Commit a27bf274 authored by Lu Baolu's avatar Lu Baolu Committed by Will Deacon
Browse files

iommu: Add iommu_paging_domain_alloc() interface 



Commit <17de3f5f> ("iommu: Retire bus ops") removes iommu ops from
bus. The iommu subsystem no longer relies on bus for operations. So the
bus parameter in iommu_domain_alloc() is no longer relevant.

Add a new interface named iommu_paging_domain_alloc(), which explicitly
indicates the allocation of a paging domain for DMA managed by a kernel
driver. The new interface takes a device pointer as its parameter, that
better aligns with the current iommu subsystem.

Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarVasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20240610085555.88197-2-baolu.lu@linux.intel.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 83a7eefe

drivers/iommu/iommu.c

+20 −0
Original line number Diff line number Diff line
@@ -2016,6 +2016,10 @@ static int __iommu_domain_alloc_dev(struct device *dev, void *data) 
	return 0;

}



/*

 * The iommu ops in bus has been retired. Do not use this interface in

 * new drivers.

 */

struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus)

{

	const struct iommu_ops *ops = NULL;
@@ -2032,6 +2036,22 @@ struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus) 
}

EXPORT_SYMBOL_GPL(iommu_domain_alloc);



/**

 * iommu_paging_domain_alloc() - Allocate a paging domain

 * @dev: device for which the domain is allocated

 *

 * Allocate a paging domain which will be managed by a kernel driver. Return

 * allocated domain if successful, or a ERR pointer for failure.

 */

struct iommu_domain *iommu_paging_domain_alloc(struct device *dev)

{

	if (!dev_has_iommu(dev))

		return ERR_PTR(-ENODEV);



	return __iommu_domain_alloc(dev_iommu_ops(dev), dev, IOMMU_DOMAIN_UNMANAGED);

}

EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc);



void iommu_domain_free(struct iommu_domain *domain)

{

	if (domain->type == IOMMU_DOMAIN_SVA)

include/linux/iommu.h

+6 −0
Original line number Diff line number Diff line
@@ -780,6 +780,7 @@ extern bool iommu_present(const struct bus_type *bus); 
extern bool device_iommu_capable(struct device *dev, enum iommu_cap cap);

extern bool iommu_group_has_isolated_msi(struct iommu_group *group);

extern struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus);

struct iommu_domain *iommu_paging_domain_alloc(struct device *dev);

extern void iommu_domain_free(struct iommu_domain *domain);

extern int iommu_attach_device(struct iommu_domain *domain,

			       struct device *dev);
@@ -1086,6 +1087,11 @@ static inline struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus 
	return NULL;

}



static inline struct iommu_domain *iommu_paging_domain_alloc(struct device *dev)

{

	return ERR_PTR(-ENODEV);

}



static inline void iommu_domain_free(struct iommu_domain *domain)

{

}