intr.c

xenomai 很好的linux实时补丁

 * @param intr The descriptor address of the interrupt object to
 * enable.
 *
 * @return 0 is returned upon success. Otherwise:
 *
 * - -EINVAL is returned if @a intr is not a interrupt object
 * descriptor.
 *
 * - -EIDRM is returned if @a intr is a deleted interrupt object
 * descriptor.
 *
 * Environments:
 *
 * This service can be called from:
 *
 * - Kernel module initialization/cleanup code
 * - Kernel-based task
 * - User-space task
 *
 * Rescheduling: never.
 */

int rt_intr_enable (RT_INTR *intr)

{
    int err;
    spl_t s;

    xnlock_get_irqsave(&nklock,s);

    intr = xeno_h2obj_validate(intr,XENO_INTR_MAGIC,RT_INTR);

    if (!intr)
        {
        err = xeno_handle_error(intr,XENO_INTR_MAGIC,RT_INTR);
        goto unlock_and_exit;
        }
    
    err = xnintr_enable(&intr->intr_base);

 unlock_and_exit:

    xnlock_put_irqrestore(&nklock,s);

    return err;
}

/*! 
 * \fn int rt_intr_disable (RT_INTR *intr)
 * \brief Disable an interrupt object.
 *
 * Disables the hardware interrupt line associated with an interrupt
 * object. This operation invalidates further interrupt requests from
 * the given source until the IRQ line is re-enabled anew through
 * rt_intr_enable().
 *
 * @param intr The descriptor address of the interrupt object to
 * enable.
 *
 * @return 0 is returned upon success. Otherwise:
 *
 * - -EINVAL is returned if @a intr is not a interrupt object
 * descriptor.
 *
 * - -EIDRM is returned if @a intr is a deleted interrupt object
 * descriptor.
 *
 * Environments:
 *
 * This service can be called from:
 *
 * - Kernel module initialization/cleanup code
 * - Kernel-based task
 * - User-space task
 *
 * Rescheduling: never.
 */

int rt_intr_disable (RT_INTR *intr)

{
    int err;
    spl_t s;

    xnlock_get_irqsave(&nklock,s);

    intr = xeno_h2obj_validate(intr,XENO_INTR_MAGIC,RT_INTR);

    if (!intr)
        {
        err = xeno_handle_error(intr,XENO_INTR_MAGIC,RT_INTR);
        goto unlock_and_exit;
        }
    
    err = xnintr_disable(&intr->intr_base);

 unlock_and_exit:

    xnlock_put_irqrestore(&nklock,s);

    return err;
}

/**
 * @fn int rt_intr_inquire(RT_INTR *intr, RT_INTR_INFO *info)
 * @brief Inquire about an interrupt object.
 *
 * Return various information about the status of a given interrupt
 * object.
 *
 * @param intr The descriptor address of the inquired interrupt
 * object.
 *
 * @param info The address of a structure the interrupt object
 * information will be written to.

 * @return 0 is returned and status information is written to the
 * structure pointed at by @a info upon success. Otherwise:
 *
 * - -EINVAL is returned if @a intr is not a interrupt object
 * descriptor.
 *
 * - -EIDRM is returned if @a intr is a deleted interrupt object
 * descriptor.
 *
 * Environments:
 *
 * This service can be called from:
 *
 * - Kernel module initialization/cleanup code
 * - Interrupt service routine
 * - Kernel-based task
 * - User-space task
 *
 * Rescheduling: never.
 */

int rt_intr_inquire (RT_INTR *intr,
		     RT_INTR_INFO *info)
{
    int err = 0;
    spl_t s;

    xnlock_get_irqsave(&nklock,s);

    intr = xeno_h2obj_validate(intr,XENO_INTR_MAGIC,RT_INTR);

    if (!intr)
        {
        err = xeno_handle_error(intr,XENO_INTR_MAGIC,RT_INTR);
        goto unlock_and_exit;
        }
    
