Re: [RFC/PATCH 2/7] iommu-api: Add map_range/unmap_range functions

[Olav Haugan <ohaugan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>]

On 7/11/2014 3:20 AM, Joerg Roedel wrote:
> On Mon, Jun 30, 2014 at 09:51:51AM -0700, Olav Haugan wrote:
>> +int iommu_map_range(struct iommu_domain *domain, unsigned int iova,
>> +		    struct scatterlist *sg, unsigned int len, int prot)
>> +{
>> +	if (unlikely(domain->ops->map_range == NULL))
>> +		return -ENODEV;
>> +
>> +	BUG_ON(iova & (~PAGE_MASK));
>> +
>> +	return domain->ops->map_range(domain, iova, sg, len, prot);
>> +}
>> +EXPORT_SYMBOL_GPL(iommu_map_range);
>> +
>> +int iommu_unmap_range(struct iommu_domain *domain, unsigned int iova,
>> +		      unsigned int len)
>> +{
>> +	if (unlikely(domain->ops->unmap_range == NULL))
>> +		return -ENODEV;
>> +
>> +	BUG_ON(iova & (~PAGE_MASK));
>> +
>> +	return domain->ops->unmap_range(domain, iova, len);
>> +}
>> +EXPORT_SYMBOL_GPL(iommu_unmap_range);
> 
> Before introducing these new API functions there should be a fall-back
> for IOMMU drivers that do (not yet) implement the map_range and
> unmap_range call-backs.
> 
> The last thing we want is this kind of functional partitioning between
> different IOMMU drivers.

Yes, I can definitely add a fallback instead of returning -ENODEV.


Thanks,

Olav

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