[PATCH v6 02/25] iommu: Add IOMMU_DOMAIN_PLATFORM

[Baolu Lu]

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