28 Oct, 2020

1 commit


27 Oct, 2020

1 commit


09 Sep, 2020

1 commit

  • Add a CONFIG_SET_FS option that is selected by architecturess that
    implement set_fs, which is all of them initially. If the option is not
    set stubs for routines related to overriding the address space are
    provided so that architectures can start to opt out of providing set_fs.

    Signed-off-by: Christoph Hellwig
    Reviewed-by: Kees Cook
    Signed-off-by: Al Viro

    Christoph Hellwig
     

12 Apr, 2020

1 commit

  • Pull nios2 updates from Ley Foon Tan:

    - Remove nios2-dev@lists.rocketboards.org from MAINTAINERS

    - remove 'resetvalue' property

    - rename 'altr,gpio-bank-width' -> 'altr,ngpio'

    - enable the common clk subsystem on Nios2

    * tag 'nios2-v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
    MAINTAINERS: Remove nios2-dev@lists.rocketboards.org
    arch: nios2: remove 'resetvalue' property
    arch: nios2: rename 'altr,gpio-bank-width' -> 'altr,ngpio'
    arch: nios2: Enable the common clk subsystem on Nios2

    Linus Torvalds
     

11 Apr, 2020

1 commit


16 Mar, 2020

1 commit

  • Rename the symbol to arch_dma_set_uncached, and pass a size to it as
    well as allow an error return. That will allow reusing this hook for
    in-place pagetable remapping.

    As the in-place remap doesn't always require an explicit cache flush,
    also detangle ARCH_HAS_DMA_PREP_COHERENT from ARCH_HAS_DMA_SET_UNCACHED.

    Signed-off-by: Christoph Hellwig
    Reviewed-by: Robin Murphy

    Christoph Hellwig
     

25 Jun, 2019

1 commit


15 May, 2019

1 commit

  • Most architectures do not need the memblock memory after the page
    allocator is initialized, but only few enable ARCH_DISCARD_MEMBLOCK in the
    arch Kconfig.

    Replacing ARCH_DISCARD_MEMBLOCK with ARCH_KEEP_MEMBLOCK and inverting the
    logic makes it clear which architectures actually use memblock after
    system initialization and skips the necessity to add ARCH_DISCARD_MEMBLOCK
    to the architectures that are still missing that option.

    Link: http://lkml.kernel.org/r/1556102150-32517-1-git-send-email-rppt@linux.ibm.com
    Signed-off-by: Mike Rapoport
    Acked-by: Michael Ellerman (powerpc)
    Cc: Russell King
    Cc: Catalin Marinas
    Cc: Will Deacon
    Cc: Richard Kuo
    Cc: Tony Luck
    Cc: Fenghua Yu
    Cc: Geert Uytterhoeven
    Cc: Ralf Baechle
    Cc: Paul Burton
    Cc: James Hogan
    Cc: Ley Foon Tan
    Cc: Benjamin Herrenschmidt
    Cc: Paul Mackerras
    Cc: Martin Schwidefsky
    Cc: Heiko Carstens
    Cc: Yoshinori Sato
    Cc: Rich Felker
    Cc: Thomas Gleixner
    Cc: Ingo Molnar
    Cc: Borislav Petkov
    Cc: "H. Peter Anvin"
    Cc: Eric Biederman
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mike Rapoport
     

07 May, 2019

1 commit

  • Pull locking updates from Ingo Molnar:
    "Here are the locking changes in this cycle:

    - rwsem unification and simpler micro-optimizations to prepare for
    more intrusive (and more lucrative) scalability improvements in
    v5.3 (Waiman Long)

    - Lockdep irq state tracking flag usage cleanups (Frederic
    Weisbecker)

    - static key improvements (Jakub Kicinski, Peter Zijlstra)

    - misc updates, cleanups and smaller fixes"

    * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
    locking/lockdep: Remove unnecessary unlikely()
    locking/static_key: Don't take sleeping locks in __static_key_slow_dec_deferred()
    locking/static_key: Factor out the fast path of static_key_slow_dec()
    locking/static_key: Add support for deferred static branches
    locking/lockdep: Test all incompatible scenarios at once in check_irq_usage()
    locking/lockdep: Avoid bogus Clang warning
    locking/lockdep: Generate LOCKF_ bit composites
    locking/lockdep: Use expanded masks on find_usage_*() functions
    locking/lockdep: Map remaining magic numbers to lock usage mask names
    locking/lockdep: Move valid_state() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING
    locking/rwsem: Prevent unneeded warning during locking selftest
    locking/rwsem: Optimize rwsem structure for uncontended lock acquisition
    locking/rwsem: Enable lock event counting
    locking/lock_events: Don't show pvqspinlock events on bare metal
    locking/lock_events: Make lock_events available for all archs & other locks
    locking/qspinlock_stat: Introduce generic lockevent_*() counting APIs
    locking/rwsem: Enhance DEBUG_RWSEMS_WARN_ON() macro
    locking/rwsem: Add debug check for __down_read*()
    locking/rwsem: Micro-optimize rwsem_try_read_lock_unqueued()
    locking/rwsem: Move rwsem internal function declarations to rwsem-xadd.h
    ...

    Linus Torvalds
     

03 Apr, 2019

2 commits

  • Currently, we have two different implementation of rwsem:

    1) CONFIG_RWSEM_GENERIC_SPINLOCK (rwsem-spinlock.c)
    2) CONFIG_RWSEM_XCHGADD_ALGORITHM (rwsem-xadd.c)

    As we are going to use a single generic implementation for rwsem-xadd.c
    and no architecture-specific code will be needed, there is no point
    in keeping two different implementations of rwsem. In most cases, the
    performance of rwsem-spinlock.c will be worse. It also doesn't get all
    the performance tuning and optimizations that had been implemented in
    rwsem-xadd.c over the years.

    For simplication, we are going to remove rwsem-spinlock.c and make all
    architectures use a single implementation of rwsem - rwsem-xadd.c.

    All references to RWSEM_GENERIC_SPINLOCK and RWSEM_XCHGADD_ALGORITHM
    in the code are removed.

    Suggested-by: Peter Zijlstra
    Signed-off-by: Waiman Long
    Signed-off-by: Peter Zijlstra (Intel)
    Acked-by: Linus Torvalds
    Cc: Andrew Morton
    Cc: Arnd Bergmann
    Cc: Borislav Petkov
    Cc: Davidlohr Bueso
    Cc: H. Peter Anvin
    Cc: Paul E. McKenney
    Cc: Thomas Gleixner
    Cc: Tim Chen
    Cc: Will Deacon
    Cc: linux-arm-kernel@lists.infradead.org
    Cc: linux-c6x-dev@linux-c6x.org
    Cc: linux-m68k@lists.linux-m68k.org
    Cc: linux-riscv@lists.infradead.org
    Cc: linux-um@lists.infradead.org
    Cc: linux-xtensa@linux-xtensa.org
    Cc: linuxppc-dev@lists.ozlabs.org
    Cc: nios2-dev@lists.rocketboards.org
    Cc: openrisc@lists.librecores.org
    Cc: uclinux-h8-devel@lists.sourceforge.jp
    Link: https://lkml.kernel.org/r/20190322143008.21313-3-longman@redhat.com
    Signed-off-by: Ingo Molnar

    Waiman Long
     
  • For the architectures that do not implement their own tlb_flush() but
    do already use the generic mmu_gather, there are two options:

    1) the platform has an efficient flush_tlb_range() and
    asm-generic/tlb.h doesn't need any overrides at all.

    2) the platform lacks an efficient flush_tlb_range() and
    we select MMU_GATHER_NO_RANGE to minimize full invalidates.

