Changes in atomic.h

d12157ef - locking/atomic: make atomic*_{cmp,}xchg optional

Mon, 05 Jun 2023 07:01:01 +0000

locking/atomic: make atomic*_{cmp,}xchg optionalMost architectures define the atomic/atomic64 xchg and cmpxchgoperations in terms of arch_xchg and arch_cmpxchg respectfully.Add fallbacks for these cases and remove the trivial cases from archcode. On some architectures the existing definitions are kept as theseare used to build other arch_atomic*() operations.Signed-off-by: Mark Rutland Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20230605070124.3741859-5-mark.rutland@arm.com List of files: /linux-6.15/arch/sh/include/asm/atomic.h

8c641755 - locking/atomic: sh: move to ARCH_ATOMIC

Tue, 25 May 2021 14:02:28 +0000

locking/atomic: sh: move to ARCH_ATOMICWe'd like all architectures to convert to ARCH_ATOMIC, as once allarchitectures are converted it will be possible to make significantcleanups to the atomics headers, and this will make it much easier togenerically enable atomic functionality (e.g. debug logic in theinstrumented wrappers).As a step towards that, this patch migrates sh to ARCH_ATOMIC. Thearch code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and commoncode wraps these with optional instrumentation to provide the regularfunctions.Signed-off-by: Mark Rutland Cc: Boqun Feng Cc: Peter Zijlstra Cc: Rich Felker Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20210525140232.53872-30-mark.rutland@arm.com List of files: /linux-6.15/arch/sh/include/asm/atomic.h

7ca8cf53 - locking/atomic: Move ATOMIC_INIT into linux/types.h

Wed, 29 Jul 2020 12:31:05 +0000

locking/atomic: Move ATOMIC_INIT into linux/types.hThis patch moves ATOMIC_INIT from asm/atomic.h into linux/types.h.This allows users of atomic_t to use ATOMIC_INIT without having toinclude atomic.h as that way may lead to header loops.Signed-off-by: Herbert Xu Signed-off-by: Peter Zijlstra (Intel) Acked-by: Waiman Long Link: https://lkml.kernel.org/r/20200729123105.GB7047@gondor.apana.org.au List of files: /linux-6.15/arch/sh/include/asm/atomic.h

9837559d - atomics/treewide: Make unconditional inc/dec ops optional

Thu, 21 Jun 2018 12:13:19 +0000

atomics/treewide: Make unconditional inc/dec ops optionalMany of the inc/dec ops are mandatory, but for most architectures inc/dec aresimply trivial wrappers around their corresponding add/sub ops.Let's make all the inc/dec ops optional, so that we can get rid of theseboilerplate wrappers.The instrumented atomics are updated accordingly.There should be no functional change as a result of this patch.Signed-off-by: Mark Rutland Reviewed-by: Will Deacon Acked-by: Peter Zijlstra (Intel) Acked-by: Palmer Dabbelt Cc: Boqun Feng Cc: Linus Torvalds Cc: Thomas Gleixner Link: https://lore.kernel.org/lkml/20180621121321.4761-17-mark.rutland@arm.comSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/sh/include/asm/atomic.h

18cc1814 - atomics/treewide: Make test ops optional

Thu, 21 Jun 2018 12:13:18 +0000

atomics/treewide: Make test ops optionalSome of the atomics return the result of a test applied after the atomicoperation, and almost all architectures implement these as trivialwrappers around the underlying atomic. Specifically: * _inc_and_test(v) is (_inc_return(v) == 0) * _dec_and_test(v) is (_dec_return(v) == 0) * _sub_and_test(i, v) is (_sub_return(i, v) == 0) * _add_negative(i, v) is (_add_return(i, v) < 0)Rather than have these definitions duplicated in all architectures, withminor inconsistencies in formatting and documentation, let's make theseoperations optional, with default fallbacks as above. Implementationsmust now provide a preprocessor symbol.The instrumented atomics are updated accordingly.Both x86 and m68k have custom implementations, which are left as-is,given preprocessor symbols to avoid being overridden.There should be no functional change as a result of this patch.Signed-off-by: Mark Rutland Reviewed-by: Will Deacon Acked-by: Geert Uytterhoeven Acked-by: Peter Zijlstra (Intel) Acked-by: Palmer Dabbelt Cc: Boqun Feng Cc: Linus Torvalds Cc: Thomas Gleixner Link: https://lore.kernel.org/lkml/20180621121321.4761-16-mark.rutland@arm.comSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/sh/include/asm/atomic.h

