s390/qdio: make thinint registration symmetric
tiqdio_add_device() adds the device to the tiq_list of eligible targets for a data IRQ, which gets walked on each QDIO Adapter Interrupt to inspect their DSCIs. But currently the tiqdio_add_device() / tiqdio_remove_device() calls are not symmetric - the device is removed within qdio_shutdown(), but only added by qdio_activate(). So depending on the call sequence and encountered errors, we might be trying to remove a list entry in qdio_shutdown() that was never even added to the list. This required additional INIT_LIST_HEAD() calls to ensure that the list entry was always in a consistent state. All drivers now fence the IRQ delivery via qdio_start_irq() / qdio_stop_irq(), so we can nicely integrate this tiq_list management with the other steps needed for QDIO Adapter IRQ (de-)registration (qdio_establish_thinint() / qdio_shutdown_thinint()). As the naming suggests these get called during qdio_establish() and qdio_shutdown(), with proper symmetry and roll-back after errors. With this we longer need to worry about misplaced list removals, and thus can clean up the list API abuse (INIT_LIST_HEAD() should not be called on list entries). Signed-off-by:Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by:
Benjamin Block <bblock@linux.ibm.com> Signed-off-by:
Vasily Gorbik <gor@linux.ibm.com>
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6bb7a51b
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