Eric Lee / smarc-fsl-linux-kernel

15 Dec, 2009

1 commit

17 Aug, 2009

1 commit

  • 70aedd24d   genirq: Add buslock support ... Browse Code »

    Some interrupt chips are connected to a "slow" bus (i2c, spi ...). The
    bus access needs to sleep and therefor cannot be called in atomic
    contexts.

    Some of the generic interrupt management functions like disable_irq(),
    enable_irq() ... call interrupt chip functions with the irq_desc->lock
    held and interrupts disabled. This does not work for such devices.

    Provide a separate synchronization mechanism for such interrupt
    chips. The irq_chip structure is extended by two optional functions
    (bus_lock and bus_sync_and_unlock).

    The idea is to serialize the bus access for those operations in the
    core code so that drivers which are behind that bus operated interrupt
    controller do not have to worry about it and just can use the normal
    interfaces. To achieve this we add two function pointers to the
    irq_chip: bus_lock and bus_sync_unlock.

    bus_lock() is called to serialize access to the interrupt controller
    bus.

    Now the core code can issue chip->mask/unmask ... commands without
    changing the fast path code at all. The chip implementation merily
    stores that information in a chip private data structure and
    returns. No bus interaction as these functions are called from atomic
    context.

    After that bus_sync_unlock() is called outside the atomic context. Now
    the chip implementation issues the bus commands, waits for completion
    and unlocks the interrupt controller bus.

    The irq_chip implementation as pseudo code:

    struct irq_chip_data {
    struct mutex mutex;
    unsigned int irq_offset;
    unsigned long mask;
    unsigned long mask_status;
    }

    static void bus_lock(unsigned int irq)
    {
    struct irq_chip_data *data = get_irq_desc_chip_data(irq);

    mutex_lock(&data->mutex);
    }

    static void mask(unsigned int irq)
    {
    struct irq_chip_data *data = get_irq_desc_chip_data(irq);

    irq -= data->irq_offset;
    data->mask |= (1 << irq);
    }

    static void unmask(unsigned int irq)
    {
    struct irq_chip_data *data = get_irq_desc_chip_data(irq);

    irq -= data->irq_offset;
    data->mask &= ~(1 << irq);
    }

    static void bus_sync_unlock(unsigned int irq)
    {
    struct irq_chip_data *data = get_irq_desc_chip_data(irq);

    if (data->mask != data->mask_status) {
    do_bus_magic_to_set_mask(data->mask);
    data->mask_status = data->mask;
    }
    mutex_unlock(&data->mutex);
    }

    The device drivers can use request_threaded_irq, free_irq, disable_irq
    and enable_irq as usual with the only restriction that the calls need
    to come from non atomic context.

    Signed-off-by: Thomas Gleixner
    Cc: Mark Brown
    Cc: Dmitry Torokhov
    Cc: Trilok Soni
    Cc: Pavel Machek
    Cc: Brian Swetland
    Cc: Joonyoung Shim
    Cc: m.szyprowski@samsung.com
    Cc: t.fujak@samsung.com
    Cc: kyungmin.park@samsung.com,
    Cc: David Brownell
    Cc: Daniel Ribeiro
    Cc: arve@android.com
    Cc: Barry Song

    Thomas Gleixner
     

21 Jul, 2009

1 commit

  • 591d2fb02   genirq: Delegate irq affinity setting to the irq thread ... Browse Code »

    irq_set_thread_affinity() calls set_cpus_allowed_ptr() which might
    sleep, but irq_set_thread_affinity() is called with desc->lock held
    and can be called from hard interrupt context as well. The code has
    another bug as it does not hold a ref on the task struct as required
    by set_cpus_allowed_ptr().

    Just set the IRQTF_AFFINITY bit in action->thread_flags. The next time
    the thread runs it migrates itself. Solves all of the above problems
    nicely.

    Add kerneldoc to irq_set_thread_affinity() while at it.

