[PATCH 07/37] iommu: Add a page fault handler
Jean-Philippe Brucker
jean-philippe.brucker at arm.com
Wed Mar 14 06:08:07 PDT 2018
Hi Jonathan,
Thanks for reviewing
On 08/03/18 15:40, Jonathan Cameron wrote:
>> +/**
>> + * iommu_fault_queue_unregister() - Unregister an IOMMU driver from the fault
>> + * queue.
>> + * @flush_notifier: same parameter as iommu_fault_queue_register
>> + */
>> +void iommu_fault_queue_unregister(struct notifier_block *flush_notifier)
>> +{
>> + down_write(&iommu_fault_queue_sem);
>> + if (refcount_dec_and_test(&iommu_fault_queue_refs)) {
>> + destroy_workqueue(iommu_fault_queue);
>> + iommu_fault_queue = NULL;
>> + }
>> + up_write(&iommu_fault_queue_sem);
>> +
>> + if (flush_notifier)
>> + blocking_notifier_chain_unregister(&iommu_fault_queue_flush_notifiers,
>> + flush_notifier);
> I would expect the ordering in queue_unregister to be the reverse of queue
> register (to make it obvious there are no races).
>
> That would put this last block at the start before potentially destroying
> the work queue. If I'm missing something then perhaps a comment to
> explain why the ordering is not the obvious one?
Sure, I'll fix the order, I don't think there was any good reason for it
Thanks,
Jean
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