On Tue, Sep 20, 2016 at 10:44:46PM +0900, Magnus Damm wrote:
> +#ifdef CONFIG_IOMMU_DMA
> +
> +static struct iommu_domain *ipmmu_domain_alloc_dma(unsigned type)
> +{
> + struct iommu_domain *io_domain;
> +
> + if (type != IOMMU_DOMAIN_DMA)
> + return NULL;
> +
> + io_domain = __ipmmu_domain_alloc(type);
> + if (io_domain)
> + iommu_get_dma_cookie(io_domain);
> +
> + return io_domain;
> +}
> +
> +static void ipmmu_domain_free_dma(struct iommu_domain *io_domain)
> +{
> + iommu_put_dma_cookie(io_domain);
> + ipmmu_domain_free(io_domain);
> +}
> [...]
> +static const struct iommu_ops ipmmu_ops = {
> + .domain_alloc = ipmmu_domain_alloc_dma,
> + .domain_free = ipmmu_domain_free_dma,
Okay, so when CONFIG_IOMMU_DMA is enabled, you only support allocation
of DMA domains, not UNMANAGED domains anymore. Is there a reason for
that?
You can reduce the #ifdef'ed coded by supporting both types of domains
and call into allocation-subfunctions for DMA and UNMANAGED domains. The
#ifdef could then only let the dma-allocation function return NULL.
This would be much more compatible to what other IOMMU drivers do and
will allow VFIO usage in the future.
Joerg