    Signed-off-by: Thomas Gleixner
    LKML-Reference:

    Thomas Gleixner
     

28 Apr, 2009

2 commits

  • 85ac16d03   x86/irq: change irq_desc_alloc() to take node instead of cpu ... Browse Code »

    This simplifies the node awareness of the code. All our allocators
    only deal with a NUMA node ID locality not with CPU ids anyway - so
    there's no need to maintain (and transform) a CPU id all across the
    IRq layer.

    v2: keep move_irq_desc related

    [ Impact: cleanup, prepare IRQ code to be NUMA-aware ]

    Signed-off-by: Yinghai Lu
    Cc: Andrew Morton
    Cc: Suresh Siddha
    Cc: "Eric W. Biederman"
    Cc: Rusty Russell
    Cc: Jeremy Fitzhardinge
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Yinghai Lu
     
  • 57b150cce   irq: only update affinity if ->set_affinity() is sucessfull ... Browse Code »

    irq_set_affinity() and move_masked_irq() try to assign affinity
    before calling chip set_affinity(). Some archs are assigning it
    in ->set_affinity() again.

    We do something like:

    cpumask_cpy(desc->affinity, mask);
    desc->chip->set_affinity(mask);

    But in the failure path, affinity should not be touched - otherwise
    we'll end up with a different affinity mask despite the failure to
    migrate the IRQ.

    So try to update the afffinity only if set_affinity returns with 0.
    Also call irq_set_thread_affinity accordingly.

    v2: update after "irq, x86: Remove IRQ_DISABLED check in process context IRQ move"
    v3: according to Ingo, change set_affinity() in irq_chip should return int.
    v4: update comments by removing moving irq_desc code.

    [ Impact: fix /proc/irq/*/smp_affinity setting corner case bug ]

    Signed-off-by: Yinghai Lu
    Cc: Andrew Morton
    Cc: Suresh Siddha
    Cc: "Eric W. Biederman"
    Cc: Rusty Russell
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Yinghai Lu
     

31 Mar, 2009

1 commit

  • 0a0c5168d   PM: Introduce functions for suspending and resuming device interrupts ... Browse Code »

    Introduce helper functions allowing us to prevent device drivers from
    getting any interrupts (without disabling interrupts on the CPU)
    during suspend (or hibernation) and to make them start to receive
    interrupts again during the subsequent resume. These functions make it
    possible to keep timer interrupts enabled while the "late" suspend and
    "early" resume callbacks provided by device drivers are being
    executed. In turn, this allows device drivers' "late" suspend and
    "early" resume callbacks to sleep, execute ACPI callbacks etc.

    The functions introduced here will be used to rework the handling of
    interrupts during suspend (hibernation) and resume. Namely,
    interrupts will only be disabled on the CPU right before suspending
    sysdevs, while device drivers will be prevented from receiving
    interrupts, with the help of the new helper function, before their
    "late" suspend callbacks run (and analogously during resume).

    Signed-off-by: Rafael J. Wysocki
    Acked-by: Ingo Molnar

    Rafael J. Wysocki
     

28 Mar, 2009

1 commit

09 Feb, 2009

1 commit

  • 0f3c2a89c   irq: clear kstat_irqs ... Browse Code »

    Impact: get correct kstat_irqs [/proc/interrupts] for msi/msi-x etc

    need to call clear_kstat_irqs(), so when we reuse that irq_desc,
    we get correct kstat in /proc/interrupts.

    This makes /proc/interrupts not have entries.

    Don't need to worry about arch that doesn't support genirq, because they
    will not call dynamic_irq_cleanup().

    v2: simplify and make clear_kstat_irqs more robust

    Signed-off-by: Yinghai Lu
    Signed-off-by: Ingo Molnar

    Yinghai Lu
     

12 Jan, 2009

1 commit

  • 0fa0ebbf1   irq: allocate irq_desc_ptrs array based on nr_irqs ... Browse Code »

    Impact: allocate irq_desc_ptrs in preparation for making it variable-sized.