    Convert all 'simple' architectures to one of these two forms.

    alpha: has no range invalidate -> 2
    arc: already used flush_tlb_range() -> 1
    c6x: has no range invalidate -> 2
    hexagon: has an efficient flush_tlb_range() -> 1
    (flush_tlb_mm() is in fact a full range invalidate,
    so no need to shoot down everything)
    m68k: has inefficient flush_tlb_range() -> 2
    microblaze: has no flush_tlb_range() -> 2
    mips: has efficient flush_tlb_range() -> 1
    (even though it currently seems to use flush_tlb_mm())
    nds32: already uses flush_tlb_range() -> 1
    nios2: has inefficient flush_tlb_range() -> 2
    (no limit on range iteration)
    openrisc: has inefficient flush_tlb_range() -> 2
    (no limit on range iteration)
    parisc: already uses flush_tlb_range() -> 1
    sparc32: already uses flush_tlb_range() -> 1
    unicore32: has inefficient flush_tlb_range() -> 2
    (no limit on range iteration)
    xtensa: has efficient flush_tlb_range() -> 1

    Note this also fixes a bug in the existing code for a number
    platforms. Those platforms that did:

    tlb_end_vma() -> if (!full_mm) flush_tlb_*()
    tlb_flush -> if (full_mm) flush_tlb_mm()

    missed the case of shift_arg_pages(), which doesn't have @fullmm set,
    nor calls into tlb_*vma(), but still frees page-tables and thus needs
    an invalidate. The new code handles this by detecting a non-empty
    range, and either issuing the matching range invalidate or a full
    invalidate, depending on the capabilities.

    No change in behavior intended.

    Signed-off-by: Peter Zijlstra (Intel)
    Cc: Andrew Morton
    Cc: Andy Lutomirski
    Cc: Aneesh Kumar K.V
    Cc: Borislav Petkov
    Cc: Dave Hansen
    Cc: David S. Miller
    Cc: Greentime Hu
    Cc: Guan Xuetao
    Cc: H. Peter Anvin
    Cc: Helge Deller
    Cc: Jonas Bonn
    Cc: Ley Foon Tan
    Cc: Linus Torvalds
    Cc: Mark Salter
    Cc: Max Filippov
    Cc: Michal Simek
    Cc: Nick Piggin
    Cc: Paul Burton
    Cc: Peter Zijlstra
    Cc: Richard Henderson
    Cc: Richard Kuo
    Cc: Rik van Riel
    Cc: Thomas Gleixner
    Cc: Vineet Gupta
    Cc: Will Deacon
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

11 Mar, 2019

1 commit

  • Pull nios2 updates from Ley Foon Tan:
    "Most of updates are MMU related"

    * tag 'nios2-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
    nios2: Fix update_mmu_cache preload the TLB with the new PTE
    nios2: update_mmu_cache preload the TLB with the new PTE
    nios2: User address TLB flush break after finding the matching entry
    nios2: flush_tlb_all use TLBMISC way auto-increment feature
    nios2: improve readability of tlb functions
    nios2: flush_tlb_mm flush only the pid
    nios2: flush_tlb_pid can just restore TLBMISC once
    nios2: TLBMISC writes do not require PID bits to be set
    nios2: Use an invalid TLB entry address helper function
    nios2: pte_clear does not need to flush TLB
    nios2: flush_tlb_page use PID based flush
    nios2: update_mmu_cache clear the old entry from the TLB
    nios2: remove redundant 'default n' from Kconfig-s
    nios2: ksyms: Add missing symbol exports

    Linus Torvalds
     

07 Mar, 2019

1 commit

  • 'default n' is the default value for any bool or tristate Kconfig
    setting so there is no need to write it explicitly.

    Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO
    is not set' for visible symbols") the Kconfig behavior is the same
    regardless of 'default n' being present or not:

    ...
    One side effect of (and the main motivation for) this change is making
    the following two definitions behave exactly the same:

    config FOO
    bool

    config FOO
    bool
    default n

    With this change, neither of these will generate a
    '# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
    That might make it clearer to people that a bare 'default n' is
    redundant.
    ...

