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398 /* Tasklets --- multithreaded analogue of BHs.
399
400 Main feature differing them of generic softirqs: tasklet
401 is running only on one CPU simultaneously.
402
403 Main feature differing them of BHs: different tasklets
404 may be run simultaneously on different CPUs.
405
406 Properties:
407 * If tasklet_schedule() is called, then tasklet is guaranteed
408 to be executed on some cpu at least once after this.
409 * If the tasklet is already scheduled, but its excecution is still not
410 started, it will be executed only once.
411 * If this tasklet is already running on another CPU (or schedule is called
412 from tasklet itself), it is rescheduled for later.
413 * Tasklet is strictly serialized wrt itself, but not
414 wrt another tasklets. If client needs some intertask synchronization,
415 he makes it with spinlocks.
416 */

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879 /**
880 * request_threaded_irq - allocate an interrupt line
881 * @irq: Interrupt line to allocate
882 * @handler: Function to be called when the IRQ occurs.
883 * Primary handler for threaded interrupts
884 * @thread_fn: Function called from the irq handler thread
885 * If NULL, no irq thread is created
886 * @irqflags: Interrupt type flags
887 * @devname: An ascii name for the claiming device
888 * @dev_id: A cookie passed back to the handler function
889 *
890 * This call allocates interrupt resources and enables the
891 * interrupt line and IRQ handling. From the point this
892 * call is made your handler function may be invoked. Since
893 * your handler function must clear any interrupt the board
894 * raises, you must take care both to initialise your hardware
895 * and to set up the interrupt handler in the right order.
896 *
897 * If you want to set up a threaded irq handler for your device
898 * then you need to supply @handler and @thread_fn. @handler ist
899 * still called in hard interrupt context and has to check
900 * whether the interrupt originates from the device. If yes it
901 * needs to disable the interrupt on the device and return
902 * IRQ_WAKE_THREAD which will wake up the handler thread and run
903 * @thread_fn. This split handler design is necessary to support
904 * shared interrupts.
905 *
906 * Dev_id must be globally unique. Normally the address of the
907 * device data structure is used as the cookie. Since the handler
908 * receives this value it makes sense to use it.
909 *
910 * If your interrupt is shared you must pass a non NULL dev_id
911 * as this is required when freeing the interrupt.
912 *
913 * Flags:
914 *
915 * IRQF_SHARED Interrupt is shared
916 * IRQF_DISABLED Disable local interrupts while processing
917 * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
918 * IRQF_TRIGGER_* Specify active edge(s) or level
919 *
920 */

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