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Commit 8539c7c1 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu: Introduce iommu domain types 



This allows to handle domains differently based on their
type in the future. An IOMMU driver can implement certain
optimizations for DMA-API domains for example.

The domain types can be extended later and some of the
existing domain attributes can be migrated to become domain
flags.

Tested-by: default avatarThierry Reding <treding@nvidia.com>
Tested-by: default avatarHeiko Stuebner <heiko@sntech.de>
Reviewed-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 938c4709

drivers/iommu/iommu.c

+3 −2
Original line number Diff line number Diff line
@@ -909,7 +909,7 @@ struct iommu_domain *iommu_domain_alloc(struct bus_type *bus) 
	ops = bus->iommu_ops;



	if (ops->domain_alloc)

		domain = ops->domain_alloc();

		domain = ops->domain_alloc(IOMMU_DOMAIN_UNMANAGED);

	else

		domain = kzalloc(sizeof(*domain), GFP_KERNEL);
@@ -917,6 +917,7 @@ struct iommu_domain *iommu_domain_alloc(struct bus_type *bus) 
		return NULL;



	domain->ops  = bus->iommu_ops;

	domain->type = IOMMU_DOMAIN_UNMANAGED;



	if (ops->domain_init && domain->ops->domain_init(domain))

		goto out_free;

include/linux/iommu.h

+26 −1
Original line number Diff line number Diff line
@@ -51,7 +51,32 @@ struct iommu_domain_geometry { 
	bool force_aperture;       /* DMA only allowed in mappable range? */

};



/* Domain feature flags */

#define __IOMMU_DOMAIN_PAGING	(1U << 0)  /* Support for iommu_map/unmap */

#define __IOMMU_DOMAIN_DMA_API	(1U << 1)  /* Domain for use in DMA-API

					      implementation              */

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



/*

 * This are the possible domain-types

 *

 *	IOMMU_DOMAIN_BLOCKED	- All DMA is blocked, can be used to isolate

 *				  devices

 *	IOMMU_DOMAIN_IDENTITY	- DMA addresses are system physical addresses

 *	IOMMU_DOMAIN_UNMANAGED	- DMA mappings managed by IOMMU-API user, used

 *				  for VMs

 *	IOMMU_DOMAIN_DMA	- Internally used for DMA-API implementations.

 *				  This flag allows IOMMU drivers to implement

 *				  certain optimizations for these domains

 */

#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)



struct iommu_domain {

	unsigned type;

	const struct iommu_ops *ops;

	void *priv;

	iommu_fault_handler_t handler;
@@ -117,7 +142,7 @@ struct iommu_ops { 
	void (*domain_destroy)(struct iommu_domain *domain);



	/* Domain allocation and freeing by the iommu driver */

	struct iommu_domain *(*domain_alloc)(void);

	struct iommu_domain *(*domain_alloc)(unsigned iommu_domain_type);

	void (*domain_free)(struct iommu_domain *);



	int (*attach_dev)(struct iommu_domain *domain, struct device *dev);