eccc2da8 - atomics/treewide: Make atomic_fetch_add_unless() optional

Thu, 21 Jun 2018 12:13:09 +0000

atomics/treewide: Make atomic_fetch_add_unless() optionalSeveral architectures these have a near-identical implementation basedon atomic_read() and atomic_cmpxchg() which we can instead define in, so let's do so, using something close to the existingx86 implementation with try_cmpxchg().Where an architecture provides its own atomic_fetch_add_unless(), itmust define a preprocessor symbol for it. The instrumented atomics areupdated accordingly.Note that arch/arc's existing atomic_fetch_add_unless() had redundantbarriers, as these are already present in its atomic_cmpxchg()implementation.There should be no functional change as a result of this patch.Signed-off-by: Mark Rutland Reviewed-by: Geert Uytterhoeven Reviewed-by: Will Deacon Acked-by: Geert Uytterhoeven Acked-by: Peter Zijlstra (Intel) Acked-by: Palmer Dabbelt Cc: Boqun Feng Cc: Linus Torvalds Cc: Thomas Gleixner Cc: Vineet Gupta Link: https://lore.kernel.org/lkml/20180621121321.4761-7-mark.rutland@arm.comSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/sh/include/asm/atomic.h

bfc18e38 - atomics/treewide: Rename __atomic_add_unless() => atomic_fetch_add_unless()

Thu, 21 Jun 2018 12:13:04 +0000

atomics/treewide: Rename __atomic_add_unless() => atomic_fetch_add_unless()While __atomic_add_unless() was originally intended as a building-blockfor atomic_add_unless(), it's now used in a number of places around thekernel. It's the only common atomic operation named __atomic*(), ratherthan atomic_*(), and for consistency it would be better namedatomic_fetch_add_unless().This lack of consistency is slightly confusing, and gets in the way ofscripting atomics. Given that, let's clean things up and promote it toan official part of the atomics API, in the form ofatomic_fetch_add_unless().This patch converts definitions and invocations over to the new name,including the instrumented version, using the following script: ---- git grep -w __atomic_add_unless | while read line; do sed -i '{s/\<__atomic_add_unless\>/atomic_fetch_add_unless/}' "${line%%:*}"; done git grep -w __arch_atomic_add_unless | while read line; do sed -i '{s/\<__arch_atomic_add_unless\>/arch_atomic_fetch_add_unless/}' "${line%%:*}"; done ----Note that we do not have atomic{64,_long}_fetch_add_unless(), which willbe introduced by later patches.There should be no functional change as a result of this patch.Signed-off-by: Mark Rutland Reviewed-by: Will Deacon Acked-by: Geert Uytterhoeven Acked-by: Peter Zijlstra (Intel) Acked-by: Palmer Dabbelt Cc: Boqun Feng Cc: Linus Torvalds Cc: Thomas Gleixner Link: https://lore.kernel.org/lkml/20180621121321.4761-2-mark.rutland@arm.comSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/sh/include/asm/atomic.h

b2441318 - License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Wed, 01 Nov 2017 14:07:57 +0000

