Re: [PATCH 18/23] iommu: Express DMA strictness via the domain type

[Robin Murphy]

On 2021-07-26 13:29, Lu Baolu wrote:
[...]
> > > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> > > > index b1af1ff324c5..a114a7ad88ec 100644
> > > > --- a/drivers/iommu/dma-iommu.c
> > > > +++ b/drivers/iommu/dma-iommu.c
> > > > @@ -363,13 +363,15 @@ static int iommu_dma_init_domain(struct 
> > > > iommu_domain *domain, dma_addr_t base,
> > > >       init_iova_domain(iovad, 1UL << order, base_pfn);
> > > > -    if (!cookie->fq_domain && !dev_is_untrusted(dev) &&
> > > > -        domain->ops->flush_iotlb_all && 
> > > > !iommu_get_dma_strict(domain)) {
> > > > +    if (domain->type == IOMMU_DOMAIN_DMA_FQ && !cookie->fq_domain &&
> > > > +        domain->ops->flush_iotlb_all) {
>
> Perhaps we can remove the ops->flush_iotlb_all check with the
> assumption that any vendor iommu driver with DMA_FQ domain support
> should always provides this callback?

Oh yes, indeed it wouldn't make sense for a driver to claim 
IOMMU_DOMAIN_DMA_FQ support but not implement the one thing that that 
needs the driver to provide. That's yet another neat little cleanup, thanks!

Robin.