summaryrefslogtreecommitdiff
path: root/arch/powerpc/include/asm/cmpxchg.h
AgeCommit message (Collapse)Author
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
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>
2016-11-25powerpc: Fix __cmpxchg() to take a volatile ptr againMichael Ellerman
In commit d0563a1297e2 ("powerpc: Implement {cmp}xchg for u8 and u16") we removed the volatile from __cmpxchg(). This is leading to warnings such as: drivers/gpu/drm/drm_lock.c: In function ‘drm_lock_take’: arch/powerpc/include/asm/cmpxchg.h:484:37: warning: passing argument 1 of ‘__cmpxchg’ discards ‘volatile’ qualifier from pointer target (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ There doesn't seem to be consensus across architectures whether the argument is volatile or not, so at least for now put the volatile back. Fixes: d0563a1297e2 ("powerpc: Implement {cmp}xchg for u8 and u16") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-23powerpc: Implement {cmp}xchg for u8 and u16Pan Xinhui
Implement xchg{u8,u16}{local,relaxed}, and cmpxchg{u8,u16}{,local,acquire,relaxed}. It works on all ppc. remove volatile of first parameter in __cmpxchg_local and __cmpxchg Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Acked-by: Boqun Feng <boqun.feng@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-24powerpc: Use BUILD_BUG_ON_MSG() for unsupported {cmp}xchg sizespan xinhui
__xchg_called_with_bad_pointer() can't tell us which code uses {cmp}xchg with an unsupported size, and no error is reported until the link stage. To make such problems easier to debug, use BUILD_BUG_ON_MSG() instead. Signed-off-by: pan xinhui <xinhui.pan@linux.vnet.ibm.com> [mpe: Tweak change log wording & add relaxed/acquire] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-18powerpc: atomic: Implement acquire/release/relaxed variants for cmpxchgBoqun Feng
Implement cmpxchg{,64}_relaxed and atomic{,64}_cmpxchg_relaxed, based on which _release variants can be built. To avoid superfluous barriers in _acquire variants, we implement these operations with assembly code rather use __atomic_op_acquire() to build them automatically. For the same reason, we keep the assembly implementation of fully ordered cmpxchg operations. However, we don't do the similar for _release, because that will require putting barriers in the middle of ll/sc loops, which is probably a bad idea. Note cmpxchg{,64}_relaxed and atomic{,64}_cmpxchg_relaxed are not compiler barriers. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-18powerpc: atomic: Implement acquire/release/relaxed variants for xchgBoqun Feng
Implement xchg{,64}_relaxed and atomic{,64}_xchg_relaxed, based on these _relaxed variants, release/acquire variants and fully ordered versions can be built. Note that xchg{,64}_relaxed and atomic_{,64}_xchg_relaxed are not compiler barriers. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-14powerpc: Make {cmp}xchg* and their atomic_ versions fully orderedBoqun Feng
According to memory-barriers.txt, xchg*, cmpxchg* and their atomic_ versions all need to be fully ordered, however they are now just RELEASE+ACQUIRE, which are not fully ordered. So also replace PPC_RELEASE_BARRIER and PPC_ACQUIRE_BARRIER with PPC_ATOMIC_ENTRY_BARRIER and PPC_ATOMIC_EXIT_BARRIER in __{cmp,}xchg_{u32,u64} respectively to guarantee fully ordered semantics of atomic{,64}_{cmp,}xchg() and {cmp,}xchg(), as a complement of commit b97021f85517 ("powerpc: Fix atomic_xxx_return barrier semantics") This patch depends on patch "powerpc: Make value-returning atomics fully ordered" for PPC_ATOMIC_ENTRY_BARRIER definition. Cc: stable@vger.kernel.org # 3.2+ Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-13arch: Remove __ARCH_HAVE_CMPXCHGThomas Gleixner
We removed the only user of this define in the rtmutex code. Get rid of it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2014-01-28powerpc: Add support for the optimised lockref implementationMichael Ellerman
This commit adds the architecture support required to enable the optimised implementation of lockrefs. That's as simple as defining arch_spin_value_unlocked() and selecting the Kconfig option. We also define cmpxchg64_relaxed(), because the lockref code does not need the cmpxchg to have barrier semantics. Using Linus' test case[1] on one system I see a 4x improvement for the basic enablement, and a further 1.3x for cmpxchg64_relaxed(), for a total of 5.3x vs the baseline. On another system I see more like 2x improvement. [1]: http://marc.info/?l=linux-fsdevel&m=137782380714721&w=4 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-28Disintegrate asm/system.h for PowerPCDavid Howells
Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org