ddi_get_iblock_cookie() retrieves the interrupt block cookie associated with a particular interrupt specification. This routine should be called before ddi_add_intr() to retrieve the interrupt block cookie needed to initialize locks (mutex(9F), rwlock(9F)) used by the interrupt routine. The interrupt number inumber determines for which interrupt specification to retrieve the cookie. inumber is associated with information provided either by the device (see sbus(4)) or the hardware configuration file (see sysbus(4), isa(4), eisa(4), and driver.conf(4)). If only one interrupt is associated with the device, inumber should be 0.

On a successful return, *iblock_cookiep contains information needed for initializing locks associated with the interrupt specification corresponding to inumber (see mutex_init(9F) and rw_init(9F)). The driver can then initialize locks acquired by the interrupt routine before calling ddi_add_intr() which prevents a possible race condition where the driver's interrupt handler is called immediately after the driver has called ddi_add_intr() but before the driver has initialized the locks. This may happen when an interrupt for a different device occurs on the same interrupt level. If the interrupt routine acquires the lock before the lock has been initialized, undefined behavior may result.

ddi_add_intr() adds an interrupt handler to the system. The interrupt number inumber determines which interrupt the handler will be associated with. (Refer to ddi_get_iblock_cookie() above.)

On a successful return, iblock_cookiep contains information used for initializing locks associated with this interrupt specification (see mutex_init(9F) and rw_init(9F)). Note that the interrupt block cookie is usually obtained using ddi_get_iblock_cookie() to avoid the race conditions described above (refer to ddi_get_iblock_cookie() above). For this reason, iblock_cookiep is no longer useful and should be set to NULL.

On a successful return, idevice_cookiep contains a pointer to a ddi_idevice_cookie_t structure (see ddi_idevice_cookie(9S)) containing information useful for some devices that have programmable interrupts. If idevice_cookiep is set to NULL, no value is returned.

The routine intr_handler, with its argument int_handler_arg, is called upon receipt of the appropriate interrupt. The interrupt handler should return DDI_INTR_CLAIMED if the interrupt was claimed, DDI_INTR_UNCLAIMED otherwise.

If successful, ddi_add_intr() will return DDI_SUCCESS. DDI_INTR_NOTFOUND is returned on i86pc and sun4m architectures if the interrupt information cannot be found. If the interrupt information cannot be found on the sun4u architecture, either DDI_INTR_NOTFOUND or DDI_FAILURE can be returned.

ddi_remove_intr() removes an interrupt handler from the system. Unloadable drivers should call this routine during their detach(9E) routine to remove their interrupt handler from the system.

The device interrupt routine for this instance of the device will not execute after ddi_remove_intr() returns. ddi_remove_intr() may need to wait for the device interrupt routine to complete before returning. Therefore, locks acquired by the interrupt handler should not be held across the call to ddi_remove_intr() or deadlock may result.

For certain bus types, you can call these DDI functions from a high-interrupt context. These types include ISA, EISA, and SBus buses. See sysbus(4), isa(4), eisa(4), and sbus(4) for details.