    Signed-off-by: Bartlomiej Zolnierkiewicz
    Signed-off-by: Ley Foon Tan

    Bartlomiej Zolnierkiewicz
     

19 Feb, 2019

1 commit

  • All new 32-bit architectures should have 64-bit userspace off_t type, but
    existing architectures has 32-bit ones.

    To enforce the rule, new config option is added to arch/Kconfig that defaults
    ARCH_32BIT_OFF_T to be disabled for new 32-bit architectures. All existing
    32-bit architectures enable it explicitly.

    New option affects force_o_largefile() behaviour. Namely, if userspace
    off_t is 64-bits long, we have no reason to reject user to open big files.

    Note that even if architectures has only 64-bit off_t in the kernel
    (arc, c6x, h8300, hexagon, nios2, openrisc, and unicore32),
    a libc may use 32-bit off_t, and therefore want to limit the file size
    to 4GB unless specified differently in the open flags.

    Signed-off-by: Yury Norov
    Acked-by: Arnd Bergmann
    Signed-off-by: Yury Norov
    Signed-off-by: Arnd Bergmann

    Yury Norov
     

06 Jan, 2019

1 commit


14 Dec, 2018

1 commit

  • All architectures except for sparc64 use the dma-direct code in some
    form, and even for sparc64 we had the discussion of a direct mapping
    mode a while ago. In preparation for directly calling the direct
    mapping code don't bother having it optionally but always build the
    code in. This is a minor hardship for some powerpc and arm configs
    that don't pull it in yet (although they should in a relase ot two),
    and sparc64 which currently doesn't need it at all, but it will
    reduce the ifdef mess we'd otherwise need significantly.

    Signed-off-by: Christoph Hellwig
    Acked-by: Jesper Dangaard Brouer
    Tested-by: Jesper Dangaard Brouer
    Tested-by: Tony Luck

    Christoph Hellwig
     

31 Oct, 2018

2 commits

  • All architecures use memblock for early memory management. There is no need
    for the CONFIG_HAVE_MEMBLOCK configuration option.

    [rppt@linux.vnet.ibm.com: of/fdt: fixup #ifdefs]
    Link: http://lkml.kernel.org/r/20180919103457.GA20545@rapoport-lnx
    [rppt@linux.vnet.ibm.com: csky: fixups after bootmem removal]
    Link: http://lkml.kernel.org/r/20180926112744.GC4628@rapoport-lnx
    [rppt@linux.vnet.ibm.com: remove stale #else and the code it protects]
    Link: http://lkml.kernel.org/r/1538067825-24835-1-git-send-email-rppt@linux.vnet.ibm.com
    Link: http://lkml.kernel.org/r/1536927045-23536-4-git-send-email-rppt@linux.vnet.ibm.com
    Signed-off-by: Mike Rapoport
    Acked-by: Michal Hocko
    Tested-by: Jonathan Cameron
    Cc: Catalin Marinas
    Cc: Chris Zankel
    Cc: "David S. Miller"
    Cc: Geert Uytterhoeven
    Cc: Greentime Hu
    Cc: Greg Kroah-Hartman
    Cc: Guan Xuetao
    Cc: Ingo Molnar
    Cc: "James E.J. Bottomley"
    Cc: Jonas Bonn
    Cc: Jonathan Corbet
    Cc: Ley Foon Tan
    Cc: Mark Salter
    Cc: Martin Schwidefsky
    Cc: Matt Turner
    Cc: Michael Ellerman
    Cc: Michal Simek
    Cc: Palmer Dabbelt
    Cc: Paul Burton
    Cc: Richard Kuo
    Cc: Richard Weinberger
    Cc: Rich Felker
    Cc: Russell King
    Cc: Serge Semin
    Cc: Thomas Gleixner
    Cc: Tony Luck
    Cc: Vineet Gupta
    Cc: Yoshinori Sato
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mike Rapoport
     
  • All achitectures select NO_BOOTMEM which essentially becomes 'Y' for any
    kernel configuration and therefore it can be removed.

    [alexander.h.duyck@linux.intel.com: remove now defunct NO_BOOTMEM from depends list for deferred init]
    Link: http://lkml.kernel.org/r/20180925201814.3576.15105.stgit@localhost.localdomain
    Link: http://lkml.kernel.org/r/1536927045-23536-3-git-send-email-rppt@linux.vnet.ibm.com
    Signed-off-by: Mike Rapoport
    Signed-off-by: Alexander Duyck
    Acked-by: Michal Hocko
    Cc: Catalin Marinas
    Cc: Chris Zankel
    Cc: "David S. Miller"
    Cc: Geert Uytterhoeven
    Cc: Greentime Hu
    Cc: Greg Kroah-Hartman
    Cc: Guan Xuetao
    Cc: Ingo Molnar
    Cc: "James E.J. Bottomley"
    Cc: Jonas Bonn
    Cc: Jonathan Corbet
    Cc: Ley Foon Tan
    Cc: Mark Salter
    Cc: Martin Schwidefsky
    Cc: Matt Turner
    Cc: Michael Ellerman
    Cc: Michal Simek
    Cc: Palmer Dabbelt
    Cc: Paul Burton
    Cc: Richard Kuo
    Cc: Richard Weinberger
    Cc: Rich Felker
    Cc: Russell King
    Cc: Serge Semin
    Cc: Thomas Gleixner
    Cc: Tony Luck
    Cc: Vineet Gupta
    Cc: Yoshinori Sato
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mike Rapoport
     

27 Oct, 2018

2 commits

  • Remove bootmem bitmap initialization and replace reserve_bootmem() with
    memblock_reserve().

    Link: http://lkml.kernel.org/r/1533326330-31677-5-git-send-email-rppt@linux.vnet.ibm.com
    Signed-off-by: Mike Rapoport
    Acked-by: Ley Foon Tan
    Cc: Guan Xuetao
    Cc: Richard Kuo
    Cc: Richard Weinberger
    Cc: Rob Herring
    Cc: Michal Hocko
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mike Rapoport
     
  • All we have to do is to enable memblock, the generic FDT code will take
    care of the rest.

    Link: http://lkml.kernel.org/r/1533326330-31677-4-git-send-email-rppt@linux.vnet.ibm.com
    Signed-off-by: Mike Rapoport
    Acked-by: Ley Foon Tan
    Cc: Guan Xuetao
    Cc: Richard Kuo
    Cc: Richard Weinberger
    Cc: Rob Herring
    Cc: Michal Hocko
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mike Rapoport
     

20 Sep, 2018

1 commit


16 Aug, 2018

1 commit

  • Pull Kconfig consolidation from Masahiro Yamada:
    "Consolidation of Kconfig files by Christoph Hellwig.

    Move the source statements of arch-independent Kconfig files instead
    of duplicating the includes in every arch/$(SRCARCH)/Kconfig"

    * tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
    kconfig: add a Memory Management options" menu
    kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt
    kconfig: use a menu in arch/Kconfig to reduce clutter
    kconfig: include kernel/Kconfig.preempt from init/Kconfig
    Kconfig: consolidate the "Kernel hacking" menu
    kconfig: include common Kconfig files from top-level Kconfig
    kconfig: remove duplicate SWAP symbol defintions
    um: create a proper drivers Kconfig
    um: cleanup Kconfig files
    um: stop abusing KBUILD_KCONFIG

    Linus Torvalds
     

02 Aug, 2018

4 commits

  • Almost all architectures include it. Add a ARCH_NO_PREEMPT symbol to
    disable preempt support for alpha, hexagon, non-coldfire m68k and
    user mode Linux.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Masahiro Yamada

    Christoph Hellwig
     
  • Move the source of lib/Kconfig.debug and arch/$(ARCH)/Kconfig.debug to
    the top-level Kconfig. For two architectures that means moving their
    arch-specific symbols in that menu into a new arch Kconfig.debug file,
    and for a few more creating a dummy file so that we can include it
    unconditionally.

