Re: [PATCH v6 02/25] iommu: Add IOMMU_DOMAIN_PLATFORM

Baolu Lu
2023-08-12T01:42:07Z

On 2023/8/3 8:07, Jason Gunthorpe wrote:
> @@ -1967,7 +1978,8 @@ void iommu_domain_free(struct iommu_domain *domain)
> if (domain->type == IOMMU_DOMAIN_SVA)
> mmdrop(domain->mm);
> iommu_put_dma_cookie(domain);
> - domain->ops->free(domain);
> + if (domain->ops->free)
> + domain->ops->free(domain);
> }
> EXPORT_SYMBOL_GPL(iommu_domain_free);
>
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index e05c93b6c37fba..87aebba474e093 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -64,6 +64,7 @@ struct iommu_domain_geometry {
> #define __IOMMU_DOMAIN_DMA_FQ (1U << 3) /* DMA-API uses flush queue */
>
> #define __IOMMU_DOMAIN_SVA (1U << 4) /* Shared process address space */
> +#define __IOMMU_DOMAIN_PLATFORM (1U << 5)
>
> #define IOMMU_DOMAIN_ALLOC_FLAGS ~__IOMMU_DOMAIN_DMA_FQ
> /*
> @@ -81,6 +82,8 @@ struct iommu_domain_geometry {
> * invalidation.
> * IOMMU_DOMAIN_SVA - DMA addresses are shared process addresses
> * represented by mm_struct's.
> + * IOMMU_DOMAIN_PLATFORM - Legacy domain for drivers that do their own
> + * dma_api stuff. Do not use in new drivers.
> */
> #define IOMMU_DOMAIN_BLOCKED (0U)
> #define IOMMU_DOMAIN_IDENTITY (__IOMMU_DOMAIN_PT)
> @@ -91,6 +94,7 @@ struct iommu_domain_geometry {
> __IOMMU_DOMAIN_DMA_API | \
> __IOMMU_DOMAIN_DMA_FQ)
> #define IOMMU_DOMAIN_SVA (__IOMMU_DOMAIN_SVA)
> +#define IOMMU_DOMAIN_PLATFORM (__IOMMU_DOMAIN_PLATFORM)

Nit: As a default domain could be the type of IOMMU_DOMAIN_PLATFORM,

static const char *iommu_domain_type_str(unsigned int t)

needs to be updated, so that users can get a right string when reading
/sys/.../[group_id]/type.

Best regards,
baolu