License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseMany source files in the tree are missing licensing information, whichmakes it harder for compliance tools to determine the correct license.By default all files without license information are under the defaultlicense 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 bindingshorthand, which can be used instead of the full boiler plate text.This patch is based on work done by Thomas Gleixner and Kate Stewart andPhilippe Ombredanne.How this work was done:Patches were generated and checked against linux-4.14-rc6 for a subset ofthe 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 caseswhere non-standard license headers were used, and references to licensehad to be inferred by heuristics based on keywords.The analysis to determine which SPDX License Identifier to be applied toa file was done in a spreadsheet of side by side results from of theoutput of two independent scanners (ScanCode & Windriver) producing SPDXtag:value files created by Philippe Ombredanne. Philippe prepared thebase 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 filesassessed. Kate Stewart did a file by file comparison of the scannerresults in the spreadsheet to determine which SPDX license identifier(s)to be applied to the file. She confirmed any determination that was notimmediately 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 licenseidentifiers 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 thespreadsheet to determine the SPDX license identifiers to apply to thesource files by Kate, Philippe, Thomas and, in some cases, confirmationby lawyers working with the Linux Foundation.Kate also obtained a third independent scan of the 4.13 code base fromFOSSology, and compared selected files where the other two scannersdisagreed against that SPDX file, to see if there was new insights. TheWindriver scanner is based on an older version of FOSSology in part, sothey are related.Thomas did random spot checks in about 500 files from the spreadsheetsfor the uapi headers and agreed with SPDX license identifier in thefiles he inspected. For the non-uapi files Thomas did random spot checksin about 15000 files.In initial set of patches against 4.14-rc6, 3 files were found to havecopy/paste license identifier errors, and have been fixed to reflect thecorrect identifier.Additionally Philippe spent 10 hours this week doing a detailed manualinspection and review of the 12,461 patched files from the initial patchversion 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 correctThis produced a worksheet with 20 files needing minor correction. Thisworksheet was then exported into 3 different .csv files for thedifferent types of files to be modified.These .csv files were then reviewed by Greg. Thomas wrote a script toparse the csv files and add the proper SPDX tag to the file, in theformat that the file expected. This script was further refined by Gregbased on the output to detect more types of files automatically and todistinguish between header and source .c files (which need differentcomment types.) Finally Greg ran the script using the .csv files togenerate the patches.Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/arch/sh/include/asm/atomic.h

2b47d54e - sh: add J2 atomics using the cas.l instruction

Thu, 28 Jul 2016 19:21:10 +0000

sh: add J2 atomics using the cas.l instructionSigned-off-by: Rich Felker List of files: /linux-6.15/arch/sh/include/asm/atomic.h

b53d6bed - locking/atomic: Remove linux/atomic.h:atomic_fetch_or()

Sun, 17 Apr 2016 22:58:25 +0000

locking/atomic: Remove linux/atomic.h:atomic_fetch_or()Since all architectures have this implemented now natively, remove thisdead code.Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.orgCc: linux-kernel@vger.kernel.orgSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/sh/include/asm/atomic.h

7d9794e7 - locking/atomic, arch/sh: Implement atomic_fetch_{add,sub,and,or,xor}()

Sun, 17 Apr 2016 23:16:04 +0000

locking/atomic, arch/sh: Implement atomic_fetch_{add,sub,and,or,xor}()Implement FETCH-OP atomic primitives, these are very similar to theexisting OP-RETURN primitives we already have, except they return thevalue of the atomic variable _before_ modification.This is especially useful for irreversible operations -- such asbitops (because it becomes impossible to reconstruct the state priorto modification).Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Rich Felker Cc: Thomas Gleixner Cc: Yoshinori Sato Cc: linux-arch@vger.kernel.orgCc: linux-kernel@vger.kernel.orgCc: linux-sh@vger.kernel.orgSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/sh/include/asm/atomic.h

62e8a325 - atomic, arch: Audit atomic_{read,set}()

Fri, 18 Sep 2015 09:13:10 +0000

atomic, arch: Audit atomic_{read,set}()This patch makes sure that atomic_{read,set}() are at least{READ,WRITE}_ONCE().We already had the 'requirement' that atomic_read() should useACCESS_ONCE(), and most archs had this, but a few were lacking.All are now converted to use READ_ONCE().And, by a symmetry and general paranoia argument, upgrade atomic_set()to use WRITE_ONCE().Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Dmitry Vyukov Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: james.hogan@imgtec.comCc: linux-kernel@vger.kernel.orgCc: oleg@redhat.comCc: will.deacon@arm.comSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/sh/include/asm/atomic.h

de9e432c - atomic: Collapse all atomic_{set,clear}_mask definitions

Thu, 23 Apr 2015 23:12:32 +0000

atomic: Collapse all atomic_{set,clear}_mask definitionsMove the now generic definitions of atomic_{set,clear}_mask() intolinux/atomic.h to avoid endless and pointless repetition.Also, provide an atomic_andnot() wrapper for those few archs that canimplement that.Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner List of files: /linux-6.15/arch/sh/include/asm/atomic.h

658aa514 - sh: Provide atomic_{or,xor,and}

Wed, 23 Apr 2014 17:44:20 +0000

sh: Provide atomic_{or,xor,and}Implement atomic logic ops -- atomic_{or,xor,and}.These will replace the atomic_{set,clear}_mask functions that areavailable on some archs.Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner List of files: /linux-6.15/arch/sh/include/asm/atomic.h