    strcpy(info->name,intr->name);
    info->hits = intr->intr_base.hits;
    info->irq = intr->intr_base.irq;

 unlock_and_exit:

    xnlock_put_irqrestore(&nklock,s);

    return err;
}

/*! 
 * \fn int rt_intr_create (RT_INTR *intr,const char *name,unsigned irq,int mode)
 * \brief Create an interrupt object from user-space.
 *
 * Initializes and associates an interrupt object with an IRQ line
 * from a user-space application. In this mode, the basic principle is
 * to define some interrupt server task which routinely waits for the
 * next incoming IRQ event through the rt_intr_wait() syscall.
 *
 * When an interrupt occurs on the given @a irq line, any task pending
 * on the interrupt object through rt_intr_wait() is imediately awaken
 * in order to deal with the hardware event. The interrupt service
 * code may then call any Xenomai service available from user-space.
 *
 * @param intr The address of a interrupt object descriptor Xenomai will
 * use to store the object-specific data.  This descriptor must always
 * be valid while the object is active therefore it must be allocated
 * in permanent memory.
 *
 * @param name An ASCII string standing for the symbolic name of the
 * interrupt object. When non-NULL and non-empty, this string is copied
 * to a safe place into the descriptor, and passed to the registry package
 * if enabled for indexing the created interrupt objects.
 * 
 * @param irq The hardware interrupt channel associated with the
 * interrupt object. This value is architecture-dependent.
 *
 * @param mode The interrupt object creation mode. The following flags
 * can be OR'ed into this bitmask:
 *
 * - I_NOAUTOENA asks Xenomai not to re-enable the IRQ line before awakening
 * the interrupt server task. This flag is functionally equivalent as
 * always returning RT_INTR_NOENABLE from a kernel space interrupt
 * handler.
 *
 * - I_PROPAGATE asks Xenomai to propagate the IRQ down the pipeline; in
 * other words, the interrupt occurrence is chained to Linux after it
 * has been processed by the Xenomai task. This flag is functionally
 * equivalent as always returning RT_INTR_PROPAGATE from a kernel space
 * interrupt handler.
 *
 * @return 0 is returned upon success. Otherwise:
 *
 * - -ENOMEM is returned if the system fails to get enough dynamic
 * memory from the global real-time heap in order to register the
 * interrupt object.
 *
 * - -EBUSY is returned if the interrupt line is already in use by
 * another interrupt object. Only a single interrupt object can be
 * associated to any given interrupt line using rt_intr_create() at
 * any time, regardless of the caller's execution space (kernel or
 * user).
 *
 * Environments:
 *
 * This service can be called from:
 *
 * - User-space task
 *
 * Rescheduling: possible.
 *
 * @note The interrupt source associated to the interrupt descriptor
 * remains masked upon creation. rt_intr_enable() should be called for
 * the new interrupt object to unmask it.
 */

/**
 * @fn int rt_intr_wait(RT_INTR *intr, RTIME timeout)
 * @brief Wait for the next interrupt.
 *
 * This user-space only call allows the current task to suspend
 * execution until the associated interrupt event triggers. The
 * priority of the current task is raised above all other Xenomai tasks -
 * except those also undergoing an interrupt or alarm wait (see
 * rt_alarm_wait()) - so that it would preempt any of them under
 * normal circumstances (i.e. no scheduler lock).
 *
 * Interrupt receipts are logged if they cannot be delivered
 * immediately to some interrupt server task, so that a call to
 * rt_intr_wait() might return immediately if an IRQ is already
 * pending on entry of the service.
 *
 * @param intr The descriptor address of the awaited interrupt.
 *
 * @param timeout The number of clock ticks to wait for an interrupt
 * to occur (see note). Passing TM_INFINITE causes the caller to block
 * indefinitely until an interrupt triggers. Passing TM_NONBLOCK is
 * invalid.
 *
 * @return A positive value is returned upon success, representing the
 * number of pending interrupts to process. Otherwise:
 *
 * - -ETIMEDOUT is returned if no interrupt occurred within the
 * specified amount of time.
 *
 * - -EINVAL is returned if @a intr is not an interrupt object
 * descriptor, or @a timeout is equal to TM_NONBLOCK.
 *
 * - -EIDRM is returned if @a intr is a deleted interrupt object
 * descriptor, including if the deletion occurred while the caller was
 * waiting for its next interrupt.
 *
 * - -EINTR is returned if rt_task_unblock() has been called for the
 * current task before the next interrupt occurrence.
 *
 * Environments:
 *
 * This service can be called from:
 *
 * - User-space task
 *
 * Rescheduling: always, unless an interrupt is already pending on
 * entry.
 *
 * @note This service is sensitive to the current operation mode of
 * the system timer, as defined by the rt_timer_start() service. In
 * periodic mode, clock ticks are interpreted as periodic jiffies. In
 * oneshot mode, clock ticks are interpreted as nanoseconds.
 */

