Commit 20858d4e authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Joerg Roedel
Browse files

iommu: Introduce iommu_paging_domain_alloc_flags() 



Currently drivers calls iommu_paging_domain_alloc(dev) to get an
UNMANAGED domain. This is not sufficient to support PASID with
UNMANAGED domain as some HW like AMD requires certain page table type
to support PASIDs.

Also the domain_alloc_paging op only passes device as param for domain
allocation. This is not sufficient for AMD driver to decide the right
page table.

Instead of extending ops->domain_alloc_paging() it was decided to
enhance ops->domain_alloc_user() so that caller can pass various
additional flags.

Hence add iommu_paging_domain_alloc_flags() API which takes flags as
parameter. Caller can pass additional parameter to indicate type of
domain required, etc. iommu_paging_domain_alloc_flags() internally calls
appropriate callback function to allocate a domain.

Signed-off-by: default avatarJason Gunthorpe <jgg@ziepe.ca>
[Added description - Vasant]
Signed-off-by: default avatarVasant Hegde <vasant.hegde@amd.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarYi Liu <yi.l.liu@intel.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20241028093810.5901-3-vasant.hegde@amd.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 541b967f

drivers/iommu/iommu.c

+27 −5
Original line number Diff line number Diff line
@@ -1962,20 +1962,42 @@ __iommu_group_domain_alloc(struct iommu_group *group, unsigned int type) 
}



/**

 * iommu_paging_domain_alloc() - Allocate a paging domain

 * iommu_paging_domain_alloc_flags() - Allocate a paging domain

 * @dev: device for which the domain is allocated

 * @flags: Enum of iommufd_hwpt_alloc_flags

 *

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

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

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

 */

struct iommu_domain *iommu_paging_domain_alloc(struct device *dev)

struct iommu_domain *iommu_paging_domain_alloc_flags(struct device *dev,

						     unsigned int flags)

{

	const struct iommu_ops *ops;

	struct iommu_domain *domain;



	if (!dev_has_iommu(dev))

		return ERR_PTR(-ENODEV);



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

	ops = dev_iommu_ops(dev);



	if (ops->domain_alloc_paging && !flags)

		domain = ops->domain_alloc_paging(dev);

	else if (ops->domain_alloc_user)

		domain = ops->domain_alloc_user(dev, flags, NULL, NULL);

	else if (ops->domain_alloc && !flags)

		domain = ops->domain_alloc(IOMMU_DOMAIN_UNMANAGED);

	else

		return ERR_PTR(-EOPNOTSUPP);



	if (IS_ERR(domain))

		return domain;

	if (!domain)

		return ERR_PTR(-ENOMEM);



	iommu_domain_init(domain, IOMMU_DOMAIN_UNMANAGED, ops);

	return domain;

}

EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc);

EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc_flags);



void iommu_domain_free(struct iommu_domain *domain)

{

include/linux/iommu.h

+11 −3
Original line number Diff line number Diff line
@@ -511,8 +511,6 @@ static inline int __iommu_copy_struct_from_user_array( 
 *                the caller iommu_domain_alloc() returns.

 * @domain_alloc_user: Allocate an iommu domain corresponding to the input

 *                     parameters as defined in include/uapi/linux/iommufd.h.

 *                     Unlike @domain_alloc, it is called only by IOMMUFD and

 *                     must fully initialize the new domain before return.

 *                     Upon success, if the @user_data is valid and the @parent

 *                     points to a kernel-managed domain, the new domain must be

 *                     IOMMU_DOMAIN_NESTED type; otherwise, the @parent must be
@@ -787,7 +785,11 @@ static inline void iommu_iotlb_gather_init(struct iommu_iotlb_gather *gather) 
extern int bus_iommu_probe(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);

struct iommu_domain *iommu_paging_domain_alloc(struct device *dev);

struct iommu_domain *iommu_paging_domain_alloc_flags(struct device *dev, unsigned int flags);

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

{

	return iommu_paging_domain_alloc_flags(dev, 0);

}

extern void iommu_domain_free(struct iommu_domain *domain);

extern int iommu_attach_device(struct iommu_domain *domain,

			       struct device *dev);
@@ -1078,6 +1080,12 @@ static inline bool device_iommu_capable(struct device *dev, enum iommu_cap cap) 
	return false;

}



struct iommu_domain *iommu_paging_domain_alloc_flags(struct device *dev,

						     unsigned int flags)

{

	return ERR_PTR(-ENODEV);

}



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

{

	return ERR_PTR(-ENODEV);