Commit bf3aed46 authored by Robin Murphy's avatar Robin Murphy Committed by Joerg Roedel
Browse files

iommu: Introduce explicit type for non-strict DMA domains 



Promote the difference between strict and non-strict DMA domains from an
internal detail to a distinct domain feature and type, to pave the road
for exposing it through the sysfs default domain interface.

Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarJean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/08cd2afaf6b63c58ad49acec3517c9b32c2bb946.1628682049.git.robin.murphy@arm.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent a8e5f044

drivers/iommu/dma-iommu.c

+1 −1
Original line number Diff line number Diff line
@@ -1319,7 +1319,7 @@ void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit) 
	 * The IOMMU core code allocates the default DMA domain, which the

	 * underlying IOMMU driver needs to support via the dma-iommu layer.

	 */

	if (domain->type == IOMMU_DOMAIN_DMA) {

	if (iommu_is_dma_domain(domain)) {

		if (iommu_dma_init_domain(domain, dma_base, dma_limit, dev))

			goto out_err;

		dev->dma_ops = &iommu_dma_ops;

drivers/iommu/iommu.c

+6 −2
Original line number Diff line number Diff line
@@ -115,6 +115,7 @@ static const char *iommu_domain_type_str(unsigned int t) 
	case IOMMU_DOMAIN_UNMANAGED:

		return "Unmanaged";

	case IOMMU_DOMAIN_DMA:

	case IOMMU_DOMAIN_DMA_FQ:

		return "Translated";

	default:

		return "Unknown";
@@ -552,6 +553,9 @@ static ssize_t iommu_group_show_type(struct iommu_group *group, 
		case IOMMU_DOMAIN_DMA:

			type = "DMA\n";

			break;

		case IOMMU_DOMAIN_DMA_FQ:

			type = "DMA-FQ\n";

			break;

		}

	}

	mutex_unlock(&group->mutex);
@@ -765,7 +769,7 @@ static int iommu_create_device_direct_mappings(struct iommu_group *group, 
	unsigned long pg_size;

	int ret = 0;



	if (!domain || domain->type != IOMMU_DOMAIN_DMA)

	if (!domain || !iommu_is_dma_domain(domain))

		return 0;



	BUG_ON(!domain->pgsize_bitmap);
@@ -1948,7 +1952,7 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, 
	domain->pgsize_bitmap  = bus->iommu_ops->pgsize_bitmap;



	/* Temporarily avoid -EEXIST while drivers still get their own cookies */

	if (type == IOMMU_DOMAIN_DMA && !domain->iova_cookie && iommu_get_dma_cookie(domain)) {

	if (iommu_is_dma_domain(domain) && !domain->iova_cookie && iommu_get_dma_cookie(domain)) {

		iommu_domain_free(domain);

		domain = NULL;

	}

include/linux/iommu.h

+11 −0
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ struct iommu_domain_geometry { 
#define __IOMMU_DOMAIN_DMA_API	(1U << 1)  /* Domain for use in DMA-API

					      implementation              */

#define __IOMMU_DOMAIN_PT	(1U << 2)  /* Domain is identity mapped   */

#define __IOMMU_DOMAIN_DMA_FQ	(1U << 3)  /* DMA-API uses flush queue    */



/*

 * This are the possible domain-types
@@ -73,12 +74,17 @@ struct iommu_domain_geometry { 
 *	IOMMU_DOMAIN_DMA	- Internally used for DMA-API implementations.

 *				  This flag allows IOMMU drivers to implement

 *				  certain optimizations for these domains

 *	IOMMU_DOMAIN_DMA_FQ	- As above, but definitely using batched TLB

 *				  invalidation.

 */

#define IOMMU_DOMAIN_BLOCKED	(0U)

#define IOMMU_DOMAIN_IDENTITY	(__IOMMU_DOMAIN_PT)

#define IOMMU_DOMAIN_UNMANAGED	(__IOMMU_DOMAIN_PAGING)

#define IOMMU_DOMAIN_DMA	(__IOMMU_DOMAIN_PAGING |	\

				 __IOMMU_DOMAIN_DMA_API)

#define IOMMU_DOMAIN_DMA_FQ	(__IOMMU_DOMAIN_PAGING |	\

				 __IOMMU_DOMAIN_DMA_API |	\

				 __IOMMU_DOMAIN_DMA_FQ)



struct iommu_domain {

	unsigned type;
@@ -90,6 +96,11 @@ struct iommu_domain { 
	struct iommu_dma_cookie *iova_cookie;

};



static inline bool iommu_is_dma_domain(struct iommu_domain *domain)

{

	return domain->type & __IOMMU_DOMAIN_DMA_API;

}



enum iommu_cap {

	IOMMU_CAP_CACHE_COHERENCY,	/* IOMMU can enforce cache coherent DMA

					   transactions */