Eric Lee / smarc-fsl-linux-kernel

06 Feb, 2008

2 commits

  • a5a678c80   uml: current.h cleanup ... Browse Code »

    Tidy current-related stuff. There was a comment in current.h saying
    that current_thread was obsolete, so this patch turns all instances of
    current_thread into current_thread_info(). There's some simplifying
    of the result in arch/um/sys-i386/signal.c.

    current.h and thread_info also get style cleanups.

    Signed-off-by: Jeff Dike
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jeff Dike
     
  • 8192ab42b   uml: header untangling ... Browse Code »

    Untangle UML headers somewhat and add some includes where they were
    needed explicitly, but gotten accidentally via some other header.

    arch/um/include/um_uaccess.h loses asm/fixmap.h because it uses no
    fixmap stuff and gains elf.h, because it needs FIXADDR_USER_*, and
    archsetjmp.h, because it needs jmp_buf.

    pmd_alloc_one is uninlined because it needs mm_struct, and that's
    inconvenient to provide in asm-um/pgtable-3level.h.

    elf_core_copy_fpregs is also uninlined from elf-i386.h and
    elf-x86_64.h, which duplicated the code anyway, to
    arch/um/kernel/process.c, so that the reference to current_thread
    doesn't pull sched.h or anything related into asm/elf.h.

    arch/um/sys-i386/ldt.c, arch/um/kernel/tlb.c and
    arch/um/kernel/skas/uaccess.c got sched.h because they dereference
    task_structs. Its includes of linux and asm headers got turned from
    "" to <>.

    arch/um/sys-i386/bug.c gets asm/errno.h because it needs errno
    constants.

    asm/elf-i386 gets asm/user.h because it needs user_regs_struct.

    asm/fixmap.h gets page.h because it needs PAGE_SIZE and PAGE_MASK and
    system.h for BUG_ON.

    asm/pgtable doesn't need sched.h.

    asm/processor-generic.h defined mm_segment_t, but didn't use it. So,
    that definition is moved to uaccess.h, which defines a bunch of
    mm_segment_t-related stuff. thread_info.h uses mm_segment_t, and
    includes uaccess.h, which causes a recursion. So, the definition is
    placed above the include of thread_info. in uaccess.h. thread_info.h
    also gets page.h because it needs PAGE_SIZE.

    ObCheckpatchViolationJustification - I'm not adding a typedef; I'm
    moving mm_segment_t from one place to another.

    Signed-off-by: Jeff Dike
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jeff Dike
     

17 Jul, 2007

2 commits

11 May, 2007

1 commit

  • c14b84949   uml: iRQ stacks ... Browse Code »

    Add a separate IRQ stack. This differs from i386 in having the entire
    interrupt run on a separate stack rather than starting on the normal kernel
    stack and switching over once some preparation has been done. The underlying
    mechanism, is of course, sigaltstack.

    Another difference is that interrupts that happen in userspace are handled on
    the normal kernel stack. These cause a wait wakeup instead of a signal
    delivery so there is no point in trying to switch stacks for these. There's
    no other stuff on the stack, so there is no extra stack consumption.

    This quirk makes it possible to have the entire interrupt run on a separate
    stack - process preemption (and calls to schedule()) happens on a normal
    kernel stack. If we enable CONFIG_PREEMPT, this will need to be rethought.

    The IRQ stack for CPU 0 is declared in the same way as the initial kernel
    stack. IRQ stacks for other CPUs will be allocated dynamically.

    An extra field was added to the thread_info structure. When the active
    thread_info is copied to the IRQ stack, the real_thread field points back to
    the original stack. This makes it easy to tell where to copy the thread_info
    struct back to when the interrupt is finished. It also serves as a marker of
    a nested interrupt. It is NULL for the first interrupt on the stack, and
    non-NULL for any nested interrupts.

    Care is taken to behave correctly if a second interrupt comes in when the
    thread_info structure is being set up or taken down. I could just disable
    interrupts here, but I don't feel like giving up any of the performance gained
    by not flipping signals on and off.

    If an interrupt comes in during these critical periods, the handler can't run
    because it has no idea what shape the stack is in. So, it sets a bit for its
    signal in a global mask and returns. The outer handler will deal with this
    signal itself.

    Atomicity is had with xchg. A nested interrupt that needs to bail out will
    xchg its signal mask into pending_mask and repeat in case yet another
    interrupt hit at the same time, until the mask stabilizes.

    The outermost interrupt will set up the thread_info and xchg a zero into
    pending_mask when it is done. At this point, nested interrupts will look at
    ->real_thread and see that no setup needs to be done. They can just continue
    normally.

    Similar care needs to be taken when exiting the outer handler. If another
    interrupt comes in while it is copying the thread_info, it will drop a bit
    into pending_mask. The outer handler will check this and if it is non-zero,
    will loop, set up the stack again, and handle the interrupt.

    Signed-off-by: Jeff Dike
    Cc: Paolo 'Blaisorblade' Giarrusso
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jeff Dike
     

26 Apr, 2006

1 commit

01 Apr, 2006

1 commit

19 Jan, 2006

1 commit

  • 2fc10620e   [PATCH] uml: add TIF_RESTORE_SIGMASK support ... Browse Code »

    Add support for TIF_RESTORE_SIGMASK. I copy the i386 handling of the flag.
    sys_sigsuspend is also changed to follow i386.
    Also a bit of cleanup -
    turn an if into a switch
    get rid of a couple more emacs formatting comments

    Signed-off-by: Jeff Dike
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jeff Dike
     

13 Jan, 2006

1 commit

24 Jun, 2005

1 commit

  • dcd497f99   [PATCH] streamline preempt_count type across archs ... Browse Code »

    The preempt_count member of struct thread_info is currently either defined
    as int, unsigned int or __s32 depending on arch. This patch makes the type
    of preempt_count an int on all archs.

    Having preempt_count be an unsigned type prevents the catching of
    preempt_count < 0 bugs, and using int on some archs and __s32 on others is
    not exactely "neat" - much nicer when it's just int all over.

    A previous version of this patch was already ACK'ed by Robert Love, and the
    only change in this version of the patch compared to the one he ACK'ed is
    that this one also makes sure the preempt_count member is consistently
    commented.

    Signed-off-by: Jesper Juhl
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jesper Juhl
     

29 May, 2005

2 commits

03 May, 2005

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