2291059c - locking,arch: Use ACCESS_ONCE() instead of cast to volatile in atomic_read()

Tue, 23 Sep 2014 14:29:50 +0000

locking,arch: Use ACCESS_ONCE() instead of cast to volatile in atomic_read()Use the much more reader friendly ACCESS_ONCE() instead of the cast to volatile.This is purely a stylistic change.Signed-off-by: Pranith Kumar Acked-by: Jesper Nilsson Acked-by: Hans-Christian Egtvedt Acked-by: Max Filippov Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: linux-arch@vger.kernel.orgLink: http://lkml.kernel.org/r/1411482607-20948-1-git-send-email-bobby.prani@gmail.comSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/sh/include/asm/atomic.h

603228bc - arch,sh: Convert smp_mb__*()

Thu, 13 Mar 2014 18:00:35 +0000

arch,sh: Convert smp_mb__*()SH can use the asm-generic/barrier.h implementation since that usessmp_mb().Signed-off-by: Peter Zijlstra Acked-by: Paul E. McKenney Link: http://lkml.kernel.org/n/tip-2z962by2ppzcd984ybw2mwdw@git.kernel.orgCc: Linus Torvalds Cc: linux-kernel@vger.kernel.orgCc: linux-sh@vger.kernel.orgSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/sh/include/asm/atomic.h

ec2ccd88 - sh: Fix up tracepoint build fallout from static key introduction.

Fri, 27 Apr 2012 01:42:38 +0000

sh: Fix up tracepoint build fallout from static key introduction.With the introduction of static keys, anything using tracepoints blows upin the following manner:include/trace/events/oom.h:8:13: error: initializer element is not constantinclude/trace/events/oom.h:8:13: error: (near initialization for '__tracepoint_oom_score_adj_update')include/trace/events/oom.h:8:13: error: initializer element is not constantinclude/trace/events/oom.h:8:13: error: (near initialization for '__tracepoint_oom_score_adj_update.key')This is a result of the STATIC_KEY_INIT_xxx defs wrapping ATOMIC_INIT()which on sh includes an atomic_t typecast. Given that we don't reallyneed the typecast for anything anymore, the simplest solution is simplyto kill off the cast.Signed-off-by: Nobuhiro Iwamatsu Signed-off-by: Paul Mundt List of files: /linux-6.15/arch/sh/include/asm/atomic.h

e839ca52 - Disintegrate asm/system.h for SH

Wed, 28 Mar 2012 17:30:03 +0000

Disintegrate asm/system.h for SHDisintegrate asm/system.h for SH.Signed-off-by: David Howells cc: linux-sh@vger.kernel.org List of files: /linux-6.15/arch/sh/include/asm/atomic.h

7847777a - atomic: cleanup asm-generic atomic*.h inclusion

Tue, 26 Jul 2011 23:09:08 +0000

atomic: cleanup asm-generic atomic*.h inclusionAfter changing all consumers of atomics to include , weran into some compile time errors due to this dependency chain:linux/atomic.h -> asm/atomic.h -> asm-generic/atomic-long.hwhere atomic-long.h could use funcs defined later in linux/atomic.hwithout a prototype. This patches moves the code that includesasm-generic/atomic*.h to linux/atomic.h.Archs that need need to selectCONFIG_GENERIC_ATOMIC64 from now on (some of them used to include itunconditionally).Compile tested on i386 and x86_64 with allnoconfig.Signed-off-by: Arun Sharma Cc: Eric Dumazet Cc: Ingo Molnar Cc: David Miller Acked-by: Mike Frysinger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/sh/include/asm/atomic.h

f24219b4 - atomic: move atomic_add_unless to generic code

Tue, 26 Jul 2011 23:09:07 +0000

atomic: move atomic_add_unless to generic codeThis is in preparation for more generic atomic primitives based on__atomic_add_unless.Signed-off-by: Arun Sharma Signed-off-by: Hans-Christian Egtvedt Reviewed-by: Eric Dumazet Cc: Ingo Molnar Cc: David Miller Acked-by: Mike Frysinger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/sh/include/asm/atomic.h