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2019-02-26ARM: 8843/1: use unified assembler in headersStefan Agner
Use unified assembler syntax (UAL) in headers. Divided syntax is considered deprecated. This will also allow to build the kernel using LLVM's integrated assembler. Signed-off-by: Stefan Agner <stefan@agner.ch> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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>
2016-11-23Revert "arm: move exports to definitions"Russell King
This reverts commit 4dd1837d7589f468ed109556513f476e7a7f9121. Moving the exports for assembly code into the assembly files breaks KSYM trimming, but also breaks modversions. While fixing the KSYM trimming is trivial, fixing modversions brings us to a technically worse position that we had prior to the above change: - We end up with the prototype definitions divorsed from everything else, which means that adding or removing assembly level ksyms become more fragile: * if adding a new assembly ksyms export, a missed prototype in asm-prototypes.h results in a successful build if no module in the selected configuration makes use of the symbol. * when removing a ksyms export, asm-prototypes.h will get forgotten, with armksyms.c, you'll get a build error if you forget to touch the file. - We end up with the same amount of include files and prototypes, they're just in a header file instead of a .c file with their exports. As for lines of code, we don't get much of a size reduction: (original commit) 47 files changed, 131 insertions(+), 208 deletions(-) (fix for ksyms trimming) 7 files changed, 18 insertions(+), 5 deletions(-) (two fixes for modversions) 1 file changed, 34 insertions(+) 3 files changed, 7 insertions(+), 2 deletions(-) which results in a net total of only 25 lines deleted. As there does not seem to be much benefit from this change of approach, revert the change. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2016-08-07arm: move exports to definitionsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-07-18ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+Russell King
ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-02-25ARM: 7984/1: prefetch: add prefetchw invocations for barriered atomicsWill Deacon
After a bunch of benchmarking on the interaction between dmb and pldw, it turns out that issuing the pldw *after* the dmb instruction can give modest performance gains (~3% atomic_add_return improvement on a dual A15). This patch adds prefetchw invocations to our barriered atomic operations including cmpxchg, test_and_xxx and futexes. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-11-20ARM: 7893/1: bitops: only emit .arch_extension mp if CONFIG_SMPWill Deacon
Uwe reported a build failure when targetting a NOMMU platform with my recent prefetch changes: arch/arm/lib/changebit.S: Assembler messages: arch/arm/lib/changebit.S:15: Error: architectural extension `mp' is not allowed for the current base architecture This is due to use of the .arch_extension mp directive immediately prior to an ALT_SMP(...) instruction. Whilst the ALT_SMP macro will expand to nothing if !CONFIG_SMP, gas will still choke on the directive. This patch fixes the issue by only emitting the sequence (including the directive) if CONFIG_SMP=y. Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-09-30ARM: bitops: prefetch the destination word for write prior to strexWill Deacon
The cost of changing a cacheline from shared to exclusive state can be significant, especially when this is triggered by an exclusive store, since it may result in having to retry the transaction. This patch prefixes our atomic bitops implementation with prefetchw, to try and grab the line in exclusive state from the start. The testop macro is left alone, since the barrier semantics limit the usefulness of prefetching data. Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-11-26ARM: 7171/1: unwind: add unwind directives to bitops assembly macrosWill Deacon
The bitops functions (e.g. _test_and_set_bit) on ARM do not have unwind annotations and therefore the kernel cannot backtrace out of them on a fatal error (for example, NULL pointer dereference). This patch annotates the bitops assembly macros with UNWIND annotations so that we can produce a meaningful backtrace on error. Callers of the macros are modified to pass their function name as a macro parameter, enforcing that the macros are used as standalone function implementations. Acked-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-19ARM: 6653/1: bitops: Use BX instead of MOV PC,LRDave Martin
The kernel doesn't officially need to interwork, but using BX wherever appropriate will help educate people into good assembler coding habits. BX is appropriate here because this code is predicated on __LINUX_ARM_ARCH__ >= 6 Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-02ARM: bitops: switch set/clear/change bitops to use ldrex/strexRussell King
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>
2011-02-02ARM: bitops: ensure set/clear/change bitops take a word-aligned pointerRussell King
Add additional instructions to our assembly bitops functions to ensure that they only operate on word-aligned pointers. This will be necessary when we switch these operations to use the word-based exclusive operations. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-08-13Complete irq tracing support for ARMUwe Kleine-König
Before this patch enabling and disabling irqs in assembler code and by the hardware wasn't tracked completly. I had to transpose two instructions in arch/arm/lib/bitops.h because restore_irqs doesn't preserve the flags with CONFIG_TRACE_IRQFLAGS=y Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2009-05-28[ARM] barriers: improve xchg, bitops and atomic SMP barriersRussell King
Mathieu Desnoyers pointed out that the ARM barriers were lacking: - cmpxchg, xchg and atomic add return need memory barriers on architectures which can reorder the relative order in which memory read/writes can be seen between CPUs, which seems to include recent ARM architectures. Those barriers are currently missing on ARM. - test_and_xxx_bit were missing SMP barriers. So put these barriers in. Provide separate atomic_add/atomic_sub operations which do not require barriers. Reported-Reviewed-and-Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-05-20[ARM] spelling fixesSimon Arlott
Spelling fixes in arch/arm/. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2005-11-09[ARM] Clean up save_and_disable_irqs macro and allow use of ARMv6 CPSIDRussell King
save_and_disable_irqs does not need to use mov + msr (which was introduced to work around a documentation bug which was propagated into binutils.) Use msr with an immediate constant, and if we're building for ARMv6 or later, use the new CPSID instruction. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-03[ARM SMP] Add configuration option for ARMv6K processorsRussell King
The 'K' extension adds several new instructions to the ARMv6 ISA which are primerily useful for SMP. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-08-10[ARM SMP] Only enable V6K instructions on V6 MP core CPUsRussell King
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-07-28[ARM SMP] Fix another ARMv6 bitop problemRussell King
We sometimes forgot to check whether the exclusive store succeeded. Ensure that we always check. Also ensure that we always use the out of line versions, since the inline versions are not SMP safe. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-07-27[ARM SMP] Fix data corruption in test_* bitopsRussell King
If we found that the bit was already in the desired state, we would skip performing the operation, and write random data back. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-07-16[PATCH] ARM: Convert bitops to use ARMv6 ldrex/strex instructionsRussell King
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-04-18[PATCH] ARM: Add missing new file for bitops patchRussell King
Signed-off-by: Russell King <rmk@arm.linux.org.uk>