Re: [PATCH 03/15] [swiotlb] Add swiotlb_register_engine function.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

> > +EXPORT_SYMBOL(iommu_sw);
> 
> should be EXPORT_SYMBOL_GPL

Yup.
> 
> >  static int late_alloc;
> >  
> >  static int __init
> > @@ -126,6 +132,48 @@ static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
> >  	return phys_to_dma(hwdev, virt_to_phys(address));
> >  }
> >  
> > +/*
> > + * Register a software IO TLB engine.
> > + *
> > + * The registration allows the software IO TLB functions in the
> > + * swiotlb library to function properly.
> > + *
> > + * All the values in the iotlb structure must be set.
> > + *
> > + * If the registration fails, it is assumed that the caller will free
> > + * all of the resources allocated in the swiotlb_engine structure.
> > + */
> > +int swiotlb_register_engine(struct swiotlb_engine *iommu)
> > +{
> > +	if (!iommu || !iommu->name || !iommu->release) {
> > +		printk(KERN_ERR "DMA: Trying to register a SWIOTLB engine" \
> > +				" improperly!");
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (iommu_sw && iommu_sw->name) {
> 
> According to above, you can't have !iommu_sw->name.

Yup. Artificats of previous implementation.
> 
> > +		int retval = -EINVAL;
> > +
> > +		/* 'release' must check for out-standing DMAs and flush them
> > +		 *  out or fail. */
> > +		if (iommu_sw->release)
> > +			retval = iommu_sw->release(iommu_sw);
> 
> Same here, you can't have !iommu_sw->release, just call unconditionally.

Ok.