    This addresses this memory usage bump when NR_CPUS bumped from 128 to 4096:

    34816 +229376 264192 +658% irq_desc_ptrs(.data.read_mostly)

    The patch is split into two parts, the first simply allocates the
    irq_desc_ptrs array. Then next will deal with making it variable.
    This is only when CONFIG_SPARSE_IRQS=y.

    Signed-off-by: Mike Travis

    Mike Travis
     

17 Dec, 2008

1 commit

  • 48a1b10af   x86, sparseirq: move irq_desc according to smp_affinity, v7 ... Browse Code »

    Impact: improve NUMA handling by migrating irq_desc on smp_affinity changes

    if CONFIG_NUMA_MIGRATE_IRQ_DESC is set:

    - make irq_desc to go with affinity aka irq_desc moving etc
    - call move_irq_desc in irq_complete_move()
    - legacy irq_desc is not moved, because they are allocated via static array

    for logical apic mode, need to add move_desc_in_progress_in_same_domain,
    otherwise it will not be moved ==> also could need two phases to get
    irq_desc moved.

    Signed-off-by: Yinghai Lu
    Signed-off-by: Ingo Molnar

    Yinghai Lu
     

10 Nov, 2008

1 commit

  • f6d87f4bd   genirq: keep affinities set from userspace across free/request_irq() ... Browse Code »

    Impact: preserve user-modified affinities on interrupts

    Kumar Galak noticed that commit
    18404756765c713a0be4eb1082920c04822ce588 (genirq: Expose default irq
    affinity mask (take 3))

    overrides an already set affinity setting across a free /
    request_irq(). Happens e.g. with ifdown/ifup of a network device.

    Change the logic to mark the affinities as set and keep them
    intact. This also fixes the unlocked access to irq_desc in
    irq_select_affinity() when called from irq_affinity_proc_write()

    Signed-off-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar

    Thomas Gleixner
     

16 Oct, 2008

1 commit

  • 2c6927a38   irq: replace loop with nr_irqs with for_each_irq_desc ... Browse Code »

    There are a handful of loops that go from 0 to nr_irqs and use
    get_irq_desc() on them. These would allocate all the irq_desc
    entries, regardless of the need for them.

    Use the smarter for_each_irq_desc() iterator that will only iterate
    over the present ones.

    v2: make sure arch without GENERIC_HARDIRQS work too

    Signed-off-by: Yinghai Lu
    Signed-off-by: Ingo Molnar

    Yinghai Lu
     

02 Oct, 2008

1 commit

  • 0c5d1eb77   genirq: record trigger type ... Browse Code »
    47

    Genirq hasn't previously recorded the trigger type used by any given IRQ,
    although some irq_chip support has done so. That data can be useful when
    troubleshooting. This patch records it in the relevant irq_desc.status
    bits, and improves consistency between the two driver-visible calls
    affected:

    - Make set_irq_type() usage match request_irq() usage:
    * IRQ_TYPE_NONE should be a NOP; succeed, so irq_chip methods
    won't have to handle that case any more (many do it wrong).
    * IRQ_TYPE_PROBE is ignored; any buggy out-of-tree callers
    might need to switch over to the real IRQ probing code.
    * emit the same diagnostics (from shared utility code)

    - Their kerneldoc now reflects usage:
    * request_irq() flags include IRQF_TRIGGER_* to specify
    active edge(s)/level ... docs previously omitted that
    * set_irq_type() is declared in so callers
    should use the (bit-equivalent) IRQ_TYPE_* symbols there

    Also: adds a warning about shared IRQs that don't end up using the
    requested trigger mode; and fix an unrelated "sparse" warning.

    Signed-off-by: David Brownell
    Signed-off-by: Andrew Morton
    Acked-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar

    David Brownell
     

30 Jun, 2006

2 commits

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