[PATCH 07/37] iommu: Add a page fault handler

[Jean-Philippe Brucker]

On 05/03/18 21:44, Sinan Kaya wrote:
> On 2/12/2018 1:33 PM, Jean-Philippe Brucker wrote:
>> +static int iommu_queue_fault(struct iommu_domain *domain, struct device *dev,
>> +			     struct iommu_fault_event *evt)
>> +{
>> +	struct iommu_fault_group *group;
>> +	struct iommu_fault_context *fault, *next;
>> +
>> +	if (!iommu_fault_queue)
>> +		return -ENOSYS;
>> +
>> +	if (!evt->last_req) {
>> +		fault = kzalloc(sizeof(*fault), GFP_KERNEL);
>> +		if (!fault)
>> +			return -ENOMEM;
>> +
>> +		fault->evt = *evt;
>> +		fault->dev = dev;
>> +
>> +		/* Non-last request of a group. Postpone until the last one */
>> +		spin_lock(&iommu_partial_faults_lock);
>> +		list_add_tail(&fault->head, &iommu_partial_faults);
>> +		spin_unlock(&iommu_partial_faults_lock);
>> +
>> +		return IOMMU_PAGE_RESP_HANDLED;
>> +	}
>> +
>> +	group = kzalloc(sizeof(*group), GFP_KERNEL);
>> +	if (!group)
>> +		return -ENOMEM;
> 
> Release the requests in iommu_partial_faults here.

We move these requests to the group->faults list (which btw should use
list_move instead of the current list_del+list_add) and we release them in
iommu_fault_handle_group()

Thanks,
Jean