/**
 * @fn int rt_intr_bind(RT_INTR *intr,const char *name,RTIME timeout)
 * @brief Bind to an interrupt object.
 *
 * This user-space only service retrieves the uniform descriptor of a
 * given Xenomai interrupt object identified by its IRQ number. If the
 * object does not exist on entry, this service blocks the caller
 * until an interrupt object of the given number is created. An
 * interrupt is registered whenever a kernel-space task invokes the
 * rt_intr_create() service successfully for the given IRQ line.
 *
 * @param intr The address of an interrupt object descriptor retrieved
 * by the operation. Contents of this memory is undefined upon
 * failure.
 *
 * @param name An ASCII string standing for the symbolic name of the
 * interrupt object to search for.
 *
 * @param timeout The number of clock ticks to wait for the
 * registration to occur (see note). Passing TM_INFINITE causes the
 * caller to block indefinitely until the object is
 * registered. Passing TM_NONBLOCK causes the service to return
 * immediately without waiting if the object is not registered on
 * entry.
 *
 * @return 0 is returned upon success. Otherwise:
 *
 * - -EFAULT is returned if @a intr is referencing invalid memory.
 *
 * - -EINVAL is returned if @a irq is invalid.
 *
 * - -EINTR is returned if rt_task_unblock() has been called for the
 * waiting task before the retrieval has completed.
 *
 * - -EWOULDBLOCK is returned if @a timeout is equal to TM_NONBLOCK
 * and the searched object is not registered on entry.
 *
 * - -ETIMEDOUT is returned if the object cannot be retrieved within
 * the specified amount of time.
 *
 * - -EPERM is returned if this service should block, but was called
 * from a context which cannot sleep (e.g. interrupt, non-realtime or
 * scheduler locked).
 *
 * Environments:
 *
 * This service can be called from:
 *
 * - User-space task (switches to primary mode)
 *
 * Rescheduling: always unless the request is immediately satisfied or
 * @a timeout specifies a non-blocking operation.
 *
 * @note This service is sensitive to the current operation mode of
 * the system timer, as defined by the rt_timer_start() service. In
 * periodic mode, clock ticks are interpreted as periodic jiffies. In
 * oneshot mode, clock ticks are interpreted as nanoseconds.
 */

/**
 * @fn int rt_intr_unbind(RT_INTR *intr)
 *
 * @brief Unbind from an interrupt object.
 *
 * This user-space only service unbinds the calling task from the
 * interrupt object previously retrieved by a call to rt_intr_bind().
 *
 * @param intr The address of a interrupt object descriptor to unbind
 * from.
 *
 * @return 0 is always returned.
 *
 * This service can be called from:
 *
 * - User-space task.
 *
 * Rescheduling: never.
 */

/*@}*/

EXPORT_SYMBOL(rt_intr_create);
EXPORT_SYMBOL(rt_intr_delete);
EXPORT_SYMBOL(rt_intr_enable);
EXPORT_SYMBOL(rt_intr_disable);
EXPORT_SYMBOL(rt_intr_inquire);