    Also move the actual 'Kernel hacking' menu to lib/Kconfig.debug, where
    it belongs.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Masahiro Yamada

    Christoph Hellwig
     
  • Instead of duplicating the source statements in every architecture just
    do it once in the toplevel Kconfig file.

    Note that with this the inclusion of arch/$(SRCARCH/Kconfig moves out of
    the top-level Kconfig into arch/Kconfig so that don't violate ordering
    constraits while keeping a sensible menu structure.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Masahiro Yamada

    Christoph Hellwig
     
  • microblaze and nios2 define their own always n SWAP symbols. Remove those
    and let the generic defintion do the right thing by adding a new symbol
    to disable swap entirely.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Masahiro Yamada

    Christoph Hellwig
     

25 Jul, 2018

1 commit


02 Feb, 2018

1 commit

  • Blank help texts are probably either a typo, a Kconfig misunderstanding,
    or some kind of half-committing to adding a help text (in which case a
    TODO comment would be clearer, if the help text really can't be added
    right away).

    Best to remove them, IMO.

    Signed-off-by: Ulf Magnusson
    Acked-by: Randy Dunlap
    Acked-by: Ley Foon Tan
    Signed-off-by: Masahiro Yamada

    Ulf Magnusson
     

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
     

14 Jun, 2017

1 commit


08 May, 2017

1 commit


21 May, 2016

1 commit

  • The binary GCD algorithm is based on the following facts:
    1. If a and b are all evens, then gcd(a,b) = 2 * gcd(a/2, b/2)
    2. If a is even and b is odd, then gcd(a,b) = gcd(a/2, b)
    3. If a and b are all odds, then gcd(a,b) = gcd((a-b)/2, b) = gcd((a+b)/2, b)

    Even on x86 machines with reasonable division hardware, the binary
    algorithm runs about 25% faster (80% the execution time) than the
    division-based Euclidian algorithm.

    On platforms like Alpha and ARMv6 where division is a function call to
    emulation code, it's even more significant.

    There are two variants of the code here, depending on whether a fast
    __ffs (find least significant set bit) instruction is available. This
    allows the unpredictable branches in the bit-at-a-time shifting loop to
    be eliminated.

    If fast __ffs is not available, the "even/odd" GCD variant is used.

    I use the following code to benchmark:

    #include
    #include
    #include
    #include
    #include
    #include

    #define swap(a, b) \
    do { \
    a ^= b; \
    b ^= a; \
    a ^= b; \
    } while (0)

    unsigned long gcd0(unsigned long a, unsigned long b)
    {
    unsigned long r;

    if (a < b) {
    swap(a, b);
    }

    if (b == 0)
    return a;

    while ((r = a % b) != 0) {
    a = b;
    b = r;
    }

    return b;
    }

    unsigned long gcd1(unsigned long a, unsigned long b)
    {
    unsigned long r = a | b;

    if (!a || !b)
    return r;

    b >>= __builtin_ctzl(b);

    for (;;) {
    a >>= __builtin_ctzl(a);
    if (a == b)
    return a << __builtin_ctzl(r);

    if (a < b)
    swap(a, b);
    a -= b;
    }
    }

    unsigned long gcd2(unsigned long a, unsigned long b)
    {
    unsigned long r = a | b;

    if (!a || !b)
    return r;

    r &= -r;

    while (!(b & r))
    b >>= 1;

    for (;;) {
    while (!(a & r))
    a >>= 1;
    if (a == b)
    return a;

    if (a < b)
    swap(a, b);
    a -= b;
    a >>= 1;
    if (a & r)
    a += b;
    a >>= 1;
    }
    }

    unsigned long gcd3(unsigned long a, unsigned long b)
    {
    unsigned long r = a | b;

