Eric Lee / smarc-fsl-linux-kernel

18 May, 2010

1 commit

23 Dec, 2009

1 commit

  • 454654878   kfifo: move struct kfifo in place ... Browse Code »

    This is a new generic kernel FIFO implementation.

    The current kernel fifo API is not very widely used, because it has to
    many constrains. Only 17 files in the current 2.6.31-rc5 used it.
    FIFO's are like list's a very basic thing and a kfifo API which handles
    the most use case would save a lot of development time and memory
    resources.

    I think this are the reasons why kfifo is not in use:

    - The API is to simple, important functions are missing
    - A fifo can be only allocated dynamically
    - There is a requirement of a spinlock whether you need it or not
    - There is no support for data records inside a fifo

    So I decided to extend the kfifo in a more generic way without blowing up
    the API to much. The new API has the following benefits:

    - Generic usage: For kernel internal use and/or device driver.
    - Provide an API for the most use case.
    - Slim API: The whole API provides 25 functions.
    - Linux style habit.
    - DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
    - Direct copy_to_user from the fifo and copy_from_user into the fifo.
    - The kfifo itself is an in place member of the using data structure, this save an
    indirection access and does not waste the kernel allocator.
    - Lockless access: if only one reader and one writer is active on the fifo,
    which is the common use case, no additional locking is necessary.
    - Remove spinlock - give the user the freedom of choice what kind of locking to use if
    one is required.
    - Ability to handle records. Three type of records are supported:
    - Variable length records between 0-255 bytes, with a record size
    field of 1 bytes.
    - Variable length records between 0-65535 bytes, with a record size
    field of 2 bytes.
    - Fixed size records, which no record size field.
    - Preserve memory resource.
    - Performance!
    - Easy to use!

    This patch:

    Since most users want to have the kfifo as part of another object,
    reorganize the code to allow including struct kfifo in another data
    structure. This requires changing the kfifo_alloc and kfifo_init
    prototypes so that we pass an existing kfifo pointer into them. This
    patch changes the implementation and all existing users.

    [akpm@linux-foundation.org: fix warning]
    Signed-off-by: Stefani Seibold
    Acked-by: Greg Kroah-Hartman
    Acked-by: Mauro Carvalho Chehab
    Acked-by: Andi Kleen
    Acked-by: Arnd Bergmann
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Stefani Seibold
     

12 Oct, 2008

1 commit

20 Oct, 2007

1 commit

  • 96de0e252   Convert files to UTF-8 and some cleanups ... Browse Code »

    * Convert files to UTF-8.

    * Also correct some people's names
    (one example is Eißfeldt, which was found in a source file.
    Given that the author used an ß at all in a source file
    indicates that the real name has in fact a 'ß' and not an 'ss',
    which is commonly used as a substitute for 'ß' when limited to
    7bit.)

    * Correct town names (Goettingen -> Göttingen)

    * Update Eberhard Mönkeberg's address (http://lkml.org/lkml/2007/1/8/313)

    Signed-off-by: Jan Engelhardt
    Signed-off-by: Adrian Bunk

    Jan Engelhardt
     

29 Apr, 2007

1 commit

01 Jul, 2006

1 commit

07 Feb, 2006

1 commit

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    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