Eric Lee / smarc-fsl-linux-kernel

21 Jun, 2008

2 commits

13 Jul, 2007

1 commit

24 Jan, 2007

1 commit

09 Dec, 2006

1 commit

05 Oct, 2006

1 commit

  • 7d12e780e   IRQ: Maintain regs pointer globally rather than passing to IRQ handlers ... Browse Code »

    Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
    of passing regs around manually through all ~1800 interrupt handlers in the
    Linux kernel.

    The regs pointer is used in few places, but it potentially costs both stack
    space and code to pass it around. On the FRV arch, removing the regs parameter
    from all the genirq function results in a 20% speed up of the IRQ exit path
    (ie: from leaving timer_interrupt() to leaving do_IRQ()).

    Where appropriate, an arch may override the generic storage facility and do
    something different with the variable. On FRV, for instance, the address is
    maintained in GR28 at all times inside the kernel as part of general exception
    handling.

    Having looked over the code, it appears that the parameter may be handed down
    through up to twenty or so layers of functions. Consider a USB character
    device attached to a USB hub, attached to a USB controller that posts its
    interrupts through a cascaded auxiliary interrupt controller. A character
    device driver may want to pass regs to the sysrq handler through the input
    layer which adds another few layers of parameter passing.

    I've build this code with allyesconfig for x86_64 and i386. I've runtested the
    main part of the code on FRV and i386, though I can't test most of the drivers.
    I've also done partial conversion for powerpc and MIPS - these at least compile
    with minimal configurations.

    This will affect all archs. Mostly the changes should be relatively easy.
    Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

    struct pt_regs *old_regs = set_irq_regs(regs);

    And put the old one back at the end:

    set_irq_regs(old_regs);

    Don't pass regs through to generic_handle_irq() or __do_IRQ().

    In timer_interrupt(), this sort of change will be necessary:

    - update_process_times(user_mode(regs));
    - profile_tick(CPU_PROFILING, regs);
    + update_process_times(user_mode(get_irq_regs()));
    + profile_tick(CPU_PROFILING);

    I'd like to move update_process_times()'s use of get_irq_regs() into itself,
    except that i386, alone of the archs, uses something other than user_mode().

    Some notes on the interrupt handling in the drivers:

    (*) input_dev() is now gone entirely. The regs pointer is no longer stored in
    the input_dev struct.

    (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
    something different depending on whether it's been supplied with a regs
    pointer or not.

    (*) Various IRQ handler function pointers have been moved to type
    irq_handler_t.

    Signed-Off-By: David Howells
    (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

    David Howells
     

14 Jul, 2006

1 commit

04 Jul, 2006

1 commit

  • 62322d255   [PATCH] make more file_operation structs static ... Browse Code »

    Mark the static struct file_operations in drivers/char as const. Making
    them const prevents accidental bugs, and moves them to the .rodata section
    so that they no longer do any false sharing; in addition with the proper
    debug option they are then protected against corruption..

    [akpm@osdl.org: build fix]
    Signed-off-by: Arjan van de Ven
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arjan van de Ven
     

30 Jun, 2006

1 commit

  • d1bef4ed5   [PATCH] genirq: rename desc->handler to desc->chip ... Browse Code »

    This patch-queue improves the generic IRQ layer to be truly generic, by adding
    various abstractions and features to it, without impacting existing
    functionality.

    While the queue can be best described as "fix and improve everything in the
    generic IRQ layer that we could think of", and thus it consists of many
    smaller features and lots of cleanups, the one feature that stands out most is
    the new 'irq chip' abstraction.

    The irq-chip abstraction is about describing and coding and IRQ controller
    driver by mapping its raw hardware capabilities [and quirks, if needed] in a
    straightforward way, without having to think about "IRQ flow"
    (level/edge/etc.) type of details.

    This stands in contrast with the current 'irq-type' model of genirq
    architectures, which 'mixes' raw hardware capabilities with 'flow' details.
    The patchset supports both types of irq controller designs at once, and
    converts i386 and x86_64 to the new irq-chip design.

    As a bonus side-effect of the irq-chip approach, chained interrupt controllers
    (master/slave PIC constructs, etc.) are now supported by design as well.

    The end result of this patchset intends to be simpler architecture-level code
    and more consolidation between architectures.

    We reused many bits of code and many concepts from Russell King's ARM IRQ
    layer, the merging of which was one of the motivations for this patchset.

    This patch:

    rename desc->handler to desc->chip.

    Originally i did not want to do this, because it's a big patch. But having
    both "desc->handler", "desc->handle_irq" and "action->handler" caused a
    large degree of confusion and made the code appear alot less clean than it
    truly is.

    I have also attempted a dual approach as well by introducing a
    desc->chip alias - but that just wasnt robust enough and broke
    frequently.

    So lets get over with this quickly. The conversion was done automatically
    via scripts and converts all the code in the kernel.

    This renaming patch is the first one amongst the patches, so that the
    remaining patches can stay flexible and can be merged and split up
    without having some big monolithic patch act as a merge barrier.

    [akpm@osdl.org: build fix]
    [akpm@osdl.org: another build fix]
    Signed-off-by: Ingo Molnar
    Signed-off-by: Thomas Gleixner
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ingo Molnar
     

22 Mar, 2006

1 commit

  • d39b6cfe6   [PATCH] vr41xx: convert to the new platform device interface ... Browse Code »

    The patch does the following for v441xx seris drivers:

    - stop using platform_device_register_simple() as it is going away
    - mark ->probe() and ->remove() methods as __devinit and __devexit
    respectively
    - initialize "owner" field in driver structure so there is a link
    from /sys/modules to the driver
    - mark *_init() and *_exit() functions as __init and __exit

    Signed-off-by: Dmitry Torokhov
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Dmitry Torokhov
     

10 Jan, 2006

1 commit

09 Jan, 2006

1 commit

  • e701e85b9   [PATCH] vr41xx: section tags fix ... Browse Code »

    module_init functions must be tagged __init rather than __devinit; likewise,
    module_exit functions must be tagged __exit rather than __devexit.

    Signed-off-by: Jean Delvare
    Cc: Yoichi Yuasa
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jean Delvare
     

10 Nov, 2005

1 commit

30 Oct, 2005

1 commit

22 Jun, 2005

1 commit