    if (!a || !b)
    return r;

    b >>= __builtin_ctzl(b);
    if (b == 1)
    return r & -r;

    for (;;) {
    a >>= __builtin_ctzl(a);
    if (a == 1)
    return r & -r;
    if (a == b)
    return a << __builtin_ctzl(r);

    if (a < b)
    swap(a, b);
    a -= b;
    }
    }

    unsigned long gcd4(unsigned long a, unsigned long b)
    {
    unsigned long r = a | b;

    if (!a || !b)
    return r;

    r &= -r;

    while (!(b & r))
    b >>= 1;
    if (b == r)
    return r;

    for (;;) {
    while (!(a & r))
    a >>= 1;
    if (a == r)
    return r;
    if (a == b)
    return a;

    if (a < b)
    swap(a, b);
    a -= b;
    a >>= 1;
    if (a & r)
    a += b;
    a >>= 1;
    }
    }

    static unsigned long (*gcd_func[])(unsigned long a, unsigned long b) = {
    gcd0, gcd1, gcd2, gcd3, gcd4,
    };

    #define TEST_ENTRIES (sizeof(gcd_func) / sizeof(gcd_func[0]))

    #if defined(__x86_64__)

    #define rdtscll(val) do { \
    unsigned long __a,__d; \
    __asm__ __volatile__("rdtsc" : "=a" (__a), "=d" (__d)); \
    (val) = ((unsigned long long)__a) | (((unsigned long long)__d)<= start)
    ret = end - start;
    else
    ret = ~0ULL - start + 1 + end;

    *res = gcd_res;
    return ret;
    }

    #else

    static inline struct timespec read_time(void)
    {
    struct timespec time;
    clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time);
    return time;
    }

    static inline unsigned long long diff_time(struct timespec start, struct timespec end)
    {
    struct timespec temp;

    if ((end.tv_nsec - start.tv_nsec) < 0) {
    temp.tv_sec = end.tv_sec - start.tv_sec - 1;
    temp.tv_nsec = 1000000000ULL + end.tv_nsec - start.tv_nsec;
    } else {
    temp.tv_sec = end.tv_sec - start.tv_sec;
    temp.tv_nsec = end.tv_nsec - start.tv_nsec;
    }

    return temp.tv_sec * 1000000000ULL + temp.tv_nsec;
    }

    static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long),
    unsigned long a, unsigned long b, unsigned long *res)
    {
    struct timespec start, end;
    unsigned long gcd_res;

    start = read_time();
    gcd_res = gcd(a, b);
    end = read_time();

    *res = gcd_res;
    return diff_time(start, end);
    }

    #endif

    static inline unsigned long get_rand()
    {
    if (sizeof(long) == 8)
    return (unsigned long)rand() << 32 | rand();
    else
    return rand();
    }

    int main(int argc, char **argv)
    {
    unsigned int seed = time(0);
    int loops = 100;
    int repeats = 1000;
    unsigned long (*res)[TEST_ENTRIES];
    unsigned long long elapsed[TEST_ENTRIES];
    int i, j, k;

    for (;;) {
    int opt = getopt(argc, argv, "n:r:s:");
    /* End condition always first */
    if (opt == -1)
    break;

    switch (opt) {
    case 'n':
    loops = atoi(optarg);
    break;
    case 'r':
    repeats = atoi(optarg);
    break;
    case 's':
    seed = strtoul(optarg, NULL, 10);
    break;
    default:
    /* You won't actually get here. */
    break;
    }
    }

    res = malloc(sizeof(unsigned long) * TEST_ENTRIES * loops);
    memset(elapsed, 0, sizeof(elapsed));

    srand(seed);
    for (j = 0; j < loops; j++) {
    unsigned long a = get_rand();
    /* Do we have args? */
    unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand();
    unsigned long long min_elapsed[TEST_ENTRIES];
    for (k = 0; k < repeats; k++) {
    for (i = 0; i < TEST_ENTRIES; i++) {
    unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &res[j][i]);
    if (k == 0 || min_elapsed[i] > tmp)
    min_elapsed[i] = tmp;
    }
    }
    for (i = 0; i < TEST_ENTRIES; i++)
    elapsed[i] += min_elapsed[i];
    }

