iommu: Add iommu_paging_domain_alloc() interface

Commit <17de3f5fdd35> ("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: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20240610085555.88197-2-baolu.lu@linux.intel.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Lu Baolu 2024-06-10 16:55:35 +08:00 committed by Will Deacon
parent 83a7eefedc
commit a27bf2743c
2 changed files with 26 additions and 0 deletions

View File

@ -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)

View File

@ -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)
{
}