctzl() to implement ffs(), __ffs(), fls() and __fls(). The compiler does inline the clz instruction and even the rbit instruction when available, or provide a constant value when possible. On ARMv4 the compiler calls out to helper functions for those built-ins so it is best to keep the open coded versions in that case. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-02-06lib: optimize cpumask_next_and()Clement Courbet1-0/+1
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>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-18ARM: 8679/1: bitops: Align prototypes to generic APIMarc Gonzalez1-4/+4
include/asm-generic/bitops/find.h declares: extern unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size); while arch/arm/include/asm/bitops.h declares: #define find_first_zero_bit(p,sz) _find_first_zero_bit_le(p,sz) extern int _find_first_zero_bit_le(const void * p, unsigned size); Align the arm prototypes to the generic API, to have gcc report inadequate arguments, such as pointer to u32. Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2015-08-18ARM: 8417/1: refactor bitops functions with BIT_MASK() and BIT_WORD()Masahiro Yamada1-12/+12
Use BIT_MASK() and BIT_WORD() rather than hard-coding the size of the "long" type. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-18arch,arm: Convert smp_mb__*()Peter Zijlstra1-3/+1
ARM uses ll/sc primitives that do not imply barriers for all regular atomic ops, therefore smp_mb__{before,after} need be a full barrier. Since ARM doesn't use asm-generic/barrier.h include the required definitions in its asm/barrier.h 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-yijo7sglsl7uusbp13upcuvo@git.kernel.org Cc: Albin Tonnerre <albin.tonnerre@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen Gang <gang.chen@asianux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Victor Kamensky <victor.kamensky@linaro.org> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13ARM: fix ffs/fls implementations to match x86Russell King1-10/+44
ARMs ffs/fls implementations are not type compatible with x86, so when they're used in combination with min()/max(), they provoke warnings. Change these to be inline functions with the correct types, providing the clz as a separate documentation, and document their individual behaviours. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-03-28Disintegrate asm/system.h for ARMDavid Howells1-1/+1
Disintegrate asm/system.h for ARM. Signed-off-by: David Howells <dhowells@redhat.com> cc: Russell King <linux@arm.linux.org.uk> cc: linux-arm-kernel@lists.infradead.org
2011-07-26asm-generic: add another generic ext2 atomic bitopsAkinobu Mita1-4/+1
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>
2011-07-22ARM: 6998/2: kernel: use proper memory barriers for bitopsHeechul Yun1-2/+2
Improve scalability by avoiding costly and unnecessary L2 cache sync in handling bitops. Signed-off-by: Heechul Yun <hyun@nvidia.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-26arm: use asm-generic/bitops/le.hAkinobu Mita1-38/+5
The previous style change enables to use asm-generic/bitops/le.h on arm. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26arch: add #define for each of optimized find bitopsAkinobu Mita1-0/+3
The style that we normally use in asm-generic is to test the macro itself for existence, so in asm-generic, do: #ifndef find_next_zero_bit_le extern unsigned long find_next_zero_bit_le(const void *addr, unsigned long size, unsigned long offset); #endif and in the architectures, write static inline unsigned long find_next_zero_bit_le(const void *addr, unsigned long size, unsigned long offset) #define find_next_zero_bit_le find_next_zero_bit_le This adds the #define for each of the optimized find bitops in the architectures. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Greg Ungerer <gerg@uclinux.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23bitops: remove minix bitops from asm/bitops.hAkinobu Mita1-10/+0
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>
2011-03-23bitops: remove ext2 non-atomic bitops from asm/bitops.hAkinobu Mita1-7/+0
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>
2011-03-23arm: introduce little-endian bitopsAkinobu Mita1-26/+65
Introduce little-endian bit operations by renaming native ext2 bit operations. The ext2 and minix bit operations are kept as wrapper macros using little-endian bit operations to maintain bisectability until the conversions are finished. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-02ARM: bitops: switch set/clear/change bitops to use ldrex/strexRussell King1-38/+22
Switch the set/clear/change bitops to use the word-based exclusive operations, which are only present in a wider range of ARM architectures than the byte-based exclusive operations. Tested record: - Nicolas Pitre: ext3,rw,le - Sourav Poddar: nfs,le - Will Deacon: ext3,rw,le - Tony Lindgren: ext3+nfs,le Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Sourav Poddar <sourav.poddar@ti.com> Tested-by: Will Deacon <will.deacon@arm.com> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-12ARM: 6621/1: bitops: remove condition code clobber for CLZRabin Vincent1-1/+1
The CLZ instruction does not alter the condition flags, so remove the "cc" clobber from the inline asm for fls(). Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-10-11ARM: boolean bit testingJohannes Weiner1-3/+3
Bit testing (test, testset, testclear, testchange) for bit numbers known at compile time returns a word with the tested-for bit set. Change it to return a true boolean value so to make it consistent with the out-of-line path and all the other bitops implementations. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-12-04[ARM] 5339/1: fix __fls() on ARMNicolas Pitre1-6/+10
Commit 0c65f459ce6c intended to fix truncation issues with fls() on ARMv5+ by renaming it to __fls() and wrapping it into a C function. However that didn't take into account the fact that __fls() already already had different semantics in the kernel. Let's move the __fls() code into fls() function directly, and redefine __fls() with the appropriate semantics. While at it, bring a generic __fls() definition for pre ARMv5 too. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-02[ARM] move include/asm-arm to arch/arm/include/asmRussell King1-0/+340
Move platform independent header files to arch/arm/include/asm, leaving those in asm/arch* and asm/plat* alone. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>