    for (i = 0; i < TEST_ENTRIES; i++)
    printf("gcd%d: elapsed %llu\n", i, elapsed[i]);

    k = 0;
    srand(seed);
    for (j = 0; j < loops; j++) {
    unsigned long a = get_rand();
    unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand();
    for (i = 1; i < TEST_ENTRIES; i++) {
    if (res[j][i] != res[j][0])
    break;
    }
    if (i < TEST_ENTRIES) {
    if (k == 0) {
    k = 1;
    fprintf(stderr, "Error:\n");
    }
    fprintf(stderr, "gcd(%lu, %lu): ", a, b);
    for (i = 0; i < TEST_ENTRIES; i++)
    fprintf(stderr, "%ld%s", res[j][i], i < TEST_ENTRIES - 1 ? ", " : "\n");
    }
    }

    if (k == 0)
    fprintf(stderr, "PASS\n");

    free(res);

    return 0;
    }

    Compiled with "-O2", on "VirtualBox 4.4.0-22-generic #38-Ubuntu x86_64" got:

    zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
    gcd0: elapsed 10174
    gcd1: elapsed 2120
    gcd2: elapsed 2902
    gcd3: elapsed 2039
    gcd4: elapsed 2812
    PASS
    zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
    gcd0: elapsed 9309
    gcd1: elapsed 2280
    gcd2: elapsed 2822
    gcd3: elapsed 2217
    gcd4: elapsed 2710
    PASS
    zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
    gcd0: elapsed 9589
    gcd1: elapsed 2098
    gcd2: elapsed 2815
    gcd3: elapsed 2030
    gcd4: elapsed 2718
    PASS
    zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
    gcd0: elapsed 9914
    gcd1: elapsed 2309
    gcd2: elapsed 2779
    gcd3: elapsed 2228
    gcd4: elapsed 2709
    PASS

    [akpm@linux-foundation.org: avoid #defining a CONFIG_ variable]
    Signed-off-by: Zhaoxiu Zeng
    Signed-off-by: George Spelvin
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Zhaoxiu Zeng
     

26 Apr, 2016

1 commit


16 Feb, 2015

1 commit


10 Feb, 2015

1 commit


08 Dec, 2014

3 commits

  • If NIOS2_CMDLINE_IGNORE_DTB is selected but CMDLINE_BOOL isn't and thus
    CONFIG_CMDLINE is not defined, the build fails with the following error:

    arch/nios2/kernel/setup.c: In function 'nios2_boot_init':
    arch/nios2/kernel/setup.c:131:30: error: 'CONFIG_CMDLINE' undeclared
    (first use in this function)
    strncpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);

    This can be reproduced using randconfig with KCONFIG_SEED=0xE5B8749E, i.e.
    'make KCONFIG_SEED=0xE5B8749E ARCH=nios2 randconfig'.

    Fix this by letting NIOS2_CMDLINE_IGNORE_DTB depend on CMDLINE_BOOL, so we
    actually have a default kernel command string to fall back to.

    Signed-off-by: Tobias Klauser
    Acked-by: Ley Foon Tan

    Tobias Klauser
     
  • kernel/time/Kconfig expects that NR_CPUS is defined.

    This fixes the following config warning:
    "kernel/time/Kconfig:163:warning: range is invalid"

    Follow 4cbbbb43d666 ("microblaze: Fix missing NR_CPUS in menuconfig")

    Signed-off-by: Tobias Klauser
    Acked-by: Ley Foon Tan

    Tobias Klauser
     
  • This patch adds Makefile and Kconfig files required for building a
    nios2 kernel.

    Signed-off-by: Ley Foon Tan

    Ley Foon Tan