06 Mar, 2020

1 commit

  • The comment in 'asm-generic/bitops.h' states that you should "recode
    these in the native assembly language, if at all possible". This is
    pretty crappy advice now that the generic implementation is defined in
    terms of atomic_long_t rather than a spinlock, so update the comment and
    hopefully save future architecture maintainers a bit of work.

    Reported-by: Stefan Asserhall
    Signed-off-by: Will Deacon
    Signed-off-by: Peter Zijlstra (Intel)
    Link: https://lkml.kernel.org/r/20200213093927.1836-1-will@kernel.org

    Will Deacon
     

02 Nov, 2017

1 commit

  • 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
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

18 Apr, 2014

1 commit

  • Since the smp_mb__{before,after}*() ops are fundamentally dependent on
    how an arch can implement atomics it doesn't make sense to have 3
    variants of them. They must all be the same.

    Furthermore, the 3 variants suggest they're only valid for those 3
    atomic ops, while we have many more where they could be applied.

    So move away from
    smp_mb__{before,after}_{atomic,clear}_{dec,inc,bit}() and reduce the
    interface to just the two: smp_mb__{before,after}_atomic().

    This patch prepares the way by introducing default implementations in
    asm-generic/barrier.h that default to a full barrier and providing
    __deprecated inlines for the previous 6 barriers if they're not
    provided by the arch.

    This should allow for a mostly painless transition (lots of deprecated
    warns in the interim).

    Signed-off-by: Peter Zijlstra
    Acked-by: Paul E. McKenney
    Link: http://lkml.kernel.org/n/tip-wr59327qdyi9mbzn6x937s4e@git.kernel.org
    Cc: Arnd Bergmann
    Cc: "Chen, Gong"
    Cc: John Sullivan
    Cc: Linus Torvalds
    Cc: Mauro Carvalho Chehab
    Cc: Srinivas Pandruvada
    Cc: "Theodore Ts'o"
    Cc: linux-arch@vger.kernel.org
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

24 Mar, 2011

3 commits

  • 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
    Acked-by: Arnd Bergmann
    Acked-by: Greg Ungerer
    Cc: Geert Uytterhoeven
    Cc: Roman Zippel
    Cc: Andreas Schwab
    Cc: Martin Schwidefsky
    Cc: Heiko Carstens
    Cc: Yoshinori Sato
    Cc: Michal Simek
    Cc: "David S. Miller"
    Cc: Hirokazu Takata
    Acked-by: Ralf Baechle
    Acked-by: Paul Mundt
    Cc: Chris Zankel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • 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
    Cc: Jan Kara
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • Introduce little-endian bit operations to the big-endian architectures
    which do not have native little-endian bit operations and the
    little-endian architectures. (alpha, avr32, blackfin, cris, frv, h8300,
    ia64, m32r, mips, mn10300, parisc, sh, sparc, tile, x86, xtensa)

    These architectures can just include generic implementation
    (asm-generic/bitops/le.h).

    Signed-off-by: Akinobu Mita
    Cc: Richard Henderson
    Cc: Ivan Kokshaysky
    Cc: Mikael Starvik
    Cc: David Howells
    Cc: Yoshinori Sato
    Cc: "Luck, Tony"
    Cc: Ralf Baechle
    Cc: Kyle McMartin
    Cc: Matthew Wilcox
    Cc: Grant Grundler
    Cc: Paul Mundt
    Cc: Kazumoto Kojima
    Cc: Hirokazu Takata
    Cc: "David S. Miller"
    Cc: Chris Zankel
    Cc: Ingo Molnar
    Cc: Thomas Gleixner
    Acked-by: Hans-Christian Egtvedt
    Acked-by: "H. Peter Anvin"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     

12 Jun, 2009

1 commit

  • bitops.h apparently suffered from some level of bitrot, it
    was missing the smp_mb__{before,after}_clear_bit functions,
    and included other headers in an invalid order.

    This changes the file so that new architectures can use
    it out of the box.

    Signed-off-by: Remis Lima Baima
    Signed-off-by: Arnd Bergmann

    Arnd Bergmann
     

30 Apr, 2008

1 commit


20 Oct, 2007

1 commit

  • forbid asm/bitops.h direct inclusion

    Because of compile errors that may occur after bit changes if asm/bitops.h is
    included directly without e.g. linux/kernel.h which includes linux/bitops.h,
    forbid direct inclusion of asm/bitops.h. Thanks to Adrian Bunk.

    Signed-off-by: Jiri Slaby
    Cc: Adrian Bunk
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jiri Slaby
     

19 Oct, 2007

1 commit

  • Introduce test_and_set_bit_lock / clear_bit_unlock bitops with lock semantics.
    Convert all architectures to use the generic implementation.

    Signed-off-by: Nick Piggin
    Acked-By: David Howells
    Cc: Richard Henderson
    Cc: Ivan Kokshaysky
    Cc: Russell King
    Cc: Haavard Skinnemoen
    Cc: Bryan Wu
    Cc: Mikael Starvik
    Cc: David Howells
    Cc: Yoshinori Sato
    Cc: "Luck, Tony"
    Cc: Hirokazu Takata
    Cc: Geert Uytterhoeven
    Cc: Roman Zippel
    Cc: Greg Ungerer
    Cc: Ralf Baechle
    Cc: Kyle McMartin
    Cc: Matthew Wilcox
    Cc: Paul Mackerras
    Cc: Benjamin Herrenschmidt
    Cc: Heiko Carstens
    Cc: Martin Schwidefsky
    Cc: Paul Mundt
    Cc: Kazumoto Kojima
    Cc: Richard Curnow
    Cc: William Lee Irwin III
    Cc: "David S. Miller"
    Cc: Jeff Dike
    Cc: Paolo 'Blaisorblade' Giarrusso
    Cc: Miles Bader
    Cc: Andi Kleen
    Cc: Chris Zankel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Nick Piggin
     

27 Mar, 2006

1 commit


04 Jan, 2006

1 commit


17 Apr, 2005

1 commit

  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds